1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2004, 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Debug_A; use Debug_A;
31 with Einfo; use Einfo;
32 with Errout; use Errout;
33 with Expander; use Expander;
34 with Exp_Ch7; use Exp_Ch7;
35 with Exp_Tss; use Exp_Tss;
36 with Exp_Util; use Exp_Util;
37 with Freeze; use Freeze;
38 with Itypes; use Itypes;
40 with Lib.Xref; use Lib.Xref;
41 with Namet; use Namet;
42 with Nmake; use Nmake;
43 with Nlists; use Nlists;
45 with Output; use Output;
46 with Restrict; use Restrict;
47 with Rident; use Rident;
48 with Rtsfind; use Rtsfind;
50 with Sem_Aggr; use Sem_Aggr;
51 with Sem_Attr; use Sem_Attr;
52 with Sem_Cat; use Sem_Cat;
53 with Sem_Ch4; use Sem_Ch4;
54 with Sem_Ch6; use Sem_Ch6;
55 with Sem_Ch8; use Sem_Ch8;
56 with Sem_Disp; use Sem_Disp;
57 with Sem_Dist; use Sem_Dist;
58 with Sem_Elab; use Sem_Elab;
59 with Sem_Eval; use Sem_Eval;
60 with Sem_Intr; use Sem_Intr;
61 with Sem_Util; use Sem_Util;
62 with Sem_Type; use Sem_Type;
63 with Sem_Warn; use Sem_Warn;
64 with Sinfo; use Sinfo;
65 with Snames; use Snames;
66 with Stand; use Stand;
67 with Stringt; use Stringt;
68 with Targparm; use Targparm;
69 with Tbuild; use Tbuild;
70 with Uintp; use Uintp;
71 with Urealp; use Urealp;
73 package body Sem_Res is
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
79 -- Second pass (top-down) type checking and overload resolution procedures
80 -- Typ is the type required by context. These procedures propagate the
81 -- type information recursively to the descendants of N. If the node
82 -- is not overloaded, its Etype is established in the first pass. If
83 -- overloaded, the Resolve routines set the correct type. For arith.
84 -- operators, the Etype is the base type of the context.
86 -- Note that Resolve_Attribute is separated off in Sem_Attr
88 procedure Ambiguous_Character (C : Node_Id);
89 -- Give list of candidate interpretations when a character literal cannot
92 procedure Check_Direct_Boolean_Op (N : Node_Id);
93 -- N is a binary operator node which may possibly operate on Boolean
94 -- operands. If the operator does have Boolean operands, then a call is
95 -- made to check the restriction No_Direct_Boolean_Operators.
97 procedure Check_Discriminant_Use (N : Node_Id);
98 -- Enforce the restrictions on the use of discriminants when constraining
99 -- a component of a discriminated type (record or concurrent type).
101 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
102 -- Given a node for an operator associated with type T, check that
103 -- the operator is visible. Operators all of whose operands are
104 -- universal must be checked for visibility during resolution
105 -- because their type is not determinable based on their operands.
107 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
108 -- Given a call node, N, which is known to occur immediately within the
109 -- subprogram being called, determines whether it is a detectable case of
110 -- an infinite recursion, and if so, outputs appropriate messages. Returns
111 -- True if an infinite recursion is detected, and False otherwise.
113 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
114 -- If the type of the object being initialized uses the secondary stack
115 -- directly or indirectly, create a transient scope for the call to the
116 -- init proc. This is because we do not create transient scopes for the
117 -- initialization of individual components within the init proc itself.
118 -- Could be optimized away perhaps?
120 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
121 -- Utility to check whether the name in the call is a predefined
122 -- operator, in which case the call is made into an operator node.
123 -- An instance of an intrinsic conversion operation may be given
124 -- an operator name, but is not treated like an operator.
126 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
127 -- If a default expression in entry call N depends on the discriminants
128 -- of the task, it must be replaced with a reference to the discriminant
129 -- of the task being called.
131 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
132 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
133 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
134 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
135 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
136 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
137 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
138 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
139 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
140 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
141 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
142 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
143 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
144 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
145 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
146 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
147 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
148 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
149 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
150 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
151 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
152 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
153 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
154 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
155 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
156 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
157 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
158 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
159 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
160 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
161 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
162 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
164 function Operator_Kind
168 -- Utility to map the name of an operator into the corresponding Node. Used
169 -- by other node rewriting procedures.
171 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
172 -- Resolve actuals of call, and add default expressions for missing ones.
174 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
175 -- Called from Resolve_Call, when the prefix denotes an entry or element
176 -- of entry family. Actuals are resolved as for subprograms, and the node
177 -- is rebuilt as an entry call. Also called for protected operations. Typ
178 -- is the context type, which is used when the operation is a protected
179 -- function with no arguments, and the return value is indexed.
181 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
182 -- A call to a user-defined intrinsic operator is rewritten as a call
183 -- to the corresponding predefined operator, with suitable conversions.
185 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
186 -- Ditto, for unary operators (only arithmetic ones).
188 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
189 -- If an operator node resolves to a call to a user-defined operator,
190 -- rewrite the node as a function call.
192 procedure Make_Call_Into_Operator
196 -- Inverse transformation: if an operator is given in functional notation,
197 -- then after resolving the node, transform into an operator node, so
198 -- that operands are resolved properly. Recall that predefined operators
199 -- do not have a full signature and special resolution rules apply.
201 procedure Rewrite_Renamed_Operator (N : Node_Id; Op : Entity_Id);
202 -- An operator can rename another, e.g. in an instantiation. In that
203 -- case, the proper operator node must be constructed.
205 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
206 -- The String_Literal_Subtype is built for all strings that are not
207 -- operands of a static concatenation operation. If the argument is
208 -- not a N_String_Literal node, then the call has no effect.
210 procedure Set_Slice_Subtype (N : Node_Id);
211 -- Build subtype of array type, with the range specified by the slice
213 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
214 -- A universal_fixed expression in an universal context is unambiguous
215 -- if there is only one applicable fixed point type. Determining whether
216 -- there is only one requires a search over all visible entities, and
217 -- happens only in very pathological cases (see 6115-006).
219 function Valid_Conversion
224 -- Verify legality rules given in 4.6 (8-23). Target is the target
225 -- type of the conversion, which may be an implicit conversion of
226 -- an actual parameter to an anonymous access type (in which case
227 -- N denotes the actual parameter and N = Operand).
229 -------------------------
230 -- Ambiguous_Character --
231 -------------------------
233 procedure Ambiguous_Character (C : Node_Id) is
237 if Nkind (C) = N_Character_Literal then
238 Error_Msg_N ("ambiguous character literal", C);
240 ("\possible interpretations: Character, Wide_Character!", C);
242 E := Current_Entity (C);
246 while Present (E) loop
247 Error_Msg_NE ("\possible interpretation:}!", C, Etype (E));
252 end Ambiguous_Character;
254 -------------------------
255 -- Analyze_And_Resolve --
256 -------------------------
258 procedure Analyze_And_Resolve (N : Node_Id) is
262 end Analyze_And_Resolve;
264 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
268 end Analyze_And_Resolve;
270 -- Version withs check(s) suppressed
272 procedure Analyze_And_Resolve
277 Scop : constant Entity_Id := Current_Scope;
280 if Suppress = All_Checks then
282 Svg : constant Suppress_Array := Scope_Suppress;
285 Scope_Suppress := (others => True);
286 Analyze_And_Resolve (N, Typ);
287 Scope_Suppress := Svg;
292 Svg : constant Boolean := Scope_Suppress (Suppress);
295 Scope_Suppress (Suppress) := True;
296 Analyze_And_Resolve (N, Typ);
297 Scope_Suppress (Suppress) := Svg;
301 if Current_Scope /= Scop
302 and then Scope_Is_Transient
304 -- This can only happen if a transient scope was created
305 -- for an inner expression, which will be removed upon
306 -- completion of the analysis of an enclosing construct.
307 -- The transient scope must have the suppress status of
308 -- the enclosing environment, not of this Analyze call.
310 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
313 end Analyze_And_Resolve;
315 procedure Analyze_And_Resolve
319 Scop : constant Entity_Id := Current_Scope;
322 if Suppress = All_Checks then
324 Svg : constant Suppress_Array := Scope_Suppress;
327 Scope_Suppress := (others => True);
328 Analyze_And_Resolve (N);
329 Scope_Suppress := Svg;
334 Svg : constant Boolean := Scope_Suppress (Suppress);
337 Scope_Suppress (Suppress) := True;
338 Analyze_And_Resolve (N);
339 Scope_Suppress (Suppress) := Svg;
343 if Current_Scope /= Scop
344 and then Scope_Is_Transient
346 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
349 end Analyze_And_Resolve;
351 -----------------------------
352 -- Check_Direct_Boolean_Op --
353 -----------------------------
355 procedure Check_Direct_Boolean_Op (N : Node_Id) is
357 if Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean then
358 Check_Restriction (No_Direct_Boolean_Operators, N);
360 end Check_Direct_Boolean_Op;
362 ----------------------------
363 -- Check_Discriminant_Use --
364 ----------------------------
366 procedure Check_Discriminant_Use (N : Node_Id) is
367 PN : constant Node_Id := Parent (N);
368 Disc : constant Entity_Id := Entity (N);
373 -- Any use in a default expression is legal.
375 if In_Default_Expression then
378 elsif Nkind (PN) = N_Range then
380 -- Discriminant cannot be used to constrain a scalar type.
384 if Nkind (P) = N_Range_Constraint
385 and then Nkind (Parent (P)) = N_Subtype_Indication
386 and then Nkind (Parent (Parent (P))) = N_Component_Definition
388 Error_Msg_N ("discriminant cannot constrain scalar type", N);
390 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
392 -- The following check catches the unusual case where
393 -- a discriminant appears within an index constraint
394 -- that is part of a larger expression within a constraint
395 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
396 -- For now we only check case of record components, and
397 -- note that a similar check should also apply in the
398 -- case of discriminant constraints below. ???
400 -- Note that the check for N_Subtype_Declaration below is to
401 -- detect the valid use of discriminants in the constraints of a
402 -- subtype declaration when this subtype declaration appears
403 -- inside the scope of a record type (which is syntactically
404 -- illegal, but which may be created as part of derived type
405 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
408 if Ekind (Current_Scope) = E_Record_Type
409 and then Scope (Disc) = Current_Scope
411 (Nkind (Parent (P)) = N_Subtype_Indication
413 (Nkind (Parent (Parent (P))) = N_Component_Definition
415 Nkind (Parent (Parent (P))) = N_Subtype_Declaration)
416 and then Paren_Count (N) = 0)
419 ("discriminant must appear alone in component constraint", N);
423 -- Detect a common beginner error:
425 -- type R (D : Positive := 100) is record
426 -- Name : String (1 .. D);
429 -- The default value causes an object of type R to be
430 -- allocated with room for Positive'Last characters.
438 function Large_Storage_Type (T : Entity_Id) return Boolean;
439 -- Return True if type T has a large enough range that
440 -- any array whose index type covered the whole range of
441 -- the type would likely raise Storage_Error.
443 ------------------------
444 -- Large_Storage_Type --
445 ------------------------
447 function Large_Storage_Type (T : Entity_Id) return Boolean is
452 T = Standard_Positive
454 T = Standard_Natural;
455 end Large_Storage_Type;
458 -- Check that the Disc has a large range
460 if not Large_Storage_Type (Etype (Disc)) then
464 -- If the enclosing type is limited, we allocate only the
465 -- default value, not the maximum, and there is no need for
468 if Is_Limited_Type (Scope (Disc)) then
472 -- Check that it is the high bound
474 if N /= High_Bound (PN)
475 or else not Present (Discriminant_Default_Value (Disc))
480 -- Check the array allows a large range at this bound.
481 -- First find the array
485 if Nkind (SI) /= N_Subtype_Indication then
489 T := Entity (Subtype_Mark (SI));
491 if not Is_Array_Type (T) then
495 -- Next, find the dimension
497 TB := First_Index (T);
498 CB := First (Constraints (P));
500 and then Present (TB)
501 and then Present (CB)
512 -- Now, check the dimension has a large range
514 if not Large_Storage_Type (Etype (TB)) then
518 -- Warn about the danger
521 ("creation of & object may raise Storage_Error?",
530 -- Legal case is in index or discriminant constraint
532 elsif Nkind (PN) = N_Index_Or_Discriminant_Constraint
533 or else Nkind (PN) = N_Discriminant_Association
535 if Paren_Count (N) > 0 then
537 ("discriminant in constraint must appear alone", N);
542 -- Otherwise, context is an expression. It should not be within
543 -- (i.e. a subexpression of) a constraint for a component.
549 while Nkind (P) /= N_Component_Declaration
550 and then Nkind (P) /= N_Subtype_Indication
551 and then Nkind (P) /= N_Entry_Declaration
558 -- If the discriminant is used in an expression that is a bound
559 -- of a scalar type, an Itype is created and the bounds are attached
560 -- to its range, not to the original subtype indication. Such use
561 -- is of course a double fault.
563 if (Nkind (P) = N_Subtype_Indication
565 (Nkind (Parent (P)) = N_Component_Definition
567 Nkind (Parent (P)) = N_Derived_Type_Definition)
568 and then D = Constraint (P))
570 -- The constraint itself may be given by a subtype indication,
571 -- rather than by a more common discrete range.
573 or else (Nkind (P) = N_Subtype_Indication
575 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
576 or else Nkind (P) = N_Entry_Declaration
577 or else Nkind (D) = N_Defining_Identifier
580 ("discriminant in constraint must appear alone", N);
583 end Check_Discriminant_Use;
585 --------------------------------
586 -- Check_For_Visible_Operator --
587 --------------------------------
589 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
591 if Is_Invisible_Operator (N, T) then
593 ("operator for} is not directly visible!", N, First_Subtype (T));
594 Error_Msg_N ("use clause would make operation legal!", N);
596 end Check_For_Visible_Operator;
598 ------------------------------
599 -- Check_Infinite_Recursion --
600 ------------------------------
602 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
606 function Same_Argument_List return Boolean;
607 -- Check whether list of actuals is identical to list of formals
608 -- of called function (which is also the enclosing scope).
610 ------------------------
611 -- Same_Argument_List --
612 ------------------------
614 function Same_Argument_List return Boolean is
620 if not Is_Entity_Name (Name (N)) then
623 Subp := Entity (Name (N));
626 F := First_Formal (Subp);
627 A := First_Actual (N);
629 while Present (F) and then Present (A) loop
630 if not Is_Entity_Name (A)
631 or else Entity (A) /= F
641 end Same_Argument_List;
643 -- Start of processing for Check_Infinite_Recursion
646 -- Loop moving up tree, quitting if something tells us we are
647 -- definitely not in an infinite recursion situation.
652 exit when Nkind (P) = N_Subprogram_Body;
654 if Nkind (P) = N_Or_Else or else
655 Nkind (P) = N_And_Then or else
656 Nkind (P) = N_If_Statement or else
657 Nkind (P) = N_Case_Statement
661 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
662 and then C /= First (Statements (P))
664 -- If the call is the expression of a return statement and
665 -- the actuals are identical to the formals, it's worth a
666 -- warning. However, we skip this if there is an immediately
667 -- preceding raise statement, since the call is never executed.
669 -- Furthermore, this corresponds to a common idiom:
671 -- function F (L : Thing) return Boolean is
673 -- raise Program_Error;
677 -- for generating a stub function
679 if Nkind (Parent (N)) = N_Return_Statement
680 and then Same_Argument_List
682 exit when not Is_List_Member (Parent (N))
683 or else (Nkind (Prev (Parent (N))) /= N_Raise_Statement
685 (Nkind (Prev (Parent (N))) not in N_Raise_xxx_Error
687 Present (Condition (Prev (Parent (N))))));
697 Error_Msg_N ("possible infinite recursion?", N);
698 Error_Msg_N ("\Storage_Error may be raised at run time?", N);
701 end Check_Infinite_Recursion;
703 -------------------------------
704 -- Check_Initialization_Call --
705 -------------------------------
707 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
708 Typ : constant Entity_Id := Etype (First_Formal (Nam));
710 function Uses_SS (T : Entity_Id) return Boolean;
711 -- Check whether the creation of an object of the type will involve
712 -- use of the secondary stack. If T is a record type, this is true
713 -- if the expression for some component uses the secondary stack, eg.
714 -- through a call to a function that returns an unconstrained value.
715 -- False if T is controlled, because cleanups occur elsewhere.
721 function Uses_SS (T : Entity_Id) return Boolean is
726 if Is_Controlled (T) then
729 elsif Is_Array_Type (T) then
730 return Uses_SS (Component_Type (T));
732 elsif Is_Record_Type (T) then
733 Comp := First_Component (T);
735 while Present (Comp) loop
737 if Ekind (Comp) = E_Component
738 and then Nkind (Parent (Comp)) = N_Component_Declaration
740 Expr := Expression (Parent (Comp));
742 -- The expression for a dynamic component may be
743 -- rewritten as a dereference. Retrieve original
746 if Nkind (Original_Node (Expr)) = N_Function_Call
747 and then Requires_Transient_Scope (Etype (Expr))
751 elsif Uses_SS (Etype (Comp)) then
756 Next_Component (Comp);
766 -- Start of processing for Check_Initialization_Call
769 -- Nothing to do if functions do not use the secondary stack for
770 -- returns (i.e. they use a depressed stack pointer instead).
772 if Functions_Return_By_DSP_On_Target then
775 -- Otherwise establish a transient scope if the type needs it
777 elsif Uses_SS (Typ) then
778 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
780 end Check_Initialization_Call;
782 ------------------------------
783 -- Check_Parameterless_Call --
784 ------------------------------
786 procedure Check_Parameterless_Call (N : Node_Id) is
790 -- Defend against junk stuff if errors already detected
792 if Total_Errors_Detected /= 0 then
793 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
795 elsif Nkind (N) in N_Has_Chars
796 and then Chars (N) in Error_Name_Or_No_Name
804 -- If the context expects a value, and the name is a procedure,
805 -- this is most likely a missing 'Access. Do not try to resolve
806 -- the parameterless call, error will be caught when the outer
809 if Is_Entity_Name (N)
810 and then Ekind (Entity (N)) = E_Procedure
811 and then not Is_Overloaded (N)
813 (Nkind (Parent (N)) = N_Parameter_Association
814 or else Nkind (Parent (N)) = N_Function_Call
815 or else Nkind (Parent (N)) = N_Procedure_Call_Statement)
820 -- Rewrite as call if overloadable entity that is (or could be, in
821 -- the overloaded case) a function call. If we know for sure that
822 -- the entity is an enumeration literal, we do not rewrite it.
824 if (Is_Entity_Name (N)
825 and then Is_Overloadable (Entity (N))
826 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
827 or else Is_Overloaded (N)))
829 -- Rewrite as call if it is an explicit deference of an expression of
830 -- a subprogram access type, and the suprogram type is not that of a
831 -- procedure or entry.
834 (Nkind (N) = N_Explicit_Dereference
835 and then Ekind (Etype (N)) = E_Subprogram_Type
836 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type)
838 -- Rewrite as call if it is a selected component which is a function,
839 -- this is the case of a call to a protected function (which may be
840 -- overloaded with other protected operations).
843 (Nkind (N) = N_Selected_Component
844 and then (Ekind (Entity (Selector_Name (N))) = E_Function
846 ((Ekind (Entity (Selector_Name (N))) = E_Entry
848 Ekind (Entity (Selector_Name (N))) = E_Procedure)
849 and then Is_Overloaded (Selector_Name (N)))))
851 -- If one of the above three conditions is met, rewrite as call.
852 -- Apply the rewriting only once.
855 if Nkind (Parent (N)) /= N_Function_Call
856 or else N /= Name (Parent (N))
860 -- If overloaded, overload set belongs to new copy.
862 Save_Interps (N, Nam);
864 -- Change node to parameterless function call (note that the
865 -- Parameter_Associations associations field is left set to Empty,
866 -- its normal default value since there are no parameters)
868 Change_Node (N, N_Function_Call);
870 Set_Sloc (N, Sloc (Nam));
874 elsif Nkind (N) = N_Parameter_Association then
875 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
877 end Check_Parameterless_Call;
879 ----------------------
880 -- Is_Predefined_Op --
881 ----------------------
883 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
885 return Is_Intrinsic_Subprogram (Nam)
886 and then not Is_Generic_Instance (Nam)
887 and then Chars (Nam) in Any_Operator_Name
888 and then (No (Alias (Nam))
889 or else Is_Predefined_Op (Alias (Nam)));
890 end Is_Predefined_Op;
892 -----------------------------
893 -- Make_Call_Into_Operator --
894 -----------------------------
896 procedure Make_Call_Into_Operator
901 Op_Name : constant Name_Id := Chars (Op_Id);
902 Act1 : Node_Id := First_Actual (N);
903 Act2 : Node_Id := Next_Actual (Act1);
904 Error : Boolean := False;
905 Func : constant Entity_Id := Entity (Name (N));
906 Is_Binary : constant Boolean := Present (Act2);
908 Opnd_Type : Entity_Id;
909 Orig_Type : Entity_Id := Empty;
912 type Kind_Test is access function (E : Entity_Id) return Boolean;
914 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
915 -- Determine whether E is an access type declared by an access decla-
916 -- ration, and not an (anonymous) allocator type.
918 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
919 -- If the operand is not universal, and the operator is given by a
920 -- expanded name, verify that the operand has an interpretation with
921 -- a type defined in the given scope of the operator.
923 function Type_In_P (Test : Kind_Test) return Entity_Id;
924 -- Find a type of the given class in the package Pack that contains
927 -----------------------------
928 -- Is_Definite_Access_Type --
929 -----------------------------
931 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
932 Btyp : constant Entity_Id := Base_Type (E);
934 return Ekind (Btyp) = E_Access_Type
935 or else (Ekind (Btyp) = E_Access_Subprogram_Type
936 and then Comes_From_Source (Btyp));
937 end Is_Definite_Access_Type;
939 ---------------------------
940 -- Operand_Type_In_Scope --
941 ---------------------------
943 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
944 Nod : constant Node_Id := Right_Opnd (Op_Node);
949 if not Is_Overloaded (Nod) then
950 return Scope (Base_Type (Etype (Nod))) = S;
953 Get_First_Interp (Nod, I, It);
955 while Present (It.Typ) loop
957 if Scope (Base_Type (It.Typ)) = S then
961 Get_Next_Interp (I, It);
966 end Operand_Type_In_Scope;
972 function Type_In_P (Test : Kind_Test) return Entity_Id is
975 function In_Decl return Boolean;
976 -- Verify that node is not part of the type declaration for the
977 -- candidate type, which would otherwise be invisible.
983 function In_Decl return Boolean is
984 Decl_Node : constant Node_Id := Parent (E);
990 if Etype (E) = Any_Type then
993 elsif No (Decl_Node) then
998 and then Nkind (N2) /= N_Compilation_Unit
1000 if N2 = Decl_Node then
1011 -- Start of processing for Type_In_P
1014 -- If the context type is declared in the prefix package, this
1015 -- is the desired base type.
1017 if Scope (Base_Type (Typ)) = Pack
1020 return Base_Type (Typ);
1023 E := First_Entity (Pack);
1025 while Present (E) loop
1028 and then not In_Decl
1040 -- Start of processing for Make_Call_Into_Operator
1043 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1048 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1049 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1050 Save_Interps (Act1, Left_Opnd (Op_Node));
1051 Save_Interps (Act2, Right_Opnd (Op_Node));
1052 Act1 := Left_Opnd (Op_Node);
1053 Act2 := Right_Opnd (Op_Node);
1058 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1059 Save_Interps (Act1, Right_Opnd (Op_Node));
1060 Act1 := Right_Opnd (Op_Node);
1063 -- If the operator is denoted by an expanded name, and the prefix is
1064 -- not Standard, but the operator is a predefined one whose scope is
1065 -- Standard, then this is an implicit_operator, inserted as an
1066 -- interpretation by the procedure of the same name. This procedure
1067 -- overestimates the presence of implicit operators, because it does
1068 -- not examine the type of the operands. Verify now that the operand
1069 -- type appears in the given scope. If right operand is universal,
1070 -- check the other operand. In the case of concatenation, either
1071 -- argument can be the component type, so check the type of the result.
1072 -- If both arguments are literals, look for a type of the right kind
1073 -- defined in the given scope. This elaborate nonsense is brought to
1074 -- you courtesy of b33302a. The type itself must be frozen, so we must
1075 -- find the type of the proper class in the given scope.
1077 -- A final wrinkle is the multiplication operator for fixed point
1078 -- types, which is defined in Standard only, and not in the scope of
1079 -- the fixed_point type itself.
1081 if Nkind (Name (N)) = N_Expanded_Name then
1082 Pack := Entity (Prefix (Name (N)));
1084 -- If the entity being called is defined in the given package,
1085 -- it is a renaming of a predefined operator, and known to be
1088 if Scope (Entity (Name (N))) = Pack
1089 and then Pack /= Standard_Standard
1093 elsif (Op_Name = Name_Op_Multiply
1094 or else Op_Name = Name_Op_Divide)
1095 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1096 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1098 if Pack /= Standard_Standard then
1103 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1105 if Op_Name = Name_Op_Concat then
1106 Opnd_Type := Base_Type (Typ);
1108 elsif (Scope (Opnd_Type) = Standard_Standard
1110 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1112 and then not Comes_From_Source (Opnd_Type))
1114 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1117 if Scope (Opnd_Type) = Standard_Standard then
1119 -- Verify that the scope contains a type that corresponds to
1120 -- the given literal. Optimize the case where Pack is Standard.
1122 if Pack /= Standard_Standard then
1124 if Opnd_Type = Universal_Integer then
1125 Orig_Type := Type_In_P (Is_Integer_Type'Access);
1127 elsif Opnd_Type = Universal_Real then
1128 Orig_Type := Type_In_P (Is_Real_Type'Access);
1130 elsif Opnd_Type = Any_String then
1131 Orig_Type := Type_In_P (Is_String_Type'Access);
1133 elsif Opnd_Type = Any_Access then
1134 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
1136 elsif Opnd_Type = Any_Composite then
1137 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1139 if Present (Orig_Type) then
1140 if Has_Private_Component (Orig_Type) then
1143 Set_Etype (Act1, Orig_Type);
1146 Set_Etype (Act2, Orig_Type);
1155 Error := No (Orig_Type);
1158 elsif Ekind (Opnd_Type) = E_Allocator_Type
1159 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1163 -- If the type is defined elsewhere, and the operator is not
1164 -- defined in the given scope (by a renaming declaration, e.g.)
1165 -- then this is an error as well. If an extension of System is
1166 -- present, and the type may be defined there, Pack must be
1169 elsif Scope (Opnd_Type) /= Pack
1170 and then Scope (Op_Id) /= Pack
1171 and then (No (System_Aux_Id)
1172 or else Scope (Opnd_Type) /= System_Aux_Id
1173 or else Pack /= Scope (System_Aux_Id))
1177 elsif Pack = Standard_Standard
1178 and then not Operand_Type_In_Scope (Standard_Standard)
1185 Error_Msg_Node_2 := Pack;
1187 ("& not declared in&", N, Selector_Name (Name (N)));
1188 Set_Etype (N, Any_Type);
1193 Set_Chars (Op_Node, Op_Name);
1195 if not Is_Private_Type (Etype (N)) then
1196 Set_Etype (Op_Node, Base_Type (Etype (N)));
1198 Set_Etype (Op_Node, Etype (N));
1201 -- If this is a call to a function that renames a predefined equality,
1202 -- the renaming declaration provides a type that must be used to
1203 -- resolve the operands. This must be done now because resolution of
1204 -- the equality node will not resolve any remaining ambiguity, and it
1205 -- assumes that the first operand is not overloaded.
1207 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1208 and then Ekind (Func) = E_Function
1209 and then Is_Overloaded (Act1)
1211 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1212 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1215 Set_Entity (Op_Node, Op_Id);
1216 Generate_Reference (Op_Id, N, ' ');
1217 Rewrite (N, Op_Node);
1219 -- If this is an arithmetic operator and the result type is private,
1220 -- the operands and the result must be wrapped in conversion to
1221 -- expose the underlying numeric type and expand the proper checks,
1222 -- e.g. on division.
1224 if Is_Private_Type (Typ) then
1226 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1227 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
1228 Resolve_Intrinsic_Operator (N, Typ);
1230 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
1231 Resolve_Intrinsic_Unary_Operator (N, Typ);
1240 -- For predefined operators on literals, the operation freezes
1243 if Present (Orig_Type) then
1244 Set_Etype (Act1, Orig_Type);
1245 Freeze_Expression (Act1);
1247 end Make_Call_Into_Operator;
1253 function Operator_Kind
1255 Is_Binary : Boolean)
1262 if Op_Name = Name_Op_And then Kind := N_Op_And;
1263 elsif Op_Name = Name_Op_Or then Kind := N_Op_Or;
1264 elsif Op_Name = Name_Op_Xor then Kind := N_Op_Xor;
1265 elsif Op_Name = Name_Op_Eq then Kind := N_Op_Eq;
1266 elsif Op_Name = Name_Op_Ne then Kind := N_Op_Ne;
1267 elsif Op_Name = Name_Op_Lt then Kind := N_Op_Lt;
1268 elsif Op_Name = Name_Op_Le then Kind := N_Op_Le;
1269 elsif Op_Name = Name_Op_Gt then Kind := N_Op_Gt;
1270 elsif Op_Name = Name_Op_Ge then Kind := N_Op_Ge;
1271 elsif Op_Name = Name_Op_Add then Kind := N_Op_Add;
1272 elsif Op_Name = Name_Op_Subtract then Kind := N_Op_Subtract;
1273 elsif Op_Name = Name_Op_Concat then Kind := N_Op_Concat;
1274 elsif Op_Name = Name_Op_Multiply then Kind := N_Op_Multiply;
1275 elsif Op_Name = Name_Op_Divide then Kind := N_Op_Divide;
1276 elsif Op_Name = Name_Op_Mod then Kind := N_Op_Mod;
1277 elsif Op_Name = Name_Op_Rem then Kind := N_Op_Rem;
1278 elsif Op_Name = Name_Op_Expon then Kind := N_Op_Expon;
1280 raise Program_Error;
1286 if Op_Name = Name_Op_Add then Kind := N_Op_Plus;
1287 elsif Op_Name = Name_Op_Subtract then Kind := N_Op_Minus;
1288 elsif Op_Name = Name_Op_Abs then Kind := N_Op_Abs;
1289 elsif Op_Name = Name_Op_Not then Kind := N_Op_Not;
1291 raise Program_Error;
1298 -----------------------------
1299 -- Pre_Analyze_And_Resolve --
1300 -----------------------------
1302 procedure Pre_Analyze_And_Resolve (N : Node_Id; T : Entity_Id) is
1303 Save_Full_Analysis : constant Boolean := Full_Analysis;
1306 Full_Analysis := False;
1307 Expander_Mode_Save_And_Set (False);
1309 -- We suppress all checks for this analysis, since the checks will
1310 -- be applied properly, and in the right location, when the default
1311 -- expression is reanalyzed and reexpanded later on.
1313 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1315 Expander_Mode_Restore;
1316 Full_Analysis := Save_Full_Analysis;
1317 end Pre_Analyze_And_Resolve;
1319 -- Version without context type.
1321 procedure Pre_Analyze_And_Resolve (N : Node_Id) is
1322 Save_Full_Analysis : constant Boolean := Full_Analysis;
1325 Full_Analysis := False;
1326 Expander_Mode_Save_And_Set (False);
1329 Resolve (N, Etype (N), Suppress => All_Checks);
1331 Expander_Mode_Restore;
1332 Full_Analysis := Save_Full_Analysis;
1333 end Pre_Analyze_And_Resolve;
1335 ----------------------------------
1336 -- Replace_Actual_Discriminants --
1337 ----------------------------------
1339 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1340 Loc : constant Source_Ptr := Sloc (N);
1341 Tsk : Node_Id := Empty;
1343 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1349 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1353 if Nkind (Nod) = N_Identifier then
1354 Ent := Entity (Nod);
1357 and then Ekind (Ent) = E_Discriminant
1360 Make_Selected_Component (Loc,
1361 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1362 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1364 Set_Etype (Nod, Etype (Ent));
1372 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1374 -- Start of processing for Replace_Actual_Discriminants
1377 if not Expander_Active then
1381 if Nkind (Name (N)) = N_Selected_Component then
1382 Tsk := Prefix (Name (N));
1384 elsif Nkind (Name (N)) = N_Indexed_Component then
1385 Tsk := Prefix (Prefix (Name (N)));
1391 Replace_Discrs (Default);
1393 end Replace_Actual_Discriminants;
1399 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
1401 I1 : Interp_Index := 0; -- prevent junk warning
1404 Found : Boolean := False;
1405 Seen : Entity_Id := Empty; -- prevent junk warning
1406 Ctx_Type : Entity_Id := Typ;
1407 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1408 Err_Type : Entity_Id := Empty;
1409 Ambiguous : Boolean := False;
1411 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1412 -- Try and fix up a literal so that it matches its expected type. New
1413 -- literals are manufactured if necessary to avoid cascaded errors.
1415 procedure Resolution_Failed;
1416 -- Called when attempt at resolving current expression fails
1418 --------------------
1419 -- Patch_Up_Value --
1420 --------------------
1422 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1424 if Nkind (N) = N_Integer_Literal
1425 and then Is_Real_Type (Typ)
1428 Make_Real_Literal (Sloc (N),
1429 Realval => UR_From_Uint (Intval (N))));
1430 Set_Etype (N, Universal_Real);
1431 Set_Is_Static_Expression (N);
1433 elsif Nkind (N) = N_Real_Literal
1434 and then Is_Integer_Type (Typ)
1437 Make_Integer_Literal (Sloc (N),
1438 Intval => UR_To_Uint (Realval (N))));
1439 Set_Etype (N, Universal_Integer);
1440 Set_Is_Static_Expression (N);
1441 elsif Nkind (N) = N_String_Literal
1442 and then Is_Character_Type (Typ)
1444 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1446 Make_Character_Literal (Sloc (N),
1448 Char_Literal_Value => Char_Code (Character'Pos ('A'))));
1449 Set_Etype (N, Any_Character);
1450 Set_Is_Static_Expression (N);
1452 elsif Nkind (N) /= N_String_Literal
1453 and then Is_String_Type (Typ)
1456 Make_String_Literal (Sloc (N),
1457 Strval => End_String));
1459 elsif Nkind (N) = N_Range then
1460 Patch_Up_Value (Low_Bound (N), Typ);
1461 Patch_Up_Value (High_Bound (N), Typ);
1465 -----------------------
1466 -- Resolution_Failed --
1467 -----------------------
1469 procedure Resolution_Failed is
1471 Patch_Up_Value (N, Typ);
1473 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1474 Set_Is_Overloaded (N, False);
1476 -- The caller will return without calling the expander, so we need
1477 -- to set the analyzed flag. Note that it is fine to set Analyzed
1478 -- to True even if we are in the middle of a shallow analysis,
1479 -- (see the spec of sem for more details) since this is an error
1480 -- situation anyway, and there is no point in repeating the
1481 -- analysis later (indeed it won't work to repeat it later, since
1482 -- we haven't got a clear resolution of which entity is being
1485 Set_Analyzed (N, True);
1487 end Resolution_Failed;
1489 -- Start of processing for Resolve
1496 -- Access attribute on remote subprogram cannot be used for
1497 -- a non-remote access-to-subprogram type.
1499 if Nkind (N) = N_Attribute_Reference
1500 and then (Attribute_Name (N) = Name_Access
1501 or else Attribute_Name (N) = Name_Unrestricted_Access
1502 or else Attribute_Name (N) = Name_Unchecked_Access)
1503 and then Comes_From_Source (N)
1504 and then Is_Entity_Name (Prefix (N))
1505 and then Is_Subprogram (Entity (Prefix (N)))
1506 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1507 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1510 ("prefix must statically denote a non-remote subprogram", N);
1513 -- If the context is a Remote_Access_To_Subprogram, access attributes
1514 -- must be resolved with the corresponding fat pointer. There is no need
1515 -- to check for the attribute name since the return type of an
1516 -- attribute is never a remote type.
1518 if Nkind (N) = N_Attribute_Reference
1519 and then Comes_From_Source (N)
1520 and then (Is_Remote_Call_Interface (Typ)
1521 or else Is_Remote_Types (Typ))
1524 Attr : constant Attribute_Id :=
1525 Get_Attribute_Id (Attribute_Name (N));
1526 Pref : constant Node_Id := Prefix (N);
1529 Is_Remote : Boolean := True;
1532 -- Check that Typ is a fat pointer with a reference to a RAS as
1533 -- original access type.
1536 (Ekind (Typ) = E_Access_Subprogram_Type
1537 and then Present (Equivalent_Type (Typ)))
1539 (Ekind (Typ) = E_Record_Type
1540 and then Present (Corresponding_Remote_Type (Typ)))
1543 -- Prefix (N) must statically denote a remote subprogram
1544 -- declared in a package specification.
1546 if Attr = Attribute_Access then
1547 Decl := Unit_Declaration_Node (Entity (Pref));
1549 if Nkind (Decl) = N_Subprogram_Body then
1550 Spec := Corresponding_Spec (Decl);
1552 if not No (Spec) then
1553 Decl := Unit_Declaration_Node (Spec);
1557 Spec := Parent (Decl);
1559 if not Is_Entity_Name (Prefix (N))
1560 or else Nkind (Spec) /= N_Package_Specification
1562 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1566 ("prefix must statically denote a remote subprogram ",
1571 -- If we are generating code for a distributed program.
1572 -- perform semantic checks against the corresponding
1575 if (Attr = Attribute_Access
1576 or else Attr = Attribute_Unchecked_Access
1577 or else Attr = Attribute_Unrestricted_Access)
1578 and then Expander_Active
1580 Check_Subtype_Conformant
1581 (New_Id => Entity (Prefix (N)),
1582 Old_Id => Designated_Type
1583 (Corresponding_Remote_Type (Typ)),
1586 Process_Remote_AST_Attribute (N, Typ);
1593 Debug_A_Entry ("resolving ", N);
1595 if Comes_From_Source (N) then
1596 if Is_Fixed_Point_Type (Typ) then
1597 Check_Restriction (No_Fixed_Point, N);
1599 elsif Is_Floating_Point_Type (Typ)
1600 and then Typ /= Universal_Real
1601 and then Typ /= Any_Real
1603 Check_Restriction (No_Floating_Point, N);
1607 -- Return if already analyzed
1609 if Analyzed (N) then
1610 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
1613 -- Return if type = Any_Type (previous error encountered)
1615 elsif Etype (N) = Any_Type then
1616 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
1620 Check_Parameterless_Call (N);
1622 -- If not overloaded, then we know the type, and all that needs doing
1623 -- is to check that this type is compatible with the context.
1625 if not Is_Overloaded (N) then
1626 Found := Covers (Typ, Etype (N));
1627 Expr_Type := Etype (N);
1629 -- In the overloaded case, we must select the interpretation that
1630 -- is compatible with the context (i.e. the type passed to Resolve)
1633 Get_First_Interp (N, I, It);
1635 -- Loop through possible interpretations
1637 Interp_Loop : while Present (It.Typ) loop
1639 -- We are only interested in interpretations that are compatible
1640 -- with the expected type, any other interpretations are ignored
1642 if not Covers (Typ, It.Typ) then
1643 if Debug_Flag_V then
1644 Write_Str (" interpretation incompatible with context");
1649 -- First matching interpretation
1655 Expr_Type := It.Typ;
1657 -- Matching interpretation that is not the first, maybe an
1658 -- error, but there are some cases where preference rules are
1659 -- used to choose between the two possibilities. These and
1660 -- some more obscure cases are handled in Disambiguate.
1663 Error_Msg_Sloc := Sloc (Seen);
1664 It1 := Disambiguate (N, I1, I, Typ);
1666 -- Disambiguation has succeeded. Skip the remaining
1669 if It1 /= No_Interp then
1671 Expr_Type := It1.Typ;
1673 while Present (It.Typ) loop
1674 Get_Next_Interp (I, It);
1678 -- Before we issue an ambiguity complaint, check for
1679 -- the case of a subprogram call where at least one
1680 -- of the arguments is Any_Type, and if so, suppress
1681 -- the message, since it is a cascaded error.
1683 if Nkind (N) = N_Function_Call
1684 or else Nkind (N) = N_Procedure_Call_Statement
1687 A : Node_Id := First_Actual (N);
1691 while Present (A) loop
1694 if Nkind (E) = N_Parameter_Association then
1695 E := Explicit_Actual_Parameter (E);
1698 if Etype (E) = Any_Type then
1699 if Debug_Flag_V then
1700 Write_Str ("Any_Type in call");
1711 elsif Nkind (N) in N_Binary_Op
1712 and then (Etype (Left_Opnd (N)) = Any_Type
1713 or else Etype (Right_Opnd (N)) = Any_Type)
1717 elsif Nkind (N) in N_Unary_Op
1718 and then Etype (Right_Opnd (N)) = Any_Type
1723 -- Not that special case, so issue message using the
1724 -- flag Ambiguous to control printing of the header
1725 -- message only at the start of an ambiguous set.
1727 if not Ambiguous then
1729 ("ambiguous expression (cannot resolve&)!",
1733 ("possible interpretation#!", N);
1737 Error_Msg_Sloc := Sloc (It.Nam);
1739 -- By default, the error message refers to the candidate
1740 -- interpretation. But if it is a predefined operator,
1741 -- it is implicitly declared at the declaration of
1742 -- the type of the operand. Recover the sloc of that
1743 -- declaration for the error message.
1745 if Nkind (N) in N_Op
1746 and then Scope (It.Nam) = Standard_Standard
1747 and then not Is_Overloaded (Right_Opnd (N))
1748 and then Scope (Base_Type (Etype (Right_Opnd (N))))
1749 /= Standard_Standard
1751 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
1753 if Comes_From_Source (Err_Type)
1754 and then Present (Parent (Err_Type))
1756 Error_Msg_Sloc := Sloc (Parent (Err_Type));
1759 elsif Nkind (N) in N_Binary_Op
1760 and then Scope (It.Nam) = Standard_Standard
1761 and then not Is_Overloaded (Left_Opnd (N))
1762 and then Scope (Base_Type (Etype (Left_Opnd (N))))
1763 /= Standard_Standard
1765 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
1767 if Comes_From_Source (Err_Type)
1768 and then Present (Parent (Err_Type))
1770 Error_Msg_Sloc := Sloc (Parent (Err_Type));
1776 if Nkind (N) in N_Op
1777 and then Scope (It.Nam) = Standard_Standard
1778 and then Present (Err_Type)
1781 ("possible interpretation (predefined)#!", N);
1783 Error_Msg_N ("possible interpretation#!", N);
1789 -- We have a matching interpretation, Expr_Type is the
1790 -- type from this interpretation, and Seen is the entity.
1792 -- For an operator, just set the entity name. The type will
1793 -- be set by the specific operator resolution routine.
1795 if Nkind (N) in N_Op then
1796 Set_Entity (N, Seen);
1797 Generate_Reference (Seen, N);
1799 elsif Nkind (N) = N_Character_Literal then
1800 Set_Etype (N, Expr_Type);
1802 -- For an explicit dereference, attribute reference, range,
1803 -- short-circuit form (which is not an operator node),
1804 -- or a call with a name that is an explicit dereference,
1805 -- there is nothing to be done at this point.
1807 elsif Nkind (N) = N_Explicit_Dereference
1808 or else Nkind (N) = N_Attribute_Reference
1809 or else Nkind (N) = N_And_Then
1810 or else Nkind (N) = N_Indexed_Component
1811 or else Nkind (N) = N_Or_Else
1812 or else Nkind (N) = N_Range
1813 or else Nkind (N) = N_Selected_Component
1814 or else Nkind (N) = N_Slice
1815 or else Nkind (Name (N)) = N_Explicit_Dereference
1819 -- For procedure or function calls, set the type of the
1820 -- name, and also the entity pointer for the prefix
1822 elsif (Nkind (N) = N_Procedure_Call_Statement
1823 or else Nkind (N) = N_Function_Call)
1824 and then (Is_Entity_Name (Name (N))
1825 or else Nkind (Name (N)) = N_Operator_Symbol)
1827 Set_Etype (Name (N), Expr_Type);
1828 Set_Entity (Name (N), Seen);
1829 Generate_Reference (Seen, Name (N));
1831 elsif Nkind (N) = N_Function_Call
1832 and then Nkind (Name (N)) = N_Selected_Component
1834 Set_Etype (Name (N), Expr_Type);
1835 Set_Entity (Selector_Name (Name (N)), Seen);
1836 Generate_Reference (Seen, Selector_Name (Name (N)));
1838 -- For all other cases, just set the type of the Name
1841 Set_Etype (Name (N), Expr_Type);
1846 -- Move to next interpretation
1848 exit Interp_Loop when not Present (It.Typ);
1850 Get_Next_Interp (I, It);
1851 end loop Interp_Loop;
1854 -- At this stage Found indicates whether or not an acceptable
1855 -- interpretation exists. If not, then we have an error, except
1856 -- that if the context is Any_Type as a result of some other error,
1857 -- then we suppress the error report.
1860 if Typ /= Any_Type then
1862 -- If type we are looking for is Void, then this is the
1863 -- procedure call case, and the error is simply that what
1864 -- we gave is not a procedure name (we think of procedure
1865 -- calls as expressions with types internally, but the user
1866 -- doesn't think of them this way!)
1868 if Typ = Standard_Void_Type then
1870 -- Special case message if function used as a procedure
1872 if Nkind (N) = N_Procedure_Call_Statement
1873 and then Is_Entity_Name (Name (N))
1874 and then Ekind (Entity (Name (N))) = E_Function
1877 ("cannot use function & in a procedure call",
1878 Name (N), Entity (Name (N)));
1880 -- Otherwise give general message (not clear what cases
1881 -- this covers, but no harm in providing for them!)
1884 Error_Msg_N ("expect procedure name in procedure call", N);
1889 -- Otherwise we do have a subexpression with the wrong type
1891 -- Check for the case of an allocator which uses an access
1892 -- type instead of the designated type. This is a common
1893 -- error and we specialize the message, posting an error
1894 -- on the operand of the allocator, complaining that we
1895 -- expected the designated type of the allocator.
1897 elsif Nkind (N) = N_Allocator
1898 and then Ekind (Typ) in Access_Kind
1899 and then Ekind (Etype (N)) in Access_Kind
1900 and then Designated_Type (Etype (N)) = Typ
1902 Wrong_Type (Expression (N), Designated_Type (Typ));
1905 -- Check for view mismatch on Null in instances, for
1906 -- which the view-swapping mechanism has no identifier.
1908 elsif (In_Instance or else In_Inlined_Body)
1909 and then (Nkind (N) = N_Null)
1910 and then Is_Private_Type (Typ)
1911 and then Is_Access_Type (Full_View (Typ))
1913 Resolve (N, Full_View (Typ));
1917 -- Check for an aggregate. Sometimes we can get bogus
1918 -- aggregates from misuse of parentheses, and we are
1919 -- about to complain about the aggregate without even
1920 -- looking inside it.
1922 -- Instead, if we have an aggregate of type Any_Composite,
1923 -- then analyze and resolve the component fields, and then
1924 -- only issue another message if we get no errors doing
1925 -- this (otherwise assume that the errors in the aggregate
1926 -- caused the problem).
1928 elsif Nkind (N) = N_Aggregate
1929 and then Etype (N) = Any_Composite
1931 -- Disable expansion in any case. If there is a type mismatch
1932 -- it may be fatal to try to expand the aggregate. The flag
1933 -- would otherwise be set to false when the error is posted.
1935 Expander_Active := False;
1938 procedure Check_Aggr (Aggr : Node_Id);
1939 -- Check one aggregate, and set Found to True if we
1940 -- have a definite error in any of its elements
1942 procedure Check_Elmt (Aelmt : Node_Id);
1943 -- Check one element of aggregate and set Found to
1944 -- True if we definitely have an error in the element.
1946 procedure Check_Aggr (Aggr : Node_Id) is
1950 if Present (Expressions (Aggr)) then
1951 Elmt := First (Expressions (Aggr));
1952 while Present (Elmt) loop
1958 if Present (Component_Associations (Aggr)) then
1959 Elmt := First (Component_Associations (Aggr));
1960 while Present (Elmt) loop
1961 Check_Elmt (Expression (Elmt));
1971 procedure Check_Elmt (Aelmt : Node_Id) is
1973 -- If we have a nested aggregate, go inside it (to
1974 -- attempt a naked analyze-resolve of the aggregate
1975 -- can cause undesirable cascaded errors). Do not
1976 -- resolve expression if it needs a type from context,
1977 -- as for integer * fixed expression.
1979 if Nkind (Aelmt) = N_Aggregate then
1985 if not Is_Overloaded (Aelmt)
1986 and then Etype (Aelmt) /= Any_Fixed
1991 if Etype (Aelmt) = Any_Type then
2002 -- If an error message was issued already, Found got reset
2003 -- to True, so if it is still False, issue the standard
2004 -- Wrong_Type message.
2007 if Is_Overloaded (N)
2008 and then Nkind (N) = N_Function_Call
2011 Subp_Name : Node_Id;
2013 if Is_Entity_Name (Name (N)) then
2014 Subp_Name := Name (N);
2016 elsif Nkind (Name (N)) = N_Selected_Component then
2018 -- Protected operation: retrieve operation name.
2020 Subp_Name := Selector_Name (Name (N));
2022 raise Program_Error;
2025 Error_Msg_Node_2 := Typ;
2026 Error_Msg_NE ("no visible interpretation of&" &
2027 " matches expected type&", N, Subp_Name);
2030 if All_Errors_Mode then
2032 Index : Interp_Index;
2036 Error_Msg_N ("\possible interpretations:", N);
2037 Get_First_Interp (Name (N), Index, It);
2039 while Present (It.Nam) loop
2041 Error_Msg_Sloc := Sloc (It.Nam);
2042 Error_Msg_Node_2 := It.Typ;
2043 Error_Msg_NE ("\& declared#, type&",
2046 Get_Next_Interp (Index, It);
2050 Error_Msg_N ("\use -gnatf for details", N);
2053 Wrong_Type (N, Typ);
2061 -- Test if we have more than one interpretation for the context
2063 elsif Ambiguous then
2067 -- Here we have an acceptable interpretation for the context
2070 -- A user-defined operator is tranformed into a function call at
2071 -- this point, so that further processing knows that operators are
2072 -- really operators (i.e. are predefined operators). User-defined
2073 -- operators that are intrinsic are just renamings of the predefined
2074 -- ones, and need not be turned into calls either, but if they rename
2075 -- a different operator, we must transform the node accordingly.
2076 -- Instantiations of Unchecked_Conversion are intrinsic but are
2077 -- treated as functions, even if given an operator designator.
2079 if Nkind (N) in N_Op
2080 and then Present (Entity (N))
2081 and then Ekind (Entity (N)) /= E_Operator
2084 if not Is_Predefined_Op (Entity (N)) then
2085 Rewrite_Operator_As_Call (N, Entity (N));
2087 elsif Present (Alias (Entity (N))) then
2088 Rewrite_Renamed_Operator (N, Alias (Entity (N)));
2092 -- Propagate type information and normalize tree for various
2093 -- predefined operations. If the context only imposes a class of
2094 -- types, rather than a specific type, propagate the actual type
2097 if Typ = Any_Integer
2098 or else Typ = Any_Boolean
2099 or else Typ = Any_Modular
2100 or else Typ = Any_Real
2101 or else Typ = Any_Discrete
2103 Ctx_Type := Expr_Type;
2105 -- Any_Fixed is legal in a real context only if a specific
2106 -- fixed point type is imposed. If Norman Cohen can be
2107 -- confused by this, it deserves a separate message.
2110 and then Expr_Type = Any_Fixed
2112 Error_Msg_N ("Illegal context for mixed mode operation", N);
2113 Set_Etype (N, Universal_Real);
2114 Ctx_Type := Universal_Real;
2118 case N_Subexpr'(Nkind (N)) is
2120 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2122 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2124 when N_And_Then | N_Or_Else
2125 => Resolve_Short_Circuit (N, Ctx_Type);
2127 when N_Attribute_Reference
2128 => Resolve_Attribute (N, Ctx_Type);
2130 when N_Character_Literal
2131 => Resolve_Character_Literal (N, Ctx_Type);
2133 when N_Conditional_Expression
2134 => Resolve_Conditional_Expression (N, Ctx_Type);
2136 when N_Expanded_Name
2137 => Resolve_Entity_Name (N, Ctx_Type);
2139 when N_Extension_Aggregate
2140 => Resolve_Extension_Aggregate (N, Ctx_Type);
2142 when N_Explicit_Dereference
2143 => Resolve_Explicit_Dereference (N, Ctx_Type);
2145 when N_Function_Call
2146 => Resolve_Call (N, Ctx_Type);
2149 => Resolve_Entity_Name (N, Ctx_Type);
2151 when N_In | N_Not_In
2152 => Resolve_Membership_Op (N, Ctx_Type);
2154 when N_Indexed_Component
2155 => Resolve_Indexed_Component (N, Ctx_Type);
2157 when N_Integer_Literal
2158 => Resolve_Integer_Literal (N, Ctx_Type);
2160 when N_Null => Resolve_Null (N, Ctx_Type);
2162 when N_Op_And | N_Op_Or | N_Op_Xor
2163 => Resolve_Logical_Op (N, Ctx_Type);
2165 when N_Op_Eq | N_Op_Ne
2166 => Resolve_Equality_Op (N, Ctx_Type);
2168 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2169 => Resolve_Comparison_Op (N, Ctx_Type);
2171 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2173 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2174 N_Op_Divide | N_Op_Mod | N_Op_Rem
2176 => Resolve_Arithmetic_Op (N, Ctx_Type);
2178 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2180 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2182 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2183 => Resolve_Unary_Op (N, Ctx_Type);
2185 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2187 when N_Procedure_Call_Statement
2188 => Resolve_Call (N, Ctx_Type);
2190 when N_Operator_Symbol
2191 => Resolve_Operator_Symbol (N, Ctx_Type);
2193 when N_Qualified_Expression
2194 => Resolve_Qualified_Expression (N, Ctx_Type);
2196 when N_Raise_xxx_Error
2197 => Set_Etype (N, Ctx_Type);
2199 when N_Range => Resolve_Range (N, Ctx_Type);
2202 => Resolve_Real_Literal (N, Ctx_Type);
2204 when N_Reference => Resolve_Reference (N, Ctx_Type);
2206 when N_Selected_Component
2207 => Resolve_Selected_Component (N, Ctx_Type);
2209 when N_Slice => Resolve_Slice (N, Ctx_Type);
2211 when N_String_Literal
2212 => Resolve_String_Literal (N, Ctx_Type);
2214 when N_Subprogram_Info
2215 => Resolve_Subprogram_Info (N, Ctx_Type);
2217 when N_Type_Conversion
2218 => Resolve_Type_Conversion (N, Ctx_Type);
2220 when N_Unchecked_Expression =>
2221 Resolve_Unchecked_Expression (N, Ctx_Type);
2223 when N_Unchecked_Type_Conversion =>
2224 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2228 -- If the subexpression was replaced by a non-subexpression, then
2229 -- all we do is to expand it. The only legitimate case we know of
2230 -- is converting procedure call statement to entry call statements,
2231 -- but there may be others, so we are making this test general.
2233 if Nkind (N) not in N_Subexpr then
2234 Debug_A_Exit ("resolving ", N, " (done)");
2239 -- The expression is definitely NOT overloaded at this point, so
2240 -- we reset the Is_Overloaded flag to avoid any confusion when
2241 -- reanalyzing the node.
2243 Set_Is_Overloaded (N, False);
2245 -- Freeze expression type, entity if it is a name, and designated
2246 -- type if it is an allocator (RM 13.14(10,11,13)).
2248 -- Now that the resolution of the type of the node is complete,
2249 -- and we did not detect an error, we can expand this node. We
2250 -- skip the expand call if we are in a default expression, see
2251 -- section "Handling of Default Expressions" in Sem spec.
2253 Debug_A_Exit ("resolving ", N, " (done)");
2255 -- We unconditionally freeze the expression, even if we are in
2256 -- default expression mode (the Freeze_Expression routine tests
2257 -- this flag and only freezes static types if it is set).
2259 Freeze_Expression (N);
2261 -- Now we can do the expansion
2271 -- Version with check(s) suppressed
2273 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2275 if Suppress = All_Checks then
2277 Svg : constant Suppress_Array := Scope_Suppress;
2280 Scope_Suppress := (others => True);
2282 Scope_Suppress := Svg;
2287 Svg : constant Boolean := Scope_Suppress (Suppress);
2290 Scope_Suppress (Suppress) := True;
2292 Scope_Suppress (Suppress) := Svg;
2301 -- Version with implicit type
2303 procedure Resolve (N : Node_Id) is
2305 Resolve (N, Etype (N));
2308 ---------------------
2309 -- Resolve_Actuals --
2310 ---------------------
2312 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2313 Loc : constant Source_Ptr := Sloc (N);
2318 Prev : Node_Id := Empty;
2320 procedure Insert_Default;
2321 -- If the actual is missing in a call, insert in the actuals list
2322 -- an instance of the default expression. The insertion is always
2323 -- a named association.
2325 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2326 -- Check whether T1 and T2, or their full views, are derived from a
2327 -- common type. Used to enforce the restrictions on array conversions
2330 --------------------
2331 -- Insert_Default --
2332 --------------------
2334 procedure Insert_Default is
2339 -- Missing argument in call, nothing to insert
2341 if No (Default_Value (F)) then
2345 -- Note that we do a full New_Copy_Tree, so that any associated
2346 -- Itypes are properly copied. This may not be needed any more,
2347 -- but it does no harm as a safety measure! Defaults of a generic
2348 -- formal may be out of bounds of the corresponding actual (see
2349 -- cc1311b) and an additional check may be required.
2351 Actval := New_Copy_Tree (Default_Value (F),
2352 New_Scope => Current_Scope, New_Sloc => Loc);
2354 if Is_Concurrent_Type (Scope (Nam))
2355 and then Has_Discriminants (Scope (Nam))
2357 Replace_Actual_Discriminants (N, Actval);
2360 if Is_Overloadable (Nam)
2361 and then Present (Alias (Nam))
2363 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2364 and then not Is_Tagged_Type (Etype (F))
2366 -- If default is a real literal, do not introduce a
2367 -- conversion whose effect may depend on the run-time
2368 -- size of universal real.
2370 if Nkind (Actval) = N_Real_Literal then
2371 Set_Etype (Actval, Base_Type (Etype (F)));
2373 Actval := Unchecked_Convert_To (Etype (F), Actval);
2377 if Is_Scalar_Type (Etype (F)) then
2378 Enable_Range_Check (Actval);
2381 Set_Parent (Actval, N);
2383 -- Resolve aggregates with their base type, to avoid scope
2384 -- anomalies: the subtype was first built in the suprogram
2385 -- declaration, and the current call may be nested.
2387 if Nkind (Actval) = N_Aggregate
2388 and then Has_Discriminants (Etype (Actval))
2390 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2392 Analyze_And_Resolve (Actval, Etype (Actval));
2396 Set_Parent (Actval, N);
2398 -- See note above concerning aggregates.
2400 if Nkind (Actval) = N_Aggregate
2401 and then Has_Discriminants (Etype (Actval))
2403 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2405 -- Resolve entities with their own type, which may differ
2406 -- from the type of a reference in a generic context (the
2407 -- view swapping mechanism did not anticipate the re-analysis
2408 -- of default values in calls).
2410 elsif Is_Entity_Name (Actval) then
2411 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2414 Analyze_And_Resolve (Actval, Etype (Actval));
2418 -- If default is a tag indeterminate function call, propagate
2419 -- tag to obtain proper dispatching.
2421 if Is_Controlling_Formal (F)
2422 and then Nkind (Default_Value (F)) = N_Function_Call
2424 Set_Is_Controlling_Actual (Actval);
2429 -- If the default expression raises constraint error, then just
2430 -- silently replace it with an N_Raise_Constraint_Error node,
2431 -- since we already gave the warning on the subprogram spec.
2433 if Raises_Constraint_Error (Actval) then
2435 Make_Raise_Constraint_Error (Loc,
2436 Reason => CE_Range_Check_Failed));
2437 Set_Raises_Constraint_Error (Actval);
2438 Set_Etype (Actval, Etype (F));
2442 Make_Parameter_Association (Loc,
2443 Explicit_Actual_Parameter => Actval,
2444 Selector_Name => Make_Identifier (Loc, Chars (F)));
2446 -- Case of insertion is first named actual
2448 if No (Prev) or else
2449 Nkind (Parent (Prev)) /= N_Parameter_Association
2451 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
2452 Set_First_Named_Actual (N, Actval);
2455 if not Present (Parameter_Associations (N)) then
2456 Set_Parameter_Associations (N, New_List (Assoc));
2458 Append (Assoc, Parameter_Associations (N));
2462 Insert_After (Prev, Assoc);
2465 -- Case of insertion is not first named actual
2468 Set_Next_Named_Actual
2469 (Assoc, Next_Named_Actual (Parent (Prev)));
2470 Set_Next_Named_Actual (Parent (Prev), Actval);
2471 Append (Assoc, Parameter_Associations (N));
2474 Mark_Rewrite_Insertion (Assoc);
2475 Mark_Rewrite_Insertion (Actval);
2484 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
2485 FT1 : Entity_Id := T1;
2486 FT2 : Entity_Id := T2;
2489 if Is_Private_Type (T1)
2490 and then Present (Full_View (T1))
2492 FT1 := Full_View (T1);
2495 if Is_Private_Type (T2)
2496 and then Present (Full_View (T2))
2498 FT2 := Full_View (T2);
2501 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
2504 -- Start of processing for Resolve_Actuals
2507 A := First_Actual (N);
2508 F := First_Formal (Nam);
2510 while Present (F) loop
2511 if No (A) and then Needs_No_Actuals (Nam) then
2514 -- If we have an error in any actual or formal, indicated by
2515 -- a type of Any_Type, then abandon resolution attempt, and
2516 -- set result type to Any_Type.
2518 elsif (Present (A) and then Etype (A) = Any_Type)
2519 or else Etype (F) = Any_Type
2521 Set_Etype (N, Any_Type);
2526 and then (Nkind (Parent (A)) /= N_Parameter_Association
2528 Chars (Selector_Name (Parent (A))) = Chars (F))
2530 -- If the formal is Out or In_Out, do not resolve and expand the
2531 -- conversion, because it is subsequently expanded into explicit
2532 -- temporaries and assignments. However, the object of the
2533 -- conversion can be resolved. An exception is the case of
2534 -- a tagged type conversion with a class-wide actual. In that
2535 -- case we want the tag check to occur and no temporary will
2536 -- will be needed (no representation change can occur) and
2537 -- the parameter is passed by reference, so we go ahead and
2538 -- resolve the type conversion.
2540 if Ekind (F) /= E_In_Parameter
2541 and then Nkind (A) = N_Type_Conversion
2542 and then not Is_Class_Wide_Type (Etype (Expression (A)))
2544 if Ekind (F) = E_In_Out_Parameter
2545 and then Is_Array_Type (Etype (F))
2547 if Has_Aliased_Components (Etype (Expression (A)))
2548 /= Has_Aliased_Components (Etype (F))
2551 ("both component types in a view conversion must be"
2552 & " aliased, or neither", A);
2554 elsif not Same_Ancestor (Etype (F), Etype (Expression (A)))
2556 (Is_By_Reference_Type (Etype (F))
2557 or else Is_By_Reference_Type (Etype (Expression (A))))
2560 ("view conversion between unrelated by_reference "
2561 & "array types not allowed (\A\I-00246)?", A);
2565 if Conversion_OK (A)
2566 or else Valid_Conversion (A, Etype (A), Expression (A))
2568 Resolve (Expression (A));
2572 if Nkind (A) = N_Type_Conversion
2573 and then Is_Array_Type (Etype (F))
2574 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
2576 (Is_Limited_Type (Etype (F))
2577 or else Is_Limited_Type (Etype (Expression (A))))
2580 ("Conversion between unrelated limited array types "
2581 & "not allowed (\A\I-00246)?", A);
2583 -- Disable explanation (which produces additional errors)
2584 -- until AI is approved and warning becomes an error.
2586 -- if Is_Limited_Type (Etype (F)) then
2587 -- Explain_Limited_Type (Etype (F), A);
2590 -- if Is_Limited_Type (Etype (Expression (A))) then
2591 -- Explain_Limited_Type (Etype (Expression (A)), A);
2595 Resolve (A, Etype (F));
2601 -- Perform error checks for IN and IN OUT parameters
2603 if Ekind (F) /= E_Out_Parameter then
2605 -- Check unset reference. For scalar parameters, it is clearly
2606 -- wrong to pass an uninitialized value as either an IN or
2607 -- IN-OUT parameter. For composites, it is also clearly an
2608 -- error to pass a completely uninitialized value as an IN
2609 -- parameter, but the case of IN OUT is trickier. We prefer
2610 -- not to give a warning here. For example, suppose there is
2611 -- a routine that sets some component of a record to False.
2612 -- It is perfectly reasonable to make this IN-OUT and allow
2613 -- either initialized or uninitialized records to be passed
2616 -- For partially initialized composite values, we also avoid
2617 -- warnings, since it is quite likely that we are passing a
2618 -- partially initialized value and only the initialized fields
2619 -- will in fact be read in the subprogram.
2621 if Is_Scalar_Type (A_Typ)
2622 or else (Ekind (F) = E_In_Parameter
2623 and then not Is_Partially_Initialized_Type (A_Typ))
2625 Check_Unset_Reference (A);
2628 -- In Ada 83 we cannot pass an OUT parameter as an IN
2629 -- or IN OUT actual to a nested call, since this is a
2630 -- case of reading an out parameter, which is not allowed.
2633 and then Is_Entity_Name (A)
2634 and then Ekind (Entity (A)) = E_Out_Parameter
2636 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
2640 if Ekind (F) /= E_In_Parameter
2641 and then not Is_OK_Variable_For_Out_Formal (A)
2643 Error_Msg_NE ("actual for& must be a variable", A, F);
2645 if Is_Entity_Name (A) then
2646 Kill_Checks (Entity (A));
2652 if Etype (A) = Any_Type then
2653 Set_Etype (N, Any_Type);
2657 -- Apply appropriate range checks for in, out, and in-out
2658 -- parameters. Out and in-out parameters also need a separate
2659 -- check, if there is a type conversion, to make sure the return
2660 -- value meets the constraints of the variable before the
2663 -- Gigi looks at the check flag and uses the appropriate types.
2664 -- For now since one flag is used there is an optimization which
2665 -- might not be done in the In Out case since Gigi does not do
2666 -- any analysis. More thought required about this ???
2668 if Ekind (F) = E_In_Parameter
2669 or else Ekind (F) = E_In_Out_Parameter
2671 if Is_Scalar_Type (Etype (A)) then
2672 Apply_Scalar_Range_Check (A, F_Typ);
2674 elsif Is_Array_Type (Etype (A)) then
2675 Apply_Length_Check (A, F_Typ);
2677 elsif Is_Record_Type (F_Typ)
2678 and then Has_Discriminants (F_Typ)
2679 and then Is_Constrained (F_Typ)
2680 and then (not Is_Derived_Type (F_Typ)
2681 or else Comes_From_Source (Nam))
2683 Apply_Discriminant_Check (A, F_Typ);
2685 elsif Is_Access_Type (F_Typ)
2686 and then Is_Array_Type (Designated_Type (F_Typ))
2687 and then Is_Constrained (Designated_Type (F_Typ))
2689 Apply_Length_Check (A, F_Typ);
2691 elsif Is_Access_Type (F_Typ)
2692 and then Has_Discriminants (Designated_Type (F_Typ))
2693 and then Is_Constrained (Designated_Type (F_Typ))
2695 Apply_Discriminant_Check (A, F_Typ);
2698 Apply_Range_Check (A, F_Typ);
2703 if Extensions_Allowed
2704 and then Is_Access_Type (F_Typ)
2705 and then (Can_Never_Be_Null (F)
2706 or else Can_Never_Be_Null (F_Typ))
2708 if Nkind (A) = N_Null then
2709 Error_Msg_NE ("(Ada 0Y) not allowed for null-exclusion " &
2710 "formal", A, F_Typ);
2715 if Ekind (F) = E_Out_Parameter
2716 or else Ekind (F) = E_In_Out_Parameter
2718 if Nkind (A) = N_Type_Conversion then
2719 if Is_Scalar_Type (A_Typ) then
2720 Apply_Scalar_Range_Check
2721 (Expression (A), Etype (Expression (A)), A_Typ);
2724 (Expression (A), Etype (Expression (A)), A_Typ);
2728 if Is_Scalar_Type (F_Typ) then
2729 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
2731 elsif Is_Array_Type (F_Typ)
2732 and then Ekind (F) = E_Out_Parameter
2734 Apply_Length_Check (A, F_Typ);
2737 Apply_Range_Check (A, A_Typ, F_Typ);
2742 -- An actual associated with an access parameter is implicitly
2743 -- converted to the anonymous access type of the formal and
2744 -- must satisfy the legality checks for access conversions.
2746 if Ekind (F_Typ) = E_Anonymous_Access_Type then
2747 if not Valid_Conversion (A, F_Typ, A) then
2749 ("invalid implicit conversion for access parameter", A);
2753 -- Check bad case of atomic/volatile argument (RM C.6(12))
2755 if Is_By_Reference_Type (Etype (F))
2756 and then Comes_From_Source (N)
2758 if Is_Atomic_Object (A)
2759 and then not Is_Atomic (Etype (F))
2762 ("cannot pass atomic argument to non-atomic formal",
2765 elsif Is_Volatile_Object (A)
2766 and then not Is_Volatile (Etype (F))
2769 ("cannot pass volatile argument to non-volatile formal",
2774 -- Check that subprograms don't have improper controlling
2775 -- arguments (RM 3.9.2 (9))
2777 if Is_Controlling_Formal (F) then
2778 Set_Is_Controlling_Actual (A);
2779 elsif Nkind (A) = N_Explicit_Dereference then
2780 Validate_Remote_Access_To_Class_Wide_Type (A);
2783 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
2784 and then not Is_Class_Wide_Type (F_Typ)
2785 and then not Is_Controlling_Formal (F)
2787 Error_Msg_N ("class-wide argument not allowed here!", A);
2789 if Is_Subprogram (Nam)
2790 and then Comes_From_Source (Nam)
2792 Error_Msg_Node_2 := F_Typ;
2794 ("& is not a primitive operation of &!", A, Nam);
2797 elsif Is_Access_Type (A_Typ)
2798 and then Is_Access_Type (F_Typ)
2799 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
2800 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
2801 or else (Nkind (A) = N_Attribute_Reference
2803 Is_Class_Wide_Type (Etype (Prefix (A)))))
2804 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
2805 and then not Is_Controlling_Formal (F)
2808 ("access to class-wide argument not allowed here!", A);
2810 if Is_Subprogram (Nam)
2811 and then Comes_From_Source (Nam)
2813 Error_Msg_Node_2 := Designated_Type (F_Typ);
2815 ("& is not a primitive operation of &!", A, Nam);
2821 -- If it is a named association, treat the selector_name as
2822 -- a proper identifier, and mark the corresponding entity.
2824 if Nkind (Parent (A)) = N_Parameter_Association then
2825 Set_Entity (Selector_Name (Parent (A)), F);
2826 Generate_Reference (F, Selector_Name (Parent (A)));
2827 Set_Etype (Selector_Name (Parent (A)), F_Typ);
2828 Generate_Reference (F_Typ, N, ' ');
2833 if Ekind (F) /= E_Out_Parameter then
2834 Check_Unset_Reference (A);
2839 -- Case where actual is not present
2847 end Resolve_Actuals;
2849 -----------------------
2850 -- Resolve_Allocator --
2851 -----------------------
2853 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
2854 E : constant Node_Id := Expression (N);
2856 Discrim : Entity_Id;
2860 function In_Dispatching_Context return Boolean;
2861 -- If the allocator is an actual in a call, it is allowed to be
2862 -- class-wide when the context is not because it is a controlling
2865 ----------------------------
2866 -- In_Dispatching_Context --
2867 ----------------------------
2869 function In_Dispatching_Context return Boolean is
2870 Par : constant Node_Id := Parent (N);
2873 return (Nkind (Par) = N_Function_Call
2874 or else Nkind (Par) = N_Procedure_Call_Statement)
2875 and then Is_Entity_Name (Name (Par))
2876 and then Is_Dispatching_Operation (Entity (Name (Par)));
2877 end In_Dispatching_Context;
2879 -- Start of processing for Resolve_Allocator
2882 -- Replace general access with specific type
2884 if Ekind (Etype (N)) = E_Allocator_Type then
2885 Set_Etype (N, Base_Type (Typ));
2888 if Is_Abstract (Typ) then
2889 Error_Msg_N ("type of allocator cannot be abstract", N);
2892 -- For qualified expression, resolve the expression using the
2893 -- given subtype (nothing to do for type mark, subtype indication)
2895 if Nkind (E) = N_Qualified_Expression then
2896 if Is_Class_Wide_Type (Etype (E))
2897 and then not Is_Class_Wide_Type (Designated_Type (Typ))
2898 and then not In_Dispatching_Context
2901 ("class-wide allocator not allowed for this access type", N);
2904 Resolve (Expression (E), Etype (E));
2905 Check_Unset_Reference (Expression (E));
2907 -- A qualified expression requires an exact match of the type,
2908 -- class-wide matching is not allowed.
2910 if (Is_Class_Wide_Type (Etype (Expression (E)))
2911 or else Is_Class_Wide_Type (Etype (E)))
2912 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
2914 Wrong_Type (Expression (E), Etype (E));
2917 -- For a subtype mark or subtype indication, freeze the subtype
2920 Freeze_Expression (E);
2922 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
2924 ("initialization required for access-to-constant allocator", N);
2927 -- A special accessibility check is needed for allocators that
2928 -- constrain access discriminants. The level of the type of the
2929 -- expression used to contrain an access discriminant cannot be
2930 -- deeper than the type of the allocator (in constrast to access
2931 -- parameters, where the level of the actual can be arbitrary).
2932 -- We can't use Valid_Conversion to perform this check because
2933 -- in general the type of the allocator is unrelated to the type
2934 -- of the access discriminant. Note that specialized checks are
2935 -- needed for the cases of a constraint expression which is an
2936 -- access attribute or an access discriminant.
2938 if Nkind (Original_Node (E)) = N_Subtype_Indication
2939 and then Ekind (Typ) /= E_Anonymous_Access_Type
2941 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
2943 if Has_Discriminants (Subtyp) then
2944 Discrim := First_Discriminant (Base_Type (Subtyp));
2945 Constr := First (Constraints (Constraint (Original_Node (E))));
2947 while Present (Discrim) and then Present (Constr) loop
2948 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
2949 if Nkind (Constr) = N_Discriminant_Association then
2950 Disc_Exp := Original_Node (Expression (Constr));
2952 Disc_Exp := Original_Node (Constr);
2955 if Type_Access_Level (Etype (Disc_Exp))
2956 > Type_Access_Level (Typ)
2959 ("operand type has deeper level than allocator type",
2962 elsif Nkind (Disc_Exp) = N_Attribute_Reference
2963 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
2965 and then Object_Access_Level (Prefix (Disc_Exp))
2966 > Type_Access_Level (Typ)
2969 ("prefix of attribute has deeper level than"
2970 & " allocator type", Disc_Exp);
2972 -- When the operand is an access discriminant the check
2973 -- is against the level of the prefix object.
2975 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
2976 and then Nkind (Disc_Exp) = N_Selected_Component
2977 and then Object_Access_Level (Prefix (Disc_Exp))
2978 > Type_Access_Level (Typ)
2981 ("access discriminant has deeper level than"
2982 & " allocator type", Disc_Exp);
2985 Next_Discriminant (Discrim);
2992 -- Check for allocation from an empty storage pool
2994 if No_Pool_Assigned (Typ) then
2996 Loc : constant Source_Ptr := Sloc (N);
2999 Error_Msg_N ("?allocation from empty storage pool!", N);
3000 Error_Msg_N ("?Storage_Error will be raised at run time!", N);
3002 Make_Raise_Storage_Error (Loc,
3003 Reason => SE_Empty_Storage_Pool));
3006 end Resolve_Allocator;
3008 ---------------------------
3009 -- Resolve_Arithmetic_Op --
3010 ---------------------------
3012 -- Used for resolving all arithmetic operators except exponentiation
3014 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
3015 L : constant Node_Id := Left_Opnd (N);
3016 R : constant Node_Id := Right_Opnd (N);
3017 TL : constant Entity_Id := Base_Type (Etype (L));
3018 TR : constant Entity_Id := Base_Type (Etype (R));
3022 B_Typ : constant Entity_Id := Base_Type (Typ);
3023 -- We do the resolution using the base type, because intermediate values
3024 -- in expressions always are of the base type, not a subtype of it.
3026 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
3027 -- Return True iff given type is Integer or universal real/integer
3029 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
3030 -- Choose type of integer literal in fixed-point operation to conform
3031 -- to available fixed-point type. T is the type of the other operand,
3032 -- which is needed to determine the expected type of N.
3034 procedure Set_Operand_Type (N : Node_Id);
3035 -- Set operand type to T if universal
3037 -----------------------------
3038 -- Is_Integer_Or_Universal --
3039 -----------------------------
3041 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
3043 Index : Interp_Index;
3047 if not Is_Overloaded (N) then
3049 return Base_Type (T) = Base_Type (Standard_Integer)
3050 or else T = Universal_Integer
3051 or else T = Universal_Real;
3053 Get_First_Interp (N, Index, It);
3055 while Present (It.Typ) loop
3057 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
3058 or else It.Typ = Universal_Integer
3059 or else It.Typ = Universal_Real
3064 Get_Next_Interp (Index, It);
3069 end Is_Integer_Or_Universal;
3071 ----------------------------
3072 -- Set_Mixed_Mode_Operand --
3073 ----------------------------
3075 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
3076 Index : Interp_Index;
3080 if Universal_Interpretation (N) = Universal_Integer then
3082 -- A universal integer literal is resolved as standard integer
3083 -- except in the case of a fixed-point result, where we leave
3084 -- it as universal (to be handled by Exp_Fixd later on)
3086 if Is_Fixed_Point_Type (T) then
3087 Resolve (N, Universal_Integer);
3089 Resolve (N, Standard_Integer);
3092 elsif Universal_Interpretation (N) = Universal_Real
3093 and then (T = Base_Type (Standard_Integer)
3094 or else T = Universal_Integer
3095 or else T = Universal_Real)
3097 -- A universal real can appear in a fixed-type context. We resolve
3098 -- the literal with that context, even though this might raise an
3099 -- exception prematurely (the other operand may be zero).
3103 elsif Etype (N) = Base_Type (Standard_Integer)
3104 and then T = Universal_Real
3105 and then Is_Overloaded (N)
3107 -- Integer arg in mixed-mode operation. Resolve with universal
3108 -- type, in case preference rule must be applied.
3110 Resolve (N, Universal_Integer);
3113 and then B_Typ /= Universal_Fixed
3115 -- Not a mixed-mode operation. Resolve with context.
3119 elsif Etype (N) = Any_Fixed then
3121 -- N may itself be a mixed-mode operation, so use context type.
3125 elsif Is_Fixed_Point_Type (T)
3126 and then B_Typ = Universal_Fixed
3127 and then Is_Overloaded (N)
3129 -- Must be (fixed * fixed) operation, operand must have one
3130 -- compatible interpretation.
3132 Resolve (N, Any_Fixed);
3134 elsif Is_Fixed_Point_Type (B_Typ)
3135 and then (T = Universal_Real
3136 or else Is_Fixed_Point_Type (T))
3137 and then Is_Overloaded (N)
3139 -- C * F(X) in a fixed context, where C is a real literal or a
3140 -- fixed-point expression. F must have either a fixed type
3141 -- interpretation or an integer interpretation, but not both.
3143 Get_First_Interp (N, Index, It);
3145 while Present (It.Typ) loop
3146 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
3148 if Analyzed (N) then
3149 Error_Msg_N ("ambiguous operand in fixed operation", N);
3151 Resolve (N, Standard_Integer);
3154 elsif Is_Fixed_Point_Type (It.Typ) then
3156 if Analyzed (N) then
3157 Error_Msg_N ("ambiguous operand in fixed operation", N);
3159 Resolve (N, It.Typ);
3163 Get_Next_Interp (Index, It);
3166 -- Reanalyze the literal with the fixed type of the context.
3169 Set_Analyzed (R, False);
3172 Set_Analyzed (L, False);
3179 end Set_Mixed_Mode_Operand;
3181 ----------------------
3182 -- Set_Operand_Type --
3183 ----------------------
3185 procedure Set_Operand_Type (N : Node_Id) is
3187 if Etype (N) = Universal_Integer
3188 or else Etype (N) = Universal_Real
3192 end Set_Operand_Type;
3194 -- Start of processing for Resolve_Arithmetic_Op
3197 if Comes_From_Source (N)
3198 and then Ekind (Entity (N)) = E_Function
3199 and then Is_Imported (Entity (N))
3200 and then Is_Intrinsic_Subprogram (Entity (N))
3202 Resolve_Intrinsic_Operator (N, Typ);
3205 -- Special-case for mixed-mode universal expressions or fixed point
3206 -- type operation: each argument is resolved separately. The same
3207 -- treatment is required if one of the operands of a fixed point
3208 -- operation is universal real, since in this case we don't do a
3209 -- conversion to a specific fixed-point type (instead the expander
3210 -- takes care of the case).
3212 elsif (B_Typ = Universal_Integer
3213 or else B_Typ = Universal_Real)
3214 and then Present (Universal_Interpretation (L))
3215 and then Present (Universal_Interpretation (R))
3217 Resolve (L, Universal_Interpretation (L));
3218 Resolve (R, Universal_Interpretation (R));
3219 Set_Etype (N, B_Typ);
3221 elsif (B_Typ = Universal_Real
3222 or else Etype (N) = Universal_Fixed
3223 or else (Etype (N) = Any_Fixed
3224 and then Is_Fixed_Point_Type (B_Typ))
3225 or else (Is_Fixed_Point_Type (B_Typ)
3226 and then (Is_Integer_Or_Universal (L)
3228 Is_Integer_Or_Universal (R))))
3229 and then (Nkind (N) = N_Op_Multiply or else
3230 Nkind (N) = N_Op_Divide)
3232 if TL = Universal_Integer or else TR = Universal_Integer then
3233 Check_For_Visible_Operator (N, B_Typ);
3236 -- If context is a fixed type and one operand is integer, the
3237 -- other is resolved with the type of the context.
3239 if Is_Fixed_Point_Type (B_Typ)
3240 and then (Base_Type (TL) = Base_Type (Standard_Integer)
3241 or else TL = Universal_Integer)
3246 elsif Is_Fixed_Point_Type (B_Typ)
3247 and then (Base_Type (TR) = Base_Type (Standard_Integer)
3248 or else TR = Universal_Integer)
3254 Set_Mixed_Mode_Operand (L, TR);
3255 Set_Mixed_Mode_Operand (R, TL);
3258 if Etype (N) = Universal_Fixed
3259 or else Etype (N) = Any_Fixed
3261 if B_Typ = Universal_Fixed
3262 and then Nkind (Parent (N)) /= N_Type_Conversion
3263 and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion
3266 ("type cannot be determined from context!", N);
3268 ("\explicit conversion to result type required", N);
3270 Set_Etype (L, Any_Type);
3271 Set_Etype (R, Any_Type);
3275 and then Etype (N) = Universal_Fixed
3276 and then Nkind (Parent (N)) /= N_Type_Conversion
3277 and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion
3280 ("(Ada 83) fixed-point operation " &
3281 "needs explicit conversion",
3285 Set_Etype (N, B_Typ);
3288 elsif Is_Fixed_Point_Type (B_Typ)
3289 and then (Is_Integer_Or_Universal (L)
3290 or else Nkind (L) = N_Real_Literal
3291 or else Nkind (R) = N_Real_Literal
3293 Is_Integer_Or_Universal (R))
3295 Set_Etype (N, B_Typ);
3297 elsif Etype (N) = Any_Fixed then
3299 -- If no previous errors, this is only possible if one operand
3300 -- is overloaded and the context is universal. Resolve as such.
3302 Set_Etype (N, B_Typ);
3306 if (TL = Universal_Integer or else TL = Universal_Real)
3307 and then (TR = Universal_Integer or else TR = Universal_Real)
3309 Check_For_Visible_Operator (N, B_Typ);
3312 -- If the context is Universal_Fixed and the operands are also
3313 -- universal fixed, this is an error, unless there is only one
3314 -- applicable fixed_point type (usually duration).
3316 if B_Typ = Universal_Fixed
3317 and then Etype (L) = Universal_Fixed
3319 T := Unique_Fixed_Point_Type (N);
3321 if T = Any_Type then
3334 -- If one of the arguments was resolved to a non-universal type.
3335 -- label the result of the operation itself with the same type.
3336 -- Do the same for the universal argument, if any.
3338 T := Intersect_Types (L, R);
3339 Set_Etype (N, Base_Type (T));
3340 Set_Operand_Type (L);
3341 Set_Operand_Type (R);
3344 Generate_Operator_Reference (N, Typ);
3345 Eval_Arithmetic_Op (N);
3347 -- Set overflow and division checking bit. Much cleverer code needed
3348 -- here eventually and perhaps the Resolve routines should be separated
3349 -- for the various arithmetic operations, since they will need
3350 -- different processing. ???
3352 if Nkind (N) in N_Op then
3353 if not Overflow_Checks_Suppressed (Etype (N)) then
3354 Enable_Overflow_Check (N);
3357 -- Give warning if explicit division by zero
3359 if (Nkind (N) = N_Op_Divide
3360 or else Nkind (N) = N_Op_Rem
3361 or else Nkind (N) = N_Op_Mod)
3362 and then not Division_Checks_Suppressed (Etype (N))
3364 Rop := Right_Opnd (N);
3366 if Compile_Time_Known_Value (Rop)
3367 and then ((Is_Integer_Type (Etype (Rop))
3368 and then Expr_Value (Rop) = Uint_0)
3370 (Is_Real_Type (Etype (Rop))
3371 and then Expr_Value_R (Rop) = Ureal_0))
3373 Apply_Compile_Time_Constraint_Error
3374 (N, "division by zero?", CE_Divide_By_Zero,
3375 Loc => Sloc (Right_Opnd (N)));
3377 -- Otherwise just set the flag to check at run time
3380 Set_Do_Division_Check (N);
3385 Check_Unset_Reference (L);
3386 Check_Unset_Reference (R);
3387 end Resolve_Arithmetic_Op;
3393 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
3394 Loc : constant Source_Ptr := Sloc (N);
3395 Subp : constant Node_Id := Name (N);
3404 -- The context imposes a unique interpretation with type Typ on
3405 -- a procedure or function call. Find the entity of the subprogram
3406 -- that yields the expected type, and propagate the corresponding
3407 -- formal constraints on the actuals. The caller has established
3408 -- that an interpretation exists, and emitted an error if not unique.
3410 -- First deal with the case of a call to an access-to-subprogram,
3411 -- dereference made explicit in Analyze_Call.
3413 if Ekind (Etype (Subp)) = E_Subprogram_Type then
3414 if not Is_Overloaded (Subp) then
3415 Nam := Etype (Subp);
3418 -- Find the interpretation whose type (a subprogram type)
3419 -- has a return type that is compatible with the context.
3420 -- Analysis of the node has established that one exists.
3422 Get_First_Interp (Subp, I, It);
3425 while Present (It.Typ) loop
3426 if Covers (Typ, Etype (It.Typ)) then
3431 Get_Next_Interp (I, It);
3435 raise Program_Error;
3439 -- If the prefix is not an entity, then resolve it
3441 if not Is_Entity_Name (Subp) then
3442 Resolve (Subp, Nam);
3445 -- For an indirect call, we always invalidate checks, since we
3446 -- do not know whether the subprogram is local or global. Yes
3447 -- we could do better here, e.g. by knowing that there are no
3448 -- local subprograms, but it does not seem worth the effort.
3449 -- Similarly, we kill al knowledge of current constant values.
3451 Kill_Current_Values;
3453 -- If this is a procedure call which is really an entry call, do
3454 -- the conversion of the procedure call to an entry call. Protected
3455 -- operations use the same circuitry because the name in the call
3456 -- can be an arbitrary expression with special resolution rules.
3458 elsif Nkind (Subp) = N_Selected_Component
3459 or else Nkind (Subp) = N_Indexed_Component
3460 or else (Is_Entity_Name (Subp)
3461 and then Ekind (Entity (Subp)) = E_Entry)
3463 Resolve_Entry_Call (N, Typ);
3464 Check_Elab_Call (N);
3466 -- Kill checks and constant values, as above for indirect case
3467 -- Who knows what happens when another task is activated?
3469 Kill_Current_Values;
3472 -- Normal subprogram call with name established in Resolve
3474 elsif not (Is_Type (Entity (Subp))) then
3475 Nam := Entity (Subp);
3476 Set_Entity_With_Style_Check (Subp, Nam);
3477 Generate_Reference (Nam, Subp);
3479 -- Otherwise we must have the case of an overloaded call
3482 pragma Assert (Is_Overloaded (Subp));
3483 Nam := Empty; -- We know that it will be assigned in loop below.
3485 Get_First_Interp (Subp, I, It);
3487 while Present (It.Typ) loop
3488 if Covers (Typ, It.Typ) then
3490 Set_Entity_With_Style_Check (Subp, Nam);
3491 Generate_Reference (Nam, Subp);
3495 Get_Next_Interp (I, It);
3499 -- Check that a call to Current_Task does not occur in an entry body
3501 if Is_RTE (Nam, RE_Current_Task) then
3511 if Nkind (P) = N_Entry_Body then
3513 ("& should not be used in entry body ('R'M C.7(17))",
3521 -- Cannot call thread body directly
3523 if Is_Thread_Body (Nam) then
3524 Error_Msg_N ("cannot call thread body directly", N);
3527 -- If the subprogram is not global, then kill all checks. This is
3528 -- a bit conservative, since in many cases we could do better, but
3529 -- it is not worth the effort. Similarly, we kill constant values.
3530 -- However we do not need to do this for internal entities (unless
3531 -- they are inherited user-defined subprograms), since they are not
3532 -- in the business of molesting global values.
3534 if not Is_Library_Level_Entity (Nam)
3535 and then (Comes_From_Source (Nam)
3536 or else (Present (Alias (Nam))
3537 and then Comes_From_Source (Alias (Nam))))
3539 Kill_Current_Values;
3542 -- Check for call to obsolescent subprogram
3544 if Warn_On_Obsolescent_Feature then
3545 Decl := Parent (Parent (Nam));
3547 if Nkind (Decl) = N_Subprogram_Declaration
3548 and then Is_List_Member (Decl)
3549 and then Nkind (Next (Decl)) = N_Pragma
3552 P : constant Node_Id := Next (Decl);
3555 if Chars (P) = Name_Obsolescent then
3556 Error_Msg_NE ("call to obsolescent subprogram&?", N, Nam);
3558 if Pragma_Argument_Associations (P) /= No_List then
3559 Name_Buffer (1) := '|';
3560 Name_Buffer (2) := '?';
3562 Add_String_To_Name_Buffer
3564 (First (Pragma_Argument_Associations (P)))));
3565 Error_Msg_N (Name_Buffer (1 .. Name_Len), N);
3572 -- Check that a procedure call does not occur in the context
3573 -- of the entry call statement of a conditional or timed
3574 -- entry call. Note that the case of a call to a subprogram
3575 -- renaming of an entry will also be rejected. The test
3576 -- for N not being an N_Entry_Call_Statement is defensive,
3577 -- covering the possibility that the processing of entry
3578 -- calls might reach this point due to later modifications
3579 -- of the code above.
3581 if Nkind (Parent (N)) = N_Entry_Call_Alternative
3582 and then Nkind (N) /= N_Entry_Call_Statement
3583 and then Entry_Call_Statement (Parent (N)) = N
3585 Error_Msg_N ("entry call required in select statement", N);
3588 -- Check that this is not a call to a protected procedure or
3589 -- entry from within a protected function.
3591 if Ekind (Current_Scope) = E_Function
3592 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
3593 and then Ekind (Nam) /= E_Function
3594 and then Scope (Nam) = Scope (Current_Scope)
3596 Error_Msg_N ("within protected function, protected " &
3597 "object is constant", N);
3598 Error_Msg_N ("\cannot call operation that may modify it", N);
3601 -- Freeze the subprogram name if not in default expression. Note
3602 -- that we freeze procedure calls as well as function calls.
3603 -- Procedure calls are not frozen according to the rules (RM
3604 -- 13.14(14)) because it is impossible to have a procedure call to
3605 -- a non-frozen procedure in pure Ada, but in the code that we
3606 -- generate in the expander, this rule needs extending because we
3607 -- can generate procedure calls that need freezing.
3609 if Is_Entity_Name (Subp) and then not In_Default_Expression then
3610 Freeze_Expression (Subp);
3613 -- For a predefined operator, the type of the result is the type
3614 -- imposed by context, except for a predefined operation on universal
3615 -- fixed. Otherwise The type of the call is the type returned by the
3616 -- subprogram being called.
3618 if Is_Predefined_Op (Nam) then
3619 if Etype (N) /= Universal_Fixed then
3623 -- If the subprogram returns an array type, and the context
3624 -- requires the component type of that array type, the node is
3625 -- really an indexing of the parameterless call. Resolve as such.
3626 -- A pathological case occurs when the type of the component is
3627 -- an access to the array type. In this case the call is truly
3630 elsif Needs_No_Actuals (Nam)
3632 ((Is_Array_Type (Etype (Nam))
3633 and then Covers (Typ, Component_Type (Etype (Nam))))
3634 or else (Is_Access_Type (Etype (Nam))
3635 and then Is_Array_Type (Designated_Type (Etype (Nam)))
3638 Component_Type (Designated_Type (Etype (Nam))))))
3641 Index_Node : Node_Id;
3643 Ret_Type : constant Entity_Id := Etype (Nam);
3646 if Is_Access_Type (Ret_Type)
3647 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
3650 ("cannot disambiguate function call and indexing", N);
3652 New_Subp := Relocate_Node (Subp);
3653 Set_Entity (Subp, Nam);
3655 if Component_Type (Ret_Type) /= Any_Type then
3657 Make_Indexed_Component (Loc,
3659 Make_Function_Call (Loc,
3661 Expressions => Parameter_Associations (N));
3663 -- Since we are correcting a node classification error made
3664 -- by the parser, we call Replace rather than Rewrite.
3666 Replace (N, Index_Node);
3667 Set_Etype (Prefix (N), Ret_Type);
3669 Resolve_Indexed_Component (N, Typ);
3670 Check_Elab_Call (Prefix (N));
3678 Set_Etype (N, Etype (Nam));
3681 -- In the case where the call is to an overloaded subprogram, Analyze
3682 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
3683 -- such a case Normalize_Actuals needs to be called once more to order
3684 -- the actuals correctly. Otherwise the call will have the ordering
3685 -- given by the last overloaded subprogram whether this is the correct
3686 -- one being called or not.
3688 if Is_Overloaded (Subp) then
3689 Normalize_Actuals (N, Nam, False, Norm_OK);
3690 pragma Assert (Norm_OK);
3693 -- In any case, call is fully resolved now. Reset Overload flag, to
3694 -- prevent subsequent overload resolution if node is analyzed again
3696 Set_Is_Overloaded (Subp, False);
3697 Set_Is_Overloaded (N, False);
3699 -- If we are calling the current subprogram from immediately within
3700 -- its body, then that is the case where we can sometimes detect
3701 -- cases of infinite recursion statically. Do not try this in case
3702 -- restriction No_Recursion is in effect anyway.
3704 Scop := Current_Scope;
3707 and then not Restriction_Active (No_Recursion)
3708 and then Check_Infinite_Recursion (N)
3710 -- Here we detected and flagged an infinite recursion, so we do
3711 -- not need to test the case below for further warnings.
3715 -- If call is to immediately containing subprogram, then check for
3716 -- the case of a possible run-time detectable infinite recursion.
3719 while Scop /= Standard_Standard loop
3721 -- Although in general recursion is not statically checkable,
3722 -- the case of calling an immediately containing subprogram
3723 -- is easy to catch.
3725 Check_Restriction (No_Recursion, N);
3727 -- If the recursive call is to a parameterless procedure, then
3728 -- even if we can't statically detect infinite recursion, this
3729 -- is pretty suspicious, and we output a warning. Furthermore,
3730 -- we will try later to detect some cases here at run time by
3731 -- expanding checking code (see Detect_Infinite_Recursion in
3732 -- package Exp_Ch6).
3733 -- If the recursive call is within a handler we do not emit a
3734 -- warning, because this is a common idiom: loop until input
3735 -- is correct, catch illegal input in handler and restart.
3737 if No (First_Formal (Nam))
3738 and then Etype (Nam) = Standard_Void_Type
3739 and then not Error_Posted (N)
3740 and then Nkind (Parent (N)) /= N_Exception_Handler
3742 Set_Has_Recursive_Call (Nam);
3743 Error_Msg_N ("possible infinite recursion?", N);
3744 Error_Msg_N ("Storage_Error may be raised at run time?", N);
3750 Scop := Scope (Scop);
3754 -- If subprogram name is a predefined operator, it was given in
3755 -- functional notation. Replace call node with operator node, so
3756 -- that actuals can be resolved appropriately.
3758 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
3759 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
3762 elsif Present (Alias (Nam))
3763 and then Is_Predefined_Op (Alias (Nam))
3765 Resolve_Actuals (N, Nam);
3766 Make_Call_Into_Operator (N, Typ, Alias (Nam));
3770 -- Create a transient scope if the resulting type requires it
3772 -- There are 3 notable exceptions: in init procs, the transient scope
3773 -- overhead is not needed and even incorrect due to the actual expansion
3774 -- of adjust calls; the second case is enumeration literal pseudo calls,
3775 -- the other case is intrinsic subprograms (Unchecked_Conversion and
3776 -- source information functions) that do not use the secondary stack
3777 -- even though the return type is unconstrained.
3779 -- If this is an initialization call for a type whose initialization
3780 -- uses the secondary stack, we also need to create a transient scope
3781 -- for it, precisely because we will not do it within the init proc
3785 and then Is_Type (Etype (Nam))
3786 and then Requires_Transient_Scope (Etype (Nam))
3787 and then Ekind (Nam) /= E_Enumeration_Literal
3788 and then not Within_Init_Proc
3789 and then not Is_Intrinsic_Subprogram (Nam)
3791 Establish_Transient_Scope
3792 (N, Sec_Stack => not Functions_Return_By_DSP_On_Target);
3794 -- If the call appears within the bounds of a loop, it will
3795 -- be rewritten and reanalyzed, nothing left to do here.
3797 if Nkind (N) /= N_Function_Call then
3801 elsif Is_Init_Proc (Nam)
3802 and then not Within_Init_Proc
3804 Check_Initialization_Call (N, Nam);
3807 -- A protected function cannot be called within the definition of the
3808 -- enclosing protected type.
3810 if Is_Protected_Type (Scope (Nam))
3811 and then In_Open_Scopes (Scope (Nam))
3812 and then not Has_Completion (Scope (Nam))
3815 ("& cannot be called before end of protected definition", N, Nam);
3818 -- Propagate interpretation to actuals, and add default expressions
3821 if Present (First_Formal (Nam)) then
3822 Resolve_Actuals (N, Nam);
3824 -- Overloaded literals are rewritten as function calls, for
3825 -- purpose of resolution. After resolution, we can replace
3826 -- the call with the literal itself.
3828 elsif Ekind (Nam) = E_Enumeration_Literal then
3829 Copy_Node (Subp, N);
3830 Resolve_Entity_Name (N, Typ);
3832 -- Avoid validation, since it is a static function call
3837 -- If the subprogram is a primitive operation, check whether or not
3838 -- it is a correct dispatching call.
3840 if Is_Overloadable (Nam)
3841 and then Is_Dispatching_Operation (Nam)
3843 Check_Dispatching_Call (N);
3845 elsif Is_Abstract (Nam)
3846 and then not In_Instance
3848 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
3851 if Is_Intrinsic_Subprogram (Nam) then
3852 Check_Intrinsic_Call (N);
3856 Check_Elab_Call (N);
3859 -------------------------------
3860 -- Resolve_Character_Literal --
3861 -------------------------------
3863 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
3864 B_Typ : constant Entity_Id := Base_Type (Typ);
3868 -- Verify that the character does belong to the type of the context
3870 Set_Etype (N, B_Typ);
3871 Eval_Character_Literal (N);
3873 -- Wide_Character literals must always be defined, since the set of
3874 -- wide character literals is complete, i.e. if a character literal
3875 -- is accepted by the parser, then it is OK for wide character.
3877 if Root_Type (B_Typ) = Standard_Wide_Character then
3880 -- Always accept character literal for type Any_Character, which
3881 -- occurs in error situations and in comparisons of literals, both
3882 -- of which should accept all literals.
3884 elsif B_Typ = Any_Character then
3887 -- For Standard.Character or a type derived from it, check that
3888 -- the literal is in range
3890 elsif Root_Type (B_Typ) = Standard_Character then
3891 if In_Character_Range (Char_Literal_Value (N)) then
3895 -- If the entity is already set, this has already been resolved in
3896 -- a generic context, or comes from expansion. Nothing else to do.
3898 elsif Present (Entity (N)) then
3901 -- Otherwise we have a user defined character type, and we can use
3902 -- the standard visibility mechanisms to locate the referenced entity
3905 C := Current_Entity (N);
3907 while Present (C) loop
3908 if Etype (C) = B_Typ then
3909 Set_Entity_With_Style_Check (N, C);
3910 Generate_Reference (C, N);
3918 -- If we fall through, then the literal does not match any of the
3919 -- entries of the enumeration type. This isn't just a constraint
3920 -- error situation, it is an illegality (see RM 4.2).
3923 ("character not defined for }", N, First_Subtype (B_Typ));
3924 end Resolve_Character_Literal;
3926 ---------------------------
3927 -- Resolve_Comparison_Op --
3928 ---------------------------
3930 -- Context requires a boolean type, and plays no role in resolution.
3931 -- Processing identical to that for equality operators. The result
3932 -- type is the base type, which matters when pathological subtypes of
3933 -- booleans with limited ranges are used.
3935 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
3936 L : constant Node_Id := Left_Opnd (N);
3937 R : constant Node_Id := Right_Opnd (N);
3941 Check_Direct_Boolean_Op (N);
3943 -- If this is an intrinsic operation which is not predefined, use
3944 -- the types of its declared arguments to resolve the possibly
3945 -- overloaded operands. Otherwise the operands are unambiguous and
3946 -- specify the expected type.
3948 if Scope (Entity (N)) /= Standard_Standard then
3949 T := Etype (First_Entity (Entity (N)));
3951 T := Find_Unique_Type (L, R);
3953 if T = Any_Fixed then
3954 T := Unique_Fixed_Point_Type (L);
3958 Set_Etype (N, Base_Type (Typ));
3959 Generate_Reference (T, N, ' ');
3961 if T /= Any_Type then
3963 or else T = Any_Composite
3964 or else T = Any_Character
3966 if T = Any_Character then
3967 Ambiguous_Character (L);
3969 Error_Msg_N ("ambiguous operands for comparison", N);
3972 Set_Etype (N, Any_Type);
3976 if Comes_From_Source (N)
3977 and then Has_Unchecked_Union (T)
3980 ("cannot compare Unchecked_Union values", N);
3985 Check_Unset_Reference (L);
3986 Check_Unset_Reference (R);
3987 Generate_Operator_Reference (N, T);
3988 Eval_Relational_Op (N);
3991 end Resolve_Comparison_Op;
3993 ------------------------------------
3994 -- Resolve_Conditional_Expression --
3995 ------------------------------------
3997 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
3998 Condition : constant Node_Id := First (Expressions (N));
3999 Then_Expr : constant Node_Id := Next (Condition);
4000 Else_Expr : constant Node_Id := Next (Then_Expr);
4003 Resolve (Condition, Standard_Boolean);
4004 Resolve (Then_Expr, Typ);
4005 Resolve (Else_Expr, Typ);
4008 Eval_Conditional_Expression (N);
4009 end Resolve_Conditional_Expression;
4011 -----------------------------------------
4012 -- Resolve_Discrete_Subtype_Indication --
4013 -----------------------------------------
4015 procedure Resolve_Discrete_Subtype_Indication
4023 Analyze (Subtype_Mark (N));
4024 S := Entity (Subtype_Mark (N));
4026 if Nkind (Constraint (N)) /= N_Range_Constraint then
4027 Error_Msg_N ("expect range constraint for discrete type", N);
4028 Set_Etype (N, Any_Type);
4031 R := Range_Expression (Constraint (N));
4039 if Base_Type (S) /= Base_Type (Typ) then
4041 ("expect subtype of }", N, First_Subtype (Typ));
4043 -- Rewrite the constraint as a range of Typ
4044 -- to allow compilation to proceed further.
4047 Rewrite (Low_Bound (R),
4048 Make_Attribute_Reference (Sloc (Low_Bound (R)),
4049 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
4050 Attribute_Name => Name_First));
4051 Rewrite (High_Bound (R),
4052 Make_Attribute_Reference (Sloc (High_Bound (R)),
4053 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
4054 Attribute_Name => Name_First));
4058 Set_Etype (N, Etype (R));
4060 -- Additionally, we must check that the bounds are compatible
4061 -- with the given subtype, which might be different from the
4062 -- type of the context.
4064 Apply_Range_Check (R, S);
4066 -- ??? If the above check statically detects a Constraint_Error
4067 -- it replaces the offending bound(s) of the range R with a
4068 -- Constraint_Error node. When the itype which uses these bounds
4069 -- is frozen the resulting call to Duplicate_Subexpr generates
4070 -- a new temporary for the bounds.
4072 -- Unfortunately there are other itypes that are also made depend
4073 -- on these bounds, so when Duplicate_Subexpr is called they get
4074 -- a forward reference to the newly created temporaries and Gigi
4075 -- aborts on such forward references. This is probably sign of a
4076 -- more fundamental problem somewhere else in either the order of
4077 -- itype freezing or the way certain itypes are constructed.
4079 -- To get around this problem we call Remove_Side_Effects right
4080 -- away if either bounds of R are a Constraint_Error.
4083 L : constant Node_Id := Low_Bound (R);
4084 H : constant Node_Id := High_Bound (R);
4087 if Nkind (L) = N_Raise_Constraint_Error then
4088 Remove_Side_Effects (L);
4091 if Nkind (H) = N_Raise_Constraint_Error then
4092 Remove_Side_Effects (H);
4096 Check_Unset_Reference (Low_Bound (R));
4097 Check_Unset_Reference (High_Bound (R));
4100 end Resolve_Discrete_Subtype_Indication;
4102 -------------------------
4103 -- Resolve_Entity_Name --
4104 -------------------------
4106 -- Used to resolve identifiers and expanded names
4108 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
4109 E : constant Entity_Id := Entity (N);
4112 -- If garbage from errors, set to Any_Type and return
4114 if No (E) and then Total_Errors_Detected /= 0 then
4115 Set_Etype (N, Any_Type);
4119 -- Replace named numbers by corresponding literals. Note that this is
4120 -- the one case where Resolve_Entity_Name must reset the Etype, since
4121 -- it is currently marked as universal.
4123 if Ekind (E) = E_Named_Integer then
4125 Eval_Named_Integer (N);
4127 elsif Ekind (E) = E_Named_Real then
4129 Eval_Named_Real (N);
4131 -- Allow use of subtype only if it is a concurrent type where we are
4132 -- currently inside the body. This will eventually be expanded
4133 -- into a call to Self (for tasks) or _object (for protected
4134 -- objects). Any other use of a subtype is invalid.
4136 elsif Is_Type (E) then
4137 if Is_Concurrent_Type (E)
4138 and then In_Open_Scopes (E)
4143 ("Invalid use of subtype mark in expression or call", N);
4146 -- Check discriminant use if entity is discriminant in current scope,
4147 -- i.e. discriminant of record or concurrent type currently being
4148 -- analyzed. Uses in corresponding body are unrestricted.
4150 elsif Ekind (E) = E_Discriminant
4151 and then Scope (E) = Current_Scope
4152 and then not Has_Completion (Current_Scope)
4154 Check_Discriminant_Use (N);
4156 -- A parameterless generic function cannot appear in a context that
4157 -- requires resolution.
4159 elsif Ekind (E) = E_Generic_Function then
4160 Error_Msg_N ("illegal use of generic function", N);
4162 elsif Ekind (E) = E_Out_Parameter
4164 and then (Nkind (Parent (N)) in N_Op
4165 or else (Nkind (Parent (N)) = N_Assignment_Statement
4166 and then N = Expression (Parent (N)))
4167 or else Nkind (Parent (N)) = N_Explicit_Dereference)
4169 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
4171 -- In all other cases, just do the possible static evaluation
4174 -- A deferred constant that appears in an expression must have
4175 -- a completion, unless it has been removed by in-place expansion
4178 if Ekind (E) = E_Constant
4179 and then Comes_From_Source (E)
4180 and then No (Constant_Value (E))
4181 and then Is_Frozen (Etype (E))
4182 and then not In_Default_Expression
4183 and then not Is_Imported (E)
4186 if No_Initialization (Parent (E))
4187 or else (Present (Full_View (E))
4188 and then No_Initialization (Parent (Full_View (E))))
4193 "deferred constant is frozen before completion", N);
4197 Eval_Entity_Name (N);
4199 end Resolve_Entity_Name;
4205 procedure Resolve_Entry (Entry_Name : Node_Id) is
4206 Loc : constant Source_Ptr := Sloc (Entry_Name);
4214 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
4215 -- If the bounds of the entry family being called depend on task
4216 -- discriminants, build a new index subtype where a discriminant is
4217 -- replaced with the value of the discriminant of the target task.
4218 -- The target task is the prefix of the entry name in the call.
4220 -----------------------
4221 -- Actual_Index_Type --
4222 -----------------------
4224 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
4225 Typ : constant Entity_Id := Entry_Index_Type (E);
4226 Tsk : constant Entity_Id := Scope (E);
4227 Lo : constant Node_Id := Type_Low_Bound (Typ);
4228 Hi : constant Node_Id := Type_High_Bound (Typ);
4231 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
4232 -- If the bound is given by a discriminant, replace with a reference
4233 -- to the discriminant of the same name in the target task.
4234 -- If the entry name is the target of a requeue statement and the
4235 -- entry is in the current protected object, the bound to be used
4236 -- is the discriminal of the object (see apply_range_checks for
4237 -- details of the transformation).
4239 -----------------------------
4240 -- Actual_Discriminant_Ref --
4241 -----------------------------
4243 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
4244 Typ : constant Entity_Id := Etype (Bound);
4248 Remove_Side_Effects (Bound);
4250 if not Is_Entity_Name (Bound)
4251 or else Ekind (Entity (Bound)) /= E_Discriminant
4255 elsif Is_Protected_Type (Tsk)
4256 and then In_Open_Scopes (Tsk)
4257 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
4259 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
4263 Make_Selected_Component (Loc,
4264 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
4265 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
4270 end Actual_Discriminant_Ref;
4272 -- Start of processing for Actual_Index_Type
4275 if not Has_Discriminants (Tsk)
4276 or else (not Is_Entity_Name (Lo)
4277 and then not Is_Entity_Name (Hi))
4279 return Entry_Index_Type (E);
4282 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
4283 Set_Etype (New_T, Base_Type (Typ));
4284 Set_Size_Info (New_T, Typ);
4285 Set_RM_Size (New_T, RM_Size (Typ));
4286 Set_Scalar_Range (New_T,
4287 Make_Range (Sloc (Entry_Name),
4288 Low_Bound => Actual_Discriminant_Ref (Lo),
4289 High_Bound => Actual_Discriminant_Ref (Hi)));
4293 end Actual_Index_Type;
4295 -- Start of processing of Resolve_Entry
4298 -- Find name of entry being called, and resolve prefix of name
4299 -- with its own type. The prefix can be overloaded, and the name
4300 -- and signature of the entry must be taken into account.
4302 if Nkind (Entry_Name) = N_Indexed_Component then
4304 -- Case of dealing with entry family within the current tasks
4306 E_Name := Prefix (Entry_Name);
4309 E_Name := Entry_Name;
4312 if Is_Entity_Name (E_Name) then
4313 -- Entry call to an entry (or entry family) in the current task.
4314 -- This is legal even though the task will deadlock. Rewrite as
4315 -- call to current task.
4317 -- This can also be a call to an entry in an enclosing task.
4318 -- If this is a single task, we have to retrieve its name,
4319 -- because the scope of the entry is the task type, not the
4320 -- object. If the enclosing task is a task type, the identity
4321 -- of the task is given by its own self variable.
4323 -- Finally this can be a requeue on an entry of the same task
4324 -- or protected object.
4326 S := Scope (Entity (E_Name));
4328 for J in reverse 0 .. Scope_Stack.Last loop
4330 if Is_Task_Type (Scope_Stack.Table (J).Entity)
4331 and then not Comes_From_Source (S)
4333 -- S is an enclosing task or protected object. The concurrent
4334 -- declaration has been converted into a type declaration, and
4335 -- the object itself has an object declaration that follows
4336 -- the type in the same declarative part.
4338 Tsk := Next_Entity (S);
4340 while Etype (Tsk) /= S loop
4347 elsif S = Scope_Stack.Table (J).Entity then
4349 -- Call to current task. Will be transformed into call to Self
4357 Make_Selected_Component (Loc,
4358 Prefix => New_Occurrence_Of (S, Loc),
4360 New_Occurrence_Of (Entity (E_Name), Loc));
4361 Rewrite (E_Name, New_N);
4364 elsif Nkind (Entry_Name) = N_Selected_Component
4365 and then Is_Overloaded (Prefix (Entry_Name))
4367 -- Use the entry name (which must be unique at this point) to
4368 -- find the prefix that returns the corresponding task type or
4372 Pref : constant Node_Id := Prefix (Entry_Name);
4373 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
4378 Get_First_Interp (Pref, I, It);
4380 while Present (It.Typ) loop
4382 if Scope (Ent) = It.Typ then
4383 Set_Etype (Pref, It.Typ);
4387 Get_Next_Interp (I, It);
4392 if Nkind (Entry_Name) = N_Selected_Component then
4393 Resolve (Prefix (Entry_Name));
4395 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
4396 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
4397 Resolve (Prefix (Prefix (Entry_Name)));
4398 Index := First (Expressions (Entry_Name));
4399 Resolve (Index, Entry_Index_Type (Nam));
4401 -- Up to this point the expression could have been the actual
4402 -- in a simple entry call, and be given by a named association.
4404 if Nkind (Index) = N_Parameter_Association then
4405 Error_Msg_N ("expect expression for entry index", Index);
4407 Apply_Range_Check (Index, Actual_Index_Type (Nam));
4412 ------------------------
4413 -- Resolve_Entry_Call --
4414 ------------------------
4416 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
4417 Entry_Name : constant Node_Id := Name (N);
4418 Loc : constant Source_Ptr := Sloc (Entry_Name);
4420 First_Named : Node_Id;
4427 -- We kill all checks here, because it does not seem worth the
4428 -- effort to do anything better, an entry call is a big operation.
4432 -- Processing of the name is similar for entry calls and protected
4433 -- operation calls. Once the entity is determined, we can complete
4434 -- the resolution of the actuals.
4436 -- The selector may be overloaded, in the case of a protected object
4437 -- with overloaded functions. The type of the context is used for
4440 if Nkind (Entry_Name) = N_Selected_Component
4441 and then Is_Overloaded (Selector_Name (Entry_Name))
4442 and then Typ /= Standard_Void_Type
4449 Get_First_Interp (Selector_Name (Entry_Name), I, It);
4451 while Present (It.Typ) loop
4453 if Covers (Typ, It.Typ) then
4454 Set_Entity (Selector_Name (Entry_Name), It.Nam);
4455 Set_Etype (Entry_Name, It.Typ);
4457 Generate_Reference (It.Typ, N, ' ');
4460 Get_Next_Interp (I, It);
4465 Resolve_Entry (Entry_Name);
4467 if Nkind (Entry_Name) = N_Selected_Component then
4469 -- Simple entry call.
4471 Nam := Entity (Selector_Name (Entry_Name));
4472 Obj := Prefix (Entry_Name);
4473 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
4475 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
4477 -- Call to member of entry family.
4479 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
4480 Obj := Prefix (Prefix (Entry_Name));
4481 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
4484 -- We cannot in general check the maximum depth of protected entry
4485 -- calls at compile time. But we can tell that any protected entry
4486 -- call at all violates a specified nesting depth of zero.
4488 if Is_Protected_Type (Scope (Nam)) then
4489 Check_Restriction (Max_Entry_Queue_Depth, N);
4492 -- Use context type to disambiguate a protected function that can be
4493 -- called without actuals and that returns an array type, and where
4494 -- the argument list may be an indexing of the returned value.
4496 if Ekind (Nam) = E_Function
4497 and then Needs_No_Actuals (Nam)
4498 and then Present (Parameter_Associations (N))
4500 ((Is_Array_Type (Etype (Nam))
4501 and then Covers (Typ, Component_Type (Etype (Nam))))
4503 or else (Is_Access_Type (Etype (Nam))
4504 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4505 and then Covers (Typ,
4506 Component_Type (Designated_Type (Etype (Nam))))))
4509 Index_Node : Node_Id;
4513 Make_Indexed_Component (Loc,
4515 Make_Function_Call (Loc,
4516 Name => Relocate_Node (Entry_Name)),
4517 Expressions => Parameter_Associations (N));
4519 -- Since we are correcting a node classification error made by
4520 -- the parser, we call Replace rather than Rewrite.
4522 Replace (N, Index_Node);
4523 Set_Etype (Prefix (N), Etype (Nam));
4525 Resolve_Indexed_Component (N, Typ);
4530 -- The operation name may have been overloaded. Order the actuals
4531 -- according to the formals of the resolved entity, and set the
4532 -- return type to that of the operation.
4535 Normalize_Actuals (N, Nam, False, Norm_OK);
4536 pragma Assert (Norm_OK);
4537 Set_Etype (N, Etype (Nam));
4540 Resolve_Actuals (N, Nam);
4541 Generate_Reference (Nam, Entry_Name);
4543 if Ekind (Nam) = E_Entry
4544 or else Ekind (Nam) = E_Entry_Family
4546 Check_Potentially_Blocking_Operation (N);
4549 -- Verify that a procedure call cannot masquerade as an entry
4550 -- call where an entry call is expected.
4552 if Ekind (Nam) = E_Procedure then
4553 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4554 and then N = Entry_Call_Statement (Parent (N))
4556 Error_Msg_N ("entry call required in select statement", N);
4558 elsif Nkind (Parent (N)) = N_Triggering_Alternative
4559 and then N = Triggering_Statement (Parent (N))
4561 Error_Msg_N ("triggering statement cannot be procedure call", N);
4563 elsif Ekind (Scope (Nam)) = E_Task_Type
4564 and then not In_Open_Scopes (Scope (Nam))
4566 Error_Msg_N ("Task has no entry with this name", Entry_Name);
4570 -- After resolution, entry calls and protected procedure calls
4571 -- are changed into entry calls, for expansion. The structure
4572 -- of the node does not change, so it can safely be done in place.
4573 -- Protected function calls must keep their structure because they
4574 -- are subexpressions.
4576 if Ekind (Nam) /= E_Function then
4578 -- A protected operation that is not a function may modify the
4579 -- corresponding object, and cannot apply to a constant.
4580 -- If this is an internal call, the prefix is the type itself.
4582 if Is_Protected_Type (Scope (Nam))
4583 and then not Is_Variable (Obj)
4584 and then (not Is_Entity_Name (Obj)
4585 or else not Is_Type (Entity (Obj)))
4588 ("prefix of protected procedure or entry call must be variable",
4592 Actuals := Parameter_Associations (N);
4593 First_Named := First_Named_Actual (N);
4596 Make_Entry_Call_Statement (Loc,
4598 Parameter_Associations => Actuals));
4600 Set_First_Named_Actual (N, First_Named);
4601 Set_Analyzed (N, True);
4603 -- Protected functions can return on the secondary stack, in which
4604 -- case we must trigger the transient scope mechanism
4606 elsif Expander_Active
4607 and then Requires_Transient_Scope (Etype (Nam))
4609 Establish_Transient_Scope (N,
4610 Sec_Stack => not Functions_Return_By_DSP_On_Target);
4612 end Resolve_Entry_Call;
4614 -------------------------
4615 -- Resolve_Equality_Op --
4616 -------------------------
4618 -- Both arguments must have the same type, and the boolean context
4619 -- does not participate in the resolution. The first pass verifies
4620 -- that the interpretation is not ambiguous, and the type of the left
4621 -- argument is correctly set, or is Any_Type in case of ambiguity.
4622 -- If both arguments are strings or aggregates, allocators, or Null,
4623 -- they are ambiguous even though they carry a single (universal) type.
4624 -- Diagnose this case here.
4626 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
4627 L : constant Node_Id := Left_Opnd (N);
4628 R : constant Node_Id := Right_Opnd (N);
4629 T : Entity_Id := Find_Unique_Type (L, R);
4631 function Find_Unique_Access_Type return Entity_Id;
4632 -- In the case of allocators, make a last-ditch attempt to find a single
4633 -- access type with the right designated type. This is semantically
4634 -- dubious, and of no interest to any real code, but c48008a makes it
4637 -----------------------------
4638 -- Find_Unique_Access_Type --
4639 -----------------------------
4641 function Find_Unique_Access_Type return Entity_Id is
4644 S : Entity_Id := Current_Scope;
4647 if Ekind (Etype (R)) = E_Allocator_Type then
4648 Acc := Designated_Type (Etype (R));
4650 elsif Ekind (Etype (L)) = E_Allocator_Type then
4651 Acc := Designated_Type (Etype (L));
4657 while S /= Standard_Standard loop
4658 E := First_Entity (S);
4660 while Present (E) loop
4663 and then Is_Access_Type (E)
4664 and then Ekind (E) /= E_Allocator_Type
4665 and then Designated_Type (E) = Base_Type (Acc)
4677 end Find_Unique_Access_Type;
4679 -- Start of processing for Resolve_Equality_Op
4682 Check_Direct_Boolean_Op (N);
4684 Set_Etype (N, Base_Type (Typ));
4685 Generate_Reference (T, N, ' ');
4687 if T = Any_Fixed then
4688 T := Unique_Fixed_Point_Type (L);
4691 if T /= Any_Type then
4694 or else T = Any_Composite
4695 or else T = Any_Character
4698 if T = Any_Character then
4699 Ambiguous_Character (L);
4701 Error_Msg_N ("ambiguous operands for equality", N);
4704 Set_Etype (N, Any_Type);
4707 elsif T = Any_Access
4708 or else Ekind (T) = E_Allocator_Type
4710 T := Find_Unique_Access_Type;
4713 Error_Msg_N ("ambiguous operands for equality", N);
4714 Set_Etype (N, Any_Type);
4719 if Comes_From_Source (N)
4720 and then Has_Unchecked_Union (T)
4723 ("cannot compare Unchecked_Union values", N);
4729 if Warn_On_Redundant_Constructs
4730 and then Comes_From_Source (N)
4731 and then Is_Entity_Name (R)
4732 and then Entity (R) = Standard_True
4733 and then Comes_From_Source (R)
4735 Error_Msg_N ("comparison with True is redundant?", R);
4738 Check_Unset_Reference (L);
4739 Check_Unset_Reference (R);
4740 Generate_Operator_Reference (N, T);
4742 -- If this is an inequality, it may be the implicit inequality
4743 -- created for a user-defined operation, in which case the corres-
4744 -- ponding equality operation is not intrinsic, and the operation
4745 -- cannot be constant-folded. Else fold.
4747 if Nkind (N) = N_Op_Eq
4748 or else Comes_From_Source (Entity (N))
4749 or else Ekind (Entity (N)) = E_Operator
4750 or else Is_Intrinsic_Subprogram
4751 (Corresponding_Equality (Entity (N)))
4753 Eval_Relational_Op (N);
4754 elsif Nkind (N) = N_Op_Ne
4755 and then Is_Abstract (Entity (N))
4757 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
4760 end Resolve_Equality_Op;
4762 ----------------------------------
4763 -- Resolve_Explicit_Dereference --
4764 ----------------------------------
4766 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
4767 P : constant Node_Id := Prefix (N);
4772 -- Now that we know the type, check that this is not a
4773 -- dereference of an uncompleted type. Note that this
4774 -- is not entirely correct, because dereferences of
4775 -- private types are legal in default expressions.
4776 -- This consideration also applies to similar checks
4777 -- for allocators, qualified expressions, and type
4780 Check_Fully_Declared (Typ, N);
4782 if Is_Overloaded (P) then
4784 -- Use the context type to select the prefix that has the
4785 -- correct designated type.
4787 Get_First_Interp (P, I, It);
4788 while Present (It.Typ) loop
4789 exit when Is_Access_Type (It.Typ)
4790 and then Covers (Typ, Designated_Type (It.Typ));
4792 Get_Next_Interp (I, It);
4795 Resolve (P, It.Typ);
4796 Set_Etype (N, Designated_Type (It.Typ));
4802 if Is_Access_Type (Etype (P)) then
4803 Apply_Access_Check (N);
4806 -- If the designated type is a packed unconstrained array type,
4807 -- and the explicit dereference is not in the context of an
4808 -- attribute reference, then we must compute and set the actual
4809 -- subtype, since it is needed by Gigi. The reason we exclude
4810 -- the attribute case is that this is handled fine by Gigi, and
4811 -- in fact we use such attributes to build the actual subtype.
4812 -- We also exclude generated code (which builds actual subtypes
4813 -- directly if they are needed).
4815 if Is_Array_Type (Etype (N))
4816 and then Is_Packed (Etype (N))
4817 and then not Is_Constrained (Etype (N))
4818 and then Nkind (Parent (N)) /= N_Attribute_Reference
4819 and then Comes_From_Source (N)
4821 Set_Etype (N, Get_Actual_Subtype (N));
4824 -- Note: there is no Eval processing required for an explicit
4825 -- deference, because the type is known to be an allocators, and
4826 -- allocator expressions can never be static.
4828 end Resolve_Explicit_Dereference;
4830 -------------------------------
4831 -- Resolve_Indexed_Component --
4832 -------------------------------
4834 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
4835 Name : constant Node_Id := Prefix (N);
4837 Array_Type : Entity_Id := Empty; -- to prevent junk warning
4841 if Is_Overloaded (Name) then
4843 -- Use the context type to select the prefix that yields the
4844 -- correct component type.
4849 I1 : Interp_Index := 0;
4850 P : constant Node_Id := Prefix (N);
4851 Found : Boolean := False;
4854 Get_First_Interp (P, I, It);
4856 while Present (It.Typ) loop
4858 if (Is_Array_Type (It.Typ)
4859 and then Covers (Typ, Component_Type (It.Typ)))
4860 or else (Is_Access_Type (It.Typ)
4861 and then Is_Array_Type (Designated_Type (It.Typ))
4863 (Typ, Component_Type (Designated_Type (It.Typ))))
4866 It := Disambiguate (P, I1, I, Any_Type);
4868 if It = No_Interp then
4869 Error_Msg_N ("ambiguous prefix for indexing", N);
4875 Array_Type := It.Typ;
4881 Array_Type := It.Typ;
4886 Get_Next_Interp (I, It);
4891 Array_Type := Etype (Name);
4894 Resolve (Name, Array_Type);
4895 Array_Type := Get_Actual_Subtype_If_Available (Name);
4897 -- If prefix is access type, dereference to get real array type.
4898 -- Note: we do not apply an access check because the expander always
4899 -- introduces an explicit dereference, and the check will happen there.
4901 if Is_Access_Type (Array_Type) then
4902 Array_Type := Designated_Type (Array_Type);
4905 -- If name was overloaded, set component type correctly now.
4907 Set_Etype (N, Component_Type (Array_Type));
4909 Index := First_Index (Array_Type);
4910 Expr := First (Expressions (N));
4912 -- The prefix may have resolved to a string literal, in which case
4913 -- its etype has a special representation. This is only possible
4914 -- currently if the prefix is a static concatenation, written in
4915 -- functional notation.
4917 if Ekind (Array_Type) = E_String_Literal_Subtype then
4918 Resolve (Expr, Standard_Positive);
4921 while Present (Index) and Present (Expr) loop
4922 Resolve (Expr, Etype (Index));
4923 Check_Unset_Reference (Expr);
4925 if Is_Scalar_Type (Etype (Expr)) then
4926 Apply_Scalar_Range_Check (Expr, Etype (Index));
4928 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
4936 Eval_Indexed_Component (N);
4937 end Resolve_Indexed_Component;
4939 -----------------------------
4940 -- Resolve_Integer_Literal --
4941 -----------------------------
4943 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
4946 Eval_Integer_Literal (N);
4947 end Resolve_Integer_Literal;
4949 ---------------------------------
4950 -- Resolve_Intrinsic_Operator --
4951 ---------------------------------
4953 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
4954 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
4962 while Scope (Op) /= Standard_Standard loop
4964 pragma Assert (Present (Op));
4969 -- If the operand type is private, rewrite with suitable
4970 -- conversions on the operands and the result, to expose
4971 -- the proper underlying numeric type.
4973 if Is_Private_Type (Typ) then
4974 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
4976 if Nkind (N) = N_Op_Expon then
4977 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
4979 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
4982 Save_Interps (Left_Opnd (N), Expression (Arg1));
4983 Save_Interps (Right_Opnd (N), Expression (Arg2));
4985 Set_Left_Opnd (N, Arg1);
4986 Set_Right_Opnd (N, Arg2);
4988 Set_Etype (N, Btyp);
4989 Rewrite (N, Unchecked_Convert_To (Typ, N));
4992 elsif Typ /= Etype (Left_Opnd (N))
4993 or else Typ /= Etype (Right_Opnd (N))
4995 -- Add explicit conversion where needed, and save interpretations
4996 -- if operands are overloaded.
4998 Arg1 := Convert_To (Typ, Left_Opnd (N));
4999 Arg2 := Convert_To (Typ, Right_Opnd (N));
5001 if Nkind (Arg1) = N_Type_Conversion then
5002 Save_Interps (Left_Opnd (N), Expression (Arg1));
5005 if Nkind (Arg2) = N_Type_Conversion then
5006 Save_Interps (Right_Opnd (N), Expression (Arg2));
5009 Rewrite (Left_Opnd (N), Arg1);
5010 Rewrite (Right_Opnd (N), Arg2);
5013 Resolve_Arithmetic_Op (N, Typ);
5016 Resolve_Arithmetic_Op (N, Typ);
5018 end Resolve_Intrinsic_Operator;
5020 --------------------------------------
5021 -- Resolve_Intrinsic_Unary_Operator --
5022 --------------------------------------
5024 procedure Resolve_Intrinsic_Unary_Operator
5028 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
5035 while Scope (Op) /= Standard_Standard loop
5037 pragma Assert (Present (Op));
5042 if Is_Private_Type (Typ) then
5043 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
5044 Save_Interps (Right_Opnd (N), Expression (Arg2));
5046 Set_Right_Opnd (N, Arg2);
5048 Set_Etype (N, Btyp);
5049 Rewrite (N, Unchecked_Convert_To (Typ, N));
5053 Resolve_Unary_Op (N, Typ);
5055 end Resolve_Intrinsic_Unary_Operator;
5057 ------------------------
5058 -- Resolve_Logical_Op --
5059 ------------------------
5061 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
5065 Check_Direct_Boolean_Op (N);
5067 -- Predefined operations on scalar types yield the base type. On
5068 -- the other hand, logical operations on arrays yield the type of
5069 -- the arguments (and the context).
5071 if Is_Array_Type (Typ) then
5074 B_Typ := Base_Type (Typ);
5077 -- The following test is required because the operands of the operation
5078 -- may be literals, in which case the resulting type appears to be
5079 -- compatible with a signed integer type, when in fact it is compatible
5080 -- only with modular types. If the context itself is universal, the
5081 -- operation is illegal.
5083 if not Valid_Boolean_Arg (Typ) then
5084 Error_Msg_N ("invalid context for logical operation", N);
5085 Set_Etype (N, Any_Type);
5088 elsif Typ = Any_Modular then
5090 ("no modular type available in this context", N);
5091 Set_Etype (N, Any_Type);
5093 elsif Is_Modular_Integer_Type (Typ)
5094 and then Etype (Left_Opnd (N)) = Universal_Integer
5095 and then Etype (Right_Opnd (N)) = Universal_Integer
5097 Check_For_Visible_Operator (N, B_Typ);
5100 Resolve (Left_Opnd (N), B_Typ);
5101 Resolve (Right_Opnd (N), B_Typ);
5103 Check_Unset_Reference (Left_Opnd (N));
5104 Check_Unset_Reference (Right_Opnd (N));
5106 Set_Etype (N, B_Typ);
5107 Generate_Operator_Reference (N, B_Typ);
5108 Eval_Logical_Op (N);
5109 end Resolve_Logical_Op;
5111 ---------------------------
5112 -- Resolve_Membership_Op --
5113 ---------------------------
5115 -- The context can only be a boolean type, and does not determine
5116 -- the arguments. Arguments should be unambiguous, but the preference
5117 -- rule for universal types applies.
5119 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
5120 pragma Warnings (Off, Typ);
5122 L : constant Node_Id := Left_Opnd (N);
5123 R : constant Node_Id := Right_Opnd (N);
5127 if L = Error or else R = Error then
5131 if not Is_Overloaded (R)
5133 (Etype (R) = Universal_Integer or else
5134 Etype (R) = Universal_Real)
5135 and then Is_Overloaded (L)
5139 T := Intersect_Types (L, R);
5143 Check_Unset_Reference (L);
5145 if Nkind (R) = N_Range
5146 and then not Is_Scalar_Type (T)
5148 Error_Msg_N ("scalar type required for range", R);
5151 if Is_Entity_Name (R) then
5152 Freeze_Expression (R);
5155 Check_Unset_Reference (R);
5158 Eval_Membership_Op (N);
5159 end Resolve_Membership_Op;
5165 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
5167 -- For now allow circumvention of the restriction against
5168 -- anonymous null access values via a debug switch to allow
5169 -- for easier transition.
5171 -- Ada 0Y (AI-231): Remove restriction
5173 if not Extensions_Allowed
5174 and then not Debug_Flag_J
5175 and then Ekind (Typ) = E_Anonymous_Access_Type
5176 and then Comes_From_Source (N)
5178 -- In the common case of a call which uses an explicitly null
5179 -- value for an access parameter, give specialized error msg
5181 if Nkind (Parent (N)) = N_Procedure_Call_Statement
5183 Nkind (Parent (N)) = N_Function_Call
5186 ("null is not allowed as argument for an access parameter", N);
5188 -- Standard message for all other cases (are there any?)
5192 ("null cannot be of an anonymous access type", N);
5196 -- In a distributed context, null for a remote access to subprogram
5197 -- may need to be replaced with a special record aggregate. In this
5198 -- case, return after having done the transformation.
5200 if (Ekind (Typ) = E_Record_Type
5201 or else Is_Remote_Access_To_Subprogram_Type (Typ))
5202 and then Remote_AST_Null_Value (N, Typ)
5207 -- The null literal takes its type from the context.
5212 -----------------------
5213 -- Resolve_Op_Concat --
5214 -----------------------
5216 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
5217 Btyp : constant Entity_Id := Base_Type (Typ);
5218 Op1 : constant Node_Id := Left_Opnd (N);
5219 Op2 : constant Node_Id := Right_Opnd (N);
5221 procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean);
5222 -- Internal procedure to resolve one operand of concatenation operator.
5223 -- The operand is either of the array type or of the component type.
5224 -- If the operand is an aggregate, and the component type is composite,
5225 -- this is ambiguous if component type has aggregates.
5227 -------------------------------
5228 -- Resolve_Concatenation_Arg --
5229 -------------------------------
5231 procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean) is
5235 or else (not Is_Overloaded (Arg)
5236 and then Etype (Arg) /= Any_Composite
5237 and then Covers (Component_Type (Typ), Etype (Arg)))
5239 Resolve (Arg, Component_Type (Typ));
5241 Resolve (Arg, Btyp);
5244 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
5246 if Nkind (Arg) = N_Aggregate
5247 and then Is_Composite_Type (Component_Type (Typ))
5249 if Is_Private_Type (Component_Type (Typ)) then
5250 Resolve (Arg, Btyp);
5253 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
5254 Set_Etype (Arg, Any_Type);
5258 if Is_Overloaded (Arg)
5259 and then Has_Compatible_Type (Arg, Typ)
5260 and then Etype (Arg) /= Any_Type
5262 Error_Msg_N ("ambiguous operand for concatenation!", Arg);
5269 Get_First_Interp (Arg, I, It);
5271 while Present (It.Nam) loop
5273 if Base_Type (Etype (It.Nam)) = Base_Type (Typ)
5274 or else Base_Type (Etype (It.Nam)) =
5275 Base_Type (Component_Type (Typ))
5277 Error_Msg_Sloc := Sloc (It.Nam);
5278 Error_Msg_N ("\possible interpretation#", Arg);
5281 Get_Next_Interp (I, It);
5286 Resolve (Arg, Component_Type (Typ));
5288 if Nkind (Arg) = N_String_Literal then
5289 Set_Etype (Arg, Component_Type (Typ));
5292 if Arg = Left_Opnd (N) then
5293 Set_Is_Component_Left_Opnd (N);
5295 Set_Is_Component_Right_Opnd (N);
5300 Resolve (Arg, Btyp);
5303 Check_Unset_Reference (Arg);
5304 end Resolve_Concatenation_Arg;
5306 -- Start of processing for Resolve_Op_Concat
5309 Set_Etype (N, Btyp);
5311 if Is_Limited_Composite (Btyp) then
5312 Error_Msg_N ("concatenation not available for limited array", N);
5313 Explain_Limited_Type (Btyp, N);
5316 -- If the operands are themselves concatenations, resolve them as
5317 -- such directly. This removes several layers of recursion and allows
5318 -- GNAT to handle larger multiple concatenations.
5320 if Nkind (Op1) = N_Op_Concat
5321 and then not Is_Array_Type (Component_Type (Typ))
5322 and then Entity (Op1) = Entity (N)
5324 Resolve_Op_Concat (Op1, Typ);
5326 Resolve_Concatenation_Arg
5327 (Op1, Is_Component_Left_Opnd (N));
5330 if Nkind (Op2) = N_Op_Concat
5331 and then not Is_Array_Type (Component_Type (Typ))
5332 and then Entity (Op2) = Entity (N)
5334 Resolve_Op_Concat (Op2, Typ);
5336 Resolve_Concatenation_Arg
5337 (Op2, Is_Component_Right_Opnd (N));
5340 Generate_Operator_Reference (N, Typ);
5342 if Is_String_Type (Typ) then
5343 Eval_Concatenation (N);
5346 -- If this is not a static concatenation, but the result is a
5347 -- string type (and not an array of strings) insure that static
5348 -- string operands have their subtypes properly constructed.
5350 if Nkind (N) /= N_String_Literal
5351 and then Is_Character_Type (Component_Type (Typ))
5353 Set_String_Literal_Subtype (Op1, Typ);
5354 Set_String_Literal_Subtype (Op2, Typ);
5356 end Resolve_Op_Concat;
5358 ----------------------
5359 -- Resolve_Op_Expon --
5360 ----------------------
5362 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
5363 B_Typ : constant Entity_Id := Base_Type (Typ);
5366 -- Catch attempts to do fixed-point exponentation with universal
5367 -- operands, which is a case where the illegality is not caught
5368 -- during normal operator analysis.
5370 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
5371 Error_Msg_N ("exponentiation not available for fixed point", N);
5375 if Comes_From_Source (N)
5376 and then Ekind (Entity (N)) = E_Function
5377 and then Is_Imported (Entity (N))
5378 and then Is_Intrinsic_Subprogram (Entity (N))
5380 Resolve_Intrinsic_Operator (N, Typ);
5384 if Etype (Left_Opnd (N)) = Universal_Integer
5385 or else Etype (Left_Opnd (N)) = Universal_Real
5387 Check_For_Visible_Operator (N, B_Typ);
5390 -- We do the resolution using the base type, because intermediate values
5391 -- in expressions always are of the base type, not a subtype of it.
5393 Resolve (Left_Opnd (N), B_Typ);
5394 Resolve (Right_Opnd (N), Standard_Integer);
5396 Check_Unset_Reference (Left_Opnd (N));
5397 Check_Unset_Reference (Right_Opnd (N));
5399 Set_Etype (N, B_Typ);
5400 Generate_Operator_Reference (N, B_Typ);
5403 -- Set overflow checking bit. Much cleverer code needed here eventually
5404 -- and perhaps the Resolve routines should be separated for the various
5405 -- arithmetic operations, since they will need different processing. ???
5407 if Nkind (N) in N_Op then
5408 if not Overflow_Checks_Suppressed (Etype (N)) then
5409 Enable_Overflow_Check (N);
5412 end Resolve_Op_Expon;
5414 --------------------
5415 -- Resolve_Op_Not --
5416 --------------------
5418 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
5421 function Parent_Is_Boolean return Boolean;
5422 -- This function determines if the parent node is a boolean operator
5423 -- or operation (comparison op, membership test, or short circuit form)
5424 -- and the not in question is the left operand of this operation.
5425 -- Note that if the not is in parens, then false is returned.
5427 function Parent_Is_Boolean return Boolean is
5429 if Paren_Count (N) /= 0 then
5433 case Nkind (Parent (N)) is
5448 return Left_Opnd (Parent (N)) = N;
5454 end Parent_Is_Boolean;
5456 -- Start of processing for Resolve_Op_Not
5459 -- Predefined operations on scalar types yield the base type. On
5460 -- the other hand, logical operations on arrays yield the type of
5461 -- the arguments (and the context).
5463 if Is_Array_Type (Typ) then
5466 B_Typ := Base_Type (Typ);
5469 if not Valid_Boolean_Arg (Typ) then
5470 Error_Msg_N ("invalid operand type for operator&", N);
5471 Set_Etype (N, Any_Type);
5474 elsif Typ = Universal_Integer or else Typ = Any_Modular then
5475 if Parent_Is_Boolean then
5477 ("operand of not must be enclosed in parentheses",
5481 ("no modular type available in this context", N);
5484 Set_Etype (N, Any_Type);
5488 if not Is_Boolean_Type (Typ)
5489 and then Parent_Is_Boolean
5491 Error_Msg_N ("?not expression should be parenthesized here", N);
5494 Resolve (Right_Opnd (N), B_Typ);
5495 Check_Unset_Reference (Right_Opnd (N));
5496 Set_Etype (N, B_Typ);
5497 Generate_Operator_Reference (N, B_Typ);
5502 -----------------------------
5503 -- Resolve_Operator_Symbol --
5504 -----------------------------
5506 -- Nothing to be done, all resolved already
5508 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
5509 pragma Warnings (Off, N);
5510 pragma Warnings (Off, Typ);
5514 end Resolve_Operator_Symbol;
5516 ----------------------------------
5517 -- Resolve_Qualified_Expression --
5518 ----------------------------------
5520 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
5521 pragma Warnings (Off, Typ);
5523 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
5524 Expr : constant Node_Id := Expression (N);
5527 Resolve (Expr, Target_Typ);
5529 -- A qualified expression requires an exact match of the type,
5530 -- class-wide matching is not allowed.
5532 if Is_Class_Wide_Type (Target_Typ)
5533 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
5535 Wrong_Type (Expr, Target_Typ);
5538 -- If the target type is unconstrained, then we reset the type of
5539 -- the result from the type of the expression. For other cases, the
5540 -- actual subtype of the expression is the target type.
5542 if Is_Composite_Type (Target_Typ)
5543 and then not Is_Constrained (Target_Typ)
5545 Set_Etype (N, Etype (Expr));
5548 Eval_Qualified_Expression (N);
5549 end Resolve_Qualified_Expression;
5555 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
5556 L : constant Node_Id := Low_Bound (N);
5557 H : constant Node_Id := High_Bound (N);
5564 Check_Unset_Reference (L);
5565 Check_Unset_Reference (H);
5567 -- We have to check the bounds for being within the base range as
5568 -- required for a non-static context. Normally this is automatic
5569 -- and done as part of evaluating expressions, but the N_Range
5570 -- node is an exception, since in GNAT we consider this node to
5571 -- be a subexpression, even though in Ada it is not. The circuit
5572 -- in Sem_Eval could check for this, but that would put the test
5573 -- on the main evaluation path for expressions.
5575 Check_Non_Static_Context (L);
5576 Check_Non_Static_Context (H);
5578 -- If bounds are static, constant-fold them, so size computations
5579 -- are identical between front-end and back-end. Do not perform this
5580 -- transformation while analyzing generic units, as type information
5581 -- would then be lost when reanalyzing the constant node in the
5584 if Is_Discrete_Type (Typ) and then Expander_Active then
5585 if Is_OK_Static_Expression (L) then
5586 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
5589 if Is_OK_Static_Expression (H) then
5590 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
5595 --------------------------
5596 -- Resolve_Real_Literal --
5597 --------------------------
5599 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
5600 Actual_Typ : constant Entity_Id := Etype (N);
5603 -- Special processing for fixed-point literals to make sure that the
5604 -- value is an exact multiple of small where this is required. We
5605 -- skip this for the universal real case, and also for generic types.
5607 if Is_Fixed_Point_Type (Typ)
5608 and then Typ /= Universal_Fixed
5609 and then Typ /= Any_Fixed
5610 and then not Is_Generic_Type (Typ)
5613 Val : constant Ureal := Realval (N);
5614 Cintr : constant Ureal := Val / Small_Value (Typ);
5615 Cint : constant Uint := UR_Trunc (Cintr);
5616 Den : constant Uint := Norm_Den (Cintr);
5620 -- Case of literal is not an exact multiple of the Small
5624 -- For a source program literal for a decimal fixed-point
5625 -- type, this is statically illegal (RM 4.9(36)).
5627 if Is_Decimal_Fixed_Point_Type (Typ)
5628 and then Actual_Typ = Universal_Real
5629 and then Comes_From_Source (N)
5631 Error_Msg_N ("value has extraneous low order digits", N);
5634 -- Replace literal by a value that is the exact representation
5635 -- of a value of the type, i.e. a multiple of the small value,
5636 -- by truncation, since Machine_Rounds is false for all GNAT
5637 -- fixed-point types (RM 4.9(38)).
5639 Stat := Is_Static_Expression (N);
5641 Make_Real_Literal (Sloc (N),
5642 Realval => Small_Value (Typ) * Cint));
5644 Set_Is_Static_Expression (N, Stat);
5647 -- In all cases, set the corresponding integer field
5649 Set_Corresponding_Integer_Value (N, Cint);
5653 -- Now replace the actual type by the expected type as usual
5656 Eval_Real_Literal (N);
5657 end Resolve_Real_Literal;
5659 -----------------------
5660 -- Resolve_Reference --
5661 -----------------------
5663 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
5664 P : constant Node_Id := Prefix (N);
5667 -- Replace general access with specific type
5669 if Ekind (Etype (N)) = E_Allocator_Type then
5670 Set_Etype (N, Base_Type (Typ));
5673 Resolve (P, Designated_Type (Etype (N)));
5675 -- If we are taking the reference of a volatile entity, then treat
5676 -- it as a potential modification of this entity. This is much too
5677 -- conservative, but is necessary because remove side effects can
5678 -- result in transformations of normal assignments into reference
5679 -- sequences that otherwise fail to notice the modification.
5681 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
5682 Note_Possible_Modification (P);
5684 end Resolve_Reference;
5686 --------------------------------
5687 -- Resolve_Selected_Component --
5688 --------------------------------
5690 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
5692 Comp1 : Entity_Id := Empty; -- prevent junk warning
5693 P : constant Node_Id := Prefix (N);
5694 S : constant Node_Id := Selector_Name (N);
5695 T : Entity_Id := Etype (P);
5697 I1 : Interp_Index := 0; -- prevent junk warning
5702 function Init_Component return Boolean;
5703 -- Check whether this is the initialization of a component within an
5704 -- init proc (by assignment or call to another init proc). If true,
5705 -- there is no need for a discriminant check.
5707 --------------------
5708 -- Init_Component --
5709 --------------------
5711 function Init_Component return Boolean is
5713 return Inside_Init_Proc
5714 and then Nkind (Prefix (N)) = N_Identifier
5715 and then Chars (Prefix (N)) = Name_uInit
5716 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
5719 -- Start of processing for Resolve_Selected_Component
5722 if Is_Overloaded (P) then
5724 -- Use the context type to select the prefix that has a selector
5725 -- of the correct name and type.
5728 Get_First_Interp (P, I, It);
5730 Search : while Present (It.Typ) loop
5731 if Is_Access_Type (It.Typ) then
5732 T := Designated_Type (It.Typ);
5737 if Is_Record_Type (T) then
5738 Comp := First_Entity (T);
5740 while Present (Comp) loop
5742 if Chars (Comp) = Chars (S)
5743 and then Covers (Etype (Comp), Typ)
5752 It := Disambiguate (P, I1, I, Any_Type);
5754 if It = No_Interp then
5756 ("ambiguous prefix for selected component", N);
5763 if Scope (Comp1) /= It1.Typ then
5765 -- Resolution chooses the new interpretation.
5766 -- Find the component with the right name.
5768 Comp1 := First_Entity (It1.Typ);
5770 while Present (Comp1)
5771 and then Chars (Comp1) /= Chars (S)
5773 Comp1 := Next_Entity (Comp1);
5782 Comp := Next_Entity (Comp);
5787 Get_Next_Interp (I, It);
5790 Resolve (P, It1.Typ);
5792 Set_Entity (S, Comp1);
5795 -- Resolve prefix with its type
5800 -- Deal with access type case
5802 if Is_Access_Type (Etype (P)) then
5803 Apply_Access_Check (N);
5804 T := Designated_Type (Etype (P));
5809 if Has_Discriminants (T)
5810 and then (Ekind (Entity (S)) = E_Component
5812 Ekind (Entity (S)) = E_Discriminant)
5813 and then Present (Original_Record_Component (Entity (S)))
5814 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
5815 and then Present (Discriminant_Checking_Func
5816 (Original_Record_Component (Entity (S))))
5817 and then not Discriminant_Checks_Suppressed (T)
5818 and then not Init_Component
5820 Set_Do_Discriminant_Check (N);
5823 if Ekind (Entity (S)) = E_Void then
5824 Error_Msg_N ("premature use of component", S);
5827 -- If the prefix is a record conversion, this may be a renamed
5828 -- discriminant whose bounds differ from those of the original
5829 -- one, so we must ensure that a range check is performed.
5831 if Nkind (P) = N_Type_Conversion
5832 and then Ekind (Entity (S)) = E_Discriminant
5833 and then Is_Discrete_Type (Typ)
5835 Set_Etype (N, Base_Type (Typ));
5838 -- Note: No Eval processing is required, because the prefix is of a
5839 -- record type, or protected type, and neither can possibly be static.
5841 end Resolve_Selected_Component;
5847 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
5848 B_Typ : constant Entity_Id := Base_Type (Typ);
5849 L : constant Node_Id := Left_Opnd (N);
5850 R : constant Node_Id := Right_Opnd (N);
5853 -- We do the resolution using the base type, because intermediate values
5854 -- in expressions always are of the base type, not a subtype of it.
5857 Resolve (R, Standard_Natural);
5859 Check_Unset_Reference (L);
5860 Check_Unset_Reference (R);
5862 Set_Etype (N, B_Typ);
5863 Generate_Operator_Reference (N, B_Typ);
5867 ---------------------------
5868 -- Resolve_Short_Circuit --
5869 ---------------------------
5871 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
5872 B_Typ : constant Entity_Id := Base_Type (Typ);
5873 L : constant Node_Id := Left_Opnd (N);
5874 R : constant Node_Id := Right_Opnd (N);
5880 Check_Unset_Reference (L);
5881 Check_Unset_Reference (R);
5883 Set_Etype (N, B_Typ);
5884 Eval_Short_Circuit (N);
5885 end Resolve_Short_Circuit;
5891 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
5892 Name : constant Node_Id := Prefix (N);
5893 Drange : constant Node_Id := Discrete_Range (N);
5894 Array_Type : Entity_Id := Empty;
5898 if Is_Overloaded (Name) then
5900 -- Use the context type to select the prefix that yields the
5901 -- correct array type.
5905 I1 : Interp_Index := 0;
5907 P : constant Node_Id := Prefix (N);
5908 Found : Boolean := False;
5911 Get_First_Interp (P, I, It);
5913 while Present (It.Typ) loop
5915 if (Is_Array_Type (It.Typ)
5916 and then Covers (Typ, It.Typ))
5917 or else (Is_Access_Type (It.Typ)
5918 and then Is_Array_Type (Designated_Type (It.Typ))
5919 and then Covers (Typ, Designated_Type (It.Typ)))
5922 It := Disambiguate (P, I1, I, Any_Type);
5924 if It = No_Interp then
5925 Error_Msg_N ("ambiguous prefix for slicing", N);
5930 Array_Type := It.Typ;
5935 Array_Type := It.Typ;
5940 Get_Next_Interp (I, It);
5945 Array_Type := Etype (Name);
5948 Resolve (Name, Array_Type);
5950 if Is_Access_Type (Array_Type) then
5951 Apply_Access_Check (N);
5952 Array_Type := Designated_Type (Array_Type);
5954 elsif Is_Entity_Name (Name)
5955 or else (Nkind (Name) = N_Function_Call
5956 and then not Is_Constrained (Etype (Name)))
5958 Array_Type := Get_Actual_Subtype (Name);
5961 -- If name was overloaded, set slice type correctly now
5963 Set_Etype (N, Array_Type);
5965 -- If the range is specified by a subtype mark, no resolution
5968 if not Is_Entity_Name (Drange) then
5969 Index := First_Index (Array_Type);
5970 Resolve (Drange, Base_Type (Etype (Index)));
5972 if Nkind (Drange) = N_Range then
5973 Apply_Range_Check (Drange, Etype (Index));
5977 Set_Slice_Subtype (N);
5981 ----------------------------
5982 -- Resolve_String_Literal --
5983 ----------------------------
5985 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
5986 C_Typ : constant Entity_Id := Component_Type (Typ);
5987 R_Typ : constant Entity_Id := Root_Type (C_Typ);
5988 Loc : constant Source_Ptr := Sloc (N);
5989 Str : constant String_Id := Strval (N);
5990 Strlen : constant Nat := String_Length (Str);
5991 Subtype_Id : Entity_Id;
5992 Need_Check : Boolean;
5995 -- For a string appearing in a concatenation, defer creation of the
5996 -- string_literal_subtype until the end of the resolution of the
5997 -- concatenation, because the literal may be constant-folded away.
5998 -- This is a useful optimization for long concatenation expressions.
6000 -- If the string is an aggregate built for a single character (which
6001 -- happens in a non-static context) or a is null string to which special
6002 -- checks may apply, we build the subtype. Wide strings must also get
6003 -- a string subtype if they come from a one character aggregate. Strings
6004 -- generated by attributes might be static, but it is often hard to
6005 -- determine whether the enclosing context is static, so we generate
6006 -- subtypes for them as well, thus losing some rarer optimizations ???
6007 -- Same for strings that come from a static conversion.
6010 (Strlen = 0 and then Typ /= Standard_String)
6011 or else Nkind (Parent (N)) /= N_Op_Concat
6012 or else (N /= Left_Opnd (Parent (N))
6013 and then N /= Right_Opnd (Parent (N)))
6014 or else (Typ = Standard_Wide_String
6015 and then Nkind (Original_Node (N)) /= N_String_Literal);
6017 -- If the resolving type is itself a string literal subtype, we
6018 -- can just reuse it, since there is no point in creating another.
6020 if Ekind (Typ) = E_String_Literal_Subtype then
6023 elsif Nkind (Parent (N)) = N_Op_Concat
6024 and then not Need_Check
6025 and then Nkind (Original_Node (N)) /= N_Character_Literal
6026 and then Nkind (Original_Node (N)) /= N_Attribute_Reference
6027 and then Nkind (Original_Node (N)) /= N_Qualified_Expression
6028 and then Nkind (Original_Node (N)) /= N_Type_Conversion
6032 -- Otherwise we must create a string literal subtype. Note that the
6033 -- whole idea of string literal subtypes is simply to avoid the need
6034 -- for building a full fledged array subtype for each literal.
6036 Set_String_Literal_Subtype (N, Typ);
6037 Subtype_Id := Etype (N);
6040 if Nkind (Parent (N)) /= N_Op_Concat
6043 Set_Etype (N, Subtype_Id);
6044 Eval_String_Literal (N);
6047 if Is_Limited_Composite (Typ)
6048 or else Is_Private_Composite (Typ)
6050 Error_Msg_N ("string literal not available for private array", N);
6051 Set_Etype (N, Any_Type);
6055 -- The validity of a null string has been checked in the
6056 -- call to Eval_String_Literal.
6061 -- Always accept string literal with component type Any_Character,
6062 -- which occurs in error situations and in comparisons of literals,
6063 -- both of which should accept all literals.
6065 elsif R_Typ = Any_Character then
6068 -- If the type is bit-packed, then we always tranform the string
6069 -- literal into a full fledged aggregate.
6071 elsif Is_Bit_Packed_Array (Typ) then
6074 -- Deal with cases of Wide_String and String
6077 -- For Standard.Wide_String, or any other type whose component
6078 -- type is Standard.Wide_Character, we know that all the
6079 -- characters in the string must be acceptable, since the parser
6080 -- accepted the characters as valid character literals.
6082 if R_Typ = Standard_Wide_Character then
6085 -- For the case of Standard.String, or any other type whose
6086 -- component type is Standard.Character, we must make sure that
6087 -- there are no wide characters in the string, i.e. that it is
6088 -- entirely composed of characters in range of type String.
6090 -- If the string literal is the result of a static concatenation,
6091 -- the test has already been performed on the components, and need
6094 elsif R_Typ = Standard_Character
6095 and then Nkind (Original_Node (N)) /= N_Op_Concat
6097 for J in 1 .. Strlen loop
6098 if not In_Character_Range (Get_String_Char (Str, J)) then
6100 -- If we are out of range, post error. This is one of the
6101 -- very few places that we place the flag in the middle of
6102 -- a token, right under the offending wide character.
6105 ("literal out of range of type Character",
6106 Source_Ptr (Int (Loc) + J));
6111 -- If the root type is not a standard character, then we will convert
6112 -- the string into an aggregate and will let the aggregate code do
6120 -- See if the component type of the array corresponding to the
6121 -- string has compile time known bounds. If yes we can directly
6122 -- check whether the evaluation of the string will raise constraint
6123 -- error. Otherwise we need to transform the string literal into
6124 -- the corresponding character aggregate and let the aggregate
6125 -- code do the checking.
6127 if R_Typ = Standard_Wide_Character
6128 or else R_Typ = Standard_Character
6130 -- Check for the case of full range, where we are definitely OK
6132 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
6136 -- Here the range is not the complete base type range, so check
6139 Comp_Typ_Lo : constant Node_Id :=
6140 Type_Low_Bound (Component_Type (Typ));
6141 Comp_Typ_Hi : constant Node_Id :=
6142 Type_High_Bound (Component_Type (Typ));
6147 if Compile_Time_Known_Value (Comp_Typ_Lo)
6148 and then Compile_Time_Known_Value (Comp_Typ_Hi)
6150 for J in 1 .. Strlen loop
6151 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
6153 if Char_Val < Expr_Value (Comp_Typ_Lo)
6154 or else Char_Val > Expr_Value (Comp_Typ_Hi)
6156 Apply_Compile_Time_Constraint_Error
6157 (N, "character out of range?", CE_Range_Check_Failed,
6158 Loc => Source_Ptr (Int (Loc) + J));
6168 -- If we got here we meed to transform the string literal into the
6169 -- equivalent qualified positional array aggregate. This is rather
6170 -- heavy artillery for this situation, but it is hard work to avoid.
6173 Lits : constant List_Id := New_List;
6174 P : Source_Ptr := Loc + 1;
6178 -- Build the character literals, we give them source locations
6179 -- that correspond to the string positions, which is a bit tricky
6180 -- given the possible presence of wide character escape sequences.
6182 for J in 1 .. Strlen loop
6183 C := Get_String_Char (Str, J);
6184 Set_Character_Literal_Name (C);
6187 Make_Character_Literal (P, Name_Find, C));
6189 if In_Character_Range (C) then
6192 -- Should we have a call to Skip_Wide here ???
6200 Make_Qualified_Expression (Loc,
6201 Subtype_Mark => New_Reference_To (Typ, Loc),
6203 Make_Aggregate (Loc, Expressions => Lits)));
6205 Analyze_And_Resolve (N, Typ);
6207 end Resolve_String_Literal;
6209 -----------------------------
6210 -- Resolve_Subprogram_Info --
6211 -----------------------------
6213 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
6216 end Resolve_Subprogram_Info;
6218 -----------------------------
6219 -- Resolve_Type_Conversion --
6220 -----------------------------
6222 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
6223 Target_Type : constant Entity_Id := Etype (N);
6224 Conv_OK : constant Boolean := Conversion_OK (N);
6226 Opnd_Type : Entity_Id;
6232 Operand := Expression (N);
6235 and then not Valid_Conversion (N, Target_Type, Operand)
6240 if Etype (Operand) = Any_Fixed then
6242 -- Mixed-mode operation involving a literal. Context must be a fixed
6243 -- type which is applied to the literal subsequently.
6245 if Is_Fixed_Point_Type (Typ) then
6246 Set_Etype (Operand, Universal_Real);
6248 elsif Is_Numeric_Type (Typ)
6249 and then (Nkind (Operand) = N_Op_Multiply
6250 or else Nkind (Operand) = N_Op_Divide)
6251 and then (Etype (Right_Opnd (Operand)) = Universal_Real
6252 or else Etype (Left_Opnd (Operand)) = Universal_Real)
6254 if Unique_Fixed_Point_Type (N) = Any_Type then
6255 return; -- expression is ambiguous.
6257 Set_Etype (Operand, Standard_Duration);
6260 if Etype (Right_Opnd (Operand)) = Universal_Real then
6261 Rop := New_Copy_Tree (Right_Opnd (Operand));
6263 Rop := New_Copy_Tree (Left_Opnd (Operand));
6266 Resolve (Rop, Standard_Long_Long_Float);
6268 if Realval (Rop) /= Ureal_0
6269 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
6271 Error_Msg_N ("universal real operand can only be interpreted?",
6273 Error_Msg_N ("\as Duration, and will lose precision?", Rop);
6276 elsif Is_Numeric_Type (Typ)
6277 and then Nkind (Operand) in N_Op
6278 and then Unique_Fixed_Point_Type (N) /= Any_Type
6280 Set_Etype (Operand, Standard_Duration);
6283 Error_Msg_N ("invalid context for mixed mode operation", N);
6284 Set_Etype (Operand, Any_Type);
6289 Opnd_Type := Etype (Operand);
6292 -- Note: we do the Eval_Type_Conversion call before applying the
6293 -- required checks for a subtype conversion. This is important,
6294 -- since both are prepared under certain circumstances to change
6295 -- the type conversion to a constraint error node, but in the case
6296 -- of Eval_Type_Conversion this may reflect an illegality in the
6297 -- static case, and we would miss the illegality (getting only a
6298 -- warning message), if we applied the type conversion checks first.
6300 Eval_Type_Conversion (N);
6302 -- If after evaluation, we still have a type conversion, then we
6303 -- may need to apply checks required for a subtype conversion.
6305 -- Skip these type conversion checks if universal fixed operands
6306 -- operands involved, since range checks are handled separately for
6307 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
6309 if Nkind (N) = N_Type_Conversion
6310 and then not Is_Generic_Type (Root_Type (Target_Type))
6311 and then Target_Type /= Universal_Fixed
6312 and then Opnd_Type /= Universal_Fixed
6314 Apply_Type_Conversion_Checks (N);
6317 -- Issue warning for conversion of simple object to its own type
6318 -- We have to test the original nodes, since they may have been
6319 -- rewritten by various optimizations.
6321 Orig_N := Original_Node (N);
6323 if Warn_On_Redundant_Constructs
6324 and then Comes_From_Source (Orig_N)
6325 and then Nkind (Orig_N) = N_Type_Conversion
6327 Orig_N := Original_Node (Expression (Orig_N));
6328 Orig_T := Target_Type;
6330 -- If the node is part of a larger expression, the Target_Type
6331 -- may not be the original type of the node if the context is a
6332 -- condition. Recover original type to see if conversion is needed.
6334 if Is_Boolean_Type (Orig_T)
6335 and then Nkind (Parent (N)) in N_Op
6337 Orig_T := Etype (Parent (N));
6340 if Is_Entity_Name (Orig_N)
6341 and then Etype (Entity (Orig_N)) = Orig_T
6344 ("?useless conversion, & has this type", N, Entity (Orig_N));
6347 end Resolve_Type_Conversion;
6349 ----------------------
6350 -- Resolve_Unary_Op --
6351 ----------------------
6353 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
6354 B_Typ : constant Entity_Id := Base_Type (Typ);
6355 R : constant Node_Id := Right_Opnd (N);
6361 -- Generate warning for expressions like abs (x mod 2)
6363 if Warn_On_Redundant_Constructs
6364 and then Nkind (N) = N_Op_Abs
6366 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
6368 if OK and then Hi >= Lo and then Lo >= 0 then
6370 ("?abs applied to known non-negative value has no effect", N);
6374 -- Generate warning for expressions like -5 mod 3
6376 if Paren_Count (N) = 0
6377 and then Nkind (N) = N_Op_Minus
6378 and then Nkind (Right_Opnd (N)) = N_Op_Mod
6379 and then Comes_From_Source (N)
6382 ("?unary minus expression should be parenthesized here", N);
6385 if Comes_From_Source (N)
6386 and then Ekind (Entity (N)) = E_Function
6387 and then Is_Imported (Entity (N))
6388 and then Is_Intrinsic_Subprogram (Entity (N))
6390 Resolve_Intrinsic_Unary_Operator (N, Typ);
6394 if Etype (R) = Universal_Integer
6395 or else Etype (R) = Universal_Real
6397 Check_For_Visible_Operator (N, B_Typ);
6400 Set_Etype (N, B_Typ);
6403 Check_Unset_Reference (R);
6404 Generate_Operator_Reference (N, B_Typ);
6407 -- Set overflow checking bit. Much cleverer code needed here eventually
6408 -- and perhaps the Resolve routines should be separated for the various
6409 -- arithmetic operations, since they will need different processing ???
6411 if Nkind (N) in N_Op then
6412 if not Overflow_Checks_Suppressed (Etype (N)) then
6413 Enable_Overflow_Check (N);
6416 end Resolve_Unary_Op;
6418 ----------------------------------
6419 -- Resolve_Unchecked_Expression --
6420 ----------------------------------
6422 procedure Resolve_Unchecked_Expression
6427 Resolve (Expression (N), Typ, Suppress => All_Checks);
6429 end Resolve_Unchecked_Expression;
6431 ---------------------------------------
6432 -- Resolve_Unchecked_Type_Conversion --
6433 ---------------------------------------
6435 procedure Resolve_Unchecked_Type_Conversion
6439 pragma Warnings (Off, Typ);
6441 Operand : constant Node_Id := Expression (N);
6442 Opnd_Type : constant Entity_Id := Etype (Operand);
6445 -- Resolve operand using its own type.
6447 Resolve (Operand, Opnd_Type);
6448 Eval_Unchecked_Conversion (N);
6450 end Resolve_Unchecked_Type_Conversion;
6452 ------------------------------
6453 -- Rewrite_Operator_As_Call --
6454 ------------------------------
6456 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
6457 Loc : constant Source_Ptr := Sloc (N);
6458 Actuals : constant List_Id := New_List;
6462 if Nkind (N) in N_Binary_Op then
6463 Append (Left_Opnd (N), Actuals);
6466 Append (Right_Opnd (N), Actuals);
6469 Make_Function_Call (Sloc => Loc,
6470 Name => New_Occurrence_Of (Nam, Loc),
6471 Parameter_Associations => Actuals);
6473 Preserve_Comes_From_Source (New_N, N);
6474 Preserve_Comes_From_Source (Name (New_N), N);
6476 Set_Etype (N, Etype (Nam));
6477 end Rewrite_Operator_As_Call;
6479 ------------------------------
6480 -- Rewrite_Renamed_Operator --
6481 ------------------------------
6483 procedure Rewrite_Renamed_Operator (N : Node_Id; Op : Entity_Id) is
6484 Nam : constant Name_Id := Chars (Op);
6485 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
6489 -- Rewrite the operator node using the real operator, not its
6490 -- renaming. Exclude user-defined intrinsic operations, which
6491 -- are treated separately.
6493 if Ekind (Op) /= E_Function then
6494 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
6495 Set_Chars (Op_Node, Nam);
6496 Set_Etype (Op_Node, Etype (N));
6497 Set_Entity (Op_Node, Op);
6498 Set_Right_Opnd (Op_Node, Right_Opnd (N));
6500 -- Indicate that both the original entity and its renaming
6501 -- are referenced at this point.
6503 Generate_Reference (Entity (N), N);
6504 Generate_Reference (Op, N);
6507 Set_Left_Opnd (Op_Node, Left_Opnd (N));
6510 Rewrite (N, Op_Node);
6512 end Rewrite_Renamed_Operator;
6514 -----------------------
6515 -- Set_Slice_Subtype --
6516 -----------------------
6518 -- Build an implicit subtype declaration to represent the type delivered
6519 -- by the slice. This is an abbreviated version of an array subtype. We
6520 -- define an index subtype for the slice, using either the subtype name
6521 -- or the discrete range of the slice. To be consistent with index usage
6522 -- elsewhere, we create a list header to hold the single index. This list
6523 -- is not otherwise attached to the syntax tree.
6525 procedure Set_Slice_Subtype (N : Node_Id) is
6526 Loc : constant Source_Ptr := Sloc (N);
6527 Index_List : constant List_Id := New_List;
6529 Index_Subtype : Entity_Id;
6530 Index_Type : Entity_Id;
6531 Slice_Subtype : Entity_Id;
6532 Drange : constant Node_Id := Discrete_Range (N);
6535 if Is_Entity_Name (Drange) then
6536 Index_Subtype := Entity (Drange);
6539 -- We force the evaluation of a range. This is definitely needed in
6540 -- the renamed case, and seems safer to do unconditionally. Note in
6541 -- any case that since we will create and insert an Itype referring
6542 -- to this range, we must make sure any side effect removal actions
6543 -- are inserted before the Itype definition.
6545 if Nkind (Drange) = N_Range then
6546 Force_Evaluation (Low_Bound (Drange));
6547 Force_Evaluation (High_Bound (Drange));
6550 Index_Type := Base_Type (Etype (Drange));
6552 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
6554 Set_Scalar_Range (Index_Subtype, Drange);
6555 Set_Etype (Index_Subtype, Index_Type);
6556 Set_Size_Info (Index_Subtype, Index_Type);
6557 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
6560 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
6562 Index := New_Occurrence_Of (Index_Subtype, Loc);
6563 Set_Etype (Index, Index_Subtype);
6564 Append (Index, Index_List);
6566 Set_First_Index (Slice_Subtype, Index);
6567 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
6568 Set_Is_Constrained (Slice_Subtype, True);
6569 Init_Size_Align (Slice_Subtype);
6571 Check_Compile_Time_Size (Slice_Subtype);
6573 -- The Etype of the existing Slice node is reset to this slice
6574 -- subtype. Its bounds are obtained from its first index.
6576 Set_Etype (N, Slice_Subtype);
6578 -- In the packed case, this must be immediately frozen
6580 -- Couldn't we always freeze here??? and if we did, then the above
6581 -- call to Check_Compile_Time_Size could be eliminated, which would
6582 -- be nice, because then that routine could be made private to Freeze.
6584 if Is_Packed (Slice_Subtype) and not In_Default_Expression then
6585 Freeze_Itype (Slice_Subtype, N);
6588 end Set_Slice_Subtype;
6590 --------------------------------
6591 -- Set_String_Literal_Subtype --
6592 --------------------------------
6594 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
6595 Subtype_Id : Entity_Id;
6598 if Nkind (N) /= N_String_Literal then
6601 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
6604 Set_String_Literal_Length (Subtype_Id, UI_From_Int
6605 (String_Length (Strval (N))));
6606 Set_Etype (Subtype_Id, Base_Type (Typ));
6607 Set_Is_Constrained (Subtype_Id);
6609 -- The low bound is set from the low bound of the corresponding
6610 -- index type. Note that we do not store the high bound in the
6611 -- string literal subtype, but it can be deduced if necssary
6612 -- from the length and the low bound.
6614 Set_String_Literal_Low_Bound
6615 (Subtype_Id, Type_Low_Bound (Etype (First_Index (Typ))));
6617 Set_Etype (N, Subtype_Id);
6618 end Set_String_Literal_Subtype;
6620 -----------------------------
6621 -- Unique_Fixed_Point_Type --
6622 -----------------------------
6624 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
6625 T1 : Entity_Id := Empty;
6630 procedure Fixed_Point_Error;
6631 -- If true ambiguity, give details.
6633 procedure Fixed_Point_Error is
6635 Error_Msg_N ("ambiguous universal_fixed_expression", N);
6636 Error_Msg_NE ("\possible interpretation as}", N, T1);
6637 Error_Msg_NE ("\possible interpretation as}", N, T2);
6638 end Fixed_Point_Error;
6641 -- The operations on Duration are visible, so Duration is always a
6642 -- possible interpretation.
6644 T1 := Standard_Duration;
6646 -- Look for fixed-point types in enclosing scopes.
6648 Scop := Current_Scope;
6649 while Scop /= Standard_Standard loop
6650 T2 := First_Entity (Scop);
6652 while Present (T2) loop
6653 if Is_Fixed_Point_Type (T2)
6654 and then Current_Entity (T2) = T2
6655 and then Scope (Base_Type (T2)) = Scop
6657 if Present (T1) then
6668 Scop := Scope (Scop);
6671 -- Look for visible fixed type declarations in the context.
6673 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
6675 while Present (Item) loop
6676 if Nkind (Item) = N_With_Clause then
6677 Scop := Entity (Name (Item));
6678 T2 := First_Entity (Scop);
6680 while Present (T2) loop
6681 if Is_Fixed_Point_Type (T2)
6682 and then Scope (Base_Type (T2)) = Scop
6683 and then (Is_Potentially_Use_Visible (T2)
6684 or else In_Use (T2))
6686 if Present (T1) then
6701 if Nkind (N) = N_Real_Literal then
6702 Error_Msg_NE ("real literal interpreted as }?", N, T1);
6705 Error_Msg_NE ("universal_fixed expression interpreted as }?", N, T1);
6709 end Unique_Fixed_Point_Type;
6711 ----------------------
6712 -- Valid_Conversion --
6713 ----------------------
6715 function Valid_Conversion
6721 Target_Type : constant Entity_Id := Base_Type (Target);
6722 Opnd_Type : Entity_Id := Etype (Operand);
6724 function Conversion_Check
6728 -- Little routine to post Msg if Valid is False, returns Valid value
6730 function Valid_Tagged_Conversion
6731 (Target_Type : Entity_Id;
6732 Opnd_Type : Entity_Id)
6734 -- Specifically test for validity of tagged conversions
6736 ----------------------
6737 -- Conversion_Check --
6738 ----------------------
6740 function Conversion_Check
6747 Error_Msg_N (Msg, Operand);
6751 end Conversion_Check;
6753 -----------------------------
6754 -- Valid_Tagged_Conversion --
6755 -----------------------------
6757 function Valid_Tagged_Conversion
6758 (Target_Type : Entity_Id;
6759 Opnd_Type : Entity_Id)
6763 -- Upward conversions are allowed (RM 4.6(22)).
6765 if Covers (Target_Type, Opnd_Type)
6766 or else Is_Ancestor (Target_Type, Opnd_Type)
6770 -- Downward conversion are allowed if the operand is
6771 -- is class-wide (RM 4.6(23)).
6773 elsif Is_Class_Wide_Type (Opnd_Type)
6774 and then Covers (Opnd_Type, Target_Type)
6778 elsif Covers (Opnd_Type, Target_Type)
6779 or else Is_Ancestor (Opnd_Type, Target_Type)
6782 Conversion_Check (False,
6783 "downward conversion of tagged objects not allowed");
6786 ("invalid tagged conversion, not compatible with}",
6787 N, First_Subtype (Opnd_Type));
6790 end Valid_Tagged_Conversion;
6792 -- Start of processing for Valid_Conversion
6795 Check_Parameterless_Call (Operand);
6797 if Is_Overloaded (Operand) then
6806 -- Remove procedure calls, which syntactically cannot appear
6807 -- in this context, but which cannot be removed by type checking,
6808 -- because the context does not impose a type.
6810 Get_First_Interp (Operand, I, It);
6812 while Present (It.Typ) loop
6814 if It.Typ = Standard_Void_Type then
6818 Get_Next_Interp (I, It);
6821 Get_First_Interp (Operand, I, It);
6826 Error_Msg_N ("illegal operand in conversion", Operand);
6830 Get_Next_Interp (I, It);
6832 if Present (It.Typ) then
6834 It1 := Disambiguate (Operand, I1, I, Any_Type);
6836 if It1 = No_Interp then
6837 Error_Msg_N ("ambiguous operand in conversion", Operand);
6839 Error_Msg_Sloc := Sloc (It.Nam);
6840 Error_Msg_N ("possible interpretation#!", Operand);
6842 Error_Msg_Sloc := Sloc (N1);
6843 Error_Msg_N ("possible interpretation#!", Operand);
6849 Set_Etype (Operand, It1.Typ);
6850 Opnd_Type := It1.Typ;
6854 if Chars (Current_Scope) = Name_Unchecked_Conversion then
6856 -- This check is dubious, what if there were a user defined
6857 -- scope whose name was Unchecked_Conversion ???
6861 elsif Is_Numeric_Type (Target_Type) then
6862 if Opnd_Type = Universal_Fixed then
6865 return Conversion_Check (Is_Numeric_Type (Opnd_Type),
6866 "illegal operand for numeric conversion");
6869 elsif Is_Array_Type (Target_Type) then
6870 if not Is_Array_Type (Opnd_Type)
6871 or else Opnd_Type = Any_Composite
6872 or else Opnd_Type = Any_String
6875 ("illegal operand for array conversion", Operand);
6878 elsif Number_Dimensions (Target_Type) /=
6879 Number_Dimensions (Opnd_Type)
6882 ("incompatible number of dimensions for conversion", Operand);
6887 Target_Index : Node_Id := First_Index (Target_Type);
6888 Opnd_Index : Node_Id := First_Index (Opnd_Type);
6890 Target_Index_Type : Entity_Id;
6891 Opnd_Index_Type : Entity_Id;
6893 Target_Comp_Type : constant Entity_Id :=
6894 Component_Type (Target_Type);
6895 Opnd_Comp_Type : constant Entity_Id :=
6896 Component_Type (Opnd_Type);
6899 while Present (Target_Index) and then Present (Opnd_Index) loop
6900 Target_Index_Type := Etype (Target_Index);
6901 Opnd_Index_Type := Etype (Opnd_Index);
6903 if not (Is_Integer_Type (Target_Index_Type)
6904 and then Is_Integer_Type (Opnd_Index_Type))
6905 and then (Root_Type (Target_Index_Type)
6906 /= Root_Type (Opnd_Index_Type))
6909 ("incompatible index types for array conversion",
6914 Next_Index (Target_Index);
6915 Next_Index (Opnd_Index);
6918 if Base_Type (Target_Comp_Type) /=
6919 Base_Type (Opnd_Comp_Type)
6922 ("incompatible component types for array conversion",
6927 Is_Constrained (Target_Comp_Type)
6928 /= Is_Constrained (Opnd_Comp_Type)
6929 or else not Subtypes_Statically_Match
6930 (Target_Comp_Type, Opnd_Comp_Type)
6933 ("component subtypes must statically match", Operand);
6942 elsif (Ekind (Target_Type) = E_General_Access_Type
6943 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
6946 (Is_Access_Type (Opnd_Type)
6947 and then Ekind (Opnd_Type) /=
6948 E_Access_Subprogram_Type
6949 and then Ekind (Opnd_Type) /=
6950 E_Access_Protected_Subprogram_Type,
6951 "must be an access-to-object type")
6953 if Is_Access_Constant (Opnd_Type)
6954 and then not Is_Access_Constant (Target_Type)
6957 ("access-to-constant operand type not allowed", Operand);
6961 -- Check the static accessibility rule of 4.6(17). Note that
6962 -- the check is not enforced when within an instance body, since
6963 -- the RM requires such cases to be caught at run time.
6965 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
6966 if Type_Access_Level (Opnd_Type)
6967 > Type_Access_Level (Target_Type)
6969 -- In an instance, this is a run-time check, but one we
6970 -- know will fail, so generate an appropriate warning.
6971 -- The raise will be generated by Expand_N_Type_Conversion.
6973 if In_Instance_Body then
6975 ("?cannot convert local pointer to non-local access type",
6978 ("?Program_Error will be raised at run time", Operand);
6982 ("cannot convert local pointer to non-local access type",
6987 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type then
6989 -- When the operand is a selected access discriminant
6990 -- the check needs to be made against the level of the
6991 -- object denoted by the prefix of the selected name.
6992 -- (Object_Access_Level handles checking the prefix
6993 -- of the operand for this case.)
6995 if Nkind (Operand) = N_Selected_Component
6996 and then Object_Access_Level (Operand)
6997 > Type_Access_Level (Target_Type)
6999 -- In an instance, this is a run-time check, but one we
7000 -- know will fail, so generate an appropriate warning.
7001 -- The raise will be generated by Expand_N_Type_Conversion.
7003 if In_Instance_Body then
7005 ("?cannot convert access discriminant to non-local" &
7006 " access type", Operand);
7008 ("?Program_Error will be raised at run time", Operand);
7012 ("cannot convert access discriminant to non-local" &
7013 " access type", Operand);
7018 -- The case of a reference to an access discriminant
7019 -- from within a type declaration (which will appear
7020 -- as a discriminal) is always illegal because the
7021 -- level of the discriminant is considered to be
7022 -- deeper than any (namable) access type.
7024 if Is_Entity_Name (Operand)
7025 and then (Ekind (Entity (Operand)) = E_In_Parameter
7026 or else Ekind (Entity (Operand)) = E_Constant)
7027 and then Present (Discriminal_Link (Entity (Operand)))
7030 ("discriminant has deeper accessibility level than target",
7038 Target : constant Entity_Id := Designated_Type (Target_Type);
7039 Opnd : constant Entity_Id := Designated_Type (Opnd_Type);
7042 if Is_Tagged_Type (Target) then
7043 return Valid_Tagged_Conversion (Target, Opnd);
7046 if Base_Type (Target) /= Base_Type (Opnd) then
7048 ("target designated type not compatible with }",
7049 N, Base_Type (Opnd));
7052 elsif not Subtypes_Statically_Match (Target, Opnd)
7053 and then (not Has_Discriminants (Target)
7054 or else Is_Constrained (Target))
7057 ("target designated subtype not compatible with }",
7067 elsif Ekind (Target_Type) = E_Access_Subprogram_Type
7068 and then Conversion_Check
7069 (Ekind (Base_Type (Opnd_Type)) = E_Access_Subprogram_Type,
7070 "illegal operand for access subprogram conversion")
7072 -- Check that the designated types are subtype conformant
7074 if not Subtype_Conformant (Designated_Type (Opnd_Type),
7075 Designated_Type (Target_Type))
7078 ("operand type is not subtype conformant with target type",
7082 -- Check the static accessibility rule of 4.6(20)
7084 if Type_Access_Level (Opnd_Type) >
7085 Type_Access_Level (Target_Type)
7088 ("operand type has deeper accessibility level than target",
7091 -- Check that if the operand type is declared in a generic body,
7092 -- then the target type must be declared within that same body
7093 -- (enforces last sentence of 4.6(20)).
7095 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
7097 O_Gen : constant Node_Id :=
7098 Enclosing_Generic_Body (Opnd_Type);
7101 Enclosing_Generic_Body (Target_Type);
7104 while Present (T_Gen) and then T_Gen /= O_Gen loop
7105 T_Gen := Enclosing_Generic_Body (T_Gen);
7108 if T_Gen /= O_Gen then
7110 ("target type must be declared in same generic body"
7111 & " as operand type", N);
7118 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
7119 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
7121 -- It is valid to convert from one RAS type to another provided
7122 -- that their specification statically match.
7124 Check_Subtype_Conformant
7126 Designated_Type (Corresponding_Remote_Type (Target_Type)),
7128 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
7133 elsif Is_Tagged_Type (Target_Type) then
7134 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
7136 -- Types derived from the same root type are convertible.
7138 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
7141 -- In an instance, there may be inconsistent views of the same
7142 -- type, or types derived from the same type.
7145 and then Underlying_Type (Target_Type) = Underlying_Type (Opnd_Type)
7149 -- Special check for common access type error case
7151 elsif Ekind (Target_Type) = E_Access_Type
7152 and then Is_Access_Type (Opnd_Type)
7154 Error_Msg_N ("target type must be general access type!", N);
7155 Error_Msg_NE ("add ALL to }!", N, Target_Type);
7160 Error_Msg_NE ("invalid conversion, not compatible with }",
7165 end Valid_Conversion;