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
166 Is_Binary
: Boolean) return Node_Kind
;
167 -- Utility to map the name of an operator into the corresponding Node. Used
168 -- by other node rewriting procedures.
170 procedure Resolve_Actuals
(N
: Node_Id
; Nam
: Entity_Id
);
171 -- Resolve actuals of call, and add default expressions for missing ones.
173 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
);
174 -- Called from Resolve_Call, when the prefix denotes an entry or element
175 -- of entry family. Actuals are resolved as for subprograms, and the node
176 -- is rebuilt as an entry call. Also called for protected operations. Typ
177 -- is the context type, which is used when the operation is a protected
178 -- function with no arguments, and the return value is indexed.
180 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
181 -- A call to a user-defined intrinsic operator is rewritten as a call
182 -- to the corresponding predefined operator, with suitable conversions.
184 procedure Resolve_Intrinsic_Unary_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
185 -- Ditto, for unary operators (only arithmetic ones).
187 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
);
188 -- If an operator node resolves to a call to a user-defined operator,
189 -- rewrite the node as a function call.
191 procedure Make_Call_Into_Operator
195 -- Inverse transformation: if an operator is given in functional notation,
196 -- then after resolving the node, transform into an operator node, so
197 -- that operands are resolved properly. Recall that predefined operators
198 -- do not have a full signature and special resolution rules apply.
200 procedure Rewrite_Renamed_Operator
204 -- An operator can rename another, e.g. in an instantiation. In that
205 -- case, the proper operator node must be constructed and resolved.
207 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
);
208 -- The String_Literal_Subtype is built for all strings that are not
209 -- operands of a static concatenation operation. If the argument is
210 -- not a N_String_Literal node, then the call has no effect.
212 procedure Set_Slice_Subtype
(N
: Node_Id
);
213 -- Build subtype of array type, with the range specified by the slice
215 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
;
216 -- A universal_fixed expression in an universal context is unambiguous
217 -- if there is only one applicable fixed point type. Determining whether
218 -- there is only one requires a search over all visible entities, and
219 -- happens only in very pathological cases (see 6115-006).
221 function Valid_Conversion
224 Operand
: Node_Id
) return Boolean;
225 -- Verify legality rules given in 4.6 (8-23). Target is the target
226 -- type of the conversion, which may be an implicit conversion of
227 -- an actual parameter to an anonymous access type (in which case
228 -- N denotes the actual parameter and N = Operand).
230 -------------------------
231 -- Ambiguous_Character --
232 -------------------------
234 procedure Ambiguous_Character
(C
: Node_Id
) is
238 if Nkind
(C
) = N_Character_Literal
then
239 Error_Msg_N
("ambiguous character literal", C
);
241 ("\possible interpretations: Character, Wide_Character!", C
);
243 E
:= Current_Entity
(C
);
247 while Present
(E
) loop
248 Error_Msg_NE
("\possible interpretation:}!", C
, Etype
(E
));
253 end Ambiguous_Character
;
255 -------------------------
256 -- Analyze_And_Resolve --
257 -------------------------
259 procedure Analyze_And_Resolve
(N
: Node_Id
) is
263 end Analyze_And_Resolve
;
265 procedure Analyze_And_Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
269 end Analyze_And_Resolve
;
271 -- Version withs check(s) suppressed
273 procedure Analyze_And_Resolve
278 Scop
: constant Entity_Id
:= Current_Scope
;
281 if Suppress
= All_Checks
then
283 Svg
: constant Suppress_Array
:= Scope_Suppress
;
286 Scope_Suppress
:= (others => True);
287 Analyze_And_Resolve
(N
, Typ
);
288 Scope_Suppress
:= Svg
;
293 Svg
: constant Boolean := Scope_Suppress
(Suppress
);
296 Scope_Suppress
(Suppress
) := True;
297 Analyze_And_Resolve
(N
, Typ
);
298 Scope_Suppress
(Suppress
) := Svg
;
302 if Current_Scope
/= Scop
303 and then Scope_Is_Transient
305 -- This can only happen if a transient scope was created
306 -- for an inner expression, which will be removed upon
307 -- completion of the analysis of an enclosing construct.
308 -- The transient scope must have the suppress status of
309 -- the enclosing environment, not of this Analyze call.
311 Scope_Stack
.Table
(Scope_Stack
.Last
).Save_Scope_Suppress
:=
314 end Analyze_And_Resolve
;
316 procedure Analyze_And_Resolve
320 Scop
: constant Entity_Id
:= Current_Scope
;
323 if Suppress
= All_Checks
then
325 Svg
: constant Suppress_Array
:= Scope_Suppress
;
328 Scope_Suppress
:= (others => True);
329 Analyze_And_Resolve
(N
);
330 Scope_Suppress
:= Svg
;
335 Svg
: constant Boolean := Scope_Suppress
(Suppress
);
338 Scope_Suppress
(Suppress
) := True;
339 Analyze_And_Resolve
(N
);
340 Scope_Suppress
(Suppress
) := Svg
;
344 if Current_Scope
/= Scop
345 and then Scope_Is_Transient
347 Scope_Stack
.Table
(Scope_Stack
.Last
).Save_Scope_Suppress
:=
350 end Analyze_And_Resolve
;
352 -----------------------------
353 -- Check_Direct_Boolean_Op --
354 -----------------------------
356 procedure Check_Direct_Boolean_Op
(N
: Node_Id
) is
358 if Root_Type
(Etype
(Left_Opnd
(N
))) = Standard_Boolean
then
359 Check_Restriction
(No_Direct_Boolean_Operators
, N
);
361 end Check_Direct_Boolean_Op
;
363 ----------------------------
364 -- Check_Discriminant_Use --
365 ----------------------------
367 procedure Check_Discriminant_Use
(N
: Node_Id
) is
368 PN
: constant Node_Id
:= Parent
(N
);
369 Disc
: constant Entity_Id
:= Entity
(N
);
374 -- Any use in a default expression is legal.
376 if In_Default_Expression
then
379 elsif Nkind
(PN
) = N_Range
then
381 -- Discriminant cannot be used to constrain a scalar type.
385 if Nkind
(P
) = N_Range_Constraint
386 and then Nkind
(Parent
(P
)) = N_Subtype_Indication
387 and then Nkind
(Parent
(Parent
(P
))) = N_Component_Definition
389 Error_Msg_N
("discriminant cannot constrain scalar type", N
);
391 elsif Nkind
(P
) = N_Index_Or_Discriminant_Constraint
then
393 -- The following check catches the unusual case where
394 -- a discriminant appears within an index constraint
395 -- that is part of a larger expression within a constraint
396 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
397 -- For now we only check case of record components, and
398 -- note that a similar check should also apply in the
399 -- case of discriminant constraints below. ???
401 -- Note that the check for N_Subtype_Declaration below is to
402 -- detect the valid use of discriminants in the constraints of a
403 -- subtype declaration when this subtype declaration appears
404 -- inside the scope of a record type (which is syntactically
405 -- illegal, but which may be created as part of derived type
406 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
409 if Ekind
(Current_Scope
) = E_Record_Type
410 and then Scope
(Disc
) = Current_Scope
412 (Nkind
(Parent
(P
)) = N_Subtype_Indication
414 (Nkind
(Parent
(Parent
(P
))) = N_Component_Definition
416 Nkind
(Parent
(Parent
(P
))) = N_Subtype_Declaration
)
417 and then Paren_Count
(N
) = 0)
420 ("discriminant must appear alone in component constraint", N
);
424 -- Detect a common beginner error:
426 -- type R (D : Positive := 100) is record
427 -- Name : String (1 .. D);
430 -- The default value causes an object of type R to be
431 -- allocated with room for Positive'Last characters.
439 function Large_Storage_Type
(T
: Entity_Id
) return Boolean;
440 -- Return True if type T has a large enough range that
441 -- any array whose index type covered the whole range of
442 -- the type would likely raise Storage_Error.
444 ------------------------
445 -- Large_Storage_Type --
446 ------------------------
448 function Large_Storage_Type
(T
: Entity_Id
) return Boolean is
453 T
= Standard_Positive
455 T
= Standard_Natural
;
456 end Large_Storage_Type
;
459 -- Check that the Disc has a large range
461 if not Large_Storage_Type
(Etype
(Disc
)) then
465 -- If the enclosing type is limited, we allocate only the
466 -- default value, not the maximum, and there is no need for
469 if Is_Limited_Type
(Scope
(Disc
)) then
473 -- Check that it is the high bound
475 if N
/= High_Bound
(PN
)
476 or else not Present
(Discriminant_Default_Value
(Disc
))
481 -- Check the array allows a large range at this bound.
482 -- First find the array
486 if Nkind
(SI
) /= N_Subtype_Indication
then
490 T
:= Entity
(Subtype_Mark
(SI
));
492 if not Is_Array_Type
(T
) then
496 -- Next, find the dimension
498 TB
:= First_Index
(T
);
499 CB
:= First
(Constraints
(P
));
501 and then Present
(TB
)
502 and then Present
(CB
)
513 -- Now, check the dimension has a large range
515 if not Large_Storage_Type
(Etype
(TB
)) then
519 -- Warn about the danger
522 ("creation of & object may raise Storage_Error?",
531 -- Legal case is in index or discriminant constraint
533 elsif Nkind
(PN
) = N_Index_Or_Discriminant_Constraint
534 or else Nkind
(PN
) = N_Discriminant_Association
536 if Paren_Count
(N
) > 0 then
538 ("discriminant in constraint must appear alone", N
);
543 -- Otherwise, context is an expression. It should not be within
544 -- (i.e. a subexpression of) a constraint for a component.
550 while Nkind
(P
) /= N_Component_Declaration
551 and then Nkind
(P
) /= N_Subtype_Indication
552 and then Nkind
(P
) /= N_Entry_Declaration
559 -- If the discriminant is used in an expression that is a bound
560 -- of a scalar type, an Itype is created and the bounds are attached
561 -- to its range, not to the original subtype indication. Such use
562 -- is of course a double fault.
564 if (Nkind
(P
) = N_Subtype_Indication
566 (Nkind
(Parent
(P
)) = N_Component_Definition
568 Nkind
(Parent
(P
)) = N_Derived_Type_Definition
)
569 and then D
= Constraint
(P
))
571 -- The constraint itself may be given by a subtype indication,
572 -- rather than by a more common discrete range.
574 or else (Nkind
(P
) = N_Subtype_Indication
576 Nkind
(Parent
(P
)) = N_Index_Or_Discriminant_Constraint
)
577 or else Nkind
(P
) = N_Entry_Declaration
578 or else Nkind
(D
) = N_Defining_Identifier
581 ("discriminant in constraint must appear alone", N
);
584 end Check_Discriminant_Use
;
586 --------------------------------
587 -- Check_For_Visible_Operator --
588 --------------------------------
590 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
) is
592 if Is_Invisible_Operator
(N
, T
) then
594 ("operator for} is not directly visible!", N
, First_Subtype
(T
));
595 Error_Msg_N
("use clause would make operation legal!", N
);
597 end Check_For_Visible_Operator
;
599 ------------------------------
600 -- Check_Infinite_Recursion --
601 ------------------------------
603 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean is
607 function Same_Argument_List
return Boolean;
608 -- Check whether list of actuals is identical to list of formals
609 -- of called function (which is also the enclosing scope).
611 ------------------------
612 -- Same_Argument_List --
613 ------------------------
615 function Same_Argument_List
return Boolean is
621 if not Is_Entity_Name
(Name
(N
)) then
624 Subp
:= Entity
(Name
(N
));
627 F
:= First_Formal
(Subp
);
628 A
:= First_Actual
(N
);
630 while Present
(F
) and then Present
(A
) loop
631 if not Is_Entity_Name
(A
)
632 or else Entity
(A
) /= F
642 end Same_Argument_List
;
644 -- Start of processing for Check_Infinite_Recursion
647 -- Loop moving up tree, quitting if something tells us we are
648 -- definitely not in an infinite recursion situation.
653 exit when Nkind
(P
) = N_Subprogram_Body
;
655 if Nkind
(P
) = N_Or_Else
or else
656 Nkind
(P
) = N_And_Then
or else
657 Nkind
(P
) = N_If_Statement
or else
658 Nkind
(P
) = N_Case_Statement
662 elsif Nkind
(P
) = N_Handled_Sequence_Of_Statements
663 and then C
/= First
(Statements
(P
))
665 -- If the call is the expression of a return statement and
666 -- the actuals are identical to the formals, it's worth a
667 -- warning. However, we skip this if there is an immediately
668 -- preceding raise statement, since the call is never executed.
670 -- Furthermore, this corresponds to a common idiom:
672 -- function F (L : Thing) return Boolean is
674 -- raise Program_Error;
678 -- for generating a stub function
680 if Nkind
(Parent
(N
)) = N_Return_Statement
681 and then Same_Argument_List
683 exit when not Is_List_Member
(Parent
(N
))
684 or else (Nkind
(Prev
(Parent
(N
))) /= N_Raise_Statement
686 (Nkind
(Prev
(Parent
(N
))) not in N_Raise_xxx_Error
688 Present
(Condition
(Prev
(Parent
(N
))))));
698 Error_Msg_N
("possible infinite recursion?", N
);
699 Error_Msg_N
("\Storage_Error may be raised at run time?", N
);
702 end Check_Infinite_Recursion
;
704 -------------------------------
705 -- Check_Initialization_Call --
706 -------------------------------
708 procedure Check_Initialization_Call
(N
: Entity_Id
; Nam
: Entity_Id
) is
709 Typ
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
711 function Uses_SS
(T
: Entity_Id
) return Boolean;
712 -- Check whether the creation of an object of the type will involve
713 -- use of the secondary stack. If T is a record type, this is true
714 -- if the expression for some component uses the secondary stack, eg.
715 -- through a call to a function that returns an unconstrained value.
716 -- False if T is controlled, because cleanups occur elsewhere.
722 function Uses_SS
(T
: Entity_Id
) return Boolean is
727 if Is_Controlled
(T
) then
730 elsif Is_Array_Type
(T
) then
731 return Uses_SS
(Component_Type
(T
));
733 elsif Is_Record_Type
(T
) then
734 Comp
:= First_Component
(T
);
736 while Present
(Comp
) loop
738 if Ekind
(Comp
) = E_Component
739 and then Nkind
(Parent
(Comp
)) = N_Component_Declaration
741 Expr
:= Expression
(Parent
(Comp
));
743 -- The expression for a dynamic component may be
744 -- rewritten as a dereference. Retrieve original
747 if Nkind
(Original_Node
(Expr
)) = N_Function_Call
748 and then Requires_Transient_Scope
(Etype
(Expr
))
752 elsif Uses_SS
(Etype
(Comp
)) then
757 Next_Component
(Comp
);
767 -- Start of processing for Check_Initialization_Call
770 -- Nothing to do if functions do not use the secondary stack for
771 -- returns (i.e. they use a depressed stack pointer instead).
773 if Functions_Return_By_DSP_On_Target
then
776 -- Otherwise establish a transient scope if the type needs it
778 elsif Uses_SS
(Typ
) then
779 Establish_Transient_Scope
(First_Actual
(N
), Sec_Stack
=> True);
781 end Check_Initialization_Call
;
783 ------------------------------
784 -- Check_Parameterless_Call --
785 ------------------------------
787 procedure Check_Parameterless_Call
(N
: Node_Id
) is
791 -- Defend against junk stuff if errors already detected
793 if Total_Errors_Detected
/= 0 then
794 if Nkind
(N
) in N_Has_Etype
and then Etype
(N
) = Any_Type
then
796 elsif Nkind
(N
) in N_Has_Chars
797 and then Chars
(N
) in Error_Name_Or_No_Name
805 -- If the context expects a value, and the name is a procedure,
806 -- this is most likely a missing 'Access. Do not try to resolve
807 -- the parameterless call, error will be caught when the outer
810 if Is_Entity_Name
(N
)
811 and then Ekind
(Entity
(N
)) = E_Procedure
812 and then not Is_Overloaded
(N
)
814 (Nkind
(Parent
(N
)) = N_Parameter_Association
815 or else Nkind
(Parent
(N
)) = N_Function_Call
816 or else Nkind
(Parent
(N
)) = N_Procedure_Call_Statement
)
821 -- Rewrite as call if overloadable entity that is (or could be, in
822 -- the overloaded case) a function call. If we know for sure that
823 -- the entity is an enumeration literal, we do not rewrite it.
825 if (Is_Entity_Name
(N
)
826 and then Is_Overloadable
(Entity
(N
))
827 and then (Ekind
(Entity
(N
)) /= E_Enumeration_Literal
828 or else Is_Overloaded
(N
)))
830 -- Rewrite as call if it is an explicit deference of an expression of
831 -- a subprogram access type, and the suprogram type is not that of a
832 -- procedure or entry.
835 (Nkind
(N
) = N_Explicit_Dereference
836 and then Ekind
(Etype
(N
)) = E_Subprogram_Type
837 and then Base_Type
(Etype
(Etype
(N
))) /= Standard_Void_Type
)
839 -- Rewrite as call if it is a selected component which is a function,
840 -- this is the case of a call to a protected function (which may be
841 -- overloaded with other protected operations).
844 (Nkind
(N
) = N_Selected_Component
845 and then (Ekind
(Entity
(Selector_Name
(N
))) = E_Function
847 ((Ekind
(Entity
(Selector_Name
(N
))) = E_Entry
849 Ekind
(Entity
(Selector_Name
(N
))) = E_Procedure
)
850 and then Is_Overloaded
(Selector_Name
(N
)))))
852 -- If one of the above three conditions is met, rewrite as call.
853 -- Apply the rewriting only once.
856 if Nkind
(Parent
(N
)) /= N_Function_Call
857 or else N
/= Name
(Parent
(N
))
861 -- If overloaded, overload set belongs to new copy.
863 Save_Interps
(N
, Nam
);
865 -- Change node to parameterless function call (note that the
866 -- Parameter_Associations associations field is left set to Empty,
867 -- its normal default value since there are no parameters)
869 Change_Node
(N
, N_Function_Call
);
871 Set_Sloc
(N
, Sloc
(Nam
));
875 elsif Nkind
(N
) = N_Parameter_Association
then
876 Check_Parameterless_Call
(Explicit_Actual_Parameter
(N
));
878 end Check_Parameterless_Call
;
880 ----------------------
881 -- Is_Predefined_Op --
882 ----------------------
884 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean is
886 return Is_Intrinsic_Subprogram
(Nam
)
887 and then not Is_Generic_Instance
(Nam
)
888 and then Chars
(Nam
) in Any_Operator_Name
889 and then (No
(Alias
(Nam
))
890 or else Is_Predefined_Op
(Alias
(Nam
)));
891 end Is_Predefined_Op
;
893 -----------------------------
894 -- Make_Call_Into_Operator --
895 -----------------------------
897 procedure Make_Call_Into_Operator
902 Op_Name
: constant Name_Id
:= Chars
(Op_Id
);
903 Act1
: Node_Id
:= First_Actual
(N
);
904 Act2
: Node_Id
:= Next_Actual
(Act1
);
905 Error
: Boolean := False;
906 Func
: constant Entity_Id
:= Entity
(Name
(N
));
907 Is_Binary
: constant Boolean := Present
(Act2
);
909 Opnd_Type
: Entity_Id
;
910 Orig_Type
: Entity_Id
:= Empty
;
913 type Kind_Test
is access function (E
: Entity_Id
) return Boolean;
915 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean;
916 -- Determine whether E is an access type declared by an access decla-
917 -- ration, and not an (anonymous) allocator type.
919 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean;
920 -- If the operand is not universal, and the operator is given by a
921 -- expanded name, verify that the operand has an interpretation with
922 -- a type defined in the given scope of the operator.
924 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
;
925 -- Find a type of the given class in the package Pack that contains
928 -----------------------------
929 -- Is_Definite_Access_Type --
930 -----------------------------
932 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean is
933 Btyp
: constant Entity_Id
:= Base_Type
(E
);
935 return Ekind
(Btyp
) = E_Access_Type
936 or else (Ekind
(Btyp
) = E_Access_Subprogram_Type
937 and then Comes_From_Source
(Btyp
));
938 end Is_Definite_Access_Type
;
940 ---------------------------
941 -- Operand_Type_In_Scope --
942 ---------------------------
944 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean is
945 Nod
: constant Node_Id
:= Right_Opnd
(Op_Node
);
950 if not Is_Overloaded
(Nod
) then
951 return Scope
(Base_Type
(Etype
(Nod
))) = S
;
954 Get_First_Interp
(Nod
, I
, It
);
956 while Present
(It
.Typ
) loop
958 if Scope
(Base_Type
(It
.Typ
)) = S
then
962 Get_Next_Interp
(I
, It
);
967 end Operand_Type_In_Scope
;
973 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
is
976 function In_Decl
return Boolean;
977 -- Verify that node is not part of the type declaration for the
978 -- candidate type, which would otherwise be invisible.
984 function In_Decl
return Boolean is
985 Decl_Node
: constant Node_Id
:= Parent
(E
);
991 if Etype
(E
) = Any_Type
then
994 elsif No
(Decl_Node
) then
999 and then Nkind
(N2
) /= N_Compilation_Unit
1001 if N2
= Decl_Node
then
1012 -- Start of processing for Type_In_P
1015 -- If the context type is declared in the prefix package, this
1016 -- is the desired base type.
1018 if Scope
(Base_Type
(Typ
)) = Pack
1021 return Base_Type
(Typ
);
1024 E
:= First_Entity
(Pack
);
1026 while Present
(E
) loop
1029 and then not In_Decl
1041 -- Start of processing for Make_Call_Into_Operator
1044 Op_Node
:= New_Node
(Operator_Kind
(Op_Name
, Is_Binary
), Sloc
(N
));
1049 Set_Left_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1050 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act2
));
1051 Save_Interps
(Act1
, Left_Opnd
(Op_Node
));
1052 Save_Interps
(Act2
, Right_Opnd
(Op_Node
));
1053 Act1
:= Left_Opnd
(Op_Node
);
1054 Act2
:= Right_Opnd
(Op_Node
);
1059 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1060 Save_Interps
(Act1
, Right_Opnd
(Op_Node
));
1061 Act1
:= Right_Opnd
(Op_Node
);
1064 -- If the operator is denoted by an expanded name, and the prefix is
1065 -- not Standard, but the operator is a predefined one whose scope is
1066 -- Standard, then this is an implicit_operator, inserted as an
1067 -- interpretation by the procedure of the same name. This procedure
1068 -- overestimates the presence of implicit operators, because it does
1069 -- not examine the type of the operands. Verify now that the operand
1070 -- type appears in the given scope. If right operand is universal,
1071 -- check the other operand. In the case of concatenation, either
1072 -- argument can be the component type, so check the type of the result.
1073 -- If both arguments are literals, look for a type of the right kind
1074 -- defined in the given scope. This elaborate nonsense is brought to
1075 -- you courtesy of b33302a. The type itself must be frozen, so we must
1076 -- find the type of the proper class in the given scope.
1078 -- A final wrinkle is the multiplication operator for fixed point
1079 -- types, which is defined in Standard only, and not in the scope of
1080 -- the fixed_point type itself.
1082 if Nkind
(Name
(N
)) = N_Expanded_Name
then
1083 Pack
:= Entity
(Prefix
(Name
(N
)));
1085 -- If the entity being called is defined in the given package,
1086 -- it is a renaming of a predefined operator, and known to be
1089 if Scope
(Entity
(Name
(N
))) = Pack
1090 and then Pack
/= Standard_Standard
1094 elsif (Op_Name
= Name_Op_Multiply
1095 or else Op_Name
= Name_Op_Divide
)
1096 and then Is_Fixed_Point_Type
(Etype
(Left_Opnd
(Op_Node
)))
1097 and then Is_Fixed_Point_Type
(Etype
(Right_Opnd
(Op_Node
)))
1099 if Pack
/= Standard_Standard
then
1104 Opnd_Type
:= Base_Type
(Etype
(Right_Opnd
(Op_Node
)));
1106 if Op_Name
= Name_Op_Concat
then
1107 Opnd_Type
:= Base_Type
(Typ
);
1109 elsif (Scope
(Opnd_Type
) = Standard_Standard
1111 or else (Nkind
(Right_Opnd
(Op_Node
)) = N_Attribute_Reference
1113 and then not Comes_From_Source
(Opnd_Type
))
1115 Opnd_Type
:= Base_Type
(Etype
(Left_Opnd
(Op_Node
)));
1118 if Scope
(Opnd_Type
) = Standard_Standard
then
1120 -- Verify that the scope contains a type that corresponds to
1121 -- the given literal. Optimize the case where Pack is Standard.
1123 if Pack
/= Standard_Standard
then
1125 if Opnd_Type
= Universal_Integer
then
1126 Orig_Type
:= Type_In_P
(Is_Integer_Type
'Access);
1128 elsif Opnd_Type
= Universal_Real
then
1129 Orig_Type
:= Type_In_P
(Is_Real_Type
'Access);
1131 elsif Opnd_Type
= Any_String
then
1132 Orig_Type
:= Type_In_P
(Is_String_Type
'Access);
1134 elsif Opnd_Type
= Any_Access
then
1135 Orig_Type
:= Type_In_P
(Is_Definite_Access_Type
'Access);
1137 elsif Opnd_Type
= Any_Composite
then
1138 Orig_Type
:= Type_In_P
(Is_Composite_Type
'Access);
1140 if Present
(Orig_Type
) then
1141 if Has_Private_Component
(Orig_Type
) then
1144 Set_Etype
(Act1
, Orig_Type
);
1147 Set_Etype
(Act2
, Orig_Type
);
1156 Error
:= No
(Orig_Type
);
1159 elsif Ekind
(Opnd_Type
) = E_Allocator_Type
1160 and then No
(Type_In_P
(Is_Definite_Access_Type
'Access))
1164 -- If the type is defined elsewhere, and the operator is not
1165 -- defined in the given scope (by a renaming declaration, e.g.)
1166 -- then this is an error as well. If an extension of System is
1167 -- present, and the type may be defined there, Pack must be
1170 elsif Scope
(Opnd_Type
) /= Pack
1171 and then Scope
(Op_Id
) /= Pack
1172 and then (No
(System_Aux_Id
)
1173 or else Scope
(Opnd_Type
) /= System_Aux_Id
1174 or else Pack
/= Scope
(System_Aux_Id
))
1176 if not Is_Overloaded
(Right_Opnd
(Op_Node
)) then
1179 Error
:= not Operand_Type_In_Scope
(Pack
);
1182 elsif Pack
= Standard_Standard
1183 and then not Operand_Type_In_Scope
(Standard_Standard
)
1190 Error_Msg_Node_2
:= Pack
;
1192 ("& not declared in&", N
, Selector_Name
(Name
(N
)));
1193 Set_Etype
(N
, Any_Type
);
1198 Set_Chars
(Op_Node
, Op_Name
);
1200 if not Is_Private_Type
(Etype
(N
)) then
1201 Set_Etype
(Op_Node
, Base_Type
(Etype
(N
)));
1203 Set_Etype
(Op_Node
, Etype
(N
));
1206 -- If this is a call to a function that renames a predefined equality,
1207 -- the renaming declaration provides a type that must be used to
1208 -- resolve the operands. This must be done now because resolution of
1209 -- the equality node will not resolve any remaining ambiguity, and it
1210 -- assumes that the first operand is not overloaded.
1212 if (Op_Name
= Name_Op_Eq
or else Op_Name
= Name_Op_Ne
)
1213 and then Ekind
(Func
) = E_Function
1214 and then Is_Overloaded
(Act1
)
1216 Resolve
(Act1
, Base_Type
(Etype
(First_Formal
(Func
))));
1217 Resolve
(Act2
, Base_Type
(Etype
(First_Formal
(Func
))));
1220 Set_Entity
(Op_Node
, Op_Id
);
1221 Generate_Reference
(Op_Id
, N
, ' ');
1222 Rewrite
(N
, Op_Node
);
1224 -- If this is an arithmetic operator and the result type is private,
1225 -- the operands and the result must be wrapped in conversion to
1226 -- expose the underlying numeric type and expand the proper checks,
1227 -- e.g. on division.
1229 if Is_Private_Type
(Typ
) then
1231 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1232 N_Op_Expon | N_Op_Mod | N_Op_Rem
=>
1233 Resolve_Intrinsic_Operator
(N
, Typ
);
1235 when N_Op_Plus | N_Op_Minus | N_Op_Abs
=>
1236 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
1245 -- For predefined operators on literals, the operation freezes
1248 if Present
(Orig_Type
) then
1249 Set_Etype
(Act1
, Orig_Type
);
1250 Freeze_Expression
(Act1
);
1252 end Make_Call_Into_Operator
;
1258 function Operator_Kind
1260 Is_Binary
: Boolean) return Node_Kind
1266 if Op_Name
= Name_Op_And
then Kind
:= N_Op_And
;
1267 elsif Op_Name
= Name_Op_Or
then Kind
:= N_Op_Or
;
1268 elsif Op_Name
= Name_Op_Xor
then Kind
:= N_Op_Xor
;
1269 elsif Op_Name
= Name_Op_Eq
then Kind
:= N_Op_Eq
;
1270 elsif Op_Name
= Name_Op_Ne
then Kind
:= N_Op_Ne
;
1271 elsif Op_Name
= Name_Op_Lt
then Kind
:= N_Op_Lt
;
1272 elsif Op_Name
= Name_Op_Le
then Kind
:= N_Op_Le
;
1273 elsif Op_Name
= Name_Op_Gt
then Kind
:= N_Op_Gt
;
1274 elsif Op_Name
= Name_Op_Ge
then Kind
:= N_Op_Ge
;
1275 elsif Op_Name
= Name_Op_Add
then Kind
:= N_Op_Add
;
1276 elsif Op_Name
= Name_Op_Subtract
then Kind
:= N_Op_Subtract
;
1277 elsif Op_Name
= Name_Op_Concat
then Kind
:= N_Op_Concat
;
1278 elsif Op_Name
= Name_Op_Multiply
then Kind
:= N_Op_Multiply
;
1279 elsif Op_Name
= Name_Op_Divide
then Kind
:= N_Op_Divide
;
1280 elsif Op_Name
= Name_Op_Mod
then Kind
:= N_Op_Mod
;
1281 elsif Op_Name
= Name_Op_Rem
then Kind
:= N_Op_Rem
;
1282 elsif Op_Name
= Name_Op_Expon
then Kind
:= N_Op_Expon
;
1284 raise Program_Error
;
1290 if Op_Name
= Name_Op_Add
then Kind
:= N_Op_Plus
;
1291 elsif Op_Name
= Name_Op_Subtract
then Kind
:= N_Op_Minus
;
1292 elsif Op_Name
= Name_Op_Abs
then Kind
:= N_Op_Abs
;
1293 elsif Op_Name
= Name_Op_Not
then Kind
:= N_Op_Not
;
1295 raise Program_Error
;
1302 -----------------------------
1303 -- Pre_Analyze_And_Resolve --
1304 -----------------------------
1306 procedure Pre_Analyze_And_Resolve
(N
: Node_Id
; T
: Entity_Id
) is
1307 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1310 Full_Analysis
:= False;
1311 Expander_Mode_Save_And_Set
(False);
1313 -- We suppress all checks for this analysis, since the checks will
1314 -- be applied properly, and in the right location, when the default
1315 -- expression is reanalyzed and reexpanded later on.
1317 Analyze_And_Resolve
(N
, T
, Suppress
=> All_Checks
);
1319 Expander_Mode_Restore
;
1320 Full_Analysis
:= Save_Full_Analysis
;
1321 end Pre_Analyze_And_Resolve
;
1323 -- Version without context type.
1325 procedure Pre_Analyze_And_Resolve
(N
: Node_Id
) is
1326 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1329 Full_Analysis
:= False;
1330 Expander_Mode_Save_And_Set
(False);
1333 Resolve
(N
, Etype
(N
), Suppress
=> All_Checks
);
1335 Expander_Mode_Restore
;
1336 Full_Analysis
:= Save_Full_Analysis
;
1337 end Pre_Analyze_And_Resolve
;
1339 ----------------------------------
1340 -- Replace_Actual_Discriminants --
1341 ----------------------------------
1343 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
) is
1344 Loc
: constant Source_Ptr
:= Sloc
(N
);
1345 Tsk
: Node_Id
:= Empty
;
1347 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
;
1353 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
is
1357 if Nkind
(Nod
) = N_Identifier
then
1358 Ent
:= Entity
(Nod
);
1361 and then Ekind
(Ent
) = E_Discriminant
1364 Make_Selected_Component
(Loc
,
1365 Prefix
=> New_Copy_Tree
(Tsk
, New_Sloc
=> Loc
),
1366 Selector_Name
=> Make_Identifier
(Loc
, Chars
(Ent
))));
1368 Set_Etype
(Nod
, Etype
(Ent
));
1376 procedure Replace_Discrs
is new Traverse_Proc
(Process_Discr
);
1378 -- Start of processing for Replace_Actual_Discriminants
1381 if not Expander_Active
then
1385 if Nkind
(Name
(N
)) = N_Selected_Component
then
1386 Tsk
:= Prefix
(Name
(N
));
1388 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
1389 Tsk
:= Prefix
(Prefix
(Name
(N
)));
1395 Replace_Discrs
(Default
);
1397 end Replace_Actual_Discriminants
;
1403 procedure Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
1405 I1
: Interp_Index
:= 0; -- prevent junk warning
1408 Found
: Boolean := False;
1409 Seen
: Entity_Id
:= Empty
; -- prevent junk warning
1410 Ctx_Type
: Entity_Id
:= Typ
;
1411 Expr_Type
: Entity_Id
:= Empty
; -- prevent junk warning
1412 Err_Type
: Entity_Id
:= Empty
;
1413 Ambiguous
: Boolean := False;
1415 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
);
1416 -- Try and fix up a literal so that it matches its expected type. New
1417 -- literals are manufactured if necessary to avoid cascaded errors.
1419 procedure Resolution_Failed
;
1420 -- Called when attempt at resolving current expression fails
1422 --------------------
1423 -- Patch_Up_Value --
1424 --------------------
1426 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
) is
1428 if Nkind
(N
) = N_Integer_Literal
1429 and then Is_Real_Type
(Typ
)
1432 Make_Real_Literal
(Sloc
(N
),
1433 Realval
=> UR_From_Uint
(Intval
(N
))));
1434 Set_Etype
(N
, Universal_Real
);
1435 Set_Is_Static_Expression
(N
);
1437 elsif Nkind
(N
) = N_Real_Literal
1438 and then Is_Integer_Type
(Typ
)
1441 Make_Integer_Literal
(Sloc
(N
),
1442 Intval
=> UR_To_Uint
(Realval
(N
))));
1443 Set_Etype
(N
, Universal_Integer
);
1444 Set_Is_Static_Expression
(N
);
1445 elsif Nkind
(N
) = N_String_Literal
1446 and then Is_Character_Type
(Typ
)
1448 Set_Character_Literal_Name
(Char_Code
(Character'Pos ('A')));
1450 Make_Character_Literal
(Sloc
(N
),
1452 Char_Literal_Value
=> Char_Code
(Character'Pos ('A'))));
1453 Set_Etype
(N
, Any_Character
);
1454 Set_Is_Static_Expression
(N
);
1456 elsif Nkind
(N
) /= N_String_Literal
1457 and then Is_String_Type
(Typ
)
1460 Make_String_Literal
(Sloc
(N
),
1461 Strval
=> End_String
));
1463 elsif Nkind
(N
) = N_Range
then
1464 Patch_Up_Value
(Low_Bound
(N
), Typ
);
1465 Patch_Up_Value
(High_Bound
(N
), Typ
);
1469 -----------------------
1470 -- Resolution_Failed --
1471 -----------------------
1473 procedure Resolution_Failed
is
1475 Patch_Up_Value
(N
, Typ
);
1477 Debug_A_Exit
("resolving ", N
, " (done, resolution failed)");
1478 Set_Is_Overloaded
(N
, False);
1480 -- The caller will return without calling the expander, so we need
1481 -- to set the analyzed flag. Note that it is fine to set Analyzed
1482 -- to True even if we are in the middle of a shallow analysis,
1483 -- (see the spec of sem for more details) since this is an error
1484 -- situation anyway, and there is no point in repeating the
1485 -- analysis later (indeed it won't work to repeat it later, since
1486 -- we haven't got a clear resolution of which entity is being
1489 Set_Analyzed
(N
, True);
1491 end Resolution_Failed
;
1493 -- Start of processing for Resolve
1500 -- Access attribute on remote subprogram cannot be used for
1501 -- a non-remote access-to-subprogram type.
1503 if Nkind
(N
) = N_Attribute_Reference
1504 and then (Attribute_Name
(N
) = Name_Access
1505 or else Attribute_Name
(N
) = Name_Unrestricted_Access
1506 or else Attribute_Name
(N
) = Name_Unchecked_Access
)
1507 and then Comes_From_Source
(N
)
1508 and then Is_Entity_Name
(Prefix
(N
))
1509 and then Is_Subprogram
(Entity
(Prefix
(N
)))
1510 and then Is_Remote_Call_Interface
(Entity
(Prefix
(N
)))
1511 and then not Is_Remote_Access_To_Subprogram_Type
(Typ
)
1514 ("prefix must statically denote a non-remote subprogram", N
);
1517 -- If the context is a Remote_Access_To_Subprogram, access attributes
1518 -- must be resolved with the corresponding fat pointer. There is no need
1519 -- to check for the attribute name since the return type of an
1520 -- attribute is never a remote type.
1522 if Nkind
(N
) = N_Attribute_Reference
1523 and then Comes_From_Source
(N
)
1524 and then (Is_Remote_Call_Interface
(Typ
)
1525 or else Is_Remote_Types
(Typ
))
1528 Attr
: constant Attribute_Id
:=
1529 Get_Attribute_Id
(Attribute_Name
(N
));
1530 Pref
: constant Node_Id
:= Prefix
(N
);
1533 Is_Remote
: Boolean := True;
1536 -- Check that Typ is a fat pointer with a reference to a RAS as
1537 -- original access type.
1540 (Ekind
(Typ
) = E_Access_Subprogram_Type
1541 and then Present
(Equivalent_Type
(Typ
)))
1543 (Ekind
(Typ
) = E_Record_Type
1544 and then Present
(Corresponding_Remote_Type
(Typ
)))
1547 -- Prefix (N) must statically denote a remote subprogram
1548 -- declared in a package specification.
1550 if Attr
= Attribute_Access
then
1551 Decl
:= Unit_Declaration_Node
(Entity
(Pref
));
1553 if Nkind
(Decl
) = N_Subprogram_Body
then
1554 Spec
:= Corresponding_Spec
(Decl
);
1556 if not No
(Spec
) then
1557 Decl
:= Unit_Declaration_Node
(Spec
);
1561 Spec
:= Parent
(Decl
);
1563 if not Is_Entity_Name
(Prefix
(N
))
1564 or else Nkind
(Spec
) /= N_Package_Specification
1566 not Is_Remote_Call_Interface
(Defining_Entity
(Spec
))
1570 ("prefix must statically denote a remote subprogram ",
1575 -- If we are generating code for a distributed program.
1576 -- perform semantic checks against the corresponding
1579 if (Attr
= Attribute_Access
1580 or else Attr
= Attribute_Unchecked_Access
1581 or else Attr
= Attribute_Unrestricted_Access
)
1582 and then Expander_Active
1584 Check_Subtype_Conformant
1585 (New_Id
=> Entity
(Prefix
(N
)),
1586 Old_Id
=> Designated_Type
1587 (Corresponding_Remote_Type
(Typ
)),
1590 Process_Remote_AST_Attribute
(N
, Typ
);
1597 Debug_A_Entry
("resolving ", N
);
1599 if Comes_From_Source
(N
) then
1600 if Is_Fixed_Point_Type
(Typ
) then
1601 Check_Restriction
(No_Fixed_Point
, N
);
1603 elsif Is_Floating_Point_Type
(Typ
)
1604 and then Typ
/= Universal_Real
1605 and then Typ
/= Any_Real
1607 Check_Restriction
(No_Floating_Point
, N
);
1611 -- Return if already analyzed
1613 if Analyzed
(N
) then
1614 Debug_A_Exit
("resolving ", N
, " (done, already analyzed)");
1617 -- Return if type = Any_Type (previous error encountered)
1619 elsif Etype
(N
) = Any_Type
then
1620 Debug_A_Exit
("resolving ", N
, " (done, Etype = Any_Type)");
1624 Check_Parameterless_Call
(N
);
1626 -- If not overloaded, then we know the type, and all that needs doing
1627 -- is to check that this type is compatible with the context.
1629 if not Is_Overloaded
(N
) then
1630 Found
:= Covers
(Typ
, Etype
(N
));
1631 Expr_Type
:= Etype
(N
);
1633 -- In the overloaded case, we must select the interpretation that
1634 -- is compatible with the context (i.e. the type passed to Resolve)
1637 Get_First_Interp
(N
, I
, It
);
1639 -- Loop through possible interpretations
1641 Interp_Loop
: while Present
(It
.Typ
) loop
1643 -- We are only interested in interpretations that are compatible
1644 -- with the expected type, any other interpretations are ignored
1646 if not Covers
(Typ
, It
.Typ
) then
1647 if Debug_Flag_V
then
1648 Write_Str
(" interpretation incompatible with context");
1653 -- First matching interpretation
1659 Expr_Type
:= It
.Typ
;
1661 -- Matching interpretation that is not the first, maybe an
1662 -- error, but there are some cases where preference rules are
1663 -- used to choose between the two possibilities. These and
1664 -- some more obscure cases are handled in Disambiguate.
1667 Error_Msg_Sloc
:= Sloc
(Seen
);
1668 It1
:= Disambiguate
(N
, I1
, I
, Typ
);
1670 -- Disambiguation has succeeded. Skip the remaining
1673 if It1
/= No_Interp
then
1675 Expr_Type
:= It1
.Typ
;
1677 while Present
(It
.Typ
) loop
1678 Get_Next_Interp
(I
, It
);
1682 -- Before we issue an ambiguity complaint, check for
1683 -- the case of a subprogram call where at least one
1684 -- of the arguments is Any_Type, and if so, suppress
1685 -- the message, since it is a cascaded error.
1687 if Nkind
(N
) = N_Function_Call
1688 or else Nkind
(N
) = N_Procedure_Call_Statement
1691 A
: Node_Id
:= First_Actual
(N
);
1695 while Present
(A
) loop
1698 if Nkind
(E
) = N_Parameter_Association
then
1699 E
:= Explicit_Actual_Parameter
(E
);
1702 if Etype
(E
) = Any_Type
then
1703 if Debug_Flag_V
then
1704 Write_Str
("Any_Type in call");
1715 elsif Nkind
(N
) in N_Binary_Op
1716 and then (Etype
(Left_Opnd
(N
)) = Any_Type
1717 or else Etype
(Right_Opnd
(N
)) = Any_Type
)
1721 elsif Nkind
(N
) in N_Unary_Op
1722 and then Etype
(Right_Opnd
(N
)) = Any_Type
1727 -- Not that special case, so issue message using the
1728 -- flag Ambiguous to control printing of the header
1729 -- message only at the start of an ambiguous set.
1731 if not Ambiguous
then
1733 ("ambiguous expression (cannot resolve&)!",
1737 ("possible interpretation#!", N
);
1741 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
1743 -- By default, the error message refers to the candidate
1744 -- interpretation. But if it is a predefined operator,
1745 -- it is implicitly declared at the declaration of
1746 -- the type of the operand. Recover the sloc of that
1747 -- declaration for the error message.
1749 if Nkind
(N
) in N_Op
1750 and then Scope
(It
.Nam
) = Standard_Standard
1751 and then not Is_Overloaded
(Right_Opnd
(N
))
1752 and then Scope
(Base_Type
(Etype
(Right_Opnd
(N
))))
1753 /= Standard_Standard
1755 Err_Type
:= First_Subtype
(Etype
(Right_Opnd
(N
)));
1757 if Comes_From_Source
(Err_Type
)
1758 and then Present
(Parent
(Err_Type
))
1760 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
1763 elsif Nkind
(N
) in N_Binary_Op
1764 and then Scope
(It
.Nam
) = Standard_Standard
1765 and then not Is_Overloaded
(Left_Opnd
(N
))
1766 and then Scope
(Base_Type
(Etype
(Left_Opnd
(N
))))
1767 /= Standard_Standard
1769 Err_Type
:= First_Subtype
(Etype
(Left_Opnd
(N
)));
1771 if Comes_From_Source
(Err_Type
)
1772 and then Present
(Parent
(Err_Type
))
1774 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
1780 if Nkind
(N
) in N_Op
1781 and then Scope
(It
.Nam
) = Standard_Standard
1782 and then Present
(Err_Type
)
1785 ("possible interpretation (predefined)#!", N
);
1787 Error_Msg_N
("possible interpretation#!", N
);
1793 -- We have a matching interpretation, Expr_Type is the
1794 -- type from this interpretation, and Seen is the entity.
1796 -- For an operator, just set the entity name. The type will
1797 -- be set by the specific operator resolution routine.
1799 if Nkind
(N
) in N_Op
then
1800 Set_Entity
(N
, Seen
);
1801 Generate_Reference
(Seen
, N
);
1803 elsif Nkind
(N
) = N_Character_Literal
then
1804 Set_Etype
(N
, Expr_Type
);
1806 -- For an explicit dereference, attribute reference, range,
1807 -- short-circuit form (which is not an operator node),
1808 -- or a call with a name that is an explicit dereference,
1809 -- there is nothing to be done at this point.
1811 elsif Nkind
(N
) = N_Explicit_Dereference
1812 or else Nkind
(N
) = N_Attribute_Reference
1813 or else Nkind
(N
) = N_And_Then
1814 or else Nkind
(N
) = N_Indexed_Component
1815 or else Nkind
(N
) = N_Or_Else
1816 or else Nkind
(N
) = N_Range
1817 or else Nkind
(N
) = N_Selected_Component
1818 or else Nkind
(N
) = N_Slice
1819 or else Nkind
(Name
(N
)) = N_Explicit_Dereference
1823 -- For procedure or function calls, set the type of the
1824 -- name, and also the entity pointer for the prefix
1826 elsif (Nkind
(N
) = N_Procedure_Call_Statement
1827 or else Nkind
(N
) = N_Function_Call
)
1828 and then (Is_Entity_Name
(Name
(N
))
1829 or else Nkind
(Name
(N
)) = N_Operator_Symbol
)
1831 Set_Etype
(Name
(N
), Expr_Type
);
1832 Set_Entity
(Name
(N
), Seen
);
1833 Generate_Reference
(Seen
, Name
(N
));
1835 elsif Nkind
(N
) = N_Function_Call
1836 and then Nkind
(Name
(N
)) = N_Selected_Component
1838 Set_Etype
(Name
(N
), Expr_Type
);
1839 Set_Entity
(Selector_Name
(Name
(N
)), Seen
);
1840 Generate_Reference
(Seen
, Selector_Name
(Name
(N
)));
1842 -- For all other cases, just set the type of the Name
1845 Set_Etype
(Name
(N
), Expr_Type
);
1850 -- Move to next interpretation
1852 exit Interp_Loop
when not Present
(It
.Typ
);
1854 Get_Next_Interp
(I
, It
);
1855 end loop Interp_Loop
;
1858 -- At this stage Found indicates whether or not an acceptable
1859 -- interpretation exists. If not, then we have an error, except
1860 -- that if the context is Any_Type as a result of some other error,
1861 -- then we suppress the error report.
1864 if Typ
/= Any_Type
then
1866 -- If type we are looking for is Void, then this is the
1867 -- procedure call case, and the error is simply that what
1868 -- we gave is not a procedure name (we think of procedure
1869 -- calls as expressions with types internally, but the user
1870 -- doesn't think of them this way!)
1872 if Typ
= Standard_Void_Type
then
1874 -- Special case message if function used as a procedure
1876 if Nkind
(N
) = N_Procedure_Call_Statement
1877 and then Is_Entity_Name
(Name
(N
))
1878 and then Ekind
(Entity
(Name
(N
))) = E_Function
1881 ("cannot use function & in a procedure call",
1882 Name
(N
), Entity
(Name
(N
)));
1884 -- Otherwise give general message (not clear what cases
1885 -- this covers, but no harm in providing for them!)
1888 Error_Msg_N
("expect procedure name in procedure call", N
);
1893 -- Otherwise we do have a subexpression with the wrong type
1895 -- Check for the case of an allocator which uses an access
1896 -- type instead of the designated type. This is a common
1897 -- error and we specialize the message, posting an error
1898 -- on the operand of the allocator, complaining that we
1899 -- expected the designated type of the allocator.
1901 elsif Nkind
(N
) = N_Allocator
1902 and then Ekind
(Typ
) in Access_Kind
1903 and then Ekind
(Etype
(N
)) in Access_Kind
1904 and then Designated_Type
(Etype
(N
)) = Typ
1906 Wrong_Type
(Expression
(N
), Designated_Type
(Typ
));
1909 -- Check for view mismatch on Null in instances, for
1910 -- which the view-swapping mechanism has no identifier.
1912 elsif (In_Instance
or else In_Inlined_Body
)
1913 and then (Nkind
(N
) = N_Null
)
1914 and then Is_Private_Type
(Typ
)
1915 and then Is_Access_Type
(Full_View
(Typ
))
1917 Resolve
(N
, Full_View
(Typ
));
1921 -- Check for an aggregate. Sometimes we can get bogus
1922 -- aggregates from misuse of parentheses, and we are
1923 -- about to complain about the aggregate without even
1924 -- looking inside it.
1926 -- Instead, if we have an aggregate of type Any_Composite,
1927 -- then analyze and resolve the component fields, and then
1928 -- only issue another message if we get no errors doing
1929 -- this (otherwise assume that the errors in the aggregate
1930 -- caused the problem).
1932 elsif Nkind
(N
) = N_Aggregate
1933 and then Etype
(N
) = Any_Composite
1935 -- Disable expansion in any case. If there is a type mismatch
1936 -- it may be fatal to try to expand the aggregate. The flag
1937 -- would otherwise be set to false when the error is posted.
1939 Expander_Active
:= False;
1942 procedure Check_Aggr
(Aggr
: Node_Id
);
1943 -- Check one aggregate, and set Found to True if we
1944 -- have a definite error in any of its elements
1946 procedure Check_Elmt
(Aelmt
: Node_Id
);
1947 -- Check one element of aggregate and set Found to
1948 -- True if we definitely have an error in the element.
1950 procedure Check_Aggr
(Aggr
: Node_Id
) is
1954 if Present
(Expressions
(Aggr
)) then
1955 Elmt
:= First
(Expressions
(Aggr
));
1956 while Present
(Elmt
) loop
1962 if Present
(Component_Associations
(Aggr
)) then
1963 Elmt
:= First
(Component_Associations
(Aggr
));
1964 while Present
(Elmt
) loop
1965 Check_Elmt
(Expression
(Elmt
));
1975 procedure Check_Elmt
(Aelmt
: Node_Id
) is
1977 -- If we have a nested aggregate, go inside it (to
1978 -- attempt a naked analyze-resolve of the aggregate
1979 -- can cause undesirable cascaded errors). Do not
1980 -- resolve expression if it needs a type from context,
1981 -- as for integer * fixed expression.
1983 if Nkind
(Aelmt
) = N_Aggregate
then
1989 if not Is_Overloaded
(Aelmt
)
1990 and then Etype
(Aelmt
) /= Any_Fixed
1995 if Etype
(Aelmt
) = Any_Type
then
2006 -- If an error message was issued already, Found got reset
2007 -- to True, so if it is still False, issue the standard
2008 -- Wrong_Type message.
2011 if Is_Overloaded
(N
)
2012 and then Nkind
(N
) = N_Function_Call
2015 Subp_Name
: Node_Id
;
2017 if Is_Entity_Name
(Name
(N
)) then
2018 Subp_Name
:= Name
(N
);
2020 elsif Nkind
(Name
(N
)) = N_Selected_Component
then
2022 -- Protected operation: retrieve operation name.
2024 Subp_Name
:= Selector_Name
(Name
(N
));
2026 raise Program_Error
;
2029 Error_Msg_Node_2
:= Typ
;
2030 Error_Msg_NE
("no visible interpretation of&" &
2031 " matches expected type&", N
, Subp_Name
);
2034 if All_Errors_Mode
then
2036 Index
: Interp_Index
;
2040 Error_Msg_N
("\possible interpretations:", N
);
2041 Get_First_Interp
(Name
(N
), Index
, It
);
2043 while Present
(It
.Nam
) loop
2045 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2046 Error_Msg_Node_2
:= It
.Typ
;
2047 Error_Msg_NE
("\& declared#, type&",
2050 Get_Next_Interp
(Index
, It
);
2054 Error_Msg_N
("\use -gnatf for details", N
);
2057 Wrong_Type
(N
, Typ
);
2065 -- Test if we have more than one interpretation for the context
2067 elsif Ambiguous
then
2071 -- Here we have an acceptable interpretation for the context
2074 -- Propagate type information and normalize tree for various
2075 -- predefined operations. If the context only imposes a class of
2076 -- types, rather than a specific type, propagate the actual type
2079 if Typ
= Any_Integer
2080 or else Typ
= Any_Boolean
2081 or else Typ
= Any_Modular
2082 or else Typ
= Any_Real
2083 or else Typ
= Any_Discrete
2085 Ctx_Type
:= Expr_Type
;
2087 -- Any_Fixed is legal in a real context only if a specific
2088 -- fixed point type is imposed. If Norman Cohen can be
2089 -- confused by this, it deserves a separate message.
2092 and then Expr_Type
= Any_Fixed
2094 Error_Msg_N
("Illegal context for mixed mode operation", N
);
2095 Set_Etype
(N
, Universal_Real
);
2096 Ctx_Type
:= Universal_Real
;
2100 -- A user-defined operator is tranformed into a function call at
2101 -- this point, so that further processing knows that operators are
2102 -- really operators (i.e. are predefined operators). User-defined
2103 -- operators that are intrinsic are just renamings of the predefined
2104 -- ones, and need not be turned into calls either, but if they rename
2105 -- a different operator, we must transform the node accordingly.
2106 -- Instantiations of Unchecked_Conversion are intrinsic but are
2107 -- treated as functions, even if given an operator designator.
2109 if Nkind
(N
) in N_Op
2110 and then Present
(Entity
(N
))
2111 and then Ekind
(Entity
(N
)) /= E_Operator
2114 if not Is_Predefined_Op
(Entity
(N
)) then
2115 Rewrite_Operator_As_Call
(N
, Entity
(N
));
2117 elsif Present
(Alias
(Entity
(N
)))
2119 Nkind
(Parent
(Parent
(Entity
(N
))))
2120 = N_Subprogram_Renaming_Declaration
2122 Rewrite_Renamed_Operator
(N
, Alias
(Entity
(N
)), Typ
);
2124 -- If the node is rewritten, it will be fully resolved in
2125 -- Rewrite_Renamed_Operator.
2127 if Analyzed
(N
) then
2133 case N_Subexpr
'(Nkind (N)) is
2135 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2137 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2139 when N_And_Then | N_Or_Else
2140 => Resolve_Short_Circuit (N, Ctx_Type);
2142 when N_Attribute_Reference
2143 => Resolve_Attribute (N, Ctx_Type);
2145 when N_Character_Literal
2146 => Resolve_Character_Literal (N, Ctx_Type);
2148 when N_Conditional_Expression
2149 => Resolve_Conditional_Expression (N, Ctx_Type);
2151 when N_Expanded_Name
2152 => Resolve_Entity_Name (N, Ctx_Type);
2154 when N_Extension_Aggregate
2155 => Resolve_Extension_Aggregate (N, Ctx_Type);
2157 when N_Explicit_Dereference
2158 => Resolve_Explicit_Dereference (N, Ctx_Type);
2160 when N_Function_Call
2161 => Resolve_Call (N, Ctx_Type);
2164 => Resolve_Entity_Name (N, Ctx_Type);
2166 when N_In | N_Not_In
2167 => Resolve_Membership_Op (N, Ctx_Type);
2169 when N_Indexed_Component
2170 => Resolve_Indexed_Component (N, Ctx_Type);
2172 when N_Integer_Literal
2173 => Resolve_Integer_Literal (N, Ctx_Type);
2175 when N_Null => Resolve_Null (N, Ctx_Type);
2177 when N_Op_And | N_Op_Or | N_Op_Xor
2178 => Resolve_Logical_Op (N, Ctx_Type);
2180 when N_Op_Eq | N_Op_Ne
2181 => Resolve_Equality_Op (N, Ctx_Type);
2183 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2184 => Resolve_Comparison_Op (N, Ctx_Type);
2186 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2188 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2189 N_Op_Divide | N_Op_Mod | N_Op_Rem
2191 => Resolve_Arithmetic_Op (N, Ctx_Type);
2193 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2195 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2197 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2198 => Resolve_Unary_Op (N, Ctx_Type);
2200 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2202 when N_Procedure_Call_Statement
2203 => Resolve_Call (N, Ctx_Type);
2205 when N_Operator_Symbol
2206 => Resolve_Operator_Symbol (N, Ctx_Type);
2208 when N_Qualified_Expression
2209 => Resolve_Qualified_Expression (N, Ctx_Type);
2211 when N_Raise_xxx_Error
2212 => Set_Etype (N, Ctx_Type);
2214 when N_Range => Resolve_Range (N, Ctx_Type);
2217 => Resolve_Real_Literal (N, Ctx_Type);
2219 when N_Reference => Resolve_Reference (N, Ctx_Type);
2221 when N_Selected_Component
2222 => Resolve_Selected_Component (N, Ctx_Type);
2224 when N_Slice => Resolve_Slice (N, Ctx_Type);
2226 when N_String_Literal
2227 => Resolve_String_Literal (N, Ctx_Type);
2229 when N_Subprogram_Info
2230 => Resolve_Subprogram_Info (N, Ctx_Type);
2232 when N_Type_Conversion
2233 => Resolve_Type_Conversion (N, Ctx_Type);
2235 when N_Unchecked_Expression =>
2236 Resolve_Unchecked_Expression (N, Ctx_Type);
2238 when N_Unchecked_Type_Conversion =>
2239 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2243 -- If the subexpression was replaced by a non-subexpression, then
2244 -- all we do is to expand it. The only legitimate case we know of
2245 -- is converting procedure call statement to entry call statements,
2246 -- but there may be others, so we are making this test general.
2248 if Nkind (N) not in N_Subexpr then
2249 Debug_A_Exit ("resolving ", N, " (done)");
2254 -- The expression is definitely NOT overloaded at this point, so
2255 -- we reset the Is_Overloaded flag to avoid any confusion when
2256 -- reanalyzing the node.
2258 Set_Is_Overloaded (N, False);
2260 -- Freeze expression type, entity if it is a name, and designated
2261 -- type if it is an allocator (RM 13.14(10,11,13)).
2263 -- Now that the resolution of the type of the node is complete,
2264 -- and we did not detect an error, we can expand this node. We
2265 -- skip the expand call if we are in a default expression, see
2266 -- section "Handling of Default Expressions" in Sem spec.
2268 Debug_A_Exit ("resolving ", N, " (done)");
2270 -- We unconditionally freeze the expression, even if we are in
2271 -- default expression mode (the Freeze_Expression routine tests
2272 -- this flag and only freezes static types if it is set).
2274 Freeze_Expression (N);
2276 -- Now we can do the expansion
2286 -- Version with check(s) suppressed
2288 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2290 if Suppress = All_Checks then
2292 Svg : constant Suppress_Array := Scope_Suppress;
2295 Scope_Suppress := (others => True);
2297 Scope_Suppress := Svg;
2302 Svg : constant Boolean := Scope_Suppress (Suppress);
2305 Scope_Suppress (Suppress) := True;
2307 Scope_Suppress (Suppress) := Svg;
2316 -- Version with implicit type
2318 procedure Resolve (N : Node_Id) is
2320 Resolve (N, Etype (N));
2323 ---------------------
2324 -- Resolve_Actuals --
2325 ---------------------
2327 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2328 Loc : constant Source_Ptr := Sloc (N);
2333 Prev : Node_Id := Empty;
2335 procedure Insert_Default;
2336 -- If the actual is missing in a call, insert in the actuals list
2337 -- an instance of the default expression. The insertion is always
2338 -- a named association.
2340 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2341 -- Check whether T1 and T2, or their full views, are derived from a
2342 -- common type. Used to enforce the restrictions on array conversions
2345 --------------------
2346 -- Insert_Default --
2347 --------------------
2349 procedure Insert_Default is
2354 -- Missing argument in call, nothing to insert
2356 if No (Default_Value (F)) then
2360 -- Note that we do a full New_Copy_Tree, so that any associated
2361 -- Itypes are properly copied. This may not be needed any more,
2362 -- but it does no harm as a safety measure! Defaults of a generic
2363 -- formal may be out of bounds of the corresponding actual (see
2364 -- cc1311b) and an additional check may be required.
2366 Actval := New_Copy_Tree (Default_Value (F),
2367 New_Scope => Current_Scope, New_Sloc => Loc);
2369 if Is_Concurrent_Type (Scope (Nam))
2370 and then Has_Discriminants (Scope (Nam))
2372 Replace_Actual_Discriminants (N, Actval);
2375 if Is_Overloadable (Nam)
2376 and then Present (Alias (Nam))
2378 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
2379 and then not Is_Tagged_Type (Etype (F))
2381 -- If default is a real literal, do not introduce a
2382 -- conversion whose effect may depend on the run-time
2383 -- size of universal real.
2385 if Nkind (Actval) = N_Real_Literal then
2386 Set_Etype (Actval, Base_Type (Etype (F)));
2388 Actval := Unchecked_Convert_To (Etype (F), Actval);
2392 if Is_Scalar_Type (Etype (F)) then
2393 Enable_Range_Check (Actval);
2396 Set_Parent (Actval, N);
2398 -- Resolve aggregates with their base type, to avoid scope
2399 -- anomalies: the subtype was first built in the suprogram
2400 -- declaration, and the current call may be nested.
2402 if Nkind (Actval) = N_Aggregate
2403 and then Has_Discriminants (Etype (Actval))
2405 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2407 Analyze_And_Resolve (Actval, Etype (Actval));
2411 Set_Parent (Actval, N);
2413 -- See note above concerning aggregates.
2415 if Nkind (Actval) = N_Aggregate
2416 and then Has_Discriminants (Etype (Actval))
2418 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
2420 -- Resolve entities with their own type, which may differ
2421 -- from the type of a reference in a generic context (the
2422 -- view swapping mechanism did not anticipate the re-analysis
2423 -- of default values in calls).
2425 elsif Is_Entity_Name (Actval) then
2426 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
2429 Analyze_And_Resolve (Actval, Etype (Actval));
2433 -- If default is a tag indeterminate function call, propagate
2434 -- tag to obtain proper dispatching.
2436 if Is_Controlling_Formal (F)
2437 and then Nkind (Default_Value (F)) = N_Function_Call
2439 Set_Is_Controlling_Actual (Actval);
2444 -- If the default expression raises constraint error, then just
2445 -- silently replace it with an N_Raise_Constraint_Error node,
2446 -- since we already gave the warning on the subprogram spec.
2448 if Raises_Constraint_Error (Actval) then
2450 Make_Raise_Constraint_Error (Loc,
2451 Reason => CE_Range_Check_Failed));
2452 Set_Raises_Constraint_Error (Actval);
2453 Set_Etype (Actval, Etype (F));
2457 Make_Parameter_Association (Loc,
2458 Explicit_Actual_Parameter => Actval,
2459 Selector_Name => Make_Identifier (Loc, Chars (F)));
2461 -- Case of insertion is first named actual
2463 if No (Prev) or else
2464 Nkind (Parent (Prev)) /= N_Parameter_Association
2466 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
2467 Set_First_Named_Actual (N, Actval);
2470 if not Present (Parameter_Associations (N)) then
2471 Set_Parameter_Associations (N, New_List (Assoc));
2473 Append (Assoc, Parameter_Associations (N));
2477 Insert_After (Prev, Assoc);
2480 -- Case of insertion is not first named actual
2483 Set_Next_Named_Actual
2484 (Assoc, Next_Named_Actual (Parent (Prev)));
2485 Set_Next_Named_Actual (Parent (Prev), Actval);
2486 Append (Assoc, Parameter_Associations (N));
2489 Mark_Rewrite_Insertion (Assoc);
2490 Mark_Rewrite_Insertion (Actval);
2499 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
2500 FT1 : Entity_Id := T1;
2501 FT2 : Entity_Id := T2;
2504 if Is_Private_Type (T1)
2505 and then Present (Full_View (T1))
2507 FT1 := Full_View (T1);
2510 if Is_Private_Type (T2)
2511 and then Present (Full_View (T2))
2513 FT2 := Full_View (T2);
2516 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
2519 -- Start of processing for Resolve_Actuals
2522 A := First_Actual (N);
2523 F := First_Formal (Nam);
2525 while Present (F) loop
2526 if No (A) and then Needs_No_Actuals (Nam) then
2529 -- If we have an error in any actual or formal, indicated by
2530 -- a type of Any_Type, then abandon resolution attempt, and
2531 -- set result type to Any_Type.
2533 elsif (Present (A) and then Etype (A) = Any_Type)
2534 or else Etype (F) = Any_Type
2536 Set_Etype (N, Any_Type);
2541 and then (Nkind (Parent (A)) /= N_Parameter_Association
2543 Chars (Selector_Name (Parent (A))) = Chars (F))
2545 -- If the formal is Out or In_Out, do not resolve and expand the
2546 -- conversion, because it is subsequently expanded into explicit
2547 -- temporaries and assignments. However, the object of the
2548 -- conversion can be resolved. An exception is the case of
2549 -- a tagged type conversion with a class-wide actual. In that
2550 -- case we want the tag check to occur and no temporary will
2551 -- will be needed (no representation change can occur) and
2552 -- the parameter is passed by reference, so we go ahead and
2553 -- resolve the type conversion.
2555 if Ekind (F) /= E_In_Parameter
2556 and then Nkind (A) = N_Type_Conversion
2557 and then not Is_Class_Wide_Type (Etype (Expression (A)))
2559 if Ekind (F) = E_In_Out_Parameter
2560 and then Is_Array_Type (Etype (F))
2562 if Has_Aliased_Components (Etype (Expression (A)))
2563 /= Has_Aliased_Components (Etype (F))
2566 ("both component types in a view conversion must be"
2567 & " aliased, or neither", A);
2569 elsif not Same_Ancestor (Etype (F), Etype (Expression (A)))
2571 (Is_By_Reference_Type (Etype (F))
2572 or else Is_By_Reference_Type (Etype (Expression (A))))
2575 ("view conversion between unrelated by_reference "
2576 & "array types not allowed (\A\I-00246)?", A);
2580 if Conversion_OK (A)
2581 or else Valid_Conversion (A, Etype (A), Expression (A))
2583 Resolve (Expression (A));
2587 if Nkind (A) = N_Type_Conversion
2588 and then Is_Array_Type (Etype (F))
2589 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
2591 (Is_Limited_Type (Etype (F))
2592 or else Is_Limited_Type (Etype (Expression (A))))
2595 ("Conversion between unrelated limited array types "
2596 & "not allowed (\A\I-00246)?", A);
2598 -- Disable explanation (which produces additional errors)
2599 -- until AI is approved and warning becomes an error.
2601 -- if Is_Limited_Type (Etype (F)) then
2602 -- Explain_Limited_Type (Etype (F), A);
2605 -- if Is_Limited_Type (Etype (Expression (A))) then
2606 -- Explain_Limited_Type (Etype (Expression (A)), A);
2610 Resolve (A, Etype (F));
2616 -- Perform error checks for IN and IN OUT parameters
2618 if Ekind (F) /= E_Out_Parameter then
2620 -- Check unset reference. For scalar parameters, it is clearly
2621 -- wrong to pass an uninitialized value as either an IN or
2622 -- IN-OUT parameter. For composites, it is also clearly an
2623 -- error to pass a completely uninitialized value as an IN
2624 -- parameter, but the case of IN OUT is trickier. We prefer
2625 -- not to give a warning here. For example, suppose there is
2626 -- a routine that sets some component of a record to False.
2627 -- It is perfectly reasonable to make this IN-OUT and allow
2628 -- either initialized or uninitialized records to be passed
2631 -- For partially initialized composite values, we also avoid
2632 -- warnings, since it is quite likely that we are passing a
2633 -- partially initialized value and only the initialized fields
2634 -- will in fact be read in the subprogram.
2636 if Is_Scalar_Type (A_Typ)
2637 or else (Ekind (F) = E_In_Parameter
2638 and then not Is_Partially_Initialized_Type (A_Typ))
2640 Check_Unset_Reference (A);
2643 -- In Ada 83 we cannot pass an OUT parameter as an IN
2644 -- or IN OUT actual to a nested call, since this is a
2645 -- case of reading an out parameter, which is not allowed.
2647 if Ada_Version = Ada_83
2648 and then Is_Entity_Name (A)
2649 and then Ekind (Entity (A)) = E_Out_Parameter
2651 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
2655 if Ekind (F) /= E_In_Parameter
2656 and then not Is_OK_Variable_For_Out_Formal (A)
2658 Error_Msg_NE ("actual for& must be a variable", A, F);
2660 if Is_Entity_Name (A) then
2661 Kill_Checks (Entity (A));
2667 if Etype (A) = Any_Type then
2668 Set_Etype (N, Any_Type);
2672 -- Apply appropriate range checks for in, out, and in-out
2673 -- parameters. Out and in-out parameters also need a separate
2674 -- check, if there is a type conversion, to make sure the return
2675 -- value meets the constraints of the variable before the
2678 -- Gigi looks at the check flag and uses the appropriate types.
2679 -- For now since one flag is used there is an optimization which
2680 -- might not be done in the In Out case since Gigi does not do
2681 -- any analysis. More thought required about this ???
2683 if Ekind (F) = E_In_Parameter
2684 or else Ekind (F) = E_In_Out_Parameter
2686 if Is_Scalar_Type (Etype (A)) then
2687 Apply_Scalar_Range_Check (A, F_Typ);
2689 elsif Is_Array_Type (Etype (A)) then
2690 Apply_Length_Check (A, F_Typ);
2692 elsif Is_Record_Type (F_Typ)
2693 and then Has_Discriminants (F_Typ)
2694 and then Is_Constrained (F_Typ)
2695 and then (not Is_Derived_Type (F_Typ)
2696 or else Comes_From_Source (Nam))
2698 Apply_Discriminant_Check (A, F_Typ);
2700 elsif Is_Access_Type (F_Typ)
2701 and then Is_Array_Type (Designated_Type (F_Typ))
2702 and then Is_Constrained (Designated_Type (F_Typ))
2704 Apply_Length_Check (A, F_Typ);
2706 elsif Is_Access_Type (F_Typ)
2707 and then Has_Discriminants (Designated_Type (F_Typ))
2708 and then Is_Constrained (Designated_Type (F_Typ))
2710 Apply_Discriminant_Check (A, F_Typ);
2713 Apply_Range_Check (A, F_Typ);
2716 -- Ada 2005 (AI-231)
2718 if Ada_Version >= Ada_05
2719 and then Is_Access_Type (F_Typ)
2720 and then (Can_Never_Be_Null (F)
2721 or else Can_Never_Be_Null (F_Typ))
2723 if Nkind (A) = N_Null then
2725 ("(Ada 2005) not allowed for " &
2726 "null-exclusion formal", A, F_Typ);
2731 if Ekind (F) = E_Out_Parameter
2732 or else Ekind (F) = E_In_Out_Parameter
2734 if Nkind (A) = N_Type_Conversion then
2735 if Is_Scalar_Type (A_Typ) then
2736 Apply_Scalar_Range_Check
2737 (Expression (A), Etype (Expression (A)), A_Typ);
2740 (Expression (A), Etype (Expression (A)), A_Typ);
2744 if Is_Scalar_Type (F_Typ) then
2745 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
2747 elsif Is_Array_Type (F_Typ)
2748 and then Ekind (F) = E_Out_Parameter
2750 Apply_Length_Check (A, F_Typ);
2753 Apply_Range_Check (A, A_Typ, F_Typ);
2758 -- An actual associated with an access parameter is implicitly
2759 -- converted to the anonymous access type of the formal and
2760 -- must satisfy the legality checks for access conversions.
2762 if Ekind (F_Typ) = E_Anonymous_Access_Type then
2763 if not Valid_Conversion (A, F_Typ, A) then
2765 ("invalid implicit conversion for access parameter", A);
2769 -- Check bad case of atomic/volatile argument (RM C.6(12))
2771 if Is_By_Reference_Type (Etype (F))
2772 and then Comes_From_Source (N)
2774 if Is_Atomic_Object (A)
2775 and then not Is_Atomic (Etype (F))
2778 ("cannot pass atomic argument to non-atomic formal",
2781 elsif Is_Volatile_Object (A)
2782 and then not Is_Volatile (Etype (F))
2785 ("cannot pass volatile argument to non-volatile formal",
2790 -- Check that subprograms don't have improper controlling
2791 -- arguments (RM 3.9.2 (9))
2793 if Is_Controlling_Formal (F) then
2794 Set_Is_Controlling_Actual (A);
2795 elsif Nkind (A) = N_Explicit_Dereference then
2796 Validate_Remote_Access_To_Class_Wide_Type (A);
2799 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
2800 and then not Is_Class_Wide_Type (F_Typ)
2801 and then not Is_Controlling_Formal (F)
2803 Error_Msg_N ("class-wide argument not allowed here!", A);
2805 if Is_Subprogram (Nam)
2806 and then Comes_From_Source (Nam)
2808 Error_Msg_Node_2 := F_Typ;
2810 ("& is not a primitive operation of &!", A, Nam);
2813 elsif Is_Access_Type (A_Typ)
2814 and then Is_Access_Type (F_Typ)
2815 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
2816 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
2817 or else (Nkind (A) = N_Attribute_Reference
2819 Is_Class_Wide_Type (Etype (Prefix (A)))))
2820 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
2821 and then not Is_Controlling_Formal (F)
2824 ("access to class-wide argument not allowed here!", A);
2826 if Is_Subprogram (Nam)
2827 and then Comes_From_Source (Nam)
2829 Error_Msg_Node_2 := Designated_Type (F_Typ);
2831 ("& is not a primitive operation of &!", A, Nam);
2837 -- If it is a named association, treat the selector_name as
2838 -- a proper identifier, and mark the corresponding entity.
2840 if Nkind (Parent (A)) = N_Parameter_Association then
2841 Set_Entity (Selector_Name (Parent (A)), F);
2842 Generate_Reference (F, Selector_Name (Parent (A)));
2843 Set_Etype (Selector_Name (Parent (A)), F_Typ);
2844 Generate_Reference (F_Typ, N, ' ');
2849 if Ekind (F) /= E_Out_Parameter then
2850 Check_Unset_Reference (A);
2855 -- Case where actual is not present
2863 end Resolve_Actuals;
2865 -----------------------
2866 -- Resolve_Allocator --
2867 -----------------------
2869 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
2870 E : constant Node_Id := Expression (N);
2872 Discrim : Entity_Id;
2876 function In_Dispatching_Context return Boolean;
2877 -- If the allocator is an actual in a call, it is allowed to be
2878 -- class-wide when the context is not because it is a controlling
2881 ----------------------------
2882 -- In_Dispatching_Context --
2883 ----------------------------
2885 function In_Dispatching_Context return Boolean is
2886 Par : constant Node_Id := Parent (N);
2889 return (Nkind (Par) = N_Function_Call
2890 or else Nkind (Par) = N_Procedure_Call_Statement)
2891 and then Is_Entity_Name (Name (Par))
2892 and then Is_Dispatching_Operation (Entity (Name (Par)));
2893 end In_Dispatching_Context;
2895 -- Start of processing for Resolve_Allocator
2898 -- Replace general access with specific type
2900 if Ekind (Etype (N)) = E_Allocator_Type then
2901 Set_Etype (N, Base_Type (Typ));
2904 if Is_Abstract (Typ) then
2905 Error_Msg_N ("type of allocator cannot be abstract", N);
2908 -- For qualified expression, resolve the expression using the
2909 -- given subtype (nothing to do for type mark, subtype indication)
2911 if Nkind (E) = N_Qualified_Expression then
2912 if Is_Class_Wide_Type (Etype (E))
2913 and then not Is_Class_Wide_Type (Designated_Type (Typ))
2914 and then not In_Dispatching_Context
2917 ("class-wide allocator not allowed for this access type", N);
2920 Resolve (Expression (E), Etype (E));
2921 Check_Unset_Reference (Expression (E));
2923 -- A qualified expression requires an exact match of the type,
2924 -- class-wide matching is not allowed.
2926 if (Is_Class_Wide_Type (Etype (Expression (E)))
2927 or else Is_Class_Wide_Type (Etype (E)))
2928 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
2930 Wrong_Type (Expression (E), Etype (E));
2933 -- For a subtype mark or subtype indication, freeze the subtype
2936 Freeze_Expression (E);
2938 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
2940 ("initialization required for access-to-constant allocator", N);
2943 -- A special accessibility check is needed for allocators that
2944 -- constrain access discriminants. The level of the type of the
2945 -- expression used to contrain an access discriminant cannot be
2946 -- deeper than the type of the allocator (in constrast to access
2947 -- parameters, where the level of the actual can be arbitrary).
2948 -- We can't use Valid_Conversion to perform this check because
2949 -- in general the type of the allocator is unrelated to the type
2950 -- of the access discriminant. Note that specialized checks are
2951 -- needed for the cases of a constraint expression which is an
2952 -- access attribute or an access discriminant.
2954 if Nkind (Original_Node (E)) = N_Subtype_Indication
2955 and then Ekind (Typ) /= E_Anonymous_Access_Type
2957 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
2959 if Has_Discriminants (Subtyp) then
2960 Discrim := First_Discriminant (Base_Type (Subtyp));
2961 Constr := First (Constraints (Constraint (Original_Node (E))));
2963 while Present (Discrim) and then Present (Constr) loop
2964 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
2965 if Nkind (Constr) = N_Discriminant_Association then
2966 Disc_Exp := Original_Node (Expression (Constr));
2968 Disc_Exp := Original_Node (Constr);
2971 if Type_Access_Level (Etype (Disc_Exp))
2972 > Type_Access_Level (Typ)
2975 ("operand type has deeper level than allocator type",
2978 elsif Nkind (Disc_Exp) = N_Attribute_Reference
2979 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
2981 and then Object_Access_Level (Prefix (Disc_Exp))
2982 > Type_Access_Level (Typ)
2985 ("prefix of attribute has deeper level than"
2986 & " allocator type", Disc_Exp);
2988 -- When the operand is an access discriminant the check
2989 -- is against the level of the prefix object.
2991 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
2992 and then Nkind (Disc_Exp) = N_Selected_Component
2993 and then Object_Access_Level (Prefix (Disc_Exp))
2994 > Type_Access_Level (Typ)
2997 ("access discriminant has deeper level than"
2998 & " allocator type", Disc_Exp);
3001 Next_Discriminant (Discrim);
3008 -- Check for allocation from an empty storage pool
3010 if No_Pool_Assigned (Typ) then
3012 Loc : constant Source_Ptr := Sloc (N);
3015 Error_Msg_N ("?allocation from empty storage pool!", N);
3016 Error_Msg_N ("?Storage_Error will be raised at run time!", N);
3018 Make_Raise_Storage_Error (Loc,
3019 Reason => SE_Empty_Storage_Pool));
3022 end Resolve_Allocator;
3024 ---------------------------
3025 -- Resolve_Arithmetic_Op --
3026 ---------------------------
3028 -- Used for resolving all arithmetic operators except exponentiation
3030 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
3031 L : constant Node_Id := Left_Opnd (N);
3032 R : constant Node_Id := Right_Opnd (N);
3033 TL : constant Entity_Id := Base_Type (Etype (L));
3034 TR : constant Entity_Id := Base_Type (Etype (R));
3038 B_Typ : constant Entity_Id := Base_Type (Typ);
3039 -- We do the resolution using the base type, because intermediate values
3040 -- in expressions always are of the base type, not a subtype of it.
3042 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
3043 -- Return True iff given type is Integer or universal real/integer
3045 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
3046 -- Choose type of integer literal in fixed-point operation to conform
3047 -- to available fixed-point type. T is the type of the other operand,
3048 -- which is needed to determine the expected type of N.
3050 procedure Set_Operand_Type (N : Node_Id);
3051 -- Set operand type to T if universal
3053 -----------------------------
3054 -- Is_Integer_Or_Universal --
3055 -----------------------------
3057 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
3059 Index : Interp_Index;
3063 if not Is_Overloaded (N) then
3065 return Base_Type (T) = Base_Type (Standard_Integer)
3066 or else T = Universal_Integer
3067 or else T = Universal_Real;
3069 Get_First_Interp (N, Index, It);
3071 while Present (It.Typ) loop
3073 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
3074 or else It.Typ = Universal_Integer
3075 or else It.Typ = Universal_Real
3080 Get_Next_Interp (Index, It);
3085 end Is_Integer_Or_Universal;
3087 ----------------------------
3088 -- Set_Mixed_Mode_Operand --
3089 ----------------------------
3091 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
3092 Index : Interp_Index;
3096 if Universal_Interpretation (N) = Universal_Integer then
3098 -- A universal integer literal is resolved as standard integer
3099 -- except in the case of a fixed-point result, where we leave
3100 -- it as universal (to be handled by Exp_Fixd later on)
3102 if Is_Fixed_Point_Type (T) then
3103 Resolve (N, Universal_Integer);
3105 Resolve (N, Standard_Integer);
3108 elsif Universal_Interpretation (N) = Universal_Real
3109 and then (T = Base_Type (Standard_Integer)
3110 or else T = Universal_Integer
3111 or else T = Universal_Real)
3113 -- A universal real can appear in a fixed-type context. We resolve
3114 -- the literal with that context, even though this might raise an
3115 -- exception prematurely (the other operand may be zero).
3119 elsif Etype (N) = Base_Type (Standard_Integer)
3120 and then T = Universal_Real
3121 and then Is_Overloaded (N)
3123 -- Integer arg in mixed-mode operation. Resolve with universal
3124 -- type, in case preference rule must be applied.
3126 Resolve (N, Universal_Integer);
3129 and then B_Typ /= Universal_Fixed
3131 -- Not a mixed-mode operation. Resolve with context.
3135 elsif Etype (N) = Any_Fixed then
3137 -- N may itself be a mixed-mode operation, so use context type.
3141 elsif Is_Fixed_Point_Type (T)
3142 and then B_Typ = Universal_Fixed
3143 and then Is_Overloaded (N)
3145 -- Must be (fixed * fixed) operation, operand must have one
3146 -- compatible interpretation.
3148 Resolve (N, Any_Fixed);
3150 elsif Is_Fixed_Point_Type (B_Typ)
3151 and then (T = Universal_Real
3152 or else Is_Fixed_Point_Type (T))
3153 and then Is_Overloaded (N)
3155 -- C * F(X) in a fixed context, where C is a real literal or a
3156 -- fixed-point expression. F must have either a fixed type
3157 -- interpretation or an integer interpretation, but not both.
3159 Get_First_Interp (N, Index, It);
3161 while Present (It.Typ) loop
3162 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
3164 if Analyzed (N) then
3165 Error_Msg_N ("ambiguous operand in fixed operation", N);
3167 Resolve (N, Standard_Integer);
3170 elsif Is_Fixed_Point_Type (It.Typ) then
3172 if Analyzed (N) then
3173 Error_Msg_N ("ambiguous operand in fixed operation", N);
3175 Resolve (N, It.Typ);
3179 Get_Next_Interp (Index, It);
3182 -- Reanalyze the literal with the fixed type of the context.
3183 -- If context is Universal_Fixed, we are within a conversion,
3184 -- leave the literal as a universal real because there is no
3185 -- usable fixed type, and the target of the conversion plays
3186 -- no role in the resolution.
3199 if B_Typ = Universal_Fixed
3200 and then Nkind (Op2) = N_Real_Literal
3202 T2 := Universal_Real;
3207 Set_Analyzed (Op2, False);
3214 end Set_Mixed_Mode_Operand;
3216 ----------------------
3217 -- Set_Operand_Type --
3218 ----------------------
3220 procedure Set_Operand_Type (N : Node_Id) is
3222 if Etype (N) = Universal_Integer
3223 or else Etype (N) = Universal_Real
3227 end Set_Operand_Type;
3229 -- Start of processing for Resolve_Arithmetic_Op
3232 if Comes_From_Source (N)
3233 and then Ekind (Entity (N)) = E_Function
3234 and then Is_Imported (Entity (N))
3235 and then Is_Intrinsic_Subprogram (Entity (N))
3237 Resolve_Intrinsic_Operator (N, Typ);
3240 -- Special-case for mixed-mode universal expressions or fixed point
3241 -- type operation: each argument is resolved separately. The same
3242 -- treatment is required if one of the operands of a fixed point
3243 -- operation is universal real, since in this case we don't do a
3244 -- conversion to a specific fixed-point type (instead the expander
3245 -- takes care of the case).
3247 elsif (B_Typ = Universal_Integer
3248 or else B_Typ = Universal_Real)
3249 and then Present (Universal_Interpretation (L))
3250 and then Present (Universal_Interpretation (R))
3252 Resolve (L, Universal_Interpretation (L));
3253 Resolve (R, Universal_Interpretation (R));
3254 Set_Etype (N, B_Typ);
3256 elsif (B_Typ = Universal_Real
3257 or else Etype (N) = Universal_Fixed
3258 or else (Etype (N) = Any_Fixed
3259 and then Is_Fixed_Point_Type (B_Typ))
3260 or else (Is_Fixed_Point_Type (B_Typ)
3261 and then (Is_Integer_Or_Universal (L)
3263 Is_Integer_Or_Universal (R))))
3264 and then (Nkind (N) = N_Op_Multiply or else
3265 Nkind (N) = N_Op_Divide)
3267 if TL = Universal_Integer or else TR = Universal_Integer then
3268 Check_For_Visible_Operator (N, B_Typ);
3271 -- If context is a fixed type and one operand is integer, the
3272 -- other is resolved with the type of the context.
3274 if Is_Fixed_Point_Type (B_Typ)
3275 and then (Base_Type (TL) = Base_Type (Standard_Integer)
3276 or else TL = Universal_Integer)
3281 elsif Is_Fixed_Point_Type (B_Typ)
3282 and then (Base_Type (TR) = Base_Type (Standard_Integer)
3283 or else TR = Universal_Integer)
3289 Set_Mixed_Mode_Operand (L, TR);
3290 Set_Mixed_Mode_Operand (R, TL);
3293 if Etype (N) = Universal_Fixed
3294 or else Etype (N) = Any_Fixed
3296 if B_Typ = Universal_Fixed
3297 and then Nkind (Parent (N)) /= N_Type_Conversion
3298 and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion
3301 ("type cannot be determined from context!", N);
3303 ("\explicit conversion to result type required", N);
3305 Set_Etype (L, Any_Type);
3306 Set_Etype (R, Any_Type);
3309 if Ada_Version = Ada_83
3310 and then Etype (N) = Universal_Fixed
3311 and then Nkind (Parent (N)) /= N_Type_Conversion
3312 and then Nkind (Parent (N)) /= N_Unchecked_Type_Conversion
3315 ("(Ada 83) fixed-point operation " &
3316 "needs explicit conversion",
3320 Set_Etype (N, B_Typ);
3323 elsif Is_Fixed_Point_Type (B_Typ)
3324 and then (Is_Integer_Or_Universal (L)
3325 or else Nkind (L) = N_Real_Literal
3326 or else Nkind (R) = N_Real_Literal
3328 Is_Integer_Or_Universal (R))
3330 Set_Etype (N, B_Typ);
3332 elsif Etype (N) = Any_Fixed then
3334 -- If no previous errors, this is only possible if one operand
3335 -- is overloaded and the context is universal. Resolve as such.
3337 Set_Etype (N, B_Typ);
3341 if (TL = Universal_Integer or else TL = Universal_Real)
3342 and then (TR = Universal_Integer or else TR = Universal_Real)
3344 Check_For_Visible_Operator (N, B_Typ);
3347 -- If the context is Universal_Fixed and the operands are also
3348 -- universal fixed, this is an error, unless there is only one
3349 -- applicable fixed_point type (usually duration).
3351 if B_Typ = Universal_Fixed
3352 and then Etype (L) = Universal_Fixed
3354 T := Unique_Fixed_Point_Type (N);
3356 if T = Any_Type then
3369 -- If one of the arguments was resolved to a non-universal type.
3370 -- label the result of the operation itself with the same type.
3371 -- Do the same for the universal argument, if any.
3373 T := Intersect_Types (L, R);
3374 Set_Etype (N, Base_Type (T));
3375 Set_Operand_Type (L);
3376 Set_Operand_Type (R);
3379 Generate_Operator_Reference (N, Typ);
3380 Eval_Arithmetic_Op (N);
3382 -- Set overflow and division checking bit. Much cleverer code needed
3383 -- here eventually and perhaps the Resolve routines should be separated
3384 -- for the various arithmetic operations, since they will need
3385 -- different processing. ???
3387 if Nkind (N) in N_Op then
3388 if not Overflow_Checks_Suppressed (Etype (N)) then
3389 Enable_Overflow_Check (N);
3392 -- Give warning if explicit division by zero
3394 if (Nkind (N) = N_Op_Divide
3395 or else Nkind (N) = N_Op_Rem
3396 or else Nkind (N) = N_Op_Mod)
3397 and then not Division_Checks_Suppressed (Etype (N))
3399 Rop := Right_Opnd (N);
3401 if Compile_Time_Known_Value (Rop)
3402 and then ((Is_Integer_Type (Etype (Rop))
3403 and then Expr_Value (Rop) = Uint_0)
3405 (Is_Real_Type (Etype (Rop))
3406 and then Expr_Value_R (Rop) = Ureal_0))
3408 Apply_Compile_Time_Constraint_Error
3409 (N, "division by zero?", CE_Divide_By_Zero,
3410 Loc => Sloc (Right_Opnd (N)));
3412 -- Otherwise just set the flag to check at run time
3415 Set_Do_Division_Check (N);
3420 Check_Unset_Reference (L);
3421 Check_Unset_Reference (R);
3422 end Resolve_Arithmetic_Op;
3428 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
3429 Loc : constant Source_Ptr := Sloc (N);
3430 Subp : constant Node_Id := Name (N);
3439 -- The context imposes a unique interpretation with type Typ on
3440 -- a procedure or function call. Find the entity of the subprogram
3441 -- that yields the expected type, and propagate the corresponding
3442 -- formal constraints on the actuals. The caller has established
3443 -- that an interpretation exists, and emitted an error if not unique.
3445 -- First deal with the case of a call to an access-to-subprogram,
3446 -- dereference made explicit in Analyze_Call.
3448 if Ekind (Etype (Subp)) = E_Subprogram_Type then
3449 if not Is_Overloaded (Subp) then
3450 Nam := Etype (Subp);
3453 -- Find the interpretation whose type (a subprogram type)
3454 -- has a return type that is compatible with the context.
3455 -- Analysis of the node has established that one exists.
3457 Get_First_Interp (Subp, I, It);
3460 while Present (It.Typ) loop
3461 if Covers (Typ, Etype (It.Typ)) then
3466 Get_Next_Interp (I, It);
3470 raise Program_Error;
3474 -- If the prefix is not an entity, then resolve it
3476 if not Is_Entity_Name (Subp) then
3477 Resolve (Subp, Nam);
3480 -- For an indirect call, we always invalidate checks, since we
3481 -- do not know whether the subprogram is local or global. Yes
3482 -- we could do better here, e.g. by knowing that there are no
3483 -- local subprograms, but it does not seem worth the effort.
3484 -- Similarly, we kill al knowledge of current constant values.
3486 Kill_Current_Values;
3488 -- If this is a procedure call which is really an entry call, do
3489 -- the conversion of the procedure call to an entry call. Protected
3490 -- operations use the same circuitry because the name in the call
3491 -- can be an arbitrary expression with special resolution rules.
3493 elsif Nkind (Subp) = N_Selected_Component
3494 or else Nkind (Subp) = N_Indexed_Component
3495 or else (Is_Entity_Name (Subp)
3496 and then Ekind (Entity (Subp)) = E_Entry)
3498 Resolve_Entry_Call (N, Typ);
3499 Check_Elab_Call (N);
3501 -- Kill checks and constant values, as above for indirect case
3502 -- Who knows what happens when another task is activated?
3504 Kill_Current_Values;
3507 -- Normal subprogram call with name established in Resolve
3509 elsif not (Is_Type (Entity (Subp))) then
3510 Nam := Entity (Subp);
3511 Set_Entity_With_Style_Check (Subp, Nam);
3512 Generate_Reference (Nam, Subp);
3514 -- Otherwise we must have the case of an overloaded call
3517 pragma Assert (Is_Overloaded (Subp));
3518 Nam := Empty; -- We know that it will be assigned in loop below.
3520 Get_First_Interp (Subp, I, It);
3522 while Present (It.Typ) loop
3523 if Covers (Typ, It.Typ) then
3525 Set_Entity_With_Style_Check (Subp, Nam);
3526 Generate_Reference (Nam, Subp);
3530 Get_Next_Interp (I, It);
3534 -- Check that a call to Current_Task does not occur in an entry body
3536 if Is_RTE (Nam, RE_Current_Task) then
3546 if Nkind (P) = N_Entry_Body then
3548 ("& should not be used in entry body ('R
'M C
.7(17))",
3556 -- Cannot call thread body directly
3558 if Is_Thread_Body (Nam) then
3559 Error_Msg_N ("cannot call thread
body directly
", N);
3562 -- If the subprogram is not global, then kill all checks. This is
3563 -- a bit conservative, since in many cases we could do better, but
3564 -- it is not worth the effort. Similarly, we kill constant values.
3565 -- However we do not need to do this for internal entities (unless
3566 -- they are inherited user-defined subprograms), since they are not
3567 -- in the business of molesting global values.
3569 if not Is_Library_Level_Entity (Nam)
3570 and then (Comes_From_Source (Nam)
3571 or else (Present (Alias (Nam))
3572 and then Comes_From_Source (Alias (Nam))))
3574 Kill_Current_Values;
3577 -- Check for call to obsolescent subprogram
3579 if Warn_On_Obsolescent_Feature then
3580 Decl := Parent (Parent (Nam));
3582 if Nkind (Decl) = N_Subprogram_Declaration
3583 and then Is_List_Member (Decl)
3584 and then Nkind (Next (Decl)) = N_Pragma
3587 P : constant Node_Id := Next (Decl);
3590 if Chars (P) = Name_Obsolescent then
3591 Error_Msg_NE ("call to obsolescent subprogram
&?
", N, Nam);
3593 if Pragma_Argument_Associations (P) /= No_List then
3594 Name_Buffer (1) := '|';
3595 Name_Buffer (2) := '?';
3597 Add_String_To_Name_Buffer
3599 (First (Pragma_Argument_Associations (P)))));
3600 Error_Msg_N (Name_Buffer (1 .. Name_Len), N);
3607 -- Check that a procedure call does not occur in the context
3608 -- of the entry call statement of a conditional or timed
3609 -- entry call. Note that the case of a call to a subprogram
3610 -- renaming of an entry will also be rejected. The test
3611 -- for N not being an N_Entry_Call_Statement is defensive,
3612 -- covering the possibility that the processing of entry
3613 -- calls might reach this point due to later modifications
3614 -- of the code above.
3616 if Nkind (Parent (N)) = N_Entry_Call_Alternative
3617 and then Nkind (N) /= N_Entry_Call_Statement
3618 and then Entry_Call_Statement (Parent (N)) = N
3620 Error_Msg_N ("entry call required
in select statement
", N);
3623 -- Check that this is not a call to a protected procedure or
3624 -- entry from within a protected function.
3626 if Ekind (Current_Scope) = E_Function
3627 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
3628 and then Ekind (Nam) /= E_Function
3629 and then Scope (Nam) = Scope (Current_Scope)
3631 Error_Msg_N ("within
protected function, protected " &
3632 "object
is constant", N);
3633 Error_Msg_N ("\cannot call operation that may modify it
", N);
3636 -- Freeze the subprogram name if not in default expression. Note
3637 -- that we freeze procedure calls as well as function calls.
3638 -- Procedure calls are not frozen according to the rules (RM
3639 -- 13.14(14)) because it is impossible to have a procedure call to
3640 -- a non-frozen procedure in pure Ada, but in the code that we
3641 -- generate in the expander, this rule needs extending because we
3642 -- can generate procedure calls that need freezing.
3644 if Is_Entity_Name (Subp) and then not In_Default_Expression then
3645 Freeze_Expression (Subp);
3648 -- For a predefined operator, the type of the result is the type
3649 -- imposed by context, except for a predefined operation on universal
3650 -- fixed. Otherwise The type of the call is the type returned by the
3651 -- subprogram being called.
3653 if Is_Predefined_Op (Nam) then
3654 if Etype (N) /= Universal_Fixed then
3658 -- If the subprogram returns an array type, and the context
3659 -- requires the component type of that array type, the node is
3660 -- really an indexing of the parameterless call. Resolve as such.
3661 -- A pathological case occurs when the type of the component is
3662 -- an access to the array type. In this case the call is truly
3665 elsif Needs_No_Actuals (Nam)
3667 ((Is_Array_Type (Etype (Nam))
3668 and then Covers (Typ, Component_Type (Etype (Nam))))
3669 or else (Is_Access_Type (Etype (Nam))
3670 and then Is_Array_Type (Designated_Type (Etype (Nam)))
3673 Component_Type (Designated_Type (Etype (Nam))))))
3676 Index_Node : Node_Id;
3678 Ret_Type : constant Entity_Id := Etype (Nam);
3681 if Is_Access_Type (Ret_Type)
3682 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
3685 ("cannot disambiguate
function call
and indexing
", N);
3687 New_Subp := Relocate_Node (Subp);
3688 Set_Entity (Subp, Nam);
3690 if Component_Type (Ret_Type) /= Any_Type then
3692 Make_Indexed_Component (Loc,
3694 Make_Function_Call (Loc,
3696 Expressions => Parameter_Associations (N));
3698 -- Since we are correcting a node classification error made
3699 -- by the parser, we call Replace rather than Rewrite.
3701 Replace (N, Index_Node);
3702 Set_Etype (Prefix (N), Ret_Type);
3704 Resolve_Indexed_Component (N, Typ);
3705 Check_Elab_Call (Prefix (N));
3713 Set_Etype (N, Etype (Nam));
3716 -- In the case where the call is to an overloaded subprogram, Analyze
3717 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
3718 -- such a case Normalize_Actuals needs to be called once more to order
3719 -- the actuals correctly. Otherwise the call will have the ordering
3720 -- given by the last overloaded subprogram whether this is the correct
3721 -- one being called or not.
3723 if Is_Overloaded (Subp) then
3724 Normalize_Actuals (N, Nam, False, Norm_OK);
3725 pragma Assert (Norm_OK);
3728 -- In any case, call is fully resolved now. Reset Overload flag, to
3729 -- prevent subsequent overload resolution if node is analyzed again
3731 Set_Is_Overloaded (Subp, False);
3732 Set_Is_Overloaded (N, False);
3734 -- If we are calling the current subprogram from immediately within
3735 -- its body, then that is the case where we can sometimes detect
3736 -- cases of infinite recursion statically. Do not try this in case
3737 -- restriction No_Recursion is in effect anyway.
3739 Scop := Current_Scope;
3742 and then not Restriction_Active (No_Recursion)
3743 and then Check_Infinite_Recursion (N)
3745 -- Here we detected and flagged an infinite recursion, so we do
3746 -- not need to test the case below for further warnings.
3750 -- If call is to immediately containing subprogram, then check for
3751 -- the case of a possible run-time detectable infinite recursion.
3754 while Scop /= Standard_Standard loop
3756 -- Although in general recursion is not statically checkable,
3757 -- the case of calling an immediately containing subprogram
3758 -- is easy to catch.
3760 Check_Restriction (No_Recursion, N);
3762 -- If the recursive call is to a parameterless procedure, then
3763 -- even if we can't statically detect infinite recursion, this
3764 -- is pretty suspicious, and we output a warning. Furthermore,
3765 -- we will try later to detect some cases here at run time by
3766 -- expanding checking code (see Detect_Infinite_Recursion in
3767 -- package Exp_Ch6).
3769 -- If the recursive call is within a handler we do not emit a
3770 -- warning, because this is a common idiom: loop until input
3771 -- is correct, catch illegal input in handler and restart.
3773 if No (First_Formal (Nam))
3774 and then Etype (Nam) = Standard_Void_Type
3775 and then not Error_Posted (N)
3776 and then Nkind (Parent (N)) /= N_Exception_Handler
3778 Set_Has_Recursive_Call (Nam);
3779 Error_Msg_N ("possible infinite recursion?
", N);
3780 Error_Msg_N ("Storage_Error may be raised
at run time?
", N);
3786 Scop := Scope (Scop);
3790 -- If subprogram name is a predefined operator, it was given in
3791 -- functional notation. Replace call node with operator node, so
3792 -- that actuals can be resolved appropriately.
3794 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
3795 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
3798 elsif Present (Alias (Nam))
3799 and then Is_Predefined_Op (Alias (Nam))
3801 Resolve_Actuals (N, Nam);
3802 Make_Call_Into_Operator (N, Typ, Alias (Nam));
3806 -- Create a transient scope if the resulting type requires it
3808 -- There are 3 notable exceptions: in init procs, the transient scope
3809 -- overhead is not needed and even incorrect due to the actual expansion
3810 -- of adjust calls; the second case is enumeration literal pseudo calls,
3811 -- the other case is intrinsic subprograms (Unchecked_Conversion and
3812 -- source information functions) that do not use the secondary stack
3813 -- even though the return type is unconstrained.
3815 -- If this is an initialization call for a type whose initialization
3816 -- uses the secondary stack, we also need to create a transient scope
3817 -- for it, precisely because we will not do it within the init proc
3821 and then Is_Type (Etype (Nam))
3822 and then Requires_Transient_Scope (Etype (Nam))
3823 and then Ekind (Nam) /= E_Enumeration_Literal
3824 and then not Within_Init_Proc
3825 and then not Is_Intrinsic_Subprogram (Nam)
3827 Establish_Transient_Scope
3828 (N, Sec_Stack => not Functions_Return_By_DSP_On_Target);
3830 -- If the call appears within the bounds of a loop, it will
3831 -- be rewritten and reanalyzed, nothing left to do here.
3833 if Nkind (N) /= N_Function_Call then
3837 elsif Is_Init_Proc (Nam)
3838 and then not Within_Init_Proc
3840 Check_Initialization_Call (N, Nam);
3843 -- A protected function cannot be called within the definition of the
3844 -- enclosing protected type.
3846 if Is_Protected_Type (Scope (Nam))
3847 and then In_Open_Scopes (Scope (Nam))
3848 and then not Has_Completion (Scope (Nam))
3851 ("& cannot be called before
end of protected definition
", N, Nam);
3854 -- Propagate interpretation to actuals, and add default expressions
3857 if Present (First_Formal (Nam)) then
3858 Resolve_Actuals (N, Nam);
3860 -- Overloaded literals are rewritten as function calls, for
3861 -- purpose of resolution. After resolution, we can replace
3862 -- the call with the literal itself.
3864 elsif Ekind (Nam) = E_Enumeration_Literal then
3865 Copy_Node (Subp, N);
3866 Resolve_Entity_Name (N, Typ);
3868 -- Avoid validation, since it is a static function call
3873 -- If the subprogram is a primitive operation, check whether or not
3874 -- it is a correct dispatching call.
3876 if Is_Overloadable (Nam)
3877 and then Is_Dispatching_Operation (Nam)
3879 Check_Dispatching_Call (N);
3881 elsif Is_Abstract (Nam)
3882 and then not In_Instance
3884 Error_Msg_NE ("cannot call
abstract subprogram
&!", N, Nam);
3887 if Is_Intrinsic_Subprogram (Nam) then
3888 Check_Intrinsic_Call (N);
3892 Check_Elab_Call (N);
3895 -------------------------------
3896 -- Resolve_Character_Literal --
3897 -------------------------------
3899 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
3900 B_Typ : constant Entity_Id := Base_Type (Typ);
3904 -- Verify that the character does belong to the type of the context
3906 Set_Etype (N, B_Typ);
3907 Eval_Character_Literal (N);
3909 -- Wide_Character literals must always be defined, since the set of
3910 -- wide character literals is complete, i.e. if a character literal
3911 -- is accepted by the parser, then it is OK for wide character.
3913 if Root_Type (B_Typ) = Standard_Wide_Character then
3916 -- Always accept character literal for type Any_Character, which
3917 -- occurs in error situations and in comparisons of literals, both
3918 -- of which should accept all literals.
3920 elsif B_Typ = Any_Character then
3923 -- For Standard.Character or a type derived from it, check that
3924 -- the literal is in range
3926 elsif Root_Type (B_Typ) = Standard_Character then
3927 if In_Character_Range (Char_Literal_Value (N)) then
3931 -- If the entity is already set, this has already been resolved in
3932 -- a generic context, or comes from expansion. Nothing else to do.
3934 elsif Present (Entity (N)) then
3937 -- Otherwise we have a user defined character type, and we can use
3938 -- the standard visibility mechanisms to locate the referenced entity
3941 C := Current_Entity (N);
3943 while Present (C) loop
3944 if Etype (C) = B_Typ then
3945 Set_Entity_With_Style_Check (N, C);
3946 Generate_Reference (C, N);
3954 -- If we fall through, then the literal does not match any of the
3955 -- entries of the enumeration type. This isn't just a constraint
3956 -- error situation, it is an illegality (see RM 4.2).
3959 ("character not defined
for }", N, First_Subtype (B_Typ));
3960 end Resolve_Character_Literal;
3962 ---------------------------
3963 -- Resolve_Comparison_Op --
3964 ---------------------------
3966 -- Context requires a boolean type, and plays no role in resolution.
3967 -- Processing identical to that for equality operators. The result
3968 -- type is the base type, which matters when pathological subtypes of
3969 -- booleans with limited ranges are used.
3971 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
3972 L : constant Node_Id := Left_Opnd (N);
3973 R : constant Node_Id := Right_Opnd (N);
3977 Check_Direct_Boolean_Op (N);
3979 -- If this is an intrinsic operation which is not predefined, use
3980 -- the types of its declared arguments to resolve the possibly
3981 -- overloaded operands. Otherwise the operands are unambiguous and
3982 -- specify the expected type.
3984 if Scope (Entity (N)) /= Standard_Standard then
3985 T := Etype (First_Entity (Entity (N)));
3987 T := Find_Unique_Type (L, R);
3989 if T = Any_Fixed then
3990 T := Unique_Fixed_Point_Type (L);
3994 Set_Etype (N, Base_Type (Typ));
3995 Generate_Reference (T, N, ' ');
3997 if T /= Any_Type then
3999 or else T = Any_Composite
4000 or else T = Any_Character
4002 if T = Any_Character then
4003 Ambiguous_Character (L);
4005 Error_Msg_N ("ambiguous operands
for comparison
", N);
4008 Set_Etype (N, Any_Type);
4014 Check_Unset_Reference (L);
4015 Check_Unset_Reference (R);
4016 Generate_Operator_Reference (N, T);
4017 Eval_Relational_Op (N);
4020 end Resolve_Comparison_Op;
4022 ------------------------------------
4023 -- Resolve_Conditional_Expression --
4024 ------------------------------------
4026 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
4027 Condition : constant Node_Id := First (Expressions (N));
4028 Then_Expr : constant Node_Id := Next (Condition);
4029 Else_Expr : constant Node_Id := Next (Then_Expr);
4032 Resolve (Condition, Standard_Boolean);
4033 Resolve (Then_Expr, Typ);
4034 Resolve (Else_Expr, Typ);
4037 Eval_Conditional_Expression (N);
4038 end Resolve_Conditional_Expression;
4040 -----------------------------------------
4041 -- Resolve_Discrete_Subtype_Indication --
4042 -----------------------------------------
4044 procedure Resolve_Discrete_Subtype_Indication
4052 Analyze (Subtype_Mark (N));
4053 S := Entity (Subtype_Mark (N));
4055 if Nkind (Constraint (N)) /= N_Range_Constraint then
4056 Error_Msg_N ("expect
range constraint
for discrete
type", N);
4057 Set_Etype (N, Any_Type);
4060 R := Range_Expression (Constraint (N));
4068 if Base_Type (S) /= Base_Type (Typ) then
4070 ("expect
subtype of }", N, First_Subtype (Typ));
4072 -- Rewrite the constraint as a range of Typ
4073 -- to allow compilation to proceed further.
4076 Rewrite (Low_Bound (R),
4077 Make_Attribute_Reference (Sloc (Low_Bound (R)),
4078 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
4079 Attribute_Name => Name_First));
4080 Rewrite (High_Bound (R),
4081 Make_Attribute_Reference (Sloc (High_Bound (R)),
4082 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
4083 Attribute_Name => Name_First));
4087 Set_Etype (N, Etype (R));
4089 -- Additionally, we must check that the bounds are compatible
4090 -- with the given subtype, which might be different from the
4091 -- type of the context.
4093 Apply_Range_Check (R, S);
4095 -- ??? If the above check statically detects a Constraint_Error
4096 -- it replaces the offending bound(s) of the range R with a
4097 -- Constraint_Error node. When the itype which uses these bounds
4098 -- is frozen the resulting call to Duplicate_Subexpr generates
4099 -- a new temporary for the bounds.
4101 -- Unfortunately there are other itypes that are also made depend
4102 -- on these bounds, so when Duplicate_Subexpr is called they get
4103 -- a forward reference to the newly created temporaries and Gigi
4104 -- aborts on such forward references. This is probably sign of a
4105 -- more fundamental problem somewhere else in either the order of
4106 -- itype freezing or the way certain itypes are constructed.
4108 -- To get around this problem we call Remove_Side_Effects right
4109 -- away if either bounds of R are a Constraint_Error.
4112 L : constant Node_Id := Low_Bound (R);
4113 H : constant Node_Id := High_Bound (R);
4116 if Nkind (L) = N_Raise_Constraint_Error then
4117 Remove_Side_Effects (L);
4120 if Nkind (H) = N_Raise_Constraint_Error then
4121 Remove_Side_Effects (H);
4125 Check_Unset_Reference (Low_Bound (R));
4126 Check_Unset_Reference (High_Bound (R));
4129 end Resolve_Discrete_Subtype_Indication;
4131 -------------------------
4132 -- Resolve_Entity_Name --
4133 -------------------------
4135 -- Used to resolve identifiers and expanded names
4137 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
4138 E : constant Entity_Id := Entity (N);
4141 -- If garbage from errors, set to Any_Type and return
4143 if No (E) and then Total_Errors_Detected /= 0 then
4144 Set_Etype (N, Any_Type);
4148 -- Replace named numbers by corresponding literals. Note that this is
4149 -- the one case where Resolve_Entity_Name must reset the Etype, since
4150 -- it is currently marked as universal.
4152 if Ekind (E) = E_Named_Integer then
4154 Eval_Named_Integer (N);
4156 elsif Ekind (E) = E_Named_Real then
4158 Eval_Named_Real (N);
4160 -- Allow use of subtype only if it is a concurrent type where we are
4161 -- currently inside the body. This will eventually be expanded
4162 -- into a call to Self (for tasks) or _object (for protected
4163 -- objects). Any other use of a subtype is invalid.
4165 elsif Is_Type (E) then
4166 if Is_Concurrent_Type (E)
4167 and then In_Open_Scopes (E)
4172 ("Invalid
use of subtype mark
in expression
or call
", N);
4175 -- Check discriminant use if entity is discriminant in current scope,
4176 -- i.e. discriminant of record or concurrent type currently being
4177 -- analyzed. Uses in corresponding body are unrestricted.
4179 elsif Ekind (E) = E_Discriminant
4180 and then Scope (E) = Current_Scope
4181 and then not Has_Completion (Current_Scope)
4183 Check_Discriminant_Use (N);
4185 -- A parameterless generic function cannot appear in a context that
4186 -- requires resolution.
4188 elsif Ekind (E) = E_Generic_Function then
4189 Error_Msg_N ("illegal
use of generic function", N);
4191 elsif Ekind (E) = E_Out_Parameter
4192 and then Ada_Version = Ada_83
4193 and then (Nkind (Parent (N)) in N_Op
4194 or else (Nkind (Parent (N)) = N_Assignment_Statement
4195 and then N = Expression (Parent (N)))
4196 or else Nkind (Parent (N)) = N_Explicit_Dereference)
4198 Error_Msg_N ("(Ada
83) illegal reading
of out parameter
", N);
4200 -- In all other cases, just do the possible static evaluation
4203 -- A deferred constant that appears in an expression must have
4204 -- a completion, unless it has been removed by in-place expansion
4207 if Ekind (E) = E_Constant
4208 and then Comes_From_Source (E)
4209 and then No (Constant_Value (E))
4210 and then Is_Frozen (Etype (E))
4211 and then not In_Default_Expression
4212 and then not Is_Imported (E)
4215 if No_Initialization (Parent (E))
4216 or else (Present (Full_View (E))
4217 and then No_Initialization (Parent (Full_View (E))))
4222 "deferred
constant is frozen before completion
", N);
4226 Eval_Entity_Name (N);
4228 end Resolve_Entity_Name;
4234 procedure Resolve_Entry (Entry_Name : Node_Id) is
4235 Loc : constant Source_Ptr := Sloc (Entry_Name);
4243 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
4244 -- If the bounds of the entry family being called depend on task
4245 -- discriminants, build a new index subtype where a discriminant is
4246 -- replaced with the value of the discriminant of the target task.
4247 -- The target task is the prefix of the entry name in the call.
4249 -----------------------
4250 -- Actual_Index_Type --
4251 -----------------------
4253 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
4254 Typ : constant Entity_Id := Entry_Index_Type (E);
4255 Tsk : constant Entity_Id := Scope (E);
4256 Lo : constant Node_Id := Type_Low_Bound (Typ);
4257 Hi : constant Node_Id := Type_High_Bound (Typ);
4260 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
4261 -- If the bound is given by a discriminant, replace with a reference
4262 -- to the discriminant of the same name in the target task.
4263 -- If the entry name is the target of a requeue statement and the
4264 -- entry is in the current protected object, the bound to be used
4265 -- is the discriminal of the object (see apply_range_checks for
4266 -- details of the transformation).
4268 -----------------------------
4269 -- Actual_Discriminant_Ref --
4270 -----------------------------
4272 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
4273 Typ : constant Entity_Id := Etype (Bound);
4277 Remove_Side_Effects (Bound);
4279 if not Is_Entity_Name (Bound)
4280 or else Ekind (Entity (Bound)) /= E_Discriminant
4284 elsif Is_Protected_Type (Tsk)
4285 and then In_Open_Scopes (Tsk)
4286 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
4288 return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc);
4292 Make_Selected_Component (Loc,
4293 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
4294 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
4299 end Actual_Discriminant_Ref;
4301 -- Start of processing for Actual_Index_Type
4304 if not Has_Discriminants (Tsk)
4305 or else (not Is_Entity_Name (Lo)
4306 and then not Is_Entity_Name (Hi))
4308 return Entry_Index_Type (E);
4311 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
4312 Set_Etype (New_T, Base_Type (Typ));
4313 Set_Size_Info (New_T, Typ);
4314 Set_RM_Size (New_T, RM_Size (Typ));
4315 Set_Scalar_Range (New_T,
4316 Make_Range (Sloc (Entry_Name),
4317 Low_Bound => Actual_Discriminant_Ref (Lo),
4318 High_Bound => Actual_Discriminant_Ref (Hi)));
4322 end Actual_Index_Type;
4324 -- Start of processing of Resolve_Entry
4327 -- Find name of entry being called, and resolve prefix of name
4328 -- with its own type. The prefix can be overloaded, and the name
4329 -- and signature of the entry must be taken into account.
4331 if Nkind (Entry_Name) = N_Indexed_Component then
4333 -- Case of dealing with entry family within the current tasks
4335 E_Name := Prefix (Entry_Name);
4338 E_Name := Entry_Name;
4341 if Is_Entity_Name (E_Name) then
4342 -- Entry call to an entry (or entry family) in the current task.
4343 -- This is legal even though the task will deadlock. Rewrite as
4344 -- call to current task.
4346 -- This can also be a call to an entry in an enclosing task.
4347 -- If this is a single task, we have to retrieve its name,
4348 -- because the scope of the entry is the task type, not the
4349 -- object. If the enclosing task is a task type, the identity
4350 -- of the task is given by its own self variable.
4352 -- Finally this can be a requeue on an entry of the same task
4353 -- or protected object.
4355 S := Scope (Entity (E_Name));
4357 for J in reverse 0 .. Scope_Stack.Last loop
4359 if Is_Task_Type (Scope_Stack.Table (J).Entity)
4360 and then not Comes_From_Source (S)
4362 -- S is an enclosing task or protected object. The concurrent
4363 -- declaration has been converted into a type declaration, and
4364 -- the object itself has an object declaration that follows
4365 -- the type in the same declarative part.
4367 Tsk := Next_Entity (S);
4369 while Etype (Tsk) /= S loop
4376 elsif S = Scope_Stack.Table (J).Entity then
4378 -- Call to current task. Will be transformed into call to Self
4386 Make_Selected_Component (Loc,
4387 Prefix => New_Occurrence_Of (S, Loc),
4389 New_Occurrence_Of (Entity (E_Name), Loc));
4390 Rewrite (E_Name, New_N);
4393 elsif Nkind (Entry_Name) = N_Selected_Component
4394 and then Is_Overloaded (Prefix (Entry_Name))
4396 -- Use the entry name (which must be unique at this point) to
4397 -- find the prefix that returns the corresponding task type or
4401 Pref : constant Node_Id := Prefix (Entry_Name);
4402 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
4407 Get_First_Interp (Pref, I, It);
4409 while Present (It.Typ) loop
4411 if Scope (Ent) = It.Typ then
4412 Set_Etype (Pref, It.Typ);
4416 Get_Next_Interp (I, It);
4421 if Nkind (Entry_Name) = N_Selected_Component then
4422 Resolve (Prefix (Entry_Name));
4424 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
4425 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
4426 Resolve (Prefix (Prefix (Entry_Name)));
4427 Index := First (Expressions (Entry_Name));
4428 Resolve (Index, Entry_Index_Type (Nam));
4430 -- Up to this point the expression could have been the actual
4431 -- in a simple entry call, and be given by a named association.
4433 if Nkind (Index) = N_Parameter_Association then
4434 Error_Msg_N ("expect expression
for entry index
", Index);
4436 Apply_Range_Check (Index, Actual_Index_Type (Nam));
4441 ------------------------
4442 -- Resolve_Entry_Call --
4443 ------------------------
4445 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
4446 Entry_Name : constant Node_Id := Name (N);
4447 Loc : constant Source_Ptr := Sloc (Entry_Name);
4449 First_Named : Node_Id;
4456 -- We kill all checks here, because it does not seem worth the
4457 -- effort to do anything better, an entry call is a big operation.
4461 -- Processing of the name is similar for entry calls and protected
4462 -- operation calls. Once the entity is determined, we can complete
4463 -- the resolution of the actuals.
4465 -- The selector may be overloaded, in the case of a protected object
4466 -- with overloaded functions. The type of the context is used for
4469 if Nkind (Entry_Name) = N_Selected_Component
4470 and then Is_Overloaded (Selector_Name (Entry_Name))
4471 and then Typ /= Standard_Void_Type
4478 Get_First_Interp (Selector_Name (Entry_Name), I, It);
4480 while Present (It.Typ) loop
4482 if Covers (Typ, It.Typ) then
4483 Set_Entity (Selector_Name (Entry_Name), It.Nam);
4484 Set_Etype (Entry_Name, It.Typ);
4486 Generate_Reference (It.Typ, N, ' ');
4489 Get_Next_Interp (I, It);
4494 Resolve_Entry (Entry_Name);
4496 if Nkind (Entry_Name) = N_Selected_Component then
4498 -- Simple entry call.
4500 Nam := Entity (Selector_Name (Entry_Name));
4501 Obj := Prefix (Entry_Name);
4502 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
4504 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
4506 -- Call to member of entry family.
4508 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
4509 Obj := Prefix (Prefix (Entry_Name));
4510 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
4513 -- We cannot in general check the maximum depth of protected entry
4514 -- calls at compile time. But we can tell that any protected entry
4515 -- call at all violates a specified nesting depth of zero.
4517 if Is_Protected_Type (Scope (Nam)) then
4518 Check_Restriction (Max_Entry_Queue_Length, N);
4521 -- Use context type to disambiguate a protected function that can be
4522 -- called without actuals and that returns an array type, and where
4523 -- the argument list may be an indexing of the returned value.
4525 if Ekind (Nam) = E_Function
4526 and then Needs_No_Actuals (Nam)
4527 and then Present (Parameter_Associations (N))
4529 ((Is_Array_Type (Etype (Nam))
4530 and then Covers (Typ, Component_Type (Etype (Nam))))
4532 or else (Is_Access_Type (Etype (Nam))
4533 and then Is_Array_Type (Designated_Type (Etype (Nam)))
4534 and then Covers (Typ,
4535 Component_Type (Designated_Type (Etype (Nam))))))
4538 Index_Node : Node_Id;
4542 Make_Indexed_Component (Loc,
4544 Make_Function_Call (Loc,
4545 Name => Relocate_Node (Entry_Name)),
4546 Expressions => Parameter_Associations (N));
4548 -- Since we are correcting a node classification error made by
4549 -- the parser, we call Replace rather than Rewrite.
4551 Replace (N, Index_Node);
4552 Set_Etype (Prefix (N), Etype (Nam));
4554 Resolve_Indexed_Component (N, Typ);
4559 -- The operation name may have been overloaded. Order the actuals
4560 -- according to the formals of the resolved entity, and set the
4561 -- return type to that of the operation.
4564 Normalize_Actuals (N, Nam, False, Norm_OK);
4565 pragma Assert (Norm_OK);
4566 Set_Etype (N, Etype (Nam));
4569 Resolve_Actuals (N, Nam);
4570 Generate_Reference (Nam, Entry_Name);
4572 if Ekind (Nam) = E_Entry
4573 or else Ekind (Nam) = E_Entry_Family
4575 Check_Potentially_Blocking_Operation (N);
4578 -- Verify that a procedure call cannot masquerade as an entry
4579 -- call where an entry call is expected.
4581 if Ekind (Nam) = E_Procedure then
4582 if Nkind (Parent (N)) = N_Entry_Call_Alternative
4583 and then N = Entry_Call_Statement (Parent (N))
4585 Error_Msg_N ("entry call required
in select statement
", N);
4587 elsif Nkind (Parent (N)) = N_Triggering_Alternative
4588 and then N = Triggering_Statement (Parent (N))
4590 Error_Msg_N ("triggering statement cannot be
procedure call
", N);
4592 elsif Ekind (Scope (Nam)) = E_Task_Type
4593 and then not In_Open_Scopes (Scope (Nam))
4595 Error_Msg_N ("Task has no
entry with this name
", Entry_Name);
4599 -- After resolution, entry calls and protected procedure calls
4600 -- are changed into entry calls, for expansion. The structure
4601 -- of the node does not change, so it can safely be done in place.
4602 -- Protected function calls must keep their structure because they
4603 -- are subexpressions.
4605 if Ekind (Nam) /= E_Function then
4607 -- A protected operation that is not a function may modify the
4608 -- corresponding object, and cannot apply to a constant.
4609 -- If this is an internal call, the prefix is the type itself.
4611 if Is_Protected_Type (Scope (Nam))
4612 and then not Is_Variable (Obj)
4613 and then (not Is_Entity_Name (Obj)
4614 or else not Is_Type (Entity (Obj)))
4617 ("prefix
of protected procedure or entry call must be variable
",
4621 Actuals := Parameter_Associations (N);
4622 First_Named := First_Named_Actual (N);
4625 Make_Entry_Call_Statement (Loc,
4627 Parameter_Associations => Actuals));
4629 Set_First_Named_Actual (N, First_Named);
4630 Set_Analyzed (N, True);
4632 -- Protected functions can return on the secondary stack, in which
4633 -- case we must trigger the transient scope mechanism
4635 elsif Expander_Active
4636 and then Requires_Transient_Scope (Etype (Nam))
4638 Establish_Transient_Scope (N,
4639 Sec_Stack => not Functions_Return_By_DSP_On_Target);
4641 end Resolve_Entry_Call;
4643 -------------------------
4644 -- Resolve_Equality_Op --
4645 -------------------------
4647 -- Both arguments must have the same type, and the boolean context
4648 -- does not participate in the resolution. The first pass verifies
4649 -- that the interpretation is not ambiguous, and the type of the left
4650 -- argument is correctly set, or is Any_Type in case of ambiguity.
4651 -- If both arguments are strings or aggregates, allocators, or Null,
4652 -- they are ambiguous even though they carry a single (universal) type.
4653 -- Diagnose this case here.
4655 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
4656 L : constant Node_Id := Left_Opnd (N);
4657 R : constant Node_Id := Right_Opnd (N);
4658 T : Entity_Id := Find_Unique_Type (L, R);
4660 function Find_Unique_Access_Type return Entity_Id;
4661 -- In the case of allocators, make a last-ditch attempt to find a single
4662 -- access type with the right designated type. This is semantically
4663 -- dubious, and of no interest to any real code, but c48008a makes it
4666 -----------------------------
4667 -- Find_Unique_Access_Type --
4668 -----------------------------
4670 function Find_Unique_Access_Type return Entity_Id is
4673 S : Entity_Id := Current_Scope;
4676 if Ekind (Etype (R)) = E_Allocator_Type then
4677 Acc := Designated_Type (Etype (R));
4679 elsif Ekind (Etype (L)) = E_Allocator_Type then
4680 Acc := Designated_Type (Etype (L));
4686 while S /= Standard_Standard loop
4687 E := First_Entity (S);
4689 while Present (E) loop
4692 and then Is_Access_Type (E)
4693 and then Ekind (E) /= E_Allocator_Type
4694 and then Designated_Type (E) = Base_Type (Acc)
4706 end Find_Unique_Access_Type;
4708 -- Start of processing for Resolve_Equality_Op
4711 Check_Direct_Boolean_Op (N);
4713 Set_Etype (N, Base_Type (Typ));
4714 Generate_Reference (T, N, ' ');
4716 if T = Any_Fixed then
4717 T := Unique_Fixed_Point_Type (L);
4720 if T /= Any_Type then
4723 or else T = Any_Composite
4724 or else T = Any_Character
4727 if T = Any_Character then
4728 Ambiguous_Character (L);
4730 Error_Msg_N ("ambiguous operands
for equality
", N);
4733 Set_Etype (N, Any_Type);
4736 elsif T = Any_Access
4737 or else Ekind (T) = E_Allocator_Type
4739 T := Find_Unique_Access_Type;
4742 Error_Msg_N ("ambiguous operands
for equality
", N);
4743 Set_Etype (N, Any_Type);
4751 if Warn_On_Redundant_Constructs
4752 and then Comes_From_Source (N)
4753 and then Is_Entity_Name (R)
4754 and then Entity (R) = Standard_True
4755 and then Comes_From_Source (R)
4757 Error_Msg_N ("comparison
with True is redundant?
", R);
4760 Check_Unset_Reference (L);
4761 Check_Unset_Reference (R);
4762 Generate_Operator_Reference (N, T);
4764 -- If this is an inequality, it may be the implicit inequality
4765 -- created for a user-defined operation, in which case the corres-
4766 -- ponding equality operation is not intrinsic, and the operation
4767 -- cannot be constant-folded. Else fold.
4769 if Nkind (N) = N_Op_Eq
4770 or else Comes_From_Source (Entity (N))
4771 or else Ekind (Entity (N)) = E_Operator
4772 or else Is_Intrinsic_Subprogram
4773 (Corresponding_Equality (Entity (N)))
4775 Eval_Relational_Op (N);
4776 elsif Nkind (N) = N_Op_Ne
4777 and then Is_Abstract (Entity (N))
4779 Error_Msg_NE ("cannot call
abstract subprogram
&!", N, Entity (N));
4782 end Resolve_Equality_Op;
4784 ----------------------------------
4785 -- Resolve_Explicit_Dereference --
4786 ----------------------------------
4788 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
4789 P : constant Node_Id := Prefix (N);
4794 -- Now that we know the type, check that this is not a
4795 -- dereference of an uncompleted type. Note that this
4796 -- is not entirely correct, because dereferences of
4797 -- private types are legal in default expressions.
4798 -- This consideration also applies to similar checks
4799 -- for allocators, qualified expressions, and type
4802 Check_Fully_Declared (Typ, N);
4804 if Is_Overloaded (P) then
4806 -- Use the context type to select the prefix that has the
4807 -- correct designated type.
4809 Get_First_Interp (P, I, It);
4810 while Present (It.Typ) loop
4811 exit when Is_Access_Type (It.Typ)
4812 and then Covers (Typ, Designated_Type (It.Typ));
4814 Get_Next_Interp (I, It);
4817 Resolve (P, It.Typ);
4818 Set_Etype (N, Designated_Type (It.Typ));
4824 if Is_Access_Type (Etype (P)) then
4825 Apply_Access_Check (N);
4828 -- If the designated type is a packed unconstrained array type,
4829 -- and the explicit dereference is not in the context of an
4830 -- attribute reference, then we must compute and set the actual
4831 -- subtype, since it is needed by Gigi. The reason we exclude
4832 -- the attribute case is that this is handled fine by Gigi, and
4833 -- in fact we use such attributes to build the actual subtype.
4834 -- We also exclude generated code (which builds actual subtypes
4835 -- directly if they are needed).
4837 if Is_Array_Type (Etype (N))
4838 and then Is_Packed (Etype (N))
4839 and then not Is_Constrained (Etype (N))
4840 and then Nkind (Parent (N)) /= N_Attribute_Reference
4841 and then Comes_From_Source (N)
4843 Set_Etype (N, Get_Actual_Subtype (N));
4846 -- Note: there is no Eval processing required for an explicit
4847 -- deference, because the type is known to be an allocators, and
4848 -- allocator expressions can never be static.
4850 end Resolve_Explicit_Dereference;
4852 -------------------------------
4853 -- Resolve_Indexed_Component --
4854 -------------------------------
4856 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
4857 Name : constant Node_Id := Prefix (N);
4859 Array_Type : Entity_Id := Empty; -- to prevent junk warning
4863 if Is_Overloaded (Name) then
4865 -- Use the context type to select the prefix that yields the
4866 -- correct component type.
4871 I1 : Interp_Index := 0;
4872 P : constant Node_Id := Prefix (N);
4873 Found : Boolean := False;
4876 Get_First_Interp (P, I, It);
4878 while Present (It.Typ) loop
4880 if (Is_Array_Type (It.Typ)
4881 and then Covers (Typ, Component_Type (It.Typ)))
4882 or else (Is_Access_Type (It.Typ)
4883 and then Is_Array_Type (Designated_Type (It.Typ))
4885 (Typ, Component_Type (Designated_Type (It.Typ))))
4888 It := Disambiguate (P, I1, I, Any_Type);
4890 if It = No_Interp then
4891 Error_Msg_N ("ambiguous prefix
for indexing
", N);
4897 Array_Type := It.Typ;
4903 Array_Type := It.Typ;
4908 Get_Next_Interp (I, It);
4913 Array_Type := Etype (Name);
4916 Resolve (Name, Array_Type);
4917 Array_Type := Get_Actual_Subtype_If_Available (Name);
4919 -- If prefix is access type, dereference to get real array type.
4920 -- Note: we do not apply an access check because the expander always
4921 -- introduces an explicit dereference, and the check will happen there.
4923 if Is_Access_Type (Array_Type) then
4924 Array_Type := Designated_Type (Array_Type);
4927 -- If name was overloaded, set component type correctly now.
4929 Set_Etype (N, Component_Type (Array_Type));
4931 Index := First_Index (Array_Type);
4932 Expr := First (Expressions (N));
4934 -- The prefix may have resolved to a string literal, in which case
4935 -- its etype has a special representation. This is only possible
4936 -- currently if the prefix is a static concatenation, written in
4937 -- functional notation.
4939 if Ekind (Array_Type) = E_String_Literal_Subtype then
4940 Resolve (Expr, Standard_Positive);
4943 while Present (Index) and Present (Expr) loop
4944 Resolve (Expr, Etype (Index));
4945 Check_Unset_Reference (Expr);
4947 if Is_Scalar_Type (Etype (Expr)) then
4948 Apply_Scalar_Range_Check (Expr, Etype (Index));
4950 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
4958 Eval_Indexed_Component (N);
4959 end Resolve_Indexed_Component;
4961 -----------------------------
4962 -- Resolve_Integer_Literal --
4963 -----------------------------
4965 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
4968 Eval_Integer_Literal (N);
4969 end Resolve_Integer_Literal;
4971 --------------------------------
4972 -- Resolve_Intrinsic_Operator --
4973 --------------------------------
4975 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
4976 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
4984 while Scope (Op) /= Standard_Standard loop
4986 pragma Assert (Present (Op));
4990 Set_Is_Overloaded (N, False);
4992 -- If the operand type is private, rewrite with suitable
4993 -- conversions on the operands and the result, to expose
4994 -- the proper underlying numeric type.
4996 if Is_Private_Type (Typ) then
4997 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
4999 if Nkind (N) = N_Op_Expon then
5000 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
5002 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
5005 Save_Interps (Left_Opnd (N), Expression (Arg1));
5006 Save_Interps (Right_Opnd (N), Expression (Arg2));
5008 Set_Left_Opnd (N, Arg1);
5009 Set_Right_Opnd (N, Arg2);
5011 Set_Etype (N, Btyp);
5012 Rewrite (N, Unchecked_Convert_To (Typ, N));
5015 elsif Typ /= Etype (Left_Opnd (N))
5016 or else Typ /= Etype (Right_Opnd (N))
5018 -- Add explicit conversion where needed, and save interpretations
5019 -- in case operands are overloaded.
5021 Arg1 := Convert_To (Typ, Left_Opnd (N));
5022 Arg2 := Convert_To (Typ, Right_Opnd (N));
5024 if Nkind (Arg1) = N_Type_Conversion then
5025 Save_Interps (Left_Opnd (N), Expression (Arg1));
5027 Save_Interps (Left_Opnd (N), Arg1);
5030 if Nkind (Arg2) = N_Type_Conversion then
5031 Save_Interps (Right_Opnd (N), Expression (Arg2));
5033 Save_Interps (Right_Opnd (N), Arg2);
5036 Rewrite (Left_Opnd (N), Arg1);
5037 Rewrite (Right_Opnd (N), Arg2);
5040 Resolve_Arithmetic_Op (N, Typ);
5043 Resolve_Arithmetic_Op (N, Typ);
5045 end Resolve_Intrinsic_Operator;
5047 --------------------------------------
5048 -- Resolve_Intrinsic_Unary_Operator --
5049 --------------------------------------
5051 procedure Resolve_Intrinsic_Unary_Operator
5055 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
5062 while Scope (Op) /= Standard_Standard loop
5064 pragma Assert (Present (Op));
5069 if Is_Private_Type (Typ) then
5070 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
5071 Save_Interps (Right_Opnd (N), Expression (Arg2));
5073 Set_Right_Opnd (N, Arg2);
5075 Set_Etype (N, Btyp);
5076 Rewrite (N, Unchecked_Convert_To (Typ, N));
5080 Resolve_Unary_Op (N, Typ);
5082 end Resolve_Intrinsic_Unary_Operator;
5084 ------------------------
5085 -- Resolve_Logical_Op --
5086 ------------------------
5088 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
5092 Check_Direct_Boolean_Op (N);
5094 -- Predefined operations on scalar types yield the base type. On
5095 -- the other hand, logical operations on arrays yield the type of
5096 -- the arguments (and the context).
5098 if Is_Array_Type (Typ) then
5101 B_Typ := Base_Type (Typ);
5104 -- The following test is required because the operands of the operation
5105 -- may be literals, in which case the resulting type appears to be
5106 -- compatible with a signed integer type, when in fact it is compatible
5107 -- only with modular types. If the context itself is universal, the
5108 -- operation is illegal.
5110 if not Valid_Boolean_Arg (Typ) then
5111 Error_Msg_N ("invalid context
for logical operation
", N);
5112 Set_Etype (N, Any_Type);
5115 elsif Typ = Any_Modular then
5117 ("no modular
type available
in this context
", N);
5118 Set_Etype (N, Any_Type);
5120 elsif Is_Modular_Integer_Type (Typ)
5121 and then Etype (Left_Opnd (N)) = Universal_Integer
5122 and then Etype (Right_Opnd (N)) = Universal_Integer
5124 Check_For_Visible_Operator (N, B_Typ);
5127 Resolve (Left_Opnd (N), B_Typ);
5128 Resolve (Right_Opnd (N), B_Typ);
5130 Check_Unset_Reference (Left_Opnd (N));
5131 Check_Unset_Reference (Right_Opnd (N));
5133 Set_Etype (N, B_Typ);
5134 Generate_Operator_Reference (N, B_Typ);
5135 Eval_Logical_Op (N);
5136 end Resolve_Logical_Op;
5138 ---------------------------
5139 -- Resolve_Membership_Op --
5140 ---------------------------
5142 -- The context can only be a boolean type, and does not determine
5143 -- the arguments. Arguments should be unambiguous, but the preference
5144 -- rule for universal types applies.
5146 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
5147 pragma Warnings (Off, Typ);
5149 L : constant Node_Id := Left_Opnd (N);
5150 R : constant Node_Id := Right_Opnd (N);
5154 if L = Error or else R = Error then
5158 if not Is_Overloaded (R)
5160 (Etype (R) = Universal_Integer or else
5161 Etype (R) = Universal_Real)
5162 and then Is_Overloaded (L)
5166 T := Intersect_Types (L, R);
5170 Check_Unset_Reference (L);
5172 if Nkind (R) = N_Range
5173 and then not Is_Scalar_Type (T)
5175 Error_Msg_N ("scalar
type required
for range", R);
5178 if Is_Entity_Name (R) then
5179 Freeze_Expression (R);
5182 Check_Unset_Reference (R);
5185 Eval_Membership_Op (N);
5186 end Resolve_Membership_Op;
5192 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
5194 -- Handle restriction against anonymous null access values
5195 -- This restriction can be turned off using -gnatdh.
5197 -- Ada 2005 (AI-231): Remove restriction
5199 if Ada_Version < Ada_05
5200 and then not Debug_Flag_J
5201 and then Ekind (Typ) = E_Anonymous_Access_Type
5202 and then Comes_From_Source (N)
5204 -- In the common case of a call which uses an explicitly null
5205 -- value for an access parameter, give specialized error msg
5207 if Nkind (Parent (N)) = N_Procedure_Call_Statement
5209 Nkind (Parent (N)) = N_Function_Call
5212 ("null is not allowed as argument
for an
access parameter
", N);
5214 -- Standard message for all other cases (are there any?)
5218 ("null cannot be
of an anonymous
access type", N);
5222 -- In a distributed context, null for a remote access to subprogram
5223 -- may need to be replaced with a special record aggregate. In this
5224 -- case, return after having done the transformation.
5226 if (Ekind (Typ) = E_Record_Type
5227 or else Is_Remote_Access_To_Subprogram_Type (Typ))
5228 and then Remote_AST_Null_Value (N, Typ)
5233 -- The null literal takes its type from the context.
5238 -----------------------
5239 -- Resolve_Op_Concat --
5240 -----------------------
5242 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
5243 Btyp : constant Entity_Id := Base_Type (Typ);
5244 Op1 : constant Node_Id := Left_Opnd (N);
5245 Op2 : constant Node_Id := Right_Opnd (N);
5247 procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean);
5248 -- Internal procedure to resolve one operand of concatenation operator.
5249 -- The operand is either of the array type or of the component type.
5250 -- If the operand is an aggregate, and the component type is composite,
5251 -- this is ambiguous if component type has aggregates.
5253 -------------------------------
5254 -- Resolve_Concatenation_Arg --
5255 -------------------------------
5257 procedure Resolve_Concatenation_Arg (Arg : Node_Id; Is_Comp : Boolean) is
5261 or else (not Is_Overloaded (Arg)
5262 and then Etype (Arg) /= Any_Composite
5263 and then Covers (Component_Type (Typ), Etype (Arg)))
5265 Resolve (Arg, Component_Type (Typ));
5267 Resolve (Arg, Btyp);
5270 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
5272 if Nkind (Arg) = N_Aggregate
5273 and then Is_Composite_Type (Component_Type (Typ))
5275 if Is_Private_Type (Component_Type (Typ)) then
5276 Resolve (Arg, Btyp);
5279 Error_Msg_N ("ambiguous aggregate must be qualified
", Arg);
5280 Set_Etype (Arg, Any_Type);
5284 if Is_Overloaded (Arg)
5285 and then Has_Compatible_Type (Arg, Typ)
5286 and then Etype (Arg) /= Any_Type
5288 Error_Msg_N ("ambiguous operand
for concatenation
!", Arg);
5295 Get_First_Interp (Arg, I, It);
5297 while Present (It.Nam) loop
5299 if Base_Type (Etype (It.Nam)) = Base_Type (Typ)
5300 or else Base_Type (Etype (It.Nam)) =
5301 Base_Type (Component_Type (Typ))
5303 Error_Msg_Sloc := Sloc (It.Nam);
5304 Error_Msg_N ("\possible interpretation#
", Arg);
5307 Get_Next_Interp (I, It);
5312 Resolve (Arg, Component_Type (Typ));
5314 if Nkind (Arg) = N_String_Literal then
5315 Set_Etype (Arg, Component_Type (Typ));
5318 if Arg = Left_Opnd (N) then
5319 Set_Is_Component_Left_Opnd (N);
5321 Set_Is_Component_Right_Opnd (N);
5326 Resolve (Arg, Btyp);
5329 Check_Unset_Reference (Arg);
5330 end Resolve_Concatenation_Arg;
5332 -- Start of processing for Resolve_Op_Concat
5335 Set_Etype (N, Btyp);
5337 if Is_Limited_Composite (Btyp) then
5338 Error_Msg_N ("concatenation
not available
for limited array", N);
5339 Explain_Limited_Type (Btyp, N);
5342 -- If the operands are themselves concatenations, resolve them as
5343 -- such directly. This removes several layers of recursion and allows
5344 -- GNAT to handle larger multiple concatenations.
5346 if Nkind (Op1) = N_Op_Concat
5347 and then not Is_Array_Type (Component_Type (Typ))
5348 and then Entity (Op1) = Entity (N)
5350 Resolve_Op_Concat (Op1, Typ);
5352 Resolve_Concatenation_Arg
5353 (Op1, Is_Component_Left_Opnd (N));
5356 if Nkind (Op2) = N_Op_Concat
5357 and then not Is_Array_Type (Component_Type (Typ))
5358 and then Entity (Op2) = Entity (N)
5360 Resolve_Op_Concat (Op2, Typ);
5362 Resolve_Concatenation_Arg
5363 (Op2, Is_Component_Right_Opnd (N));
5366 Generate_Operator_Reference (N, Typ);
5368 if Is_String_Type (Typ) then
5369 Eval_Concatenation (N);
5372 -- If this is not a static concatenation, but the result is a
5373 -- string type (and not an array of strings) insure that static
5374 -- string operands have their subtypes properly constructed.
5376 if Nkind (N) /= N_String_Literal
5377 and then Is_Character_Type (Component_Type (Typ))
5379 Set_String_Literal_Subtype (Op1, Typ);
5380 Set_String_Literal_Subtype (Op2, Typ);
5382 end Resolve_Op_Concat;
5384 ----------------------
5385 -- Resolve_Op_Expon --
5386 ----------------------
5388 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
5389 B_Typ : constant Entity_Id := Base_Type (Typ);
5392 -- Catch attempts to do fixed-point exponentation with universal
5393 -- operands, which is a case where the illegality is not caught
5394 -- during normal operator analysis.
5396 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
5397 Error_Msg_N ("exponentiation
not available
for fixed point
", N);
5401 if Comes_From_Source (N)
5402 and then Ekind (Entity (N)) = E_Function
5403 and then Is_Imported (Entity (N))
5404 and then Is_Intrinsic_Subprogram (Entity (N))
5406 Resolve_Intrinsic_Operator (N, Typ);
5410 if Etype (Left_Opnd (N)) = Universal_Integer
5411 or else Etype (Left_Opnd (N)) = Universal_Real
5413 Check_For_Visible_Operator (N, B_Typ);
5416 -- We do the resolution using the base type, because intermediate values
5417 -- in expressions always are of the base type, not a subtype of it.
5419 Resolve (Left_Opnd (N), B_Typ);
5420 Resolve (Right_Opnd (N), Standard_Integer);
5422 Check_Unset_Reference (Left_Opnd (N));
5423 Check_Unset_Reference (Right_Opnd (N));
5425 Set_Etype (N, B_Typ);
5426 Generate_Operator_Reference (N, B_Typ);
5429 -- Set overflow checking bit. Much cleverer code needed here eventually
5430 -- and perhaps the Resolve routines should be separated for the various
5431 -- arithmetic operations, since they will need different processing. ???
5433 if Nkind (N) in N_Op then
5434 if not Overflow_Checks_Suppressed (Etype (N)) then
5435 Enable_Overflow_Check (N);
5438 end Resolve_Op_Expon;
5440 --------------------
5441 -- Resolve_Op_Not --
5442 --------------------
5444 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
5447 function Parent_Is_Boolean return Boolean;
5448 -- This function determines if the parent node is a boolean operator
5449 -- or operation (comparison op, membership test, or short circuit form)
5450 -- and the not in question is the left operand of this operation.
5451 -- Note that if the not is in parens, then false is returned.
5453 function Parent_Is_Boolean return Boolean is
5455 if Paren_Count (N) /= 0 then
5459 case Nkind (Parent (N)) is
5474 return Left_Opnd (Parent (N)) = N;
5480 end Parent_Is_Boolean;
5482 -- Start of processing for Resolve_Op_Not
5485 -- Predefined operations on scalar types yield the base type. On
5486 -- the other hand, logical operations on arrays yield the type of
5487 -- the arguments (and the context).
5489 if Is_Array_Type (Typ) then
5492 B_Typ := Base_Type (Typ);
5495 if not Valid_Boolean_Arg (Typ) then
5496 Error_Msg_N ("invalid operand
type for operator
&", N);
5497 Set_Etype (N, Any_Type);
5500 elsif Typ = Universal_Integer or else Typ = Any_Modular then
5501 if Parent_Is_Boolean then
5503 ("operand
of not must be enclosed
in parentheses
",
5507 ("no modular
type available
in this context
", N);
5510 Set_Etype (N, Any_Type);
5514 if not Is_Boolean_Type (Typ)
5515 and then Parent_Is_Boolean
5517 Error_Msg_N ("?
not expression should be parenthesized here
", N);
5520 Resolve (Right_Opnd (N), B_Typ);
5521 Check_Unset_Reference (Right_Opnd (N));
5522 Set_Etype (N, B_Typ);
5523 Generate_Operator_Reference (N, B_Typ);
5528 -----------------------------
5529 -- Resolve_Operator_Symbol --
5530 -----------------------------
5532 -- Nothing to be done, all resolved already
5534 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
5535 pragma Warnings (Off, N);
5536 pragma Warnings (Off, Typ);
5540 end Resolve_Operator_Symbol;
5542 ----------------------------------
5543 -- Resolve_Qualified_Expression --
5544 ----------------------------------
5546 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
5547 pragma Warnings (Off, Typ);
5549 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
5550 Expr : constant Node_Id := Expression (N);
5553 Resolve (Expr, Target_Typ);
5555 -- A qualified expression requires an exact match of the type,
5556 -- class-wide matching is not allowed.
5558 if Is_Class_Wide_Type (Target_Typ)
5559 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
5561 Wrong_Type (Expr, Target_Typ);
5564 -- If the target type is unconstrained, then we reset the type of
5565 -- the result from the type of the expression. For other cases, the
5566 -- actual subtype of the expression is the target type.
5568 if Is_Composite_Type (Target_Typ)
5569 and then not Is_Constrained (Target_Typ)
5571 Set_Etype (N, Etype (Expr));
5574 Eval_Qualified_Expression (N);
5575 end Resolve_Qualified_Expression;
5581 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
5582 L : constant Node_Id := Low_Bound (N);
5583 H : constant Node_Id := High_Bound (N);
5590 Check_Unset_Reference (L);
5591 Check_Unset_Reference (H);
5593 -- We have to check the bounds for being within the base range as
5594 -- required for a non-static context. Normally this is automatic
5595 -- and done as part of evaluating expressions, but the N_Range
5596 -- node is an exception, since in GNAT we consider this node to
5597 -- be a subexpression, even though in Ada it is not. The circuit
5598 -- in Sem_Eval could check for this, but that would put the test
5599 -- on the main evaluation path for expressions.
5601 Check_Non_Static_Context (L);
5602 Check_Non_Static_Context (H);
5604 -- If bounds are static, constant-fold them, so size computations
5605 -- are identical between front-end and back-end. Do not perform this
5606 -- transformation while analyzing generic units, as type information
5607 -- would then be lost when reanalyzing the constant node in the
5610 if Is_Discrete_Type (Typ) and then Expander_Active then
5611 if Is_OK_Static_Expression (L) then
5612 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
5615 if Is_OK_Static_Expression (H) then
5616 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
5621 --------------------------
5622 -- Resolve_Real_Literal --
5623 --------------------------
5625 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
5626 Actual_Typ : constant Entity_Id := Etype (N);
5629 -- Special processing for fixed-point literals to make sure that the
5630 -- value is an exact multiple of small where this is required. We
5631 -- skip this for the universal real case, and also for generic types.
5633 if Is_Fixed_Point_Type (Typ)
5634 and then Typ /= Universal_Fixed
5635 and then Typ /= Any_Fixed
5636 and then not Is_Generic_Type (Typ)
5639 Val : constant Ureal := Realval (N);
5640 Cintr : constant Ureal := Val / Small_Value (Typ);
5641 Cint : constant Uint := UR_Trunc (Cintr);
5642 Den : constant Uint := Norm_Den (Cintr);
5646 -- Case of literal is not an exact multiple of the Small
5650 -- For a source program literal for a decimal fixed-point
5651 -- type, this is statically illegal (RM 4.9(36)).
5653 if Is_Decimal_Fixed_Point_Type (Typ)
5654 and then Actual_Typ = Universal_Real
5655 and then Comes_From_Source (N)
5657 Error_Msg_N ("value has extraneous low order
digits", N);
5660 -- Replace literal by a value that is the exact representation
5661 -- of a value of the type, i.e. a multiple of the small value,
5662 -- by truncation, since Machine_Rounds is false for all GNAT
5663 -- fixed-point types (RM 4.9(38)).
5665 Stat := Is_Static_Expression (N);
5667 Make_Real_Literal (Sloc (N),
5668 Realval => Small_Value (Typ) * Cint));
5670 Set_Is_Static_Expression (N, Stat);
5673 -- In all cases, set the corresponding integer field
5675 Set_Corresponding_Integer_Value (N, Cint);
5679 -- Now replace the actual type by the expected type as usual
5682 Eval_Real_Literal (N);
5683 end Resolve_Real_Literal;
5685 -----------------------
5686 -- Resolve_Reference --
5687 -----------------------
5689 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
5690 P : constant Node_Id := Prefix (N);
5693 -- Replace general access with specific type
5695 if Ekind (Etype (N)) = E_Allocator_Type then
5696 Set_Etype (N, Base_Type (Typ));
5699 Resolve (P, Designated_Type (Etype (N)));
5701 -- If we are taking the reference of a volatile entity, then treat
5702 -- it as a potential modification of this entity. This is much too
5703 -- conservative, but is necessary because remove side effects can
5704 -- result in transformations of normal assignments into reference
5705 -- sequences that otherwise fail to notice the modification.
5707 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
5708 Note_Possible_Modification (P);
5710 end Resolve_Reference;
5712 --------------------------------
5713 -- Resolve_Selected_Component --
5714 --------------------------------
5716 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
5718 Comp1 : Entity_Id := Empty; -- prevent junk warning
5719 P : constant Node_Id := Prefix (N);
5720 S : constant Node_Id := Selector_Name (N);
5721 T : Entity_Id := Etype (P);
5723 I1 : Interp_Index := 0; -- prevent junk warning
5728 function Init_Component return Boolean;
5729 -- Check whether this is the initialization of a component within an
5730 -- init proc (by assignment or call to another init proc). If true,
5731 -- there is no need for a discriminant check.
5733 --------------------
5734 -- Init_Component --
5735 --------------------
5737 function Init_Component return Boolean is
5739 return Inside_Init_Proc
5740 and then Nkind (Prefix (N)) = N_Identifier
5741 and then Chars (Prefix (N)) = Name_uInit
5742 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
5745 -- Start of processing for Resolve_Selected_Component
5748 if Is_Overloaded (P) then
5750 -- Use the context type to select the prefix that has a selector
5751 -- of the correct name and type.
5754 Get_First_Interp (P, I, It);
5756 Search : while Present (It.Typ) loop
5757 if Is_Access_Type (It.Typ) then
5758 T := Designated_Type (It.Typ);
5763 if Is_Record_Type (T) then
5764 Comp := First_Entity (T);
5766 while Present (Comp) loop
5768 if Chars (Comp) = Chars (S)
5769 and then Covers (Etype (Comp), Typ)
5778 It := Disambiguate (P, I1, I, Any_Type);
5780 if It = No_Interp then
5782 ("ambiguous prefix
for selected component
", N);
5789 if Scope (Comp1) /= It1.Typ then
5791 -- Resolution chooses the new interpretation.
5792 -- Find the component with the right name.
5794 Comp1 := First_Entity (It1.Typ);
5796 while Present (Comp1)
5797 and then Chars (Comp1) /= Chars (S)
5799 Comp1 := Next_Entity (Comp1);
5808 Comp := Next_Entity (Comp);
5813 Get_Next_Interp (I, It);
5816 Resolve (P, It1.Typ);
5818 Set_Entity (S, Comp1);
5821 -- Resolve prefix with its type
5826 -- Deal with access type case
5828 if Is_Access_Type (Etype (P)) then
5829 Apply_Access_Check (N);
5830 T := Designated_Type (Etype (P));
5835 if Has_Discriminants (T)
5836 and then (Ekind (Entity (S)) = E_Component
5838 Ekind (Entity (S)) = E_Discriminant)
5839 and then Present (Original_Record_Component (Entity (S)))
5840 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
5841 and then Present (Discriminant_Checking_Func
5842 (Original_Record_Component (Entity (S))))
5843 and then not Discriminant_Checks_Suppressed (T)
5844 and then not Init_Component
5846 Set_Do_Discriminant_Check (N);
5849 if Ekind (Entity (S)) = E_Void then
5850 Error_Msg_N ("premature
use of component
", S);
5853 -- If the prefix is a record conversion, this may be a renamed
5854 -- discriminant whose bounds differ from those of the original
5855 -- one, so we must ensure that a range check is performed.
5857 if Nkind (P) = N_Type_Conversion
5858 and then Ekind (Entity (S)) = E_Discriminant
5859 and then Is_Discrete_Type (Typ)
5861 Set_Etype (N, Base_Type (Typ));
5864 -- Note: No Eval processing is required, because the prefix is of a
5865 -- record type, or protected type, and neither can possibly be static.
5867 end Resolve_Selected_Component;
5873 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
5874 B_Typ : constant Entity_Id := Base_Type (Typ);
5875 L : constant Node_Id := Left_Opnd (N);
5876 R : constant Node_Id := Right_Opnd (N);
5879 -- We do the resolution using the base type, because intermediate values
5880 -- in expressions always are of the base type, not a subtype of it.
5883 Resolve (R, Standard_Natural);
5885 Check_Unset_Reference (L);
5886 Check_Unset_Reference (R);
5888 Set_Etype (N, B_Typ);
5889 Generate_Operator_Reference (N, B_Typ);
5893 ---------------------------
5894 -- Resolve_Short_Circuit --
5895 ---------------------------
5897 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
5898 B_Typ : constant Entity_Id := Base_Type (Typ);
5899 L : constant Node_Id := Left_Opnd (N);
5900 R : constant Node_Id := Right_Opnd (N);
5906 Check_Unset_Reference (L);
5907 Check_Unset_Reference (R);
5909 Set_Etype (N, B_Typ);
5910 Eval_Short_Circuit (N);
5911 end Resolve_Short_Circuit;
5917 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
5918 Name : constant Node_Id := Prefix (N);
5919 Drange : constant Node_Id := Discrete_Range (N);
5920 Array_Type : Entity_Id := Empty;
5924 if Is_Overloaded (Name) then
5926 -- Use the context type to select the prefix that yields the
5927 -- correct array type.
5931 I1 : Interp_Index := 0;
5933 P : constant Node_Id := Prefix (N);
5934 Found : Boolean := False;
5937 Get_First_Interp (P, I, It);
5939 while Present (It.Typ) loop
5941 if (Is_Array_Type (It.Typ)
5942 and then Covers (Typ, It.Typ))
5943 or else (Is_Access_Type (It.Typ)
5944 and then Is_Array_Type (Designated_Type (It.Typ))
5945 and then Covers (Typ, Designated_Type (It.Typ)))
5948 It := Disambiguate (P, I1, I, Any_Type);
5950 if It = No_Interp then
5951 Error_Msg_N ("ambiguous prefix
for slicing
", N);
5956 Array_Type := It.Typ;
5961 Array_Type := It.Typ;
5966 Get_Next_Interp (I, It);
5971 Array_Type := Etype (Name);
5974 Resolve (Name, Array_Type);
5976 if Is_Access_Type (Array_Type) then
5977 Apply_Access_Check (N);
5978 Array_Type := Designated_Type (Array_Type);
5980 elsif Is_Entity_Name (Name)
5981 or else (Nkind (Name) = N_Function_Call
5982 and then not Is_Constrained (Etype (Name)))
5984 Array_Type := Get_Actual_Subtype (Name);
5987 -- If name was overloaded, set slice type correctly now
5989 Set_Etype (N, Array_Type);
5991 -- If the range is specified by a subtype mark, no resolution
5994 if not Is_Entity_Name (Drange) then
5995 Index := First_Index (Array_Type);
5996 Resolve (Drange, Base_Type (Etype (Index)));
5998 if Nkind (Drange) = N_Range then
5999 Apply_Range_Check (Drange, Etype (Index));
6003 Set_Slice_Subtype (N);
6007 ----------------------------
6008 -- Resolve_String_Literal --
6009 ----------------------------
6011 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
6012 C_Typ : constant Entity_Id := Component_Type (Typ);
6013 R_Typ : constant Entity_Id := Root_Type (C_Typ);
6014 Loc : constant Source_Ptr := Sloc (N);
6015 Str : constant String_Id := Strval (N);
6016 Strlen : constant Nat := String_Length (Str);
6017 Subtype_Id : Entity_Id;
6018 Need_Check : Boolean;
6021 -- For a string appearing in a concatenation, defer creation of the
6022 -- string_literal_subtype until the end of the resolution of the
6023 -- concatenation, because the literal may be constant-folded away.
6024 -- This is a useful optimization for long concatenation expressions.
6026 -- If the string is an aggregate built for a single character (which
6027 -- happens in a non-static context) or a is null string to which special
6028 -- checks may apply, we build the subtype. Wide strings must also get
6029 -- a string subtype if they come from a one character aggregate. Strings
6030 -- generated by attributes might be static, but it is often hard to
6031 -- determine whether the enclosing context is static, so we generate
6032 -- subtypes for them as well, thus losing some rarer optimizations ???
6033 -- Same for strings that come from a static conversion.
6036 (Strlen = 0 and then Typ /= Standard_String)
6037 or else Nkind (Parent (N)) /= N_Op_Concat
6038 or else (N /= Left_Opnd (Parent (N))
6039 and then N /= Right_Opnd (Parent (N)))
6040 or else (Typ = Standard_Wide_String
6041 and then Nkind (Original_Node (N)) /= N_String_Literal);
6043 -- If the resolving type is itself a string literal subtype, we
6044 -- can just reuse it, since there is no point in creating another.
6046 if Ekind (Typ) = E_String_Literal_Subtype then
6049 elsif Nkind (Parent (N)) = N_Op_Concat
6050 and then not Need_Check
6051 and then Nkind (Original_Node (N)) /= N_Character_Literal
6052 and then Nkind (Original_Node (N)) /= N_Attribute_Reference
6053 and then Nkind (Original_Node (N)) /= N_Qualified_Expression
6054 and then Nkind (Original_Node (N)) /= N_Type_Conversion
6058 -- Otherwise we must create a string literal subtype. Note that the
6059 -- whole idea of string literal subtypes is simply to avoid the need
6060 -- for building a full fledged array subtype for each literal.
6062 Set_String_Literal_Subtype (N, Typ);
6063 Subtype_Id := Etype (N);
6066 if Nkind (Parent (N)) /= N_Op_Concat
6069 Set_Etype (N, Subtype_Id);
6070 Eval_String_Literal (N);
6073 if Is_Limited_Composite (Typ)
6074 or else Is_Private_Composite (Typ)
6076 Error_Msg_N ("string literal
not available
for private array", N);
6077 Set_Etype (N, Any_Type);
6081 -- The validity of a null string has been checked in the
6082 -- call to Eval_String_Literal.
6087 -- Always accept string literal with component type Any_Character,
6088 -- which occurs in error situations and in comparisons of literals,
6089 -- both of which should accept all literals.
6091 elsif R_Typ = Any_Character then
6094 -- If the type is bit-packed, then we always tranform the string
6095 -- literal into a full fledged aggregate.
6097 elsif Is_Bit_Packed_Array (Typ) then
6100 -- Deal with cases of Wide_String and String
6103 -- For Standard.Wide_String, or any other type whose component
6104 -- type is Standard.Wide_Character, we know that all the
6105 -- characters in the string must be acceptable, since the parser
6106 -- accepted the characters as valid character literals.
6108 if R_Typ = Standard_Wide_Character then
6111 -- For the case of Standard.String, or any other type whose
6112 -- component type is Standard.Character, we must make sure that
6113 -- there are no wide characters in the string, i.e. that it is
6114 -- entirely composed of characters in range of type String.
6116 -- If the string literal is the result of a static concatenation,
6117 -- the test has already been performed on the components, and need
6120 elsif R_Typ = Standard_Character
6121 and then Nkind (Original_Node (N)) /= N_Op_Concat
6123 for J in 1 .. Strlen loop
6124 if not In_Character_Range (Get_String_Char (Str, J)) then
6126 -- If we are out of range, post error. This is one of the
6127 -- very few places that we place the flag in the middle of
6128 -- a token, right under the offending wide character.
6131 ("literal
out of range of type Character",
6132 Source_Ptr (Int (Loc) + J));
6137 -- If the root type is not a standard character, then we will convert
6138 -- the string into an aggregate and will let the aggregate code do
6146 -- See if the component type of the array corresponding to the
6147 -- string has compile time known bounds. If yes we can directly
6148 -- check whether the evaluation of the string will raise constraint
6149 -- error. Otherwise we need to transform the string literal into
6150 -- the corresponding character aggregate and let the aggregate
6151 -- code do the checking.
6153 if R_Typ = Standard_Wide_Character
6154 or else R_Typ = Standard_Character
6156 -- Check for the case of full range, where we are definitely OK
6158 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
6162 -- Here the range is not the complete base type range, so check
6165 Comp_Typ_Lo : constant Node_Id :=
6166 Type_Low_Bound (Component_Type (Typ));
6167 Comp_Typ_Hi : constant Node_Id :=
6168 Type_High_Bound (Component_Type (Typ));
6173 if Compile_Time_Known_Value (Comp_Typ_Lo)
6174 and then Compile_Time_Known_Value (Comp_Typ_Hi)
6176 for J in 1 .. Strlen loop
6177 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
6179 if Char_Val < Expr_Value (Comp_Typ_Lo)
6180 or else Char_Val > Expr_Value (Comp_Typ_Hi)
6182 Apply_Compile_Time_Constraint_Error
6183 (N, "character out of range?
", CE_Range_Check_Failed,
6184 Loc => Source_Ptr (Int (Loc) + J));
6194 -- If we got here we meed to transform the string literal into the
6195 -- equivalent qualified positional array aggregate. This is rather
6196 -- heavy artillery for this situation, but it is hard work to avoid.
6199 Lits : constant List_Id := New_List;
6200 P : Source_Ptr := Loc + 1;
6204 -- Build the character literals, we give them source locations
6205 -- that correspond to the string positions, which is a bit tricky
6206 -- given the possible presence of wide character escape sequences.
6208 for J in 1 .. Strlen loop
6209 C := Get_String_Char (Str, J);
6210 Set_Character_Literal_Name (C);
6213 Make_Character_Literal (P, Name_Find, C));
6215 if In_Character_Range (C) then
6218 -- Should we have a call to Skip_Wide here ???
6226 Make_Qualified_Expression (Loc,
6227 Subtype_Mark => New_Reference_To (Typ, Loc),
6229 Make_Aggregate (Loc, Expressions => Lits)));
6231 Analyze_And_Resolve (N, Typ);
6233 end Resolve_String_Literal;
6235 -----------------------------
6236 -- Resolve_Subprogram_Info --
6237 -----------------------------
6239 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
6242 end Resolve_Subprogram_Info;
6244 -----------------------------
6245 -- Resolve_Type_Conversion --
6246 -----------------------------
6248 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
6249 Target_Type : constant Entity_Id := Etype (N);
6250 Conv_OK : constant Boolean := Conversion_OK (N);
6252 Opnd_Type : Entity_Id;
6258 Operand := Expression (N);
6261 and then not Valid_Conversion (N, Target_Type, Operand)
6266 if Etype (Operand) = Any_Fixed then
6268 -- Mixed-mode operation involving a literal. Context must be a fixed
6269 -- type which is applied to the literal subsequently.
6271 if Is_Fixed_Point_Type (Typ) then
6272 Set_Etype (Operand, Universal_Real);
6274 elsif Is_Numeric_Type (Typ)
6275 and then (Nkind (Operand) = N_Op_Multiply
6276 or else Nkind (Operand) = N_Op_Divide)
6277 and then (Etype (Right_Opnd (Operand)) = Universal_Real
6278 or else Etype (Left_Opnd (Operand)) = Universal_Real)
6280 if Unique_Fixed_Point_Type (N) = Any_Type then
6281 return; -- expression is ambiguous.
6283 Set_Etype (Operand, Standard_Duration);
6286 if Etype (Right_Opnd (Operand)) = Universal_Real then
6287 Rop := New_Copy_Tree (Right_Opnd (Operand));
6289 Rop := New_Copy_Tree (Left_Opnd (Operand));
6292 Resolve (Rop, Standard_Long_Long_Float);
6294 if Realval (Rop) /= Ureal_0
6295 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
6297 Error_Msg_N ("universal real operand can only be interpreted?
",
6299 Error_Msg_N ("\as
Duration, and will lose precision?
", Rop);
6302 elsif Is_Numeric_Type (Typ)
6303 and then Nkind (Operand) in N_Op
6304 and then Unique_Fixed_Point_Type (N) /= Any_Type
6306 Set_Etype (Operand, Standard_Duration);
6309 Error_Msg_N ("invalid context
for mixed mode operation
", N);
6310 Set_Etype (Operand, Any_Type);
6315 Opnd_Type := Etype (Operand);
6318 -- Note: we do the Eval_Type_Conversion call before applying the
6319 -- required checks for a subtype conversion. This is important,
6320 -- since both are prepared under certain circumstances to change
6321 -- the type conversion to a constraint error node, but in the case
6322 -- of Eval_Type_Conversion this may reflect an illegality in the
6323 -- static case, and we would miss the illegality (getting only a
6324 -- warning message), if we applied the type conversion checks first.
6326 Eval_Type_Conversion (N);
6328 -- If after evaluation, we still have a type conversion, then we
6329 -- may need to apply checks required for a subtype conversion.
6331 -- Skip these type conversion checks if universal fixed operands
6332 -- operands involved, since range checks are handled separately for
6333 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
6335 if Nkind (N) = N_Type_Conversion
6336 and then not Is_Generic_Type (Root_Type (Target_Type))
6337 and then Target_Type /= Universal_Fixed
6338 and then Opnd_Type /= Universal_Fixed
6340 Apply_Type_Conversion_Checks (N);
6343 -- Issue warning for conversion of simple object to its own type
6344 -- We have to test the original nodes, since they may have been
6345 -- rewritten by various optimizations.
6347 Orig_N := Original_Node (N);
6349 if Warn_On_Redundant_Constructs
6350 and then Comes_From_Source (Orig_N)
6351 and then Nkind (Orig_N) = N_Type_Conversion
6352 and then not In_Instance
6354 Orig_N := Original_Node (Expression (Orig_N));
6355 Orig_T := Target_Type;
6357 -- If the node is part of a larger expression, the Target_Type
6358 -- may not be the original type of the node if the context is a
6359 -- condition. Recover original type to see if conversion is needed.
6361 if Is_Boolean_Type (Orig_T)
6362 and then Nkind (Parent (N)) in N_Op
6364 Orig_T := Etype (Parent (N));
6367 if Is_Entity_Name (Orig_N)
6368 and then Etype (Entity (Orig_N)) = Orig_T
6371 ("?useless conversion
, & has this
type", N, Entity (Orig_N));
6374 end Resolve_Type_Conversion;
6376 ----------------------
6377 -- Resolve_Unary_Op --
6378 ----------------------
6380 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
6381 B_Typ : constant Entity_Id := Base_Type (Typ);
6382 R : constant Node_Id := Right_Opnd (N);
6388 -- Generate warning for expressions like abs (x mod 2)
6390 if Warn_On_Redundant_Constructs
6391 and then Nkind (N) = N_Op_Abs
6393 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
6395 if OK and then Hi >= Lo and then Lo >= 0 then
6397 ("?
abs applied to known non
-negative value has no effect
", N);
6401 -- Generate warning for expressions like -5 mod 3
6403 if Paren_Count (N) = 0
6404 and then Nkind (N) = N_Op_Minus
6405 and then Nkind (Right_Opnd (N)) = N_Op_Mod
6406 and then Comes_From_Source (N)
6409 ("?unary minus expression should be parenthesized here
", N);
6412 if Comes_From_Source (N)
6413 and then Ekind (Entity (N)) = E_Function
6414 and then Is_Imported (Entity (N))
6415 and then Is_Intrinsic_Subprogram (Entity (N))
6417 Resolve_Intrinsic_Unary_Operator (N, Typ);
6421 if Etype (R) = Universal_Integer
6422 or else Etype (R) = Universal_Real
6424 Check_For_Visible_Operator (N, B_Typ);
6427 Set_Etype (N, B_Typ);
6430 Check_Unset_Reference (R);
6431 Generate_Operator_Reference (N, B_Typ);
6434 -- Set overflow checking bit. Much cleverer code needed here eventually
6435 -- and perhaps the Resolve routines should be separated for the various
6436 -- arithmetic operations, since they will need different processing ???
6438 if Nkind (N) in N_Op then
6439 if not Overflow_Checks_Suppressed (Etype (N)) then
6440 Enable_Overflow_Check (N);
6443 end Resolve_Unary_Op;
6445 ----------------------------------
6446 -- Resolve_Unchecked_Expression --
6447 ----------------------------------
6449 procedure Resolve_Unchecked_Expression
6454 Resolve (Expression (N), Typ, Suppress => All_Checks);
6456 end Resolve_Unchecked_Expression;
6458 ---------------------------------------
6459 -- Resolve_Unchecked_Type_Conversion --
6460 ---------------------------------------
6462 procedure Resolve_Unchecked_Type_Conversion
6466 pragma Warnings (Off, Typ);
6468 Operand : constant Node_Id := Expression (N);
6469 Opnd_Type : constant Entity_Id := Etype (Operand);
6472 -- Resolve operand using its own type.
6474 Resolve (Operand, Opnd_Type);
6475 Eval_Unchecked_Conversion (N);
6477 end Resolve_Unchecked_Type_Conversion;
6479 ------------------------------
6480 -- Rewrite_Operator_As_Call --
6481 ------------------------------
6483 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
6484 Loc : constant Source_Ptr := Sloc (N);
6485 Actuals : constant List_Id := New_List;
6489 if Nkind (N) in N_Binary_Op then
6490 Append (Left_Opnd (N), Actuals);
6493 Append (Right_Opnd (N), Actuals);
6496 Make_Function_Call (Sloc => Loc,
6497 Name => New_Occurrence_Of (Nam, Loc),
6498 Parameter_Associations => Actuals);
6500 Preserve_Comes_From_Source (New_N, N);
6501 Preserve_Comes_From_Source (Name (New_N), N);
6503 Set_Etype (N, Etype (Nam));
6504 end Rewrite_Operator_As_Call;
6506 ------------------------------
6507 -- Rewrite_Renamed_Operator --
6508 ------------------------------
6510 procedure Rewrite_Renamed_Operator
6515 Nam : constant Name_Id := Chars (Op);
6516 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
6520 -- Rewrite the operator node using the real operator, not its
6521 -- renaming. Exclude user-defined intrinsic operations of the same
6522 -- name, which are treated separately and rewritten as calls.
6524 if Ekind (Op) /= E_Function
6525 or else Chars (N) /= Nam
6527 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
6528 Set_Chars (Op_Node, Nam);
6529 Set_Etype (Op_Node, Etype (N));
6530 Set_Entity (Op_Node, Op);
6531 Set_Right_Opnd (Op_Node, Right_Opnd (N));
6533 -- Indicate that both the original entity and its renaming
6534 -- are referenced at this point.
6536 Generate_Reference (Entity (N), N);
6537 Generate_Reference (Op, N);
6540 Set_Left_Opnd (Op_Node, Left_Opnd (N));
6543 Rewrite (N, Op_Node);
6545 -- If the context type is private, add the appropriate conversions
6546 -- so that the operator is applied to the full view. This is done
6547 -- in the routines that resolve intrinsic operators,
6549 if Is_Intrinsic_Subprogram (Op)
6550 and then Is_Private_Type (Typ)
6553 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
6554 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
6555 Resolve_Intrinsic_Operator (N, Typ);
6557 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
6558 Resolve_Intrinsic_Unary_Operator (N, Typ);
6565 elsif Ekind (Op) = E_Function
6566 and then Is_Intrinsic_Subprogram (Op)
6568 -- Operator renames a user-defined operator of the same name. Use
6569 -- the original operator in the node, which is the one that gigi
6573 Set_Is_Overloaded (N, False);
6575 end Rewrite_Renamed_Operator;
6577 -----------------------
6578 -- Set_Slice_Subtype --
6579 -----------------------
6581 -- Build an implicit subtype declaration to represent the type delivered
6582 -- by the slice. This is an abbreviated version of an array subtype. We
6583 -- define an index subtype for the slice, using either the subtype name
6584 -- or the discrete range of the slice. To be consistent with index usage
6585 -- elsewhere, we create a list header to hold the single index. This list
6586 -- is not otherwise attached to the syntax tree.
6588 procedure Set_Slice_Subtype (N : Node_Id) is
6589 Loc : constant Source_Ptr := Sloc (N);
6590 Index_List : constant List_Id := New_List;
6592 Index_Subtype : Entity_Id;
6593 Index_Type : Entity_Id;
6594 Slice_Subtype : Entity_Id;
6595 Drange : constant Node_Id := Discrete_Range (N);
6598 if Is_Entity_Name (Drange) then
6599 Index_Subtype := Entity (Drange);
6602 -- We force the evaluation of a range. This is definitely needed in
6603 -- the renamed case, and seems safer to do unconditionally. Note in
6604 -- any case that since we will create and insert an Itype referring
6605 -- to this range, we must make sure any side effect removal actions
6606 -- are inserted before the Itype definition.
6608 if Nkind (Drange) = N_Range then
6609 Force_Evaluation (Low_Bound (Drange));
6610 Force_Evaluation (High_Bound (Drange));
6613 Index_Type := Base_Type (Etype (Drange));
6615 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
6617 Set_Scalar_Range (Index_Subtype, Drange);
6618 Set_Etype (Index_Subtype, Index_Type);
6619 Set_Size_Info (Index_Subtype, Index_Type);
6620 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
6623 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
6625 Index := New_Occurrence_Of (Index_Subtype, Loc);
6626 Set_Etype (Index, Index_Subtype);
6627 Append (Index, Index_List);
6629 Set_First_Index (Slice_Subtype, Index);
6630 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
6631 Set_Is_Constrained (Slice_Subtype, True);
6632 Init_Size_Align (Slice_Subtype);
6634 Check_Compile_Time_Size (Slice_Subtype);
6636 -- The Etype of the existing Slice node is reset to this slice
6637 -- subtype. Its bounds are obtained from its first index.
6639 Set_Etype (N, Slice_Subtype);
6641 -- In the packed case, this must be immediately frozen
6643 -- Couldn't we always freeze here??? and if we did, then the above
6644 -- call to Check_Compile_Time_Size could be eliminated, which would
6645 -- be nice, because then that routine could be made private to Freeze.
6647 if Is_Packed (Slice_Subtype) and not In_Default_Expression then
6648 Freeze_Itype (Slice_Subtype, N);
6651 end Set_Slice_Subtype;
6653 --------------------------------
6654 -- Set_String_Literal_Subtype --
6655 --------------------------------
6657 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
6658 Subtype_Id : Entity_Id;
6661 if Nkind (N) /= N_String_Literal then
6664 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
6667 Set_String_Literal_Length (Subtype_Id, UI_From_Int
6668 (String_Length (Strval (N))));
6669 Set_Etype (Subtype_Id, Base_Type (Typ));
6670 Set_Is_Constrained (Subtype_Id);
6672 -- The low bound is set from the low bound of the corresponding
6673 -- index type. Note that we do not store the high bound in the
6674 -- string literal subtype, but it can be deduced if necssary
6675 -- from the length and the low bound.
6677 Set_String_Literal_Low_Bound
6678 (Subtype_Id, Type_Low_Bound (Etype (First_Index (Typ))));
6680 Set_Etype (N, Subtype_Id);
6681 end Set_String_Literal_Subtype;
6683 -----------------------------
6684 -- Unique_Fixed_Point_Type --
6685 -----------------------------
6687 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
6688 T1 : Entity_Id := Empty;
6693 procedure Fixed_Point_Error;
6694 -- If true ambiguity, give details.
6696 procedure Fixed_Point_Error is
6698 Error_Msg_N ("ambiguous universal_fixed_expression
", N);
6699 Error_Msg_NE ("\possible interpretation as
}", N, T1);
6700 Error_Msg_NE ("\possible interpretation as
}", N, T2);
6701 end Fixed_Point_Error;
6704 -- The operations on Duration are visible, so Duration is always a
6705 -- possible interpretation.
6707 T1 := Standard_Duration;
6709 -- Look for fixed-point types in enclosing scopes.
6711 Scop := Current_Scope;
6712 while Scop /= Standard_Standard loop
6713 T2 := First_Entity (Scop);
6715 while Present (T2) loop
6716 if Is_Fixed_Point_Type (T2)
6717 and then Current_Entity (T2) = T2
6718 and then Scope (Base_Type (T2)) = Scop
6720 if Present (T1) then
6731 Scop := Scope (Scop);
6734 -- Look for visible fixed type declarations in the context.
6736 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
6737 while Present (Item) loop
6738 if Nkind (Item) = N_With_Clause then
6739 Scop := Entity (Name (Item));
6740 T2 := First_Entity (Scop);
6742 while Present (T2) loop
6743 if Is_Fixed_Point_Type (T2)
6744 and then Scope (Base_Type (T2)) = Scop
6745 and then (Is_Potentially_Use_Visible (T2)
6746 or else In_Use (T2))
6748 if Present (T1) then
6763 if Nkind (N) = N_Real_Literal then
6764 Error_Msg_NE ("real literal interpreted as
}?
", N, T1);
6767 Error_Msg_NE ("universal_fixed expression interpreted as
}?
", N, T1);
6771 end Unique_Fixed_Point_Type;
6773 ----------------------
6774 -- Valid_Conversion --
6775 ----------------------
6777 function Valid_Conversion
6780 Operand : Node_Id) return Boolean
6782 Target_Type : constant Entity_Id := Base_Type (Target);
6783 Opnd_Type : Entity_Id := Etype (Operand);
6785 function Conversion_Check
6787 Msg : String) return Boolean;
6788 -- Little routine to post Msg if Valid is False, returns Valid value
6790 function Valid_Tagged_Conversion
6791 (Target_Type : Entity_Id;
6792 Opnd_Type : Entity_Id) return Boolean;
6793 -- Specifically test for validity of tagged conversions
6795 ----------------------
6796 -- Conversion_Check --
6797 ----------------------
6799 function Conversion_Check
6801 Msg : String) return Boolean
6805 Error_Msg_N (Msg, Operand);
6809 end Conversion_Check;
6811 -----------------------------
6812 -- Valid_Tagged_Conversion --
6813 -----------------------------
6815 function Valid_Tagged_Conversion
6816 (Target_Type : Entity_Id;
6817 Opnd_Type : Entity_Id) return Boolean
6820 -- Upward conversions are allowed (RM 4.6(22)).
6822 if Covers (Target_Type, Opnd_Type)
6823 or else Is_Ancestor (Target_Type, Opnd_Type)
6827 -- Downward conversion are allowed if the operand is
6828 -- is class-wide (RM 4.6(23)).
6830 elsif Is_Class_Wide_Type (Opnd_Type)
6831 and then Covers (Opnd_Type, Target_Type)
6835 elsif Covers (Opnd_Type, Target_Type)
6836 or else Is_Ancestor (Opnd_Type, Target_Type)
6839 Conversion_Check (False,
6840 "downward conversion
of tagged objects
not allowed
");
6843 ("invalid
tagged conversion
, not compatible
with}",
6844 N, First_Subtype (Opnd_Type));
6847 end Valid_Tagged_Conversion;
6849 -- Start of processing for Valid_Conversion
6852 Check_Parameterless_Call (Operand);
6854 if Is_Overloaded (Operand) then
6863 -- Remove procedure calls, which syntactically cannot appear
6864 -- in this context, but which cannot be removed by type checking,
6865 -- because the context does not impose a type.
6867 Get_First_Interp (Operand, I, It);
6869 while Present (It.Typ) loop
6871 if It.Typ = Standard_Void_Type then
6875 Get_Next_Interp (I, It);
6878 Get_First_Interp (Operand, I, It);
6883 Error_Msg_N ("illegal operand
in conversion
", Operand);
6887 Get_Next_Interp (I, It);
6889 if Present (It.Typ) then
6891 It1 := Disambiguate (Operand, I1, I, Any_Type);
6893 if It1 = No_Interp then
6894 Error_Msg_N ("ambiguous operand
in conversion
", Operand);
6896 Error_Msg_Sloc := Sloc (It.Nam);
6897 Error_Msg_N ("possible interpretation#
!", Operand);
6899 Error_Msg_Sloc := Sloc (N1);
6900 Error_Msg_N ("possible interpretation#
!", Operand);
6906 Set_Etype (Operand, It1.Typ);
6907 Opnd_Type := It1.Typ;
6911 if Chars (Current_Scope) = Name_Unchecked_Conversion then
6913 -- This check is dubious, what if there were a user defined
6914 -- scope whose name was Unchecked_Conversion ???
6918 elsif Is_Numeric_Type (Target_Type) then
6919 if Opnd_Type = Universal_Fixed then
6922 elsif (In_Instance or else In_Inlined_Body)
6923 and then not Comes_From_Source (N)
6928 return Conversion_Check (Is_Numeric_Type (Opnd_Type),
6929 "illegal operand
for numeric conversion
");
6932 elsif Is_Array_Type (Target_Type) then
6933 if not Is_Array_Type (Opnd_Type)
6934 or else Opnd_Type = Any_Composite
6935 or else Opnd_Type = Any_String
6938 ("illegal operand
for array conversion
", Operand);
6941 elsif Number_Dimensions (Target_Type) /=
6942 Number_Dimensions (Opnd_Type)
6945 ("incompatible number
of dimensions
for conversion
", Operand);
6950 Target_Index : Node_Id := First_Index (Target_Type);
6951 Opnd_Index : Node_Id := First_Index (Opnd_Type);
6953 Target_Index_Type : Entity_Id;
6954 Opnd_Index_Type : Entity_Id;
6956 Target_Comp_Type : constant Entity_Id :=
6957 Component_Type (Target_Type);
6958 Opnd_Comp_Type : constant Entity_Id :=
6959 Component_Type (Opnd_Type);
6962 while Present (Target_Index) and then Present (Opnd_Index) loop
6963 Target_Index_Type := Etype (Target_Index);
6964 Opnd_Index_Type := Etype (Opnd_Index);
6966 if not (Is_Integer_Type (Target_Index_Type)
6967 and then Is_Integer_Type (Opnd_Index_Type))
6968 and then (Root_Type (Target_Index_Type)
6969 /= Root_Type (Opnd_Index_Type))
6972 ("incompatible index types
for array conversion
",
6977 Next_Index (Target_Index);
6978 Next_Index (Opnd_Index);
6981 if Base_Type (Target_Comp_Type) /=
6982 Base_Type (Opnd_Comp_Type)
6985 ("incompatible component types
for array conversion
",
6990 Is_Constrained (Target_Comp_Type)
6991 /= Is_Constrained (Opnd_Comp_Type)
6992 or else not Subtypes_Statically_Match
6993 (Target_Comp_Type, Opnd_Comp_Type)
6996 ("component subtypes must statically match
", Operand);
7005 elsif (Ekind (Target_Type) = E_General_Access_Type
7006 or else Ekind (Target_Type) = E_Anonymous_Access_Type)
7009 (Is_Access_Type (Opnd_Type)
7010 and then Ekind (Opnd_Type) /=
7011 E_Access_Subprogram_Type
7012 and then Ekind (Opnd_Type) /=
7013 E_Access_Protected_Subprogram_Type,
7014 "must be an
access-to
-object
type")
7016 if Is_Access_Constant (Opnd_Type)
7017 and then not Is_Access_Constant (Target_Type)
7020 ("access-to
-constant operand
type not allowed
", Operand);
7024 -- Check the static accessibility rule of 4.6(17). Note that
7025 -- the check is not enforced when within an instance body, since
7026 -- the RM requires such cases to be caught at run time.
7028 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
7029 if Type_Access_Level (Opnd_Type)
7030 > Type_Access_Level (Target_Type)
7032 -- In an instance, this is a run-time check, but one we
7033 -- know will fail, so generate an appropriate warning.
7034 -- The raise will be generated by Expand_N_Type_Conversion.
7036 if In_Instance_Body then
7038 ("?cannot convert local pointer to non
-local
access type",
7041 ("?Program_Error will be raised
at run time
", Operand);
7045 ("cannot convert local pointer to non
-local
access type",
7050 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type then
7052 -- When the operand is a selected access discriminant
7053 -- the check needs to be made against the level of the
7054 -- object denoted by the prefix of the selected name.
7055 -- (Object_Access_Level handles checking the prefix
7056 -- of the operand for this case.)
7058 if Nkind (Operand) = N_Selected_Component
7059 and then Object_Access_Level (Operand)
7060 > Type_Access_Level (Target_Type)
7062 -- In an instance, this is a run-time check, but one we
7063 -- know will fail, so generate an appropriate warning.
7064 -- The raise will be generated by Expand_N_Type_Conversion.
7066 if In_Instance_Body then
7068 ("?cannot convert
access discriminant to non
-local
" &
7069 " access type", Operand);
7071 ("?Program_Error will be raised
at run time
", Operand);
7075 ("cannot convert
access discriminant to non
-local
" &
7076 " access type", Operand);
7081 -- The case of a reference to an access discriminant
7082 -- from within a type declaration (which will appear
7083 -- as a discriminal) is always illegal because the
7084 -- level of the discriminant is considered to be
7085 -- deeper than any (namable) access type.
7087 if Is_Entity_Name (Operand)
7088 and then (Ekind (Entity (Operand)) = E_In_Parameter
7089 or else Ekind (Entity (Operand)) = E_Constant)
7090 and then Present (Discriminal_Link (Entity (Operand)))
7093 ("discriminant has deeper accessibility level than target
",
7101 Target : constant Entity_Id := Designated_Type (Target_Type);
7102 Opnd : constant Entity_Id := Designated_Type (Opnd_Type);
7105 if Is_Tagged_Type (Target) then
7106 return Valid_Tagged_Conversion (Target, Opnd);
7109 if Base_Type (Target) /= Base_Type (Opnd) then
7111 ("target designated
type not compatible
with }",
7112 N, Base_Type (Opnd));
7115 elsif not Subtypes_Statically_Match (Target, Opnd)
7116 and then (not Has_Discriminants (Target)
7117 or else Is_Constrained (Target))
7120 ("target designated
subtype not compatible
with }",
7130 elsif (Ekind (Target_Type) = E_Access_Subprogram_Type
7132 Ekind (Target_Type) = E_Anonymous_Access_Subprogram_Type)
7133 and then Conversion_Check
7134 (Ekind (Base_Type (Opnd_Type)) = E_Access_Subprogram_Type,
7135 "illegal operand
for access subprogram conversion
")
7137 -- Check that the designated types are subtype conformant
7139 if not Subtype_Conformant (Designated_Type (Opnd_Type),
7140 Designated_Type (Target_Type))
7143 ("operand
type is not subtype conformant
with target
type",
7147 -- Check the static accessibility rule of 4.6(20)
7149 if Type_Access_Level (Opnd_Type) >
7150 Type_Access_Level (Target_Type)
7153 ("operand
type has deeper accessibility level than target
",
7156 -- Check that if the operand type is declared in a generic body,
7157 -- then the target type must be declared within that same body
7158 -- (enforces last sentence of 4.6(20)).
7160 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
7162 O_Gen : constant Node_Id :=
7163 Enclosing_Generic_Body (Opnd_Type);
7166 Enclosing_Generic_Body (Target_Type);
7169 while Present (T_Gen) and then T_Gen /= O_Gen loop
7170 T_Gen := Enclosing_Generic_Body (T_Gen);
7173 if T_Gen /= O_Gen then
7175 ("target
type must be declared
in same
generic body"
7176 & " as operand
type", N);
7183 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
7184 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
7186 -- It is valid to convert from one RAS type to another provided
7187 -- that their specification statically match.
7189 Check_Subtype_Conformant
7191 Designated_Type (Corresponding_Remote_Type (Target_Type)),
7193 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
7198 elsif Is_Tagged_Type (Target_Type) then
7199 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
7201 -- Types derived from the same root type are convertible.
7203 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
7206 -- In an instance, there may be inconsistent views of the same
7207 -- type, or types derived from the same type.
7210 and then Underlying_Type (Target_Type) = Underlying_Type (Opnd_Type)
7214 -- Special check for common access type error case
7216 elsif Ekind (Target_Type) = E_Access_Type
7217 and then Is_Access_Type (Opnd_Type)
7219 Error_Msg_N ("target
type must be general
access type!", N);
7220 Error_Msg_NE ("add
ALL to
}!", N, Target_Type);
7225 Error_Msg_NE ("invalid conversion
, not compatible
with }",
7230 end Valid_Conversion;