1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree
; use Atree
;
27 with Checks
; use Checks
;
28 with Debug
; use Debug
;
29 with Debug_A
; use Debug_A
;
30 with Einfo
; use Einfo
;
31 with Elists
; use Elists
;
32 with Errout
; use Errout
;
33 with Expander
; use Expander
;
34 with Exp_Disp
; use Exp_Disp
;
35 with Exp_Ch6
; use Exp_Ch6
;
36 with Exp_Ch7
; use Exp_Ch7
;
37 with Exp_Tss
; use Exp_Tss
;
38 with Exp_Util
; use Exp_Util
;
39 with Fname
; use Fname
;
40 with Freeze
; use Freeze
;
41 with Itypes
; use Itypes
;
43 with Lib
.Xref
; use Lib
.Xref
;
44 with Namet
; use Namet
;
45 with Nmake
; use Nmake
;
46 with Nlists
; use Nlists
;
48 with Output
; use Output
;
49 with Restrict
; use Restrict
;
50 with Rident
; use Rident
;
51 with Rtsfind
; use Rtsfind
;
53 with Sem_Aux
; use Sem_Aux
;
54 with Sem_Aggr
; use Sem_Aggr
;
55 with Sem_Attr
; use Sem_Attr
;
56 with Sem_Cat
; use Sem_Cat
;
57 with Sem_Ch4
; use Sem_Ch4
;
58 with Sem_Ch6
; use Sem_Ch6
;
59 with Sem_Ch8
; use Sem_Ch8
;
60 with Sem_Ch13
; use Sem_Ch13
;
61 with Sem_Disp
; use Sem_Disp
;
62 with Sem_Dist
; use Sem_Dist
;
63 with Sem_Elim
; use Sem_Elim
;
64 with Sem_Elab
; use Sem_Elab
;
65 with Sem_Eval
; use Sem_Eval
;
66 with Sem_Intr
; use Sem_Intr
;
67 with Sem_Util
; use Sem_Util
;
68 with Sem_Type
; use Sem_Type
;
69 with Sem_Warn
; use Sem_Warn
;
70 with Sinfo
; use Sinfo
;
71 with Snames
; use Snames
;
72 with Stand
; use Stand
;
73 with Stringt
; use Stringt
;
74 with Style
; use Style
;
75 with Tbuild
; use Tbuild
;
76 with Uintp
; use Uintp
;
77 with Urealp
; use Urealp
;
79 package body Sem_Res
is
81 -----------------------
82 -- Local Subprograms --
83 -----------------------
85 -- Second pass (top-down) type checking and overload resolution procedures
86 -- Typ is the type required by context. These procedures propagate the
87 -- type information recursively to the descendants of N. If the node
88 -- is not overloaded, its Etype is established in the first pass. If
89 -- overloaded, the Resolve routines set the correct type. For arith.
90 -- operators, the Etype is the base type of the context.
92 -- Note that Resolve_Attribute is separated off in Sem_Attr
94 procedure Check_Discriminant_Use
(N
: Node_Id
);
95 -- Enforce the restrictions on the use of discriminants when constraining
96 -- a component of a discriminated type (record or concurrent type).
98 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
);
99 -- Given a node for an operator associated with type T, check that
100 -- the operator is visible. Operators all of whose operands are
101 -- universal must be checked for visibility during resolution
102 -- because their type is not determinable based on their operands.
104 procedure Check_Fully_Declared_Prefix
107 -- Check that the type of the prefix of a dereference is not incomplete
109 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean;
110 -- Given a call node, N, which is known to occur immediately within the
111 -- subprogram being called, determines whether it is a detectable case of
112 -- an infinite recursion, and if so, outputs appropriate messages. Returns
113 -- True if an infinite recursion is detected, and False otherwise.
115 procedure Check_Initialization_Call
(N
: Entity_Id
; Nam
: Entity_Id
);
116 -- If the type of the object being initialized uses the secondary stack
117 -- directly or indirectly, create a transient scope for the call to the
118 -- init proc. This is because we do not create transient scopes for the
119 -- initialization of individual components within the init proc itself.
120 -- Could be optimized away perhaps?
122 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
);
123 -- N is the node for a logical operator. If the operator is predefined, and
124 -- the root type of the operands is Standard.Boolean, then a check is made
125 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
126 -- the style check for Style_Check_Boolean_And_Or.
128 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean;
129 -- Determine whether E is an access type declared by an access
130 -- declaration, and not an (anonymous) allocator type.
132 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean;
133 -- Utility to check whether the name in the call is a predefined
134 -- operator, in which case the call is made into an operator node.
135 -- An instance of an intrinsic conversion operation may be given
136 -- an operator name, but is not treated like an operator.
138 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
);
139 -- If a default expression in entry call N depends on the discriminants
140 -- of the task, it must be replaced with a reference to the discriminant
141 -- of the task being called.
143 procedure Resolve_Op_Concat_Arg
148 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
149 -- concatenation operator. The operand is either of the array type or of
150 -- the component type. If the operand is an aggregate, and the component
151 -- type is composite, this is ambiguous if component type has aggregates.
153 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
);
154 -- Does the first part of the work of Resolve_Op_Concat
156 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
);
157 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
158 -- has been resolved. See Resolve_Op_Concat for details.
160 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
);
161 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
);
162 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
);
163 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
164 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
);
165 procedure Resolve_Conditional_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
166 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
);
167 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
);
168 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
);
169 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
);
170 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
171 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
);
172 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
);
173 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
);
174 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
);
175 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
);
176 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
);
177 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
);
178 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
179 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
);
180 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
181 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
);
182 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
);
183 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
);
184 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
);
185 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
);
186 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
187 procedure Resolve_Subprogram_Info
(N
: Node_Id
; Typ
: Entity_Id
);
188 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
189 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
);
190 procedure Resolve_Unchecked_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
191 procedure Resolve_Unchecked_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
193 function Operator_Kind
195 Is_Binary
: Boolean) return Node_Kind
;
196 -- Utility to map the name of an operator into the corresponding Node. Used
197 -- by other node rewriting procedures.
199 procedure Resolve_Actuals
(N
: Node_Id
; Nam
: Entity_Id
);
200 -- Resolve actuals of call, and add default expressions for missing ones.
201 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
202 -- called subprogram.
204 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
);
205 -- Called from Resolve_Call, when the prefix denotes an entry or element
206 -- of entry family. Actuals are resolved as for subprograms, and the node
207 -- is rebuilt as an entry call. Also called for protected operations. Typ
208 -- is the context type, which is used when the operation is a protected
209 -- function with no arguments, and the return value is indexed.
211 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
212 -- A call to a user-defined intrinsic operator is rewritten as a call
213 -- to the corresponding predefined operator, with suitable conversions.
215 procedure Resolve_Intrinsic_Unary_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
216 -- Ditto, for unary operators (only arithmetic ones)
218 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
);
219 -- If an operator node resolves to a call to a user-defined operator,
220 -- rewrite the node as a function call.
222 procedure Make_Call_Into_Operator
226 -- Inverse transformation: if an operator is given in functional notation,
227 -- then after resolving the node, transform into an operator node, so
228 -- that operands are resolved properly. Recall that predefined operators
229 -- do not have a full signature and special resolution rules apply.
231 procedure Rewrite_Renamed_Operator
235 -- An operator can rename another, e.g. in an instantiation. In that
236 -- case, the proper operator node must be constructed and resolved.
238 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
);
239 -- The String_Literal_Subtype is built for all strings that are not
240 -- operands of a static concatenation operation. If the argument is
241 -- not a N_String_Literal node, then the call has no effect.
243 procedure Set_Slice_Subtype
(N
: Node_Id
);
244 -- Build subtype of array type, with the range specified by the slice
246 procedure Simplify_Type_Conversion
(N
: Node_Id
);
247 -- Called after N has been resolved and evaluated, but before range checks
248 -- have been applied. Currently simplifies a combination of floating-point
249 -- to integer conversion and Truncation attribute.
251 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
;
252 -- A universal_fixed expression in an universal context is unambiguous
253 -- if there is only one applicable fixed point type. Determining whether
254 -- there is only one requires a search over all visible entities, and
255 -- happens only in very pathological cases (see 6115-006).
257 function Valid_Conversion
260 Operand
: Node_Id
) return Boolean;
261 -- Verify legality rules given in 4.6 (8-23). Target is the target
262 -- type of the conversion, which may be an implicit conversion of
263 -- an actual parameter to an anonymous access type (in which case
264 -- N denotes the actual parameter and N = Operand).
266 -------------------------
267 -- Ambiguous_Character --
268 -------------------------
270 procedure Ambiguous_Character
(C
: Node_Id
) is
274 if Nkind
(C
) = N_Character_Literal
then
275 Error_Msg_N
("ambiguous character literal", C
);
277 -- First the ones in Standard
280 ("\\possible interpretation: Character!", C
);
282 ("\\possible interpretation: Wide_Character!", C
);
284 -- Include Wide_Wide_Character in Ada 2005 mode
286 if Ada_Version
>= Ada_05
then
288 ("\\possible interpretation: Wide_Wide_Character!", C
);
291 -- Now any other types that match
293 E
:= Current_Entity
(C
);
294 while Present
(E
) loop
295 Error_Msg_NE
("\\possible interpretation:}!", C
, Etype
(E
));
299 end Ambiguous_Character
;
301 -------------------------
302 -- Analyze_And_Resolve --
303 -------------------------
305 procedure Analyze_And_Resolve
(N
: Node_Id
) is
309 end Analyze_And_Resolve
;
311 procedure Analyze_And_Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
315 end Analyze_And_Resolve
;
317 -- Version withs check(s) suppressed
319 procedure Analyze_And_Resolve
324 Scop
: constant Entity_Id
:= Current_Scope
;
327 if Suppress
= All_Checks
then
329 Svg
: constant Suppress_Array
:= Scope_Suppress
;
331 Scope_Suppress
:= (others => True);
332 Analyze_And_Resolve
(N
, Typ
);
333 Scope_Suppress
:= Svg
;
338 Svg
: constant Boolean := Scope_Suppress
(Suppress
);
341 Scope_Suppress
(Suppress
) := True;
342 Analyze_And_Resolve
(N
, Typ
);
343 Scope_Suppress
(Suppress
) := Svg
;
347 if Current_Scope
/= Scop
348 and then Scope_Is_Transient
350 -- This can only happen if a transient scope was created
351 -- for an inner expression, which will be removed upon
352 -- completion of the analysis of an enclosing construct.
353 -- The transient scope must have the suppress status of
354 -- the enclosing environment, not of this Analyze call.
356 Scope_Stack
.Table
(Scope_Stack
.Last
).Save_Scope_Suppress
:=
359 end Analyze_And_Resolve
;
361 procedure Analyze_And_Resolve
365 Scop
: constant Entity_Id
:= Current_Scope
;
368 if Suppress
= All_Checks
then
370 Svg
: constant Suppress_Array
:= Scope_Suppress
;
372 Scope_Suppress
:= (others => True);
373 Analyze_And_Resolve
(N
);
374 Scope_Suppress
:= Svg
;
379 Svg
: constant Boolean := Scope_Suppress
(Suppress
);
382 Scope_Suppress
(Suppress
) := True;
383 Analyze_And_Resolve
(N
);
384 Scope_Suppress
(Suppress
) := Svg
;
388 if Current_Scope
/= Scop
389 and then Scope_Is_Transient
391 Scope_Stack
.Table
(Scope_Stack
.Last
).Save_Scope_Suppress
:=
394 end Analyze_And_Resolve
;
396 ----------------------------
397 -- Check_Discriminant_Use --
398 ----------------------------
400 procedure Check_Discriminant_Use
(N
: Node_Id
) is
401 PN
: constant Node_Id
:= Parent
(N
);
402 Disc
: constant Entity_Id
:= Entity
(N
);
407 -- Any use in a spec-expression is legal
409 if In_Spec_Expression
then
412 elsif Nkind
(PN
) = N_Range
then
414 -- Discriminant cannot be used to constrain a scalar type
418 if Nkind
(P
) = N_Range_Constraint
419 and then Nkind
(Parent
(P
)) = N_Subtype_Indication
420 and then Nkind
(Parent
(Parent
(P
))) = N_Component_Definition
422 Error_Msg_N
("discriminant cannot constrain scalar type", N
);
424 elsif Nkind
(P
) = N_Index_Or_Discriminant_Constraint
then
426 -- The following check catches the unusual case where
427 -- a discriminant appears within an index constraint
428 -- that is part of a larger expression within a constraint
429 -- on a component, e.g. "C : Int range 1 .. F (new A(1 .. D))".
430 -- For now we only check case of record components, and
431 -- note that a similar check should also apply in the
432 -- case of discriminant constraints below. ???
434 -- Note that the check for N_Subtype_Declaration below is to
435 -- detect the valid use of discriminants in the constraints of a
436 -- subtype declaration when this subtype declaration appears
437 -- inside the scope of a record type (which is syntactically
438 -- illegal, but which may be created as part of derived type
439 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
442 if Ekind
(Current_Scope
) = E_Record_Type
443 and then Scope
(Disc
) = Current_Scope
445 (Nkind
(Parent
(P
)) = N_Subtype_Indication
447 Nkind_In
(Parent
(Parent
(P
)), N_Component_Definition
,
448 N_Subtype_Declaration
)
449 and then Paren_Count
(N
) = 0)
452 ("discriminant must appear alone in component constraint", N
);
456 -- Detect a common error:
458 -- type R (D : Positive := 100) is record
459 -- Name : String (1 .. D);
462 -- The default value causes an object of type R to be allocated
463 -- with room for Positive'Last characters. The RM does not mandate
464 -- the allocation of the maximum size, but that is what GNAT does
465 -- so we should warn the programmer that there is a problem.
467 Check_Large
: declare
473 function Large_Storage_Type
(T
: Entity_Id
) return Boolean;
474 -- Return True if type T has a large enough range that
475 -- any array whose index type covered the whole range of
476 -- the type would likely raise Storage_Error.
478 ------------------------
479 -- Large_Storage_Type --
480 ------------------------
482 function Large_Storage_Type
(T
: Entity_Id
) return Boolean is
484 -- The type is considered large if its bounds are known at
485 -- compile time and if it requires at least as many bits as
486 -- a Positive to store the possible values.
488 return Compile_Time_Known_Value
(Type_Low_Bound
(T
))
489 and then Compile_Time_Known_Value
(Type_High_Bound
(T
))
491 Minimum_Size
(T
, Biased
=> True) >=
492 RM_Size
(Standard_Positive
);
493 end Large_Storage_Type
;
495 -- Start of processing for Check_Large
498 -- Check that the Disc has a large range
500 if not Large_Storage_Type
(Etype
(Disc
)) then
504 -- If the enclosing type is limited, we allocate only the
505 -- default value, not the maximum, and there is no need for
508 if Is_Limited_Type
(Scope
(Disc
)) then
512 -- Check that it is the high bound
514 if N
/= High_Bound
(PN
)
515 or else No
(Discriminant_Default_Value
(Disc
))
520 -- Check the array allows a large range at this bound.
521 -- First find the array
525 if Nkind
(SI
) /= N_Subtype_Indication
then
529 T
:= Entity
(Subtype_Mark
(SI
));
531 if not Is_Array_Type
(T
) then
535 -- Next, find the dimension
537 TB
:= First_Index
(T
);
538 CB
:= First
(Constraints
(P
));
540 and then Present
(TB
)
541 and then Present
(CB
)
552 -- Now, check the dimension has a large range
554 if not Large_Storage_Type
(Etype
(TB
)) then
558 -- Warn about the danger
561 ("?creation of & object may raise Storage_Error!",
570 -- Legal case is in index or discriminant constraint
572 elsif Nkind_In
(PN
, N_Index_Or_Discriminant_Constraint
,
573 N_Discriminant_Association
)
575 if Paren_Count
(N
) > 0 then
577 ("discriminant in constraint must appear alone", N
);
579 elsif Nkind
(N
) = N_Expanded_Name
580 and then Comes_From_Source
(N
)
583 ("discriminant must appear alone as a direct name", N
);
588 -- Otherwise, context is an expression. It should not be within
589 -- (i.e. a subexpression of) a constraint for a component.
594 while not Nkind_In
(P
, N_Component_Declaration
,
595 N_Subtype_Indication
,
603 -- If the discriminant is used in an expression that is a bound
604 -- of a scalar type, an Itype is created and the bounds are attached
605 -- to its range, not to the original subtype indication. Such use
606 -- is of course a double fault.
608 if (Nkind
(P
) = N_Subtype_Indication
609 and then Nkind_In
(Parent
(P
), N_Component_Definition
,
610 N_Derived_Type_Definition
)
611 and then D
= Constraint
(P
))
613 -- The constraint itself may be given by a subtype indication,
614 -- rather than by a more common discrete range.
616 or else (Nkind
(P
) = N_Subtype_Indication
618 Nkind
(Parent
(P
)) = N_Index_Or_Discriminant_Constraint
)
619 or else Nkind
(P
) = N_Entry_Declaration
620 or else Nkind
(D
) = N_Defining_Identifier
623 ("discriminant in constraint must appear alone", N
);
626 end Check_Discriminant_Use
;
628 --------------------------------
629 -- Check_For_Visible_Operator --
630 --------------------------------
632 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
) is
634 if Is_Invisible_Operator
(N
, T
) then
636 ("operator for} is not directly visible!", N
, First_Subtype
(T
));
637 Error_Msg_N
("use clause would make operation legal!", N
);
639 end Check_For_Visible_Operator
;
641 ----------------------------------
642 -- Check_Fully_Declared_Prefix --
643 ----------------------------------
645 procedure Check_Fully_Declared_Prefix
650 -- Check that the designated type of the prefix of a dereference is
651 -- not an incomplete type. This cannot be done unconditionally, because
652 -- dereferences of private types are legal in default expressions. This
653 -- case is taken care of in Check_Fully_Declared, called below. There
654 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
656 -- This consideration also applies to similar checks for allocators,
657 -- qualified expressions, and type conversions.
659 -- An additional exception concerns other per-object expressions that
660 -- are not directly related to component declarations, in particular
661 -- representation pragmas for tasks. These will be per-object
662 -- expressions if they depend on discriminants or some global entity.
663 -- If the task has access discriminants, the designated type may be
664 -- incomplete at the point the expression is resolved. This resolution
665 -- takes place within the body of the initialization procedure, where
666 -- the discriminant is replaced by its discriminal.
668 if Is_Entity_Name
(Pref
)
669 and then Ekind
(Entity
(Pref
)) = E_In_Parameter
673 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
674 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
675 -- Analyze_Object_Renaming, and Freeze_Entity.
677 elsif Ada_Version
>= Ada_05
678 and then Is_Entity_Name
(Pref
)
679 and then Is_Access_Type
(Etype
(Pref
))
680 and then Ekind
(Directly_Designated_Type
(Etype
(Pref
))) =
682 and then Is_Tagged_Type
(Directly_Designated_Type
(Etype
(Pref
)))
686 Check_Fully_Declared
(Typ
, Parent
(Pref
));
688 end Check_Fully_Declared_Prefix
;
690 ------------------------------
691 -- Check_Infinite_Recursion --
692 ------------------------------
694 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean is
698 function Same_Argument_List
return Boolean;
699 -- Check whether list of actuals is identical to list of formals
700 -- of called function (which is also the enclosing scope).
702 ------------------------
703 -- Same_Argument_List --
704 ------------------------
706 function Same_Argument_List
return Boolean is
712 if not Is_Entity_Name
(Name
(N
)) then
715 Subp
:= Entity
(Name
(N
));
718 F
:= First_Formal
(Subp
);
719 A
:= First_Actual
(N
);
720 while Present
(F
) and then Present
(A
) loop
721 if not Is_Entity_Name
(A
)
722 or else Entity
(A
) /= F
732 end Same_Argument_List
;
734 -- Start of processing for Check_Infinite_Recursion
737 -- Special case, if this is a procedure call and is a call to the
738 -- current procedure with the same argument list, then this is for
739 -- sure an infinite recursion and we insert a call to raise SE.
741 if Is_List_Member
(N
)
742 and then List_Length
(List_Containing
(N
)) = 1
743 and then Same_Argument_List
746 P
: constant Node_Id
:= Parent
(N
);
748 if Nkind
(P
) = N_Handled_Sequence_Of_Statements
749 and then Nkind
(Parent
(P
)) = N_Subprogram_Body
750 and then Is_Empty_List
(Declarations
(Parent
(P
)))
752 Error_Msg_N
("!?infinite recursion", N
);
753 Error_Msg_N
("\!?Storage_Error will be raised at run time", N
);
755 Make_Raise_Storage_Error
(Sloc
(N
),
756 Reason
=> SE_Infinite_Recursion
));
762 -- If not that special case, search up tree, quitting if we reach a
763 -- construct (e.g. a conditional) that tells us that this is not a
764 -- case for an infinite recursion warning.
770 -- If no parent, then we were not inside a subprogram, this can for
771 -- example happen when processing certain pragmas in a spec. Just
772 -- return False in this case.
778 -- Done if we get to subprogram body, this is definitely an infinite
779 -- recursion case if we did not find anything to stop us.
781 exit when Nkind
(P
) = N_Subprogram_Body
;
783 -- If appearing in conditional, result is false
785 if Nkind_In
(P
, N_Or_Else
,
792 elsif Nkind
(P
) = N_Handled_Sequence_Of_Statements
793 and then C
/= First
(Statements
(P
))
795 -- If the call is the expression of a return statement and the
796 -- actuals are identical to the formals, it's worth a warning.
797 -- However, we skip this if there is an immediately preceding
798 -- raise statement, since the call is never executed.
800 -- Furthermore, this corresponds to a common idiom:
802 -- function F (L : Thing) return Boolean is
804 -- raise Program_Error;
808 -- for generating a stub function
810 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
811 and then Same_Argument_List
813 exit when not Is_List_Member
(Parent
(N
));
815 -- OK, return statement is in a statement list, look for raise
821 -- Skip past N_Freeze_Entity nodes generated by expansion
823 Nod
:= Prev
(Parent
(N
));
825 and then Nkind
(Nod
) = N_Freeze_Entity
830 -- If no raise statement, give warning
832 exit when Nkind
(Nod
) /= N_Raise_Statement
834 (Nkind
(Nod
) not in N_Raise_xxx_Error
835 or else Present
(Condition
(Nod
)));
846 Error_Msg_N
("!?possible infinite recursion", N
);
847 Error_Msg_N
("\!?Storage_Error may be raised at run time", N
);
850 end Check_Infinite_Recursion
;
852 -------------------------------
853 -- Check_Initialization_Call --
854 -------------------------------
856 procedure Check_Initialization_Call
(N
: Entity_Id
; Nam
: Entity_Id
) is
857 Typ
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
859 function Uses_SS
(T
: Entity_Id
) return Boolean;
860 -- Check whether the creation of an object of the type will involve
861 -- use of the secondary stack. If T is a record type, this is true
862 -- if the expression for some component uses the secondary stack, e.g.
863 -- through a call to a function that returns an unconstrained value.
864 -- False if T is controlled, because cleanups occur elsewhere.
870 function Uses_SS
(T
: Entity_Id
) return Boolean is
873 Full_Type
: Entity_Id
:= Underlying_Type
(T
);
876 -- Normally we want to use the underlying type, but if it's not set
877 -- then continue with T.
879 if not Present
(Full_Type
) then
883 if Is_Controlled
(Full_Type
) then
886 elsif Is_Array_Type
(Full_Type
) then
887 return Uses_SS
(Component_Type
(Full_Type
));
889 elsif Is_Record_Type
(Full_Type
) then
890 Comp
:= First_Component
(Full_Type
);
891 while Present
(Comp
) loop
892 if Ekind
(Comp
) = E_Component
893 and then Nkind
(Parent
(Comp
)) = N_Component_Declaration
895 -- The expression for a dynamic component may be rewritten
896 -- as a dereference, so retrieve original node.
898 Expr
:= Original_Node
(Expression
(Parent
(Comp
)));
900 -- Return True if the expression is a call to a function
901 -- (including an attribute function such as Image) with
902 -- a result that requires a transient scope.
904 if (Nkind
(Expr
) = N_Function_Call
905 or else (Nkind
(Expr
) = N_Attribute_Reference
906 and then Present
(Expressions
(Expr
))))
907 and then Requires_Transient_Scope
(Etype
(Expr
))
911 elsif Uses_SS
(Etype
(Comp
)) then
916 Next_Component
(Comp
);
926 -- Start of processing for Check_Initialization_Call
929 -- Establish a transient scope if the type needs it
931 if Uses_SS
(Typ
) then
932 Establish_Transient_Scope
(First_Actual
(N
), Sec_Stack
=> True);
934 end Check_Initialization_Call
;
936 ---------------------------------------
937 -- Check_No_Direct_Boolean_Operators --
938 ---------------------------------------
940 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
) is
942 if Scope
(Entity
(N
)) = Standard_Standard
943 and then Root_Type
(Etype
(Left_Opnd
(N
))) = Standard_Boolean
945 -- Restriction only applies to original source code
947 if Comes_From_Source
(N
) then
948 Check_Restriction
(No_Direct_Boolean_Operators
, N
);
953 Check_Boolean_Operator
(N
);
955 end Check_No_Direct_Boolean_Operators
;
957 ------------------------------
958 -- Check_Parameterless_Call --
959 ------------------------------
961 procedure Check_Parameterless_Call
(N
: Node_Id
) is
964 function Prefix_Is_Access_Subp
return Boolean;
965 -- If the prefix is of an access_to_subprogram type, the node must be
966 -- rewritten as a call. Ditto if the prefix is overloaded and all its
967 -- interpretations are access to subprograms.
969 ---------------------------
970 -- Prefix_Is_Access_Subp --
971 ---------------------------
973 function Prefix_Is_Access_Subp
return Boolean is
978 if not Is_Overloaded
(N
) then
980 Ekind
(Etype
(N
)) = E_Subprogram_Type
981 and then Base_Type
(Etype
(Etype
(N
))) /= Standard_Void_Type
;
983 Get_First_Interp
(N
, I
, It
);
984 while Present
(It
.Typ
) loop
985 if Ekind
(It
.Typ
) /= E_Subprogram_Type
986 or else Base_Type
(Etype
(It
.Typ
)) = Standard_Void_Type
991 Get_Next_Interp
(I
, It
);
996 end Prefix_Is_Access_Subp
;
998 -- Start of processing for Check_Parameterless_Call
1001 -- Defend against junk stuff if errors already detected
1003 if Total_Errors_Detected
/= 0 then
1004 if Nkind
(N
) in N_Has_Etype
and then Etype
(N
) = Any_Type
then
1006 elsif Nkind
(N
) in N_Has_Chars
1007 and then Chars
(N
) in Error_Name_Or_No_Name
1015 -- If the context expects a value, and the name is a procedure, this is
1016 -- most likely a missing 'Access. Don't try to resolve the parameterless
1017 -- call, error will be caught when the outer call is analyzed.
1019 if Is_Entity_Name
(N
)
1020 and then Ekind
(Entity
(N
)) = E_Procedure
1021 and then not Is_Overloaded
(N
)
1023 Nkind_In
(Parent
(N
), N_Parameter_Association
,
1025 N_Procedure_Call_Statement
)
1030 -- Rewrite as call if overloadable entity that is (or could be, in the
1031 -- overloaded case) a function call. If we know for sure that the entity
1032 -- is an enumeration literal, we do not rewrite it.
1034 if (Is_Entity_Name
(N
)
1035 and then Is_Overloadable
(Entity
(N
))
1036 and then (Ekind
(Entity
(N
)) /= E_Enumeration_Literal
1037 or else Is_Overloaded
(N
)))
1039 -- Rewrite as call if it is an explicit dereference of an expression of
1040 -- a subprogram access type, and the subprogram type is not that of a
1041 -- procedure or entry.
1044 (Nkind
(N
) = N_Explicit_Dereference
and then Prefix_Is_Access_Subp
)
1046 -- Rewrite as call if it is a selected component which is a function,
1047 -- this is the case of a call to a protected function (which may be
1048 -- overloaded with other protected operations).
1051 (Nkind
(N
) = N_Selected_Component
1052 and then (Ekind
(Entity
(Selector_Name
(N
))) = E_Function
1054 ((Ekind
(Entity
(Selector_Name
(N
))) = E_Entry
1056 Ekind
(Entity
(Selector_Name
(N
))) = E_Procedure
)
1057 and then Is_Overloaded
(Selector_Name
(N
)))))
1059 -- If one of the above three conditions is met, rewrite as call.
1060 -- Apply the rewriting only once.
1063 if Nkind
(Parent
(N
)) /= N_Function_Call
1064 or else N
/= Name
(Parent
(N
))
1066 Nam
:= New_Copy
(N
);
1068 -- If overloaded, overload set belongs to new copy
1070 Save_Interps
(N
, Nam
);
1072 -- Change node to parameterless function call (note that the
1073 -- Parameter_Associations associations field is left set to Empty,
1074 -- its normal default value since there are no parameters)
1076 Change_Node
(N
, N_Function_Call
);
1078 Set_Sloc
(N
, Sloc
(Nam
));
1082 elsif Nkind
(N
) = N_Parameter_Association
then
1083 Check_Parameterless_Call
(Explicit_Actual_Parameter
(N
));
1085 end Check_Parameterless_Call
;
1087 -----------------------------
1088 -- Is_Definite_Access_Type --
1089 -----------------------------
1091 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean is
1092 Btyp
: constant Entity_Id
:= Base_Type
(E
);
1094 return Ekind
(Btyp
) = E_Access_Type
1095 or else (Ekind
(Btyp
) = E_Access_Subprogram_Type
1096 and then Comes_From_Source
(Btyp
));
1097 end Is_Definite_Access_Type
;
1099 ----------------------
1100 -- Is_Predefined_Op --
1101 ----------------------
1103 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean is
1105 return Is_Intrinsic_Subprogram
(Nam
)
1106 and then not Is_Generic_Instance
(Nam
)
1107 and then Chars
(Nam
) in Any_Operator_Name
1108 and then (No
(Alias
(Nam
))
1109 or else Is_Predefined_Op
(Alias
(Nam
)));
1110 end Is_Predefined_Op
;
1112 -----------------------------
1113 -- Make_Call_Into_Operator --
1114 -----------------------------
1116 procedure Make_Call_Into_Operator
1121 Op_Name
: constant Name_Id
:= Chars
(Op_Id
);
1122 Act1
: Node_Id
:= First_Actual
(N
);
1123 Act2
: Node_Id
:= Next_Actual
(Act1
);
1124 Error
: Boolean := False;
1125 Func
: constant Entity_Id
:= Entity
(Name
(N
));
1126 Is_Binary
: constant Boolean := Present
(Act2
);
1128 Opnd_Type
: Entity_Id
;
1129 Orig_Type
: Entity_Id
:= Empty
;
1132 type Kind_Test
is access function (E
: Entity_Id
) return Boolean;
1134 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean;
1135 -- If the operand is not universal, and the operator is given by a
1136 -- expanded name, verify that the operand has an interpretation with
1137 -- a type defined in the given scope of the operator.
1139 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
;
1140 -- Find a type of the given class in the package Pack that contains
1143 ---------------------------
1144 -- Operand_Type_In_Scope --
1145 ---------------------------
1147 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean is
1148 Nod
: constant Node_Id
:= Right_Opnd
(Op_Node
);
1153 if not Is_Overloaded
(Nod
) then
1154 return Scope
(Base_Type
(Etype
(Nod
))) = S
;
1157 Get_First_Interp
(Nod
, I
, It
);
1158 while Present
(It
.Typ
) loop
1159 if Scope
(Base_Type
(It
.Typ
)) = S
then
1163 Get_Next_Interp
(I
, It
);
1168 end Operand_Type_In_Scope
;
1174 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
is
1177 function In_Decl
return Boolean;
1178 -- Verify that node is not part of the type declaration for the
1179 -- candidate type, which would otherwise be invisible.
1185 function In_Decl
return Boolean is
1186 Decl_Node
: constant Node_Id
:= Parent
(E
);
1192 if Etype
(E
) = Any_Type
then
1195 elsif No
(Decl_Node
) then
1200 and then Nkind
(N2
) /= N_Compilation_Unit
1202 if N2
= Decl_Node
then
1213 -- Start of processing for Type_In_P
1216 -- If the context type is declared in the prefix package, this
1217 -- is the desired base type.
1219 if Scope
(Base_Type
(Typ
)) = Pack
1222 return Base_Type
(Typ
);
1225 E
:= First_Entity
(Pack
);
1226 while Present
(E
) loop
1228 and then not In_Decl
1240 -- Start of processing for Make_Call_Into_Operator
1243 Op_Node
:= New_Node
(Operator_Kind
(Op_Name
, Is_Binary
), Sloc
(N
));
1248 Set_Left_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1249 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act2
));
1250 Save_Interps
(Act1
, Left_Opnd
(Op_Node
));
1251 Save_Interps
(Act2
, Right_Opnd
(Op_Node
));
1252 Act1
:= Left_Opnd
(Op_Node
);
1253 Act2
:= Right_Opnd
(Op_Node
);
1258 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1259 Save_Interps
(Act1
, Right_Opnd
(Op_Node
));
1260 Act1
:= Right_Opnd
(Op_Node
);
1263 -- If the operator is denoted by an expanded name, and the prefix is
1264 -- not Standard, but the operator is a predefined one whose scope is
1265 -- Standard, then this is an implicit_operator, inserted as an
1266 -- interpretation by the procedure of the same name. This procedure
1267 -- overestimates the presence of implicit operators, because it does
1268 -- not examine the type of the operands. Verify now that the operand
1269 -- type appears in the given scope. If right operand is universal,
1270 -- check the other operand. In the case of concatenation, either
1271 -- argument can be the component type, so check the type of the result.
1272 -- If both arguments are literals, look for a type of the right kind
1273 -- defined in the given scope. This elaborate nonsense is brought to
1274 -- you courtesy of b33302a. The type itself must be frozen, so we must
1275 -- find the type of the proper class in the given scope.
1277 -- A final wrinkle is the multiplication operator for fixed point
1278 -- types, which is defined in Standard only, and not in the scope of
1279 -- the fixed_point type itself.
1281 if Nkind
(Name
(N
)) = N_Expanded_Name
then
1282 Pack
:= Entity
(Prefix
(Name
(N
)));
1284 -- If the entity being called is defined in the given package,
1285 -- it is a renaming of a predefined operator, and known to be
1288 if Scope
(Entity
(Name
(N
))) = Pack
1289 and then Pack
/= Standard_Standard
1293 -- Visibility does not need to be checked in an instance: if the
1294 -- operator was not visible in the generic it has been diagnosed
1295 -- already, else there is an implicit copy of it in the instance.
1297 elsif In_Instance
then
1300 elsif (Op_Name
= Name_Op_Multiply
1301 or else Op_Name
= Name_Op_Divide
)
1302 and then Is_Fixed_Point_Type
(Etype
(Left_Opnd
(Op_Node
)))
1303 and then Is_Fixed_Point_Type
(Etype
(Right_Opnd
(Op_Node
)))
1305 if Pack
/= Standard_Standard
then
1309 -- Ada 2005, AI-420: Predefined equality on Universal_Access
1312 elsif Ada_Version
>= Ada_05
1313 and then (Op_Name
= Name_Op_Eq
or else Op_Name
= Name_Op_Ne
)
1314 and then Ekind
(Etype
(Act1
)) = E_Anonymous_Access_Type
1319 Opnd_Type
:= Base_Type
(Etype
(Right_Opnd
(Op_Node
)));
1321 if Op_Name
= Name_Op_Concat
then
1322 Opnd_Type
:= Base_Type
(Typ
);
1324 elsif (Scope
(Opnd_Type
) = Standard_Standard
1326 or else (Nkind
(Right_Opnd
(Op_Node
)) = N_Attribute_Reference
1328 and then not Comes_From_Source
(Opnd_Type
))
1330 Opnd_Type
:= Base_Type
(Etype
(Left_Opnd
(Op_Node
)));
1333 if Scope
(Opnd_Type
) = Standard_Standard
then
1335 -- Verify that the scope contains a type that corresponds to
1336 -- the given literal. Optimize the case where Pack is Standard.
1338 if Pack
/= Standard_Standard
then
1340 if Opnd_Type
= Universal_Integer
then
1341 Orig_Type
:= Type_In_P
(Is_Integer_Type
'Access);
1343 elsif Opnd_Type
= Universal_Real
then
1344 Orig_Type
:= Type_In_P
(Is_Real_Type
'Access);
1346 elsif Opnd_Type
= Any_String
then
1347 Orig_Type
:= Type_In_P
(Is_String_Type
'Access);
1349 elsif Opnd_Type
= Any_Access
then
1350 Orig_Type
:= Type_In_P
(Is_Definite_Access_Type
'Access);
1352 elsif Opnd_Type
= Any_Composite
then
1353 Orig_Type
:= Type_In_P
(Is_Composite_Type
'Access);
1355 if Present
(Orig_Type
) then
1356 if Has_Private_Component
(Orig_Type
) then
1359 Set_Etype
(Act1
, Orig_Type
);
1362 Set_Etype
(Act2
, Orig_Type
);
1371 Error
:= No
(Orig_Type
);
1374 elsif Ekind
(Opnd_Type
) = E_Allocator_Type
1375 and then No
(Type_In_P
(Is_Definite_Access_Type
'Access))
1379 -- If the type is defined elsewhere, and the operator is not
1380 -- defined in the given scope (by a renaming declaration, e.g.)
1381 -- then this is an error as well. If an extension of System is
1382 -- present, and the type may be defined there, Pack must be
1385 elsif Scope
(Opnd_Type
) /= Pack
1386 and then Scope
(Op_Id
) /= Pack
1387 and then (No
(System_Aux_Id
)
1388 or else Scope
(Opnd_Type
) /= System_Aux_Id
1389 or else Pack
/= Scope
(System_Aux_Id
))
1391 if not Is_Overloaded
(Right_Opnd
(Op_Node
)) then
1394 Error
:= not Operand_Type_In_Scope
(Pack
);
1397 elsif Pack
= Standard_Standard
1398 and then not Operand_Type_In_Scope
(Standard_Standard
)
1405 Error_Msg_Node_2
:= Pack
;
1407 ("& not declared in&", N
, Selector_Name
(Name
(N
)));
1408 Set_Etype
(N
, Any_Type
);
1413 Set_Chars
(Op_Node
, Op_Name
);
1415 if not Is_Private_Type
(Etype
(N
)) then
1416 Set_Etype
(Op_Node
, Base_Type
(Etype
(N
)));
1418 Set_Etype
(Op_Node
, Etype
(N
));
1421 -- If this is a call to a function that renames a predefined equality,
1422 -- the renaming declaration provides a type that must be used to
1423 -- resolve the operands. This must be done now because resolution of
1424 -- the equality node will not resolve any remaining ambiguity, and it
1425 -- assumes that the first operand is not overloaded.
1427 if (Op_Name
= Name_Op_Eq
or else Op_Name
= Name_Op_Ne
)
1428 and then Ekind
(Func
) = E_Function
1429 and then Is_Overloaded
(Act1
)
1431 Resolve
(Act1
, Base_Type
(Etype
(First_Formal
(Func
))));
1432 Resolve
(Act2
, Base_Type
(Etype
(First_Formal
(Func
))));
1435 Set_Entity
(Op_Node
, Op_Id
);
1436 Generate_Reference
(Op_Id
, N
, ' ');
1438 -- Do rewrite setting Comes_From_Source on the result if the original
1439 -- call came from source. Although it is not strictly the case that the
1440 -- operator as such comes from the source, logically it corresponds
1441 -- exactly to the function call in the source, so it should be marked
1442 -- this way (e.g. to make sure that validity checks work fine).
1445 CS
: constant Boolean := Comes_From_Source
(N
);
1447 Rewrite
(N
, Op_Node
);
1448 Set_Comes_From_Source
(N
, CS
);
1451 -- If this is an arithmetic operator and the result type is private,
1452 -- the operands and the result must be wrapped in conversion to
1453 -- expose the underlying numeric type and expand the proper checks,
1454 -- e.g. on division.
1456 if Is_Private_Type
(Typ
) then
1458 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1459 N_Op_Expon | N_Op_Mod | N_Op_Rem
=>
1460 Resolve_Intrinsic_Operator
(N
, Typ
);
1462 when N_Op_Plus | N_Op_Minus | N_Op_Abs
=>
1463 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
1472 -- For predefined operators on literals, the operation freezes
1475 if Present
(Orig_Type
) then
1476 Set_Etype
(Act1
, Orig_Type
);
1477 Freeze_Expression
(Act1
);
1479 end Make_Call_Into_Operator
;
1485 function Operator_Kind
1487 Is_Binary
: Boolean) return Node_Kind
1493 if Op_Name
= Name_Op_And
then
1495 elsif Op_Name
= Name_Op_Or
then
1497 elsif Op_Name
= Name_Op_Xor
then
1499 elsif Op_Name
= Name_Op_Eq
then
1501 elsif Op_Name
= Name_Op_Ne
then
1503 elsif Op_Name
= Name_Op_Lt
then
1505 elsif Op_Name
= Name_Op_Le
then
1507 elsif Op_Name
= Name_Op_Gt
then
1509 elsif Op_Name
= Name_Op_Ge
then
1511 elsif Op_Name
= Name_Op_Add
then
1513 elsif Op_Name
= Name_Op_Subtract
then
1514 Kind
:= N_Op_Subtract
;
1515 elsif Op_Name
= Name_Op_Concat
then
1516 Kind
:= N_Op_Concat
;
1517 elsif Op_Name
= Name_Op_Multiply
then
1518 Kind
:= N_Op_Multiply
;
1519 elsif Op_Name
= Name_Op_Divide
then
1520 Kind
:= N_Op_Divide
;
1521 elsif Op_Name
= Name_Op_Mod
then
1523 elsif Op_Name
= Name_Op_Rem
then
1525 elsif Op_Name
= Name_Op_Expon
then
1528 raise Program_Error
;
1534 if Op_Name
= Name_Op_Add
then
1536 elsif Op_Name
= Name_Op_Subtract
then
1538 elsif Op_Name
= Name_Op_Abs
then
1540 elsif Op_Name
= Name_Op_Not
then
1543 raise Program_Error
;
1550 ----------------------------
1551 -- Preanalyze_And_Resolve --
1552 ----------------------------
1554 procedure Preanalyze_And_Resolve
(N
: Node_Id
; T
: Entity_Id
) is
1555 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1558 Full_Analysis
:= False;
1559 Expander_Mode_Save_And_Set
(False);
1561 -- We suppress all checks for this analysis, since the checks will
1562 -- be applied properly, and in the right location, when the default
1563 -- expression is reanalyzed and reexpanded later on.
1565 Analyze_And_Resolve
(N
, T
, Suppress
=> All_Checks
);
1567 Expander_Mode_Restore
;
1568 Full_Analysis
:= Save_Full_Analysis
;
1569 end Preanalyze_And_Resolve
;
1571 -- Version without context type
1573 procedure Preanalyze_And_Resolve
(N
: Node_Id
) is
1574 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1577 Full_Analysis
:= False;
1578 Expander_Mode_Save_And_Set
(False);
1581 Resolve
(N
, Etype
(N
), Suppress
=> All_Checks
);
1583 Expander_Mode_Restore
;
1584 Full_Analysis
:= Save_Full_Analysis
;
1585 end Preanalyze_And_Resolve
;
1587 ----------------------------------
1588 -- Replace_Actual_Discriminants --
1589 ----------------------------------
1591 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
) is
1592 Loc
: constant Source_Ptr
:= Sloc
(N
);
1593 Tsk
: Node_Id
:= Empty
;
1595 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
;
1601 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
is
1605 if Nkind
(Nod
) = N_Identifier
then
1606 Ent
:= Entity
(Nod
);
1609 and then Ekind
(Ent
) = E_Discriminant
1612 Make_Selected_Component
(Loc
,
1613 Prefix
=> New_Copy_Tree
(Tsk
, New_Sloc
=> Loc
),
1614 Selector_Name
=> Make_Identifier
(Loc
, Chars
(Ent
))));
1616 Set_Etype
(Nod
, Etype
(Ent
));
1624 procedure Replace_Discrs
is new Traverse_Proc
(Process_Discr
);
1626 -- Start of processing for Replace_Actual_Discriminants
1629 if not Expander_Active
then
1633 if Nkind
(Name
(N
)) = N_Selected_Component
then
1634 Tsk
:= Prefix
(Name
(N
));
1636 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
1637 Tsk
:= Prefix
(Prefix
(Name
(N
)));
1643 Replace_Discrs
(Default
);
1645 end Replace_Actual_Discriminants
;
1651 procedure Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
1652 Ambiguous
: Boolean := False;
1653 Ctx_Type
: Entity_Id
:= Typ
;
1654 Expr_Type
: Entity_Id
:= Empty
; -- prevent junk warning
1655 Err_Type
: Entity_Id
:= Empty
;
1656 Found
: Boolean := False;
1659 I1
: Interp_Index
:= 0; -- prevent junk warning
1662 Seen
: Entity_Id
:= Empty
; -- prevent junk warning
1664 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean;
1665 -- Determine whether a node comes from a predefined library unit or
1668 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
);
1669 -- Try and fix up a literal so that it matches its expected type. New
1670 -- literals are manufactured if necessary to avoid cascaded errors.
1672 procedure Resolution_Failed
;
1673 -- Called when attempt at resolving current expression fails
1675 ------------------------------------
1676 -- Comes_From_Predefined_Lib_Unit --
1677 -------------------------------------
1679 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean is
1682 Sloc
(Nod
) = Standard_Location
1683 or else Is_Predefined_File_Name
(Unit_File_Name
(
1684 Get_Source_Unit
(Sloc
(Nod
))));
1685 end Comes_From_Predefined_Lib_Unit
;
1687 --------------------
1688 -- Patch_Up_Value --
1689 --------------------
1691 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
) is
1693 if Nkind
(N
) = N_Integer_Literal
1694 and then Is_Real_Type
(Typ
)
1697 Make_Real_Literal
(Sloc
(N
),
1698 Realval
=> UR_From_Uint
(Intval
(N
))));
1699 Set_Etype
(N
, Universal_Real
);
1700 Set_Is_Static_Expression
(N
);
1702 elsif Nkind
(N
) = N_Real_Literal
1703 and then Is_Integer_Type
(Typ
)
1706 Make_Integer_Literal
(Sloc
(N
),
1707 Intval
=> UR_To_Uint
(Realval
(N
))));
1708 Set_Etype
(N
, Universal_Integer
);
1709 Set_Is_Static_Expression
(N
);
1711 elsif Nkind
(N
) = N_String_Literal
1712 and then Is_Character_Type
(Typ
)
1714 Set_Character_Literal_Name
(Char_Code
(Character'Pos ('A')));
1716 Make_Character_Literal
(Sloc
(N
),
1718 Char_Literal_Value
=>
1719 UI_From_Int
(Character'Pos ('A'))));
1720 Set_Etype
(N
, Any_Character
);
1721 Set_Is_Static_Expression
(N
);
1723 elsif Nkind
(N
) /= N_String_Literal
1724 and then Is_String_Type
(Typ
)
1727 Make_String_Literal
(Sloc
(N
),
1728 Strval
=> End_String
));
1730 elsif Nkind
(N
) = N_Range
then
1731 Patch_Up_Value
(Low_Bound
(N
), Typ
);
1732 Patch_Up_Value
(High_Bound
(N
), Typ
);
1736 -----------------------
1737 -- Resolution_Failed --
1738 -----------------------
1740 procedure Resolution_Failed
is
1742 Patch_Up_Value
(N
, Typ
);
1744 Debug_A_Exit
("resolving ", N
, " (done, resolution failed)");
1745 Set_Is_Overloaded
(N
, False);
1747 -- The caller will return without calling the expander, so we need
1748 -- to set the analyzed flag. Note that it is fine to set Analyzed
1749 -- to True even if we are in the middle of a shallow analysis,
1750 -- (see the spec of sem for more details) since this is an error
1751 -- situation anyway, and there is no point in repeating the
1752 -- analysis later (indeed it won't work to repeat it later, since
1753 -- we haven't got a clear resolution of which entity is being
1756 Set_Analyzed
(N
, True);
1758 end Resolution_Failed
;
1760 -- Start of processing for Resolve
1767 -- Access attribute on remote subprogram cannot be used for
1768 -- a non-remote access-to-subprogram type.
1770 if Nkind
(N
) = N_Attribute_Reference
1771 and then (Attribute_Name
(N
) = Name_Access
1772 or else Attribute_Name
(N
) = Name_Unrestricted_Access
1773 or else Attribute_Name
(N
) = Name_Unchecked_Access
)
1774 and then Comes_From_Source
(N
)
1775 and then Is_Entity_Name
(Prefix
(N
))
1776 and then Is_Subprogram
(Entity
(Prefix
(N
)))
1777 and then Is_Remote_Call_Interface
(Entity
(Prefix
(N
)))
1778 and then not Is_Remote_Access_To_Subprogram_Type
(Typ
)
1781 ("prefix must statically denote a non-remote subprogram", N
);
1784 From_Lib
:= Comes_From_Predefined_Lib_Unit
(N
);
1786 -- If the context is a Remote_Access_To_Subprogram, access attributes
1787 -- must be resolved with the corresponding fat pointer. There is no need
1788 -- to check for the attribute name since the return type of an
1789 -- attribute is never a remote type.
1791 if Nkind
(N
) = N_Attribute_Reference
1792 and then Comes_From_Source
(N
)
1793 and then (Is_Remote_Call_Interface
(Typ
)
1794 or else Is_Remote_Types
(Typ
))
1797 Attr
: constant Attribute_Id
:=
1798 Get_Attribute_Id
(Attribute_Name
(N
));
1799 Pref
: constant Node_Id
:= Prefix
(N
);
1802 Is_Remote
: Boolean := True;
1805 -- Check that Typ is a remote access-to-subprogram type
1807 if Is_Remote_Access_To_Subprogram_Type
(Typ
) then
1808 -- Prefix (N) must statically denote a remote subprogram
1809 -- declared in a package specification.
1811 if Attr
= Attribute_Access
then
1812 Decl
:= Unit_Declaration_Node
(Entity
(Pref
));
1814 if Nkind
(Decl
) = N_Subprogram_Body
then
1815 Spec
:= Corresponding_Spec
(Decl
);
1817 if not No
(Spec
) then
1818 Decl
:= Unit_Declaration_Node
(Spec
);
1822 Spec
:= Parent
(Decl
);
1824 if not Is_Entity_Name
(Prefix
(N
))
1825 or else Nkind
(Spec
) /= N_Package_Specification
1827 not Is_Remote_Call_Interface
(Defining_Entity
(Spec
))
1831 ("prefix must statically denote a remote subprogram ",
1836 -- If we are generating code for a distributed program.
1837 -- perform semantic checks against the corresponding
1840 if (Attr
= Attribute_Access
1841 or else Attr
= Attribute_Unchecked_Access
1842 or else Attr
= Attribute_Unrestricted_Access
)
1843 and then Expander_Active
1844 and then Get_PCS_Name
/= Name_No_DSA
1846 Check_Subtype_Conformant
1847 (New_Id
=> Entity
(Prefix
(N
)),
1848 Old_Id
=> Designated_Type
1849 (Corresponding_Remote_Type
(Typ
)),
1853 Process_Remote_AST_Attribute
(N
, Typ
);
1860 Debug_A_Entry
("resolving ", N
);
1862 if Comes_From_Source
(N
) then
1863 if Is_Fixed_Point_Type
(Typ
) then
1864 Check_Restriction
(No_Fixed_Point
, N
);
1866 elsif Is_Floating_Point_Type
(Typ
)
1867 and then Typ
/= Universal_Real
1868 and then Typ
/= Any_Real
1870 Check_Restriction
(No_Floating_Point
, N
);
1874 -- Return if already analyzed
1876 if Analyzed
(N
) then
1877 Debug_A_Exit
("resolving ", N
, " (done, already analyzed)");
1880 -- Return if type = Any_Type (previous error encountered)
1882 elsif Etype
(N
) = Any_Type
then
1883 Debug_A_Exit
("resolving ", N
, " (done, Etype = Any_Type)");
1887 Check_Parameterless_Call
(N
);
1889 -- If not overloaded, then we know the type, and all that needs doing
1890 -- is to check that this type is compatible with the context.
1892 if not Is_Overloaded
(N
) then
1893 Found
:= Covers
(Typ
, Etype
(N
));
1894 Expr_Type
:= Etype
(N
);
1896 -- In the overloaded case, we must select the interpretation that
1897 -- is compatible with the context (i.e. the type passed to Resolve)
1900 -- Loop through possible interpretations
1902 Get_First_Interp
(N
, I
, It
);
1903 Interp_Loop
: while Present
(It
.Typ
) loop
1905 -- We are only interested in interpretations that are compatible
1906 -- with the expected type, any other interpretations are ignored.
1908 if not Covers
(Typ
, It
.Typ
) then
1909 if Debug_Flag_V
then
1910 Write_Str
(" interpretation incompatible with context");
1915 -- Skip the current interpretation if it is disabled by an
1916 -- abstract operator. This action is performed only when the
1917 -- type against which we are resolving is the same as the
1918 -- type of the interpretation.
1920 if Ada_Version
>= Ada_05
1921 and then It
.Typ
= Typ
1922 and then Typ
/= Universal_Integer
1923 and then Typ
/= Universal_Real
1924 and then Present
(It
.Abstract_Op
)
1929 -- First matching interpretation
1935 Expr_Type
:= It
.Typ
;
1937 -- Matching interpretation that is not the first, maybe an
1938 -- error, but there are some cases where preference rules are
1939 -- used to choose between the two possibilities. These and
1940 -- some more obscure cases are handled in Disambiguate.
1943 -- If the current statement is part of a predefined library
1944 -- unit, then all interpretations which come from user level
1945 -- packages should not be considered.
1948 and then not Comes_From_Predefined_Lib_Unit
(It
.Nam
)
1953 Error_Msg_Sloc
:= Sloc
(Seen
);
1954 It1
:= Disambiguate
(N
, I1
, I
, Typ
);
1956 -- Disambiguation has succeeded. Skip the remaining
1959 if It1
/= No_Interp
then
1961 Expr_Type
:= It1
.Typ
;
1963 while Present
(It
.Typ
) loop
1964 Get_Next_Interp
(I
, It
);
1968 -- Before we issue an ambiguity complaint, check for
1969 -- the case of a subprogram call where at least one
1970 -- of the arguments is Any_Type, and if so, suppress
1971 -- the message, since it is a cascaded error.
1973 if Nkind_In
(N
, N_Function_Call
,
1974 N_Procedure_Call_Statement
)
1981 A
:= First_Actual
(N
);
1982 while Present
(A
) loop
1985 if Nkind
(E
) = N_Parameter_Association
then
1986 E
:= Explicit_Actual_Parameter
(E
);
1989 if Etype
(E
) = Any_Type
then
1990 if Debug_Flag_V
then
1991 Write_Str
("Any_Type in call");
2002 elsif Nkind
(N
) in N_Binary_Op
2003 and then (Etype
(Left_Opnd
(N
)) = Any_Type
2004 or else Etype
(Right_Opnd
(N
)) = Any_Type
)
2008 elsif Nkind
(N
) in N_Unary_Op
2009 and then Etype
(Right_Opnd
(N
)) = Any_Type
2014 -- Not that special case, so issue message using the
2015 -- flag Ambiguous to control printing of the header
2016 -- message only at the start of an ambiguous set.
2018 if not Ambiguous
then
2019 if Nkind
(N
) = N_Function_Call
2020 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2023 ("ambiguous expression "
2024 & "(cannot resolve indirect call)!", N
);
2026 Error_Msg_NE
-- CODEFIX
2027 ("ambiguous expression (cannot resolve&)!",
2033 if Nkind
(Parent
(Seen
)) = N_Full_Type_Declaration
then
2035 ("\\possible interpretation (inherited)#!", N
);
2037 Error_Msg_N
-- CODEFIX
2038 ("\\possible interpretation#!", N
);
2042 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2044 -- By default, the error message refers to the candidate
2045 -- interpretation. But if it is a predefined operator, it
2046 -- is implicitly declared at the declaration of the type
2047 -- of the operand. Recover the sloc of that declaration
2048 -- for the error message.
2050 if Nkind
(N
) in N_Op
2051 and then Scope
(It
.Nam
) = Standard_Standard
2052 and then not Is_Overloaded
(Right_Opnd
(N
))
2053 and then Scope
(Base_Type
(Etype
(Right_Opnd
(N
)))) /=
2056 Err_Type
:= First_Subtype
(Etype
(Right_Opnd
(N
)));
2058 if Comes_From_Source
(Err_Type
)
2059 and then Present
(Parent
(Err_Type
))
2061 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2064 elsif Nkind
(N
) in N_Binary_Op
2065 and then Scope
(It
.Nam
) = Standard_Standard
2066 and then not Is_Overloaded
(Left_Opnd
(N
))
2067 and then Scope
(Base_Type
(Etype
(Left_Opnd
(N
)))) /=
2070 Err_Type
:= First_Subtype
(Etype
(Left_Opnd
(N
)));
2072 if Comes_From_Source
(Err_Type
)
2073 and then Present
(Parent
(Err_Type
))
2075 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2078 -- If this is an indirect call, use the subprogram_type
2079 -- in the message, to have a meaningful location.
2080 -- Indicate as well if this is an inherited operation,
2081 -- created by a type declaration.
2083 elsif Nkind
(N
) = N_Function_Call
2084 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2085 and then Is_Type
(It
.Nam
)
2089 Sloc
(Associated_Node_For_Itype
(Err_Type
));
2094 if Nkind
(N
) in N_Op
2095 and then Scope
(It
.Nam
) = Standard_Standard
2096 and then Present
(Err_Type
)
2098 -- Special-case the message for universal_fixed
2099 -- operators, which are not declared with the type
2100 -- of the operand, but appear forever in Standard.
2102 if It
.Typ
= Universal_Fixed
2103 and then Scope
(It
.Nam
) = Standard_Standard
2106 ("\\possible interpretation as " &
2107 "universal_fixed operation " &
2108 "(RM 4.5.5 (19))", N
);
2111 ("\\possible interpretation (predefined)#!", N
);
2115 Nkind
(Parent
(It
.Nam
)) = N_Full_Type_Declaration
2118 ("\\possible interpretation (inherited)#!", N
);
2120 Error_Msg_N
-- CODEFIX
2121 ("\\possible interpretation#!", N
);
2127 -- We have a matching interpretation, Expr_Type is the type
2128 -- from this interpretation, and Seen is the entity.
2130 -- For an operator, just set the entity name. The type will be
2131 -- set by the specific operator resolution routine.
2133 if Nkind
(N
) in N_Op
then
2134 Set_Entity
(N
, Seen
);
2135 Generate_Reference
(Seen
, N
);
2137 elsif Nkind
(N
) = N_Character_Literal
then
2138 Set_Etype
(N
, Expr_Type
);
2140 elsif Nkind
(N
) = N_Conditional_Expression
then
2141 Set_Etype
(N
, Expr_Type
);
2143 -- For an explicit dereference, attribute reference, range,
2144 -- short-circuit form (which is not an operator node), or call
2145 -- with a name that is an explicit dereference, there is
2146 -- nothing to be done at this point.
2148 elsif Nkind_In
(N
, N_Explicit_Dereference
,
2149 N_Attribute_Reference
,
2151 N_Indexed_Component
,
2154 N_Selected_Component
,
2156 or else Nkind
(Name
(N
)) = N_Explicit_Dereference
2160 -- For procedure or function calls, set the type of the name,
2161 -- and also the entity pointer for the prefix
2163 elsif Nkind_In
(N
, N_Procedure_Call_Statement
, N_Function_Call
)
2164 and then (Is_Entity_Name
(Name
(N
))
2165 or else Nkind
(Name
(N
)) = N_Operator_Symbol
)
2167 Set_Etype
(Name
(N
), Expr_Type
);
2168 Set_Entity
(Name
(N
), Seen
);
2169 Generate_Reference
(Seen
, Name
(N
));
2171 elsif Nkind
(N
) = N_Function_Call
2172 and then Nkind
(Name
(N
)) = N_Selected_Component
2174 Set_Etype
(Name
(N
), Expr_Type
);
2175 Set_Entity
(Selector_Name
(Name
(N
)), Seen
);
2176 Generate_Reference
(Seen
, Selector_Name
(Name
(N
)));
2178 -- For all other cases, just set the type of the Name
2181 Set_Etype
(Name
(N
), Expr_Type
);
2188 -- Move to next interpretation
2190 exit Interp_Loop
when No
(It
.Typ
);
2192 Get_Next_Interp
(I
, It
);
2193 end loop Interp_Loop
;
2196 -- At this stage Found indicates whether or not an acceptable
2197 -- interpretation exists. If not, then we have an error, except
2198 -- that if the context is Any_Type as a result of some other error,
2199 -- then we suppress the error report.
2202 if Typ
/= Any_Type
then
2204 -- If type we are looking for is Void, then this is the procedure
2205 -- call case, and the error is simply that what we gave is not a
2206 -- procedure name (we think of procedure calls as expressions with
2207 -- types internally, but the user doesn't think of them this way!)
2209 if Typ
= Standard_Void_Type
then
2211 -- Special case message if function used as a procedure
2213 if Nkind
(N
) = N_Procedure_Call_Statement
2214 and then Is_Entity_Name
(Name
(N
))
2215 and then Ekind
(Entity
(Name
(N
))) = E_Function
2218 ("cannot use function & in a procedure call",
2219 Name
(N
), Entity
(Name
(N
)));
2221 -- Otherwise give general message (not clear what cases this
2222 -- covers, but no harm in providing for them!)
2225 Error_Msg_N
("expect procedure name in procedure call", N
);
2230 -- Otherwise we do have a subexpression with the wrong type
2232 -- Check for the case of an allocator which uses an access type
2233 -- instead of the designated type. This is a common error and we
2234 -- specialize the message, posting an error on the operand of the
2235 -- allocator, complaining that we expected the designated type of
2238 elsif Nkind
(N
) = N_Allocator
2239 and then Ekind
(Typ
) in Access_Kind
2240 and then Ekind
(Etype
(N
)) in Access_Kind
2241 and then Designated_Type
(Etype
(N
)) = Typ
2243 Wrong_Type
(Expression
(N
), Designated_Type
(Typ
));
2246 -- Check for view mismatch on Null in instances, for which the
2247 -- view-swapping mechanism has no identifier.
2249 elsif (In_Instance
or else In_Inlined_Body
)
2250 and then (Nkind
(N
) = N_Null
)
2251 and then Is_Private_Type
(Typ
)
2252 and then Is_Access_Type
(Full_View
(Typ
))
2254 Resolve
(N
, Full_View
(Typ
));
2258 -- Check for an aggregate. Sometimes we can get bogus aggregates
2259 -- from misuse of parentheses, and we are about to complain about
2260 -- the aggregate without even looking inside it.
2262 -- Instead, if we have an aggregate of type Any_Composite, then
2263 -- analyze and resolve the component fields, and then only issue
2264 -- another message if we get no errors doing this (otherwise
2265 -- assume that the errors in the aggregate caused the problem).
2267 elsif Nkind
(N
) = N_Aggregate
2268 and then Etype
(N
) = Any_Composite
2270 -- Disable expansion in any case. If there is a type mismatch
2271 -- it may be fatal to try to expand the aggregate. The flag
2272 -- would otherwise be set to false when the error is posted.
2274 Expander_Active
:= False;
2277 procedure Check_Aggr
(Aggr
: Node_Id
);
2278 -- Check one aggregate, and set Found to True if we have a
2279 -- definite error in any of its elements
2281 procedure Check_Elmt
(Aelmt
: Node_Id
);
2282 -- Check one element of aggregate and set Found to True if
2283 -- we definitely have an error in the element.
2289 procedure Check_Aggr
(Aggr
: Node_Id
) is
2293 if Present
(Expressions
(Aggr
)) then
2294 Elmt
:= First
(Expressions
(Aggr
));
2295 while Present
(Elmt
) loop
2301 if Present
(Component_Associations
(Aggr
)) then
2302 Elmt
:= First
(Component_Associations
(Aggr
));
2303 while Present
(Elmt
) loop
2305 -- If this is a default-initialized component, then
2306 -- there is nothing to check. The box will be
2307 -- replaced by the appropriate call during late
2310 if not Box_Present
(Elmt
) then
2311 Check_Elmt
(Expression
(Elmt
));
2323 procedure Check_Elmt
(Aelmt
: Node_Id
) is
2325 -- If we have a nested aggregate, go inside it (to
2326 -- attempt a naked analyze-resolve of the aggregate
2327 -- can cause undesirable cascaded errors). Do not
2328 -- resolve expression if it needs a type from context,
2329 -- as for integer * fixed expression.
2331 if Nkind
(Aelmt
) = N_Aggregate
then
2337 if not Is_Overloaded
(Aelmt
)
2338 and then Etype
(Aelmt
) /= Any_Fixed
2343 if Etype
(Aelmt
) = Any_Type
then
2354 -- If an error message was issued already, Found got reset
2355 -- to True, so if it is still False, issue the standard
2356 -- Wrong_Type message.
2359 if Is_Overloaded
(N
)
2360 and then Nkind
(N
) = N_Function_Call
2363 Subp_Name
: Node_Id
;
2365 if Is_Entity_Name
(Name
(N
)) then
2366 Subp_Name
:= Name
(N
);
2368 elsif Nkind
(Name
(N
)) = N_Selected_Component
then
2370 -- Protected operation: retrieve operation name
2372 Subp_Name
:= Selector_Name
(Name
(N
));
2374 raise Program_Error
;
2377 Error_Msg_Node_2
:= Typ
;
2378 Error_Msg_NE
("no visible interpretation of&" &
2379 " matches expected type&", N
, Subp_Name
);
2382 if All_Errors_Mode
then
2384 Index
: Interp_Index
;
2388 Error_Msg_N
("\\possible interpretations:", N
);
2390 Get_First_Interp
(Name
(N
), Index
, It
);
2391 while Present
(It
.Nam
) loop
2392 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2393 Error_Msg_Node_2
:= It
.Nam
;
2395 ("\\ type& for & declared#", N
, It
.Typ
);
2396 Get_Next_Interp
(Index
, It
);
2401 Error_Msg_N
("\use -gnatf for details", N
);
2404 Wrong_Type
(N
, Typ
);
2412 -- Test if we have more than one interpretation for the context
2414 elsif Ambiguous
then
2418 -- Here we have an acceptable interpretation for the context
2421 -- Propagate type information and normalize tree for various
2422 -- predefined operations. If the context only imposes a class of
2423 -- types, rather than a specific type, propagate the actual type
2426 if Typ
= Any_Integer
2427 or else Typ
= Any_Boolean
2428 or else Typ
= Any_Modular
2429 or else Typ
= Any_Real
2430 or else Typ
= Any_Discrete
2432 Ctx_Type
:= Expr_Type
;
2434 -- Any_Fixed is legal in a real context only if a specific
2435 -- fixed point type is imposed. If Norman Cohen can be
2436 -- confused by this, it deserves a separate message.
2439 and then Expr_Type
= Any_Fixed
2441 Error_Msg_N
("illegal context for mixed mode operation", N
);
2442 Set_Etype
(N
, Universal_Real
);
2443 Ctx_Type
:= Universal_Real
;
2447 -- A user-defined operator is transformed into a function call at
2448 -- this point, so that further processing knows that operators are
2449 -- really operators (i.e. are predefined operators). User-defined
2450 -- operators that are intrinsic are just renamings of the predefined
2451 -- ones, and need not be turned into calls either, but if they rename
2452 -- a different operator, we must transform the node accordingly.
2453 -- Instantiations of Unchecked_Conversion are intrinsic but are
2454 -- treated as functions, even if given an operator designator.
2456 if Nkind
(N
) in N_Op
2457 and then Present
(Entity
(N
))
2458 and then Ekind
(Entity
(N
)) /= E_Operator
2461 if not Is_Predefined_Op
(Entity
(N
)) then
2462 Rewrite_Operator_As_Call
(N
, Entity
(N
));
2464 elsif Present
(Alias
(Entity
(N
)))
2466 Nkind
(Parent
(Parent
(Entity
(N
)))) =
2467 N_Subprogram_Renaming_Declaration
2469 Rewrite_Renamed_Operator
(N
, Alias
(Entity
(N
)), Typ
);
2471 -- If the node is rewritten, it will be fully resolved in
2472 -- Rewrite_Renamed_Operator.
2474 if Analyzed
(N
) then
2480 case N_Subexpr
'(Nkind (N)) is
2482 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2484 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2486 when N_Short_Circuit
2487 => Resolve_Short_Circuit (N, Ctx_Type);
2489 when N_Attribute_Reference
2490 => Resolve_Attribute (N, Ctx_Type);
2492 when N_Character_Literal
2493 => Resolve_Character_Literal (N, Ctx_Type);
2495 when N_Conditional_Expression
2496 => Resolve_Conditional_Expression (N, Ctx_Type);
2498 when N_Expanded_Name
2499 => Resolve_Entity_Name (N, Ctx_Type);
2501 when N_Extension_Aggregate
2502 => Resolve_Extension_Aggregate (N, Ctx_Type);
2504 when N_Explicit_Dereference
2505 => Resolve_Explicit_Dereference (N, Ctx_Type);
2507 when N_Function_Call
2508 => Resolve_Call (N, Ctx_Type);
2511 => Resolve_Entity_Name (N, Ctx_Type);
2513 when N_Indexed_Component
2514 => Resolve_Indexed_Component (N, Ctx_Type);
2516 when N_Integer_Literal
2517 => Resolve_Integer_Literal (N, Ctx_Type);
2519 when N_Membership_Test
2520 => Resolve_Membership_Op (N, Ctx_Type);
2522 when N_Null => Resolve_Null (N, Ctx_Type);
2524 when N_Op_And | N_Op_Or | N_Op_Xor
2525 => Resolve_Logical_Op (N, Ctx_Type);
2527 when N_Op_Eq | N_Op_Ne
2528 => Resolve_Equality_Op (N, Ctx_Type);
2530 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2531 => Resolve_Comparison_Op (N, Ctx_Type);
2533 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2535 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2536 N_Op_Divide | N_Op_Mod | N_Op_Rem
2538 => Resolve_Arithmetic_Op (N, Ctx_Type);
2540 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2542 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2544 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2545 => Resolve_Unary_Op (N, Ctx_Type);
2547 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2549 when N_Procedure_Call_Statement
2550 => Resolve_Call (N, Ctx_Type);
2552 when N_Operator_Symbol
2553 => Resolve_Operator_Symbol (N, Ctx_Type);
2555 when N_Qualified_Expression
2556 => Resolve_Qualified_Expression (N, Ctx_Type);
2558 when N_Raise_xxx_Error
2559 => Set_Etype (N, Ctx_Type);
2561 when N_Range => Resolve_Range (N, Ctx_Type);
2564 => Resolve_Real_Literal (N, Ctx_Type);
2566 when N_Reference => Resolve_Reference (N, Ctx_Type);
2568 when N_Selected_Component
2569 => Resolve_Selected_Component (N, Ctx_Type);
2571 when N_Slice => Resolve_Slice (N, Ctx_Type);
2573 when N_String_Literal
2574 => Resolve_String_Literal (N, Ctx_Type);
2576 when N_Subprogram_Info
2577 => Resolve_Subprogram_Info (N, Ctx_Type);
2579 when N_Type_Conversion
2580 => Resolve_Type_Conversion (N, Ctx_Type);
2582 when N_Unchecked_Expression =>
2583 Resolve_Unchecked_Expression (N, Ctx_Type);
2585 when N_Unchecked_Type_Conversion =>
2586 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2590 -- If the subexpression was replaced by a non-subexpression, then
2591 -- all we do is to expand it. The only legitimate case we know of
2592 -- is converting procedure call statement to entry call statements,
2593 -- but there may be others, so we are making this test general.
2595 if Nkind (N) not in N_Subexpr then
2596 Debug_A_Exit ("resolving ", N, " (done)");
2601 -- The expression is definitely NOT overloaded at this point, so
2602 -- we reset the Is_Overloaded flag to avoid any confusion when
2603 -- reanalyzing the node.
2605 Set_Is_Overloaded (N, False);
2607 -- Freeze expression type, entity if it is a name, and designated
2608 -- type if it is an allocator (RM 13.14(10,11,13)).
2610 -- Now that the resolution of the type of the node is complete,
2611 -- and we did not detect an error, we can expand this node. We
2612 -- skip the expand call if we are in a default expression, see
2613 -- section "Handling of Default Expressions" in Sem spec.
2615 Debug_A_Exit ("resolving ", N, " (done)");
2617 -- We unconditionally freeze the expression, even if we are in
2618 -- default expression mode (the Freeze_Expression routine tests
2619 -- this flag and only freezes static types if it is set).
2621 Freeze_Expression (N);
2623 -- Now we can do the expansion
2633 -- Version with check(s) suppressed
2635 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2637 if Suppress = All_Checks then
2639 Svg : constant Suppress_Array := Scope_Suppress;
2641 Scope_Suppress := (others => True);
2643 Scope_Suppress := Svg;
2648 Svg : constant Boolean := Scope_Suppress (Suppress);
2650 Scope_Suppress (Suppress) := True;
2652 Scope_Suppress (Suppress) := Svg;
2661 -- Version with implicit type
2663 procedure Resolve (N : Node_Id) is
2665 Resolve (N, Etype (N));
2668 ---------------------
2669 -- Resolve_Actuals --
2670 ---------------------
2672 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2673 Loc : constant Source_Ptr := Sloc (N);
2678 Prev : Node_Id := Empty;
2681 procedure Check_Argument_Order;
2682 -- Performs a check for the case where the actuals are all simple
2683 -- identifiers that correspond to the formal names, but in the wrong
2684 -- order, which is considered suspicious and cause for a warning.
2686 procedure Check_Prefixed_Call;
2687 -- If the original node is an overloaded call in prefix notation,
2688 -- insert an 'Access or a dereference as needed over the first actual
.
2689 -- Try_Object_Operation has already verified that there is a valid
2690 -- interpretation, but the form of the actual can only be determined
2691 -- once the primitive operation is identified.
2693 procedure Insert_Default
;
2694 -- If the actual is missing in a call, insert in the actuals list
2695 -- an instance of the default expression. The insertion is always
2696 -- a named association.
2698 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean;
2699 -- Check whether T1 and T2, or their full views, are derived from a
2700 -- common type. Used to enforce the restrictions on array conversions
2703 function Static_Concatenation
(N
: Node_Id
) return Boolean;
2704 -- Predicate to determine whether an actual that is a concatenation
2705 -- will be evaluated statically and does not need a transient scope.
2706 -- This must be determined before the actual is resolved and expanded
2707 -- because if needed the transient scope must be introduced earlier.
2709 --------------------------
2710 -- Check_Argument_Order --
2711 --------------------------
2713 procedure Check_Argument_Order
is
2715 -- Nothing to do if no parameters, or original node is neither a
2716 -- function call nor a procedure call statement (happens in the
2717 -- operator-transformed-to-function call case), or the call does
2718 -- not come from source, or this warning is off.
2720 if not Warn_On_Parameter_Order
2722 No
(Parameter_Associations
(N
))
2724 not Nkind_In
(Original_Node
(N
), N_Procedure_Call_Statement
,
2727 not Comes_From_Source
(N
)
2733 Nargs
: constant Nat
:= List_Length
(Parameter_Associations
(N
));
2736 -- Nothing to do if only one parameter
2742 -- Here if at least two arguments
2745 Actuals
: array (1 .. Nargs
) of Node_Id
;
2749 Wrong_Order
: Boolean := False;
2750 -- Set True if an out of order case is found
2753 -- Collect identifier names of actuals, fail if any actual is
2754 -- not a simple identifier, and record max length of name.
2756 Actual
:= First
(Parameter_Associations
(N
));
2757 for J
in Actuals
'Range loop
2758 if Nkind
(Actual
) /= N_Identifier
then
2761 Actuals
(J
) := Actual
;
2766 -- If we got this far, all actuals are identifiers and the list
2767 -- of their names is stored in the Actuals array.
2769 Formal
:= First_Formal
(Nam
);
2770 for J
in Actuals
'Range loop
2772 -- If we ran out of formals, that's odd, probably an error
2773 -- which will be detected elsewhere, but abandon the search.
2779 -- If name matches and is in order OK
2781 if Chars
(Formal
) = Chars
(Actuals
(J
)) then
2785 -- If no match, see if it is elsewhere in list and if so
2786 -- flag potential wrong order if type is compatible.
2788 for K
in Actuals
'Range loop
2789 if Chars
(Formal
) = Chars
(Actuals
(K
))
2791 Has_Compatible_Type
(Actuals
(K
), Etype
(Formal
))
2793 Wrong_Order
:= True;
2803 <<Continue
>> Next_Formal
(Formal
);
2806 -- If Formals left over, also probably an error, skip warning
2808 if Present
(Formal
) then
2812 -- Here we give the warning if something was out of order
2816 ("actuals for this call may be in wrong order?", N
);
2820 end Check_Argument_Order
;
2822 -------------------------
2823 -- Check_Prefixed_Call --
2824 -------------------------
2826 procedure Check_Prefixed_Call
is
2827 Act
: constant Node_Id
:= First_Actual
(N
);
2828 A_Type
: constant Entity_Id
:= Etype
(Act
);
2829 F_Type
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
2830 Orig
: constant Node_Id
:= Original_Node
(N
);
2834 -- Check whether the call is a prefixed call, with or without
2835 -- additional actuals.
2837 if Nkind
(Orig
) = N_Selected_Component
2839 (Nkind
(Orig
) = N_Indexed_Component
2840 and then Nkind
(Prefix
(Orig
)) = N_Selected_Component
2841 and then Is_Entity_Name
(Prefix
(Prefix
(Orig
)))
2842 and then Is_Entity_Name
(Act
)
2843 and then Chars
(Act
) = Chars
(Prefix
(Prefix
(Orig
))))
2845 if Is_Access_Type
(A_Type
)
2846 and then not Is_Access_Type
(F_Type
)
2848 -- Introduce dereference on object in prefix
2851 Make_Explicit_Dereference
(Sloc
(Act
),
2852 Prefix
=> Relocate_Node
(Act
));
2853 Rewrite
(Act
, New_A
);
2856 elsif Is_Access_Type
(F_Type
)
2857 and then not Is_Access_Type
(A_Type
)
2859 -- Introduce an implicit 'Access in prefix
2861 if not Is_Aliased_View
(Act
) then
2863 ("object in prefixed call to& must be aliased"
2864 & " (RM-2005 4.3.1 (13))",
2869 Make_Attribute_Reference
(Loc
,
2870 Attribute_Name
=> Name_Access
,
2871 Prefix
=> Relocate_Node
(Act
)));
2876 end Check_Prefixed_Call
;
2878 --------------------
2879 -- Insert_Default --
2880 --------------------
2882 procedure Insert_Default
is
2887 -- Missing argument in call, nothing to insert
2889 if No
(Default_Value
(F
)) then
2893 -- Note that we do a full New_Copy_Tree, so that any associated
2894 -- Itypes are properly copied. This may not be needed any more,
2895 -- but it does no harm as a safety measure! Defaults of a generic
2896 -- formal may be out of bounds of the corresponding actual (see
2897 -- cc1311b) and an additional check may be required.
2902 New_Scope
=> Current_Scope
,
2905 if Is_Concurrent_Type
(Scope
(Nam
))
2906 and then Has_Discriminants
(Scope
(Nam
))
2908 Replace_Actual_Discriminants
(N
, Actval
);
2911 if Is_Overloadable
(Nam
)
2912 and then Present
(Alias
(Nam
))
2914 if Base_Type
(Etype
(F
)) /= Base_Type
(Etype
(Actval
))
2915 and then not Is_Tagged_Type
(Etype
(F
))
2917 -- If default is a real literal, do not introduce a
2918 -- conversion whose effect may depend on the run-time
2919 -- size of universal real.
2921 if Nkind
(Actval
) = N_Real_Literal
then
2922 Set_Etype
(Actval
, Base_Type
(Etype
(F
)));
2924 Actval
:= Unchecked_Convert_To
(Etype
(F
), Actval
);
2928 if Is_Scalar_Type
(Etype
(F
)) then
2929 Enable_Range_Check
(Actval
);
2932 Set_Parent
(Actval
, N
);
2934 -- Resolve aggregates with their base type, to avoid scope
2935 -- anomalies: the subtype was first built in the subprogram
2936 -- declaration, and the current call may be nested.
2938 if Nkind
(Actval
) = N_Aggregate
then
2939 Analyze_And_Resolve
(Actval
, Etype
(F
));
2941 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
2945 Set_Parent
(Actval
, N
);
2947 -- See note above concerning aggregates
2949 if Nkind
(Actval
) = N_Aggregate
2950 and then Has_Discriminants
(Etype
(Actval
))
2952 Analyze_And_Resolve
(Actval
, Base_Type
(Etype
(Actval
)));
2954 -- Resolve entities with their own type, which may differ
2955 -- from the type of a reference in a generic context (the
2956 -- view swapping mechanism did not anticipate the re-analysis
2957 -- of default values in calls).
2959 elsif Is_Entity_Name
(Actval
) then
2960 Analyze_And_Resolve
(Actval
, Etype
(Entity
(Actval
)));
2963 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
2967 -- If default is a tag indeterminate function call, propagate
2968 -- tag to obtain proper dispatching.
2970 if Is_Controlling_Formal
(F
)
2971 and then Nkind
(Default_Value
(F
)) = N_Function_Call
2973 Set_Is_Controlling_Actual
(Actval
);
2978 -- If the default expression raises constraint error, then just
2979 -- silently replace it with an N_Raise_Constraint_Error node,
2980 -- since we already gave the warning on the subprogram spec.
2982 if Raises_Constraint_Error
(Actval
) then
2984 Make_Raise_Constraint_Error
(Loc
,
2985 Reason
=> CE_Range_Check_Failed
));
2986 Set_Raises_Constraint_Error
(Actval
);
2987 Set_Etype
(Actval
, Etype
(F
));
2991 Make_Parameter_Association
(Loc
,
2992 Explicit_Actual_Parameter
=> Actval
,
2993 Selector_Name
=> Make_Identifier
(Loc
, Chars
(F
)));
2995 -- Case of insertion is first named actual
2997 if No
(Prev
) or else
2998 Nkind
(Parent
(Prev
)) /= N_Parameter_Association
3000 Set_Next_Named_Actual
(Assoc
, First_Named_Actual
(N
));
3001 Set_First_Named_Actual
(N
, Actval
);
3004 if No
(Parameter_Associations
(N
)) then
3005 Set_Parameter_Associations
(N
, New_List
(Assoc
));
3007 Append
(Assoc
, Parameter_Associations
(N
));
3011 Insert_After
(Prev
, Assoc
);
3014 -- Case of insertion is not first named actual
3017 Set_Next_Named_Actual
3018 (Assoc
, Next_Named_Actual
(Parent
(Prev
)));
3019 Set_Next_Named_Actual
(Parent
(Prev
), Actval
);
3020 Append
(Assoc
, Parameter_Associations
(N
));
3023 Mark_Rewrite_Insertion
(Assoc
);
3024 Mark_Rewrite_Insertion
(Actval
);
3033 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean is
3034 FT1
: Entity_Id
:= T1
;
3035 FT2
: Entity_Id
:= T2
;
3038 if Is_Private_Type
(T1
)
3039 and then Present
(Full_View
(T1
))
3041 FT1
:= Full_View
(T1
);
3044 if Is_Private_Type
(T2
)
3045 and then Present
(Full_View
(T2
))
3047 FT2
:= Full_View
(T2
);
3050 return Root_Type
(Base_Type
(FT1
)) = Root_Type
(Base_Type
(FT2
));
3053 --------------------------
3054 -- Static_Concatenation --
3055 --------------------------
3057 function Static_Concatenation
(N
: Node_Id
) return Boolean is
3060 when N_String_Literal
=>
3065 -- Concatenation is static when both operands are static
3066 -- and the concatenation operator is a predefined one.
3068 return Scope
(Entity
(N
)) = Standard_Standard
3070 Static_Concatenation
(Left_Opnd
(N
))
3072 Static_Concatenation
(Right_Opnd
(N
));
3075 if Is_Entity_Name
(N
) then
3077 Ent
: constant Entity_Id
:= Entity
(N
);
3079 return Ekind
(Ent
) = E_Constant
3080 and then Present
(Constant_Value
(Ent
))
3082 Is_Static_Expression
(Constant_Value
(Ent
));
3089 end Static_Concatenation
;
3091 -- Start of processing for Resolve_Actuals
3094 Check_Argument_Order
;
3096 if Present
(First_Actual
(N
)) then
3097 Check_Prefixed_Call
;
3100 A
:= First_Actual
(N
);
3101 F
:= First_Formal
(Nam
);
3102 while Present
(F
) loop
3103 if No
(A
) and then Needs_No_Actuals
(Nam
) then
3106 -- If we have an error in any actual or formal, indicated by a type
3107 -- of Any_Type, then abandon resolution attempt, and set result type
3110 elsif (Present
(A
) and then Etype
(A
) = Any_Type
)
3111 or else Etype
(F
) = Any_Type
3113 Set_Etype
(N
, Any_Type
);
3117 -- Case where actual is present
3119 -- If the actual is an entity, generate a reference to it now. We
3120 -- do this before the actual is resolved, because a formal of some
3121 -- protected subprogram, or a task discriminant, will be rewritten
3122 -- during expansion, and the reference to the source entity may
3126 and then Is_Entity_Name
(A
)
3127 and then Comes_From_Source
(N
)
3129 Orig_A
:= Entity
(A
);
3131 if Present
(Orig_A
) then
3132 if Is_Formal
(Orig_A
)
3133 and then Ekind
(F
) /= E_In_Parameter
3135 Generate_Reference
(Orig_A
, A
, 'm');
3136 elsif not Is_Overloaded
(A
) then
3137 Generate_Reference
(Orig_A
, A
);
3143 and then (Nkind
(Parent
(A
)) /= N_Parameter_Association
3145 Chars
(Selector_Name
(Parent
(A
))) = Chars
(F
))
3147 -- If style checking mode on, check match of formal name
3150 if Nkind
(Parent
(A
)) = N_Parameter_Association
then
3151 Check_Identifier
(Selector_Name
(Parent
(A
)), F
);
3155 -- If the formal is Out or In_Out, do not resolve and expand the
3156 -- conversion, because it is subsequently expanded into explicit
3157 -- temporaries and assignments. However, the object of the
3158 -- conversion can be resolved. An exception is the case of tagged
3159 -- type conversion with a class-wide actual. In that case we want
3160 -- the tag check to occur and no temporary will be needed (no
3161 -- representation change can occur) and the parameter is passed by
3162 -- reference, so we go ahead and resolve the type conversion.
3163 -- Another exception is the case of reference to component or
3164 -- subcomponent of a bit-packed array, in which case we want to
3165 -- defer expansion to the point the in and out assignments are
3168 if Ekind
(F
) /= E_In_Parameter
3169 and then Nkind
(A
) = N_Type_Conversion
3170 and then not Is_Class_Wide_Type
(Etype
(Expression
(A
)))
3172 if Ekind
(F
) = E_In_Out_Parameter
3173 and then Is_Array_Type
(Etype
(F
))
3175 if Has_Aliased_Components
(Etype
(Expression
(A
)))
3176 /= Has_Aliased_Components
(Etype
(F
))
3179 -- In a view conversion, the conversion must be legal in
3180 -- both directions, and thus both component types must be
3181 -- aliased, or neither (4.6 (8)).
3183 -- The additional rule 4.6 (24.9.2) seems unduly
3184 -- restrictive: the privacy requirement should not apply
3185 -- to generic types, and should be checked in an
3186 -- instance. ARG query is in order ???
3189 ("both component types in a view conversion must be"
3190 & " aliased, or neither", A
);
3193 not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3195 if Is_By_Reference_Type
(Etype
(F
))
3196 or else Is_By_Reference_Type
(Etype
(Expression
(A
)))
3199 ("view conversion between unrelated by reference " &
3200 "array types not allowed (\'A'I-00246)", A
);
3203 Comp_Type
: constant Entity_Id
:=
3205 (Etype
(Expression
(A
)));
3207 if Comes_From_Source
(A
)
3208 and then Ada_Version
>= Ada_05
3210 ((Is_Private_Type
(Comp_Type
)
3211 and then not Is_Generic_Type
(Comp_Type
))
3212 or else Is_Tagged_Type
(Comp_Type
)
3213 or else Is_Volatile
(Comp_Type
))
3216 ("component type of a view conversion cannot"
3217 & " be private, tagged, or volatile"
3226 if (Conversion_OK
(A
)
3227 or else Valid_Conversion
(A
, Etype
(A
), Expression
(A
)))
3228 and then not Is_Ref_To_Bit_Packed_Array
(Expression
(A
))
3230 Resolve
(Expression
(A
));
3233 -- If the actual is a function call that returns a limited
3234 -- unconstrained object that needs finalization, create a
3235 -- transient scope for it, so that it can receive the proper
3236 -- finalization list.
3238 elsif Nkind
(A
) = N_Function_Call
3239 and then Is_Limited_Record
(Etype
(F
))
3240 and then not Is_Constrained
(Etype
(F
))
3241 and then Expander_Active
3243 (Is_Controlled
(Etype
(F
)) or else Has_Task
(Etype
(F
)))
3245 Establish_Transient_Scope
(A
, False);
3247 -- A small optimization: if one of the actuals is a concatenation
3248 -- create a block around a procedure call to recover stack space.
3249 -- This alleviates stack usage when several procedure calls in
3250 -- the same statement list use concatenation. We do not perform
3251 -- this wrapping for code statements, where the argument is a
3252 -- static string, and we want to preserve warnings involving
3253 -- sequences of such statements.
3255 elsif Nkind
(A
) = N_Op_Concat
3256 and then Nkind
(N
) = N_Procedure_Call_Statement
3257 and then Expander_Active
3259 not (Is_Intrinsic_Subprogram
(Nam
)
3260 and then Chars
(Nam
) = Name_Asm
)
3261 and then not Static_Concatenation
(A
)
3263 Establish_Transient_Scope
(A
, False);
3264 Resolve
(A
, Etype
(F
));
3267 if Nkind
(A
) = N_Type_Conversion
3268 and then Is_Array_Type
(Etype
(F
))
3269 and then not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3271 (Is_Limited_Type
(Etype
(F
))
3272 or else Is_Limited_Type
(Etype
(Expression
(A
))))
3275 ("conversion between unrelated limited array types " &
3276 "not allowed (\A\I-00246)", A
);
3278 if Is_Limited_Type
(Etype
(F
)) then
3279 Explain_Limited_Type
(Etype
(F
), A
);
3282 if Is_Limited_Type
(Etype
(Expression
(A
))) then
3283 Explain_Limited_Type
(Etype
(Expression
(A
)), A
);
3287 -- (Ada 2005: AI-251): If the actual is an allocator whose
3288 -- directly designated type is a class-wide interface, we build
3289 -- an anonymous access type to use it as the type of the
3290 -- allocator. Later, when the subprogram call is expanded, if
3291 -- the interface has a secondary dispatch table the expander
3292 -- will add a type conversion to force the correct displacement
3295 if Nkind
(A
) = N_Allocator
then
3297 DDT
: constant Entity_Id
:=
3298 Directly_Designated_Type
(Base_Type
(Etype
(F
)));
3300 New_Itype
: Entity_Id
;
3303 if Is_Class_Wide_Type
(DDT
)
3304 and then Is_Interface
(DDT
)
3306 New_Itype
:= Create_Itype
(E_Anonymous_Access_Type
, A
);
3307 Set_Etype
(New_Itype
, Etype
(A
));
3308 Set_Directly_Designated_Type
(New_Itype
,
3309 Directly_Designated_Type
(Etype
(A
)));
3310 Set_Etype
(A
, New_Itype
);
3313 -- Ada 2005, AI-162:If the actual is an allocator, the
3314 -- innermost enclosing statement is the master of the
3315 -- created object. This needs to be done with expansion
3316 -- enabled only, otherwise the transient scope will not
3317 -- be removed in the expansion of the wrapped construct.
3319 if (Is_Controlled
(DDT
) or else Has_Task
(DDT
))
3320 and then Expander_Active
3322 Establish_Transient_Scope
(A
, False);
3327 -- (Ada 2005): The call may be to a primitive operation of
3328 -- a tagged synchronized type, declared outside of the type.
3329 -- In this case the controlling actual must be converted to
3330 -- its corresponding record type, which is the formal type.
3331 -- The actual may be a subtype, either because of a constraint
3332 -- or because it is a generic actual, so use base type to
3333 -- locate concurrent type.
3335 A_Typ
:= Base_Type
(Etype
(A
));
3336 F_Typ
:= Base_Type
(Etype
(F
));
3339 Full_A_Typ
: Entity_Id
;
3342 if Present
(Full_View
(A_Typ
)) then
3343 Full_A_Typ
:= Base_Type
(Full_View
(A_Typ
));
3345 Full_A_Typ
:= A_Typ
;
3348 -- Tagged synchronized type (case 1): the actual is a
3351 if Is_Concurrent_Type
(A_Typ
)
3352 and then Corresponding_Record_Type
(A_Typ
) = F_Typ
3355 Unchecked_Convert_To
3356 (Corresponding_Record_Type
(A_Typ
), A
));
3357 Resolve
(A
, Etype
(F
));
3359 -- Tagged synchronized type (case 2): the formal is a
3362 elsif Ekind
(Full_A_Typ
) = E_Record_Type
3364 (Corresponding_Concurrent_Type
(Full_A_Typ
))
3365 and then Is_Concurrent_Type
(F_Typ
)
3366 and then Present
(Corresponding_Record_Type
(F_Typ
))
3367 and then Full_A_Typ
= Corresponding_Record_Type
(F_Typ
)
3369 Resolve
(A
, Corresponding_Record_Type
(F_Typ
));
3374 Resolve
(A
, Etype
(F
));
3382 -- For mode IN, if actual is an entity, and the type of the formal
3383 -- has warnings suppressed, then we reset Never_Set_In_Source for
3384 -- the calling entity. The reason for this is to catch cases like
3385 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3386 -- uses trickery to modify an IN parameter.
3388 if Ekind
(F
) = E_In_Parameter
3389 and then Is_Entity_Name
(A
)
3390 and then Present
(Entity
(A
))
3391 and then Ekind
(Entity
(A
)) = E_Variable
3392 and then Has_Warnings_Off
(F_Typ
)
3394 Set_Never_Set_In_Source
(Entity
(A
), False);
3397 -- Perform error checks for IN and IN OUT parameters
3399 if Ekind
(F
) /= E_Out_Parameter
then
3401 -- Check unset reference. For scalar parameters, it is clearly
3402 -- wrong to pass an uninitialized value as either an IN or
3403 -- IN-OUT parameter. For composites, it is also clearly an
3404 -- error to pass a completely uninitialized value as an IN
3405 -- parameter, but the case of IN OUT is trickier. We prefer
3406 -- not to give a warning here. For example, suppose there is
3407 -- a routine that sets some component of a record to False.
3408 -- It is perfectly reasonable to make this IN-OUT and allow
3409 -- either initialized or uninitialized records to be passed
3412 -- For partially initialized composite values, we also avoid
3413 -- warnings, since it is quite likely that we are passing a
3414 -- partially initialized value and only the initialized fields
3415 -- will in fact be read in the subprogram.
3417 if Is_Scalar_Type
(A_Typ
)
3418 or else (Ekind
(F
) = E_In_Parameter
3419 and then not Is_Partially_Initialized_Type
(A_Typ
))
3421 Check_Unset_Reference
(A
);
3424 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3425 -- actual to a nested call, since this is case of reading an
3426 -- out parameter, which is not allowed.
3428 if Ada_Version
= Ada_83
3429 and then Is_Entity_Name
(A
)
3430 and then Ekind
(Entity
(A
)) = E_Out_Parameter
3432 Error_Msg_N
("(Ada 83) illegal reading of out parameter", A
);
3436 -- Case of OUT or IN OUT parameter
3438 if Ekind
(F
) /= E_In_Parameter
then
3440 -- For an Out parameter, check for useless assignment. Note
3441 -- that we can't set Last_Assignment this early, because we may
3442 -- kill current values in Resolve_Call, and that call would
3443 -- clobber the Last_Assignment field.
3445 -- Note: call Warn_On_Useless_Assignment before doing the check
3446 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3447 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3448 -- reflects the last assignment, not this one!
3450 if Ekind
(F
) = E_Out_Parameter
then
3451 if Warn_On_Modified_As_Out_Parameter
(F
)
3452 and then Is_Entity_Name
(A
)
3453 and then Present
(Entity
(A
))
3454 and then Comes_From_Source
(N
)
3456 Warn_On_Useless_Assignment
(Entity
(A
), A
);
3460 -- Validate the form of the actual. Note that the call to
3461 -- Is_OK_Variable_For_Out_Formal generates the required
3462 -- reference in this case.
3464 if not Is_OK_Variable_For_Out_Formal
(A
) then
3465 Error_Msg_NE
("actual for& must be a variable", A
, F
);
3468 -- What's the following about???
3470 if Is_Entity_Name
(A
) then
3471 Kill_Checks
(Entity
(A
));
3477 if Etype
(A
) = Any_Type
then
3478 Set_Etype
(N
, Any_Type
);
3482 -- Apply appropriate range checks for in, out, and in-out
3483 -- parameters. Out and in-out parameters also need a separate
3484 -- check, if there is a type conversion, to make sure the return
3485 -- value meets the constraints of the variable before the
3488 -- Gigi looks at the check flag and uses the appropriate types.
3489 -- For now since one flag is used there is an optimization which
3490 -- might not be done in the In Out case since Gigi does not do
3491 -- any analysis. More thought required about this ???
3493 if Ekind
(F
) = E_In_Parameter
3494 or else Ekind
(F
) = E_In_Out_Parameter
3496 if Is_Scalar_Type
(Etype
(A
)) then
3497 Apply_Scalar_Range_Check
(A
, F_Typ
);
3499 elsif Is_Array_Type
(Etype
(A
)) then
3500 Apply_Length_Check
(A
, F_Typ
);
3502 elsif Is_Record_Type
(F_Typ
)
3503 and then Has_Discriminants
(F_Typ
)
3504 and then Is_Constrained
(F_Typ
)
3505 and then (not Is_Derived_Type
(F_Typ
)
3506 or else Comes_From_Source
(Nam
))
3508 Apply_Discriminant_Check
(A
, F_Typ
);
3510 elsif Is_Access_Type
(F_Typ
)
3511 and then Is_Array_Type
(Designated_Type
(F_Typ
))
3512 and then Is_Constrained
(Designated_Type
(F_Typ
))
3514 Apply_Length_Check
(A
, F_Typ
);
3516 elsif Is_Access_Type
(F_Typ
)
3517 and then Has_Discriminants
(Designated_Type
(F_Typ
))
3518 and then Is_Constrained
(Designated_Type
(F_Typ
))
3520 Apply_Discriminant_Check
(A
, F_Typ
);
3523 Apply_Range_Check
(A
, F_Typ
);
3526 -- Ada 2005 (AI-231)
3528 if Ada_Version
>= Ada_05
3529 and then Is_Access_Type
(F_Typ
)
3530 and then Can_Never_Be_Null
(F_Typ
)
3531 and then Known_Null
(A
)
3533 Apply_Compile_Time_Constraint_Error
3535 Msg
=> "(Ada 2005) null not allowed in "
3536 & "null-excluding formal?",
3537 Reason
=> CE_Null_Not_Allowed
);
3541 if Ekind
(F
) = E_Out_Parameter
3542 or else Ekind
(F
) = E_In_Out_Parameter
3544 if Nkind
(A
) = N_Type_Conversion
then
3545 if Is_Scalar_Type
(A_Typ
) then
3546 Apply_Scalar_Range_Check
3547 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
3550 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
3554 if Is_Scalar_Type
(F_Typ
) then
3555 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
3557 elsif Is_Array_Type
(F_Typ
)
3558 and then Ekind
(F
) = E_Out_Parameter
3560 Apply_Length_Check
(A
, F_Typ
);
3563 Apply_Range_Check
(A
, A_Typ
, F_Typ
);
3568 -- An actual associated with an access parameter is implicitly
3569 -- converted to the anonymous access type of the formal and must
3570 -- satisfy the legality checks for access conversions.
3572 if Ekind
(F_Typ
) = E_Anonymous_Access_Type
then
3573 if not Valid_Conversion
(A
, F_Typ
, A
) then
3575 ("invalid implicit conversion for access parameter", A
);
3579 -- Check bad case of atomic/volatile argument (RM C.6(12))
3581 if Is_By_Reference_Type
(Etype
(F
))
3582 and then Comes_From_Source
(N
)
3584 if Is_Atomic_Object
(A
)
3585 and then not Is_Atomic
(Etype
(F
))
3588 ("cannot pass atomic argument to non-atomic formal",
3591 elsif Is_Volatile_Object
(A
)
3592 and then not Is_Volatile
(Etype
(F
))
3595 ("cannot pass volatile argument to non-volatile formal",
3600 -- Check that subprograms don't have improper controlling
3601 -- arguments (RM 3.9.2 (9)).
3603 -- A primitive operation may have an access parameter of an
3604 -- incomplete tagged type, but a dispatching call is illegal
3605 -- if the type is still incomplete.
3607 if Is_Controlling_Formal
(F
) then
3608 Set_Is_Controlling_Actual
(A
);
3610 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
3612 Desig
: constant Entity_Id
:= Designated_Type
(Etype
(F
));
3614 if Ekind
(Desig
) = E_Incomplete_Type
3615 and then No
(Full_View
(Desig
))
3616 and then No
(Non_Limited_View
(Desig
))
3619 ("premature use of incomplete type& " &
3620 "in dispatching call", A
, Desig
);
3625 elsif Nkind
(A
) = N_Explicit_Dereference
then
3626 Validate_Remote_Access_To_Class_Wide_Type
(A
);
3629 if (Is_Class_Wide_Type
(A_Typ
) or else Is_Dynamically_Tagged
(A
))
3630 and then not Is_Class_Wide_Type
(F_Typ
)
3631 and then not Is_Controlling_Formal
(F
)
3633 Error_Msg_N
("class-wide argument not allowed here!", A
);
3635 if Is_Subprogram
(Nam
)
3636 and then Comes_From_Source
(Nam
)
3638 Error_Msg_Node_2
:= F_Typ
;
3640 ("& is not a dispatching operation of &!", A
, Nam
);
3643 elsif Is_Access_Type
(A_Typ
)
3644 and then Is_Access_Type
(F_Typ
)
3645 and then Ekind
(F_Typ
) /= E_Access_Subprogram_Type
3646 and then Ekind
(F_Typ
) /= E_Anonymous_Access_Subprogram_Type
3647 and then (Is_Class_Wide_Type
(Designated_Type
(A_Typ
))
3648 or else (Nkind
(A
) = N_Attribute_Reference
3650 Is_Class_Wide_Type
(Etype
(Prefix
(A
)))))
3651 and then not Is_Class_Wide_Type
(Designated_Type
(F_Typ
))
3652 and then not Is_Controlling_Formal
(F
)
3654 -- Disable these checks for call to imported C++ subprograms
3657 (Is_Entity_Name
(Name
(N
))
3658 and then Is_Imported
(Entity
(Name
(N
)))
3659 and then Convention
(Entity
(Name
(N
))) = Convention_CPP
)
3662 ("access to class-wide argument not allowed here!", A
);
3664 if Is_Subprogram
(Nam
)
3665 and then Comes_From_Source
(Nam
)
3667 Error_Msg_Node_2
:= Designated_Type
(F_Typ
);
3669 ("& is not a dispatching operation of &!", A
, Nam
);
3675 -- If it is a named association, treat the selector_name as
3676 -- a proper identifier, and mark the corresponding entity.
3678 if Nkind
(Parent
(A
)) = N_Parameter_Association
then
3679 Set_Entity
(Selector_Name
(Parent
(A
)), F
);
3680 Generate_Reference
(F
, Selector_Name
(Parent
(A
)));
3681 Set_Etype
(Selector_Name
(Parent
(A
)), F_Typ
);
3682 Generate_Reference
(F_Typ
, N
, ' ');
3687 if Ekind
(F
) /= E_Out_Parameter
then
3688 Check_Unset_Reference
(A
);
3693 -- Case where actual is not present
3701 end Resolve_Actuals
;
3703 -----------------------
3704 -- Resolve_Allocator --
3705 -----------------------
3707 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
) is
3708 E
: constant Node_Id
:= Expression
(N
);
3710 Discrim
: Entity_Id
;
3713 Assoc
: Node_Id
:= Empty
;
3716 procedure Check_Allocator_Discrim_Accessibility
3717 (Disc_Exp
: Node_Id
;
3718 Alloc_Typ
: Entity_Id
);
3719 -- Check that accessibility level associated with an access discriminant
3720 -- initialized in an allocator by the expression Disc_Exp is not deeper
3721 -- than the level of the allocator type Alloc_Typ. An error message is
3722 -- issued if this condition is violated. Specialized checks are done for
3723 -- the cases of a constraint expression which is an access attribute or
3724 -- an access discriminant.
3726 function In_Dispatching_Context
return Boolean;
3727 -- If the allocator is an actual in a call, it is allowed to be class-
3728 -- wide when the context is not because it is a controlling actual.
3730 procedure Propagate_Coextensions
(Root
: Node_Id
);
3731 -- Propagate all nested coextensions which are located one nesting
3732 -- level down the tree to the node Root. Example:
3735 -- Level_1_Coextension
3736 -- Level_2_Coextension
3738 -- The algorithm is paired with delay actions done by the Expander. In
3739 -- the above example, assume all coextensions are controlled types.
3740 -- The cycle of analysis, resolution and expansion will yield:
3742 -- 1) Analyze Top_Record
3743 -- 2) Analyze Level_1_Coextension
3744 -- 3) Analyze Level_2_Coextension
3745 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
3747 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
3748 -- generated to capture the allocated object. Temp_1 is attached
3749 -- to the coextension chain of Level_2_Coextension.
3750 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
3751 -- coextension. A forward tree traversal is performed which finds
3752 -- Level_2_Coextension's list and copies its contents into its
3754 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
3755 -- generated to capture the allocated object. Temp_2 is attached
3756 -- to the coextension chain of Level_1_Coextension. Currently, the
3757 -- contents of the list are [Temp_2, Temp_1].
3758 -- 8) Resolve Top_Record. A forward tree traversal is performed which
3759 -- finds Level_1_Coextension's list and copies its contents into
3761 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
3762 -- Temp_2 and attach them to Top_Record's finalization list.
3764 -------------------------------------------
3765 -- Check_Allocator_Discrim_Accessibility --
3766 -------------------------------------------
3768 procedure Check_Allocator_Discrim_Accessibility
3769 (Disc_Exp
: Node_Id
;
3770 Alloc_Typ
: Entity_Id
)
3773 if Type_Access_Level
(Etype
(Disc_Exp
)) >
3774 Type_Access_Level
(Alloc_Typ
)
3777 ("operand type has deeper level than allocator type", Disc_Exp
);
3779 -- When the expression is an Access attribute the level of the prefix
3780 -- object must not be deeper than that of the allocator's type.
3782 elsif Nkind
(Disc_Exp
) = N_Attribute_Reference
3783 and then Get_Attribute_Id
(Attribute_Name
(Disc_Exp
))
3785 and then Object_Access_Level
(Prefix
(Disc_Exp
))
3786 > Type_Access_Level
(Alloc_Typ
)
3789 ("prefix of attribute has deeper level than allocator type",
3792 -- When the expression is an access discriminant the check is against
3793 -- the level of the prefix object.
3795 elsif Ekind
(Etype
(Disc_Exp
)) = E_Anonymous_Access_Type
3796 and then Nkind
(Disc_Exp
) = N_Selected_Component
3797 and then Object_Access_Level
(Prefix
(Disc_Exp
))
3798 > Type_Access_Level
(Alloc_Typ
)
3801 ("access discriminant has deeper level than allocator type",
3804 -- All other cases are legal
3809 end Check_Allocator_Discrim_Accessibility
;
3811 ----------------------------
3812 -- In_Dispatching_Context --
3813 ----------------------------
3815 function In_Dispatching_Context
return Boolean is
3816 Par
: constant Node_Id
:= Parent
(N
);
3818 return Nkind_In
(Par
, N_Function_Call
, N_Procedure_Call_Statement
)
3819 and then Is_Entity_Name
(Name
(Par
))
3820 and then Is_Dispatching_Operation
(Entity
(Name
(Par
)));
3821 end In_Dispatching_Context
;
3823 ----------------------------
3824 -- Propagate_Coextensions --
3825 ----------------------------
3827 procedure Propagate_Coextensions
(Root
: Node_Id
) is
3829 procedure Copy_List
(From
: Elist_Id
; To
: Elist_Id
);
3830 -- Copy the contents of list From into list To, preserving the
3831 -- order of elements.
3833 function Process_Allocator
(Nod
: Node_Id
) return Traverse_Result
;
3834 -- Recognize an allocator or a rewritten allocator node and add it
3835 -- along with its nested coextensions to the list of Root.
3841 procedure Copy_List
(From
: Elist_Id
; To
: Elist_Id
) is
3842 From_Elmt
: Elmt_Id
;
3844 From_Elmt
:= First_Elmt
(From
);
3845 while Present
(From_Elmt
) loop
3846 Append_Elmt
(Node
(From_Elmt
), To
);
3847 Next_Elmt
(From_Elmt
);
3851 -----------------------
3852 -- Process_Allocator --
3853 -----------------------
3855 function Process_Allocator
(Nod
: Node_Id
) return Traverse_Result
is
3856 Orig_Nod
: Node_Id
:= Nod
;
3859 -- This is a possible rewritten subtype indication allocator. Any
3860 -- nested coextensions will appear as discriminant constraints.
3862 if Nkind
(Nod
) = N_Identifier
3863 and then Present
(Original_Node
(Nod
))
3864 and then Nkind
(Original_Node
(Nod
)) = N_Subtype_Indication
3868 Discr_Elmt
: Elmt_Id
;
3871 if Is_Record_Type
(Entity
(Nod
)) then
3873 First_Elmt
(Discriminant_Constraint
(Entity
(Nod
)));
3874 while Present
(Discr_Elmt
) loop
3875 Discr
:= Node
(Discr_Elmt
);
3877 if Nkind
(Discr
) = N_Identifier
3878 and then Present
(Original_Node
(Discr
))
3879 and then Nkind
(Original_Node
(Discr
)) = N_Allocator
3880 and then Present
(Coextensions
(
3881 Original_Node
(Discr
)))
3883 if No
(Coextensions
(Root
)) then
3884 Set_Coextensions
(Root
, New_Elmt_List
);
3888 (From
=> Coextensions
(Original_Node
(Discr
)),
3889 To
=> Coextensions
(Root
));
3892 Next_Elmt
(Discr_Elmt
);
3895 -- There is no need to continue the traversal of this
3896 -- subtree since all the information has already been
3903 -- Case of either a stand alone allocator or a rewritten allocator
3904 -- with an aggregate.
3907 if Present
(Original_Node
(Nod
)) then
3908 Orig_Nod
:= Original_Node
(Nod
);
3911 if Nkind
(Orig_Nod
) = N_Allocator
then
3913 -- Propagate the list of nested coextensions to the Root
3914 -- allocator. This is done through list copy since a single
3915 -- allocator may have multiple coextensions. Do not touch
3916 -- coextensions roots.
3918 if not Is_Coextension_Root
(Orig_Nod
)
3919 and then Present
(Coextensions
(Orig_Nod
))
3921 if No
(Coextensions
(Root
)) then
3922 Set_Coextensions
(Root
, New_Elmt_List
);
3926 (From
=> Coextensions
(Orig_Nod
),
3927 To
=> Coextensions
(Root
));
3930 -- There is no need to continue the traversal of this
3931 -- subtree since all the information has already been
3938 -- Keep on traversing, looking for the next allocator
3941 end Process_Allocator
;
3943 procedure Process_Allocators
is
3944 new Traverse_Proc
(Process_Allocator
);
3946 -- Start of processing for Propagate_Coextensions
3949 Process_Allocators
(Expression
(Root
));
3950 end Propagate_Coextensions
;
3952 -- Start of processing for Resolve_Allocator
3955 -- Replace general access with specific type
3957 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
3958 Set_Etype
(N
, Base_Type
(Typ
));
3961 if Is_Abstract_Type
(Typ
) then
3962 Error_Msg_N
("type of allocator cannot be abstract", N
);
3965 -- For qualified expression, resolve the expression using the
3966 -- given subtype (nothing to do for type mark, subtype indication)
3968 if Nkind
(E
) = N_Qualified_Expression
then
3969 if Is_Class_Wide_Type
(Etype
(E
))
3970 and then not Is_Class_Wide_Type
(Designated_Type
(Typ
))
3971 and then not In_Dispatching_Context
3974 ("class-wide allocator not allowed for this access type", N
);
3977 Resolve
(Expression
(E
), Etype
(E
));
3978 Check_Unset_Reference
(Expression
(E
));
3980 -- A qualified expression requires an exact match of the type,
3981 -- class-wide matching is not allowed.
3983 if (Is_Class_Wide_Type
(Etype
(Expression
(E
)))
3984 or else Is_Class_Wide_Type
(Etype
(E
)))
3985 and then Base_Type
(Etype
(Expression
(E
))) /= Base_Type
(Etype
(E
))
3987 Wrong_Type
(Expression
(E
), Etype
(E
));
3990 -- A special accessibility check is needed for allocators that
3991 -- constrain access discriminants. The level of the type of the
3992 -- expression used to constrain an access discriminant cannot be
3993 -- deeper than the type of the allocator (in contrast to access
3994 -- parameters, where the level of the actual can be arbitrary).
3996 -- We can't use Valid_Conversion to perform this check because
3997 -- in general the type of the allocator is unrelated to the type
3998 -- of the access discriminant.
4000 if Ekind
(Typ
) /= E_Anonymous_Access_Type
4001 or else Is_Local_Anonymous_Access
(Typ
)
4003 Subtyp
:= Entity
(Subtype_Mark
(E
));
4005 Aggr
:= Original_Node
(Expression
(E
));
4007 if Has_Discriminants
(Subtyp
)
4008 and then Nkind_In
(Aggr
, N_Aggregate
, N_Extension_Aggregate
)
4010 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4012 -- Get the first component expression of the aggregate
4014 if Present
(Expressions
(Aggr
)) then
4015 Disc_Exp
:= First
(Expressions
(Aggr
));
4017 elsif Present
(Component_Associations
(Aggr
)) then
4018 Assoc
:= First
(Component_Associations
(Aggr
));
4020 if Present
(Assoc
) then
4021 Disc_Exp
:= Expression
(Assoc
);
4030 while Present
(Discrim
) and then Present
(Disc_Exp
) loop
4031 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4032 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4035 Next_Discriminant
(Discrim
);
4037 if Present
(Discrim
) then
4038 if Present
(Assoc
) then
4040 Disc_Exp
:= Expression
(Assoc
);
4042 elsif Present
(Next
(Disc_Exp
)) then
4046 Assoc
:= First
(Component_Associations
(Aggr
));
4048 if Present
(Assoc
) then
4049 Disc_Exp
:= Expression
(Assoc
);
4059 -- For a subtype mark or subtype indication, freeze the subtype
4062 Freeze_Expression
(E
);
4064 if Is_Access_Constant
(Typ
) and then not No_Initialization
(N
) then
4066 ("initialization required for access-to-constant allocator", N
);
4069 -- A special accessibility check is needed for allocators that
4070 -- constrain access discriminants. The level of the type of the
4071 -- expression used to constrain an access discriminant cannot be
4072 -- deeper than the type of the allocator (in contrast to access
4073 -- parameters, where the level of the actual can be arbitrary).
4074 -- We can't use Valid_Conversion to perform this check because
4075 -- in general the type of the allocator is unrelated to the type
4076 -- of the access discriminant.
4078 if Nkind
(Original_Node
(E
)) = N_Subtype_Indication
4079 and then (Ekind
(Typ
) /= E_Anonymous_Access_Type
4080 or else Is_Local_Anonymous_Access
(Typ
))
4082 Subtyp
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4084 if Has_Discriminants
(Subtyp
) then
4085 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4086 Constr
:= First
(Constraints
(Constraint
(Original_Node
(E
))));
4087 while Present
(Discrim
) and then Present
(Constr
) loop
4088 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4089 if Nkind
(Constr
) = N_Discriminant_Association
then
4090 Disc_Exp
:= Original_Node
(Expression
(Constr
));
4092 Disc_Exp
:= Original_Node
(Constr
);
4095 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4098 Next_Discriminant
(Discrim
);
4105 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4106 -- check that the level of the type of the created object is not deeper
4107 -- than the level of the allocator's access type, since extensions can
4108 -- now occur at deeper levels than their ancestor types. This is a
4109 -- static accessibility level check; a run-time check is also needed in
4110 -- the case of an initialized allocator with a class-wide argument (see
4111 -- Expand_Allocator_Expression).
4113 if Ada_Version
>= Ada_05
4114 and then Is_Class_Wide_Type
(Designated_Type
(Typ
))
4117 Exp_Typ
: Entity_Id
;
4120 if Nkind
(E
) = N_Qualified_Expression
then
4121 Exp_Typ
:= Etype
(E
);
4122 elsif Nkind
(E
) = N_Subtype_Indication
then
4123 Exp_Typ
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4125 Exp_Typ
:= Entity
(E
);
4128 if Type_Access_Level
(Exp_Typ
) > Type_Access_Level
(Typ
) then
4129 if In_Instance_Body
then
4130 Error_Msg_N
("?type in allocator has deeper level than" &
4131 " designated class-wide type", E
);
4132 Error_Msg_N
("\?Program_Error will be raised at run time",
4135 Make_Raise_Program_Error
(Sloc
(N
),
4136 Reason
=> PE_Accessibility_Check_Failed
));
4139 -- Do not apply Ada 2005 accessibility checks on a class-wide
4140 -- allocator if the type given in the allocator is a formal
4141 -- type. A run-time check will be performed in the instance.
4143 elsif not Is_Generic_Type
(Exp_Typ
) then
4144 Error_Msg_N
("type in allocator has deeper level than" &
4145 " designated class-wide type", E
);
4151 -- Check for allocation from an empty storage pool
4153 if No_Pool_Assigned
(Typ
) then
4155 Loc
: constant Source_Ptr
:= Sloc
(N
);
4157 Error_Msg_N
("?allocation from empty storage pool!", N
);
4158 Error_Msg_N
("\?Storage_Error will be raised at run time!", N
);
4160 Make_Raise_Storage_Error
(Loc
,
4161 Reason
=> SE_Empty_Storage_Pool
));
4164 -- If the context is an unchecked conversion, as may happen within
4165 -- an inlined subprogram, the allocator is being resolved with its
4166 -- own anonymous type. In that case, if the target type has a specific
4167 -- storage pool, it must be inherited explicitly by the allocator type.
4169 elsif Nkind
(Parent
(N
)) = N_Unchecked_Type_Conversion
4170 and then No
(Associated_Storage_Pool
(Typ
))
4172 Set_Associated_Storage_Pool
4173 (Typ
, Associated_Storage_Pool
(Etype
(Parent
(N
))));
4176 -- An erroneous allocator may be rewritten as a raise Program_Error
4179 if Nkind
(N
) = N_Allocator
then
4181 -- An anonymous access discriminant is the definition of a
4184 if Ekind
(Typ
) = E_Anonymous_Access_Type
4185 and then Nkind
(Associated_Node_For_Itype
(Typ
)) =
4186 N_Discriminant_Specification
4188 -- Avoid marking an allocator as a dynamic coextension if it is
4189 -- within a static construct.
4191 if not Is_Static_Coextension
(N
) then
4192 Set_Is_Dynamic_Coextension
(N
);
4195 -- Cleanup for potential static coextensions
4198 Set_Is_Dynamic_Coextension
(N
, False);
4199 Set_Is_Static_Coextension
(N
, False);
4202 -- There is no need to propagate any nested coextensions if they
4203 -- are marked as static since they will be rewritten on the spot.
4205 if not Is_Static_Coextension
(N
) then
4206 Propagate_Coextensions
(N
);
4209 end Resolve_Allocator
;
4211 ---------------------------
4212 -- Resolve_Arithmetic_Op --
4213 ---------------------------
4215 -- Used for resolving all arithmetic operators except exponentiation
4217 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
4218 L
: constant Node_Id
:= Left_Opnd
(N
);
4219 R
: constant Node_Id
:= Right_Opnd
(N
);
4220 TL
: constant Entity_Id
:= Base_Type
(Etype
(L
));
4221 TR
: constant Entity_Id
:= Base_Type
(Etype
(R
));
4225 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
4226 -- We do the resolution using the base type, because intermediate values
4227 -- in expressions always are of the base type, not a subtype of it.
4229 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean;
4230 -- Returns True if N is in a context that expects "any real type"
4232 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean;
4233 -- Return True iff given type is Integer or universal real/integer
4235 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
);
4236 -- Choose type of integer literal in fixed-point operation to conform
4237 -- to available fixed-point type. T is the type of the other operand,
4238 -- which is needed to determine the expected type of N.
4240 procedure Set_Operand_Type
(N
: Node_Id
);
4241 -- Set operand type to T if universal
4243 -------------------------------
4244 -- Expected_Type_Is_Any_Real --
4245 -------------------------------
4247 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean is
4249 -- N is the expression after "delta" in a fixed_point_definition;
4252 return Nkind_In
(Parent
(N
), N_Ordinary_Fixed_Point_Definition
,
4253 N_Decimal_Fixed_Point_Definition
,
4255 -- N is one of the bounds in a real_range_specification;
4258 N_Real_Range_Specification
,
4260 -- N is the expression of a delta_constraint;
4263 N_Delta_Constraint
);
4264 end Expected_Type_Is_Any_Real
;
4266 -----------------------------
4267 -- Is_Integer_Or_Universal --
4268 -----------------------------
4270 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean is
4272 Index
: Interp_Index
;
4276 if not Is_Overloaded
(N
) then
4278 return Base_Type
(T
) = Base_Type
(Standard_Integer
)
4279 or else T
= Universal_Integer
4280 or else T
= Universal_Real
;
4282 Get_First_Interp
(N
, Index
, It
);
4283 while Present
(It
.Typ
) loop
4284 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
)
4285 or else It
.Typ
= Universal_Integer
4286 or else It
.Typ
= Universal_Real
4291 Get_Next_Interp
(Index
, It
);
4296 end Is_Integer_Or_Universal
;
4298 ----------------------------
4299 -- Set_Mixed_Mode_Operand --
4300 ----------------------------
4302 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
) is
4303 Index
: Interp_Index
;
4307 if Universal_Interpretation
(N
) = Universal_Integer
then
4309 -- A universal integer literal is resolved as standard integer
4310 -- except in the case of a fixed-point result, where we leave it
4311 -- as universal (to be handled by Exp_Fixd later on)
4313 if Is_Fixed_Point_Type
(T
) then
4314 Resolve
(N
, Universal_Integer
);
4316 Resolve
(N
, Standard_Integer
);
4319 elsif Universal_Interpretation
(N
) = Universal_Real
4320 and then (T
= Base_Type
(Standard_Integer
)
4321 or else T
= Universal_Integer
4322 or else T
= Universal_Real
)
4324 -- A universal real can appear in a fixed-type context. We resolve
4325 -- the literal with that context, even though this might raise an
4326 -- exception prematurely (the other operand may be zero).
4330 elsif Etype
(N
) = Base_Type
(Standard_Integer
)
4331 and then T
= Universal_Real
4332 and then Is_Overloaded
(N
)
4334 -- Integer arg in mixed-mode operation. Resolve with universal
4335 -- type, in case preference rule must be applied.
4337 Resolve
(N
, Universal_Integer
);
4340 and then B_Typ
/= Universal_Fixed
4342 -- Not a mixed-mode operation, resolve with context
4346 elsif Etype
(N
) = Any_Fixed
then
4348 -- N may itself be a mixed-mode operation, so use context type
4352 elsif Is_Fixed_Point_Type
(T
)
4353 and then B_Typ
= Universal_Fixed
4354 and then Is_Overloaded
(N
)
4356 -- Must be (fixed * fixed) operation, operand must have one
4357 -- compatible interpretation.
4359 Resolve
(N
, Any_Fixed
);
4361 elsif Is_Fixed_Point_Type
(B_Typ
)
4362 and then (T
= Universal_Real
4363 or else Is_Fixed_Point_Type
(T
))
4364 and then Is_Overloaded
(N
)
4366 -- C * F(X) in a fixed context, where C is a real literal or a
4367 -- fixed-point expression. F must have either a fixed type
4368 -- interpretation or an integer interpretation, but not both.
4370 Get_First_Interp
(N
, Index
, It
);
4371 while Present
(It
.Typ
) loop
4372 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
) then
4374 if Analyzed
(N
) then
4375 Error_Msg_N
("ambiguous operand in fixed operation", N
);
4377 Resolve
(N
, Standard_Integer
);
4380 elsif Is_Fixed_Point_Type
(It
.Typ
) then
4382 if Analyzed
(N
) then
4383 Error_Msg_N
("ambiguous operand in fixed operation", N
);
4385 Resolve
(N
, It
.Typ
);
4389 Get_Next_Interp
(Index
, It
);
4392 -- Reanalyze the literal with the fixed type of the context. If
4393 -- context is Universal_Fixed, we are within a conversion, leave
4394 -- the literal as a universal real because there is no usable
4395 -- fixed type, and the target of the conversion plays no role in
4409 if B_Typ
= Universal_Fixed
4410 and then Nkind
(Op2
) = N_Real_Literal
4412 T2
:= Universal_Real
;
4417 Set_Analyzed
(Op2
, False);
4424 end Set_Mixed_Mode_Operand
;
4426 ----------------------
4427 -- Set_Operand_Type --
4428 ----------------------
4430 procedure Set_Operand_Type
(N
: Node_Id
) is
4432 if Etype
(N
) = Universal_Integer
4433 or else Etype
(N
) = Universal_Real
4437 end Set_Operand_Type
;
4439 -- Start of processing for Resolve_Arithmetic_Op
4442 if Comes_From_Source
(N
)
4443 and then Ekind
(Entity
(N
)) = E_Function
4444 and then Is_Imported
(Entity
(N
))
4445 and then Is_Intrinsic_Subprogram
(Entity
(N
))
4447 Resolve_Intrinsic_Operator
(N
, Typ
);
4450 -- Special-case for mixed-mode universal expressions or fixed point
4451 -- type operation: each argument is resolved separately. The same
4452 -- treatment is required if one of the operands of a fixed point
4453 -- operation is universal real, since in this case we don't do a
4454 -- conversion to a specific fixed-point type (instead the expander
4455 -- takes care of the case).
4457 elsif (B_Typ
= Universal_Integer
or else B_Typ
= Universal_Real
)
4458 and then Present
(Universal_Interpretation
(L
))
4459 and then Present
(Universal_Interpretation
(R
))
4461 Resolve
(L
, Universal_Interpretation
(L
));
4462 Resolve
(R
, Universal_Interpretation
(R
));
4463 Set_Etype
(N
, B_Typ
);
4465 elsif (B_Typ
= Universal_Real
4466 or else Etype
(N
) = Universal_Fixed
4467 or else (Etype
(N
) = Any_Fixed
4468 and then Is_Fixed_Point_Type
(B_Typ
))
4469 or else (Is_Fixed_Point_Type
(B_Typ
)
4470 and then (Is_Integer_Or_Universal
(L
)
4472 Is_Integer_Or_Universal
(R
))))
4473 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
4475 if TL
= Universal_Integer
or else TR
= Universal_Integer
then
4476 Check_For_Visible_Operator
(N
, B_Typ
);
4479 -- If context is a fixed type and one operand is integer, the
4480 -- other is resolved with the type of the context.
4482 if Is_Fixed_Point_Type
(B_Typ
)
4483 and then (Base_Type
(TL
) = Base_Type
(Standard_Integer
)
4484 or else TL
= Universal_Integer
)
4489 elsif Is_Fixed_Point_Type
(B_Typ
)
4490 and then (Base_Type
(TR
) = Base_Type
(Standard_Integer
)
4491 or else TR
= Universal_Integer
)
4497 Set_Mixed_Mode_Operand
(L
, TR
);
4498 Set_Mixed_Mode_Operand
(R
, TL
);
4501 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4502 -- multiplying operators from being used when the expected type is
4503 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4504 -- some cases where the expected type is actually Any_Real;
4505 -- Expected_Type_Is_Any_Real takes care of that case.
4507 if Etype
(N
) = Universal_Fixed
4508 or else Etype
(N
) = Any_Fixed
4510 if B_Typ
= Universal_Fixed
4511 and then not Expected_Type_Is_Any_Real
(N
)
4512 and then not Nkind_In
(Parent
(N
), N_Type_Conversion
,
4513 N_Unchecked_Type_Conversion
)
4515 Error_Msg_N
("type cannot be determined from context!", N
);
4516 Error_Msg_N
("\explicit conversion to result type required", N
);
4518 Set_Etype
(L
, Any_Type
);
4519 Set_Etype
(R
, Any_Type
);
4522 if Ada_Version
= Ada_83
4523 and then Etype
(N
) = Universal_Fixed
4525 Nkind_In
(Parent
(N
), N_Type_Conversion
,
4526 N_Unchecked_Type_Conversion
)
4529 ("(Ada 83) fixed-point operation "
4530 & "needs explicit conversion", N
);
4533 -- The expected type is "any real type" in contexts like
4534 -- type T is delta <universal_fixed-expression> ...
4535 -- in which case we need to set the type to Universal_Real
4536 -- so that static expression evaluation will work properly.
4538 if Expected_Type_Is_Any_Real
(N
) then
4539 Set_Etype
(N
, Universal_Real
);
4541 Set_Etype
(N
, B_Typ
);
4545 elsif Is_Fixed_Point_Type
(B_Typ
)
4546 and then (Is_Integer_Or_Universal
(L
)
4547 or else Nkind
(L
) = N_Real_Literal
4548 or else Nkind
(R
) = N_Real_Literal
4549 or else Is_Integer_Or_Universal
(R
))
4551 Set_Etype
(N
, B_Typ
);
4553 elsif Etype
(N
) = Any_Fixed
then
4555 -- If no previous errors, this is only possible if one operand
4556 -- is overloaded and the context is universal. Resolve as such.
4558 Set_Etype
(N
, B_Typ
);
4562 if (TL
= Universal_Integer
or else TL
= Universal_Real
)
4564 (TR
= Universal_Integer
or else TR
= Universal_Real
)
4566 Check_For_Visible_Operator
(N
, B_Typ
);
4569 -- If the context is Universal_Fixed and the operands are also
4570 -- universal fixed, this is an error, unless there is only one
4571 -- applicable fixed_point type (usually duration).
4573 if B_Typ
= Universal_Fixed
and then Etype
(L
) = Universal_Fixed
then
4574 T
:= Unique_Fixed_Point_Type
(N
);
4576 if T
= Any_Type
then
4589 -- If one of the arguments was resolved to a non-universal type.
4590 -- label the result of the operation itself with the same type.
4591 -- Do the same for the universal argument, if any.
4593 T
:= Intersect_Types
(L
, R
);
4594 Set_Etype
(N
, Base_Type
(T
));
4595 Set_Operand_Type
(L
);
4596 Set_Operand_Type
(R
);
4599 Generate_Operator_Reference
(N
, Typ
);
4600 Eval_Arithmetic_Op
(N
);
4602 -- Set overflow and division checking bit. Much cleverer code needed
4603 -- here eventually and perhaps the Resolve routines should be separated
4604 -- for the various arithmetic operations, since they will need
4605 -- different processing. ???
4607 if Nkind
(N
) in N_Op
then
4608 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
4609 Enable_Overflow_Check
(N
);
4612 -- Give warning if explicit division by zero
4614 if Nkind_In
(N
, N_Op_Divide
, N_Op_Rem
, N_Op_Mod
)
4615 and then not Division_Checks_Suppressed
(Etype
(N
))
4617 Rop
:= Right_Opnd
(N
);
4619 if Compile_Time_Known_Value
(Rop
)
4620 and then ((Is_Integer_Type
(Etype
(Rop
))
4621 and then Expr_Value
(Rop
) = Uint_0
)
4623 (Is_Real_Type
(Etype
(Rop
))
4624 and then Expr_Value_R
(Rop
) = Ureal_0
))
4626 -- Specialize the warning message according to the operation
4630 Apply_Compile_Time_Constraint_Error
4631 (N
, "division by zero?", CE_Divide_By_Zero
,
4632 Loc
=> Sloc
(Right_Opnd
(N
)));
4635 Apply_Compile_Time_Constraint_Error
4636 (N
, "rem with zero divisor?", CE_Divide_By_Zero
,
4637 Loc
=> Sloc
(Right_Opnd
(N
)));
4640 Apply_Compile_Time_Constraint_Error
4641 (N
, "mod with zero divisor?", CE_Divide_By_Zero
,
4642 Loc
=> Sloc
(Right_Opnd
(N
)));
4644 -- Division by zero can only happen with division, rem,
4645 -- and mod operations.
4648 raise Program_Error
;
4651 -- Otherwise just set the flag to check at run time
4654 Activate_Division_Check
(N
);
4658 -- If Restriction No_Implicit_Conditionals is active, then it is
4659 -- violated if either operand can be negative for mod, or for rem
4660 -- if both operands can be negative.
4662 if Restrictions
.Set
(No_Implicit_Conditionals
)
4663 and then Nkind_In
(N
, N_Op_Rem
, N_Op_Mod
)
4672 -- Set if corresponding operand might be negative
4676 (Left_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
4677 LNeg
:= (not OK
) or else Lo
< 0;
4680 (Right_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
4681 RNeg
:= (not OK
) or else Lo
< 0;
4683 -- Check if we will be generating conditionals. There are two
4684 -- cases where that can happen, first for REM, the only case
4685 -- is largest negative integer mod -1, where the division can
4686 -- overflow, but we still have to give the right result. The
4687 -- front end generates a test for this annoying case. Here we
4688 -- just test if both operands can be negative (that's what the
4689 -- expander does, so we match its logic here).
4691 -- The second case is mod where either operand can be negative.
4692 -- In this case, the back end has to generate additonal tests.
4694 if (Nkind
(N
) = N_Op_Rem
and then (LNeg
and RNeg
))
4696 (Nkind
(N
) = N_Op_Mod
and then (LNeg
or RNeg
))
4698 Check_Restriction
(No_Implicit_Conditionals
, N
);
4704 Check_Unset_Reference
(L
);
4705 Check_Unset_Reference
(R
);
4706 end Resolve_Arithmetic_Op
;
4712 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
4713 Loc
: constant Source_Ptr
:= Sloc
(N
);
4714 Subp
: constant Node_Id
:= Name
(N
);
4723 -- The context imposes a unique interpretation with type Typ on a
4724 -- procedure or function call. Find the entity of the subprogram that
4725 -- yields the expected type, and propagate the corresponding formal
4726 -- constraints on the actuals. The caller has established that an
4727 -- interpretation exists, and emitted an error if not unique.
4729 -- First deal with the case of a call to an access-to-subprogram,
4730 -- dereference made explicit in Analyze_Call.
4732 if Ekind
(Etype
(Subp
)) = E_Subprogram_Type
then
4733 if not Is_Overloaded
(Subp
) then
4734 Nam
:= Etype
(Subp
);
4737 -- Find the interpretation whose type (a subprogram type) has a
4738 -- return type that is compatible with the context. Analysis of
4739 -- the node has established that one exists.
4743 Get_First_Interp
(Subp
, I
, It
);
4744 while Present
(It
.Typ
) loop
4745 if Covers
(Typ
, Etype
(It
.Typ
)) then
4750 Get_Next_Interp
(I
, It
);
4754 raise Program_Error
;
4758 -- If the prefix is not an entity, then resolve it
4760 if not Is_Entity_Name
(Subp
) then
4761 Resolve
(Subp
, Nam
);
4764 -- For an indirect call, we always invalidate checks, since we do not
4765 -- know whether the subprogram is local or global. Yes we could do
4766 -- better here, e.g. by knowing that there are no local subprograms,
4767 -- but it does not seem worth the effort. Similarly, we kill all
4768 -- knowledge of current constant values.
4770 Kill_Current_Values
;
4772 -- If this is a procedure call which is really an entry call, do
4773 -- the conversion of the procedure call to an entry call. Protected
4774 -- operations use the same circuitry because the name in the call
4775 -- can be an arbitrary expression with special resolution rules.
4777 elsif Nkind_In
(Subp
, N_Selected_Component
, N_Indexed_Component
)
4778 or else (Is_Entity_Name
(Subp
)
4779 and then Ekind
(Entity
(Subp
)) = E_Entry
)
4781 Resolve_Entry_Call
(N
, Typ
);
4782 Check_Elab_Call
(N
);
4784 -- Kill checks and constant values, as above for indirect case
4785 -- Who knows what happens when another task is activated?
4787 Kill_Current_Values
;
4790 -- Normal subprogram call with name established in Resolve
4792 elsif not (Is_Type
(Entity
(Subp
))) then
4793 Nam
:= Entity
(Subp
);
4794 Set_Entity_With_Style_Check
(Subp
, Nam
);
4796 -- Otherwise we must have the case of an overloaded call
4799 pragma Assert
(Is_Overloaded
(Subp
));
4801 -- Initialize Nam to prevent warning (we know it will be assigned
4802 -- in the loop below, but the compiler does not know that).
4806 Get_First_Interp
(Subp
, I
, It
);
4807 while Present
(It
.Typ
) loop
4808 if Covers
(Typ
, It
.Typ
) then
4810 Set_Entity_With_Style_Check
(Subp
, Nam
);
4814 Get_Next_Interp
(I
, It
);
4818 if Is_Access_Subprogram_Type
(Base_Type
(Etype
(Nam
)))
4819 and then not Is_Access_Subprogram_Type
(Base_Type
(Typ
))
4820 and then Nkind
(Subp
) /= N_Explicit_Dereference
4821 and then Present
(Parameter_Associations
(N
))
4823 -- The prefix is a parameterless function call that returns an access
4824 -- to subprogram. If parameters are present in the current call, add
4825 -- add an explicit dereference. We use the base type here because
4826 -- within an instance these may be subtypes.
4828 -- The dereference is added either in Analyze_Call or here. Should
4829 -- be consolidated ???
4831 Set_Is_Overloaded
(Subp
, False);
4832 Set_Etype
(Subp
, Etype
(Nam
));
4833 Insert_Explicit_Dereference
(Subp
);
4834 Nam
:= Designated_Type
(Etype
(Nam
));
4835 Resolve
(Subp
, Nam
);
4838 -- Check that a call to Current_Task does not occur in an entry body
4840 if Is_RTE
(Nam
, RE_Current_Task
) then
4849 -- Exclude calls that occur within the default of a formal
4850 -- parameter of the entry, since those are evaluated outside
4853 exit when No
(P
) or else Nkind
(P
) = N_Parameter_Specification
;
4855 if Nkind
(P
) = N_Entry_Body
4856 or else (Nkind
(P
) = N_Subprogram_Body
4857 and then Is_Entry_Barrier_Function
(P
))
4861 ("?& should not be used in entry body (RM C.7(17))",
4864 ("\Program_Error will be raised at run time?", N
, Nam
);
4866 Make_Raise_Program_Error
(Loc
,
4867 Reason
=> PE_Current_Task_In_Entry_Body
));
4868 Set_Etype
(N
, Rtype
);
4875 -- Check that a procedure call does not occur in the context of the
4876 -- entry call statement of a conditional or timed entry call. Note that
4877 -- the case of a call to a subprogram renaming of an entry will also be
4878 -- rejected. The test for N not being an N_Entry_Call_Statement is
4879 -- defensive, covering the possibility that the processing of entry
4880 -- calls might reach this point due to later modifications of the code
4883 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
4884 and then Nkind
(N
) /= N_Entry_Call_Statement
4885 and then Entry_Call_Statement
(Parent
(N
)) = N
4887 if Ada_Version
< Ada_05
then
4888 Error_Msg_N
("entry call required in select statement", N
);
4890 -- Ada 2005 (AI-345): If a procedure_call_statement is used
4891 -- for a procedure_or_entry_call, the procedure_name or
4892 -- procedure_prefix of the procedure_call_statement shall denote
4893 -- an entry renamed by a procedure, or (a view of) a primitive
4894 -- subprogram of a limited interface whose first parameter is
4895 -- a controlling parameter.
4897 elsif Nkind
(N
) = N_Procedure_Call_Statement
4898 and then not Is_Renamed_Entry
(Nam
)
4899 and then not Is_Controlling_Limited_Procedure
(Nam
)
4902 ("entry call or dispatching primitive of interface required", N
);
4906 -- Check that this is not a call to a protected procedure or entry from
4907 -- within a protected function.
4909 if Ekind
(Current_Scope
) = E_Function
4910 and then Ekind
(Scope
(Current_Scope
)) = E_Protected_Type
4911 and then Ekind
(Nam
) /= E_Function
4912 and then Scope
(Nam
) = Scope
(Current_Scope
)
4914 Error_Msg_N
("within protected function, protected " &
4915 "object is constant", N
);
4916 Error_Msg_N
("\cannot call operation that may modify it", N
);
4919 -- Freeze the subprogram name if not in a spec-expression. Note that we
4920 -- freeze procedure calls as well as function calls. Procedure calls are
4921 -- not frozen according to the rules (RM 13.14(14)) because it is
4922 -- impossible to have a procedure call to a non-frozen procedure in pure
4923 -- Ada, but in the code that we generate in the expander, this rule
4924 -- needs extending because we can generate procedure calls that need
4927 if Is_Entity_Name
(Subp
) and then not In_Spec_Expression
then
4928 Freeze_Expression
(Subp
);
4931 -- For a predefined operator, the type of the result is the type imposed
4932 -- by context, except for a predefined operation on universal fixed.
4933 -- Otherwise The type of the call is the type returned by the subprogram
4936 if Is_Predefined_Op
(Nam
) then
4937 if Etype
(N
) /= Universal_Fixed
then
4941 -- If the subprogram returns an array type, and the context requires the
4942 -- component type of that array type, the node is really an indexing of
4943 -- the parameterless call. Resolve as such. A pathological case occurs
4944 -- when the type of the component is an access to the array type. In
4945 -- this case the call is truly ambiguous.
4947 elsif (Needs_No_Actuals
(Nam
) or else Needs_One_Actual
(Nam
))
4949 ((Is_Array_Type
(Etype
(Nam
))
4950 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
4951 or else (Is_Access_Type
(Etype
(Nam
))
4952 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
4955 Component_Type
(Designated_Type
(Etype
(Nam
))))))
4958 Index_Node
: Node_Id
;
4960 Ret_Type
: constant Entity_Id
:= Etype
(Nam
);
4963 if Is_Access_Type
(Ret_Type
)
4964 and then Ret_Type
= Component_Type
(Designated_Type
(Ret_Type
))
4967 ("cannot disambiguate function call and indexing", N
);
4969 New_Subp
:= Relocate_Node
(Subp
);
4970 Set_Entity
(Subp
, Nam
);
4972 if (Is_Array_Type
(Ret_Type
)
4973 and then Component_Type
(Ret_Type
) /= Any_Type
)
4975 (Is_Access_Type
(Ret_Type
)
4977 Component_Type
(Designated_Type
(Ret_Type
)) /= Any_Type
)
4979 if Needs_No_Actuals
(Nam
) then
4981 -- Indexed call to a parameterless function
4984 Make_Indexed_Component
(Loc
,
4986 Make_Function_Call
(Loc
,
4988 Expressions
=> Parameter_Associations
(N
));
4990 -- An Ada 2005 prefixed call to a primitive operation
4991 -- whose first parameter is the prefix. This prefix was
4992 -- prepended to the parameter list, which is actually a
4993 -- list of indices. Remove the prefix in order to build
4994 -- the proper indexed component.
4997 Make_Indexed_Component
(Loc
,
4999 Make_Function_Call
(Loc
,
5001 Parameter_Associations
=>
5003 (Remove_Head
(Parameter_Associations
(N
)))),
5004 Expressions
=> Parameter_Associations
(N
));
5007 -- Since we are correcting a node classification error made
5008 -- by the parser, we call Replace rather than Rewrite.
5010 Replace
(N
, Index_Node
);
5011 Set_Etype
(Prefix
(N
), Ret_Type
);
5013 Resolve_Indexed_Component
(N
, Typ
);
5014 Check_Elab_Call
(Prefix
(N
));
5022 Set_Etype
(N
, Etype
(Nam
));
5025 -- In the case where the call is to an overloaded subprogram, Analyze
5026 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5027 -- such a case Normalize_Actuals needs to be called once more to order
5028 -- the actuals correctly. Otherwise the call will have the ordering
5029 -- given by the last overloaded subprogram whether this is the correct
5030 -- one being called or not.
5032 if Is_Overloaded
(Subp
) then
5033 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
5034 pragma Assert
(Norm_OK
);
5037 -- In any case, call is fully resolved now. Reset Overload flag, to
5038 -- prevent subsequent overload resolution if node is analyzed again
5040 Set_Is_Overloaded
(Subp
, False);
5041 Set_Is_Overloaded
(N
, False);
5043 -- If we are calling the current subprogram from immediately within its
5044 -- body, then that is the case where we can sometimes detect cases of
5045 -- infinite recursion statically. Do not try this in case restriction
5046 -- No_Recursion is in effect anyway, and do it only for source calls.
5048 if Comes_From_Source
(N
) then
5049 Scop
:= Current_Scope
;
5051 -- Issue warning for possible infinite recursion in the absence
5052 -- of the No_Recursion restriction.
5055 and then not Restriction_Active
(No_Recursion
)
5056 and then Check_Infinite_Recursion
(N
)
5058 -- Here we detected and flagged an infinite recursion, so we do
5059 -- not need to test the case below for further warnings. Also if
5060 -- we now have a raise SE node, we are all done.
5062 if Nkind
(N
) = N_Raise_Storage_Error
then
5066 -- If call is to immediately containing subprogram, then check for
5067 -- the case of a possible run-time detectable infinite recursion.
5070 Scope_Loop
: while Scop
/= Standard_Standard
loop
5073 -- Although in general case, recursion is not statically
5074 -- checkable, the case of calling an immediately containing
5075 -- subprogram is easy to catch.
5077 Check_Restriction
(No_Recursion
, N
);
5079 -- If the recursive call is to a parameterless subprogram,
5080 -- then even if we can't statically detect infinite
5081 -- recursion, this is pretty suspicious, and we output a
5082 -- warning. Furthermore, we will try later to detect some
5083 -- cases here at run time by expanding checking code (see
5084 -- Detect_Infinite_Recursion in package Exp_Ch6).
5086 -- If the recursive call is within a handler, do not emit a
5087 -- warning, because this is a common idiom: loop until input
5088 -- is correct, catch illegal input in handler and restart.
5090 if No
(First_Formal
(Nam
))
5091 and then Etype
(Nam
) = Standard_Void_Type
5092 and then not Error_Posted
(N
)
5093 and then Nkind
(Parent
(N
)) /= N_Exception_Handler
5095 -- For the case of a procedure call. We give the message
5096 -- only if the call is the first statement in a sequence
5097 -- of statements, or if all previous statements are
5098 -- simple assignments. This is simply a heuristic to
5099 -- decrease false positives, without losing too many good
5100 -- warnings. The idea is that these previous statements
5101 -- may affect global variables the procedure depends on.
5103 if Nkind
(N
) = N_Procedure_Call_Statement
5104 and then Is_List_Member
(N
)
5110 while Present
(P
) loop
5111 if Nkind
(P
) /= N_Assignment_Statement
then
5120 -- Do not give warning if we are in a conditional context
5123 K
: constant Node_Kind
:= Nkind
(Parent
(N
));
5125 if (K
= N_Loop_Statement
5126 and then Present
(Iteration_Scheme
(Parent
(N
))))
5127 or else K
= N_If_Statement
5128 or else K
= N_Elsif_Part
5129 or else K
= N_Case_Statement_Alternative
5135 -- Here warning is to be issued
5137 Set_Has_Recursive_Call
(Nam
);
5139 ("?possible infinite recursion!", N
);
5141 ("\?Storage_Error may be raised at run time!", N
);
5147 Scop
:= Scope
(Scop
);
5148 end loop Scope_Loop
;
5152 -- If subprogram name is a predefined operator, it was given in
5153 -- functional notation. Replace call node with operator node, so
5154 -- that actuals can be resolved appropriately.
5156 if Is_Predefined_Op
(Nam
) or else Ekind
(Nam
) = E_Operator
then
5157 Make_Call_Into_Operator
(N
, Typ
, Entity
(Name
(N
)));
5160 elsif Present
(Alias
(Nam
))
5161 and then Is_Predefined_Op
(Alias
(Nam
))
5163 Resolve_Actuals
(N
, Nam
);
5164 Make_Call_Into_Operator
(N
, Typ
, Alias
(Nam
));
5168 -- Create a transient scope if the resulting type requires it
5170 -- There are several notable exceptions:
5172 -- a) In init procs, the transient scope overhead is not needed, and is
5173 -- even incorrect when the call is a nested initialization call for a
5174 -- component whose expansion may generate adjust calls. However, if the
5175 -- call is some other procedure call within an initialization procedure
5176 -- (for example a call to Create_Task in the init_proc of the task
5177 -- run-time record) a transient scope must be created around this call.
5179 -- b) Enumeration literal pseudo-calls need no transient scope
5181 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5182 -- functions) do not use the secondary stack even though the return
5183 -- type may be unconstrained.
5185 -- d) Calls to a build-in-place function, since such functions may
5186 -- allocate their result directly in a target object, and cases where
5187 -- the result does get allocated in the secondary stack are checked for
5188 -- within the specialized Exp_Ch6 procedures for expanding those
5189 -- build-in-place calls.
5191 -- e) If the subprogram is marked Inline_Always, then even if it returns
5192 -- an unconstrained type the call does not require use of the secondary
5193 -- stack. However, inlining will only take place if the body to inline
5194 -- is already present. It may not be available if e.g. the subprogram is
5195 -- declared in a child instance.
5197 -- If this is an initialization call for a type whose construction
5198 -- uses the secondary stack, and it is not a nested call to initialize
5199 -- a component, we do need to create a transient scope for it. We
5200 -- check for this by traversing the type in Check_Initialization_Call.
5203 and then Has_Pragma_Inline_Always
(Nam
)
5204 and then Nkind
(Unit_Declaration_Node
(Nam
)) = N_Subprogram_Declaration
5205 and then Present
(Body_To_Inline
(Unit_Declaration_Node
(Nam
)))
5209 elsif Ekind
(Nam
) = E_Enumeration_Literal
5210 or else Is_Build_In_Place_Function
(Nam
)
5211 or else Is_Intrinsic_Subprogram
(Nam
)
5215 elsif Expander_Active
5216 and then Is_Type
(Etype
(Nam
))
5217 and then Requires_Transient_Scope
(Etype
(Nam
))
5219 (not Within_Init_Proc
5221 (not Is_Init_Proc
(Nam
) and then Ekind
(Nam
) /= E_Function
))
5223 Establish_Transient_Scope
(N
, Sec_Stack
=> True);
5225 -- If the call appears within the bounds of a loop, it will
5226 -- be rewritten and reanalyzed, nothing left to do here.
5228 if Nkind
(N
) /= N_Function_Call
then
5232 elsif Is_Init_Proc
(Nam
)
5233 and then not Within_Init_Proc
5235 Check_Initialization_Call
(N
, Nam
);
5238 -- A protected function cannot be called within the definition of the
5239 -- enclosing protected type.
5241 if Is_Protected_Type
(Scope
(Nam
))
5242 and then In_Open_Scopes
(Scope
(Nam
))
5243 and then not Has_Completion
(Scope
(Nam
))
5246 ("& cannot be called before end of protected definition", N
, Nam
);
5249 -- Propagate interpretation to actuals, and add default expressions
5252 if Present
(First_Formal
(Nam
)) then
5253 Resolve_Actuals
(N
, Nam
);
5255 -- Overloaded literals are rewritten as function calls, for purpose of
5256 -- resolution. After resolution, we can replace the call with the
5259 elsif Ekind
(Nam
) = E_Enumeration_Literal
then
5260 Copy_Node
(Subp
, N
);
5261 Resolve_Entity_Name
(N
, Typ
);
5263 -- Avoid validation, since it is a static function call
5265 Generate_Reference
(Nam
, Subp
);
5269 -- If the subprogram is not global, then kill all saved values and
5270 -- checks. This is a bit conservative, since in many cases we could do
5271 -- better, but it is not worth the effort. Similarly, we kill constant
5272 -- values. However we do not need to do this for internal entities
5273 -- (unless they are inherited user-defined subprograms), since they
5274 -- are not in the business of molesting local values.
5276 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5277 -- kill all checks and values for calls to global subprograms. This
5278 -- takes care of the case where an access to a local subprogram is
5279 -- taken, and could be passed directly or indirectly and then called
5280 -- from almost any context.
5282 -- Note: we do not do this step till after resolving the actuals. That
5283 -- way we still take advantage of the current value information while
5284 -- scanning the actuals.
5286 -- We suppress killing values if we are processing the nodes associated
5287 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5288 -- type kills all the values as part of analyzing the code that
5289 -- initializes the dispatch tables.
5291 if Inside_Freezing_Actions
= 0
5292 and then (not Is_Library_Level_Entity
(Nam
)
5293 or else Suppress_Value_Tracking_On_Call
5294 (Nearest_Dynamic_Scope
(Current_Scope
)))
5295 and then (Comes_From_Source
(Nam
)
5296 or else (Present
(Alias
(Nam
))
5297 and then Comes_From_Source
(Alias
(Nam
))))
5299 Kill_Current_Values
;
5302 -- If we are warning about unread OUT parameters, this is the place to
5303 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5304 -- after the above call to Kill_Current_Values (since that call clears
5305 -- the Last_Assignment field of all local variables).
5307 if (Warn_On_Modified_Unread
or Warn_On_All_Unread_Out_Parameters
)
5308 and then Comes_From_Source
(N
)
5309 and then In_Extended_Main_Source_Unit
(N
)
5316 F
:= First_Formal
(Nam
);
5317 A
:= First_Actual
(N
);
5318 while Present
(F
) and then Present
(A
) loop
5319 if (Ekind
(F
) = E_Out_Parameter
5321 Ekind
(F
) = E_In_Out_Parameter
)
5322 and then Warn_On_Modified_As_Out_Parameter
(F
)
5323 and then Is_Entity_Name
(A
)
5324 and then Present
(Entity
(A
))
5325 and then Comes_From_Source
(N
)
5326 and then Safe_To_Capture_Value
(N
, Entity
(A
))
5328 Set_Last_Assignment
(Entity
(A
), A
);
5337 -- If the subprogram is a primitive operation, check whether or not
5338 -- it is a correct dispatching call.
5340 if Is_Overloadable
(Nam
)
5341 and then Is_Dispatching_Operation
(Nam
)
5343 Check_Dispatching_Call
(N
);
5345 elsif Ekind
(Nam
) /= E_Subprogram_Type
5346 and then Is_Abstract_Subprogram
(Nam
)
5347 and then not In_Instance
5349 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Nam
);
5352 -- If this is a dispatching call, generate the appropriate reference,
5353 -- for better source navigation in GPS.
5355 if Is_Overloadable
(Nam
)
5356 and then Present
(Controlling_Argument
(N
))
5358 Generate_Reference
(Nam
, Subp
, 'R');
5360 -- Normal case, not a dispatching call
5363 Generate_Reference
(Nam
, Subp
);
5366 if Is_Intrinsic_Subprogram
(Nam
) then
5367 Check_Intrinsic_Call
(N
);
5370 -- Check for violation of restriction No_Specific_Termination_Handlers
5371 -- and warn on a potentially blocking call to Abort_Task.
5373 if Is_RTE
(Nam
, RE_Set_Specific_Handler
)
5375 Is_RTE
(Nam
, RE_Specific_Handler
)
5377 Check_Restriction
(No_Specific_Termination_Handlers
, N
);
5379 elsif Is_RTE
(Nam
, RE_Abort_Task
) then
5380 Check_Potentially_Blocking_Operation
(N
);
5383 -- Issue an error for a call to an eliminated subprogram
5385 Check_For_Eliminated_Subprogram
(Subp
, Nam
);
5387 -- All done, evaluate call and deal with elaboration issues
5390 Check_Elab_Call
(N
);
5391 Warn_On_Overlapping_Actuals
(Nam
, N
);
5394 -------------------------------
5395 -- Resolve_Character_Literal --
5396 -------------------------------
5398 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
5399 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
5403 -- Verify that the character does belong to the type of the context
5405 Set_Etype
(N
, B_Typ
);
5406 Eval_Character_Literal
(N
);
5408 -- Wide_Wide_Character literals must always be defined, since the set
5409 -- of wide wide character literals is complete, i.e. if a character
5410 -- literal is accepted by the parser, then it is OK for wide wide
5411 -- character (out of range character literals are rejected).
5413 if Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
5416 -- Always accept character literal for type Any_Character, which
5417 -- occurs in error situations and in comparisons of literals, both
5418 -- of which should accept all literals.
5420 elsif B_Typ
= Any_Character
then
5423 -- For Standard.Character or a type derived from it, check that
5424 -- the literal is in range
5426 elsif Root_Type
(B_Typ
) = Standard_Character
then
5427 if In_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
5431 -- For Standard.Wide_Character or a type derived from it, check
5432 -- that the literal is in range
5434 elsif Root_Type
(B_Typ
) = Standard_Wide_Character
then
5435 if In_Wide_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
5439 -- For Standard.Wide_Wide_Character or a type derived from it, we
5440 -- know the literal is in range, since the parser checked!
5442 elsif Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
5445 -- If the entity is already set, this has already been resolved in a
5446 -- generic context, or comes from expansion. Nothing else to do.
5448 elsif Present
(Entity
(N
)) then
5451 -- Otherwise we have a user defined character type, and we can use the
5452 -- standard visibility mechanisms to locate the referenced entity.
5455 C
:= Current_Entity
(N
);
5456 while Present
(C
) loop
5457 if Etype
(C
) = B_Typ
then
5458 Set_Entity_With_Style_Check
(N
, C
);
5459 Generate_Reference
(C
, N
);
5467 -- If we fall through, then the literal does not match any of the
5468 -- entries of the enumeration type. This isn't just a constraint
5469 -- error situation, it is an illegality (see RM 4.2).
5472 ("character not defined for }", N
, First_Subtype
(B_Typ
));
5473 end Resolve_Character_Literal
;
5475 ---------------------------
5476 -- Resolve_Comparison_Op --
5477 ---------------------------
5479 -- Context requires a boolean type, and plays no role in resolution.
5480 -- Processing identical to that for equality operators. The result
5481 -- type is the base type, which matters when pathological subtypes of
5482 -- booleans with limited ranges are used.
5484 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
5485 L
: constant Node_Id
:= Left_Opnd
(N
);
5486 R
: constant Node_Id
:= Right_Opnd
(N
);
5490 -- If this is an intrinsic operation which is not predefined, use the
5491 -- types of its declared arguments to resolve the possibly overloaded
5492 -- operands. Otherwise the operands are unambiguous and specify the
5495 if Scope
(Entity
(N
)) /= Standard_Standard
then
5496 T
:= Etype
(First_Entity
(Entity
(N
)));
5499 T
:= Find_Unique_Type
(L
, R
);
5501 if T
= Any_Fixed
then
5502 T
:= Unique_Fixed_Point_Type
(L
);
5506 Set_Etype
(N
, Base_Type
(Typ
));
5507 Generate_Reference
(T
, N
, ' ');
5509 if T
/= Any_Type
then
5510 if T
= Any_String
or else
5511 T
= Any_Composite
or else
5514 if T
= Any_Character
then
5515 Ambiguous_Character
(L
);
5517 Error_Msg_N
("ambiguous operands for comparison", N
);
5520 Set_Etype
(N
, Any_Type
);
5526 Check_Unset_Reference
(L
);
5527 Check_Unset_Reference
(R
);
5528 Generate_Operator_Reference
(N
, T
);
5529 Check_Low_Bound_Tested
(N
);
5530 Eval_Relational_Op
(N
);
5533 end Resolve_Comparison_Op
;
5535 ------------------------------------
5536 -- Resolve_Conditional_Expression --
5537 ------------------------------------
5539 procedure Resolve_Conditional_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
5540 Condition
: constant Node_Id
:= First
(Expressions
(N
));
5541 Then_Expr
: constant Node_Id
:= Next
(Condition
);
5542 Else_Expr
: Node_Id
:= Next
(Then_Expr
);
5545 Resolve
(Condition
, Any_Boolean
);
5546 Resolve
(Then_Expr
, Typ
);
5548 -- If ELSE expression present, just resolve using the determined type
5550 if Present
(Else_Expr
) then
5551 Resolve
(Else_Expr
, Typ
);
5553 -- If no ELSE expression is present, root type must be Standard.Boolean
5554 -- and we provide a Standard.True result converted to the appropriate
5555 -- Boolean type (in case it is a derived boolean type).
5557 elsif Root_Type
(Typ
) = Standard_Boolean
then
5559 Convert_To
(Typ
, New_Occurrence_Of
(Standard_True
, Sloc
(N
)));
5560 Analyze_And_Resolve
(Else_Expr
, Typ
);
5561 Append_To
(Expressions
(N
), Else_Expr
);
5564 Error_Msg_N
("can only omit ELSE expression in Boolean case", N
);
5565 Append_To
(Expressions
(N
), Error
);
5569 Eval_Conditional_Expression
(N
);
5570 end Resolve_Conditional_Expression
;
5572 -----------------------------------------
5573 -- Resolve_Discrete_Subtype_Indication --
5574 -----------------------------------------
5576 procedure Resolve_Discrete_Subtype_Indication
5584 Analyze
(Subtype_Mark
(N
));
5585 S
:= Entity
(Subtype_Mark
(N
));
5587 if Nkind
(Constraint
(N
)) /= N_Range_Constraint
then
5588 Error_Msg_N
("expect range constraint for discrete type", N
);
5589 Set_Etype
(N
, Any_Type
);
5592 R
:= Range_Expression
(Constraint
(N
));
5600 if Base_Type
(S
) /= Base_Type
(Typ
) then
5602 ("expect subtype of }", N
, First_Subtype
(Typ
));
5604 -- Rewrite the constraint as a range of Typ
5605 -- to allow compilation to proceed further.
5608 Rewrite
(Low_Bound
(R
),
5609 Make_Attribute_Reference
(Sloc
(Low_Bound
(R
)),
5610 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
5611 Attribute_Name
=> Name_First
));
5612 Rewrite
(High_Bound
(R
),
5613 Make_Attribute_Reference
(Sloc
(High_Bound
(R
)),
5614 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
5615 Attribute_Name
=> Name_First
));
5619 Set_Etype
(N
, Etype
(R
));
5621 -- Additionally, we must check that the bounds are compatible
5622 -- with the given subtype, which might be different from the
5623 -- type of the context.
5625 Apply_Range_Check
(R
, S
);
5627 -- ??? If the above check statically detects a Constraint_Error
5628 -- it replaces the offending bound(s) of the range R with a
5629 -- Constraint_Error node. When the itype which uses these bounds
5630 -- is frozen the resulting call to Duplicate_Subexpr generates
5631 -- a new temporary for the bounds.
5633 -- Unfortunately there are other itypes that are also made depend
5634 -- on these bounds, so when Duplicate_Subexpr is called they get
5635 -- a forward reference to the newly created temporaries and Gigi
5636 -- aborts on such forward references. This is probably sign of a
5637 -- more fundamental problem somewhere else in either the order of
5638 -- itype freezing or the way certain itypes are constructed.
5640 -- To get around this problem we call Remove_Side_Effects right
5641 -- away if either bounds of R are a Constraint_Error.
5644 L
: constant Node_Id
:= Low_Bound
(R
);
5645 H
: constant Node_Id
:= High_Bound
(R
);
5648 if Nkind
(L
) = N_Raise_Constraint_Error
then
5649 Remove_Side_Effects
(L
);
5652 if Nkind
(H
) = N_Raise_Constraint_Error
then
5653 Remove_Side_Effects
(H
);
5657 Check_Unset_Reference
(Low_Bound
(R
));
5658 Check_Unset_Reference
(High_Bound
(R
));
5661 end Resolve_Discrete_Subtype_Indication
;
5663 -------------------------
5664 -- Resolve_Entity_Name --
5665 -------------------------
5667 -- Used to resolve identifiers and expanded names
5669 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
) is
5670 E
: constant Entity_Id
:= Entity
(N
);
5673 -- If garbage from errors, set to Any_Type and return
5675 if No
(E
) and then Total_Errors_Detected
/= 0 then
5676 Set_Etype
(N
, Any_Type
);
5680 -- Replace named numbers by corresponding literals. Note that this is
5681 -- the one case where Resolve_Entity_Name must reset the Etype, since
5682 -- it is currently marked as universal.
5684 if Ekind
(E
) = E_Named_Integer
then
5686 Eval_Named_Integer
(N
);
5688 elsif Ekind
(E
) = E_Named_Real
then
5690 Eval_Named_Real
(N
);
5692 -- Allow use of subtype only if it is a concurrent type where we are
5693 -- currently inside the body. This will eventually be expanded into a
5694 -- call to Self (for tasks) or _object (for protected objects). Any
5695 -- other use of a subtype is invalid.
5697 elsif Is_Type
(E
) then
5698 if Is_Concurrent_Type
(E
)
5699 and then In_Open_Scopes
(E
)
5704 ("invalid use of subtype mark in expression or call", N
);
5707 -- Check discriminant use if entity is discriminant in current scope,
5708 -- i.e. discriminant of record or concurrent type currently being
5709 -- analyzed. Uses in corresponding body are unrestricted.
5711 elsif Ekind
(E
) = E_Discriminant
5712 and then Scope
(E
) = Current_Scope
5713 and then not Has_Completion
(Current_Scope
)
5715 Check_Discriminant_Use
(N
);
5717 -- A parameterless generic function cannot appear in a context that
5718 -- requires resolution.
5720 elsif Ekind
(E
) = E_Generic_Function
then
5721 Error_Msg_N
("illegal use of generic function", N
);
5723 elsif Ekind
(E
) = E_Out_Parameter
5724 and then Ada_Version
= Ada_83
5725 and then (Nkind
(Parent
(N
)) in N_Op
5726 or else (Nkind
(Parent
(N
)) = N_Assignment_Statement
5727 and then N
= Expression
(Parent
(N
)))
5728 or else Nkind
(Parent
(N
)) = N_Explicit_Dereference
)
5730 Error_Msg_N
("(Ada 83) illegal reading of out parameter", N
);
5732 -- In all other cases, just do the possible static evaluation
5735 -- A deferred constant that appears in an expression must have a
5736 -- completion, unless it has been removed by in-place expansion of
5739 if Ekind
(E
) = E_Constant
5740 and then Comes_From_Source
(E
)
5741 and then No
(Constant_Value
(E
))
5742 and then Is_Frozen
(Etype
(E
))
5743 and then not In_Spec_Expression
5744 and then not Is_Imported
(E
)
5747 if No_Initialization
(Parent
(E
))
5748 or else (Present
(Full_View
(E
))
5749 and then No_Initialization
(Parent
(Full_View
(E
))))
5754 "deferred constant is frozen before completion", N
);
5758 Eval_Entity_Name
(N
);
5760 end Resolve_Entity_Name
;
5766 procedure Resolve_Entry
(Entry_Name
: Node_Id
) is
5767 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
5775 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
;
5776 -- If the bounds of the entry family being called depend on task
5777 -- discriminants, build a new index subtype where a discriminant is
5778 -- replaced with the value of the discriminant of the target task.
5779 -- The target task is the prefix of the entry name in the call.
5781 -----------------------
5782 -- Actual_Index_Type --
5783 -----------------------
5785 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
is
5786 Typ
: constant Entity_Id
:= Entry_Index_Type
(E
);
5787 Tsk
: constant Entity_Id
:= Scope
(E
);
5788 Lo
: constant Node_Id
:= Type_Low_Bound
(Typ
);
5789 Hi
: constant Node_Id
:= Type_High_Bound
(Typ
);
5792 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
;
5793 -- If the bound is given by a discriminant, replace with a reference
5794 -- to the discriminant of the same name in the target task. If the
5795 -- entry name is the target of a requeue statement and the entry is
5796 -- in the current protected object, the bound to be used is the
5797 -- discriminal of the object (see apply_range_checks for details of
5798 -- the transformation).
5800 -----------------------------
5801 -- Actual_Discriminant_Ref --
5802 -----------------------------
5804 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
is
5805 Typ
: constant Entity_Id
:= Etype
(Bound
);
5809 Remove_Side_Effects
(Bound
);
5811 if not Is_Entity_Name
(Bound
)
5812 or else Ekind
(Entity
(Bound
)) /= E_Discriminant
5816 elsif Is_Protected_Type
(Tsk
)
5817 and then In_Open_Scopes
(Tsk
)
5818 and then Nkind
(Parent
(Entry_Name
)) = N_Requeue_Statement
5820 return New_Occurrence_Of
(Discriminal
(Entity
(Bound
)), Loc
);
5824 Make_Selected_Component
(Loc
,
5825 Prefix
=> New_Copy_Tree
(Prefix
(Prefix
(Entry_Name
))),
5826 Selector_Name
=> New_Occurrence_Of
(Entity
(Bound
), Loc
));
5831 end Actual_Discriminant_Ref
;
5833 -- Start of processing for Actual_Index_Type
5836 if not Has_Discriminants
(Tsk
)
5837 or else (not Is_Entity_Name
(Lo
)
5839 not Is_Entity_Name
(Hi
))
5841 return Entry_Index_Type
(E
);
5844 New_T
:= Create_Itype
(Ekind
(Typ
), Parent
(Entry_Name
));
5845 Set_Etype
(New_T
, Base_Type
(Typ
));
5846 Set_Size_Info
(New_T
, Typ
);
5847 Set_RM_Size
(New_T
, RM_Size
(Typ
));
5848 Set_Scalar_Range
(New_T
,
5849 Make_Range
(Sloc
(Entry_Name
),
5850 Low_Bound
=> Actual_Discriminant_Ref
(Lo
),
5851 High_Bound
=> Actual_Discriminant_Ref
(Hi
)));
5855 end Actual_Index_Type
;
5857 -- Start of processing of Resolve_Entry
5860 -- Find name of entry being called, and resolve prefix of name
5861 -- with its own type. The prefix can be overloaded, and the name
5862 -- and signature of the entry must be taken into account.
5864 if Nkind
(Entry_Name
) = N_Indexed_Component
then
5866 -- Case of dealing with entry family within the current tasks
5868 E_Name
:= Prefix
(Entry_Name
);
5871 E_Name
:= Entry_Name
;
5874 if Is_Entity_Name
(E_Name
) then
5876 -- Entry call to an entry (or entry family) in the current task. This
5877 -- is legal even though the task will deadlock. Rewrite as call to
5880 -- This can also be a call to an entry in an enclosing task. If this
5881 -- is a single task, we have to retrieve its name, because the scope
5882 -- of the entry is the task type, not the object. If the enclosing
5883 -- task is a task type, the identity of the task is given by its own
5886 -- Finally this can be a requeue on an entry of the same task or
5887 -- protected object.
5889 S
:= Scope
(Entity
(E_Name
));
5891 for J
in reverse 0 .. Scope_Stack
.Last
loop
5892 if Is_Task_Type
(Scope_Stack
.Table
(J
).Entity
)
5893 and then not Comes_From_Source
(S
)
5895 -- S is an enclosing task or protected object. The concurrent
5896 -- declaration has been converted into a type declaration, and
5897 -- the object itself has an object declaration that follows
5898 -- the type in the same declarative part.
5900 Tsk
:= Next_Entity
(S
);
5901 while Etype
(Tsk
) /= S
loop
5908 elsif S
= Scope_Stack
.Table
(J
).Entity
then
5910 -- Call to current task. Will be transformed into call to Self
5918 Make_Selected_Component
(Loc
,
5919 Prefix
=> New_Occurrence_Of
(S
, Loc
),
5921 New_Occurrence_Of
(Entity
(E_Name
), Loc
));
5922 Rewrite
(E_Name
, New_N
);
5925 elsif Nkind
(Entry_Name
) = N_Selected_Component
5926 and then Is_Overloaded
(Prefix
(Entry_Name
))
5928 -- Use the entry name (which must be unique at this point) to find
5929 -- the prefix that returns the corresponding task type or protected
5933 Pref
: constant Node_Id
:= Prefix
(Entry_Name
);
5934 Ent
: constant Entity_Id
:= Entity
(Selector_Name
(Entry_Name
));
5939 Get_First_Interp
(Pref
, I
, It
);
5940 while Present
(It
.Typ
) loop
5941 if Scope
(Ent
) = It
.Typ
then
5942 Set_Etype
(Pref
, It
.Typ
);
5946 Get_Next_Interp
(I
, It
);
5951 if Nkind
(Entry_Name
) = N_Selected_Component
then
5952 Resolve
(Prefix
(Entry_Name
));
5954 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
5955 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
5956 Resolve
(Prefix
(Prefix
(Entry_Name
)));
5957 Index
:= First
(Expressions
(Entry_Name
));
5958 Resolve
(Index
, Entry_Index_Type
(Nam
));
5960 -- Up to this point the expression could have been the actual in a
5961 -- simple entry call, and be given by a named association.
5963 if Nkind
(Index
) = N_Parameter_Association
then
5964 Error_Msg_N
("expect expression for entry index", Index
);
5966 Apply_Range_Check
(Index
, Actual_Index_Type
(Nam
));
5971 ------------------------
5972 -- Resolve_Entry_Call --
5973 ------------------------
5975 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
5976 Entry_Name
: constant Node_Id
:= Name
(N
);
5977 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
5979 First_Named
: Node_Id
;
5986 -- We kill all checks here, because it does not seem worth the effort to
5987 -- do anything better, an entry call is a big operation.
5991 -- Processing of the name is similar for entry calls and protected
5992 -- operation calls. Once the entity is determined, we can complete
5993 -- the resolution of the actuals.
5995 -- The selector may be overloaded, in the case of a protected object
5996 -- with overloaded functions. The type of the context is used for
5999 if Nkind
(Entry_Name
) = N_Selected_Component
6000 and then Is_Overloaded
(Selector_Name
(Entry_Name
))
6001 and then Typ
/= Standard_Void_Type
6008 Get_First_Interp
(Selector_Name
(Entry_Name
), I
, It
);
6009 while Present
(It
.Typ
) loop
6010 if Covers
(Typ
, It
.Typ
) then
6011 Set_Entity
(Selector_Name
(Entry_Name
), It
.Nam
);
6012 Set_Etype
(Entry_Name
, It
.Typ
);
6014 Generate_Reference
(It
.Typ
, N
, ' ');
6017 Get_Next_Interp
(I
, It
);
6022 Resolve_Entry
(Entry_Name
);
6024 if Nkind
(Entry_Name
) = N_Selected_Component
then
6026 -- Simple entry call
6028 Nam
:= Entity
(Selector_Name
(Entry_Name
));
6029 Obj
:= Prefix
(Entry_Name
);
6030 Was_Over
:= Is_Overloaded
(Selector_Name
(Entry_Name
));
6032 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
6034 -- Call to member of entry family
6036 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
6037 Obj
:= Prefix
(Prefix
(Entry_Name
));
6038 Was_Over
:= Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)));
6041 -- We cannot in general check the maximum depth of protected entry
6042 -- calls at compile time. But we can tell that any protected entry
6043 -- call at all violates a specified nesting depth of zero.
6045 if Is_Protected_Type
(Scope
(Nam
)) then
6046 Check_Restriction
(Max_Entry_Queue_Length
, N
);
6049 -- Use context type to disambiguate a protected function that can be
6050 -- called without actuals and that returns an array type, and where
6051 -- the argument list may be an indexing of the returned value.
6053 if Ekind
(Nam
) = E_Function
6054 and then Needs_No_Actuals
(Nam
)
6055 and then Present
(Parameter_Associations
(N
))
6057 ((Is_Array_Type
(Etype
(Nam
))
6058 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
6060 or else (Is_Access_Type
(Etype
(Nam
))
6061 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
6062 and then Covers
(Typ
,
6063 Component_Type
(Designated_Type
(Etype
(Nam
))))))
6066 Index_Node
: Node_Id
;
6070 Make_Indexed_Component
(Loc
,
6072 Make_Function_Call
(Loc
,
6073 Name
=> Relocate_Node
(Entry_Name
)),
6074 Expressions
=> Parameter_Associations
(N
));
6076 -- Since we are correcting a node classification error made by
6077 -- the parser, we call Replace rather than Rewrite.
6079 Replace
(N
, Index_Node
);
6080 Set_Etype
(Prefix
(N
), Etype
(Nam
));
6082 Resolve_Indexed_Component
(N
, Typ
);
6087 -- The operation name may have been overloaded. Order the actuals
6088 -- according to the formals of the resolved entity, and set the
6089 -- return type to that of the operation.
6092 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
6093 pragma Assert
(Norm_OK
);
6094 Set_Etype
(N
, Etype
(Nam
));
6097 Resolve_Actuals
(N
, Nam
);
6098 Generate_Reference
(Nam
, Entry_Name
);
6100 if Ekind
(Nam
) = E_Entry
6101 or else Ekind
(Nam
) = E_Entry_Family
6103 Check_Potentially_Blocking_Operation
(N
);
6106 -- Verify that a procedure call cannot masquerade as an entry
6107 -- call where an entry call is expected.
6109 if Ekind
(Nam
) = E_Procedure
then
6110 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
6111 and then N
= Entry_Call_Statement
(Parent
(N
))
6113 Error_Msg_N
("entry call required in select statement", N
);
6115 elsif Nkind
(Parent
(N
)) = N_Triggering_Alternative
6116 and then N
= Triggering_Statement
(Parent
(N
))
6118 Error_Msg_N
("triggering statement cannot be procedure call", N
);
6120 elsif Ekind
(Scope
(Nam
)) = E_Task_Type
6121 and then not In_Open_Scopes
(Scope
(Nam
))
6123 Error_Msg_N
("task has no entry with this name", Entry_Name
);
6127 -- After resolution, entry calls and protected procedure calls are
6128 -- changed into entry calls, for expansion. The structure of the node
6129 -- does not change, so it can safely be done in place. Protected
6130 -- function calls must keep their structure because they are
6133 if Ekind
(Nam
) /= E_Function
then
6135 -- A protected operation that is not a function may modify the
6136 -- corresponding object, and cannot apply to a constant. If this
6137 -- is an internal call, the prefix is the type itself.
6139 if Is_Protected_Type
(Scope
(Nam
))
6140 and then not Is_Variable
(Obj
)
6141 and then (not Is_Entity_Name
(Obj
)
6142 or else not Is_Type
(Entity
(Obj
)))
6145 ("prefix of protected procedure or entry call must be variable",
6149 Actuals
:= Parameter_Associations
(N
);
6150 First_Named
:= First_Named_Actual
(N
);
6153 Make_Entry_Call_Statement
(Loc
,
6155 Parameter_Associations
=> Actuals
));
6157 Set_First_Named_Actual
(N
, First_Named
);
6158 Set_Analyzed
(N
, True);
6160 -- Protected functions can return on the secondary stack, in which
6161 -- case we must trigger the transient scope mechanism.
6163 elsif Expander_Active
6164 and then Requires_Transient_Scope
(Etype
(Nam
))
6166 Establish_Transient_Scope
(N
, Sec_Stack
=> True);
6168 end Resolve_Entry_Call
;
6170 -------------------------
6171 -- Resolve_Equality_Op --
6172 -------------------------
6174 -- Both arguments must have the same type, and the boolean context does
6175 -- not participate in the resolution. The first pass verifies that the
6176 -- interpretation is not ambiguous, and the type of the left argument is
6177 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6178 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6179 -- though they carry a single (universal) type. Diagnose this case here.
6181 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
6182 L
: constant Node_Id
:= Left_Opnd
(N
);
6183 R
: constant Node_Id
:= Right_Opnd
(N
);
6184 T
: Entity_Id
:= Find_Unique_Type
(L
, R
);
6186 function Find_Unique_Access_Type
return Entity_Id
;
6187 -- In the case of allocators, make a last-ditch attempt to find a single
6188 -- access type with the right designated type. This is semantically
6189 -- dubious, and of no interest to any real code, but c48008a makes it
6192 -----------------------------
6193 -- Find_Unique_Access_Type --
6194 -----------------------------
6196 function Find_Unique_Access_Type
return Entity_Id
is
6202 if Ekind
(Etype
(R
)) = E_Allocator_Type
then
6203 Acc
:= Designated_Type
(Etype
(R
));
6204 elsif Ekind
(Etype
(L
)) = E_Allocator_Type
then
6205 Acc
:= Designated_Type
(Etype
(L
));
6211 while S
/= Standard_Standard
loop
6212 E
:= First_Entity
(S
);
6213 while Present
(E
) loop
6215 and then Is_Access_Type
(E
)
6216 and then Ekind
(E
) /= E_Allocator_Type
6217 and then Designated_Type
(E
) = Base_Type
(Acc
)
6229 end Find_Unique_Access_Type
;
6231 -- Start of processing for Resolve_Equality_Op
6234 Set_Etype
(N
, Base_Type
(Typ
));
6235 Generate_Reference
(T
, N
, ' ');
6237 if T
= Any_Fixed
then
6238 T
:= Unique_Fixed_Point_Type
(L
);
6241 if T
/= Any_Type
then
6243 or else T
= Any_Composite
6244 or else T
= Any_Character
6246 if T
= Any_Character
then
6247 Ambiguous_Character
(L
);
6249 Error_Msg_N
("ambiguous operands for equality", N
);
6252 Set_Etype
(N
, Any_Type
);
6255 elsif T
= Any_Access
6256 or else Ekind
(T
) = E_Allocator_Type
6257 or else Ekind
(T
) = E_Access_Attribute_Type
6259 T
:= Find_Unique_Access_Type
;
6262 Error_Msg_N
("ambiguous operands for equality", N
);
6263 Set_Etype
(N
, Any_Type
);
6271 -- If the unique type is a class-wide type then it will be expanded
6272 -- into a dispatching call to the predefined primitive. Therefore we
6273 -- check here for potential violation of such restriction.
6275 if Is_Class_Wide_Type
(T
) then
6276 Check_Restriction
(No_Dispatching_Calls
, N
);
6279 if Warn_On_Redundant_Constructs
6280 and then Comes_From_Source
(N
)
6281 and then Is_Entity_Name
(R
)
6282 and then Entity
(R
) = Standard_True
6283 and then Comes_From_Source
(R
)
6285 Error_Msg_N
("?comparison with True is redundant!", R
);
6288 Check_Unset_Reference
(L
);
6289 Check_Unset_Reference
(R
);
6290 Generate_Operator_Reference
(N
, T
);
6291 Check_Low_Bound_Tested
(N
);
6293 -- If this is an inequality, it may be the implicit inequality
6294 -- created for a user-defined operation, in which case the corres-
6295 -- ponding equality operation is not intrinsic, and the operation
6296 -- cannot be constant-folded. Else fold.
6298 if Nkind
(N
) = N_Op_Eq
6299 or else Comes_From_Source
(Entity
(N
))
6300 or else Ekind
(Entity
(N
)) = E_Operator
6301 or else Is_Intrinsic_Subprogram
6302 (Corresponding_Equality
(Entity
(N
)))
6304 Eval_Relational_Op
(N
);
6306 elsif Nkind
(N
) = N_Op_Ne
6307 and then Is_Abstract_Subprogram
(Entity
(N
))
6309 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Entity
(N
));
6312 -- Ada 2005: If one operand is an anonymous access type, convert the
6313 -- other operand to it, to ensure that the underlying types match in
6314 -- the back-end. Same for access_to_subprogram, and the conversion
6315 -- verifies that the types are subtype conformant.
6317 -- We apply the same conversion in the case one of the operands is a
6318 -- private subtype of the type of the other.
6320 -- Why the Expander_Active test here ???
6324 (Ekind
(T
) = E_Anonymous_Access_Type
6325 or else Ekind
(T
) = E_Anonymous_Access_Subprogram_Type
6326 or else Is_Private_Type
(T
))
6328 if Etype
(L
) /= T
then
6330 Make_Unchecked_Type_Conversion
(Sloc
(L
),
6331 Subtype_Mark
=> New_Occurrence_Of
(T
, Sloc
(L
)),
6332 Expression
=> Relocate_Node
(L
)));
6333 Analyze_And_Resolve
(L
, T
);
6336 if (Etype
(R
)) /= T
then
6338 Make_Unchecked_Type_Conversion
(Sloc
(R
),
6339 Subtype_Mark
=> New_Occurrence_Of
(Etype
(L
), Sloc
(R
)),
6340 Expression
=> Relocate_Node
(R
)));
6341 Analyze_And_Resolve
(R
, T
);
6345 end Resolve_Equality_Op
;
6347 ----------------------------------
6348 -- Resolve_Explicit_Dereference --
6349 ----------------------------------
6351 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
) is
6352 Loc
: constant Source_Ptr
:= Sloc
(N
);
6354 P
: constant Node_Id
:= Prefix
(N
);
6359 Check_Fully_Declared_Prefix
(Typ
, P
);
6361 if Is_Overloaded
(P
) then
6363 -- Use the context type to select the prefix that has the correct
6366 Get_First_Interp
(P
, I
, It
);
6367 while Present
(It
.Typ
) loop
6368 exit when Is_Access_Type
(It
.Typ
)
6369 and then Covers
(Typ
, Designated_Type
(It
.Typ
));
6370 Get_Next_Interp
(I
, It
);
6373 if Present
(It
.Typ
) then
6374 Resolve
(P
, It
.Typ
);
6376 -- If no interpretation covers the designated type of the prefix,
6377 -- this is the pathological case where not all implementations of
6378 -- the prefix allow the interpretation of the node as a call. Now
6379 -- that the expected type is known, Remove other interpretations
6380 -- from prefix, rewrite it as a call, and resolve again, so that
6381 -- the proper call node is generated.
6383 Get_First_Interp
(P
, I
, It
);
6384 while Present
(It
.Typ
) loop
6385 if Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
6389 Get_Next_Interp
(I
, It
);
6393 Make_Function_Call
(Loc
,
6395 Make_Explicit_Dereference
(Loc
,
6397 Parameter_Associations
=> New_List
);
6399 Save_Interps
(N
, New_N
);
6401 Analyze_And_Resolve
(N
, Typ
);
6405 Set_Etype
(N
, Designated_Type
(It
.Typ
));
6411 if Is_Access_Type
(Etype
(P
)) then
6412 Apply_Access_Check
(N
);
6415 -- If the designated type is a packed unconstrained array type, and the
6416 -- explicit dereference is not in the context of an attribute reference,
6417 -- then we must compute and set the actual subtype, since it is needed
6418 -- by Gigi. The reason we exclude the attribute case is that this is
6419 -- handled fine by Gigi, and in fact we use such attributes to build the
6420 -- actual subtype. We also exclude generated code (which builds actual
6421 -- subtypes directly if they are needed).
6423 if Is_Array_Type
(Etype
(N
))
6424 and then Is_Packed
(Etype
(N
))
6425 and then not Is_Constrained
(Etype
(N
))
6426 and then Nkind
(Parent
(N
)) /= N_Attribute_Reference
6427 and then Comes_From_Source
(N
)
6429 Set_Etype
(N
, Get_Actual_Subtype
(N
));
6432 -- Note: No Eval processing is required for an explicit dereference,
6433 -- because such a name can never be static.
6435 end Resolve_Explicit_Dereference
;
6437 -------------------------------
6438 -- Resolve_Indexed_Component --
6439 -------------------------------
6441 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
6442 Name
: constant Node_Id
:= Prefix
(N
);
6444 Array_Type
: Entity_Id
:= Empty
; -- to prevent junk warning
6448 if Is_Overloaded
(Name
) then
6450 -- Use the context type to select the prefix that yields the correct
6456 I1
: Interp_Index
:= 0;
6457 P
: constant Node_Id
:= Prefix
(N
);
6458 Found
: Boolean := False;
6461 Get_First_Interp
(P
, I
, It
);
6462 while Present
(It
.Typ
) loop
6463 if (Is_Array_Type
(It
.Typ
)
6464 and then Covers
(Typ
, Component_Type
(It
.Typ
)))
6465 or else (Is_Access_Type
(It
.Typ
)
6466 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
6468 (Typ
, Component_Type
(Designated_Type
(It
.Typ
))))
6471 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
6473 if It
= No_Interp
then
6474 Error_Msg_N
("ambiguous prefix for indexing", N
);
6480 Array_Type
:= It
.Typ
;
6486 Array_Type
:= It
.Typ
;
6491 Get_Next_Interp
(I
, It
);
6496 Array_Type
:= Etype
(Name
);
6499 Resolve
(Name
, Array_Type
);
6500 Array_Type
:= Get_Actual_Subtype_If_Available
(Name
);
6502 -- If prefix is access type, dereference to get real array type.
6503 -- Note: we do not apply an access check because the expander always
6504 -- introduces an explicit dereference, and the check will happen there.
6506 if Is_Access_Type
(Array_Type
) then
6507 Array_Type
:= Designated_Type
(Array_Type
);
6510 -- If name was overloaded, set component type correctly now
6511 -- If a misplaced call to an entry family (which has no index types)
6512 -- return. Error will be diagnosed from calling context.
6514 if Is_Array_Type
(Array_Type
) then
6515 Set_Etype
(N
, Component_Type
(Array_Type
));
6520 Index
:= First_Index
(Array_Type
);
6521 Expr
:= First
(Expressions
(N
));
6523 -- The prefix may have resolved to a string literal, in which case its
6524 -- etype has a special representation. This is only possible currently
6525 -- if the prefix is a static concatenation, written in functional
6528 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
6529 Resolve
(Expr
, Standard_Positive
);
6532 while Present
(Index
) and Present
(Expr
) loop
6533 Resolve
(Expr
, Etype
(Index
));
6534 Check_Unset_Reference
(Expr
);
6536 if Is_Scalar_Type
(Etype
(Expr
)) then
6537 Apply_Scalar_Range_Check
(Expr
, Etype
(Index
));
6539 Apply_Range_Check
(Expr
, Get_Actual_Subtype
(Index
));
6547 -- Do not generate the warning on suspicious index if we are analyzing
6548 -- package Ada.Tags; otherwise we will report the warning with the
6549 -- Prims_Ptr field of the dispatch table.
6551 if Scope
(Etype
(Prefix
(N
))) = Standard_Standard
6553 Is_RTU
(Cunit_Entity
(Get_Source_Unit
(Etype
(Prefix
(N
)))),
6556 Warn_On_Suspicious_Index
(Name
, First
(Expressions
(N
)));
6557 Eval_Indexed_Component
(N
);
6559 end Resolve_Indexed_Component
;
6561 -----------------------------
6562 -- Resolve_Integer_Literal --
6563 -----------------------------
6565 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
6568 Eval_Integer_Literal
(N
);
6569 end Resolve_Integer_Literal
;
6571 --------------------------------
6572 -- Resolve_Intrinsic_Operator --
6573 --------------------------------
6575 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
) is
6576 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
6583 while Scope
(Op
) /= Standard_Standard
loop
6585 pragma Assert
(Present
(Op
));
6589 Set_Is_Overloaded
(N
, False);
6591 -- If the operand type is private, rewrite with suitable conversions on
6592 -- the operands and the result, to expose the proper underlying numeric
6595 if Is_Private_Type
(Typ
) then
6596 Arg1
:= Unchecked_Convert_To
(Btyp
, Left_Opnd
(N
));
6598 if Nkind
(N
) = N_Op_Expon
then
6599 Arg2
:= Unchecked_Convert_To
(Standard_Integer
, Right_Opnd
(N
));
6601 Arg2
:= Unchecked_Convert_To
(Btyp
, Right_Opnd
(N
));
6604 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
6605 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
6607 Set_Left_Opnd
(N
, Arg1
);
6608 Set_Right_Opnd
(N
, Arg2
);
6610 Set_Etype
(N
, Btyp
);
6611 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
6614 elsif Typ
/= Etype
(Left_Opnd
(N
))
6615 or else Typ
/= Etype
(Right_Opnd
(N
))
6617 -- Add explicit conversion where needed, and save interpretations in
6618 -- case operands are overloaded.
6620 Arg1
:= Convert_To
(Typ
, Left_Opnd
(N
));
6621 Arg2
:= Convert_To
(Typ
, Right_Opnd
(N
));
6623 if Nkind
(Arg1
) = N_Type_Conversion
then
6624 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
6626 Save_Interps
(Left_Opnd
(N
), Arg1
);
6629 if Nkind
(Arg2
) = N_Type_Conversion
then
6630 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
6632 Save_Interps
(Right_Opnd
(N
), Arg2
);
6635 Rewrite
(Left_Opnd
(N
), Arg1
);
6636 Rewrite
(Right_Opnd
(N
), Arg2
);
6639 Resolve_Arithmetic_Op
(N
, Typ
);
6642 Resolve_Arithmetic_Op
(N
, Typ
);
6644 end Resolve_Intrinsic_Operator
;
6646 --------------------------------------
6647 -- Resolve_Intrinsic_Unary_Operator --
6648 --------------------------------------
6650 procedure Resolve_Intrinsic_Unary_Operator
6654 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
6660 while Scope
(Op
) /= Standard_Standard
loop
6662 pragma Assert
(Present
(Op
));
6667 if Is_Private_Type
(Typ
) then
6668 Arg2
:= Unchecked_Convert_To
(Btyp
, Right_Opnd
(N
));
6669 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
6671 Set_Right_Opnd
(N
, Arg2
);
6673 Set_Etype
(N
, Btyp
);
6674 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
6678 Resolve_Unary_Op
(N
, Typ
);
6680 end Resolve_Intrinsic_Unary_Operator
;
6682 ------------------------
6683 -- Resolve_Logical_Op --
6684 ------------------------
6686 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
6690 Check_No_Direct_Boolean_Operators
(N
);
6692 -- Predefined operations on scalar types yield the base type. On the
6693 -- other hand, logical operations on arrays yield the type of the
6694 -- arguments (and the context).
6696 if Is_Array_Type
(Typ
) then
6699 B_Typ
:= Base_Type
(Typ
);
6702 -- The following test is required because the operands of the operation
6703 -- may be literals, in which case the resulting type appears to be
6704 -- compatible with a signed integer type, when in fact it is compatible
6705 -- only with modular types. If the context itself is universal, the
6706 -- operation is illegal.
6708 if not Valid_Boolean_Arg
(Typ
) then
6709 Error_Msg_N
("invalid context for logical operation", N
);
6710 Set_Etype
(N
, Any_Type
);
6713 elsif Typ
= Any_Modular
then
6715 ("no modular type available in this context", N
);
6716 Set_Etype
(N
, Any_Type
);
6718 elsif Is_Modular_Integer_Type
(Typ
)
6719 and then Etype
(Left_Opnd
(N
)) = Universal_Integer
6720 and then Etype
(Right_Opnd
(N
)) = Universal_Integer
6722 Check_For_Visible_Operator
(N
, B_Typ
);
6725 Resolve
(Left_Opnd
(N
), B_Typ
);
6726 Resolve
(Right_Opnd
(N
), B_Typ
);
6728 Check_Unset_Reference
(Left_Opnd
(N
));
6729 Check_Unset_Reference
(Right_Opnd
(N
));
6731 Set_Etype
(N
, B_Typ
);
6732 Generate_Operator_Reference
(N
, B_Typ
);
6733 Eval_Logical_Op
(N
);
6734 end Resolve_Logical_Op
;
6736 ---------------------------
6737 -- Resolve_Membership_Op --
6738 ---------------------------
6740 -- The context can only be a boolean type, and does not determine
6741 -- the arguments. Arguments should be unambiguous, but the preference
6742 -- rule for universal types applies.
6744 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
6745 pragma Warnings
(Off
, Typ
);
6747 L
: constant Node_Id
:= Left_Opnd
(N
);
6748 R
: constant Node_Id
:= Right_Opnd
(N
);
6751 procedure Resolve_Set_Membership
;
6752 -- Analysis has determined a unique type for the left operand.
6753 -- Use it to resolve the disjuncts.
6755 ----------------------------
6756 -- Resolve_Set_Membership --
6757 ----------------------------
6759 procedure Resolve_Set_Membership
is
6763 Resolve
(L
, Etype
(L
));
6765 Alt
:= First
(Alternatives
(N
));
6766 while Present
(Alt
) loop
6768 -- Alternative is an expression, a range
6769 -- or a subtype mark.
6771 if not Is_Entity_Name
(Alt
)
6772 or else not Is_Type
(Entity
(Alt
))
6774 Resolve
(Alt
, Etype
(L
));
6779 end Resolve_Set_Membership
;
6781 -- Start of processing for Resolve_Membership_Op
6784 if L
= Error
or else R
= Error
then
6788 if Present
(Alternatives
(N
)) then
6789 Resolve_Set_Membership
;
6792 elsif not Is_Overloaded
(R
)
6794 (Etype
(R
) = Universal_Integer
or else
6795 Etype
(R
) = Universal_Real
)
6796 and then Is_Overloaded
(L
)
6800 -- Ada 2005 (AI-251): Support the following case:
6802 -- type I is interface;
6803 -- type T is tagged ...
6805 -- function Test (O : I'Class) is
6807 -- return O in T'Class.
6810 -- In this case we have nothing else to do. The membership test will be
6811 -- done at run-time.
6813 elsif Ada_Version
>= Ada_05
6814 and then Is_Class_Wide_Type
(Etype
(L
))
6815 and then Is_Interface
(Etype
(L
))
6816 and then Is_Class_Wide_Type
(Etype
(R
))
6817 and then not Is_Interface
(Etype
(R
))
6822 T
:= Intersect_Types
(L
, R
);
6826 Check_Unset_Reference
(L
);
6828 if Nkind
(R
) = N_Range
6829 and then not Is_Scalar_Type
(T
)
6831 Error_Msg_N
("scalar type required for range", R
);
6834 if Is_Entity_Name
(R
) then
6835 Freeze_Expression
(R
);
6838 Check_Unset_Reference
(R
);
6841 Eval_Membership_Op
(N
);
6842 end Resolve_Membership_Op
;
6848 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
) is
6849 Loc
: constant Source_Ptr
:= Sloc
(N
);
6852 -- Handle restriction against anonymous null access values This
6853 -- restriction can be turned off using -gnatdj.
6855 -- Ada 2005 (AI-231): Remove restriction
6857 if Ada_Version
< Ada_05
6858 and then not Debug_Flag_J
6859 and then Ekind
(Typ
) = E_Anonymous_Access_Type
6860 and then Comes_From_Source
(N
)
6862 -- In the common case of a call which uses an explicitly null value
6863 -- for an access parameter, give specialized error message.
6865 if Nkind_In
(Parent
(N
), N_Procedure_Call_Statement
,
6869 ("null is not allowed as argument for an access parameter", N
);
6871 -- Standard message for all other cases (are there any?)
6875 ("null cannot be of an anonymous access type", N
);
6879 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
6880 -- assignment to a null-excluding object
6882 if Ada_Version
>= Ada_05
6883 and then Can_Never_Be_Null
(Typ
)
6884 and then Nkind
(Parent
(N
)) = N_Assignment_Statement
6886 if not Inside_Init_Proc
then
6888 (Compile_Time_Constraint_Error
(N
,
6889 "(Ada 2005) null not allowed in null-excluding objects?"),
6890 Make_Raise_Constraint_Error
(Loc
,
6891 Reason
=> CE_Access_Check_Failed
));
6894 Make_Raise_Constraint_Error
(Loc
,
6895 Reason
=> CE_Access_Check_Failed
));
6899 -- In a distributed context, null for a remote access to subprogram may
6900 -- need to be replaced with a special record aggregate. In this case,
6901 -- return after having done the transformation.
6903 if (Ekind
(Typ
) = E_Record_Type
6904 or else Is_Remote_Access_To_Subprogram_Type
(Typ
))
6905 and then Remote_AST_Null_Value
(N
, Typ
)
6910 -- The null literal takes its type from the context
6915 -----------------------
6916 -- Resolve_Op_Concat --
6917 -----------------------
6919 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
) is
6921 -- We wish to avoid deep recursion, because concatenations are often
6922 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
6923 -- operands nonrecursively until we find something that is not a simple
6924 -- concatenation (A in this case). We resolve that, and then walk back
6925 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
6926 -- to do the rest of the work at each level. The Parent pointers allow
6927 -- us to avoid recursion, and thus avoid running out of memory. See also
6928 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
6934 -- The following code is equivalent to:
6936 -- Resolve_Op_Concat_First (NN, Typ);
6937 -- Resolve_Op_Concat_Arg (N, ...);
6938 -- Resolve_Op_Concat_Rest (N, Typ);
6940 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
6941 -- operand is a concatenation.
6943 -- Walk down left operands
6946 Resolve_Op_Concat_First
(NN
, Typ
);
6947 Op1
:= Left_Opnd
(NN
);
6948 exit when not (Nkind
(Op1
) = N_Op_Concat
6949 and then not Is_Array_Type
(Component_Type
(Typ
))
6950 and then Entity
(Op1
) = Entity
(NN
));
6954 -- Now (given the above example) NN is A&B and Op1 is A
6956 -- First resolve Op1 ...
6958 Resolve_Op_Concat_Arg
(NN
, Op1
, Typ
, Is_Component_Left_Opnd
(NN
));
6960 -- ... then walk NN back up until we reach N (where we started), calling
6961 -- Resolve_Op_Concat_Rest along the way.
6964 Resolve_Op_Concat_Rest
(NN
, Typ
);
6968 end Resolve_Op_Concat
;
6970 ---------------------------
6971 -- Resolve_Op_Concat_Arg --
6972 ---------------------------
6974 procedure Resolve_Op_Concat_Arg
6980 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
6985 or else (not Is_Overloaded
(Arg
)
6986 and then Etype
(Arg
) /= Any_Composite
6987 and then Covers
(Component_Type
(Typ
), Etype
(Arg
)))
6989 Resolve
(Arg
, Component_Type
(Typ
));
6991 Resolve
(Arg
, Btyp
);
6994 elsif Has_Compatible_Type
(Arg
, Component_Type
(Typ
)) then
6995 if Nkind
(Arg
) = N_Aggregate
6996 and then Is_Composite_Type
(Component_Type
(Typ
))
6998 if Is_Private_Type
(Component_Type
(Typ
)) then
6999 Resolve
(Arg
, Btyp
);
7001 Error_Msg_N
("ambiguous aggregate must be qualified", Arg
);
7002 Set_Etype
(Arg
, Any_Type
);
7006 if Is_Overloaded
(Arg
)
7007 and then Has_Compatible_Type
(Arg
, Typ
)
7008 and then Etype
(Arg
) /= Any_Type
7016 Get_First_Interp
(Arg
, I
, It
);
7018 Get_Next_Interp
(I
, It
);
7020 -- Special-case the error message when the overloading is
7021 -- caused by a function that yields an array and can be
7022 -- called without parameters.
7024 if It
.Nam
= Func
then
7025 Error_Msg_Sloc
:= Sloc
(Func
);
7026 Error_Msg_N
("ambiguous call to function#", Arg
);
7028 ("\\interpretation as call yields&", Arg
, Typ
);
7030 ("\\interpretation as indexing of call yields&",
7031 Arg
, Component_Type
(Typ
));
7035 ("ambiguous operand for concatenation!", Arg
);
7036 Get_First_Interp
(Arg
, I
, It
);
7037 while Present
(It
.Nam
) loop
7038 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
7040 if Base_Type
(It
.Typ
) = Base_Type
(Typ
)
7041 or else Base_Type
(It
.Typ
) =
7042 Base_Type
(Component_Type
(Typ
))
7044 Error_Msg_N
-- CODEFIX
7045 ("\\possible interpretation#", Arg
);
7048 Get_Next_Interp
(I
, It
);
7054 Resolve
(Arg
, Component_Type
(Typ
));
7056 if Nkind
(Arg
) = N_String_Literal
then
7057 Set_Etype
(Arg
, Component_Type
(Typ
));
7060 if Arg
= Left_Opnd
(N
) then
7061 Set_Is_Component_Left_Opnd
(N
);
7063 Set_Is_Component_Right_Opnd
(N
);
7068 Resolve
(Arg
, Btyp
);
7071 Check_Unset_Reference
(Arg
);
7072 end Resolve_Op_Concat_Arg
;
7074 -----------------------------
7075 -- Resolve_Op_Concat_First --
7076 -----------------------------
7078 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
) is
7079 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
7080 Op1
: constant Node_Id
:= Left_Opnd
(N
);
7081 Op2
: constant Node_Id
:= Right_Opnd
(N
);
7084 -- The parser folds an enormous sequence of concatenations of string
7085 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
7086 -- in the right operand. If the expression resolves to a predefined "&"
7087 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7088 -- we give an error. See P_Simple_Expression in Par.Ch4.
7090 if Nkind
(Op2
) = N_String_Literal
7091 and then Is_Folded_In_Parser
(Op2
)
7092 and then Ekind
(Entity
(N
)) = E_Function
7094 pragma Assert
(Nkind
(Op1
) = N_String_Literal
-- should be ""
7095 and then String_Length
(Strval
(Op1
)) = 0);
7096 Error_Msg_N
("too many user-defined concatenations", N
);
7100 Set_Etype
(N
, Btyp
);
7102 if Is_Limited_Composite
(Btyp
) then
7103 Error_Msg_N
("concatenation not available for limited array", N
);
7104 Explain_Limited_Type
(Btyp
, N
);
7106 end Resolve_Op_Concat_First
;
7108 ----------------------------
7109 -- Resolve_Op_Concat_Rest --
7110 ----------------------------
7112 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
) is
7113 Op1
: constant Node_Id
:= Left_Opnd
(N
);
7114 Op2
: constant Node_Id
:= Right_Opnd
(N
);
7117 Resolve_Op_Concat_Arg
(N
, Op2
, Typ
, Is_Component_Right_Opnd
(N
));
7119 Generate_Operator_Reference
(N
, Typ
);
7121 if Is_String_Type
(Typ
) then
7122 Eval_Concatenation
(N
);
7125 -- If this is not a static concatenation, but the result is a string
7126 -- type (and not an array of strings) ensure that static string operands
7127 -- have their subtypes properly constructed.
7129 if Nkind
(N
) /= N_String_Literal
7130 and then Is_Character_Type
(Component_Type
(Typ
))
7132 Set_String_Literal_Subtype
(Op1
, Typ
);
7133 Set_String_Literal_Subtype
(Op2
, Typ
);
7135 end Resolve_Op_Concat_Rest
;
7137 ----------------------
7138 -- Resolve_Op_Expon --
7139 ----------------------
7141 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
) is
7142 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
7145 -- Catch attempts to do fixed-point exponentiation with universal
7146 -- operands, which is a case where the illegality is not caught during
7147 -- normal operator analysis.
7149 if Is_Fixed_Point_Type
(Typ
) and then Comes_From_Source
(N
) then
7150 Error_Msg_N
("exponentiation not available for fixed point", N
);
7154 if Comes_From_Source
(N
)
7155 and then Ekind
(Entity
(N
)) = E_Function
7156 and then Is_Imported
(Entity
(N
))
7157 and then Is_Intrinsic_Subprogram
(Entity
(N
))
7159 Resolve_Intrinsic_Operator
(N
, Typ
);
7163 if Etype
(Left_Opnd
(N
)) = Universal_Integer
7164 or else Etype
(Left_Opnd
(N
)) = Universal_Real
7166 Check_For_Visible_Operator
(N
, B_Typ
);
7169 -- We do the resolution using the base type, because intermediate values
7170 -- in expressions always are of the base type, not a subtype of it.
7172 Resolve
(Left_Opnd
(N
), B_Typ
);
7173 Resolve
(Right_Opnd
(N
), Standard_Integer
);
7175 Check_Unset_Reference
(Left_Opnd
(N
));
7176 Check_Unset_Reference
(Right_Opnd
(N
));
7178 Set_Etype
(N
, B_Typ
);
7179 Generate_Operator_Reference
(N
, B_Typ
);
7182 -- Set overflow checking bit. Much cleverer code needed here eventually
7183 -- and perhaps the Resolve routines should be separated for the various
7184 -- arithmetic operations, since they will need different processing. ???
7186 if Nkind
(N
) in N_Op
then
7187 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
7188 Enable_Overflow_Check
(N
);
7191 end Resolve_Op_Expon
;
7193 --------------------
7194 -- Resolve_Op_Not --
7195 --------------------
7197 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
) is
7200 function Parent_Is_Boolean
return Boolean;
7201 -- This function determines if the parent node is a boolean operator
7202 -- or operation (comparison op, membership test, or short circuit form)
7203 -- and the not in question is the left operand of this operation.
7204 -- Note that if the not is in parens, then false is returned.
7206 -----------------------
7207 -- Parent_Is_Boolean --
7208 -----------------------
7210 function Parent_Is_Boolean
return Boolean is
7212 if Paren_Count
(N
) /= 0 then
7216 case Nkind
(Parent
(N
)) is
7231 return Left_Opnd
(Parent
(N
)) = N
;
7237 end Parent_Is_Boolean
;
7239 -- Start of processing for Resolve_Op_Not
7242 -- Predefined operations on scalar types yield the base type. On the
7243 -- other hand, logical operations on arrays yield the type of the
7244 -- arguments (and the context).
7246 if Is_Array_Type
(Typ
) then
7249 B_Typ
:= Base_Type
(Typ
);
7252 -- Straightforward case of incorrect arguments
7254 if not Valid_Boolean_Arg
(Typ
) then
7255 Error_Msg_N
("invalid operand type for operator&", N
);
7256 Set_Etype
(N
, Any_Type
);
7259 -- Special case of probable missing parens
7261 elsif Typ
= Universal_Integer
or else Typ
= Any_Modular
then
7262 if Parent_Is_Boolean
then
7264 ("operand of not must be enclosed in parentheses",
7268 ("no modular type available in this context", N
);
7271 Set_Etype
(N
, Any_Type
);
7274 -- OK resolution of not
7277 -- Warn if non-boolean types involved. This is a case like not a < b
7278 -- where a and b are modular, where we will get (not a) < b and most
7279 -- likely not (a < b) was intended.
7281 if Warn_On_Questionable_Missing_Parens
7282 and then not Is_Boolean_Type
(Typ
)
7283 and then Parent_Is_Boolean
7285 Error_Msg_N
("?not expression should be parenthesized here!", N
);
7288 -- Warn on double negation if checking redundant constructs
7290 if Warn_On_Redundant_Constructs
7291 and then Comes_From_Source
(N
)
7292 and then Comes_From_Source
(Right_Opnd
(N
))
7293 and then Root_Type
(Typ
) = Standard_Boolean
7294 and then Nkind
(Right_Opnd
(N
)) = N_Op_Not
7296 Error_Msg_N
("redundant double negation?", N
);
7299 -- Complete resolution and evaluation of NOT
7301 Resolve
(Right_Opnd
(N
), B_Typ
);
7302 Check_Unset_Reference
(Right_Opnd
(N
));
7303 Set_Etype
(N
, B_Typ
);
7304 Generate_Operator_Reference
(N
, B_Typ
);
7309 -----------------------------
7310 -- Resolve_Operator_Symbol --
7311 -----------------------------
7313 -- Nothing to be done, all resolved already
7315 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
) is
7316 pragma Warnings
(Off
, N
);
7317 pragma Warnings
(Off
, Typ
);
7321 end Resolve_Operator_Symbol
;
7323 ----------------------------------
7324 -- Resolve_Qualified_Expression --
7325 ----------------------------------
7327 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
7328 pragma Warnings
(Off
, Typ
);
7330 Target_Typ
: constant Entity_Id
:= Entity
(Subtype_Mark
(N
));
7331 Expr
: constant Node_Id
:= Expression
(N
);
7334 Resolve
(Expr
, Target_Typ
);
7336 -- A qualified expression requires an exact match of the type,
7337 -- class-wide matching is not allowed. However, if the qualifying
7338 -- type is specific and the expression has a class-wide type, it
7339 -- may still be okay, since it can be the result of the expansion
7340 -- of a call to a dispatching function, so we also have to check
7341 -- class-wideness of the type of the expression's original node.
7343 if (Is_Class_Wide_Type
(Target_Typ
)
7345 (Is_Class_Wide_Type
(Etype
(Expr
))
7346 and then Is_Class_Wide_Type
(Etype
(Original_Node
(Expr
)))))
7347 and then Base_Type
(Etype
(Expr
)) /= Base_Type
(Target_Typ
)
7349 Wrong_Type
(Expr
, Target_Typ
);
7352 -- If the target type is unconstrained, then we reset the type of
7353 -- the result from the type of the expression. For other cases, the
7354 -- actual subtype of the expression is the target type.
7356 if Is_Composite_Type
(Target_Typ
)
7357 and then not Is_Constrained
(Target_Typ
)
7359 Set_Etype
(N
, Etype
(Expr
));
7362 Eval_Qualified_Expression
(N
);
7363 end Resolve_Qualified_Expression
;
7369 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
) is
7370 L
: constant Node_Id
:= Low_Bound
(N
);
7371 H
: constant Node_Id
:= High_Bound
(N
);
7378 Check_Unset_Reference
(L
);
7379 Check_Unset_Reference
(H
);
7381 -- We have to check the bounds for being within the base range as
7382 -- required for a non-static context. Normally this is automatic and
7383 -- done as part of evaluating expressions, but the N_Range node is an
7384 -- exception, since in GNAT we consider this node to be a subexpression,
7385 -- even though in Ada it is not. The circuit in Sem_Eval could check for
7386 -- this, but that would put the test on the main evaluation path for
7389 Check_Non_Static_Context
(L
);
7390 Check_Non_Static_Context
(H
);
7392 -- Check for an ambiguous range over character literals. This will
7393 -- happen with a membership test involving only literals.
7395 if Typ
= Any_Character
then
7396 Ambiguous_Character
(L
);
7397 Set_Etype
(N
, Any_Type
);
7401 -- If bounds are static, constant-fold them, so size computations
7402 -- are identical between front-end and back-end. Do not perform this
7403 -- transformation while analyzing generic units, as type information
7404 -- would then be lost when reanalyzing the constant node in the
7407 if Is_Discrete_Type
(Typ
) and then Expander_Active
then
7408 if Is_OK_Static_Expression
(L
) then
7409 Fold_Uint
(L
, Expr_Value
(L
), Is_Static_Expression
(L
));
7412 if Is_OK_Static_Expression
(H
) then
7413 Fold_Uint
(H
, Expr_Value
(H
), Is_Static_Expression
(H
));
7418 --------------------------
7419 -- Resolve_Real_Literal --
7420 --------------------------
7422 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
7423 Actual_Typ
: constant Entity_Id
:= Etype
(N
);
7426 -- Special processing for fixed-point literals to make sure that the
7427 -- value is an exact multiple of small where this is required. We
7428 -- skip this for the universal real case, and also for generic types.
7430 if Is_Fixed_Point_Type
(Typ
)
7431 and then Typ
/= Universal_Fixed
7432 and then Typ
/= Any_Fixed
7433 and then not Is_Generic_Type
(Typ
)
7436 Val
: constant Ureal
:= Realval
(N
);
7437 Cintr
: constant Ureal
:= Val
/ Small_Value
(Typ
);
7438 Cint
: constant Uint
:= UR_Trunc
(Cintr
);
7439 Den
: constant Uint
:= Norm_Den
(Cintr
);
7443 -- Case of literal is not an exact multiple of the Small
7447 -- For a source program literal for a decimal fixed-point
7448 -- type, this is statically illegal (RM 4.9(36)).
7450 if Is_Decimal_Fixed_Point_Type
(Typ
)
7451 and then Actual_Typ
= Universal_Real
7452 and then Comes_From_Source
(N
)
7454 Error_Msg_N
("value has extraneous low order digits", N
);
7457 -- Generate a warning if literal from source
7459 if Is_Static_Expression
(N
)
7460 and then Warn_On_Bad_Fixed_Value
7463 ("?static fixed-point value is not a multiple of Small!",
7467 -- Replace literal by a value that is the exact representation
7468 -- of a value of the type, i.e. a multiple of the small value,
7469 -- by truncation, since Machine_Rounds is false for all GNAT
7470 -- fixed-point types (RM 4.9(38)).
7472 Stat
:= Is_Static_Expression
(N
);
7474 Make_Real_Literal
(Sloc
(N
),
7475 Realval
=> Small_Value
(Typ
) * Cint
));
7477 Set_Is_Static_Expression
(N
, Stat
);
7480 -- In all cases, set the corresponding integer field
7482 Set_Corresponding_Integer_Value
(N
, Cint
);
7486 -- Now replace the actual type by the expected type as usual
7489 Eval_Real_Literal
(N
);
7490 end Resolve_Real_Literal
;
7492 -----------------------
7493 -- Resolve_Reference --
7494 -----------------------
7496 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
) is
7497 P
: constant Node_Id
:= Prefix
(N
);
7500 -- Replace general access with specific type
7502 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
7503 Set_Etype
(N
, Base_Type
(Typ
));
7506 Resolve
(P
, Designated_Type
(Etype
(N
)));
7508 -- If we are taking the reference of a volatile entity, then treat
7509 -- it as a potential modification of this entity. This is much too
7510 -- conservative, but is necessary because remove side effects can
7511 -- result in transformations of normal assignments into reference
7512 -- sequences that otherwise fail to notice the modification.
7514 if Is_Entity_Name
(P
) and then Treat_As_Volatile
(Entity
(P
)) then
7515 Note_Possible_Modification
(P
, Sure
=> False);
7517 end Resolve_Reference
;
7519 --------------------------------
7520 -- Resolve_Selected_Component --
7521 --------------------------------
7523 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
7525 Comp1
: Entity_Id
:= Empty
; -- prevent junk warning
7526 P
: constant Node_Id
:= Prefix
(N
);
7527 S
: constant Node_Id
:= Selector_Name
(N
);
7528 T
: Entity_Id
:= Etype
(P
);
7530 I1
: Interp_Index
:= 0; -- prevent junk warning
7535 function Init_Component
return Boolean;
7536 -- Check whether this is the initialization of a component within an
7537 -- init proc (by assignment or call to another init proc). If true,
7538 -- there is no need for a discriminant check.
7540 --------------------
7541 -- Init_Component --
7542 --------------------
7544 function Init_Component
return Boolean is
7546 return Inside_Init_Proc
7547 and then Nkind
(Prefix
(N
)) = N_Identifier
7548 and then Chars
(Prefix
(N
)) = Name_uInit
7549 and then Nkind
(Parent
(Parent
(N
))) = N_Case_Statement_Alternative
;
7552 -- Start of processing for Resolve_Selected_Component
7555 if Is_Overloaded
(P
) then
7557 -- Use the context type to select the prefix that has a selector
7558 -- of the correct name and type.
7561 Get_First_Interp
(P
, I
, It
);
7563 Search
: while Present
(It
.Typ
) loop
7564 if Is_Access_Type
(It
.Typ
) then
7565 T
:= Designated_Type
(It
.Typ
);
7570 if Is_Record_Type
(T
) then
7572 -- The visible components of a class-wide type are those of
7575 if Is_Class_Wide_Type
(T
) then
7579 Comp
:= First_Entity
(T
);
7580 while Present
(Comp
) loop
7581 if Chars
(Comp
) = Chars
(S
)
7582 and then Covers
(Etype
(Comp
), Typ
)
7591 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
7593 if It
= No_Interp
then
7595 ("ambiguous prefix for selected component", N
);
7602 -- There may be an implicit dereference. Retrieve
7603 -- designated record type.
7605 if Is_Access_Type
(It1
.Typ
) then
7606 T
:= Designated_Type
(It1
.Typ
);
7611 if Scope
(Comp1
) /= T
then
7613 -- Resolution chooses the new interpretation.
7614 -- Find the component with the right name.
7616 Comp1
:= First_Entity
(T
);
7617 while Present
(Comp1
)
7618 and then Chars
(Comp1
) /= Chars
(S
)
7620 Comp1
:= Next_Entity
(Comp1
);
7629 Comp
:= Next_Entity
(Comp
);
7634 Get_Next_Interp
(I
, It
);
7637 Resolve
(P
, It1
.Typ
);
7639 Set_Entity_With_Style_Check
(S
, Comp1
);
7642 -- Resolve prefix with its type
7647 -- Generate cross-reference. We needed to wait until full overloading
7648 -- resolution was complete to do this, since otherwise we can't tell if
7649 -- we are an lvalue or not.
7651 if May_Be_Lvalue
(N
) then
7652 Generate_Reference
(Entity
(S
), S
, 'm');
7654 Generate_Reference
(Entity
(S
), S
, 'r');
7657 -- If prefix is an access type, the node will be transformed into an
7658 -- explicit dereference during expansion. The type of the node is the
7659 -- designated type of that of the prefix.
7661 if Is_Access_Type
(Etype
(P
)) then
7662 T
:= Designated_Type
(Etype
(P
));
7663 Check_Fully_Declared_Prefix
(T
, P
);
7668 if Has_Discriminants
(T
)
7669 and then (Ekind
(Entity
(S
)) = E_Component
7671 Ekind
(Entity
(S
)) = E_Discriminant
)
7672 and then Present
(Original_Record_Component
(Entity
(S
)))
7673 and then Ekind
(Original_Record_Component
(Entity
(S
))) = E_Component
7674 and then Present
(Discriminant_Checking_Func
7675 (Original_Record_Component
(Entity
(S
))))
7676 and then not Discriminant_Checks_Suppressed
(T
)
7677 and then not Init_Component
7679 Set_Do_Discriminant_Check
(N
);
7682 if Ekind
(Entity
(S
)) = E_Void
then
7683 Error_Msg_N
("premature use of component", S
);
7686 -- If the prefix is a record conversion, this may be a renamed
7687 -- discriminant whose bounds differ from those of the original
7688 -- one, so we must ensure that a range check is performed.
7690 if Nkind
(P
) = N_Type_Conversion
7691 and then Ekind
(Entity
(S
)) = E_Discriminant
7692 and then Is_Discrete_Type
(Typ
)
7694 Set_Etype
(N
, Base_Type
(Typ
));
7697 -- Note: No Eval processing is required, because the prefix is of a
7698 -- record type, or protected type, and neither can possibly be static.
7700 end Resolve_Selected_Component
;
7706 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
) is
7707 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
7708 L
: constant Node_Id
:= Left_Opnd
(N
);
7709 R
: constant Node_Id
:= Right_Opnd
(N
);
7712 -- We do the resolution using the base type, because intermediate values
7713 -- in expressions always are of the base type, not a subtype of it.
7716 Resolve
(R
, Standard_Natural
);
7718 Check_Unset_Reference
(L
);
7719 Check_Unset_Reference
(R
);
7721 Set_Etype
(N
, B_Typ
);
7722 Generate_Operator_Reference
(N
, B_Typ
);
7726 ---------------------------
7727 -- Resolve_Short_Circuit --
7728 ---------------------------
7730 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
) is
7731 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
7732 L
: constant Node_Id
:= Left_Opnd
(N
);
7733 R
: constant Node_Id
:= Right_Opnd
(N
);
7739 -- Check for issuing warning for always False assert/check, this happens
7740 -- when assertions are turned off, in which case the pragma Assert/Check
7741 -- was transformed into:
7743 -- if False and then <condition> then ...
7745 -- and we detect this pattern
7747 if Warn_On_Assertion_Failure
7748 and then Is_Entity_Name
(R
)
7749 and then Entity
(R
) = Standard_False
7750 and then Nkind
(Parent
(N
)) = N_If_Statement
7751 and then Nkind
(N
) = N_And_Then
7752 and then Is_Entity_Name
(L
)
7753 and then Entity
(L
) = Standard_False
7756 Orig
: constant Node_Id
:= Original_Node
(Parent
(N
));
7759 if Nkind
(Orig
) = N_Pragma
7760 and then Pragma_Name
(Orig
) = Name_Assert
7762 -- Don't want to warn if original condition is explicit False
7765 Expr
: constant Node_Id
:=
7768 (First
(Pragma_Argument_Associations
(Orig
))));
7770 if Is_Entity_Name
(Expr
)
7771 and then Entity
(Expr
) = Standard_False
7775 -- Issue warning. Note that we don't want to make this
7776 -- an unconditional warning, because if the assert is
7777 -- within deleted code we do not want the warning. But
7778 -- we do not want the deletion of the IF/AND-THEN to
7779 -- take this message with it. We achieve this by making
7780 -- sure that the expanded code points to the Sloc of
7781 -- the expression, not the original pragma.
7783 Error_Msg_N
("?assertion would fail at run-time", Orig
);
7787 -- Similar processing for Check pragma
7789 elsif Nkind
(Orig
) = N_Pragma
7790 and then Pragma_Name
(Orig
) = Name_Check
7792 -- Don't want to warn if original condition is explicit False
7795 Expr
: constant Node_Id
:=
7799 (Pragma_Argument_Associations
(Orig
)))));
7801 if Is_Entity_Name
(Expr
)
7802 and then Entity
(Expr
) = Standard_False
7806 Error_Msg_N
("?check would fail at run-time", Orig
);
7813 -- Continue with processing of short circuit
7815 Check_Unset_Reference
(L
);
7816 Check_Unset_Reference
(R
);
7818 Set_Etype
(N
, B_Typ
);
7819 Eval_Short_Circuit
(N
);
7820 end Resolve_Short_Circuit
;
7826 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
) is
7827 Name
: constant Node_Id
:= Prefix
(N
);
7828 Drange
: constant Node_Id
:= Discrete_Range
(N
);
7829 Array_Type
: Entity_Id
:= Empty
;
7833 if Is_Overloaded
(Name
) then
7835 -- Use the context type to select the prefix that yields the correct
7840 I1
: Interp_Index
:= 0;
7842 P
: constant Node_Id
:= Prefix
(N
);
7843 Found
: Boolean := False;
7846 Get_First_Interp
(P
, I
, It
);
7847 while Present
(It
.Typ
) loop
7848 if (Is_Array_Type
(It
.Typ
)
7849 and then Covers
(Typ
, It
.Typ
))
7850 or else (Is_Access_Type
(It
.Typ
)
7851 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
7852 and then Covers
(Typ
, Designated_Type
(It
.Typ
)))
7855 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
7857 if It
= No_Interp
then
7858 Error_Msg_N
("ambiguous prefix for slicing", N
);
7863 Array_Type
:= It
.Typ
;
7868 Array_Type
:= It
.Typ
;
7873 Get_Next_Interp
(I
, It
);
7878 Array_Type
:= Etype
(Name
);
7881 Resolve
(Name
, Array_Type
);
7883 if Is_Access_Type
(Array_Type
) then
7884 Apply_Access_Check
(N
);
7885 Array_Type
:= Designated_Type
(Array_Type
);
7887 -- If the prefix is an access to an unconstrained array, we must use
7888 -- the actual subtype of the object to perform the index checks. The
7889 -- object denoted by the prefix is implicit in the node, so we build
7890 -- an explicit representation for it in order to compute the actual
7893 if not Is_Constrained
(Array_Type
) then
7894 Remove_Side_Effects
(Prefix
(N
));
7897 Obj
: constant Node_Id
:=
7898 Make_Explicit_Dereference
(Sloc
(N
),
7899 Prefix
=> New_Copy_Tree
(Prefix
(N
)));
7901 Set_Etype
(Obj
, Array_Type
);
7902 Set_Parent
(Obj
, Parent
(N
));
7903 Array_Type
:= Get_Actual_Subtype
(Obj
);
7907 elsif Is_Entity_Name
(Name
)
7908 or else (Nkind
(Name
) = N_Function_Call
7909 and then not Is_Constrained
(Etype
(Name
)))
7911 Array_Type
:= Get_Actual_Subtype
(Name
);
7913 -- If the name is a selected component that depends on discriminants,
7914 -- build an actual subtype for it. This can happen only when the name
7915 -- itself is overloaded; otherwise the actual subtype is created when
7916 -- the selected component is analyzed.
7918 elsif Nkind
(Name
) = N_Selected_Component
7919 and then Full_Analysis
7920 and then Depends_On_Discriminant
(First_Index
(Array_Type
))
7923 Act_Decl
: constant Node_Id
:=
7924 Build_Actual_Subtype_Of_Component
(Array_Type
, Name
);
7926 Insert_Action
(N
, Act_Decl
);
7927 Array_Type
:= Defining_Identifier
(Act_Decl
);
7930 -- Maybe this should just be "else", instead of checking for the
7931 -- specific case of slice??? This is needed for the case where
7932 -- the prefix is an Image attribute, which gets expanded to a
7933 -- slice, and so has a constrained subtype which we want to use
7934 -- for the slice range check applied below (the range check won't
7935 -- get done if the unconstrained subtype of the 'Image is used).
7937 elsif Nkind
(Name
) = N_Slice
then
7938 Array_Type
:= Etype
(Name
);
7941 -- If name was overloaded, set slice type correctly now
7943 Set_Etype
(N
, Array_Type
);
7945 -- If the range is specified by a subtype mark, no resolution is
7946 -- necessary. Else resolve the bounds, and apply needed checks.
7948 if not Is_Entity_Name
(Drange
) then
7949 Index
:= First_Index
(Array_Type
);
7950 Resolve
(Drange
, Base_Type
(Etype
(Index
)));
7952 if Nkind
(Drange
) = N_Range
7954 -- Do not apply the range check to nodes associated with the
7955 -- frontend expansion of the dispatch table. We first check
7956 -- if Ada.Tags is already loaded to void the addition of an
7957 -- undesired dependence on such run-time unit.
7960 (not Tagged_Type_Expansion
7962 (RTU_Loaded
(Ada_Tags
)
7963 and then Nkind
(Prefix
(N
)) = N_Selected_Component
7964 and then Present
(Entity
(Selector_Name
(Prefix
(N
))))
7965 and then Entity
(Selector_Name
(Prefix
(N
))) =
7966 RTE_Record_Component
(RE_Prims_Ptr
)))
7968 Apply_Range_Check
(Drange
, Etype
(Index
));
7972 Set_Slice_Subtype
(N
);
7974 if Nkind
(Drange
) = N_Range
then
7975 Warn_On_Suspicious_Index
(Name
, Low_Bound
(Drange
));
7976 Warn_On_Suspicious_Index
(Name
, High_Bound
(Drange
));
7982 ----------------------------
7983 -- Resolve_String_Literal --
7984 ----------------------------
7986 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
7987 C_Typ
: constant Entity_Id
:= Component_Type
(Typ
);
7988 R_Typ
: constant Entity_Id
:= Root_Type
(C_Typ
);
7989 Loc
: constant Source_Ptr
:= Sloc
(N
);
7990 Str
: constant String_Id
:= Strval
(N
);
7991 Strlen
: constant Nat
:= String_Length
(Str
);
7992 Subtype_Id
: Entity_Id
;
7993 Need_Check
: Boolean;
7996 -- For a string appearing in a concatenation, defer creation of the
7997 -- string_literal_subtype until the end of the resolution of the
7998 -- concatenation, because the literal may be constant-folded away. This
7999 -- is a useful optimization for long concatenation expressions.
8001 -- If the string is an aggregate built for a single character (which
8002 -- happens in a non-static context) or a is null string to which special
8003 -- checks may apply, we build the subtype. Wide strings must also get a
8004 -- string subtype if they come from a one character aggregate. Strings
8005 -- generated by attributes might be static, but it is often hard to
8006 -- determine whether the enclosing context is static, so we generate
8007 -- subtypes for them as well, thus losing some rarer optimizations ???
8008 -- Same for strings that come from a static conversion.
8011 (Strlen
= 0 and then Typ
/= Standard_String
)
8012 or else Nkind
(Parent
(N
)) /= N_Op_Concat
8013 or else (N
/= Left_Opnd
(Parent
(N
))
8014 and then N
/= Right_Opnd
(Parent
(N
)))
8015 or else ((Typ
= Standard_Wide_String
8016 or else Typ
= Standard_Wide_Wide_String
)
8017 and then Nkind
(Original_Node
(N
)) /= N_String_Literal
);
8019 -- If the resolving type is itself a string literal subtype, we can just
8020 -- reuse it, since there is no point in creating another.
8022 if Ekind
(Typ
) = E_String_Literal_Subtype
then
8025 elsif Nkind
(Parent
(N
)) = N_Op_Concat
8026 and then not Need_Check
8027 and then not Nkind_In
(Original_Node
(N
), N_Character_Literal
,
8028 N_Attribute_Reference
,
8029 N_Qualified_Expression
,
8034 -- Otherwise we must create a string literal subtype. Note that the
8035 -- whole idea of string literal subtypes is simply to avoid the need
8036 -- for building a full fledged array subtype for each literal.
8039 Set_String_Literal_Subtype
(N
, Typ
);
8040 Subtype_Id
:= Etype
(N
);
8043 if Nkind
(Parent
(N
)) /= N_Op_Concat
8046 Set_Etype
(N
, Subtype_Id
);
8047 Eval_String_Literal
(N
);
8050 if Is_Limited_Composite
(Typ
)
8051 or else Is_Private_Composite
(Typ
)
8053 Error_Msg_N
("string literal not available for private array", N
);
8054 Set_Etype
(N
, Any_Type
);
8058 -- The validity of a null string has been checked in the call to
8059 -- Eval_String_Literal.
8064 -- Always accept string literal with component type Any_Character, which
8065 -- occurs in error situations and in comparisons of literals, both of
8066 -- which should accept all literals.
8068 elsif R_Typ
= Any_Character
then
8071 -- If the type is bit-packed, then we always transform the string
8072 -- literal into a full fledged aggregate.
8074 elsif Is_Bit_Packed_Array
(Typ
) then
8077 -- Deal with cases of Wide_Wide_String, Wide_String, and String
8080 -- For Standard.Wide_Wide_String, or any other type whose component
8081 -- type is Standard.Wide_Wide_Character, we know that all the
8082 -- characters in the string must be acceptable, since the parser
8083 -- accepted the characters as valid character literals.
8085 if R_Typ
= Standard_Wide_Wide_Character
then
8088 -- For the case of Standard.String, or any other type whose component
8089 -- type is Standard.Character, we must make sure that there are no
8090 -- wide characters in the string, i.e. that it is entirely composed
8091 -- of characters in range of type Character.
8093 -- If the string literal is the result of a static concatenation, the
8094 -- test has already been performed on the components, and need not be
8097 elsif R_Typ
= Standard_Character
8098 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
8100 for J
in 1 .. Strlen
loop
8101 if not In_Character_Range
(Get_String_Char
(Str
, J
)) then
8103 -- If we are out of range, post error. This is one of the
8104 -- very few places that we place the flag in the middle of
8105 -- a token, right under the offending wide character. Not
8106 -- quite clear if this is right wrt wide character encoding
8107 -- sequences, but it's only an error message!
8110 ("literal out of range of type Standard.Character",
8111 Source_Ptr
(Int
(Loc
) + J
));
8116 -- For the case of Standard.Wide_String, or any other type whose
8117 -- component type is Standard.Wide_Character, we must make sure that
8118 -- there are no wide characters in the string, i.e. that it is
8119 -- entirely composed of characters in range of type Wide_Character.
8121 -- If the string literal is the result of a static concatenation,
8122 -- the test has already been performed on the components, and need
8125 elsif R_Typ
= Standard_Wide_Character
8126 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
8128 for J
in 1 .. Strlen
loop
8129 if not In_Wide_Character_Range
(Get_String_Char
(Str
, J
)) then
8131 -- If we are out of range, post error. This is one of the
8132 -- very few places that we place the flag in the middle of
8133 -- a token, right under the offending wide character.
8135 -- This is not quite right, because characters in general
8136 -- will take more than one character position ???
8139 ("literal out of range of type Standard.Wide_Character",
8140 Source_Ptr
(Int
(Loc
) + J
));
8145 -- If the root type is not a standard character, then we will convert
8146 -- the string into an aggregate and will let the aggregate code do
8147 -- the checking. Standard Wide_Wide_Character is also OK here.
8153 -- See if the component type of the array corresponding to the string
8154 -- has compile time known bounds. If yes we can directly check
8155 -- whether the evaluation of the string will raise constraint error.
8156 -- Otherwise we need to transform the string literal into the
8157 -- corresponding character aggregate and let the aggregate
8158 -- code do the checking.
8160 if Is_Standard_Character_Type
(R_Typ
) then
8162 -- Check for the case of full range, where we are definitely OK
8164 if Component_Type
(Typ
) = Base_Type
(Component_Type
(Typ
)) then
8168 -- Here the range is not the complete base type range, so check
8171 Comp_Typ_Lo
: constant Node_Id
:=
8172 Type_Low_Bound
(Component_Type
(Typ
));
8173 Comp_Typ_Hi
: constant Node_Id
:=
8174 Type_High_Bound
(Component_Type
(Typ
));
8179 if Compile_Time_Known_Value
(Comp_Typ_Lo
)
8180 and then Compile_Time_Known_Value
(Comp_Typ_Hi
)
8182 for J
in 1 .. Strlen
loop
8183 Char_Val
:= UI_From_Int
(Int
(Get_String_Char
(Str
, J
)));
8185 if Char_Val
< Expr_Value
(Comp_Typ_Lo
)
8186 or else Char_Val
> Expr_Value
(Comp_Typ_Hi
)
8188 Apply_Compile_Time_Constraint_Error
8189 (N
, "character out of range?", CE_Range_Check_Failed
,
8190 Loc
=> Source_Ptr
(Int
(Loc
) + J
));
8200 -- If we got here we meed to transform the string literal into the
8201 -- equivalent qualified positional array aggregate. This is rather
8202 -- heavy artillery for this situation, but it is hard work to avoid.
8205 Lits
: constant List_Id
:= New_List
;
8206 P
: Source_Ptr
:= Loc
+ 1;
8210 -- Build the character literals, we give them source locations that
8211 -- correspond to the string positions, which is a bit tricky given
8212 -- the possible presence of wide character escape sequences.
8214 for J
in 1 .. Strlen
loop
8215 C
:= Get_String_Char
(Str
, J
);
8216 Set_Character_Literal_Name
(C
);
8219 Make_Character_Literal
(P
,
8221 Char_Literal_Value
=> UI_From_CC
(C
)));
8223 if In_Character_Range
(C
) then
8226 -- Should we have a call to Skip_Wide here ???
8234 Make_Qualified_Expression
(Loc
,
8235 Subtype_Mark
=> New_Reference_To
(Typ
, Loc
),
8237 Make_Aggregate
(Loc
, Expressions
=> Lits
)));
8239 Analyze_And_Resolve
(N
, Typ
);
8241 end Resolve_String_Literal
;
8243 -----------------------------
8244 -- Resolve_Subprogram_Info --
8245 -----------------------------
8247 procedure Resolve_Subprogram_Info
(N
: Node_Id
; Typ
: Entity_Id
) is
8250 end Resolve_Subprogram_Info
;
8252 -----------------------------
8253 -- Resolve_Type_Conversion --
8254 -----------------------------
8256 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
) is
8257 Conv_OK
: constant Boolean := Conversion_OK
(N
);
8258 Operand
: constant Node_Id
:= Expression
(N
);
8259 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
8260 Target_Typ
: constant Entity_Id
:= Etype
(N
);
8267 and then not Valid_Conversion
(N
, Target_Typ
, Operand
)
8272 if Etype
(Operand
) = Any_Fixed
then
8274 -- Mixed-mode operation involving a literal. Context must be a fixed
8275 -- type which is applied to the literal subsequently.
8277 if Is_Fixed_Point_Type
(Typ
) then
8278 Set_Etype
(Operand
, Universal_Real
);
8280 elsif Is_Numeric_Type
(Typ
)
8281 and then Nkind_In
(Operand
, N_Op_Multiply
, N_Op_Divide
)
8282 and then (Etype
(Right_Opnd
(Operand
)) = Universal_Real
8284 Etype
(Left_Opnd
(Operand
)) = Universal_Real
)
8286 -- Return if expression is ambiguous
8288 if Unique_Fixed_Point_Type
(N
) = Any_Type
then
8291 -- If nothing else, the available fixed type is Duration
8294 Set_Etype
(Operand
, Standard_Duration
);
8297 -- Resolve the real operand with largest available precision
8299 if Etype
(Right_Opnd
(Operand
)) = Universal_Real
then
8300 Rop
:= New_Copy_Tree
(Right_Opnd
(Operand
));
8302 Rop
:= New_Copy_Tree
(Left_Opnd
(Operand
));
8305 Resolve
(Rop
, Universal_Real
);
8307 -- If the operand is a literal (it could be a non-static and
8308 -- illegal exponentiation) check whether the use of Duration
8309 -- is potentially inaccurate.
8311 if Nkind
(Rop
) = N_Real_Literal
8312 and then Realval
(Rop
) /= Ureal_0
8313 and then abs (Realval
(Rop
)) < Delta_Value
(Standard_Duration
)
8316 ("?universal real operand can only " &
8317 "be interpreted as Duration!",
8320 ("\?precision will be lost in the conversion!", Rop
);
8323 elsif Is_Numeric_Type
(Typ
)
8324 and then Nkind
(Operand
) in N_Op
8325 and then Unique_Fixed_Point_Type
(N
) /= Any_Type
8327 Set_Etype
(Operand
, Standard_Duration
);
8330 Error_Msg_N
("invalid context for mixed mode operation", N
);
8331 Set_Etype
(Operand
, Any_Type
);
8338 -- Note: we do the Eval_Type_Conversion call before applying the
8339 -- required checks for a subtype conversion. This is important, since
8340 -- both are prepared under certain circumstances to change the type
8341 -- conversion to a constraint error node, but in the case of
8342 -- Eval_Type_Conversion this may reflect an illegality in the static
8343 -- case, and we would miss the illegality (getting only a warning
8344 -- message), if we applied the type conversion checks first.
8346 Eval_Type_Conversion
(N
);
8348 -- Even when evaluation is not possible, we may be able to simplify the
8349 -- conversion or its expression. This needs to be done before applying
8350 -- checks, since otherwise the checks may use the original expression
8351 -- and defeat the simplifications. This is specifically the case for
8352 -- elimination of the floating-point Truncation attribute in
8353 -- float-to-int conversions.
8355 Simplify_Type_Conversion
(N
);
8357 -- If after evaluation we still have a type conversion, then we may need
8358 -- to apply checks required for a subtype conversion.
8360 -- Skip these type conversion checks if universal fixed operands
8361 -- operands involved, since range checks are handled separately for
8362 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
8364 if Nkind
(N
) = N_Type_Conversion
8365 and then not Is_Generic_Type
(Root_Type
(Target_Typ
))
8366 and then Target_Typ
/= Universal_Fixed
8367 and then Operand_Typ
/= Universal_Fixed
8369 Apply_Type_Conversion_Checks
(N
);
8372 -- Issue warning for conversion of simple object to its own type. We
8373 -- have to test the original nodes, since they may have been rewritten
8374 -- by various optimizations.
8376 Orig_N
:= Original_Node
(N
);
8378 if Warn_On_Redundant_Constructs
8379 and then Comes_From_Source
(Orig_N
)
8380 and then Nkind
(Orig_N
) = N_Type_Conversion
8381 and then not In_Instance
8383 Orig_N
:= Original_Node
(Expression
(Orig_N
));
8384 Orig_T
:= Target_Typ
;
8386 -- If the node is part of a larger expression, the Target_Type
8387 -- may not be the original type of the node if the context is a
8388 -- condition. Recover original type to see if conversion is needed.
8390 if Is_Boolean_Type
(Orig_T
)
8391 and then Nkind
(Parent
(N
)) in N_Op
8393 Orig_T
:= Etype
(Parent
(N
));
8396 if Is_Entity_Name
(Orig_N
)
8398 (Etype
(Entity
(Orig_N
)) = Orig_T
8400 (Ekind
(Entity
(Orig_N
)) = E_Loop_Parameter
8401 and then Covers
(Orig_T
, Etype
(Entity
(Orig_N
)))))
8403 -- One more check, do not give warning if the analyzed conversion
8404 -- has an expression with non-static bounds, and the bounds of the
8405 -- target are static. This avoids junk warnings in cases where the
8406 -- conversion is necessary to establish staticness, for example in
8407 -- a case statement.
8409 if not Is_OK_Static_Subtype
(Operand_Typ
)
8410 and then Is_OK_Static_Subtype
(Target_Typ
)
8414 -- Here we give the redundant conversion warning
8417 Error_Msg_Node_2
:= Orig_T
;
8418 Error_Msg_NE
-- CODEFIX
8419 ("?redundant conversion, & is of type &!",
8420 N
, Entity
(Orig_N
));
8425 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
8426 -- No need to perform any interface conversion if the type of the
8427 -- expression coincides with the target type.
8429 if Ada_Version
>= Ada_05
8430 and then Expander_Active
8431 and then Operand_Typ
/= Target_Typ
8434 Opnd
: Entity_Id
:= Operand_Typ
;
8435 Target
: Entity_Id
:= Target_Typ
;
8438 if Is_Access_Type
(Opnd
) then
8439 Opnd
:= Directly_Designated_Type
(Opnd
);
8442 if Is_Access_Type
(Target_Typ
) then
8443 Target
:= Directly_Designated_Type
(Target
);
8446 if Opnd
= Target
then
8449 -- Conversion from interface type
8451 elsif Is_Interface
(Opnd
) then
8453 -- Ada 2005 (AI-217): Handle entities from limited views
8455 if From_With_Type
(Opnd
) then
8456 Error_Msg_Qual_Level
:= 99;
8457 Error_Msg_NE
("missing WITH clause on package &", N
,
8458 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Opnd
))));
8460 ("type conversions require visibility of the full view",
8463 elsif From_With_Type
(Target
)
8465 (Is_Access_Type
(Target_Typ
)
8466 and then Present
(Non_Limited_View
(Etype
(Target
))))
8468 Error_Msg_Qual_Level
:= 99;
8469 Error_Msg_NE
("missing WITH clause on package &", N
,
8470 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Target
))));
8472 ("type conversions require visibility of the full view",
8476 Expand_Interface_Conversion
(N
, Is_Static
=> False);
8479 -- Conversion to interface type
8481 elsif Is_Interface
(Target
) then
8485 if Ekind
(Opnd
) = E_Protected_Subtype
8486 or else Ekind
(Opnd
) = E_Task_Subtype
8488 Opnd
:= Etype
(Opnd
);
8491 if not Interface_Present_In_Ancestor
8495 if Is_Class_Wide_Type
(Opnd
) then
8497 -- The static analysis is not enough to know if the
8498 -- interface is implemented or not. Hence we must pass
8499 -- the work to the expander to generate code to evaluate
8500 -- the conversion at run-time.
8502 Expand_Interface_Conversion
(N
, Is_Static
=> False);
8505 Error_Msg_Name_1
:= Chars
(Etype
(Target
));
8506 Error_Msg_Name_2
:= Chars
(Opnd
);
8508 ("wrong interface conversion (% is not a progenitor " &
8513 Expand_Interface_Conversion
(N
);
8518 end Resolve_Type_Conversion
;
8520 ----------------------
8521 -- Resolve_Unary_Op --
8522 ----------------------
8524 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
8525 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
8526 R
: constant Node_Id
:= Right_Opnd
(N
);
8532 -- Deal with intrinsic unary operators
8534 if Comes_From_Source
(N
)
8535 and then Ekind
(Entity
(N
)) = E_Function
8536 and then Is_Imported
(Entity
(N
))
8537 and then Is_Intrinsic_Subprogram
(Entity
(N
))
8539 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
8543 -- Deal with universal cases
8545 if Etype
(R
) = Universal_Integer
8547 Etype
(R
) = Universal_Real
8549 Check_For_Visible_Operator
(N
, B_Typ
);
8552 Set_Etype
(N
, B_Typ
);
8555 -- Generate warning for expressions like abs (x mod 2)
8557 if Warn_On_Redundant_Constructs
8558 and then Nkind
(N
) = N_Op_Abs
8560 Determine_Range
(Right_Opnd
(N
), OK
, Lo
, Hi
);
8562 if OK
and then Hi
>= Lo
and then Lo
>= 0 then
8564 ("?abs applied to known non-negative value has no effect", N
);
8568 -- Deal with reference generation
8570 Check_Unset_Reference
(R
);
8571 Generate_Operator_Reference
(N
, B_Typ
);
8574 -- Set overflow checking bit. Much cleverer code needed here eventually
8575 -- and perhaps the Resolve routines should be separated for the various
8576 -- arithmetic operations, since they will need different processing ???
8578 if Nkind
(N
) in N_Op
then
8579 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
8580 Enable_Overflow_Check
(N
);
8584 -- Generate warning for expressions like -5 mod 3 for integers. No need
8585 -- to worry in the floating-point case, since parens do not affect the
8586 -- result so there is no point in giving in a warning.
8589 Norig
: constant Node_Id
:= Original_Node
(N
);
8598 if Warn_On_Questionable_Missing_Parens
8599 and then Comes_From_Source
(Norig
)
8600 and then Is_Integer_Type
(Typ
)
8601 and then Nkind
(Norig
) = N_Op_Minus
8603 Rorig
:= Original_Node
(Right_Opnd
(Norig
));
8605 -- We are looking for cases where the right operand is not
8606 -- parenthesized, and is a binary operator, multiply, divide, or
8607 -- mod. These are the cases where the grouping can affect results.
8609 if Paren_Count
(Rorig
) = 0
8610 and then Nkind_In
(Rorig
, N_Op_Mod
, N_Op_Multiply
, N_Op_Divide
)
8612 -- For mod, we always give the warning, since the value is
8613 -- affected by the parenthesization (e.g. (-5) mod 315 /=
8614 -- -(5 mod 315)). But for the other cases, the only concern is
8615 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
8616 -- overflows, but (-2) * 64 does not). So we try to give the
8617 -- message only when overflow is possible.
8619 if Nkind
(Rorig
) /= N_Op_Mod
8620 and then Compile_Time_Known_Value
(R
)
8622 Val
:= Expr_Value
(R
);
8624 if Compile_Time_Known_Value
(Type_High_Bound
(Typ
)) then
8625 HB
:= Expr_Value
(Type_High_Bound
(Typ
));
8627 HB
:= Expr_Value
(Type_High_Bound
(Base_Type
(Typ
)));
8630 if Compile_Time_Known_Value
(Type_Low_Bound
(Typ
)) then
8631 LB
:= Expr_Value
(Type_Low_Bound
(Typ
));
8633 LB
:= Expr_Value
(Type_Low_Bound
(Base_Type
(Typ
)));
8636 -- Note that the test below is deliberately excluding the
8637 -- largest negative number, since that is a potentially
8638 -- troublesome case (e.g. -2 * x, where the result is the
8639 -- largest negative integer has an overflow with 2 * x).
8641 if Val
> LB
and then Val
<= HB
then
8646 -- For the multiplication case, the only case we have to worry
8647 -- about is when (-a)*b is exactly the largest negative number
8648 -- so that -(a*b) can cause overflow. This can only happen if
8649 -- a is a power of 2, and more generally if any operand is a
8650 -- constant that is not a power of 2, then the parentheses
8651 -- cannot affect whether overflow occurs. We only bother to
8652 -- test the left most operand
8654 -- Loop looking at left operands for one that has known value
8657 Opnd_Loop
: while Nkind
(Opnd
) = N_Op_Multiply
loop
8658 if Compile_Time_Known_Value
(Left_Opnd
(Opnd
)) then
8659 Lval
:= UI_Abs
(Expr_Value
(Left_Opnd
(Opnd
)));
8661 -- Operand value of 0 or 1 skips warning
8666 -- Otherwise check power of 2, if power of 2, warn, if
8667 -- anything else, skip warning.
8670 while Lval
/= 2 loop
8671 if Lval
mod 2 = 1 then
8682 -- Keep looking at left operands
8684 Opnd
:= Left_Opnd
(Opnd
);
8687 -- For rem or "/" we can only have a problematic situation
8688 -- if the divisor has a value of minus one or one. Otherwise
8689 -- overflow is impossible (divisor > 1) or we have a case of
8690 -- division by zero in any case.
8692 if Nkind_In
(Rorig
, N_Op_Divide
, N_Op_Rem
)
8693 and then Compile_Time_Known_Value
(Right_Opnd
(Rorig
))
8694 and then UI_Abs
(Expr_Value
(Right_Opnd
(Rorig
))) /= 1
8699 -- If we fall through warning should be issued
8702 ("?unary minus expression should be parenthesized here!", N
);
8706 end Resolve_Unary_Op
;
8708 ----------------------------------
8709 -- Resolve_Unchecked_Expression --
8710 ----------------------------------
8712 procedure Resolve_Unchecked_Expression
8717 Resolve
(Expression
(N
), Typ
, Suppress
=> All_Checks
);
8719 end Resolve_Unchecked_Expression
;
8721 ---------------------------------------
8722 -- Resolve_Unchecked_Type_Conversion --
8723 ---------------------------------------
8725 procedure Resolve_Unchecked_Type_Conversion
8729 pragma Warnings
(Off
, Typ
);
8731 Operand
: constant Node_Id
:= Expression
(N
);
8732 Opnd_Type
: constant Entity_Id
:= Etype
(Operand
);
8735 -- Resolve operand using its own type
8737 Resolve
(Operand
, Opnd_Type
);
8738 Eval_Unchecked_Conversion
(N
);
8740 end Resolve_Unchecked_Type_Conversion
;
8742 ------------------------------
8743 -- Rewrite_Operator_As_Call --
8744 ------------------------------
8746 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
) is
8747 Loc
: constant Source_Ptr
:= Sloc
(N
);
8748 Actuals
: constant List_Id
:= New_List
;
8752 if Nkind
(N
) in N_Binary_Op
then
8753 Append
(Left_Opnd
(N
), Actuals
);
8756 Append
(Right_Opnd
(N
), Actuals
);
8759 Make_Function_Call
(Sloc
=> Loc
,
8760 Name
=> New_Occurrence_Of
(Nam
, Loc
),
8761 Parameter_Associations
=> Actuals
);
8763 Preserve_Comes_From_Source
(New_N
, N
);
8764 Preserve_Comes_From_Source
(Name
(New_N
), N
);
8766 Set_Etype
(N
, Etype
(Nam
));
8767 end Rewrite_Operator_As_Call
;
8769 ------------------------------
8770 -- Rewrite_Renamed_Operator --
8771 ------------------------------
8773 procedure Rewrite_Renamed_Operator
8778 Nam
: constant Name_Id
:= Chars
(Op
);
8779 Is_Binary
: constant Boolean := Nkind
(N
) in N_Binary_Op
;
8783 -- Rewrite the operator node using the real operator, not its renaming.
8784 -- Exclude user-defined intrinsic operations of the same name, which are
8785 -- treated separately and rewritten as calls.
8787 if Ekind
(Op
) /= E_Function
8788 or else Chars
(N
) /= Nam
8790 Op_Node
:= New_Node
(Operator_Kind
(Nam
, Is_Binary
), Sloc
(N
));
8791 Set_Chars
(Op_Node
, Nam
);
8792 Set_Etype
(Op_Node
, Etype
(N
));
8793 Set_Entity
(Op_Node
, Op
);
8794 Set_Right_Opnd
(Op_Node
, Right_Opnd
(N
));
8796 -- Indicate that both the original entity and its renaming are
8797 -- referenced at this point.
8799 Generate_Reference
(Entity
(N
), N
);
8800 Generate_Reference
(Op
, N
);
8803 Set_Left_Opnd
(Op_Node
, Left_Opnd
(N
));
8806 Rewrite
(N
, Op_Node
);
8808 -- If the context type is private, add the appropriate conversions
8809 -- so that the operator is applied to the full view. This is done
8810 -- in the routines that resolve intrinsic operators,
8812 if Is_Intrinsic_Subprogram
(Op
)
8813 and then Is_Private_Type
(Typ
)
8816 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
8817 N_Op_Expon | N_Op_Mod | N_Op_Rem
=>
8818 Resolve_Intrinsic_Operator
(N
, Typ
);
8820 when N_Op_Plus | N_Op_Minus | N_Op_Abs
=>
8821 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
8828 elsif Ekind
(Op
) = E_Function
8829 and then Is_Intrinsic_Subprogram
(Op
)
8831 -- Operator renames a user-defined operator of the same name. Use
8832 -- the original operator in the node, which is the one that Gigi
8836 Set_Is_Overloaded
(N
, False);
8838 end Rewrite_Renamed_Operator
;
8840 -----------------------
8841 -- Set_Slice_Subtype --
8842 -----------------------
8844 -- Build an implicit subtype declaration to represent the type delivered
8845 -- by the slice. This is an abbreviated version of an array subtype. We
8846 -- define an index subtype for the slice, using either the subtype name
8847 -- or the discrete range of the slice. To be consistent with index usage
8848 -- elsewhere, we create a list header to hold the single index. This list
8849 -- is not otherwise attached to the syntax tree.
8851 procedure Set_Slice_Subtype
(N
: Node_Id
) is
8852 Loc
: constant Source_Ptr
:= Sloc
(N
);
8853 Index_List
: constant List_Id
:= New_List
;
8855 Index_Subtype
: Entity_Id
;
8856 Index_Type
: Entity_Id
;
8857 Slice_Subtype
: Entity_Id
;
8858 Drange
: constant Node_Id
:= Discrete_Range
(N
);
8861 if Is_Entity_Name
(Drange
) then
8862 Index_Subtype
:= Entity
(Drange
);
8865 -- We force the evaluation of a range. This is definitely needed in
8866 -- the renamed case, and seems safer to do unconditionally. Note in
8867 -- any case that since we will create and insert an Itype referring
8868 -- to this range, we must make sure any side effect removal actions
8869 -- are inserted before the Itype definition.
8871 if Nkind
(Drange
) = N_Range
then
8872 Force_Evaluation
(Low_Bound
(Drange
));
8873 Force_Evaluation
(High_Bound
(Drange
));
8876 Index_Type
:= Base_Type
(Etype
(Drange
));
8878 Index_Subtype
:= Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
8880 Set_Scalar_Range
(Index_Subtype
, Drange
);
8881 Set_Etype
(Index_Subtype
, Index_Type
);
8882 Set_Size_Info
(Index_Subtype
, Index_Type
);
8883 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
8886 Slice_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
8888 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
8889 Set_Etype
(Index
, Index_Subtype
);
8890 Append
(Index
, Index_List
);
8892 Set_First_Index
(Slice_Subtype
, Index
);
8893 Set_Etype
(Slice_Subtype
, Base_Type
(Etype
(N
)));
8894 Set_Is_Constrained
(Slice_Subtype
, True);
8896 Check_Compile_Time_Size
(Slice_Subtype
);
8898 -- The Etype of the existing Slice node is reset to this slice subtype.
8899 -- Its bounds are obtained from its first index.
8901 Set_Etype
(N
, Slice_Subtype
);
8903 -- In the packed case, this must be immediately frozen
8905 -- Couldn't we always freeze here??? and if we did, then the above
8906 -- call to Check_Compile_Time_Size could be eliminated, which would
8907 -- be nice, because then that routine could be made private to Freeze.
8909 -- Why the test for In_Spec_Expression here ???
8911 if Is_Packed
(Slice_Subtype
) and not In_Spec_Expression
then
8912 Freeze_Itype
(Slice_Subtype
, N
);
8915 end Set_Slice_Subtype
;
8917 --------------------------------
8918 -- Set_String_Literal_Subtype --
8919 --------------------------------
8921 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
) is
8922 Loc
: constant Source_Ptr
:= Sloc
(N
);
8923 Low_Bound
: constant Node_Id
:=
8924 Type_Low_Bound
(Etype
(First_Index
(Typ
)));
8925 Subtype_Id
: Entity_Id
;
8928 if Nkind
(N
) /= N_String_Literal
then
8932 Subtype_Id
:= Create_Itype
(E_String_Literal_Subtype
, N
);
8933 Set_String_Literal_Length
(Subtype_Id
, UI_From_Int
8934 (String_Length
(Strval
(N
))));
8935 Set_Etype
(Subtype_Id
, Base_Type
(Typ
));
8936 Set_Is_Constrained
(Subtype_Id
);
8937 Set_Etype
(N
, Subtype_Id
);
8939 if Is_OK_Static_Expression
(Low_Bound
) then
8941 -- The low bound is set from the low bound of the corresponding
8942 -- index type. Note that we do not store the high bound in the
8943 -- string literal subtype, but it can be deduced if necessary
8944 -- from the length and the low bound.
8946 Set_String_Literal_Low_Bound
(Subtype_Id
, Low_Bound
);
8949 Set_String_Literal_Low_Bound
8950 (Subtype_Id
, Make_Integer_Literal
(Loc
, 1));
8951 Set_Etype
(String_Literal_Low_Bound
(Subtype_Id
), Standard_Positive
);
8953 -- Build bona fide subtype for the string, and wrap it in an
8954 -- unchecked conversion, because the backend expects the
8955 -- String_Literal_Subtype to have a static lower bound.
8958 Index_List
: constant List_Id
:= New_List
;
8959 Index_Type
: constant Entity_Id
:= Etype
(First_Index
(Typ
));
8960 High_Bound
: constant Node_Id
:=
8962 Left_Opnd
=> New_Copy_Tree
(Low_Bound
),
8964 Make_Integer_Literal
(Loc
,
8965 String_Length
(Strval
(N
)) - 1));
8966 Array_Subtype
: Entity_Id
;
8967 Index_Subtype
: Entity_Id
;
8973 Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
8974 Drange
:= Make_Range
(Loc
, New_Copy_Tree
(Low_Bound
), High_Bound
);
8975 Set_Scalar_Range
(Index_Subtype
, Drange
);
8976 Set_Parent
(Drange
, N
);
8977 Analyze_And_Resolve
(Drange
, Index_Type
);
8979 -- In the context, the Index_Type may already have a constraint,
8980 -- so use common base type on string subtype. The base type may
8981 -- be used when generating attributes of the string, for example
8982 -- in the context of a slice assignment.
8984 Set_Etype
(Index_Subtype
, Base_Type
(Index_Type
));
8985 Set_Size_Info
(Index_Subtype
, Index_Type
);
8986 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
8988 Array_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
8990 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
8991 Set_Etype
(Index
, Index_Subtype
);
8992 Append
(Index
, Index_List
);
8994 Set_First_Index
(Array_Subtype
, Index
);
8995 Set_Etype
(Array_Subtype
, Base_Type
(Typ
));
8996 Set_Is_Constrained
(Array_Subtype
, True);
8999 Make_Unchecked_Type_Conversion
(Loc
,
9000 Subtype_Mark
=> New_Occurrence_Of
(Array_Subtype
, Loc
),
9001 Expression
=> Relocate_Node
(N
)));
9002 Set_Etype
(N
, Array_Subtype
);
9005 end Set_String_Literal_Subtype
;
9007 ------------------------------
9008 -- Simplify_Type_Conversion --
9009 ------------------------------
9011 procedure Simplify_Type_Conversion
(N
: Node_Id
) is
9013 if Nkind
(N
) = N_Type_Conversion
then
9015 Operand
: constant Node_Id
:= Expression
(N
);
9016 Target_Typ
: constant Entity_Id
:= Etype
(N
);
9017 Opnd_Typ
: constant Entity_Id
:= Etype
(Operand
);
9020 if Is_Floating_Point_Type
(Opnd_Typ
)
9022 (Is_Integer_Type
(Target_Typ
)
9023 or else (Is_Fixed_Point_Type
(Target_Typ
)
9024 and then Conversion_OK
(N
)))
9025 and then Nkind
(Operand
) = N_Attribute_Reference
9026 and then Attribute_Name
(Operand
) = Name_Truncation
9028 -- Special processing required if the conversion is the expression
9029 -- of a Truncation attribute reference. In this case we replace:
9031 -- ityp (ftyp'Truncation (x))
9037 -- with the Float_Truncate flag set, which is more efficient
9041 Relocate_Node
(First
(Expressions
(Operand
))));
9042 Set_Float_Truncate
(N
, True);
9046 end Simplify_Type_Conversion
;
9048 -----------------------------
9049 -- Unique_Fixed_Point_Type --
9050 -----------------------------
9052 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
is
9053 T1
: Entity_Id
:= Empty
;
9058 procedure Fixed_Point_Error
;
9059 -- Give error messages for true ambiguity. Messages are posted on node
9060 -- N, and entities T1, T2 are the possible interpretations.
9062 -----------------------
9063 -- Fixed_Point_Error --
9064 -----------------------
9066 procedure Fixed_Point_Error
is
9068 Error_Msg_N
("ambiguous universal_fixed_expression", N
);
9069 Error_Msg_NE
("\\possible interpretation as}", N
, T1
);
9070 Error_Msg_NE
("\\possible interpretation as}", N
, T2
);
9071 end Fixed_Point_Error
;
9073 -- Start of processing for Unique_Fixed_Point_Type
9076 -- The operations on Duration are visible, so Duration is always a
9077 -- possible interpretation.
9079 T1
:= Standard_Duration
;
9081 -- Look for fixed-point types in enclosing scopes
9083 Scop
:= Current_Scope
;
9084 while Scop
/= Standard_Standard
loop
9085 T2
:= First_Entity
(Scop
);
9086 while Present
(T2
) loop
9087 if Is_Fixed_Point_Type
(T2
)
9088 and then Current_Entity
(T2
) = T2
9089 and then Scope
(Base_Type
(T2
)) = Scop
9091 if Present
(T1
) then
9102 Scop
:= Scope
(Scop
);
9105 -- Look for visible fixed type declarations in the context
9107 Item
:= First
(Context_Items
(Cunit
(Current_Sem_Unit
)));
9108 while Present
(Item
) loop
9109 if Nkind
(Item
) = N_With_Clause
then
9110 Scop
:= Entity
(Name
(Item
));
9111 T2
:= First_Entity
(Scop
);
9112 while Present
(T2
) loop
9113 if Is_Fixed_Point_Type
(T2
)
9114 and then Scope
(Base_Type
(T2
)) = Scop
9115 and then (Is_Potentially_Use_Visible
(T2
)
9116 or else In_Use
(T2
))
9118 if Present
(T1
) then
9133 if Nkind
(N
) = N_Real_Literal
then
9134 Error_Msg_NE
("?real literal interpreted as }!", N
, T1
);
9136 Error_Msg_NE
("?universal_fixed expression interpreted as }!", N
, T1
);
9140 end Unique_Fixed_Point_Type
;
9142 ----------------------
9143 -- Valid_Conversion --
9144 ----------------------
9146 function Valid_Conversion
9149 Operand
: Node_Id
) return Boolean
9151 Target_Type
: constant Entity_Id
:= Base_Type
(Target
);
9152 Opnd_Type
: Entity_Id
:= Etype
(Operand
);
9154 function Conversion_Check
9156 Msg
: String) return Boolean;
9157 -- Little routine to post Msg if Valid is False, returns Valid value
9159 function Valid_Tagged_Conversion
9160 (Target_Type
: Entity_Id
;
9161 Opnd_Type
: Entity_Id
) return Boolean;
9162 -- Specifically test for validity of tagged conversions
9164 function Valid_Array_Conversion
return Boolean;
9165 -- Check index and component conformance, and accessibility levels
9166 -- if the component types are anonymous access types (Ada 2005)
9168 ----------------------
9169 -- Conversion_Check --
9170 ----------------------
9172 function Conversion_Check
9174 Msg
: String) return Boolean
9178 Error_Msg_N
(Msg
, Operand
);
9182 end Conversion_Check
;
9184 ----------------------------
9185 -- Valid_Array_Conversion --
9186 ----------------------------
9188 function Valid_Array_Conversion
return Boolean
9190 Opnd_Comp_Type
: constant Entity_Id
:= Component_Type
(Opnd_Type
);
9191 Opnd_Comp_Base
: constant Entity_Id
:= Base_Type
(Opnd_Comp_Type
);
9193 Opnd_Index
: Node_Id
;
9194 Opnd_Index_Type
: Entity_Id
;
9196 Target_Comp_Type
: constant Entity_Id
:=
9197 Component_Type
(Target_Type
);
9198 Target_Comp_Base
: constant Entity_Id
:=
9199 Base_Type
(Target_Comp_Type
);
9201 Target_Index
: Node_Id
;
9202 Target_Index_Type
: Entity_Id
;
9205 -- Error if wrong number of dimensions
9208 Number_Dimensions
(Target_Type
) /= Number_Dimensions
(Opnd_Type
)
9211 ("incompatible number of dimensions for conversion", Operand
);
9214 -- Number of dimensions matches
9217 -- Loop through indexes of the two arrays
9219 Target_Index
:= First_Index
(Target_Type
);
9220 Opnd_Index
:= First_Index
(Opnd_Type
);
9221 while Present
(Target_Index
) and then Present
(Opnd_Index
) loop
9222 Target_Index_Type
:= Etype
(Target_Index
);
9223 Opnd_Index_Type
:= Etype
(Opnd_Index
);
9225 -- Error if index types are incompatible
9227 if not (Is_Integer_Type
(Target_Index_Type
)
9228 and then Is_Integer_Type
(Opnd_Index_Type
))
9229 and then (Root_Type
(Target_Index_Type
)
9230 /= Root_Type
(Opnd_Index_Type
))
9233 ("incompatible index types for array conversion",
9238 Next_Index
(Target_Index
);
9239 Next_Index
(Opnd_Index
);
9242 -- If component types have same base type, all set
9244 if Target_Comp_Base
= Opnd_Comp_Base
then
9247 -- Here if base types of components are not the same. The only
9248 -- time this is allowed is if we have anonymous access types.
9250 -- The conversion of arrays of anonymous access types can lead
9251 -- to dangling pointers. AI-392 formalizes the accessibility
9252 -- checks that must be applied to such conversions to prevent
9253 -- out-of-scope references.
9256 (Ekind
(Target_Comp_Base
) = E_Anonymous_Access_Type
9258 Ekind
(Target_Comp_Base
) = E_Anonymous_Access_Subprogram_Type
)
9259 and then Ekind
(Opnd_Comp_Base
) = Ekind
(Target_Comp_Base
)
9261 Subtypes_Statically_Match
(Target_Comp_Type
, Opnd_Comp_Type
)
9263 if Type_Access_Level
(Target_Type
) <
9264 Type_Access_Level
(Opnd_Type
)
9266 if In_Instance_Body
then
9267 Error_Msg_N
("?source array type " &
9268 "has deeper accessibility level than target", Operand
);
9269 Error_Msg_N
("\?Program_Error will be raised at run time",
9272 Make_Raise_Program_Error
(Sloc
(N
),
9273 Reason
=> PE_Accessibility_Check_Failed
));
9274 Set_Etype
(N
, Target_Type
);
9277 -- Conversion not allowed because of accessibility levels
9280 Error_Msg_N
("source array type " &
9281 "has deeper accessibility level than target", Operand
);
9288 -- All other cases where component base types do not match
9292 ("incompatible component types for array conversion",
9297 -- Check that component subtypes statically match. For numeric
9298 -- types this means that both must be either constrained or
9299 -- unconstrained. For enumeration types the bounds must match.
9300 -- All of this is checked in Subtypes_Statically_Match.
9302 if not Subtypes_Statically_Match
9303 (Target_Comp_Type
, Opnd_Comp_Type
)
9306 ("component subtypes must statically match", Operand
);
9312 end Valid_Array_Conversion
;
9314 -----------------------------
9315 -- Valid_Tagged_Conversion --
9316 -----------------------------
9318 function Valid_Tagged_Conversion
9319 (Target_Type
: Entity_Id
;
9320 Opnd_Type
: Entity_Id
) return Boolean
9323 -- Upward conversions are allowed (RM 4.6(22))
9325 if Covers
(Target_Type
, Opnd_Type
)
9326 or else Is_Ancestor
(Target_Type
, Opnd_Type
)
9330 -- Downward conversion are allowed if the operand is class-wide
9333 elsif Is_Class_Wide_Type
(Opnd_Type
)
9334 and then Covers
(Opnd_Type
, Target_Type
)
9338 elsif Covers
(Opnd_Type
, Target_Type
)
9339 or else Is_Ancestor
(Opnd_Type
, Target_Type
)
9342 Conversion_Check
(False,
9343 "downward conversion of tagged objects not allowed");
9345 -- Ada 2005 (AI-251): The conversion to/from interface types is
9348 elsif Is_Interface
(Target_Type
) or else Is_Interface
(Opnd_Type
) then
9351 -- If the operand is a class-wide type obtained through a limited_
9352 -- with clause, and the context includes the non-limited view, use
9353 -- it to determine whether the conversion is legal.
9355 elsif Is_Class_Wide_Type
(Opnd_Type
)
9356 and then From_With_Type
(Opnd_Type
)
9357 and then Present
(Non_Limited_View
(Etype
(Opnd_Type
)))
9358 and then Is_Interface
(Non_Limited_View
(Etype
(Opnd_Type
)))
9362 elsif Is_Access_Type
(Opnd_Type
)
9363 and then Is_Interface
(Directly_Designated_Type
(Opnd_Type
))
9369 ("invalid tagged conversion, not compatible with}",
9370 N
, First_Subtype
(Opnd_Type
));
9373 end Valid_Tagged_Conversion
;
9375 -- Start of processing for Valid_Conversion
9378 Check_Parameterless_Call
(Operand
);
9380 if Is_Overloaded
(Operand
) then
9389 -- Remove procedure calls, which syntactically cannot appear in
9390 -- this context, but which cannot be removed by type checking,
9391 -- because the context does not impose a type.
9393 -- When compiling for VMS, spurious ambiguities can be produced
9394 -- when arithmetic operations have a literal operand and return
9395 -- System.Address or a descendant of it. These ambiguities are
9396 -- otherwise resolved by the context, but for conversions there
9397 -- is no context type and the removal of the spurious operations
9398 -- must be done explicitly here.
9400 -- The node may be labelled overloaded, but still contain only
9401 -- one interpretation because others were discarded in previous
9402 -- filters. If this is the case, retain the single interpretation
9405 Get_First_Interp
(Operand
, I
, It
);
9406 Opnd_Type
:= It
.Typ
;
9407 Get_Next_Interp
(I
, It
);
9410 and then Opnd_Type
/= Standard_Void_Type
9412 -- More than one candidate interpretation is available
9414 Get_First_Interp
(Operand
, I
, It
);
9415 while Present
(It
.Typ
) loop
9416 if It
.Typ
= Standard_Void_Type
then
9420 if Present
(System_Aux_Id
)
9421 and then Is_Descendent_Of_Address
(It
.Typ
)
9426 Get_Next_Interp
(I
, It
);
9430 Get_First_Interp
(Operand
, I
, It
);
9435 Error_Msg_N
("illegal operand in conversion", Operand
);
9439 Get_Next_Interp
(I
, It
);
9441 if Present
(It
.Typ
) then
9443 It1
:= Disambiguate
(Operand
, I1
, I
, Any_Type
);
9445 if It1
= No_Interp
then
9446 Error_Msg_N
("ambiguous operand in conversion", Operand
);
9448 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
9449 Error_Msg_N
-- CODEFIX
9450 ("\\possible interpretation#!", Operand
);
9452 Error_Msg_Sloc
:= Sloc
(N1
);
9453 Error_Msg_N
-- CODEFIX
9454 ("\\possible interpretation#!", Operand
);
9460 Set_Etype
(Operand
, It1
.Typ
);
9461 Opnd_Type
:= It1
.Typ
;
9467 if Is_Numeric_Type
(Target_Type
) then
9469 -- A universal fixed expression can be converted to any numeric type
9471 if Opnd_Type
= Universal_Fixed
then
9474 -- Also no need to check when in an instance or inlined body, because
9475 -- the legality has been established when the template was analyzed.
9476 -- Furthermore, numeric conversions may occur where only a private
9477 -- view of the operand type is visible at the instantiation point.
9478 -- This results in a spurious error if we check that the operand type
9479 -- is a numeric type.
9481 -- Note: in a previous version of this unit, the following tests were
9482 -- applied only for generated code (Comes_From_Source set to False),
9483 -- but in fact the test is required for source code as well, since
9484 -- this situation can arise in source code.
9486 elsif In_Instance
or else In_Inlined_Body
then
9489 -- Otherwise we need the conversion check
9492 return Conversion_Check
9493 (Is_Numeric_Type
(Opnd_Type
),
9494 "illegal operand for numeric conversion");
9499 elsif Is_Array_Type
(Target_Type
) then
9500 if not Is_Array_Type
(Opnd_Type
)
9501 or else Opnd_Type
= Any_Composite
9502 or else Opnd_Type
= Any_String
9505 ("illegal operand for array conversion", Operand
);
9508 return Valid_Array_Conversion
;
9511 -- Ada 2005 (AI-251): Anonymous access types where target references an
9514 elsif (Ekind
(Target_Type
) = E_General_Access_Type
9516 Ekind
(Target_Type
) = E_Anonymous_Access_Type
)
9517 and then Is_Interface
(Directly_Designated_Type
(Target_Type
))
9519 -- Check the static accessibility rule of 4.6(17). Note that the
9520 -- check is not enforced when within an instance body, since the
9521 -- RM requires such cases to be caught at run time.
9523 if Ekind
(Target_Type
) /= E_Anonymous_Access_Type
then
9524 if Type_Access_Level
(Opnd_Type
) >
9525 Type_Access_Level
(Target_Type
)
9527 -- In an instance, this is a run-time check, but one we know
9528 -- will fail, so generate an appropriate warning. The raise
9529 -- will be generated by Expand_N_Type_Conversion.
9531 if In_Instance_Body
then
9533 ("?cannot convert local pointer to non-local access type",
9536 ("\?Program_Error will be raised at run time", Operand
);
9539 ("cannot convert local pointer to non-local access type",
9544 -- Special accessibility checks are needed in the case of access
9545 -- discriminants declared for a limited type.
9547 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
9548 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
9550 -- When the operand is a selected access discriminant the check
9551 -- needs to be made against the level of the object denoted by
9552 -- the prefix of the selected name (Object_Access_Level handles
9553 -- checking the prefix of the operand for this case).
9555 if Nkind
(Operand
) = N_Selected_Component
9556 and then Object_Access_Level
(Operand
) >
9557 Type_Access_Level
(Target_Type
)
9559 -- In an instance, this is a run-time check, but one we know
9560 -- will fail, so generate an appropriate warning. The raise
9561 -- will be generated by Expand_N_Type_Conversion.
9563 if In_Instance_Body
then
9565 ("?cannot convert access discriminant to non-local" &
9566 " access type", Operand
);
9568 ("\?Program_Error will be raised at run time", Operand
);
9571 ("cannot convert access discriminant to non-local" &
9572 " access type", Operand
);
9577 -- The case of a reference to an access discriminant from
9578 -- within a limited type declaration (which will appear as
9579 -- a discriminal) is always illegal because the level of the
9580 -- discriminant is considered to be deeper than any (nameable)
9583 if Is_Entity_Name
(Operand
)
9584 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
9585 and then (Ekind
(Entity
(Operand
)) = E_In_Parameter
9586 or else Ekind
(Entity
(Operand
)) = E_Constant
)
9587 and then Present
(Discriminal_Link
(Entity
(Operand
)))
9590 ("discriminant has deeper accessibility level than target",
9599 -- General and anonymous access types
9601 elsif (Ekind
(Target_Type
) = E_General_Access_Type
9602 or else Ekind
(Target_Type
) = E_Anonymous_Access_Type
)
9605 (Is_Access_Type
(Opnd_Type
)
9606 and then Ekind
(Opnd_Type
) /=
9607 E_Access_Subprogram_Type
9608 and then Ekind
(Opnd_Type
) /=
9609 E_Access_Protected_Subprogram_Type
,
9610 "must be an access-to-object type")
9612 if Is_Access_Constant
(Opnd_Type
)
9613 and then not Is_Access_Constant
(Target_Type
)
9616 ("access-to-constant operand type not allowed", Operand
);
9620 -- Check the static accessibility rule of 4.6(17). Note that the
9621 -- check is not enforced when within an instance body, since the RM
9622 -- requires such cases to be caught at run time.
9624 if Ekind
(Target_Type
) /= E_Anonymous_Access_Type
9625 or else Is_Local_Anonymous_Access
(Target_Type
)
9627 if Type_Access_Level
(Opnd_Type
)
9628 > Type_Access_Level
(Target_Type
)
9630 -- In an instance, this is a run-time check, but one we know
9631 -- will fail, so generate an appropriate warning. The raise
9632 -- will be generated by Expand_N_Type_Conversion.
9634 if In_Instance_Body
then
9636 ("?cannot convert local pointer to non-local access type",
9639 ("\?Program_Error will be raised at run time", Operand
);
9642 -- Avoid generation of spurious error message
9644 if not Error_Posted
(N
) then
9646 ("cannot convert local pointer to non-local access type",
9653 -- Special accessibility checks are needed in the case of access
9654 -- discriminants declared for a limited type.
9656 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
9657 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
9660 -- When the operand is a selected access discriminant the check
9661 -- needs to be made against the level of the object denoted by
9662 -- the prefix of the selected name (Object_Access_Level handles
9663 -- checking the prefix of the operand for this case).
9665 if Nkind
(Operand
) = N_Selected_Component
9666 and then Object_Access_Level
(Operand
) >
9667 Type_Access_Level
(Target_Type
)
9669 -- In an instance, this is a run-time check, but one we know
9670 -- will fail, so generate an appropriate warning. The raise
9671 -- will be generated by Expand_N_Type_Conversion.
9673 if In_Instance_Body
then
9675 ("?cannot convert access discriminant to non-local" &
9676 " access type", Operand
);
9678 ("\?Program_Error will be raised at run time",
9683 ("cannot convert access discriminant to non-local" &
9684 " access type", Operand
);
9689 -- The case of a reference to an access discriminant from
9690 -- within a limited type declaration (which will appear as
9691 -- a discriminal) is always illegal because the level of the
9692 -- discriminant is considered to be deeper than any (nameable)
9695 if Is_Entity_Name
(Operand
)
9696 and then (Ekind
(Entity
(Operand
)) = E_In_Parameter
9697 or else Ekind
(Entity
(Operand
)) = E_Constant
)
9698 and then Present
(Discriminal_Link
(Entity
(Operand
)))
9701 ("discriminant has deeper accessibility level than target",
9708 -- In the presence of limited_with clauses we have to use non-limited
9709 -- views, if available.
9711 Check_Limited
: declare
9712 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
;
9713 -- Helper function to handle limited views
9715 --------------------------
9716 -- Full_Designated_Type --
9717 --------------------------
9719 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
is
9720 Desig
: constant Entity_Id
:= Designated_Type
(T
);
9723 -- Handle the limited view of a type
9725 if Is_Incomplete_Type
(Desig
)
9726 and then From_With_Type
(Desig
)
9727 and then Present
(Non_Limited_View
(Desig
))
9729 return Available_View
(Desig
);
9733 end Full_Designated_Type
;
9735 -- Local Declarations
9737 Target
: constant Entity_Id
:= Full_Designated_Type
(Target_Type
);
9738 Opnd
: constant Entity_Id
:= Full_Designated_Type
(Opnd_Type
);
9740 Same_Base
: constant Boolean :=
9741 Base_Type
(Target
) = Base_Type
(Opnd
);
9743 -- Start of processing for Check_Limited
9746 if Is_Tagged_Type
(Target
) then
9747 return Valid_Tagged_Conversion
(Target
, Opnd
);
9750 if not Same_Base
then
9752 ("target designated type not compatible with }",
9753 N
, Base_Type
(Opnd
));
9756 -- Ada 2005 AI-384: legality rule is symmetric in both
9757 -- designated types. The conversion is legal (with possible
9758 -- constraint check) if either designated type is
9761 elsif Subtypes_Statically_Match
(Target
, Opnd
)
9763 (Has_Discriminants
(Target
)
9765 (not Is_Constrained
(Opnd
)
9766 or else not Is_Constrained
(Target
)))
9768 -- Special case, if Value_Size has been used to make the
9769 -- sizes different, the conversion is not allowed even
9770 -- though the subtypes statically match.
9772 if Known_Static_RM_Size
(Target
)
9773 and then Known_Static_RM_Size
(Opnd
)
9774 and then RM_Size
(Target
) /= RM_Size
(Opnd
)
9777 ("target designated subtype not compatible with }",
9780 ("\because sizes of the two designated subtypes differ",
9784 -- Normal case where conversion is allowed
9792 ("target designated subtype not compatible with }",
9799 -- Access to subprogram types. If the operand is an access parameter,
9800 -- the type has a deeper accessibility that any master, and cannot
9801 -- be assigned. We must make an exception if the conversion is part
9802 -- of an assignment and the target is the return object of an extended
9803 -- return statement, because in that case the accessibility check
9804 -- takes place after the return.
9806 elsif Is_Access_Subprogram_Type
(Target_Type
)
9807 and then No
(Corresponding_Remote_Type
(Opnd_Type
))
9809 if Ekind
(Base_Type
(Opnd_Type
)) = E_Anonymous_Access_Subprogram_Type
9810 and then Is_Entity_Name
(Operand
)
9811 and then Ekind
(Entity
(Operand
)) = E_In_Parameter
9813 (Nkind
(Parent
(N
)) /= N_Assignment_Statement
9814 or else not Is_Entity_Name
(Name
(Parent
(N
)))
9815 or else not Is_Return_Object
(Entity
(Name
(Parent
(N
)))))
9818 ("illegal attempt to store anonymous access to subprogram",
9821 ("\value has deeper accessibility than any master " &
9826 ("\use named access type for& instead of access parameter",
9827 Operand
, Entity
(Operand
));
9830 -- Check that the designated types are subtype conformant
9832 Check_Subtype_Conformant
(New_Id
=> Designated_Type
(Target_Type
),
9833 Old_Id
=> Designated_Type
(Opnd_Type
),
9836 -- Check the static accessibility rule of 4.6(20)
9838 if Type_Access_Level
(Opnd_Type
) >
9839 Type_Access_Level
(Target_Type
)
9842 ("operand type has deeper accessibility level than target",
9845 -- Check that if the operand type is declared in a generic body,
9846 -- then the target type must be declared within that same body
9847 -- (enforces last sentence of 4.6(20)).
9849 elsif Present
(Enclosing_Generic_Body
(Opnd_Type
)) then
9851 O_Gen
: constant Node_Id
:=
9852 Enclosing_Generic_Body
(Opnd_Type
);
9857 T_Gen
:= Enclosing_Generic_Body
(Target_Type
);
9858 while Present
(T_Gen
) and then T_Gen
/= O_Gen
loop
9859 T_Gen
:= Enclosing_Generic_Body
(T_Gen
);
9862 if T_Gen
/= O_Gen
then
9864 ("target type must be declared in same generic body"
9865 & " as operand type", N
);
9872 -- Remote subprogram access types
9874 elsif Is_Remote_Access_To_Subprogram_Type
(Target_Type
)
9875 and then Is_Remote_Access_To_Subprogram_Type
(Opnd_Type
)
9877 -- It is valid to convert from one RAS type to another provided
9878 -- that their specification statically match.
9880 Check_Subtype_Conformant
9882 Designated_Type
(Corresponding_Remote_Type
(Target_Type
)),
9884 Designated_Type
(Corresponding_Remote_Type
(Opnd_Type
)),
9889 -- If both are tagged types, check legality of view conversions
9891 elsif Is_Tagged_Type
(Target_Type
)
9892 and then Is_Tagged_Type
(Opnd_Type
)
9894 return Valid_Tagged_Conversion
(Target_Type
, Opnd_Type
);
9896 -- Types derived from the same root type are convertible
9898 elsif Root_Type
(Target_Type
) = Root_Type
(Opnd_Type
) then
9901 -- In an instance or an inlined body, there may be inconsistent
9902 -- views of the same type, or of types derived from a common root.
9904 elsif (In_Instance
or In_Inlined_Body
)
9906 Root_Type
(Underlying_Type
(Target_Type
)) =
9907 Root_Type
(Underlying_Type
(Opnd_Type
))
9911 -- Special check for common access type error case
9913 elsif Ekind
(Target_Type
) = E_Access_Type
9914 and then Is_Access_Type
(Opnd_Type
)
9916 Error_Msg_N
("target type must be general access type!", N
);
9917 Error_Msg_NE
("add ALL to }!", N
, Target_Type
);
9921 Error_Msg_NE
("invalid conversion, not compatible with }",
9925 end Valid_Conversion
;