1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2018, 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 Errout
; use Errout
;
32 with Expander
; use Expander
;
33 with Exp_Disp
; use Exp_Disp
;
34 with Exp_Ch6
; use Exp_Ch6
;
35 with Exp_Ch7
; use Exp_Ch7
;
36 with Exp_Tss
; use Exp_Tss
;
37 with Exp_Util
; use Exp_Util
;
38 with Freeze
; use Freeze
;
39 with Ghost
; use Ghost
;
40 with Inline
; use Inline
;
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 Par_SCO
; use Par_SCO
;
50 with Restrict
; use Restrict
;
51 with Rident
; use Rident
;
52 with Rtsfind
; use Rtsfind
;
54 with Sem_Aux
; use Sem_Aux
;
55 with Sem_Aggr
; use Sem_Aggr
;
56 with Sem_Attr
; use Sem_Attr
;
57 with Sem_Cat
; use Sem_Cat
;
58 with Sem_Ch4
; use Sem_Ch4
;
59 with Sem_Ch3
; use Sem_Ch3
;
60 with Sem_Ch6
; use Sem_Ch6
;
61 with Sem_Ch8
; use Sem_Ch8
;
62 with Sem_Ch13
; use Sem_Ch13
;
63 with Sem_Dim
; use Sem_Dim
;
64 with Sem_Disp
; use Sem_Disp
;
65 with Sem_Dist
; use Sem_Dist
;
66 with Sem_Elab
; use Sem_Elab
;
67 with Sem_Elim
; use Sem_Elim
;
68 with Sem_Eval
; use Sem_Eval
;
69 with Sem_Intr
; use Sem_Intr
;
70 with Sem_Util
; use Sem_Util
;
71 with Targparm
; use Targparm
;
72 with Sem_Type
; use Sem_Type
;
73 with Sem_Warn
; use Sem_Warn
;
74 with Sinfo
; use Sinfo
;
75 with Sinfo
.CN
; use Sinfo
.CN
;
76 with Snames
; use Snames
;
77 with Stand
; use Stand
;
78 with Stringt
; use Stringt
;
79 with Style
; use Style
;
80 with Tbuild
; use Tbuild
;
81 with Uintp
; use Uintp
;
82 with Urealp
; use Urealp
;
84 package body Sem_Res
is
86 -----------------------
87 -- Local Subprograms --
88 -----------------------
90 -- Second pass (top-down) type checking and overload resolution procedures
91 -- Typ is the type required by context. These procedures propagate the
92 -- type information recursively to the descendants of N. If the node is not
93 -- overloaded, its Etype is established in the first pass. If overloaded,
94 -- the Resolve routines set the correct type. For arithmetic operators, the
95 -- Etype is the base type of the context.
97 -- Note that Resolve_Attribute is separated off in Sem_Attr
99 procedure Check_Discriminant_Use
(N
: Node_Id
);
100 -- Enforce the restrictions on the use of discriminants when constraining
101 -- a component of a discriminated type (record or concurrent type).
103 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
);
104 -- Given a node for an operator associated with type T, check that the
105 -- operator is visible. Operators all of whose operands are universal must
106 -- be checked for visibility during resolution because their type is not
107 -- determinable based on their operands.
109 procedure Check_Fully_Declared_Prefix
112 -- Check that the type of the prefix of a dereference is not incomplete
114 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean;
115 -- Given a call node, N, which is known to occur immediately within the
116 -- subprogram being called, determines whether it is a detectable case of
117 -- an infinite recursion, and if so, outputs appropriate messages. Returns
118 -- True if an infinite recursion is detected, and False otherwise.
120 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
);
121 -- N is the node for a logical operator. If the operator is predefined, and
122 -- the root type of the operands is Standard.Boolean, then a check is made
123 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
124 -- the style check for Style_Check_Boolean_And_Or.
126 function Is_Atomic_Ref_With_Address
(N
: Node_Id
) return Boolean;
127 -- N is either an indexed component or a selected component. This function
128 -- returns true if the prefix refers to an object that has an address
129 -- clause (the case in which we may want to issue a warning).
131 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean;
132 -- Determine whether E is an access type declared by an access declaration,
133 -- and not an (anonymous) allocator type.
135 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean;
136 -- Utility to check whether the entity for an operator is a predefined
137 -- operator, in which case the expression is left as an operator in the
138 -- tree (else it is rewritten into a call). An instance of an intrinsic
139 -- conversion operation may be given an operator name, but is not treated
140 -- like an operator. Note that an operator that is an imported back-end
141 -- builtin has convention Intrinsic, but is expected to be rewritten into
142 -- a call, so such an operator is not treated as predefined by this
145 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
);
146 -- If a default expression in entry call N depends on the discriminants
147 -- of the task, it must be replaced with a reference to the discriminant
148 -- of the task being called.
150 procedure Resolve_Op_Concat_Arg
155 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
156 -- concatenation operator. The operand is either of the array type or of
157 -- the component type. If the operand is an aggregate, and the component
158 -- type is composite, this is ambiguous if component type has aggregates.
160 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
);
161 -- Does the first part of the work of Resolve_Op_Concat
163 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
);
164 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
165 -- has been resolved. See Resolve_Op_Concat for details.
167 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
);
168 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
);
169 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
);
170 procedure Resolve_Case_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
171 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
172 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
);
173 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
);
174 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
);
175 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
);
176 procedure Resolve_Expression_With_Actions
(N
: Node_Id
; Typ
: Entity_Id
);
177 procedure Resolve_If_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
178 procedure Resolve_Generalized_Indexing
(N
: Node_Id
; Typ
: Entity_Id
);
179 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
);
180 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
181 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
);
182 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
);
183 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
);
184 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
);
185 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
);
186 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
);
187 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
);
188 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
189 procedure Resolve_Raise_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
190 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
);
191 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
192 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
);
193 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
);
194 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
);
195 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
);
196 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
);
197 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
198 procedure Resolve_Target_Name
(N
: Node_Id
; Typ
: Entity_Id
);
199 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
200 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
);
201 procedure Resolve_Unchecked_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
202 procedure Resolve_Unchecked_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
204 function Operator_Kind
206 Is_Binary
: Boolean) return Node_Kind
;
207 -- Utility to map the name of an operator into the corresponding Node. Used
208 -- by other node rewriting procedures.
210 procedure Resolve_Actuals
(N
: Node_Id
; Nam
: Entity_Id
);
211 -- Resolve actuals of call, and add default expressions for missing ones.
212 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
213 -- called subprogram.
215 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
);
216 -- Called from Resolve_Call, when the prefix denotes an entry or element
217 -- of entry family. Actuals are resolved as for subprograms, and the node
218 -- is rebuilt as an entry call. Also called for protected operations. Typ
219 -- is the context type, which is used when the operation is a protected
220 -- function with no arguments, and the return value is indexed.
222 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
223 -- A call to a user-defined intrinsic operator is rewritten as a call to
224 -- the corresponding predefined operator, with suitable conversions. Note
225 -- that this applies only for intrinsic operators that denote predefined
226 -- operators, not ones that are intrinsic imports of back-end builtins.
228 procedure Resolve_Intrinsic_Unary_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
229 -- Ditto, for arithmetic unary operators
231 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
);
232 -- If an operator node resolves to a call to a user-defined operator,
233 -- rewrite the node as a function call.
235 procedure Make_Call_Into_Operator
239 -- Inverse transformation: if an operator is given in functional notation,
240 -- then after resolving the node, transform into an operator node, so that
241 -- operands are resolved properly. Recall that predefined operators do not
242 -- have a full signature and special resolution rules apply.
244 procedure Rewrite_Renamed_Operator
248 -- An operator can rename another, e.g. in an instantiation. In that
249 -- case, the proper operator node must be constructed and resolved.
251 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
);
252 -- The String_Literal_Subtype is built for all strings that are not
253 -- operands of a static concatenation operation. If the argument is not
254 -- a N_String_Literal node, then the call has no effect.
256 procedure Set_Slice_Subtype
(N
: Node_Id
);
257 -- Build subtype of array type, with the range specified by the slice
259 procedure Simplify_Type_Conversion
(N
: Node_Id
);
260 -- Called after N has been resolved and evaluated, but before range checks
261 -- have been applied. Currently simplifies a combination of floating-point
262 -- to integer conversion and Rounding or Truncation attribute.
264 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
;
265 -- A universal_fixed expression in an universal context is unambiguous if
266 -- there is only one applicable fixed point type. Determining whether there
267 -- is only one requires a search over all visible entities, and happens
268 -- only in very pathological cases (see 6115-006).
270 -------------------------
271 -- Ambiguous_Character --
272 -------------------------
274 procedure Ambiguous_Character
(C
: Node_Id
) is
278 if Nkind
(C
) = N_Character_Literal
then
279 Error_Msg_N
("ambiguous character literal", C
);
281 -- First the ones in Standard
283 Error_Msg_N
("\\possible interpretation: Character!", C
);
284 Error_Msg_N
("\\possible interpretation: Wide_Character!", C
);
286 -- Include Wide_Wide_Character in Ada 2005 mode
288 if Ada_Version
>= Ada_2005
then
289 Error_Msg_N
("\\possible interpretation: Wide_Wide_Character!", C
);
292 -- Now any other types that match
294 E
:= Current_Entity
(C
);
295 while Present
(E
) loop
296 Error_Msg_NE
("\\possible interpretation:}!", C
, Etype
(E
));
300 end Ambiguous_Character
;
302 -------------------------
303 -- Analyze_And_Resolve --
304 -------------------------
306 procedure Analyze_And_Resolve
(N
: Node_Id
) is
310 end Analyze_And_Resolve
;
312 procedure Analyze_And_Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
316 end Analyze_And_Resolve
;
318 -- Versions with check(s) suppressed
320 procedure Analyze_And_Resolve
325 Scop
: constant Entity_Id
:= Current_Scope
;
328 if Suppress
= All_Checks
then
330 Sva
: constant Suppress_Array
:= Scope_Suppress
.Suppress
;
332 Scope_Suppress
.Suppress
:= (others => True);
333 Analyze_And_Resolve
(N
, Typ
);
334 Scope_Suppress
.Suppress
:= Sva
;
339 Svg
: constant Boolean := Scope_Suppress
.Suppress
(Suppress
);
341 Scope_Suppress
.Suppress
(Suppress
) := True;
342 Analyze_And_Resolve
(N
, Typ
);
343 Scope_Suppress
.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 for an inner
351 -- expression, which will be removed upon completion of the analysis
352 -- of an enclosing construct. The transient scope must have the
353 -- suppress status of the enclosing environment, not of this Analyze
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 Sva
: constant Suppress_Array
:= Scope_Suppress
.Suppress
;
372 Scope_Suppress
.Suppress
:= (others => True);
373 Analyze_And_Resolve
(N
);
374 Scope_Suppress
.Suppress
:= Sva
;
379 Svg
: constant Boolean := Scope_Suppress
.Suppress
(Suppress
);
381 Scope_Suppress
.Suppress
(Suppress
) := True;
382 Analyze_And_Resolve
(N
);
383 Scope_Suppress
.Suppress
(Suppress
) := Svg
;
387 if Current_Scope
/= Scop
and then Scope_Is_Transient
then
388 Scope_Stack
.Table
(Scope_Stack
.Last
).Save_Scope_Suppress
:=
391 end Analyze_And_Resolve
;
393 ----------------------------
394 -- Check_Discriminant_Use --
395 ----------------------------
397 procedure Check_Discriminant_Use
(N
: Node_Id
) is
398 PN
: constant Node_Id
:= Parent
(N
);
399 Disc
: constant Entity_Id
:= Entity
(N
);
404 -- Any use in a spec-expression is legal
406 if In_Spec_Expression
then
409 elsif Nkind
(PN
) = N_Range
then
411 -- Discriminant cannot be used to constrain a scalar type
415 if Nkind
(P
) = N_Range_Constraint
416 and then Nkind
(Parent
(P
)) = N_Subtype_Indication
417 and then Nkind
(Parent
(Parent
(P
))) = N_Component_Definition
419 Error_Msg_N
("discriminant cannot constrain scalar type", N
);
421 elsif Nkind
(P
) = N_Index_Or_Discriminant_Constraint
then
423 -- The following check catches the unusual case where a
424 -- discriminant appears within an index constraint that is part
425 -- of a larger expression within a constraint on a component,
426 -- e.g. "C : Int range 1 .. F (new A(1 .. D))". For now we only
427 -- check case of record components, and note that a similar check
428 -- should also apply in the case of discriminant constraints
431 -- Note that the check for N_Subtype_Declaration below is to
432 -- detect the valid use of discriminants in the constraints of a
433 -- subtype declaration when this subtype declaration appears
434 -- inside the scope of a record type (which is syntactically
435 -- illegal, but which may be created as part of derived type
436 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
439 if Ekind
(Current_Scope
) = E_Record_Type
440 and then Scope
(Disc
) = Current_Scope
442 (Nkind
(Parent
(P
)) = N_Subtype_Indication
444 Nkind_In
(Parent
(Parent
(P
)), N_Component_Definition
,
445 N_Subtype_Declaration
)
446 and then Paren_Count
(N
) = 0)
449 ("discriminant must appear alone in component constraint", N
);
453 -- Detect a common error:
455 -- type R (D : Positive := 100) is record
456 -- Name : String (1 .. D);
459 -- The default value causes an object of type R to be allocated
460 -- with room for Positive'Last characters. The RM does not mandate
461 -- the allocation of the maximum size, but that is what GNAT does
462 -- so we should warn the programmer that there is a problem.
464 Check_Large
: declare
470 function Large_Storage_Type
(T
: Entity_Id
) return Boolean;
471 -- Return True if type T has a large enough range that any
472 -- array whose index type covered the whole range of the type
473 -- would likely raise Storage_Error.
475 ------------------------
476 -- Large_Storage_Type --
477 ------------------------
479 function Large_Storage_Type
(T
: Entity_Id
) return Boolean is
481 -- The type is considered large if its bounds are known at
482 -- compile time and if it requires at least as many bits as
483 -- a Positive to store the possible values.
485 return Compile_Time_Known_Value
(Type_Low_Bound
(T
))
486 and then Compile_Time_Known_Value
(Type_High_Bound
(T
))
488 Minimum_Size
(T
, Biased
=> True) >=
489 RM_Size
(Standard_Positive
);
490 end Large_Storage_Type
;
492 -- Start of processing for Check_Large
495 -- Check that the Disc has a large range
497 if not Large_Storage_Type
(Etype
(Disc
)) then
501 -- If the enclosing type is limited, we allocate only the
502 -- default value, not the maximum, and there is no need for
505 if Is_Limited_Type
(Scope
(Disc
)) then
509 -- Check that it is the high bound
511 if N
/= High_Bound
(PN
)
512 or else No
(Discriminant_Default_Value
(Disc
))
517 -- Check the array allows a large range at this bound. First
522 if Nkind
(SI
) /= N_Subtype_Indication
then
526 T
:= Entity
(Subtype_Mark
(SI
));
528 if not Is_Array_Type
(T
) then
532 -- Next, find the dimension
534 TB
:= First_Index
(T
);
535 CB
:= First
(Constraints
(P
));
537 and then Present
(TB
)
538 and then Present
(CB
)
549 -- Now, check the dimension has a large range
551 if not Large_Storage_Type
(Etype
(TB
)) then
555 -- Warn about the danger
558 ("??creation of & object may raise Storage_Error!",
567 -- Legal case is in index or discriminant constraint
569 elsif Nkind_In
(PN
, N_Index_Or_Discriminant_Constraint
,
570 N_Discriminant_Association
)
572 if Paren_Count
(N
) > 0 then
574 ("discriminant in constraint must appear alone", N
);
576 elsif Nkind
(N
) = N_Expanded_Name
577 and then Comes_From_Source
(N
)
580 ("discriminant must appear alone as a direct name", N
);
585 -- Otherwise, context is an expression. It should not be within (i.e. a
586 -- subexpression of) a constraint for a component.
591 while not Nkind_In
(P
, N_Component_Declaration
,
592 N_Subtype_Indication
,
600 -- If the discriminant is used in an expression that is a bound of a
601 -- scalar type, an Itype is created and the bounds are attached to
602 -- its range, not to the original subtype indication. Such use is of
603 -- course a double fault.
605 if (Nkind
(P
) = N_Subtype_Indication
606 and then Nkind_In
(Parent
(P
), N_Component_Definition
,
607 N_Derived_Type_Definition
)
608 and then D
= Constraint
(P
))
610 -- The constraint itself may be given by a subtype indication,
611 -- rather than by a more common discrete range.
613 or else (Nkind
(P
) = N_Subtype_Indication
615 Nkind
(Parent
(P
)) = N_Index_Or_Discriminant_Constraint
)
616 or else Nkind
(P
) = N_Entry_Declaration
617 or else Nkind
(D
) = N_Defining_Identifier
620 ("discriminant in constraint must appear alone", N
);
623 end Check_Discriminant_Use
;
625 --------------------------------
626 -- Check_For_Visible_Operator --
627 --------------------------------
629 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
) is
631 if Is_Invisible_Operator
(N
, T
) then
632 Error_Msg_NE
-- CODEFIX
633 ("operator for} is not directly visible!", N
, First_Subtype
(T
));
634 Error_Msg_N
-- CODEFIX
635 ("use clause would make operation legal!", N
);
637 end Check_For_Visible_Operator
;
639 ----------------------------------
640 -- Check_Fully_Declared_Prefix --
641 ----------------------------------
643 procedure Check_Fully_Declared_Prefix
648 -- Check that the designated type of the prefix of a dereference is
649 -- not an incomplete type. This cannot be done unconditionally, because
650 -- dereferences of private types are legal in default expressions. This
651 -- case is taken care of in Check_Fully_Declared, called below. There
652 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
654 -- This consideration also applies to similar checks for allocators,
655 -- qualified expressions, and type conversions.
657 -- An additional exception concerns other per-object expressions that
658 -- are not directly related to component declarations, in particular
659 -- representation pragmas for tasks. These will be per-object
660 -- expressions if they depend on discriminants or some global entity.
661 -- If the task has access discriminants, the designated type may be
662 -- incomplete at the point the expression is resolved. This resolution
663 -- takes place within the body of the initialization procedure, where
664 -- the discriminant is replaced by its discriminal.
666 if Is_Entity_Name
(Pref
)
667 and then Ekind
(Entity
(Pref
)) = E_In_Parameter
671 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
672 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
673 -- Analyze_Object_Renaming, and Freeze_Entity.
675 elsif Ada_Version
>= Ada_2005
676 and then Is_Entity_Name
(Pref
)
677 and then Is_Access_Type
(Etype
(Pref
))
678 and then Ekind
(Directly_Designated_Type
(Etype
(Pref
))) =
680 and then Is_Tagged_Type
(Directly_Designated_Type
(Etype
(Pref
)))
684 Check_Fully_Declared
(Typ
, Parent
(Pref
));
686 end Check_Fully_Declared_Prefix
;
688 ------------------------------
689 -- Check_Infinite_Recursion --
690 ------------------------------
692 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean is
696 function Same_Argument_List
return Boolean;
697 -- Check whether list of actuals is identical to list of formals of
698 -- called function (which is also the enclosing scope).
700 ------------------------
701 -- Same_Argument_List --
702 ------------------------
704 function Same_Argument_List
return Boolean is
710 if not Is_Entity_Name
(Name
(N
)) then
713 Subp
:= Entity
(Name
(N
));
716 F
:= First_Formal
(Subp
);
717 A
:= First_Actual
(N
);
718 while Present
(F
) and then Present
(A
) loop
719 if not Is_Entity_Name
(A
) or else Entity
(A
) /= F
then
728 end Same_Argument_List
;
730 -- Start of processing for Check_Infinite_Recursion
733 -- Special case, if this is a procedure call and is a call to the
734 -- current procedure with the same argument list, then this is for
735 -- sure an infinite recursion and we insert a call to raise SE.
737 if Is_List_Member
(N
)
738 and then List_Length
(List_Containing
(N
)) = 1
739 and then Same_Argument_List
742 P
: constant Node_Id
:= Parent
(N
);
744 if Nkind
(P
) = N_Handled_Sequence_Of_Statements
745 and then Nkind
(Parent
(P
)) = N_Subprogram_Body
746 and then Is_Empty_List
(Declarations
(Parent
(P
)))
748 Error_Msg_Warn
:= SPARK_Mode
/= On
;
749 Error_Msg_N
("!infinite recursion<<", N
);
750 Error_Msg_N
("\!Storage_Error [<<", N
);
752 Make_Raise_Storage_Error
(Sloc
(N
),
753 Reason
=> SE_Infinite_Recursion
));
759 -- If not that special case, search up tree, quitting if we reach a
760 -- construct (e.g. a conditional) that tells us that this is not a
761 -- case for an infinite recursion warning.
767 -- If no parent, then we were not inside a subprogram, this can for
768 -- example happen when processing certain pragmas in a spec. Just
769 -- return False in this case.
775 -- Done if we get to subprogram body, this is definitely an infinite
776 -- recursion case if we did not find anything to stop us.
778 exit when Nkind
(P
) = N_Subprogram_Body
;
780 -- If appearing in conditional, result is false
782 if Nkind_In
(P
, N_Or_Else
,
791 elsif Nkind
(P
) = N_Handled_Sequence_Of_Statements
792 and then C
/= First
(Statements
(P
))
794 -- If the call is the expression of a return statement and the
795 -- actuals are identical to the formals, it's worth a warning.
796 -- However, we skip this if there is an immediately preceding
797 -- raise statement, since the call is never executed.
799 -- Furthermore, this corresponds to a common idiom:
801 -- function F (L : Thing) return Boolean is
803 -- raise Program_Error;
807 -- for generating a stub function
809 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
810 and then Same_Argument_List
812 exit when not Is_List_Member
(Parent
(N
));
814 -- OK, return statement is in a statement list, look for raise
820 -- Skip past N_Freeze_Entity nodes generated by expansion
822 Nod
:= Prev
(Parent
(N
));
824 and then Nkind
(Nod
) = N_Freeze_Entity
829 -- If no raise statement, give warning. We look at the
830 -- original node, because in the case of "raise ... with
831 -- ...", the node has been transformed into a call.
833 exit when Nkind
(Original_Node
(Nod
)) /= N_Raise_Statement
835 (Nkind
(Nod
) not in N_Raise_xxx_Error
836 or else Present
(Condition
(Nod
)));
847 Error_Msg_Warn
:= SPARK_Mode
/= On
;
848 Error_Msg_N
("!possible infinite recursion<<", N
);
849 Error_Msg_N
("\!??Storage_Error ]<<", N
);
852 end Check_Infinite_Recursion
;
854 ---------------------------------------
855 -- Check_No_Direct_Boolean_Operators --
856 ---------------------------------------
858 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
) is
860 if Scope
(Entity
(N
)) = Standard_Standard
861 and then Root_Type
(Etype
(Left_Opnd
(N
))) = Standard_Boolean
863 -- Restriction only applies to original source code
865 if Comes_From_Source
(N
) then
866 Check_Restriction
(No_Direct_Boolean_Operators
, N
);
870 -- Do style check (but skip if in instance, error is on template)
873 if not In_Instance
then
874 Check_Boolean_Operator
(N
);
877 end Check_No_Direct_Boolean_Operators
;
879 ------------------------------
880 -- Check_Parameterless_Call --
881 ------------------------------
883 procedure Check_Parameterless_Call
(N
: Node_Id
) is
886 function Prefix_Is_Access_Subp
return Boolean;
887 -- If the prefix is of an access_to_subprogram type, the node must be
888 -- rewritten as a call. Ditto if the prefix is overloaded and all its
889 -- interpretations are access to subprograms.
891 ---------------------------
892 -- Prefix_Is_Access_Subp --
893 ---------------------------
895 function Prefix_Is_Access_Subp
return Boolean is
900 -- If the context is an attribute reference that can apply to
901 -- functions, this is never a parameterless call (RM 4.1.4(6)).
903 if Nkind
(Parent
(N
)) = N_Attribute_Reference
904 and then Nam_In
(Attribute_Name
(Parent
(N
)), Name_Address
,
911 if not Is_Overloaded
(N
) then
913 Ekind
(Etype
(N
)) = E_Subprogram_Type
914 and then Base_Type
(Etype
(Etype
(N
))) /= Standard_Void_Type
;
916 Get_First_Interp
(N
, I
, It
);
917 while Present
(It
.Typ
) loop
918 if Ekind
(It
.Typ
) /= E_Subprogram_Type
919 or else Base_Type
(Etype
(It
.Typ
)) = Standard_Void_Type
924 Get_Next_Interp
(I
, It
);
929 end Prefix_Is_Access_Subp
;
931 -- Start of processing for Check_Parameterless_Call
934 -- Defend against junk stuff if errors already detected
936 if Total_Errors_Detected
/= 0 then
937 if Nkind
(N
) in N_Has_Etype
and then Etype
(N
) = Any_Type
then
939 elsif Nkind
(N
) in N_Has_Chars
940 and then not Is_Valid_Name
(Chars
(N
))
948 -- If the context expects a value, and the name is a procedure, this is
949 -- most likely a missing 'Access. Don't try to resolve the parameterless
950 -- call, error will be caught when the outer call is analyzed.
952 if Is_Entity_Name
(N
)
953 and then Ekind
(Entity
(N
)) = E_Procedure
954 and then not Is_Overloaded
(N
)
956 Nkind_In
(Parent
(N
), N_Parameter_Association
,
958 N_Procedure_Call_Statement
)
963 -- Rewrite as call if overloadable entity that is (or could be, in the
964 -- overloaded case) a function call. If we know for sure that the entity
965 -- is an enumeration literal, we do not rewrite it.
967 -- If the entity is the name of an operator, it cannot be a call because
968 -- operators cannot have default parameters. In this case, this must be
969 -- a string whose contents coincide with an operator name. Set the kind
970 -- of the node appropriately.
972 if (Is_Entity_Name
(N
)
973 and then Nkind
(N
) /= N_Operator_Symbol
974 and then Is_Overloadable
(Entity
(N
))
975 and then (Ekind
(Entity
(N
)) /= E_Enumeration_Literal
976 or else Is_Overloaded
(N
)))
978 -- Rewrite as call if it is an explicit dereference of an expression of
979 -- a subprogram access type, and the subprogram type is not that of a
980 -- procedure or entry.
983 (Nkind
(N
) = N_Explicit_Dereference
and then Prefix_Is_Access_Subp
)
985 -- Rewrite as call if it is a selected component which is a function,
986 -- this is the case of a call to a protected function (which may be
987 -- overloaded with other protected operations).
990 (Nkind
(N
) = N_Selected_Component
991 and then (Ekind
(Entity
(Selector_Name
(N
))) = E_Function
993 (Ekind_In
(Entity
(Selector_Name
(N
)), E_Entry
,
995 and then Is_Overloaded
(Selector_Name
(N
)))))
997 -- If one of the above three conditions is met, rewrite as call. Apply
998 -- the rewriting only once.
1001 if Nkind
(Parent
(N
)) /= N_Function_Call
1002 or else N
/= Name
(Parent
(N
))
1005 -- This may be a prefixed call that was not fully analyzed, e.g.
1006 -- an actual in an instance.
1008 if Ada_Version
>= Ada_2005
1009 and then Nkind
(N
) = N_Selected_Component
1010 and then Is_Dispatching_Operation
(Entity
(Selector_Name
(N
)))
1012 Analyze_Selected_Component
(N
);
1014 if Nkind
(N
) /= N_Selected_Component
then
1019 -- The node is the name of the parameterless call. Preserve its
1020 -- descendants, which may be complex expressions.
1022 Nam
:= Relocate_Node
(N
);
1024 -- If overloaded, overload set belongs to new copy
1026 Save_Interps
(N
, Nam
);
1028 -- Change node to parameterless function call (note that the
1029 -- Parameter_Associations associations field is left set to Empty,
1030 -- its normal default value since there are no parameters)
1032 Change_Node
(N
, N_Function_Call
);
1034 Set_Sloc
(N
, Sloc
(Nam
));
1038 elsif Nkind
(N
) = N_Parameter_Association
then
1039 Check_Parameterless_Call
(Explicit_Actual_Parameter
(N
));
1041 elsif Nkind
(N
) = N_Operator_Symbol
then
1042 Change_Operator_Symbol_To_String_Literal
(N
);
1043 Set_Is_Overloaded
(N
, False);
1044 Set_Etype
(N
, Any_String
);
1046 end Check_Parameterless_Call
;
1048 --------------------------------
1049 -- Is_Atomic_Ref_With_Address --
1050 --------------------------------
1052 function Is_Atomic_Ref_With_Address
(N
: Node_Id
) return Boolean is
1053 Pref
: constant Node_Id
:= Prefix
(N
);
1056 if not Is_Entity_Name
(Pref
) then
1061 Pent
: constant Entity_Id
:= Entity
(Pref
);
1062 Ptyp
: constant Entity_Id
:= Etype
(Pent
);
1064 return not Is_Access_Type
(Ptyp
)
1065 and then (Is_Atomic
(Ptyp
) or else Is_Atomic
(Pent
))
1066 and then Present
(Address_Clause
(Pent
));
1069 end Is_Atomic_Ref_With_Address
;
1071 -----------------------------
1072 -- Is_Definite_Access_Type --
1073 -----------------------------
1075 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean is
1076 Btyp
: constant Entity_Id
:= Base_Type
(E
);
1078 return Ekind
(Btyp
) = E_Access_Type
1079 or else (Ekind
(Btyp
) = E_Access_Subprogram_Type
1080 and then Comes_From_Source
(Btyp
));
1081 end Is_Definite_Access_Type
;
1083 ----------------------
1084 -- Is_Predefined_Op --
1085 ----------------------
1087 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean is
1089 -- Predefined operators are intrinsic subprograms
1091 if not Is_Intrinsic_Subprogram
(Nam
) then
1095 -- A call to a back-end builtin is never a predefined operator
1097 if Is_Imported
(Nam
) and then Present
(Interface_Name
(Nam
)) then
1101 return not Is_Generic_Instance
(Nam
)
1102 and then Chars
(Nam
) in Any_Operator_Name
1103 and then (No
(Alias
(Nam
)) or else Is_Predefined_Op
(Alias
(Nam
)));
1104 end Is_Predefined_Op
;
1106 -----------------------------
1107 -- Make_Call_Into_Operator --
1108 -----------------------------
1110 procedure Make_Call_Into_Operator
1115 Op_Name
: constant Name_Id
:= Chars
(Op_Id
);
1116 Act1
: Node_Id
:= First_Actual
(N
);
1117 Act2
: Node_Id
:= Next_Actual
(Act1
);
1118 Error
: Boolean := False;
1119 Func
: constant Entity_Id
:= Entity
(Name
(N
));
1120 Is_Binary
: constant Boolean := Present
(Act2
);
1122 Opnd_Type
: Entity_Id
:= Empty
;
1123 Orig_Type
: Entity_Id
:= Empty
;
1126 type Kind_Test
is access function (E
: Entity_Id
) return Boolean;
1128 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean;
1129 -- If the operand is not universal, and the operator is given by an
1130 -- expanded name, verify that the operand has an interpretation with a
1131 -- type defined in the given scope of the operator.
1133 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
;
1134 -- Find a type of the given class in package Pack that contains the
1137 ---------------------------
1138 -- Operand_Type_In_Scope --
1139 ---------------------------
1141 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean is
1142 Nod
: constant Node_Id
:= Right_Opnd
(Op_Node
);
1147 if not Is_Overloaded
(Nod
) then
1148 return Scope
(Base_Type
(Etype
(Nod
))) = S
;
1151 Get_First_Interp
(Nod
, I
, It
);
1152 while Present
(It
.Typ
) loop
1153 if Scope
(Base_Type
(It
.Typ
)) = S
then
1157 Get_Next_Interp
(I
, It
);
1162 end Operand_Type_In_Scope
;
1168 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
is
1171 function In_Decl
return Boolean;
1172 -- Verify that node is not part of the type declaration for the
1173 -- candidate type, which would otherwise be invisible.
1179 function In_Decl
return Boolean is
1180 Decl_Node
: constant Node_Id
:= Parent
(E
);
1186 if Etype
(E
) = Any_Type
then
1189 elsif No
(Decl_Node
) then
1194 and then Nkind
(N2
) /= N_Compilation_Unit
1196 if N2
= Decl_Node
then
1207 -- Start of processing for Type_In_P
1210 -- If the context type is declared in the prefix package, this is the
1211 -- desired base type.
1213 if Scope
(Base_Type
(Typ
)) = Pack
and then Test
(Typ
) then
1214 return Base_Type
(Typ
);
1217 E
:= First_Entity
(Pack
);
1218 while Present
(E
) loop
1219 if Test
(E
) and then not In_Decl
then
1230 -- Start of processing for Make_Call_Into_Operator
1233 Op_Node
:= New_Node
(Operator_Kind
(Op_Name
, Is_Binary
), Sloc
(N
));
1235 -- Ensure that the corresponding operator has the same parent as the
1236 -- original call. This guarantees that parent traversals performed by
1237 -- the ABE mechanism succeed.
1239 Set_Parent
(Op_Node
, Parent
(N
));
1244 Set_Left_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1245 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act2
));
1246 Save_Interps
(Act1
, Left_Opnd
(Op_Node
));
1247 Save_Interps
(Act2
, Right_Opnd
(Op_Node
));
1248 Act1
:= Left_Opnd
(Op_Node
);
1249 Act2
:= Right_Opnd
(Op_Node
);
1254 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1255 Save_Interps
(Act1
, Right_Opnd
(Op_Node
));
1256 Act1
:= Right_Opnd
(Op_Node
);
1259 -- If the operator is denoted by an expanded name, and the prefix is
1260 -- not Standard, but the operator is a predefined one whose scope is
1261 -- Standard, then this is an implicit_operator, inserted as an
1262 -- interpretation by the procedure of the same name. This procedure
1263 -- overestimates the presence of implicit operators, because it does
1264 -- not examine the type of the operands. Verify now that the operand
1265 -- type appears in the given scope. If right operand is universal,
1266 -- check the other operand. In the case of concatenation, either
1267 -- argument can be the component type, so check the type of the result.
1268 -- If both arguments are literals, look for a type of the right kind
1269 -- defined in the given scope. This elaborate nonsense is brought to
1270 -- you courtesy of b33302a. The type itself must be frozen, so we must
1271 -- find the type of the proper class in the given scope.
1273 -- A final wrinkle is the multiplication operator for fixed point types,
1274 -- which is defined in Standard only, and not in the scope of the
1275 -- fixed point type itself.
1277 if Nkind
(Name
(N
)) = N_Expanded_Name
then
1278 Pack
:= Entity
(Prefix
(Name
(N
)));
1280 -- If this is a package renaming, get renamed entity, which will be
1281 -- the scope of the operands if operaton is type-correct.
1283 if Present
(Renamed_Entity
(Pack
)) then
1284 Pack
:= Renamed_Entity
(Pack
);
1287 -- If the entity being called is defined in the given package, it is
1288 -- a renaming of a predefined operator, and known to be legal.
1290 if Scope
(Entity
(Name
(N
))) = Pack
1291 and then Pack
/= Standard_Standard
1295 -- Visibility does not need to be checked in an instance: if the
1296 -- operator was not visible in the generic it has been diagnosed
1297 -- already, else there is an implicit copy of it in the instance.
1299 elsif In_Instance
then
1302 elsif Nam_In
(Op_Name
, Name_Op_Multiply
, Name_Op_Divide
)
1303 and then Is_Fixed_Point_Type
(Etype
(Left_Opnd
(Op_Node
)))
1304 and then Is_Fixed_Point_Type
(Etype
(Right_Opnd
(Op_Node
)))
1306 if Pack
/= Standard_Standard
then
1310 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1313 elsif Ada_Version
>= Ada_2005
1314 and then Nam_In
(Op_Name
, Name_Op_Eq
, Name_Op_Ne
)
1315 and then Ekind
(Etype
(Act1
)) = E_Anonymous_Access_Type
1320 Opnd_Type
:= Base_Type
(Etype
(Right_Opnd
(Op_Node
)));
1322 if Op_Name
= Name_Op_Concat
then
1323 Opnd_Type
:= Base_Type
(Typ
);
1325 elsif (Scope
(Opnd_Type
) = Standard_Standard
1327 or else (Nkind
(Right_Opnd
(Op_Node
)) = N_Attribute_Reference
1329 and then not Comes_From_Source
(Opnd_Type
))
1331 Opnd_Type
:= Base_Type
(Etype
(Left_Opnd
(Op_Node
)));
1334 if Scope
(Opnd_Type
) = Standard_Standard
then
1336 -- Verify that the scope contains a type that corresponds to
1337 -- the given literal. Optimize the case where Pack is Standard.
1339 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
);
1411 -- Detect a mismatch between the context type and the result type
1412 -- in the named package, which is otherwise not detected if the
1413 -- operands are universal. Check is only needed if source entity is
1414 -- an operator, not a function that renames an operator.
1416 elsif Nkind
(Parent
(N
)) /= N_Type_Conversion
1417 and then Ekind
(Entity
(Name
(N
))) = E_Operator
1418 and then Is_Numeric_Type
(Typ
)
1419 and then not Is_Universal_Numeric_Type
(Typ
)
1420 and then Scope
(Base_Type
(Typ
)) /= Pack
1421 and then not In_Instance
1423 if Is_Fixed_Point_Type
(Typ
)
1424 and then Nam_In
(Op_Name
, Name_Op_Multiply
, Name_Op_Divide
)
1426 -- Already checked above
1430 -- Operator may be defined in an extension of System
1432 elsif Present
(System_Aux_Id
)
1433 and then Present
(Opnd_Type
)
1434 and then Scope
(Opnd_Type
) = System_Aux_Id
1439 -- Could we use Wrong_Type here??? (this would require setting
1440 -- Etype (N) to the actual type found where Typ was expected).
1442 Error_Msg_NE
("expect }", N
, Typ
);
1447 Set_Chars
(Op_Node
, Op_Name
);
1449 if not Is_Private_Type
(Etype
(N
)) then
1450 Set_Etype
(Op_Node
, Base_Type
(Etype
(N
)));
1452 Set_Etype
(Op_Node
, Etype
(N
));
1455 -- If this is a call to a function that renames a predefined equality,
1456 -- the renaming declaration provides a type that must be used to
1457 -- resolve the operands. This must be done now because resolution of
1458 -- the equality node will not resolve any remaining ambiguity, and it
1459 -- assumes that the first operand is not overloaded.
1461 if Nam_In
(Op_Name
, Name_Op_Eq
, Name_Op_Ne
)
1462 and then Ekind
(Func
) = E_Function
1463 and then Is_Overloaded
(Act1
)
1465 Resolve
(Act1
, Base_Type
(Etype
(First_Formal
(Func
))));
1466 Resolve
(Act2
, Base_Type
(Etype
(First_Formal
(Func
))));
1469 Set_Entity
(Op_Node
, Op_Id
);
1470 Generate_Reference
(Op_Id
, N
, ' ');
1472 -- Do rewrite setting Comes_From_Source on the result if the original
1473 -- call came from source. Although it is not strictly the case that the
1474 -- operator as such comes from the source, logically it corresponds
1475 -- exactly to the function call in the source, so it should be marked
1476 -- this way (e.g. to make sure that validity checks work fine).
1479 CS
: constant Boolean := Comes_From_Source
(N
);
1481 Rewrite
(N
, Op_Node
);
1482 Set_Comes_From_Source
(N
, CS
);
1485 -- If this is an arithmetic operator and the result type is private,
1486 -- the operands and the result must be wrapped in conversion to
1487 -- expose the underlying numeric type and expand the proper checks,
1488 -- e.g. on division.
1490 if Is_Private_Type
(Typ
) then
1500 Resolve_Intrinsic_Operator
(N
, Typ
);
1506 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
1515 -- If in ASIS_Mode, propagate operand types to original actuals of
1516 -- function call, which would otherwise not be fully resolved. If
1517 -- the call has already been constant-folded, nothing to do. We
1518 -- relocate the operand nodes rather than copy them, to preserve
1519 -- original_node pointers, given that the operands themselves may
1520 -- have been rewritten. If the call was itself a rewriting of an
1521 -- operator node, nothing to do.
1524 and then Nkind
(N
) in N_Op
1525 and then Nkind
(Original_Node
(N
)) = N_Function_Call
1529 R
: constant Node_Id
:= Right_Opnd
(N
);
1531 Old_First
: constant Node_Id
:=
1532 First
(Parameter_Associations
(Original_Node
(N
)));
1538 Old_Sec
:= Next
(Old_First
);
1540 -- If the original call has named associations, replace the
1541 -- explicit actual parameter in the association with the proper
1542 -- resolved operand.
1544 if Nkind
(Old_First
) = N_Parameter_Association
then
1545 if Chars
(Selector_Name
(Old_First
)) =
1546 Chars
(First_Entity
(Op_Id
))
1548 Rewrite
(Explicit_Actual_Parameter
(Old_First
),
1551 Rewrite
(Explicit_Actual_Parameter
(Old_First
),
1556 Rewrite
(Old_First
, Relocate_Node
(L
));
1559 if Nkind
(Old_Sec
) = N_Parameter_Association
then
1560 if Chars
(Selector_Name
(Old_Sec
)) =
1561 Chars
(First_Entity
(Op_Id
))
1563 Rewrite
(Explicit_Actual_Parameter
(Old_Sec
),
1566 Rewrite
(Explicit_Actual_Parameter
(Old_Sec
),
1571 Rewrite
(Old_Sec
, Relocate_Node
(R
));
1575 if Nkind
(Old_First
) = N_Parameter_Association
then
1576 Rewrite
(Explicit_Actual_Parameter
(Old_First
),
1579 Rewrite
(Old_First
, Relocate_Node
(R
));
1584 Set_Parent
(Original_Node
(N
), Parent
(N
));
1586 end Make_Call_Into_Operator
;
1592 function Operator_Kind
1594 Is_Binary
: Boolean) return Node_Kind
1599 -- Use CASE statement or array???
1602 if Op_Name
= Name_Op_And
then
1604 elsif Op_Name
= Name_Op_Or
then
1606 elsif Op_Name
= Name_Op_Xor
then
1608 elsif Op_Name
= Name_Op_Eq
then
1610 elsif Op_Name
= Name_Op_Ne
then
1612 elsif Op_Name
= Name_Op_Lt
then
1614 elsif Op_Name
= Name_Op_Le
then
1616 elsif Op_Name
= Name_Op_Gt
then
1618 elsif Op_Name
= Name_Op_Ge
then
1620 elsif Op_Name
= Name_Op_Add
then
1622 elsif Op_Name
= Name_Op_Subtract
then
1623 Kind
:= N_Op_Subtract
;
1624 elsif Op_Name
= Name_Op_Concat
then
1625 Kind
:= N_Op_Concat
;
1626 elsif Op_Name
= Name_Op_Multiply
then
1627 Kind
:= N_Op_Multiply
;
1628 elsif Op_Name
= Name_Op_Divide
then
1629 Kind
:= N_Op_Divide
;
1630 elsif Op_Name
= Name_Op_Mod
then
1632 elsif Op_Name
= Name_Op_Rem
then
1634 elsif Op_Name
= Name_Op_Expon
then
1637 raise Program_Error
;
1643 if Op_Name
= Name_Op_Add
then
1645 elsif Op_Name
= Name_Op_Subtract
then
1647 elsif Op_Name
= Name_Op_Abs
then
1649 elsif Op_Name
= Name_Op_Not
then
1652 raise Program_Error
;
1659 ----------------------------
1660 -- Preanalyze_And_Resolve --
1661 ----------------------------
1663 procedure Preanalyze_And_Resolve
(N
: Node_Id
; T
: Entity_Id
) is
1664 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1667 Full_Analysis
:= False;
1668 Expander_Mode_Save_And_Set
(False);
1670 -- Normally, we suppress all checks for this preanalysis. There is no
1671 -- point in processing them now, since they will be applied properly
1672 -- and in the proper location when the default expressions reanalyzed
1673 -- and reexpanded later on. We will also have more information at that
1674 -- point for possible suppression of individual checks.
1676 -- However, in SPARK mode, most expansion is suppressed, and this
1677 -- later reanalysis and reexpansion may not occur. SPARK mode does
1678 -- require the setting of checking flags for proof purposes, so we
1679 -- do the SPARK preanalysis without suppressing checks.
1681 -- This special handling for SPARK mode is required for example in the
1682 -- case of Ada 2012 constructs such as quantified expressions, which are
1683 -- expanded in two separate steps.
1685 if GNATprove_Mode
then
1686 Analyze_And_Resolve
(N
, T
);
1688 Analyze_And_Resolve
(N
, T
, Suppress
=> All_Checks
);
1691 Expander_Mode_Restore
;
1692 Full_Analysis
:= Save_Full_Analysis
;
1693 end Preanalyze_And_Resolve
;
1695 -- Version without context type
1697 procedure Preanalyze_And_Resolve
(N
: Node_Id
) is
1698 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1701 Full_Analysis
:= False;
1702 Expander_Mode_Save_And_Set
(False);
1705 Resolve
(N
, Etype
(N
), Suppress
=> All_Checks
);
1707 Expander_Mode_Restore
;
1708 Full_Analysis
:= Save_Full_Analysis
;
1709 end Preanalyze_And_Resolve
;
1711 ----------------------------------
1712 -- Replace_Actual_Discriminants --
1713 ----------------------------------
1715 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
) is
1716 Loc
: constant Source_Ptr
:= Sloc
(N
);
1717 Tsk
: Node_Id
:= Empty
;
1719 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
;
1720 -- Comment needed???
1726 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
is
1730 if Nkind
(Nod
) = N_Identifier
then
1731 Ent
:= Entity
(Nod
);
1734 and then Ekind
(Ent
) = E_Discriminant
1737 Make_Selected_Component
(Loc
,
1738 Prefix
=> New_Copy_Tree
(Tsk
, New_Sloc
=> Loc
),
1739 Selector_Name
=> Make_Identifier
(Loc
, Chars
(Ent
))));
1741 Set_Etype
(Nod
, Etype
(Ent
));
1749 procedure Replace_Discrs
is new Traverse_Proc
(Process_Discr
);
1751 -- Start of processing for Replace_Actual_Discriminants
1754 if Expander_Active
then
1757 -- Allow the replacement of concurrent discriminants in GNATprove even
1758 -- though this is a light expansion activity. Note that generic units
1759 -- are not modified.
1761 elsif GNATprove_Mode
and not Inside_A_Generic
then
1768 if Nkind
(Name
(N
)) = N_Selected_Component
then
1769 Tsk
:= Prefix
(Name
(N
));
1771 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
1772 Tsk
:= Prefix
(Prefix
(Name
(N
)));
1775 if Present
(Tsk
) then
1776 Replace_Discrs
(Default
);
1778 end Replace_Actual_Discriminants
;
1784 procedure Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
1785 Ambiguous
: Boolean := False;
1786 Ctx_Type
: Entity_Id
:= Typ
;
1787 Expr_Type
: Entity_Id
:= Empty
; -- prevent junk warning
1788 Err_Type
: Entity_Id
:= Empty
;
1789 Found
: Boolean := False;
1792 I1
: Interp_Index
:= 0; -- prevent junk warning
1795 Seen
: Entity_Id
:= Empty
; -- prevent junk warning
1797 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean;
1798 -- Determine whether a node comes from a predefined library unit or
1801 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
);
1802 -- Try and fix up a literal so that it matches its expected type. New
1803 -- literals are manufactured if necessary to avoid cascaded errors.
1805 procedure Report_Ambiguous_Argument
;
1806 -- Additional diagnostics when an ambiguous call has an ambiguous
1807 -- argument (typically a controlling actual).
1809 procedure Resolution_Failed
;
1810 -- Called when attempt at resolving current expression fails
1812 ------------------------------------
1813 -- Comes_From_Predefined_Lib_Unit --
1814 -------------------------------------
1816 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean is
1819 Sloc
(Nod
) = Standard_Location
or else In_Predefined_Unit
(Nod
);
1820 end Comes_From_Predefined_Lib_Unit
;
1822 --------------------
1823 -- Patch_Up_Value --
1824 --------------------
1826 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
) is
1828 if Nkind
(N
) = N_Integer_Literal
and then Is_Real_Type
(Typ
) then
1830 Make_Real_Literal
(Sloc
(N
),
1831 Realval
=> UR_From_Uint
(Intval
(N
))));
1832 Set_Etype
(N
, Universal_Real
);
1833 Set_Is_Static_Expression
(N
);
1835 elsif Nkind
(N
) = N_Real_Literal
and then Is_Integer_Type
(Typ
) then
1837 Make_Integer_Literal
(Sloc
(N
),
1838 Intval
=> UR_To_Uint
(Realval
(N
))));
1839 Set_Etype
(N
, Universal_Integer
);
1840 Set_Is_Static_Expression
(N
);
1842 elsif Nkind
(N
) = N_String_Literal
1843 and then Is_Character_Type
(Typ
)
1845 Set_Character_Literal_Name
(Char_Code
(Character'Pos ('A')));
1847 Make_Character_Literal
(Sloc
(N
),
1849 Char_Literal_Value
=>
1850 UI_From_Int
(Character'Pos ('A'))));
1851 Set_Etype
(N
, Any_Character
);
1852 Set_Is_Static_Expression
(N
);
1854 elsif Nkind
(N
) /= N_String_Literal
and then Is_String_Type
(Typ
) then
1856 Make_String_Literal
(Sloc
(N
),
1857 Strval
=> End_String
));
1859 elsif Nkind
(N
) = N_Range
then
1860 Patch_Up_Value
(Low_Bound
(N
), Typ
);
1861 Patch_Up_Value
(High_Bound
(N
), Typ
);
1865 -------------------------------
1866 -- Report_Ambiguous_Argument --
1867 -------------------------------
1869 procedure Report_Ambiguous_Argument
is
1870 Arg
: constant Node_Id
:= First
(Parameter_Associations
(N
));
1875 if Nkind
(Arg
) = N_Function_Call
1876 and then Is_Entity_Name
(Name
(Arg
))
1877 and then Is_Overloaded
(Name
(Arg
))
1879 Error_Msg_NE
("ambiguous call to&", Arg
, Name
(Arg
));
1881 -- Could use comments on what is going on here???
1883 Get_First_Interp
(Name
(Arg
), I
, It
);
1884 while Present
(It
.Nam
) loop
1885 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
1887 if Nkind
(Parent
(It
.Nam
)) = N_Full_Type_Declaration
then
1888 Error_Msg_N
("interpretation (inherited) #!", Arg
);
1890 Error_Msg_N
("interpretation #!", Arg
);
1893 Get_Next_Interp
(I
, It
);
1896 end Report_Ambiguous_Argument
;
1898 -----------------------
1899 -- Resolution_Failed --
1900 -----------------------
1902 procedure Resolution_Failed
is
1904 Patch_Up_Value
(N
, Typ
);
1906 -- Set the type to the desired one to minimize cascaded errors. Note
1907 -- that this is an approximation and does not work in all cases.
1911 Debug_A_Exit
("resolving ", N
, " (done, resolution failed)");
1912 Set_Is_Overloaded
(N
, False);
1914 -- The caller will return without calling the expander, so we need
1915 -- to set the analyzed flag. Note that it is fine to set Analyzed
1916 -- to True even if we are in the middle of a shallow analysis,
1917 -- (see the spec of sem for more details) since this is an error
1918 -- situation anyway, and there is no point in repeating the
1919 -- analysis later (indeed it won't work to repeat it later, since
1920 -- we haven't got a clear resolution of which entity is being
1923 Set_Analyzed
(N
, True);
1925 end Resolution_Failed
;
1927 -- Start of processing for Resolve
1934 -- Access attribute on remote subprogram cannot be used for a non-remote
1935 -- access-to-subprogram type.
1937 if Nkind
(N
) = N_Attribute_Reference
1938 and then Nam_In
(Attribute_Name
(N
), Name_Access
,
1939 Name_Unrestricted_Access
,
1940 Name_Unchecked_Access
)
1941 and then Comes_From_Source
(N
)
1942 and then Is_Entity_Name
(Prefix
(N
))
1943 and then Is_Subprogram
(Entity
(Prefix
(N
)))
1944 and then Is_Remote_Call_Interface
(Entity
(Prefix
(N
)))
1945 and then not Is_Remote_Access_To_Subprogram_Type
(Typ
)
1948 ("prefix must statically denote a non-remote subprogram", N
);
1951 From_Lib
:= Comes_From_Predefined_Lib_Unit
(N
);
1953 -- If the context is a Remote_Access_To_Subprogram, access attributes
1954 -- must be resolved with the corresponding fat pointer. There is no need
1955 -- to check for the attribute name since the return type of an
1956 -- attribute is never a remote type.
1958 if Nkind
(N
) = N_Attribute_Reference
1959 and then Comes_From_Source
(N
)
1960 and then (Is_Remote_Call_Interface
(Typ
) or else Is_Remote_Types
(Typ
))
1963 Attr
: constant Attribute_Id
:=
1964 Get_Attribute_Id
(Attribute_Name
(N
));
1965 Pref
: constant Node_Id
:= Prefix
(N
);
1968 Is_Remote
: Boolean := True;
1971 -- Check that Typ is a remote access-to-subprogram type
1973 if Is_Remote_Access_To_Subprogram_Type
(Typ
) then
1975 -- Prefix (N) must statically denote a remote subprogram
1976 -- declared in a package specification.
1978 if Attr
= Attribute_Access
or else
1979 Attr
= Attribute_Unchecked_Access
or else
1980 Attr
= Attribute_Unrestricted_Access
1982 Decl
:= Unit_Declaration_Node
(Entity
(Pref
));
1984 if Nkind
(Decl
) = N_Subprogram_Body
then
1985 Spec
:= Corresponding_Spec
(Decl
);
1987 if Present
(Spec
) then
1988 Decl
:= Unit_Declaration_Node
(Spec
);
1992 Spec
:= Parent
(Decl
);
1994 if not Is_Entity_Name
(Prefix
(N
))
1995 or else Nkind
(Spec
) /= N_Package_Specification
1997 not Is_Remote_Call_Interface
(Defining_Entity
(Spec
))
2001 ("prefix must statically denote a remote subprogram ",
2005 -- If we are generating code in distributed mode, perform
2006 -- semantic checks against corresponding remote entities.
2009 and then Get_PCS_Name
/= Name_No_DSA
2011 Check_Subtype_Conformant
2012 (New_Id
=> Entity
(Prefix
(N
)),
2013 Old_Id
=> Designated_Type
2014 (Corresponding_Remote_Type
(Typ
)),
2018 Process_Remote_AST_Attribute
(N
, Typ
);
2026 Debug_A_Entry
("resolving ", N
);
2028 if Debug_Flag_V
then
2029 Write_Overloads
(N
);
2032 if Comes_From_Source
(N
) then
2033 if Is_Fixed_Point_Type
(Typ
) then
2034 Check_Restriction
(No_Fixed_Point
, N
);
2036 elsif Is_Floating_Point_Type
(Typ
)
2037 and then Typ
/= Universal_Real
2038 and then Typ
/= Any_Real
2040 Check_Restriction
(No_Floating_Point
, N
);
2044 -- Return if already analyzed
2046 if Analyzed
(N
) then
2047 Debug_A_Exit
("resolving ", N
, " (done, already analyzed)");
2048 Analyze_Dimension
(N
);
2051 -- Any case of Any_Type as the Etype value means that we had a
2054 elsif Etype
(N
) = Any_Type
then
2055 Debug_A_Exit
("resolving ", N
, " (done, Etype = Any_Type)");
2059 Check_Parameterless_Call
(N
);
2061 -- The resolution of an Expression_With_Actions is determined by
2064 if Nkind
(N
) = N_Expression_With_Actions
then
2065 Resolve
(Expression
(N
), Typ
);
2068 Expr_Type
:= Etype
(Expression
(N
));
2070 -- If not overloaded, then we know the type, and all that needs doing
2071 -- is to check that this type is compatible with the context.
2073 elsif not Is_Overloaded
(N
) then
2074 Found
:= Covers
(Typ
, Etype
(N
));
2075 Expr_Type
:= Etype
(N
);
2077 -- In the overloaded case, we must select the interpretation that
2078 -- is compatible with the context (i.e. the type passed to Resolve)
2081 -- Loop through possible interpretations
2083 Get_First_Interp
(N
, I
, It
);
2084 Interp_Loop
: while Present
(It
.Typ
) loop
2085 if Debug_Flag_V
then
2086 Write_Str
("Interp: ");
2090 -- We are only interested in interpretations that are compatible
2091 -- with the expected type, any other interpretations are ignored.
2093 if not Covers
(Typ
, It
.Typ
) then
2094 if Debug_Flag_V
then
2095 Write_Str
(" interpretation incompatible with context");
2100 -- Skip the current interpretation if it is disabled by an
2101 -- abstract operator. This action is performed only when the
2102 -- type against which we are resolving is the same as the
2103 -- type of the interpretation.
2105 if Ada_Version
>= Ada_2005
2106 and then It
.Typ
= Typ
2107 and then Typ
/= Universal_Integer
2108 and then Typ
/= Universal_Real
2109 and then Present
(It
.Abstract_Op
)
2111 if Debug_Flag_V
then
2112 Write_Line
("Skip.");
2118 -- First matching interpretation
2124 Expr_Type
:= It
.Typ
;
2126 -- Matching interpretation that is not the first, maybe an
2127 -- error, but there are some cases where preference rules are
2128 -- used to choose between the two possibilities. These and
2129 -- some more obscure cases are handled in Disambiguate.
2132 -- If the current statement is part of a predefined library
2133 -- unit, then all interpretations which come from user level
2134 -- packages should not be considered. Check previous and
2138 if not Comes_From_Predefined_Lib_Unit
(It
.Nam
) then
2141 elsif not Comes_From_Predefined_Lib_Unit
(Seen
) then
2143 -- Previous interpretation must be discarded
2147 Expr_Type
:= It
.Typ
;
2148 Set_Entity
(N
, Seen
);
2153 -- Otherwise apply further disambiguation steps
2155 Error_Msg_Sloc
:= Sloc
(Seen
);
2156 It1
:= Disambiguate
(N
, I1
, I
, Typ
);
2158 -- Disambiguation has succeeded. Skip the remaining
2161 if It1
/= No_Interp
then
2163 Expr_Type
:= It1
.Typ
;
2165 while Present
(It
.Typ
) loop
2166 Get_Next_Interp
(I
, It
);
2170 -- Before we issue an ambiguity complaint, check for the
2171 -- case of a subprogram call where at least one of the
2172 -- arguments is Any_Type, and if so suppress the message,
2173 -- since it is a cascaded error. This can also happen for
2174 -- a generalized indexing operation.
2176 if Nkind
(N
) in N_Subprogram_Call
2177 or else (Nkind
(N
) = N_Indexed_Component
2178 and then Present
(Generalized_Indexing
(N
)))
2185 if Nkind
(N
) = N_Indexed_Component
then
2186 Rewrite
(N
, Generalized_Indexing
(N
));
2189 A
:= First_Actual
(N
);
2190 while Present
(A
) loop
2193 if Nkind
(E
) = N_Parameter_Association
then
2194 E
:= Explicit_Actual_Parameter
(E
);
2197 if Etype
(E
) = Any_Type
then
2198 if Debug_Flag_V
then
2199 Write_Str
("Any_Type in call");
2210 elsif Nkind
(N
) in N_Binary_Op
2211 and then (Etype
(Left_Opnd
(N
)) = Any_Type
2212 or else Etype
(Right_Opnd
(N
)) = Any_Type
)
2216 elsif Nkind
(N
) in N_Unary_Op
2217 and then Etype
(Right_Opnd
(N
)) = Any_Type
2222 -- Not that special case, so issue message using the flag
2223 -- Ambiguous to control printing of the header message
2224 -- only at the start of an ambiguous set.
2226 if not Ambiguous
then
2227 if Nkind
(N
) = N_Function_Call
2228 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2231 ("ambiguous expression (cannot resolve indirect "
2234 Error_Msg_NE
-- CODEFIX
2235 ("ambiguous expression (cannot resolve&)!",
2241 if Nkind
(Parent
(Seen
)) = N_Full_Type_Declaration
then
2243 ("\\possible interpretation (inherited)#!", N
);
2245 Error_Msg_N
-- CODEFIX
2246 ("\\possible interpretation#!", N
);
2249 if Nkind
(N
) in N_Subprogram_Call
2250 and then Present
(Parameter_Associations
(N
))
2252 Report_Ambiguous_Argument
;
2256 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2258 -- By default, the error message refers to the candidate
2259 -- interpretation. But if it is a predefined operator, it
2260 -- is implicitly declared at the declaration of the type
2261 -- of the operand. Recover the sloc of that declaration
2262 -- for the error message.
2264 if Nkind
(N
) in N_Op
2265 and then Scope
(It
.Nam
) = Standard_Standard
2266 and then not Is_Overloaded
(Right_Opnd
(N
))
2267 and then Scope
(Base_Type
(Etype
(Right_Opnd
(N
)))) /=
2270 Err_Type
:= First_Subtype
(Etype
(Right_Opnd
(N
)));
2272 if Comes_From_Source
(Err_Type
)
2273 and then Present
(Parent
(Err_Type
))
2275 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2278 elsif Nkind
(N
) in N_Binary_Op
2279 and then Scope
(It
.Nam
) = Standard_Standard
2280 and then not Is_Overloaded
(Left_Opnd
(N
))
2281 and then Scope
(Base_Type
(Etype
(Left_Opnd
(N
)))) /=
2284 Err_Type
:= First_Subtype
(Etype
(Left_Opnd
(N
)));
2286 if Comes_From_Source
(Err_Type
)
2287 and then Present
(Parent
(Err_Type
))
2289 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2292 -- If this is an indirect call, use the subprogram_type
2293 -- in the message, to have a meaningful location. Also
2294 -- indicate if this is an inherited operation, created
2295 -- by a type declaration.
2297 elsif Nkind
(N
) = N_Function_Call
2298 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2299 and then Is_Type
(It
.Nam
)
2303 Sloc
(Associated_Node_For_Itype
(Err_Type
));
2308 if Nkind
(N
) in N_Op
2309 and then Scope
(It
.Nam
) = Standard_Standard
2310 and then Present
(Err_Type
)
2312 -- Special-case the message for universal_fixed
2313 -- operators, which are not declared with the type
2314 -- of the operand, but appear forever in Standard.
2316 if It
.Typ
= Universal_Fixed
2317 and then Scope
(It
.Nam
) = Standard_Standard
2320 ("\\possible interpretation as universal_fixed "
2321 & "operation (RM 4.5.5 (19))", N
);
2324 ("\\possible interpretation (predefined)#!", N
);
2328 Nkind
(Parent
(It
.Nam
)) = N_Full_Type_Declaration
2331 ("\\possible interpretation (inherited)#!", N
);
2333 Error_Msg_N
-- CODEFIX
2334 ("\\possible interpretation#!", N
);
2340 -- We have a matching interpretation, Expr_Type is the type
2341 -- from this interpretation, and Seen is the entity.
2343 -- For an operator, just set the entity name. The type will be
2344 -- set by the specific operator resolution routine.
2346 if Nkind
(N
) in N_Op
then
2347 Set_Entity
(N
, Seen
);
2348 Generate_Reference
(Seen
, N
);
2350 elsif Nkind_In
(N
, N_Case_Expression
,
2351 N_Character_Literal
,
2355 Set_Etype
(N
, Expr_Type
);
2357 -- AI05-0139-2: Expression is overloaded because type has
2358 -- implicit dereference. If type matches context, no implicit
2359 -- dereference is involved. If the expression is an entity,
2360 -- generate a reference to it, as this is not done for an
2361 -- overloaded construct during analysis.
2363 elsif Has_Implicit_Dereference
(Expr_Type
) then
2364 Set_Etype
(N
, Expr_Type
);
2365 Set_Is_Overloaded
(N
, False);
2367 if Is_Entity_Name
(N
) then
2368 Generate_Reference
(Entity
(N
), N
);
2373 elsif Is_Overloaded
(N
)
2374 and then Present
(It
.Nam
)
2375 and then Ekind
(It
.Nam
) = E_Discriminant
2376 and then Has_Implicit_Dereference
(It
.Nam
)
2378 -- If the node is a general indexing, the dereference is
2379 -- is inserted when resolving the rewritten form, else
2382 if Nkind
(N
) /= N_Indexed_Component
2383 or else No
(Generalized_Indexing
(N
))
2385 Build_Explicit_Dereference
(N
, It
.Nam
);
2388 -- For an explicit dereference, attribute reference, range,
2389 -- short-circuit form (which is not an operator node), or call
2390 -- with a name that is an explicit dereference, there is
2391 -- nothing to be done at this point.
2393 elsif Nkind_In
(N
, N_Attribute_Reference
,
2395 N_Explicit_Dereference
,
2397 N_Indexed_Component
,
2400 N_Selected_Component
,
2402 or else Nkind
(Name
(N
)) = N_Explicit_Dereference
2406 -- For procedure or function calls, set the type of the name,
2407 -- and also the entity pointer for the prefix.
2409 elsif Nkind
(N
) in N_Subprogram_Call
2410 and then Is_Entity_Name
(Name
(N
))
2412 Set_Etype
(Name
(N
), Expr_Type
);
2413 Set_Entity
(Name
(N
), Seen
);
2414 Generate_Reference
(Seen
, Name
(N
));
2416 elsif Nkind
(N
) = N_Function_Call
2417 and then Nkind
(Name
(N
)) = N_Selected_Component
2419 Set_Etype
(Name
(N
), Expr_Type
);
2420 Set_Entity
(Selector_Name
(Name
(N
)), Seen
);
2421 Generate_Reference
(Seen
, Selector_Name
(Name
(N
)));
2423 -- For all other cases, just set the type of the Name
2426 Set_Etype
(Name
(N
), Expr_Type
);
2433 -- Move to next interpretation
2435 exit Interp_Loop
when No
(It
.Typ
);
2437 Get_Next_Interp
(I
, It
);
2438 end loop Interp_Loop
;
2441 -- At this stage Found indicates whether or not an acceptable
2442 -- interpretation exists. If not, then we have an error, except that if
2443 -- the context is Any_Type as a result of some other error, then we
2444 -- suppress the error report.
2447 if Typ
/= Any_Type
then
2449 -- If type we are looking for is Void, then this is the procedure
2450 -- call case, and the error is simply that what we gave is not a
2451 -- procedure name (we think of procedure calls as expressions with
2452 -- types internally, but the user doesn't think of them this way).
2454 if Typ
= Standard_Void_Type
then
2456 -- Special case message if function used as a procedure
2458 if Nkind
(N
) = N_Procedure_Call_Statement
2459 and then Is_Entity_Name
(Name
(N
))
2460 and then Ekind
(Entity
(Name
(N
))) = E_Function
2463 ("cannot use call to function & as a statement",
2464 Name
(N
), Entity
(Name
(N
)));
2466 ("\return value of a function call cannot be ignored",
2469 -- Otherwise give general message (not clear what cases this
2470 -- covers, but no harm in providing for them).
2473 Error_Msg_N
("expect procedure name in procedure call", N
);
2478 -- Otherwise we do have a subexpression with the wrong type
2480 -- Check for the case of an allocator which uses an access type
2481 -- instead of the designated type. This is a common error and we
2482 -- specialize the message, posting an error on the operand of the
2483 -- allocator, complaining that we expected the designated type of
2486 elsif Nkind
(N
) = N_Allocator
2487 and then Is_Access_Type
(Typ
)
2488 and then Is_Access_Type
(Etype
(N
))
2489 and then Designated_Type
(Etype
(N
)) = Typ
2491 Wrong_Type
(Expression
(N
), Designated_Type
(Typ
));
2494 -- Check for view mismatch on Null in instances, for which the
2495 -- view-swapping mechanism has no identifier.
2497 elsif (In_Instance
or else In_Inlined_Body
)
2498 and then (Nkind
(N
) = N_Null
)
2499 and then Is_Private_Type
(Typ
)
2500 and then Is_Access_Type
(Full_View
(Typ
))
2502 Resolve
(N
, Full_View
(Typ
));
2506 -- Check for an aggregate. Sometimes we can get bogus aggregates
2507 -- from misuse of parentheses, and we are about to complain about
2508 -- the aggregate without even looking inside it.
2510 -- Instead, if we have an aggregate of type Any_Composite, then
2511 -- analyze and resolve the component fields, and then only issue
2512 -- another message if we get no errors doing this (otherwise
2513 -- assume that the errors in the aggregate caused the problem).
2515 elsif Nkind
(N
) = N_Aggregate
2516 and then Etype
(N
) = Any_Composite
2518 -- Disable expansion in any case. If there is a type mismatch
2519 -- it may be fatal to try to expand the aggregate. The flag
2520 -- would otherwise be set to false when the error is posted.
2522 Expander_Active
:= False;
2525 procedure Check_Aggr
(Aggr
: Node_Id
);
2526 -- Check one aggregate, and set Found to True if we have a
2527 -- definite error in any of its elements
2529 procedure Check_Elmt
(Aelmt
: Node_Id
);
2530 -- Check one element of aggregate and set Found to True if
2531 -- we definitely have an error in the element.
2537 procedure Check_Aggr
(Aggr
: Node_Id
) is
2541 if Present
(Expressions
(Aggr
)) then
2542 Elmt
:= First
(Expressions
(Aggr
));
2543 while Present
(Elmt
) loop
2549 if Present
(Component_Associations
(Aggr
)) then
2550 Elmt
:= First
(Component_Associations
(Aggr
));
2551 while Present
(Elmt
) loop
2553 -- If this is a default-initialized component, then
2554 -- there is nothing to check. The box will be
2555 -- replaced by the appropriate call during late
2558 if Nkind
(Elmt
) /= N_Iterated_Component_Association
2559 and then not Box_Present
(Elmt
)
2561 Check_Elmt
(Expression
(Elmt
));
2573 procedure Check_Elmt
(Aelmt
: Node_Id
) is
2575 -- If we have a nested aggregate, go inside it (to
2576 -- attempt a naked analyze-resolve of the aggregate can
2577 -- cause undesirable cascaded errors). Do not resolve
2578 -- expression if it needs a type from context, as for
2579 -- integer * fixed expression.
2581 if Nkind
(Aelmt
) = N_Aggregate
then
2587 if not Is_Overloaded
(Aelmt
)
2588 and then Etype
(Aelmt
) /= Any_Fixed
2593 if Etype
(Aelmt
) = Any_Type
then
2604 -- Looks like we have a type error, but check for special case
2605 -- of Address wanted, integer found, with the configuration pragma
2606 -- Allow_Integer_Address active. If we have this case, introduce
2607 -- an unchecked conversion to allow the integer expression to be
2608 -- treated as an Address. The reverse case of integer wanted,
2609 -- Address found, is treated in an analogous manner.
2611 if Address_Integer_Convert_OK
(Typ
, Etype
(N
)) then
2612 Rewrite
(N
, Unchecked_Convert_To
(Typ
, Relocate_Node
(N
)));
2613 Analyze_And_Resolve
(N
, Typ
);
2616 -- Under relaxed RM semantics silently replace occurrences of null
2617 -- by System.Address_Null.
2619 elsif Null_To_Null_Address_Convert_OK
(N
, Typ
) then
2620 Replace_Null_By_Null_Address
(N
);
2621 Analyze_And_Resolve
(N
, Typ
);
2625 -- That special Allow_Integer_Address check did not apply, so we
2626 -- have a real type error. If an error message was issued already,
2627 -- Found got reset to True, so if it's still False, issue standard
2628 -- Wrong_Type message.
2631 if Is_Overloaded
(N
) and then Nkind
(N
) = N_Function_Call
then
2633 Subp_Name
: Node_Id
;
2636 if Is_Entity_Name
(Name
(N
)) then
2637 Subp_Name
:= Name
(N
);
2639 elsif Nkind
(Name
(N
)) = N_Selected_Component
then
2641 -- Protected operation: retrieve operation name
2643 Subp_Name
:= Selector_Name
(Name
(N
));
2646 raise Program_Error
;
2649 Error_Msg_Node_2
:= Typ
;
2651 ("no visible interpretation of& matches expected type&",
2655 if All_Errors_Mode
then
2657 Index
: Interp_Index
;
2661 Error_Msg_N
("\\possible interpretations:", N
);
2663 Get_First_Interp
(Name
(N
), Index
, It
);
2664 while Present
(It
.Nam
) loop
2665 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2666 Error_Msg_Node_2
:= It
.Nam
;
2668 ("\\ type& for & declared#", N
, It
.Typ
);
2669 Get_Next_Interp
(Index
, It
);
2674 Error_Msg_N
("\use -gnatf for details", N
);
2678 Wrong_Type
(N
, Typ
);
2686 -- Test if we have more than one interpretation for the context
2688 elsif Ambiguous
then
2692 -- Only one intepretation
2695 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2696 -- the "+" on T is abstract, and the operands are of universal type,
2697 -- the above code will have (incorrectly) resolved the "+" to the
2698 -- universal one in Standard. Therefore check for this case and give
2699 -- an error. We can't do this earlier, because it would cause legal
2700 -- cases to get errors (when some other type has an abstract "+").
2702 if Ada_Version
>= Ada_2005
2703 and then Nkind
(N
) in N_Op
2704 and then Is_Overloaded
(N
)
2705 and then Is_Universal_Numeric_Type
(Etype
(Entity
(N
)))
2707 Get_First_Interp
(N
, I
, It
);
2708 while Present
(It
.Typ
) loop
2709 if Present
(It
.Abstract_Op
) and then
2710 Etype
(It
.Abstract_Op
) = Typ
2713 ("cannot call abstract subprogram &!", N
, It
.Abstract_Op
);
2717 Get_Next_Interp
(I
, It
);
2721 -- Here we have an acceptable interpretation for the context
2723 -- Propagate type information and normalize tree for various
2724 -- predefined operations. If the context only imposes a class of
2725 -- types, rather than a specific type, propagate the actual type
2728 if Typ
= Any_Integer
or else
2729 Typ
= Any_Boolean
or else
2730 Typ
= Any_Modular
or else
2731 Typ
= Any_Real
or else
2734 Ctx_Type
:= Expr_Type
;
2736 -- Any_Fixed is legal in a real context only if a specific fixed-
2737 -- point type is imposed. If Norman Cohen can be confused by this,
2738 -- it deserves a separate message.
2741 and then Expr_Type
= Any_Fixed
2743 Error_Msg_N
("illegal context for mixed mode operation", N
);
2744 Set_Etype
(N
, Universal_Real
);
2745 Ctx_Type
:= Universal_Real
;
2749 -- A user-defined operator is transformed into a function call at
2750 -- this point, so that further processing knows that operators are
2751 -- really operators (i.e. are predefined operators). User-defined
2752 -- operators that are intrinsic are just renamings of the predefined
2753 -- ones, and need not be turned into calls either, but if they rename
2754 -- a different operator, we must transform the node accordingly.
2755 -- Instantiations of Unchecked_Conversion are intrinsic but are
2756 -- treated as functions, even if given an operator designator.
2758 if Nkind
(N
) in N_Op
2759 and then Present
(Entity
(N
))
2760 and then Ekind
(Entity
(N
)) /= E_Operator
2762 if not Is_Predefined_Op
(Entity
(N
)) then
2763 Rewrite_Operator_As_Call
(N
, Entity
(N
));
2765 elsif Present
(Alias
(Entity
(N
)))
2767 Nkind
(Parent
(Parent
(Entity
(N
)))) =
2768 N_Subprogram_Renaming_Declaration
2770 Rewrite_Renamed_Operator
(N
, Alias
(Entity
(N
)), Typ
);
2772 -- If the node is rewritten, it will be fully resolved in
2773 -- Rewrite_Renamed_Operator.
2775 if Analyzed
(N
) then
2781 case N_Subexpr
'(Nkind (N)) is
2783 Resolve_Aggregate (N, Ctx_Type);
2786 Resolve_Allocator (N, Ctx_Type);
2788 when N_Short_Circuit =>
2789 Resolve_Short_Circuit (N, Ctx_Type);
2791 when N_Attribute_Reference =>
2792 Resolve_Attribute (N, Ctx_Type);
2794 when N_Case_Expression =>
2795 Resolve_Case_Expression (N, Ctx_Type);
2797 when N_Character_Literal =>
2798 Resolve_Character_Literal (N, Ctx_Type);
2800 when N_Delta_Aggregate =>
2801 Resolve_Delta_Aggregate (N, Ctx_Type);
2803 when N_Expanded_Name =>
2804 Resolve_Entity_Name (N, Ctx_Type);
2806 when N_Explicit_Dereference =>
2807 Resolve_Explicit_Dereference (N, Ctx_Type);
2809 when N_Expression_With_Actions =>
2810 Resolve_Expression_With_Actions (N, Ctx_Type);
2812 when N_Extension_Aggregate =>
2813 Resolve_Extension_Aggregate (N, Ctx_Type);
2815 when N_Function_Call =>
2816 Resolve_Call (N, Ctx_Type);
2818 when N_Identifier =>
2819 Resolve_Entity_Name (N, Ctx_Type);
2821 when N_If_Expression =>
2822 Resolve_If_Expression (N, Ctx_Type);
2824 when N_Indexed_Component =>
2825 Resolve_Indexed_Component (N, Ctx_Type);
2827 when N_Integer_Literal =>
2828 Resolve_Integer_Literal (N, Ctx_Type);
2830 when N_Membership_Test =>
2831 Resolve_Membership_Op (N, Ctx_Type);
2834 Resolve_Null (N, Ctx_Type);
2840 Resolve_Logical_Op (N, Ctx_Type);
2845 Resolve_Equality_Op (N, Ctx_Type);
2852 Resolve_Comparison_Op (N, Ctx_Type);
2855 Resolve_Op_Not (N, Ctx_Type);
2864 Resolve_Arithmetic_Op (N, Ctx_Type);
2867 Resolve_Op_Concat (N, Ctx_Type);
2870 Resolve_Op_Expon (N, Ctx_Type);
2876 Resolve_Unary_Op (N, Ctx_Type);
2879 Resolve_Shift (N, Ctx_Type);
2881 when N_Procedure_Call_Statement =>
2882 Resolve_Call (N, Ctx_Type);
2884 when N_Operator_Symbol =>
2885 Resolve_Operator_Symbol (N, Ctx_Type);
2887 when N_Qualified_Expression =>
2888 Resolve_Qualified_Expression (N, Ctx_Type);
2890 -- Why is the following null, needs a comment ???
2892 when N_Quantified_Expression =>
2895 when N_Raise_Expression =>
2896 Resolve_Raise_Expression (N, Ctx_Type);
2898 when N_Raise_xxx_Error =>
2899 Set_Etype (N, Ctx_Type);
2902 Resolve_Range (N, Ctx_Type);
2904 when N_Real_Literal =>
2905 Resolve_Real_Literal (N, Ctx_Type);
2908 Resolve_Reference (N, Ctx_Type);
2910 when N_Selected_Component =>
2911 Resolve_Selected_Component (N, Ctx_Type);
2914 Resolve_Slice (N, Ctx_Type);
2916 when N_String_Literal =>
2917 Resolve_String_Literal (N, Ctx_Type);
2919 when N_Target_Name =>
2920 Resolve_Target_Name (N, Ctx_Type);
2922 when N_Type_Conversion =>
2923 Resolve_Type_Conversion (N, Ctx_Type);
2925 when N_Unchecked_Expression =>
2926 Resolve_Unchecked_Expression (N, Ctx_Type);
2928 when N_Unchecked_Type_Conversion =>
2929 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2932 -- Mark relevant use-type and use-package clauses as effective using
2933 -- the original node because constant folding may have occured and
2934 -- removed references that need to be examined.
2936 if Nkind (Original_Node (N)) in N_Op then
2937 Mark_Use_Clauses (Original_Node (N));
2940 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2941 -- expression of an anonymous access type that occurs in the context
2942 -- of a named general access type, except when the expression is that
2943 -- of a membership test. This ensures proper legality checking in
2944 -- terms of allowed conversions (expressions that would be illegal to
2945 -- convert implicitly are allowed in membership tests).
2947 if Ada_Version >= Ada_2012
2948 and then Ekind (Ctx_Type) = E_General_Access_Type
2949 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
2950 and then Nkind (Parent (N)) not in N_Membership_Test
2952 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
2953 Analyze_And_Resolve (N, Ctx_Type);
2956 -- If the subexpression was replaced by a non-subexpression, then
2957 -- all we do is to expand it. The only legitimate case we know of
2958 -- is converting procedure call statement to entry call statements,
2959 -- but there may be others, so we are making this test general.
2961 if Nkind (N) not in N_Subexpr then
2962 Debug_A_Exit ("resolving ", N, " (done)");
2967 -- The expression is definitely NOT overloaded at this point, so
2968 -- we reset the Is_Overloaded flag to avoid any confusion when
2969 -- reanalyzing the node.
2971 Set_Is_Overloaded (N, False);
2973 -- Freeze expression type, entity if it is a name, and designated
2974 -- type if it is an allocator (RM 13.14(10,11,13)).
2976 -- Now that the resolution of the type of the node is complete, and
2977 -- we did not detect an error, we can expand this node. We skip the
2978 -- expand call if we are in a default expression, see section
2979 -- "Handling of Default Expressions" in Sem spec.
2981 Debug_A_Exit ("resolving ", N, " (done)");
2983 -- We unconditionally freeze the expression, even if we are in
2984 -- default expression mode (the Freeze_Expression routine tests this
2985 -- flag and only freezes static types if it is set).
2987 -- Ada 2012 (AI05-177): The declaration of an expression function
2988 -- does not cause freezing, but we never reach here in that case.
2989 -- Here we are resolving the corresponding expanded body, so we do
2990 -- need to perform normal freezing.
2992 -- As elsewhere we do not emit freeze node within a generic. We make
2993 -- an exception for entities that are expressions, only to detect
2994 -- misuses of deferred constants and preserve the output of various
2997 if not Inside_A_Generic or else Is_Entity_Name (N) then
2998 Freeze_Expression (N);
3001 -- Now we can do the expansion
3011 -- Version with check(s) suppressed
3013 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3015 if Suppress = All_Checks then
3017 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3019 Scope_Suppress.Suppress := (others => True);
3021 Scope_Suppress.Suppress := Sva;
3026 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3028 Scope_Suppress.Suppress (Suppress) := True;
3030 Scope_Suppress.Suppress (Suppress) := Svg;
3039 -- Version with implicit type
3041 procedure Resolve (N : Node_Id) is
3043 Resolve (N, Etype (N));
3046 ---------------------
3047 -- Resolve_Actuals --
3048 ---------------------
3050 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3051 Loc : constant Source_Ptr := Sloc (N);
3054 A_Typ : Entity_Id := Empty; -- init to avoid warning
3057 Prev : Node_Id := Empty;
3059 Real_F : Entity_Id := Empty; -- init to avoid warning
3061 Real_Subp : Entity_Id;
3062 -- If the subprogram being called is an inherited operation for
3063 -- a formal derived type in an instance, Real_Subp is the subprogram
3064 -- that will be called. It may have different formal names than the
3065 -- operation of the formal in the generic, so after actual is resolved
3066 -- the name of the actual in a named association must carry the name
3067 -- of the actual of the subprogram being called.
3069 procedure Check_Aliased_Parameter;
3070 -- Check rules on aliased parameters and related accessibility rules
3071 -- in (RM 3.10.2 (10.2-10.4)).
3073 procedure Check_Argument_Order;
3074 -- Performs a check for the case where the actuals are all simple
3075 -- identifiers that correspond to the formal names, but in the wrong
3076 -- order, which is considered suspicious and cause for a warning.
3078 procedure Check_Prefixed_Call;
3079 -- If the original node is an overloaded call in prefix notation,
3080 -- insert an 'Access or a dereference as needed over the first actual
.
3081 -- Try_Object_Operation has already verified that there is a valid
3082 -- interpretation, but the form of the actual can only be determined
3083 -- once the primitive operation is identified.
3085 procedure Flag_Effectively_Volatile_Objects
(Expr
: Node_Id
);
3086 -- Emit an error concerning the illegal usage of an effectively volatile
3087 -- object in interfering context (SPARK RM 7.13(12)).
3089 procedure Insert_Default
;
3090 -- If the actual is missing in a call, insert in the actuals list
3091 -- an instance of the default expression. The insertion is always
3092 -- a named association.
3094 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean;
3095 -- Check whether T1 and T2, or their full views, are derived from a
3096 -- common type. Used to enforce the restrictions on array conversions
3099 function Static_Concatenation
(N
: Node_Id
) return Boolean;
3100 -- Predicate to determine whether an actual that is a concatenation
3101 -- will be evaluated statically and does not need a transient scope.
3102 -- This must be determined before the actual is resolved and expanded
3103 -- because if needed the transient scope must be introduced earlier.
3105 -----------------------------
3106 -- Check_Aliased_Parameter --
3107 -----------------------------
3109 procedure Check_Aliased_Parameter
is
3110 Nominal_Subt
: Entity_Id
;
3113 if Is_Aliased
(F
) then
3114 if Is_Tagged_Type
(A_Typ
) then
3117 elsif Is_Aliased_View
(A
) then
3118 if Is_Constr_Subt_For_U_Nominal
(A_Typ
) then
3119 Nominal_Subt
:= Base_Type
(A_Typ
);
3121 Nominal_Subt
:= A_Typ
;
3124 if Subtypes_Statically_Match
(F_Typ
, Nominal_Subt
) then
3127 -- In a generic body assume the worst for generic formals:
3128 -- they can have a constrained partial view (AI05-041).
3130 elsif Has_Discriminants
(F_Typ
)
3131 and then not Is_Constrained
(F_Typ
)
3132 and then not Has_Constrained_Partial_View
(F_Typ
)
3133 and then not Is_Generic_Type
(F_Typ
)
3138 Error_Msg_NE
("untagged actual does not match "
3139 & "aliased formal&", A
, F
);
3143 Error_Msg_NE
("actual for aliased formal& must be "
3144 & "aliased object", A
, F
);
3147 if Ekind
(Nam
) = E_Procedure
then
3150 elsif Ekind
(Etype
(Nam
)) = E_Anonymous_Access_Type
then
3151 if Nkind
(Parent
(N
)) = N_Type_Conversion
3152 and then Type_Access_Level
(Etype
(Parent
(N
))) <
3153 Object_Access_Level
(A
)
3155 Error_Msg_N
("aliased actual has wrong accessibility", A
);
3158 elsif Nkind
(Parent
(N
)) = N_Qualified_Expression
3159 and then Nkind
(Parent
(Parent
(N
))) = N_Allocator
3160 and then Type_Access_Level
(Etype
(Parent
(Parent
(N
)))) <
3161 Object_Access_Level
(A
)
3164 ("aliased actual in allocator has wrong accessibility", A
);
3167 end Check_Aliased_Parameter
;
3169 --------------------------
3170 -- Check_Argument_Order --
3171 --------------------------
3173 procedure Check_Argument_Order
is
3175 -- Nothing to do if no parameters, or original node is neither a
3176 -- function call nor a procedure call statement (happens in the
3177 -- operator-transformed-to-function call case), or the call does
3178 -- not come from source, or this warning is off.
3180 if not Warn_On_Parameter_Order
3181 or else No
(Parameter_Associations
(N
))
3182 or else Nkind
(Original_Node
(N
)) not in N_Subprogram_Call
3183 or else not Comes_From_Source
(N
)
3189 Nargs
: constant Nat
:= List_Length
(Parameter_Associations
(N
));
3192 -- Nothing to do if only one parameter
3198 -- Here if at least two arguments
3201 Actuals
: array (1 .. Nargs
) of Node_Id
;
3205 Wrong_Order
: Boolean := False;
3206 -- Set True if an out of order case is found
3209 -- Collect identifier names of actuals, fail if any actual is
3210 -- not a simple identifier, and record max length of name.
3212 Actual
:= First
(Parameter_Associations
(N
));
3213 for J
in Actuals
'Range loop
3214 if Nkind
(Actual
) /= N_Identifier
then
3217 Actuals
(J
) := Actual
;
3222 -- If we got this far, all actuals are identifiers and the list
3223 -- of their names is stored in the Actuals array.
3225 Formal
:= First_Formal
(Nam
);
3226 for J
in Actuals
'Range loop
3228 -- If we ran out of formals, that's odd, probably an error
3229 -- which will be detected elsewhere, but abandon the search.
3235 -- If name matches and is in order OK
3237 if Chars
(Formal
) = Chars
(Actuals
(J
)) then
3241 -- If no match, see if it is elsewhere in list and if so
3242 -- flag potential wrong order if type is compatible.
3244 for K
in Actuals
'Range loop
3245 if Chars
(Formal
) = Chars
(Actuals
(K
))
3247 Has_Compatible_Type
(Actuals
(K
), Etype
(Formal
))
3249 Wrong_Order
:= True;
3259 <<Continue
>> Next_Formal
(Formal
);
3262 -- If Formals left over, also probably an error, skip warning
3264 if Present
(Formal
) then
3268 -- Here we give the warning if something was out of order
3272 ("?P?actuals for this call may be in wrong order", N
);
3276 end Check_Argument_Order
;
3278 -------------------------
3279 -- Check_Prefixed_Call --
3280 -------------------------
3282 procedure Check_Prefixed_Call
is
3283 Act
: constant Node_Id
:= First_Actual
(N
);
3284 A_Type
: constant Entity_Id
:= Etype
(Act
);
3285 F_Type
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
3286 Orig
: constant Node_Id
:= Original_Node
(N
);
3290 -- Check whether the call is a prefixed call, with or without
3291 -- additional actuals.
3293 if Nkind
(Orig
) = N_Selected_Component
3295 (Nkind
(Orig
) = N_Indexed_Component
3296 and then Nkind
(Prefix
(Orig
)) = N_Selected_Component
3297 and then Is_Entity_Name
(Prefix
(Prefix
(Orig
)))
3298 and then Is_Entity_Name
(Act
)
3299 and then Chars
(Act
) = Chars
(Prefix
(Prefix
(Orig
))))
3301 if Is_Access_Type
(A_Type
)
3302 and then not Is_Access_Type
(F_Type
)
3304 -- Introduce dereference on object in prefix
3307 Make_Explicit_Dereference
(Sloc
(Act
),
3308 Prefix
=> Relocate_Node
(Act
));
3309 Rewrite
(Act
, New_A
);
3312 elsif Is_Access_Type
(F_Type
)
3313 and then not Is_Access_Type
(A_Type
)
3315 -- Introduce an implicit 'Access in prefix
3317 if not Is_Aliased_View
(Act
) then
3319 ("object in prefixed call to& must be aliased "
3320 & "(RM 4.1.3 (13 1/2))",
3325 Make_Attribute_Reference
(Loc
,
3326 Attribute_Name
=> Name_Access
,
3327 Prefix
=> Relocate_Node
(Act
)));
3332 end Check_Prefixed_Call
;
3334 ---------------------------------------
3335 -- Flag_Effectively_Volatile_Objects --
3336 ---------------------------------------
3338 procedure Flag_Effectively_Volatile_Objects
(Expr
: Node_Id
) is
3339 function Flag_Object
(N
: Node_Id
) return Traverse_Result
;
3340 -- Determine whether arbitrary node N denotes an effectively volatile
3341 -- object and if it does, emit an error.
3347 function Flag_Object
(N
: Node_Id
) return Traverse_Result
is
3351 -- Do not consider nested function calls because they have already
3352 -- been processed during their own resolution.
3354 if Nkind
(N
) = N_Function_Call
then
3357 elsif Is_Entity_Name
(N
) and then Present
(Entity
(N
)) then
3361 and then Is_Effectively_Volatile
(Id
)
3362 and then (Async_Writers_Enabled
(Id
)
3363 or else Effective_Reads_Enabled
(Id
))
3366 ("volatile object cannot appear in this context (SPARK "
3367 & "RM 7.1.3(11))", N
);
3375 procedure Flag_Objects
is new Traverse_Proc
(Flag_Object
);
3377 -- Start of processing for Flag_Effectively_Volatile_Objects
3380 Flag_Objects
(Expr
);
3381 end Flag_Effectively_Volatile_Objects
;
3383 --------------------
3384 -- Insert_Default --
3385 --------------------
3387 procedure Insert_Default
is
3392 -- Missing argument in call, nothing to insert
3394 if No
(Default_Value
(F
)) then
3398 -- Note that we do a full New_Copy_Tree, so that any associated
3399 -- Itypes are properly copied. This may not be needed any more,
3400 -- but it does no harm as a safety measure. Defaults of a generic
3401 -- formal may be out of bounds of the corresponding actual (see
3402 -- cc1311b) and an additional check may be required.
3407 New_Scope
=> Current_Scope
,
3410 -- Propagate dimension information, if any.
3412 Copy_Dimensions
(Default_Value
(F
), Actval
);
3414 if Is_Concurrent_Type
(Scope
(Nam
))
3415 and then Has_Discriminants
(Scope
(Nam
))
3417 Replace_Actual_Discriminants
(N
, Actval
);
3420 if Is_Overloadable
(Nam
)
3421 and then Present
(Alias
(Nam
))
3423 if Base_Type
(Etype
(F
)) /= Base_Type
(Etype
(Actval
))
3424 and then not Is_Tagged_Type
(Etype
(F
))
3426 -- If default is a real literal, do not introduce a
3427 -- conversion whose effect may depend on the run-time
3428 -- size of universal real.
3430 if Nkind
(Actval
) = N_Real_Literal
then
3431 Set_Etype
(Actval
, Base_Type
(Etype
(F
)));
3433 Actval
:= Unchecked_Convert_To
(Etype
(F
), Actval
);
3437 if Is_Scalar_Type
(Etype
(F
)) then
3438 Enable_Range_Check
(Actval
);
3441 Set_Parent
(Actval
, N
);
3443 -- Resolve aggregates with their base type, to avoid scope
3444 -- anomalies: the subtype was first built in the subprogram
3445 -- declaration, and the current call may be nested.
3447 if Nkind
(Actval
) = N_Aggregate
then
3448 Analyze_And_Resolve
(Actval
, Etype
(F
));
3450 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3454 Set_Parent
(Actval
, N
);
3456 -- See note above concerning aggregates
3458 if Nkind
(Actval
) = N_Aggregate
3459 and then Has_Discriminants
(Etype
(Actval
))
3461 Analyze_And_Resolve
(Actval
, Base_Type
(Etype
(Actval
)));
3463 -- Resolve entities with their own type, which may differ from
3464 -- the type of a reference in a generic context (the view
3465 -- swapping mechanism did not anticipate the re-analysis of
3466 -- default values in calls).
3468 elsif Is_Entity_Name
(Actval
) then
3469 Analyze_And_Resolve
(Actval
, Etype
(Entity
(Actval
)));
3472 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3476 -- If default is a tag indeterminate function call, propagate tag
3477 -- to obtain proper dispatching.
3479 if Is_Controlling_Formal
(F
)
3480 and then Nkind
(Default_Value
(F
)) = N_Function_Call
3482 Set_Is_Controlling_Actual
(Actval
);
3486 -- If the default expression raises constraint error, then just
3487 -- silently replace it with an N_Raise_Constraint_Error node, since
3488 -- we already gave the warning on the subprogram spec. If node is
3489 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3490 -- the warnings removal machinery.
3492 if Raises_Constraint_Error
(Actval
)
3493 and then Nkind
(Actval
) /= N_Raise_Constraint_Error
3496 Make_Raise_Constraint_Error
(Loc
,
3497 Reason
=> CE_Range_Check_Failed
));
3499 Set_Raises_Constraint_Error
(Actval
);
3500 Set_Etype
(Actval
, Etype
(F
));
3504 Make_Parameter_Association
(Loc
,
3505 Explicit_Actual_Parameter
=> Actval
,
3506 Selector_Name
=> Make_Identifier
(Loc
, Chars
(F
)));
3508 -- Case of insertion is first named actual
3511 or else Nkind
(Parent
(Prev
)) /= N_Parameter_Association
3513 Set_Next_Named_Actual
(Assoc
, First_Named_Actual
(N
));
3514 Set_First_Named_Actual
(N
, Actval
);
3517 if No
(Parameter_Associations
(N
)) then
3518 Set_Parameter_Associations
(N
, New_List
(Assoc
));
3520 Append
(Assoc
, Parameter_Associations
(N
));
3524 Insert_After
(Prev
, Assoc
);
3527 -- Case of insertion is not first named actual
3530 Set_Next_Named_Actual
3531 (Assoc
, Next_Named_Actual
(Parent
(Prev
)));
3532 Set_Next_Named_Actual
(Parent
(Prev
), Actval
);
3533 Append
(Assoc
, Parameter_Associations
(N
));
3536 Mark_Rewrite_Insertion
(Assoc
);
3537 Mark_Rewrite_Insertion
(Actval
);
3546 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean is
3547 FT1
: Entity_Id
:= T1
;
3548 FT2
: Entity_Id
:= T2
;
3551 if Is_Private_Type
(T1
)
3552 and then Present
(Full_View
(T1
))
3554 FT1
:= Full_View
(T1
);
3557 if Is_Private_Type
(T2
)
3558 and then Present
(Full_View
(T2
))
3560 FT2
:= Full_View
(T2
);
3563 return Root_Type
(Base_Type
(FT1
)) = Root_Type
(Base_Type
(FT2
));
3566 --------------------------
3567 -- Static_Concatenation --
3568 --------------------------
3570 function Static_Concatenation
(N
: Node_Id
) return Boolean is
3573 when N_String_Literal
=>
3578 -- Concatenation is static when both operands are static and
3579 -- the concatenation operator is a predefined one.
3581 return Scope
(Entity
(N
)) = Standard_Standard
3583 Static_Concatenation
(Left_Opnd
(N
))
3585 Static_Concatenation
(Right_Opnd
(N
));
3588 if Is_Entity_Name
(N
) then
3590 Ent
: constant Entity_Id
:= Entity
(N
);
3592 return Ekind
(Ent
) = E_Constant
3593 and then Present
(Constant_Value
(Ent
))
3595 Is_OK_Static_Expression
(Constant_Value
(Ent
));
3602 end Static_Concatenation
;
3604 -- Start of processing for Resolve_Actuals
3607 Check_Argument_Order
;
3609 if Is_Overloadable
(Nam
)
3610 and then Is_Inherited_Operation
(Nam
)
3611 and then In_Instance
3612 and then Present
(Alias
(Nam
))
3613 and then Present
(Overridden_Operation
(Alias
(Nam
)))
3615 Real_Subp
:= Alias
(Nam
);
3620 if Present
(First_Actual
(N
)) then
3621 Check_Prefixed_Call
;
3624 A
:= First_Actual
(N
);
3625 F
:= First_Formal
(Nam
);
3627 if Present
(Real_Subp
) then
3628 Real_F
:= First_Formal
(Real_Subp
);
3631 while Present
(F
) loop
3632 if No
(A
) and then Needs_No_Actuals
(Nam
) then
3635 -- If we have an error in any actual or formal, indicated by a type
3636 -- of Any_Type, then abandon resolution attempt, and set result type
3637 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3638 -- type is imposed from context.
3640 elsif (Present
(A
) and then Etype
(A
) = Any_Type
)
3641 or else Etype
(F
) = Any_Type
3643 if Nkind
(A
) /= N_Raise_Expression
then
3644 Set_Etype
(N
, Any_Type
);
3649 -- Case where actual is present
3651 -- If the actual is an entity, generate a reference to it now. We
3652 -- do this before the actual is resolved, because a formal of some
3653 -- protected subprogram, or a task discriminant, will be rewritten
3654 -- during expansion, and the source entity reference may be lost.
3657 and then Is_Entity_Name
(A
)
3658 and then Comes_From_Source
(A
)
3660 -- Annotate the tree by creating a variable reference marker when
3661 -- the actual denotes a variable reference, in case the reference
3662 -- is folded or optimized away. The variable reference marker is
3663 -- automatically saved for later examination by the ABE Processing
3664 -- phase. The status of the reference is set as follows:
3668 -- write IN OUT, OUT
3670 Build_Variable_Reference_Marker
3672 Read
=> Ekind
(F
) /= E_Out_Parameter
,
3673 Write
=> Ekind
(F
) /= E_In_Parameter
);
3675 Orig_A
:= Entity
(A
);
3677 if Present
(Orig_A
) then
3678 if Is_Formal
(Orig_A
)
3679 and then Ekind
(F
) /= E_In_Parameter
3681 Generate_Reference
(Orig_A
, A
, 'm');
3683 elsif not Is_Overloaded
(A
) then
3684 if Ekind
(F
) /= E_Out_Parameter
then
3685 Generate_Reference
(Orig_A
, A
);
3687 -- RM 6.4.1(12): For an out parameter that is passed by
3688 -- copy, the formal parameter object is created, and:
3690 -- * For an access type, the formal parameter is initialized
3691 -- from the value of the actual, without checking that the
3692 -- value satisfies any constraint, any predicate, or any
3693 -- exclusion of the null value.
3695 -- * For a scalar type that has the Default_Value aspect
3696 -- specified, the formal parameter is initialized from the
3697 -- value of the actual, without checking that the value
3698 -- satisfies any constraint or any predicate.
3699 -- I do not understand why this case is included??? this is
3700 -- not a case where an OUT parameter is treated as IN OUT.
3702 -- * For a composite type with discriminants or that has
3703 -- implicit initial values for any subcomponents, the
3704 -- behavior is as for an in out parameter passed by copy.
3706 -- Hence for these cases we generate the read reference now
3707 -- (the write reference will be generated later by
3708 -- Note_Possible_Modification).
3710 elsif Is_By_Copy_Type
(Etype
(F
))
3712 (Is_Access_Type
(Etype
(F
))
3714 (Is_Scalar_Type
(Etype
(F
))
3716 Present
(Default_Aspect_Value
(Etype
(F
))))
3718 (Is_Composite_Type
(Etype
(F
))
3719 and then (Has_Discriminants
(Etype
(F
))
3720 or else Is_Partially_Initialized_Type
3723 Generate_Reference
(Orig_A
, A
);
3730 and then (Nkind
(Parent
(A
)) /= N_Parameter_Association
3731 or else Chars
(Selector_Name
(Parent
(A
))) = Chars
(F
))
3733 -- If style checking mode on, check match of formal name
3736 if Nkind
(Parent
(A
)) = N_Parameter_Association
then
3737 Check_Identifier
(Selector_Name
(Parent
(A
)), F
);
3741 -- If the formal is Out or In_Out, do not resolve and expand the
3742 -- conversion, because it is subsequently expanded into explicit
3743 -- temporaries and assignments. However, the object of the
3744 -- conversion can be resolved. An exception is the case of tagged
3745 -- type conversion with a class-wide actual. In that case we want
3746 -- the tag check to occur and no temporary will be needed (no
3747 -- representation change can occur) and the parameter is passed by
3748 -- reference, so we go ahead and resolve the type conversion.
3749 -- Another exception is the case of reference to component or
3750 -- subcomponent of a bit-packed array, in which case we want to
3751 -- defer expansion to the point the in and out assignments are
3754 if Ekind
(F
) /= E_In_Parameter
3755 and then Nkind
(A
) = N_Type_Conversion
3756 and then not Is_Class_Wide_Type
(Etype
(Expression
(A
)))
3758 if Ekind
(F
) = E_In_Out_Parameter
3759 and then Is_Array_Type
(Etype
(F
))
3761 -- In a view conversion, the conversion must be legal in
3762 -- both directions, and thus both component types must be
3763 -- aliased, or neither (4.6 (8)).
3765 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3766 -- the privacy requirement should not apply to generic
3767 -- types, and should be checked in an instance. ARG query
3770 if Has_Aliased_Components
(Etype
(Expression
(A
))) /=
3771 Has_Aliased_Components
(Etype
(F
))
3774 ("both component types in a view conversion must be"
3775 & " aliased, or neither", A
);
3777 -- Comment here??? what set of cases???
3780 not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3782 -- Check view conv between unrelated by ref array types
3784 if Is_By_Reference_Type
(Etype
(F
))
3785 or else Is_By_Reference_Type
(Etype
(Expression
(A
)))
3788 ("view conversion between unrelated by reference "
3789 & "array types not allowed (\'A'I-00246)", A
);
3791 -- In Ada 2005 mode, check view conversion component
3792 -- type cannot be private, tagged, or volatile. Note
3793 -- that we only apply this to source conversions. The
3794 -- generated code can contain conversions which are
3795 -- not subject to this test, and we cannot extract the
3796 -- component type in such cases since it is not present.
3798 elsif Comes_From_Source
(A
)
3799 and then Ada_Version
>= Ada_2005
3802 Comp_Type
: constant Entity_Id
:=
3804 (Etype
(Expression
(A
)));
3806 if (Is_Private_Type
(Comp_Type
)
3807 and then not Is_Generic_Type
(Comp_Type
))
3808 or else Is_Tagged_Type
(Comp_Type
)
3809 or else Is_Volatile
(Comp_Type
)
3812 ("component type of a view conversion cannot"
3813 & " be private, tagged, or volatile"
3822 -- Resolve expression if conversion is all OK
3824 if (Conversion_OK
(A
)
3825 or else Valid_Conversion
(A
, Etype
(A
), Expression
(A
)))
3826 and then not Is_Ref_To_Bit_Packed_Array
(Expression
(A
))
3828 Resolve
(Expression
(A
));
3831 -- If the actual is a function call that returns a limited
3832 -- unconstrained object that needs finalization, create a
3833 -- transient scope for it, so that it can receive the proper
3834 -- finalization list.
3836 elsif Expander_Active
3837 and then Nkind
(A
) = N_Function_Call
3838 and then Is_Limited_Record
(Etype
(F
))
3839 and then not Is_Constrained
(Etype
(F
))
3840 and then (Needs_Finalization
(Etype
(F
))
3841 or else Has_Task
(Etype
(F
)))
3843 Establish_Transient_Scope
(A
, Manage_Sec_Stack
=> False);
3844 Resolve
(A
, Etype
(F
));
3846 -- A small optimization: if one of the actuals is a concatenation
3847 -- create a block around a procedure call to recover stack space.
3848 -- This alleviates stack usage when several procedure calls in
3849 -- the same statement list use concatenation. We do not perform
3850 -- this wrapping for code statements, where the argument is a
3851 -- static string, and we want to preserve warnings involving
3852 -- sequences of such statements.
3854 elsif Expander_Active
3855 and then Nkind
(A
) = N_Op_Concat
3856 and then Nkind
(N
) = N_Procedure_Call_Statement
3857 and then not (Is_Intrinsic_Subprogram
(Nam
)
3858 and then Chars
(Nam
) = Name_Asm
)
3859 and then not Static_Concatenation
(A
)
3861 Establish_Transient_Scope
(A
, Manage_Sec_Stack
=> False);
3862 Resolve
(A
, Etype
(F
));
3865 if Nkind
(A
) = N_Type_Conversion
3866 and then Is_Array_Type
(Etype
(F
))
3867 and then not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3869 (Is_Limited_Type
(Etype
(F
))
3870 or else Is_Limited_Type
(Etype
(Expression
(A
))))
3873 ("conversion between unrelated limited array types not "
3874 & "allowed ('A'I-00246)", A
);
3876 if Is_Limited_Type
(Etype
(F
)) then
3877 Explain_Limited_Type
(Etype
(F
), A
);
3880 if Is_Limited_Type
(Etype
(Expression
(A
))) then
3881 Explain_Limited_Type
(Etype
(Expression
(A
)), A
);
3885 -- (Ada 2005: AI-251): If the actual is an allocator whose
3886 -- directly designated type is a class-wide interface, we build
3887 -- an anonymous access type to use it as the type of the
3888 -- allocator. Later, when the subprogram call is expanded, if
3889 -- the interface has a secondary dispatch table the expander
3890 -- will add a type conversion to force the correct displacement
3893 if Nkind
(A
) = N_Allocator
then
3895 DDT
: constant Entity_Id
:=
3896 Directly_Designated_Type
(Base_Type
(Etype
(F
)));
3898 New_Itype
: Entity_Id
;
3901 if Is_Class_Wide_Type
(DDT
)
3902 and then Is_Interface
(DDT
)
3904 New_Itype
:= Create_Itype
(E_Anonymous_Access_Type
, A
);
3905 Set_Etype
(New_Itype
, Etype
(A
));
3906 Set_Directly_Designated_Type
3907 (New_Itype
, Directly_Designated_Type
(Etype
(A
)));
3908 Set_Etype
(A
, New_Itype
);
3911 -- Ada 2005, AI-162:If the actual is an allocator, the
3912 -- innermost enclosing statement is the master of the
3913 -- created object. This needs to be done with expansion
3914 -- enabled only, otherwise the transient scope will not
3915 -- be removed in the expansion of the wrapped construct.
3918 and then (Needs_Finalization
(DDT
)
3919 or else Has_Task
(DDT
))
3921 Establish_Transient_Scope
3922 (A
, Manage_Sec_Stack
=> False);
3926 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
3927 Check_Restriction
(No_Access_Parameter_Allocators
, A
);
3931 -- (Ada 2005): The call may be to a primitive operation of a
3932 -- tagged synchronized type, declared outside of the type. In
3933 -- this case the controlling actual must be converted to its
3934 -- corresponding record type, which is the formal type. The
3935 -- actual may be a subtype, either because of a constraint or
3936 -- because it is a generic actual, so use base type to locate
3939 F_Typ
:= Base_Type
(Etype
(F
));
3941 if Is_Tagged_Type
(F_Typ
)
3942 and then (Is_Concurrent_Type
(F_Typ
)
3943 or else Is_Concurrent_Record_Type
(F_Typ
))
3945 -- If the actual is overloaded, look for an interpretation
3946 -- that has a synchronized type.
3948 if not Is_Overloaded
(A
) then
3949 A_Typ
:= Base_Type
(Etype
(A
));
3953 Index
: Interp_Index
;
3957 Get_First_Interp
(A
, Index
, It
);
3958 while Present
(It
.Typ
) loop
3959 if Is_Concurrent_Type
(It
.Typ
)
3960 or else Is_Concurrent_Record_Type
(It
.Typ
)
3962 A_Typ
:= Base_Type
(It
.Typ
);
3966 Get_Next_Interp
(Index
, It
);
3972 Full_A_Typ
: Entity_Id
;
3975 if Present
(Full_View
(A_Typ
)) then
3976 Full_A_Typ
:= Base_Type
(Full_View
(A_Typ
));
3978 Full_A_Typ
:= A_Typ
;
3981 -- Tagged synchronized type (case 1): the actual is a
3984 if Is_Concurrent_Type
(A_Typ
)
3985 and then Corresponding_Record_Type
(A_Typ
) = F_Typ
3988 Unchecked_Convert_To
3989 (Corresponding_Record_Type
(A_Typ
), A
));
3990 Resolve
(A
, Etype
(F
));
3992 -- Tagged synchronized type (case 2): the formal is a
3995 elsif Ekind
(Full_A_Typ
) = E_Record_Type
3997 (Corresponding_Concurrent_Type
(Full_A_Typ
))
3998 and then Is_Concurrent_Type
(F_Typ
)
3999 and then Present
(Corresponding_Record_Type
(F_Typ
))
4000 and then Full_A_Typ
= Corresponding_Record_Type
(F_Typ
)
4002 Resolve
(A
, Corresponding_Record_Type
(F_Typ
));
4007 Resolve
(A
, Etype
(F
));
4011 -- Not a synchronized operation
4014 Resolve
(A
, Etype
(F
));
4021 -- An actual cannot be an untagged formal incomplete type
4023 if Ekind
(A_Typ
) = E_Incomplete_Type
4024 and then not Is_Tagged_Type
(A_Typ
)
4025 and then Is_Generic_Type
(A_Typ
)
4028 ("invalid use of untagged formal incomplete type", A
);
4031 if Comes_From_Source
(Original_Node
(N
))
4032 and then Nkind_In
(Original_Node
(N
), N_Function_Call
,
4033 N_Procedure_Call_Statement
)
4035 -- In formal mode, check that actual parameters matching
4036 -- formals of tagged types are objects (or ancestor type
4037 -- conversions of objects), not general expressions.
4039 if Is_Actual_Tagged_Parameter
(A
) then
4040 if Is_SPARK_05_Object_Reference
(A
) then
4043 elsif Nkind
(A
) = N_Type_Conversion
then
4045 Operand
: constant Node_Id
:= Expression
(A
);
4046 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
4047 Target_Typ
: constant Entity_Id
:= A_Typ
;
4050 if not Is_SPARK_05_Object_Reference
(Operand
) then
4051 Check_SPARK_05_Restriction
4052 ("object required", Operand
);
4054 -- In formal mode, the only view conversions are those
4055 -- involving ancestor conversion of an extended type.
4058 (Is_Tagged_Type
(Target_Typ
)
4059 and then not Is_Class_Wide_Type
(Target_Typ
)
4060 and then Is_Tagged_Type
(Operand_Typ
)
4061 and then not Is_Class_Wide_Type
(Operand_Typ
)
4062 and then Is_Ancestor
(Target_Typ
, Operand_Typ
))
4065 (F
, E_Out_Parameter
, E_In_Out_Parameter
)
4067 Check_SPARK_05_Restriction
4068 ("ancestor conversion is the only permitted "
4069 & "view conversion", A
);
4071 Check_SPARK_05_Restriction
4072 ("ancestor conversion required", A
);
4081 Check_SPARK_05_Restriction
("object required", A
);
4084 -- In formal mode, the only view conversions are those
4085 -- involving ancestor conversion of an extended type.
4087 elsif Nkind
(A
) = N_Type_Conversion
4088 and then Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
4090 Check_SPARK_05_Restriction
4091 ("ancestor conversion is the only permitted view "
4096 -- has warnings suppressed, then we reset Never_Set_In_Source for
4097 -- the calling entity. The reason for this is to catch cases like
4098 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4099 -- uses trickery to modify an IN parameter.
4101 if Ekind
(F
) = E_In_Parameter
4102 and then Is_Entity_Name
(A
)
4103 and then Present
(Entity
(A
))
4104 and then Ekind
(Entity
(A
)) = E_Variable
4105 and then Has_Warnings_Off
(F_Typ
)
4107 Set_Never_Set_In_Source
(Entity
(A
), False);
4110 -- Perform error checks for IN and IN OUT parameters
4112 if Ekind
(F
) /= E_Out_Parameter
then
4114 -- Check unset reference. For scalar parameters, it is clearly
4115 -- wrong to pass an uninitialized value as either an IN or
4116 -- IN-OUT parameter. For composites, it is also clearly an
4117 -- error to pass a completely uninitialized value as an IN
4118 -- parameter, but the case of IN OUT is trickier. We prefer
4119 -- not to give a warning here. For example, suppose there is
4120 -- a routine that sets some component of a record to False.
4121 -- It is perfectly reasonable to make this IN-OUT and allow
4122 -- either initialized or uninitialized records to be passed
4125 -- For partially initialized composite values, we also avoid
4126 -- warnings, since it is quite likely that we are passing a
4127 -- partially initialized value and only the initialized fields
4128 -- will in fact be read in the subprogram.
4130 if Is_Scalar_Type
(A_Typ
)
4131 or else (Ekind
(F
) = E_In_Parameter
4132 and then not Is_Partially_Initialized_Type
(A_Typ
))
4134 Check_Unset_Reference
(A
);
4137 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4138 -- actual to a nested call, since this constitutes a reading of
4139 -- the parameter, which is not allowed.
4141 if Ada_Version
= Ada_83
4142 and then Is_Entity_Name
(A
)
4143 and then Ekind
(Entity
(A
)) = E_Out_Parameter
4145 Error_Msg_N
("(Ada 83) illegal reading of out parameter", A
);
4149 -- In -gnatd.q mode, forget that a given array is constant when
4150 -- it is passed as an IN parameter to a foreign-convention
4151 -- subprogram. This is in case the subprogram evilly modifies the
4152 -- object. Of course, correct code would use IN OUT.
4155 and then Ekind
(F
) = E_In_Parameter
4156 and then Has_Foreign_Convention
(Nam
)
4157 and then Is_Array_Type
(F_Typ
)
4158 and then Nkind
(A
) in N_Has_Entity
4159 and then Present
(Entity
(A
))
4161 Set_Is_True_Constant
(Entity
(A
), False);
4164 -- Case of OUT or IN OUT parameter
4166 if Ekind
(F
) /= E_In_Parameter
then
4168 -- For an Out parameter, check for useless assignment. Note
4169 -- that we can't set Last_Assignment this early, because we may
4170 -- kill current values in Resolve_Call, and that call would
4171 -- clobber the Last_Assignment field.
4173 -- Note: call Warn_On_Useless_Assignment before doing the check
4174 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4175 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4176 -- reflects the last assignment, not this one.
4178 if Ekind
(F
) = E_Out_Parameter
then
4179 if Warn_On_Modified_As_Out_Parameter
(F
)
4180 and then Is_Entity_Name
(A
)
4181 and then Present
(Entity
(A
))
4182 and then Comes_From_Source
(N
)
4184 Warn_On_Useless_Assignment
(Entity
(A
), A
);
4188 -- Validate the form of the actual. Note that the call to
4189 -- Is_OK_Variable_For_Out_Formal generates the required
4190 -- reference in this case.
4192 -- A call to an initialization procedure for an aggregate
4193 -- component may initialize a nested component of a constant
4194 -- designated object. In this context the object is variable.
4196 if not Is_OK_Variable_For_Out_Formal
(A
)
4197 and then not Is_Init_Proc
(Nam
)
4199 Error_Msg_NE
("actual for& must be a variable", A
, F
);
4201 if Is_Subprogram
(Current_Scope
) then
4202 if Is_Invariant_Procedure
(Current_Scope
)
4203 or else Is_Partial_Invariant_Procedure
(Current_Scope
)
4206 ("function used in invariant cannot modify its "
4209 elsif Is_Predicate_Function
(Current_Scope
) then
4211 ("function used in predicate cannot modify its "
4217 -- What's the following about???
4219 if Is_Entity_Name
(A
) then
4220 Kill_Checks
(Entity
(A
));
4226 if Etype
(A
) = Any_Type
then
4227 Set_Etype
(N
, Any_Type
);
4231 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4233 if Ekind_In
(F
, E_In_Parameter
, E_In_Out_Parameter
) then
4235 -- Apply predicate tests except in certain special cases. Note
4236 -- that it might be more consistent to apply these only when
4237 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4238 -- for the outbound predicate tests ??? In any case indicate
4239 -- the function being called, for better warnings if the call
4240 -- leads to an infinite recursion.
4242 if Predicate_Tests_On_Arguments
(Nam
) then
4243 Apply_Predicate_Check
(A
, F_Typ
, Nam
);
4246 -- Apply required constraint checks
4248 -- Gigi looks at the check flag and uses the appropriate types.
4249 -- For now since one flag is used there is an optimization
4250 -- which might not be done in the IN OUT case since Gigi does
4251 -- not do any analysis. More thought required about this ???
4253 -- In fact is this comment obsolete??? doesn't the expander now
4254 -- generate all these tests anyway???
4256 if Is_Scalar_Type
(Etype
(A
)) then
4257 Apply_Scalar_Range_Check
(A
, F_Typ
);
4259 elsif Is_Array_Type
(Etype
(A
)) then
4260 Apply_Length_Check
(A
, F_Typ
);
4262 elsif Is_Record_Type
(F_Typ
)
4263 and then Has_Discriminants
(F_Typ
)
4264 and then Is_Constrained
(F_Typ
)
4265 and then (not Is_Derived_Type
(F_Typ
)
4266 or else Comes_From_Source
(Nam
))
4268 Apply_Discriminant_Check
(A
, F_Typ
);
4270 -- For view conversions of a discriminated object, apply
4271 -- check to object itself, the conversion alreay has the
4274 if Nkind
(A
) = N_Type_Conversion
4275 and then Is_Constrained
(Etype
(Expression
(A
)))
4277 Apply_Discriminant_Check
(Expression
(A
), F_Typ
);
4280 elsif Is_Access_Type
(F_Typ
)
4281 and then Is_Array_Type
(Designated_Type
(F_Typ
))
4282 and then Is_Constrained
(Designated_Type
(F_Typ
))
4284 Apply_Length_Check
(A
, F_Typ
);
4286 elsif Is_Access_Type
(F_Typ
)
4287 and then Has_Discriminants
(Designated_Type
(F_Typ
))
4288 and then Is_Constrained
(Designated_Type
(F_Typ
))
4290 Apply_Discriminant_Check
(A
, F_Typ
);
4293 Apply_Range_Check
(A
, F_Typ
);
4296 -- Ada 2005 (AI-231): Note that the controlling parameter case
4297 -- already existed in Ada 95, which is partially checked
4298 -- elsewhere (see Checks), and we don't want the warning
4299 -- message to differ.
4301 if Is_Access_Type
(F_Typ
)
4302 and then Can_Never_Be_Null
(F_Typ
)
4303 and then Known_Null
(A
)
4305 if Is_Controlling_Formal
(F
) then
4306 Apply_Compile_Time_Constraint_Error
4308 Msg
=> "null value not allowed here??",
4309 Reason
=> CE_Access_Check_Failed
);
4311 elsif Ada_Version
>= Ada_2005
then
4312 Apply_Compile_Time_Constraint_Error
4314 Msg
=> "(Ada 2005) null not allowed in "
4315 & "null-excluding formal??",
4316 Reason
=> CE_Null_Not_Allowed
);
4321 -- Checks for OUT parameters and IN OUT parameters
4323 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
) then
4325 -- If there is a type conversion, make sure the return value
4326 -- meets the constraints of the variable before the conversion.
4328 if Nkind
(A
) = N_Type_Conversion
then
4329 if Is_Scalar_Type
(A_Typ
) then
4330 Apply_Scalar_Range_Check
4331 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4333 -- In addition, the returned value of the parameter must
4334 -- satisfy the bounds of the object type (see comment
4337 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
4341 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4344 -- If no conversion, apply scalar range checks and length check
4345 -- based on the subtype of the actual (NOT that of the formal).
4346 -- This indicates that the check takes place on return from the
4347 -- call. During expansion the required constraint checks are
4348 -- inserted. In GNATprove mode, in the absence of expansion,
4349 -- the flag indicates that the returned value is valid.
4352 if Is_Scalar_Type
(F_Typ
) then
4353 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
4355 elsif Is_Array_Type
(F_Typ
)
4356 and then Ekind
(F
) = E_Out_Parameter
4358 Apply_Length_Check
(A
, F_Typ
);
4360 Apply_Range_Check
(A
, A_Typ
, F_Typ
);
4364 -- Note: we do not apply the predicate checks for the case of
4365 -- OUT and IN OUT parameters. They are instead applied in the
4366 -- Expand_Actuals routine in Exp_Ch6.
4369 -- An actual associated with an access parameter is implicitly
4370 -- converted to the anonymous access type of the formal and must
4371 -- satisfy the legality checks for access conversions.
4373 if Ekind
(F_Typ
) = E_Anonymous_Access_Type
then
4374 if not Valid_Conversion
(A
, F_Typ
, A
) then
4376 ("invalid implicit conversion for access parameter", A
);
4379 -- If the actual is an access selected component of a variable,
4380 -- the call may modify its designated object. It is reasonable
4381 -- to treat this as a potential modification of the enclosing
4382 -- record, to prevent spurious warnings that it should be
4383 -- declared as a constant, because intuitively programmers
4384 -- regard the designated subcomponent as part of the record.
4386 if Nkind
(A
) = N_Selected_Component
4387 and then Is_Entity_Name
(Prefix
(A
))
4388 and then not Is_Constant_Object
(Entity
(Prefix
(A
)))
4390 Note_Possible_Modification
(A
, Sure
=> False);
4394 -- Check bad case of atomic/volatile argument (RM C.6(12))
4396 if Is_By_Reference_Type
(Etype
(F
))
4397 and then Comes_From_Source
(N
)
4399 if Is_Atomic_Object
(A
)
4400 and then not Is_Atomic
(Etype
(F
))
4403 ("cannot pass atomic argument to non-atomic formal&",
4406 elsif Is_Volatile_Object
(A
)
4407 and then not Is_Volatile
(Etype
(F
))
4410 ("cannot pass volatile argument to non-volatile formal&",
4415 -- Check that subprograms don't have improper controlling
4416 -- arguments (RM 3.9.2 (9)).
4418 -- A primitive operation may have an access parameter of an
4419 -- incomplete tagged type, but a dispatching call is illegal
4420 -- if the type is still incomplete.
4422 if Is_Controlling_Formal
(F
) then
4423 Set_Is_Controlling_Actual
(A
);
4425 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
4427 Desig
: constant Entity_Id
:= Designated_Type
(Etype
(F
));
4429 if Ekind
(Desig
) = E_Incomplete_Type
4430 and then No
(Full_View
(Desig
))
4431 and then No
(Non_Limited_View
(Desig
))
4434 ("premature use of incomplete type& "
4435 & "in dispatching call", A
, Desig
);
4440 elsif Nkind
(A
) = N_Explicit_Dereference
then
4441 Validate_Remote_Access_To_Class_Wide_Type
(A
);
4444 -- Apply legality rule 3.9.2 (9/1)
4446 if (Is_Class_Wide_Type
(A_Typ
) or else Is_Dynamically_Tagged
(A
))
4447 and then not Is_Class_Wide_Type
(F_Typ
)
4448 and then not Is_Controlling_Formal
(F
)
4449 and then not In_Instance
4451 Error_Msg_N
("class-wide argument not allowed here!", A
);
4453 if Is_Subprogram
(Nam
) and then Comes_From_Source
(Nam
) then
4454 Error_Msg_Node_2
:= F_Typ
;
4456 ("& is not a dispatching operation of &!", A
, Nam
);
4459 -- Apply the checks described in 3.10.2(27): if the context is a
4460 -- specific access-to-object, the actual cannot be class-wide.
4461 -- Use base type to exclude access_to_subprogram cases.
4463 elsif Is_Access_Type
(A_Typ
)
4464 and then Is_Access_Type
(F_Typ
)
4465 and then not Is_Access_Subprogram_Type
(Base_Type
(F_Typ
))
4466 and then (Is_Class_Wide_Type
(Designated_Type
(A_Typ
))
4467 or else (Nkind
(A
) = N_Attribute_Reference
4469 Is_Class_Wide_Type
(Etype
(Prefix
(A
)))))
4470 and then not Is_Class_Wide_Type
(Designated_Type
(F_Typ
))
4471 and then not Is_Controlling_Formal
(F
)
4473 -- Disable these checks for call to imported C++ subprograms
4476 (Is_Entity_Name
(Name
(N
))
4477 and then Is_Imported
(Entity
(Name
(N
)))
4478 and then Convention
(Entity
(Name
(N
))) = Convention_CPP
)
4481 ("access to class-wide argument not allowed here!", A
);
4483 if Is_Subprogram
(Nam
) and then Comes_From_Source
(Nam
) then
4484 Error_Msg_Node_2
:= Designated_Type
(F_Typ
);
4486 ("& is not a dispatching operation of &!", A
, Nam
);
4490 Check_Aliased_Parameter
;
4494 -- If it is a named association, treat the selector_name as a
4495 -- proper identifier, and mark the corresponding entity.
4497 if Nkind
(Parent
(A
)) = N_Parameter_Association
4499 -- Ignore reference in SPARK mode, as it refers to an entity not
4500 -- in scope at the point of reference, so the reference should
4501 -- be ignored for computing effects of subprograms.
4503 and then not GNATprove_Mode
4505 -- If subprogram is overridden, use name of formal that
4508 if Present
(Real_Subp
) then
4509 Set_Entity
(Selector_Name
(Parent
(A
)), Real_F
);
4510 Set_Etype
(Selector_Name
(Parent
(A
)), Etype
(Real_F
));
4513 Set_Entity
(Selector_Name
(Parent
(A
)), F
);
4514 Generate_Reference
(F
, Selector_Name
(Parent
(A
)));
4515 Set_Etype
(Selector_Name
(Parent
(A
)), F_Typ
);
4516 Generate_Reference
(F_Typ
, N
, ' ');
4522 if Ekind
(F
) /= E_Out_Parameter
then
4523 Check_Unset_Reference
(A
);
4526 -- The following checks are only relevant when SPARK_Mode is on as
4527 -- they are not standard Ada legality rule. Internally generated
4528 -- temporaries are ignored.
4530 if SPARK_Mode
= On
and then Comes_From_Source
(A
) then
4532 -- An effectively volatile object may act as an actual when the
4533 -- corresponding formal is of a non-scalar effectively volatile
4534 -- type (SPARK RM 7.1.3(11)).
4536 if not Is_Scalar_Type
(Etype
(F
))
4537 and then Is_Effectively_Volatile
(Etype
(F
))
4541 -- An effectively volatile object may act as an actual in a
4542 -- call to an instance of Unchecked_Conversion.
4543 -- (SPARK RM 7.1.3(11)).
4545 elsif Is_Unchecked_Conversion_Instance
(Nam
) then
4548 -- The actual denotes an object
4550 elsif Is_Effectively_Volatile_Object
(A
) then
4552 ("volatile object cannot act as actual in a call (SPARK "
4553 & "RM 7.1.3(11))", A
);
4555 -- Otherwise the actual denotes an expression. Inspect the
4556 -- expression and flag each effectively volatile object with
4557 -- enabled property Async_Writers or Effective_Reads as illegal
4558 -- because it apprears within an interfering context. Note that
4559 -- this is usually done in Resolve_Entity_Name, but when the
4560 -- effectively volatile object appears as an actual in a call,
4561 -- the call must be resolved first.
4564 Flag_Effectively_Volatile_Objects
(A
);
4567 -- An effectively volatile variable cannot act as an actual
4568 -- parameter in a procedure call when the variable has enabled
4569 -- property Effective_Reads and the corresponding formal is of
4570 -- mode IN (SPARK RM 7.1.3(10)).
4572 if Ekind
(Nam
) = E_Procedure
4573 and then Ekind
(F
) = E_In_Parameter
4574 and then Is_Entity_Name
(A
)
4578 if Ekind
(A_Id
) = E_Variable
4579 and then Is_Effectively_Volatile
(Etype
(A_Id
))
4580 and then Effective_Reads_Enabled
(A_Id
)
4583 ("effectively volatile variable & cannot appear as "
4584 & "actual in procedure call", A
, A_Id
);
4586 Error_Msg_Name_1
:= Name_Effective_Reads
;
4587 Error_Msg_N
("\\variable has enabled property %", A
);
4588 Error_Msg_N
("\\corresponding formal has mode IN", A
);
4593 -- A formal parameter of a specific tagged type whose related
4594 -- subprogram is subject to pragma Extensions_Visible with value
4595 -- "False" cannot act as an actual in a subprogram with value
4596 -- "True" (SPARK RM 6.1.7(3)).
4598 if Is_EVF_Expression
(A
)
4599 and then Extensions_Visible_Status
(Nam
) =
4600 Extensions_Visible_True
4603 ("formal parameter cannot act as actual parameter when "
4604 & "Extensions_Visible is False", A
);
4606 ("\subprogram & has Extensions_Visible True", A
, Nam
);
4609 -- The actual parameter of a Ghost subprogram whose formal is of
4610 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(12)).
4612 if Comes_From_Source
(Nam
)
4613 and then Is_Ghost_Entity
(Nam
)
4614 and then Ekind_In
(F
, E_In_Out_Parameter
, E_Out_Parameter
)
4615 and then Is_Entity_Name
(A
)
4616 and then Present
(Entity
(A
))
4617 and then not Is_Ghost_Entity
(Entity
(A
))
4620 ("non-ghost variable & cannot appear as actual in call to "
4621 & "ghost procedure", A
, Entity
(A
));
4623 if Ekind
(F
) = E_In_Out_Parameter
then
4624 Error_Msg_N
("\corresponding formal has mode `IN OUT`", A
);
4626 Error_Msg_N
("\corresponding formal has mode OUT", A
);
4632 -- Case where actual is not present
4640 if Present
(Real_Subp
) then
4641 Next_Formal
(Real_F
);
4644 end Resolve_Actuals
;
4646 -----------------------
4647 -- Resolve_Allocator --
4648 -----------------------
4650 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
) is
4651 Desig_T
: constant Entity_Id
:= Designated_Type
(Typ
);
4652 E
: constant Node_Id
:= Expression
(N
);
4654 Discrim
: Entity_Id
;
4657 Assoc
: Node_Id
:= Empty
;
4660 procedure Check_Allocator_Discrim_Accessibility
4661 (Disc_Exp
: Node_Id
;
4662 Alloc_Typ
: Entity_Id
);
4663 -- Check that accessibility level associated with an access discriminant
4664 -- initialized in an allocator by the expression Disc_Exp is not deeper
4665 -- than the level of the allocator type Alloc_Typ. An error message is
4666 -- issued if this condition is violated. Specialized checks are done for
4667 -- the cases of a constraint expression which is an access attribute or
4668 -- an access discriminant.
4670 function In_Dispatching_Context
return Boolean;
4671 -- If the allocator is an actual in a call, it is allowed to be class-
4672 -- wide when the context is not because it is a controlling actual.
4674 -------------------------------------------
4675 -- Check_Allocator_Discrim_Accessibility --
4676 -------------------------------------------
4678 procedure Check_Allocator_Discrim_Accessibility
4679 (Disc_Exp
: Node_Id
;
4680 Alloc_Typ
: Entity_Id
)
4683 if Type_Access_Level
(Etype
(Disc_Exp
)) >
4684 Deepest_Type_Access_Level
(Alloc_Typ
)
4687 ("operand type has deeper level than allocator type", Disc_Exp
);
4689 -- When the expression is an Access attribute the level of the prefix
4690 -- object must not be deeper than that of the allocator's type.
4692 elsif Nkind
(Disc_Exp
) = N_Attribute_Reference
4693 and then Get_Attribute_Id
(Attribute_Name
(Disc_Exp
)) =
4695 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4696 Deepest_Type_Access_Level
(Alloc_Typ
)
4699 ("prefix of attribute has deeper level than allocator type",
4702 -- When the expression is an access discriminant the check is against
4703 -- the level of the prefix object.
4705 elsif Ekind
(Etype
(Disc_Exp
)) = E_Anonymous_Access_Type
4706 and then Nkind
(Disc_Exp
) = N_Selected_Component
4707 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4708 Deepest_Type_Access_Level
(Alloc_Typ
)
4711 ("access discriminant has deeper level than allocator type",
4714 -- All other cases are legal
4719 end Check_Allocator_Discrim_Accessibility
;
4721 ----------------------------
4722 -- In_Dispatching_Context --
4723 ----------------------------
4725 function In_Dispatching_Context
return Boolean is
4726 Par
: constant Node_Id
:= Parent
(N
);
4729 return Nkind
(Par
) in N_Subprogram_Call
4730 and then Is_Entity_Name
(Name
(Par
))
4731 and then Is_Dispatching_Operation
(Entity
(Name
(Par
)));
4732 end In_Dispatching_Context
;
4734 -- Start of processing for Resolve_Allocator
4737 -- Replace general access with specific type
4739 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
4740 Set_Etype
(N
, Base_Type
(Typ
));
4743 if Is_Abstract_Type
(Typ
) then
4744 Error_Msg_N
("type of allocator cannot be abstract", N
);
4747 -- For qualified expression, resolve the expression using the given
4748 -- subtype (nothing to do for type mark, subtype indication)
4750 if Nkind
(E
) = N_Qualified_Expression
then
4751 if Is_Class_Wide_Type
(Etype
(E
))
4752 and then not Is_Class_Wide_Type
(Desig_T
)
4753 and then not In_Dispatching_Context
4756 ("class-wide allocator not allowed for this access type", N
);
4759 Resolve
(Expression
(E
), Etype
(E
));
4760 Check_Non_Static_Context
(Expression
(E
));
4761 Check_Unset_Reference
(Expression
(E
));
4763 -- Allocators generated by the build-in-place expansion mechanism
4764 -- are explicitly marked as coming from source but do not need to be
4765 -- checked for limited initialization. To exclude this case, ensure
4766 -- that the parent of the allocator is a source node.
4767 -- The return statement constructed for an Expression_Function does
4768 -- not come from source but requires a limited check.
4770 if Is_Limited_Type
(Etype
(E
))
4771 and then Comes_From_Source
(N
)
4773 (Comes_From_Source
(Parent
(N
))
4775 (Ekind
(Current_Scope
) = E_Function
4776 and then Nkind
(Original_Node
(Unit_Declaration_Node
4777 (Current_Scope
))) = N_Expression_Function
))
4778 and then not In_Instance_Body
4780 if not OK_For_Limited_Init
(Etype
(E
), Expression
(E
)) then
4781 if Nkind
(Parent
(N
)) = N_Assignment_Statement
then
4783 ("illegal expression for initialized allocator of a "
4784 & "limited type (RM 7.5 (2.7/2))", N
);
4787 ("initialization not allowed for limited types", N
);
4790 Explain_Limited_Type
(Etype
(E
), N
);
4794 -- A qualified expression requires an exact match of the type. Class-
4795 -- wide matching is not allowed.
4797 if (Is_Class_Wide_Type
(Etype
(Expression
(E
)))
4798 or else Is_Class_Wide_Type
(Etype
(E
)))
4799 and then Base_Type
(Etype
(Expression
(E
))) /= Base_Type
(Etype
(E
))
4801 Wrong_Type
(Expression
(E
), Etype
(E
));
4804 -- Calls to build-in-place functions are not currently supported in
4805 -- allocators for access types associated with a simple storage pool.
4806 -- Supporting such allocators may require passing additional implicit
4807 -- parameters to build-in-place functions (or a significant revision
4808 -- of the current b-i-p implementation to unify the handling for
4809 -- multiple kinds of storage pools). ???
4811 if Is_Limited_View
(Desig_T
)
4812 and then Nkind
(Expression
(E
)) = N_Function_Call
4815 Pool
: constant Entity_Id
:=
4816 Associated_Storage_Pool
(Root_Type
(Typ
));
4820 Present
(Get_Rep_Pragma
4821 (Etype
(Pool
), Name_Simple_Storage_Pool_Type
))
4824 ("limited function calls not yet supported in simple "
4825 & "storage pool allocators", Expression
(E
));
4830 -- A special accessibility check is needed for allocators that
4831 -- constrain access discriminants. The level of the type of the
4832 -- expression used to constrain an access discriminant cannot be
4833 -- deeper than the type of the allocator (in contrast to access
4834 -- parameters, where the level of the actual can be arbitrary).
4836 -- We can't use Valid_Conversion to perform this check because in
4837 -- general the type of the allocator is unrelated to the type of
4838 -- the access discriminant.
4840 if Ekind
(Typ
) /= E_Anonymous_Access_Type
4841 or else Is_Local_Anonymous_Access
(Typ
)
4843 Subtyp
:= Entity
(Subtype_Mark
(E
));
4845 Aggr
:= Original_Node
(Expression
(E
));
4847 if Has_Discriminants
(Subtyp
)
4848 and then Nkind_In
(Aggr
, N_Aggregate
, N_Extension_Aggregate
)
4850 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4852 -- Get the first component expression of the aggregate
4854 if Present
(Expressions
(Aggr
)) then
4855 Disc_Exp
:= First
(Expressions
(Aggr
));
4857 elsif Present
(Component_Associations
(Aggr
)) then
4858 Assoc
:= First
(Component_Associations
(Aggr
));
4860 if Present
(Assoc
) then
4861 Disc_Exp
:= Expression
(Assoc
);
4870 while Present
(Discrim
) and then Present
(Disc_Exp
) loop
4871 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4872 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4875 Next_Discriminant
(Discrim
);
4877 if Present
(Discrim
) then
4878 if Present
(Assoc
) then
4880 Disc_Exp
:= Expression
(Assoc
);
4882 elsif Present
(Next
(Disc_Exp
)) then
4886 Assoc
:= First
(Component_Associations
(Aggr
));
4888 if Present
(Assoc
) then
4889 Disc_Exp
:= Expression
(Assoc
);
4899 -- For a subtype mark or subtype indication, freeze the subtype
4902 Freeze_Expression
(E
);
4904 if Is_Access_Constant
(Typ
) and then not No_Initialization
(N
) then
4906 ("initialization required for access-to-constant allocator", N
);
4909 -- A special accessibility check is needed for allocators that
4910 -- constrain access discriminants. The level of the type of the
4911 -- expression used to constrain an access discriminant cannot be
4912 -- deeper than the type of the allocator (in contrast to access
4913 -- parameters, where the level of the actual can be arbitrary).
4914 -- We can't use Valid_Conversion to perform this check because
4915 -- in general the type of the allocator is unrelated to the type
4916 -- of the access discriminant.
4918 if Nkind
(Original_Node
(E
)) = N_Subtype_Indication
4919 and then (Ekind
(Typ
) /= E_Anonymous_Access_Type
4920 or else Is_Local_Anonymous_Access
(Typ
))
4922 Subtyp
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4924 if Has_Discriminants
(Subtyp
) then
4925 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4926 Constr
:= First
(Constraints
(Constraint
(Original_Node
(E
))));
4927 while Present
(Discrim
) and then Present
(Constr
) loop
4928 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4929 if Nkind
(Constr
) = N_Discriminant_Association
then
4930 Disc_Exp
:= Original_Node
(Expression
(Constr
));
4932 Disc_Exp
:= Original_Node
(Constr
);
4935 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4938 Next_Discriminant
(Discrim
);
4945 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4946 -- check that the level of the type of the created object is not deeper
4947 -- than the level of the allocator's access type, since extensions can
4948 -- now occur at deeper levels than their ancestor types. This is a
4949 -- static accessibility level check; a run-time check is also needed in
4950 -- the case of an initialized allocator with a class-wide argument (see
4951 -- Expand_Allocator_Expression).
4953 if Ada_Version
>= Ada_2005
4954 and then Is_Class_Wide_Type
(Desig_T
)
4957 Exp_Typ
: Entity_Id
;
4960 if Nkind
(E
) = N_Qualified_Expression
then
4961 Exp_Typ
:= Etype
(E
);
4962 elsif Nkind
(E
) = N_Subtype_Indication
then
4963 Exp_Typ
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4965 Exp_Typ
:= Entity
(E
);
4968 if Type_Access_Level
(Exp_Typ
) >
4969 Deepest_Type_Access_Level
(Typ
)
4971 if In_Instance_Body
then
4972 Error_Msg_Warn
:= SPARK_Mode
/= On
;
4974 ("type in allocator has deeper level than "
4975 & "designated class-wide type<<", E
);
4976 Error_Msg_N
("\Program_Error [<<", E
);
4978 Make_Raise_Program_Error
(Sloc
(N
),
4979 Reason
=> PE_Accessibility_Check_Failed
));
4982 -- Do not apply Ada 2005 accessibility checks on a class-wide
4983 -- allocator if the type given in the allocator is a formal
4984 -- type. A run-time check will be performed in the instance.
4986 elsif not Is_Generic_Type
(Exp_Typ
) then
4987 Error_Msg_N
("type in allocator has deeper level than "
4988 & "designated class-wide type", E
);
4994 -- Check for allocation from an empty storage pool
4996 if No_Pool_Assigned
(Typ
) then
4997 Error_Msg_N
("allocation from empty storage pool!", N
);
4999 -- If the context is an unchecked conversion, as may happen within an
5000 -- inlined subprogram, the allocator is being resolved with its own
5001 -- anonymous type. In that case, if the target type has a specific
5002 -- storage pool, it must be inherited explicitly by the allocator type.
5004 elsif Nkind
(Parent
(N
)) = N_Unchecked_Type_Conversion
5005 and then No
(Associated_Storage_Pool
(Typ
))
5007 Set_Associated_Storage_Pool
5008 (Typ
, Associated_Storage_Pool
(Etype
(Parent
(N
))));
5011 if Ekind
(Etype
(N
)) = E_Anonymous_Access_Type
then
5012 Check_Restriction
(No_Anonymous_Allocators
, N
);
5015 -- Check that an allocator with task parts isn't for a nested access
5016 -- type when restriction No_Task_Hierarchy applies.
5018 if not Is_Library_Level_Entity
(Base_Type
(Typ
))
5019 and then Has_Task
(Base_Type
(Desig_T
))
5021 Check_Restriction
(No_Task_Hierarchy
, N
);
5024 -- An illegal allocator may be rewritten as a raise Program_Error
5027 if Nkind
(N
) = N_Allocator
then
5029 -- Avoid coextension processing for an allocator that is the
5030 -- expansion of a build-in-place function call.
5032 if Nkind
(Original_Node
(N
)) = N_Allocator
5033 and then Nkind
(Expression
(Original_Node
(N
))) =
5034 N_Qualified_Expression
5035 and then Nkind
(Expression
(Expression
(Original_Node
(N
)))) =
5037 and then Is_Expanded_Build_In_Place_Call
5038 (Expression
(Expression
(Original_Node
(N
))))
5040 null; -- b-i-p function call case
5043 -- An anonymous access discriminant is the definition of a
5046 if Ekind
(Typ
) = E_Anonymous_Access_Type
5047 and then Nkind
(Associated_Node_For_Itype
(Typ
)) =
5048 N_Discriminant_Specification
5051 Discr
: constant Entity_Id
:=
5052 Defining_Identifier
(Associated_Node_For_Itype
(Typ
));
5055 Check_Restriction
(No_Coextensions
, N
);
5057 -- Ada 2012 AI05-0052: If the designated type of the
5058 -- allocator is limited, then the allocator shall not
5059 -- be used to define the value of an access discriminant
5060 -- unless the discriminated type is immutably limited.
5062 if Ada_Version
>= Ada_2012
5063 and then Is_Limited_Type
(Desig_T
)
5064 and then not Is_Limited_View
(Scope
(Discr
))
5067 ("only immutably limited types can have anonymous "
5068 & "access discriminants designating a limited type",
5073 -- Avoid marking an allocator as a dynamic coextension if it is
5074 -- within a static construct.
5076 if not Is_Static_Coextension
(N
) then
5077 Set_Is_Dynamic_Coextension
(N
);
5079 -- Finalization and deallocation of coextensions utilizes an
5080 -- approximate implementation which does not directly adhere
5081 -- to the semantic rules. Warn on potential issues involving
5084 if Is_Controlled
(Desig_T
) then
5086 ("??coextension will not be finalized when its "
5087 & "associated owner is deallocated or finalized", N
);
5090 ("??coextension will not be deallocated when its "
5091 & "associated owner is deallocated", N
);
5095 -- Cleanup for potential static coextensions
5098 Set_Is_Dynamic_Coextension
(N
, False);
5099 Set_Is_Static_Coextension
(N
, False);
5101 -- Anonymous access-to-controlled objects are not finalized on
5102 -- time because this involves run-time ownership and currently
5103 -- this property is not available. In rare cases the object may
5104 -- not be finalized at all. Warn on potential issues involving
5105 -- anonymous access-to-controlled objects.
5107 if Ekind
(Typ
) = E_Anonymous_Access_Type
5108 and then Is_Controlled_Active
(Desig_T
)
5111 ("??object designated by anonymous access object might "
5112 & "not be finalized until its enclosing library unit "
5113 & "goes out of scope", N
);
5114 Error_Msg_N
("\use named access type instead", N
);
5120 -- Report a simple error: if the designated object is a local task,
5121 -- its body has not been seen yet, and its activation will fail an
5122 -- elaboration check.
5124 if Is_Task_Type
(Desig_T
)
5125 and then Scope
(Base_Type
(Desig_T
)) = Current_Scope
5126 and then Is_Compilation_Unit
(Current_Scope
)
5127 and then Ekind
(Current_Scope
) = E_Package
5128 and then not In_Package_Body
(Current_Scope
)
5130 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5131 Error_Msg_N
("cannot activate task before body seen<<", N
);
5132 Error_Msg_N
("\Program_Error [<<", N
);
5135 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5136 -- type with a task component on a subpool. This action must raise
5137 -- Program_Error at runtime.
5139 if Ada_Version
>= Ada_2012
5140 and then Nkind
(N
) = N_Allocator
5141 and then Present
(Subpool_Handle_Name
(N
))
5142 and then Has_Task
(Desig_T
)
5144 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5145 Error_Msg_N
("cannot allocate task on subpool<<", N
);
5146 Error_Msg_N
("\Program_Error [<<", N
);
5149 Make_Raise_Program_Error
(Sloc
(N
),
5150 Reason
=> PE_Explicit_Raise
));
5153 end Resolve_Allocator
;
5155 ---------------------------
5156 -- Resolve_Arithmetic_Op --
5157 ---------------------------
5159 -- Used for resolving all arithmetic operators except exponentiation
5161 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
5162 L
: constant Node_Id
:= Left_Opnd
(N
);
5163 R
: constant Node_Id
:= Right_Opnd
(N
);
5164 TL
: constant Entity_Id
:= Base_Type
(Etype
(L
));
5165 TR
: constant Entity_Id
:= Base_Type
(Etype
(R
));
5169 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
5170 -- We do the resolution using the base type, because intermediate values
5171 -- in expressions always are of the base type, not a subtype of it.
5173 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean;
5174 -- Returns True if N is in a context that expects "any real type"
5176 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean;
5177 -- Return True iff given type is Integer or universal real/integer
5179 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
);
5180 -- Choose type of integer literal in fixed-point operation to conform
5181 -- to available fixed-point type. T is the type of the other operand,
5182 -- which is needed to determine the expected type of N.
5184 procedure Set_Operand_Type
(N
: Node_Id
);
5185 -- Set operand type to T if universal
5187 -------------------------------
5188 -- Expected_Type_Is_Any_Real --
5189 -------------------------------
5191 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean is
5193 -- N is the expression after "delta" in a fixed_point_definition;
5196 return Nkind_In
(Parent
(N
), N_Ordinary_Fixed_Point_Definition
,
5197 N_Decimal_Fixed_Point_Definition
,
5199 -- N is one of the bounds in a real_range_specification;
5202 N_Real_Range_Specification
,
5204 -- N is the expression of a delta_constraint;
5207 N_Delta_Constraint
);
5208 end Expected_Type_Is_Any_Real
;
5210 -----------------------------
5211 -- Is_Integer_Or_Universal --
5212 -----------------------------
5214 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean is
5216 Index
: Interp_Index
;
5220 if not Is_Overloaded
(N
) then
5222 return Base_Type
(T
) = Base_Type
(Standard_Integer
)
5223 or else T
= Universal_Integer
5224 or else T
= Universal_Real
;
5226 Get_First_Interp
(N
, Index
, It
);
5227 while Present
(It
.Typ
) loop
5228 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
)
5229 or else It
.Typ
= Universal_Integer
5230 or else It
.Typ
= Universal_Real
5235 Get_Next_Interp
(Index
, It
);
5240 end Is_Integer_Or_Universal
;
5242 ----------------------------
5243 -- Set_Mixed_Mode_Operand --
5244 ----------------------------
5246 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
) is
5247 Index
: Interp_Index
;
5251 if Universal_Interpretation
(N
) = Universal_Integer
then
5253 -- A universal integer literal is resolved as standard integer
5254 -- except in the case of a fixed-point result, where we leave it
5255 -- as universal (to be handled by Exp_Fixd later on)
5257 if Is_Fixed_Point_Type
(T
) then
5258 Resolve
(N
, Universal_Integer
);
5260 Resolve
(N
, Standard_Integer
);
5263 elsif Universal_Interpretation
(N
) = Universal_Real
5264 and then (T
= Base_Type
(Standard_Integer
)
5265 or else T
= Universal_Integer
5266 or else T
= Universal_Real
)
5268 -- A universal real can appear in a fixed-type context. We resolve
5269 -- the literal with that context, even though this might raise an
5270 -- exception prematurely (the other operand may be zero).
5274 elsif Etype
(N
) = Base_Type
(Standard_Integer
)
5275 and then T
= Universal_Real
5276 and then Is_Overloaded
(N
)
5278 -- Integer arg in mixed-mode operation. Resolve with universal
5279 -- type, in case preference rule must be applied.
5281 Resolve
(N
, Universal_Integer
);
5284 and then B_Typ
/= Universal_Fixed
5286 -- Not a mixed-mode operation, resolve with context
5290 elsif Etype
(N
) = Any_Fixed
then
5292 -- N may itself be a mixed-mode operation, so use context type
5296 elsif Is_Fixed_Point_Type
(T
)
5297 and then B_Typ
= Universal_Fixed
5298 and then Is_Overloaded
(N
)
5300 -- Must be (fixed * fixed) operation, operand must have one
5301 -- compatible interpretation.
5303 Resolve
(N
, Any_Fixed
);
5305 elsif Is_Fixed_Point_Type
(B_Typ
)
5306 and then (T
= Universal_Real
or else Is_Fixed_Point_Type
(T
))
5307 and then Is_Overloaded
(N
)
5309 -- C * F(X) in a fixed context, where C is a real literal or a
5310 -- fixed-point expression. F must have either a fixed type
5311 -- interpretation or an integer interpretation, but not both.
5313 Get_First_Interp
(N
, Index
, It
);
5314 while Present
(It
.Typ
) loop
5315 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
) then
5316 if Analyzed
(N
) then
5317 Error_Msg_N
("ambiguous operand in fixed operation", N
);
5319 Resolve
(N
, Standard_Integer
);
5322 elsif Is_Fixed_Point_Type
(It
.Typ
) then
5323 if Analyzed
(N
) then
5324 Error_Msg_N
("ambiguous operand in fixed operation", N
);
5326 Resolve
(N
, It
.Typ
);
5330 Get_Next_Interp
(Index
, It
);
5333 -- Reanalyze the literal with the fixed type of the context. If
5334 -- context is Universal_Fixed, we are within a conversion, leave
5335 -- the literal as a universal real because there is no usable
5336 -- fixed type, and the target of the conversion plays no role in
5350 if B_Typ
= Universal_Fixed
5351 and then Nkind
(Op2
) = N_Real_Literal
5353 T2
:= Universal_Real
;
5358 Set_Analyzed
(Op2
, False);
5362 -- A universal real conditional expression can appear in a fixed-type
5363 -- context and must be resolved with that context to facilitate the
5364 -- code generation to the backend.
5366 elsif Nkind_In
(N
, N_Case_Expression
, N_If_Expression
)
5367 and then Etype
(N
) = Universal_Real
5368 and then Is_Fixed_Point_Type
(B_Typ
)
5375 end Set_Mixed_Mode_Operand
;
5377 ----------------------
5378 -- Set_Operand_Type --
5379 ----------------------
5381 procedure Set_Operand_Type
(N
: Node_Id
) is
5383 if Etype
(N
) = Universal_Integer
5384 or else Etype
(N
) = Universal_Real
5388 end Set_Operand_Type
;
5390 -- Start of processing for Resolve_Arithmetic_Op
5393 if Comes_From_Source
(N
)
5394 and then Ekind
(Entity
(N
)) = E_Function
5395 and then Is_Imported
(Entity
(N
))
5396 and then Is_Intrinsic_Subprogram
(Entity
(N
))
5398 Resolve_Intrinsic_Operator
(N
, Typ
);
5401 -- Special-case for mixed-mode universal expressions or fixed point type
5402 -- operation: each argument is resolved separately. The same treatment
5403 -- is required if one of the operands of a fixed point operation is
5404 -- universal real, since in this case we don't do a conversion to a
5405 -- specific fixed-point type (instead the expander handles the case).
5407 -- Set the type of the node to its universal interpretation because
5408 -- legality checks on an exponentiation operand need the context.
5410 elsif (B_Typ
= Universal_Integer
or else B_Typ
= Universal_Real
)
5411 and then Present
(Universal_Interpretation
(L
))
5412 and then Present
(Universal_Interpretation
(R
))
5414 Set_Etype
(N
, B_Typ
);
5415 Resolve
(L
, Universal_Interpretation
(L
));
5416 Resolve
(R
, Universal_Interpretation
(R
));
5418 elsif (B_Typ
= Universal_Real
5419 or else Etype
(N
) = Universal_Fixed
5420 or else (Etype
(N
) = Any_Fixed
5421 and then Is_Fixed_Point_Type
(B_Typ
))
5422 or else (Is_Fixed_Point_Type
(B_Typ
)
5423 and then (Is_Integer_Or_Universal
(L
)
5425 Is_Integer_Or_Universal
(R
))))
5426 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
5428 if TL
= Universal_Integer
or else TR
= Universal_Integer
then
5429 Check_For_Visible_Operator
(N
, B_Typ
);
5432 -- If context is a fixed type and one operand is integer, the other
5433 -- is resolved with the type of the context.
5435 if Is_Fixed_Point_Type
(B_Typ
)
5436 and then (Base_Type
(TL
) = Base_Type
(Standard_Integer
)
5437 or else TL
= Universal_Integer
)
5442 elsif Is_Fixed_Point_Type
(B_Typ
)
5443 and then (Base_Type
(TR
) = Base_Type
(Standard_Integer
)
5444 or else TR
= Universal_Integer
)
5449 -- If both operands are universal and the context is a floating
5450 -- point type, the operands are resolved to the type of the context.
5452 elsif Is_Floating_Point_Type
(B_Typ
) then
5457 Set_Mixed_Mode_Operand
(L
, TR
);
5458 Set_Mixed_Mode_Operand
(R
, TL
);
5461 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5462 -- multiplying operators from being used when the expected type is
5463 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5464 -- some cases where the expected type is actually Any_Real;
5465 -- Expected_Type_Is_Any_Real takes care of that case.
5467 if Etype
(N
) = Universal_Fixed
5468 or else Etype
(N
) = Any_Fixed
5470 if B_Typ
= Universal_Fixed
5471 and then not Expected_Type_Is_Any_Real
(N
)
5472 and then not Nkind_In
(Parent
(N
), N_Type_Conversion
,
5473 N_Unchecked_Type_Conversion
)
5475 Error_Msg_N
("type cannot be determined from context!", N
);
5476 Error_Msg_N
("\explicit conversion to result type required", N
);
5478 Set_Etype
(L
, Any_Type
);
5479 Set_Etype
(R
, Any_Type
);
5482 if Ada_Version
= Ada_83
5483 and then Etype
(N
) = Universal_Fixed
5485 Nkind_In
(Parent
(N
), N_Type_Conversion
,
5486 N_Unchecked_Type_Conversion
)
5489 ("(Ada 83) fixed-point operation needs explicit "
5493 -- The expected type is "any real type" in contexts like
5495 -- type T is delta <universal_fixed-expression> ...
5497 -- in which case we need to set the type to Universal_Real
5498 -- so that static expression evaluation will work properly.
5500 if Expected_Type_Is_Any_Real
(N
) then
5501 Set_Etype
(N
, Universal_Real
);
5503 Set_Etype
(N
, B_Typ
);
5507 elsif Is_Fixed_Point_Type
(B_Typ
)
5508 and then (Is_Integer_Or_Universal
(L
)
5509 or else Nkind
(L
) = N_Real_Literal
5510 or else Nkind
(R
) = N_Real_Literal
5511 or else Is_Integer_Or_Universal
(R
))
5513 Set_Etype
(N
, B_Typ
);
5515 elsif Etype
(N
) = Any_Fixed
then
5517 -- If no previous errors, this is only possible if one operand is
5518 -- overloaded and the context is universal. Resolve as such.
5520 Set_Etype
(N
, B_Typ
);
5524 if (TL
= Universal_Integer
or else TL
= Universal_Real
)
5526 (TR
= Universal_Integer
or else TR
= Universal_Real
)
5528 Check_For_Visible_Operator
(N
, B_Typ
);
5531 -- If the context is Universal_Fixed and the operands are also
5532 -- universal fixed, this is an error, unless there is only one
5533 -- applicable fixed_point type (usually Duration).
5535 if B_Typ
= Universal_Fixed
and then Etype
(L
) = Universal_Fixed
then
5536 T
:= Unique_Fixed_Point_Type
(N
);
5538 if T
= Any_Type
then
5551 -- If one of the arguments was resolved to a non-universal type.
5552 -- label the result of the operation itself with the same type.
5553 -- Do the same for the universal argument, if any.
5555 T
:= Intersect_Types
(L
, R
);
5556 Set_Etype
(N
, Base_Type
(T
));
5557 Set_Operand_Type
(L
);
5558 Set_Operand_Type
(R
);
5561 Generate_Operator_Reference
(N
, Typ
);
5562 Analyze_Dimension
(N
);
5563 Eval_Arithmetic_Op
(N
);
5565 -- In SPARK, a multiplication or division with operands of fixed point
5566 -- types must be qualified or explicitly converted to identify the
5569 if (Is_Fixed_Point_Type
(Etype
(L
))
5570 or else Is_Fixed_Point_Type
(Etype
(R
)))
5571 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
5573 not Nkind_In
(Parent
(N
), N_Qualified_Expression
, N_Type_Conversion
)
5575 Check_SPARK_05_Restriction
5576 ("operation should be qualified or explicitly converted", N
);
5579 -- Set overflow and division checking bit
5581 if Nkind
(N
) in N_Op
then
5582 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
5583 Enable_Overflow_Check
(N
);
5586 -- Give warning if explicit division by zero
5588 if Nkind_In
(N
, N_Op_Divide
, N_Op_Rem
, N_Op_Mod
)
5589 and then not Division_Checks_Suppressed
(Etype
(N
))
5591 Rop
:= Right_Opnd
(N
);
5593 if Compile_Time_Known_Value
(Rop
)
5594 and then ((Is_Integer_Type
(Etype
(Rop
))
5595 and then Expr_Value
(Rop
) = Uint_0
)
5597 (Is_Real_Type
(Etype
(Rop
))
5598 and then Expr_Value_R
(Rop
) = Ureal_0
))
5600 -- Specialize the warning message according to the operation.
5601 -- When SPARK_Mode is On, force a warning instead of an error
5602 -- in that case, as this likely corresponds to deactivated
5603 -- code. The following warnings are for the case
5608 -- For division, we have two cases, for float division
5609 -- of an unconstrained float type, on a machine where
5610 -- Machine_Overflows is false, we don't get an exception
5611 -- at run-time, but rather an infinity or Nan. The Nan
5612 -- case is pretty obscure, so just warn about infinities.
5614 if Is_Floating_Point_Type
(Typ
)
5615 and then not Is_Constrained
(Typ
)
5616 and then not Machine_Overflows_On_Target
5619 ("float division by zero, may generate "
5620 & "'+'/'- infinity??", Right_Opnd
(N
));
5622 -- For all other cases, we get a Constraint_Error
5625 Apply_Compile_Time_Constraint_Error
5626 (N
, "division by zero??", CE_Divide_By_Zero
,
5627 Loc
=> Sloc
(Right_Opnd
(N
)),
5628 Warn
=> SPARK_Mode
= On
);
5632 Apply_Compile_Time_Constraint_Error
5633 (N
, "rem with zero divisor??", CE_Divide_By_Zero
,
5634 Loc
=> Sloc
(Right_Opnd
(N
)),
5635 Warn
=> SPARK_Mode
= On
);
5638 Apply_Compile_Time_Constraint_Error
5639 (N
, "mod with zero divisor??", CE_Divide_By_Zero
,
5640 Loc
=> Sloc
(Right_Opnd
(N
)),
5641 Warn
=> SPARK_Mode
= On
);
5643 -- Division by zero can only happen with division, rem,
5644 -- and mod operations.
5647 raise Program_Error
;
5650 -- In GNATprove mode, we enable the division check so that
5651 -- GNATprove will issue a message if it cannot be proved.
5653 if GNATprove_Mode
then
5654 Activate_Division_Check
(N
);
5657 -- Otherwise just set the flag to check at run time
5660 Activate_Division_Check
(N
);
5664 -- If Restriction No_Implicit_Conditionals is active, then it is
5665 -- violated if either operand can be negative for mod, or for rem
5666 -- if both operands can be negative.
5668 if Restriction_Check_Required
(No_Implicit_Conditionals
)
5669 and then Nkind_In
(N
, N_Op_Rem
, N_Op_Mod
)
5678 -- Set if corresponding operand might be negative
5682 (Left_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5683 LNeg
:= (not OK
) or else Lo
< 0;
5686 (Right_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5687 RNeg
:= (not OK
) or else Lo
< 0;
5689 -- Check if we will be generating conditionals. There are two
5690 -- cases where that can happen, first for REM, the only case
5691 -- is largest negative integer mod -1, where the division can
5692 -- overflow, but we still have to give the right result. The
5693 -- front end generates a test for this annoying case. Here we
5694 -- just test if both operands can be negative (that's what the
5695 -- expander does, so we match its logic here).
5697 -- The second case is mod where either operand can be negative.
5698 -- In this case, the back end has to generate additional tests.
5700 if (Nkind
(N
) = N_Op_Rem
and then (LNeg
and RNeg
))
5702 (Nkind
(N
) = N_Op_Mod
and then (LNeg
or RNeg
))
5704 Check_Restriction
(No_Implicit_Conditionals
, N
);
5710 Check_Unset_Reference
(L
);
5711 Check_Unset_Reference
(R
);
5712 end Resolve_Arithmetic_Op
;
5718 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
5719 function Same_Or_Aliased_Subprograms
5721 E
: Entity_Id
) return Boolean;
5722 -- Returns True if the subprogram entity S is the same as E or else
5723 -- S is an alias of E.
5725 ---------------------------------
5726 -- Same_Or_Aliased_Subprograms --
5727 ---------------------------------
5729 function Same_Or_Aliased_Subprograms
5731 E
: Entity_Id
) return Boolean
5733 Subp_Alias
: constant Entity_Id
:= Alias
(S
);
5735 return S
= E
or else (Present
(Subp_Alias
) and then Subp_Alias
= E
);
5736 end Same_Or_Aliased_Subprograms
;
5740 Loc
: constant Source_Ptr
:= Sloc
(N
);
5741 Subp
: constant Node_Id
:= Name
(N
);
5742 Body_Id
: Entity_Id
;
5752 -- Start of processing for Resolve_Call
5755 -- Preserve relevant elaboration-related attributes of the context which
5756 -- are no longer available or very expensive to recompute once analysis,
5757 -- resolution, and expansion are over.
5759 Mark_Elaboration_Attributes
5765 -- The context imposes a unique interpretation with type Typ on a
5766 -- procedure or function call. Find the entity of the subprogram that
5767 -- yields the expected type, and propagate the corresponding formal
5768 -- constraints on the actuals. The caller has established that an
5769 -- interpretation exists, and emitted an error if not unique.
5771 -- First deal with the case of a call to an access-to-subprogram,
5772 -- dereference made explicit in Analyze_Call.
5774 if Ekind
(Etype
(Subp
)) = E_Subprogram_Type
then
5775 if not Is_Overloaded
(Subp
) then
5776 Nam
:= Etype
(Subp
);
5779 -- Find the interpretation whose type (a subprogram type) has a
5780 -- return type that is compatible with the context. Analysis of
5781 -- the node has established that one exists.
5785 Get_First_Interp
(Subp
, I
, It
);
5786 while Present
(It
.Typ
) loop
5787 if Covers
(Typ
, Etype
(It
.Typ
)) then
5792 Get_Next_Interp
(I
, It
);
5796 raise Program_Error
;
5800 -- If the prefix is not an entity, then resolve it
5802 if not Is_Entity_Name
(Subp
) then
5803 Resolve
(Subp
, Nam
);
5806 -- For an indirect call, we always invalidate checks, since we do not
5807 -- know whether the subprogram is local or global. Yes we could do
5808 -- better here, e.g. by knowing that there are no local subprograms,
5809 -- but it does not seem worth the effort. Similarly, we kill all
5810 -- knowledge of current constant values.
5812 Kill_Current_Values
;
5814 -- If this is a procedure call which is really an entry call, do
5815 -- the conversion of the procedure call to an entry call. Protected
5816 -- operations use the same circuitry because the name in the call
5817 -- can be an arbitrary expression with special resolution rules.
5819 elsif Nkind_In
(Subp
, N_Selected_Component
, N_Indexed_Component
)
5820 or else (Is_Entity_Name
(Subp
)
5821 and then Ekind_In
(Entity
(Subp
), E_Entry
, E_Entry_Family
))
5823 Resolve_Entry_Call
(N
, Typ
);
5825 if Legacy_Elaboration_Checks
then
5826 Check_Elab_Call
(N
);
5829 -- Annotate the tree by creating a call marker in case the original
5830 -- call is transformed by expansion. The call marker is automatically
5831 -- saved for later examination by the ABE Processing phase.
5833 Build_Call_Marker
(N
);
5835 -- Kill checks and constant values, as above for indirect case
5836 -- Who knows what happens when another task is activated?
5838 Kill_Current_Values
;
5841 -- Normal subprogram call with name established in Resolve
5843 elsif not (Is_Type
(Entity
(Subp
))) then
5844 Nam
:= Entity
(Subp
);
5845 Set_Entity_With_Checks
(Subp
, Nam
);
5847 -- Otherwise we must have the case of an overloaded call
5850 pragma Assert
(Is_Overloaded
(Subp
));
5852 -- Initialize Nam to prevent warning (we know it will be assigned
5853 -- in the loop below, but the compiler does not know that).
5857 Get_First_Interp
(Subp
, I
, It
);
5858 while Present
(It
.Typ
) loop
5859 if Covers
(Typ
, It
.Typ
) then
5861 Set_Entity_With_Checks
(Subp
, Nam
);
5865 Get_Next_Interp
(I
, It
);
5869 if Is_Access_Subprogram_Type
(Base_Type
(Etype
(Nam
)))
5870 and then not Is_Access_Subprogram_Type
(Base_Type
(Typ
))
5871 and then Nkind
(Subp
) /= N_Explicit_Dereference
5872 and then Present
(Parameter_Associations
(N
))
5874 -- The prefix is a parameterless function call that returns an access
5875 -- to subprogram. If parameters are present in the current call, add
5876 -- add an explicit dereference. We use the base type here because
5877 -- within an instance these may be subtypes.
5879 -- The dereference is added either in Analyze_Call or here. Should
5880 -- be consolidated ???
5882 Set_Is_Overloaded
(Subp
, False);
5883 Set_Etype
(Subp
, Etype
(Nam
));
5884 Insert_Explicit_Dereference
(Subp
);
5885 Nam
:= Designated_Type
(Etype
(Nam
));
5886 Resolve
(Subp
, Nam
);
5889 -- Check that a call to Current_Task does not occur in an entry body
5891 if Is_RTE
(Nam
, RE_Current_Task
) then
5900 -- Exclude calls that occur within the default of a formal
5901 -- parameter of the entry, since those are evaluated outside
5904 exit when No
(P
) or else Nkind
(P
) = N_Parameter_Specification
;
5906 if Nkind
(P
) = N_Entry_Body
5907 or else (Nkind
(P
) = N_Subprogram_Body
5908 and then Is_Entry_Barrier_Function
(P
))
5911 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5913 ("& should not be used in entry body (RM C.7(17))<<",
5915 Error_Msg_NE
("\Program_Error [<<", N
, Nam
);
5917 Make_Raise_Program_Error
(Loc
,
5918 Reason
=> PE_Current_Task_In_Entry_Body
));
5919 Set_Etype
(N
, Rtype
);
5926 -- Check that a procedure call does not occur in the context of the
5927 -- entry call statement of a conditional or timed entry call. Note that
5928 -- the case of a call to a subprogram renaming of an entry will also be
5929 -- rejected. The test for N not being an N_Entry_Call_Statement is
5930 -- defensive, covering the possibility that the processing of entry
5931 -- calls might reach this point due to later modifications of the code
5934 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
5935 and then Nkind
(N
) /= N_Entry_Call_Statement
5936 and then Entry_Call_Statement
(Parent
(N
)) = N
5938 if Ada_Version
< Ada_2005
then
5939 Error_Msg_N
("entry call required in select statement", N
);
5941 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5942 -- for a procedure_or_entry_call, the procedure_name or
5943 -- procedure_prefix of the procedure_call_statement shall denote
5944 -- an entry renamed by a procedure, or (a view of) a primitive
5945 -- subprogram of a limited interface whose first parameter is
5946 -- a controlling parameter.
5948 elsif Nkind
(N
) = N_Procedure_Call_Statement
5949 and then not Is_Renamed_Entry
(Nam
)
5950 and then not Is_Controlling_Limited_Procedure
(Nam
)
5953 ("entry call or dispatching primitive of interface required", N
);
5957 -- If the SPARK_05 restriction is active, we are not allowed
5958 -- to have a call to a subprogram before we see its completion.
5960 if not Has_Completion
(Nam
)
5961 and then Restriction_Check_Required
(SPARK_05
)
5963 -- Don't flag strange internal calls
5965 and then Comes_From_Source
(N
)
5966 and then Comes_From_Source
(Nam
)
5968 -- Only flag calls in extended main source
5970 and then In_Extended_Main_Source_Unit
(Nam
)
5971 and then In_Extended_Main_Source_Unit
(N
)
5973 -- Exclude enumeration literals from this processing
5975 and then Ekind
(Nam
) /= E_Enumeration_Literal
5977 Check_SPARK_05_Restriction
5978 ("call to subprogram cannot appear before its body", N
);
5981 -- Check that this is not a call to a protected procedure or entry from
5982 -- within a protected function.
5984 Check_Internal_Protected_Use
(N
, Nam
);
5986 -- Freeze the subprogram name if not in a spec-expression. Note that
5987 -- we freeze procedure calls as well as function calls. Procedure calls
5988 -- are not frozen according to the rules (RM 13.14(14)) because it is
5989 -- impossible to have a procedure call to a non-frozen procedure in
5990 -- pure Ada, but in the code that we generate in the expander, this
5991 -- rule needs extending because we can generate procedure calls that
5994 -- In Ada 2012, expression functions may be called within pre/post
5995 -- conditions of subsequent functions or expression functions. Such
5996 -- calls do not freeze when they appear within generated bodies,
5997 -- (including the body of another expression function) which would
5998 -- place the freeze node in the wrong scope. An expression function
5999 -- is frozen in the usual fashion, by the appearance of a real body,
6000 -- or at the end of a declarative part.
6002 if Is_Entity_Name
(Subp
)
6003 and then not In_Spec_Expression
6004 and then not Is_Expression_Function_Or_Completion
(Current_Scope
)
6006 (not Is_Expression_Function_Or_Completion
(Entity
(Subp
))
6007 or else Scope
(Entity
(Subp
)) = Current_Scope
)
6009 Freeze_Expression
(Subp
);
6012 -- For a predefined operator, the type of the result is the type imposed
6013 -- by context, except for a predefined operation on universal fixed.
6014 -- Otherwise The type of the call is the type returned by the subprogram
6017 if Is_Predefined_Op
(Nam
) then
6018 if Etype
(N
) /= Universal_Fixed
then
6022 -- If the subprogram returns an array type, and the context requires the
6023 -- component type of that array type, the node is really an indexing of
6024 -- the parameterless call. Resolve as such. A pathological case occurs
6025 -- when the type of the component is an access to the array type. In
6026 -- this case the call is truly ambiguous. If the call is to an intrinsic
6027 -- subprogram, it can't be an indexed component. This check is necessary
6028 -- because if it's Unchecked_Conversion, and we have "type T_Ptr is
6029 -- access T;" and "type T is array (...) of T_Ptr;" (i.e. an array of
6030 -- pointers to the same array), the compiler gets confused and does an
6031 -- infinite recursion.
6033 elsif (Needs_No_Actuals
(Nam
) or else Needs_One_Actual
(Nam
))
6035 ((Is_Array_Type
(Etype
(Nam
))
6036 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
6038 (Is_Access_Type
(Etype
(Nam
))
6039 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
6041 Covers
(Typ
, Component_Type
(Designated_Type
(Etype
(Nam
))))
6042 and then not Is_Intrinsic_Subprogram
(Entity
(Subp
))))
6045 Index_Node
: Node_Id
;
6047 Ret_Type
: constant Entity_Id
:= Etype
(Nam
);
6050 if Is_Access_Type
(Ret_Type
)
6051 and then Ret_Type
= Component_Type
(Designated_Type
(Ret_Type
))
6054 ("cannot disambiguate function call and indexing", N
);
6056 New_Subp
:= Relocate_Node
(Subp
);
6058 -- The called entity may be an explicit dereference, in which
6059 -- case there is no entity to set.
6061 if Nkind
(New_Subp
) /= N_Explicit_Dereference
then
6062 Set_Entity
(Subp
, Nam
);
6065 if (Is_Array_Type
(Ret_Type
)
6066 and then Component_Type
(Ret_Type
) /= Any_Type
)
6068 (Is_Access_Type
(Ret_Type
)
6070 Component_Type
(Designated_Type
(Ret_Type
)) /= Any_Type
)
6072 if Needs_No_Actuals
(Nam
) then
6074 -- Indexed call to a parameterless function
6077 Make_Indexed_Component
(Loc
,
6079 Make_Function_Call
(Loc
, Name
=> New_Subp
),
6080 Expressions
=> Parameter_Associations
(N
));
6082 -- An Ada 2005 prefixed call to a primitive operation
6083 -- whose first parameter is the prefix. This prefix was
6084 -- prepended to the parameter list, which is actually a
6085 -- list of indexes. Remove the prefix in order to build
6086 -- the proper indexed component.
6089 Make_Indexed_Component
(Loc
,
6091 Make_Function_Call
(Loc
,
6093 Parameter_Associations
=>
6095 (Remove_Head
(Parameter_Associations
(N
)))),
6096 Expressions
=> Parameter_Associations
(N
));
6099 -- Preserve the parenthesis count of the node
6101 Set_Paren_Count
(Index_Node
, Paren_Count
(N
));
6103 -- Since we are correcting a node classification error made
6104 -- by the parser, we call Replace rather than Rewrite.
6106 Replace
(N
, Index_Node
);
6108 Set_Etype
(Prefix
(N
), Ret_Type
);
6110 Resolve_Indexed_Component
(N
, Typ
);
6112 if Legacy_Elaboration_Checks
then
6113 Check_Elab_Call
(Prefix
(N
));
6116 -- Annotate the tree by creating a call marker in case
6117 -- the original call is transformed by expansion. The call
6118 -- marker is automatically saved for later examination by
6119 -- the ABE Processing phase.
6121 Build_Call_Marker
(Prefix
(N
));
6129 -- If the called function is not declared in the main unit and it
6130 -- returns the limited view of type then use the available view (as
6131 -- is done in Try_Object_Operation) to prevent back-end confusion;
6132 -- for the function entity itself. The call must appear in a context
6133 -- where the nonlimited view is available. If the function entity is
6134 -- in the extended main unit then no action is needed, because the
6135 -- back end handles this case. In either case the type of the call
6136 -- is the nonlimited view.
6138 if From_Limited_With
(Etype
(Nam
))
6139 and then Present
(Available_View
(Etype
(Nam
)))
6141 Set_Etype
(N
, Available_View
(Etype
(Nam
)));
6143 if not In_Extended_Main_Code_Unit
(Nam
) then
6144 Set_Etype
(Nam
, Available_View
(Etype
(Nam
)));
6148 Set_Etype
(N
, Etype
(Nam
));
6152 -- In the case where the call is to an overloaded subprogram, Analyze
6153 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6154 -- such a case Normalize_Actuals needs to be called once more to order
6155 -- the actuals correctly. Otherwise the call will have the ordering
6156 -- given by the last overloaded subprogram whether this is the correct
6157 -- one being called or not.
6159 if Is_Overloaded
(Subp
) then
6160 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
6161 pragma Assert
(Norm_OK
);
6164 -- In any case, call is fully resolved now. Reset Overload flag, to
6165 -- prevent subsequent overload resolution if node is analyzed again
6167 Set_Is_Overloaded
(Subp
, False);
6168 Set_Is_Overloaded
(N
, False);
6170 -- A Ghost entity must appear in a specific context
6172 if Is_Ghost_Entity
(Nam
) and then Comes_From_Source
(N
) then
6173 Check_Ghost_Context
(Nam
, N
);
6176 -- If we are calling the current subprogram from immediately within its
6177 -- body, then that is the case where we can sometimes detect cases of
6178 -- infinite recursion statically. Do not try this in case restriction
6179 -- No_Recursion is in effect anyway, and do it only for source calls.
6181 if Comes_From_Source
(N
) then
6182 Scop
:= Current_Scope
;
6184 -- Check violation of SPARK_05 restriction which does not permit
6185 -- a subprogram body to contain a call to the subprogram directly.
6187 if Restriction_Check_Required
(SPARK_05
)
6188 and then Same_Or_Aliased_Subprograms
(Nam
, Scop
)
6190 Check_SPARK_05_Restriction
6191 ("subprogram may not contain direct call to itself", N
);
6194 -- Issue warning for possible infinite recursion in the absence
6195 -- of the No_Recursion restriction.
6197 if Same_Or_Aliased_Subprograms
(Nam
, Scop
)
6198 and then not Restriction_Active
(No_Recursion
)
6199 and then Check_Infinite_Recursion
(N
)
6201 -- Here we detected and flagged an infinite recursion, so we do
6202 -- not need to test the case below for further warnings. Also we
6203 -- are all done if we now have a raise SE node.
6205 if Nkind
(N
) = N_Raise_Storage_Error
then
6209 -- If call is to immediately containing subprogram, then check for
6210 -- the case of a possible run-time detectable infinite recursion.
6213 Scope_Loop
: while Scop
/= Standard_Standard
loop
6214 if Same_Or_Aliased_Subprograms
(Nam
, Scop
) then
6216 -- Although in general case, recursion is not statically
6217 -- checkable, the case of calling an immediately containing
6218 -- subprogram is easy to catch.
6220 Check_Restriction
(No_Recursion
, N
);
6222 -- If the recursive call is to a parameterless subprogram,
6223 -- then even if we can't statically detect infinite
6224 -- recursion, this is pretty suspicious, and we output a
6225 -- warning. Furthermore, we will try later to detect some
6226 -- cases here at run time by expanding checking code (see
6227 -- Detect_Infinite_Recursion in package Exp_Ch6).
6229 -- If the recursive call is within a handler, do not emit a
6230 -- warning, because this is a common idiom: loop until input
6231 -- is correct, catch illegal input in handler and restart.
6233 if No
(First_Formal
(Nam
))
6234 and then Etype
(Nam
) = Standard_Void_Type
6235 and then not Error_Posted
(N
)
6236 and then Nkind
(Parent
(N
)) /= N_Exception_Handler
6238 -- For the case of a procedure call. We give the message
6239 -- only if the call is the first statement in a sequence
6240 -- of statements, or if all previous statements are
6241 -- simple assignments. This is simply a heuristic to
6242 -- decrease false positives, without losing too many good
6243 -- warnings. The idea is that these previous statements
6244 -- may affect global variables the procedure depends on.
6245 -- We also exclude raise statements, that may arise from
6246 -- constraint checks and are probably unrelated to the
6247 -- intended control flow.
6249 if Nkind
(N
) = N_Procedure_Call_Statement
6250 and then Is_List_Member
(N
)
6256 while Present
(P
) loop
6257 if not Nkind_In
(P
, N_Assignment_Statement
,
6258 N_Raise_Constraint_Error
)
6268 -- Do not give warning if we are in a conditional context
6271 K
: constant Node_Kind
:= Nkind
(Parent
(N
));
6273 if (K
= N_Loop_Statement
6274 and then Present
(Iteration_Scheme
(Parent
(N
))))
6275 or else K
= N_If_Statement
6276 or else K
= N_Elsif_Part
6277 or else K
= N_Case_Statement_Alternative
6283 -- Here warning is to be issued
6285 Set_Has_Recursive_Call
(Nam
);
6286 Error_Msg_Warn
:= SPARK_Mode
/= On
;
6287 Error_Msg_N
("possible infinite recursion<<!", N
);
6288 Error_Msg_N
("\Storage_Error ]<<!", N
);
6294 Scop
:= Scope
(Scop
);
6295 end loop Scope_Loop
;
6299 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6301 Check_Obsolescent_2005_Entity
(Nam
, Subp
);
6303 -- If subprogram name is a predefined operator, it was given in
6304 -- functional notation. Replace call node with operator node, so
6305 -- that actuals can be resolved appropriately.
6307 if Is_Predefined_Op
(Nam
) or else Ekind
(Nam
) = E_Operator
then
6308 Make_Call_Into_Operator
(N
, Typ
, Entity
(Name
(N
)));
6311 elsif Present
(Alias
(Nam
))
6312 and then Is_Predefined_Op
(Alias
(Nam
))
6314 Resolve_Actuals
(N
, Nam
);
6315 Make_Call_Into_Operator
(N
, Typ
, Alias
(Nam
));
6319 -- Create a transient scope if the resulting type requires it
6321 -- There are several notable exceptions:
6323 -- a) In init procs, the transient scope overhead is not needed, and is
6324 -- even incorrect when the call is a nested initialization call for a
6325 -- component whose expansion may generate adjust calls. However, if the
6326 -- call is some other procedure call within an initialization procedure
6327 -- (for example a call to Create_Task in the init_proc of the task
6328 -- run-time record) a transient scope must be created around this call.
6330 -- b) Enumeration literal pseudo-calls need no transient scope
6332 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6333 -- functions) do not use the secondary stack even though the return
6334 -- type may be unconstrained.
6336 -- d) Calls to a build-in-place function, since such functions may
6337 -- allocate their result directly in a target object, and cases where
6338 -- the result does get allocated in the secondary stack are checked for
6339 -- within the specialized Exp_Ch6 procedures for expanding those
6340 -- build-in-place calls.
6342 -- e) Calls to inlinable expression functions do not use the secondary
6343 -- stack (since the call will be replaced by its returned object).
6345 -- f) If the subprogram is marked Inline_Always, then even if it returns
6346 -- an unconstrained type the call does not require use of the secondary
6347 -- stack. However, inlining will only take place if the body to inline
6348 -- is already present. It may not be available if e.g. the subprogram is
6349 -- declared in a child instance.
6352 and then Has_Pragma_Inline
(Nam
)
6353 and then Nkind
(Unit_Declaration_Node
(Nam
)) = N_Subprogram_Declaration
6354 and then Present
(Body_To_Inline
(Unit_Declaration_Node
(Nam
)))
6358 elsif Ekind
(Nam
) = E_Enumeration_Literal
6359 or else Is_Build_In_Place_Function
(Nam
)
6360 or else Is_Intrinsic_Subprogram
(Nam
)
6361 or else Is_Inlinable_Expression_Function
(Nam
)
6365 elsif Expander_Active
6366 and then Ekind
(Nam
) = E_Function
6367 and then Requires_Transient_Scope
(Etype
(Nam
))
6369 Establish_Transient_Scope
(N
, Manage_Sec_Stack
=> True);
6371 -- If the call appears within the bounds of a loop, it will be
6372 -- rewritten and reanalyzed, nothing left to do here.
6374 if Nkind
(N
) /= N_Function_Call
then
6379 -- A protected function cannot be called within the definition of the
6380 -- enclosing protected type, unless it is part of a pre/postcondition
6381 -- on another protected operation. This may appear in the entry wrapper
6382 -- created for an entry with preconditions.
6384 if Is_Protected_Type
(Scope
(Nam
))
6385 and then In_Open_Scopes
(Scope
(Nam
))
6386 and then not Has_Completion
(Scope
(Nam
))
6387 and then not In_Spec_Expression
6388 and then not Is_Entry_Wrapper
(Current_Scope
)
6391 ("& cannot be called before end of protected definition", N
, Nam
);
6394 -- Propagate interpretation to actuals, and add default expressions
6397 if Present
(First_Formal
(Nam
)) then
6398 Resolve_Actuals
(N
, Nam
);
6400 -- Overloaded literals are rewritten as function calls, for purpose of
6401 -- resolution. After resolution, we can replace the call with the
6404 elsif Ekind
(Nam
) = E_Enumeration_Literal
then
6405 Copy_Node
(Subp
, N
);
6406 Resolve_Entity_Name
(N
, Typ
);
6408 -- Avoid validation, since it is a static function call
6410 Generate_Reference
(Nam
, Subp
);
6414 -- If the subprogram is not global, then kill all saved values and
6415 -- checks. This is a bit conservative, since in many cases we could do
6416 -- better, but it is not worth the effort. Similarly, we kill constant
6417 -- values. However we do not need to do this for internal entities
6418 -- (unless they are inherited user-defined subprograms), since they
6419 -- are not in the business of molesting local values.
6421 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6422 -- kill all checks and values for calls to global subprograms. This
6423 -- takes care of the case where an access to a local subprogram is
6424 -- taken, and could be passed directly or indirectly and then called
6425 -- from almost any context.
6427 -- Note: we do not do this step till after resolving the actuals. That
6428 -- way we still take advantage of the current value information while
6429 -- scanning the actuals.
6431 -- We suppress killing values if we are processing the nodes associated
6432 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6433 -- type kills all the values as part of analyzing the code that
6434 -- initializes the dispatch tables.
6436 if Inside_Freezing_Actions
= 0
6437 and then (not Is_Library_Level_Entity
(Nam
)
6438 or else Suppress_Value_Tracking_On_Call
6439 (Nearest_Dynamic_Scope
(Current_Scope
)))
6440 and then (Comes_From_Source
(Nam
)
6441 or else (Present
(Alias
(Nam
))
6442 and then Comes_From_Source
(Alias
(Nam
))))
6444 Kill_Current_Values
;
6447 -- If we are warning about unread OUT parameters, this is the place to
6448 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6449 -- after the above call to Kill_Current_Values (since that call clears
6450 -- the Last_Assignment field of all local variables).
6452 if (Warn_On_Modified_Unread
or Warn_On_All_Unread_Out_Parameters
)
6453 and then Comes_From_Source
(N
)
6454 and then In_Extended_Main_Source_Unit
(N
)
6461 F
:= First_Formal
(Nam
);
6462 A
:= First_Actual
(N
);
6463 while Present
(F
) and then Present
(A
) loop
6464 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
6465 and then Warn_On_Modified_As_Out_Parameter
(F
)
6466 and then Is_Entity_Name
(A
)
6467 and then Present
(Entity
(A
))
6468 and then Comes_From_Source
(N
)
6469 and then Safe_To_Capture_Value
(N
, Entity
(A
))
6471 Set_Last_Assignment
(Entity
(A
), A
);
6480 -- If the subprogram is a primitive operation, check whether or not
6481 -- it is a correct dispatching call.
6483 if Is_Overloadable
(Nam
)
6484 and then Is_Dispatching_Operation
(Nam
)
6486 Check_Dispatching_Call
(N
);
6488 elsif Ekind
(Nam
) /= E_Subprogram_Type
6489 and then Is_Abstract_Subprogram
(Nam
)
6490 and then not In_Instance
6492 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Nam
);
6495 -- If this is a dispatching call, generate the appropriate reference,
6496 -- for better source navigation in GPS.
6498 if Is_Overloadable
(Nam
)
6499 and then Present
(Controlling_Argument
(N
))
6501 Generate_Reference
(Nam
, Subp
, 'R');
6503 -- Normal case, not a dispatching call: generate a call reference
6506 Generate_Reference
(Nam
, Subp
, 's');
6509 if Is_Intrinsic_Subprogram
(Nam
) then
6510 Check_Intrinsic_Call
(N
);
6513 -- Check for violation of restriction No_Specific_Termination_Handlers
6514 -- and warn on a potentially blocking call to Abort_Task.
6516 if Restriction_Check_Required
(No_Specific_Termination_Handlers
)
6517 and then (Is_RTE
(Nam
, RE_Set_Specific_Handler
)
6519 Is_RTE
(Nam
, RE_Specific_Handler
))
6521 Check_Restriction
(No_Specific_Termination_Handlers
, N
);
6523 elsif Is_RTE
(Nam
, RE_Abort_Task
) then
6524 Check_Potentially_Blocking_Operation
(N
);
6527 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6528 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6529 -- need to check the second argument to determine whether it is an
6530 -- absolute or relative timing event.
6532 if Restriction_Check_Required
(No_Relative_Delay
)
6533 and then Is_RTE
(Nam
, RE_Set_Handler
)
6534 and then Is_RTE
(Etype
(Next_Actual
(First_Actual
(N
))), RE_Time_Span
)
6536 Check_Restriction
(No_Relative_Delay
, N
);
6539 -- Issue an error for a call to an eliminated subprogram. This routine
6540 -- will not perform the check if the call appears within a default
6543 Check_For_Eliminated_Subprogram
(Subp
, Nam
);
6545 -- In formal mode, the primitive operations of a tagged type or type
6546 -- extension do not include functions that return the tagged type.
6548 if Nkind
(N
) = N_Function_Call
6549 and then Is_Tagged_Type
(Etype
(N
))
6550 and then Is_Entity_Name
(Name
(N
))
6551 and then Is_Inherited_Operation_For_Type
(Entity
(Name
(N
)), Etype
(N
))
6553 Check_SPARK_05_Restriction
("function not inherited", N
);
6556 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6557 -- class-wide and the call dispatches on result in a context that does
6558 -- not provide a tag, the call raises Program_Error.
6560 if Nkind
(N
) = N_Function_Call
6561 and then In_Instance
6562 and then Is_Generic_Actual_Type
(Typ
)
6563 and then Is_Class_Wide_Type
(Typ
)
6564 and then Has_Controlling_Result
(Nam
)
6565 and then Nkind
(Parent
(N
)) = N_Object_Declaration
6567 -- Verify that none of the formals are controlling
6570 Call_OK
: Boolean := False;
6574 F
:= First_Formal
(Nam
);
6575 while Present
(F
) loop
6576 if Is_Controlling_Formal
(F
) then
6585 Error_Msg_Warn
:= SPARK_Mode
/= On
;
6586 Error_Msg_N
("!cannot determine tag of result<<", N
);
6587 Error_Msg_N
("\Program_Error [<<!", N
);
6589 Make_Raise_Program_Error
(Sloc
(N
),
6590 Reason
=> PE_Explicit_Raise
));
6595 -- Check for calling a function with OUT or IN OUT parameter when the
6596 -- calling context (us right now) is not Ada 2012, so does not allow
6597 -- OUT or IN OUT parameters in function calls. Functions declared in
6598 -- a predefined unit are OK, as they may be called indirectly from a
6599 -- user-declared instantiation.
6601 if Ada_Version
< Ada_2012
6602 and then Ekind
(Nam
) = E_Function
6603 and then Has_Out_Or_In_Out_Parameter
(Nam
)
6604 and then not In_Predefined_Unit
(Nam
)
6606 Error_Msg_NE
("& has at least one OUT or `IN OUT` parameter", N
, Nam
);
6607 Error_Msg_N
("\call to this function only allowed in Ada 2012", N
);
6610 -- Check the dimensions of the actuals in the call. For function calls,
6611 -- propagate the dimensions from the returned type to N.
6613 Analyze_Dimension_Call
(N
, Nam
);
6615 -- All done, evaluate call and deal with elaboration issues
6619 if Legacy_Elaboration_Checks
then
6620 Check_Elab_Call
(N
);
6623 -- Annotate the tree by creating a call marker in case the original call
6624 -- is transformed by expansion. The call marker is automatically saved
6625 -- for later examination by the ABE Processing phase.
6627 Build_Call_Marker
(N
);
6629 -- In GNATprove mode, expansion is disabled, but we want to inline some
6630 -- subprograms to facilitate formal verification. Indirect calls through
6631 -- a subprogram type or within a generic cannot be inlined. Inlining is
6632 -- performed only for calls subject to SPARK_Mode on.
6635 and then SPARK_Mode
= On
6636 and then Is_Overloadable
(Nam
)
6637 and then not Inside_A_Generic
6639 Nam_UA
:= Ultimate_Alias
(Nam
);
6640 Nam_Decl
:= Unit_Declaration_Node
(Nam_UA
);
6642 if Nkind
(Nam_Decl
) = N_Subprogram_Declaration
then
6643 Body_Id
:= Corresponding_Body
(Nam_Decl
);
6645 -- Nothing to do if the subprogram is not eligible for inlining in
6646 -- GNATprove mode, or inlining is disabled with switch -gnatdm
6648 if not Is_Inlined_Always
(Nam_UA
)
6649 or else not Can_Be_Inlined_In_GNATprove_Mode
(Nam_UA
, Body_Id
)
6650 or else Debug_Flag_M
6654 -- Calls cannot be inlined inside assertions, as GNATprove treats
6655 -- assertions as logic expressions. Only issue a message when the
6656 -- body has been seen, otherwise this leads to spurious messages
6657 -- on expression functions.
6659 elsif In_Assertion_Expr
/= 0 then
6660 if Present
(Body_Id
) then
6662 ("cannot inline & (in assertion expression)?", N
, Nam_UA
);
6665 -- Calls cannot be inlined inside default expressions
6667 elsif In_Default_Expr
then
6669 ("cannot inline & (in default expression)?", N
, Nam_UA
);
6671 -- Inlining should not be performed during pre-analysis
6673 elsif Full_Analysis
then
6675 -- Do not inline calls inside expression functions, as this
6676 -- would prevent interpreting them as logical formulas in
6677 -- GNATprove. Only issue a message when the body has been seen,
6678 -- otherwise this leads to spurious messages on callees that
6679 -- are themselves expression functions.
6681 if Present
(Current_Subprogram
)
6682 and then Is_Expression_Function_Or_Completion
6683 (Current_Subprogram
)
6685 if Present
(Body_Id
)
6686 and then Present
(Body_To_Inline
(Nam_Decl
))
6689 ("cannot inline & (inside expression function)?",
6693 -- With the one-pass inlining technique, a call cannot be
6694 -- inlined if the corresponding body has not been seen yet.
6696 elsif No
(Body_Id
) then
6698 ("cannot inline & (body not seen yet)?", N
, Nam_UA
);
6700 -- Nothing to do if there is no body to inline, indicating that
6701 -- the subprogram is not suitable for inlining in GNATprove
6704 elsif No
(Body_To_Inline
(Nam_Decl
)) then
6707 -- Calls cannot be inlined inside potentially unevaluated
6708 -- expressions, as this would create complex actions inside
6709 -- expressions, that are not handled by GNATprove.
6711 elsif Is_Potentially_Unevaluated
(N
) then
6713 ("cannot inline & (in potentially unevaluated context)?",
6716 -- Do not inline calls which would possibly lead to missing a
6717 -- type conversion check on an input parameter.
6719 elsif not Call_Can_Be_Inlined_In_GNATprove_Mode
(N
, Nam
) then
6721 ("cannot inline & (possible check on input parameters)?",
6724 -- Otherwise, inline the call
6727 Expand_Inlined_Call
(N
, Nam_UA
, Nam
);
6733 Mark_Use_Clauses
(Subp
);
6735 Warn_On_Overlapping_Actuals
(Nam
, N
);
6738 -----------------------------
6739 -- Resolve_Case_Expression --
6740 -----------------------------
6742 procedure Resolve_Case_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
6745 Alt_Typ
: Entity_Id
;
6749 Alt
:= First
(Alternatives
(N
));
6750 while Present
(Alt
) loop
6751 Alt_Expr
:= Expression
(Alt
);
6753 if Error_Posted
(Alt_Expr
) then
6757 Resolve
(Alt_Expr
, Typ
);
6758 Alt_Typ
:= Etype
(Alt_Expr
);
6760 -- When the expression is of a scalar subtype different from the
6761 -- result subtype, then insert a conversion to ensure the generation
6762 -- of a constraint check.
6764 if Is_Scalar_Type
(Alt_Typ
) and then Alt_Typ
/= Typ
then
6765 Rewrite
(Alt_Expr
, Convert_To
(Typ
, Alt_Expr
));
6766 Analyze_And_Resolve
(Alt_Expr
, Typ
);
6772 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
6773 -- dynamically tagged must be known statically.
6775 if Is_Tagged_Type
(Typ
) and then not Is_Class_Wide_Type
(Typ
) then
6776 Alt
:= First
(Alternatives
(N
));
6777 Is_Dyn
:= Is_Dynamically_Tagged
(Expression
(Alt
));
6779 while Present
(Alt
) loop
6780 if Is_Dynamically_Tagged
(Expression
(Alt
)) /= Is_Dyn
then
6782 ("all or none of the dependent expressions can be "
6783 & "dynamically tagged", N
);
6791 Eval_Case_Expression
(N
);
6792 Analyze_Dimension
(N
);
6793 end Resolve_Case_Expression
;
6795 -------------------------------
6796 -- Resolve_Character_Literal --
6797 -------------------------------
6799 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
6800 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
6804 -- Verify that the character does belong to the type of the context
6806 Set_Etype
(N
, B_Typ
);
6807 Eval_Character_Literal
(N
);
6809 -- Wide_Wide_Character literals must always be defined, since the set
6810 -- of wide wide character literals is complete, i.e. if a character
6811 -- literal is accepted by the parser, then it is OK for wide wide
6812 -- character (out of range character literals are rejected).
6814 if Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
6817 -- Always accept character literal for type Any_Character, which
6818 -- occurs in error situations and in comparisons of literals, both
6819 -- of which should accept all literals.
6821 elsif B_Typ
= Any_Character
then
6824 -- For Standard.Character or a type derived from it, check that the
6825 -- literal is in range.
6827 elsif Root_Type
(B_Typ
) = Standard_Character
then
6828 if In_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6832 -- For Standard.Wide_Character or a type derived from it, check that the
6833 -- literal is in range.
6835 elsif Root_Type
(B_Typ
) = Standard_Wide_Character
then
6836 if In_Wide_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6840 -- If the entity is already set, this has already been resolved in a
6841 -- generic context, or comes from expansion. Nothing else to do.
6843 elsif Present
(Entity
(N
)) then
6846 -- Otherwise we have a user defined character type, and we can use the
6847 -- standard visibility mechanisms to locate the referenced entity.
6850 C
:= Current_Entity
(N
);
6851 while Present
(C
) loop
6852 if Etype
(C
) = B_Typ
then
6853 Set_Entity_With_Checks
(N
, C
);
6854 Generate_Reference
(C
, N
);
6862 -- If we fall through, then the literal does not match any of the
6863 -- entries of the enumeration type. This isn't just a constraint error
6864 -- situation, it is an illegality (see RM 4.2).
6867 ("character not defined for }", N
, First_Subtype
(B_Typ
));
6868 end Resolve_Character_Literal
;
6870 ---------------------------
6871 -- Resolve_Comparison_Op --
6872 ---------------------------
6874 -- Context requires a boolean type, and plays no role in resolution.
6875 -- Processing identical to that for equality operators. The result type is
6876 -- the base type, which matters when pathological subtypes of booleans with
6877 -- limited ranges are used.
6879 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
6880 L
: constant Node_Id
:= Left_Opnd
(N
);
6881 R
: constant Node_Id
:= Right_Opnd
(N
);
6885 -- If this is an intrinsic operation which is not predefined, use the
6886 -- types of its declared arguments to resolve the possibly overloaded
6887 -- operands. Otherwise the operands are unambiguous and specify the
6890 if Scope
(Entity
(N
)) /= Standard_Standard
then
6891 T
:= Etype
(First_Entity
(Entity
(N
)));
6894 T
:= Find_Unique_Type
(L
, R
);
6896 if T
= Any_Fixed
then
6897 T
:= Unique_Fixed_Point_Type
(L
);
6901 Set_Etype
(N
, Base_Type
(Typ
));
6902 Generate_Reference
(T
, N
, ' ');
6904 -- Skip remaining processing if already set to Any_Type
6906 if T
= Any_Type
then
6910 -- Deal with other error cases
6912 if T
= Any_String
or else
6913 T
= Any_Composite
or else
6916 if T
= Any_Character
then
6917 Ambiguous_Character
(L
);
6919 Error_Msg_N
("ambiguous operands for comparison", N
);
6922 Set_Etype
(N
, Any_Type
);
6926 -- Resolve the operands if types OK
6930 Check_Unset_Reference
(L
);
6931 Check_Unset_Reference
(R
);
6932 Generate_Operator_Reference
(N
, T
);
6933 Check_Low_Bound_Tested
(N
);
6935 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6936 -- types or array types except String.
6938 if Is_Boolean_Type
(T
) then
6939 Check_SPARK_05_Restriction
6940 ("comparison is not defined on Boolean type", N
);
6942 elsif Is_Array_Type
(T
)
6943 and then Base_Type
(T
) /= Standard_String
6945 Check_SPARK_05_Restriction
6946 ("comparison is not defined on array types other than String", N
);
6949 -- Check comparison on unordered enumeration
6951 if Bad_Unordered_Enumeration_Reference
(N
, Etype
(L
)) then
6952 Error_Msg_Sloc
:= Sloc
(Etype
(L
));
6954 ("comparison on unordered enumeration type& declared#?U?",
6958 Analyze_Dimension
(N
);
6960 -- Evaluate the relation (note we do this after the above check since
6961 -- this Eval call may change N to True/False. Skip this evaluation
6962 -- inside assertions, in order to keep assertions as written by users
6963 -- for tools that rely on these, e.g. GNATprove for loop invariants.
6964 -- Except evaluation is still performed even inside assertions for
6965 -- comparisons between values of universal type, which are useless
6966 -- for static analysis tools, and not supported even by GNATprove.
6968 if In_Assertion_Expr
= 0
6969 or else (Is_Universal_Numeric_Type
(Etype
(L
))
6971 Is_Universal_Numeric_Type
(Etype
(R
)))
6973 Eval_Relational_Op
(N
);
6975 end Resolve_Comparison_Op
;
6977 -----------------------------------------
6978 -- Resolve_Discrete_Subtype_Indication --
6979 -----------------------------------------
6981 procedure Resolve_Discrete_Subtype_Indication
6989 Analyze
(Subtype_Mark
(N
));
6990 S
:= Entity
(Subtype_Mark
(N
));
6992 if Nkind
(Constraint
(N
)) /= N_Range_Constraint
then
6993 Error_Msg_N
("expect range constraint for discrete type", N
);
6994 Set_Etype
(N
, Any_Type
);
6997 R
:= Range_Expression
(Constraint
(N
));
7005 if Base_Type
(S
) /= Base_Type
(Typ
) then
7007 ("expect subtype of }", N
, First_Subtype
(Typ
));
7009 -- Rewrite the constraint as a range of Typ
7010 -- to allow compilation to proceed further.
7013 Rewrite
(Low_Bound
(R
),
7014 Make_Attribute_Reference
(Sloc
(Low_Bound
(R
)),
7015 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
7016 Attribute_Name
=> Name_First
));
7017 Rewrite
(High_Bound
(R
),
7018 Make_Attribute_Reference
(Sloc
(High_Bound
(R
)),
7019 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
7020 Attribute_Name
=> Name_First
));
7024 Set_Etype
(N
, Etype
(R
));
7026 -- Additionally, we must check that the bounds are compatible
7027 -- with the given subtype, which might be different from the
7028 -- type of the context.
7030 Apply_Range_Check
(R
, S
);
7032 -- ??? If the above check statically detects a Constraint_Error
7033 -- it replaces the offending bound(s) of the range R with a
7034 -- Constraint_Error node. When the itype which uses these bounds
7035 -- is frozen the resulting call to Duplicate_Subexpr generates
7036 -- a new temporary for the bounds.
7038 -- Unfortunately there are other itypes that are also made depend
7039 -- on these bounds, so when Duplicate_Subexpr is called they get
7040 -- a forward reference to the newly created temporaries and Gigi
7041 -- aborts on such forward references. This is probably sign of a
7042 -- more fundamental problem somewhere else in either the order of
7043 -- itype freezing or the way certain itypes are constructed.
7045 -- To get around this problem we call Remove_Side_Effects right
7046 -- away if either bounds of R are a Constraint_Error.
7049 L
: constant Node_Id
:= Low_Bound
(R
);
7050 H
: constant Node_Id
:= High_Bound
(R
);
7053 if Nkind
(L
) = N_Raise_Constraint_Error
then
7054 Remove_Side_Effects
(L
);
7057 if Nkind
(H
) = N_Raise_Constraint_Error
then
7058 Remove_Side_Effects
(H
);
7062 Check_Unset_Reference
(Low_Bound
(R
));
7063 Check_Unset_Reference
(High_Bound
(R
));
7066 end Resolve_Discrete_Subtype_Indication
;
7068 -------------------------
7069 -- Resolve_Entity_Name --
7070 -------------------------
7072 -- Used to resolve identifiers and expanded names
7074 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
) is
7075 function Is_Assignment_Or_Object_Expression
7077 Expr
: Node_Id
) return Boolean;
7078 -- Determine whether node Context denotes an assignment statement or an
7079 -- object declaration whose expression is node Expr.
7081 ----------------------------------------
7082 -- Is_Assignment_Or_Object_Expression --
7083 ----------------------------------------
7085 function Is_Assignment_Or_Object_Expression
7087 Expr
: Node_Id
) return Boolean
7090 if Nkind_In
(Context
, N_Assignment_Statement
,
7091 N_Object_Declaration
)
7092 and then Expression
(Context
) = Expr
7096 -- Check whether a construct that yields a name is the expression of
7097 -- an assignment statement or an object declaration.
7099 elsif (Nkind_In
(Context
, N_Attribute_Reference
,
7100 N_Explicit_Dereference
,
7101 N_Indexed_Component
,
7102 N_Selected_Component
,
7104 and then Prefix
(Context
) = Expr
)
7106 (Nkind_In
(Context
, N_Type_Conversion
,
7107 N_Unchecked_Type_Conversion
)
7108 and then Expression
(Context
) = Expr
)
7111 Is_Assignment_Or_Object_Expression
7112 (Context
=> Parent
(Context
),
7115 -- Otherwise the context is not an assignment statement or an object
7121 end Is_Assignment_Or_Object_Expression
;
7125 E
: constant Entity_Id
:= Entity
(N
);
7128 -- Start of processing for Resolve_Entity_Name
7131 -- If garbage from errors, set to Any_Type and return
7133 if No
(E
) and then Total_Errors_Detected
/= 0 then
7134 Set_Etype
(N
, Any_Type
);
7138 -- Replace named numbers by corresponding literals. Note that this is
7139 -- the one case where Resolve_Entity_Name must reset the Etype, since
7140 -- it is currently marked as universal.
7142 if Ekind
(E
) = E_Named_Integer
then
7144 Eval_Named_Integer
(N
);
7146 elsif Ekind
(E
) = E_Named_Real
then
7148 Eval_Named_Real
(N
);
7150 -- For enumeration literals, we need to make sure that a proper style
7151 -- check is done, since such literals are overloaded, and thus we did
7152 -- not do a style check during the first phase of analysis.
7154 elsif Ekind
(E
) = E_Enumeration_Literal
then
7155 Set_Entity_With_Checks
(N
, E
);
7156 Eval_Entity_Name
(N
);
7158 -- Case of (sub)type name appearing in a context where an expression
7159 -- is expected. This is legal if occurrence is a current instance.
7160 -- See RM 8.6 (17/3).
7162 elsif Is_Type
(E
) then
7163 if Is_Current_Instance
(N
) then
7166 -- Any other use is an error
7170 ("invalid use of subtype mark in expression or call", N
);
7173 -- Check discriminant use if entity is discriminant in current scope,
7174 -- i.e. discriminant of record or concurrent type currently being
7175 -- analyzed. Uses in corresponding body are unrestricted.
7177 elsif Ekind
(E
) = E_Discriminant
7178 and then Scope
(E
) = Current_Scope
7179 and then not Has_Completion
(Current_Scope
)
7181 Check_Discriminant_Use
(N
);
7183 -- A parameterless generic function cannot appear in a context that
7184 -- requires resolution.
7186 elsif Ekind
(E
) = E_Generic_Function
then
7187 Error_Msg_N
("illegal use of generic function", N
);
7189 -- In Ada 83 an OUT parameter cannot be read, but attributes of
7190 -- array types (i.e. bounds and length) are legal.
7192 elsif Ekind
(E
) = E_Out_Parameter
7193 and then (Nkind
(Parent
(N
)) /= N_Attribute_Reference
7194 or else Is_Scalar_Type
(Etype
(E
)))
7196 and then (Nkind
(Parent
(N
)) in N_Op
7197 or else Nkind
(Parent
(N
)) = N_Explicit_Dereference
7198 or else Is_Assignment_Or_Object_Expression
7199 (Context
=> Parent
(N
),
7202 if Ada_Version
= Ada_83
then
7203 Error_Msg_N
("(Ada 83) illegal reading of out parameter", N
);
7206 -- In all other cases, just do the possible static evaluation
7209 -- A deferred constant that appears in an expression must have a
7210 -- completion, unless it has been removed by in-place expansion of
7211 -- an aggregate. A constant that is a renaming does not need
7214 if Ekind
(E
) = E_Constant
7215 and then Comes_From_Source
(E
)
7216 and then No
(Constant_Value
(E
))
7217 and then Is_Frozen
(Etype
(E
))
7218 and then not In_Spec_Expression
7219 and then not Is_Imported
(E
)
7220 and then Nkind
(Parent
(E
)) /= N_Object_Renaming_Declaration
7222 if No_Initialization
(Parent
(E
))
7223 or else (Present
(Full_View
(E
))
7224 and then No_Initialization
(Parent
(Full_View
(E
))))
7229 ("deferred constant is frozen before completion", N
);
7233 Eval_Entity_Name
(N
);
7238 -- When the entity appears in a parameter association, retrieve the
7239 -- related subprogram call.
7241 if Nkind
(Par
) = N_Parameter_Association
then
7242 Par
:= Parent
(Par
);
7245 if Comes_From_Source
(N
) then
7247 -- The following checks are only relevant when SPARK_Mode is on as
7248 -- they are not standard Ada legality rules.
7250 if SPARK_Mode
= On
then
7252 -- An effectively volatile object subject to enabled properties
7253 -- Async_Writers or Effective_Reads must appear in non-interfering
7254 -- context (SPARK RM 7.1.3(12)).
7257 and then Is_Effectively_Volatile
(E
)
7258 and then (Async_Writers_Enabled
(E
)
7259 or else Effective_Reads_Enabled
(E
))
7260 and then not Is_OK_Volatile_Context
(Par
, N
)
7263 ("volatile object cannot appear in this context "
7264 & "(SPARK RM 7.1.3(12))", N
);
7267 -- Check for possible elaboration issues with respect to reads of
7268 -- variables. The act of renaming the variable is not considered a
7269 -- read as it simply establishes an alias.
7271 if Legacy_Elaboration_Checks
7272 and then Ekind
(E
) = E_Variable
7273 and then Dynamic_Elaboration_Checks
7274 and then Nkind
(Par
) /= N_Object_Renaming_Declaration
7276 Check_Elab_Call
(N
);
7280 -- The variable may eventually become a constituent of a single
7281 -- protected/task type. Record the reference now and verify its
7282 -- legality when analyzing the contract of the variable
7285 if Ekind
(E
) = E_Variable
then
7286 Record_Possible_Part_Of_Reference
(E
, N
);
7289 -- A Ghost entity must appear in a specific context
7291 if Is_Ghost_Entity
(E
) then
7292 Check_Ghost_Context
(E
, N
);
7296 Mark_Use_Clauses
(E
);
7297 end Resolve_Entity_Name
;
7303 procedure Resolve_Entry
(Entry_Name
: Node_Id
) is
7304 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
7312 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
;
7313 -- If the bounds of the entry family being called depend on task
7314 -- discriminants, build a new index subtype where a discriminant is
7315 -- replaced with the value of the discriminant of the target task.
7316 -- The target task is the prefix of the entry name in the call.
7318 -----------------------
7319 -- Actual_Index_Type --
7320 -----------------------
7322 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
is
7323 Typ
: constant Entity_Id
:= Entry_Index_Type
(E
);
7324 Tsk
: constant Entity_Id
:= Scope
(E
);
7325 Lo
: constant Node_Id
:= Type_Low_Bound
(Typ
);
7326 Hi
: constant Node_Id
:= Type_High_Bound
(Typ
);
7329 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
;
7330 -- If the bound is given by a discriminant, replace with a reference
7331 -- to the discriminant of the same name in the target task. If the
7332 -- entry name is the target of a requeue statement and the entry is
7333 -- in the current protected object, the bound to be used is the
7334 -- discriminal of the object (see Apply_Range_Checks for details of
7335 -- the transformation).
7337 -----------------------------
7338 -- Actual_Discriminant_Ref --
7339 -----------------------------
7341 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
is
7342 Typ
: constant Entity_Id
:= Etype
(Bound
);
7346 Remove_Side_Effects
(Bound
);
7348 if not Is_Entity_Name
(Bound
)
7349 or else Ekind
(Entity
(Bound
)) /= E_Discriminant
7353 elsif Is_Protected_Type
(Tsk
)
7354 and then In_Open_Scopes
(Tsk
)
7355 and then Nkind
(Parent
(Entry_Name
)) = N_Requeue_Statement
7357 -- Note: here Bound denotes a discriminant of the corresponding
7358 -- record type tskV, whose discriminal is a formal of the
7359 -- init-proc tskVIP. What we want is the body discriminal,
7360 -- which is associated to the discriminant of the original
7361 -- concurrent type tsk.
7363 return New_Occurrence_Of
7364 (Find_Body_Discriminal
(Entity
(Bound
)), Loc
);
7368 Make_Selected_Component
(Loc
,
7369 Prefix
=> New_Copy_Tree
(Prefix
(Prefix
(Entry_Name
))),
7370 Selector_Name
=> New_Occurrence_Of
(Entity
(Bound
), Loc
));
7375 end Actual_Discriminant_Ref
;
7377 -- Start of processing for Actual_Index_Type
7380 if not Has_Discriminants
(Tsk
)
7381 or else (not Is_Entity_Name
(Lo
) and then not Is_Entity_Name
(Hi
))
7383 return Entry_Index_Type
(E
);
7386 New_T
:= Create_Itype
(Ekind
(Typ
), Parent
(Entry_Name
));
7387 Set_Etype
(New_T
, Base_Type
(Typ
));
7388 Set_Size_Info
(New_T
, Typ
);
7389 Set_RM_Size
(New_T
, RM_Size
(Typ
));
7390 Set_Scalar_Range
(New_T
,
7391 Make_Range
(Sloc
(Entry_Name
),
7392 Low_Bound
=> Actual_Discriminant_Ref
(Lo
),
7393 High_Bound
=> Actual_Discriminant_Ref
(Hi
)));
7397 end Actual_Index_Type
;
7399 -- Start of processing for Resolve_Entry
7402 -- Find name of entry being called, and resolve prefix of name with its
7403 -- own type. The prefix can be overloaded, and the name and signature of
7404 -- the entry must be taken into account.
7406 if Nkind
(Entry_Name
) = N_Indexed_Component
then
7408 -- Case of dealing with entry family within the current tasks
7410 E_Name
:= Prefix
(Entry_Name
);
7413 E_Name
:= Entry_Name
;
7416 if Is_Entity_Name
(E_Name
) then
7418 -- Entry call to an entry (or entry family) in the current task. This
7419 -- is legal even though the task will deadlock. Rewrite as call to
7422 -- This can also be a call to an entry in an enclosing task. If this
7423 -- is a single task, we have to retrieve its name, because the scope
7424 -- of the entry is the task type, not the object. If the enclosing
7425 -- task is a task type, the identity of the task is given by its own
7428 -- Finally this can be a requeue on an entry of the same task or
7429 -- protected object.
7431 S
:= Scope
(Entity
(E_Name
));
7433 for J
in reverse 0 .. Scope_Stack
.Last
loop
7434 if Is_Task_Type
(Scope_Stack
.Table
(J
).Entity
)
7435 and then not Comes_From_Source
(S
)
7437 -- S is an enclosing task or protected object. The concurrent
7438 -- declaration has been converted into a type declaration, and
7439 -- the object itself has an object declaration that follows
7440 -- the type in the same declarative part.
7442 Tsk
:= Next_Entity
(S
);
7443 while Etype
(Tsk
) /= S
loop
7450 elsif S
= Scope_Stack
.Table
(J
).Entity
then
7452 -- Call to current task. Will be transformed into call to Self
7460 Make_Selected_Component
(Loc
,
7461 Prefix
=> New_Occurrence_Of
(S
, Loc
),
7463 New_Occurrence_Of
(Entity
(E_Name
), Loc
));
7464 Rewrite
(E_Name
, New_N
);
7467 elsif Nkind
(Entry_Name
) = N_Selected_Component
7468 and then Is_Overloaded
(Prefix
(Entry_Name
))
7470 -- Use the entry name (which must be unique at this point) to find
7471 -- the prefix that returns the corresponding task/protected type.
7474 Pref
: constant Node_Id
:= Prefix
(Entry_Name
);
7475 Ent
: constant Entity_Id
:= Entity
(Selector_Name
(Entry_Name
));
7480 Get_First_Interp
(Pref
, I
, It
);
7481 while Present
(It
.Typ
) loop
7482 if Scope
(Ent
) = It
.Typ
then
7483 Set_Etype
(Pref
, It
.Typ
);
7487 Get_Next_Interp
(I
, It
);
7492 if Nkind
(Entry_Name
) = N_Selected_Component
then
7493 Resolve
(Prefix
(Entry_Name
));
7495 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7496 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
7497 Resolve
(Prefix
(Prefix
(Entry_Name
)));
7498 Index
:= First
(Expressions
(Entry_Name
));
7499 Resolve
(Index
, Entry_Index_Type
(Nam
));
7501 -- Generate a reference for the index when it denotes an entity
7503 if Is_Entity_Name
(Index
) then
7504 Generate_Reference
(Entity
(Index
), Nam
);
7507 -- Up to this point the expression could have been the actual in a
7508 -- simple entry call, and be given by a named association.
7510 if Nkind
(Index
) = N_Parameter_Association
then
7511 Error_Msg_N
("expect expression for entry index", Index
);
7513 Apply_Range_Check
(Index
, Actual_Index_Type
(Nam
));
7518 ------------------------
7519 -- Resolve_Entry_Call --
7520 ------------------------
7522 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
7523 Entry_Name
: constant Node_Id
:= Name
(N
);
7524 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
7532 -- We kill all checks here, because it does not seem worth the effort to
7533 -- do anything better, an entry call is a big operation.
7537 -- Processing of the name is similar for entry calls and protected
7538 -- operation calls. Once the entity is determined, we can complete
7539 -- the resolution of the actuals.
7541 -- The selector may be overloaded, in the case of a protected object
7542 -- with overloaded functions. The type of the context is used for
7545 if Nkind
(Entry_Name
) = N_Selected_Component
7546 and then Is_Overloaded
(Selector_Name
(Entry_Name
))
7547 and then Typ
/= Standard_Void_Type
7554 Get_First_Interp
(Selector_Name
(Entry_Name
), I
, It
);
7555 while Present
(It
.Typ
) loop
7556 if Covers
(Typ
, It
.Typ
) then
7557 Set_Entity
(Selector_Name
(Entry_Name
), It
.Nam
);
7558 Set_Etype
(Entry_Name
, It
.Typ
);
7560 Generate_Reference
(It
.Typ
, N
, ' ');
7563 Get_Next_Interp
(I
, It
);
7568 Resolve_Entry
(Entry_Name
);
7570 if Nkind
(Entry_Name
) = N_Selected_Component
then
7572 -- Simple entry or protected operation call
7574 Nam
:= Entity
(Selector_Name
(Entry_Name
));
7575 Obj
:= Prefix
(Entry_Name
);
7577 if Is_Subprogram
(Nam
) then
7578 Check_For_Eliminated_Subprogram
(Entry_Name
, Nam
);
7581 Was_Over
:= Is_Overloaded
(Selector_Name
(Entry_Name
));
7583 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7585 -- Call to member of entry family
7587 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
7588 Obj
:= Prefix
(Prefix
(Entry_Name
));
7589 Was_Over
:= Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)));
7592 -- We cannot in general check the maximum depth of protected entry calls
7593 -- at compile time. But we can tell that any protected entry call at all
7594 -- violates a specified nesting depth of zero.
7596 if Is_Protected_Type
(Scope
(Nam
)) then
7597 Check_Restriction
(Max_Entry_Queue_Length
, N
);
7600 -- Use context type to disambiguate a protected function that can be
7601 -- called without actuals and that returns an array type, and where the
7602 -- argument list may be an indexing of the returned value.
7604 if Ekind
(Nam
) = E_Function
7605 and then Needs_No_Actuals
(Nam
)
7606 and then Present
(Parameter_Associations
(N
))
7608 ((Is_Array_Type
(Etype
(Nam
))
7609 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
7611 or else (Is_Access_Type
(Etype
(Nam
))
7612 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
7616 Component_Type
(Designated_Type
(Etype
(Nam
))))))
7619 Index_Node
: Node_Id
;
7623 Make_Indexed_Component
(Loc
,
7625 Make_Function_Call
(Loc
, Name
=> Relocate_Node
(Entry_Name
)),
7626 Expressions
=> Parameter_Associations
(N
));
7628 -- Since we are correcting a node classification error made by the
7629 -- parser, we call Replace rather than Rewrite.
7631 Replace
(N
, Index_Node
);
7632 Set_Etype
(Prefix
(N
), Etype
(Nam
));
7634 Resolve_Indexed_Component
(N
, Typ
);
7639 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
)
7640 and then Present
(Contract_Wrapper
(Nam
))
7641 and then Current_Scope
/= Contract_Wrapper
(Nam
)
7643 -- Note the entity being called before rewriting the call, so that
7644 -- it appears used at this point.
7646 Generate_Reference
(Nam
, Entry_Name
, 'r');
7648 -- Rewrite as call to the precondition wrapper, adding the task
7649 -- object to the list of actuals. If the call is to a member of an
7650 -- entry family, include the index as well.
7654 New_Actuals
: List_Id
;
7657 New_Actuals
:= New_List
(Obj
);
7659 if Nkind
(Entry_Name
) = N_Indexed_Component
then
7660 Append_To
(New_Actuals
,
7661 New_Copy_Tree
(First
(Expressions
(Entry_Name
))));
7664 Append_List
(Parameter_Associations
(N
), New_Actuals
);
7666 Make_Procedure_Call_Statement
(Loc
,
7668 New_Occurrence_Of
(Contract_Wrapper
(Nam
), Loc
),
7669 Parameter_Associations
=> New_Actuals
);
7670 Rewrite
(N
, New_Call
);
7672 -- Preanalyze and resolve new call. Current procedure is called
7673 -- from Resolve_Call, after which expansion will take place.
7675 Preanalyze_And_Resolve
(N
);
7680 -- The operation name may have been overloaded. Order the actuals
7681 -- according to the formals of the resolved entity, and set the return
7682 -- type to that of the operation.
7685 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
7686 pragma Assert
(Norm_OK
);
7687 Set_Etype
(N
, Etype
(Nam
));
7689 -- Reset the Is_Overloaded flag, since resolution is now completed
7691 -- Simple entry call
7693 if Nkind
(Entry_Name
) = N_Selected_Component
then
7694 Set_Is_Overloaded
(Selector_Name
(Entry_Name
), False);
7696 -- Call to a member of an entry family
7698 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7699 Set_Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)), False);
7703 Resolve_Actuals
(N
, Nam
);
7704 Check_Internal_Protected_Use
(N
, Nam
);
7706 -- Create a call reference to the entry
7708 Generate_Reference
(Nam
, Entry_Name
, 's');
7710 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
) then
7711 Check_Potentially_Blocking_Operation
(N
);
7714 -- Verify that a procedure call cannot masquerade as an entry
7715 -- call where an entry call is expected.
7717 if Ekind
(Nam
) = E_Procedure
then
7718 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
7719 and then N
= Entry_Call_Statement
(Parent
(N
))
7721 Error_Msg_N
("entry call required in select statement", N
);
7723 elsif Nkind
(Parent
(N
)) = N_Triggering_Alternative
7724 and then N
= Triggering_Statement
(Parent
(N
))
7726 Error_Msg_N
("triggering statement cannot be procedure call", N
);
7728 elsif Ekind
(Scope
(Nam
)) = E_Task_Type
7729 and then not In_Open_Scopes
(Scope
(Nam
))
7731 Error_Msg_N
("task has no entry with this name", Entry_Name
);
7735 -- After resolution, entry calls and protected procedure calls are
7736 -- changed into entry calls, for expansion. The structure of the node
7737 -- does not change, so it can safely be done in place. Protected
7738 -- function calls must keep their structure because they are
7741 if Ekind
(Nam
) /= E_Function
then
7743 -- A protected operation that is not a function may modify the
7744 -- corresponding object, and cannot apply to a constant. If this
7745 -- is an internal call, the prefix is the type itself.
7747 if Is_Protected_Type
(Scope
(Nam
))
7748 and then not Is_Variable
(Obj
)
7749 and then (not Is_Entity_Name
(Obj
)
7750 or else not Is_Type
(Entity
(Obj
)))
7753 ("prefix of protected procedure or entry call must be variable",
7758 Entry_Call
: Node_Id
;
7762 Make_Entry_Call_Statement
(Loc
,
7764 Parameter_Associations
=> Parameter_Associations
(N
));
7766 -- Inherit relevant attributes from the original call
7768 Set_First_Named_Actual
7769 (Entry_Call
, First_Named_Actual
(N
));
7771 Set_Is_Elaboration_Checks_OK_Node
7772 (Entry_Call
, Is_Elaboration_Checks_OK_Node
(N
));
7774 Set_Is_Elaboration_Warnings_OK_Node
7775 (Entry_Call
, Is_Elaboration_Warnings_OK_Node
(N
));
7777 Set_Is_SPARK_Mode_On_Node
7778 (Entry_Call
, Is_SPARK_Mode_On_Node
(N
));
7780 Rewrite
(N
, Entry_Call
);
7781 Set_Analyzed
(N
, True);
7784 -- Protected functions can return on the secondary stack, in which case
7785 -- we must trigger the transient scope mechanism.
7787 elsif Expander_Active
7788 and then Requires_Transient_Scope
(Etype
(Nam
))
7790 Establish_Transient_Scope
(N
, Manage_Sec_Stack
=> True);
7792 end Resolve_Entry_Call
;
7794 -------------------------
7795 -- Resolve_Equality_Op --
7796 -------------------------
7798 -- Both arguments must have the same type, and the boolean context does
7799 -- not participate in the resolution. The first pass verifies that the
7800 -- interpretation is not ambiguous, and the type of the left argument is
7801 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7802 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7803 -- though they carry a single (universal) type. Diagnose this case here.
7805 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
7806 L
: constant Node_Id
:= Left_Opnd
(N
);
7807 R
: constant Node_Id
:= Right_Opnd
(N
);
7808 T
: Entity_Id
:= Find_Unique_Type
(L
, R
);
7810 procedure Check_If_Expression
(Cond
: Node_Id
);
7811 -- The resolution rule for if expressions requires that each such must
7812 -- have a unique type. This means that if several dependent expressions
7813 -- are of a non-null anonymous access type, and the context does not
7814 -- impose an expected type (as can be the case in an equality operation)
7815 -- the expression must be rejected.
7817 procedure Explain_Redundancy
(N
: Node_Id
);
7818 -- Attempt to explain the nature of a redundant comparison with True. If
7819 -- the expression N is too complex, this routine issues a general error
7822 function Find_Unique_Access_Type
return Entity_Id
;
7823 -- In the case of allocators and access attributes, the context must
7824 -- provide an indication of the specific access type to be used. If
7825 -- one operand is of such a "generic" access type, check whether there
7826 -- is a specific visible access type that has the same designated type.
7827 -- This is semantically dubious, and of no interest to any real code,
7828 -- but c48008a makes it all worthwhile.
7830 -------------------------
7831 -- Check_If_Expression --
7832 -------------------------
7834 procedure Check_If_Expression
(Cond
: Node_Id
) is
7835 Then_Expr
: Node_Id
;
7836 Else_Expr
: Node_Id
;
7839 if Nkind
(Cond
) = N_If_Expression
then
7840 Then_Expr
:= Next
(First
(Expressions
(Cond
)));
7841 Else_Expr
:= Next
(Then_Expr
);
7843 if Nkind
(Then_Expr
) /= N_Null
7844 and then Nkind
(Else_Expr
) /= N_Null
7846 Error_Msg_N
("cannot determine type of if expression", Cond
);
7849 end Check_If_Expression
;
7851 ------------------------
7852 -- Explain_Redundancy --
7853 ------------------------
7855 procedure Explain_Redundancy
(N
: Node_Id
) is
7863 -- Strip the operand down to an entity
7866 if Nkind
(Val
) = N_Selected_Component
then
7867 Val
:= Selector_Name
(Val
);
7873 -- The construct denotes an entity
7875 if Is_Entity_Name
(Val
) and then Present
(Entity
(Val
)) then
7876 Val_Id
:= Entity
(Val
);
7878 -- Do not generate an error message when the comparison is done
7879 -- against the enumeration literal Standard.True.
7881 if Ekind
(Val_Id
) /= E_Enumeration_Literal
then
7883 -- Build a customized error message
7886 Add_Str_To_Name_Buffer
("?r?");
7888 if Ekind
(Val_Id
) = E_Component
then
7889 Add_Str_To_Name_Buffer
("component ");
7891 elsif Ekind
(Val_Id
) = E_Constant
then
7892 Add_Str_To_Name_Buffer
("constant ");
7894 elsif Ekind
(Val_Id
) = E_Discriminant
then
7895 Add_Str_To_Name_Buffer
("discriminant ");
7897 elsif Is_Formal
(Val_Id
) then
7898 Add_Str_To_Name_Buffer
("parameter ");
7900 elsif Ekind
(Val_Id
) = E_Variable
then
7901 Add_Str_To_Name_Buffer
("variable ");
7904 Add_Str_To_Name_Buffer
("& is always True!");
7907 Error_Msg_NE
(Get_Name_String
(Error
), Val
, Val_Id
);
7910 -- The construct is too complex to disect, issue a general message
7913 Error_Msg_N
("?r?expression is always True!", Val
);
7915 end Explain_Redundancy
;
7917 -----------------------------
7918 -- Find_Unique_Access_Type --
7919 -----------------------------
7921 function Find_Unique_Access_Type
return Entity_Id
is
7927 if Ekind_In
(Etype
(R
), E_Allocator_Type
,
7928 E_Access_Attribute_Type
)
7930 Acc
:= Designated_Type
(Etype
(R
));
7932 elsif Ekind_In
(Etype
(L
), E_Allocator_Type
,
7933 E_Access_Attribute_Type
)
7935 Acc
:= Designated_Type
(Etype
(L
));
7941 while S
/= Standard_Standard
loop
7942 E
:= First_Entity
(S
);
7943 while Present
(E
) loop
7945 and then Is_Access_Type
(E
)
7946 and then Ekind
(E
) /= E_Allocator_Type
7947 and then Designated_Type
(E
) = Base_Type
(Acc
)
7959 end Find_Unique_Access_Type
;
7961 -- Start of processing for Resolve_Equality_Op
7964 Set_Etype
(N
, Base_Type
(Typ
));
7965 Generate_Reference
(T
, N
, ' ');
7967 if T
= Any_Fixed
then
7968 T
:= Unique_Fixed_Point_Type
(L
);
7971 if T
/= Any_Type
then
7972 if T
= Any_String
or else
7973 T
= Any_Composite
or else
7976 if T
= Any_Character
then
7977 Ambiguous_Character
(L
);
7979 Error_Msg_N
("ambiguous operands for equality", N
);
7982 Set_Etype
(N
, Any_Type
);
7985 elsif T
= Any_Access
7986 or else Ekind_In
(T
, E_Allocator_Type
, E_Access_Attribute_Type
)
7988 T
:= Find_Unique_Access_Type
;
7991 Error_Msg_N
("ambiguous operands for equality", N
);
7992 Set_Etype
(N
, Any_Type
);
7996 -- If expressions must have a single type, and if the context does
7997 -- not impose one the dependent expressions cannot be anonymous
8000 -- Why no similar processing for case expressions???
8002 elsif Ada_Version
>= Ada_2012
8003 and then Ekind_In
(Etype
(L
), E_Anonymous_Access_Type
,
8004 E_Anonymous_Access_Subprogram_Type
)
8005 and then Ekind_In
(Etype
(R
), E_Anonymous_Access_Type
,
8006 E_Anonymous_Access_Subprogram_Type
)
8008 Check_If_Expression
(L
);
8009 Check_If_Expression
(R
);
8015 -- In SPARK, equality operators = and /= for array types other than
8016 -- String are only defined when, for each index position, the
8017 -- operands have equal static bounds.
8019 if Is_Array_Type
(T
) then
8021 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8022 -- operation if not needed.
8024 if Restriction_Check_Required
(SPARK_05
)
8025 and then Base_Type
(T
) /= Standard_String
8026 and then Base_Type
(Etype
(L
)) = Base_Type
(Etype
(R
))
8027 and then Etype
(L
) /= Any_Composite
-- or else L in error
8028 and then Etype
(R
) /= Any_Composite
-- or else R in error
8029 and then not Matching_Static_Array_Bounds
(Etype
(L
), Etype
(R
))
8031 Check_SPARK_05_Restriction
8032 ("array types should have matching static bounds", N
);
8036 -- If the unique type is a class-wide type then it will be expanded
8037 -- into a dispatching call to the predefined primitive. Therefore we
8038 -- check here for potential violation of such restriction.
8040 if Is_Class_Wide_Type
(T
) then
8041 Check_Restriction
(No_Dispatching_Calls
, N
);
8044 -- Only warn for redundant equality comparison to True for objects
8045 -- (e.g. "X = True") and operations (e.g. "(X < Y) = True"). For
8046 -- other expressions, it may be a matter of preference to write
8047 -- "Expr = True" or "Expr".
8049 if Warn_On_Redundant_Constructs
8050 and then Comes_From_Source
(N
)
8051 and then Comes_From_Source
(R
)
8052 and then Is_Entity_Name
(R
)
8053 and then Entity
(R
) = Standard_True
8055 ((Is_Entity_Name
(L
) and then Is_Object
(Entity
(L
)))
8059 Error_Msg_N
-- CODEFIX
8060 ("?r?comparison with True is redundant!", N
);
8061 Explain_Redundancy
(Original_Node
(R
));
8064 Check_Unset_Reference
(L
);
8065 Check_Unset_Reference
(R
);
8066 Generate_Operator_Reference
(N
, T
);
8067 Check_Low_Bound_Tested
(N
);
8069 -- If this is an inequality, it may be the implicit inequality
8070 -- created for a user-defined operation, in which case the corres-
8071 -- ponding equality operation is not intrinsic, and the operation
8072 -- cannot be constant-folded. Else fold.
8074 if Nkind
(N
) = N_Op_Eq
8075 or else Comes_From_Source
(Entity
(N
))
8076 or else Ekind
(Entity
(N
)) = E_Operator
8077 or else Is_Intrinsic_Subprogram
8078 (Corresponding_Equality
(Entity
(N
)))
8080 Analyze_Dimension
(N
);
8081 Eval_Relational_Op
(N
);
8083 elsif Nkind
(N
) = N_Op_Ne
8084 and then Is_Abstract_Subprogram
(Entity
(N
))
8086 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Entity
(N
));
8089 -- Ada 2005: If one operand is an anonymous access type, convert the
8090 -- other operand to it, to ensure that the underlying types match in
8091 -- the back-end. Same for access_to_subprogram, and the conversion
8092 -- verifies that the types are subtype conformant.
8094 -- We apply the same conversion in the case one of the operands is a
8095 -- private subtype of the type of the other.
8097 -- Why the Expander_Active test here ???
8101 (Ekind_In
(T
, E_Anonymous_Access_Type
,
8102 E_Anonymous_Access_Subprogram_Type
)
8103 or else Is_Private_Type
(T
))
8105 if Etype
(L
) /= T
then
8107 Make_Unchecked_Type_Conversion
(Sloc
(L
),
8108 Subtype_Mark
=> New_Occurrence_Of
(T
, Sloc
(L
)),
8109 Expression
=> Relocate_Node
(L
)));
8110 Analyze_And_Resolve
(L
, T
);
8113 if (Etype
(R
)) /= T
then
8115 Make_Unchecked_Type_Conversion
(Sloc
(R
),
8116 Subtype_Mark
=> New_Occurrence_Of
(Etype
(L
), Sloc
(R
)),
8117 Expression
=> Relocate_Node
(R
)));
8118 Analyze_And_Resolve
(R
, T
);
8122 end Resolve_Equality_Op
;
8124 ----------------------------------
8125 -- Resolve_Explicit_Dereference --
8126 ----------------------------------
8128 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
) is
8129 Loc
: constant Source_Ptr
:= Sloc
(N
);
8131 P
: constant Node_Id
:= Prefix
(N
);
8134 -- The candidate prefix type, if overloaded
8140 Check_Fully_Declared_Prefix
(Typ
, P
);
8143 -- A useful optimization: check whether the dereference denotes an
8144 -- element of a container, and if so rewrite it as a call to the
8145 -- corresponding Element function.
8147 -- Disabled for now, on advice of ARG. A more restricted form of the
8148 -- predicate might be acceptable ???
8150 -- if Is_Container_Element (N) then
8154 if Is_Overloaded
(P
) then
8156 -- Use the context type to select the prefix that has the correct
8157 -- designated type. Keep the first match, which will be the inner-
8160 Get_First_Interp
(P
, I
, It
);
8162 while Present
(It
.Typ
) loop
8163 if Is_Access_Type
(It
.Typ
)
8164 and then Covers
(Typ
, Designated_Type
(It
.Typ
))
8170 -- Remove access types that do not match, but preserve access
8171 -- to subprogram interpretations, in case a further dereference
8172 -- is needed (see below).
8174 elsif Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
8178 Get_Next_Interp
(I
, It
);
8181 if Present
(P_Typ
) then
8183 Set_Etype
(N
, Designated_Type
(P_Typ
));
8186 -- If no interpretation covers the designated type of the prefix,
8187 -- this is the pathological case where not all implementations of
8188 -- the prefix allow the interpretation of the node as a call. Now
8189 -- that the expected type is known, Remove other interpretations
8190 -- from prefix, rewrite it as a call, and resolve again, so that
8191 -- the proper call node is generated.
8193 Get_First_Interp
(P
, I
, It
);
8194 while Present
(It
.Typ
) loop
8195 if Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
8199 Get_Next_Interp
(I
, It
);
8203 Make_Function_Call
(Loc
,
8205 Make_Explicit_Dereference
(Loc
,
8207 Parameter_Associations
=> New_List
);
8209 Save_Interps
(N
, New_N
);
8211 Analyze_And_Resolve
(N
, Typ
);
8215 -- If not overloaded, resolve P with its own type
8221 -- If the prefix might be null, add an access check
8223 if Is_Access_Type
(Etype
(P
))
8224 and then not Can_Never_Be_Null
(Etype
(P
))
8226 Apply_Access_Check
(N
);
8229 -- If the designated type is a packed unconstrained array type, and the
8230 -- explicit dereference is not in the context of an attribute reference,
8231 -- then we must compute and set the actual subtype, since it is needed
8232 -- by Gigi. The reason we exclude the attribute case is that this is
8233 -- handled fine by Gigi, and in fact we use such attributes to build the
8234 -- actual subtype. We also exclude generated code (which builds actual
8235 -- subtypes directly if they are needed).
8237 if Is_Array_Type
(Etype
(N
))
8238 and then Is_Packed
(Etype
(N
))
8239 and then not Is_Constrained
(Etype
(N
))
8240 and then Nkind
(Parent
(N
)) /= N_Attribute_Reference
8241 and then Comes_From_Source
(N
)
8243 Set_Etype
(N
, Get_Actual_Subtype
(N
));
8246 Analyze_Dimension
(N
);
8248 -- Note: No Eval processing is required for an explicit dereference,
8249 -- because such a name can never be static.
8251 end Resolve_Explicit_Dereference
;
8253 -------------------------------------
8254 -- Resolve_Expression_With_Actions --
8255 -------------------------------------
8257 procedure Resolve_Expression_With_Actions
(N
: Node_Id
; Typ
: Entity_Id
) is
8261 -- If N has no actions, and its expression has been constant folded,
8262 -- then rewrite N as just its expression. Note, we can't do this in
8263 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8264 -- Expression (N) to be expanded again.
8266 if Is_Empty_List
(Actions
(N
))
8267 and then Compile_Time_Known_Value
(Expression
(N
))
8269 Rewrite
(N
, Expression
(N
));
8271 end Resolve_Expression_With_Actions
;
8273 ----------------------------------
8274 -- Resolve_Generalized_Indexing --
8275 ----------------------------------
8277 procedure Resolve_Generalized_Indexing
(N
: Node_Id
; Typ
: Entity_Id
) is
8278 Indexing
: constant Node_Id
:= Generalized_Indexing
(N
);
8284 -- In ASIS mode, propagate the information about the indexes back to
8285 -- to the original indexing node. The generalized indexing is either
8286 -- a function call, or a dereference of one. The actuals include the
8287 -- prefix of the original node, which is the container expression.
8290 Resolve
(Indexing
, Typ
);
8291 Set_Etype
(N
, Etype
(Indexing
));
8292 Set_Is_Overloaded
(N
, False);
8295 while Nkind_In
(Call
, N_Explicit_Dereference
, N_Selected_Component
)
8297 Call
:= Prefix
(Call
);
8300 if Nkind
(Call
) = N_Function_Call
then
8301 Indexes
:= New_Copy_List
(Parameter_Associations
(Call
));
8302 Pref
:= Remove_Head
(Indexes
);
8303 Set_Expressions
(N
, Indexes
);
8305 -- If expression is to be reanalyzed, reset Generalized_Indexing
8306 -- to recreate call node, as is the case when the expression is
8307 -- part of an expression function.
8309 if In_Spec_Expression
then
8310 Set_Generalized_Indexing
(N
, Empty
);
8313 Set_Prefix
(N
, Pref
);
8317 Rewrite
(N
, Indexing
);
8320 end Resolve_Generalized_Indexing
;
8322 ---------------------------
8323 -- Resolve_If_Expression --
8324 ---------------------------
8326 procedure Resolve_If_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
8327 Condition
: constant Node_Id
:= First
(Expressions
(N
));
8328 Then_Expr
: Node_Id
;
8329 Else_Expr
: Node_Id
;
8330 Else_Typ
: Entity_Id
;
8331 Then_Typ
: Entity_Id
;
8334 -- Defend against malformed expressions
8336 if No
(Condition
) then
8340 Then_Expr
:= Next
(Condition
);
8342 if No
(Then_Expr
) then
8346 Else_Expr
:= Next
(Then_Expr
);
8348 Resolve
(Condition
, Any_Boolean
);
8349 Resolve
(Then_Expr
, Typ
);
8350 Then_Typ
:= Etype
(Then_Expr
);
8352 -- When the "then" expression is of a scalar subtype different from the
8353 -- result subtype, then insert a conversion to ensure the generation of
8354 -- a constraint check. The same is done for the else part below, again
8355 -- comparing subtypes rather than base types.
8357 if Is_Scalar_Type
(Then_Typ
) and then Then_Typ
/= Typ
then
8358 Rewrite
(Then_Expr
, Convert_To
(Typ
, Then_Expr
));
8359 Analyze_And_Resolve
(Then_Expr
, Typ
);
8362 -- If ELSE expression present, just resolve using the determined type
8363 -- If type is universal, resolve to any member of the class.
8365 if Present
(Else_Expr
) then
8366 if Typ
= Universal_Integer
then
8367 Resolve
(Else_Expr
, Any_Integer
);
8369 elsif Typ
= Universal_Real
then
8370 Resolve
(Else_Expr
, Any_Real
);
8373 Resolve
(Else_Expr
, Typ
);
8376 Else_Typ
:= Etype
(Else_Expr
);
8378 if Is_Scalar_Type
(Else_Typ
) and then Else_Typ
/= Typ
then
8379 Rewrite
(Else_Expr
, Convert_To
(Typ
, Else_Expr
));
8380 Analyze_And_Resolve
(Else_Expr
, Typ
);
8382 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8383 -- dynamically tagged must be known statically.
8385 elsif Is_Tagged_Type
(Typ
) and then not Is_Class_Wide_Type
(Typ
) then
8386 if Is_Dynamically_Tagged
(Then_Expr
) /=
8387 Is_Dynamically_Tagged
(Else_Expr
)
8389 Error_Msg_N
("all or none of the dependent expressions "
8390 & "can be dynamically tagged", N
);
8394 -- If no ELSE expression is present, root type must be Standard.Boolean
8395 -- and we provide a Standard.True result converted to the appropriate
8396 -- Boolean type (in case it is a derived boolean type).
8398 elsif Root_Type
(Typ
) = Standard_Boolean
then
8400 Convert_To
(Typ
, New_Occurrence_Of
(Standard_True
, Sloc
(N
)));
8401 Analyze_And_Resolve
(Else_Expr
, Typ
);
8402 Append_To
(Expressions
(N
), Else_Expr
);
8405 Error_Msg_N
("can only omit ELSE expression in Boolean case", N
);
8406 Append_To
(Expressions
(N
), Error
);
8411 if not Error_Posted
(N
) then
8412 Eval_If_Expression
(N
);
8415 Analyze_Dimension
(N
);
8416 end Resolve_If_Expression
;
8418 -------------------------------
8419 -- Resolve_Indexed_Component --
8420 -------------------------------
8422 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
8423 Name
: constant Node_Id
:= Prefix
(N
);
8425 Array_Type
: Entity_Id
:= Empty
; -- to prevent junk warning
8429 if Present
(Generalized_Indexing
(N
)) then
8430 Resolve_Generalized_Indexing
(N
, Typ
);
8434 if Is_Overloaded
(Name
) then
8436 -- Use the context type to select the prefix that yields the correct
8442 I1
: Interp_Index
:= 0;
8443 P
: constant Node_Id
:= Prefix
(N
);
8444 Found
: Boolean := False;
8447 Get_First_Interp
(P
, I
, It
);
8448 while Present
(It
.Typ
) loop
8449 if (Is_Array_Type
(It
.Typ
)
8450 and then Covers
(Typ
, Component_Type
(It
.Typ
)))
8451 or else (Is_Access_Type
(It
.Typ
)
8452 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
8456 Component_Type
(Designated_Type
(It
.Typ
))))
8459 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
8461 if It
= No_Interp
then
8462 Error_Msg_N
("ambiguous prefix for indexing", N
);
8468 Array_Type
:= It
.Typ
;
8474 Array_Type
:= It
.Typ
;
8479 Get_Next_Interp
(I
, It
);
8484 Array_Type
:= Etype
(Name
);
8487 Resolve
(Name
, Array_Type
);
8488 Array_Type
:= Get_Actual_Subtype_If_Available
(Name
);
8490 -- If prefix is access type, dereference to get real array type.
8491 -- Note: we do not apply an access check because the expander always
8492 -- introduces an explicit dereference, and the check will happen there.
8494 if Is_Access_Type
(Array_Type
) then
8495 Array_Type
:= Designated_Type
(Array_Type
);
8498 -- If name was overloaded, set component type correctly now
8499 -- If a misplaced call to an entry family (which has no index types)
8500 -- return. Error will be diagnosed from calling context.
8502 if Is_Array_Type
(Array_Type
) then
8503 Set_Etype
(N
, Component_Type
(Array_Type
));
8508 Index
:= First_Index
(Array_Type
);
8509 Expr
:= First
(Expressions
(N
));
8511 -- The prefix may have resolved to a string literal, in which case its
8512 -- etype has a special representation. This is only possible currently
8513 -- if the prefix is a static concatenation, written in functional
8516 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
8517 Resolve
(Expr
, Standard_Positive
);
8520 while Present
(Index
) and Present
(Expr
) loop
8521 Resolve
(Expr
, Etype
(Index
));
8522 Check_Unset_Reference
(Expr
);
8524 if Is_Scalar_Type
(Etype
(Expr
)) then
8525 Apply_Scalar_Range_Check
(Expr
, Etype
(Index
));
8527 Apply_Range_Check
(Expr
, Get_Actual_Subtype
(Index
));
8535 Analyze_Dimension
(N
);
8537 -- Do not generate the warning on suspicious index if we are analyzing
8538 -- package Ada.Tags; otherwise we will report the warning with the
8539 -- Prims_Ptr field of the dispatch table.
8541 if Scope
(Etype
(Prefix
(N
))) = Standard_Standard
8543 Is_RTU
(Cunit_Entity
(Get_Source_Unit
(Etype
(Prefix
(N
)))),
8546 Warn_On_Suspicious_Index
(Name
, First
(Expressions
(N
)));
8547 Eval_Indexed_Component
(N
);
8550 -- If the array type is atomic, and the component is not atomic, then
8551 -- this is worth a warning, since we have a situation where the access
8552 -- to the component may cause extra read/writes of the atomic array
8553 -- object, or partial word accesses, which could be unexpected.
8555 if Nkind
(N
) = N_Indexed_Component
8556 and then Is_Atomic_Ref_With_Address
(N
)
8557 and then not (Has_Atomic_Components
(Array_Type
)
8558 or else (Is_Entity_Name
(Prefix
(N
))
8559 and then Has_Atomic_Components
8560 (Entity
(Prefix
(N
)))))
8561 and then not Is_Atomic
(Component_Type
(Array_Type
))
8564 ("??access to non-atomic component of atomic array", Prefix
(N
));
8566 ("??\may cause unexpected accesses to atomic object", Prefix
(N
));
8568 end Resolve_Indexed_Component
;
8570 -----------------------------
8571 -- Resolve_Integer_Literal --
8572 -----------------------------
8574 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
8577 Eval_Integer_Literal
(N
);
8578 end Resolve_Integer_Literal
;
8580 --------------------------------
8581 -- Resolve_Intrinsic_Operator --
8582 --------------------------------
8584 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
) is
8585 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
8590 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
;
8591 -- If the operand is a literal, it cannot be the expression in a
8592 -- conversion. Use a qualified expression instead.
8594 ---------------------
8595 -- Convert_Operand --
8596 ---------------------
8598 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
is
8599 Loc
: constant Source_Ptr
:= Sloc
(Opnd
);
8603 if Nkind_In
(Opnd
, N_Integer_Literal
, N_Real_Literal
) then
8605 Make_Qualified_Expression
(Loc
,
8606 Subtype_Mark
=> New_Occurrence_Of
(Btyp
, Loc
),
8607 Expression
=> Relocate_Node
(Opnd
));
8611 Res
:= Unchecked_Convert_To
(Btyp
, Opnd
);
8615 end Convert_Operand
;
8617 -- Start of processing for Resolve_Intrinsic_Operator
8620 -- We must preserve the original entity in a generic setting, so that
8621 -- the legality of the operation can be verified in an instance.
8623 if not Expander_Active
then
8628 while Scope
(Op
) /= Standard_Standard
loop
8630 pragma Assert
(Present
(Op
));
8634 Set_Is_Overloaded
(N
, False);
8636 -- If the result or operand types are private, rewrite with unchecked
8637 -- conversions on the operands and the result, to expose the proper
8638 -- underlying numeric type.
8640 if Is_Private_Type
(Typ
)
8641 or else Is_Private_Type
(Etype
(Left_Opnd
(N
)))
8642 or else Is_Private_Type
(Etype
(Right_Opnd
(N
)))
8644 Arg1
:= Convert_Operand
(Left_Opnd
(N
));
8646 if Nkind
(N
) = N_Op_Expon
then
8647 Arg2
:= Unchecked_Convert_To
(Standard_Integer
, Right_Opnd
(N
));
8649 Arg2
:= Convert_Operand
(Right_Opnd
(N
));
8652 if Nkind
(Arg1
) = N_Type_Conversion
then
8653 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
8656 if Nkind
(Arg2
) = N_Type_Conversion
then
8657 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8660 Set_Left_Opnd
(N
, Arg1
);
8661 Set_Right_Opnd
(N
, Arg2
);
8663 Set_Etype
(N
, Btyp
);
8664 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
8667 elsif Typ
/= Etype
(Left_Opnd
(N
))
8668 or else Typ
/= Etype
(Right_Opnd
(N
))
8670 -- Add explicit conversion where needed, and save interpretations in
8671 -- case operands are overloaded.
8673 Arg1
:= Convert_To
(Typ
, Left_Opnd
(N
));
8674 Arg2
:= Convert_To
(Typ
, Right_Opnd
(N
));
8676 if Nkind
(Arg1
) = N_Type_Conversion
then
8677 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
8679 Save_Interps
(Left_Opnd
(N
), Arg1
);
8682 if Nkind
(Arg2
) = N_Type_Conversion
then
8683 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8685 Save_Interps
(Right_Opnd
(N
), Arg2
);
8688 Rewrite
(Left_Opnd
(N
), Arg1
);
8689 Rewrite
(Right_Opnd
(N
), Arg2
);
8692 Resolve_Arithmetic_Op
(N
, Typ
);
8695 Resolve_Arithmetic_Op
(N
, Typ
);
8697 end Resolve_Intrinsic_Operator
;
8699 --------------------------------------
8700 -- Resolve_Intrinsic_Unary_Operator --
8701 --------------------------------------
8703 procedure Resolve_Intrinsic_Unary_Operator
8707 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
8713 while Scope
(Op
) /= Standard_Standard
loop
8715 pragma Assert
(Present
(Op
));
8720 if Is_Private_Type
(Typ
) then
8721 Arg2
:= Unchecked_Convert_To
(Btyp
, Right_Opnd
(N
));
8722 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8724 Set_Right_Opnd
(N
, Arg2
);
8726 Set_Etype
(N
, Btyp
);
8727 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
8731 Resolve_Unary_Op
(N
, Typ
);
8733 end Resolve_Intrinsic_Unary_Operator
;
8735 ------------------------
8736 -- Resolve_Logical_Op --
8737 ------------------------
8739 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
8743 Check_No_Direct_Boolean_Operators
(N
);
8745 -- Predefined operations on scalar types yield the base type. On the
8746 -- other hand, logical operations on arrays yield the type of the
8747 -- arguments (and the context).
8749 if Is_Array_Type
(Typ
) then
8752 B_Typ
:= Base_Type
(Typ
);
8755 -- The following test is required because the operands of the operation
8756 -- may be literals, in which case the resulting type appears to be
8757 -- compatible with a signed integer type, when in fact it is compatible
8758 -- only with modular types. If the context itself is universal, the
8759 -- operation is illegal.
8761 if not Valid_Boolean_Arg
(Typ
) then
8762 Error_Msg_N
("invalid context for logical operation", N
);
8763 Set_Etype
(N
, Any_Type
);
8766 elsif Typ
= Any_Modular
then
8768 ("no modular type available in this context", N
);
8769 Set_Etype
(N
, Any_Type
);
8772 elsif Is_Modular_Integer_Type
(Typ
)
8773 and then Etype
(Left_Opnd
(N
)) = Universal_Integer
8774 and then Etype
(Right_Opnd
(N
)) = Universal_Integer
8776 Check_For_Visible_Operator
(N
, B_Typ
);
8779 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8780 -- is active and the result type is standard Boolean (do not mess with
8781 -- ops that return a nonstandard Boolean type, because something strange
8784 -- Note: you might expect this replacement to be done during expansion,
8785 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8786 -- is used, no part of the right operand of an "and" or "or" operator
8787 -- should be executed if the left operand would short-circuit the
8788 -- evaluation of the corresponding "and then" or "or else". If we left
8789 -- the replacement to expansion time, then run-time checks associated
8790 -- with such operands would be evaluated unconditionally, due to being
8791 -- before the condition prior to the rewriting as short-circuit forms
8792 -- during expansion.
8794 if Short_Circuit_And_Or
8795 and then B_Typ
= Standard_Boolean
8796 and then Nkind_In
(N
, N_Op_And
, N_Op_Or
)
8798 -- Mark the corresponding putative SCO operator as truly a logical
8799 -- (and short-circuit) operator.
8801 if Generate_SCO
and then Comes_From_Source
(N
) then
8802 Set_SCO_Logical_Operator
(N
);
8805 if Nkind
(N
) = N_Op_And
then
8807 Make_And_Then
(Sloc
(N
),
8808 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
8809 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
8810 Analyze_And_Resolve
(N
, B_Typ
);
8812 -- Case of OR changed to OR ELSE
8816 Make_Or_Else
(Sloc
(N
),
8817 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
8818 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
8819 Analyze_And_Resolve
(N
, B_Typ
);
8822 -- Return now, since analysis of the rewritten ops will take care of
8823 -- other reference bookkeeping and expression folding.
8828 Resolve
(Left_Opnd
(N
), B_Typ
);
8829 Resolve
(Right_Opnd
(N
), B_Typ
);
8831 Check_Unset_Reference
(Left_Opnd
(N
));
8832 Check_Unset_Reference
(Right_Opnd
(N
));
8834 Set_Etype
(N
, B_Typ
);
8835 Generate_Operator_Reference
(N
, B_Typ
);
8836 Eval_Logical_Op
(N
);
8838 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8839 -- only when both operands have same static lower and higher bounds. Of
8840 -- course the types have to match, so only check if operands are
8841 -- compatible and the node itself has no errors.
8843 if Is_Array_Type
(B_Typ
)
8844 and then Nkind
(N
) in N_Binary_Op
8847 Left_Typ
: constant Node_Id
:= Etype
(Left_Opnd
(N
));
8848 Right_Typ
: constant Node_Id
:= Etype
(Right_Opnd
(N
));
8851 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8852 -- operation if not needed.
8854 if Restriction_Check_Required
(SPARK_05
)
8855 and then Base_Type
(Left_Typ
) = Base_Type
(Right_Typ
)
8856 and then Left_Typ
/= Any_Composite
-- or Left_Opnd in error
8857 and then Right_Typ
/= Any_Composite
-- or Right_Opnd in error
8858 and then not Matching_Static_Array_Bounds
(Left_Typ
, Right_Typ
)
8860 Check_SPARK_05_Restriction
8861 ("array types should have matching static bounds", N
);
8865 end Resolve_Logical_Op
;
8867 ---------------------------
8868 -- Resolve_Membership_Op --
8869 ---------------------------
8871 -- The context can only be a boolean type, and does not determine the
8872 -- arguments. Arguments should be unambiguous, but the preference rule for
8873 -- universal types applies.
8875 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
8876 pragma Warnings
(Off
, Typ
);
8878 L
: constant Node_Id
:= Left_Opnd
(N
);
8879 R
: constant Node_Id
:= Right_Opnd
(N
);
8882 procedure Resolve_Set_Membership
;
8883 -- Analysis has determined a unique type for the left operand. Use it to
8884 -- resolve the disjuncts.
8886 ----------------------------
8887 -- Resolve_Set_Membership --
8888 ----------------------------
8890 procedure Resolve_Set_Membership
is
8895 -- If the left operand is overloaded, find type compatible with not
8896 -- overloaded alternative of the right operand.
8898 if Is_Overloaded
(L
) then
8900 Alt
:= First
(Alternatives
(N
));
8901 while Present
(Alt
) loop
8902 if not Is_Overloaded
(Alt
) then
8903 Ltyp
:= Intersect_Types
(L
, Alt
);
8910 -- Unclear how to resolve expression if all alternatives are also
8914 Error_Msg_N
("ambiguous expression", N
);
8923 Alt
:= First
(Alternatives
(N
));
8924 while Present
(Alt
) loop
8926 -- Alternative is an expression, a range
8927 -- or a subtype mark.
8929 if not Is_Entity_Name
(Alt
)
8930 or else not Is_Type
(Entity
(Alt
))
8932 Resolve
(Alt
, Ltyp
);
8938 -- Check for duplicates for discrete case
8940 if Is_Discrete_Type
(Ltyp
) then
8947 Alts
: array (0 .. List_Length
(Alternatives
(N
))) of Ent
;
8951 -- Loop checking duplicates. This is quadratic, but giant sets
8952 -- are unlikely in this context so it's a reasonable choice.
8955 Alt
:= First
(Alternatives
(N
));
8956 while Present
(Alt
) loop
8957 if Is_OK_Static_Expression
(Alt
)
8958 and then (Nkind_In
(Alt
, N_Integer_Literal
,
8959 N_Character_Literal
)
8960 or else Nkind
(Alt
) in N_Has_Entity
)
8963 Alts
(Nalts
) := (Alt
, Expr_Value
(Alt
));
8965 for J
in 1 .. Nalts
- 1 loop
8966 if Alts
(J
).Val
= Alts
(Nalts
).Val
then
8967 Error_Msg_Sloc
:= Sloc
(Alts
(J
).Alt
);
8968 Error_Msg_N
("duplicate of value given#??", Alt
);
8978 -- RM 4.5.2 (28.1/3) specifies that for types other than records or
8979 -- limited types, evaluation of a membership test uses the predefined
8980 -- equality for the type. This may be confusing to users, and the
8981 -- following warning appears useful for the most common case.
8983 if Is_Scalar_Type
(Ltyp
)
8984 and then Present
(Get_User_Defined_Eq
(Ltyp
))
8987 ("membership test on& uses predefined equality?", N
, Ltyp
);
8989 ("\even if user-defined equality exists (RM 4.5.2 (28.1/3)?", N
);
8991 end Resolve_Set_Membership
;
8993 -- Start of processing for Resolve_Membership_Op
8996 if L
= Error
or else R
= Error
then
9000 if Present
(Alternatives
(N
)) then
9001 Resolve_Set_Membership
;
9004 elsif not Is_Overloaded
(R
)
9006 (Etype
(R
) = Universal_Integer
9008 Etype
(R
) = Universal_Real
)
9009 and then Is_Overloaded
(L
)
9013 -- Ada 2005 (AI-251): Support the following case:
9015 -- type I is interface;
9016 -- type T is tagged ...
9018 -- function Test (O : I'Class) is
9020 -- return O in T'Class.
9023 -- In this case we have nothing else to do. The membership test will be
9024 -- done at run time.
9026 elsif Ada_Version
>= Ada_2005
9027 and then Is_Class_Wide_Type
(Etype
(L
))
9028 and then Is_Interface
(Etype
(L
))
9029 and then Is_Class_Wide_Type
(Etype
(R
))
9030 and then not Is_Interface
(Etype
(R
))
9034 T
:= Intersect_Types
(L
, R
);
9037 -- If mixed-mode operations are present and operands are all literal,
9038 -- the only interpretation involves Duration, which is probably not
9039 -- the intention of the programmer.
9041 if T
= Any_Fixed
then
9042 T
:= Unique_Fixed_Point_Type
(N
);
9044 if T
= Any_Type
then
9050 Check_Unset_Reference
(L
);
9052 if Nkind
(R
) = N_Range
9053 and then not Is_Scalar_Type
(T
)
9055 Error_Msg_N
("scalar type required for range", R
);
9058 if Is_Entity_Name
(R
) then
9059 Freeze_Expression
(R
);
9062 Check_Unset_Reference
(R
);
9065 -- Here after resolving membership operation
9069 Eval_Membership_Op
(N
);
9070 end Resolve_Membership_Op
;
9076 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
) is
9077 Loc
: constant Source_Ptr
:= Sloc
(N
);
9080 -- Handle restriction against anonymous null access values This
9081 -- restriction can be turned off using -gnatdj.
9083 -- Ada 2005 (AI-231): Remove restriction
9085 if Ada_Version
< Ada_2005
9086 and then not Debug_Flag_J
9087 and then Ekind
(Typ
) = E_Anonymous_Access_Type
9088 and then Comes_From_Source
(N
)
9090 -- In the common case of a call which uses an explicitly null value
9091 -- for an access parameter, give specialized error message.
9093 if Nkind
(Parent
(N
)) in N_Subprogram_Call
then
9095 ("null is not allowed as argument for an access parameter", N
);
9097 -- Standard message for all other cases (are there any?)
9101 ("null cannot be of an anonymous access type", N
);
9105 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
9106 -- assignment to a null-excluding object
9108 if Ada_Version
>= Ada_2005
9109 and then Can_Never_Be_Null
(Typ
)
9110 and then Nkind
(Parent
(N
)) = N_Assignment_Statement
9112 if not Inside_Init_Proc
then
9114 (Compile_Time_Constraint_Error
(N
,
9115 "(Ada 2005) null not allowed in null-excluding objects??"),
9116 Make_Raise_Constraint_Error
(Loc
,
9117 Reason
=> CE_Access_Check_Failed
));
9120 Make_Raise_Constraint_Error
(Loc
,
9121 Reason
=> CE_Access_Check_Failed
));
9125 -- In a distributed context, null for a remote access to subprogram may
9126 -- need to be replaced with a special record aggregate. In this case,
9127 -- return after having done the transformation.
9129 if (Ekind
(Typ
) = E_Record_Type
9130 or else Is_Remote_Access_To_Subprogram_Type
(Typ
))
9131 and then Remote_AST_Null_Value
(N
, Typ
)
9136 -- The null literal takes its type from the context
9141 -----------------------
9142 -- Resolve_Op_Concat --
9143 -----------------------
9145 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
) is
9147 -- We wish to avoid deep recursion, because concatenations are often
9148 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
9149 -- operands nonrecursively until we find something that is not a simple
9150 -- concatenation (A in this case). We resolve that, and then walk back
9151 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
9152 -- to do the rest of the work at each level. The Parent pointers allow
9153 -- us to avoid recursion, and thus avoid running out of memory. See also
9154 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
9160 -- The following code is equivalent to:
9162 -- Resolve_Op_Concat_First (NN, Typ);
9163 -- Resolve_Op_Concat_Arg (N, ...);
9164 -- Resolve_Op_Concat_Rest (N, Typ);
9166 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
9167 -- operand is a concatenation.
9169 -- Walk down left operands
9172 Resolve_Op_Concat_First
(NN
, Typ
);
9173 Op1
:= Left_Opnd
(NN
);
9174 exit when not (Nkind
(Op1
) = N_Op_Concat
9175 and then not Is_Array_Type
(Component_Type
(Typ
))
9176 and then Entity
(Op1
) = Entity
(NN
));
9180 -- Now (given the above example) NN is A&B and Op1 is A
9182 -- First resolve Op1 ...
9184 Resolve_Op_Concat_Arg
(NN
, Op1
, Typ
, Is_Component_Left_Opnd
(NN
));
9186 -- ... then walk NN back up until we reach N (where we started), calling
9187 -- Resolve_Op_Concat_Rest along the way.
9190 Resolve_Op_Concat_Rest
(NN
, Typ
);
9195 if Base_Type
(Etype
(N
)) /= Standard_String
then
9196 Check_SPARK_05_Restriction
9197 ("result of concatenation should have type String", N
);
9199 end Resolve_Op_Concat
;
9201 ---------------------------
9202 -- Resolve_Op_Concat_Arg --
9203 ---------------------------
9205 procedure Resolve_Op_Concat_Arg
9211 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
9212 Ctyp
: constant Entity_Id
:= Component_Type
(Typ
);
9217 or else (not Is_Overloaded
(Arg
)
9218 and then Etype
(Arg
) /= Any_Composite
9219 and then Covers
(Ctyp
, Etype
(Arg
)))
9221 Resolve
(Arg
, Ctyp
);
9223 Resolve
(Arg
, Btyp
);
9226 -- If both Array & Array and Array & Component are visible, there is a
9227 -- potential ambiguity that must be reported.
9229 elsif Has_Compatible_Type
(Arg
, Ctyp
) then
9230 if Nkind
(Arg
) = N_Aggregate
9231 and then Is_Composite_Type
(Ctyp
)
9233 if Is_Private_Type
(Ctyp
) then
9234 Resolve
(Arg
, Btyp
);
9236 -- If the operation is user-defined and not overloaded use its
9237 -- profile. The operation may be a renaming, in which case it has
9238 -- been rewritten, and we want the original profile.
9240 elsif not Is_Overloaded
(N
)
9241 and then Comes_From_Source
(Entity
(Original_Node
(N
)))
9242 and then Ekind
(Entity
(Original_Node
(N
))) = E_Function
9246 (Next_Formal
(First_Formal
(Entity
(Original_Node
(N
))))));
9249 -- Otherwise an aggregate may match both the array type and the
9253 Error_Msg_N
("ambiguous aggregate must be qualified", Arg
);
9254 Set_Etype
(Arg
, Any_Type
);
9258 if Is_Overloaded
(Arg
)
9259 and then Has_Compatible_Type
(Arg
, Typ
)
9260 and then Etype
(Arg
) /= Any_Type
9268 Get_First_Interp
(Arg
, I
, It
);
9270 Get_Next_Interp
(I
, It
);
9272 -- Special-case the error message when the overloading is
9273 -- caused by a function that yields an array and can be
9274 -- called without parameters.
9276 if It
.Nam
= Func
then
9277 Error_Msg_Sloc
:= Sloc
(Func
);
9278 Error_Msg_N
("ambiguous call to function#", Arg
);
9280 ("\\interpretation as call yields&", Arg
, Typ
);
9282 ("\\interpretation as indexing of call yields&",
9283 Arg
, Component_Type
(Typ
));
9286 Error_Msg_N
("ambiguous operand for concatenation!", Arg
);
9288 Get_First_Interp
(Arg
, I
, It
);
9289 while Present
(It
.Nam
) loop
9290 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
9292 if Base_Type
(It
.Typ
) = Btyp
9294 Base_Type
(It
.Typ
) = Base_Type
(Ctyp
)
9296 Error_Msg_N
-- CODEFIX
9297 ("\\possible interpretation#", Arg
);
9300 Get_Next_Interp
(I
, It
);
9306 Resolve
(Arg
, Component_Type
(Typ
));
9308 if Nkind
(Arg
) = N_String_Literal
then
9309 Set_Etype
(Arg
, Component_Type
(Typ
));
9312 if Arg
= Left_Opnd
(N
) then
9313 Set_Is_Component_Left_Opnd
(N
);
9315 Set_Is_Component_Right_Opnd
(N
);
9320 Resolve
(Arg
, Btyp
);
9323 -- Concatenation is restricted in SPARK: each operand must be either a
9324 -- string literal, the name of a string constant, a static character or
9325 -- string expression, or another concatenation. Arg cannot be a
9326 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9327 -- separately on each final operand, past concatenation operations.
9329 if Is_Character_Type
(Etype
(Arg
)) then
9330 if not Is_OK_Static_Expression
(Arg
) then
9331 Check_SPARK_05_Restriction
9332 ("character operand for concatenation should be static", Arg
);
9335 elsif Is_String_Type
(Etype
(Arg
)) then
9336 if not (Nkind_In
(Arg
, N_Identifier
, N_Expanded_Name
)
9337 and then Is_Constant_Object
(Entity
(Arg
)))
9338 and then not Is_OK_Static_Expression
(Arg
)
9340 Check_SPARK_05_Restriction
9341 ("string operand for concatenation should be static", Arg
);
9344 -- Do not issue error on an operand that is neither a character nor a
9345 -- string, as the error is issued in Resolve_Op_Concat.
9351 Check_Unset_Reference
(Arg
);
9352 end Resolve_Op_Concat_Arg
;
9354 -----------------------------
9355 -- Resolve_Op_Concat_First --
9356 -----------------------------
9358 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
) is
9359 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
9360 Op1
: constant Node_Id
:= Left_Opnd
(N
);
9361 Op2
: constant Node_Id
:= Right_Opnd
(N
);
9364 -- The parser folds an enormous sequence of concatenations of string
9365 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9366 -- in the right operand. If the expression resolves to a predefined "&"
9367 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9368 -- we give an error. See P_Simple_Expression in Par.Ch4.
9370 if Nkind
(Op2
) = N_String_Literal
9371 and then Is_Folded_In_Parser
(Op2
)
9372 and then Ekind
(Entity
(N
)) = E_Function
9374 pragma Assert
(Nkind
(Op1
) = N_String_Literal
-- should be ""
9375 and then String_Length
(Strval
(Op1
)) = 0);
9376 Error_Msg_N
("too many user-defined concatenations", N
);
9380 Set_Etype
(N
, Btyp
);
9382 if Is_Limited_Composite
(Btyp
) then
9383 Error_Msg_N
("concatenation not available for limited array", N
);
9384 Explain_Limited_Type
(Btyp
, N
);
9386 end Resolve_Op_Concat_First
;
9388 ----------------------------
9389 -- Resolve_Op_Concat_Rest --
9390 ----------------------------
9392 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
) is
9393 Op1
: constant Node_Id
:= Left_Opnd
(N
);
9394 Op2
: constant Node_Id
:= Right_Opnd
(N
);
9397 Resolve_Op_Concat_Arg
(N
, Op2
, Typ
, Is_Component_Right_Opnd
(N
));
9399 Generate_Operator_Reference
(N
, Typ
);
9401 if Is_String_Type
(Typ
) then
9402 Eval_Concatenation
(N
);
9405 -- If this is not a static concatenation, but the result is a string
9406 -- type (and not an array of strings) ensure that static string operands
9407 -- have their subtypes properly constructed.
9409 if Nkind
(N
) /= N_String_Literal
9410 and then Is_Character_Type
(Component_Type
(Typ
))
9412 Set_String_Literal_Subtype
(Op1
, Typ
);
9413 Set_String_Literal_Subtype
(Op2
, Typ
);
9415 end Resolve_Op_Concat_Rest
;
9417 ----------------------
9418 -- Resolve_Op_Expon --
9419 ----------------------
9421 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
) is
9422 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
9425 -- Catch attempts to do fixed-point exponentiation with universal
9426 -- operands, which is a case where the illegality is not caught during
9427 -- normal operator analysis. This is not done in preanalysis mode
9428 -- since the tree is not fully decorated during preanalysis.
9430 if Full_Analysis
then
9431 if Is_Fixed_Point_Type
(Typ
) and then Comes_From_Source
(N
) then
9432 Error_Msg_N
("exponentiation not available for fixed point", N
);
9435 elsif Nkind
(Parent
(N
)) in N_Op
9436 and then Present
(Etype
(Parent
(N
)))
9437 and then Is_Fixed_Point_Type
(Etype
(Parent
(N
)))
9438 and then Etype
(N
) = Universal_Real
9439 and then Comes_From_Source
(N
)
9441 Error_Msg_N
("exponentiation not available for fixed point", N
);
9446 if Comes_From_Source
(N
)
9447 and then Ekind
(Entity
(N
)) = E_Function
9448 and then Is_Imported
(Entity
(N
))
9449 and then Is_Intrinsic_Subprogram
(Entity
(N
))
9451 Resolve_Intrinsic_Operator
(N
, Typ
);
9455 if Etype
(Left_Opnd
(N
)) = Universal_Integer
9456 or else Etype
(Left_Opnd
(N
)) = Universal_Real
9458 Check_For_Visible_Operator
(N
, B_Typ
);
9461 -- We do the resolution using the base type, because intermediate values
9462 -- in expressions are always of the base type, not a subtype of it.
9464 Resolve
(Left_Opnd
(N
), B_Typ
);
9465 Resolve
(Right_Opnd
(N
), Standard_Integer
);
9467 -- For integer types, right argument must be in Natural range
9469 if Is_Integer_Type
(Typ
) then
9470 Apply_Scalar_Range_Check
(Right_Opnd
(N
), Standard_Natural
);
9473 Check_Unset_Reference
(Left_Opnd
(N
));
9474 Check_Unset_Reference
(Right_Opnd
(N
));
9476 Set_Etype
(N
, B_Typ
);
9477 Generate_Operator_Reference
(N
, B_Typ
);
9479 Analyze_Dimension
(N
);
9481 if Ada_Version
>= Ada_2012
and then Has_Dimension_System
(B_Typ
) then
9482 -- Evaluate the exponentiation operator for dimensioned type
9484 Eval_Op_Expon_For_Dimensioned_Type
(N
, B_Typ
);
9489 -- Set overflow checking bit. Much cleverer code needed here eventually
9490 -- and perhaps the Resolve routines should be separated for the various
9491 -- arithmetic operations, since they will need different processing. ???
9493 if Nkind
(N
) in N_Op
then
9494 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
9495 Enable_Overflow_Check
(N
);
9498 end Resolve_Op_Expon
;
9500 --------------------
9501 -- Resolve_Op_Not --
9502 --------------------
9504 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
) is
9507 function Parent_Is_Boolean
return Boolean;
9508 -- This function determines if the parent node is a boolean operator or
9509 -- operation (comparison op, membership test, or short circuit form) and
9510 -- the not in question is the left operand of this operation. Note that
9511 -- if the not is in parens, then false is returned.
9513 -----------------------
9514 -- Parent_Is_Boolean --
9515 -----------------------
9517 function Parent_Is_Boolean
return Boolean is
9519 if Paren_Count
(N
) /= 0 then
9523 case Nkind
(Parent
(N
)) is
9538 return Left_Opnd
(Parent
(N
)) = N
;
9544 end Parent_Is_Boolean
;
9546 -- Start of processing for Resolve_Op_Not
9549 -- Predefined operations on scalar types yield the base type. On the
9550 -- other hand, logical operations on arrays yield the type of the
9551 -- arguments (and the context).
9553 if Is_Array_Type
(Typ
) then
9556 B_Typ
:= Base_Type
(Typ
);
9559 -- Straightforward case of incorrect arguments
9561 if not Valid_Boolean_Arg
(Typ
) then
9562 Error_Msg_N
("invalid operand type for operator&", N
);
9563 Set_Etype
(N
, Any_Type
);
9566 -- Special case of probable missing parens
9568 elsif Typ
= Universal_Integer
or else Typ
= Any_Modular
then
9569 if Parent_Is_Boolean
then
9571 ("operand of not must be enclosed in parentheses",
9575 ("no modular type available in this context", N
);
9578 Set_Etype
(N
, Any_Type
);
9581 -- OK resolution of NOT
9584 -- Warn if non-boolean types involved. This is a case like not a < b
9585 -- where a and b are modular, where we will get (not a) < b and most
9586 -- likely not (a < b) was intended.
9588 if Warn_On_Questionable_Missing_Parens
9589 and then not Is_Boolean_Type
(Typ
)
9590 and then Parent_Is_Boolean
9592 Error_Msg_N
("?q?not expression should be parenthesized here!", N
);
9595 -- Warn on double negation if checking redundant constructs
9597 if Warn_On_Redundant_Constructs
9598 and then Comes_From_Source
(N
)
9599 and then Comes_From_Source
(Right_Opnd
(N
))
9600 and then Root_Type
(Typ
) = Standard_Boolean
9601 and then Nkind
(Right_Opnd
(N
)) = N_Op_Not
9603 Error_Msg_N
("redundant double negation?r?", N
);
9606 -- Complete resolution and evaluation of NOT
9608 Resolve
(Right_Opnd
(N
), B_Typ
);
9609 Check_Unset_Reference
(Right_Opnd
(N
));
9610 Set_Etype
(N
, B_Typ
);
9611 Generate_Operator_Reference
(N
, B_Typ
);
9616 -----------------------------
9617 -- Resolve_Operator_Symbol --
9618 -----------------------------
9620 -- Nothing to be done, all resolved already
9622 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
) is
9623 pragma Warnings
(Off
, N
);
9624 pragma Warnings
(Off
, Typ
);
9628 end Resolve_Operator_Symbol
;
9630 ----------------------------------
9631 -- Resolve_Qualified_Expression --
9632 ----------------------------------
9634 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
9635 pragma Warnings
(Off
, Typ
);
9637 Target_Typ
: constant Entity_Id
:= Entity
(Subtype_Mark
(N
));
9638 Expr
: constant Node_Id
:= Expression
(N
);
9641 Resolve
(Expr
, Target_Typ
);
9643 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9644 -- operation if not needed.
9646 if Restriction_Check_Required
(SPARK_05
)
9647 and then Is_Array_Type
(Target_Typ
)
9648 and then Is_Array_Type
(Etype
(Expr
))
9649 and then Etype
(Expr
) /= Any_Composite
-- or else Expr in error
9650 and then not Matching_Static_Array_Bounds
(Target_Typ
, Etype
(Expr
))
9652 Check_SPARK_05_Restriction
9653 ("array types should have matching static bounds", N
);
9656 -- A qualified expression requires an exact match of the type, class-
9657 -- wide matching is not allowed. However, if the qualifying type is
9658 -- specific and the expression has a class-wide type, it may still be
9659 -- okay, since it can be the result of the expansion of a call to a
9660 -- dispatching function, so we also have to check class-wideness of the
9661 -- type of the expression's original node.
9663 if (Is_Class_Wide_Type
(Target_Typ
)
9665 (Is_Class_Wide_Type
(Etype
(Expr
))
9666 and then Is_Class_Wide_Type
(Etype
(Original_Node
(Expr
)))))
9667 and then Base_Type
(Etype
(Expr
)) /= Base_Type
(Target_Typ
)
9669 Wrong_Type
(Expr
, Target_Typ
);
9672 -- If the target type is unconstrained, then we reset the type of the
9673 -- result from the type of the expression. For other cases, the actual
9674 -- subtype of the expression is the target type.
9676 if Is_Composite_Type
(Target_Typ
)
9677 and then not Is_Constrained
(Target_Typ
)
9679 Set_Etype
(N
, Etype
(Expr
));
9682 Analyze_Dimension
(N
);
9683 Eval_Qualified_Expression
(N
);
9685 -- If we still have a qualified expression after the static evaluation,
9686 -- then apply a scalar range check if needed. The reason that we do this
9687 -- after the Eval call is that otherwise, the application of the range
9688 -- check may convert an illegal static expression and result in warning
9689 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9691 if Nkind
(N
) = N_Qualified_Expression
and then Is_Scalar_Type
(Typ
) then
9692 Apply_Scalar_Range_Check
(Expr
, Typ
);
9695 -- Finally, check whether a predicate applies to the target type. This
9696 -- comes from AI12-0100. As for type conversions, check the enclosing
9697 -- context to prevent an infinite expansion.
9699 if Has_Predicates
(Target_Typ
) then
9700 if Nkind
(Parent
(N
)) = N_Function_Call
9701 and then Present
(Name
(Parent
(N
)))
9702 and then (Is_Predicate_Function
(Entity
(Name
(Parent
(N
))))
9704 Is_Predicate_Function_M
(Entity
(Name
(Parent
(N
)))))
9708 -- In the case of a qualified expression in an allocator, the check
9709 -- is applied when expanding the allocator, so avoid redundant check.
9711 elsif Nkind
(N
) = N_Qualified_Expression
9712 and then Nkind
(Parent
(N
)) /= N_Allocator
9714 Apply_Predicate_Check
(N
, Target_Typ
);
9717 end Resolve_Qualified_Expression
;
9719 ------------------------------
9720 -- Resolve_Raise_Expression --
9721 ------------------------------
9723 procedure Resolve_Raise_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
9725 if Typ
= Raise_Type
then
9726 Error_Msg_N
("cannot find unique type for raise expression", N
);
9727 Set_Etype
(N
, Any_Type
);
9731 end Resolve_Raise_Expression
;
9737 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
) is
9738 L
: constant Node_Id
:= Low_Bound
(N
);
9739 H
: constant Node_Id
:= High_Bound
(N
);
9741 function First_Last_Ref
return Boolean;
9742 -- Returns True if N is of the form X'First .. X'Last where X is the
9743 -- same entity for both attributes.
9745 --------------------
9746 -- First_Last_Ref --
9747 --------------------
9749 function First_Last_Ref
return Boolean is
9750 Lorig
: constant Node_Id
:= Original_Node
(L
);
9751 Horig
: constant Node_Id
:= Original_Node
(H
);
9754 if Nkind
(Lorig
) = N_Attribute_Reference
9755 and then Nkind
(Horig
) = N_Attribute_Reference
9756 and then Attribute_Name
(Lorig
) = Name_First
9757 and then Attribute_Name
(Horig
) = Name_Last
9760 PL
: constant Node_Id
:= Prefix
(Lorig
);
9761 PH
: constant Node_Id
:= Prefix
(Horig
);
9763 if Is_Entity_Name
(PL
)
9764 and then Is_Entity_Name
(PH
)
9765 and then Entity
(PL
) = Entity
(PH
)
9775 -- Start of processing for Resolve_Range
9780 -- The lower bound should be in Typ. The higher bound can be in Typ's
9781 -- base type if the range is null. It may still be invalid if it is
9782 -- higher than the lower bound. This is checked later in the context in
9783 -- which the range appears.
9786 Resolve
(H
, Base_Type
(Typ
));
9788 -- Check for inappropriate range on unordered enumeration type
9790 if Bad_Unordered_Enumeration_Reference
(N
, Typ
)
9792 -- Exclude X'First .. X'Last if X is the same entity for both
9794 and then not First_Last_Ref
9796 Error_Msg_Sloc
:= Sloc
(Typ
);
9798 ("subrange of unordered enumeration type& declared#?U?", N
, Typ
);
9801 Check_Unset_Reference
(L
);
9802 Check_Unset_Reference
(H
);
9804 -- We have to check the bounds for being within the base range as
9805 -- required for a non-static context. Normally this is automatic and
9806 -- done as part of evaluating expressions, but the N_Range node is an
9807 -- exception, since in GNAT we consider this node to be a subexpression,
9808 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9809 -- this, but that would put the test on the main evaluation path for
9812 Check_Non_Static_Context
(L
);
9813 Check_Non_Static_Context
(H
);
9815 -- Check for an ambiguous range over character literals. This will
9816 -- happen with a membership test involving only literals.
9818 if Typ
= Any_Character
then
9819 Ambiguous_Character
(L
);
9820 Set_Etype
(N
, Any_Type
);
9824 -- If bounds are static, constant-fold them, so size computations are
9825 -- identical between front-end and back-end. Do not perform this
9826 -- transformation while analyzing generic units, as type information
9827 -- would be lost when reanalyzing the constant node in the instance.
9829 if Is_Discrete_Type
(Typ
) and then Expander_Active
then
9830 if Is_OK_Static_Expression
(L
) then
9831 Fold_Uint
(L
, Expr_Value
(L
), Is_OK_Static_Expression
(L
));
9834 if Is_OK_Static_Expression
(H
) then
9835 Fold_Uint
(H
, Expr_Value
(H
), Is_OK_Static_Expression
(H
));
9840 --------------------------
9841 -- Resolve_Real_Literal --
9842 --------------------------
9844 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
9845 Actual_Typ
: constant Entity_Id
:= Etype
(N
);
9848 -- Special processing for fixed-point literals to make sure that the
9849 -- value is an exact multiple of small where this is required. We skip
9850 -- this for the universal real case, and also for generic types.
9852 if Is_Fixed_Point_Type
(Typ
)
9853 and then Typ
/= Universal_Fixed
9854 and then Typ
/= Any_Fixed
9855 and then not Is_Generic_Type
(Typ
)
9858 Val
: constant Ureal
:= Realval
(N
);
9859 Cintr
: constant Ureal
:= Val
/ Small_Value
(Typ
);
9860 Cint
: constant Uint
:= UR_Trunc
(Cintr
);
9861 Den
: constant Uint
:= Norm_Den
(Cintr
);
9865 -- Case of literal is not an exact multiple of the Small
9869 -- For a source program literal for a decimal fixed-point type,
9870 -- this is statically illegal (RM 4.9(36)).
9872 if Is_Decimal_Fixed_Point_Type
(Typ
)
9873 and then Actual_Typ
= Universal_Real
9874 and then Comes_From_Source
(N
)
9876 Error_Msg_N
("value has extraneous low order digits", N
);
9879 -- Generate a warning if literal from source
9881 if Is_OK_Static_Expression
(N
)
9882 and then Warn_On_Bad_Fixed_Value
9885 ("?b?static fixed-point value is not a multiple of Small!",
9889 -- Replace literal by a value that is the exact representation
9890 -- of a value of the type, i.e. a multiple of the small value,
9891 -- by truncation, since Machine_Rounds is false for all GNAT
9892 -- fixed-point types (RM 4.9(38)).
9894 Stat
:= Is_OK_Static_Expression
(N
);
9896 Make_Real_Literal
(Sloc
(N
),
9897 Realval
=> Small_Value
(Typ
) * Cint
));
9899 Set_Is_Static_Expression
(N
, Stat
);
9902 -- In all cases, set the corresponding integer field
9904 Set_Corresponding_Integer_Value
(N
, Cint
);
9908 -- Now replace the actual type by the expected type as usual
9911 Eval_Real_Literal
(N
);
9912 end Resolve_Real_Literal
;
9914 -----------------------
9915 -- Resolve_Reference --
9916 -----------------------
9918 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
) is
9919 P
: constant Node_Id
:= Prefix
(N
);
9922 -- Replace general access with specific type
9924 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
9925 Set_Etype
(N
, Base_Type
(Typ
));
9928 Resolve
(P
, Designated_Type
(Etype
(N
)));
9930 -- If we are taking the reference of a volatile entity, then treat it as
9931 -- a potential modification of this entity. This is too conservative,
9932 -- but necessary because remove side effects can cause transformations
9933 -- of normal assignments into reference sequences that otherwise fail to
9934 -- notice the modification.
9936 if Is_Entity_Name
(P
) and then Treat_As_Volatile
(Entity
(P
)) then
9937 Note_Possible_Modification
(P
, Sure
=> False);
9939 end Resolve_Reference
;
9941 --------------------------------
9942 -- Resolve_Selected_Component --
9943 --------------------------------
9945 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
9947 Comp1
: Entity_Id
:= Empty
; -- prevent junk warning
9948 P
: constant Node_Id
:= Prefix
(N
);
9949 S
: constant Node_Id
:= Selector_Name
(N
);
9950 T
: Entity_Id
:= Etype
(P
);
9952 I1
: Interp_Index
:= 0; -- prevent junk warning
9957 function Init_Component
return Boolean;
9958 -- Check whether this is the initialization of a component within an
9959 -- init proc (by assignment or call to another init proc). If true,
9960 -- there is no need for a discriminant check.
9962 --------------------
9963 -- Init_Component --
9964 --------------------
9966 function Init_Component
return Boolean is
9968 return Inside_Init_Proc
9969 and then Nkind
(Prefix
(N
)) = N_Identifier
9970 and then Chars
(Prefix
(N
)) = Name_uInit
9971 and then Nkind
(Parent
(Parent
(N
))) = N_Case_Statement_Alternative
;
9974 -- Start of processing for Resolve_Selected_Component
9977 if Is_Overloaded
(P
) then
9979 -- Use the context type to select the prefix that has a selector
9980 -- of the correct name and type.
9983 Get_First_Interp
(P
, I
, It
);
9985 Search
: while Present
(It
.Typ
) loop
9986 if Is_Access_Type
(It
.Typ
) then
9987 T
:= Designated_Type
(It
.Typ
);
9992 -- Locate selected component. For a private prefix the selector
9993 -- can denote a discriminant.
9995 if Is_Record_Type
(T
) or else Is_Private_Type
(T
) then
9997 -- The visible components of a class-wide type are those of
10000 if Is_Class_Wide_Type
(T
) then
10004 Comp
:= First_Entity
(T
);
10005 while Present
(Comp
) loop
10006 if Chars
(Comp
) = Chars
(S
)
10007 and then Covers
(Typ
, Etype
(Comp
))
10016 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
10018 if It
= No_Interp
then
10020 ("ambiguous prefix for selected component", N
);
10021 Set_Etype
(N
, Typ
);
10027 -- There may be an implicit dereference. Retrieve
10028 -- designated record type.
10030 if Is_Access_Type
(It1
.Typ
) then
10031 T
:= Designated_Type
(It1
.Typ
);
10036 if Scope
(Comp1
) /= T
then
10038 -- Resolution chooses the new interpretation.
10039 -- Find the component with the right name.
10041 Comp1
:= First_Entity
(T
);
10042 while Present
(Comp1
)
10043 and then Chars
(Comp1
) /= Chars
(S
)
10045 Comp1
:= Next_Entity
(Comp1
);
10054 Comp
:= Next_Entity
(Comp
);
10058 Get_Next_Interp
(I
, It
);
10061 -- There must be a legal interpretation at this point
10063 pragma Assert
(Found
);
10064 Resolve
(P
, It1
.Typ
);
10065 Set_Etype
(N
, Typ
);
10066 Set_Entity_With_Checks
(S
, Comp1
);
10069 -- Resolve prefix with its type
10074 -- Generate cross-reference. We needed to wait until full overloading
10075 -- resolution was complete to do this, since otherwise we can't tell if
10076 -- we are an lvalue or not.
10078 if May_Be_Lvalue
(N
) then
10079 Generate_Reference
(Entity
(S
), S
, 'm');
10081 Generate_Reference
(Entity
(S
), S
, 'r');
10084 -- If prefix is an access type, the node will be transformed into an
10085 -- explicit dereference during expansion. The type of the node is the
10086 -- designated type of that of the prefix.
10088 if Is_Access_Type
(Etype
(P
)) then
10089 T
:= Designated_Type
(Etype
(P
));
10090 Check_Fully_Declared_Prefix
(T
, P
);
10095 -- Set flag for expander if discriminant check required on a component
10096 -- appearing within a variant.
10098 if Has_Discriminants
(T
)
10099 and then Ekind
(Entity
(S
)) = E_Component
10100 and then Present
(Original_Record_Component
(Entity
(S
)))
10101 and then Ekind
(Original_Record_Component
(Entity
(S
))) = E_Component
10103 Is_Declared_Within_Variant
(Original_Record_Component
(Entity
(S
)))
10104 and then not Discriminant_Checks_Suppressed
(T
)
10105 and then not Init_Component
10107 Set_Do_Discriminant_Check
(N
);
10110 if Ekind
(Entity
(S
)) = E_Void
then
10111 Error_Msg_N
("premature use of component", S
);
10114 -- If the prefix is a record conversion, this may be a renamed
10115 -- discriminant whose bounds differ from those of the original
10116 -- one, so we must ensure that a range check is performed.
10118 if Nkind
(P
) = N_Type_Conversion
10119 and then Ekind
(Entity
(S
)) = E_Discriminant
10120 and then Is_Discrete_Type
(Typ
)
10122 Set_Etype
(N
, Base_Type
(Typ
));
10125 -- Note: No Eval processing is required, because the prefix is of a
10126 -- record type, or protected type, and neither can possibly be static.
10128 -- If the record type is atomic, and the component is non-atomic, then
10129 -- this is worth a warning, since we have a situation where the access
10130 -- to the component may cause extra read/writes of the atomic array
10131 -- object, or partial word accesses, both of which may be unexpected.
10133 if Nkind
(N
) = N_Selected_Component
10134 and then Is_Atomic_Ref_With_Address
(N
)
10135 and then not Is_Atomic
(Entity
(S
))
10136 and then not Is_Atomic
(Etype
(Entity
(S
)))
10139 ("??access to non-atomic component of atomic record",
10142 ("\??may cause unexpected accesses to atomic object",
10146 Analyze_Dimension
(N
);
10147 end Resolve_Selected_Component
;
10149 -------------------
10150 -- Resolve_Shift --
10151 -------------------
10153 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
) is
10154 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
10155 L
: constant Node_Id
:= Left_Opnd
(N
);
10156 R
: constant Node_Id
:= Right_Opnd
(N
);
10159 -- We do the resolution using the base type, because intermediate values
10160 -- in expressions always are of the base type, not a subtype of it.
10162 Resolve
(L
, B_Typ
);
10163 Resolve
(R
, Standard_Natural
);
10165 Check_Unset_Reference
(L
);
10166 Check_Unset_Reference
(R
);
10168 Set_Etype
(N
, B_Typ
);
10169 Generate_Operator_Reference
(N
, B_Typ
);
10173 ---------------------------
10174 -- Resolve_Short_Circuit --
10175 ---------------------------
10177 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
) is
10178 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
10179 L
: constant Node_Id
:= Left_Opnd
(N
);
10180 R
: constant Node_Id
:= Right_Opnd
(N
);
10183 -- Ensure all actions associated with the left operand (e.g.
10184 -- finalization of transient objects) are fully evaluated locally within
10185 -- an expression with actions. This is particularly helpful for coverage
10186 -- analysis. However this should not happen in generics or if option
10187 -- Minimize_Expression_With_Actions is set.
10189 if Expander_Active
and not Minimize_Expression_With_Actions
then
10191 Reloc_L
: constant Node_Id
:= Relocate_Node
(L
);
10193 Save_Interps
(Old_N
=> L
, New_N
=> Reloc_L
);
10196 Make_Expression_With_Actions
(Sloc
(L
),
10197 Actions
=> New_List
,
10198 Expression
=> Reloc_L
));
10200 -- Set Comes_From_Source on L to preserve warnings for unset
10203 Set_Comes_From_Source
(L
, Comes_From_Source
(Reloc_L
));
10207 Resolve
(L
, B_Typ
);
10208 Resolve
(R
, B_Typ
);
10210 -- Check for issuing warning for always False assert/check, this happens
10211 -- when assertions are turned off, in which case the pragma Assert/Check
10212 -- was transformed into:
10214 -- if False and then <condition> then ...
10216 -- and we detect this pattern
10218 if Warn_On_Assertion_Failure
10219 and then Is_Entity_Name
(R
)
10220 and then Entity
(R
) = Standard_False
10221 and then Nkind
(Parent
(N
)) = N_If_Statement
10222 and then Nkind
(N
) = N_And_Then
10223 and then Is_Entity_Name
(L
)
10224 and then Entity
(L
) = Standard_False
10227 Orig
: constant Node_Id
:= Original_Node
(Parent
(N
));
10230 -- Special handling of Asssert pragma
10232 if Nkind
(Orig
) = N_Pragma
10233 and then Pragma_Name
(Orig
) = Name_Assert
10236 Expr
: constant Node_Id
:=
10239 (First
(Pragma_Argument_Associations
(Orig
))));
10242 -- Don't warn if original condition is explicit False,
10243 -- since obviously the failure is expected in this case.
10245 if Is_Entity_Name
(Expr
)
10246 and then Entity
(Expr
) = Standard_False
10250 -- Issue warning. We do not want the deletion of the
10251 -- IF/AND-THEN to take this message with it. We achieve this
10252 -- by making sure that the expanded code points to the Sloc
10253 -- of the expression, not the original pragma.
10256 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
10257 -- The source location of the expression is not usually
10258 -- the best choice here. For example, it gets located on
10259 -- the last AND keyword in a chain of boolean expressiond
10260 -- AND'ed together. It is best to put the message on the
10261 -- first character of the assertion, which is the effect
10262 -- of the First_Node call here.
10265 ("?A?assertion would fail at run time!",
10267 (First
(Pragma_Argument_Associations
(Orig
))));
10271 -- Similar processing for Check pragma
10273 elsif Nkind
(Orig
) = N_Pragma
10274 and then Pragma_Name
(Orig
) = Name_Check
10276 -- Don't want to warn if original condition is explicit False
10279 Expr
: constant Node_Id
:=
10282 (Next
(First
(Pragma_Argument_Associations
(Orig
)))));
10284 if Is_Entity_Name
(Expr
)
10285 and then Entity
(Expr
) = Standard_False
10292 -- Again use Error_Msg_F rather than Error_Msg_N, see
10293 -- comment above for an explanation of why we do this.
10296 ("?A?check would fail at run time!",
10298 (Last
(Pragma_Argument_Associations
(Orig
))));
10305 -- Continue with processing of short circuit
10307 Check_Unset_Reference
(L
);
10308 Check_Unset_Reference
(R
);
10310 Set_Etype
(N
, B_Typ
);
10311 Eval_Short_Circuit
(N
);
10312 end Resolve_Short_Circuit
;
10314 -------------------
10315 -- Resolve_Slice --
10316 -------------------
10318 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
) is
10319 Drange
: constant Node_Id
:= Discrete_Range
(N
);
10320 Name
: constant Node_Id
:= Prefix
(N
);
10321 Array_Type
: Entity_Id
:= Empty
;
10322 Dexpr
: Node_Id
:= Empty
;
10323 Index_Type
: Entity_Id
;
10326 if Is_Overloaded
(Name
) then
10328 -- Use the context type to select the prefix that yields the correct
10333 I1
: Interp_Index
:= 0;
10335 P
: constant Node_Id
:= Prefix
(N
);
10336 Found
: Boolean := False;
10339 Get_First_Interp
(P
, I
, It
);
10340 while Present
(It
.Typ
) loop
10341 if (Is_Array_Type
(It
.Typ
)
10342 and then Covers
(Typ
, It
.Typ
))
10343 or else (Is_Access_Type
(It
.Typ
)
10344 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
10345 and then Covers
(Typ
, Designated_Type
(It
.Typ
)))
10348 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
10350 if It
= No_Interp
then
10351 Error_Msg_N
("ambiguous prefix for slicing", N
);
10352 Set_Etype
(N
, Typ
);
10356 Array_Type
:= It
.Typ
;
10361 Array_Type
:= It
.Typ
;
10366 Get_Next_Interp
(I
, It
);
10371 Array_Type
:= Etype
(Name
);
10374 Resolve
(Name
, Array_Type
);
10376 if Is_Access_Type
(Array_Type
) then
10377 Apply_Access_Check
(N
);
10378 Array_Type
:= Designated_Type
(Array_Type
);
10380 -- If the prefix is an access to an unconstrained array, we must use
10381 -- the actual subtype of the object to perform the index checks. The
10382 -- object denoted by the prefix is implicit in the node, so we build
10383 -- an explicit representation for it in order to compute the actual
10386 if not Is_Constrained
(Array_Type
) then
10387 Remove_Side_Effects
(Prefix
(N
));
10390 Obj
: constant Node_Id
:=
10391 Make_Explicit_Dereference
(Sloc
(N
),
10392 Prefix
=> New_Copy_Tree
(Prefix
(N
)));
10394 Set_Etype
(Obj
, Array_Type
);
10395 Set_Parent
(Obj
, Parent
(N
));
10396 Array_Type
:= Get_Actual_Subtype
(Obj
);
10400 elsif Is_Entity_Name
(Name
)
10401 or else Nkind
(Name
) = N_Explicit_Dereference
10402 or else (Nkind
(Name
) = N_Function_Call
10403 and then not Is_Constrained
(Etype
(Name
)))
10405 Array_Type
:= Get_Actual_Subtype
(Name
);
10407 -- If the name is a selected component that depends on discriminants,
10408 -- build an actual subtype for it. This can happen only when the name
10409 -- itself is overloaded; otherwise the actual subtype is created when
10410 -- the selected component is analyzed.
10412 elsif Nkind
(Name
) = N_Selected_Component
10413 and then Full_Analysis
10414 and then Depends_On_Discriminant
(First_Index
(Array_Type
))
10417 Act_Decl
: constant Node_Id
:=
10418 Build_Actual_Subtype_Of_Component
(Array_Type
, Name
);
10420 Insert_Action
(N
, Act_Decl
);
10421 Array_Type
:= Defining_Identifier
(Act_Decl
);
10424 -- Maybe this should just be "else", instead of checking for the
10425 -- specific case of slice??? This is needed for the case where the
10426 -- prefix is an Image attribute, which gets expanded to a slice, and so
10427 -- has a constrained subtype which we want to use for the slice range
10428 -- check applied below (the range check won't get done if the
10429 -- unconstrained subtype of the 'Image is used).
10431 elsif Nkind
(Name
) = N_Slice
then
10432 Array_Type
:= Etype
(Name
);
10435 -- Obtain the type of the array index
10437 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
10438 Index_Type
:= Etype
(String_Literal_Low_Bound
(Array_Type
));
10440 Index_Type
:= Etype
(First_Index
(Array_Type
));
10443 -- If name was overloaded, set slice type correctly now
10445 Set_Etype
(N
, Array_Type
);
10447 -- Handle the generation of a range check that compares the array index
10448 -- against the discrete_range. The check is not applied to internally
10449 -- built nodes associated with the expansion of dispatch tables. Check
10450 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10453 if Tagged_Type_Expansion
10454 and then RTU_Loaded
(Ada_Tags
)
10455 and then Nkind
(Prefix
(N
)) = N_Selected_Component
10456 and then Present
(Entity
(Selector_Name
(Prefix
(N
))))
10457 and then Entity
(Selector_Name
(Prefix
(N
))) =
10458 RTE_Record_Component
(RE_Prims_Ptr
)
10462 -- The discrete_range is specified by a subtype indication. Create a
10463 -- shallow copy and inherit the type, parent and source location from
10464 -- the discrete_range. This ensures that the range check is inserted
10465 -- relative to the slice and that the runtime exception points to the
10466 -- proper construct.
10468 elsif Is_Entity_Name
(Drange
) then
10469 Dexpr
:= New_Copy
(Scalar_Range
(Entity
(Drange
)));
10471 Set_Etype
(Dexpr
, Etype
(Drange
));
10472 Set_Parent
(Dexpr
, Parent
(Drange
));
10473 Set_Sloc
(Dexpr
, Sloc
(Drange
));
10475 -- The discrete_range is a regular range. Resolve the bounds and remove
10476 -- their side effects.
10479 Resolve
(Drange
, Base_Type
(Index_Type
));
10481 if Nkind
(Drange
) = N_Range
then
10482 Force_Evaluation
(Low_Bound
(Drange
));
10483 Force_Evaluation
(High_Bound
(Drange
));
10489 if Present
(Dexpr
) then
10490 Apply_Range_Check
(Dexpr
, Index_Type
);
10493 Set_Slice_Subtype
(N
);
10495 -- Check bad use of type with predicates
10501 if Nkind
(Drange
) = N_Subtype_Indication
10502 and then Has_Predicates
(Entity
(Subtype_Mark
(Drange
)))
10504 Subt
:= Entity
(Subtype_Mark
(Drange
));
10506 Subt
:= Etype
(Drange
);
10509 if Has_Predicates
(Subt
) then
10510 Bad_Predicated_Subtype_Use
10511 ("subtype& has predicate, not allowed in slice", Drange
, Subt
);
10515 -- Otherwise here is where we check suspicious indexes
10517 if Nkind
(Drange
) = N_Range
then
10518 Warn_On_Suspicious_Index
(Name
, Low_Bound
(Drange
));
10519 Warn_On_Suspicious_Index
(Name
, High_Bound
(Drange
));
10522 Analyze_Dimension
(N
);
10526 ----------------------------
10527 -- Resolve_String_Literal --
10528 ----------------------------
10530 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
10531 C_Typ
: constant Entity_Id
:= Component_Type
(Typ
);
10532 R_Typ
: constant Entity_Id
:= Root_Type
(C_Typ
);
10533 Loc
: constant Source_Ptr
:= Sloc
(N
);
10534 Str
: constant String_Id
:= Strval
(N
);
10535 Strlen
: constant Nat
:= String_Length
(Str
);
10536 Subtype_Id
: Entity_Id
;
10537 Need_Check
: Boolean;
10540 -- For a string appearing in a concatenation, defer creation of the
10541 -- string_literal_subtype until the end of the resolution of the
10542 -- concatenation, because the literal may be constant-folded away. This
10543 -- is a useful optimization for long concatenation expressions.
10545 -- If the string is an aggregate built for a single character (which
10546 -- happens in a non-static context) or a is null string to which special
10547 -- checks may apply, we build the subtype. Wide strings must also get a
10548 -- string subtype if they come from a one character aggregate. Strings
10549 -- generated by attributes might be static, but it is often hard to
10550 -- determine whether the enclosing context is static, so we generate
10551 -- subtypes for them as well, thus losing some rarer optimizations ???
10552 -- Same for strings that come from a static conversion.
10555 (Strlen
= 0 and then Typ
/= Standard_String
)
10556 or else Nkind
(Parent
(N
)) /= N_Op_Concat
10557 or else (N
/= Left_Opnd
(Parent
(N
))
10558 and then N
/= Right_Opnd
(Parent
(N
)))
10559 or else ((Typ
= Standard_Wide_String
10560 or else Typ
= Standard_Wide_Wide_String
)
10561 and then Nkind
(Original_Node
(N
)) /= N_String_Literal
);
10563 -- If the resolving type is itself a string literal subtype, we can just
10564 -- reuse it, since there is no point in creating another.
10566 if Ekind
(Typ
) = E_String_Literal_Subtype
then
10569 elsif Nkind
(Parent
(N
)) = N_Op_Concat
10570 and then not Need_Check
10571 and then not Nkind_In
(Original_Node
(N
), N_Character_Literal
,
10572 N_Attribute_Reference
,
10573 N_Qualified_Expression
,
10578 -- Do not generate a string literal subtype for the default expression
10579 -- of a formal parameter in GNATprove mode. This is because the string
10580 -- subtype is associated with the freezing actions of the subprogram,
10581 -- however freezing is disabled in GNATprove mode and as a result the
10582 -- subtype is unavailable.
10584 elsif GNATprove_Mode
10585 and then Nkind
(Parent
(N
)) = N_Parameter_Specification
10589 -- Otherwise we must create a string literal subtype. Note that the
10590 -- whole idea of string literal subtypes is simply to avoid the need
10591 -- for building a full fledged array subtype for each literal.
10594 Set_String_Literal_Subtype
(N
, Typ
);
10595 Subtype_Id
:= Etype
(N
);
10598 if Nkind
(Parent
(N
)) /= N_Op_Concat
10601 Set_Etype
(N
, Subtype_Id
);
10602 Eval_String_Literal
(N
);
10605 if Is_Limited_Composite
(Typ
)
10606 or else Is_Private_Composite
(Typ
)
10608 Error_Msg_N
("string literal not available for private array", N
);
10609 Set_Etype
(N
, Any_Type
);
10613 -- The validity of a null string has been checked in the call to
10614 -- Eval_String_Literal.
10619 -- Always accept string literal with component type Any_Character, which
10620 -- occurs in error situations and in comparisons of literals, both of
10621 -- which should accept all literals.
10623 elsif R_Typ
= Any_Character
then
10626 -- If the type is bit-packed, then we always transform the string
10627 -- literal into a full fledged aggregate.
10629 elsif Is_Bit_Packed_Array
(Typ
) then
10632 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10635 -- For Standard.Wide_Wide_String, or any other type whose component
10636 -- type is Standard.Wide_Wide_Character, we know that all the
10637 -- characters in the string must be acceptable, since the parser
10638 -- accepted the characters as valid character literals.
10640 if R_Typ
= Standard_Wide_Wide_Character
then
10643 -- For the case of Standard.String, or any other type whose component
10644 -- type is Standard.Character, we must make sure that there are no
10645 -- wide characters in the string, i.e. that it is entirely composed
10646 -- of characters in range of type Character.
10648 -- If the string literal is the result of a static concatenation, the
10649 -- test has already been performed on the components, and need not be
10652 elsif R_Typ
= Standard_Character
10653 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
10655 for J
in 1 .. Strlen
loop
10656 if not In_Character_Range
(Get_String_Char
(Str
, J
)) then
10658 -- If we are out of range, post error. This is one of the
10659 -- very few places that we place the flag in the middle of
10660 -- a token, right under the offending wide character. Not
10661 -- quite clear if this is right wrt wide character encoding
10662 -- sequences, but it's only an error message.
10665 ("literal out of range of type Standard.Character",
10666 Source_Ptr
(Int
(Loc
) + J
));
10671 -- For the case of Standard.Wide_String, or any other type whose
10672 -- component type is Standard.Wide_Character, we must make sure that
10673 -- there are no wide characters in the string, i.e. that it is
10674 -- entirely composed of characters in range of type Wide_Character.
10676 -- If the string literal is the result of a static concatenation,
10677 -- the test has already been performed on the components, and need
10678 -- not be repeated.
10680 elsif R_Typ
= Standard_Wide_Character
10681 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
10683 for J
in 1 .. Strlen
loop
10684 if not In_Wide_Character_Range
(Get_String_Char
(Str
, J
)) then
10686 -- If we are out of range, post error. This is one of the
10687 -- very few places that we place the flag in the middle of
10688 -- a token, right under the offending wide character.
10690 -- This is not quite right, because characters in general
10691 -- will take more than one character position ???
10694 ("literal out of range of type Standard.Wide_Character",
10695 Source_Ptr
(Int
(Loc
) + J
));
10700 -- If the root type is not a standard character, then we will convert
10701 -- the string into an aggregate and will let the aggregate code do
10702 -- the checking. Standard Wide_Wide_Character is also OK here.
10708 -- See if the component type of the array corresponding to the string
10709 -- has compile time known bounds. If yes we can directly check
10710 -- whether the evaluation of the string will raise constraint error.
10711 -- Otherwise we need to transform the string literal into the
10712 -- corresponding character aggregate and let the aggregate code do
10715 if Is_Standard_Character_Type
(R_Typ
) then
10717 -- Check for the case of full range, where we are definitely OK
10719 if Component_Type
(Typ
) = Base_Type
(Component_Type
(Typ
)) then
10723 -- Here the range is not the complete base type range, so check
10726 Comp_Typ_Lo
: constant Node_Id
:=
10727 Type_Low_Bound
(Component_Type
(Typ
));
10728 Comp_Typ_Hi
: constant Node_Id
:=
10729 Type_High_Bound
(Component_Type
(Typ
));
10734 if Compile_Time_Known_Value
(Comp_Typ_Lo
)
10735 and then Compile_Time_Known_Value
(Comp_Typ_Hi
)
10737 for J
in 1 .. Strlen
loop
10738 Char_Val
:= UI_From_Int
(Int
(Get_String_Char
(Str
, J
)));
10740 if Char_Val
< Expr_Value
(Comp_Typ_Lo
)
10741 or else Char_Val
> Expr_Value
(Comp_Typ_Hi
)
10743 Apply_Compile_Time_Constraint_Error
10744 (N
, "character out of range??",
10745 CE_Range_Check_Failed
,
10746 Loc
=> Source_Ptr
(Int
(Loc
) + J
));
10756 -- If we got here we meed to transform the string literal into the
10757 -- equivalent qualified positional array aggregate. This is rather
10758 -- heavy artillery for this situation, but it is hard work to avoid.
10761 Lits
: constant List_Id
:= New_List
;
10762 P
: Source_Ptr
:= Loc
+ 1;
10766 -- Build the character literals, we give them source locations that
10767 -- correspond to the string positions, which is a bit tricky given
10768 -- the possible presence of wide character escape sequences.
10770 for J
in 1 .. Strlen
loop
10771 C
:= Get_String_Char
(Str
, J
);
10772 Set_Character_Literal_Name
(C
);
10775 Make_Character_Literal
(P
,
10776 Chars
=> Name_Find
,
10777 Char_Literal_Value
=> UI_From_CC
(C
)));
10779 if In_Character_Range
(C
) then
10782 -- Should we have a call to Skip_Wide here ???
10791 Make_Qualified_Expression
(Loc
,
10792 Subtype_Mark
=> New_Occurrence_Of
(Typ
, Loc
),
10794 Make_Aggregate
(Loc
, Expressions
=> Lits
)));
10796 Analyze_And_Resolve
(N
, Typ
);
10798 end Resolve_String_Literal
;
10800 -------------------------
10801 -- Resolve_Target_Name --
10802 -------------------------
10804 procedure Resolve_Target_Name
(N
: Node_Id
; Typ
: Entity_Id
) is
10806 Set_Etype
(N
, Typ
);
10807 end Resolve_Target_Name
;
10809 -----------------------------
10810 -- Resolve_Type_Conversion --
10811 -----------------------------
10813 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
) is
10814 Conv_OK
: constant Boolean := Conversion_OK
(N
);
10815 Operand
: constant Node_Id
:= Expression
(N
);
10816 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
10817 Target_Typ
: constant Entity_Id
:= Etype
(N
);
10822 Test_Redundant
: Boolean := Warn_On_Redundant_Constructs
;
10823 -- Set to False to suppress cases where we want to suppress the test
10824 -- for redundancy to avoid possible false positives on this warning.
10828 and then not Valid_Conversion
(N
, Target_Typ
, Operand
)
10833 -- If the Operand Etype is Universal_Fixed, then the conversion is
10834 -- never redundant. We need this check because by the time we have
10835 -- finished the rather complex transformation, the conversion looks
10836 -- redundant when it is not.
10838 if Operand_Typ
= Universal_Fixed
then
10839 Test_Redundant
:= False;
10841 -- If the operand is marked as Any_Fixed, then special processing is
10842 -- required. This is also a case where we suppress the test for a
10843 -- redundant conversion, since most certainly it is not redundant.
10845 elsif Operand_Typ
= Any_Fixed
then
10846 Test_Redundant
:= False;
10848 -- Mixed-mode operation involving a literal. Context must be a fixed
10849 -- type which is applied to the literal subsequently.
10851 -- Multiplication and division involving two fixed type operands must
10852 -- yield a universal real because the result is computed in arbitrary
10855 if Is_Fixed_Point_Type
(Typ
)
10856 and then Nkind_In
(Operand
, N_Op_Divide
, N_Op_Multiply
)
10857 and then Etype
(Left_Opnd
(Operand
)) = Any_Fixed
10858 and then Etype
(Right_Opnd
(Operand
)) = Any_Fixed
10860 Set_Etype
(Operand
, Universal_Real
);
10862 elsif Is_Numeric_Type
(Typ
)
10863 and then Nkind_In
(Operand
, N_Op_Multiply
, N_Op_Divide
)
10864 and then (Etype
(Right_Opnd
(Operand
)) = Universal_Real
10866 Etype
(Left_Opnd
(Operand
)) = Universal_Real
)
10868 -- Return if expression is ambiguous
10870 if Unique_Fixed_Point_Type
(N
) = Any_Type
then
10873 -- If nothing else, the available fixed type is Duration
10876 Set_Etype
(Operand
, Standard_Duration
);
10879 -- Resolve the real operand with largest available precision
10881 if Etype
(Right_Opnd
(Operand
)) = Universal_Real
then
10882 Rop
:= New_Copy_Tree
(Right_Opnd
(Operand
));
10884 Rop
:= New_Copy_Tree
(Left_Opnd
(Operand
));
10887 Resolve
(Rop
, Universal_Real
);
10889 -- If the operand is a literal (it could be a non-static and
10890 -- illegal exponentiation) check whether the use of Duration
10891 -- is potentially inaccurate.
10893 if Nkind
(Rop
) = N_Real_Literal
10894 and then Realval
(Rop
) /= Ureal_0
10895 and then abs (Realval
(Rop
)) < Delta_Value
(Standard_Duration
)
10898 ("??universal real operand can only "
10899 & "be interpreted as Duration!", Rop
);
10901 ("\??precision will be lost in the conversion!", Rop
);
10904 elsif Is_Numeric_Type
(Typ
)
10905 and then Nkind
(Operand
) in N_Op
10906 and then Unique_Fixed_Point_Type
(N
) /= Any_Type
10908 Set_Etype
(Operand
, Standard_Duration
);
10911 Error_Msg_N
("invalid context for mixed mode operation", N
);
10912 Set_Etype
(Operand
, Any_Type
);
10919 -- In SPARK, a type conversion between array types should be restricted
10920 -- to types which have matching static bounds.
10922 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10923 -- operation if not needed.
10925 if Restriction_Check_Required
(SPARK_05
)
10926 and then Is_Array_Type
(Target_Typ
)
10927 and then Is_Array_Type
(Operand_Typ
)
10928 and then Operand_Typ
/= Any_Composite
-- or else Operand in error
10929 and then not Matching_Static_Array_Bounds
(Target_Typ
, Operand_Typ
)
10931 Check_SPARK_05_Restriction
10932 ("array types should have matching static bounds", N
);
10935 -- In formal mode, the operand of an ancestor type conversion must be an
10936 -- object (not an expression).
10938 if Is_Tagged_Type
(Target_Typ
)
10939 and then not Is_Class_Wide_Type
(Target_Typ
)
10940 and then Is_Tagged_Type
(Operand_Typ
)
10941 and then not Is_Class_Wide_Type
(Operand_Typ
)
10942 and then Is_Ancestor
(Target_Typ
, Operand_Typ
)
10943 and then not Is_SPARK_05_Object_Reference
(Operand
)
10945 Check_SPARK_05_Restriction
("object required", Operand
);
10948 Analyze_Dimension
(N
);
10950 -- Note: we do the Eval_Type_Conversion call before applying the
10951 -- required checks for a subtype conversion. This is important, since
10952 -- both are prepared under certain circumstances to change the type
10953 -- conversion to a constraint error node, but in the case of
10954 -- Eval_Type_Conversion this may reflect an illegality in the static
10955 -- case, and we would miss the illegality (getting only a warning
10956 -- message), if we applied the type conversion checks first.
10958 Eval_Type_Conversion
(N
);
10960 -- Even when evaluation is not possible, we may be able to simplify the
10961 -- conversion or its expression. This needs to be done before applying
10962 -- checks, since otherwise the checks may use the original expression
10963 -- and defeat the simplifications. This is specifically the case for
10964 -- elimination of the floating-point Truncation attribute in
10965 -- float-to-int conversions.
10967 Simplify_Type_Conversion
(N
);
10969 -- If after evaluation we still have a type conversion, then we may need
10970 -- to apply checks required for a subtype conversion.
10972 -- Skip these type conversion checks if universal fixed operands
10973 -- operands involved, since range checks are handled separately for
10974 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10976 if Nkind
(N
) = N_Type_Conversion
10977 and then not Is_Generic_Type
(Root_Type
(Target_Typ
))
10978 and then Target_Typ
/= Universal_Fixed
10979 and then Operand_Typ
/= Universal_Fixed
10981 Apply_Type_Conversion_Checks
(N
);
10984 -- Issue warning for conversion of simple object to its own type. We
10985 -- have to test the original nodes, since they may have been rewritten
10986 -- by various optimizations.
10988 Orig_N
:= Original_Node
(N
);
10990 -- Here we test for a redundant conversion if the warning mode is
10991 -- active (and was not locally reset), and we have a type conversion
10992 -- from source not appearing in a generic instance.
10995 and then Nkind
(Orig_N
) = N_Type_Conversion
10996 and then Comes_From_Source
(Orig_N
)
10997 and then not In_Instance
10999 Orig_N
:= Original_Node
(Expression
(Orig_N
));
11000 Orig_T
:= Target_Typ
;
11002 -- If the node is part of a larger expression, the Target_Type
11003 -- may not be the original type of the node if the context is a
11004 -- condition. Recover original type to see if conversion is needed.
11006 if Is_Boolean_Type
(Orig_T
)
11007 and then Nkind
(Parent
(N
)) in N_Op
11009 Orig_T
:= Etype
(Parent
(N
));
11012 -- If we have an entity name, then give the warning if the entity
11013 -- is the right type, or if it is a loop parameter covered by the
11014 -- original type (that's needed because loop parameters have an
11015 -- odd subtype coming from the bounds).
11017 if (Is_Entity_Name
(Orig_N
)
11019 (Etype
(Entity
(Orig_N
)) = Orig_T
11021 (Ekind
(Entity
(Orig_N
)) = E_Loop_Parameter
11022 and then Covers
(Orig_T
, Etype
(Entity
(Orig_N
))))))
11024 -- If not an entity, then type of expression must match
11026 or else Etype
(Orig_N
) = Orig_T
11028 -- One more check, do not give warning if the analyzed conversion
11029 -- has an expression with non-static bounds, and the bounds of the
11030 -- target are static. This avoids junk warnings in cases where the
11031 -- conversion is necessary to establish staticness, for example in
11032 -- a case statement.
11034 if not Is_OK_Static_Subtype
(Operand_Typ
)
11035 and then Is_OK_Static_Subtype
(Target_Typ
)
11039 -- Finally, if this type conversion occurs in a context requiring
11040 -- a prefix, and the expression is a qualified expression then the
11041 -- type conversion is not redundant, since a qualified expression
11042 -- is not a prefix, whereas a type conversion is. For example, "X
11043 -- := T'(Funx(...)).Y;" is illegal because a selected component
11044 -- requires a prefix, but a type conversion makes it legal: "X :=
11045 -- T(T'(Funx(...))).Y;"
11047 -- In Ada 2012, a qualified expression is a name, so this idiom is
11048 -- no longer needed, but we still suppress the warning because it
11049 -- seems unfriendly for warnings to pop up when you switch to the
11050 -- newer language version.
11052 elsif Nkind
(Orig_N
) = N_Qualified_Expression
11053 and then Nkind_In
(Parent
(N
), N_Attribute_Reference
,
11054 N_Indexed_Component
,
11055 N_Selected_Component
,
11057 N_Explicit_Dereference
)
11061 -- Never warn on conversion to Long_Long_Integer'Base since
11062 -- that is most likely an artifact of the extended overflow
11063 -- checking and comes from complex expanded code.
11065 elsif Orig_T
= Base_Type
(Standard_Long_Long_Integer
) then
11068 -- Here we give the redundant conversion warning. If it is an
11069 -- entity, give the name of the entity in the message. If not,
11070 -- just mention the expression.
11072 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
11075 if Is_Entity_Name
(Orig_N
) then
11076 Error_Msg_Node_2
:= Orig_T
;
11077 Error_Msg_NE
-- CODEFIX
11078 ("??redundant conversion, & is of type &!",
11079 N
, Entity
(Orig_N
));
11082 ("??redundant conversion, expression is of type&!",
11089 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
11090 -- No need to perform any interface conversion if the type of the
11091 -- expression coincides with the target type.
11093 if Ada_Version
>= Ada_2005
11094 and then Expander_Active
11095 and then Operand_Typ
/= Target_Typ
11098 Opnd
: Entity_Id
:= Operand_Typ
;
11099 Target
: Entity_Id
:= Target_Typ
;
11102 -- If the type of the operand is a limited view, use nonlimited
11103 -- view when available. If it is a class-wide type, recover the
11104 -- class-wide type of the nonlimited view.
11106 if From_Limited_With
(Opnd
)
11107 and then Has_Non_Limited_View
(Opnd
)
11109 Opnd
:= Non_Limited_View
(Opnd
);
11110 Set_Etype
(Expression
(N
), Opnd
);
11113 if Is_Access_Type
(Opnd
) then
11114 Opnd
:= Designated_Type
(Opnd
);
11117 if Is_Access_Type
(Target_Typ
) then
11118 Target
:= Designated_Type
(Target
);
11121 if Opnd
= Target
then
11124 -- Conversion from interface type
11126 elsif Is_Interface
(Opnd
) then
11128 -- Ada 2005 (AI-217): Handle entities from limited views
11130 if From_Limited_With
(Opnd
) then
11131 Error_Msg_Qual_Level
:= 99;
11132 Error_Msg_NE
-- CODEFIX
11133 ("missing WITH clause on package &", N
,
11134 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Opnd
))));
11136 ("type conversions require visibility of the full view",
11139 elsif From_Limited_With
(Target
)
11141 (Is_Access_Type
(Target_Typ
)
11142 and then Present
(Non_Limited_View
(Etype
(Target
))))
11144 Error_Msg_Qual_Level
:= 99;
11145 Error_Msg_NE
-- CODEFIX
11146 ("missing WITH clause on package &", N
,
11147 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Target
))));
11149 ("type conversions require visibility of the full view",
11153 Expand_Interface_Conversion
(N
);
11156 -- Conversion to interface type
11158 elsif Is_Interface
(Target
) then
11162 if Ekind_In
(Opnd
, E_Protected_Subtype
, E_Task_Subtype
) then
11163 Opnd
:= Etype
(Opnd
);
11166 if Is_Class_Wide_Type
(Opnd
)
11167 or else Interface_Present_In_Ancestor
11171 Expand_Interface_Conversion
(N
);
11173 Error_Msg_Name_1
:= Chars
(Etype
(Target
));
11174 Error_Msg_Name_2
:= Chars
(Opnd
);
11176 ("wrong interface conversion (% is not a progenitor "
11183 -- Ada 2012: once the type conversion is resolved, check whether the
11184 -- operand statisfies the static predicate of the target type.
11186 if Has_Predicates
(Target_Typ
) then
11187 Check_Expression_Against_Static_Predicate
(N
, Target_Typ
);
11190 -- If at this stage we have a real to integer conversion, make sure that
11191 -- the Do_Range_Check flag is set, because such conversions in general
11192 -- need a range check. We only need this if expansion is off.
11193 -- In GNATprove mode, we only do that when converting from fixed-point
11194 -- (as floating-point to integer conversions are now handled in
11195 -- GNATprove mode).
11197 if Nkind
(N
) = N_Type_Conversion
11198 and then not Expander_Active
11199 and then Is_Integer_Type
(Target_Typ
)
11200 and then (Is_Fixed_Point_Type
(Operand_Typ
)
11201 or else (not GNATprove_Mode
11202 and then Is_Floating_Point_Type
(Operand_Typ
)))
11204 Set_Do_Range_Check
(Operand
);
11207 -- Generating C code a type conversion of an access to constrained
11208 -- array type to access to unconstrained array type involves building
11209 -- a fat pointer which in general cannot be generated on the fly. We
11210 -- remove side effects in order to store the result of the conversion
11211 -- into a temporary.
11213 if Modify_Tree_For_C
11214 and then Nkind
(N
) = N_Type_Conversion
11215 and then Nkind
(Parent
(N
)) /= N_Object_Declaration
11216 and then Is_Access_Type
(Etype
(N
))
11217 and then Is_Array_Type
(Designated_Type
(Etype
(N
)))
11218 and then not Is_Constrained
(Designated_Type
(Etype
(N
)))
11219 and then Is_Constrained
(Designated_Type
(Etype
(Expression
(N
))))
11221 Remove_Side_Effects
(N
);
11223 end Resolve_Type_Conversion
;
11225 ----------------------
11226 -- Resolve_Unary_Op --
11227 ----------------------
11229 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
11230 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
11231 R
: constant Node_Id
:= Right_Opnd
(N
);
11237 if Is_Modular_Integer_Type
(Typ
) and then Nkind
(N
) /= N_Op_Not
then
11238 Error_Msg_Name_1
:= Chars
(Typ
);
11239 Check_SPARK_05_Restriction
11240 ("unary operator not defined for modular type%", N
);
11243 -- Deal with intrinsic unary operators
11245 if Comes_From_Source
(N
)
11246 and then Ekind
(Entity
(N
)) = E_Function
11247 and then Is_Imported
(Entity
(N
))
11248 and then Is_Intrinsic_Subprogram
(Entity
(N
))
11250 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
11254 -- Deal with universal cases
11256 if Etype
(R
) = Universal_Integer
11258 Etype
(R
) = Universal_Real
11260 Check_For_Visible_Operator
(N
, B_Typ
);
11263 Set_Etype
(N
, B_Typ
);
11264 Resolve
(R
, B_Typ
);
11266 -- Generate warning for expressions like abs (x mod 2)
11268 if Warn_On_Redundant_Constructs
11269 and then Nkind
(N
) = N_Op_Abs
11271 Determine_Range
(Right_Opnd
(N
), OK
, Lo
, Hi
);
11273 if OK
and then Hi
>= Lo
and then Lo
>= 0 then
11274 Error_Msg_N
-- CODEFIX
11275 ("?r?abs applied to known non-negative value has no effect", N
);
11279 -- Deal with reference generation
11281 Check_Unset_Reference
(R
);
11282 Generate_Operator_Reference
(N
, B_Typ
);
11283 Analyze_Dimension
(N
);
11286 -- Set overflow checking bit. Much cleverer code needed here eventually
11287 -- and perhaps the Resolve routines should be separated for the various
11288 -- arithmetic operations, since they will need different processing ???
11290 if Nkind
(N
) in N_Op
then
11291 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
11292 Enable_Overflow_Check
(N
);
11296 -- Generate warning for expressions like -5 mod 3 for integers. No need
11297 -- to worry in the floating-point case, since parens do not affect the
11298 -- result so there is no point in giving in a warning.
11301 Norig
: constant Node_Id
:= Original_Node
(N
);
11310 if Warn_On_Questionable_Missing_Parens
11311 and then Comes_From_Source
(Norig
)
11312 and then Is_Integer_Type
(Typ
)
11313 and then Nkind
(Norig
) = N_Op_Minus
11315 Rorig
:= Original_Node
(Right_Opnd
(Norig
));
11317 -- We are looking for cases where the right operand is not
11318 -- parenthesized, and is a binary operator, multiply, divide, or
11319 -- mod. These are the cases where the grouping can affect results.
11321 if Paren_Count
(Rorig
) = 0
11322 and then Nkind_In
(Rorig
, N_Op_Mod
, N_Op_Multiply
, N_Op_Divide
)
11324 -- For mod, we always give the warning, since the value is
11325 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11326 -- -(5 mod 315)). But for the other cases, the only concern is
11327 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11328 -- overflows, but (-2) * 64 does not). So we try to give the
11329 -- message only when overflow is possible.
11331 if Nkind
(Rorig
) /= N_Op_Mod
11332 and then Compile_Time_Known_Value
(R
)
11334 Val
:= Expr_Value
(R
);
11336 if Compile_Time_Known_Value
(Type_High_Bound
(Typ
)) then
11337 HB
:= Expr_Value
(Type_High_Bound
(Typ
));
11339 HB
:= Expr_Value
(Type_High_Bound
(Base_Type
(Typ
)));
11342 if Compile_Time_Known_Value
(Type_Low_Bound
(Typ
)) then
11343 LB
:= Expr_Value
(Type_Low_Bound
(Typ
));
11345 LB
:= Expr_Value
(Type_Low_Bound
(Base_Type
(Typ
)));
11348 -- Note that the test below is deliberately excluding the
11349 -- largest negative number, since that is a potentially
11350 -- troublesome case (e.g. -2 * x, where the result is the
11351 -- largest negative integer has an overflow with 2 * x).
11353 if Val
> LB
and then Val
<= HB
then
11358 -- For the multiplication case, the only case we have to worry
11359 -- about is when (-a)*b is exactly the largest negative number
11360 -- so that -(a*b) can cause overflow. This can only happen if
11361 -- a is a power of 2, and more generally if any operand is a
11362 -- constant that is not a power of 2, then the parentheses
11363 -- cannot affect whether overflow occurs. We only bother to
11364 -- test the left most operand
11366 -- Loop looking at left operands for one that has known value
11369 Opnd_Loop
: while Nkind
(Opnd
) = N_Op_Multiply
loop
11370 if Compile_Time_Known_Value
(Left_Opnd
(Opnd
)) then
11371 Lval
:= UI_Abs
(Expr_Value
(Left_Opnd
(Opnd
)));
11373 -- Operand value of 0 or 1 skips warning
11378 -- Otherwise check power of 2, if power of 2, warn, if
11379 -- anything else, skip warning.
11382 while Lval
/= 2 loop
11383 if Lval
mod 2 = 1 then
11394 -- Keep looking at left operands
11396 Opnd
:= Left_Opnd
(Opnd
);
11397 end loop Opnd_Loop
;
11399 -- For rem or "/" we can only have a problematic situation
11400 -- if the divisor has a value of minus one or one. Otherwise
11401 -- overflow is impossible (divisor > 1) or we have a case of
11402 -- division by zero in any case.
11404 if Nkind_In
(Rorig
, N_Op_Divide
, N_Op_Rem
)
11405 and then Compile_Time_Known_Value
(Right_Opnd
(Rorig
))
11406 and then UI_Abs
(Expr_Value
(Right_Opnd
(Rorig
))) /= 1
11411 -- If we fall through warning should be issued
11413 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11416 ("??unary minus expression should be parenthesized here!", N
);
11420 end Resolve_Unary_Op
;
11422 ----------------------------------
11423 -- Resolve_Unchecked_Expression --
11424 ----------------------------------
11426 procedure Resolve_Unchecked_Expression
11431 Resolve
(Expression
(N
), Typ
, Suppress
=> All_Checks
);
11432 Set_Etype
(N
, Typ
);
11433 end Resolve_Unchecked_Expression
;
11435 ---------------------------------------
11436 -- Resolve_Unchecked_Type_Conversion --
11437 ---------------------------------------
11439 procedure Resolve_Unchecked_Type_Conversion
11443 pragma Warnings
(Off
, Typ
);
11445 Operand
: constant Node_Id
:= Expression
(N
);
11446 Opnd_Type
: constant Entity_Id
:= Etype
(Operand
);
11449 -- Resolve operand using its own type
11451 Resolve
(Operand
, Opnd_Type
);
11453 -- In an inlined context, the unchecked conversion may be applied
11454 -- to a literal, in which case its type is the type of the context.
11455 -- (In other contexts conversions cannot apply to literals).
11458 and then (Opnd_Type
= Any_Character
or else
11459 Opnd_Type
= Any_Integer
or else
11460 Opnd_Type
= Any_Real
)
11462 Set_Etype
(Operand
, Typ
);
11465 Analyze_Dimension
(N
);
11466 Eval_Unchecked_Conversion
(N
);
11467 end Resolve_Unchecked_Type_Conversion
;
11469 ------------------------------
11470 -- Rewrite_Operator_As_Call --
11471 ------------------------------
11473 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
) is
11474 Loc
: constant Source_Ptr
:= Sloc
(N
);
11475 Actuals
: constant List_Id
:= New_List
;
11479 if Nkind
(N
) in N_Binary_Op
then
11480 Append
(Left_Opnd
(N
), Actuals
);
11483 Append
(Right_Opnd
(N
), Actuals
);
11486 Make_Function_Call
(Sloc
=> Loc
,
11487 Name
=> New_Occurrence_Of
(Nam
, Loc
),
11488 Parameter_Associations
=> Actuals
);
11490 Preserve_Comes_From_Source
(New_N
, N
);
11491 Preserve_Comes_From_Source
(Name
(New_N
), N
);
11492 Rewrite
(N
, New_N
);
11493 Set_Etype
(N
, Etype
(Nam
));
11494 end Rewrite_Operator_As_Call
;
11496 ------------------------------
11497 -- Rewrite_Renamed_Operator --
11498 ------------------------------
11500 procedure Rewrite_Renamed_Operator
11505 Nam
: constant Name_Id
:= Chars
(Op
);
11506 Is_Binary
: constant Boolean := Nkind
(N
) in N_Binary_Op
;
11510 -- Do not perform this transformation within a pre/postcondition,
11511 -- because the expression will be reanalyzed, and the transformation
11512 -- might affect the visibility of the operator, e.g. in an instance.
11513 -- Note that fully analyzed and expanded pre/postconditions appear as
11514 -- pragma Check equivalents.
11516 if In_Pre_Post_Condition
(N
) then
11520 -- Likewise when an expression function is being preanalyzed, since the
11521 -- expression will be reanalyzed as part of the generated body.
11523 if In_Spec_Expression
then
11525 S
: constant Entity_Id
:= Current_Scope_No_Loops
;
11527 if Ekind
(S
) = E_Function
11528 and then Nkind
(Original_Node
(Unit_Declaration_Node
(S
))) =
11529 N_Expression_Function
11536 -- Rewrite the operator node using the real operator, not its renaming.
11537 -- Exclude user-defined intrinsic operations of the same name, which are
11538 -- treated separately and rewritten as calls.
11540 if Ekind
(Op
) /= E_Function
or else Chars
(N
) /= Nam
then
11541 Op_Node
:= New_Node
(Operator_Kind
(Nam
, Is_Binary
), Sloc
(N
));
11542 Set_Chars
(Op_Node
, Nam
);
11543 Set_Etype
(Op_Node
, Etype
(N
));
11544 Set_Entity
(Op_Node
, Op
);
11545 Set_Right_Opnd
(Op_Node
, Right_Opnd
(N
));
11547 -- Indicate that both the original entity and its renaming are
11548 -- referenced at this point.
11550 Generate_Reference
(Entity
(N
), N
);
11551 Generate_Reference
(Op
, N
);
11554 Set_Left_Opnd
(Op_Node
, Left_Opnd
(N
));
11557 Rewrite
(N
, Op_Node
);
11559 -- If the context type is private, add the appropriate conversions so
11560 -- that the operator is applied to the full view. This is done in the
11561 -- routines that resolve intrinsic operators.
11563 if Is_Intrinsic_Subprogram
(Op
) and then Is_Private_Type
(Typ
) then
11573 Resolve_Intrinsic_Operator
(N
, Typ
);
11579 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
11586 elsif Ekind
(Op
) = E_Function
and then Is_Intrinsic_Subprogram
(Op
) then
11588 -- Operator renames a user-defined operator of the same name. Use the
11589 -- original operator in the node, which is the one Gigi knows about.
11591 Set_Entity
(N
, Op
);
11592 Set_Is_Overloaded
(N
, False);
11594 end Rewrite_Renamed_Operator
;
11596 -----------------------
11597 -- Set_Slice_Subtype --
11598 -----------------------
11600 -- Build an implicit subtype declaration to represent the type delivered by
11601 -- the slice. This is an abbreviated version of an array subtype. We define
11602 -- an index subtype for the slice, using either the subtype name or the
11603 -- discrete range of the slice. To be consistent with index usage elsewhere
11604 -- we create a list header to hold the single index. This list is not
11605 -- otherwise attached to the syntax tree.
11607 procedure Set_Slice_Subtype
(N
: Node_Id
) is
11608 Loc
: constant Source_Ptr
:= Sloc
(N
);
11609 Index_List
: constant List_Id
:= New_List
;
11611 Index_Subtype
: Entity_Id
;
11612 Index_Type
: Entity_Id
;
11613 Slice_Subtype
: Entity_Id
;
11614 Drange
: constant Node_Id
:= Discrete_Range
(N
);
11617 Index_Type
:= Base_Type
(Etype
(Drange
));
11619 if Is_Entity_Name
(Drange
) then
11620 Index_Subtype
:= Entity
(Drange
);
11623 -- We force the evaluation of a range. This is definitely needed in
11624 -- the renamed case, and seems safer to do unconditionally. Note in
11625 -- any case that since we will create and insert an Itype referring
11626 -- to this range, we must make sure any side effect removal actions
11627 -- are inserted before the Itype definition.
11629 if Nkind
(Drange
) = N_Range
then
11630 Force_Evaluation
(Low_Bound
(Drange
));
11631 Force_Evaluation
(High_Bound
(Drange
));
11633 -- If the discrete range is given by a subtype indication, the
11634 -- type of the slice is the base of the subtype mark.
11636 elsif Nkind
(Drange
) = N_Subtype_Indication
then
11638 R
: constant Node_Id
:= Range_Expression
(Constraint
(Drange
));
11640 Index_Type
:= Base_Type
(Entity
(Subtype_Mark
(Drange
)));
11641 Force_Evaluation
(Low_Bound
(R
));
11642 Force_Evaluation
(High_Bound
(R
));
11646 Index_Subtype
:= Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
11648 -- Take a new copy of Drange (where bounds have been rewritten to
11649 -- reference side-effect-free names). Using a separate tree ensures
11650 -- that further expansion (e.g. while rewriting a slice assignment
11651 -- into a FOR loop) does not attempt to remove side effects on the
11652 -- bounds again (which would cause the bounds in the index subtype
11653 -- definition to refer to temporaries before they are defined) (the
11654 -- reason is that some names are considered side effect free here
11655 -- for the subtype, but not in the context of a loop iteration
11658 Set_Scalar_Range
(Index_Subtype
, New_Copy_Tree
(Drange
));
11659 Set_Parent
(Scalar_Range
(Index_Subtype
), Index_Subtype
);
11660 Set_Etype
(Index_Subtype
, Index_Type
);
11661 Set_Size_Info
(Index_Subtype
, Index_Type
);
11662 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
11665 Slice_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
11667 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
11668 Set_Etype
(Index
, Index_Subtype
);
11669 Append
(Index
, Index_List
);
11671 Set_First_Index
(Slice_Subtype
, Index
);
11672 Set_Etype
(Slice_Subtype
, Base_Type
(Etype
(N
)));
11673 Set_Is_Constrained
(Slice_Subtype
, True);
11675 Check_Compile_Time_Size
(Slice_Subtype
);
11677 -- The Etype of the existing Slice node is reset to this slice subtype.
11678 -- Its bounds are obtained from its first index.
11680 Set_Etype
(N
, Slice_Subtype
);
11682 -- For bit-packed slice subtypes, freeze immediately (except in the case
11683 -- of being in a "spec expression" where we never freeze when we first
11684 -- see the expression).
11686 if Is_Bit_Packed_Array
(Slice_Subtype
) and not In_Spec_Expression
then
11687 Freeze_Itype
(Slice_Subtype
, N
);
11689 -- For all other cases insert an itype reference in the slice's actions
11690 -- so that the itype is frozen at the proper place in the tree (i.e. at
11691 -- the point where actions for the slice are analyzed). Note that this
11692 -- is different from freezing the itype immediately, which might be
11693 -- premature (e.g. if the slice is within a transient scope). This needs
11694 -- to be done only if expansion is enabled.
11696 elsif Expander_Active
then
11697 Ensure_Defined
(Typ
=> Slice_Subtype
, N
=> N
);
11699 end Set_Slice_Subtype
;
11701 --------------------------------
11702 -- Set_String_Literal_Subtype --
11703 --------------------------------
11705 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
) is
11706 Loc
: constant Source_Ptr
:= Sloc
(N
);
11707 Low_Bound
: constant Node_Id
:=
11708 Type_Low_Bound
(Etype
(First_Index
(Typ
)));
11709 Subtype_Id
: Entity_Id
;
11712 if Nkind
(N
) /= N_String_Literal
then
11716 Subtype_Id
:= Create_Itype
(E_String_Literal_Subtype
, N
);
11717 Set_String_Literal_Length
(Subtype_Id
, UI_From_Int
11718 (String_Length
(Strval
(N
))));
11719 Set_Etype
(Subtype_Id
, Base_Type
(Typ
));
11720 Set_Is_Constrained
(Subtype_Id
);
11721 Set_Etype
(N
, Subtype_Id
);
11723 -- The low bound is set from the low bound of the corresponding index
11724 -- type. Note that we do not store the high bound in the string literal
11725 -- subtype, but it can be deduced if necessary from the length and the
11728 if Is_OK_Static_Expression
(Low_Bound
) then
11729 Set_String_Literal_Low_Bound
(Subtype_Id
, Low_Bound
);
11731 -- If the lower bound is not static we create a range for the string
11732 -- literal, using the index type and the known length of the literal.
11733 -- The index type is not necessarily Positive, so the upper bound is
11734 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11738 Index_List
: constant List_Id
:= New_List
;
11739 Index_Type
: constant Entity_Id
:= Etype
(First_Index
(Typ
));
11740 High_Bound
: constant Node_Id
:=
11741 Make_Attribute_Reference
(Loc
,
11742 Attribute_Name
=> Name_Val
,
11744 New_Occurrence_Of
(Index_Type
, Loc
),
11745 Expressions
=> New_List
(
11748 Make_Attribute_Reference
(Loc
,
11749 Attribute_Name
=> Name_Pos
,
11751 New_Occurrence_Of
(Index_Type
, Loc
),
11753 New_List
(New_Copy_Tree
(Low_Bound
))),
11755 Make_Integer_Literal
(Loc
,
11756 String_Length
(Strval
(N
)) - 1))));
11758 Array_Subtype
: Entity_Id
;
11761 Index_Subtype
: Entity_Id
;
11764 if Is_Integer_Type
(Index_Type
) then
11765 Set_String_Literal_Low_Bound
11766 (Subtype_Id
, Make_Integer_Literal
(Loc
, 1));
11769 -- If the index type is an enumeration type, build bounds
11770 -- expression with attributes.
11772 Set_String_Literal_Low_Bound
11774 Make_Attribute_Reference
(Loc
,
11775 Attribute_Name
=> Name_First
,
11777 New_Occurrence_Of
(Base_Type
(Index_Type
), Loc
)));
11778 Set_Etype
(String_Literal_Low_Bound
(Subtype_Id
), Index_Type
);
11781 Analyze_And_Resolve
(String_Literal_Low_Bound
(Subtype_Id
));
11783 -- Build bona fide subtype for the string, and wrap it in an
11784 -- unchecked conversion, because the backend expects the
11785 -- String_Literal_Subtype to have a static lower bound.
11788 Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
11789 Drange
:= Make_Range
(Loc
, New_Copy_Tree
(Low_Bound
), High_Bound
);
11790 Set_Scalar_Range
(Index_Subtype
, Drange
);
11791 Set_Parent
(Drange
, N
);
11792 Analyze_And_Resolve
(Drange
, Index_Type
);
11794 -- In the context, the Index_Type may already have a constraint,
11795 -- so use common base type on string subtype. The base type may
11796 -- be used when generating attributes of the string, for example
11797 -- in the context of a slice assignment.
11799 Set_Etype
(Index_Subtype
, Base_Type
(Index_Type
));
11800 Set_Size_Info
(Index_Subtype
, Index_Type
);
11801 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
11803 Array_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
11805 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
11806 Set_Etype
(Index
, Index_Subtype
);
11807 Append
(Index
, Index_List
);
11809 Set_First_Index
(Array_Subtype
, Index
);
11810 Set_Etype
(Array_Subtype
, Base_Type
(Typ
));
11811 Set_Is_Constrained
(Array_Subtype
, True);
11814 Make_Unchecked_Type_Conversion
(Loc
,
11815 Subtype_Mark
=> New_Occurrence_Of
(Array_Subtype
, Loc
),
11816 Expression
=> Relocate_Node
(N
)));
11817 Set_Etype
(N
, Array_Subtype
);
11820 end Set_String_Literal_Subtype
;
11822 ------------------------------
11823 -- Simplify_Type_Conversion --
11824 ------------------------------
11826 procedure Simplify_Type_Conversion
(N
: Node_Id
) is
11828 if Nkind
(N
) = N_Type_Conversion
then
11830 Operand
: constant Node_Id
:= Expression
(N
);
11831 Target_Typ
: constant Entity_Id
:= Etype
(N
);
11832 Opnd_Typ
: constant Entity_Id
:= Etype
(Operand
);
11835 -- Special processing if the conversion is the expression of a
11836 -- Rounding or Truncation attribute reference. In this case we
11839 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11845 -- with the Float_Truncate flag set to False or True respectively,
11846 -- which is more efficient.
11848 if Is_Floating_Point_Type
(Opnd_Typ
)
11850 (Is_Integer_Type
(Target_Typ
)
11851 or else (Is_Fixed_Point_Type
(Target_Typ
)
11852 and then Conversion_OK
(N
)))
11853 and then Nkind
(Operand
) = N_Attribute_Reference
11854 and then Nam_In
(Attribute_Name
(Operand
), Name_Rounding
,
11858 Truncate
: constant Boolean :=
11859 Attribute_Name
(Operand
) = Name_Truncation
;
11862 Relocate_Node
(First
(Expressions
(Operand
))));
11863 Set_Float_Truncate
(N
, Truncate
);
11868 end Simplify_Type_Conversion
;
11870 -----------------------------
11871 -- Unique_Fixed_Point_Type --
11872 -----------------------------
11874 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
is
11875 procedure Fixed_Point_Error
(T1
: Entity_Id
; T2
: Entity_Id
);
11876 -- Give error messages for true ambiguity. Messages are posted on node
11877 -- N, and entities T1, T2 are the possible interpretations.
11879 -----------------------
11880 -- Fixed_Point_Error --
11881 -----------------------
11883 procedure Fixed_Point_Error
(T1
: Entity_Id
; T2
: Entity_Id
) is
11885 Error_Msg_N
("ambiguous universal_fixed_expression", N
);
11886 Error_Msg_NE
("\\possible interpretation as}", N
, T1
);
11887 Error_Msg_NE
("\\possible interpretation as}", N
, T2
);
11888 end Fixed_Point_Error
;
11898 -- Start of processing for Unique_Fixed_Point_Type
11901 -- The operations on Duration are visible, so Duration is always a
11902 -- possible interpretation.
11904 T1
:= Standard_Duration
;
11906 -- Look for fixed-point types in enclosing scopes
11908 Scop
:= Current_Scope
;
11909 while Scop
/= Standard_Standard
loop
11910 T2
:= First_Entity
(Scop
);
11911 while Present
(T2
) loop
11912 if Is_Fixed_Point_Type
(T2
)
11913 and then Current_Entity
(T2
) = T2
11914 and then Scope
(Base_Type
(T2
)) = Scop
11916 if Present
(T1
) then
11917 Fixed_Point_Error
(T1
, T2
);
11927 Scop
:= Scope
(Scop
);
11930 -- Look for visible fixed type declarations in the context
11932 Item
:= First
(Context_Items
(Cunit
(Current_Sem_Unit
)));
11933 while Present
(Item
) loop
11934 if Nkind
(Item
) = N_With_Clause
then
11935 Scop
:= Entity
(Name
(Item
));
11936 T2
:= First_Entity
(Scop
);
11937 while Present
(T2
) loop
11938 if Is_Fixed_Point_Type
(T2
)
11939 and then Scope
(Base_Type
(T2
)) = Scop
11940 and then (Is_Potentially_Use_Visible
(T2
) or else In_Use
(T2
))
11942 if Present
(T1
) then
11943 Fixed_Point_Error
(T1
, T2
);
11957 if Nkind
(N
) = N_Real_Literal
then
11958 Error_Msg_NE
("??real literal interpreted as }!", N
, T1
);
11961 -- When the context is a type conversion, issue the warning on the
11962 -- expression of the conversion because it is the actual operation.
11964 if Nkind_In
(N
, N_Type_Conversion
, N_Unchecked_Type_Conversion
) then
11965 ErrN
:= Expression
(N
);
11971 ("??universal_fixed expression interpreted as }!", ErrN
, T1
);
11975 end Unique_Fixed_Point_Type
;
11977 ----------------------
11978 -- Valid_Conversion --
11979 ----------------------
11981 function Valid_Conversion
11983 Target
: Entity_Id
;
11985 Report_Errs
: Boolean := True) return Boolean
11987 Target_Type
: constant Entity_Id
:= Base_Type
(Target
);
11988 Opnd_Type
: Entity_Id
:= Etype
(Operand
);
11989 Inc_Ancestor
: Entity_Id
;
11991 function Conversion_Check
11993 Msg
: String) return Boolean;
11994 -- Little routine to post Msg if Valid is False, returns Valid value
11996 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
);
11997 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
11999 procedure Conversion_Error_NE
12001 N
: Node_Or_Entity_Id
;
12002 E
: Node_Or_Entity_Id
);
12003 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
12005 function In_Instance_Code
return Boolean;
12006 -- Return True if expression is within an instance but is not in one of
12007 -- the actuals of the instantiation. Type conversions within an instance
12008 -- are not rechecked because type visbility may lead to spurious errors,
12009 -- but conversions in an actual for a formal object must be checked.
12011 function Valid_Tagged_Conversion
12012 (Target_Type
: Entity_Id
;
12013 Opnd_Type
: Entity_Id
) return Boolean;
12014 -- Specifically test for validity of tagged conversions
12016 function Valid_Array_Conversion
return Boolean;
12017 -- Check index and component conformance, and accessibility levels if
12018 -- the component types are anonymous access types (Ada 2005).
12020 ----------------------
12021 -- Conversion_Check --
12022 ----------------------
12024 function Conversion_Check
12026 Msg
: String) return Boolean
12031 -- A generic unit has already been analyzed and we have verified
12032 -- that a particular conversion is OK in that context. Since the
12033 -- instance is reanalyzed without relying on the relationships
12034 -- established during the analysis of the generic, it is possible
12035 -- to end up with inconsistent views of private types. Do not emit
12036 -- the error message in such cases. The rest of the machinery in
12037 -- Valid_Conversion still ensures the proper compatibility of
12038 -- target and operand types.
12040 and then not In_Instance_Code
12042 Conversion_Error_N
(Msg
, Operand
);
12046 end Conversion_Check
;
12048 ------------------------
12049 -- Conversion_Error_N --
12050 ------------------------
12052 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
) is
12054 if Report_Errs
then
12055 Error_Msg_N
(Msg
, N
);
12057 end Conversion_Error_N
;
12059 -------------------------
12060 -- Conversion_Error_NE --
12061 -------------------------
12063 procedure Conversion_Error_NE
12065 N
: Node_Or_Entity_Id
;
12066 E
: Node_Or_Entity_Id
)
12069 if Report_Errs
then
12070 Error_Msg_NE
(Msg
, N
, E
);
12072 end Conversion_Error_NE
;
12074 ----------------------
12075 -- In_Instance_Code --
12076 ----------------------
12078 function In_Instance_Code
return Boolean is
12082 if not In_Instance
then
12087 while Present
(Par
) loop
12089 -- The expression is part of an actual object if it appears in
12090 -- the generated object declaration in the instance.
12092 if Nkind
(Par
) = N_Object_Declaration
12093 and then Present
(Corresponding_Generic_Association
(Par
))
12099 Nkind
(Par
) in N_Statement_Other_Than_Procedure_Call
12100 or else Nkind
(Par
) in N_Subprogram_Call
12101 or else Nkind
(Par
) in N_Declaration
;
12104 Par
:= Parent
(Par
);
12107 -- Otherwise the expression appears within the instantiated unit
12111 end In_Instance_Code
;
12113 ----------------------------
12114 -- Valid_Array_Conversion --
12115 ----------------------------
12117 function Valid_Array_Conversion
return Boolean is
12118 Opnd_Comp_Type
: constant Entity_Id
:= Component_Type
(Opnd_Type
);
12119 Opnd_Comp_Base
: constant Entity_Id
:= Base_Type
(Opnd_Comp_Type
);
12121 Opnd_Index
: Node_Id
;
12122 Opnd_Index_Type
: Entity_Id
;
12124 Target_Comp_Type
: constant Entity_Id
:=
12125 Component_Type
(Target_Type
);
12126 Target_Comp_Base
: constant Entity_Id
:=
12127 Base_Type
(Target_Comp_Type
);
12129 Target_Index
: Node_Id
;
12130 Target_Index_Type
: Entity_Id
;
12133 -- Error if wrong number of dimensions
12136 Number_Dimensions
(Target_Type
) /= Number_Dimensions
(Opnd_Type
)
12139 ("incompatible number of dimensions for conversion", Operand
);
12142 -- Number of dimensions matches
12145 -- Loop through indexes of the two arrays
12147 Target_Index
:= First_Index
(Target_Type
);
12148 Opnd_Index
:= First_Index
(Opnd_Type
);
12149 while Present
(Target_Index
) and then Present
(Opnd_Index
) loop
12150 Target_Index_Type
:= Etype
(Target_Index
);
12151 Opnd_Index_Type
:= Etype
(Opnd_Index
);
12153 -- Error if index types are incompatible
12155 if not (Is_Integer_Type
(Target_Index_Type
)
12156 and then Is_Integer_Type
(Opnd_Index_Type
))
12157 and then (Root_Type
(Target_Index_Type
)
12158 /= Root_Type
(Opnd_Index_Type
))
12161 ("incompatible index types for array conversion",
12166 Next_Index
(Target_Index
);
12167 Next_Index
(Opnd_Index
);
12170 -- If component types have same base type, all set
12172 if Target_Comp_Base
= Opnd_Comp_Base
then
12175 -- Here if base types of components are not the same. The only
12176 -- time this is allowed is if we have anonymous access types.
12178 -- The conversion of arrays of anonymous access types can lead
12179 -- to dangling pointers. AI-392 formalizes the accessibility
12180 -- checks that must be applied to such conversions to prevent
12181 -- out-of-scope references.
12184 (Target_Comp_Base
, E_Anonymous_Access_Type
,
12185 E_Anonymous_Access_Subprogram_Type
)
12186 and then Ekind
(Opnd_Comp_Base
) = Ekind
(Target_Comp_Base
)
12188 Subtypes_Statically_Match
(Target_Comp_Type
, Opnd_Comp_Type
)
12190 if Type_Access_Level
(Target_Type
) <
12191 Deepest_Type_Access_Level
(Opnd_Type
)
12193 if In_Instance_Body
then
12194 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12196 ("source array type has deeper accessibility "
12197 & "level than target<<", Operand
);
12198 Conversion_Error_N
("\Program_Error [<<", Operand
);
12200 Make_Raise_Program_Error
(Sloc
(N
),
12201 Reason
=> PE_Accessibility_Check_Failed
));
12202 Set_Etype
(N
, Target_Type
);
12205 -- Conversion not allowed because of accessibility levels
12209 ("source array type has deeper accessibility "
12210 & "level than target", Operand
);
12218 -- All other cases where component base types do not match
12222 ("incompatible component types for array conversion",
12227 -- Check that component subtypes statically match. For numeric
12228 -- types this means that both must be either constrained or
12229 -- unconstrained. For enumeration types the bounds must match.
12230 -- All of this is checked in Subtypes_Statically_Match.
12232 if not Subtypes_Statically_Match
12233 (Target_Comp_Type
, Opnd_Comp_Type
)
12236 ("component subtypes must statically match", Operand
);
12242 end Valid_Array_Conversion
;
12244 -----------------------------
12245 -- Valid_Tagged_Conversion --
12246 -----------------------------
12248 function Valid_Tagged_Conversion
12249 (Target_Type
: Entity_Id
;
12250 Opnd_Type
: Entity_Id
) return Boolean
12253 -- Upward conversions are allowed (RM 4.6(22))
12255 if Covers
(Target_Type
, Opnd_Type
)
12256 or else Is_Ancestor
(Target_Type
, Opnd_Type
)
12260 -- Downward conversion are allowed if the operand is class-wide
12263 elsif Is_Class_Wide_Type
(Opnd_Type
)
12264 and then Covers
(Opnd_Type
, Target_Type
)
12268 elsif Covers
(Opnd_Type
, Target_Type
)
12269 or else Is_Ancestor
(Opnd_Type
, Target_Type
)
12272 Conversion_Check
(False,
12273 "downward conversion of tagged objects not allowed");
12275 -- Ada 2005 (AI-251): The conversion to/from interface types is
12276 -- always valid. The types involved may be class-wide (sub)types.
12278 elsif Is_Interface
(Etype
(Base_Type
(Target_Type
)))
12279 or else Is_Interface
(Etype
(Base_Type
(Opnd_Type
)))
12283 -- If the operand is a class-wide type obtained through a limited_
12284 -- with clause, and the context includes the nonlimited view, use
12285 -- it to determine whether the conversion is legal.
12287 elsif Is_Class_Wide_Type
(Opnd_Type
)
12288 and then From_Limited_With
(Opnd_Type
)
12289 and then Present
(Non_Limited_View
(Etype
(Opnd_Type
)))
12290 and then Is_Interface
(Non_Limited_View
(Etype
(Opnd_Type
)))
12294 elsif Is_Access_Type
(Opnd_Type
)
12295 and then Is_Interface
(Directly_Designated_Type
(Opnd_Type
))
12300 Conversion_Error_NE
12301 ("invalid tagged conversion, not compatible with}",
12302 N
, First_Subtype
(Opnd_Type
));
12305 end Valid_Tagged_Conversion
;
12307 -- Start of processing for Valid_Conversion
12310 Check_Parameterless_Call
(Operand
);
12312 if Is_Overloaded
(Operand
) then
12322 -- Remove procedure calls, which syntactically cannot appear in
12323 -- this context, but which cannot be removed by type checking,
12324 -- because the context does not impose a type.
12326 -- The node may be labelled overloaded, but still contain only one
12327 -- interpretation because others were discarded earlier. If this
12328 -- is the case, retain the single interpretation if legal.
12330 Get_First_Interp
(Operand
, I
, It
);
12331 Opnd_Type
:= It
.Typ
;
12332 Get_Next_Interp
(I
, It
);
12334 if Present
(It
.Typ
)
12335 and then Opnd_Type
/= Standard_Void_Type
12337 -- More than one candidate interpretation is available
12339 Get_First_Interp
(Operand
, I
, It
);
12340 while Present
(It
.Typ
) loop
12341 if It
.Typ
= Standard_Void_Type
then
12345 -- When compiling for a system where Address is of a visible
12346 -- integer type, spurious ambiguities can be produced when
12347 -- arithmetic operations have a literal operand and return
12348 -- System.Address or a descendant of it. These ambiguities
12349 -- are usually resolved by the context, but for conversions
12350 -- there is no context type and the removal of the spurious
12351 -- operations must be done explicitly here.
12353 if not Address_Is_Private
12354 and then Is_Descendant_Of_Address
(It
.Typ
)
12359 Get_Next_Interp
(I
, It
);
12363 Get_First_Interp
(Operand
, I
, It
);
12367 if No
(It
.Typ
) then
12368 Conversion_Error_N
("illegal operand in conversion", Operand
);
12372 Get_Next_Interp
(I
, It
);
12374 if Present
(It
.Typ
) then
12377 It1
:= Disambiguate
(Operand
, I1
, I
, Any_Type
);
12379 if It1
= No_Interp
then
12381 ("ambiguous operand in conversion", Operand
);
12383 -- If the interpretation involves a standard operator, use
12384 -- the location of the type, which may be user-defined.
12386 if Sloc
(It
.Nam
) = Standard_Location
then
12387 Error_Msg_Sloc
:= Sloc
(It
.Typ
);
12389 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
12392 Conversion_Error_N
-- CODEFIX
12393 ("\\possible interpretation#!", Operand
);
12395 if Sloc
(N1
) = Standard_Location
then
12396 Error_Msg_Sloc
:= Sloc
(T1
);
12398 Error_Msg_Sloc
:= Sloc
(N1
);
12401 Conversion_Error_N
-- CODEFIX
12402 ("\\possible interpretation#!", Operand
);
12408 Set_Etype
(Operand
, It1
.Typ
);
12409 Opnd_Type
:= It1
.Typ
;
12413 -- Deal with conversion of integer type to address if the pragma
12414 -- Allow_Integer_Address is in effect. We convert the conversion to
12415 -- an unchecked conversion in this case and we are all done.
12417 if Address_Integer_Convert_OK
(Opnd_Type
, Target_Type
) then
12418 Rewrite
(N
, Unchecked_Convert_To
(Target_Type
, Expression
(N
)));
12419 Analyze_And_Resolve
(N
, Target_Type
);
12423 -- If we are within a child unit, check whether the type of the
12424 -- expression has an ancestor in a parent unit, in which case it
12425 -- belongs to its derivation class even if the ancestor is private.
12426 -- See RM 7.3.1 (5.2/3).
12428 Inc_Ancestor
:= Get_Incomplete_View_Of_Ancestor
(Opnd_Type
);
12432 if Is_Numeric_Type
(Target_Type
) then
12434 -- A universal fixed expression can be converted to any numeric type
12436 if Opnd_Type
= Universal_Fixed
then
12439 -- Also no need to check when in an instance or inlined body, because
12440 -- the legality has been established when the template was analyzed.
12441 -- Furthermore, numeric conversions may occur where only a private
12442 -- view of the operand type is visible at the instantiation point.
12443 -- This results in a spurious error if we check that the operand type
12444 -- is a numeric type.
12446 -- Note: in a previous version of this unit, the following tests were
12447 -- applied only for generated code (Comes_From_Source set to False),
12448 -- but in fact the test is required for source code as well, since
12449 -- this situation can arise in source code.
12451 elsif In_Instance_Code
or else In_Inlined_Body
then
12454 -- Otherwise we need the conversion check
12457 return Conversion_Check
12458 (Is_Numeric_Type
(Opnd_Type
)
12460 (Present
(Inc_Ancestor
)
12461 and then Is_Numeric_Type
(Inc_Ancestor
)),
12462 "illegal operand for numeric conversion");
12467 elsif Is_Array_Type
(Target_Type
) then
12468 if not Is_Array_Type
(Opnd_Type
)
12469 or else Opnd_Type
= Any_Composite
12470 or else Opnd_Type
= Any_String
12473 ("illegal operand for array conversion", Operand
);
12477 return Valid_Array_Conversion
;
12480 -- Ada 2005 (AI-251): Internally generated conversions of access to
12481 -- interface types added to force the displacement of the pointer to
12482 -- reference the corresponding dispatch table.
12484 elsif not Comes_From_Source
(N
)
12485 and then Is_Access_Type
(Target_Type
)
12486 and then Is_Interface
(Designated_Type
(Target_Type
))
12490 -- Ada 2005 (AI-251): Anonymous access types where target references an
12493 elsif Is_Access_Type
(Opnd_Type
)
12494 and then Ekind_In
(Target_Type
, E_General_Access_Type
,
12495 E_Anonymous_Access_Type
)
12496 and then Is_Interface
(Directly_Designated_Type
(Target_Type
))
12498 -- Check the static accessibility rule of 4.6(17). Note that the
12499 -- check is not enforced when within an instance body, since the
12500 -- RM requires such cases to be caught at run time.
12502 -- If the operand is a rewriting of an allocator no check is needed
12503 -- because there are no accessibility issues.
12505 if Nkind
(Original_Node
(N
)) = N_Allocator
then
12508 elsif Ekind
(Target_Type
) /= E_Anonymous_Access_Type
then
12509 if Type_Access_Level
(Opnd_Type
) >
12510 Deepest_Type_Access_Level
(Target_Type
)
12512 -- In an instance, this is a run-time check, but one we know
12513 -- will fail, so generate an appropriate warning. The raise
12514 -- will be generated by Expand_N_Type_Conversion.
12516 if In_Instance_Body
then
12517 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12519 ("cannot convert local pointer to non-local access type<<",
12521 Conversion_Error_N
("\Program_Error [<<", Operand
);
12525 ("cannot convert local pointer to non-local access type",
12530 -- Special accessibility checks are needed in the case of access
12531 -- discriminants declared for a limited type.
12533 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12534 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12536 -- When the operand is a selected access discriminant the check
12537 -- needs to be made against the level of the object denoted by
12538 -- the prefix of the selected name (Object_Access_Level handles
12539 -- checking the prefix of the operand for this case).
12541 if Nkind
(Operand
) = N_Selected_Component
12542 and then Object_Access_Level
(Operand
) >
12543 Deepest_Type_Access_Level
(Target_Type
)
12545 -- In an instance, this is a run-time check, but one we know
12546 -- will fail, so generate an appropriate warning. The raise
12547 -- will be generated by Expand_N_Type_Conversion.
12549 if In_Instance_Body
then
12550 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12552 ("cannot convert access discriminant to non-local "
12553 & "access type<<", Operand
);
12554 Conversion_Error_N
("\Program_Error [<<", Operand
);
12556 -- Real error if not in instance body
12560 ("cannot convert access discriminant to non-local "
12561 & "access type", Operand
);
12566 -- The case of a reference to an access discriminant from
12567 -- within a limited type declaration (which will appear as
12568 -- a discriminal) is always illegal because the level of the
12569 -- discriminant is considered to be deeper than any (nameable)
12572 if Is_Entity_Name
(Operand
)
12573 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12575 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
12576 and then Present
(Discriminal_Link
(Entity
(Operand
)))
12579 ("discriminant has deeper accessibility level than target",
12588 -- General and anonymous access types
12590 elsif Ekind_In
(Target_Type
, E_General_Access_Type
,
12591 E_Anonymous_Access_Type
)
12594 (Is_Access_Type
(Opnd_Type
)
12596 Ekind_In
(Opnd_Type
, E_Access_Subprogram_Type
,
12597 E_Access_Protected_Subprogram_Type
),
12598 "must be an access-to-object type")
12600 if Is_Access_Constant
(Opnd_Type
)
12601 and then not Is_Access_Constant
(Target_Type
)
12604 ("access-to-constant operand type not allowed", Operand
);
12608 -- Check the static accessibility rule of 4.6(17). Note that the
12609 -- check is not enforced when within an instance body, since the RM
12610 -- requires such cases to be caught at run time.
12612 if Ekind
(Target_Type
) /= E_Anonymous_Access_Type
12613 or else Is_Local_Anonymous_Access
(Target_Type
)
12614 or else Nkind
(Associated_Node_For_Itype
(Target_Type
)) =
12615 N_Object_Declaration
12617 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12618 -- conversions from an anonymous access type to a named general
12619 -- access type. Such conversions are not allowed in the case of
12620 -- access parameters and stand-alone objects of an anonymous
12621 -- access type. The implicit conversion case is recognized by
12622 -- testing that Comes_From_Source is False and that it's been
12623 -- rewritten. The Comes_From_Source test isn't sufficient because
12624 -- nodes in inlined calls to predefined library routines can have
12625 -- Comes_From_Source set to False. (Is there a better way to test
12626 -- for implicit conversions???)
12628 if Ada_Version
>= Ada_2012
12629 and then not Comes_From_Source
(N
)
12630 and then N
/= Original_Node
(N
)
12631 and then Ekind
(Target_Type
) = E_General_Access_Type
12632 and then Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12634 if Is_Itype
(Opnd_Type
) then
12636 -- Implicit conversions aren't allowed for objects of an
12637 -- anonymous access type, since such objects have nonstatic
12638 -- levels in Ada 2012.
12640 if Nkind
(Associated_Node_For_Itype
(Opnd_Type
)) =
12641 N_Object_Declaration
12644 ("implicit conversion of stand-alone anonymous "
12645 & "access object not allowed", Operand
);
12648 -- Implicit conversions aren't allowed for anonymous access
12649 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12650 -- is done to exclude anonymous access results.
12652 elsif not Is_Local_Anonymous_Access
(Opnd_Type
)
12653 and then Nkind_In
(Associated_Node_For_Itype
(Opnd_Type
),
12654 N_Function_Specification
,
12655 N_Procedure_Specification
)
12658 ("implicit conversion of anonymous access formal "
12659 & "not allowed", Operand
);
12662 -- This is a case where there's an enclosing object whose
12663 -- to which the "statically deeper than" relationship does
12664 -- not apply (such as an access discriminant selected from
12665 -- a dereference of an access parameter).
12667 elsif Object_Access_Level
(Operand
)
12668 = Scope_Depth
(Standard_Standard
)
12671 ("implicit conversion of anonymous access value "
12672 & "not allowed", Operand
);
12675 -- In other cases, the level of the operand's type must be
12676 -- statically less deep than that of the target type, else
12677 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12679 elsif Type_Access_Level
(Opnd_Type
) >
12680 Deepest_Type_Access_Level
(Target_Type
)
12683 ("implicit conversion of anonymous access value "
12684 & "violates accessibility", Operand
);
12689 elsif Type_Access_Level
(Opnd_Type
) >
12690 Deepest_Type_Access_Level
(Target_Type
)
12692 -- In an instance, this is a run-time check, but one we know
12693 -- will fail, so generate an appropriate warning. The raise
12694 -- will be generated by Expand_N_Type_Conversion.
12696 if In_Instance_Body
then
12697 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12699 ("cannot convert local pointer to non-local access type<<",
12701 Conversion_Error_N
("\Program_Error [<<", Operand
);
12703 -- If not in an instance body, this is a real error
12706 -- Avoid generation of spurious error message
12708 if not Error_Posted
(N
) then
12710 ("cannot convert local pointer to non-local access type",
12717 -- Special accessibility checks are needed in the case of access
12718 -- discriminants declared for a limited type.
12720 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12721 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12723 -- When the operand is a selected access discriminant the check
12724 -- needs to be made against the level of the object denoted by
12725 -- the prefix of the selected name (Object_Access_Level handles
12726 -- checking the prefix of the operand for this case).
12728 if Nkind
(Operand
) = N_Selected_Component
12729 and then Object_Access_Level
(Operand
) >
12730 Deepest_Type_Access_Level
(Target_Type
)
12732 -- In an instance, this is a run-time check, but one we know
12733 -- will fail, so generate an appropriate warning. The raise
12734 -- will be generated by Expand_N_Type_Conversion.
12736 if In_Instance_Body
then
12737 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12739 ("cannot convert access discriminant to non-local "
12740 & "access type<<", Operand
);
12741 Conversion_Error_N
("\Program_Error [<<", Operand
);
12743 -- If not in an instance body, this is a real error
12747 ("cannot convert access discriminant to non-local "
12748 & "access type", Operand
);
12753 -- The case of a reference to an access discriminant from
12754 -- within a limited type declaration (which will appear as
12755 -- a discriminal) is always illegal because the level of the
12756 -- discriminant is considered to be deeper than any (nameable)
12759 if Is_Entity_Name
(Operand
)
12761 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
12762 and then Present
(Discriminal_Link
(Entity
(Operand
)))
12765 ("discriminant has deeper accessibility level than target",
12772 -- In the presence of limited_with clauses we have to use nonlimited
12773 -- views, if available.
12775 Check_Limited
: declare
12776 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
;
12777 -- Helper function to handle limited views
12779 --------------------------
12780 -- Full_Designated_Type --
12781 --------------------------
12783 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
is
12784 Desig
: constant Entity_Id
:= Designated_Type
(T
);
12787 -- Handle the limited view of a type
12789 if From_Limited_With
(Desig
)
12790 and then Has_Non_Limited_View
(Desig
)
12792 return Available_View
(Desig
);
12796 end Full_Designated_Type
;
12798 -- Local Declarations
12800 Target
: constant Entity_Id
:= Full_Designated_Type
(Target_Type
);
12801 Opnd
: constant Entity_Id
:= Full_Designated_Type
(Opnd_Type
);
12803 Same_Base
: constant Boolean :=
12804 Base_Type
(Target
) = Base_Type
(Opnd
);
12806 -- Start of processing for Check_Limited
12809 if Is_Tagged_Type
(Target
) then
12810 return Valid_Tagged_Conversion
(Target
, Opnd
);
12813 if not Same_Base
then
12814 Conversion_Error_NE
12815 ("target designated type not compatible with }",
12816 N
, Base_Type
(Opnd
));
12819 -- Ada 2005 AI-384: legality rule is symmetric in both
12820 -- designated types. The conversion is legal (with possible
12821 -- constraint check) if either designated type is
12824 elsif Subtypes_Statically_Match
(Target
, Opnd
)
12826 (Has_Discriminants
(Target
)
12828 (not Is_Constrained
(Opnd
)
12829 or else not Is_Constrained
(Target
)))
12831 -- Special case, if Value_Size has been used to make the
12832 -- sizes different, the conversion is not allowed even
12833 -- though the subtypes statically match.
12835 if Known_Static_RM_Size
(Target
)
12836 and then Known_Static_RM_Size
(Opnd
)
12837 and then RM_Size
(Target
) /= RM_Size
(Opnd
)
12839 Conversion_Error_NE
12840 ("target designated subtype not compatible with }",
12842 Conversion_Error_NE
12843 ("\because sizes of the two designated subtypes differ",
12847 -- Normal case where conversion is allowed
12855 ("target designated subtype not compatible with }",
12862 -- Access to subprogram types. If the operand is an access parameter,
12863 -- the type has a deeper accessibility that any master, and cannot be
12864 -- assigned. We must make an exception if the conversion is part of an
12865 -- assignment and the target is the return object of an extended return
12866 -- statement, because in that case the accessibility check takes place
12867 -- after the return.
12869 elsif Is_Access_Subprogram_Type
(Target_Type
)
12871 -- Note: this test of Opnd_Type is there to prevent entering this
12872 -- branch in the case of a remote access to subprogram type, which
12873 -- is internally represented as an E_Record_Type.
12875 and then Is_Access_Type
(Opnd_Type
)
12877 if Ekind
(Base_Type
(Opnd_Type
)) = E_Anonymous_Access_Subprogram_Type
12878 and then Is_Entity_Name
(Operand
)
12879 and then Ekind
(Entity
(Operand
)) = E_In_Parameter
12881 (Nkind
(Parent
(N
)) /= N_Assignment_Statement
12882 or else not Is_Entity_Name
(Name
(Parent
(N
)))
12883 or else not Is_Return_Object
(Entity
(Name
(Parent
(N
)))))
12886 ("illegal attempt to store anonymous access to subprogram",
12889 ("\value has deeper accessibility than any master "
12890 & "(RM 3.10.2 (13))",
12894 ("\use named access type for& instead of access parameter",
12895 Operand
, Entity
(Operand
));
12898 -- Check that the designated types are subtype conformant
12900 Check_Subtype_Conformant
(New_Id
=> Designated_Type
(Target_Type
),
12901 Old_Id
=> Designated_Type
(Opnd_Type
),
12904 -- Check the static accessibility rule of 4.6(20)
12906 if Type_Access_Level
(Opnd_Type
) >
12907 Deepest_Type_Access_Level
(Target_Type
)
12910 ("operand type has deeper accessibility level than target",
12913 -- Check that if the operand type is declared in a generic body,
12914 -- then the target type must be declared within that same body
12915 -- (enforces last sentence of 4.6(20)).
12917 elsif Present
(Enclosing_Generic_Body
(Opnd_Type
)) then
12919 O_Gen
: constant Node_Id
:=
12920 Enclosing_Generic_Body
(Opnd_Type
);
12925 T_Gen
:= Enclosing_Generic_Body
(Target_Type
);
12926 while Present
(T_Gen
) and then T_Gen
/= O_Gen
loop
12927 T_Gen
:= Enclosing_Generic_Body
(T_Gen
);
12930 if T_Gen
/= O_Gen
then
12932 ("target type must be declared in same generic body "
12933 & "as operand type", N
);
12940 -- Remote access to subprogram types
12942 elsif Is_Remote_Access_To_Subprogram_Type
(Target_Type
)
12943 and then Is_Remote_Access_To_Subprogram_Type
(Opnd_Type
)
12945 -- It is valid to convert from one RAS type to another provided
12946 -- that their specification statically match.
12948 -- Note: at this point, remote access to subprogram types have been
12949 -- expanded to their E_Record_Type representation, and we need to
12950 -- go back to the original access type definition using the
12951 -- Corresponding_Remote_Type attribute in order to check that the
12952 -- designated profiles match.
12954 pragma Assert
(Ekind
(Target_Type
) = E_Record_Type
);
12955 pragma Assert
(Ekind
(Opnd_Type
) = E_Record_Type
);
12957 Check_Subtype_Conformant
12959 Designated_Type
(Corresponding_Remote_Type
(Target_Type
)),
12961 Designated_Type
(Corresponding_Remote_Type
(Opnd_Type
)),
12966 -- If it was legal in the generic, it's legal in the instance
12968 elsif In_Instance_Body
then
12971 -- If both are tagged types, check legality of view conversions
12973 elsif Is_Tagged_Type
(Target_Type
)
12975 Is_Tagged_Type
(Opnd_Type
)
12977 return Valid_Tagged_Conversion
(Target_Type
, Opnd_Type
);
12979 -- Types derived from the same root type are convertible
12981 elsif Root_Type
(Target_Type
) = Root_Type
(Opnd_Type
) then
12984 -- In an instance or an inlined body, there may be inconsistent views of
12985 -- the same type, or of types derived from a common root.
12987 elsif (In_Instance
or In_Inlined_Body
)
12989 Root_Type
(Underlying_Type
(Target_Type
)) =
12990 Root_Type
(Underlying_Type
(Opnd_Type
))
12994 -- Special check for common access type error case
12996 elsif Ekind
(Target_Type
) = E_Access_Type
12997 and then Is_Access_Type
(Opnd_Type
)
12999 Conversion_Error_N
("target type must be general access type!", N
);
13000 Conversion_Error_NE
-- CODEFIX
13001 ("add ALL to }!", N
, Target_Type
);
13004 -- Here we have a real conversion error
13007 -- Check for missing regular with_clause when only a limited view of
13008 -- target is available.
13010 if From_Limited_With
(Opnd_Type
) and then In_Package_Body
then
13011 Conversion_Error_NE
13012 ("invalid conversion, not compatible with limited view of }",
13014 Conversion_Error_NE
13015 ("\add with_clause for& to current unit!", N
, Scope
(Opnd_Type
));
13017 elsif Is_Access_Type
(Opnd_Type
)
13018 and then From_Limited_With
(Designated_Type
(Opnd_Type
))
13019 and then In_Package_Body
13021 Conversion_Error_NE
13022 ("invalid conversion, not compatible with }", N
, Opnd_Type
);
13023 Conversion_Error_NE
13024 ("\add with_clause for& to current unit!",
13025 N
, Scope
(Designated_Type
(Opnd_Type
)));
13028 Conversion_Error_NE
13029 ("invalid conversion, not compatible with }", N
, Opnd_Type
);
13034 end Valid_Conversion
;