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);
2907 when N_Reduction_Expression =>
2909 -- Resolve (Expression (N), Ctx_Type);
2911 when N_Reduction_Expression_Parameter =>
2915 Resolve_Reference (N, Ctx_Type);
2917 when N_Selected_Component =>
2918 Resolve_Selected_Component (N, Ctx_Type);
2921 Resolve_Slice (N, Ctx_Type);
2923 when N_String_Literal =>
2924 Resolve_String_Literal (N, Ctx_Type);
2926 when N_Target_Name =>
2927 Resolve_Target_Name (N, Ctx_Type);
2929 when N_Type_Conversion =>
2930 Resolve_Type_Conversion (N, Ctx_Type);
2932 when N_Unchecked_Expression =>
2933 Resolve_Unchecked_Expression (N, Ctx_Type);
2935 when N_Unchecked_Type_Conversion =>
2936 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2939 -- Mark relevant use-type and use-package clauses as effective using
2940 -- the original node because constant folding may have occured and
2941 -- removed references that need to be examined.
2943 if Nkind (Original_Node (N)) in N_Op then
2944 Mark_Use_Clauses (Original_Node (N));
2947 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2948 -- expression of an anonymous access type that occurs in the context
2949 -- of a named general access type, except when the expression is that
2950 -- of a membership test. This ensures proper legality checking in
2951 -- terms of allowed conversions (expressions that would be illegal to
2952 -- convert implicitly are allowed in membership tests).
2954 if Ada_Version >= Ada_2012
2955 and then Ekind (Ctx_Type) = E_General_Access_Type
2956 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
2957 and then Nkind (Parent (N)) not in N_Membership_Test
2959 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
2960 Analyze_And_Resolve (N, Ctx_Type);
2963 -- If the subexpression was replaced by a non-subexpression, then
2964 -- all we do is to expand it. The only legitimate case we know of
2965 -- is converting procedure call statement to entry call statements,
2966 -- but there may be others, so we are making this test general.
2968 if Nkind (N) not in N_Subexpr then
2969 Debug_A_Exit ("resolving ", N, " (done)");
2974 -- The expression is definitely NOT overloaded at this point, so
2975 -- we reset the Is_Overloaded flag to avoid any confusion when
2976 -- reanalyzing the node.
2978 Set_Is_Overloaded (N, False);
2980 -- Freeze expression type, entity if it is a name, and designated
2981 -- type if it is an allocator (RM 13.14(10,11,13)).
2983 -- Now that the resolution of the type of the node is complete, and
2984 -- we did not detect an error, we can expand this node. We skip the
2985 -- expand call if we are in a default expression, see section
2986 -- "Handling of Default Expressions" in Sem spec.
2988 Debug_A_Exit ("resolving ", N, " (done)");
2990 -- We unconditionally freeze the expression, even if we are in
2991 -- default expression mode (the Freeze_Expression routine tests this
2992 -- flag and only freezes static types if it is set).
2994 -- Ada 2012 (AI05-177): The declaration of an expression function
2995 -- does not cause freezing, but we never reach here in that case.
2996 -- Here we are resolving the corresponding expanded body, so we do
2997 -- need to perform normal freezing.
2999 -- As elsewhere we do not emit freeze node within a generic. We make
3000 -- an exception for entities that are expressions, only to detect
3001 -- misuses of deferred constants and preserve the output of various
3004 if not Inside_A_Generic or else Is_Entity_Name (N) then
3005 Freeze_Expression (N);
3008 -- Now we can do the expansion
3018 -- Version with check(s) suppressed
3020 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3022 if Suppress = All_Checks then
3024 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3026 Scope_Suppress.Suppress := (others => True);
3028 Scope_Suppress.Suppress := Sva;
3033 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3035 Scope_Suppress.Suppress (Suppress) := True;
3037 Scope_Suppress.Suppress (Suppress) := Svg;
3046 -- Version with implicit type
3048 procedure Resolve (N : Node_Id) is
3050 Resolve (N, Etype (N));
3053 ---------------------
3054 -- Resolve_Actuals --
3055 ---------------------
3057 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3058 Loc : constant Source_Ptr := Sloc (N);
3061 A_Typ : Entity_Id := Empty; -- init to avoid warning
3064 Prev : Node_Id := Empty;
3066 Real_F : Entity_Id := Empty; -- init to avoid warning
3068 Real_Subp : Entity_Id;
3069 -- If the subprogram being called is an inherited operation for
3070 -- a formal derived type in an instance, Real_Subp is the subprogram
3071 -- that will be called. It may have different formal names than the
3072 -- operation of the formal in the generic, so after actual is resolved
3073 -- the name of the actual in a named association must carry the name
3074 -- of the actual of the subprogram being called.
3076 procedure Check_Aliased_Parameter;
3077 -- Check rules on aliased parameters and related accessibility rules
3078 -- in (RM 3.10.2 (10.2-10.4)).
3080 procedure Check_Argument_Order;
3081 -- Performs a check for the case where the actuals are all simple
3082 -- identifiers that correspond to the formal names, but in the wrong
3083 -- order, which is considered suspicious and cause for a warning.
3085 procedure Check_Prefixed_Call;
3086 -- If the original node is an overloaded call in prefix notation,
3087 -- insert an 'Access or a dereference as needed over the first actual
.
3088 -- Try_Object_Operation has already verified that there is a valid
3089 -- interpretation, but the form of the actual can only be determined
3090 -- once the primitive operation is identified.
3092 procedure Flag_Effectively_Volatile_Objects
(Expr
: Node_Id
);
3093 -- Emit an error concerning the illegal usage of an effectively volatile
3094 -- object in interfering context (SPARK RM 7.13(12)).
3096 procedure Insert_Default
;
3097 -- If the actual is missing in a call, insert in the actuals list
3098 -- an instance of the default expression. The insertion is always
3099 -- a named association.
3101 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean;
3102 -- Check whether T1 and T2, or their full views, are derived from a
3103 -- common type. Used to enforce the restrictions on array conversions
3106 function Static_Concatenation
(N
: Node_Id
) return Boolean;
3107 -- Predicate to determine whether an actual that is a concatenation
3108 -- will be evaluated statically and does not need a transient scope.
3109 -- This must be determined before the actual is resolved and expanded
3110 -- because if needed the transient scope must be introduced earlier.
3112 -----------------------------
3113 -- Check_Aliased_Parameter --
3114 -----------------------------
3116 procedure Check_Aliased_Parameter
is
3117 Nominal_Subt
: Entity_Id
;
3120 if Is_Aliased
(F
) then
3121 if Is_Tagged_Type
(A_Typ
) then
3124 elsif Is_Aliased_View
(A
) then
3125 if Is_Constr_Subt_For_U_Nominal
(A_Typ
) then
3126 Nominal_Subt
:= Base_Type
(A_Typ
);
3128 Nominal_Subt
:= A_Typ
;
3131 if Subtypes_Statically_Match
(F_Typ
, Nominal_Subt
) then
3134 -- In a generic body assume the worst for generic formals:
3135 -- they can have a constrained partial view (AI05-041).
3137 elsif Has_Discriminants
(F_Typ
)
3138 and then not Is_Constrained
(F_Typ
)
3139 and then not Has_Constrained_Partial_View
(F_Typ
)
3140 and then not Is_Generic_Type
(F_Typ
)
3145 Error_Msg_NE
("untagged actual does not match "
3146 & "aliased formal&", A
, F
);
3150 Error_Msg_NE
("actual for aliased formal& must be "
3151 & "aliased object", A
, F
);
3154 if Ekind
(Nam
) = E_Procedure
then
3157 elsif Ekind
(Etype
(Nam
)) = E_Anonymous_Access_Type
then
3158 if Nkind
(Parent
(N
)) = N_Type_Conversion
3159 and then Type_Access_Level
(Etype
(Parent
(N
))) <
3160 Object_Access_Level
(A
)
3162 Error_Msg_N
("aliased actual has wrong accessibility", A
);
3165 elsif Nkind
(Parent
(N
)) = N_Qualified_Expression
3166 and then Nkind
(Parent
(Parent
(N
))) = N_Allocator
3167 and then Type_Access_Level
(Etype
(Parent
(Parent
(N
)))) <
3168 Object_Access_Level
(A
)
3171 ("aliased actual in allocator has wrong accessibility", A
);
3174 end Check_Aliased_Parameter
;
3176 --------------------------
3177 -- Check_Argument_Order --
3178 --------------------------
3180 procedure Check_Argument_Order
is
3182 -- Nothing to do if no parameters, or original node is neither a
3183 -- function call nor a procedure call statement (happens in the
3184 -- operator-transformed-to-function call case), or the call does
3185 -- not come from source, or this warning is off.
3187 if not Warn_On_Parameter_Order
3188 or else No
(Parameter_Associations
(N
))
3189 or else Nkind
(Original_Node
(N
)) not in N_Subprogram_Call
3190 or else not Comes_From_Source
(N
)
3196 Nargs
: constant Nat
:= List_Length
(Parameter_Associations
(N
));
3199 -- Nothing to do if only one parameter
3205 -- Here if at least two arguments
3208 Actuals
: array (1 .. Nargs
) of Node_Id
;
3212 Wrong_Order
: Boolean := False;
3213 -- Set True if an out of order case is found
3216 -- Collect identifier names of actuals, fail if any actual is
3217 -- not a simple identifier, and record max length of name.
3219 Actual
:= First
(Parameter_Associations
(N
));
3220 for J
in Actuals
'Range loop
3221 if Nkind
(Actual
) /= N_Identifier
then
3224 Actuals
(J
) := Actual
;
3229 -- If we got this far, all actuals are identifiers and the list
3230 -- of their names is stored in the Actuals array.
3232 Formal
:= First_Formal
(Nam
);
3233 for J
in Actuals
'Range loop
3235 -- If we ran out of formals, that's odd, probably an error
3236 -- which will be detected elsewhere, but abandon the search.
3242 -- If name matches and is in order OK
3244 if Chars
(Formal
) = Chars
(Actuals
(J
)) then
3248 -- If no match, see if it is elsewhere in list and if so
3249 -- flag potential wrong order if type is compatible.
3251 for K
in Actuals
'Range loop
3252 if Chars
(Formal
) = Chars
(Actuals
(K
))
3254 Has_Compatible_Type
(Actuals
(K
), Etype
(Formal
))
3256 Wrong_Order
:= True;
3266 <<Continue
>> Next_Formal
(Formal
);
3269 -- If Formals left over, also probably an error, skip warning
3271 if Present
(Formal
) then
3275 -- Here we give the warning if something was out of order
3279 ("?P?actuals for this call may be in wrong order", N
);
3283 end Check_Argument_Order
;
3285 -------------------------
3286 -- Check_Prefixed_Call --
3287 -------------------------
3289 procedure Check_Prefixed_Call
is
3290 Act
: constant Node_Id
:= First_Actual
(N
);
3291 A_Type
: constant Entity_Id
:= Etype
(Act
);
3292 F_Type
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
3293 Orig
: constant Node_Id
:= Original_Node
(N
);
3297 -- Check whether the call is a prefixed call, with or without
3298 -- additional actuals.
3300 if Nkind
(Orig
) = N_Selected_Component
3302 (Nkind
(Orig
) = N_Indexed_Component
3303 and then Nkind
(Prefix
(Orig
)) = N_Selected_Component
3304 and then Is_Entity_Name
(Prefix
(Prefix
(Orig
)))
3305 and then Is_Entity_Name
(Act
)
3306 and then Chars
(Act
) = Chars
(Prefix
(Prefix
(Orig
))))
3308 if Is_Access_Type
(A_Type
)
3309 and then not Is_Access_Type
(F_Type
)
3311 -- Introduce dereference on object in prefix
3314 Make_Explicit_Dereference
(Sloc
(Act
),
3315 Prefix
=> Relocate_Node
(Act
));
3316 Rewrite
(Act
, New_A
);
3319 elsif Is_Access_Type
(F_Type
)
3320 and then not Is_Access_Type
(A_Type
)
3322 -- Introduce an implicit 'Access in prefix
3324 if not Is_Aliased_View
(Act
) then
3326 ("object in prefixed call to& must be aliased "
3327 & "(RM 4.1.3 (13 1/2))",
3332 Make_Attribute_Reference
(Loc
,
3333 Attribute_Name
=> Name_Access
,
3334 Prefix
=> Relocate_Node
(Act
)));
3339 end Check_Prefixed_Call
;
3341 ---------------------------------------
3342 -- Flag_Effectively_Volatile_Objects --
3343 ---------------------------------------
3345 procedure Flag_Effectively_Volatile_Objects
(Expr
: Node_Id
) is
3346 function Flag_Object
(N
: Node_Id
) return Traverse_Result
;
3347 -- Determine whether arbitrary node N denotes an effectively volatile
3348 -- object and if it does, emit an error.
3354 function Flag_Object
(N
: Node_Id
) return Traverse_Result
is
3358 -- Do not consider nested function calls because they have already
3359 -- been processed during their own resolution.
3361 if Nkind
(N
) = N_Function_Call
then
3364 elsif Is_Entity_Name
(N
) and then Present
(Entity
(N
)) then
3368 and then Is_Effectively_Volatile
(Id
)
3369 and then (Async_Writers_Enabled
(Id
)
3370 or else Effective_Reads_Enabled
(Id
))
3373 ("volatile object cannot appear in this context (SPARK "
3374 & "RM 7.1.3(11))", N
);
3382 procedure Flag_Objects
is new Traverse_Proc
(Flag_Object
);
3384 -- Start of processing for Flag_Effectively_Volatile_Objects
3387 Flag_Objects
(Expr
);
3388 end Flag_Effectively_Volatile_Objects
;
3390 --------------------
3391 -- Insert_Default --
3392 --------------------
3394 procedure Insert_Default
is
3399 -- Missing argument in call, nothing to insert
3401 if No
(Default_Value
(F
)) then
3405 -- Note that we do a full New_Copy_Tree, so that any associated
3406 -- Itypes are properly copied. This may not be needed any more,
3407 -- but it does no harm as a safety measure. Defaults of a generic
3408 -- formal may be out of bounds of the corresponding actual (see
3409 -- cc1311b) and an additional check may be required.
3414 New_Scope
=> Current_Scope
,
3417 -- Propagate dimension information, if any.
3419 Copy_Dimensions
(Default_Value
(F
), Actval
);
3421 if Is_Concurrent_Type
(Scope
(Nam
))
3422 and then Has_Discriminants
(Scope
(Nam
))
3424 Replace_Actual_Discriminants
(N
, Actval
);
3427 if Is_Overloadable
(Nam
)
3428 and then Present
(Alias
(Nam
))
3430 if Base_Type
(Etype
(F
)) /= Base_Type
(Etype
(Actval
))
3431 and then not Is_Tagged_Type
(Etype
(F
))
3433 -- If default is a real literal, do not introduce a
3434 -- conversion whose effect may depend on the run-time
3435 -- size of universal real.
3437 if Nkind
(Actval
) = N_Real_Literal
then
3438 Set_Etype
(Actval
, Base_Type
(Etype
(F
)));
3440 Actval
:= Unchecked_Convert_To
(Etype
(F
), Actval
);
3444 if Is_Scalar_Type
(Etype
(F
)) then
3445 Enable_Range_Check
(Actval
);
3448 Set_Parent
(Actval
, N
);
3450 -- Resolve aggregates with their base type, to avoid scope
3451 -- anomalies: the subtype was first built in the subprogram
3452 -- declaration, and the current call may be nested.
3454 if Nkind
(Actval
) = N_Aggregate
then
3455 Analyze_And_Resolve
(Actval
, Etype
(F
));
3457 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3461 Set_Parent
(Actval
, N
);
3463 -- See note above concerning aggregates
3465 if Nkind
(Actval
) = N_Aggregate
3466 and then Has_Discriminants
(Etype
(Actval
))
3468 Analyze_And_Resolve
(Actval
, Base_Type
(Etype
(Actval
)));
3470 -- Resolve entities with their own type, which may differ from
3471 -- the type of a reference in a generic context (the view
3472 -- swapping mechanism did not anticipate the re-analysis of
3473 -- default values in calls).
3475 elsif Is_Entity_Name
(Actval
) then
3476 Analyze_And_Resolve
(Actval
, Etype
(Entity
(Actval
)));
3479 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3483 -- If default is a tag indeterminate function call, propagate tag
3484 -- to obtain proper dispatching.
3486 if Is_Controlling_Formal
(F
)
3487 and then Nkind
(Default_Value
(F
)) = N_Function_Call
3489 Set_Is_Controlling_Actual
(Actval
);
3493 -- If the default expression raises constraint error, then just
3494 -- silently replace it with an N_Raise_Constraint_Error node, since
3495 -- we already gave the warning on the subprogram spec. If node is
3496 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3497 -- the warnings removal machinery.
3499 if Raises_Constraint_Error
(Actval
)
3500 and then Nkind
(Actval
) /= N_Raise_Constraint_Error
3503 Make_Raise_Constraint_Error
(Loc
,
3504 Reason
=> CE_Range_Check_Failed
));
3506 Set_Raises_Constraint_Error
(Actval
);
3507 Set_Etype
(Actval
, Etype
(F
));
3511 Make_Parameter_Association
(Loc
,
3512 Explicit_Actual_Parameter
=> Actval
,
3513 Selector_Name
=> Make_Identifier
(Loc
, Chars
(F
)));
3515 -- Case of insertion is first named actual
3518 or else Nkind
(Parent
(Prev
)) /= N_Parameter_Association
3520 Set_Next_Named_Actual
(Assoc
, First_Named_Actual
(N
));
3521 Set_First_Named_Actual
(N
, Actval
);
3524 if No
(Parameter_Associations
(N
)) then
3525 Set_Parameter_Associations
(N
, New_List
(Assoc
));
3527 Append
(Assoc
, Parameter_Associations
(N
));
3531 Insert_After
(Prev
, Assoc
);
3534 -- Case of insertion is not first named actual
3537 Set_Next_Named_Actual
3538 (Assoc
, Next_Named_Actual
(Parent
(Prev
)));
3539 Set_Next_Named_Actual
(Parent
(Prev
), Actval
);
3540 Append
(Assoc
, Parameter_Associations
(N
));
3543 Mark_Rewrite_Insertion
(Assoc
);
3544 Mark_Rewrite_Insertion
(Actval
);
3553 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean is
3554 FT1
: Entity_Id
:= T1
;
3555 FT2
: Entity_Id
:= T2
;
3558 if Is_Private_Type
(T1
)
3559 and then Present
(Full_View
(T1
))
3561 FT1
:= Full_View
(T1
);
3564 if Is_Private_Type
(T2
)
3565 and then Present
(Full_View
(T2
))
3567 FT2
:= Full_View
(T2
);
3570 return Root_Type
(Base_Type
(FT1
)) = Root_Type
(Base_Type
(FT2
));
3573 --------------------------
3574 -- Static_Concatenation --
3575 --------------------------
3577 function Static_Concatenation
(N
: Node_Id
) return Boolean is
3580 when N_String_Literal
=>
3585 -- Concatenation is static when both operands are static and
3586 -- the concatenation operator is a predefined one.
3588 return Scope
(Entity
(N
)) = Standard_Standard
3590 Static_Concatenation
(Left_Opnd
(N
))
3592 Static_Concatenation
(Right_Opnd
(N
));
3595 if Is_Entity_Name
(N
) then
3597 Ent
: constant Entity_Id
:= Entity
(N
);
3599 return Ekind
(Ent
) = E_Constant
3600 and then Present
(Constant_Value
(Ent
))
3602 Is_OK_Static_Expression
(Constant_Value
(Ent
));
3609 end Static_Concatenation
;
3611 -- Start of processing for Resolve_Actuals
3614 Check_Argument_Order
;
3616 if Is_Overloadable
(Nam
)
3617 and then Is_Inherited_Operation
(Nam
)
3618 and then In_Instance
3619 and then Present
(Alias
(Nam
))
3620 and then Present
(Overridden_Operation
(Alias
(Nam
)))
3622 Real_Subp
:= Alias
(Nam
);
3627 if Present
(First_Actual
(N
)) then
3628 Check_Prefixed_Call
;
3631 A
:= First_Actual
(N
);
3632 F
:= First_Formal
(Nam
);
3634 if Present
(Real_Subp
) then
3635 Real_F
:= First_Formal
(Real_Subp
);
3638 while Present
(F
) loop
3639 if No
(A
) and then Needs_No_Actuals
(Nam
) then
3642 -- If we have an error in any actual or formal, indicated by a type
3643 -- of Any_Type, then abandon resolution attempt, and set result type
3644 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3645 -- type is imposed from context.
3647 elsif (Present
(A
) and then Etype
(A
) = Any_Type
)
3648 or else Etype
(F
) = Any_Type
3650 if Nkind
(A
) /= N_Raise_Expression
then
3651 Set_Etype
(N
, Any_Type
);
3656 -- Case where actual is present
3658 -- If the actual is an entity, generate a reference to it now. We
3659 -- do this before the actual is resolved, because a formal of some
3660 -- protected subprogram, or a task discriminant, will be rewritten
3661 -- during expansion, and the source entity reference may be lost.
3664 and then Is_Entity_Name
(A
)
3665 and then Comes_From_Source
(A
)
3667 -- Annotate the tree by creating a variable reference marker when
3668 -- the actual denotes a variable reference, in case the reference
3669 -- is folded or optimized away. The variable reference marker is
3670 -- automatically saved for later examination by the ABE Processing
3671 -- phase. The status of the reference is set as follows:
3675 -- write IN OUT, OUT
3677 Build_Variable_Reference_Marker
3679 Read
=> Ekind
(F
) /= E_Out_Parameter
,
3680 Write
=> Ekind
(F
) /= E_In_Parameter
);
3682 Orig_A
:= Entity
(A
);
3684 if Present
(Orig_A
) then
3685 if Is_Formal
(Orig_A
)
3686 and then Ekind
(F
) /= E_In_Parameter
3688 Generate_Reference
(Orig_A
, A
, 'm');
3690 elsif not Is_Overloaded
(A
) then
3691 if Ekind
(F
) /= E_Out_Parameter
then
3692 Generate_Reference
(Orig_A
, A
);
3694 -- RM 6.4.1(12): For an out parameter that is passed by
3695 -- copy, the formal parameter object is created, and:
3697 -- * For an access type, the formal parameter is initialized
3698 -- from the value of the actual, without checking that the
3699 -- value satisfies any constraint, any predicate, or any
3700 -- exclusion of the null value.
3702 -- * For a scalar type that has the Default_Value aspect
3703 -- specified, the formal parameter is initialized from the
3704 -- value of the actual, without checking that the value
3705 -- satisfies any constraint or any predicate.
3706 -- I do not understand why this case is included??? this is
3707 -- not a case where an OUT parameter is treated as IN OUT.
3709 -- * For a composite type with discriminants or that has
3710 -- implicit initial values for any subcomponents, the
3711 -- behavior is as for an in out parameter passed by copy.
3713 -- Hence for these cases we generate the read reference now
3714 -- (the write reference will be generated later by
3715 -- Note_Possible_Modification).
3717 elsif Is_By_Copy_Type
(Etype
(F
))
3719 (Is_Access_Type
(Etype
(F
))
3721 (Is_Scalar_Type
(Etype
(F
))
3723 Present
(Default_Aspect_Value
(Etype
(F
))))
3725 (Is_Composite_Type
(Etype
(F
))
3726 and then (Has_Discriminants
(Etype
(F
))
3727 or else Is_Partially_Initialized_Type
3730 Generate_Reference
(Orig_A
, A
);
3737 and then (Nkind
(Parent
(A
)) /= N_Parameter_Association
3738 or else Chars
(Selector_Name
(Parent
(A
))) = Chars
(F
))
3740 -- If style checking mode on, check match of formal name
3743 if Nkind
(Parent
(A
)) = N_Parameter_Association
then
3744 Check_Identifier
(Selector_Name
(Parent
(A
)), F
);
3748 -- If the formal is Out or In_Out, do not resolve and expand the
3749 -- conversion, because it is subsequently expanded into explicit
3750 -- temporaries and assignments. However, the object of the
3751 -- conversion can be resolved. An exception is the case of tagged
3752 -- type conversion with a class-wide actual. In that case we want
3753 -- the tag check to occur and no temporary will be needed (no
3754 -- representation change can occur) and the parameter is passed by
3755 -- reference, so we go ahead and resolve the type conversion.
3756 -- Another exception is the case of reference to component or
3757 -- subcomponent of a bit-packed array, in which case we want to
3758 -- defer expansion to the point the in and out assignments are
3761 if Ekind
(F
) /= E_In_Parameter
3762 and then Nkind
(A
) = N_Type_Conversion
3763 and then not Is_Class_Wide_Type
(Etype
(Expression
(A
)))
3765 if Ekind
(F
) = E_In_Out_Parameter
3766 and then Is_Array_Type
(Etype
(F
))
3768 -- In a view conversion, the conversion must be legal in
3769 -- both directions, and thus both component types must be
3770 -- aliased, or neither (4.6 (8)).
3772 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3773 -- the privacy requirement should not apply to generic
3774 -- types, and should be checked in an instance. ARG query
3777 if Has_Aliased_Components
(Etype
(Expression
(A
))) /=
3778 Has_Aliased_Components
(Etype
(F
))
3781 ("both component types in a view conversion must be"
3782 & " aliased, or neither", A
);
3784 -- Comment here??? what set of cases???
3787 not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3789 -- Check view conv between unrelated by ref array types
3791 if Is_By_Reference_Type
(Etype
(F
))
3792 or else Is_By_Reference_Type
(Etype
(Expression
(A
)))
3795 ("view conversion between unrelated by reference "
3796 & "array types not allowed (\'A'I-00246)", A
);
3798 -- In Ada 2005 mode, check view conversion component
3799 -- type cannot be private, tagged, or volatile. Note
3800 -- that we only apply this to source conversions. The
3801 -- generated code can contain conversions which are
3802 -- not subject to this test, and we cannot extract the
3803 -- component type in such cases since it is not present.
3805 elsif Comes_From_Source
(A
)
3806 and then Ada_Version
>= Ada_2005
3809 Comp_Type
: constant Entity_Id
:=
3811 (Etype
(Expression
(A
)));
3813 if (Is_Private_Type
(Comp_Type
)
3814 and then not Is_Generic_Type
(Comp_Type
))
3815 or else Is_Tagged_Type
(Comp_Type
)
3816 or else Is_Volatile
(Comp_Type
)
3819 ("component type of a view conversion cannot"
3820 & " be private, tagged, or volatile"
3829 -- Resolve expression if conversion is all OK
3831 if (Conversion_OK
(A
)
3832 or else Valid_Conversion
(A
, Etype
(A
), Expression
(A
)))
3833 and then not Is_Ref_To_Bit_Packed_Array
(Expression
(A
))
3835 Resolve
(Expression
(A
));
3838 -- If the actual is a function call that returns a limited
3839 -- unconstrained object that needs finalization, create a
3840 -- transient scope for it, so that it can receive the proper
3841 -- finalization list.
3843 elsif Expander_Active
3844 and then Nkind
(A
) = N_Function_Call
3845 and then Is_Limited_Record
(Etype
(F
))
3846 and then not Is_Constrained
(Etype
(F
))
3847 and then (Needs_Finalization
(Etype
(F
))
3848 or else Has_Task
(Etype
(F
)))
3850 Establish_Transient_Scope
(A
, Manage_Sec_Stack
=> False);
3851 Resolve
(A
, Etype
(F
));
3853 -- A small optimization: if one of the actuals is a concatenation
3854 -- create a block around a procedure call to recover stack space.
3855 -- This alleviates stack usage when several procedure calls in
3856 -- the same statement list use concatenation. We do not perform
3857 -- this wrapping for code statements, where the argument is a
3858 -- static string, and we want to preserve warnings involving
3859 -- sequences of such statements.
3861 elsif Expander_Active
3862 and then Nkind
(A
) = N_Op_Concat
3863 and then Nkind
(N
) = N_Procedure_Call_Statement
3864 and then not (Is_Intrinsic_Subprogram
(Nam
)
3865 and then Chars
(Nam
) = Name_Asm
)
3866 and then not Static_Concatenation
(A
)
3868 Establish_Transient_Scope
(A
, Manage_Sec_Stack
=> False);
3869 Resolve
(A
, Etype
(F
));
3872 if Nkind
(A
) = N_Type_Conversion
3873 and then Is_Array_Type
(Etype
(F
))
3874 and then not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3876 (Is_Limited_Type
(Etype
(F
))
3877 or else Is_Limited_Type
(Etype
(Expression
(A
))))
3880 ("conversion between unrelated limited array types not "
3881 & "allowed ('A'I-00246)", A
);
3883 if Is_Limited_Type
(Etype
(F
)) then
3884 Explain_Limited_Type
(Etype
(F
), A
);
3887 if Is_Limited_Type
(Etype
(Expression
(A
))) then
3888 Explain_Limited_Type
(Etype
(Expression
(A
)), A
);
3892 -- (Ada 2005: AI-251): If the actual is an allocator whose
3893 -- directly designated type is a class-wide interface, we build
3894 -- an anonymous access type to use it as the type of the
3895 -- allocator. Later, when the subprogram call is expanded, if
3896 -- the interface has a secondary dispatch table the expander
3897 -- will add a type conversion to force the correct displacement
3900 if Nkind
(A
) = N_Allocator
then
3902 DDT
: constant Entity_Id
:=
3903 Directly_Designated_Type
(Base_Type
(Etype
(F
)));
3905 New_Itype
: Entity_Id
;
3908 if Is_Class_Wide_Type
(DDT
)
3909 and then Is_Interface
(DDT
)
3911 New_Itype
:= Create_Itype
(E_Anonymous_Access_Type
, A
);
3912 Set_Etype
(New_Itype
, Etype
(A
));
3913 Set_Directly_Designated_Type
3914 (New_Itype
, Directly_Designated_Type
(Etype
(A
)));
3915 Set_Etype
(A
, New_Itype
);
3918 -- Ada 2005, AI-162:If the actual is an allocator, the
3919 -- innermost enclosing statement is the master of the
3920 -- created object. This needs to be done with expansion
3921 -- enabled only, otherwise the transient scope will not
3922 -- be removed in the expansion of the wrapped construct.
3925 and then (Needs_Finalization
(DDT
)
3926 or else Has_Task
(DDT
))
3928 Establish_Transient_Scope
3929 (A
, Manage_Sec_Stack
=> False);
3933 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
3934 Check_Restriction
(No_Access_Parameter_Allocators
, A
);
3938 -- (Ada 2005): The call may be to a primitive operation of a
3939 -- tagged synchronized type, declared outside of the type. In
3940 -- this case the controlling actual must be converted to its
3941 -- corresponding record type, which is the formal type. The
3942 -- actual may be a subtype, either because of a constraint or
3943 -- because it is a generic actual, so use base type to locate
3946 F_Typ
:= Base_Type
(Etype
(F
));
3948 if Is_Tagged_Type
(F_Typ
)
3949 and then (Is_Concurrent_Type
(F_Typ
)
3950 or else Is_Concurrent_Record_Type
(F_Typ
))
3952 -- If the actual is overloaded, look for an interpretation
3953 -- that has a synchronized type.
3955 if not Is_Overloaded
(A
) then
3956 A_Typ
:= Base_Type
(Etype
(A
));
3960 Index
: Interp_Index
;
3964 Get_First_Interp
(A
, Index
, It
);
3965 while Present
(It
.Typ
) loop
3966 if Is_Concurrent_Type
(It
.Typ
)
3967 or else Is_Concurrent_Record_Type
(It
.Typ
)
3969 A_Typ
:= Base_Type
(It
.Typ
);
3973 Get_Next_Interp
(Index
, It
);
3979 Full_A_Typ
: Entity_Id
;
3982 if Present
(Full_View
(A_Typ
)) then
3983 Full_A_Typ
:= Base_Type
(Full_View
(A_Typ
));
3985 Full_A_Typ
:= A_Typ
;
3988 -- Tagged synchronized type (case 1): the actual is a
3991 if Is_Concurrent_Type
(A_Typ
)
3992 and then Corresponding_Record_Type
(A_Typ
) = F_Typ
3995 Unchecked_Convert_To
3996 (Corresponding_Record_Type
(A_Typ
), A
));
3997 Resolve
(A
, Etype
(F
));
3999 -- Tagged synchronized type (case 2): the formal is a
4002 elsif Ekind
(Full_A_Typ
) = E_Record_Type
4004 (Corresponding_Concurrent_Type
(Full_A_Typ
))
4005 and then Is_Concurrent_Type
(F_Typ
)
4006 and then Present
(Corresponding_Record_Type
(F_Typ
))
4007 and then Full_A_Typ
= Corresponding_Record_Type
(F_Typ
)
4009 Resolve
(A
, Corresponding_Record_Type
(F_Typ
));
4014 Resolve
(A
, Etype
(F
));
4018 -- Not a synchronized operation
4021 Resolve
(A
, Etype
(F
));
4028 -- An actual cannot be an untagged formal incomplete type
4030 if Ekind
(A_Typ
) = E_Incomplete_Type
4031 and then not Is_Tagged_Type
(A_Typ
)
4032 and then Is_Generic_Type
(A_Typ
)
4035 ("invalid use of untagged formal incomplete type", A
);
4038 if Comes_From_Source
(Original_Node
(N
))
4039 and then Nkind_In
(Original_Node
(N
), N_Function_Call
,
4040 N_Procedure_Call_Statement
)
4042 -- In formal mode, check that actual parameters matching
4043 -- formals of tagged types are objects (or ancestor type
4044 -- conversions of objects), not general expressions.
4046 if Is_Actual_Tagged_Parameter
(A
) then
4047 if Is_SPARK_05_Object_Reference
(A
) then
4050 elsif Nkind
(A
) = N_Type_Conversion
then
4052 Operand
: constant Node_Id
:= Expression
(A
);
4053 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
4054 Target_Typ
: constant Entity_Id
:= A_Typ
;
4057 if not Is_SPARK_05_Object_Reference
(Operand
) then
4058 Check_SPARK_05_Restriction
4059 ("object required", Operand
);
4061 -- In formal mode, the only view conversions are those
4062 -- involving ancestor conversion of an extended type.
4065 (Is_Tagged_Type
(Target_Typ
)
4066 and then not Is_Class_Wide_Type
(Target_Typ
)
4067 and then Is_Tagged_Type
(Operand_Typ
)
4068 and then not Is_Class_Wide_Type
(Operand_Typ
)
4069 and then Is_Ancestor
(Target_Typ
, Operand_Typ
))
4072 (F
, E_Out_Parameter
, E_In_Out_Parameter
)
4074 Check_SPARK_05_Restriction
4075 ("ancestor conversion is the only permitted "
4076 & "view conversion", A
);
4078 Check_SPARK_05_Restriction
4079 ("ancestor conversion required", A
);
4088 Check_SPARK_05_Restriction
("object required", A
);
4091 -- In formal mode, the only view conversions are those
4092 -- involving ancestor conversion of an extended type.
4094 elsif Nkind
(A
) = N_Type_Conversion
4095 and then Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
4097 Check_SPARK_05_Restriction
4098 ("ancestor conversion is the only permitted view "
4103 -- has warnings suppressed, then we reset Never_Set_In_Source for
4104 -- the calling entity. The reason for this is to catch cases like
4105 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4106 -- uses trickery to modify an IN parameter.
4108 if Ekind
(F
) = E_In_Parameter
4109 and then Is_Entity_Name
(A
)
4110 and then Present
(Entity
(A
))
4111 and then Ekind
(Entity
(A
)) = E_Variable
4112 and then Has_Warnings_Off
(F_Typ
)
4114 Set_Never_Set_In_Source
(Entity
(A
), False);
4117 -- Perform error checks for IN and IN OUT parameters
4119 if Ekind
(F
) /= E_Out_Parameter
then
4121 -- Check unset reference. For scalar parameters, it is clearly
4122 -- wrong to pass an uninitialized value as either an IN or
4123 -- IN-OUT parameter. For composites, it is also clearly an
4124 -- error to pass a completely uninitialized value as an IN
4125 -- parameter, but the case of IN OUT is trickier. We prefer
4126 -- not to give a warning here. For example, suppose there is
4127 -- a routine that sets some component of a record to False.
4128 -- It is perfectly reasonable to make this IN-OUT and allow
4129 -- either initialized or uninitialized records to be passed
4132 -- For partially initialized composite values, we also avoid
4133 -- warnings, since it is quite likely that we are passing a
4134 -- partially initialized value and only the initialized fields
4135 -- will in fact be read in the subprogram.
4137 if Is_Scalar_Type
(A_Typ
)
4138 or else (Ekind
(F
) = E_In_Parameter
4139 and then not Is_Partially_Initialized_Type
(A_Typ
))
4141 Check_Unset_Reference
(A
);
4144 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4145 -- actual to a nested call, since this constitutes a reading of
4146 -- the parameter, which is not allowed.
4148 if Ada_Version
= Ada_83
4149 and then Is_Entity_Name
(A
)
4150 and then Ekind
(Entity
(A
)) = E_Out_Parameter
4152 Error_Msg_N
("(Ada 83) illegal reading of out parameter", A
);
4156 -- In -gnatd.q mode, forget that a given array is constant when
4157 -- it is passed as an IN parameter to a foreign-convention
4158 -- subprogram. This is in case the subprogram evilly modifies the
4159 -- object. Of course, correct code would use IN OUT.
4162 and then Ekind
(F
) = E_In_Parameter
4163 and then Has_Foreign_Convention
(Nam
)
4164 and then Is_Array_Type
(F_Typ
)
4165 and then Nkind
(A
) in N_Has_Entity
4166 and then Present
(Entity
(A
))
4168 Set_Is_True_Constant
(Entity
(A
), False);
4171 -- Case of OUT or IN OUT parameter
4173 if Ekind
(F
) /= E_In_Parameter
then
4175 -- For an Out parameter, check for useless assignment. Note
4176 -- that we can't set Last_Assignment this early, because we may
4177 -- kill current values in Resolve_Call, and that call would
4178 -- clobber the Last_Assignment field.
4180 -- Note: call Warn_On_Useless_Assignment before doing the check
4181 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4182 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4183 -- reflects the last assignment, not this one.
4185 if Ekind
(F
) = E_Out_Parameter
then
4186 if Warn_On_Modified_As_Out_Parameter
(F
)
4187 and then Is_Entity_Name
(A
)
4188 and then Present
(Entity
(A
))
4189 and then Comes_From_Source
(N
)
4191 Warn_On_Useless_Assignment
(Entity
(A
), A
);
4195 -- Validate the form of the actual. Note that the call to
4196 -- Is_OK_Variable_For_Out_Formal generates the required
4197 -- reference in this case.
4199 -- A call to an initialization procedure for an aggregate
4200 -- component may initialize a nested component of a constant
4201 -- designated object. In this context the object is variable.
4203 if not Is_OK_Variable_For_Out_Formal
(A
)
4204 and then not Is_Init_Proc
(Nam
)
4206 Error_Msg_NE
("actual for& must be a variable", A
, F
);
4208 if Is_Subprogram
(Current_Scope
) then
4209 if Is_Invariant_Procedure
(Current_Scope
)
4210 or else Is_Partial_Invariant_Procedure
(Current_Scope
)
4213 ("function used in invariant cannot modify its "
4216 elsif Is_Predicate_Function
(Current_Scope
) then
4218 ("function used in predicate cannot modify its "
4224 -- What's the following about???
4226 if Is_Entity_Name
(A
) then
4227 Kill_Checks
(Entity
(A
));
4233 if Etype
(A
) = Any_Type
then
4234 Set_Etype
(N
, Any_Type
);
4238 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4240 if Ekind_In
(F
, E_In_Parameter
, E_In_Out_Parameter
) then
4242 -- Apply predicate tests except in certain special cases. Note
4243 -- that it might be more consistent to apply these only when
4244 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4245 -- for the outbound predicate tests ??? In any case indicate
4246 -- the function being called, for better warnings if the call
4247 -- leads to an infinite recursion.
4249 if Predicate_Tests_On_Arguments
(Nam
) then
4250 Apply_Predicate_Check
(A
, F_Typ
, Nam
);
4253 -- Apply required constraint checks
4255 -- Gigi looks at the check flag and uses the appropriate types.
4256 -- For now since one flag is used there is an optimization
4257 -- which might not be done in the IN OUT case since Gigi does
4258 -- not do any analysis. More thought required about this ???
4260 -- In fact is this comment obsolete??? doesn't the expander now
4261 -- generate all these tests anyway???
4263 if Is_Scalar_Type
(Etype
(A
)) then
4264 Apply_Scalar_Range_Check
(A
, F_Typ
);
4266 elsif Is_Array_Type
(Etype
(A
)) then
4267 Apply_Length_Check
(A
, F_Typ
);
4269 elsif Is_Record_Type
(F_Typ
)
4270 and then Has_Discriminants
(F_Typ
)
4271 and then Is_Constrained
(F_Typ
)
4272 and then (not Is_Derived_Type
(F_Typ
)
4273 or else Comes_From_Source
(Nam
))
4275 Apply_Discriminant_Check
(A
, F_Typ
);
4277 -- For view conversions of a discriminated object, apply
4278 -- check to object itself, the conversion alreay has the
4281 if Nkind
(A
) = N_Type_Conversion
4282 and then Is_Constrained
(Etype
(Expression
(A
)))
4284 Apply_Discriminant_Check
(Expression
(A
), F_Typ
);
4287 elsif Is_Access_Type
(F_Typ
)
4288 and then Is_Array_Type
(Designated_Type
(F_Typ
))
4289 and then Is_Constrained
(Designated_Type
(F_Typ
))
4291 Apply_Length_Check
(A
, F_Typ
);
4293 elsif Is_Access_Type
(F_Typ
)
4294 and then Has_Discriminants
(Designated_Type
(F_Typ
))
4295 and then Is_Constrained
(Designated_Type
(F_Typ
))
4297 Apply_Discriminant_Check
(A
, F_Typ
);
4300 Apply_Range_Check
(A
, F_Typ
);
4303 -- Ada 2005 (AI-231): Note that the controlling parameter case
4304 -- already existed in Ada 95, which is partially checked
4305 -- elsewhere (see Checks), and we don't want the warning
4306 -- message to differ.
4308 if Is_Access_Type
(F_Typ
)
4309 and then Can_Never_Be_Null
(F_Typ
)
4310 and then Known_Null
(A
)
4312 if Is_Controlling_Formal
(F
) then
4313 Apply_Compile_Time_Constraint_Error
4315 Msg
=> "null value not allowed here??",
4316 Reason
=> CE_Access_Check_Failed
);
4318 elsif Ada_Version
>= Ada_2005
then
4319 Apply_Compile_Time_Constraint_Error
4321 Msg
=> "(Ada 2005) null not allowed in "
4322 & "null-excluding formal??",
4323 Reason
=> CE_Null_Not_Allowed
);
4328 -- Checks for OUT parameters and IN OUT parameters
4330 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
) then
4332 -- If there is a type conversion, make sure the return value
4333 -- meets the constraints of the variable before the conversion.
4335 if Nkind
(A
) = N_Type_Conversion
then
4336 if Is_Scalar_Type
(A_Typ
) then
4337 Apply_Scalar_Range_Check
4338 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4340 -- In addition, the returned value of the parameter must
4341 -- satisfy the bounds of the object type (see comment
4344 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
4348 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4351 -- If no conversion, apply scalar range checks and length check
4352 -- based on the subtype of the actual (NOT that of the formal).
4353 -- This indicates that the check takes place on return from the
4354 -- call. During expansion the required constraint checks are
4355 -- inserted. In GNATprove mode, in the absence of expansion,
4356 -- the flag indicates that the returned value is valid.
4359 if Is_Scalar_Type
(F_Typ
) then
4360 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
4362 elsif Is_Array_Type
(F_Typ
)
4363 and then Ekind
(F
) = E_Out_Parameter
4365 Apply_Length_Check
(A
, F_Typ
);
4367 Apply_Range_Check
(A
, A_Typ
, F_Typ
);
4371 -- Note: we do not apply the predicate checks for the case of
4372 -- OUT and IN OUT parameters. They are instead applied in the
4373 -- Expand_Actuals routine in Exp_Ch6.
4376 -- An actual associated with an access parameter is implicitly
4377 -- converted to the anonymous access type of the formal and must
4378 -- satisfy the legality checks for access conversions.
4380 if Ekind
(F_Typ
) = E_Anonymous_Access_Type
then
4381 if not Valid_Conversion
(A
, F_Typ
, A
) then
4383 ("invalid implicit conversion for access parameter", A
);
4386 -- If the actual is an access selected component of a variable,
4387 -- the call may modify its designated object. It is reasonable
4388 -- to treat this as a potential modification of the enclosing
4389 -- record, to prevent spurious warnings that it should be
4390 -- declared as a constant, because intuitively programmers
4391 -- regard the designated subcomponent as part of the record.
4393 if Nkind
(A
) = N_Selected_Component
4394 and then Is_Entity_Name
(Prefix
(A
))
4395 and then not Is_Constant_Object
(Entity
(Prefix
(A
)))
4397 Note_Possible_Modification
(A
, Sure
=> False);
4401 -- Check bad case of atomic/volatile argument (RM C.6(12))
4403 if Is_By_Reference_Type
(Etype
(F
))
4404 and then Comes_From_Source
(N
)
4406 if Is_Atomic_Object
(A
)
4407 and then not Is_Atomic
(Etype
(F
))
4410 ("cannot pass atomic argument to non-atomic formal&",
4413 elsif Is_Volatile_Object
(A
)
4414 and then not Is_Volatile
(Etype
(F
))
4417 ("cannot pass volatile argument to non-volatile formal&",
4422 -- Check that subprograms don't have improper controlling
4423 -- arguments (RM 3.9.2 (9)).
4425 -- A primitive operation may have an access parameter of an
4426 -- incomplete tagged type, but a dispatching call is illegal
4427 -- if the type is still incomplete.
4429 if Is_Controlling_Formal
(F
) then
4430 Set_Is_Controlling_Actual
(A
);
4432 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
4434 Desig
: constant Entity_Id
:= Designated_Type
(Etype
(F
));
4436 if Ekind
(Desig
) = E_Incomplete_Type
4437 and then No
(Full_View
(Desig
))
4438 and then No
(Non_Limited_View
(Desig
))
4441 ("premature use of incomplete type& "
4442 & "in dispatching call", A
, Desig
);
4447 elsif Nkind
(A
) = N_Explicit_Dereference
then
4448 Validate_Remote_Access_To_Class_Wide_Type
(A
);
4451 -- Apply legality rule 3.9.2 (9/1)
4453 if (Is_Class_Wide_Type
(A_Typ
) or else Is_Dynamically_Tagged
(A
))
4454 and then not Is_Class_Wide_Type
(F_Typ
)
4455 and then not Is_Controlling_Formal
(F
)
4456 and then not In_Instance
4458 Error_Msg_N
("class-wide argument not allowed here!", A
);
4460 if Is_Subprogram
(Nam
) and then Comes_From_Source
(Nam
) then
4461 Error_Msg_Node_2
:= F_Typ
;
4463 ("& is not a dispatching operation of &!", A
, Nam
);
4466 -- Apply the checks described in 3.10.2(27): if the context is a
4467 -- specific access-to-object, the actual cannot be class-wide.
4468 -- Use base type to exclude access_to_subprogram cases.
4470 elsif Is_Access_Type
(A_Typ
)
4471 and then Is_Access_Type
(F_Typ
)
4472 and then not Is_Access_Subprogram_Type
(Base_Type
(F_Typ
))
4473 and then (Is_Class_Wide_Type
(Designated_Type
(A_Typ
))
4474 or else (Nkind
(A
) = N_Attribute_Reference
4476 Is_Class_Wide_Type
(Etype
(Prefix
(A
)))))
4477 and then not Is_Class_Wide_Type
(Designated_Type
(F_Typ
))
4478 and then not Is_Controlling_Formal
(F
)
4480 -- Disable these checks for call to imported C++ subprograms
4483 (Is_Entity_Name
(Name
(N
))
4484 and then Is_Imported
(Entity
(Name
(N
)))
4485 and then Convention
(Entity
(Name
(N
))) = Convention_CPP
)
4488 ("access to class-wide argument not allowed here!", A
);
4490 if Is_Subprogram
(Nam
) and then Comes_From_Source
(Nam
) then
4491 Error_Msg_Node_2
:= Designated_Type
(F_Typ
);
4493 ("& is not a dispatching operation of &!", A
, Nam
);
4497 Check_Aliased_Parameter
;
4501 -- If it is a named association, treat the selector_name as a
4502 -- proper identifier, and mark the corresponding entity.
4504 if Nkind
(Parent
(A
)) = N_Parameter_Association
4506 -- Ignore reference in SPARK mode, as it refers to an entity not
4507 -- in scope at the point of reference, so the reference should
4508 -- be ignored for computing effects of subprograms.
4510 and then not GNATprove_Mode
4512 -- If subprogram is overridden, use name of formal that
4515 if Present
(Real_Subp
) then
4516 Set_Entity
(Selector_Name
(Parent
(A
)), Real_F
);
4517 Set_Etype
(Selector_Name
(Parent
(A
)), Etype
(Real_F
));
4520 Set_Entity
(Selector_Name
(Parent
(A
)), F
);
4521 Generate_Reference
(F
, Selector_Name
(Parent
(A
)));
4522 Set_Etype
(Selector_Name
(Parent
(A
)), F_Typ
);
4523 Generate_Reference
(F_Typ
, N
, ' ');
4529 if Ekind
(F
) /= E_Out_Parameter
then
4530 Check_Unset_Reference
(A
);
4533 -- The following checks are only relevant when SPARK_Mode is on as
4534 -- they are not standard Ada legality rule. Internally generated
4535 -- temporaries are ignored.
4537 if SPARK_Mode
= On
and then Comes_From_Source
(A
) then
4539 -- An effectively volatile object may act as an actual when the
4540 -- corresponding formal is of a non-scalar effectively volatile
4541 -- type (SPARK RM 7.1.3(11)).
4543 if not Is_Scalar_Type
(Etype
(F
))
4544 and then Is_Effectively_Volatile
(Etype
(F
))
4548 -- An effectively volatile object may act as an actual in a
4549 -- call to an instance of Unchecked_Conversion.
4550 -- (SPARK RM 7.1.3(11)).
4552 elsif Is_Unchecked_Conversion_Instance
(Nam
) then
4555 -- The actual denotes an object
4557 elsif Is_Effectively_Volatile_Object
(A
) then
4559 ("volatile object cannot act as actual in a call (SPARK "
4560 & "RM 7.1.3(11))", A
);
4562 -- Otherwise the actual denotes an expression. Inspect the
4563 -- expression and flag each effectively volatile object with
4564 -- enabled property Async_Writers or Effective_Reads as illegal
4565 -- because it apprears within an interfering context. Note that
4566 -- this is usually done in Resolve_Entity_Name, but when the
4567 -- effectively volatile object appears as an actual in a call,
4568 -- the call must be resolved first.
4571 Flag_Effectively_Volatile_Objects
(A
);
4574 -- An effectively volatile variable cannot act as an actual
4575 -- parameter in a procedure call when the variable has enabled
4576 -- property Effective_Reads and the corresponding formal is of
4577 -- mode IN (SPARK RM 7.1.3(10)).
4579 if Ekind
(Nam
) = E_Procedure
4580 and then Ekind
(F
) = E_In_Parameter
4581 and then Is_Entity_Name
(A
)
4585 if Ekind
(A_Id
) = E_Variable
4586 and then Is_Effectively_Volatile
(Etype
(A_Id
))
4587 and then Effective_Reads_Enabled
(A_Id
)
4590 ("effectively volatile variable & cannot appear as "
4591 & "actual in procedure call", A
, A_Id
);
4593 Error_Msg_Name_1
:= Name_Effective_Reads
;
4594 Error_Msg_N
("\\variable has enabled property %", A
);
4595 Error_Msg_N
("\\corresponding formal has mode IN", A
);
4600 -- A formal parameter of a specific tagged type whose related
4601 -- subprogram is subject to pragma Extensions_Visible with value
4602 -- "False" cannot act as an actual in a subprogram with value
4603 -- "True" (SPARK RM 6.1.7(3)).
4605 if Is_EVF_Expression
(A
)
4606 and then Extensions_Visible_Status
(Nam
) =
4607 Extensions_Visible_True
4610 ("formal parameter cannot act as actual parameter when "
4611 & "Extensions_Visible is False", A
);
4613 ("\subprogram & has Extensions_Visible True", A
, Nam
);
4616 -- The actual parameter of a Ghost subprogram whose formal is of
4617 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(12)).
4619 if Comes_From_Source
(Nam
)
4620 and then Is_Ghost_Entity
(Nam
)
4621 and then Ekind_In
(F
, E_In_Out_Parameter
, E_Out_Parameter
)
4622 and then Is_Entity_Name
(A
)
4623 and then Present
(Entity
(A
))
4624 and then not Is_Ghost_Entity
(Entity
(A
))
4627 ("non-ghost variable & cannot appear as actual in call to "
4628 & "ghost procedure", A
, Entity
(A
));
4630 if Ekind
(F
) = E_In_Out_Parameter
then
4631 Error_Msg_N
("\corresponding formal has mode `IN OUT`", A
);
4633 Error_Msg_N
("\corresponding formal has mode OUT", A
);
4639 -- Case where actual is not present
4647 if Present
(Real_Subp
) then
4648 Next_Formal
(Real_F
);
4651 end Resolve_Actuals
;
4653 -----------------------
4654 -- Resolve_Allocator --
4655 -----------------------
4657 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
) is
4658 Desig_T
: constant Entity_Id
:= Designated_Type
(Typ
);
4659 E
: constant Node_Id
:= Expression
(N
);
4661 Discrim
: Entity_Id
;
4664 Assoc
: Node_Id
:= Empty
;
4667 procedure Check_Allocator_Discrim_Accessibility
4668 (Disc_Exp
: Node_Id
;
4669 Alloc_Typ
: Entity_Id
);
4670 -- Check that accessibility level associated with an access discriminant
4671 -- initialized in an allocator by the expression Disc_Exp is not deeper
4672 -- than the level of the allocator type Alloc_Typ. An error message is
4673 -- issued if this condition is violated. Specialized checks are done for
4674 -- the cases of a constraint expression which is an access attribute or
4675 -- an access discriminant.
4677 function In_Dispatching_Context
return Boolean;
4678 -- If the allocator is an actual in a call, it is allowed to be class-
4679 -- wide when the context is not because it is a controlling actual.
4681 -------------------------------------------
4682 -- Check_Allocator_Discrim_Accessibility --
4683 -------------------------------------------
4685 procedure Check_Allocator_Discrim_Accessibility
4686 (Disc_Exp
: Node_Id
;
4687 Alloc_Typ
: Entity_Id
)
4690 if Type_Access_Level
(Etype
(Disc_Exp
)) >
4691 Deepest_Type_Access_Level
(Alloc_Typ
)
4694 ("operand type has deeper level than allocator type", Disc_Exp
);
4696 -- When the expression is an Access attribute the level of the prefix
4697 -- object must not be deeper than that of the allocator's type.
4699 elsif Nkind
(Disc_Exp
) = N_Attribute_Reference
4700 and then Get_Attribute_Id
(Attribute_Name
(Disc_Exp
)) =
4702 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4703 Deepest_Type_Access_Level
(Alloc_Typ
)
4706 ("prefix of attribute has deeper level than allocator type",
4709 -- When the expression is an access discriminant the check is against
4710 -- the level of the prefix object.
4712 elsif Ekind
(Etype
(Disc_Exp
)) = E_Anonymous_Access_Type
4713 and then Nkind
(Disc_Exp
) = N_Selected_Component
4714 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4715 Deepest_Type_Access_Level
(Alloc_Typ
)
4718 ("access discriminant has deeper level than allocator type",
4721 -- All other cases are legal
4726 end Check_Allocator_Discrim_Accessibility
;
4728 ----------------------------
4729 -- In_Dispatching_Context --
4730 ----------------------------
4732 function In_Dispatching_Context
return Boolean is
4733 Par
: constant Node_Id
:= Parent
(N
);
4736 return Nkind
(Par
) in N_Subprogram_Call
4737 and then Is_Entity_Name
(Name
(Par
))
4738 and then Is_Dispatching_Operation
(Entity
(Name
(Par
)));
4739 end In_Dispatching_Context
;
4741 -- Start of processing for Resolve_Allocator
4744 -- Replace general access with specific type
4746 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
4747 Set_Etype
(N
, Base_Type
(Typ
));
4750 if Is_Abstract_Type
(Typ
) then
4751 Error_Msg_N
("type of allocator cannot be abstract", N
);
4754 -- For qualified expression, resolve the expression using the given
4755 -- subtype (nothing to do for type mark, subtype indication)
4757 if Nkind
(E
) = N_Qualified_Expression
then
4758 if Is_Class_Wide_Type
(Etype
(E
))
4759 and then not Is_Class_Wide_Type
(Desig_T
)
4760 and then not In_Dispatching_Context
4763 ("class-wide allocator not allowed for this access type", N
);
4766 Resolve
(Expression
(E
), Etype
(E
));
4767 Check_Non_Static_Context
(Expression
(E
));
4768 Check_Unset_Reference
(Expression
(E
));
4770 -- Allocators generated by the build-in-place expansion mechanism
4771 -- are explicitly marked as coming from source but do not need to be
4772 -- checked for limited initialization. To exclude this case, ensure
4773 -- that the parent of the allocator is a source node.
4774 -- The return statement constructed for an Expression_Function does
4775 -- not come from source but requires a limited check.
4777 if Is_Limited_Type
(Etype
(E
))
4778 and then Comes_From_Source
(N
)
4780 (Comes_From_Source
(Parent
(N
))
4782 (Ekind
(Current_Scope
) = E_Function
4783 and then Nkind
(Original_Node
(Unit_Declaration_Node
4784 (Current_Scope
))) = N_Expression_Function
))
4785 and then not In_Instance_Body
4787 if not OK_For_Limited_Init
(Etype
(E
), Expression
(E
)) then
4788 if Nkind
(Parent
(N
)) = N_Assignment_Statement
then
4790 ("illegal expression for initialized allocator of a "
4791 & "limited type (RM 7.5 (2.7/2))", N
);
4794 ("initialization not allowed for limited types", N
);
4797 Explain_Limited_Type
(Etype
(E
), N
);
4801 -- A qualified expression requires an exact match of the type. Class-
4802 -- wide matching is not allowed.
4804 if (Is_Class_Wide_Type
(Etype
(Expression
(E
)))
4805 or else Is_Class_Wide_Type
(Etype
(E
)))
4806 and then Base_Type
(Etype
(Expression
(E
))) /= Base_Type
(Etype
(E
))
4808 Wrong_Type
(Expression
(E
), Etype
(E
));
4811 -- Calls to build-in-place functions are not currently supported in
4812 -- allocators for access types associated with a simple storage pool.
4813 -- Supporting such allocators may require passing additional implicit
4814 -- parameters to build-in-place functions (or a significant revision
4815 -- of the current b-i-p implementation to unify the handling for
4816 -- multiple kinds of storage pools). ???
4818 if Is_Limited_View
(Desig_T
)
4819 and then Nkind
(Expression
(E
)) = N_Function_Call
4822 Pool
: constant Entity_Id
:=
4823 Associated_Storage_Pool
(Root_Type
(Typ
));
4827 Present
(Get_Rep_Pragma
4828 (Etype
(Pool
), Name_Simple_Storage_Pool_Type
))
4831 ("limited function calls not yet supported in simple "
4832 & "storage pool allocators", Expression
(E
));
4837 -- A special accessibility check is needed for allocators that
4838 -- constrain access discriminants. The level of the type of the
4839 -- expression used to constrain an access discriminant cannot be
4840 -- deeper than the type of the allocator (in contrast to access
4841 -- parameters, where the level of the actual can be arbitrary).
4843 -- We can't use Valid_Conversion to perform this check because in
4844 -- general the type of the allocator is unrelated to the type of
4845 -- the access discriminant.
4847 if Ekind
(Typ
) /= E_Anonymous_Access_Type
4848 or else Is_Local_Anonymous_Access
(Typ
)
4850 Subtyp
:= Entity
(Subtype_Mark
(E
));
4852 Aggr
:= Original_Node
(Expression
(E
));
4854 if Has_Discriminants
(Subtyp
)
4855 and then Nkind_In
(Aggr
, N_Aggregate
, N_Extension_Aggregate
)
4857 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4859 -- Get the first component expression of the aggregate
4861 if Present
(Expressions
(Aggr
)) then
4862 Disc_Exp
:= First
(Expressions
(Aggr
));
4864 elsif Present
(Component_Associations
(Aggr
)) then
4865 Assoc
:= First
(Component_Associations
(Aggr
));
4867 if Present
(Assoc
) then
4868 Disc_Exp
:= Expression
(Assoc
);
4877 while Present
(Discrim
) and then Present
(Disc_Exp
) loop
4878 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4879 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4882 Next_Discriminant
(Discrim
);
4884 if Present
(Discrim
) then
4885 if Present
(Assoc
) then
4887 Disc_Exp
:= Expression
(Assoc
);
4889 elsif Present
(Next
(Disc_Exp
)) then
4893 Assoc
:= First
(Component_Associations
(Aggr
));
4895 if Present
(Assoc
) then
4896 Disc_Exp
:= Expression
(Assoc
);
4906 -- For a subtype mark or subtype indication, freeze the subtype
4909 Freeze_Expression
(E
);
4911 if Is_Access_Constant
(Typ
) and then not No_Initialization
(N
) then
4913 ("initialization required for access-to-constant allocator", N
);
4916 -- A special accessibility check is needed for allocators that
4917 -- constrain access discriminants. The level of the type of the
4918 -- expression used to constrain an access discriminant cannot be
4919 -- deeper than the type of the allocator (in contrast to access
4920 -- parameters, where the level of the actual can be arbitrary).
4921 -- We can't use Valid_Conversion to perform this check because
4922 -- in general the type of the allocator is unrelated to the type
4923 -- of the access discriminant.
4925 if Nkind
(Original_Node
(E
)) = N_Subtype_Indication
4926 and then (Ekind
(Typ
) /= E_Anonymous_Access_Type
4927 or else Is_Local_Anonymous_Access
(Typ
))
4929 Subtyp
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4931 if Has_Discriminants
(Subtyp
) then
4932 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4933 Constr
:= First
(Constraints
(Constraint
(Original_Node
(E
))));
4934 while Present
(Discrim
) and then Present
(Constr
) loop
4935 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4936 if Nkind
(Constr
) = N_Discriminant_Association
then
4937 Disc_Exp
:= Original_Node
(Expression
(Constr
));
4939 Disc_Exp
:= Original_Node
(Constr
);
4942 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4945 Next_Discriminant
(Discrim
);
4952 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4953 -- check that the level of the type of the created object is not deeper
4954 -- than the level of the allocator's access type, since extensions can
4955 -- now occur at deeper levels than their ancestor types. This is a
4956 -- static accessibility level check; a run-time check is also needed in
4957 -- the case of an initialized allocator with a class-wide argument (see
4958 -- Expand_Allocator_Expression).
4960 if Ada_Version
>= Ada_2005
4961 and then Is_Class_Wide_Type
(Desig_T
)
4964 Exp_Typ
: Entity_Id
;
4967 if Nkind
(E
) = N_Qualified_Expression
then
4968 Exp_Typ
:= Etype
(E
);
4969 elsif Nkind
(E
) = N_Subtype_Indication
then
4970 Exp_Typ
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4972 Exp_Typ
:= Entity
(E
);
4975 if Type_Access_Level
(Exp_Typ
) >
4976 Deepest_Type_Access_Level
(Typ
)
4978 if In_Instance_Body
then
4979 Error_Msg_Warn
:= SPARK_Mode
/= On
;
4981 ("type in allocator has deeper level than "
4982 & "designated class-wide type<<", E
);
4983 Error_Msg_N
("\Program_Error [<<", E
);
4985 Make_Raise_Program_Error
(Sloc
(N
),
4986 Reason
=> PE_Accessibility_Check_Failed
));
4989 -- Do not apply Ada 2005 accessibility checks on a class-wide
4990 -- allocator if the type given in the allocator is a formal
4991 -- type. A run-time check will be performed in the instance.
4993 elsif not Is_Generic_Type
(Exp_Typ
) then
4994 Error_Msg_N
("type in allocator has deeper level than "
4995 & "designated class-wide type", E
);
5001 -- Check for allocation from an empty storage pool
5003 if No_Pool_Assigned
(Typ
) then
5004 Error_Msg_N
("allocation from empty storage pool!", N
);
5006 -- If the context is an unchecked conversion, as may happen within an
5007 -- inlined subprogram, the allocator is being resolved with its own
5008 -- anonymous type. In that case, if the target type has a specific
5009 -- storage pool, it must be inherited explicitly by the allocator type.
5011 elsif Nkind
(Parent
(N
)) = N_Unchecked_Type_Conversion
5012 and then No
(Associated_Storage_Pool
(Typ
))
5014 Set_Associated_Storage_Pool
5015 (Typ
, Associated_Storage_Pool
(Etype
(Parent
(N
))));
5018 if Ekind
(Etype
(N
)) = E_Anonymous_Access_Type
then
5019 Check_Restriction
(No_Anonymous_Allocators
, N
);
5022 -- Check that an allocator with task parts isn't for a nested access
5023 -- type when restriction No_Task_Hierarchy applies.
5025 if not Is_Library_Level_Entity
(Base_Type
(Typ
))
5026 and then Has_Task
(Base_Type
(Desig_T
))
5028 Check_Restriction
(No_Task_Hierarchy
, N
);
5031 -- An illegal allocator may be rewritten as a raise Program_Error
5034 if Nkind
(N
) = N_Allocator
then
5036 -- Avoid coextension processing for an allocator that is the
5037 -- expansion of a build-in-place function call.
5039 if Nkind
(Original_Node
(N
)) = N_Allocator
5040 and then Nkind
(Expression
(Original_Node
(N
))) =
5041 N_Qualified_Expression
5042 and then Nkind
(Expression
(Expression
(Original_Node
(N
)))) =
5044 and then Is_Expanded_Build_In_Place_Call
5045 (Expression
(Expression
(Original_Node
(N
))))
5047 null; -- b-i-p function call case
5050 -- An anonymous access discriminant is the definition of a
5053 if Ekind
(Typ
) = E_Anonymous_Access_Type
5054 and then Nkind
(Associated_Node_For_Itype
(Typ
)) =
5055 N_Discriminant_Specification
5058 Discr
: constant Entity_Id
:=
5059 Defining_Identifier
(Associated_Node_For_Itype
(Typ
));
5062 Check_Restriction
(No_Coextensions
, N
);
5064 -- Ada 2012 AI05-0052: If the designated type of the
5065 -- allocator is limited, then the allocator shall not
5066 -- be used to define the value of an access discriminant
5067 -- unless the discriminated type is immutably limited.
5069 if Ada_Version
>= Ada_2012
5070 and then Is_Limited_Type
(Desig_T
)
5071 and then not Is_Limited_View
(Scope
(Discr
))
5074 ("only immutably limited types can have anonymous "
5075 & "access discriminants designating a limited type",
5080 -- Avoid marking an allocator as a dynamic coextension if it is
5081 -- within a static construct.
5083 if not Is_Static_Coextension
(N
) then
5084 Set_Is_Dynamic_Coextension
(N
);
5086 -- Finalization and deallocation of coextensions utilizes an
5087 -- approximate implementation which does not directly adhere
5088 -- to the semantic rules. Warn on potential issues involving
5091 if Is_Controlled
(Desig_T
) then
5093 ("??coextension will not be finalized when its "
5094 & "associated owner is deallocated or finalized", N
);
5097 ("??coextension will not be deallocated when its "
5098 & "associated owner is deallocated", N
);
5102 -- Cleanup for potential static coextensions
5105 Set_Is_Dynamic_Coextension
(N
, False);
5106 Set_Is_Static_Coextension
(N
, False);
5108 -- Anonymous access-to-controlled objects are not finalized on
5109 -- time because this involves run-time ownership and currently
5110 -- this property is not available. In rare cases the object may
5111 -- not be finalized at all. Warn on potential issues involving
5112 -- anonymous access-to-controlled objects.
5114 if Ekind
(Typ
) = E_Anonymous_Access_Type
5115 and then Is_Controlled_Active
(Desig_T
)
5118 ("??object designated by anonymous access object might "
5119 & "not be finalized until its enclosing library unit "
5120 & "goes out of scope", N
);
5121 Error_Msg_N
("\use named access type instead", N
);
5127 -- Report a simple error: if the designated object is a local task,
5128 -- its body has not been seen yet, and its activation will fail an
5129 -- elaboration check.
5131 if Is_Task_Type
(Desig_T
)
5132 and then Scope
(Base_Type
(Desig_T
)) = Current_Scope
5133 and then Is_Compilation_Unit
(Current_Scope
)
5134 and then Ekind
(Current_Scope
) = E_Package
5135 and then not In_Package_Body
(Current_Scope
)
5137 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5138 Error_Msg_N
("cannot activate task before body seen<<", N
);
5139 Error_Msg_N
("\Program_Error [<<", N
);
5142 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5143 -- type with a task component on a subpool. This action must raise
5144 -- Program_Error at runtime.
5146 if Ada_Version
>= Ada_2012
5147 and then Nkind
(N
) = N_Allocator
5148 and then Present
(Subpool_Handle_Name
(N
))
5149 and then Has_Task
(Desig_T
)
5151 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5152 Error_Msg_N
("cannot allocate task on subpool<<", N
);
5153 Error_Msg_N
("\Program_Error [<<", N
);
5156 Make_Raise_Program_Error
(Sloc
(N
),
5157 Reason
=> PE_Explicit_Raise
));
5160 end Resolve_Allocator
;
5162 ---------------------------
5163 -- Resolve_Arithmetic_Op --
5164 ---------------------------
5166 -- Used for resolving all arithmetic operators except exponentiation
5168 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
5169 L
: constant Node_Id
:= Left_Opnd
(N
);
5170 R
: constant Node_Id
:= Right_Opnd
(N
);
5171 TL
: constant Entity_Id
:= Base_Type
(Etype
(L
));
5172 TR
: constant Entity_Id
:= Base_Type
(Etype
(R
));
5176 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
5177 -- We do the resolution using the base type, because intermediate values
5178 -- in expressions always are of the base type, not a subtype of it.
5180 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean;
5181 -- Returns True if N is in a context that expects "any real type"
5183 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean;
5184 -- Return True iff given type is Integer or universal real/integer
5186 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
);
5187 -- Choose type of integer literal in fixed-point operation to conform
5188 -- to available fixed-point type. T is the type of the other operand,
5189 -- which is needed to determine the expected type of N.
5191 procedure Set_Operand_Type
(N
: Node_Id
);
5192 -- Set operand type to T if universal
5194 -------------------------------
5195 -- Expected_Type_Is_Any_Real --
5196 -------------------------------
5198 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean is
5200 -- N is the expression after "delta" in a fixed_point_definition;
5203 return Nkind_In
(Parent
(N
), N_Ordinary_Fixed_Point_Definition
,
5204 N_Decimal_Fixed_Point_Definition
,
5206 -- N is one of the bounds in a real_range_specification;
5209 N_Real_Range_Specification
,
5211 -- N is the expression of a delta_constraint;
5214 N_Delta_Constraint
);
5215 end Expected_Type_Is_Any_Real
;
5217 -----------------------------
5218 -- Is_Integer_Or_Universal --
5219 -----------------------------
5221 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean is
5223 Index
: Interp_Index
;
5227 if not Is_Overloaded
(N
) then
5229 return Base_Type
(T
) = Base_Type
(Standard_Integer
)
5230 or else T
= Universal_Integer
5231 or else T
= Universal_Real
;
5233 Get_First_Interp
(N
, Index
, It
);
5234 while Present
(It
.Typ
) loop
5235 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
)
5236 or else It
.Typ
= Universal_Integer
5237 or else It
.Typ
= Universal_Real
5242 Get_Next_Interp
(Index
, It
);
5247 end Is_Integer_Or_Universal
;
5249 ----------------------------
5250 -- Set_Mixed_Mode_Operand --
5251 ----------------------------
5253 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
) is
5254 Index
: Interp_Index
;
5258 if Universal_Interpretation
(N
) = Universal_Integer
then
5260 -- A universal integer literal is resolved as standard integer
5261 -- except in the case of a fixed-point result, where we leave it
5262 -- as universal (to be handled by Exp_Fixd later on)
5264 if Is_Fixed_Point_Type
(T
) then
5265 Resolve
(N
, Universal_Integer
);
5267 Resolve
(N
, Standard_Integer
);
5270 elsif Universal_Interpretation
(N
) = Universal_Real
5271 and then (T
= Base_Type
(Standard_Integer
)
5272 or else T
= Universal_Integer
5273 or else T
= Universal_Real
)
5275 -- A universal real can appear in a fixed-type context. We resolve
5276 -- the literal with that context, even though this might raise an
5277 -- exception prematurely (the other operand may be zero).
5281 elsif Etype
(N
) = Base_Type
(Standard_Integer
)
5282 and then T
= Universal_Real
5283 and then Is_Overloaded
(N
)
5285 -- Integer arg in mixed-mode operation. Resolve with universal
5286 -- type, in case preference rule must be applied.
5288 Resolve
(N
, Universal_Integer
);
5291 and then B_Typ
/= Universal_Fixed
5293 -- Not a mixed-mode operation, resolve with context
5297 elsif Etype
(N
) = Any_Fixed
then
5299 -- N may itself be a mixed-mode operation, so use context type
5303 elsif Is_Fixed_Point_Type
(T
)
5304 and then B_Typ
= Universal_Fixed
5305 and then Is_Overloaded
(N
)
5307 -- Must be (fixed * fixed) operation, operand must have one
5308 -- compatible interpretation.
5310 Resolve
(N
, Any_Fixed
);
5312 elsif Is_Fixed_Point_Type
(B_Typ
)
5313 and then (T
= Universal_Real
or else Is_Fixed_Point_Type
(T
))
5314 and then Is_Overloaded
(N
)
5316 -- C * F(X) in a fixed context, where C is a real literal or a
5317 -- fixed-point expression. F must have either a fixed type
5318 -- interpretation or an integer interpretation, but not both.
5320 Get_First_Interp
(N
, Index
, It
);
5321 while Present
(It
.Typ
) loop
5322 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
) then
5323 if Analyzed
(N
) then
5324 Error_Msg_N
("ambiguous operand in fixed operation", N
);
5326 Resolve
(N
, Standard_Integer
);
5329 elsif Is_Fixed_Point_Type
(It
.Typ
) then
5330 if Analyzed
(N
) then
5331 Error_Msg_N
("ambiguous operand in fixed operation", N
);
5333 Resolve
(N
, It
.Typ
);
5337 Get_Next_Interp
(Index
, It
);
5340 -- Reanalyze the literal with the fixed type of the context. If
5341 -- context is Universal_Fixed, we are within a conversion, leave
5342 -- the literal as a universal real because there is no usable
5343 -- fixed type, and the target of the conversion plays no role in
5357 if B_Typ
= Universal_Fixed
5358 and then Nkind
(Op2
) = N_Real_Literal
5360 T2
:= Universal_Real
;
5365 Set_Analyzed
(Op2
, False);
5369 -- A universal real conditional expression can appear in a fixed-type
5370 -- context and must be resolved with that context to facilitate the
5371 -- code generation to the backend.
5373 elsif Nkind_In
(N
, N_Case_Expression
, N_If_Expression
)
5374 and then Etype
(N
) = Universal_Real
5375 and then Is_Fixed_Point_Type
(B_Typ
)
5382 end Set_Mixed_Mode_Operand
;
5384 ----------------------
5385 -- Set_Operand_Type --
5386 ----------------------
5388 procedure Set_Operand_Type
(N
: Node_Id
) is
5390 if Etype
(N
) = Universal_Integer
5391 or else Etype
(N
) = Universal_Real
5395 end Set_Operand_Type
;
5397 -- Start of processing for Resolve_Arithmetic_Op
5400 if Comes_From_Source
(N
)
5401 and then Ekind
(Entity
(N
)) = E_Function
5402 and then Is_Imported
(Entity
(N
))
5403 and then Is_Intrinsic_Subprogram
(Entity
(N
))
5405 Resolve_Intrinsic_Operator
(N
, Typ
);
5408 -- Special-case for mixed-mode universal expressions or fixed point type
5409 -- operation: each argument is resolved separately. The same treatment
5410 -- is required if one of the operands of a fixed point operation is
5411 -- universal real, since in this case we don't do a conversion to a
5412 -- specific fixed-point type (instead the expander handles the case).
5414 -- Set the type of the node to its universal interpretation because
5415 -- legality checks on an exponentiation operand need the context.
5417 elsif (B_Typ
= Universal_Integer
or else B_Typ
= Universal_Real
)
5418 and then Present
(Universal_Interpretation
(L
))
5419 and then Present
(Universal_Interpretation
(R
))
5421 Set_Etype
(N
, B_Typ
);
5422 Resolve
(L
, Universal_Interpretation
(L
));
5423 Resolve
(R
, Universal_Interpretation
(R
));
5425 elsif (B_Typ
= Universal_Real
5426 or else Etype
(N
) = Universal_Fixed
5427 or else (Etype
(N
) = Any_Fixed
5428 and then Is_Fixed_Point_Type
(B_Typ
))
5429 or else (Is_Fixed_Point_Type
(B_Typ
)
5430 and then (Is_Integer_Or_Universal
(L
)
5432 Is_Integer_Or_Universal
(R
))))
5433 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
5435 if TL
= Universal_Integer
or else TR
= Universal_Integer
then
5436 Check_For_Visible_Operator
(N
, B_Typ
);
5439 -- If context is a fixed type and one operand is integer, the other
5440 -- is resolved with the type of the context.
5442 if Is_Fixed_Point_Type
(B_Typ
)
5443 and then (Base_Type
(TL
) = Base_Type
(Standard_Integer
)
5444 or else TL
= Universal_Integer
)
5449 elsif Is_Fixed_Point_Type
(B_Typ
)
5450 and then (Base_Type
(TR
) = Base_Type
(Standard_Integer
)
5451 or else TR
= Universal_Integer
)
5456 -- If both operands are universal and the context is a floating
5457 -- point type, the operands are resolved to the type of the context.
5459 elsif Is_Floating_Point_Type
(B_Typ
) then
5464 Set_Mixed_Mode_Operand
(L
, TR
);
5465 Set_Mixed_Mode_Operand
(R
, TL
);
5468 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5469 -- multiplying operators from being used when the expected type is
5470 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5471 -- some cases where the expected type is actually Any_Real;
5472 -- Expected_Type_Is_Any_Real takes care of that case.
5474 if Etype
(N
) = Universal_Fixed
5475 or else Etype
(N
) = Any_Fixed
5477 if B_Typ
= Universal_Fixed
5478 and then not Expected_Type_Is_Any_Real
(N
)
5479 and then not Nkind_In
(Parent
(N
), N_Type_Conversion
,
5480 N_Unchecked_Type_Conversion
)
5482 Error_Msg_N
("type cannot be determined from context!", N
);
5483 Error_Msg_N
("\explicit conversion to result type required", N
);
5485 Set_Etype
(L
, Any_Type
);
5486 Set_Etype
(R
, Any_Type
);
5489 if Ada_Version
= Ada_83
5490 and then Etype
(N
) = Universal_Fixed
5492 Nkind_In
(Parent
(N
), N_Type_Conversion
,
5493 N_Unchecked_Type_Conversion
)
5496 ("(Ada 83) fixed-point operation needs explicit "
5500 -- The expected type is "any real type" in contexts like
5502 -- type T is delta <universal_fixed-expression> ...
5504 -- in which case we need to set the type to Universal_Real
5505 -- so that static expression evaluation will work properly.
5507 if Expected_Type_Is_Any_Real
(N
) then
5508 Set_Etype
(N
, Universal_Real
);
5510 Set_Etype
(N
, B_Typ
);
5514 elsif Is_Fixed_Point_Type
(B_Typ
)
5515 and then (Is_Integer_Or_Universal
(L
)
5516 or else Nkind
(L
) = N_Real_Literal
5517 or else Nkind
(R
) = N_Real_Literal
5518 or else Is_Integer_Or_Universal
(R
))
5520 Set_Etype
(N
, B_Typ
);
5522 elsif Etype
(N
) = Any_Fixed
then
5524 -- If no previous errors, this is only possible if one operand is
5525 -- overloaded and the context is universal. Resolve as such.
5527 Set_Etype
(N
, B_Typ
);
5531 if (TL
= Universal_Integer
or else TL
= Universal_Real
)
5533 (TR
= Universal_Integer
or else TR
= Universal_Real
)
5535 Check_For_Visible_Operator
(N
, B_Typ
);
5538 -- If the context is Universal_Fixed and the operands are also
5539 -- universal fixed, this is an error, unless there is only one
5540 -- applicable fixed_point type (usually Duration).
5542 if B_Typ
= Universal_Fixed
and then Etype
(L
) = Universal_Fixed
then
5543 T
:= Unique_Fixed_Point_Type
(N
);
5545 if T
= Any_Type
then
5558 -- If one of the arguments was resolved to a non-universal type.
5559 -- label the result of the operation itself with the same type.
5560 -- Do the same for the universal argument, if any.
5562 T
:= Intersect_Types
(L
, R
);
5563 Set_Etype
(N
, Base_Type
(T
));
5564 Set_Operand_Type
(L
);
5565 Set_Operand_Type
(R
);
5568 Generate_Operator_Reference
(N
, Typ
);
5569 Analyze_Dimension
(N
);
5570 Eval_Arithmetic_Op
(N
);
5572 -- In SPARK, a multiplication or division with operands of fixed point
5573 -- types must be qualified or explicitly converted to identify the
5576 if (Is_Fixed_Point_Type
(Etype
(L
))
5577 or else Is_Fixed_Point_Type
(Etype
(R
)))
5578 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
5580 not Nkind_In
(Parent
(N
), N_Qualified_Expression
, N_Type_Conversion
)
5582 Check_SPARK_05_Restriction
5583 ("operation should be qualified or explicitly converted", N
);
5586 -- Set overflow and division checking bit
5588 if Nkind
(N
) in N_Op
then
5589 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
5590 Enable_Overflow_Check
(N
);
5593 -- Give warning if explicit division by zero
5595 if Nkind_In
(N
, N_Op_Divide
, N_Op_Rem
, N_Op_Mod
)
5596 and then not Division_Checks_Suppressed
(Etype
(N
))
5598 Rop
:= Right_Opnd
(N
);
5600 if Compile_Time_Known_Value
(Rop
)
5601 and then ((Is_Integer_Type
(Etype
(Rop
))
5602 and then Expr_Value
(Rop
) = Uint_0
)
5604 (Is_Real_Type
(Etype
(Rop
))
5605 and then Expr_Value_R
(Rop
) = Ureal_0
))
5607 -- Specialize the warning message according to the operation.
5608 -- When SPARK_Mode is On, force a warning instead of an error
5609 -- in that case, as this likely corresponds to deactivated
5610 -- code. The following warnings are for the case
5615 -- For division, we have two cases, for float division
5616 -- of an unconstrained float type, on a machine where
5617 -- Machine_Overflows is false, we don't get an exception
5618 -- at run-time, but rather an infinity or Nan. The Nan
5619 -- case is pretty obscure, so just warn about infinities.
5621 if Is_Floating_Point_Type
(Typ
)
5622 and then not Is_Constrained
(Typ
)
5623 and then not Machine_Overflows_On_Target
5626 ("float division by zero, may generate "
5627 & "'+'/'- infinity??", Right_Opnd
(N
));
5629 -- For all other cases, we get a Constraint_Error
5632 Apply_Compile_Time_Constraint_Error
5633 (N
, "division by zero??", CE_Divide_By_Zero
,
5634 Loc
=> Sloc
(Right_Opnd
(N
)),
5635 Warn
=> SPARK_Mode
= On
);
5639 Apply_Compile_Time_Constraint_Error
5640 (N
, "rem with zero divisor??", CE_Divide_By_Zero
,
5641 Loc
=> Sloc
(Right_Opnd
(N
)),
5642 Warn
=> SPARK_Mode
= On
);
5645 Apply_Compile_Time_Constraint_Error
5646 (N
, "mod with zero divisor??", CE_Divide_By_Zero
,
5647 Loc
=> Sloc
(Right_Opnd
(N
)),
5648 Warn
=> SPARK_Mode
= On
);
5650 -- Division by zero can only happen with division, rem,
5651 -- and mod operations.
5654 raise Program_Error
;
5657 -- In GNATprove mode, we enable the division check so that
5658 -- GNATprove will issue a message if it cannot be proved.
5660 if GNATprove_Mode
then
5661 Activate_Division_Check
(N
);
5664 -- Otherwise just set the flag to check at run time
5667 Activate_Division_Check
(N
);
5671 -- If Restriction No_Implicit_Conditionals is active, then it is
5672 -- violated if either operand can be negative for mod, or for rem
5673 -- if both operands can be negative.
5675 if Restriction_Check_Required
(No_Implicit_Conditionals
)
5676 and then Nkind_In
(N
, N_Op_Rem
, N_Op_Mod
)
5685 -- Set if corresponding operand might be negative
5689 (Left_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5690 LNeg
:= (not OK
) or else Lo
< 0;
5693 (Right_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5694 RNeg
:= (not OK
) or else Lo
< 0;
5696 -- Check if we will be generating conditionals. There are two
5697 -- cases where that can happen, first for REM, the only case
5698 -- is largest negative integer mod -1, where the division can
5699 -- overflow, but we still have to give the right result. The
5700 -- front end generates a test for this annoying case. Here we
5701 -- just test if both operands can be negative (that's what the
5702 -- expander does, so we match its logic here).
5704 -- The second case is mod where either operand can be negative.
5705 -- In this case, the back end has to generate additional tests.
5707 if (Nkind
(N
) = N_Op_Rem
and then (LNeg
and RNeg
))
5709 (Nkind
(N
) = N_Op_Mod
and then (LNeg
or RNeg
))
5711 Check_Restriction
(No_Implicit_Conditionals
, N
);
5717 Check_Unset_Reference
(L
);
5718 Check_Unset_Reference
(R
);
5719 end Resolve_Arithmetic_Op
;
5725 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
5726 function Same_Or_Aliased_Subprograms
5728 E
: Entity_Id
) return Boolean;
5729 -- Returns True if the subprogram entity S is the same as E or else
5730 -- S is an alias of E.
5732 ---------------------------------
5733 -- Same_Or_Aliased_Subprograms --
5734 ---------------------------------
5736 function Same_Or_Aliased_Subprograms
5738 E
: Entity_Id
) return Boolean
5740 Subp_Alias
: constant Entity_Id
:= Alias
(S
);
5742 return S
= E
or else (Present
(Subp_Alias
) and then Subp_Alias
= E
);
5743 end Same_Or_Aliased_Subprograms
;
5747 Loc
: constant Source_Ptr
:= Sloc
(N
);
5748 Subp
: constant Node_Id
:= Name
(N
);
5749 Body_Id
: Entity_Id
;
5759 -- Start of processing for Resolve_Call
5762 -- Preserve relevant elaboration-related attributes of the context which
5763 -- are no longer available or very expensive to recompute once analysis,
5764 -- resolution, and expansion are over.
5766 Mark_Elaboration_Attributes
5772 -- The context imposes a unique interpretation with type Typ on a
5773 -- procedure or function call. Find the entity of the subprogram that
5774 -- yields the expected type, and propagate the corresponding formal
5775 -- constraints on the actuals. The caller has established that an
5776 -- interpretation exists, and emitted an error if not unique.
5778 -- First deal with the case of a call to an access-to-subprogram,
5779 -- dereference made explicit in Analyze_Call.
5781 if Ekind
(Etype
(Subp
)) = E_Subprogram_Type
then
5782 if not Is_Overloaded
(Subp
) then
5783 Nam
:= Etype
(Subp
);
5786 -- Find the interpretation whose type (a subprogram type) has a
5787 -- return type that is compatible with the context. Analysis of
5788 -- the node has established that one exists.
5792 Get_First_Interp
(Subp
, I
, It
);
5793 while Present
(It
.Typ
) loop
5794 if Covers
(Typ
, Etype
(It
.Typ
)) then
5799 Get_Next_Interp
(I
, It
);
5803 raise Program_Error
;
5807 -- If the prefix is not an entity, then resolve it
5809 if not Is_Entity_Name
(Subp
) then
5810 Resolve
(Subp
, Nam
);
5813 -- For an indirect call, we always invalidate checks, since we do not
5814 -- know whether the subprogram is local or global. Yes we could do
5815 -- better here, e.g. by knowing that there are no local subprograms,
5816 -- but it does not seem worth the effort. Similarly, we kill all
5817 -- knowledge of current constant values.
5819 Kill_Current_Values
;
5821 -- If this is a procedure call which is really an entry call, do
5822 -- the conversion of the procedure call to an entry call. Protected
5823 -- operations use the same circuitry because the name in the call
5824 -- can be an arbitrary expression with special resolution rules.
5826 elsif Nkind_In
(Subp
, N_Selected_Component
, N_Indexed_Component
)
5827 or else (Is_Entity_Name
(Subp
)
5828 and then Ekind_In
(Entity
(Subp
), E_Entry
, E_Entry_Family
))
5830 Resolve_Entry_Call
(N
, Typ
);
5832 if Legacy_Elaboration_Checks
then
5833 Check_Elab_Call
(N
);
5836 -- Annotate the tree by creating a call marker in case the original
5837 -- call is transformed by expansion. The call marker is automatically
5838 -- saved for later examination by the ABE Processing phase.
5840 Build_Call_Marker
(N
);
5842 -- Kill checks and constant values, as above for indirect case
5843 -- Who knows what happens when another task is activated?
5845 Kill_Current_Values
;
5848 -- Normal subprogram call with name established in Resolve
5850 elsif not (Is_Type
(Entity
(Subp
))) then
5851 Nam
:= Entity
(Subp
);
5852 Set_Entity_With_Checks
(Subp
, Nam
);
5854 -- Otherwise we must have the case of an overloaded call
5857 pragma Assert
(Is_Overloaded
(Subp
));
5859 -- Initialize Nam to prevent warning (we know it will be assigned
5860 -- in the loop below, but the compiler does not know that).
5864 Get_First_Interp
(Subp
, I
, It
);
5865 while Present
(It
.Typ
) loop
5866 if Covers
(Typ
, It
.Typ
) then
5868 Set_Entity_With_Checks
(Subp
, Nam
);
5872 Get_Next_Interp
(I
, It
);
5876 if Is_Access_Subprogram_Type
(Base_Type
(Etype
(Nam
)))
5877 and then not Is_Access_Subprogram_Type
(Base_Type
(Typ
))
5878 and then Nkind
(Subp
) /= N_Explicit_Dereference
5879 and then Present
(Parameter_Associations
(N
))
5881 -- The prefix is a parameterless function call that returns an access
5882 -- to subprogram. If parameters are present in the current call, add
5883 -- add an explicit dereference. We use the base type here because
5884 -- within an instance these may be subtypes.
5886 -- The dereference is added either in Analyze_Call or here. Should
5887 -- be consolidated ???
5889 Set_Is_Overloaded
(Subp
, False);
5890 Set_Etype
(Subp
, Etype
(Nam
));
5891 Insert_Explicit_Dereference
(Subp
);
5892 Nam
:= Designated_Type
(Etype
(Nam
));
5893 Resolve
(Subp
, Nam
);
5896 -- Check that a call to Current_Task does not occur in an entry body
5898 if Is_RTE
(Nam
, RE_Current_Task
) then
5907 -- Exclude calls that occur within the default of a formal
5908 -- parameter of the entry, since those are evaluated outside
5911 exit when No
(P
) or else Nkind
(P
) = N_Parameter_Specification
;
5913 if Nkind
(P
) = N_Entry_Body
5914 or else (Nkind
(P
) = N_Subprogram_Body
5915 and then Is_Entry_Barrier_Function
(P
))
5918 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5920 ("& should not be used in entry body (RM C.7(17))<<",
5922 Error_Msg_NE
("\Program_Error [<<", N
, Nam
);
5924 Make_Raise_Program_Error
(Loc
,
5925 Reason
=> PE_Current_Task_In_Entry_Body
));
5926 Set_Etype
(N
, Rtype
);
5933 -- Check that a procedure call does not occur in the context of the
5934 -- entry call statement of a conditional or timed entry call. Note that
5935 -- the case of a call to a subprogram renaming of an entry will also be
5936 -- rejected. The test for N not being an N_Entry_Call_Statement is
5937 -- defensive, covering the possibility that the processing of entry
5938 -- calls might reach this point due to later modifications of the code
5941 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
5942 and then Nkind
(N
) /= N_Entry_Call_Statement
5943 and then Entry_Call_Statement
(Parent
(N
)) = N
5945 if Ada_Version
< Ada_2005
then
5946 Error_Msg_N
("entry call required in select statement", N
);
5948 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5949 -- for a procedure_or_entry_call, the procedure_name or
5950 -- procedure_prefix of the procedure_call_statement shall denote
5951 -- an entry renamed by a procedure, or (a view of) a primitive
5952 -- subprogram of a limited interface whose first parameter is
5953 -- a controlling parameter.
5955 elsif Nkind
(N
) = N_Procedure_Call_Statement
5956 and then not Is_Renamed_Entry
(Nam
)
5957 and then not Is_Controlling_Limited_Procedure
(Nam
)
5960 ("entry call or dispatching primitive of interface required", N
);
5964 -- If the SPARK_05 restriction is active, we are not allowed
5965 -- to have a call to a subprogram before we see its completion.
5967 if not Has_Completion
(Nam
)
5968 and then Restriction_Check_Required
(SPARK_05
)
5970 -- Don't flag strange internal calls
5972 and then Comes_From_Source
(N
)
5973 and then Comes_From_Source
(Nam
)
5975 -- Only flag calls in extended main source
5977 and then In_Extended_Main_Source_Unit
(Nam
)
5978 and then In_Extended_Main_Source_Unit
(N
)
5980 -- Exclude enumeration literals from this processing
5982 and then Ekind
(Nam
) /= E_Enumeration_Literal
5984 Check_SPARK_05_Restriction
5985 ("call to subprogram cannot appear before its body", N
);
5988 -- Check that this is not a call to a protected procedure or entry from
5989 -- within a protected function.
5991 Check_Internal_Protected_Use
(N
, Nam
);
5993 -- Freeze the subprogram name if not in a spec-expression. Note that
5994 -- we freeze procedure calls as well as function calls. Procedure calls
5995 -- are not frozen according to the rules (RM 13.14(14)) because it is
5996 -- impossible to have a procedure call to a non-frozen procedure in
5997 -- pure Ada, but in the code that we generate in the expander, this
5998 -- rule needs extending because we can generate procedure calls that
6001 -- In Ada 2012, expression functions may be called within pre/post
6002 -- conditions of subsequent functions or expression functions. Such
6003 -- calls do not freeze when they appear within generated bodies,
6004 -- (including the body of another expression function) which would
6005 -- place the freeze node in the wrong scope. An expression function
6006 -- is frozen in the usual fashion, by the appearance of a real body,
6007 -- or at the end of a declarative part.
6009 if Is_Entity_Name
(Subp
)
6010 and then not In_Spec_Expression
6011 and then not Is_Expression_Function_Or_Completion
(Current_Scope
)
6013 (not Is_Expression_Function_Or_Completion
(Entity
(Subp
))
6014 or else Scope
(Entity
(Subp
)) = Current_Scope
)
6016 Freeze_Expression
(Subp
);
6019 -- For a predefined operator, the type of the result is the type imposed
6020 -- by context, except for a predefined operation on universal fixed.
6021 -- Otherwise The type of the call is the type returned by the subprogram
6024 if Is_Predefined_Op
(Nam
) then
6025 if Etype
(N
) /= Universal_Fixed
then
6029 -- If the subprogram returns an array type, and the context requires the
6030 -- component type of that array type, the node is really an indexing of
6031 -- the parameterless call. Resolve as such. A pathological case occurs
6032 -- when the type of the component is an access to the array type. In
6033 -- this case the call is truly ambiguous. If the call is to an intrinsic
6034 -- subprogram, it can't be an indexed component. This check is necessary
6035 -- because if it's Unchecked_Conversion, and we have "type T_Ptr is
6036 -- access T;" and "type T is array (...) of T_Ptr;" (i.e. an array of
6037 -- pointers to the same array), the compiler gets confused and does an
6038 -- infinite recursion.
6040 elsif (Needs_No_Actuals
(Nam
) or else Needs_One_Actual
(Nam
))
6042 ((Is_Array_Type
(Etype
(Nam
))
6043 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
6045 (Is_Access_Type
(Etype
(Nam
))
6046 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
6048 Covers
(Typ
, Component_Type
(Designated_Type
(Etype
(Nam
))))
6049 and then not Is_Intrinsic_Subprogram
(Entity
(Subp
))))
6052 Index_Node
: Node_Id
;
6054 Ret_Type
: constant Entity_Id
:= Etype
(Nam
);
6057 if Is_Access_Type
(Ret_Type
)
6058 and then Ret_Type
= Component_Type
(Designated_Type
(Ret_Type
))
6061 ("cannot disambiguate function call and indexing", N
);
6063 New_Subp
:= Relocate_Node
(Subp
);
6065 -- The called entity may be an explicit dereference, in which
6066 -- case there is no entity to set.
6068 if Nkind
(New_Subp
) /= N_Explicit_Dereference
then
6069 Set_Entity
(Subp
, Nam
);
6072 if (Is_Array_Type
(Ret_Type
)
6073 and then Component_Type
(Ret_Type
) /= Any_Type
)
6075 (Is_Access_Type
(Ret_Type
)
6077 Component_Type
(Designated_Type
(Ret_Type
)) /= Any_Type
)
6079 if Needs_No_Actuals
(Nam
) then
6081 -- Indexed call to a parameterless function
6084 Make_Indexed_Component
(Loc
,
6086 Make_Function_Call
(Loc
, Name
=> New_Subp
),
6087 Expressions
=> Parameter_Associations
(N
));
6089 -- An Ada 2005 prefixed call to a primitive operation
6090 -- whose first parameter is the prefix. This prefix was
6091 -- prepended to the parameter list, which is actually a
6092 -- list of indexes. Remove the prefix in order to build
6093 -- the proper indexed component.
6096 Make_Indexed_Component
(Loc
,
6098 Make_Function_Call
(Loc
,
6100 Parameter_Associations
=>
6102 (Remove_Head
(Parameter_Associations
(N
)))),
6103 Expressions
=> Parameter_Associations
(N
));
6106 -- Preserve the parenthesis count of the node
6108 Set_Paren_Count
(Index_Node
, Paren_Count
(N
));
6110 -- Since we are correcting a node classification error made
6111 -- by the parser, we call Replace rather than Rewrite.
6113 Replace
(N
, Index_Node
);
6115 Set_Etype
(Prefix
(N
), Ret_Type
);
6117 Resolve_Indexed_Component
(N
, Typ
);
6119 if Legacy_Elaboration_Checks
then
6120 Check_Elab_Call
(Prefix
(N
));
6123 -- Annotate the tree by creating a call marker in case
6124 -- the original call is transformed by expansion. The call
6125 -- marker is automatically saved for later examination by
6126 -- the ABE Processing phase.
6128 Build_Call_Marker
(Prefix
(N
));
6136 -- If the called function is not declared in the main unit and it
6137 -- returns the limited view of type then use the available view (as
6138 -- is done in Try_Object_Operation) to prevent back-end confusion;
6139 -- for the function entity itself. The call must appear in a context
6140 -- where the nonlimited view is available. If the function entity is
6141 -- in the extended main unit then no action is needed, because the
6142 -- back end handles this case. In either case the type of the call
6143 -- is the nonlimited view.
6145 if From_Limited_With
(Etype
(Nam
))
6146 and then Present
(Available_View
(Etype
(Nam
)))
6148 Set_Etype
(N
, Available_View
(Etype
(Nam
)));
6150 if not In_Extended_Main_Code_Unit
(Nam
) then
6151 Set_Etype
(Nam
, Available_View
(Etype
(Nam
)));
6155 Set_Etype
(N
, Etype
(Nam
));
6159 -- In the case where the call is to an overloaded subprogram, Analyze
6160 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6161 -- such a case Normalize_Actuals needs to be called once more to order
6162 -- the actuals correctly. Otherwise the call will have the ordering
6163 -- given by the last overloaded subprogram whether this is the correct
6164 -- one being called or not.
6166 if Is_Overloaded
(Subp
) then
6167 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
6168 pragma Assert
(Norm_OK
);
6171 -- In any case, call is fully resolved now. Reset Overload flag, to
6172 -- prevent subsequent overload resolution if node is analyzed again
6174 Set_Is_Overloaded
(Subp
, False);
6175 Set_Is_Overloaded
(N
, False);
6177 -- A Ghost entity must appear in a specific context
6179 if Is_Ghost_Entity
(Nam
) and then Comes_From_Source
(N
) then
6180 Check_Ghost_Context
(Nam
, N
);
6183 -- If we are calling the current subprogram from immediately within its
6184 -- body, then that is the case where we can sometimes detect cases of
6185 -- infinite recursion statically. Do not try this in case restriction
6186 -- No_Recursion is in effect anyway, and do it only for source calls.
6188 if Comes_From_Source
(N
) then
6189 Scop
:= Current_Scope
;
6191 -- Check violation of SPARK_05 restriction which does not permit
6192 -- a subprogram body to contain a call to the subprogram directly.
6194 if Restriction_Check_Required
(SPARK_05
)
6195 and then Same_Or_Aliased_Subprograms
(Nam
, Scop
)
6197 Check_SPARK_05_Restriction
6198 ("subprogram may not contain direct call to itself", N
);
6201 -- Issue warning for possible infinite recursion in the absence
6202 -- of the No_Recursion restriction.
6204 if Same_Or_Aliased_Subprograms
(Nam
, Scop
)
6205 and then not Restriction_Active
(No_Recursion
)
6206 and then Check_Infinite_Recursion
(N
)
6208 -- Here we detected and flagged an infinite recursion, so we do
6209 -- not need to test the case below for further warnings. Also we
6210 -- are all done if we now have a raise SE node.
6212 if Nkind
(N
) = N_Raise_Storage_Error
then
6216 -- If call is to immediately containing subprogram, then check for
6217 -- the case of a possible run-time detectable infinite recursion.
6220 Scope_Loop
: while Scop
/= Standard_Standard
loop
6221 if Same_Or_Aliased_Subprograms
(Nam
, Scop
) then
6223 -- Although in general case, recursion is not statically
6224 -- checkable, the case of calling an immediately containing
6225 -- subprogram is easy to catch.
6227 Check_Restriction
(No_Recursion
, N
);
6229 -- If the recursive call is to a parameterless subprogram,
6230 -- then even if we can't statically detect infinite
6231 -- recursion, this is pretty suspicious, and we output a
6232 -- warning. Furthermore, we will try later to detect some
6233 -- cases here at run time by expanding checking code (see
6234 -- Detect_Infinite_Recursion in package Exp_Ch6).
6236 -- If the recursive call is within a handler, do not emit a
6237 -- warning, because this is a common idiom: loop until input
6238 -- is correct, catch illegal input in handler and restart.
6240 if No
(First_Formal
(Nam
))
6241 and then Etype
(Nam
) = Standard_Void_Type
6242 and then not Error_Posted
(N
)
6243 and then Nkind
(Parent
(N
)) /= N_Exception_Handler
6245 -- For the case of a procedure call. We give the message
6246 -- only if the call is the first statement in a sequence
6247 -- of statements, or if all previous statements are
6248 -- simple assignments. This is simply a heuristic to
6249 -- decrease false positives, without losing too many good
6250 -- warnings. The idea is that these previous statements
6251 -- may affect global variables the procedure depends on.
6252 -- We also exclude raise statements, that may arise from
6253 -- constraint checks and are probably unrelated to the
6254 -- intended control flow.
6256 if Nkind
(N
) = N_Procedure_Call_Statement
6257 and then Is_List_Member
(N
)
6263 while Present
(P
) loop
6264 if not Nkind_In
(P
, N_Assignment_Statement
,
6265 N_Raise_Constraint_Error
)
6275 -- Do not give warning if we are in a conditional context
6278 K
: constant Node_Kind
:= Nkind
(Parent
(N
));
6280 if (K
= N_Loop_Statement
6281 and then Present
(Iteration_Scheme
(Parent
(N
))))
6282 or else K
= N_If_Statement
6283 or else K
= N_Elsif_Part
6284 or else K
= N_Case_Statement_Alternative
6290 -- Here warning is to be issued
6292 Set_Has_Recursive_Call
(Nam
);
6293 Error_Msg_Warn
:= SPARK_Mode
/= On
;
6294 Error_Msg_N
("possible infinite recursion<<!", N
);
6295 Error_Msg_N
("\Storage_Error ]<<!", N
);
6301 Scop
:= Scope
(Scop
);
6302 end loop Scope_Loop
;
6306 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6308 Check_Obsolescent_2005_Entity
(Nam
, Subp
);
6310 -- If subprogram name is a predefined operator, it was given in
6311 -- functional notation. Replace call node with operator node, so
6312 -- that actuals can be resolved appropriately.
6314 if Is_Predefined_Op
(Nam
) or else Ekind
(Nam
) = E_Operator
then
6315 Make_Call_Into_Operator
(N
, Typ
, Entity
(Name
(N
)));
6318 elsif Present
(Alias
(Nam
))
6319 and then Is_Predefined_Op
(Alias
(Nam
))
6321 Resolve_Actuals
(N
, Nam
);
6322 Make_Call_Into_Operator
(N
, Typ
, Alias
(Nam
));
6326 -- Create a transient scope if the resulting type requires it
6328 -- There are several notable exceptions:
6330 -- a) In init procs, the transient scope overhead is not needed, and is
6331 -- even incorrect when the call is a nested initialization call for a
6332 -- component whose expansion may generate adjust calls. However, if the
6333 -- call is some other procedure call within an initialization procedure
6334 -- (for example a call to Create_Task in the init_proc of the task
6335 -- run-time record) a transient scope must be created around this call.
6337 -- b) Enumeration literal pseudo-calls need no transient scope
6339 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6340 -- functions) do not use the secondary stack even though the return
6341 -- type may be unconstrained.
6343 -- d) Calls to a build-in-place function, since such functions may
6344 -- allocate their result directly in a target object, and cases where
6345 -- the result does get allocated in the secondary stack are checked for
6346 -- within the specialized Exp_Ch6 procedures for expanding those
6347 -- build-in-place calls.
6349 -- e) Calls to inlinable expression functions do not use the secondary
6350 -- stack (since the call will be replaced by its returned object).
6352 -- f) If the subprogram is marked Inline_Always, then even if it returns
6353 -- an unconstrained type the call does not require use of the secondary
6354 -- stack. However, inlining will only take place if the body to inline
6355 -- is already present. It may not be available if e.g. the subprogram is
6356 -- declared in a child instance.
6359 and then Has_Pragma_Inline
(Nam
)
6360 and then Nkind
(Unit_Declaration_Node
(Nam
)) = N_Subprogram_Declaration
6361 and then Present
(Body_To_Inline
(Unit_Declaration_Node
(Nam
)))
6365 elsif Ekind
(Nam
) = E_Enumeration_Literal
6366 or else Is_Build_In_Place_Function
(Nam
)
6367 or else Is_Intrinsic_Subprogram
(Nam
)
6368 or else Is_Inlinable_Expression_Function
(Nam
)
6372 elsif Expander_Active
6373 and then Ekind
(Nam
) = E_Function
6374 and then Requires_Transient_Scope
(Etype
(Nam
))
6376 Establish_Transient_Scope
(N
, Manage_Sec_Stack
=> True);
6378 -- If the call appears within the bounds of a loop, it will be
6379 -- rewritten and reanalyzed, nothing left to do here.
6381 if Nkind
(N
) /= N_Function_Call
then
6386 -- A protected function cannot be called within the definition of the
6387 -- enclosing protected type, unless it is part of a pre/postcondition
6388 -- on another protected operation. This may appear in the entry wrapper
6389 -- created for an entry with preconditions.
6391 if Is_Protected_Type
(Scope
(Nam
))
6392 and then In_Open_Scopes
(Scope
(Nam
))
6393 and then not Has_Completion
(Scope
(Nam
))
6394 and then not In_Spec_Expression
6395 and then not Is_Entry_Wrapper
(Current_Scope
)
6398 ("& cannot be called before end of protected definition", N
, Nam
);
6401 -- Propagate interpretation to actuals, and add default expressions
6404 if Present
(First_Formal
(Nam
)) then
6405 Resolve_Actuals
(N
, Nam
);
6407 -- Overloaded literals are rewritten as function calls, for purpose of
6408 -- resolution. After resolution, we can replace the call with the
6411 elsif Ekind
(Nam
) = E_Enumeration_Literal
then
6412 Copy_Node
(Subp
, N
);
6413 Resolve_Entity_Name
(N
, Typ
);
6415 -- Avoid validation, since it is a static function call
6417 Generate_Reference
(Nam
, Subp
);
6421 -- If the subprogram is not global, then kill all saved values and
6422 -- checks. This is a bit conservative, since in many cases we could do
6423 -- better, but it is not worth the effort. Similarly, we kill constant
6424 -- values. However we do not need to do this for internal entities
6425 -- (unless they are inherited user-defined subprograms), since they
6426 -- are not in the business of molesting local values.
6428 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6429 -- kill all checks and values for calls to global subprograms. This
6430 -- takes care of the case where an access to a local subprogram is
6431 -- taken, and could be passed directly or indirectly and then called
6432 -- from almost any context.
6434 -- Note: we do not do this step till after resolving the actuals. That
6435 -- way we still take advantage of the current value information while
6436 -- scanning the actuals.
6438 -- We suppress killing values if we are processing the nodes associated
6439 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6440 -- type kills all the values as part of analyzing the code that
6441 -- initializes the dispatch tables.
6443 if Inside_Freezing_Actions
= 0
6444 and then (not Is_Library_Level_Entity
(Nam
)
6445 or else Suppress_Value_Tracking_On_Call
6446 (Nearest_Dynamic_Scope
(Current_Scope
)))
6447 and then (Comes_From_Source
(Nam
)
6448 or else (Present
(Alias
(Nam
))
6449 and then Comes_From_Source
(Alias
(Nam
))))
6451 Kill_Current_Values
;
6454 -- If we are warning about unread OUT parameters, this is the place to
6455 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6456 -- after the above call to Kill_Current_Values (since that call clears
6457 -- the Last_Assignment field of all local variables).
6459 if (Warn_On_Modified_Unread
or Warn_On_All_Unread_Out_Parameters
)
6460 and then Comes_From_Source
(N
)
6461 and then In_Extended_Main_Source_Unit
(N
)
6468 F
:= First_Formal
(Nam
);
6469 A
:= First_Actual
(N
);
6470 while Present
(F
) and then Present
(A
) loop
6471 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
6472 and then Warn_On_Modified_As_Out_Parameter
(F
)
6473 and then Is_Entity_Name
(A
)
6474 and then Present
(Entity
(A
))
6475 and then Comes_From_Source
(N
)
6476 and then Safe_To_Capture_Value
(N
, Entity
(A
))
6478 Set_Last_Assignment
(Entity
(A
), A
);
6487 -- If the subprogram is a primitive operation, check whether or not
6488 -- it is a correct dispatching call.
6490 if Is_Overloadable
(Nam
)
6491 and then Is_Dispatching_Operation
(Nam
)
6493 Check_Dispatching_Call
(N
);
6495 elsif Ekind
(Nam
) /= E_Subprogram_Type
6496 and then Is_Abstract_Subprogram
(Nam
)
6497 and then not In_Instance
6499 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Nam
);
6502 -- If this is a dispatching call, generate the appropriate reference,
6503 -- for better source navigation in GPS.
6505 if Is_Overloadable
(Nam
)
6506 and then Present
(Controlling_Argument
(N
))
6508 Generate_Reference
(Nam
, Subp
, 'R');
6510 -- Normal case, not a dispatching call: generate a call reference
6513 Generate_Reference
(Nam
, Subp
, 's');
6516 if Is_Intrinsic_Subprogram
(Nam
) then
6517 Check_Intrinsic_Call
(N
);
6520 -- Check for violation of restriction No_Specific_Termination_Handlers
6521 -- and warn on a potentially blocking call to Abort_Task.
6523 if Restriction_Check_Required
(No_Specific_Termination_Handlers
)
6524 and then (Is_RTE
(Nam
, RE_Set_Specific_Handler
)
6526 Is_RTE
(Nam
, RE_Specific_Handler
))
6528 Check_Restriction
(No_Specific_Termination_Handlers
, N
);
6530 elsif Is_RTE
(Nam
, RE_Abort_Task
) then
6531 Check_Potentially_Blocking_Operation
(N
);
6534 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6535 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6536 -- need to check the second argument to determine whether it is an
6537 -- absolute or relative timing event.
6539 if Restriction_Check_Required
(No_Relative_Delay
)
6540 and then Is_RTE
(Nam
, RE_Set_Handler
)
6541 and then Is_RTE
(Etype
(Next_Actual
(First_Actual
(N
))), RE_Time_Span
)
6543 Check_Restriction
(No_Relative_Delay
, N
);
6546 -- Issue an error for a call to an eliminated subprogram. This routine
6547 -- will not perform the check if the call appears within a default
6550 Check_For_Eliminated_Subprogram
(Subp
, Nam
);
6552 -- In formal mode, the primitive operations of a tagged type or type
6553 -- extension do not include functions that return the tagged type.
6555 if Nkind
(N
) = N_Function_Call
6556 and then Is_Tagged_Type
(Etype
(N
))
6557 and then Is_Entity_Name
(Name
(N
))
6558 and then Is_Inherited_Operation_For_Type
(Entity
(Name
(N
)), Etype
(N
))
6560 Check_SPARK_05_Restriction
("function not inherited", N
);
6563 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6564 -- class-wide and the call dispatches on result in a context that does
6565 -- not provide a tag, the call raises Program_Error.
6567 if Nkind
(N
) = N_Function_Call
6568 and then In_Instance
6569 and then Is_Generic_Actual_Type
(Typ
)
6570 and then Is_Class_Wide_Type
(Typ
)
6571 and then Has_Controlling_Result
(Nam
)
6572 and then Nkind
(Parent
(N
)) = N_Object_Declaration
6574 -- Verify that none of the formals are controlling
6577 Call_OK
: Boolean := False;
6581 F
:= First_Formal
(Nam
);
6582 while Present
(F
) loop
6583 if Is_Controlling_Formal
(F
) then
6592 Error_Msg_Warn
:= SPARK_Mode
/= On
;
6593 Error_Msg_N
("!cannot determine tag of result<<", N
);
6594 Error_Msg_N
("\Program_Error [<<!", N
);
6596 Make_Raise_Program_Error
(Sloc
(N
),
6597 Reason
=> PE_Explicit_Raise
));
6602 -- Check for calling a function with OUT or IN OUT parameter when the
6603 -- calling context (us right now) is not Ada 2012, so does not allow
6604 -- OUT or IN OUT parameters in function calls. Functions declared in
6605 -- a predefined unit are OK, as they may be called indirectly from a
6606 -- user-declared instantiation.
6608 if Ada_Version
< Ada_2012
6609 and then Ekind
(Nam
) = E_Function
6610 and then Has_Out_Or_In_Out_Parameter
(Nam
)
6611 and then not In_Predefined_Unit
(Nam
)
6613 Error_Msg_NE
("& has at least one OUT or `IN OUT` parameter", N
, Nam
);
6614 Error_Msg_N
("\call to this function only allowed in Ada 2012", N
);
6617 -- Check the dimensions of the actuals in the call. For function calls,
6618 -- propagate the dimensions from the returned type to N.
6620 Analyze_Dimension_Call
(N
, Nam
);
6622 -- All done, evaluate call and deal with elaboration issues
6626 if Legacy_Elaboration_Checks
then
6627 Check_Elab_Call
(N
);
6630 -- Annotate the tree by creating a call marker in case the original call
6631 -- is transformed by expansion. The call marker is automatically saved
6632 -- for later examination by the ABE Processing phase.
6634 Build_Call_Marker
(N
);
6636 -- In GNATprove mode, expansion is disabled, but we want to inline some
6637 -- subprograms to facilitate formal verification. Indirect calls through
6638 -- a subprogram type or within a generic cannot be inlined. Inlining is
6639 -- performed only for calls subject to SPARK_Mode on.
6642 and then SPARK_Mode
= On
6643 and then Is_Overloadable
(Nam
)
6644 and then not Inside_A_Generic
6646 Nam_UA
:= Ultimate_Alias
(Nam
);
6647 Nam_Decl
:= Unit_Declaration_Node
(Nam_UA
);
6649 if Nkind
(Nam_Decl
) = N_Subprogram_Declaration
then
6650 Body_Id
:= Corresponding_Body
(Nam_Decl
);
6652 -- Nothing to do if the subprogram is not eligible for inlining in
6653 -- GNATprove mode, or inlining is disabled with switch -gnatdm
6655 if not Is_Inlined_Always
(Nam_UA
)
6656 or else not Can_Be_Inlined_In_GNATprove_Mode
(Nam_UA
, Body_Id
)
6657 or else Debug_Flag_M
6661 -- Calls cannot be inlined inside assertions, as GNATprove treats
6662 -- assertions as logic expressions. Only issue a message when the
6663 -- body has been seen, otherwise this leads to spurious messages
6664 -- on expression functions.
6666 elsif In_Assertion_Expr
/= 0 then
6667 if Present
(Body_Id
) then
6669 ("cannot inline & (in assertion expression)?", N
, Nam_UA
);
6672 -- Calls cannot be inlined inside default expressions
6674 elsif In_Default_Expr
then
6676 ("cannot inline & (in default expression)?", N
, Nam_UA
);
6678 -- Inlining should not be performed during pre-analysis
6680 elsif Full_Analysis
then
6682 -- Do not inline calls inside expression functions, as this
6683 -- would prevent interpreting them as logical formulas in
6684 -- GNATprove. Only issue a message when the body has been seen,
6685 -- otherwise this leads to spurious messages on callees that
6686 -- are themselves expression functions.
6688 if Present
(Current_Subprogram
)
6689 and then Is_Expression_Function_Or_Completion
6690 (Current_Subprogram
)
6692 if Present
(Body_Id
)
6693 and then Present
(Body_To_Inline
(Nam_Decl
))
6696 ("cannot inline & (inside expression function)?",
6700 -- With the one-pass inlining technique, a call cannot be
6701 -- inlined if the corresponding body has not been seen yet.
6703 elsif No
(Body_Id
) then
6705 ("cannot inline & (body not seen yet)?", N
, Nam_UA
);
6707 -- Nothing to do if there is no body to inline, indicating that
6708 -- the subprogram is not suitable for inlining in GNATprove
6711 elsif No
(Body_To_Inline
(Nam_Decl
)) then
6714 -- Calls cannot be inlined inside potentially unevaluated
6715 -- expressions, as this would create complex actions inside
6716 -- expressions, that are not handled by GNATprove.
6718 elsif Is_Potentially_Unevaluated
(N
) then
6720 ("cannot inline & (in potentially unevaluated context)?",
6723 -- Do not inline calls which would possibly lead to missing a
6724 -- type conversion check on an input parameter.
6726 elsif not Call_Can_Be_Inlined_In_GNATprove_Mode
(N
, Nam
) then
6728 ("cannot inline & (possible check on input parameters)?",
6731 -- Otherwise, inline the call
6734 Expand_Inlined_Call
(N
, Nam_UA
, Nam
);
6740 Mark_Use_Clauses
(Subp
);
6742 Warn_On_Overlapping_Actuals
(Nam
, N
);
6745 -----------------------------
6746 -- Resolve_Case_Expression --
6747 -----------------------------
6749 procedure Resolve_Case_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
6752 Alt_Typ
: Entity_Id
;
6756 Alt
:= First
(Alternatives
(N
));
6757 while Present
(Alt
) loop
6758 Alt_Expr
:= Expression
(Alt
);
6760 if Error_Posted
(Alt_Expr
) then
6764 Resolve
(Alt_Expr
, Typ
);
6765 Alt_Typ
:= Etype
(Alt_Expr
);
6767 -- When the expression is of a scalar subtype different from the
6768 -- result subtype, then insert a conversion to ensure the generation
6769 -- of a constraint check.
6771 if Is_Scalar_Type
(Alt_Typ
) and then Alt_Typ
/= Typ
then
6772 Rewrite
(Alt_Expr
, Convert_To
(Typ
, Alt_Expr
));
6773 Analyze_And_Resolve
(Alt_Expr
, Typ
);
6779 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
6780 -- dynamically tagged must be known statically.
6782 if Is_Tagged_Type
(Typ
) and then not Is_Class_Wide_Type
(Typ
) then
6783 Alt
:= First
(Alternatives
(N
));
6784 Is_Dyn
:= Is_Dynamically_Tagged
(Expression
(Alt
));
6786 while Present
(Alt
) loop
6787 if Is_Dynamically_Tagged
(Expression
(Alt
)) /= Is_Dyn
then
6789 ("all or none of the dependent expressions can be "
6790 & "dynamically tagged", N
);
6798 Eval_Case_Expression
(N
);
6799 Analyze_Dimension
(N
);
6800 end Resolve_Case_Expression
;
6802 -------------------------------
6803 -- Resolve_Character_Literal --
6804 -------------------------------
6806 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
6807 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
6811 -- Verify that the character does belong to the type of the context
6813 Set_Etype
(N
, B_Typ
);
6814 Eval_Character_Literal
(N
);
6816 -- Wide_Wide_Character literals must always be defined, since the set
6817 -- of wide wide character literals is complete, i.e. if a character
6818 -- literal is accepted by the parser, then it is OK for wide wide
6819 -- character (out of range character literals are rejected).
6821 if Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
6824 -- Always accept character literal for type Any_Character, which
6825 -- occurs in error situations and in comparisons of literals, both
6826 -- of which should accept all literals.
6828 elsif B_Typ
= Any_Character
then
6831 -- For Standard.Character or a type derived from it, check that the
6832 -- literal is in range.
6834 elsif Root_Type
(B_Typ
) = Standard_Character
then
6835 if In_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6839 -- For Standard.Wide_Character or a type derived from it, check that the
6840 -- literal is in range.
6842 elsif Root_Type
(B_Typ
) = Standard_Wide_Character
then
6843 if In_Wide_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6847 -- If the entity is already set, this has already been resolved in a
6848 -- generic context, or comes from expansion. Nothing else to do.
6850 elsif Present
(Entity
(N
)) then
6853 -- Otherwise we have a user defined character type, and we can use the
6854 -- standard visibility mechanisms to locate the referenced entity.
6857 C
:= Current_Entity
(N
);
6858 while Present
(C
) loop
6859 if Etype
(C
) = B_Typ
then
6860 Set_Entity_With_Checks
(N
, C
);
6861 Generate_Reference
(C
, N
);
6869 -- If we fall through, then the literal does not match any of the
6870 -- entries of the enumeration type. This isn't just a constraint error
6871 -- situation, it is an illegality (see RM 4.2).
6874 ("character not defined for }", N
, First_Subtype
(B_Typ
));
6875 end Resolve_Character_Literal
;
6877 ---------------------------
6878 -- Resolve_Comparison_Op --
6879 ---------------------------
6881 -- Context requires a boolean type, and plays no role in resolution.
6882 -- Processing identical to that for equality operators. The result type is
6883 -- the base type, which matters when pathological subtypes of booleans with
6884 -- limited ranges are used.
6886 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
6887 L
: constant Node_Id
:= Left_Opnd
(N
);
6888 R
: constant Node_Id
:= Right_Opnd
(N
);
6892 -- If this is an intrinsic operation which is not predefined, use the
6893 -- types of its declared arguments to resolve the possibly overloaded
6894 -- operands. Otherwise the operands are unambiguous and specify the
6897 if Scope
(Entity
(N
)) /= Standard_Standard
then
6898 T
:= Etype
(First_Entity
(Entity
(N
)));
6901 T
:= Find_Unique_Type
(L
, R
);
6903 if T
= Any_Fixed
then
6904 T
:= Unique_Fixed_Point_Type
(L
);
6908 Set_Etype
(N
, Base_Type
(Typ
));
6909 Generate_Reference
(T
, N
, ' ');
6911 -- Skip remaining processing if already set to Any_Type
6913 if T
= Any_Type
then
6917 -- Deal with other error cases
6919 if T
= Any_String
or else
6920 T
= Any_Composite
or else
6923 if T
= Any_Character
then
6924 Ambiguous_Character
(L
);
6926 Error_Msg_N
("ambiguous operands for comparison", N
);
6929 Set_Etype
(N
, Any_Type
);
6933 -- Resolve the operands if types OK
6937 Check_Unset_Reference
(L
);
6938 Check_Unset_Reference
(R
);
6939 Generate_Operator_Reference
(N
, T
);
6940 Check_Low_Bound_Tested
(N
);
6942 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6943 -- types or array types except String.
6945 if Is_Boolean_Type
(T
) then
6946 Check_SPARK_05_Restriction
6947 ("comparison is not defined on Boolean type", N
);
6949 elsif Is_Array_Type
(T
)
6950 and then Base_Type
(T
) /= Standard_String
6952 Check_SPARK_05_Restriction
6953 ("comparison is not defined on array types other than String", N
);
6956 -- Check comparison on unordered enumeration
6958 if Bad_Unordered_Enumeration_Reference
(N
, Etype
(L
)) then
6959 Error_Msg_Sloc
:= Sloc
(Etype
(L
));
6961 ("comparison on unordered enumeration type& declared#?U?",
6965 Analyze_Dimension
(N
);
6967 -- Evaluate the relation (note we do this after the above check since
6968 -- this Eval call may change N to True/False. Skip this evaluation
6969 -- inside assertions, in order to keep assertions as written by users
6970 -- for tools that rely on these, e.g. GNATprove for loop invariants.
6971 -- Except evaluation is still performed even inside assertions for
6972 -- comparisons between values of universal type, which are useless
6973 -- for static analysis tools, and not supported even by GNATprove.
6975 if In_Assertion_Expr
= 0
6976 or else (Is_Universal_Numeric_Type
(Etype
(L
))
6978 Is_Universal_Numeric_Type
(Etype
(R
)))
6980 Eval_Relational_Op
(N
);
6982 end Resolve_Comparison_Op
;
6984 -----------------------------------------
6985 -- Resolve_Discrete_Subtype_Indication --
6986 -----------------------------------------
6988 procedure Resolve_Discrete_Subtype_Indication
6996 Analyze
(Subtype_Mark
(N
));
6997 S
:= Entity
(Subtype_Mark
(N
));
6999 if Nkind
(Constraint
(N
)) /= N_Range_Constraint
then
7000 Error_Msg_N
("expect range constraint for discrete type", N
);
7001 Set_Etype
(N
, Any_Type
);
7004 R
:= Range_Expression
(Constraint
(N
));
7012 if Base_Type
(S
) /= Base_Type
(Typ
) then
7014 ("expect subtype of }", N
, First_Subtype
(Typ
));
7016 -- Rewrite the constraint as a range of Typ
7017 -- to allow compilation to proceed further.
7020 Rewrite
(Low_Bound
(R
),
7021 Make_Attribute_Reference
(Sloc
(Low_Bound
(R
)),
7022 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
7023 Attribute_Name
=> Name_First
));
7024 Rewrite
(High_Bound
(R
),
7025 Make_Attribute_Reference
(Sloc
(High_Bound
(R
)),
7026 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
7027 Attribute_Name
=> Name_First
));
7031 Set_Etype
(N
, Etype
(R
));
7033 -- Additionally, we must check that the bounds are compatible
7034 -- with the given subtype, which might be different from the
7035 -- type of the context.
7037 Apply_Range_Check
(R
, S
);
7039 -- ??? If the above check statically detects a Constraint_Error
7040 -- it replaces the offending bound(s) of the range R with a
7041 -- Constraint_Error node. When the itype which uses these bounds
7042 -- is frozen the resulting call to Duplicate_Subexpr generates
7043 -- a new temporary for the bounds.
7045 -- Unfortunately there are other itypes that are also made depend
7046 -- on these bounds, so when Duplicate_Subexpr is called they get
7047 -- a forward reference to the newly created temporaries and Gigi
7048 -- aborts on such forward references. This is probably sign of a
7049 -- more fundamental problem somewhere else in either the order of
7050 -- itype freezing or the way certain itypes are constructed.
7052 -- To get around this problem we call Remove_Side_Effects right
7053 -- away if either bounds of R are a Constraint_Error.
7056 L
: constant Node_Id
:= Low_Bound
(R
);
7057 H
: constant Node_Id
:= High_Bound
(R
);
7060 if Nkind
(L
) = N_Raise_Constraint_Error
then
7061 Remove_Side_Effects
(L
);
7064 if Nkind
(H
) = N_Raise_Constraint_Error
then
7065 Remove_Side_Effects
(H
);
7069 Check_Unset_Reference
(Low_Bound
(R
));
7070 Check_Unset_Reference
(High_Bound
(R
));
7073 end Resolve_Discrete_Subtype_Indication
;
7075 -------------------------
7076 -- Resolve_Entity_Name --
7077 -------------------------
7079 -- Used to resolve identifiers and expanded names
7081 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
) is
7082 function Is_Assignment_Or_Object_Expression
7084 Expr
: Node_Id
) return Boolean;
7085 -- Determine whether node Context denotes an assignment statement or an
7086 -- object declaration whose expression is node Expr.
7088 ----------------------------------------
7089 -- Is_Assignment_Or_Object_Expression --
7090 ----------------------------------------
7092 function Is_Assignment_Or_Object_Expression
7094 Expr
: Node_Id
) return Boolean
7097 if Nkind_In
(Context
, N_Assignment_Statement
,
7098 N_Object_Declaration
)
7099 and then Expression
(Context
) = Expr
7103 -- Check whether a construct that yields a name is the expression of
7104 -- an assignment statement or an object declaration.
7106 elsif (Nkind_In
(Context
, N_Attribute_Reference
,
7107 N_Explicit_Dereference
,
7108 N_Indexed_Component
,
7109 N_Selected_Component
,
7111 and then Prefix
(Context
) = Expr
)
7113 (Nkind_In
(Context
, N_Type_Conversion
,
7114 N_Unchecked_Type_Conversion
)
7115 and then Expression
(Context
) = Expr
)
7118 Is_Assignment_Or_Object_Expression
7119 (Context
=> Parent
(Context
),
7122 -- Otherwise the context is not an assignment statement or an object
7128 end Is_Assignment_Or_Object_Expression
;
7132 E
: constant Entity_Id
:= Entity
(N
);
7135 -- Start of processing for Resolve_Entity_Name
7138 -- If garbage from errors, set to Any_Type and return
7140 if No
(E
) and then Total_Errors_Detected
/= 0 then
7141 Set_Etype
(N
, Any_Type
);
7145 -- Replace named numbers by corresponding literals. Note that this is
7146 -- the one case where Resolve_Entity_Name must reset the Etype, since
7147 -- it is currently marked as universal.
7149 if Ekind
(E
) = E_Named_Integer
then
7151 Eval_Named_Integer
(N
);
7153 elsif Ekind
(E
) = E_Named_Real
then
7155 Eval_Named_Real
(N
);
7157 -- For enumeration literals, we need to make sure that a proper style
7158 -- check is done, since such literals are overloaded, and thus we did
7159 -- not do a style check during the first phase of analysis.
7161 elsif Ekind
(E
) = E_Enumeration_Literal
then
7162 Set_Entity_With_Checks
(N
, E
);
7163 Eval_Entity_Name
(N
);
7165 -- Case of (sub)type name appearing in a context where an expression
7166 -- is expected. This is legal if occurrence is a current instance.
7167 -- See RM 8.6 (17/3).
7169 elsif Is_Type
(E
) then
7170 if Is_Current_Instance
(N
) then
7173 -- Any other use is an error
7177 ("invalid use of subtype mark in expression or call", N
);
7180 -- Check discriminant use if entity is discriminant in current scope,
7181 -- i.e. discriminant of record or concurrent type currently being
7182 -- analyzed. Uses in corresponding body are unrestricted.
7184 elsif Ekind
(E
) = E_Discriminant
7185 and then Scope
(E
) = Current_Scope
7186 and then not Has_Completion
(Current_Scope
)
7188 Check_Discriminant_Use
(N
);
7190 -- A parameterless generic function cannot appear in a context that
7191 -- requires resolution.
7193 elsif Ekind
(E
) = E_Generic_Function
then
7194 Error_Msg_N
("illegal use of generic function", N
);
7196 -- In Ada 83 an OUT parameter cannot be read, but attributes of
7197 -- array types (i.e. bounds and length) are legal.
7199 elsif Ekind
(E
) = E_Out_Parameter
7200 and then (Nkind
(Parent
(N
)) /= N_Attribute_Reference
7201 or else Is_Scalar_Type
(Etype
(E
)))
7203 and then (Nkind
(Parent
(N
)) in N_Op
7204 or else Nkind
(Parent
(N
)) = N_Explicit_Dereference
7205 or else Is_Assignment_Or_Object_Expression
7206 (Context
=> Parent
(N
),
7209 if Ada_Version
= Ada_83
then
7210 Error_Msg_N
("(Ada 83) illegal reading of out parameter", N
);
7213 -- In all other cases, just do the possible static evaluation
7216 -- A deferred constant that appears in an expression must have a
7217 -- completion, unless it has been removed by in-place expansion of
7218 -- an aggregate. A constant that is a renaming does not need
7221 if Ekind
(E
) = E_Constant
7222 and then Comes_From_Source
(E
)
7223 and then No
(Constant_Value
(E
))
7224 and then Is_Frozen
(Etype
(E
))
7225 and then not In_Spec_Expression
7226 and then not Is_Imported
(E
)
7227 and then Nkind
(Parent
(E
)) /= N_Object_Renaming_Declaration
7229 if No_Initialization
(Parent
(E
))
7230 or else (Present
(Full_View
(E
))
7231 and then No_Initialization
(Parent
(Full_View
(E
))))
7236 ("deferred constant is frozen before completion", N
);
7240 Eval_Entity_Name
(N
);
7245 -- When the entity appears in a parameter association, retrieve the
7246 -- related subprogram call.
7248 if Nkind
(Par
) = N_Parameter_Association
then
7249 Par
:= Parent
(Par
);
7252 if Comes_From_Source
(N
) then
7254 -- The following checks are only relevant when SPARK_Mode is on as
7255 -- they are not standard Ada legality rules.
7257 if SPARK_Mode
= On
then
7259 -- An effectively volatile object subject to enabled properties
7260 -- Async_Writers or Effective_Reads must appear in non-interfering
7261 -- context (SPARK RM 7.1.3(12)).
7264 and then Is_Effectively_Volatile
(E
)
7265 and then (Async_Writers_Enabled
(E
)
7266 or else Effective_Reads_Enabled
(E
))
7267 and then not Is_OK_Volatile_Context
(Par
, N
)
7270 ("volatile object cannot appear in this context "
7271 & "(SPARK RM 7.1.3(12))", N
);
7274 -- Check for possible elaboration issues with respect to reads of
7275 -- variables. The act of renaming the variable is not considered a
7276 -- read as it simply establishes an alias.
7278 if Legacy_Elaboration_Checks
7279 and then Ekind
(E
) = E_Variable
7280 and then Dynamic_Elaboration_Checks
7281 and then Nkind
(Par
) /= N_Object_Renaming_Declaration
7283 Check_Elab_Call
(N
);
7287 -- The variable may eventually become a constituent of a single
7288 -- protected/task type. Record the reference now and verify its
7289 -- legality when analyzing the contract of the variable
7292 if Ekind
(E
) = E_Variable
then
7293 Record_Possible_Part_Of_Reference
(E
, N
);
7296 -- A Ghost entity must appear in a specific context
7298 if Is_Ghost_Entity
(E
) then
7299 Check_Ghost_Context
(E
, N
);
7303 Mark_Use_Clauses
(E
);
7304 end Resolve_Entity_Name
;
7310 procedure Resolve_Entry
(Entry_Name
: Node_Id
) is
7311 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
7319 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
;
7320 -- If the bounds of the entry family being called depend on task
7321 -- discriminants, build a new index subtype where a discriminant is
7322 -- replaced with the value of the discriminant of the target task.
7323 -- The target task is the prefix of the entry name in the call.
7325 -----------------------
7326 -- Actual_Index_Type --
7327 -----------------------
7329 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
is
7330 Typ
: constant Entity_Id
:= Entry_Index_Type
(E
);
7331 Tsk
: constant Entity_Id
:= Scope
(E
);
7332 Lo
: constant Node_Id
:= Type_Low_Bound
(Typ
);
7333 Hi
: constant Node_Id
:= Type_High_Bound
(Typ
);
7336 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
;
7337 -- If the bound is given by a discriminant, replace with a reference
7338 -- to the discriminant of the same name in the target task. If the
7339 -- entry name is the target of a requeue statement and the entry is
7340 -- in the current protected object, the bound to be used is the
7341 -- discriminal of the object (see Apply_Range_Checks for details of
7342 -- the transformation).
7344 -----------------------------
7345 -- Actual_Discriminant_Ref --
7346 -----------------------------
7348 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
is
7349 Typ
: constant Entity_Id
:= Etype
(Bound
);
7353 Remove_Side_Effects
(Bound
);
7355 if not Is_Entity_Name
(Bound
)
7356 or else Ekind
(Entity
(Bound
)) /= E_Discriminant
7360 elsif Is_Protected_Type
(Tsk
)
7361 and then In_Open_Scopes
(Tsk
)
7362 and then Nkind
(Parent
(Entry_Name
)) = N_Requeue_Statement
7364 -- Note: here Bound denotes a discriminant of the corresponding
7365 -- record type tskV, whose discriminal is a formal of the
7366 -- init-proc tskVIP. What we want is the body discriminal,
7367 -- which is associated to the discriminant of the original
7368 -- concurrent type tsk.
7370 return New_Occurrence_Of
7371 (Find_Body_Discriminal
(Entity
(Bound
)), Loc
);
7375 Make_Selected_Component
(Loc
,
7376 Prefix
=> New_Copy_Tree
(Prefix
(Prefix
(Entry_Name
))),
7377 Selector_Name
=> New_Occurrence_Of
(Entity
(Bound
), Loc
));
7382 end Actual_Discriminant_Ref
;
7384 -- Start of processing for Actual_Index_Type
7387 if not Has_Discriminants
(Tsk
)
7388 or else (not Is_Entity_Name
(Lo
) and then not Is_Entity_Name
(Hi
))
7390 return Entry_Index_Type
(E
);
7393 New_T
:= Create_Itype
(Ekind
(Typ
), Parent
(Entry_Name
));
7394 Set_Etype
(New_T
, Base_Type
(Typ
));
7395 Set_Size_Info
(New_T
, Typ
);
7396 Set_RM_Size
(New_T
, RM_Size
(Typ
));
7397 Set_Scalar_Range
(New_T
,
7398 Make_Range
(Sloc
(Entry_Name
),
7399 Low_Bound
=> Actual_Discriminant_Ref
(Lo
),
7400 High_Bound
=> Actual_Discriminant_Ref
(Hi
)));
7404 end Actual_Index_Type
;
7406 -- Start of processing for Resolve_Entry
7409 -- Find name of entry being called, and resolve prefix of name with its
7410 -- own type. The prefix can be overloaded, and the name and signature of
7411 -- the entry must be taken into account.
7413 if Nkind
(Entry_Name
) = N_Indexed_Component
then
7415 -- Case of dealing with entry family within the current tasks
7417 E_Name
:= Prefix
(Entry_Name
);
7420 E_Name
:= Entry_Name
;
7423 if Is_Entity_Name
(E_Name
) then
7425 -- Entry call to an entry (or entry family) in the current task. This
7426 -- is legal even though the task will deadlock. Rewrite as call to
7429 -- This can also be a call to an entry in an enclosing task. If this
7430 -- is a single task, we have to retrieve its name, because the scope
7431 -- of the entry is the task type, not the object. If the enclosing
7432 -- task is a task type, the identity of the task is given by its own
7435 -- Finally this can be a requeue on an entry of the same task or
7436 -- protected object.
7438 S
:= Scope
(Entity
(E_Name
));
7440 for J
in reverse 0 .. Scope_Stack
.Last
loop
7441 if Is_Task_Type
(Scope_Stack
.Table
(J
).Entity
)
7442 and then not Comes_From_Source
(S
)
7444 -- S is an enclosing task or protected object. The concurrent
7445 -- declaration has been converted into a type declaration, and
7446 -- the object itself has an object declaration that follows
7447 -- the type in the same declarative part.
7449 Tsk
:= Next_Entity
(S
);
7450 while Etype
(Tsk
) /= S
loop
7457 elsif S
= Scope_Stack
.Table
(J
).Entity
then
7459 -- Call to current task. Will be transformed into call to Self
7467 Make_Selected_Component
(Loc
,
7468 Prefix
=> New_Occurrence_Of
(S
, Loc
),
7470 New_Occurrence_Of
(Entity
(E_Name
), Loc
));
7471 Rewrite
(E_Name
, New_N
);
7474 elsif Nkind
(Entry_Name
) = N_Selected_Component
7475 and then Is_Overloaded
(Prefix
(Entry_Name
))
7477 -- Use the entry name (which must be unique at this point) to find
7478 -- the prefix that returns the corresponding task/protected type.
7481 Pref
: constant Node_Id
:= Prefix
(Entry_Name
);
7482 Ent
: constant Entity_Id
:= Entity
(Selector_Name
(Entry_Name
));
7487 Get_First_Interp
(Pref
, I
, It
);
7488 while Present
(It
.Typ
) loop
7489 if Scope
(Ent
) = It
.Typ
then
7490 Set_Etype
(Pref
, It
.Typ
);
7494 Get_Next_Interp
(I
, It
);
7499 if Nkind
(Entry_Name
) = N_Selected_Component
then
7500 Resolve
(Prefix
(Entry_Name
));
7502 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7503 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
7504 Resolve
(Prefix
(Prefix
(Entry_Name
)));
7505 Index
:= First
(Expressions
(Entry_Name
));
7506 Resolve
(Index
, Entry_Index_Type
(Nam
));
7508 -- Generate a reference for the index when it denotes an entity
7510 if Is_Entity_Name
(Index
) then
7511 Generate_Reference
(Entity
(Index
), Nam
);
7514 -- Up to this point the expression could have been the actual in a
7515 -- simple entry call, and be given by a named association.
7517 if Nkind
(Index
) = N_Parameter_Association
then
7518 Error_Msg_N
("expect expression for entry index", Index
);
7520 Apply_Range_Check
(Index
, Actual_Index_Type
(Nam
));
7525 ------------------------
7526 -- Resolve_Entry_Call --
7527 ------------------------
7529 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
7530 Entry_Name
: constant Node_Id
:= Name
(N
);
7531 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
7539 -- We kill all checks here, because it does not seem worth the effort to
7540 -- do anything better, an entry call is a big operation.
7544 -- Processing of the name is similar for entry calls and protected
7545 -- operation calls. Once the entity is determined, we can complete
7546 -- the resolution of the actuals.
7548 -- The selector may be overloaded, in the case of a protected object
7549 -- with overloaded functions. The type of the context is used for
7552 if Nkind
(Entry_Name
) = N_Selected_Component
7553 and then Is_Overloaded
(Selector_Name
(Entry_Name
))
7554 and then Typ
/= Standard_Void_Type
7561 Get_First_Interp
(Selector_Name
(Entry_Name
), I
, It
);
7562 while Present
(It
.Typ
) loop
7563 if Covers
(Typ
, It
.Typ
) then
7564 Set_Entity
(Selector_Name
(Entry_Name
), It
.Nam
);
7565 Set_Etype
(Entry_Name
, It
.Typ
);
7567 Generate_Reference
(It
.Typ
, N
, ' ');
7570 Get_Next_Interp
(I
, It
);
7575 Resolve_Entry
(Entry_Name
);
7577 if Nkind
(Entry_Name
) = N_Selected_Component
then
7579 -- Simple entry or protected operation call
7581 Nam
:= Entity
(Selector_Name
(Entry_Name
));
7582 Obj
:= Prefix
(Entry_Name
);
7584 if Is_Subprogram
(Nam
) then
7585 Check_For_Eliminated_Subprogram
(Entry_Name
, Nam
);
7588 Was_Over
:= Is_Overloaded
(Selector_Name
(Entry_Name
));
7590 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7592 -- Call to member of entry family
7594 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
7595 Obj
:= Prefix
(Prefix
(Entry_Name
));
7596 Was_Over
:= Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)));
7599 -- We cannot in general check the maximum depth of protected entry calls
7600 -- at compile time. But we can tell that any protected entry call at all
7601 -- violates a specified nesting depth of zero.
7603 if Is_Protected_Type
(Scope
(Nam
)) then
7604 Check_Restriction
(Max_Entry_Queue_Length
, N
);
7607 -- Use context type to disambiguate a protected function that can be
7608 -- called without actuals and that returns an array type, and where the
7609 -- argument list may be an indexing of the returned value.
7611 if Ekind
(Nam
) = E_Function
7612 and then Needs_No_Actuals
(Nam
)
7613 and then Present
(Parameter_Associations
(N
))
7615 ((Is_Array_Type
(Etype
(Nam
))
7616 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
7618 or else (Is_Access_Type
(Etype
(Nam
))
7619 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
7623 Component_Type
(Designated_Type
(Etype
(Nam
))))))
7626 Index_Node
: Node_Id
;
7630 Make_Indexed_Component
(Loc
,
7632 Make_Function_Call
(Loc
, Name
=> Relocate_Node
(Entry_Name
)),
7633 Expressions
=> Parameter_Associations
(N
));
7635 -- Since we are correcting a node classification error made by the
7636 -- parser, we call Replace rather than Rewrite.
7638 Replace
(N
, Index_Node
);
7639 Set_Etype
(Prefix
(N
), Etype
(Nam
));
7641 Resolve_Indexed_Component
(N
, Typ
);
7646 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
)
7647 and then Present
(Contract_Wrapper
(Nam
))
7648 and then Current_Scope
/= Contract_Wrapper
(Nam
)
7650 -- Note the entity being called before rewriting the call, so that
7651 -- it appears used at this point.
7653 Generate_Reference
(Nam
, Entry_Name
, 'r');
7655 -- Rewrite as call to the precondition wrapper, adding the task
7656 -- object to the list of actuals. If the call is to a member of an
7657 -- entry family, include the index as well.
7661 New_Actuals
: List_Id
;
7664 New_Actuals
:= New_List
(Obj
);
7666 if Nkind
(Entry_Name
) = N_Indexed_Component
then
7667 Append_To
(New_Actuals
,
7668 New_Copy_Tree
(First
(Expressions
(Entry_Name
))));
7671 Append_List
(Parameter_Associations
(N
), New_Actuals
);
7673 Make_Procedure_Call_Statement
(Loc
,
7675 New_Occurrence_Of
(Contract_Wrapper
(Nam
), Loc
),
7676 Parameter_Associations
=> New_Actuals
);
7677 Rewrite
(N
, New_Call
);
7679 -- Preanalyze and resolve new call. Current procedure is called
7680 -- from Resolve_Call, after which expansion will take place.
7682 Preanalyze_And_Resolve
(N
);
7687 -- The operation name may have been overloaded. Order the actuals
7688 -- according to the formals of the resolved entity, and set the return
7689 -- type to that of the operation.
7692 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
7693 pragma Assert
(Norm_OK
);
7694 Set_Etype
(N
, Etype
(Nam
));
7696 -- Reset the Is_Overloaded flag, since resolution is now completed
7698 -- Simple entry call
7700 if Nkind
(Entry_Name
) = N_Selected_Component
then
7701 Set_Is_Overloaded
(Selector_Name
(Entry_Name
), False);
7703 -- Call to a member of an entry family
7705 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7706 Set_Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)), False);
7710 Resolve_Actuals
(N
, Nam
);
7711 Check_Internal_Protected_Use
(N
, Nam
);
7713 -- Create a call reference to the entry
7715 Generate_Reference
(Nam
, Entry_Name
, 's');
7717 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
) then
7718 Check_Potentially_Blocking_Operation
(N
);
7721 -- Verify that a procedure call cannot masquerade as an entry
7722 -- call where an entry call is expected.
7724 if Ekind
(Nam
) = E_Procedure
then
7725 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
7726 and then N
= Entry_Call_Statement
(Parent
(N
))
7728 Error_Msg_N
("entry call required in select statement", N
);
7730 elsif Nkind
(Parent
(N
)) = N_Triggering_Alternative
7731 and then N
= Triggering_Statement
(Parent
(N
))
7733 Error_Msg_N
("triggering statement cannot be procedure call", N
);
7735 elsif Ekind
(Scope
(Nam
)) = E_Task_Type
7736 and then not In_Open_Scopes
(Scope
(Nam
))
7738 Error_Msg_N
("task has no entry with this name", Entry_Name
);
7742 -- After resolution, entry calls and protected procedure calls are
7743 -- changed into entry calls, for expansion. The structure of the node
7744 -- does not change, so it can safely be done in place. Protected
7745 -- function calls must keep their structure because they are
7748 if Ekind
(Nam
) /= E_Function
then
7750 -- A protected operation that is not a function may modify the
7751 -- corresponding object, and cannot apply to a constant. If this
7752 -- is an internal call, the prefix is the type itself.
7754 if Is_Protected_Type
(Scope
(Nam
))
7755 and then not Is_Variable
(Obj
)
7756 and then (not Is_Entity_Name
(Obj
)
7757 or else not Is_Type
(Entity
(Obj
)))
7760 ("prefix of protected procedure or entry call must be variable",
7765 Entry_Call
: Node_Id
;
7769 Make_Entry_Call_Statement
(Loc
,
7771 Parameter_Associations
=> Parameter_Associations
(N
));
7773 -- Inherit relevant attributes from the original call
7775 Set_First_Named_Actual
7776 (Entry_Call
, First_Named_Actual
(N
));
7778 Set_Is_Elaboration_Checks_OK_Node
7779 (Entry_Call
, Is_Elaboration_Checks_OK_Node
(N
));
7781 Set_Is_Elaboration_Warnings_OK_Node
7782 (Entry_Call
, Is_Elaboration_Warnings_OK_Node
(N
));
7784 Set_Is_SPARK_Mode_On_Node
7785 (Entry_Call
, Is_SPARK_Mode_On_Node
(N
));
7787 Rewrite
(N
, Entry_Call
);
7788 Set_Analyzed
(N
, True);
7791 -- Protected functions can return on the secondary stack, in which case
7792 -- we must trigger the transient scope mechanism.
7794 elsif Expander_Active
7795 and then Requires_Transient_Scope
(Etype
(Nam
))
7797 Establish_Transient_Scope
(N
, Manage_Sec_Stack
=> True);
7799 end Resolve_Entry_Call
;
7801 -------------------------
7802 -- Resolve_Equality_Op --
7803 -------------------------
7805 -- Both arguments must have the same type, and the boolean context does
7806 -- not participate in the resolution. The first pass verifies that the
7807 -- interpretation is not ambiguous, and the type of the left argument is
7808 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7809 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7810 -- though they carry a single (universal) type. Diagnose this case here.
7812 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
7813 L
: constant Node_Id
:= Left_Opnd
(N
);
7814 R
: constant Node_Id
:= Right_Opnd
(N
);
7815 T
: Entity_Id
:= Find_Unique_Type
(L
, R
);
7817 procedure Check_If_Expression
(Cond
: Node_Id
);
7818 -- The resolution rule for if expressions requires that each such must
7819 -- have a unique type. This means that if several dependent expressions
7820 -- are of a non-null anonymous access type, and the context does not
7821 -- impose an expected type (as can be the case in an equality operation)
7822 -- the expression must be rejected.
7824 procedure Explain_Redundancy
(N
: Node_Id
);
7825 -- Attempt to explain the nature of a redundant comparison with True. If
7826 -- the expression N is too complex, this routine issues a general error
7829 function Find_Unique_Access_Type
return Entity_Id
;
7830 -- In the case of allocators and access attributes, the context must
7831 -- provide an indication of the specific access type to be used. If
7832 -- one operand is of such a "generic" access type, check whether there
7833 -- is a specific visible access type that has the same designated type.
7834 -- This is semantically dubious, and of no interest to any real code,
7835 -- but c48008a makes it all worthwhile.
7837 -------------------------
7838 -- Check_If_Expression --
7839 -------------------------
7841 procedure Check_If_Expression
(Cond
: Node_Id
) is
7842 Then_Expr
: Node_Id
;
7843 Else_Expr
: Node_Id
;
7846 if Nkind
(Cond
) = N_If_Expression
then
7847 Then_Expr
:= Next
(First
(Expressions
(Cond
)));
7848 Else_Expr
:= Next
(Then_Expr
);
7850 if Nkind
(Then_Expr
) /= N_Null
7851 and then Nkind
(Else_Expr
) /= N_Null
7853 Error_Msg_N
("cannot determine type of if expression", Cond
);
7856 end Check_If_Expression
;
7858 ------------------------
7859 -- Explain_Redundancy --
7860 ------------------------
7862 procedure Explain_Redundancy
(N
: Node_Id
) is
7870 -- Strip the operand down to an entity
7873 if Nkind
(Val
) = N_Selected_Component
then
7874 Val
:= Selector_Name
(Val
);
7880 -- The construct denotes an entity
7882 if Is_Entity_Name
(Val
) and then Present
(Entity
(Val
)) then
7883 Val_Id
:= Entity
(Val
);
7885 -- Do not generate an error message when the comparison is done
7886 -- against the enumeration literal Standard.True.
7888 if Ekind
(Val_Id
) /= E_Enumeration_Literal
then
7890 -- Build a customized error message
7893 Add_Str_To_Name_Buffer
("?r?");
7895 if Ekind
(Val_Id
) = E_Component
then
7896 Add_Str_To_Name_Buffer
("component ");
7898 elsif Ekind
(Val_Id
) = E_Constant
then
7899 Add_Str_To_Name_Buffer
("constant ");
7901 elsif Ekind
(Val_Id
) = E_Discriminant
then
7902 Add_Str_To_Name_Buffer
("discriminant ");
7904 elsif Is_Formal
(Val_Id
) then
7905 Add_Str_To_Name_Buffer
("parameter ");
7907 elsif Ekind
(Val_Id
) = E_Variable
then
7908 Add_Str_To_Name_Buffer
("variable ");
7911 Add_Str_To_Name_Buffer
("& is always True!");
7914 Error_Msg_NE
(Get_Name_String
(Error
), Val
, Val_Id
);
7917 -- The construct is too complex to disect, issue a general message
7920 Error_Msg_N
("?r?expression is always True!", Val
);
7922 end Explain_Redundancy
;
7924 -----------------------------
7925 -- Find_Unique_Access_Type --
7926 -----------------------------
7928 function Find_Unique_Access_Type
return Entity_Id
is
7934 if Ekind_In
(Etype
(R
), E_Allocator_Type
,
7935 E_Access_Attribute_Type
)
7937 Acc
:= Designated_Type
(Etype
(R
));
7939 elsif Ekind_In
(Etype
(L
), E_Allocator_Type
,
7940 E_Access_Attribute_Type
)
7942 Acc
:= Designated_Type
(Etype
(L
));
7948 while S
/= Standard_Standard
loop
7949 E
:= First_Entity
(S
);
7950 while Present
(E
) loop
7952 and then Is_Access_Type
(E
)
7953 and then Ekind
(E
) /= E_Allocator_Type
7954 and then Designated_Type
(E
) = Base_Type
(Acc
)
7966 end Find_Unique_Access_Type
;
7968 -- Start of processing for Resolve_Equality_Op
7971 Set_Etype
(N
, Base_Type
(Typ
));
7972 Generate_Reference
(T
, N
, ' ');
7974 if T
= Any_Fixed
then
7975 T
:= Unique_Fixed_Point_Type
(L
);
7978 if T
/= Any_Type
then
7979 if T
= Any_String
or else
7980 T
= Any_Composite
or else
7983 if T
= Any_Character
then
7984 Ambiguous_Character
(L
);
7986 Error_Msg_N
("ambiguous operands for equality", N
);
7989 Set_Etype
(N
, Any_Type
);
7992 elsif T
= Any_Access
7993 or else Ekind_In
(T
, E_Allocator_Type
, E_Access_Attribute_Type
)
7995 T
:= Find_Unique_Access_Type
;
7998 Error_Msg_N
("ambiguous operands for equality", N
);
7999 Set_Etype
(N
, Any_Type
);
8003 -- If expressions must have a single type, and if the context does
8004 -- not impose one the dependent expressions cannot be anonymous
8007 -- Why no similar processing for case expressions???
8009 elsif Ada_Version
>= Ada_2012
8010 and then Ekind_In
(Etype
(L
), E_Anonymous_Access_Type
,
8011 E_Anonymous_Access_Subprogram_Type
)
8012 and then Ekind_In
(Etype
(R
), E_Anonymous_Access_Type
,
8013 E_Anonymous_Access_Subprogram_Type
)
8015 Check_If_Expression
(L
);
8016 Check_If_Expression
(R
);
8022 -- In SPARK, equality operators = and /= for array types other than
8023 -- String are only defined when, for each index position, the
8024 -- operands have equal static bounds.
8026 if Is_Array_Type
(T
) then
8028 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8029 -- operation if not needed.
8031 if Restriction_Check_Required
(SPARK_05
)
8032 and then Base_Type
(T
) /= Standard_String
8033 and then Base_Type
(Etype
(L
)) = Base_Type
(Etype
(R
))
8034 and then Etype
(L
) /= Any_Composite
-- or else L in error
8035 and then Etype
(R
) /= Any_Composite
-- or else R in error
8036 and then not Matching_Static_Array_Bounds
(Etype
(L
), Etype
(R
))
8038 Check_SPARK_05_Restriction
8039 ("array types should have matching static bounds", N
);
8043 -- If the unique type is a class-wide type then it will be expanded
8044 -- into a dispatching call to the predefined primitive. Therefore we
8045 -- check here for potential violation of such restriction.
8047 if Is_Class_Wide_Type
(T
) then
8048 Check_Restriction
(No_Dispatching_Calls
, N
);
8051 -- Only warn for redundant equality comparison to True for objects
8052 -- (e.g. "X = True") and operations (e.g. "(X < Y) = True"). For
8053 -- other expressions, it may be a matter of preference to write
8054 -- "Expr = True" or "Expr".
8056 if Warn_On_Redundant_Constructs
8057 and then Comes_From_Source
(N
)
8058 and then Comes_From_Source
(R
)
8059 and then Is_Entity_Name
(R
)
8060 and then Entity
(R
) = Standard_True
8062 ((Is_Entity_Name
(L
) and then Is_Object
(Entity
(L
)))
8066 Error_Msg_N
-- CODEFIX
8067 ("?r?comparison with True is redundant!", N
);
8068 Explain_Redundancy
(Original_Node
(R
));
8071 Check_Unset_Reference
(L
);
8072 Check_Unset_Reference
(R
);
8073 Generate_Operator_Reference
(N
, T
);
8074 Check_Low_Bound_Tested
(N
);
8076 -- If this is an inequality, it may be the implicit inequality
8077 -- created for a user-defined operation, in which case the corres-
8078 -- ponding equality operation is not intrinsic, and the operation
8079 -- cannot be constant-folded. Else fold.
8081 if Nkind
(N
) = N_Op_Eq
8082 or else Comes_From_Source
(Entity
(N
))
8083 or else Ekind
(Entity
(N
)) = E_Operator
8084 or else Is_Intrinsic_Subprogram
8085 (Corresponding_Equality
(Entity
(N
)))
8087 Analyze_Dimension
(N
);
8088 Eval_Relational_Op
(N
);
8090 elsif Nkind
(N
) = N_Op_Ne
8091 and then Is_Abstract_Subprogram
(Entity
(N
))
8093 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Entity
(N
));
8096 -- Ada 2005: If one operand is an anonymous access type, convert the
8097 -- other operand to it, to ensure that the underlying types match in
8098 -- the back-end. Same for access_to_subprogram, and the conversion
8099 -- verifies that the types are subtype conformant.
8101 -- We apply the same conversion in the case one of the operands is a
8102 -- private subtype of the type of the other.
8104 -- Why the Expander_Active test here ???
8108 (Ekind_In
(T
, E_Anonymous_Access_Type
,
8109 E_Anonymous_Access_Subprogram_Type
)
8110 or else Is_Private_Type
(T
))
8112 if Etype
(L
) /= T
then
8114 Make_Unchecked_Type_Conversion
(Sloc
(L
),
8115 Subtype_Mark
=> New_Occurrence_Of
(T
, Sloc
(L
)),
8116 Expression
=> Relocate_Node
(L
)));
8117 Analyze_And_Resolve
(L
, T
);
8120 if (Etype
(R
)) /= T
then
8122 Make_Unchecked_Type_Conversion
(Sloc
(R
),
8123 Subtype_Mark
=> New_Occurrence_Of
(Etype
(L
), Sloc
(R
)),
8124 Expression
=> Relocate_Node
(R
)));
8125 Analyze_And_Resolve
(R
, T
);
8129 end Resolve_Equality_Op
;
8131 ----------------------------------
8132 -- Resolve_Explicit_Dereference --
8133 ----------------------------------
8135 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
) is
8136 Loc
: constant Source_Ptr
:= Sloc
(N
);
8138 P
: constant Node_Id
:= Prefix
(N
);
8141 -- The candidate prefix type, if overloaded
8147 Check_Fully_Declared_Prefix
(Typ
, P
);
8150 -- A useful optimization: check whether the dereference denotes an
8151 -- element of a container, and if so rewrite it as a call to the
8152 -- corresponding Element function.
8154 -- Disabled for now, on advice of ARG. A more restricted form of the
8155 -- predicate might be acceptable ???
8157 -- if Is_Container_Element (N) then
8161 if Is_Overloaded
(P
) then
8163 -- Use the context type to select the prefix that has the correct
8164 -- designated type. Keep the first match, which will be the inner-
8167 Get_First_Interp
(P
, I
, It
);
8169 while Present
(It
.Typ
) loop
8170 if Is_Access_Type
(It
.Typ
)
8171 and then Covers
(Typ
, Designated_Type
(It
.Typ
))
8177 -- Remove access types that do not match, but preserve access
8178 -- to subprogram interpretations, in case a further dereference
8179 -- is needed (see below).
8181 elsif Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
8185 Get_Next_Interp
(I
, It
);
8188 if Present
(P_Typ
) then
8190 Set_Etype
(N
, Designated_Type
(P_Typ
));
8193 -- If no interpretation covers the designated type of the prefix,
8194 -- this is the pathological case where not all implementations of
8195 -- the prefix allow the interpretation of the node as a call. Now
8196 -- that the expected type is known, Remove other interpretations
8197 -- from prefix, rewrite it as a call, and resolve again, so that
8198 -- the proper call node is generated.
8200 Get_First_Interp
(P
, I
, It
);
8201 while Present
(It
.Typ
) loop
8202 if Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
8206 Get_Next_Interp
(I
, It
);
8210 Make_Function_Call
(Loc
,
8212 Make_Explicit_Dereference
(Loc
,
8214 Parameter_Associations
=> New_List
);
8216 Save_Interps
(N
, New_N
);
8218 Analyze_And_Resolve
(N
, Typ
);
8222 -- If not overloaded, resolve P with its own type
8228 -- If the prefix might be null, add an access check
8230 if Is_Access_Type
(Etype
(P
))
8231 and then not Can_Never_Be_Null
(Etype
(P
))
8233 Apply_Access_Check
(N
);
8236 -- If the designated type is a packed unconstrained array type, and the
8237 -- explicit dereference is not in the context of an attribute reference,
8238 -- then we must compute and set the actual subtype, since it is needed
8239 -- by Gigi. The reason we exclude the attribute case is that this is
8240 -- handled fine by Gigi, and in fact we use such attributes to build the
8241 -- actual subtype. We also exclude generated code (which builds actual
8242 -- subtypes directly if they are needed).
8244 if Is_Array_Type
(Etype
(N
))
8245 and then Is_Packed
(Etype
(N
))
8246 and then not Is_Constrained
(Etype
(N
))
8247 and then Nkind
(Parent
(N
)) /= N_Attribute_Reference
8248 and then Comes_From_Source
(N
)
8250 Set_Etype
(N
, Get_Actual_Subtype
(N
));
8253 Analyze_Dimension
(N
);
8255 -- Note: No Eval processing is required for an explicit dereference,
8256 -- because such a name can never be static.
8258 end Resolve_Explicit_Dereference
;
8260 -------------------------------------
8261 -- Resolve_Expression_With_Actions --
8262 -------------------------------------
8264 procedure Resolve_Expression_With_Actions
(N
: Node_Id
; Typ
: Entity_Id
) is
8268 -- If N has no actions, and its expression has been constant folded,
8269 -- then rewrite N as just its expression. Note, we can't do this in
8270 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8271 -- Expression (N) to be expanded again.
8273 if Is_Empty_List
(Actions
(N
))
8274 and then Compile_Time_Known_Value
(Expression
(N
))
8276 Rewrite
(N
, Expression
(N
));
8278 end Resolve_Expression_With_Actions
;
8280 ----------------------------------
8281 -- Resolve_Generalized_Indexing --
8282 ----------------------------------
8284 procedure Resolve_Generalized_Indexing
(N
: Node_Id
; Typ
: Entity_Id
) is
8285 Indexing
: constant Node_Id
:= Generalized_Indexing
(N
);
8291 -- In ASIS mode, propagate the information about the indexes back to
8292 -- to the original indexing node. The generalized indexing is either
8293 -- a function call, or a dereference of one. The actuals include the
8294 -- prefix of the original node, which is the container expression.
8297 Resolve
(Indexing
, Typ
);
8298 Set_Etype
(N
, Etype
(Indexing
));
8299 Set_Is_Overloaded
(N
, False);
8302 while Nkind_In
(Call
, N_Explicit_Dereference
, N_Selected_Component
)
8304 Call
:= Prefix
(Call
);
8307 if Nkind
(Call
) = N_Function_Call
then
8308 Indexes
:= New_Copy_List
(Parameter_Associations
(Call
));
8309 Pref
:= Remove_Head
(Indexes
);
8310 Set_Expressions
(N
, Indexes
);
8312 -- If expression is to be reanalyzed, reset Generalized_Indexing
8313 -- to recreate call node, as is the case when the expression is
8314 -- part of an expression function.
8316 if In_Spec_Expression
then
8317 Set_Generalized_Indexing
(N
, Empty
);
8320 Set_Prefix
(N
, Pref
);
8324 Rewrite
(N
, Indexing
);
8327 end Resolve_Generalized_Indexing
;
8329 ---------------------------
8330 -- Resolve_If_Expression --
8331 ---------------------------
8333 procedure Resolve_If_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
8334 Condition
: constant Node_Id
:= First
(Expressions
(N
));
8335 Then_Expr
: Node_Id
;
8336 Else_Expr
: Node_Id
;
8337 Else_Typ
: Entity_Id
;
8338 Then_Typ
: Entity_Id
;
8341 -- Defend against malformed expressions
8343 if No
(Condition
) then
8347 Then_Expr
:= Next
(Condition
);
8349 if No
(Then_Expr
) then
8353 Else_Expr
:= Next
(Then_Expr
);
8355 Resolve
(Condition
, Any_Boolean
);
8356 Resolve
(Then_Expr
, Typ
);
8357 Then_Typ
:= Etype
(Then_Expr
);
8359 -- When the "then" expression is of a scalar subtype different from the
8360 -- result subtype, then insert a conversion to ensure the generation of
8361 -- a constraint check. The same is done for the else part below, again
8362 -- comparing subtypes rather than base types.
8364 if Is_Scalar_Type
(Then_Typ
) and then Then_Typ
/= Typ
then
8365 Rewrite
(Then_Expr
, Convert_To
(Typ
, Then_Expr
));
8366 Analyze_And_Resolve
(Then_Expr
, Typ
);
8369 -- If ELSE expression present, just resolve using the determined type
8370 -- If type is universal, resolve to any member of the class.
8372 if Present
(Else_Expr
) then
8373 if Typ
= Universal_Integer
then
8374 Resolve
(Else_Expr
, Any_Integer
);
8376 elsif Typ
= Universal_Real
then
8377 Resolve
(Else_Expr
, Any_Real
);
8380 Resolve
(Else_Expr
, Typ
);
8383 Else_Typ
:= Etype
(Else_Expr
);
8385 if Is_Scalar_Type
(Else_Typ
) and then Else_Typ
/= Typ
then
8386 Rewrite
(Else_Expr
, Convert_To
(Typ
, Else_Expr
));
8387 Analyze_And_Resolve
(Else_Expr
, Typ
);
8389 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8390 -- dynamically tagged must be known statically.
8392 elsif Is_Tagged_Type
(Typ
) and then not Is_Class_Wide_Type
(Typ
) then
8393 if Is_Dynamically_Tagged
(Then_Expr
) /=
8394 Is_Dynamically_Tagged
(Else_Expr
)
8396 Error_Msg_N
("all or none of the dependent expressions "
8397 & "can be dynamically tagged", N
);
8401 -- If no ELSE expression is present, root type must be Standard.Boolean
8402 -- and we provide a Standard.True result converted to the appropriate
8403 -- Boolean type (in case it is a derived boolean type).
8405 elsif Root_Type
(Typ
) = Standard_Boolean
then
8407 Convert_To
(Typ
, New_Occurrence_Of
(Standard_True
, Sloc
(N
)));
8408 Analyze_And_Resolve
(Else_Expr
, Typ
);
8409 Append_To
(Expressions
(N
), Else_Expr
);
8412 Error_Msg_N
("can only omit ELSE expression in Boolean case", N
);
8413 Append_To
(Expressions
(N
), Error
);
8418 if not Error_Posted
(N
) then
8419 Eval_If_Expression
(N
);
8422 Analyze_Dimension
(N
);
8423 end Resolve_If_Expression
;
8425 -------------------------------
8426 -- Resolve_Indexed_Component --
8427 -------------------------------
8429 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
8430 Name
: constant Node_Id
:= Prefix
(N
);
8432 Array_Type
: Entity_Id
:= Empty
; -- to prevent junk warning
8436 if Present
(Generalized_Indexing
(N
)) then
8437 Resolve_Generalized_Indexing
(N
, Typ
);
8441 if Is_Overloaded
(Name
) then
8443 -- Use the context type to select the prefix that yields the correct
8449 I1
: Interp_Index
:= 0;
8450 P
: constant Node_Id
:= Prefix
(N
);
8451 Found
: Boolean := False;
8454 Get_First_Interp
(P
, I
, It
);
8455 while Present
(It
.Typ
) loop
8456 if (Is_Array_Type
(It
.Typ
)
8457 and then Covers
(Typ
, Component_Type
(It
.Typ
)))
8458 or else (Is_Access_Type
(It
.Typ
)
8459 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
8463 Component_Type
(Designated_Type
(It
.Typ
))))
8466 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
8468 if It
= No_Interp
then
8469 Error_Msg_N
("ambiguous prefix for indexing", N
);
8475 Array_Type
:= It
.Typ
;
8481 Array_Type
:= It
.Typ
;
8486 Get_Next_Interp
(I
, It
);
8491 Array_Type
:= Etype
(Name
);
8494 Resolve
(Name
, Array_Type
);
8495 Array_Type
:= Get_Actual_Subtype_If_Available
(Name
);
8497 -- If prefix is access type, dereference to get real array type.
8498 -- Note: we do not apply an access check because the expander always
8499 -- introduces an explicit dereference, and the check will happen there.
8501 if Is_Access_Type
(Array_Type
) then
8502 Array_Type
:= Designated_Type
(Array_Type
);
8505 -- If name was overloaded, set component type correctly now
8506 -- If a misplaced call to an entry family (which has no index types)
8507 -- return. Error will be diagnosed from calling context.
8509 if Is_Array_Type
(Array_Type
) then
8510 Set_Etype
(N
, Component_Type
(Array_Type
));
8515 Index
:= First_Index
(Array_Type
);
8516 Expr
:= First
(Expressions
(N
));
8518 -- The prefix may have resolved to a string literal, in which case its
8519 -- etype has a special representation. This is only possible currently
8520 -- if the prefix is a static concatenation, written in functional
8523 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
8524 Resolve
(Expr
, Standard_Positive
);
8527 while Present
(Index
) and Present
(Expr
) loop
8528 Resolve
(Expr
, Etype
(Index
));
8529 Check_Unset_Reference
(Expr
);
8531 if Is_Scalar_Type
(Etype
(Expr
)) then
8532 Apply_Scalar_Range_Check
(Expr
, Etype
(Index
));
8534 Apply_Range_Check
(Expr
, Get_Actual_Subtype
(Index
));
8542 Analyze_Dimension
(N
);
8544 -- Do not generate the warning on suspicious index if we are analyzing
8545 -- package Ada.Tags; otherwise we will report the warning with the
8546 -- Prims_Ptr field of the dispatch table.
8548 if Scope
(Etype
(Prefix
(N
))) = Standard_Standard
8550 Is_RTU
(Cunit_Entity
(Get_Source_Unit
(Etype
(Prefix
(N
)))),
8553 Warn_On_Suspicious_Index
(Name
, First
(Expressions
(N
)));
8554 Eval_Indexed_Component
(N
);
8557 -- If the array type is atomic, and the component is not atomic, then
8558 -- this is worth a warning, since we have a situation where the access
8559 -- to the component may cause extra read/writes of the atomic array
8560 -- object, or partial word accesses, which could be unexpected.
8562 if Nkind
(N
) = N_Indexed_Component
8563 and then Is_Atomic_Ref_With_Address
(N
)
8564 and then not (Has_Atomic_Components
(Array_Type
)
8565 or else (Is_Entity_Name
(Prefix
(N
))
8566 and then Has_Atomic_Components
8567 (Entity
(Prefix
(N
)))))
8568 and then not Is_Atomic
(Component_Type
(Array_Type
))
8571 ("??access to non-atomic component of atomic array", Prefix
(N
));
8573 ("??\may cause unexpected accesses to atomic object", Prefix
(N
));
8575 end Resolve_Indexed_Component
;
8577 -----------------------------
8578 -- Resolve_Integer_Literal --
8579 -----------------------------
8581 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
8584 Eval_Integer_Literal
(N
);
8585 end Resolve_Integer_Literal
;
8587 --------------------------------
8588 -- Resolve_Intrinsic_Operator --
8589 --------------------------------
8591 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
) is
8592 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
8597 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
;
8598 -- If the operand is a literal, it cannot be the expression in a
8599 -- conversion. Use a qualified expression instead.
8601 ---------------------
8602 -- Convert_Operand --
8603 ---------------------
8605 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
is
8606 Loc
: constant Source_Ptr
:= Sloc
(Opnd
);
8610 if Nkind_In
(Opnd
, N_Integer_Literal
, N_Real_Literal
) then
8612 Make_Qualified_Expression
(Loc
,
8613 Subtype_Mark
=> New_Occurrence_Of
(Btyp
, Loc
),
8614 Expression
=> Relocate_Node
(Opnd
));
8618 Res
:= Unchecked_Convert_To
(Btyp
, Opnd
);
8622 end Convert_Operand
;
8624 -- Start of processing for Resolve_Intrinsic_Operator
8627 -- We must preserve the original entity in a generic setting, so that
8628 -- the legality of the operation can be verified in an instance.
8630 if not Expander_Active
then
8635 while Scope
(Op
) /= Standard_Standard
loop
8637 pragma Assert
(Present
(Op
));
8641 Set_Is_Overloaded
(N
, False);
8643 -- If the result or operand types are private, rewrite with unchecked
8644 -- conversions on the operands and the result, to expose the proper
8645 -- underlying numeric type.
8647 if Is_Private_Type
(Typ
)
8648 or else Is_Private_Type
(Etype
(Left_Opnd
(N
)))
8649 or else Is_Private_Type
(Etype
(Right_Opnd
(N
)))
8651 Arg1
:= Convert_Operand
(Left_Opnd
(N
));
8653 if Nkind
(N
) = N_Op_Expon
then
8654 Arg2
:= Unchecked_Convert_To
(Standard_Integer
, Right_Opnd
(N
));
8656 Arg2
:= Convert_Operand
(Right_Opnd
(N
));
8659 if Nkind
(Arg1
) = N_Type_Conversion
then
8660 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
8663 if Nkind
(Arg2
) = N_Type_Conversion
then
8664 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8667 Set_Left_Opnd
(N
, Arg1
);
8668 Set_Right_Opnd
(N
, Arg2
);
8670 Set_Etype
(N
, Btyp
);
8671 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
8674 elsif Typ
/= Etype
(Left_Opnd
(N
))
8675 or else Typ
/= Etype
(Right_Opnd
(N
))
8677 -- Add explicit conversion where needed, and save interpretations in
8678 -- case operands are overloaded.
8680 Arg1
:= Convert_To
(Typ
, Left_Opnd
(N
));
8681 Arg2
:= Convert_To
(Typ
, Right_Opnd
(N
));
8683 if Nkind
(Arg1
) = N_Type_Conversion
then
8684 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
8686 Save_Interps
(Left_Opnd
(N
), Arg1
);
8689 if Nkind
(Arg2
) = N_Type_Conversion
then
8690 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8692 Save_Interps
(Right_Opnd
(N
), Arg2
);
8695 Rewrite
(Left_Opnd
(N
), Arg1
);
8696 Rewrite
(Right_Opnd
(N
), Arg2
);
8699 Resolve_Arithmetic_Op
(N
, Typ
);
8702 Resolve_Arithmetic_Op
(N
, Typ
);
8704 end Resolve_Intrinsic_Operator
;
8706 --------------------------------------
8707 -- Resolve_Intrinsic_Unary_Operator --
8708 --------------------------------------
8710 procedure Resolve_Intrinsic_Unary_Operator
8714 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
8720 while Scope
(Op
) /= Standard_Standard
loop
8722 pragma Assert
(Present
(Op
));
8727 if Is_Private_Type
(Typ
) then
8728 Arg2
:= Unchecked_Convert_To
(Btyp
, Right_Opnd
(N
));
8729 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8731 Set_Right_Opnd
(N
, Arg2
);
8733 Set_Etype
(N
, Btyp
);
8734 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
8738 Resolve_Unary_Op
(N
, Typ
);
8740 end Resolve_Intrinsic_Unary_Operator
;
8742 ------------------------
8743 -- Resolve_Logical_Op --
8744 ------------------------
8746 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
8750 Check_No_Direct_Boolean_Operators
(N
);
8752 -- Predefined operations on scalar types yield the base type. On the
8753 -- other hand, logical operations on arrays yield the type of the
8754 -- arguments (and the context).
8756 if Is_Array_Type
(Typ
) then
8759 B_Typ
:= Base_Type
(Typ
);
8762 -- The following test is required because the operands of the operation
8763 -- may be literals, in which case the resulting type appears to be
8764 -- compatible with a signed integer type, when in fact it is compatible
8765 -- only with modular types. If the context itself is universal, the
8766 -- operation is illegal.
8768 if not Valid_Boolean_Arg
(Typ
) then
8769 Error_Msg_N
("invalid context for logical operation", N
);
8770 Set_Etype
(N
, Any_Type
);
8773 elsif Typ
= Any_Modular
then
8775 ("no modular type available in this context", N
);
8776 Set_Etype
(N
, Any_Type
);
8779 elsif Is_Modular_Integer_Type
(Typ
)
8780 and then Etype
(Left_Opnd
(N
)) = Universal_Integer
8781 and then Etype
(Right_Opnd
(N
)) = Universal_Integer
8783 Check_For_Visible_Operator
(N
, B_Typ
);
8786 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8787 -- is active and the result type is standard Boolean (do not mess with
8788 -- ops that return a nonstandard Boolean type, because something strange
8791 -- Note: you might expect this replacement to be done during expansion,
8792 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8793 -- is used, no part of the right operand of an "and" or "or" operator
8794 -- should be executed if the left operand would short-circuit the
8795 -- evaluation of the corresponding "and then" or "or else". If we left
8796 -- the replacement to expansion time, then run-time checks associated
8797 -- with such operands would be evaluated unconditionally, due to being
8798 -- before the condition prior to the rewriting as short-circuit forms
8799 -- during expansion.
8801 if Short_Circuit_And_Or
8802 and then B_Typ
= Standard_Boolean
8803 and then Nkind_In
(N
, N_Op_And
, N_Op_Or
)
8805 -- Mark the corresponding putative SCO operator as truly a logical
8806 -- (and short-circuit) operator.
8808 if Generate_SCO
and then Comes_From_Source
(N
) then
8809 Set_SCO_Logical_Operator
(N
);
8812 if Nkind
(N
) = N_Op_And
then
8814 Make_And_Then
(Sloc
(N
),
8815 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
8816 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
8817 Analyze_And_Resolve
(N
, B_Typ
);
8819 -- Case of OR changed to OR ELSE
8823 Make_Or_Else
(Sloc
(N
),
8824 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
8825 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
8826 Analyze_And_Resolve
(N
, B_Typ
);
8829 -- Return now, since analysis of the rewritten ops will take care of
8830 -- other reference bookkeeping and expression folding.
8835 Resolve
(Left_Opnd
(N
), B_Typ
);
8836 Resolve
(Right_Opnd
(N
), B_Typ
);
8838 Check_Unset_Reference
(Left_Opnd
(N
));
8839 Check_Unset_Reference
(Right_Opnd
(N
));
8841 Set_Etype
(N
, B_Typ
);
8842 Generate_Operator_Reference
(N
, B_Typ
);
8843 Eval_Logical_Op
(N
);
8845 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8846 -- only when both operands have same static lower and higher bounds. Of
8847 -- course the types have to match, so only check if operands are
8848 -- compatible and the node itself has no errors.
8850 if Is_Array_Type
(B_Typ
)
8851 and then Nkind
(N
) in N_Binary_Op
8854 Left_Typ
: constant Node_Id
:= Etype
(Left_Opnd
(N
));
8855 Right_Typ
: constant Node_Id
:= Etype
(Right_Opnd
(N
));
8858 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8859 -- operation if not needed.
8861 if Restriction_Check_Required
(SPARK_05
)
8862 and then Base_Type
(Left_Typ
) = Base_Type
(Right_Typ
)
8863 and then Left_Typ
/= Any_Composite
-- or Left_Opnd in error
8864 and then Right_Typ
/= Any_Composite
-- or Right_Opnd in error
8865 and then not Matching_Static_Array_Bounds
(Left_Typ
, Right_Typ
)
8867 Check_SPARK_05_Restriction
8868 ("array types should have matching static bounds", N
);
8872 end Resolve_Logical_Op
;
8874 ---------------------------
8875 -- Resolve_Membership_Op --
8876 ---------------------------
8878 -- The context can only be a boolean type, and does not determine the
8879 -- arguments. Arguments should be unambiguous, but the preference rule for
8880 -- universal types applies.
8882 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
8883 pragma Warnings
(Off
, Typ
);
8885 L
: constant Node_Id
:= Left_Opnd
(N
);
8886 R
: constant Node_Id
:= Right_Opnd
(N
);
8889 procedure Resolve_Set_Membership
;
8890 -- Analysis has determined a unique type for the left operand. Use it to
8891 -- resolve the disjuncts.
8893 ----------------------------
8894 -- Resolve_Set_Membership --
8895 ----------------------------
8897 procedure Resolve_Set_Membership
is
8902 -- If the left operand is overloaded, find type compatible with not
8903 -- overloaded alternative of the right operand.
8905 if Is_Overloaded
(L
) then
8907 Alt
:= First
(Alternatives
(N
));
8908 while Present
(Alt
) loop
8909 if not Is_Overloaded
(Alt
) then
8910 Ltyp
:= Intersect_Types
(L
, Alt
);
8917 -- Unclear how to resolve expression if all alternatives are also
8921 Error_Msg_N
("ambiguous expression", N
);
8930 Alt
:= First
(Alternatives
(N
));
8931 while Present
(Alt
) loop
8933 -- Alternative is an expression, a range
8934 -- or a subtype mark.
8936 if not Is_Entity_Name
(Alt
)
8937 or else not Is_Type
(Entity
(Alt
))
8939 Resolve
(Alt
, Ltyp
);
8945 -- Check for duplicates for discrete case
8947 if Is_Discrete_Type
(Ltyp
) then
8954 Alts
: array (0 .. List_Length
(Alternatives
(N
))) of Ent
;
8958 -- Loop checking duplicates. This is quadratic, but giant sets
8959 -- are unlikely in this context so it's a reasonable choice.
8962 Alt
:= First
(Alternatives
(N
));
8963 while Present
(Alt
) loop
8964 if Is_OK_Static_Expression
(Alt
)
8965 and then (Nkind_In
(Alt
, N_Integer_Literal
,
8966 N_Character_Literal
)
8967 or else Nkind
(Alt
) in N_Has_Entity
)
8970 Alts
(Nalts
) := (Alt
, Expr_Value
(Alt
));
8972 for J
in 1 .. Nalts
- 1 loop
8973 if Alts
(J
).Val
= Alts
(Nalts
).Val
then
8974 Error_Msg_Sloc
:= Sloc
(Alts
(J
).Alt
);
8975 Error_Msg_N
("duplicate of value given#??", Alt
);
8985 -- RM 4.5.2 (28.1/3) specifies that for types other than records or
8986 -- limited types, evaluation of a membership test uses the predefined
8987 -- equality for the type. This may be confusing to users, and the
8988 -- following warning appears useful for the most common case.
8990 if Is_Scalar_Type
(Ltyp
)
8991 and then Present
(Get_User_Defined_Eq
(Ltyp
))
8994 ("membership test on& uses predefined equality?", N
, Ltyp
);
8996 ("\even if user-defined equality exists (RM 4.5.2 (28.1/3)?", N
);
8998 end Resolve_Set_Membership
;
9000 -- Start of processing for Resolve_Membership_Op
9003 if L
= Error
or else R
= Error
then
9007 if Present
(Alternatives
(N
)) then
9008 Resolve_Set_Membership
;
9011 elsif not Is_Overloaded
(R
)
9013 (Etype
(R
) = Universal_Integer
9015 Etype
(R
) = Universal_Real
)
9016 and then Is_Overloaded
(L
)
9020 -- Ada 2005 (AI-251): Support the following case:
9022 -- type I is interface;
9023 -- type T is tagged ...
9025 -- function Test (O : I'Class) is
9027 -- return O in T'Class.
9030 -- In this case we have nothing else to do. The membership test will be
9031 -- done at run time.
9033 elsif Ada_Version
>= Ada_2005
9034 and then Is_Class_Wide_Type
(Etype
(L
))
9035 and then Is_Interface
(Etype
(L
))
9036 and then Is_Class_Wide_Type
(Etype
(R
))
9037 and then not Is_Interface
(Etype
(R
))
9041 T
:= Intersect_Types
(L
, R
);
9044 -- If mixed-mode operations are present and operands are all literal,
9045 -- the only interpretation involves Duration, which is probably not
9046 -- the intention of the programmer.
9048 if T
= Any_Fixed
then
9049 T
:= Unique_Fixed_Point_Type
(N
);
9051 if T
= Any_Type
then
9057 Check_Unset_Reference
(L
);
9059 if Nkind
(R
) = N_Range
9060 and then not Is_Scalar_Type
(T
)
9062 Error_Msg_N
("scalar type required for range", R
);
9065 if Is_Entity_Name
(R
) then
9066 Freeze_Expression
(R
);
9069 Check_Unset_Reference
(R
);
9072 -- Here after resolving membership operation
9076 Eval_Membership_Op
(N
);
9077 end Resolve_Membership_Op
;
9083 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
) is
9084 Loc
: constant Source_Ptr
:= Sloc
(N
);
9087 -- Handle restriction against anonymous null access values This
9088 -- restriction can be turned off using -gnatdj.
9090 -- Ada 2005 (AI-231): Remove restriction
9092 if Ada_Version
< Ada_2005
9093 and then not Debug_Flag_J
9094 and then Ekind
(Typ
) = E_Anonymous_Access_Type
9095 and then Comes_From_Source
(N
)
9097 -- In the common case of a call which uses an explicitly null value
9098 -- for an access parameter, give specialized error message.
9100 if Nkind
(Parent
(N
)) in N_Subprogram_Call
then
9102 ("null is not allowed as argument for an access parameter", N
);
9104 -- Standard message for all other cases (are there any?)
9108 ("null cannot be of an anonymous access type", N
);
9112 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
9113 -- assignment to a null-excluding object
9115 if Ada_Version
>= Ada_2005
9116 and then Can_Never_Be_Null
(Typ
)
9117 and then Nkind
(Parent
(N
)) = N_Assignment_Statement
9119 if not Inside_Init_Proc
then
9121 (Compile_Time_Constraint_Error
(N
,
9122 "(Ada 2005) null not allowed in null-excluding objects??"),
9123 Make_Raise_Constraint_Error
(Loc
,
9124 Reason
=> CE_Access_Check_Failed
));
9127 Make_Raise_Constraint_Error
(Loc
,
9128 Reason
=> CE_Access_Check_Failed
));
9132 -- In a distributed context, null for a remote access to subprogram may
9133 -- need to be replaced with a special record aggregate. In this case,
9134 -- return after having done the transformation.
9136 if (Ekind
(Typ
) = E_Record_Type
9137 or else Is_Remote_Access_To_Subprogram_Type
(Typ
))
9138 and then Remote_AST_Null_Value
(N
, Typ
)
9143 -- The null literal takes its type from the context
9148 -----------------------
9149 -- Resolve_Op_Concat --
9150 -----------------------
9152 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
) is
9154 -- We wish to avoid deep recursion, because concatenations are often
9155 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
9156 -- operands nonrecursively until we find something that is not a simple
9157 -- concatenation (A in this case). We resolve that, and then walk back
9158 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
9159 -- to do the rest of the work at each level. The Parent pointers allow
9160 -- us to avoid recursion, and thus avoid running out of memory. See also
9161 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
9167 -- The following code is equivalent to:
9169 -- Resolve_Op_Concat_First (NN, Typ);
9170 -- Resolve_Op_Concat_Arg (N, ...);
9171 -- Resolve_Op_Concat_Rest (N, Typ);
9173 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
9174 -- operand is a concatenation.
9176 -- Walk down left operands
9179 Resolve_Op_Concat_First
(NN
, Typ
);
9180 Op1
:= Left_Opnd
(NN
);
9181 exit when not (Nkind
(Op1
) = N_Op_Concat
9182 and then not Is_Array_Type
(Component_Type
(Typ
))
9183 and then Entity
(Op1
) = Entity
(NN
));
9187 -- Now (given the above example) NN is A&B and Op1 is A
9189 -- First resolve Op1 ...
9191 Resolve_Op_Concat_Arg
(NN
, Op1
, Typ
, Is_Component_Left_Opnd
(NN
));
9193 -- ... then walk NN back up until we reach N (where we started), calling
9194 -- Resolve_Op_Concat_Rest along the way.
9197 Resolve_Op_Concat_Rest
(NN
, Typ
);
9202 if Base_Type
(Etype
(N
)) /= Standard_String
then
9203 Check_SPARK_05_Restriction
9204 ("result of concatenation should have type String", N
);
9206 end Resolve_Op_Concat
;
9208 ---------------------------
9209 -- Resolve_Op_Concat_Arg --
9210 ---------------------------
9212 procedure Resolve_Op_Concat_Arg
9218 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
9219 Ctyp
: constant Entity_Id
:= Component_Type
(Typ
);
9224 or else (not Is_Overloaded
(Arg
)
9225 and then Etype
(Arg
) /= Any_Composite
9226 and then Covers
(Ctyp
, Etype
(Arg
)))
9228 Resolve
(Arg
, Ctyp
);
9230 Resolve
(Arg
, Btyp
);
9233 -- If both Array & Array and Array & Component are visible, there is a
9234 -- potential ambiguity that must be reported.
9236 elsif Has_Compatible_Type
(Arg
, Ctyp
) then
9237 if Nkind
(Arg
) = N_Aggregate
9238 and then Is_Composite_Type
(Ctyp
)
9240 if Is_Private_Type
(Ctyp
) then
9241 Resolve
(Arg
, Btyp
);
9243 -- If the operation is user-defined and not overloaded use its
9244 -- profile. The operation may be a renaming, in which case it has
9245 -- been rewritten, and we want the original profile.
9247 elsif not Is_Overloaded
(N
)
9248 and then Comes_From_Source
(Entity
(Original_Node
(N
)))
9249 and then Ekind
(Entity
(Original_Node
(N
))) = E_Function
9253 (Next_Formal
(First_Formal
(Entity
(Original_Node
(N
))))));
9256 -- Otherwise an aggregate may match both the array type and the
9260 Error_Msg_N
("ambiguous aggregate must be qualified", Arg
);
9261 Set_Etype
(Arg
, Any_Type
);
9265 if Is_Overloaded
(Arg
)
9266 and then Has_Compatible_Type
(Arg
, Typ
)
9267 and then Etype
(Arg
) /= Any_Type
9275 Get_First_Interp
(Arg
, I
, It
);
9277 Get_Next_Interp
(I
, It
);
9279 -- Special-case the error message when the overloading is
9280 -- caused by a function that yields an array and can be
9281 -- called without parameters.
9283 if It
.Nam
= Func
then
9284 Error_Msg_Sloc
:= Sloc
(Func
);
9285 Error_Msg_N
("ambiguous call to function#", Arg
);
9287 ("\\interpretation as call yields&", Arg
, Typ
);
9289 ("\\interpretation as indexing of call yields&",
9290 Arg
, Component_Type
(Typ
));
9293 Error_Msg_N
("ambiguous operand for concatenation!", Arg
);
9295 Get_First_Interp
(Arg
, I
, It
);
9296 while Present
(It
.Nam
) loop
9297 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
9299 if Base_Type
(It
.Typ
) = Btyp
9301 Base_Type
(It
.Typ
) = Base_Type
(Ctyp
)
9303 Error_Msg_N
-- CODEFIX
9304 ("\\possible interpretation#", Arg
);
9307 Get_Next_Interp
(I
, It
);
9313 Resolve
(Arg
, Component_Type
(Typ
));
9315 if Nkind
(Arg
) = N_String_Literal
then
9316 Set_Etype
(Arg
, Component_Type
(Typ
));
9319 if Arg
= Left_Opnd
(N
) then
9320 Set_Is_Component_Left_Opnd
(N
);
9322 Set_Is_Component_Right_Opnd
(N
);
9327 Resolve
(Arg
, Btyp
);
9330 -- Concatenation is restricted in SPARK: each operand must be either a
9331 -- string literal, the name of a string constant, a static character or
9332 -- string expression, or another concatenation. Arg cannot be a
9333 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9334 -- separately on each final operand, past concatenation operations.
9336 if Is_Character_Type
(Etype
(Arg
)) then
9337 if not Is_OK_Static_Expression
(Arg
) then
9338 Check_SPARK_05_Restriction
9339 ("character operand for concatenation should be static", Arg
);
9342 elsif Is_String_Type
(Etype
(Arg
)) then
9343 if not (Nkind_In
(Arg
, N_Identifier
, N_Expanded_Name
)
9344 and then Is_Constant_Object
(Entity
(Arg
)))
9345 and then not Is_OK_Static_Expression
(Arg
)
9347 Check_SPARK_05_Restriction
9348 ("string operand for concatenation should be static", Arg
);
9351 -- Do not issue error on an operand that is neither a character nor a
9352 -- string, as the error is issued in Resolve_Op_Concat.
9358 Check_Unset_Reference
(Arg
);
9359 end Resolve_Op_Concat_Arg
;
9361 -----------------------------
9362 -- Resolve_Op_Concat_First --
9363 -----------------------------
9365 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
) is
9366 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
9367 Op1
: constant Node_Id
:= Left_Opnd
(N
);
9368 Op2
: constant Node_Id
:= Right_Opnd
(N
);
9371 -- The parser folds an enormous sequence of concatenations of string
9372 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9373 -- in the right operand. If the expression resolves to a predefined "&"
9374 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9375 -- we give an error. See P_Simple_Expression in Par.Ch4.
9377 if Nkind
(Op2
) = N_String_Literal
9378 and then Is_Folded_In_Parser
(Op2
)
9379 and then Ekind
(Entity
(N
)) = E_Function
9381 pragma Assert
(Nkind
(Op1
) = N_String_Literal
-- should be ""
9382 and then String_Length
(Strval
(Op1
)) = 0);
9383 Error_Msg_N
("too many user-defined concatenations", N
);
9387 Set_Etype
(N
, Btyp
);
9389 if Is_Limited_Composite
(Btyp
) then
9390 Error_Msg_N
("concatenation not available for limited array", N
);
9391 Explain_Limited_Type
(Btyp
, N
);
9393 end Resolve_Op_Concat_First
;
9395 ----------------------------
9396 -- Resolve_Op_Concat_Rest --
9397 ----------------------------
9399 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
) is
9400 Op1
: constant Node_Id
:= Left_Opnd
(N
);
9401 Op2
: constant Node_Id
:= Right_Opnd
(N
);
9404 Resolve_Op_Concat_Arg
(N
, Op2
, Typ
, Is_Component_Right_Opnd
(N
));
9406 Generate_Operator_Reference
(N
, Typ
);
9408 if Is_String_Type
(Typ
) then
9409 Eval_Concatenation
(N
);
9412 -- If this is not a static concatenation, but the result is a string
9413 -- type (and not an array of strings) ensure that static string operands
9414 -- have their subtypes properly constructed.
9416 if Nkind
(N
) /= N_String_Literal
9417 and then Is_Character_Type
(Component_Type
(Typ
))
9419 Set_String_Literal_Subtype
(Op1
, Typ
);
9420 Set_String_Literal_Subtype
(Op2
, Typ
);
9422 end Resolve_Op_Concat_Rest
;
9424 ----------------------
9425 -- Resolve_Op_Expon --
9426 ----------------------
9428 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
) is
9429 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
9432 -- Catch attempts to do fixed-point exponentiation with universal
9433 -- operands, which is a case where the illegality is not caught during
9434 -- normal operator analysis. This is not done in preanalysis mode
9435 -- since the tree is not fully decorated during preanalysis.
9437 if Full_Analysis
then
9438 if Is_Fixed_Point_Type
(Typ
) and then Comes_From_Source
(N
) then
9439 Error_Msg_N
("exponentiation not available for fixed point", N
);
9442 elsif Nkind
(Parent
(N
)) in N_Op
9443 and then Present
(Etype
(Parent
(N
)))
9444 and then Is_Fixed_Point_Type
(Etype
(Parent
(N
)))
9445 and then Etype
(N
) = Universal_Real
9446 and then Comes_From_Source
(N
)
9448 Error_Msg_N
("exponentiation not available for fixed point", N
);
9453 if Comes_From_Source
(N
)
9454 and then Ekind
(Entity
(N
)) = E_Function
9455 and then Is_Imported
(Entity
(N
))
9456 and then Is_Intrinsic_Subprogram
(Entity
(N
))
9458 Resolve_Intrinsic_Operator
(N
, Typ
);
9462 if Etype
(Left_Opnd
(N
)) = Universal_Integer
9463 or else Etype
(Left_Opnd
(N
)) = Universal_Real
9465 Check_For_Visible_Operator
(N
, B_Typ
);
9468 -- We do the resolution using the base type, because intermediate values
9469 -- in expressions are always of the base type, not a subtype of it.
9471 Resolve
(Left_Opnd
(N
), B_Typ
);
9472 Resolve
(Right_Opnd
(N
), Standard_Integer
);
9474 -- For integer types, right argument must be in Natural range
9476 if Is_Integer_Type
(Typ
) then
9477 Apply_Scalar_Range_Check
(Right_Opnd
(N
), Standard_Natural
);
9480 Check_Unset_Reference
(Left_Opnd
(N
));
9481 Check_Unset_Reference
(Right_Opnd
(N
));
9483 Set_Etype
(N
, B_Typ
);
9484 Generate_Operator_Reference
(N
, B_Typ
);
9486 Analyze_Dimension
(N
);
9488 if Ada_Version
>= Ada_2012
and then Has_Dimension_System
(B_Typ
) then
9489 -- Evaluate the exponentiation operator for dimensioned type
9491 Eval_Op_Expon_For_Dimensioned_Type
(N
, B_Typ
);
9496 -- Set overflow checking bit. Much cleverer code needed here eventually
9497 -- and perhaps the Resolve routines should be separated for the various
9498 -- arithmetic operations, since they will need different processing. ???
9500 if Nkind
(N
) in N_Op
then
9501 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
9502 Enable_Overflow_Check
(N
);
9505 end Resolve_Op_Expon
;
9507 --------------------
9508 -- Resolve_Op_Not --
9509 --------------------
9511 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
) is
9514 function Parent_Is_Boolean
return Boolean;
9515 -- This function determines if the parent node is a boolean operator or
9516 -- operation (comparison op, membership test, or short circuit form) and
9517 -- the not in question is the left operand of this operation. Note that
9518 -- if the not is in parens, then false is returned.
9520 -----------------------
9521 -- Parent_Is_Boolean --
9522 -----------------------
9524 function Parent_Is_Boolean
return Boolean is
9526 if Paren_Count
(N
) /= 0 then
9530 case Nkind
(Parent
(N
)) is
9545 return Left_Opnd
(Parent
(N
)) = N
;
9551 end Parent_Is_Boolean
;
9553 -- Start of processing for Resolve_Op_Not
9556 -- Predefined operations on scalar types yield the base type. On the
9557 -- other hand, logical operations on arrays yield the type of the
9558 -- arguments (and the context).
9560 if Is_Array_Type
(Typ
) then
9563 B_Typ
:= Base_Type
(Typ
);
9566 -- Straightforward case of incorrect arguments
9568 if not Valid_Boolean_Arg
(Typ
) then
9569 Error_Msg_N
("invalid operand type for operator&", N
);
9570 Set_Etype
(N
, Any_Type
);
9573 -- Special case of probable missing parens
9575 elsif Typ
= Universal_Integer
or else Typ
= Any_Modular
then
9576 if Parent_Is_Boolean
then
9578 ("operand of not must be enclosed in parentheses",
9582 ("no modular type available in this context", N
);
9585 Set_Etype
(N
, Any_Type
);
9588 -- OK resolution of NOT
9591 -- Warn if non-boolean types involved. This is a case like not a < b
9592 -- where a and b are modular, where we will get (not a) < b and most
9593 -- likely not (a < b) was intended.
9595 if Warn_On_Questionable_Missing_Parens
9596 and then not Is_Boolean_Type
(Typ
)
9597 and then Parent_Is_Boolean
9599 Error_Msg_N
("?q?not expression should be parenthesized here!", N
);
9602 -- Warn on double negation if checking redundant constructs
9604 if Warn_On_Redundant_Constructs
9605 and then Comes_From_Source
(N
)
9606 and then Comes_From_Source
(Right_Opnd
(N
))
9607 and then Root_Type
(Typ
) = Standard_Boolean
9608 and then Nkind
(Right_Opnd
(N
)) = N_Op_Not
9610 Error_Msg_N
("redundant double negation?r?", N
);
9613 -- Complete resolution and evaluation of NOT
9615 Resolve
(Right_Opnd
(N
), B_Typ
);
9616 Check_Unset_Reference
(Right_Opnd
(N
));
9617 Set_Etype
(N
, B_Typ
);
9618 Generate_Operator_Reference
(N
, B_Typ
);
9623 -----------------------------
9624 -- Resolve_Operator_Symbol --
9625 -----------------------------
9627 -- Nothing to be done, all resolved already
9629 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
) is
9630 pragma Warnings
(Off
, N
);
9631 pragma Warnings
(Off
, Typ
);
9635 end Resolve_Operator_Symbol
;
9637 ----------------------------------
9638 -- Resolve_Qualified_Expression --
9639 ----------------------------------
9641 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
9642 pragma Warnings
(Off
, Typ
);
9644 Target_Typ
: constant Entity_Id
:= Entity
(Subtype_Mark
(N
));
9645 Expr
: constant Node_Id
:= Expression
(N
);
9648 Resolve
(Expr
, Target_Typ
);
9650 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9651 -- operation if not needed.
9653 if Restriction_Check_Required
(SPARK_05
)
9654 and then Is_Array_Type
(Target_Typ
)
9655 and then Is_Array_Type
(Etype
(Expr
))
9656 and then Etype
(Expr
) /= Any_Composite
-- or else Expr in error
9657 and then not Matching_Static_Array_Bounds
(Target_Typ
, Etype
(Expr
))
9659 Check_SPARK_05_Restriction
9660 ("array types should have matching static bounds", N
);
9663 -- A qualified expression requires an exact match of the type, class-
9664 -- wide matching is not allowed. However, if the qualifying type is
9665 -- specific and the expression has a class-wide type, it may still be
9666 -- okay, since it can be the result of the expansion of a call to a
9667 -- dispatching function, so we also have to check class-wideness of the
9668 -- type of the expression's original node.
9670 if (Is_Class_Wide_Type
(Target_Typ
)
9672 (Is_Class_Wide_Type
(Etype
(Expr
))
9673 and then Is_Class_Wide_Type
(Etype
(Original_Node
(Expr
)))))
9674 and then Base_Type
(Etype
(Expr
)) /= Base_Type
(Target_Typ
)
9676 Wrong_Type
(Expr
, Target_Typ
);
9679 -- If the target type is unconstrained, then we reset the type of the
9680 -- result from the type of the expression. For other cases, the actual
9681 -- subtype of the expression is the target type.
9683 if Is_Composite_Type
(Target_Typ
)
9684 and then not Is_Constrained
(Target_Typ
)
9686 Set_Etype
(N
, Etype
(Expr
));
9689 Analyze_Dimension
(N
);
9690 Eval_Qualified_Expression
(N
);
9692 -- If we still have a qualified expression after the static evaluation,
9693 -- then apply a scalar range check if needed. The reason that we do this
9694 -- after the Eval call is that otherwise, the application of the range
9695 -- check may convert an illegal static expression and result in warning
9696 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9698 if Nkind
(N
) = N_Qualified_Expression
and then Is_Scalar_Type
(Typ
) then
9699 Apply_Scalar_Range_Check
(Expr
, Typ
);
9702 -- Finally, check whether a predicate applies to the target type. This
9703 -- comes from AI12-0100. As for type conversions, check the enclosing
9704 -- context to prevent an infinite expansion.
9706 if Has_Predicates
(Target_Typ
) then
9707 if Nkind
(Parent
(N
)) = N_Function_Call
9708 and then Present
(Name
(Parent
(N
)))
9709 and then (Is_Predicate_Function
(Entity
(Name
(Parent
(N
))))
9711 Is_Predicate_Function_M
(Entity
(Name
(Parent
(N
)))))
9715 -- In the case of a qualified expression in an allocator, the check
9716 -- is applied when expanding the allocator, so avoid redundant check.
9718 elsif Nkind
(N
) = N_Qualified_Expression
9719 and then Nkind
(Parent
(N
)) /= N_Allocator
9721 Apply_Predicate_Check
(N
, Target_Typ
);
9724 end Resolve_Qualified_Expression
;
9726 ------------------------------
9727 -- Resolve_Raise_Expression --
9728 ------------------------------
9730 procedure Resolve_Raise_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
9732 if Typ
= Raise_Type
then
9733 Error_Msg_N
("cannot find unique type for raise expression", N
);
9734 Set_Etype
(N
, Any_Type
);
9738 end Resolve_Raise_Expression
;
9744 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
) is
9745 L
: constant Node_Id
:= Low_Bound
(N
);
9746 H
: constant Node_Id
:= High_Bound
(N
);
9748 function First_Last_Ref
return Boolean;
9749 -- Returns True if N is of the form X'First .. X'Last where X is the
9750 -- same entity for both attributes.
9752 --------------------
9753 -- First_Last_Ref --
9754 --------------------
9756 function First_Last_Ref
return Boolean is
9757 Lorig
: constant Node_Id
:= Original_Node
(L
);
9758 Horig
: constant Node_Id
:= Original_Node
(H
);
9761 if Nkind
(Lorig
) = N_Attribute_Reference
9762 and then Nkind
(Horig
) = N_Attribute_Reference
9763 and then Attribute_Name
(Lorig
) = Name_First
9764 and then Attribute_Name
(Horig
) = Name_Last
9767 PL
: constant Node_Id
:= Prefix
(Lorig
);
9768 PH
: constant Node_Id
:= Prefix
(Horig
);
9770 if Is_Entity_Name
(PL
)
9771 and then Is_Entity_Name
(PH
)
9772 and then Entity
(PL
) = Entity
(PH
)
9782 -- Start of processing for Resolve_Range
9787 -- The lower bound should be in Typ. The higher bound can be in Typ's
9788 -- base type if the range is null. It may still be invalid if it is
9789 -- higher than the lower bound. This is checked later in the context in
9790 -- which the range appears.
9793 Resolve
(H
, Base_Type
(Typ
));
9795 -- Check for inappropriate range on unordered enumeration type
9797 if Bad_Unordered_Enumeration_Reference
(N
, Typ
)
9799 -- Exclude X'First .. X'Last if X is the same entity for both
9801 and then not First_Last_Ref
9803 Error_Msg_Sloc
:= Sloc
(Typ
);
9805 ("subrange of unordered enumeration type& declared#?U?", N
, Typ
);
9808 Check_Unset_Reference
(L
);
9809 Check_Unset_Reference
(H
);
9811 -- We have to check the bounds for being within the base range as
9812 -- required for a non-static context. Normally this is automatic and
9813 -- done as part of evaluating expressions, but the N_Range node is an
9814 -- exception, since in GNAT we consider this node to be a subexpression,
9815 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9816 -- this, but that would put the test on the main evaluation path for
9819 Check_Non_Static_Context
(L
);
9820 Check_Non_Static_Context
(H
);
9822 -- Check for an ambiguous range over character literals. This will
9823 -- happen with a membership test involving only literals.
9825 if Typ
= Any_Character
then
9826 Ambiguous_Character
(L
);
9827 Set_Etype
(N
, Any_Type
);
9831 -- If bounds are static, constant-fold them, so size computations are
9832 -- identical between front-end and back-end. Do not perform this
9833 -- transformation while analyzing generic units, as type information
9834 -- would be lost when reanalyzing the constant node in the instance.
9836 if Is_Discrete_Type
(Typ
) and then Expander_Active
then
9837 if Is_OK_Static_Expression
(L
) then
9838 Fold_Uint
(L
, Expr_Value
(L
), Is_OK_Static_Expression
(L
));
9841 if Is_OK_Static_Expression
(H
) then
9842 Fold_Uint
(H
, Expr_Value
(H
), Is_OK_Static_Expression
(H
));
9847 --------------------------
9848 -- Resolve_Real_Literal --
9849 --------------------------
9851 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
9852 Actual_Typ
: constant Entity_Id
:= Etype
(N
);
9855 -- Special processing for fixed-point literals to make sure that the
9856 -- value is an exact multiple of small where this is required. We skip
9857 -- this for the universal real case, and also for generic types.
9859 if Is_Fixed_Point_Type
(Typ
)
9860 and then Typ
/= Universal_Fixed
9861 and then Typ
/= Any_Fixed
9862 and then not Is_Generic_Type
(Typ
)
9865 Val
: constant Ureal
:= Realval
(N
);
9866 Cintr
: constant Ureal
:= Val
/ Small_Value
(Typ
);
9867 Cint
: constant Uint
:= UR_Trunc
(Cintr
);
9868 Den
: constant Uint
:= Norm_Den
(Cintr
);
9872 -- Case of literal is not an exact multiple of the Small
9876 -- For a source program literal for a decimal fixed-point type,
9877 -- this is statically illegal (RM 4.9(36)).
9879 if Is_Decimal_Fixed_Point_Type
(Typ
)
9880 and then Actual_Typ
= Universal_Real
9881 and then Comes_From_Source
(N
)
9883 Error_Msg_N
("value has extraneous low order digits", N
);
9886 -- Generate a warning if literal from source
9888 if Is_OK_Static_Expression
(N
)
9889 and then Warn_On_Bad_Fixed_Value
9892 ("?b?static fixed-point value is not a multiple of Small!",
9896 -- Replace literal by a value that is the exact representation
9897 -- of a value of the type, i.e. a multiple of the small value,
9898 -- by truncation, since Machine_Rounds is false for all GNAT
9899 -- fixed-point types (RM 4.9(38)).
9901 Stat
:= Is_OK_Static_Expression
(N
);
9903 Make_Real_Literal
(Sloc
(N
),
9904 Realval
=> Small_Value
(Typ
) * Cint
));
9906 Set_Is_Static_Expression
(N
, Stat
);
9909 -- In all cases, set the corresponding integer field
9911 Set_Corresponding_Integer_Value
(N
, Cint
);
9915 -- Now replace the actual type by the expected type as usual
9918 Eval_Real_Literal
(N
);
9919 end Resolve_Real_Literal
;
9921 -----------------------
9922 -- Resolve_Reference --
9923 -----------------------
9925 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
) is
9926 P
: constant Node_Id
:= Prefix
(N
);
9929 -- Replace general access with specific type
9931 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
9932 Set_Etype
(N
, Base_Type
(Typ
));
9935 Resolve
(P
, Designated_Type
(Etype
(N
)));
9937 -- If we are taking the reference of a volatile entity, then treat it as
9938 -- a potential modification of this entity. This is too conservative,
9939 -- but necessary because remove side effects can cause transformations
9940 -- of normal assignments into reference sequences that otherwise fail to
9941 -- notice the modification.
9943 if Is_Entity_Name
(P
) and then Treat_As_Volatile
(Entity
(P
)) then
9944 Note_Possible_Modification
(P
, Sure
=> False);
9946 end Resolve_Reference
;
9948 --------------------------------
9949 -- Resolve_Selected_Component --
9950 --------------------------------
9952 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
9954 Comp1
: Entity_Id
:= Empty
; -- prevent junk warning
9955 P
: constant Node_Id
:= Prefix
(N
);
9956 S
: constant Node_Id
:= Selector_Name
(N
);
9957 T
: Entity_Id
:= Etype
(P
);
9959 I1
: Interp_Index
:= 0; -- prevent junk warning
9964 function Init_Component
return Boolean;
9965 -- Check whether this is the initialization of a component within an
9966 -- init proc (by assignment or call to another init proc). If true,
9967 -- there is no need for a discriminant check.
9969 --------------------
9970 -- Init_Component --
9971 --------------------
9973 function Init_Component
return Boolean is
9975 return Inside_Init_Proc
9976 and then Nkind
(Prefix
(N
)) = N_Identifier
9977 and then Chars
(Prefix
(N
)) = Name_uInit
9978 and then Nkind
(Parent
(Parent
(N
))) = N_Case_Statement_Alternative
;
9981 -- Start of processing for Resolve_Selected_Component
9984 if Is_Overloaded
(P
) then
9986 -- Use the context type to select the prefix that has a selector
9987 -- of the correct name and type.
9990 Get_First_Interp
(P
, I
, It
);
9992 Search
: while Present
(It
.Typ
) loop
9993 if Is_Access_Type
(It
.Typ
) then
9994 T
:= Designated_Type
(It
.Typ
);
9999 -- Locate selected component. For a private prefix the selector
10000 -- can denote a discriminant.
10002 if Is_Record_Type
(T
) or else Is_Private_Type
(T
) then
10004 -- The visible components of a class-wide type are those of
10007 if Is_Class_Wide_Type
(T
) then
10011 Comp
:= First_Entity
(T
);
10012 while Present
(Comp
) loop
10013 if Chars
(Comp
) = Chars
(S
)
10014 and then Covers
(Typ
, Etype
(Comp
))
10023 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
10025 if It
= No_Interp
then
10027 ("ambiguous prefix for selected component", N
);
10028 Set_Etype
(N
, Typ
);
10034 -- There may be an implicit dereference. Retrieve
10035 -- designated record type.
10037 if Is_Access_Type
(It1
.Typ
) then
10038 T
:= Designated_Type
(It1
.Typ
);
10043 if Scope
(Comp1
) /= T
then
10045 -- Resolution chooses the new interpretation.
10046 -- Find the component with the right name.
10048 Comp1
:= First_Entity
(T
);
10049 while Present
(Comp1
)
10050 and then Chars
(Comp1
) /= Chars
(S
)
10052 Comp1
:= Next_Entity
(Comp1
);
10061 Comp
:= Next_Entity
(Comp
);
10065 Get_Next_Interp
(I
, It
);
10068 -- There must be a legal interpretation at this point
10070 pragma Assert
(Found
);
10071 Resolve
(P
, It1
.Typ
);
10072 Set_Etype
(N
, Typ
);
10073 Set_Entity_With_Checks
(S
, Comp1
);
10076 -- Resolve prefix with its type
10081 -- Generate cross-reference. We needed to wait until full overloading
10082 -- resolution was complete to do this, since otherwise we can't tell if
10083 -- we are an lvalue or not.
10085 if May_Be_Lvalue
(N
) then
10086 Generate_Reference
(Entity
(S
), S
, 'm');
10088 Generate_Reference
(Entity
(S
), S
, 'r');
10091 -- If prefix is an access type, the node will be transformed into an
10092 -- explicit dereference during expansion. The type of the node is the
10093 -- designated type of that of the prefix.
10095 if Is_Access_Type
(Etype
(P
)) then
10096 T
:= Designated_Type
(Etype
(P
));
10097 Check_Fully_Declared_Prefix
(T
, P
);
10102 -- Set flag for expander if discriminant check required on a component
10103 -- appearing within a variant.
10105 if Has_Discriminants
(T
)
10106 and then Ekind
(Entity
(S
)) = E_Component
10107 and then Present
(Original_Record_Component
(Entity
(S
)))
10108 and then Ekind
(Original_Record_Component
(Entity
(S
))) = E_Component
10110 Is_Declared_Within_Variant
(Original_Record_Component
(Entity
(S
)))
10111 and then not Discriminant_Checks_Suppressed
(T
)
10112 and then not Init_Component
10114 Set_Do_Discriminant_Check
(N
);
10117 if Ekind
(Entity
(S
)) = E_Void
then
10118 Error_Msg_N
("premature use of component", S
);
10121 -- If the prefix is a record conversion, this may be a renamed
10122 -- discriminant whose bounds differ from those of the original
10123 -- one, so we must ensure that a range check is performed.
10125 if Nkind
(P
) = N_Type_Conversion
10126 and then Ekind
(Entity
(S
)) = E_Discriminant
10127 and then Is_Discrete_Type
(Typ
)
10129 Set_Etype
(N
, Base_Type
(Typ
));
10132 -- Note: No Eval processing is required, because the prefix is of a
10133 -- record type, or protected type, and neither can possibly be static.
10135 -- If the record type is atomic, and the component is non-atomic, then
10136 -- this is worth a warning, since we have a situation where the access
10137 -- to the component may cause extra read/writes of the atomic array
10138 -- object, or partial word accesses, both of which may be unexpected.
10140 if Nkind
(N
) = N_Selected_Component
10141 and then Is_Atomic_Ref_With_Address
(N
)
10142 and then not Is_Atomic
(Entity
(S
))
10143 and then not Is_Atomic
(Etype
(Entity
(S
)))
10146 ("??access to non-atomic component of atomic record",
10149 ("\??may cause unexpected accesses to atomic object",
10153 Analyze_Dimension
(N
);
10154 end Resolve_Selected_Component
;
10156 -------------------
10157 -- Resolve_Shift --
10158 -------------------
10160 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
) is
10161 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
10162 L
: constant Node_Id
:= Left_Opnd
(N
);
10163 R
: constant Node_Id
:= Right_Opnd
(N
);
10166 -- We do the resolution using the base type, because intermediate values
10167 -- in expressions always are of the base type, not a subtype of it.
10169 Resolve
(L
, B_Typ
);
10170 Resolve
(R
, Standard_Natural
);
10172 Check_Unset_Reference
(L
);
10173 Check_Unset_Reference
(R
);
10175 Set_Etype
(N
, B_Typ
);
10176 Generate_Operator_Reference
(N
, B_Typ
);
10180 ---------------------------
10181 -- Resolve_Short_Circuit --
10182 ---------------------------
10184 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
) is
10185 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
10186 L
: constant Node_Id
:= Left_Opnd
(N
);
10187 R
: constant Node_Id
:= Right_Opnd
(N
);
10190 -- Ensure all actions associated with the left operand (e.g.
10191 -- finalization of transient objects) are fully evaluated locally within
10192 -- an expression with actions. This is particularly helpful for coverage
10193 -- analysis. However this should not happen in generics or if option
10194 -- Minimize_Expression_With_Actions is set.
10196 if Expander_Active
and not Minimize_Expression_With_Actions
then
10198 Reloc_L
: constant Node_Id
:= Relocate_Node
(L
);
10200 Save_Interps
(Old_N
=> L
, New_N
=> Reloc_L
);
10203 Make_Expression_With_Actions
(Sloc
(L
),
10204 Actions
=> New_List
,
10205 Expression
=> Reloc_L
));
10207 -- Set Comes_From_Source on L to preserve warnings for unset
10210 Set_Comes_From_Source
(L
, Comes_From_Source
(Reloc_L
));
10214 Resolve
(L
, B_Typ
);
10215 Resolve
(R
, B_Typ
);
10217 -- Check for issuing warning for always False assert/check, this happens
10218 -- when assertions are turned off, in which case the pragma Assert/Check
10219 -- was transformed into:
10221 -- if False and then <condition> then ...
10223 -- and we detect this pattern
10225 if Warn_On_Assertion_Failure
10226 and then Is_Entity_Name
(R
)
10227 and then Entity
(R
) = Standard_False
10228 and then Nkind
(Parent
(N
)) = N_If_Statement
10229 and then Nkind
(N
) = N_And_Then
10230 and then Is_Entity_Name
(L
)
10231 and then Entity
(L
) = Standard_False
10234 Orig
: constant Node_Id
:= Original_Node
(Parent
(N
));
10237 -- Special handling of Asssert pragma
10239 if Nkind
(Orig
) = N_Pragma
10240 and then Pragma_Name
(Orig
) = Name_Assert
10243 Expr
: constant Node_Id
:=
10246 (First
(Pragma_Argument_Associations
(Orig
))));
10249 -- Don't warn if original condition is explicit False,
10250 -- since obviously the failure is expected in this case.
10252 if Is_Entity_Name
(Expr
)
10253 and then Entity
(Expr
) = Standard_False
10257 -- Issue warning. We do not want the deletion of the
10258 -- IF/AND-THEN to take this message with it. We achieve this
10259 -- by making sure that the expanded code points to the Sloc
10260 -- of the expression, not the original pragma.
10263 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
10264 -- The source location of the expression is not usually
10265 -- the best choice here. For example, it gets located on
10266 -- the last AND keyword in a chain of boolean expressiond
10267 -- AND'ed together. It is best to put the message on the
10268 -- first character of the assertion, which is the effect
10269 -- of the First_Node call here.
10272 ("?A?assertion would fail at run time!",
10274 (First
(Pragma_Argument_Associations
(Orig
))));
10278 -- Similar processing for Check pragma
10280 elsif Nkind
(Orig
) = N_Pragma
10281 and then Pragma_Name
(Orig
) = Name_Check
10283 -- Don't want to warn if original condition is explicit False
10286 Expr
: constant Node_Id
:=
10289 (Next
(First
(Pragma_Argument_Associations
(Orig
)))));
10291 if Is_Entity_Name
(Expr
)
10292 and then Entity
(Expr
) = Standard_False
10299 -- Again use Error_Msg_F rather than Error_Msg_N, see
10300 -- comment above for an explanation of why we do this.
10303 ("?A?check would fail at run time!",
10305 (Last
(Pragma_Argument_Associations
(Orig
))));
10312 -- Continue with processing of short circuit
10314 Check_Unset_Reference
(L
);
10315 Check_Unset_Reference
(R
);
10317 Set_Etype
(N
, B_Typ
);
10318 Eval_Short_Circuit
(N
);
10319 end Resolve_Short_Circuit
;
10321 -------------------
10322 -- Resolve_Slice --
10323 -------------------
10325 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
) is
10326 Drange
: constant Node_Id
:= Discrete_Range
(N
);
10327 Name
: constant Node_Id
:= Prefix
(N
);
10328 Array_Type
: Entity_Id
:= Empty
;
10329 Dexpr
: Node_Id
:= Empty
;
10330 Index_Type
: Entity_Id
;
10333 if Is_Overloaded
(Name
) then
10335 -- Use the context type to select the prefix that yields the correct
10340 I1
: Interp_Index
:= 0;
10342 P
: constant Node_Id
:= Prefix
(N
);
10343 Found
: Boolean := False;
10346 Get_First_Interp
(P
, I
, It
);
10347 while Present
(It
.Typ
) loop
10348 if (Is_Array_Type
(It
.Typ
)
10349 and then Covers
(Typ
, It
.Typ
))
10350 or else (Is_Access_Type
(It
.Typ
)
10351 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
10352 and then Covers
(Typ
, Designated_Type
(It
.Typ
)))
10355 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
10357 if It
= No_Interp
then
10358 Error_Msg_N
("ambiguous prefix for slicing", N
);
10359 Set_Etype
(N
, Typ
);
10363 Array_Type
:= It
.Typ
;
10368 Array_Type
:= It
.Typ
;
10373 Get_Next_Interp
(I
, It
);
10378 Array_Type
:= Etype
(Name
);
10381 Resolve
(Name
, Array_Type
);
10383 if Is_Access_Type
(Array_Type
) then
10384 Apply_Access_Check
(N
);
10385 Array_Type
:= Designated_Type
(Array_Type
);
10387 -- If the prefix is an access to an unconstrained array, we must use
10388 -- the actual subtype of the object to perform the index checks. The
10389 -- object denoted by the prefix is implicit in the node, so we build
10390 -- an explicit representation for it in order to compute the actual
10393 if not Is_Constrained
(Array_Type
) then
10394 Remove_Side_Effects
(Prefix
(N
));
10397 Obj
: constant Node_Id
:=
10398 Make_Explicit_Dereference
(Sloc
(N
),
10399 Prefix
=> New_Copy_Tree
(Prefix
(N
)));
10401 Set_Etype
(Obj
, Array_Type
);
10402 Set_Parent
(Obj
, Parent
(N
));
10403 Array_Type
:= Get_Actual_Subtype
(Obj
);
10407 elsif Is_Entity_Name
(Name
)
10408 or else Nkind
(Name
) = N_Explicit_Dereference
10409 or else (Nkind
(Name
) = N_Function_Call
10410 and then not Is_Constrained
(Etype
(Name
)))
10412 Array_Type
:= Get_Actual_Subtype
(Name
);
10414 -- If the name is a selected component that depends on discriminants,
10415 -- build an actual subtype for it. This can happen only when the name
10416 -- itself is overloaded; otherwise the actual subtype is created when
10417 -- the selected component is analyzed.
10419 elsif Nkind
(Name
) = N_Selected_Component
10420 and then Full_Analysis
10421 and then Depends_On_Discriminant
(First_Index
(Array_Type
))
10424 Act_Decl
: constant Node_Id
:=
10425 Build_Actual_Subtype_Of_Component
(Array_Type
, Name
);
10427 Insert_Action
(N
, Act_Decl
);
10428 Array_Type
:= Defining_Identifier
(Act_Decl
);
10431 -- Maybe this should just be "else", instead of checking for the
10432 -- specific case of slice??? This is needed for the case where the
10433 -- prefix is an Image attribute, which gets expanded to a slice, and so
10434 -- has a constrained subtype which we want to use for the slice range
10435 -- check applied below (the range check won't get done if the
10436 -- unconstrained subtype of the 'Image is used).
10438 elsif Nkind
(Name
) = N_Slice
then
10439 Array_Type
:= Etype
(Name
);
10442 -- Obtain the type of the array index
10444 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
10445 Index_Type
:= Etype
(String_Literal_Low_Bound
(Array_Type
));
10447 Index_Type
:= Etype
(First_Index
(Array_Type
));
10450 -- If name was overloaded, set slice type correctly now
10452 Set_Etype
(N
, Array_Type
);
10454 -- Handle the generation of a range check that compares the array index
10455 -- against the discrete_range. The check is not applied to internally
10456 -- built nodes associated with the expansion of dispatch tables. Check
10457 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10460 if Tagged_Type_Expansion
10461 and then RTU_Loaded
(Ada_Tags
)
10462 and then Nkind
(Prefix
(N
)) = N_Selected_Component
10463 and then Present
(Entity
(Selector_Name
(Prefix
(N
))))
10464 and then Entity
(Selector_Name
(Prefix
(N
))) =
10465 RTE_Record_Component
(RE_Prims_Ptr
)
10469 -- The discrete_range is specified by a subtype indication. Create a
10470 -- shallow copy and inherit the type, parent and source location from
10471 -- the discrete_range. This ensures that the range check is inserted
10472 -- relative to the slice and that the runtime exception points to the
10473 -- proper construct.
10475 elsif Is_Entity_Name
(Drange
) then
10476 Dexpr
:= New_Copy
(Scalar_Range
(Entity
(Drange
)));
10478 Set_Etype
(Dexpr
, Etype
(Drange
));
10479 Set_Parent
(Dexpr
, Parent
(Drange
));
10480 Set_Sloc
(Dexpr
, Sloc
(Drange
));
10482 -- The discrete_range is a regular range. Resolve the bounds and remove
10483 -- their side effects.
10486 Resolve
(Drange
, Base_Type
(Index_Type
));
10488 if Nkind
(Drange
) = N_Range
then
10489 Force_Evaluation
(Low_Bound
(Drange
));
10490 Force_Evaluation
(High_Bound
(Drange
));
10496 if Present
(Dexpr
) then
10497 Apply_Range_Check
(Dexpr
, Index_Type
);
10500 Set_Slice_Subtype
(N
);
10502 -- Check bad use of type with predicates
10508 if Nkind
(Drange
) = N_Subtype_Indication
10509 and then Has_Predicates
(Entity
(Subtype_Mark
(Drange
)))
10511 Subt
:= Entity
(Subtype_Mark
(Drange
));
10513 Subt
:= Etype
(Drange
);
10516 if Has_Predicates
(Subt
) then
10517 Bad_Predicated_Subtype_Use
10518 ("subtype& has predicate, not allowed in slice", Drange
, Subt
);
10522 -- Otherwise here is where we check suspicious indexes
10524 if Nkind
(Drange
) = N_Range
then
10525 Warn_On_Suspicious_Index
(Name
, Low_Bound
(Drange
));
10526 Warn_On_Suspicious_Index
(Name
, High_Bound
(Drange
));
10529 Analyze_Dimension
(N
);
10533 ----------------------------
10534 -- Resolve_String_Literal --
10535 ----------------------------
10537 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
10538 C_Typ
: constant Entity_Id
:= Component_Type
(Typ
);
10539 R_Typ
: constant Entity_Id
:= Root_Type
(C_Typ
);
10540 Loc
: constant Source_Ptr
:= Sloc
(N
);
10541 Str
: constant String_Id
:= Strval
(N
);
10542 Strlen
: constant Nat
:= String_Length
(Str
);
10543 Subtype_Id
: Entity_Id
;
10544 Need_Check
: Boolean;
10547 -- For a string appearing in a concatenation, defer creation of the
10548 -- string_literal_subtype until the end of the resolution of the
10549 -- concatenation, because the literal may be constant-folded away. This
10550 -- is a useful optimization for long concatenation expressions.
10552 -- If the string is an aggregate built for a single character (which
10553 -- happens in a non-static context) or a is null string to which special
10554 -- checks may apply, we build the subtype. Wide strings must also get a
10555 -- string subtype if they come from a one character aggregate. Strings
10556 -- generated by attributes might be static, but it is often hard to
10557 -- determine whether the enclosing context is static, so we generate
10558 -- subtypes for them as well, thus losing some rarer optimizations ???
10559 -- Same for strings that come from a static conversion.
10562 (Strlen
= 0 and then Typ
/= Standard_String
)
10563 or else Nkind
(Parent
(N
)) /= N_Op_Concat
10564 or else (N
/= Left_Opnd
(Parent
(N
))
10565 and then N
/= Right_Opnd
(Parent
(N
)))
10566 or else ((Typ
= Standard_Wide_String
10567 or else Typ
= Standard_Wide_Wide_String
)
10568 and then Nkind
(Original_Node
(N
)) /= N_String_Literal
);
10570 -- If the resolving type is itself a string literal subtype, we can just
10571 -- reuse it, since there is no point in creating another.
10573 if Ekind
(Typ
) = E_String_Literal_Subtype
then
10576 elsif Nkind
(Parent
(N
)) = N_Op_Concat
10577 and then not Need_Check
10578 and then not Nkind_In
(Original_Node
(N
), N_Character_Literal
,
10579 N_Attribute_Reference
,
10580 N_Qualified_Expression
,
10585 -- Do not generate a string literal subtype for the default expression
10586 -- of a formal parameter in GNATprove mode. This is because the string
10587 -- subtype is associated with the freezing actions of the subprogram,
10588 -- however freezing is disabled in GNATprove mode and as a result the
10589 -- subtype is unavailable.
10591 elsif GNATprove_Mode
10592 and then Nkind
(Parent
(N
)) = N_Parameter_Specification
10596 -- Otherwise we must create a string literal subtype. Note that the
10597 -- whole idea of string literal subtypes is simply to avoid the need
10598 -- for building a full fledged array subtype for each literal.
10601 Set_String_Literal_Subtype
(N
, Typ
);
10602 Subtype_Id
:= Etype
(N
);
10605 if Nkind
(Parent
(N
)) /= N_Op_Concat
10608 Set_Etype
(N
, Subtype_Id
);
10609 Eval_String_Literal
(N
);
10612 if Is_Limited_Composite
(Typ
)
10613 or else Is_Private_Composite
(Typ
)
10615 Error_Msg_N
("string literal not available for private array", N
);
10616 Set_Etype
(N
, Any_Type
);
10620 -- The validity of a null string has been checked in the call to
10621 -- Eval_String_Literal.
10626 -- Always accept string literal with component type Any_Character, which
10627 -- occurs in error situations and in comparisons of literals, both of
10628 -- which should accept all literals.
10630 elsif R_Typ
= Any_Character
then
10633 -- If the type is bit-packed, then we always transform the string
10634 -- literal into a full fledged aggregate.
10636 elsif Is_Bit_Packed_Array
(Typ
) then
10639 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10642 -- For Standard.Wide_Wide_String, or any other type whose component
10643 -- type is Standard.Wide_Wide_Character, we know that all the
10644 -- characters in the string must be acceptable, since the parser
10645 -- accepted the characters as valid character literals.
10647 if R_Typ
= Standard_Wide_Wide_Character
then
10650 -- For the case of Standard.String, or any other type whose component
10651 -- type is Standard.Character, we must make sure that there are no
10652 -- wide characters in the string, i.e. that it is entirely composed
10653 -- of characters in range of type Character.
10655 -- If the string literal is the result of a static concatenation, the
10656 -- test has already been performed on the components, and need not be
10659 elsif R_Typ
= Standard_Character
10660 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
10662 for J
in 1 .. Strlen
loop
10663 if not In_Character_Range
(Get_String_Char
(Str
, J
)) then
10665 -- If we are out of range, post error. This is one of the
10666 -- very few places that we place the flag in the middle of
10667 -- a token, right under the offending wide character. Not
10668 -- quite clear if this is right wrt wide character encoding
10669 -- sequences, but it's only an error message.
10672 ("literal out of range of type Standard.Character",
10673 Source_Ptr
(Int
(Loc
) + J
));
10678 -- For the case of Standard.Wide_String, or any other type whose
10679 -- component type is Standard.Wide_Character, we must make sure that
10680 -- there are no wide characters in the string, i.e. that it is
10681 -- entirely composed of characters in range of type Wide_Character.
10683 -- If the string literal is the result of a static concatenation,
10684 -- the test has already been performed on the components, and need
10685 -- not be repeated.
10687 elsif R_Typ
= Standard_Wide_Character
10688 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
10690 for J
in 1 .. Strlen
loop
10691 if not In_Wide_Character_Range
(Get_String_Char
(Str
, J
)) then
10693 -- If we are out of range, post error. This is one of the
10694 -- very few places that we place the flag in the middle of
10695 -- a token, right under the offending wide character.
10697 -- This is not quite right, because characters in general
10698 -- will take more than one character position ???
10701 ("literal out of range of type Standard.Wide_Character",
10702 Source_Ptr
(Int
(Loc
) + J
));
10707 -- If the root type is not a standard character, then we will convert
10708 -- the string into an aggregate and will let the aggregate code do
10709 -- the checking. Standard Wide_Wide_Character is also OK here.
10715 -- See if the component type of the array corresponding to the string
10716 -- has compile time known bounds. If yes we can directly check
10717 -- whether the evaluation of the string will raise constraint error.
10718 -- Otherwise we need to transform the string literal into the
10719 -- corresponding character aggregate and let the aggregate code do
10722 if Is_Standard_Character_Type
(R_Typ
) then
10724 -- Check for the case of full range, where we are definitely OK
10726 if Component_Type
(Typ
) = Base_Type
(Component_Type
(Typ
)) then
10730 -- Here the range is not the complete base type range, so check
10733 Comp_Typ_Lo
: constant Node_Id
:=
10734 Type_Low_Bound
(Component_Type
(Typ
));
10735 Comp_Typ_Hi
: constant Node_Id
:=
10736 Type_High_Bound
(Component_Type
(Typ
));
10741 if Compile_Time_Known_Value
(Comp_Typ_Lo
)
10742 and then Compile_Time_Known_Value
(Comp_Typ_Hi
)
10744 for J
in 1 .. Strlen
loop
10745 Char_Val
:= UI_From_Int
(Int
(Get_String_Char
(Str
, J
)));
10747 if Char_Val
< Expr_Value
(Comp_Typ_Lo
)
10748 or else Char_Val
> Expr_Value
(Comp_Typ_Hi
)
10750 Apply_Compile_Time_Constraint_Error
10751 (N
, "character out of range??",
10752 CE_Range_Check_Failed
,
10753 Loc
=> Source_Ptr
(Int
(Loc
) + J
));
10763 -- If we got here we meed to transform the string literal into the
10764 -- equivalent qualified positional array aggregate. This is rather
10765 -- heavy artillery for this situation, but it is hard work to avoid.
10768 Lits
: constant List_Id
:= New_List
;
10769 P
: Source_Ptr
:= Loc
+ 1;
10773 -- Build the character literals, we give them source locations that
10774 -- correspond to the string positions, which is a bit tricky given
10775 -- the possible presence of wide character escape sequences.
10777 for J
in 1 .. Strlen
loop
10778 C
:= Get_String_Char
(Str
, J
);
10779 Set_Character_Literal_Name
(C
);
10782 Make_Character_Literal
(P
,
10783 Chars
=> Name_Find
,
10784 Char_Literal_Value
=> UI_From_CC
(C
)));
10786 if In_Character_Range
(C
) then
10789 -- Should we have a call to Skip_Wide here ???
10798 Make_Qualified_Expression
(Loc
,
10799 Subtype_Mark
=> New_Occurrence_Of
(Typ
, Loc
),
10801 Make_Aggregate
(Loc
, Expressions
=> Lits
)));
10803 Analyze_And_Resolve
(N
, Typ
);
10805 end Resolve_String_Literal
;
10807 -------------------------
10808 -- Resolve_Target_Name --
10809 -------------------------
10811 procedure Resolve_Target_Name
(N
: Node_Id
; Typ
: Entity_Id
) is
10813 Set_Etype
(N
, Typ
);
10814 end Resolve_Target_Name
;
10816 -----------------------------
10817 -- Resolve_Type_Conversion --
10818 -----------------------------
10820 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
) is
10821 Conv_OK
: constant Boolean := Conversion_OK
(N
);
10822 Operand
: constant Node_Id
:= Expression
(N
);
10823 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
10824 Target_Typ
: constant Entity_Id
:= Etype
(N
);
10829 Test_Redundant
: Boolean := Warn_On_Redundant_Constructs
;
10830 -- Set to False to suppress cases where we want to suppress the test
10831 -- for redundancy to avoid possible false positives on this warning.
10835 and then not Valid_Conversion
(N
, Target_Typ
, Operand
)
10840 -- If the Operand Etype is Universal_Fixed, then the conversion is
10841 -- never redundant. We need this check because by the time we have
10842 -- finished the rather complex transformation, the conversion looks
10843 -- redundant when it is not.
10845 if Operand_Typ
= Universal_Fixed
then
10846 Test_Redundant
:= False;
10848 -- If the operand is marked as Any_Fixed, then special processing is
10849 -- required. This is also a case where we suppress the test for a
10850 -- redundant conversion, since most certainly it is not redundant.
10852 elsif Operand_Typ
= Any_Fixed
then
10853 Test_Redundant
:= False;
10855 -- Mixed-mode operation involving a literal. Context must be a fixed
10856 -- type which is applied to the literal subsequently.
10858 -- Multiplication and division involving two fixed type operands must
10859 -- yield a universal real because the result is computed in arbitrary
10862 if Is_Fixed_Point_Type
(Typ
)
10863 and then Nkind_In
(Operand
, N_Op_Divide
, N_Op_Multiply
)
10864 and then Etype
(Left_Opnd
(Operand
)) = Any_Fixed
10865 and then Etype
(Right_Opnd
(Operand
)) = Any_Fixed
10867 Set_Etype
(Operand
, Universal_Real
);
10869 elsif Is_Numeric_Type
(Typ
)
10870 and then Nkind_In
(Operand
, N_Op_Multiply
, N_Op_Divide
)
10871 and then (Etype
(Right_Opnd
(Operand
)) = Universal_Real
10873 Etype
(Left_Opnd
(Operand
)) = Universal_Real
)
10875 -- Return if expression is ambiguous
10877 if Unique_Fixed_Point_Type
(N
) = Any_Type
then
10880 -- If nothing else, the available fixed type is Duration
10883 Set_Etype
(Operand
, Standard_Duration
);
10886 -- Resolve the real operand with largest available precision
10888 if Etype
(Right_Opnd
(Operand
)) = Universal_Real
then
10889 Rop
:= New_Copy_Tree
(Right_Opnd
(Operand
));
10891 Rop
:= New_Copy_Tree
(Left_Opnd
(Operand
));
10894 Resolve
(Rop
, Universal_Real
);
10896 -- If the operand is a literal (it could be a non-static and
10897 -- illegal exponentiation) check whether the use of Duration
10898 -- is potentially inaccurate.
10900 if Nkind
(Rop
) = N_Real_Literal
10901 and then Realval
(Rop
) /= Ureal_0
10902 and then abs (Realval
(Rop
)) < Delta_Value
(Standard_Duration
)
10905 ("??universal real operand can only "
10906 & "be interpreted as Duration!", Rop
);
10908 ("\??precision will be lost in the conversion!", Rop
);
10911 elsif Is_Numeric_Type
(Typ
)
10912 and then Nkind
(Operand
) in N_Op
10913 and then Unique_Fixed_Point_Type
(N
) /= Any_Type
10915 Set_Etype
(Operand
, Standard_Duration
);
10918 Error_Msg_N
("invalid context for mixed mode operation", N
);
10919 Set_Etype
(Operand
, Any_Type
);
10926 -- In SPARK, a type conversion between array types should be restricted
10927 -- to types which have matching static bounds.
10929 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10930 -- operation if not needed.
10932 if Restriction_Check_Required
(SPARK_05
)
10933 and then Is_Array_Type
(Target_Typ
)
10934 and then Is_Array_Type
(Operand_Typ
)
10935 and then Operand_Typ
/= Any_Composite
-- or else Operand in error
10936 and then not Matching_Static_Array_Bounds
(Target_Typ
, Operand_Typ
)
10938 Check_SPARK_05_Restriction
10939 ("array types should have matching static bounds", N
);
10942 -- In formal mode, the operand of an ancestor type conversion must be an
10943 -- object (not an expression).
10945 if Is_Tagged_Type
(Target_Typ
)
10946 and then not Is_Class_Wide_Type
(Target_Typ
)
10947 and then Is_Tagged_Type
(Operand_Typ
)
10948 and then not Is_Class_Wide_Type
(Operand_Typ
)
10949 and then Is_Ancestor
(Target_Typ
, Operand_Typ
)
10950 and then not Is_SPARK_05_Object_Reference
(Operand
)
10952 Check_SPARK_05_Restriction
("object required", Operand
);
10955 Analyze_Dimension
(N
);
10957 -- Note: we do the Eval_Type_Conversion call before applying the
10958 -- required checks for a subtype conversion. This is important, since
10959 -- both are prepared under certain circumstances to change the type
10960 -- conversion to a constraint error node, but in the case of
10961 -- Eval_Type_Conversion this may reflect an illegality in the static
10962 -- case, and we would miss the illegality (getting only a warning
10963 -- message), if we applied the type conversion checks first.
10965 Eval_Type_Conversion
(N
);
10967 -- Even when evaluation is not possible, we may be able to simplify the
10968 -- conversion or its expression. This needs to be done before applying
10969 -- checks, since otherwise the checks may use the original expression
10970 -- and defeat the simplifications. This is specifically the case for
10971 -- elimination of the floating-point Truncation attribute in
10972 -- float-to-int conversions.
10974 Simplify_Type_Conversion
(N
);
10976 -- If after evaluation we still have a type conversion, then we may need
10977 -- to apply checks required for a subtype conversion.
10979 -- Skip these type conversion checks if universal fixed operands
10980 -- operands involved, since range checks are handled separately for
10981 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10983 if Nkind
(N
) = N_Type_Conversion
10984 and then not Is_Generic_Type
(Root_Type
(Target_Typ
))
10985 and then Target_Typ
/= Universal_Fixed
10986 and then Operand_Typ
/= Universal_Fixed
10988 Apply_Type_Conversion_Checks
(N
);
10991 -- Issue warning for conversion of simple object to its own type. We
10992 -- have to test the original nodes, since they may have been rewritten
10993 -- by various optimizations.
10995 Orig_N
:= Original_Node
(N
);
10997 -- Here we test for a redundant conversion if the warning mode is
10998 -- active (and was not locally reset), and we have a type conversion
10999 -- from source not appearing in a generic instance.
11002 and then Nkind
(Orig_N
) = N_Type_Conversion
11003 and then Comes_From_Source
(Orig_N
)
11004 and then not In_Instance
11006 Orig_N
:= Original_Node
(Expression
(Orig_N
));
11007 Orig_T
:= Target_Typ
;
11009 -- If the node is part of a larger expression, the Target_Type
11010 -- may not be the original type of the node if the context is a
11011 -- condition. Recover original type to see if conversion is needed.
11013 if Is_Boolean_Type
(Orig_T
)
11014 and then Nkind
(Parent
(N
)) in N_Op
11016 Orig_T
:= Etype
(Parent
(N
));
11019 -- If we have an entity name, then give the warning if the entity
11020 -- is the right type, or if it is a loop parameter covered by the
11021 -- original type (that's needed because loop parameters have an
11022 -- odd subtype coming from the bounds).
11024 if (Is_Entity_Name
(Orig_N
)
11026 (Etype
(Entity
(Orig_N
)) = Orig_T
11028 (Ekind
(Entity
(Orig_N
)) = E_Loop_Parameter
11029 and then Covers
(Orig_T
, Etype
(Entity
(Orig_N
))))))
11031 -- If not an entity, then type of expression must match
11033 or else Etype
(Orig_N
) = Orig_T
11035 -- One more check, do not give warning if the analyzed conversion
11036 -- has an expression with non-static bounds, and the bounds of the
11037 -- target are static. This avoids junk warnings in cases where the
11038 -- conversion is necessary to establish staticness, for example in
11039 -- a case statement.
11041 if not Is_OK_Static_Subtype
(Operand_Typ
)
11042 and then Is_OK_Static_Subtype
(Target_Typ
)
11046 -- Finally, if this type conversion occurs in a context requiring
11047 -- a prefix, and the expression is a qualified expression then the
11048 -- type conversion is not redundant, since a qualified expression
11049 -- is not a prefix, whereas a type conversion is. For example, "X
11050 -- := T'(Funx(...)).Y;" is illegal because a selected component
11051 -- requires a prefix, but a type conversion makes it legal: "X :=
11052 -- T(T'(Funx(...))).Y;"
11054 -- In Ada 2012, a qualified expression is a name, so this idiom is
11055 -- no longer needed, but we still suppress the warning because it
11056 -- seems unfriendly for warnings to pop up when you switch to the
11057 -- newer language version.
11059 elsif Nkind
(Orig_N
) = N_Qualified_Expression
11060 and then Nkind_In
(Parent
(N
), N_Attribute_Reference
,
11061 N_Indexed_Component
,
11062 N_Selected_Component
,
11064 N_Explicit_Dereference
)
11068 -- Never warn on conversion to Long_Long_Integer'Base since
11069 -- that is most likely an artifact of the extended overflow
11070 -- checking and comes from complex expanded code.
11072 elsif Orig_T
= Base_Type
(Standard_Long_Long_Integer
) then
11075 -- Here we give the redundant conversion warning. If it is an
11076 -- entity, give the name of the entity in the message. If not,
11077 -- just mention the expression.
11079 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
11082 if Is_Entity_Name
(Orig_N
) then
11083 Error_Msg_Node_2
:= Orig_T
;
11084 Error_Msg_NE
-- CODEFIX
11085 ("??redundant conversion, & is of type &!",
11086 N
, Entity
(Orig_N
));
11089 ("??redundant conversion, expression is of type&!",
11096 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
11097 -- No need to perform any interface conversion if the type of the
11098 -- expression coincides with the target type.
11100 if Ada_Version
>= Ada_2005
11101 and then Expander_Active
11102 and then Operand_Typ
/= Target_Typ
11105 Opnd
: Entity_Id
:= Operand_Typ
;
11106 Target
: Entity_Id
:= Target_Typ
;
11109 -- If the type of the operand is a limited view, use nonlimited
11110 -- view when available. If it is a class-wide type, recover the
11111 -- class-wide type of the nonlimited view.
11113 if From_Limited_With
(Opnd
)
11114 and then Has_Non_Limited_View
(Opnd
)
11116 Opnd
:= Non_Limited_View
(Opnd
);
11117 Set_Etype
(Expression
(N
), Opnd
);
11120 if Is_Access_Type
(Opnd
) then
11121 Opnd
:= Designated_Type
(Opnd
);
11124 if Is_Access_Type
(Target_Typ
) then
11125 Target
:= Designated_Type
(Target
);
11128 if Opnd
= Target
then
11131 -- Conversion from interface type
11133 elsif Is_Interface
(Opnd
) then
11135 -- Ada 2005 (AI-217): Handle entities from limited views
11137 if From_Limited_With
(Opnd
) then
11138 Error_Msg_Qual_Level
:= 99;
11139 Error_Msg_NE
-- CODEFIX
11140 ("missing WITH clause on package &", N
,
11141 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Opnd
))));
11143 ("type conversions require visibility of the full view",
11146 elsif From_Limited_With
(Target
)
11148 (Is_Access_Type
(Target_Typ
)
11149 and then Present
(Non_Limited_View
(Etype
(Target
))))
11151 Error_Msg_Qual_Level
:= 99;
11152 Error_Msg_NE
-- CODEFIX
11153 ("missing WITH clause on package &", N
,
11154 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Target
))));
11156 ("type conversions require visibility of the full view",
11160 Expand_Interface_Conversion
(N
);
11163 -- Conversion to interface type
11165 elsif Is_Interface
(Target
) then
11169 if Ekind_In
(Opnd
, E_Protected_Subtype
, E_Task_Subtype
) then
11170 Opnd
:= Etype
(Opnd
);
11173 if Is_Class_Wide_Type
(Opnd
)
11174 or else Interface_Present_In_Ancestor
11178 Expand_Interface_Conversion
(N
);
11180 Error_Msg_Name_1
:= Chars
(Etype
(Target
));
11181 Error_Msg_Name_2
:= Chars
(Opnd
);
11183 ("wrong interface conversion (% is not a progenitor "
11190 -- Ada 2012: once the type conversion is resolved, check whether the
11191 -- operand statisfies the static predicate of the target type.
11193 if Has_Predicates
(Target_Typ
) then
11194 Check_Expression_Against_Static_Predicate
(N
, Target_Typ
);
11197 -- If at this stage we have a real to integer conversion, make sure that
11198 -- the Do_Range_Check flag is set, because such conversions in general
11199 -- need a range check. We only need this if expansion is off.
11200 -- In GNATprove mode, we only do that when converting from fixed-point
11201 -- (as floating-point to integer conversions are now handled in
11202 -- GNATprove mode).
11204 if Nkind
(N
) = N_Type_Conversion
11205 and then not Expander_Active
11206 and then Is_Integer_Type
(Target_Typ
)
11207 and then (Is_Fixed_Point_Type
(Operand_Typ
)
11208 or else (not GNATprove_Mode
11209 and then Is_Floating_Point_Type
(Operand_Typ
)))
11211 Set_Do_Range_Check
(Operand
);
11214 -- Generating C code a type conversion of an access to constrained
11215 -- array type to access to unconstrained array type involves building
11216 -- a fat pointer which in general cannot be generated on the fly. We
11217 -- remove side effects in order to store the result of the conversion
11218 -- into a temporary.
11220 if Modify_Tree_For_C
11221 and then Nkind
(N
) = N_Type_Conversion
11222 and then Nkind
(Parent
(N
)) /= N_Object_Declaration
11223 and then Is_Access_Type
(Etype
(N
))
11224 and then Is_Array_Type
(Designated_Type
(Etype
(N
)))
11225 and then not Is_Constrained
(Designated_Type
(Etype
(N
)))
11226 and then Is_Constrained
(Designated_Type
(Etype
(Expression
(N
))))
11228 Remove_Side_Effects
(N
);
11230 end Resolve_Type_Conversion
;
11232 ----------------------
11233 -- Resolve_Unary_Op --
11234 ----------------------
11236 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
11237 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
11238 R
: constant Node_Id
:= Right_Opnd
(N
);
11244 if Is_Modular_Integer_Type
(Typ
) and then Nkind
(N
) /= N_Op_Not
then
11245 Error_Msg_Name_1
:= Chars
(Typ
);
11246 Check_SPARK_05_Restriction
11247 ("unary operator not defined for modular type%", N
);
11250 -- Deal with intrinsic unary operators
11252 if Comes_From_Source
(N
)
11253 and then Ekind
(Entity
(N
)) = E_Function
11254 and then Is_Imported
(Entity
(N
))
11255 and then Is_Intrinsic_Subprogram
(Entity
(N
))
11257 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
11261 -- Deal with universal cases
11263 if Etype
(R
) = Universal_Integer
11265 Etype
(R
) = Universal_Real
11267 Check_For_Visible_Operator
(N
, B_Typ
);
11270 Set_Etype
(N
, B_Typ
);
11271 Resolve
(R
, B_Typ
);
11273 -- Generate warning for expressions like abs (x mod 2)
11275 if Warn_On_Redundant_Constructs
11276 and then Nkind
(N
) = N_Op_Abs
11278 Determine_Range
(Right_Opnd
(N
), OK
, Lo
, Hi
);
11280 if OK
and then Hi
>= Lo
and then Lo
>= 0 then
11281 Error_Msg_N
-- CODEFIX
11282 ("?r?abs applied to known non-negative value has no effect", N
);
11286 -- Deal with reference generation
11288 Check_Unset_Reference
(R
);
11289 Generate_Operator_Reference
(N
, B_Typ
);
11290 Analyze_Dimension
(N
);
11293 -- Set overflow checking bit. Much cleverer code needed here eventually
11294 -- and perhaps the Resolve routines should be separated for the various
11295 -- arithmetic operations, since they will need different processing ???
11297 if Nkind
(N
) in N_Op
then
11298 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
11299 Enable_Overflow_Check
(N
);
11303 -- Generate warning for expressions like -5 mod 3 for integers. No need
11304 -- to worry in the floating-point case, since parens do not affect the
11305 -- result so there is no point in giving in a warning.
11308 Norig
: constant Node_Id
:= Original_Node
(N
);
11317 if Warn_On_Questionable_Missing_Parens
11318 and then Comes_From_Source
(Norig
)
11319 and then Is_Integer_Type
(Typ
)
11320 and then Nkind
(Norig
) = N_Op_Minus
11322 Rorig
:= Original_Node
(Right_Opnd
(Norig
));
11324 -- We are looking for cases where the right operand is not
11325 -- parenthesized, and is a binary operator, multiply, divide, or
11326 -- mod. These are the cases where the grouping can affect results.
11328 if Paren_Count
(Rorig
) = 0
11329 and then Nkind_In
(Rorig
, N_Op_Mod
, N_Op_Multiply
, N_Op_Divide
)
11331 -- For mod, we always give the warning, since the value is
11332 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11333 -- -(5 mod 315)). But for the other cases, the only concern is
11334 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11335 -- overflows, but (-2) * 64 does not). So we try to give the
11336 -- message only when overflow is possible.
11338 if Nkind
(Rorig
) /= N_Op_Mod
11339 and then Compile_Time_Known_Value
(R
)
11341 Val
:= Expr_Value
(R
);
11343 if Compile_Time_Known_Value
(Type_High_Bound
(Typ
)) then
11344 HB
:= Expr_Value
(Type_High_Bound
(Typ
));
11346 HB
:= Expr_Value
(Type_High_Bound
(Base_Type
(Typ
)));
11349 if Compile_Time_Known_Value
(Type_Low_Bound
(Typ
)) then
11350 LB
:= Expr_Value
(Type_Low_Bound
(Typ
));
11352 LB
:= Expr_Value
(Type_Low_Bound
(Base_Type
(Typ
)));
11355 -- Note that the test below is deliberately excluding the
11356 -- largest negative number, since that is a potentially
11357 -- troublesome case (e.g. -2 * x, where the result is the
11358 -- largest negative integer has an overflow with 2 * x).
11360 if Val
> LB
and then Val
<= HB
then
11365 -- For the multiplication case, the only case we have to worry
11366 -- about is when (-a)*b is exactly the largest negative number
11367 -- so that -(a*b) can cause overflow. This can only happen if
11368 -- a is a power of 2, and more generally if any operand is a
11369 -- constant that is not a power of 2, then the parentheses
11370 -- cannot affect whether overflow occurs. We only bother to
11371 -- test the left most operand
11373 -- Loop looking at left operands for one that has known value
11376 Opnd_Loop
: while Nkind
(Opnd
) = N_Op_Multiply
loop
11377 if Compile_Time_Known_Value
(Left_Opnd
(Opnd
)) then
11378 Lval
:= UI_Abs
(Expr_Value
(Left_Opnd
(Opnd
)));
11380 -- Operand value of 0 or 1 skips warning
11385 -- Otherwise check power of 2, if power of 2, warn, if
11386 -- anything else, skip warning.
11389 while Lval
/= 2 loop
11390 if Lval
mod 2 = 1 then
11401 -- Keep looking at left operands
11403 Opnd
:= Left_Opnd
(Opnd
);
11404 end loop Opnd_Loop
;
11406 -- For rem or "/" we can only have a problematic situation
11407 -- if the divisor has a value of minus one or one. Otherwise
11408 -- overflow is impossible (divisor > 1) or we have a case of
11409 -- division by zero in any case.
11411 if Nkind_In
(Rorig
, N_Op_Divide
, N_Op_Rem
)
11412 and then Compile_Time_Known_Value
(Right_Opnd
(Rorig
))
11413 and then UI_Abs
(Expr_Value
(Right_Opnd
(Rorig
))) /= 1
11418 -- If we fall through warning should be issued
11420 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11423 ("??unary minus expression should be parenthesized here!", N
);
11427 end Resolve_Unary_Op
;
11429 ----------------------------------
11430 -- Resolve_Unchecked_Expression --
11431 ----------------------------------
11433 procedure Resolve_Unchecked_Expression
11438 Resolve
(Expression
(N
), Typ
, Suppress
=> All_Checks
);
11439 Set_Etype
(N
, Typ
);
11440 end Resolve_Unchecked_Expression
;
11442 ---------------------------------------
11443 -- Resolve_Unchecked_Type_Conversion --
11444 ---------------------------------------
11446 procedure Resolve_Unchecked_Type_Conversion
11450 pragma Warnings
(Off
, Typ
);
11452 Operand
: constant Node_Id
:= Expression
(N
);
11453 Opnd_Type
: constant Entity_Id
:= Etype
(Operand
);
11456 -- Resolve operand using its own type
11458 Resolve
(Operand
, Opnd_Type
);
11460 -- In an inlined context, the unchecked conversion may be applied
11461 -- to a literal, in which case its type is the type of the context.
11462 -- (In other contexts conversions cannot apply to literals).
11465 and then (Opnd_Type
= Any_Character
or else
11466 Opnd_Type
= Any_Integer
or else
11467 Opnd_Type
= Any_Real
)
11469 Set_Etype
(Operand
, Typ
);
11472 Analyze_Dimension
(N
);
11473 Eval_Unchecked_Conversion
(N
);
11474 end Resolve_Unchecked_Type_Conversion
;
11476 ------------------------------
11477 -- Rewrite_Operator_As_Call --
11478 ------------------------------
11480 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
) is
11481 Loc
: constant Source_Ptr
:= Sloc
(N
);
11482 Actuals
: constant List_Id
:= New_List
;
11486 if Nkind
(N
) in N_Binary_Op
then
11487 Append
(Left_Opnd
(N
), Actuals
);
11490 Append
(Right_Opnd
(N
), Actuals
);
11493 Make_Function_Call
(Sloc
=> Loc
,
11494 Name
=> New_Occurrence_Of
(Nam
, Loc
),
11495 Parameter_Associations
=> Actuals
);
11497 Preserve_Comes_From_Source
(New_N
, N
);
11498 Preserve_Comes_From_Source
(Name
(New_N
), N
);
11499 Rewrite
(N
, New_N
);
11500 Set_Etype
(N
, Etype
(Nam
));
11501 end Rewrite_Operator_As_Call
;
11503 ------------------------------
11504 -- Rewrite_Renamed_Operator --
11505 ------------------------------
11507 procedure Rewrite_Renamed_Operator
11512 Nam
: constant Name_Id
:= Chars
(Op
);
11513 Is_Binary
: constant Boolean := Nkind
(N
) in N_Binary_Op
;
11517 -- Do not perform this transformation within a pre/postcondition,
11518 -- because the expression will be reanalyzed, and the transformation
11519 -- might affect the visibility of the operator, e.g. in an instance.
11520 -- Note that fully analyzed and expanded pre/postconditions appear as
11521 -- pragma Check equivalents.
11523 if In_Pre_Post_Condition
(N
) then
11527 -- Likewise when an expression function is being preanalyzed, since the
11528 -- expression will be reanalyzed as part of the generated body.
11530 if In_Spec_Expression
then
11532 S
: constant Entity_Id
:= Current_Scope_No_Loops
;
11534 if Ekind
(S
) = E_Function
11535 and then Nkind
(Original_Node
(Unit_Declaration_Node
(S
))) =
11536 N_Expression_Function
11543 -- Rewrite the operator node using the real operator, not its renaming.
11544 -- Exclude user-defined intrinsic operations of the same name, which are
11545 -- treated separately and rewritten as calls.
11547 if Ekind
(Op
) /= E_Function
or else Chars
(N
) /= Nam
then
11548 Op_Node
:= New_Node
(Operator_Kind
(Nam
, Is_Binary
), Sloc
(N
));
11549 Set_Chars
(Op_Node
, Nam
);
11550 Set_Etype
(Op_Node
, Etype
(N
));
11551 Set_Entity
(Op_Node
, Op
);
11552 Set_Right_Opnd
(Op_Node
, Right_Opnd
(N
));
11554 -- Indicate that both the original entity and its renaming are
11555 -- referenced at this point.
11557 Generate_Reference
(Entity
(N
), N
);
11558 Generate_Reference
(Op
, N
);
11561 Set_Left_Opnd
(Op_Node
, Left_Opnd
(N
));
11564 Rewrite
(N
, Op_Node
);
11566 -- If the context type is private, add the appropriate conversions so
11567 -- that the operator is applied to the full view. This is done in the
11568 -- routines that resolve intrinsic operators.
11570 if Is_Intrinsic_Subprogram
(Op
) and then Is_Private_Type
(Typ
) then
11580 Resolve_Intrinsic_Operator
(N
, Typ
);
11586 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
11593 elsif Ekind
(Op
) = E_Function
and then Is_Intrinsic_Subprogram
(Op
) then
11595 -- Operator renames a user-defined operator of the same name. Use the
11596 -- original operator in the node, which is the one Gigi knows about.
11598 Set_Entity
(N
, Op
);
11599 Set_Is_Overloaded
(N
, False);
11601 end Rewrite_Renamed_Operator
;
11603 -----------------------
11604 -- Set_Slice_Subtype --
11605 -----------------------
11607 -- Build an implicit subtype declaration to represent the type delivered by
11608 -- the slice. This is an abbreviated version of an array subtype. We define
11609 -- an index subtype for the slice, using either the subtype name or the
11610 -- discrete range of the slice. To be consistent with index usage elsewhere
11611 -- we create a list header to hold the single index. This list is not
11612 -- otherwise attached to the syntax tree.
11614 procedure Set_Slice_Subtype
(N
: Node_Id
) is
11615 Loc
: constant Source_Ptr
:= Sloc
(N
);
11616 Index_List
: constant List_Id
:= New_List
;
11618 Index_Subtype
: Entity_Id
;
11619 Index_Type
: Entity_Id
;
11620 Slice_Subtype
: Entity_Id
;
11621 Drange
: constant Node_Id
:= Discrete_Range
(N
);
11624 Index_Type
:= Base_Type
(Etype
(Drange
));
11626 if Is_Entity_Name
(Drange
) then
11627 Index_Subtype
:= Entity
(Drange
);
11630 -- We force the evaluation of a range. This is definitely needed in
11631 -- the renamed case, and seems safer to do unconditionally. Note in
11632 -- any case that since we will create and insert an Itype referring
11633 -- to this range, we must make sure any side effect removal actions
11634 -- are inserted before the Itype definition.
11636 if Nkind
(Drange
) = N_Range
then
11637 Force_Evaluation
(Low_Bound
(Drange
));
11638 Force_Evaluation
(High_Bound
(Drange
));
11640 -- If the discrete range is given by a subtype indication, the
11641 -- type of the slice is the base of the subtype mark.
11643 elsif Nkind
(Drange
) = N_Subtype_Indication
then
11645 R
: constant Node_Id
:= Range_Expression
(Constraint
(Drange
));
11647 Index_Type
:= Base_Type
(Entity
(Subtype_Mark
(Drange
)));
11648 Force_Evaluation
(Low_Bound
(R
));
11649 Force_Evaluation
(High_Bound
(R
));
11653 Index_Subtype
:= Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
11655 -- Take a new copy of Drange (where bounds have been rewritten to
11656 -- reference side-effect-free names). Using a separate tree ensures
11657 -- that further expansion (e.g. while rewriting a slice assignment
11658 -- into a FOR loop) does not attempt to remove side effects on the
11659 -- bounds again (which would cause the bounds in the index subtype
11660 -- definition to refer to temporaries before they are defined) (the
11661 -- reason is that some names are considered side effect free here
11662 -- for the subtype, but not in the context of a loop iteration
11665 Set_Scalar_Range
(Index_Subtype
, New_Copy_Tree
(Drange
));
11666 Set_Parent
(Scalar_Range
(Index_Subtype
), Index_Subtype
);
11667 Set_Etype
(Index_Subtype
, Index_Type
);
11668 Set_Size_Info
(Index_Subtype
, Index_Type
);
11669 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
11672 Slice_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
11674 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
11675 Set_Etype
(Index
, Index_Subtype
);
11676 Append
(Index
, Index_List
);
11678 Set_First_Index
(Slice_Subtype
, Index
);
11679 Set_Etype
(Slice_Subtype
, Base_Type
(Etype
(N
)));
11680 Set_Is_Constrained
(Slice_Subtype
, True);
11682 Check_Compile_Time_Size
(Slice_Subtype
);
11684 -- The Etype of the existing Slice node is reset to this slice subtype.
11685 -- Its bounds are obtained from its first index.
11687 Set_Etype
(N
, Slice_Subtype
);
11689 -- For bit-packed slice subtypes, freeze immediately (except in the case
11690 -- of being in a "spec expression" where we never freeze when we first
11691 -- see the expression).
11693 if Is_Bit_Packed_Array
(Slice_Subtype
) and not In_Spec_Expression
then
11694 Freeze_Itype
(Slice_Subtype
, N
);
11696 -- For all other cases insert an itype reference in the slice's actions
11697 -- so that the itype is frozen at the proper place in the tree (i.e. at
11698 -- the point where actions for the slice are analyzed). Note that this
11699 -- is different from freezing the itype immediately, which might be
11700 -- premature (e.g. if the slice is within a transient scope). This needs
11701 -- to be done only if expansion is enabled.
11703 elsif Expander_Active
then
11704 Ensure_Defined
(Typ
=> Slice_Subtype
, N
=> N
);
11706 end Set_Slice_Subtype
;
11708 --------------------------------
11709 -- Set_String_Literal_Subtype --
11710 --------------------------------
11712 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
) is
11713 Loc
: constant Source_Ptr
:= Sloc
(N
);
11714 Low_Bound
: constant Node_Id
:=
11715 Type_Low_Bound
(Etype
(First_Index
(Typ
)));
11716 Subtype_Id
: Entity_Id
;
11719 if Nkind
(N
) /= N_String_Literal
then
11723 Subtype_Id
:= Create_Itype
(E_String_Literal_Subtype
, N
);
11724 Set_String_Literal_Length
(Subtype_Id
, UI_From_Int
11725 (String_Length
(Strval
(N
))));
11726 Set_Etype
(Subtype_Id
, Base_Type
(Typ
));
11727 Set_Is_Constrained
(Subtype_Id
);
11728 Set_Etype
(N
, Subtype_Id
);
11730 -- The low bound is set from the low bound of the corresponding index
11731 -- type. Note that we do not store the high bound in the string literal
11732 -- subtype, but it can be deduced if necessary from the length and the
11735 if Is_OK_Static_Expression
(Low_Bound
) then
11736 Set_String_Literal_Low_Bound
(Subtype_Id
, Low_Bound
);
11738 -- If the lower bound is not static we create a range for the string
11739 -- literal, using the index type and the known length of the literal.
11740 -- The index type is not necessarily Positive, so the upper bound is
11741 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11745 Index_List
: constant List_Id
:= New_List
;
11746 Index_Type
: constant Entity_Id
:= Etype
(First_Index
(Typ
));
11747 High_Bound
: constant Node_Id
:=
11748 Make_Attribute_Reference
(Loc
,
11749 Attribute_Name
=> Name_Val
,
11751 New_Occurrence_Of
(Index_Type
, Loc
),
11752 Expressions
=> New_List
(
11755 Make_Attribute_Reference
(Loc
,
11756 Attribute_Name
=> Name_Pos
,
11758 New_Occurrence_Of
(Index_Type
, Loc
),
11760 New_List
(New_Copy_Tree
(Low_Bound
))),
11762 Make_Integer_Literal
(Loc
,
11763 String_Length
(Strval
(N
)) - 1))));
11765 Array_Subtype
: Entity_Id
;
11768 Index_Subtype
: Entity_Id
;
11771 if Is_Integer_Type
(Index_Type
) then
11772 Set_String_Literal_Low_Bound
11773 (Subtype_Id
, Make_Integer_Literal
(Loc
, 1));
11776 -- If the index type is an enumeration type, build bounds
11777 -- expression with attributes.
11779 Set_String_Literal_Low_Bound
11781 Make_Attribute_Reference
(Loc
,
11782 Attribute_Name
=> Name_First
,
11784 New_Occurrence_Of
(Base_Type
(Index_Type
), Loc
)));
11785 Set_Etype
(String_Literal_Low_Bound
(Subtype_Id
), Index_Type
);
11788 Analyze_And_Resolve
(String_Literal_Low_Bound
(Subtype_Id
));
11790 -- Build bona fide subtype for the string, and wrap it in an
11791 -- unchecked conversion, because the backend expects the
11792 -- String_Literal_Subtype to have a static lower bound.
11795 Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
11796 Drange
:= Make_Range
(Loc
, New_Copy_Tree
(Low_Bound
), High_Bound
);
11797 Set_Scalar_Range
(Index_Subtype
, Drange
);
11798 Set_Parent
(Drange
, N
);
11799 Analyze_And_Resolve
(Drange
, Index_Type
);
11801 -- In the context, the Index_Type may already have a constraint,
11802 -- so use common base type on string subtype. The base type may
11803 -- be used when generating attributes of the string, for example
11804 -- in the context of a slice assignment.
11806 Set_Etype
(Index_Subtype
, Base_Type
(Index_Type
));
11807 Set_Size_Info
(Index_Subtype
, Index_Type
);
11808 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
11810 Array_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
11812 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
11813 Set_Etype
(Index
, Index_Subtype
);
11814 Append
(Index
, Index_List
);
11816 Set_First_Index
(Array_Subtype
, Index
);
11817 Set_Etype
(Array_Subtype
, Base_Type
(Typ
));
11818 Set_Is_Constrained
(Array_Subtype
, True);
11821 Make_Unchecked_Type_Conversion
(Loc
,
11822 Subtype_Mark
=> New_Occurrence_Of
(Array_Subtype
, Loc
),
11823 Expression
=> Relocate_Node
(N
)));
11824 Set_Etype
(N
, Array_Subtype
);
11827 end Set_String_Literal_Subtype
;
11829 ------------------------------
11830 -- Simplify_Type_Conversion --
11831 ------------------------------
11833 procedure Simplify_Type_Conversion
(N
: Node_Id
) is
11835 if Nkind
(N
) = N_Type_Conversion
then
11837 Operand
: constant Node_Id
:= Expression
(N
);
11838 Target_Typ
: constant Entity_Id
:= Etype
(N
);
11839 Opnd_Typ
: constant Entity_Id
:= Etype
(Operand
);
11842 -- Special processing if the conversion is the expression of a
11843 -- Rounding or Truncation attribute reference. In this case we
11846 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11852 -- with the Float_Truncate flag set to False or True respectively,
11853 -- which is more efficient.
11855 if Is_Floating_Point_Type
(Opnd_Typ
)
11857 (Is_Integer_Type
(Target_Typ
)
11858 or else (Is_Fixed_Point_Type
(Target_Typ
)
11859 and then Conversion_OK
(N
)))
11860 and then Nkind
(Operand
) = N_Attribute_Reference
11861 and then Nam_In
(Attribute_Name
(Operand
), Name_Rounding
,
11865 Truncate
: constant Boolean :=
11866 Attribute_Name
(Operand
) = Name_Truncation
;
11869 Relocate_Node
(First
(Expressions
(Operand
))));
11870 Set_Float_Truncate
(N
, Truncate
);
11875 end Simplify_Type_Conversion
;
11877 -----------------------------
11878 -- Unique_Fixed_Point_Type --
11879 -----------------------------
11881 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
is
11882 procedure Fixed_Point_Error
(T1
: Entity_Id
; T2
: Entity_Id
);
11883 -- Give error messages for true ambiguity. Messages are posted on node
11884 -- N, and entities T1, T2 are the possible interpretations.
11886 -----------------------
11887 -- Fixed_Point_Error --
11888 -----------------------
11890 procedure Fixed_Point_Error
(T1
: Entity_Id
; T2
: Entity_Id
) is
11892 Error_Msg_N
("ambiguous universal_fixed_expression", N
);
11893 Error_Msg_NE
("\\possible interpretation as}", N
, T1
);
11894 Error_Msg_NE
("\\possible interpretation as}", N
, T2
);
11895 end Fixed_Point_Error
;
11905 -- Start of processing for Unique_Fixed_Point_Type
11908 -- The operations on Duration are visible, so Duration is always a
11909 -- possible interpretation.
11911 T1
:= Standard_Duration
;
11913 -- Look for fixed-point types in enclosing scopes
11915 Scop
:= Current_Scope
;
11916 while Scop
/= Standard_Standard
loop
11917 T2
:= First_Entity
(Scop
);
11918 while Present
(T2
) loop
11919 if Is_Fixed_Point_Type
(T2
)
11920 and then Current_Entity
(T2
) = T2
11921 and then Scope
(Base_Type
(T2
)) = Scop
11923 if Present
(T1
) then
11924 Fixed_Point_Error
(T1
, T2
);
11934 Scop
:= Scope
(Scop
);
11937 -- Look for visible fixed type declarations in the context
11939 Item
:= First
(Context_Items
(Cunit
(Current_Sem_Unit
)));
11940 while Present
(Item
) loop
11941 if Nkind
(Item
) = N_With_Clause
then
11942 Scop
:= Entity
(Name
(Item
));
11943 T2
:= First_Entity
(Scop
);
11944 while Present
(T2
) loop
11945 if Is_Fixed_Point_Type
(T2
)
11946 and then Scope
(Base_Type
(T2
)) = Scop
11947 and then (Is_Potentially_Use_Visible
(T2
) or else In_Use
(T2
))
11949 if Present
(T1
) then
11950 Fixed_Point_Error
(T1
, T2
);
11964 if Nkind
(N
) = N_Real_Literal
then
11965 Error_Msg_NE
("??real literal interpreted as }!", N
, T1
);
11968 -- When the context is a type conversion, issue the warning on the
11969 -- expression of the conversion because it is the actual operation.
11971 if Nkind_In
(N
, N_Type_Conversion
, N_Unchecked_Type_Conversion
) then
11972 ErrN
:= Expression
(N
);
11978 ("??universal_fixed expression interpreted as }!", ErrN
, T1
);
11982 end Unique_Fixed_Point_Type
;
11984 ----------------------
11985 -- Valid_Conversion --
11986 ----------------------
11988 function Valid_Conversion
11990 Target
: Entity_Id
;
11992 Report_Errs
: Boolean := True) return Boolean
11994 Target_Type
: constant Entity_Id
:= Base_Type
(Target
);
11995 Opnd_Type
: Entity_Id
:= Etype
(Operand
);
11996 Inc_Ancestor
: Entity_Id
;
11998 function Conversion_Check
12000 Msg
: String) return Boolean;
12001 -- Little routine to post Msg if Valid is False, returns Valid value
12003 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
);
12004 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
12006 procedure Conversion_Error_NE
12008 N
: Node_Or_Entity_Id
;
12009 E
: Node_Or_Entity_Id
);
12010 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
12012 function In_Instance_Code
return Boolean;
12013 -- Return True if expression is within an instance but is not in one of
12014 -- the actuals of the instantiation. Type conversions within an instance
12015 -- are not rechecked because type visbility may lead to spurious errors,
12016 -- but conversions in an actual for a formal object must be checked.
12018 function Valid_Tagged_Conversion
12019 (Target_Type
: Entity_Id
;
12020 Opnd_Type
: Entity_Id
) return Boolean;
12021 -- Specifically test for validity of tagged conversions
12023 function Valid_Array_Conversion
return Boolean;
12024 -- Check index and component conformance, and accessibility levels if
12025 -- the component types are anonymous access types (Ada 2005).
12027 ----------------------
12028 -- Conversion_Check --
12029 ----------------------
12031 function Conversion_Check
12033 Msg
: String) return Boolean
12038 -- A generic unit has already been analyzed and we have verified
12039 -- that a particular conversion is OK in that context. Since the
12040 -- instance is reanalyzed without relying on the relationships
12041 -- established during the analysis of the generic, it is possible
12042 -- to end up with inconsistent views of private types. Do not emit
12043 -- the error message in such cases. The rest of the machinery in
12044 -- Valid_Conversion still ensures the proper compatibility of
12045 -- target and operand types.
12047 and then not In_Instance_Code
12049 Conversion_Error_N
(Msg
, Operand
);
12053 end Conversion_Check
;
12055 ------------------------
12056 -- Conversion_Error_N --
12057 ------------------------
12059 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
) is
12061 if Report_Errs
then
12062 Error_Msg_N
(Msg
, N
);
12064 end Conversion_Error_N
;
12066 -------------------------
12067 -- Conversion_Error_NE --
12068 -------------------------
12070 procedure Conversion_Error_NE
12072 N
: Node_Or_Entity_Id
;
12073 E
: Node_Or_Entity_Id
)
12076 if Report_Errs
then
12077 Error_Msg_NE
(Msg
, N
, E
);
12079 end Conversion_Error_NE
;
12081 ----------------------
12082 -- In_Instance_Code --
12083 ----------------------
12085 function In_Instance_Code
return Boolean is
12089 if not In_Instance
then
12094 while Present
(Par
) loop
12096 -- The expression is part of an actual object if it appears in
12097 -- the generated object declaration in the instance.
12099 if Nkind
(Par
) = N_Object_Declaration
12100 and then Present
(Corresponding_Generic_Association
(Par
))
12106 Nkind
(Par
) in N_Statement_Other_Than_Procedure_Call
12107 or else Nkind
(Par
) in N_Subprogram_Call
12108 or else Nkind
(Par
) in N_Declaration
;
12111 Par
:= Parent
(Par
);
12114 -- Otherwise the expression appears within the instantiated unit
12118 end In_Instance_Code
;
12120 ----------------------------
12121 -- Valid_Array_Conversion --
12122 ----------------------------
12124 function Valid_Array_Conversion
return Boolean is
12125 Opnd_Comp_Type
: constant Entity_Id
:= Component_Type
(Opnd_Type
);
12126 Opnd_Comp_Base
: constant Entity_Id
:= Base_Type
(Opnd_Comp_Type
);
12128 Opnd_Index
: Node_Id
;
12129 Opnd_Index_Type
: Entity_Id
;
12131 Target_Comp_Type
: constant Entity_Id
:=
12132 Component_Type
(Target_Type
);
12133 Target_Comp_Base
: constant Entity_Id
:=
12134 Base_Type
(Target_Comp_Type
);
12136 Target_Index
: Node_Id
;
12137 Target_Index_Type
: Entity_Id
;
12140 -- Error if wrong number of dimensions
12143 Number_Dimensions
(Target_Type
) /= Number_Dimensions
(Opnd_Type
)
12146 ("incompatible number of dimensions for conversion", Operand
);
12149 -- Number of dimensions matches
12152 -- Loop through indexes of the two arrays
12154 Target_Index
:= First_Index
(Target_Type
);
12155 Opnd_Index
:= First_Index
(Opnd_Type
);
12156 while Present
(Target_Index
) and then Present
(Opnd_Index
) loop
12157 Target_Index_Type
:= Etype
(Target_Index
);
12158 Opnd_Index_Type
:= Etype
(Opnd_Index
);
12160 -- Error if index types are incompatible
12162 if not (Is_Integer_Type
(Target_Index_Type
)
12163 and then Is_Integer_Type
(Opnd_Index_Type
))
12164 and then (Root_Type
(Target_Index_Type
)
12165 /= Root_Type
(Opnd_Index_Type
))
12168 ("incompatible index types for array conversion",
12173 Next_Index
(Target_Index
);
12174 Next_Index
(Opnd_Index
);
12177 -- If component types have same base type, all set
12179 if Target_Comp_Base
= Opnd_Comp_Base
then
12182 -- Here if base types of components are not the same. The only
12183 -- time this is allowed is if we have anonymous access types.
12185 -- The conversion of arrays of anonymous access types can lead
12186 -- to dangling pointers. AI-392 formalizes the accessibility
12187 -- checks that must be applied to such conversions to prevent
12188 -- out-of-scope references.
12191 (Target_Comp_Base
, E_Anonymous_Access_Type
,
12192 E_Anonymous_Access_Subprogram_Type
)
12193 and then Ekind
(Opnd_Comp_Base
) = Ekind
(Target_Comp_Base
)
12195 Subtypes_Statically_Match
(Target_Comp_Type
, Opnd_Comp_Type
)
12197 if Type_Access_Level
(Target_Type
) <
12198 Deepest_Type_Access_Level
(Opnd_Type
)
12200 if In_Instance_Body
then
12201 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12203 ("source array type has deeper accessibility "
12204 & "level than target<<", Operand
);
12205 Conversion_Error_N
("\Program_Error [<<", Operand
);
12207 Make_Raise_Program_Error
(Sloc
(N
),
12208 Reason
=> PE_Accessibility_Check_Failed
));
12209 Set_Etype
(N
, Target_Type
);
12212 -- Conversion not allowed because of accessibility levels
12216 ("source array type has deeper accessibility "
12217 & "level than target", Operand
);
12225 -- All other cases where component base types do not match
12229 ("incompatible component types for array conversion",
12234 -- Check that component subtypes statically match. For numeric
12235 -- types this means that both must be either constrained or
12236 -- unconstrained. For enumeration types the bounds must match.
12237 -- All of this is checked in Subtypes_Statically_Match.
12239 if not Subtypes_Statically_Match
12240 (Target_Comp_Type
, Opnd_Comp_Type
)
12243 ("component subtypes must statically match", Operand
);
12249 end Valid_Array_Conversion
;
12251 -----------------------------
12252 -- Valid_Tagged_Conversion --
12253 -----------------------------
12255 function Valid_Tagged_Conversion
12256 (Target_Type
: Entity_Id
;
12257 Opnd_Type
: Entity_Id
) return Boolean
12260 -- Upward conversions are allowed (RM 4.6(22))
12262 if Covers
(Target_Type
, Opnd_Type
)
12263 or else Is_Ancestor
(Target_Type
, Opnd_Type
)
12267 -- Downward conversion are allowed if the operand is class-wide
12270 elsif Is_Class_Wide_Type
(Opnd_Type
)
12271 and then Covers
(Opnd_Type
, Target_Type
)
12275 elsif Covers
(Opnd_Type
, Target_Type
)
12276 or else Is_Ancestor
(Opnd_Type
, Target_Type
)
12279 Conversion_Check
(False,
12280 "downward conversion of tagged objects not allowed");
12282 -- Ada 2005 (AI-251): The conversion to/from interface types is
12283 -- always valid. The types involved may be class-wide (sub)types.
12285 elsif Is_Interface
(Etype
(Base_Type
(Target_Type
)))
12286 or else Is_Interface
(Etype
(Base_Type
(Opnd_Type
)))
12290 -- If the operand is a class-wide type obtained through a limited_
12291 -- with clause, and the context includes the nonlimited view, use
12292 -- it to determine whether the conversion is legal.
12294 elsif Is_Class_Wide_Type
(Opnd_Type
)
12295 and then From_Limited_With
(Opnd_Type
)
12296 and then Present
(Non_Limited_View
(Etype
(Opnd_Type
)))
12297 and then Is_Interface
(Non_Limited_View
(Etype
(Opnd_Type
)))
12301 elsif Is_Access_Type
(Opnd_Type
)
12302 and then Is_Interface
(Directly_Designated_Type
(Opnd_Type
))
12307 Conversion_Error_NE
12308 ("invalid tagged conversion, not compatible with}",
12309 N
, First_Subtype
(Opnd_Type
));
12312 end Valid_Tagged_Conversion
;
12314 -- Start of processing for Valid_Conversion
12317 Check_Parameterless_Call
(Operand
);
12319 if Is_Overloaded
(Operand
) then
12329 -- Remove procedure calls, which syntactically cannot appear in
12330 -- this context, but which cannot be removed by type checking,
12331 -- because the context does not impose a type.
12333 -- The node may be labelled overloaded, but still contain only one
12334 -- interpretation because others were discarded earlier. If this
12335 -- is the case, retain the single interpretation if legal.
12337 Get_First_Interp
(Operand
, I
, It
);
12338 Opnd_Type
:= It
.Typ
;
12339 Get_Next_Interp
(I
, It
);
12341 if Present
(It
.Typ
)
12342 and then Opnd_Type
/= Standard_Void_Type
12344 -- More than one candidate interpretation is available
12346 Get_First_Interp
(Operand
, I
, It
);
12347 while Present
(It
.Typ
) loop
12348 if It
.Typ
= Standard_Void_Type
then
12352 -- When compiling for a system where Address is of a visible
12353 -- integer type, spurious ambiguities can be produced when
12354 -- arithmetic operations have a literal operand and return
12355 -- System.Address or a descendant of it. These ambiguities
12356 -- are usually resolved by the context, but for conversions
12357 -- there is no context type and the removal of the spurious
12358 -- operations must be done explicitly here.
12360 if not Address_Is_Private
12361 and then Is_Descendant_Of_Address
(It
.Typ
)
12366 Get_Next_Interp
(I
, It
);
12370 Get_First_Interp
(Operand
, I
, It
);
12374 if No
(It
.Typ
) then
12375 Conversion_Error_N
("illegal operand in conversion", Operand
);
12379 Get_Next_Interp
(I
, It
);
12381 if Present
(It
.Typ
) then
12384 It1
:= Disambiguate
(Operand
, I1
, I
, Any_Type
);
12386 if It1
= No_Interp
then
12388 ("ambiguous operand in conversion", Operand
);
12390 -- If the interpretation involves a standard operator, use
12391 -- the location of the type, which may be user-defined.
12393 if Sloc
(It
.Nam
) = Standard_Location
then
12394 Error_Msg_Sloc
:= Sloc
(It
.Typ
);
12396 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
12399 Conversion_Error_N
-- CODEFIX
12400 ("\\possible interpretation#!", Operand
);
12402 if Sloc
(N1
) = Standard_Location
then
12403 Error_Msg_Sloc
:= Sloc
(T1
);
12405 Error_Msg_Sloc
:= Sloc
(N1
);
12408 Conversion_Error_N
-- CODEFIX
12409 ("\\possible interpretation#!", Operand
);
12415 Set_Etype
(Operand
, It1
.Typ
);
12416 Opnd_Type
:= It1
.Typ
;
12420 -- Deal with conversion of integer type to address if the pragma
12421 -- Allow_Integer_Address is in effect. We convert the conversion to
12422 -- an unchecked conversion in this case and we are all done.
12424 if Address_Integer_Convert_OK
(Opnd_Type
, Target_Type
) then
12425 Rewrite
(N
, Unchecked_Convert_To
(Target_Type
, Expression
(N
)));
12426 Analyze_And_Resolve
(N
, Target_Type
);
12430 -- If we are within a child unit, check whether the type of the
12431 -- expression has an ancestor in a parent unit, in which case it
12432 -- belongs to its derivation class even if the ancestor is private.
12433 -- See RM 7.3.1 (5.2/3).
12435 Inc_Ancestor
:= Get_Incomplete_View_Of_Ancestor
(Opnd_Type
);
12439 if Is_Numeric_Type
(Target_Type
) then
12441 -- A universal fixed expression can be converted to any numeric type
12443 if Opnd_Type
= Universal_Fixed
then
12446 -- Also no need to check when in an instance or inlined body, because
12447 -- the legality has been established when the template was analyzed.
12448 -- Furthermore, numeric conversions may occur where only a private
12449 -- view of the operand type is visible at the instantiation point.
12450 -- This results in a spurious error if we check that the operand type
12451 -- is a numeric type.
12453 -- Note: in a previous version of this unit, the following tests were
12454 -- applied only for generated code (Comes_From_Source set to False),
12455 -- but in fact the test is required for source code as well, since
12456 -- this situation can arise in source code.
12458 elsif In_Instance_Code
or else In_Inlined_Body
then
12461 -- Otherwise we need the conversion check
12464 return Conversion_Check
12465 (Is_Numeric_Type
(Opnd_Type
)
12467 (Present
(Inc_Ancestor
)
12468 and then Is_Numeric_Type
(Inc_Ancestor
)),
12469 "illegal operand for numeric conversion");
12474 elsif Is_Array_Type
(Target_Type
) then
12475 if not Is_Array_Type
(Opnd_Type
)
12476 or else Opnd_Type
= Any_Composite
12477 or else Opnd_Type
= Any_String
12480 ("illegal operand for array conversion", Operand
);
12484 return Valid_Array_Conversion
;
12487 -- Ada 2005 (AI-251): Internally generated conversions of access to
12488 -- interface types added to force the displacement of the pointer to
12489 -- reference the corresponding dispatch table.
12491 elsif not Comes_From_Source
(N
)
12492 and then Is_Access_Type
(Target_Type
)
12493 and then Is_Interface
(Designated_Type
(Target_Type
))
12497 -- Ada 2005 (AI-251): Anonymous access types where target references an
12500 elsif Is_Access_Type
(Opnd_Type
)
12501 and then Ekind_In
(Target_Type
, E_General_Access_Type
,
12502 E_Anonymous_Access_Type
)
12503 and then Is_Interface
(Directly_Designated_Type
(Target_Type
))
12505 -- Check the static accessibility rule of 4.6(17). Note that the
12506 -- check is not enforced when within an instance body, since the
12507 -- RM requires such cases to be caught at run time.
12509 -- If the operand is a rewriting of an allocator no check is needed
12510 -- because there are no accessibility issues.
12512 if Nkind
(Original_Node
(N
)) = N_Allocator
then
12515 elsif Ekind
(Target_Type
) /= E_Anonymous_Access_Type
then
12516 if Type_Access_Level
(Opnd_Type
) >
12517 Deepest_Type_Access_Level
(Target_Type
)
12519 -- In an instance, this is a run-time check, but one we know
12520 -- will fail, so generate an appropriate warning. The raise
12521 -- will be generated by Expand_N_Type_Conversion.
12523 if In_Instance_Body
then
12524 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12526 ("cannot convert local pointer to non-local access type<<",
12528 Conversion_Error_N
("\Program_Error [<<", Operand
);
12532 ("cannot convert local pointer to non-local access type",
12537 -- Special accessibility checks are needed in the case of access
12538 -- discriminants declared for a limited type.
12540 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12541 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12543 -- When the operand is a selected access discriminant the check
12544 -- needs to be made against the level of the object denoted by
12545 -- the prefix of the selected name (Object_Access_Level handles
12546 -- checking the prefix of the operand for this case).
12548 if Nkind
(Operand
) = N_Selected_Component
12549 and then Object_Access_Level
(Operand
) >
12550 Deepest_Type_Access_Level
(Target_Type
)
12552 -- In an instance, this is a run-time check, but one we know
12553 -- will fail, so generate an appropriate warning. The raise
12554 -- will be generated by Expand_N_Type_Conversion.
12556 if In_Instance_Body
then
12557 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12559 ("cannot convert access discriminant to non-local "
12560 & "access type<<", Operand
);
12561 Conversion_Error_N
("\Program_Error [<<", Operand
);
12563 -- Real error if not in instance body
12567 ("cannot convert access discriminant to non-local "
12568 & "access type", Operand
);
12573 -- The case of a reference to an access discriminant from
12574 -- within a limited type declaration (which will appear as
12575 -- a discriminal) is always illegal because the level of the
12576 -- discriminant is considered to be deeper than any (nameable)
12579 if Is_Entity_Name
(Operand
)
12580 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12582 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
12583 and then Present
(Discriminal_Link
(Entity
(Operand
)))
12586 ("discriminant has deeper accessibility level than target",
12595 -- General and anonymous access types
12597 elsif Ekind_In
(Target_Type
, E_General_Access_Type
,
12598 E_Anonymous_Access_Type
)
12601 (Is_Access_Type
(Opnd_Type
)
12603 Ekind_In
(Opnd_Type
, E_Access_Subprogram_Type
,
12604 E_Access_Protected_Subprogram_Type
),
12605 "must be an access-to-object type")
12607 if Is_Access_Constant
(Opnd_Type
)
12608 and then not Is_Access_Constant
(Target_Type
)
12611 ("access-to-constant operand type not allowed", Operand
);
12615 -- Check the static accessibility rule of 4.6(17). Note that the
12616 -- check is not enforced when within an instance body, since the RM
12617 -- requires such cases to be caught at run time.
12619 if Ekind
(Target_Type
) /= E_Anonymous_Access_Type
12620 or else Is_Local_Anonymous_Access
(Target_Type
)
12621 or else Nkind
(Associated_Node_For_Itype
(Target_Type
)) =
12622 N_Object_Declaration
12624 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12625 -- conversions from an anonymous access type to a named general
12626 -- access type. Such conversions are not allowed in the case of
12627 -- access parameters and stand-alone objects of an anonymous
12628 -- access type. The implicit conversion case is recognized by
12629 -- testing that Comes_From_Source is False and that it's been
12630 -- rewritten. The Comes_From_Source test isn't sufficient because
12631 -- nodes in inlined calls to predefined library routines can have
12632 -- Comes_From_Source set to False. (Is there a better way to test
12633 -- for implicit conversions???)
12635 if Ada_Version
>= Ada_2012
12636 and then not Comes_From_Source
(N
)
12637 and then N
/= Original_Node
(N
)
12638 and then Ekind
(Target_Type
) = E_General_Access_Type
12639 and then Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12641 if Is_Itype
(Opnd_Type
) then
12643 -- Implicit conversions aren't allowed for objects of an
12644 -- anonymous access type, since such objects have nonstatic
12645 -- levels in Ada 2012.
12647 if Nkind
(Associated_Node_For_Itype
(Opnd_Type
)) =
12648 N_Object_Declaration
12651 ("implicit conversion of stand-alone anonymous "
12652 & "access object not allowed", Operand
);
12655 -- Implicit conversions aren't allowed for anonymous access
12656 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12657 -- is done to exclude anonymous access results.
12659 elsif not Is_Local_Anonymous_Access
(Opnd_Type
)
12660 and then Nkind_In
(Associated_Node_For_Itype
(Opnd_Type
),
12661 N_Function_Specification
,
12662 N_Procedure_Specification
)
12665 ("implicit conversion of anonymous access formal "
12666 & "not allowed", Operand
);
12669 -- This is a case where there's an enclosing object whose
12670 -- to which the "statically deeper than" relationship does
12671 -- not apply (such as an access discriminant selected from
12672 -- a dereference of an access parameter).
12674 elsif Object_Access_Level
(Operand
)
12675 = Scope_Depth
(Standard_Standard
)
12678 ("implicit conversion of anonymous access value "
12679 & "not allowed", Operand
);
12682 -- In other cases, the level of the operand's type must be
12683 -- statically less deep than that of the target type, else
12684 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12686 elsif Type_Access_Level
(Opnd_Type
) >
12687 Deepest_Type_Access_Level
(Target_Type
)
12690 ("implicit conversion of anonymous access value "
12691 & "violates accessibility", Operand
);
12696 elsif Type_Access_Level
(Opnd_Type
) >
12697 Deepest_Type_Access_Level
(Target_Type
)
12699 -- In an instance, this is a run-time check, but one we know
12700 -- will fail, so generate an appropriate warning. The raise
12701 -- will be generated by Expand_N_Type_Conversion.
12703 if In_Instance_Body
then
12704 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12706 ("cannot convert local pointer to non-local access type<<",
12708 Conversion_Error_N
("\Program_Error [<<", Operand
);
12710 -- If not in an instance body, this is a real error
12713 -- Avoid generation of spurious error message
12715 if not Error_Posted
(N
) then
12717 ("cannot convert local pointer to non-local access type",
12724 -- Special accessibility checks are needed in the case of access
12725 -- discriminants declared for a limited type.
12727 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12728 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12730 -- When the operand is a selected access discriminant the check
12731 -- needs to be made against the level of the object denoted by
12732 -- the prefix of the selected name (Object_Access_Level handles
12733 -- checking the prefix of the operand for this case).
12735 if Nkind
(Operand
) = N_Selected_Component
12736 and then Object_Access_Level
(Operand
) >
12737 Deepest_Type_Access_Level
(Target_Type
)
12739 -- In an instance, this is a run-time check, but one we know
12740 -- will fail, so generate an appropriate warning. The raise
12741 -- will be generated by Expand_N_Type_Conversion.
12743 if In_Instance_Body
then
12744 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12746 ("cannot convert access discriminant to non-local "
12747 & "access type<<", Operand
);
12748 Conversion_Error_N
("\Program_Error [<<", Operand
);
12750 -- If not in an instance body, this is a real error
12754 ("cannot convert access discriminant to non-local "
12755 & "access type", Operand
);
12760 -- The case of a reference to an access discriminant from
12761 -- within a limited type declaration (which will appear as
12762 -- a discriminal) is always illegal because the level of the
12763 -- discriminant is considered to be deeper than any (nameable)
12766 if Is_Entity_Name
(Operand
)
12768 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
12769 and then Present
(Discriminal_Link
(Entity
(Operand
)))
12772 ("discriminant has deeper accessibility level than target",
12779 -- In the presence of limited_with clauses we have to use nonlimited
12780 -- views, if available.
12782 Check_Limited
: declare
12783 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
;
12784 -- Helper function to handle limited views
12786 --------------------------
12787 -- Full_Designated_Type --
12788 --------------------------
12790 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
is
12791 Desig
: constant Entity_Id
:= Designated_Type
(T
);
12794 -- Handle the limited view of a type
12796 if From_Limited_With
(Desig
)
12797 and then Has_Non_Limited_View
(Desig
)
12799 return Available_View
(Desig
);
12803 end Full_Designated_Type
;
12805 -- Local Declarations
12807 Target
: constant Entity_Id
:= Full_Designated_Type
(Target_Type
);
12808 Opnd
: constant Entity_Id
:= Full_Designated_Type
(Opnd_Type
);
12810 Same_Base
: constant Boolean :=
12811 Base_Type
(Target
) = Base_Type
(Opnd
);
12813 -- Start of processing for Check_Limited
12816 if Is_Tagged_Type
(Target
) then
12817 return Valid_Tagged_Conversion
(Target
, Opnd
);
12820 if not Same_Base
then
12821 Conversion_Error_NE
12822 ("target designated type not compatible with }",
12823 N
, Base_Type
(Opnd
));
12826 -- Ada 2005 AI-384: legality rule is symmetric in both
12827 -- designated types. The conversion is legal (with possible
12828 -- constraint check) if either designated type is
12831 elsif Subtypes_Statically_Match
(Target
, Opnd
)
12833 (Has_Discriminants
(Target
)
12835 (not Is_Constrained
(Opnd
)
12836 or else not Is_Constrained
(Target
)))
12838 -- Special case, if Value_Size has been used to make the
12839 -- sizes different, the conversion is not allowed even
12840 -- though the subtypes statically match.
12842 if Known_Static_RM_Size
(Target
)
12843 and then Known_Static_RM_Size
(Opnd
)
12844 and then RM_Size
(Target
) /= RM_Size
(Opnd
)
12846 Conversion_Error_NE
12847 ("target designated subtype not compatible with }",
12849 Conversion_Error_NE
12850 ("\because sizes of the two designated subtypes differ",
12854 -- Normal case where conversion is allowed
12862 ("target designated subtype not compatible with }",
12869 -- Access to subprogram types. If the operand is an access parameter,
12870 -- the type has a deeper accessibility that any master, and cannot be
12871 -- assigned. We must make an exception if the conversion is part of an
12872 -- assignment and the target is the return object of an extended return
12873 -- statement, because in that case the accessibility check takes place
12874 -- after the return.
12876 elsif Is_Access_Subprogram_Type
(Target_Type
)
12878 -- Note: this test of Opnd_Type is there to prevent entering this
12879 -- branch in the case of a remote access to subprogram type, which
12880 -- is internally represented as an E_Record_Type.
12882 and then Is_Access_Type
(Opnd_Type
)
12884 if Ekind
(Base_Type
(Opnd_Type
)) = E_Anonymous_Access_Subprogram_Type
12885 and then Is_Entity_Name
(Operand
)
12886 and then Ekind
(Entity
(Operand
)) = E_In_Parameter
12888 (Nkind
(Parent
(N
)) /= N_Assignment_Statement
12889 or else not Is_Entity_Name
(Name
(Parent
(N
)))
12890 or else not Is_Return_Object
(Entity
(Name
(Parent
(N
)))))
12893 ("illegal attempt to store anonymous access to subprogram",
12896 ("\value has deeper accessibility than any master "
12897 & "(RM 3.10.2 (13))",
12901 ("\use named access type for& instead of access parameter",
12902 Operand
, Entity
(Operand
));
12905 -- Check that the designated types are subtype conformant
12907 Check_Subtype_Conformant
(New_Id
=> Designated_Type
(Target_Type
),
12908 Old_Id
=> Designated_Type
(Opnd_Type
),
12911 -- Check the static accessibility rule of 4.6(20)
12913 if Type_Access_Level
(Opnd_Type
) >
12914 Deepest_Type_Access_Level
(Target_Type
)
12917 ("operand type has deeper accessibility level than target",
12920 -- Check that if the operand type is declared in a generic body,
12921 -- then the target type must be declared within that same body
12922 -- (enforces last sentence of 4.6(20)).
12924 elsif Present
(Enclosing_Generic_Body
(Opnd_Type
)) then
12926 O_Gen
: constant Node_Id
:=
12927 Enclosing_Generic_Body
(Opnd_Type
);
12932 T_Gen
:= Enclosing_Generic_Body
(Target_Type
);
12933 while Present
(T_Gen
) and then T_Gen
/= O_Gen
loop
12934 T_Gen
:= Enclosing_Generic_Body
(T_Gen
);
12937 if T_Gen
/= O_Gen
then
12939 ("target type must be declared in same generic body "
12940 & "as operand type", N
);
12947 -- Remote access to subprogram types
12949 elsif Is_Remote_Access_To_Subprogram_Type
(Target_Type
)
12950 and then Is_Remote_Access_To_Subprogram_Type
(Opnd_Type
)
12952 -- It is valid to convert from one RAS type to another provided
12953 -- that their specification statically match.
12955 -- Note: at this point, remote access to subprogram types have been
12956 -- expanded to their E_Record_Type representation, and we need to
12957 -- go back to the original access type definition using the
12958 -- Corresponding_Remote_Type attribute in order to check that the
12959 -- designated profiles match.
12961 pragma Assert
(Ekind
(Target_Type
) = E_Record_Type
);
12962 pragma Assert
(Ekind
(Opnd_Type
) = E_Record_Type
);
12964 Check_Subtype_Conformant
12966 Designated_Type
(Corresponding_Remote_Type
(Target_Type
)),
12968 Designated_Type
(Corresponding_Remote_Type
(Opnd_Type
)),
12973 -- If it was legal in the generic, it's legal in the instance
12975 elsif In_Instance_Body
then
12978 -- If both are tagged types, check legality of view conversions
12980 elsif Is_Tagged_Type
(Target_Type
)
12982 Is_Tagged_Type
(Opnd_Type
)
12984 return Valid_Tagged_Conversion
(Target_Type
, Opnd_Type
);
12986 -- Types derived from the same root type are convertible
12988 elsif Root_Type
(Target_Type
) = Root_Type
(Opnd_Type
) then
12991 -- In an instance or an inlined body, there may be inconsistent views of
12992 -- the same type, or of types derived from a common root.
12994 elsif (In_Instance
or In_Inlined_Body
)
12996 Root_Type
(Underlying_Type
(Target_Type
)) =
12997 Root_Type
(Underlying_Type
(Opnd_Type
))
13001 -- Special check for common access type error case
13003 elsif Ekind
(Target_Type
) = E_Access_Type
13004 and then Is_Access_Type
(Opnd_Type
)
13006 Conversion_Error_N
("target type must be general access type!", N
);
13007 Conversion_Error_NE
-- CODEFIX
13008 ("add ALL to }!", N
, Target_Type
);
13011 -- Here we have a real conversion error
13014 Conversion_Error_NE
13015 ("invalid conversion, not compatible with }", N
, Opnd_Type
);
13018 end Valid_Conversion
;