1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2016, 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 Fname
; use Fname
;
39 with Freeze
; use Freeze
;
40 with Ghost
; use Ghost
;
41 with Inline
; use Inline
;
42 with Itypes
; use Itypes
;
44 with Lib
.Xref
; use Lib
.Xref
;
45 with Namet
; use Namet
;
46 with Nmake
; use Nmake
;
47 with Nlists
; use Nlists
;
49 with Output
; use Output
;
50 with Par_SCO
; use Par_SCO
;
51 with Restrict
; use Restrict
;
52 with Rident
; use Rident
;
53 with Rtsfind
; use Rtsfind
;
55 with Sem_Aux
; use Sem_Aux
;
56 with Sem_Aggr
; use Sem_Aggr
;
57 with Sem_Attr
; use Sem_Attr
;
58 with Sem_Cat
; use Sem_Cat
;
59 with Sem_Ch4
; use Sem_Ch4
;
60 with Sem_Ch3
; use Sem_Ch3
;
61 with Sem_Ch6
; use Sem_Ch6
;
62 with Sem_Ch8
; use Sem_Ch8
;
63 with Sem_Ch13
; use Sem_Ch13
;
64 with Sem_Dim
; use Sem_Dim
;
65 with Sem_Disp
; use Sem_Disp
;
66 with Sem_Dist
; use Sem_Dist
;
67 with Sem_Elim
; use Sem_Elim
;
68 with Sem_Elab
; use Sem_Elab
;
69 with Sem_Eval
; use Sem_Eval
;
70 with Sem_Intr
; use Sem_Intr
;
71 with Sem_Util
; use Sem_Util
;
72 with Targparm
; use Targparm
;
73 with Sem_Type
; use Sem_Type
;
74 with Sem_Warn
; use Sem_Warn
;
75 with Sinfo
; use Sinfo
;
76 with Sinfo
.CN
; use Sinfo
.CN
;
77 with Snames
; use Snames
;
78 with Stand
; use Stand
;
79 with Stringt
; use Stringt
;
80 with Style
; use Style
;
81 with Tbuild
; use Tbuild
;
82 with Uintp
; use Uintp
;
83 with Urealp
; use Urealp
;
85 package body Sem_Res
is
87 -----------------------
88 -- Local Subprograms --
89 -----------------------
91 -- Second pass (top-down) type checking and overload resolution procedures
92 -- Typ is the type required by context. These procedures propagate the
93 -- type information recursively to the descendants of N. If the node is not
94 -- overloaded, its Etype is established in the first pass. If overloaded,
95 -- the Resolve routines set the correct type. For arithmetic operators, the
96 -- Etype is the base type of the context.
98 -- Note that Resolve_Attribute is separated off in Sem_Attr
100 procedure Check_Discriminant_Use
(N
: Node_Id
);
101 -- Enforce the restrictions on the use of discriminants when constraining
102 -- a component of a discriminated type (record or concurrent type).
104 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
);
105 -- Given a node for an operator associated with type T, check that the
106 -- operator is visible. Operators all of whose operands are universal must
107 -- be checked for visibility during resolution because their type is not
108 -- determinable based on their operands.
110 procedure Check_Fully_Declared_Prefix
113 -- Check that the type of the prefix of a dereference is not incomplete
115 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean;
116 -- Given a call node, N, which is known to occur immediately within the
117 -- subprogram being called, determines whether it is a detectable case of
118 -- an infinite recursion, and if so, outputs appropriate messages. Returns
119 -- True if an infinite recursion is detected, and False otherwise.
121 procedure Check_Initialization_Call
(N
: Entity_Id
; Nam
: Entity_Id
);
122 -- If the type of the object being initialized uses the secondary stack
123 -- directly or indirectly, create a transient scope for the call to the
124 -- init proc. This is because we do not create transient scopes for the
125 -- initialization of individual components within the init proc itself.
126 -- Could be optimized away perhaps?
128 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
);
129 -- N is the node for a logical operator. If the operator is predefined, and
130 -- the root type of the operands is Standard.Boolean, then a check is made
131 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
132 -- the style check for Style_Check_Boolean_And_Or.
134 function Is_Atomic_Ref_With_Address
(N
: Node_Id
) return Boolean;
135 -- N is either an indexed component or a selected component. This function
136 -- returns true if the prefix refers to an object that has an address
137 -- clause (the case in which we may want to issue a warning).
139 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean;
140 -- Determine whether E is an access type declared by an access declaration,
141 -- and not an (anonymous) allocator type.
143 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean;
144 -- Utility to check whether the entity for an operator is a predefined
145 -- operator, in which case the expression is left as an operator in the
146 -- tree (else it is rewritten into a call). An instance of an intrinsic
147 -- conversion operation may be given an operator name, but is not treated
148 -- like an operator. Note that an operator that is an imported back-end
149 -- builtin has convention Intrinsic, but is expected to be rewritten into
150 -- a call, so such an operator is not treated as predefined by this
153 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
);
154 -- If a default expression in entry call N depends on the discriminants
155 -- of the task, it must be replaced with a reference to the discriminant
156 -- of the task being called.
158 procedure Resolve_Op_Concat_Arg
163 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
164 -- concatenation operator. The operand is either of the array type or of
165 -- the component type. If the operand is an aggregate, and the component
166 -- type is composite, this is ambiguous if component type has aggregates.
168 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
);
169 -- Does the first part of the work of Resolve_Op_Concat
171 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
);
172 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
173 -- has been resolved. See Resolve_Op_Concat for details.
175 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
);
176 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
);
177 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
);
178 procedure Resolve_Case_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
179 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
180 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
);
181 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
);
182 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
);
183 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
);
184 procedure Resolve_Expression_With_Actions
(N
: Node_Id
; Typ
: Entity_Id
);
185 procedure Resolve_If_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
186 procedure Resolve_Generalized_Indexing
(N
: Node_Id
; Typ
: Entity_Id
);
187 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
);
188 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
189 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
);
190 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
);
191 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
);
192 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
);
193 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
);
194 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
);
195 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
);
196 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
197 procedure Resolve_Raise_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
198 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
);
199 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
200 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
);
201 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
);
202 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
);
203 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
);
204 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
);
205 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
206 procedure Resolve_Target_Name
(N
: Node_Id
; Typ
: Entity_Id
);
207 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
208 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
);
209 procedure Resolve_Unchecked_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
210 procedure Resolve_Unchecked_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
212 function Operator_Kind
214 Is_Binary
: Boolean) return Node_Kind
;
215 -- Utility to map the name of an operator into the corresponding Node. Used
216 -- by other node rewriting procedures.
218 procedure Resolve_Actuals
(N
: Node_Id
; Nam
: Entity_Id
);
219 -- Resolve actuals of call, and add default expressions for missing ones.
220 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
221 -- called subprogram.
223 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
);
224 -- Called from Resolve_Call, when the prefix denotes an entry or element
225 -- of entry family. Actuals are resolved as for subprograms, and the node
226 -- is rebuilt as an entry call. Also called for protected operations. Typ
227 -- is the context type, which is used when the operation is a protected
228 -- function with no arguments, and the return value is indexed.
230 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
231 -- A call to a user-defined intrinsic operator is rewritten as a call to
232 -- the corresponding predefined operator, with suitable conversions. Note
233 -- that this applies only for intrinsic operators that denote predefined
234 -- operators, not ones that are intrinsic imports of back-end builtins.
236 procedure Resolve_Intrinsic_Unary_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
237 -- Ditto, for arithmetic unary operators
239 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
);
240 -- If an operator node resolves to a call to a user-defined operator,
241 -- rewrite the node as a function call.
243 procedure Make_Call_Into_Operator
247 -- Inverse transformation: if an operator is given in functional notation,
248 -- then after resolving the node, transform into an operator node, so that
249 -- operands are resolved properly. Recall that predefined operators do not
250 -- have a full signature and special resolution rules apply.
252 procedure Rewrite_Renamed_Operator
256 -- An operator can rename another, e.g. in an instantiation. In that
257 -- case, the proper operator node must be constructed and resolved.
259 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
);
260 -- The String_Literal_Subtype is built for all strings that are not
261 -- operands of a static concatenation operation. If the argument is not
262 -- a N_String_Literal node, then the call has no effect.
264 procedure Set_Slice_Subtype
(N
: Node_Id
);
265 -- Build subtype of array type, with the range specified by the slice
267 procedure Simplify_Type_Conversion
(N
: Node_Id
);
268 -- Called after N has been resolved and evaluated, but before range checks
269 -- have been applied. Currently simplifies a combination of floating-point
270 -- to integer conversion and Rounding or Truncation attribute.
272 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
;
273 -- A universal_fixed expression in an universal context is unambiguous if
274 -- there is only one applicable fixed point type. Determining whether there
275 -- is only one requires a search over all visible entities, and happens
276 -- only in very pathological cases (see 6115-006).
278 -------------------------
279 -- Ambiguous_Character --
280 -------------------------
282 procedure Ambiguous_Character
(C
: Node_Id
) is
286 if Nkind
(C
) = N_Character_Literal
then
287 Error_Msg_N
("ambiguous character literal", C
);
289 -- First the ones in Standard
291 Error_Msg_N
("\\possible interpretation: Character!", C
);
292 Error_Msg_N
("\\possible interpretation: Wide_Character!", C
);
294 -- Include Wide_Wide_Character in Ada 2005 mode
296 if Ada_Version
>= Ada_2005
then
297 Error_Msg_N
("\\possible interpretation: Wide_Wide_Character!", C
);
300 -- Now any other types that match
302 E
:= Current_Entity
(C
);
303 while Present
(E
) loop
304 Error_Msg_NE
("\\possible interpretation:}!", C
, Etype
(E
));
308 end Ambiguous_Character
;
310 -------------------------
311 -- Analyze_And_Resolve --
312 -------------------------
314 procedure Analyze_And_Resolve
(N
: Node_Id
) is
318 end Analyze_And_Resolve
;
320 procedure Analyze_And_Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
324 end Analyze_And_Resolve
;
326 -- Versions with check(s) suppressed
328 procedure Analyze_And_Resolve
333 Scop
: constant Entity_Id
:= Current_Scope
;
336 if Suppress
= All_Checks
then
338 Sva
: constant Suppress_Array
:= Scope_Suppress
.Suppress
;
340 Scope_Suppress
.Suppress
:= (others => True);
341 Analyze_And_Resolve
(N
, Typ
);
342 Scope_Suppress
.Suppress
:= Sva
;
347 Svg
: constant Boolean := Scope_Suppress
.Suppress
(Suppress
);
349 Scope_Suppress
.Suppress
(Suppress
) := True;
350 Analyze_And_Resolve
(N
, Typ
);
351 Scope_Suppress
.Suppress
(Suppress
) := Svg
;
355 if Current_Scope
/= Scop
356 and then Scope_Is_Transient
358 -- This can only happen if a transient scope was created for an inner
359 -- expression, which will be removed upon completion of the analysis
360 -- of an enclosing construct. The transient scope must have the
361 -- suppress status of the enclosing environment, not of this Analyze
364 Scope_Stack
.Table
(Scope_Stack
.Last
).Save_Scope_Suppress
:=
367 end Analyze_And_Resolve
;
369 procedure Analyze_And_Resolve
373 Scop
: constant Entity_Id
:= Current_Scope
;
376 if Suppress
= All_Checks
then
378 Sva
: constant Suppress_Array
:= Scope_Suppress
.Suppress
;
380 Scope_Suppress
.Suppress
:= (others => True);
381 Analyze_And_Resolve
(N
);
382 Scope_Suppress
.Suppress
:= Sva
;
387 Svg
: constant Boolean := Scope_Suppress
.Suppress
(Suppress
);
389 Scope_Suppress
.Suppress
(Suppress
) := True;
390 Analyze_And_Resolve
(N
);
391 Scope_Suppress
.Suppress
(Suppress
) := Svg
;
395 if Current_Scope
/= Scop
and then Scope_Is_Transient
then
396 Scope_Stack
.Table
(Scope_Stack
.Last
).Save_Scope_Suppress
:=
399 end Analyze_And_Resolve
;
401 ----------------------------
402 -- Check_Discriminant_Use --
403 ----------------------------
405 procedure Check_Discriminant_Use
(N
: Node_Id
) is
406 PN
: constant Node_Id
:= Parent
(N
);
407 Disc
: constant Entity_Id
:= Entity
(N
);
412 -- Any use in a spec-expression is legal
414 if In_Spec_Expression
then
417 elsif Nkind
(PN
) = N_Range
then
419 -- Discriminant cannot be used to constrain a scalar type
423 if Nkind
(P
) = N_Range_Constraint
424 and then Nkind
(Parent
(P
)) = N_Subtype_Indication
425 and then Nkind
(Parent
(Parent
(P
))) = N_Component_Definition
427 Error_Msg_N
("discriminant cannot constrain scalar type", N
);
429 elsif Nkind
(P
) = N_Index_Or_Discriminant_Constraint
then
431 -- The following check catches the unusual case where a
432 -- discriminant appears within an index constraint that is part
433 -- of a larger expression within a constraint on a component,
434 -- e.g. "C : Int range 1 .. F (new A(1 .. D))". For now we only
435 -- check case of record components, and note that a similar check
436 -- should also apply in the case of discriminant constraints
439 -- Note that the check for N_Subtype_Declaration below is to
440 -- detect the valid use of discriminants in the constraints of a
441 -- subtype declaration when this subtype declaration appears
442 -- inside the scope of a record type (which is syntactically
443 -- illegal, but which may be created as part of derived type
444 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
447 if Ekind
(Current_Scope
) = E_Record_Type
448 and then Scope
(Disc
) = Current_Scope
450 (Nkind
(Parent
(P
)) = N_Subtype_Indication
452 Nkind_In
(Parent
(Parent
(P
)), N_Component_Definition
,
453 N_Subtype_Declaration
)
454 and then Paren_Count
(N
) = 0)
457 ("discriminant must appear alone in component constraint", N
);
461 -- Detect a common error:
463 -- type R (D : Positive := 100) is record
464 -- Name : String (1 .. D);
467 -- The default value causes an object of type R to be allocated
468 -- with room for Positive'Last characters. The RM does not mandate
469 -- the allocation of the maximum size, but that is what GNAT does
470 -- so we should warn the programmer that there is a problem.
472 Check_Large
: declare
478 function Large_Storage_Type
(T
: Entity_Id
) return Boolean;
479 -- Return True if type T has a large enough range that any
480 -- array whose index type covered the whole range of the type
481 -- would likely raise Storage_Error.
483 ------------------------
484 -- Large_Storage_Type --
485 ------------------------
487 function Large_Storage_Type
(T
: Entity_Id
) return Boolean is
489 -- The type is considered large if its bounds are known at
490 -- compile time and if it requires at least as many bits as
491 -- a Positive to store the possible values.
493 return Compile_Time_Known_Value
(Type_Low_Bound
(T
))
494 and then Compile_Time_Known_Value
(Type_High_Bound
(T
))
496 Minimum_Size
(T
, Biased
=> True) >=
497 RM_Size
(Standard_Positive
);
498 end Large_Storage_Type
;
500 -- Start of processing for Check_Large
503 -- Check that the Disc has a large range
505 if not Large_Storage_Type
(Etype
(Disc
)) then
509 -- If the enclosing type is limited, we allocate only the
510 -- default value, not the maximum, and there is no need for
513 if Is_Limited_Type
(Scope
(Disc
)) then
517 -- Check that it is the high bound
519 if N
/= High_Bound
(PN
)
520 or else No
(Discriminant_Default_Value
(Disc
))
525 -- Check the array allows a large range at this bound. First
530 if Nkind
(SI
) /= N_Subtype_Indication
then
534 T
:= Entity
(Subtype_Mark
(SI
));
536 if not Is_Array_Type
(T
) then
540 -- Next, find the dimension
542 TB
:= First_Index
(T
);
543 CB
:= First
(Constraints
(P
));
545 and then Present
(TB
)
546 and then Present
(CB
)
557 -- Now, check the dimension has a large range
559 if not Large_Storage_Type
(Etype
(TB
)) then
563 -- Warn about the danger
566 ("??creation of & object may raise Storage_Error!",
575 -- Legal case is in index or discriminant constraint
577 elsif Nkind_In
(PN
, N_Index_Or_Discriminant_Constraint
,
578 N_Discriminant_Association
)
580 if Paren_Count
(N
) > 0 then
582 ("discriminant in constraint must appear alone", N
);
584 elsif Nkind
(N
) = N_Expanded_Name
585 and then Comes_From_Source
(N
)
588 ("discriminant must appear alone as a direct name", N
);
593 -- Otherwise, context is an expression. It should not be within (i.e. a
594 -- subexpression of) a constraint for a component.
599 while not Nkind_In
(P
, N_Component_Declaration
,
600 N_Subtype_Indication
,
608 -- If the discriminant is used in an expression that is a bound of a
609 -- scalar type, an Itype is created and the bounds are attached to
610 -- its range, not to the original subtype indication. Such use is of
611 -- course a double fault.
613 if (Nkind
(P
) = N_Subtype_Indication
614 and then Nkind_In
(Parent
(P
), N_Component_Definition
,
615 N_Derived_Type_Definition
)
616 and then D
= Constraint
(P
))
618 -- The constraint itself may be given by a subtype indication,
619 -- rather than by a more common discrete range.
621 or else (Nkind
(P
) = N_Subtype_Indication
623 Nkind
(Parent
(P
)) = N_Index_Or_Discriminant_Constraint
)
624 or else Nkind
(P
) = N_Entry_Declaration
625 or else Nkind
(D
) = N_Defining_Identifier
628 ("discriminant in constraint must appear alone", N
);
631 end Check_Discriminant_Use
;
633 --------------------------------
634 -- Check_For_Visible_Operator --
635 --------------------------------
637 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
) is
639 if Is_Invisible_Operator
(N
, T
) then
640 Error_Msg_NE
-- CODEFIX
641 ("operator for} is not directly visible!", N
, First_Subtype
(T
));
642 Error_Msg_N
-- CODEFIX
643 ("use clause would make operation legal!", N
);
645 end Check_For_Visible_Operator
;
647 ----------------------------------
648 -- Check_Fully_Declared_Prefix --
649 ----------------------------------
651 procedure Check_Fully_Declared_Prefix
656 -- Check that the designated type of the prefix of a dereference is
657 -- not an incomplete type. This cannot be done unconditionally, because
658 -- dereferences of private types are legal in default expressions. This
659 -- case is taken care of in Check_Fully_Declared, called below. There
660 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
662 -- This consideration also applies to similar checks for allocators,
663 -- qualified expressions, and type conversions.
665 -- An additional exception concerns other per-object expressions that
666 -- are not directly related to component declarations, in particular
667 -- representation pragmas for tasks. These will be per-object
668 -- expressions if they depend on discriminants or some global entity.
669 -- If the task has access discriminants, the designated type may be
670 -- incomplete at the point the expression is resolved. This resolution
671 -- takes place within the body of the initialization procedure, where
672 -- the discriminant is replaced by its discriminal.
674 if Is_Entity_Name
(Pref
)
675 and then Ekind
(Entity
(Pref
)) = E_In_Parameter
679 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
680 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
681 -- Analyze_Object_Renaming, and Freeze_Entity.
683 elsif Ada_Version
>= Ada_2005
684 and then Is_Entity_Name
(Pref
)
685 and then Is_Access_Type
(Etype
(Pref
))
686 and then Ekind
(Directly_Designated_Type
(Etype
(Pref
))) =
688 and then Is_Tagged_Type
(Directly_Designated_Type
(Etype
(Pref
)))
692 Check_Fully_Declared
(Typ
, Parent
(Pref
));
694 end Check_Fully_Declared_Prefix
;
696 ------------------------------
697 -- Check_Infinite_Recursion --
698 ------------------------------
700 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean is
704 function Same_Argument_List
return Boolean;
705 -- Check whether list of actuals is identical to list of formals of
706 -- called function (which is also the enclosing scope).
708 ------------------------
709 -- Same_Argument_List --
710 ------------------------
712 function Same_Argument_List
return Boolean is
718 if not Is_Entity_Name
(Name
(N
)) then
721 Subp
:= Entity
(Name
(N
));
724 F
:= First_Formal
(Subp
);
725 A
:= First_Actual
(N
);
726 while Present
(F
) and then Present
(A
) loop
727 if not Is_Entity_Name
(A
) or else Entity
(A
) /= F
then
736 end Same_Argument_List
;
738 -- Start of processing for Check_Infinite_Recursion
741 -- Special case, if this is a procedure call and is a call to the
742 -- current procedure with the same argument list, then this is for
743 -- sure an infinite recursion and we insert a call to raise SE.
745 if Is_List_Member
(N
)
746 and then List_Length
(List_Containing
(N
)) = 1
747 and then Same_Argument_List
750 P
: constant Node_Id
:= Parent
(N
);
752 if Nkind
(P
) = N_Handled_Sequence_Of_Statements
753 and then Nkind
(Parent
(P
)) = N_Subprogram_Body
754 and then Is_Empty_List
(Declarations
(Parent
(P
)))
756 Error_Msg_Warn
:= SPARK_Mode
/= On
;
757 Error_Msg_N
("!infinite recursion<<", N
);
758 Error_Msg_N
("\!Storage_Error [<<", N
);
760 Make_Raise_Storage_Error
(Sloc
(N
),
761 Reason
=> SE_Infinite_Recursion
));
767 -- If not that special case, search up tree, quitting if we reach a
768 -- construct (e.g. a conditional) that tells us that this is not a
769 -- case for an infinite recursion warning.
775 -- If no parent, then we were not inside a subprogram, this can for
776 -- example happen when processing certain pragmas in a spec. Just
777 -- return False in this case.
783 -- Done if we get to subprogram body, this is definitely an infinite
784 -- recursion case if we did not find anything to stop us.
786 exit when Nkind
(P
) = N_Subprogram_Body
;
788 -- If appearing in conditional, result is false
790 if Nkind_In
(P
, N_Or_Else
,
799 elsif Nkind
(P
) = N_Handled_Sequence_Of_Statements
800 and then C
/= First
(Statements
(P
))
802 -- If the call is the expression of a return statement and the
803 -- actuals are identical to the formals, it's worth a warning.
804 -- However, we skip this if there is an immediately preceding
805 -- raise statement, since the call is never executed.
807 -- Furthermore, this corresponds to a common idiom:
809 -- function F (L : Thing) return Boolean is
811 -- raise Program_Error;
815 -- for generating a stub function
817 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
818 and then Same_Argument_List
820 exit when not Is_List_Member
(Parent
(N
));
822 -- OK, return statement is in a statement list, look for raise
828 -- Skip past N_Freeze_Entity nodes generated by expansion
830 Nod
:= Prev
(Parent
(N
));
832 and then Nkind
(Nod
) = N_Freeze_Entity
837 -- If no raise statement, give warning. We look at the
838 -- original node, because in the case of "raise ... with
839 -- ...", the node has been transformed into a call.
841 exit when Nkind
(Original_Node
(Nod
)) /= N_Raise_Statement
843 (Nkind
(Nod
) not in N_Raise_xxx_Error
844 or else Present
(Condition
(Nod
)));
855 Error_Msg_Warn
:= SPARK_Mode
/= On
;
856 Error_Msg_N
("!possible infinite recursion<<", N
);
857 Error_Msg_N
("\!??Storage_Error ]<<", N
);
860 end Check_Infinite_Recursion
;
862 -------------------------------
863 -- Check_Initialization_Call --
864 -------------------------------
866 procedure Check_Initialization_Call
(N
: Entity_Id
; Nam
: Entity_Id
) is
867 Typ
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
869 function Uses_SS
(T
: Entity_Id
) return Boolean;
870 -- Check whether the creation of an object of the type will involve
871 -- use of the secondary stack. If T is a record type, this is true
872 -- if the expression for some component uses the secondary stack, e.g.
873 -- through a call to a function that returns an unconstrained value.
874 -- False if T is controlled, because cleanups occur elsewhere.
880 function Uses_SS
(T
: Entity_Id
) return Boolean is
883 Full_Type
: Entity_Id
:= Underlying_Type
(T
);
886 -- Normally we want to use the underlying type, but if it's not set
887 -- then continue with T.
889 if not Present
(Full_Type
) then
893 if Is_Controlled
(Full_Type
) then
896 elsif Is_Array_Type
(Full_Type
) then
897 return Uses_SS
(Component_Type
(Full_Type
));
899 elsif Is_Record_Type
(Full_Type
) then
900 Comp
:= First_Component
(Full_Type
);
901 while Present
(Comp
) loop
902 if Ekind
(Comp
) = E_Component
903 and then Nkind
(Parent
(Comp
)) = N_Component_Declaration
905 -- The expression for a dynamic component may be rewritten
906 -- as a dereference, so retrieve original node.
908 Expr
:= Original_Node
(Expression
(Parent
(Comp
)));
910 -- Return True if the expression is a call to a function
911 -- (including an attribute function such as Image, or a
912 -- user-defined operator) with a result that requires a
915 if (Nkind
(Expr
) = N_Function_Call
916 or else Nkind
(Expr
) in N_Op
917 or else (Nkind
(Expr
) = N_Attribute_Reference
918 and then Present
(Expressions
(Expr
))))
919 and then Requires_Transient_Scope
(Etype
(Expr
))
923 elsif Uses_SS
(Etype
(Comp
)) then
928 Next_Component
(Comp
);
938 -- Start of processing for Check_Initialization_Call
941 -- Establish a transient scope if the type needs it
943 if Uses_SS
(Typ
) then
944 Establish_Transient_Scope
(First_Actual
(N
), Sec_Stack
=> True);
946 end Check_Initialization_Call
;
948 ---------------------------------------
949 -- Check_No_Direct_Boolean_Operators --
950 ---------------------------------------
952 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
) is
954 if Scope
(Entity
(N
)) = Standard_Standard
955 and then Root_Type
(Etype
(Left_Opnd
(N
))) = Standard_Boolean
957 -- Restriction only applies to original source code
959 if Comes_From_Source
(N
) then
960 Check_Restriction
(No_Direct_Boolean_Operators
, N
);
964 -- Do style check (but skip if in instance, error is on template)
967 if not In_Instance
then
968 Check_Boolean_Operator
(N
);
971 end Check_No_Direct_Boolean_Operators
;
973 ------------------------------
974 -- Check_Parameterless_Call --
975 ------------------------------
977 procedure Check_Parameterless_Call
(N
: Node_Id
) is
980 function Prefix_Is_Access_Subp
return Boolean;
981 -- If the prefix is of an access_to_subprogram type, the node must be
982 -- rewritten as a call. Ditto if the prefix is overloaded and all its
983 -- interpretations are access to subprograms.
985 ---------------------------
986 -- Prefix_Is_Access_Subp --
987 ---------------------------
989 function Prefix_Is_Access_Subp
return Boolean is
994 -- If the context is an attribute reference that can apply to
995 -- functions, this is never a parameterless call (RM 4.1.4(6)).
997 if Nkind
(Parent
(N
)) = N_Attribute_Reference
998 and then Nam_In
(Attribute_Name
(Parent
(N
)), Name_Address
,
1005 if not Is_Overloaded
(N
) then
1007 Ekind
(Etype
(N
)) = E_Subprogram_Type
1008 and then Base_Type
(Etype
(Etype
(N
))) /= Standard_Void_Type
;
1010 Get_First_Interp
(N
, I
, It
);
1011 while Present
(It
.Typ
) loop
1012 if Ekind
(It
.Typ
) /= E_Subprogram_Type
1013 or else Base_Type
(Etype
(It
.Typ
)) = Standard_Void_Type
1018 Get_Next_Interp
(I
, It
);
1023 end Prefix_Is_Access_Subp
;
1025 -- Start of processing for Check_Parameterless_Call
1028 -- Defend against junk stuff if errors already detected
1030 if Total_Errors_Detected
/= 0 then
1031 if Nkind
(N
) in N_Has_Etype
and then Etype
(N
) = Any_Type
then
1033 elsif Nkind
(N
) in N_Has_Chars
1034 and then Chars
(N
) in Error_Name_Or_No_Name
1042 -- If the context expects a value, and the name is a procedure, this is
1043 -- most likely a missing 'Access. Don't try to resolve the parameterless
1044 -- call, error will be caught when the outer call is analyzed.
1046 if Is_Entity_Name
(N
)
1047 and then Ekind
(Entity
(N
)) = E_Procedure
1048 and then not Is_Overloaded
(N
)
1050 Nkind_In
(Parent
(N
), N_Parameter_Association
,
1052 N_Procedure_Call_Statement
)
1057 -- Rewrite as call if overloadable entity that is (or could be, in the
1058 -- overloaded case) a function call. If we know for sure that the entity
1059 -- is an enumeration literal, we do not rewrite it.
1061 -- If the entity is the name of an operator, it cannot be a call because
1062 -- operators cannot have default parameters. In this case, this must be
1063 -- a string whose contents coincide with an operator name. Set the kind
1064 -- of the node appropriately.
1066 if (Is_Entity_Name
(N
)
1067 and then Nkind
(N
) /= N_Operator_Symbol
1068 and then Is_Overloadable
(Entity
(N
))
1069 and then (Ekind
(Entity
(N
)) /= E_Enumeration_Literal
1070 or else Is_Overloaded
(N
)))
1072 -- Rewrite as call if it is an explicit dereference of an expression of
1073 -- a subprogram access type, and the subprogram type is not that of a
1074 -- procedure or entry.
1077 (Nkind
(N
) = N_Explicit_Dereference
and then Prefix_Is_Access_Subp
)
1079 -- Rewrite as call if it is a selected component which is a function,
1080 -- this is the case of a call to a protected function (which may be
1081 -- overloaded with other protected operations).
1084 (Nkind
(N
) = N_Selected_Component
1085 and then (Ekind
(Entity
(Selector_Name
(N
))) = E_Function
1087 (Ekind_In
(Entity
(Selector_Name
(N
)), E_Entry
,
1089 and then Is_Overloaded
(Selector_Name
(N
)))))
1091 -- If one of the above three conditions is met, rewrite as call. Apply
1092 -- the rewriting only once.
1095 if Nkind
(Parent
(N
)) /= N_Function_Call
1096 or else N
/= Name
(Parent
(N
))
1099 -- This may be a prefixed call that was not fully analyzed, e.g.
1100 -- an actual in an instance.
1102 if Ada_Version
>= Ada_2005
1103 and then Nkind
(N
) = N_Selected_Component
1104 and then Is_Dispatching_Operation
(Entity
(Selector_Name
(N
)))
1106 Analyze_Selected_Component
(N
);
1108 if Nkind
(N
) /= N_Selected_Component
then
1113 -- The node is the name of the parameterless call. Preserve its
1114 -- descendants, which may be complex expressions.
1116 Nam
:= Relocate_Node
(N
);
1118 -- If overloaded, overload set belongs to new copy
1120 Save_Interps
(N
, Nam
);
1122 -- Change node to parameterless function call (note that the
1123 -- Parameter_Associations associations field is left set to Empty,
1124 -- its normal default value since there are no parameters)
1126 Change_Node
(N
, N_Function_Call
);
1128 Set_Sloc
(N
, Sloc
(Nam
));
1132 elsif Nkind
(N
) = N_Parameter_Association
then
1133 Check_Parameterless_Call
(Explicit_Actual_Parameter
(N
));
1135 elsif Nkind
(N
) = N_Operator_Symbol
then
1136 Change_Operator_Symbol_To_String_Literal
(N
);
1137 Set_Is_Overloaded
(N
, False);
1138 Set_Etype
(N
, Any_String
);
1140 end Check_Parameterless_Call
;
1142 --------------------------------
1143 -- Is_Atomic_Ref_With_Address --
1144 --------------------------------
1146 function Is_Atomic_Ref_With_Address
(N
: Node_Id
) return Boolean is
1147 Pref
: constant Node_Id
:= Prefix
(N
);
1150 if not Is_Entity_Name
(Pref
) then
1155 Pent
: constant Entity_Id
:= Entity
(Pref
);
1156 Ptyp
: constant Entity_Id
:= Etype
(Pent
);
1158 return not Is_Access_Type
(Ptyp
)
1159 and then (Is_Atomic
(Ptyp
) or else Is_Atomic
(Pent
))
1160 and then Present
(Address_Clause
(Pent
));
1163 end Is_Atomic_Ref_With_Address
;
1165 -----------------------------
1166 -- Is_Definite_Access_Type --
1167 -----------------------------
1169 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean is
1170 Btyp
: constant Entity_Id
:= Base_Type
(E
);
1172 return Ekind
(Btyp
) = E_Access_Type
1173 or else (Ekind
(Btyp
) = E_Access_Subprogram_Type
1174 and then Comes_From_Source
(Btyp
));
1175 end Is_Definite_Access_Type
;
1177 ----------------------
1178 -- Is_Predefined_Op --
1179 ----------------------
1181 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean is
1183 -- Predefined operators are intrinsic subprograms
1185 if not Is_Intrinsic_Subprogram
(Nam
) then
1189 -- A call to a back-end builtin is never a predefined operator
1191 if Is_Imported
(Nam
) and then Present
(Interface_Name
(Nam
)) then
1195 return not Is_Generic_Instance
(Nam
)
1196 and then Chars
(Nam
) in Any_Operator_Name
1197 and then (No
(Alias
(Nam
)) or else Is_Predefined_Op
(Alias
(Nam
)));
1198 end Is_Predefined_Op
;
1200 -----------------------------
1201 -- Make_Call_Into_Operator --
1202 -----------------------------
1204 procedure Make_Call_Into_Operator
1209 Op_Name
: constant Name_Id
:= Chars
(Op_Id
);
1210 Act1
: Node_Id
:= First_Actual
(N
);
1211 Act2
: Node_Id
:= Next_Actual
(Act1
);
1212 Error
: Boolean := False;
1213 Func
: constant Entity_Id
:= Entity
(Name
(N
));
1214 Is_Binary
: constant Boolean := Present
(Act2
);
1216 Opnd_Type
: Entity_Id
;
1217 Orig_Type
: Entity_Id
:= Empty
;
1220 type Kind_Test
is access function (E
: Entity_Id
) return Boolean;
1222 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean;
1223 -- If the operand is not universal, and the operator is given by an
1224 -- expanded name, verify that the operand has an interpretation with a
1225 -- type defined in the given scope of the operator.
1227 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
;
1228 -- Find a type of the given class in package Pack that contains the
1231 ---------------------------
1232 -- Operand_Type_In_Scope --
1233 ---------------------------
1235 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean is
1236 Nod
: constant Node_Id
:= Right_Opnd
(Op_Node
);
1241 if not Is_Overloaded
(Nod
) then
1242 return Scope
(Base_Type
(Etype
(Nod
))) = S
;
1245 Get_First_Interp
(Nod
, I
, It
);
1246 while Present
(It
.Typ
) loop
1247 if Scope
(Base_Type
(It
.Typ
)) = S
then
1251 Get_Next_Interp
(I
, It
);
1256 end Operand_Type_In_Scope
;
1262 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
is
1265 function In_Decl
return Boolean;
1266 -- Verify that node is not part of the type declaration for the
1267 -- candidate type, which would otherwise be invisible.
1273 function In_Decl
return Boolean is
1274 Decl_Node
: constant Node_Id
:= Parent
(E
);
1280 if Etype
(E
) = Any_Type
then
1283 elsif No
(Decl_Node
) then
1288 and then Nkind
(N2
) /= N_Compilation_Unit
1290 if N2
= Decl_Node
then
1301 -- Start of processing for Type_In_P
1304 -- If the context type is declared in the prefix package, this is the
1305 -- desired base type.
1307 if Scope
(Base_Type
(Typ
)) = Pack
and then Test
(Typ
) then
1308 return Base_Type
(Typ
);
1311 E
:= First_Entity
(Pack
);
1312 while Present
(E
) loop
1313 if Test
(E
) and then not In_Decl
then
1324 -- Start of processing for Make_Call_Into_Operator
1327 Op_Node
:= New_Node
(Operator_Kind
(Op_Name
, Is_Binary
), Sloc
(N
));
1332 Set_Left_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1333 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act2
));
1334 Save_Interps
(Act1
, Left_Opnd
(Op_Node
));
1335 Save_Interps
(Act2
, Right_Opnd
(Op_Node
));
1336 Act1
:= Left_Opnd
(Op_Node
);
1337 Act2
:= Right_Opnd
(Op_Node
);
1342 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1343 Save_Interps
(Act1
, Right_Opnd
(Op_Node
));
1344 Act1
:= Right_Opnd
(Op_Node
);
1347 -- If the operator is denoted by an expanded name, and the prefix is
1348 -- not Standard, but the operator is a predefined one whose scope is
1349 -- Standard, then this is an implicit_operator, inserted as an
1350 -- interpretation by the procedure of the same name. This procedure
1351 -- overestimates the presence of implicit operators, because it does
1352 -- not examine the type of the operands. Verify now that the operand
1353 -- type appears in the given scope. If right operand is universal,
1354 -- check the other operand. In the case of concatenation, either
1355 -- argument can be the component type, so check the type of the result.
1356 -- If both arguments are literals, look for a type of the right kind
1357 -- defined in the given scope. This elaborate nonsense is brought to
1358 -- you courtesy of b33302a. The type itself must be frozen, so we must
1359 -- find the type of the proper class in the given scope.
1361 -- A final wrinkle is the multiplication operator for fixed point types,
1362 -- which is defined in Standard only, and not in the scope of the
1363 -- fixed point type itself.
1365 if Nkind
(Name
(N
)) = N_Expanded_Name
then
1366 Pack
:= Entity
(Prefix
(Name
(N
)));
1368 -- If this is a package renaming, get renamed entity, which will be
1369 -- the scope of the operands if operaton is type-correct.
1371 if Present
(Renamed_Entity
(Pack
)) then
1372 Pack
:= Renamed_Entity
(Pack
);
1375 -- If the entity being called is defined in the given package, it is
1376 -- a renaming of a predefined operator, and known to be legal.
1378 if Scope
(Entity
(Name
(N
))) = Pack
1379 and then Pack
/= Standard_Standard
1383 -- Visibility does not need to be checked in an instance: if the
1384 -- operator was not visible in the generic it has been diagnosed
1385 -- already, else there is an implicit copy of it in the instance.
1387 elsif In_Instance
then
1390 elsif Nam_In
(Op_Name
, Name_Op_Multiply
, Name_Op_Divide
)
1391 and then Is_Fixed_Point_Type
(Etype
(Left_Opnd
(Op_Node
)))
1392 and then Is_Fixed_Point_Type
(Etype
(Right_Opnd
(Op_Node
)))
1394 if Pack
/= Standard_Standard
then
1398 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1401 elsif Ada_Version
>= Ada_2005
1402 and then Nam_In
(Op_Name
, Name_Op_Eq
, Name_Op_Ne
)
1403 and then Ekind
(Etype
(Act1
)) = E_Anonymous_Access_Type
1408 Opnd_Type
:= Base_Type
(Etype
(Right_Opnd
(Op_Node
)));
1410 if Op_Name
= Name_Op_Concat
then
1411 Opnd_Type
:= Base_Type
(Typ
);
1413 elsif (Scope
(Opnd_Type
) = Standard_Standard
1415 or else (Nkind
(Right_Opnd
(Op_Node
)) = N_Attribute_Reference
1417 and then not Comes_From_Source
(Opnd_Type
))
1419 Opnd_Type
:= Base_Type
(Etype
(Left_Opnd
(Op_Node
)));
1422 if Scope
(Opnd_Type
) = Standard_Standard
then
1424 -- Verify that the scope contains a type that corresponds to
1425 -- the given literal. Optimize the case where Pack is Standard.
1427 if Pack
/= Standard_Standard
then
1428 if Opnd_Type
= Universal_Integer
then
1429 Orig_Type
:= Type_In_P
(Is_Integer_Type
'Access);
1431 elsif Opnd_Type
= Universal_Real
then
1432 Orig_Type
:= Type_In_P
(Is_Real_Type
'Access);
1434 elsif Opnd_Type
= Any_String
then
1435 Orig_Type
:= Type_In_P
(Is_String_Type
'Access);
1437 elsif Opnd_Type
= Any_Access
then
1438 Orig_Type
:= Type_In_P
(Is_Definite_Access_Type
'Access);
1440 elsif Opnd_Type
= Any_Composite
then
1441 Orig_Type
:= Type_In_P
(Is_Composite_Type
'Access);
1443 if Present
(Orig_Type
) then
1444 if Has_Private_Component
(Orig_Type
) then
1447 Set_Etype
(Act1
, Orig_Type
);
1450 Set_Etype
(Act2
, Orig_Type
);
1459 Error
:= No
(Orig_Type
);
1462 elsif Ekind
(Opnd_Type
) = E_Allocator_Type
1463 and then No
(Type_In_P
(Is_Definite_Access_Type
'Access))
1467 -- If the type is defined elsewhere, and the operator is not
1468 -- defined in the given scope (by a renaming declaration, e.g.)
1469 -- then this is an error as well. If an extension of System is
1470 -- present, and the type may be defined there, Pack must be
1473 elsif Scope
(Opnd_Type
) /= Pack
1474 and then Scope
(Op_Id
) /= Pack
1475 and then (No
(System_Aux_Id
)
1476 or else Scope
(Opnd_Type
) /= System_Aux_Id
1477 or else Pack
/= Scope
(System_Aux_Id
))
1479 if not Is_Overloaded
(Right_Opnd
(Op_Node
)) then
1482 Error
:= not Operand_Type_In_Scope
(Pack
);
1485 elsif Pack
= Standard_Standard
1486 and then not Operand_Type_In_Scope
(Standard_Standard
)
1493 Error_Msg_Node_2
:= Pack
;
1495 ("& not declared in&", N
, Selector_Name
(Name
(N
)));
1496 Set_Etype
(N
, Any_Type
);
1499 -- Detect a mismatch between the context type and the result type
1500 -- in the named package, which is otherwise not detected if the
1501 -- operands are universal. Check is only needed if source entity is
1502 -- an operator, not a function that renames an operator.
1504 elsif Nkind
(Parent
(N
)) /= N_Type_Conversion
1505 and then Ekind
(Entity
(Name
(N
))) = E_Operator
1506 and then Is_Numeric_Type
(Typ
)
1507 and then not Is_Universal_Numeric_Type
(Typ
)
1508 and then Scope
(Base_Type
(Typ
)) /= Pack
1509 and then not In_Instance
1511 if Is_Fixed_Point_Type
(Typ
)
1512 and then Nam_In
(Op_Name
, Name_Op_Multiply
, Name_Op_Divide
)
1514 -- Already checked above
1518 -- Operator may be defined in an extension of System
1520 elsif Present
(System_Aux_Id
)
1521 and then Scope
(Opnd_Type
) = System_Aux_Id
1526 -- Could we use Wrong_Type here??? (this would require setting
1527 -- Etype (N) to the actual type found where Typ was expected).
1529 Error_Msg_NE
("expect }", N
, Typ
);
1534 Set_Chars
(Op_Node
, Op_Name
);
1536 if not Is_Private_Type
(Etype
(N
)) then
1537 Set_Etype
(Op_Node
, Base_Type
(Etype
(N
)));
1539 Set_Etype
(Op_Node
, Etype
(N
));
1542 -- If this is a call to a function that renames a predefined equality,
1543 -- the renaming declaration provides a type that must be used to
1544 -- resolve the operands. This must be done now because resolution of
1545 -- the equality node will not resolve any remaining ambiguity, and it
1546 -- assumes that the first operand is not overloaded.
1548 if Nam_In
(Op_Name
, Name_Op_Eq
, Name_Op_Ne
)
1549 and then Ekind
(Func
) = E_Function
1550 and then Is_Overloaded
(Act1
)
1552 Resolve
(Act1
, Base_Type
(Etype
(First_Formal
(Func
))));
1553 Resolve
(Act2
, Base_Type
(Etype
(First_Formal
(Func
))));
1556 Set_Entity
(Op_Node
, Op_Id
);
1557 Generate_Reference
(Op_Id
, N
, ' ');
1559 -- Do rewrite setting Comes_From_Source on the result if the original
1560 -- call came from source. Although it is not strictly the case that the
1561 -- operator as such comes from the source, logically it corresponds
1562 -- exactly to the function call in the source, so it should be marked
1563 -- this way (e.g. to make sure that validity checks work fine).
1566 CS
: constant Boolean := Comes_From_Source
(N
);
1568 Rewrite
(N
, Op_Node
);
1569 Set_Comes_From_Source
(N
, CS
);
1572 -- If this is an arithmetic operator and the result type is private,
1573 -- the operands and the result must be wrapped in conversion to
1574 -- expose the underlying numeric type and expand the proper checks,
1575 -- e.g. on division.
1577 if Is_Private_Type
(Typ
) then
1587 Resolve_Intrinsic_Operator
(N
, Typ
);
1593 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
1602 -- If in ASIS_Mode, propagate operand types to original actuals of
1603 -- function call, which would otherwise not be fully resolved. If
1604 -- the call has already been constant-folded, nothing to do. We
1605 -- relocate the operand nodes rather than copy them, to preserve
1606 -- original_node pointers, given that the operands themselves may
1607 -- have been rewritten. If the call was itself a rewriting of an
1608 -- operator node, nothing to do.
1611 and then Nkind
(N
) in N_Op
1612 and then Nkind
(Original_Node
(N
)) = N_Function_Call
1616 R
: constant Node_Id
:= Right_Opnd
(N
);
1618 Old_First
: constant Node_Id
:=
1619 First
(Parameter_Associations
(Original_Node
(N
)));
1625 Old_Sec
:= Next
(Old_First
);
1627 -- If the original call has named associations, replace the
1628 -- explicit actual parameter in the association with the proper
1629 -- resolved operand.
1631 if Nkind
(Old_First
) = N_Parameter_Association
then
1632 if Chars
(Selector_Name
(Old_First
)) =
1633 Chars
(First_Entity
(Op_Id
))
1635 Rewrite
(Explicit_Actual_Parameter
(Old_First
),
1638 Rewrite
(Explicit_Actual_Parameter
(Old_First
),
1643 Rewrite
(Old_First
, Relocate_Node
(L
));
1646 if Nkind
(Old_Sec
) = N_Parameter_Association
then
1647 if Chars
(Selector_Name
(Old_Sec
)) =
1648 Chars
(First_Entity
(Op_Id
))
1650 Rewrite
(Explicit_Actual_Parameter
(Old_Sec
),
1653 Rewrite
(Explicit_Actual_Parameter
(Old_Sec
),
1658 Rewrite
(Old_Sec
, Relocate_Node
(R
));
1662 if Nkind
(Old_First
) = N_Parameter_Association
then
1663 Rewrite
(Explicit_Actual_Parameter
(Old_First
),
1666 Rewrite
(Old_First
, Relocate_Node
(R
));
1671 Set_Parent
(Original_Node
(N
), Parent
(N
));
1673 end Make_Call_Into_Operator
;
1679 function Operator_Kind
1681 Is_Binary
: Boolean) return Node_Kind
1686 -- Use CASE statement or array???
1689 if Op_Name
= Name_Op_And
then
1691 elsif Op_Name
= Name_Op_Or
then
1693 elsif Op_Name
= Name_Op_Xor
then
1695 elsif Op_Name
= Name_Op_Eq
then
1697 elsif Op_Name
= Name_Op_Ne
then
1699 elsif Op_Name
= Name_Op_Lt
then
1701 elsif Op_Name
= Name_Op_Le
then
1703 elsif Op_Name
= Name_Op_Gt
then
1705 elsif Op_Name
= Name_Op_Ge
then
1707 elsif Op_Name
= Name_Op_Add
then
1709 elsif Op_Name
= Name_Op_Subtract
then
1710 Kind
:= N_Op_Subtract
;
1711 elsif Op_Name
= Name_Op_Concat
then
1712 Kind
:= N_Op_Concat
;
1713 elsif Op_Name
= Name_Op_Multiply
then
1714 Kind
:= N_Op_Multiply
;
1715 elsif Op_Name
= Name_Op_Divide
then
1716 Kind
:= N_Op_Divide
;
1717 elsif Op_Name
= Name_Op_Mod
then
1719 elsif Op_Name
= Name_Op_Rem
then
1721 elsif Op_Name
= Name_Op_Expon
then
1724 raise Program_Error
;
1730 if Op_Name
= Name_Op_Add
then
1732 elsif Op_Name
= Name_Op_Subtract
then
1734 elsif Op_Name
= Name_Op_Abs
then
1736 elsif Op_Name
= Name_Op_Not
then
1739 raise Program_Error
;
1746 ----------------------------
1747 -- Preanalyze_And_Resolve --
1748 ----------------------------
1750 procedure Preanalyze_And_Resolve
(N
: Node_Id
; T
: Entity_Id
) is
1751 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1754 Full_Analysis
:= False;
1755 Expander_Mode_Save_And_Set
(False);
1757 -- Normally, we suppress all checks for this preanalysis. There is no
1758 -- point in processing them now, since they will be applied properly
1759 -- and in the proper location when the default expressions reanalyzed
1760 -- and reexpanded later on. We will also have more information at that
1761 -- point for possible suppression of individual checks.
1763 -- However, in SPARK mode, most expansion is suppressed, and this
1764 -- later reanalysis and reexpansion may not occur. SPARK mode does
1765 -- require the setting of checking flags for proof purposes, so we
1766 -- do the SPARK preanalysis without suppressing checks.
1768 -- This special handling for SPARK mode is required for example in the
1769 -- case of Ada 2012 constructs such as quantified expressions, which are
1770 -- expanded in two separate steps.
1772 if GNATprove_Mode
then
1773 Analyze_And_Resolve
(N
, T
);
1775 Analyze_And_Resolve
(N
, T
, Suppress
=> All_Checks
);
1778 Expander_Mode_Restore
;
1779 Full_Analysis
:= Save_Full_Analysis
;
1780 end Preanalyze_And_Resolve
;
1782 -- Version without context type
1784 procedure Preanalyze_And_Resolve
(N
: Node_Id
) is
1785 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1788 Full_Analysis
:= False;
1789 Expander_Mode_Save_And_Set
(False);
1792 Resolve
(N
, Etype
(N
), Suppress
=> All_Checks
);
1794 Expander_Mode_Restore
;
1795 Full_Analysis
:= Save_Full_Analysis
;
1796 end Preanalyze_And_Resolve
;
1798 ----------------------------------
1799 -- Replace_Actual_Discriminants --
1800 ----------------------------------
1802 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
) is
1803 Loc
: constant Source_Ptr
:= Sloc
(N
);
1804 Tsk
: Node_Id
:= Empty
;
1806 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
;
1807 -- Comment needed???
1813 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
is
1817 if Nkind
(Nod
) = N_Identifier
then
1818 Ent
:= Entity
(Nod
);
1821 and then Ekind
(Ent
) = E_Discriminant
1824 Make_Selected_Component
(Loc
,
1825 Prefix
=> New_Copy_Tree
(Tsk
, New_Sloc
=> Loc
),
1826 Selector_Name
=> Make_Identifier
(Loc
, Chars
(Ent
))));
1828 Set_Etype
(Nod
, Etype
(Ent
));
1836 procedure Replace_Discrs
is new Traverse_Proc
(Process_Discr
);
1838 -- Start of processing for Replace_Actual_Discriminants
1841 if not Expander_Active
then
1845 if Nkind
(Name
(N
)) = N_Selected_Component
then
1846 Tsk
:= Prefix
(Name
(N
));
1848 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
1849 Tsk
:= Prefix
(Prefix
(Name
(N
)));
1855 Replace_Discrs
(Default
);
1857 end Replace_Actual_Discriminants
;
1863 procedure Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
1864 Ambiguous
: Boolean := False;
1865 Ctx_Type
: Entity_Id
:= Typ
;
1866 Expr_Type
: Entity_Id
:= Empty
; -- prevent junk warning
1867 Err_Type
: Entity_Id
:= Empty
;
1868 Found
: Boolean := False;
1871 I1
: Interp_Index
:= 0; -- prevent junk warning
1874 Seen
: Entity_Id
:= Empty
; -- prevent junk warning
1876 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean;
1877 -- Determine whether a node comes from a predefined library unit or
1880 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
);
1881 -- Try and fix up a literal so that it matches its expected type. New
1882 -- literals are manufactured if necessary to avoid cascaded errors.
1884 procedure Report_Ambiguous_Argument
;
1885 -- Additional diagnostics when an ambiguous call has an ambiguous
1886 -- argument (typically a controlling actual).
1888 procedure Resolution_Failed
;
1889 -- Called when attempt at resolving current expression fails
1891 ------------------------------------
1892 -- Comes_From_Predefined_Lib_Unit --
1893 -------------------------------------
1895 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean is
1898 Sloc
(Nod
) = Standard_Location
1899 or else Is_Predefined_File_Name
1900 (Unit_File_Name
(Get_Source_Unit
(Sloc
(Nod
))));
1901 end Comes_From_Predefined_Lib_Unit
;
1903 --------------------
1904 -- Patch_Up_Value --
1905 --------------------
1907 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
) is
1909 if Nkind
(N
) = N_Integer_Literal
and then Is_Real_Type
(Typ
) then
1911 Make_Real_Literal
(Sloc
(N
),
1912 Realval
=> UR_From_Uint
(Intval
(N
))));
1913 Set_Etype
(N
, Universal_Real
);
1914 Set_Is_Static_Expression
(N
);
1916 elsif Nkind
(N
) = N_Real_Literal
and then Is_Integer_Type
(Typ
) then
1918 Make_Integer_Literal
(Sloc
(N
),
1919 Intval
=> UR_To_Uint
(Realval
(N
))));
1920 Set_Etype
(N
, Universal_Integer
);
1921 Set_Is_Static_Expression
(N
);
1923 elsif Nkind
(N
) = N_String_Literal
1924 and then Is_Character_Type
(Typ
)
1926 Set_Character_Literal_Name
(Char_Code
(Character'Pos ('A')));
1928 Make_Character_Literal
(Sloc
(N
),
1930 Char_Literal_Value
=>
1931 UI_From_Int
(Character'Pos ('A'))));
1932 Set_Etype
(N
, Any_Character
);
1933 Set_Is_Static_Expression
(N
);
1935 elsif Nkind
(N
) /= N_String_Literal
and then Is_String_Type
(Typ
) then
1937 Make_String_Literal
(Sloc
(N
),
1938 Strval
=> End_String
));
1940 elsif Nkind
(N
) = N_Range
then
1941 Patch_Up_Value
(Low_Bound
(N
), Typ
);
1942 Patch_Up_Value
(High_Bound
(N
), Typ
);
1946 -------------------------------
1947 -- Report_Ambiguous_Argument --
1948 -------------------------------
1950 procedure Report_Ambiguous_Argument
is
1951 Arg
: constant Node_Id
:= First
(Parameter_Associations
(N
));
1956 if Nkind
(Arg
) = N_Function_Call
1957 and then Is_Entity_Name
(Name
(Arg
))
1958 and then Is_Overloaded
(Name
(Arg
))
1960 Error_Msg_NE
("ambiguous call to&", Arg
, Name
(Arg
));
1962 -- Could use comments on what is going on here???
1964 Get_First_Interp
(Name
(Arg
), I
, It
);
1965 while Present
(It
.Nam
) loop
1966 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
1968 if Nkind
(Parent
(It
.Nam
)) = N_Full_Type_Declaration
then
1969 Error_Msg_N
("interpretation (inherited) #!", Arg
);
1971 Error_Msg_N
("interpretation #!", Arg
);
1974 Get_Next_Interp
(I
, It
);
1977 end Report_Ambiguous_Argument
;
1979 -----------------------
1980 -- Resolution_Failed --
1981 -----------------------
1983 procedure Resolution_Failed
is
1985 Patch_Up_Value
(N
, Typ
);
1987 -- Set the type to the desired one to minimize cascaded errors. Note
1988 -- that this is an approximation and does not work in all cases.
1992 Debug_A_Exit
("resolving ", N
, " (done, resolution failed)");
1993 Set_Is_Overloaded
(N
, False);
1995 -- The caller will return without calling the expander, so we need
1996 -- to set the analyzed flag. Note that it is fine to set Analyzed
1997 -- to True even if we are in the middle of a shallow analysis,
1998 -- (see the spec of sem for more details) since this is an error
1999 -- situation anyway, and there is no point in repeating the
2000 -- analysis later (indeed it won't work to repeat it later, since
2001 -- we haven't got a clear resolution of which entity is being
2004 Set_Analyzed
(N
, True);
2006 end Resolution_Failed
;
2008 -- Start of processing for Resolve
2015 -- Access attribute on remote subprogram cannot be used for a non-remote
2016 -- access-to-subprogram type.
2018 if Nkind
(N
) = N_Attribute_Reference
2019 and then Nam_In
(Attribute_Name
(N
), Name_Access
,
2020 Name_Unrestricted_Access
,
2021 Name_Unchecked_Access
)
2022 and then Comes_From_Source
(N
)
2023 and then Is_Entity_Name
(Prefix
(N
))
2024 and then Is_Subprogram
(Entity
(Prefix
(N
)))
2025 and then Is_Remote_Call_Interface
(Entity
(Prefix
(N
)))
2026 and then not Is_Remote_Access_To_Subprogram_Type
(Typ
)
2029 ("prefix must statically denote a non-remote subprogram", N
);
2032 From_Lib
:= Comes_From_Predefined_Lib_Unit
(N
);
2034 -- If the context is a Remote_Access_To_Subprogram, access attributes
2035 -- must be resolved with the corresponding fat pointer. There is no need
2036 -- to check for the attribute name since the return type of an
2037 -- attribute is never a remote type.
2039 if Nkind
(N
) = N_Attribute_Reference
2040 and then Comes_From_Source
(N
)
2041 and then (Is_Remote_Call_Interface
(Typ
) or else Is_Remote_Types
(Typ
))
2044 Attr
: constant Attribute_Id
:=
2045 Get_Attribute_Id
(Attribute_Name
(N
));
2046 Pref
: constant Node_Id
:= Prefix
(N
);
2049 Is_Remote
: Boolean := True;
2052 -- Check that Typ is a remote access-to-subprogram type
2054 if Is_Remote_Access_To_Subprogram_Type
(Typ
) then
2056 -- Prefix (N) must statically denote a remote subprogram
2057 -- declared in a package specification.
2059 if Attr
= Attribute_Access
or else
2060 Attr
= Attribute_Unchecked_Access
or else
2061 Attr
= Attribute_Unrestricted_Access
2063 Decl
:= Unit_Declaration_Node
(Entity
(Pref
));
2065 if Nkind
(Decl
) = N_Subprogram_Body
then
2066 Spec
:= Corresponding_Spec
(Decl
);
2068 if Present
(Spec
) then
2069 Decl
:= Unit_Declaration_Node
(Spec
);
2073 Spec
:= Parent
(Decl
);
2075 if not Is_Entity_Name
(Prefix
(N
))
2076 or else Nkind
(Spec
) /= N_Package_Specification
2078 not Is_Remote_Call_Interface
(Defining_Entity
(Spec
))
2082 ("prefix must statically denote a remote subprogram ",
2086 -- If we are generating code in distributed mode, perform
2087 -- semantic checks against corresponding remote entities.
2090 and then Get_PCS_Name
/= Name_No_DSA
2092 Check_Subtype_Conformant
2093 (New_Id
=> Entity
(Prefix
(N
)),
2094 Old_Id
=> Designated_Type
2095 (Corresponding_Remote_Type
(Typ
)),
2099 Process_Remote_AST_Attribute
(N
, Typ
);
2107 Debug_A_Entry
("resolving ", N
);
2109 if Debug_Flag_V
then
2110 Write_Overloads
(N
);
2113 if Comes_From_Source
(N
) then
2114 if Is_Fixed_Point_Type
(Typ
) then
2115 Check_Restriction
(No_Fixed_Point
, N
);
2117 elsif Is_Floating_Point_Type
(Typ
)
2118 and then Typ
/= Universal_Real
2119 and then Typ
/= Any_Real
2121 Check_Restriction
(No_Floating_Point
, N
);
2125 -- Return if already analyzed
2127 if Analyzed
(N
) then
2128 Debug_A_Exit
("resolving ", N
, " (done, already analyzed)");
2129 Analyze_Dimension
(N
);
2132 -- Any case of Any_Type as the Etype value means that we had a
2135 elsif Etype
(N
) = Any_Type
then
2136 Debug_A_Exit
("resolving ", N
, " (done, Etype = Any_Type)");
2140 Check_Parameterless_Call
(N
);
2142 -- The resolution of an Expression_With_Actions is determined by
2145 if Nkind
(N
) = N_Expression_With_Actions
then
2146 Resolve
(Expression
(N
), Typ
);
2149 Expr_Type
:= Etype
(Expression
(N
));
2151 -- If not overloaded, then we know the type, and all that needs doing
2152 -- is to check that this type is compatible with the context.
2154 elsif not Is_Overloaded
(N
) then
2155 Found
:= Covers
(Typ
, Etype
(N
));
2156 Expr_Type
:= Etype
(N
);
2158 -- In the overloaded case, we must select the interpretation that
2159 -- is compatible with the context (i.e. the type passed to Resolve)
2162 -- Loop through possible interpretations
2164 Get_First_Interp
(N
, I
, It
);
2165 Interp_Loop
: while Present
(It
.Typ
) loop
2166 if Debug_Flag_V
then
2167 Write_Str
("Interp: ");
2171 -- We are only interested in interpretations that are compatible
2172 -- with the expected type, any other interpretations are ignored.
2174 if not Covers
(Typ
, It
.Typ
) then
2175 if Debug_Flag_V
then
2176 Write_Str
(" interpretation incompatible with context");
2181 -- Skip the current interpretation if it is disabled by an
2182 -- abstract operator. This action is performed only when the
2183 -- type against which we are resolving is the same as the
2184 -- type of the interpretation.
2186 if Ada_Version
>= Ada_2005
2187 and then It
.Typ
= Typ
2188 and then Typ
/= Universal_Integer
2189 and then Typ
/= Universal_Real
2190 and then Present
(It
.Abstract_Op
)
2192 if Debug_Flag_V
then
2193 Write_Line
("Skip.");
2199 -- First matching interpretation
2205 Expr_Type
:= It
.Typ
;
2207 -- Matching interpretation that is not the first, maybe an
2208 -- error, but there are some cases where preference rules are
2209 -- used to choose between the two possibilities. These and
2210 -- some more obscure cases are handled in Disambiguate.
2213 -- If the current statement is part of a predefined library
2214 -- unit, then all interpretations which come from user level
2215 -- packages should not be considered. Check previous and
2219 if not Comes_From_Predefined_Lib_Unit
(It
.Nam
) then
2222 elsif not Comes_From_Predefined_Lib_Unit
(Seen
) then
2224 -- Previous interpretation must be discarded
2228 Expr_Type
:= It
.Typ
;
2229 Set_Entity
(N
, Seen
);
2234 -- Otherwise apply further disambiguation steps
2236 Error_Msg_Sloc
:= Sloc
(Seen
);
2237 It1
:= Disambiguate
(N
, I1
, I
, Typ
);
2239 -- Disambiguation has succeeded. Skip the remaining
2242 if It1
/= No_Interp
then
2244 Expr_Type
:= It1
.Typ
;
2246 while Present
(It
.Typ
) loop
2247 Get_Next_Interp
(I
, It
);
2251 -- Before we issue an ambiguity complaint, check for the
2252 -- case of a subprogram call where at least one of the
2253 -- arguments is Any_Type, and if so suppress the message,
2254 -- since it is a cascaded error. This can also happen for
2255 -- a generalized indexing operation.
2257 if Nkind
(N
) in N_Subprogram_Call
2258 or else (Nkind
(N
) = N_Indexed_Component
2259 and then Present
(Generalized_Indexing
(N
)))
2266 if Nkind
(N
) = N_Indexed_Component
then
2267 Rewrite
(N
, Generalized_Indexing
(N
));
2270 A
:= First_Actual
(N
);
2271 while Present
(A
) loop
2274 if Nkind
(E
) = N_Parameter_Association
then
2275 E
:= Explicit_Actual_Parameter
(E
);
2278 if Etype
(E
) = Any_Type
then
2279 if Debug_Flag_V
then
2280 Write_Str
("Any_Type in call");
2291 elsif Nkind
(N
) in N_Binary_Op
2292 and then (Etype
(Left_Opnd
(N
)) = Any_Type
2293 or else Etype
(Right_Opnd
(N
)) = Any_Type
)
2297 elsif Nkind
(N
) in N_Unary_Op
2298 and then Etype
(Right_Opnd
(N
)) = Any_Type
2303 -- Not that special case, so issue message using the flag
2304 -- Ambiguous to control printing of the header message
2305 -- only at the start of an ambiguous set.
2307 if not Ambiguous
then
2308 if Nkind
(N
) = N_Function_Call
2309 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2312 ("ambiguous expression (cannot resolve indirect "
2315 Error_Msg_NE
-- CODEFIX
2316 ("ambiguous expression (cannot resolve&)!",
2322 if Nkind
(Parent
(Seen
)) = N_Full_Type_Declaration
then
2324 ("\\possible interpretation (inherited)#!", N
);
2326 Error_Msg_N
-- CODEFIX
2327 ("\\possible interpretation#!", N
);
2330 if Nkind
(N
) in N_Subprogram_Call
2331 and then Present
(Parameter_Associations
(N
))
2333 Report_Ambiguous_Argument
;
2337 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2339 -- By default, the error message refers to the candidate
2340 -- interpretation. But if it is a predefined operator, it
2341 -- is implicitly declared at the declaration of the type
2342 -- of the operand. Recover the sloc of that declaration
2343 -- for the error message.
2345 if Nkind
(N
) in N_Op
2346 and then Scope
(It
.Nam
) = Standard_Standard
2347 and then not Is_Overloaded
(Right_Opnd
(N
))
2348 and then Scope
(Base_Type
(Etype
(Right_Opnd
(N
)))) /=
2351 Err_Type
:= First_Subtype
(Etype
(Right_Opnd
(N
)));
2353 if Comes_From_Source
(Err_Type
)
2354 and then Present
(Parent
(Err_Type
))
2356 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2359 elsif Nkind
(N
) in N_Binary_Op
2360 and then Scope
(It
.Nam
) = Standard_Standard
2361 and then not Is_Overloaded
(Left_Opnd
(N
))
2362 and then Scope
(Base_Type
(Etype
(Left_Opnd
(N
)))) /=
2365 Err_Type
:= First_Subtype
(Etype
(Left_Opnd
(N
)));
2367 if Comes_From_Source
(Err_Type
)
2368 and then Present
(Parent
(Err_Type
))
2370 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2373 -- If this is an indirect call, use the subprogram_type
2374 -- in the message, to have a meaningful location. Also
2375 -- indicate if this is an inherited operation, created
2376 -- by a type declaration.
2378 elsif Nkind
(N
) = N_Function_Call
2379 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2380 and then Is_Type
(It
.Nam
)
2384 Sloc
(Associated_Node_For_Itype
(Err_Type
));
2389 if Nkind
(N
) in N_Op
2390 and then Scope
(It
.Nam
) = Standard_Standard
2391 and then Present
(Err_Type
)
2393 -- Special-case the message for universal_fixed
2394 -- operators, which are not declared with the type
2395 -- of the operand, but appear forever in Standard.
2397 if It
.Typ
= Universal_Fixed
2398 and then Scope
(It
.Nam
) = Standard_Standard
2401 ("\\possible interpretation as universal_fixed "
2402 & "operation (RM 4.5.5 (19))", N
);
2405 ("\\possible interpretation (predefined)#!", N
);
2409 Nkind
(Parent
(It
.Nam
)) = N_Full_Type_Declaration
2412 ("\\possible interpretation (inherited)#!", N
);
2414 Error_Msg_N
-- CODEFIX
2415 ("\\possible interpretation#!", N
);
2421 -- We have a matching interpretation, Expr_Type is the type
2422 -- from this interpretation, and Seen is the entity.
2424 -- For an operator, just set the entity name. The type will be
2425 -- set by the specific operator resolution routine.
2427 if Nkind
(N
) in N_Op
then
2428 Set_Entity
(N
, Seen
);
2429 Generate_Reference
(Seen
, N
);
2431 elsif Nkind
(N
) = N_Case_Expression
then
2432 Set_Etype
(N
, Expr_Type
);
2434 elsif Nkind
(N
) = N_Character_Literal
then
2435 Set_Etype
(N
, Expr_Type
);
2437 elsif Nkind
(N
) = N_If_Expression
then
2438 Set_Etype
(N
, Expr_Type
);
2440 -- AI05-0139-2: Expression is overloaded because type has
2441 -- implicit dereference. If type matches context, no implicit
2442 -- dereference is involved.
2444 elsif Has_Implicit_Dereference
(Expr_Type
) then
2445 Set_Etype
(N
, Expr_Type
);
2446 Set_Is_Overloaded
(N
, False);
2449 elsif Is_Overloaded
(N
)
2450 and then Present
(It
.Nam
)
2451 and then Ekind
(It
.Nam
) = E_Discriminant
2452 and then Has_Implicit_Dereference
(It
.Nam
)
2454 -- If the node is a general indexing, the dereference is
2455 -- is inserted when resolving the rewritten form, else
2458 if Nkind
(N
) /= N_Indexed_Component
2459 or else No
(Generalized_Indexing
(N
))
2461 Build_Explicit_Dereference
(N
, It
.Nam
);
2464 -- For an explicit dereference, attribute reference, range,
2465 -- short-circuit form (which is not an operator node), or call
2466 -- with a name that is an explicit dereference, there is
2467 -- nothing to be done at this point.
2469 elsif Nkind_In
(N
, N_Attribute_Reference
,
2471 N_Explicit_Dereference
,
2473 N_Indexed_Component
,
2476 N_Selected_Component
,
2478 or else Nkind
(Name
(N
)) = N_Explicit_Dereference
2482 -- For procedure or function calls, set the type of the name,
2483 -- and also the entity pointer for the prefix.
2485 elsif Nkind
(N
) in N_Subprogram_Call
2486 and then Is_Entity_Name
(Name
(N
))
2488 Set_Etype
(Name
(N
), Expr_Type
);
2489 Set_Entity
(Name
(N
), Seen
);
2490 Generate_Reference
(Seen
, Name
(N
));
2492 elsif Nkind
(N
) = N_Function_Call
2493 and then Nkind
(Name
(N
)) = N_Selected_Component
2495 Set_Etype
(Name
(N
), Expr_Type
);
2496 Set_Entity
(Selector_Name
(Name
(N
)), Seen
);
2497 Generate_Reference
(Seen
, Selector_Name
(Name
(N
)));
2499 -- For all other cases, just set the type of the Name
2502 Set_Etype
(Name
(N
), Expr_Type
);
2509 -- Move to next interpretation
2511 exit Interp_Loop
when No
(It
.Typ
);
2513 Get_Next_Interp
(I
, It
);
2514 end loop Interp_Loop
;
2517 -- At this stage Found indicates whether or not an acceptable
2518 -- interpretation exists. If not, then we have an error, except that if
2519 -- the context is Any_Type as a result of some other error, then we
2520 -- suppress the error report.
2523 if Typ
/= Any_Type
then
2525 -- If type we are looking for is Void, then this is the procedure
2526 -- call case, and the error is simply that what we gave is not a
2527 -- procedure name (we think of procedure calls as expressions with
2528 -- types internally, but the user doesn't think of them this way).
2530 if Typ
= Standard_Void_Type
then
2532 -- Special case message if function used as a procedure
2534 if Nkind
(N
) = N_Procedure_Call_Statement
2535 and then Is_Entity_Name
(Name
(N
))
2536 and then Ekind
(Entity
(Name
(N
))) = E_Function
2539 ("cannot use function & in a procedure call",
2540 Name
(N
), Entity
(Name
(N
)));
2542 -- Otherwise give general message (not clear what cases this
2543 -- covers, but no harm in providing for them).
2546 Error_Msg_N
("expect procedure name in procedure call", N
);
2551 -- Otherwise we do have a subexpression with the wrong type
2553 -- Check for the case of an allocator which uses an access type
2554 -- instead of the designated type. This is a common error and we
2555 -- specialize the message, posting an error on the operand of the
2556 -- allocator, complaining that we expected the designated type of
2559 elsif Nkind
(N
) = N_Allocator
2560 and then Is_Access_Type
(Typ
)
2561 and then Is_Access_Type
(Etype
(N
))
2562 and then Designated_Type
(Etype
(N
)) = Typ
2564 Wrong_Type
(Expression
(N
), Designated_Type
(Typ
));
2567 -- Check for view mismatch on Null in instances, for which the
2568 -- view-swapping mechanism has no identifier.
2570 elsif (In_Instance
or else In_Inlined_Body
)
2571 and then (Nkind
(N
) = N_Null
)
2572 and then Is_Private_Type
(Typ
)
2573 and then Is_Access_Type
(Full_View
(Typ
))
2575 Resolve
(N
, Full_View
(Typ
));
2579 -- Check for an aggregate. Sometimes we can get bogus aggregates
2580 -- from misuse of parentheses, and we are about to complain about
2581 -- the aggregate without even looking inside it.
2583 -- Instead, if we have an aggregate of type Any_Composite, then
2584 -- analyze and resolve the component fields, and then only issue
2585 -- another message if we get no errors doing this (otherwise
2586 -- assume that the errors in the aggregate caused the problem).
2588 elsif Nkind
(N
) = N_Aggregate
2589 and then Etype
(N
) = Any_Composite
2591 -- Disable expansion in any case. If there is a type mismatch
2592 -- it may be fatal to try to expand the aggregate. The flag
2593 -- would otherwise be set to false when the error is posted.
2595 Expander_Active
:= False;
2598 procedure Check_Aggr
(Aggr
: Node_Id
);
2599 -- Check one aggregate, and set Found to True if we have a
2600 -- definite error in any of its elements
2602 procedure Check_Elmt
(Aelmt
: Node_Id
);
2603 -- Check one element of aggregate and set Found to True if
2604 -- we definitely have an error in the element.
2610 procedure Check_Aggr
(Aggr
: Node_Id
) is
2614 if Present
(Expressions
(Aggr
)) then
2615 Elmt
:= First
(Expressions
(Aggr
));
2616 while Present
(Elmt
) loop
2622 if Present
(Component_Associations
(Aggr
)) then
2623 Elmt
:= First
(Component_Associations
(Aggr
));
2624 while Present
(Elmt
) loop
2626 -- If this is a default-initialized component, then
2627 -- there is nothing to check. The box will be
2628 -- replaced by the appropriate call during late
2631 if Nkind
(Elmt
) /= N_Iterated_Component_Association
2632 and then not Box_Present
(Elmt
)
2634 Check_Elmt
(Expression
(Elmt
));
2646 procedure Check_Elmt
(Aelmt
: Node_Id
) is
2648 -- If we have a nested aggregate, go inside it (to
2649 -- attempt a naked analyze-resolve of the aggregate can
2650 -- cause undesirable cascaded errors). Do not resolve
2651 -- expression if it needs a type from context, as for
2652 -- integer * fixed expression.
2654 if Nkind
(Aelmt
) = N_Aggregate
then
2660 if not Is_Overloaded
(Aelmt
)
2661 and then Etype
(Aelmt
) /= Any_Fixed
2666 if Etype
(Aelmt
) = Any_Type
then
2677 -- Looks like we have a type error, but check for special case
2678 -- of Address wanted, integer found, with the configuration pragma
2679 -- Allow_Integer_Address active. If we have this case, introduce
2680 -- an unchecked conversion to allow the integer expression to be
2681 -- treated as an Address. The reverse case of integer wanted,
2682 -- Address found, is treated in an analogous manner.
2684 if Address_Integer_Convert_OK
(Typ
, Etype
(N
)) then
2685 Rewrite
(N
, Unchecked_Convert_To
(Typ
, Relocate_Node
(N
)));
2686 Analyze_And_Resolve
(N
, Typ
);
2689 -- Under relaxed RM semantics silently replace occurrences of null
2690 -- by System.Address_Null.
2692 elsif Null_To_Null_Address_Convert_OK
(N
, Typ
) then
2693 Replace_Null_By_Null_Address
(N
);
2694 Analyze_And_Resolve
(N
, Typ
);
2698 -- That special Allow_Integer_Address check did not apply, so we
2699 -- have a real type error. If an error message was issued already,
2700 -- Found got reset to True, so if it's still False, issue standard
2701 -- Wrong_Type message.
2704 if Is_Overloaded
(N
) and then Nkind
(N
) = N_Function_Call
then
2706 Subp_Name
: Node_Id
;
2709 if Is_Entity_Name
(Name
(N
)) then
2710 Subp_Name
:= Name
(N
);
2712 elsif Nkind
(Name
(N
)) = N_Selected_Component
then
2714 -- Protected operation: retrieve operation name
2716 Subp_Name
:= Selector_Name
(Name
(N
));
2719 raise Program_Error
;
2722 Error_Msg_Node_2
:= Typ
;
2724 ("no visible interpretation of& matches expected type&",
2728 if All_Errors_Mode
then
2730 Index
: Interp_Index
;
2734 Error_Msg_N
("\\possible interpretations:", N
);
2736 Get_First_Interp
(Name
(N
), Index
, It
);
2737 while Present
(It
.Nam
) loop
2738 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2739 Error_Msg_Node_2
:= It
.Nam
;
2741 ("\\ type& for & declared#", N
, It
.Typ
);
2742 Get_Next_Interp
(Index
, It
);
2747 Error_Msg_N
("\use -gnatf for details", N
);
2751 Wrong_Type
(N
, Typ
);
2759 -- Test if we have more than one interpretation for the context
2761 elsif Ambiguous
then
2765 -- Only one intepretation
2768 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2769 -- the "+" on T is abstract, and the operands are of universal type,
2770 -- the above code will have (incorrectly) resolved the "+" to the
2771 -- universal one in Standard. Therefore check for this case and give
2772 -- an error. We can't do this earlier, because it would cause legal
2773 -- cases to get errors (when some other type has an abstract "+").
2775 if Ada_Version
>= Ada_2005
2776 and then Nkind
(N
) in N_Op
2777 and then Is_Overloaded
(N
)
2778 and then Is_Universal_Numeric_Type
(Etype
(Entity
(N
)))
2780 Get_First_Interp
(N
, I
, It
);
2781 while Present
(It
.Typ
) loop
2782 if Present
(It
.Abstract_Op
) and then
2783 Etype
(It
.Abstract_Op
) = Typ
2786 ("cannot call abstract subprogram &!", N
, It
.Abstract_Op
);
2790 Get_Next_Interp
(I
, It
);
2794 -- Here we have an acceptable interpretation for the context
2796 -- Propagate type information and normalize tree for various
2797 -- predefined operations. If the context only imposes a class of
2798 -- types, rather than a specific type, propagate the actual type
2801 if Typ
= Any_Integer
or else
2802 Typ
= Any_Boolean
or else
2803 Typ
= Any_Modular
or else
2804 Typ
= Any_Real
or else
2807 Ctx_Type
:= Expr_Type
;
2809 -- Any_Fixed is legal in a real context only if a specific fixed-
2810 -- point type is imposed. If Norman Cohen can be confused by this,
2811 -- it deserves a separate message.
2814 and then Expr_Type
= Any_Fixed
2816 Error_Msg_N
("illegal context for mixed mode operation", N
);
2817 Set_Etype
(N
, Universal_Real
);
2818 Ctx_Type
:= Universal_Real
;
2822 -- A user-defined operator is transformed into a function call at
2823 -- this point, so that further processing knows that operators are
2824 -- really operators (i.e. are predefined operators). User-defined
2825 -- operators that are intrinsic are just renamings of the predefined
2826 -- ones, and need not be turned into calls either, but if they rename
2827 -- a different operator, we must transform the node accordingly.
2828 -- Instantiations of Unchecked_Conversion are intrinsic but are
2829 -- treated as functions, even if given an operator designator.
2831 if Nkind
(N
) in N_Op
2832 and then Present
(Entity
(N
))
2833 and then Ekind
(Entity
(N
)) /= E_Operator
2835 if not Is_Predefined_Op
(Entity
(N
)) then
2836 Rewrite_Operator_As_Call
(N
, Entity
(N
));
2838 elsif Present
(Alias
(Entity
(N
)))
2840 Nkind
(Parent
(Parent
(Entity
(N
)))) =
2841 N_Subprogram_Renaming_Declaration
2843 Rewrite_Renamed_Operator
(N
, Alias
(Entity
(N
)), Typ
);
2845 -- If the node is rewritten, it will be fully resolved in
2846 -- Rewrite_Renamed_Operator.
2848 if Analyzed
(N
) then
2854 case N_Subexpr
'(Nkind (N)) is
2856 Resolve_Aggregate (N, Ctx_Type);
2859 Resolve_Allocator (N, Ctx_Type);
2861 when N_Short_Circuit =>
2862 Resolve_Short_Circuit (N, Ctx_Type);
2864 when N_Attribute_Reference =>
2865 Resolve_Attribute (N, Ctx_Type);
2867 when N_Case_Expression =>
2868 Resolve_Case_Expression (N, Ctx_Type);
2870 when N_Character_Literal =>
2871 Resolve_Character_Literal (N, Ctx_Type);
2873 when N_Delta_Aggregate =>
2874 Resolve_Delta_Aggregate (N, Ctx_Type);
2876 when N_Expanded_Name =>
2877 Resolve_Entity_Name (N, Ctx_Type);
2879 when N_Explicit_Dereference =>
2880 Resolve_Explicit_Dereference (N, Ctx_Type);
2882 when N_Expression_With_Actions =>
2883 Resolve_Expression_With_Actions (N, Ctx_Type);
2885 when N_Extension_Aggregate =>
2886 Resolve_Extension_Aggregate (N, Ctx_Type);
2888 when N_Function_Call =>
2889 Resolve_Call (N, Ctx_Type);
2891 when N_Identifier =>
2892 Resolve_Entity_Name (N, Ctx_Type);
2894 when N_If_Expression =>
2895 Resolve_If_Expression (N, Ctx_Type);
2897 when N_Indexed_Component =>
2898 Resolve_Indexed_Component (N, Ctx_Type);
2900 when N_Integer_Literal =>
2901 Resolve_Integer_Literal (N, Ctx_Type);
2903 when N_Membership_Test =>
2904 Resolve_Membership_Op (N, Ctx_Type);
2907 Resolve_Null (N, Ctx_Type);
2913 Resolve_Logical_Op (N, Ctx_Type);
2918 Resolve_Equality_Op (N, Ctx_Type);
2925 Resolve_Comparison_Op (N, Ctx_Type);
2928 Resolve_Op_Not (N, Ctx_Type);
2937 Resolve_Arithmetic_Op (N, Ctx_Type);
2940 Resolve_Op_Concat (N, Ctx_Type);
2943 Resolve_Op_Expon (N, Ctx_Type);
2949 Resolve_Unary_Op (N, Ctx_Type);
2952 Resolve_Shift (N, Ctx_Type);
2954 when N_Procedure_Call_Statement =>
2955 Resolve_Call (N, Ctx_Type);
2957 when N_Operator_Symbol =>
2958 Resolve_Operator_Symbol (N, Ctx_Type);
2960 when N_Qualified_Expression =>
2961 Resolve_Qualified_Expression (N, Ctx_Type);
2963 -- Why is the following null, needs a comment ???
2965 when N_Quantified_Expression =>
2968 when N_Raise_Expression =>
2969 Resolve_Raise_Expression (N, Ctx_Type);
2971 when N_Raise_xxx_Error =>
2972 Set_Etype (N, Ctx_Type);
2975 Resolve_Range (N, Ctx_Type);
2977 when N_Real_Literal =>
2978 Resolve_Real_Literal (N, Ctx_Type);
2981 Resolve_Reference (N, Ctx_Type);
2983 when N_Selected_Component =>
2984 Resolve_Selected_Component (N, Ctx_Type);
2987 Resolve_Slice (N, Ctx_Type);
2989 when N_String_Literal =>
2990 Resolve_String_Literal (N, Ctx_Type);
2992 when N_Target_Name =>
2993 Resolve_Target_Name (N, Ctx_Type);
2995 when N_Type_Conversion =>
2996 Resolve_Type_Conversion (N, Ctx_Type);
2998 when N_Unchecked_Expression =>
2999 Resolve_Unchecked_Expression (N, Ctx_Type);
3001 when N_Unchecked_Type_Conversion =>
3002 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
3005 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
3006 -- expression of an anonymous access type that occurs in the context
3007 -- of a named general access type, except when the expression is that
3008 -- of a membership test. This ensures proper legality checking in
3009 -- terms of allowed conversions (expressions that would be illegal to
3010 -- convert implicitly are allowed in membership tests).
3012 if Ada_Version >= Ada_2012
3013 and then Ekind (Ctx_Type) = E_General_Access_Type
3014 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
3015 and then Nkind (Parent (N)) not in N_Membership_Test
3017 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
3018 Analyze_And_Resolve (N, Ctx_Type);
3021 -- If the subexpression was replaced by a non-subexpression, then
3022 -- all we do is to expand it. The only legitimate case we know of
3023 -- is converting procedure call statement to entry call statements,
3024 -- but there may be others, so we are making this test general.
3026 if Nkind (N) not in N_Subexpr then
3027 Debug_A_Exit ("resolving ", N, " (done)");
3032 -- The expression is definitely NOT overloaded at this point, so
3033 -- we reset the Is_Overloaded flag to avoid any confusion when
3034 -- reanalyzing the node.
3036 Set_Is_Overloaded (N, False);
3038 -- Freeze expression type, entity if it is a name, and designated
3039 -- type if it is an allocator (RM 13.14(10,11,13)).
3041 -- Now that the resolution of the type of the node is complete, and
3042 -- we did not detect an error, we can expand this node. We skip the
3043 -- expand call if we are in a default expression, see section
3044 -- "Handling of Default Expressions" in Sem spec.
3046 Debug_A_Exit ("resolving ", N, " (done)");
3048 -- We unconditionally freeze the expression, even if we are in
3049 -- default expression mode (the Freeze_Expression routine tests this
3050 -- flag and only freezes static types if it is set).
3052 -- Ada 2012 (AI05-177): The declaration of an expression function
3053 -- does not cause freezing, but we never reach here in that case.
3054 -- Here we are resolving the corresponding expanded body, so we do
3055 -- need to perform normal freezing.
3057 Freeze_Expression (N);
3059 -- Now we can do the expansion
3069 -- Version with check(s) suppressed
3071 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3073 if Suppress = All_Checks then
3075 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3077 Scope_Suppress.Suppress := (others => True);
3079 Scope_Suppress.Suppress := Sva;
3084 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3086 Scope_Suppress.Suppress (Suppress) := True;
3088 Scope_Suppress.Suppress (Suppress) := Svg;
3097 -- Version with implicit type
3099 procedure Resolve (N : Node_Id) is
3101 Resolve (N, Etype (N));
3104 ---------------------
3105 -- Resolve_Actuals --
3106 ---------------------
3108 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3109 Loc : constant Source_Ptr := Sloc (N);
3115 Prev : Node_Id := Empty;
3119 Real_Subp : Entity_Id;
3120 -- If the subprogram being called is an inherited operation for
3121 -- a formal derived type in an instance, Real_Subp is the subprogram
3122 -- that will be called. It may have different formal names than the
3123 -- operation of the formal in the generic, so after actual is resolved
3124 -- the name of the actual in a named association must carry the name
3125 -- of the actual of the subprogram being called.
3127 procedure Check_Aliased_Parameter;
3128 -- Check rules on aliased parameters and related accessibility rules
3129 -- in (RM 3.10.2 (10.2-10.4)).
3131 procedure Check_Argument_Order;
3132 -- Performs a check for the case where the actuals are all simple
3133 -- identifiers that correspond to the formal names, but in the wrong
3134 -- order, which is considered suspicious and cause for a warning.
3136 procedure Check_Prefixed_Call;
3137 -- If the original node is an overloaded call in prefix notation,
3138 -- insert an 'Access or a dereference as needed over the first actual
.
3139 -- Try_Object_Operation has already verified that there is a valid
3140 -- interpretation, but the form of the actual can only be determined
3141 -- once the primitive operation is identified.
3143 procedure Flag_Effectively_Volatile_Objects
(Expr
: Node_Id
);
3144 -- Emit an error concerning the illegal usage of an effectively volatile
3145 -- object in interfering context (SPARK RM 7.13(12)).
3147 procedure Insert_Default
;
3148 -- If the actual is missing in a call, insert in the actuals list
3149 -- an instance of the default expression. The insertion is always
3150 -- a named association.
3152 procedure Property_Error
3155 Prop_Nam
: Name_Id
);
3156 -- Emit an error concerning variable Var with entity Var_Id that has
3157 -- enabled property Prop_Nam when it acts as an actual parameter in a
3158 -- call and the corresponding formal parameter is of mode IN.
3160 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean;
3161 -- Check whether T1 and T2, or their full views, are derived from a
3162 -- common type. Used to enforce the restrictions on array conversions
3165 function Static_Concatenation
(N
: Node_Id
) return Boolean;
3166 -- Predicate to determine whether an actual that is a concatenation
3167 -- will be evaluated statically and does not need a transient scope.
3168 -- This must be determined before the actual is resolved and expanded
3169 -- because if needed the transient scope must be introduced earlier.
3171 -----------------------------
3172 -- Check_Aliased_Parameter --
3173 -----------------------------
3175 procedure Check_Aliased_Parameter
is
3176 Nominal_Subt
: Entity_Id
;
3179 if Is_Aliased
(F
) then
3180 if Is_Tagged_Type
(A_Typ
) then
3183 elsif Is_Aliased_View
(A
) then
3184 if Is_Constr_Subt_For_U_Nominal
(A_Typ
) then
3185 Nominal_Subt
:= Base_Type
(A_Typ
);
3187 Nominal_Subt
:= A_Typ
;
3190 if Subtypes_Statically_Match
(F_Typ
, Nominal_Subt
) then
3193 -- In a generic body assume the worst for generic formals:
3194 -- they can have a constrained partial view (AI05-041).
3196 elsif Has_Discriminants
(F_Typ
)
3197 and then not Is_Constrained
(F_Typ
)
3198 and then not Has_Constrained_Partial_View
(F_Typ
)
3199 and then not Is_Generic_Type
(F_Typ
)
3204 Error_Msg_NE
("untagged actual does not match "
3205 & "aliased formal&", A
, F
);
3209 Error_Msg_NE
("actual for aliased formal& must be "
3210 & "aliased object", A
, F
);
3213 if Ekind
(Nam
) = E_Procedure
then
3216 elsif Ekind
(Etype
(Nam
)) = E_Anonymous_Access_Type
then
3217 if Nkind
(Parent
(N
)) = N_Type_Conversion
3218 and then Type_Access_Level
(Etype
(Parent
(N
))) <
3219 Object_Access_Level
(A
)
3221 Error_Msg_N
("aliased actual has wrong accessibility", A
);
3224 elsif Nkind
(Parent
(N
)) = N_Qualified_Expression
3225 and then Nkind
(Parent
(Parent
(N
))) = N_Allocator
3226 and then Type_Access_Level
(Etype
(Parent
(Parent
(N
)))) <
3227 Object_Access_Level
(A
)
3230 ("aliased actual in allocator has wrong accessibility", A
);
3233 end Check_Aliased_Parameter
;
3235 --------------------------
3236 -- Check_Argument_Order --
3237 --------------------------
3239 procedure Check_Argument_Order
is
3241 -- Nothing to do if no parameters, or original node is neither a
3242 -- function call nor a procedure call statement (happens in the
3243 -- operator-transformed-to-function call case), or the call does
3244 -- not come from source, or this warning is off.
3246 if not Warn_On_Parameter_Order
3247 or else No
(Parameter_Associations
(N
))
3248 or else Nkind
(Original_Node
(N
)) not in N_Subprogram_Call
3249 or else not Comes_From_Source
(N
)
3255 Nargs
: constant Nat
:= List_Length
(Parameter_Associations
(N
));
3258 -- Nothing to do if only one parameter
3264 -- Here if at least two arguments
3267 Actuals
: array (1 .. Nargs
) of Node_Id
;
3271 Wrong_Order
: Boolean := False;
3272 -- Set True if an out of order case is found
3275 -- Collect identifier names of actuals, fail if any actual is
3276 -- not a simple identifier, and record max length of name.
3278 Actual
:= First
(Parameter_Associations
(N
));
3279 for J
in Actuals
'Range loop
3280 if Nkind
(Actual
) /= N_Identifier
then
3283 Actuals
(J
) := Actual
;
3288 -- If we got this far, all actuals are identifiers and the list
3289 -- of their names is stored in the Actuals array.
3291 Formal
:= First_Formal
(Nam
);
3292 for J
in Actuals
'Range loop
3294 -- If we ran out of formals, that's odd, probably an error
3295 -- which will be detected elsewhere, but abandon the search.
3301 -- If name matches and is in order OK
3303 if Chars
(Formal
) = Chars
(Actuals
(J
)) then
3307 -- If no match, see if it is elsewhere in list and if so
3308 -- flag potential wrong order if type is compatible.
3310 for K
in Actuals
'Range loop
3311 if Chars
(Formal
) = Chars
(Actuals
(K
))
3313 Has_Compatible_Type
(Actuals
(K
), Etype
(Formal
))
3315 Wrong_Order
:= True;
3325 <<Continue
>> Next_Formal
(Formal
);
3328 -- If Formals left over, also probably an error, skip warning
3330 if Present
(Formal
) then
3334 -- Here we give the warning if something was out of order
3338 ("?P?actuals for this call may be in wrong order", N
);
3342 end Check_Argument_Order
;
3344 -------------------------
3345 -- Check_Prefixed_Call --
3346 -------------------------
3348 procedure Check_Prefixed_Call
is
3349 Act
: constant Node_Id
:= First_Actual
(N
);
3350 A_Type
: constant Entity_Id
:= Etype
(Act
);
3351 F_Type
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
3352 Orig
: constant Node_Id
:= Original_Node
(N
);
3356 -- Check whether the call is a prefixed call, with or without
3357 -- additional actuals.
3359 if Nkind
(Orig
) = N_Selected_Component
3361 (Nkind
(Orig
) = N_Indexed_Component
3362 and then Nkind
(Prefix
(Orig
)) = N_Selected_Component
3363 and then Is_Entity_Name
(Prefix
(Prefix
(Orig
)))
3364 and then Is_Entity_Name
(Act
)
3365 and then Chars
(Act
) = Chars
(Prefix
(Prefix
(Orig
))))
3367 if Is_Access_Type
(A_Type
)
3368 and then not Is_Access_Type
(F_Type
)
3370 -- Introduce dereference on object in prefix
3373 Make_Explicit_Dereference
(Sloc
(Act
),
3374 Prefix
=> Relocate_Node
(Act
));
3375 Rewrite
(Act
, New_A
);
3378 elsif Is_Access_Type
(F_Type
)
3379 and then not Is_Access_Type
(A_Type
)
3381 -- Introduce an implicit 'Access in prefix
3383 if not Is_Aliased_View
(Act
) then
3385 ("object in prefixed call to& must be aliased "
3386 & "(RM 4.1.3 (13 1/2))",
3391 Make_Attribute_Reference
(Loc
,
3392 Attribute_Name
=> Name_Access
,
3393 Prefix
=> Relocate_Node
(Act
)));
3398 end Check_Prefixed_Call
;
3400 ---------------------------------------
3401 -- Flag_Effectively_Volatile_Objects --
3402 ---------------------------------------
3404 procedure Flag_Effectively_Volatile_Objects
(Expr
: Node_Id
) is
3405 function Flag_Object
(N
: Node_Id
) return Traverse_Result
;
3406 -- Determine whether arbitrary node N denotes an effectively volatile
3407 -- object and if it does, emit an error.
3413 function Flag_Object
(N
: Node_Id
) return Traverse_Result
is
3417 -- Do not consider nested function calls because they have already
3418 -- been processed during their own resolution.
3420 if Nkind
(N
) = N_Function_Call
then
3423 elsif Is_Entity_Name
(N
) and then Present
(Entity
(N
)) then
3427 and then Is_Effectively_Volatile
(Id
)
3428 and then (Async_Writers_Enabled
(Id
)
3429 or else Effective_Reads_Enabled
(Id
))
3432 ("volatile object cannot appear in this context (SPARK "
3433 & "RM 7.1.3(11))", N
);
3441 procedure Flag_Objects
is new Traverse_Proc
(Flag_Object
);
3443 -- Start of processing for Flag_Effectively_Volatile_Objects
3446 Flag_Objects
(Expr
);
3447 end Flag_Effectively_Volatile_Objects
;
3449 --------------------
3450 -- Insert_Default --
3451 --------------------
3453 procedure Insert_Default
is
3458 -- Missing argument in call, nothing to insert
3460 if No
(Default_Value
(F
)) then
3464 -- Note that we do a full New_Copy_Tree, so that any associated
3465 -- Itypes are properly copied. This may not be needed any more,
3466 -- but it does no harm as a safety measure. Defaults of a generic
3467 -- formal may be out of bounds of the corresponding actual (see
3468 -- cc1311b) and an additional check may be required.
3473 New_Scope
=> Current_Scope
,
3476 -- Propagate dimension information, if any.
3478 Copy_Dimensions
(Default_Value
(F
), Actval
);
3480 if Is_Concurrent_Type
(Scope
(Nam
))
3481 and then Has_Discriminants
(Scope
(Nam
))
3483 Replace_Actual_Discriminants
(N
, Actval
);
3486 if Is_Overloadable
(Nam
)
3487 and then Present
(Alias
(Nam
))
3489 if Base_Type
(Etype
(F
)) /= Base_Type
(Etype
(Actval
))
3490 and then not Is_Tagged_Type
(Etype
(F
))
3492 -- If default is a real literal, do not introduce a
3493 -- conversion whose effect may depend on the run-time
3494 -- size of universal real.
3496 if Nkind
(Actval
) = N_Real_Literal
then
3497 Set_Etype
(Actval
, Base_Type
(Etype
(F
)));
3499 Actval
:= Unchecked_Convert_To
(Etype
(F
), Actval
);
3503 if Is_Scalar_Type
(Etype
(F
)) then
3504 Enable_Range_Check
(Actval
);
3507 Set_Parent
(Actval
, N
);
3509 -- Resolve aggregates with their base type, to avoid scope
3510 -- anomalies: the subtype was first built in the subprogram
3511 -- declaration, and the current call may be nested.
3513 if Nkind
(Actval
) = N_Aggregate
then
3514 Analyze_And_Resolve
(Actval
, Etype
(F
));
3516 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3520 Set_Parent
(Actval
, N
);
3522 -- See note above concerning aggregates
3524 if Nkind
(Actval
) = N_Aggregate
3525 and then Has_Discriminants
(Etype
(Actval
))
3527 Analyze_And_Resolve
(Actval
, Base_Type
(Etype
(Actval
)));
3529 -- Resolve entities with their own type, which may differ from
3530 -- the type of a reference in a generic context (the view
3531 -- swapping mechanism did not anticipate the re-analysis of
3532 -- default values in calls).
3534 elsif Is_Entity_Name
(Actval
) then
3535 Analyze_And_Resolve
(Actval
, Etype
(Entity
(Actval
)));
3538 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3542 -- If default is a tag indeterminate function call, propagate tag
3543 -- to obtain proper dispatching.
3545 if Is_Controlling_Formal
(F
)
3546 and then Nkind
(Default_Value
(F
)) = N_Function_Call
3548 Set_Is_Controlling_Actual
(Actval
);
3552 -- If the default expression raises constraint error, then just
3553 -- silently replace it with an N_Raise_Constraint_Error node, since
3554 -- we already gave the warning on the subprogram spec. If node is
3555 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3556 -- the warnings removal machinery.
3558 if Raises_Constraint_Error
(Actval
)
3559 and then Nkind
(Actval
) /= N_Raise_Constraint_Error
3562 Make_Raise_Constraint_Error
(Loc
,
3563 Reason
=> CE_Range_Check_Failed
));
3564 Set_Raises_Constraint_Error
(Actval
);
3565 Set_Etype
(Actval
, Etype
(F
));
3569 Make_Parameter_Association
(Loc
,
3570 Explicit_Actual_Parameter
=> Actval
,
3571 Selector_Name
=> Make_Identifier
(Loc
, Chars
(F
)));
3573 -- Case of insertion is first named actual
3575 if No
(Prev
) or else
3576 Nkind
(Parent
(Prev
)) /= N_Parameter_Association
3578 Set_Next_Named_Actual
(Assoc
, First_Named_Actual
(N
));
3579 Set_First_Named_Actual
(N
, Actval
);
3582 if No
(Parameter_Associations
(N
)) then
3583 Set_Parameter_Associations
(N
, New_List
(Assoc
));
3585 Append
(Assoc
, Parameter_Associations
(N
));
3589 Insert_After
(Prev
, Assoc
);
3592 -- Case of insertion is not first named actual
3595 Set_Next_Named_Actual
3596 (Assoc
, Next_Named_Actual
(Parent
(Prev
)));
3597 Set_Next_Named_Actual
(Parent
(Prev
), Actval
);
3598 Append
(Assoc
, Parameter_Associations
(N
));
3601 Mark_Rewrite_Insertion
(Assoc
);
3602 Mark_Rewrite_Insertion
(Actval
);
3607 --------------------
3608 -- Property_Error --
3609 --------------------
3611 procedure Property_Error
3617 Error_Msg_Name_1
:= Prop_Nam
;
3619 ("external variable & with enabled property % cannot appear as "
3620 & "actual in procedure call (SPARK RM 7.1.3(10))", Var
, Var_Id
);
3621 Error_Msg_N
("\\corresponding formal parameter has mode In", Var
);
3628 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean is
3629 FT1
: Entity_Id
:= T1
;
3630 FT2
: Entity_Id
:= T2
;
3633 if Is_Private_Type
(T1
)
3634 and then Present
(Full_View
(T1
))
3636 FT1
:= Full_View
(T1
);
3639 if Is_Private_Type
(T2
)
3640 and then Present
(Full_View
(T2
))
3642 FT2
:= Full_View
(T2
);
3645 return Root_Type
(Base_Type
(FT1
)) = Root_Type
(Base_Type
(FT2
));
3648 --------------------------
3649 -- Static_Concatenation --
3650 --------------------------
3652 function Static_Concatenation
(N
: Node_Id
) return Boolean is
3655 when N_String_Literal
=>
3660 -- Concatenation is static when both operands are static and
3661 -- the concatenation operator is a predefined one.
3663 return Scope
(Entity
(N
)) = Standard_Standard
3665 Static_Concatenation
(Left_Opnd
(N
))
3667 Static_Concatenation
(Right_Opnd
(N
));
3670 if Is_Entity_Name
(N
) then
3672 Ent
: constant Entity_Id
:= Entity
(N
);
3674 return Ekind
(Ent
) = E_Constant
3675 and then Present
(Constant_Value
(Ent
))
3677 Is_OK_Static_Expression
(Constant_Value
(Ent
));
3684 end Static_Concatenation
;
3686 -- Start of processing for Resolve_Actuals
3689 Check_Argument_Order
;
3691 if Is_Overloadable
(Nam
)
3692 and then Is_Inherited_Operation
(Nam
)
3693 and then In_Instance
3694 and then Present
(Alias
(Nam
))
3695 and then Present
(Overridden_Operation
(Alias
(Nam
)))
3697 Real_Subp
:= Alias
(Nam
);
3702 if Present
(First_Actual
(N
)) then
3703 Check_Prefixed_Call
;
3706 A
:= First_Actual
(N
);
3707 F
:= First_Formal
(Nam
);
3709 if Present
(Real_Subp
) then
3710 Real_F
:= First_Formal
(Real_Subp
);
3713 while Present
(F
) loop
3714 if No
(A
) and then Needs_No_Actuals
(Nam
) then
3717 -- If we have an error in any actual or formal, indicated by a type
3718 -- of Any_Type, then abandon resolution attempt, and set result type
3719 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3720 -- type is imposed from context.
3722 elsif (Present
(A
) and then Etype
(A
) = Any_Type
)
3723 or else Etype
(F
) = Any_Type
3725 if Nkind
(A
) /= N_Raise_Expression
then
3726 Set_Etype
(N
, Any_Type
);
3731 -- Case where actual is present
3733 -- If the actual is an entity, generate a reference to it now. We
3734 -- do this before the actual is resolved, because a formal of some
3735 -- protected subprogram, or a task discriminant, will be rewritten
3736 -- during expansion, and the source entity reference may be lost.
3739 and then Is_Entity_Name
(A
)
3740 and then Comes_From_Source
(A
)
3742 Orig_A
:= Entity
(A
);
3744 if Present
(Orig_A
) then
3745 if Is_Formal
(Orig_A
)
3746 and then Ekind
(F
) /= E_In_Parameter
3748 Generate_Reference
(Orig_A
, A
, 'm');
3750 elsif not Is_Overloaded
(A
) then
3751 if Ekind
(F
) /= E_Out_Parameter
then
3752 Generate_Reference
(Orig_A
, A
);
3754 -- RM 6.4.1(12): For an out parameter that is passed by
3755 -- copy, the formal parameter object is created, and:
3757 -- * For an access type, the formal parameter is initialized
3758 -- from the value of the actual, without checking that the
3759 -- value satisfies any constraint, any predicate, or any
3760 -- exclusion of the null value.
3762 -- * For a scalar type that has the Default_Value aspect
3763 -- specified, the formal parameter is initialized from the
3764 -- value of the actual, without checking that the value
3765 -- satisfies any constraint or any predicate.
3766 -- I do not understand why this case is included??? this is
3767 -- not a case where an OUT parameter is treated as IN OUT.
3769 -- * For a composite type with discriminants or that has
3770 -- implicit initial values for any subcomponents, the
3771 -- behavior is as for an in out parameter passed by copy.
3773 -- Hence for these cases we generate the read reference now
3774 -- (the write reference will be generated later by
3775 -- Note_Possible_Modification).
3777 elsif Is_By_Copy_Type
(Etype
(F
))
3779 (Is_Access_Type
(Etype
(F
))
3781 (Is_Scalar_Type
(Etype
(F
))
3783 Present
(Default_Aspect_Value
(Etype
(F
))))
3785 (Is_Composite_Type
(Etype
(F
))
3786 and then (Has_Discriminants
(Etype
(F
))
3787 or else Is_Partially_Initialized_Type
3790 Generate_Reference
(Orig_A
, A
);
3797 and then (Nkind
(Parent
(A
)) /= N_Parameter_Association
3798 or else Chars
(Selector_Name
(Parent
(A
))) = Chars
(F
))
3800 -- If style checking mode on, check match of formal name
3803 if Nkind
(Parent
(A
)) = N_Parameter_Association
then
3804 Check_Identifier
(Selector_Name
(Parent
(A
)), F
);
3808 -- If the formal is Out or In_Out, do not resolve and expand the
3809 -- conversion, because it is subsequently expanded into explicit
3810 -- temporaries and assignments. However, the object of the
3811 -- conversion can be resolved. An exception is the case of tagged
3812 -- type conversion with a class-wide actual. In that case we want
3813 -- the tag check to occur and no temporary will be needed (no
3814 -- representation change can occur) and the parameter is passed by
3815 -- reference, so we go ahead and resolve the type conversion.
3816 -- Another exception is the case of reference to component or
3817 -- subcomponent of a bit-packed array, in which case we want to
3818 -- defer expansion to the point the in and out assignments are
3821 if Ekind
(F
) /= E_In_Parameter
3822 and then Nkind
(A
) = N_Type_Conversion
3823 and then not Is_Class_Wide_Type
(Etype
(Expression
(A
)))
3825 if Ekind
(F
) = E_In_Out_Parameter
3826 and then Is_Array_Type
(Etype
(F
))
3828 -- In a view conversion, the conversion must be legal in
3829 -- both directions, and thus both component types must be
3830 -- aliased, or neither (4.6 (8)).
3832 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3833 -- the privacy requirement should not apply to generic
3834 -- types, and should be checked in an instance. ARG query
3837 if Has_Aliased_Components
(Etype
(Expression
(A
))) /=
3838 Has_Aliased_Components
(Etype
(F
))
3841 ("both component types in a view conversion must be"
3842 & " aliased, or neither", A
);
3844 -- Comment here??? what set of cases???
3847 not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3849 -- Check view conv between unrelated by ref array types
3851 if Is_By_Reference_Type
(Etype
(F
))
3852 or else Is_By_Reference_Type
(Etype
(Expression
(A
)))
3855 ("view conversion between unrelated by reference "
3856 & "array types not allowed (\'A'I-00246)", A
);
3858 -- In Ada 2005 mode, check view conversion component
3859 -- type cannot be private, tagged, or volatile. Note
3860 -- that we only apply this to source conversions. The
3861 -- generated code can contain conversions which are
3862 -- not subject to this test, and we cannot extract the
3863 -- component type in such cases since it is not present.
3865 elsif Comes_From_Source
(A
)
3866 and then Ada_Version
>= Ada_2005
3869 Comp_Type
: constant Entity_Id
:=
3871 (Etype
(Expression
(A
)));
3873 if (Is_Private_Type
(Comp_Type
)
3874 and then not Is_Generic_Type
(Comp_Type
))
3875 or else Is_Tagged_Type
(Comp_Type
)
3876 or else Is_Volatile
(Comp_Type
)
3879 ("component type of a view conversion cannot"
3880 & " be private, tagged, or volatile"
3889 -- Resolve expression if conversion is all OK
3891 if (Conversion_OK
(A
)
3892 or else Valid_Conversion
(A
, Etype
(A
), Expression
(A
)))
3893 and then not Is_Ref_To_Bit_Packed_Array
(Expression
(A
))
3895 Resolve
(Expression
(A
));
3898 -- If the actual is a function call that returns a limited
3899 -- unconstrained object that needs finalization, create a
3900 -- transient scope for it, so that it can receive the proper
3901 -- finalization list.
3903 elsif Nkind
(A
) = N_Function_Call
3904 and then Is_Limited_Record
(Etype
(F
))
3905 and then not Is_Constrained
(Etype
(F
))
3906 and then Expander_Active
3907 and then (Is_Controlled
(Etype
(F
)) or else Has_Task
(Etype
(F
)))
3909 Establish_Transient_Scope
(A
, Sec_Stack
=> False);
3910 Resolve
(A
, Etype
(F
));
3912 -- A small optimization: if one of the actuals is a concatenation
3913 -- create a block around a procedure call to recover stack space.
3914 -- This alleviates stack usage when several procedure calls in
3915 -- the same statement list use concatenation. We do not perform
3916 -- this wrapping for code statements, where the argument is a
3917 -- static string, and we want to preserve warnings involving
3918 -- sequences of such statements.
3920 elsif Nkind
(A
) = N_Op_Concat
3921 and then Nkind
(N
) = N_Procedure_Call_Statement
3922 and then Expander_Active
3924 not (Is_Intrinsic_Subprogram
(Nam
)
3925 and then Chars
(Nam
) = Name_Asm
)
3926 and then not Static_Concatenation
(A
)
3928 Establish_Transient_Scope
(A
, Sec_Stack
=> False);
3929 Resolve
(A
, Etype
(F
));
3932 if Nkind
(A
) = N_Type_Conversion
3933 and then Is_Array_Type
(Etype
(F
))
3934 and then not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3936 (Is_Limited_Type
(Etype
(F
))
3937 or else Is_Limited_Type
(Etype
(Expression
(A
))))
3940 ("conversion between unrelated limited array types "
3941 & "not allowed ('A'I-00246)", A
);
3943 if Is_Limited_Type
(Etype
(F
)) then
3944 Explain_Limited_Type
(Etype
(F
), A
);
3947 if Is_Limited_Type
(Etype
(Expression
(A
))) then
3948 Explain_Limited_Type
(Etype
(Expression
(A
)), A
);
3952 -- (Ada 2005: AI-251): If the actual is an allocator whose
3953 -- directly designated type is a class-wide interface, we build
3954 -- an anonymous access type to use it as the type of the
3955 -- allocator. Later, when the subprogram call is expanded, if
3956 -- the interface has a secondary dispatch table the expander
3957 -- will add a type conversion to force the correct displacement
3960 if Nkind
(A
) = N_Allocator
then
3962 DDT
: constant Entity_Id
:=
3963 Directly_Designated_Type
(Base_Type
(Etype
(F
)));
3965 New_Itype
: Entity_Id
;
3968 if Is_Class_Wide_Type
(DDT
)
3969 and then Is_Interface
(DDT
)
3971 New_Itype
:= Create_Itype
(E_Anonymous_Access_Type
, A
);
3972 Set_Etype
(New_Itype
, Etype
(A
));
3973 Set_Directly_Designated_Type
3974 (New_Itype
, Directly_Designated_Type
(Etype
(A
)));
3975 Set_Etype
(A
, New_Itype
);
3978 -- Ada 2005, AI-162:If the actual is an allocator, the
3979 -- innermost enclosing statement is the master of the
3980 -- created object. This needs to be done with expansion
3981 -- enabled only, otherwise the transient scope will not
3982 -- be removed in the expansion of the wrapped construct.
3984 if (Is_Controlled
(DDT
) or else Has_Task
(DDT
))
3985 and then Expander_Active
3987 Establish_Transient_Scope
(A
, Sec_Stack
=> False);
3991 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
3992 Check_Restriction
(No_Access_Parameter_Allocators
, A
);
3996 -- (Ada 2005): The call may be to a primitive operation of a
3997 -- tagged synchronized type, declared outside of the type. In
3998 -- this case the controlling actual must be converted to its
3999 -- corresponding record type, which is the formal type. The
4000 -- actual may be a subtype, either because of a constraint or
4001 -- because it is a generic actual, so use base type to locate
4004 F_Typ
:= Base_Type
(Etype
(F
));
4006 if Is_Tagged_Type
(F_Typ
)
4007 and then (Is_Concurrent_Type
(F_Typ
)
4008 or else Is_Concurrent_Record_Type
(F_Typ
))
4010 -- If the actual is overloaded, look for an interpretation
4011 -- that has a synchronized type.
4013 if not Is_Overloaded
(A
) then
4014 A_Typ
:= Base_Type
(Etype
(A
));
4018 Index
: Interp_Index
;
4022 Get_First_Interp
(A
, Index
, It
);
4023 while Present
(It
.Typ
) loop
4024 if Is_Concurrent_Type
(It
.Typ
)
4025 or else Is_Concurrent_Record_Type
(It
.Typ
)
4027 A_Typ
:= Base_Type
(It
.Typ
);
4031 Get_Next_Interp
(Index
, It
);
4037 Full_A_Typ
: Entity_Id
;
4040 if Present
(Full_View
(A_Typ
)) then
4041 Full_A_Typ
:= Base_Type
(Full_View
(A_Typ
));
4043 Full_A_Typ
:= A_Typ
;
4046 -- Tagged synchronized type (case 1): the actual is a
4049 if Is_Concurrent_Type
(A_Typ
)
4050 and then Corresponding_Record_Type
(A_Typ
) = F_Typ
4053 Unchecked_Convert_To
4054 (Corresponding_Record_Type
(A_Typ
), A
));
4055 Resolve
(A
, Etype
(F
));
4057 -- Tagged synchronized type (case 2): the formal is a
4060 elsif Ekind
(Full_A_Typ
) = E_Record_Type
4062 (Corresponding_Concurrent_Type
(Full_A_Typ
))
4063 and then Is_Concurrent_Type
(F_Typ
)
4064 and then Present
(Corresponding_Record_Type
(F_Typ
))
4065 and then Full_A_Typ
= Corresponding_Record_Type
(F_Typ
)
4067 Resolve
(A
, Corresponding_Record_Type
(F_Typ
));
4072 Resolve
(A
, Etype
(F
));
4076 -- Not a synchronized operation
4079 Resolve
(A
, Etype
(F
));
4086 -- An actual cannot be an untagged formal incomplete type
4088 if Ekind
(A_Typ
) = E_Incomplete_Type
4089 and then not Is_Tagged_Type
(A_Typ
)
4090 and then Is_Generic_Type
(A_Typ
)
4093 ("invalid use of untagged formal incomplete type", A
);
4096 if Comes_From_Source
(Original_Node
(N
))
4097 and then Nkind_In
(Original_Node
(N
), N_Function_Call
,
4098 N_Procedure_Call_Statement
)
4100 -- In formal mode, check that actual parameters matching
4101 -- formals of tagged types are objects (or ancestor type
4102 -- conversions of objects), not general expressions.
4104 if Is_Actual_Tagged_Parameter
(A
) then
4105 if Is_SPARK_05_Object_Reference
(A
) then
4108 elsif Nkind
(A
) = N_Type_Conversion
then
4110 Operand
: constant Node_Id
:= Expression
(A
);
4111 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
4112 Target_Typ
: constant Entity_Id
:= A_Typ
;
4115 if not Is_SPARK_05_Object_Reference
(Operand
) then
4116 Check_SPARK_05_Restriction
4117 ("object required", Operand
);
4119 -- In formal mode, the only view conversions are those
4120 -- involving ancestor conversion of an extended type.
4123 (Is_Tagged_Type
(Target_Typ
)
4124 and then not Is_Class_Wide_Type
(Target_Typ
)
4125 and then Is_Tagged_Type
(Operand_Typ
)
4126 and then not Is_Class_Wide_Type
(Operand_Typ
)
4127 and then Is_Ancestor
(Target_Typ
, Operand_Typ
))
4130 (F
, E_Out_Parameter
, E_In_Out_Parameter
)
4132 Check_SPARK_05_Restriction
4133 ("ancestor conversion is the only permitted "
4134 & "view conversion", A
);
4136 Check_SPARK_05_Restriction
4137 ("ancestor conversion required", A
);
4146 Check_SPARK_05_Restriction
("object required", A
);
4149 -- In formal mode, the only view conversions are those
4150 -- involving ancestor conversion of an extended type.
4152 elsif Nkind
(A
) = N_Type_Conversion
4153 and then Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
4155 Check_SPARK_05_Restriction
4156 ("ancestor conversion is the only permitted view "
4161 -- has warnings suppressed, then we reset Never_Set_In_Source for
4162 -- the calling entity. The reason for this is to catch cases like
4163 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4164 -- uses trickery to modify an IN parameter.
4166 if Ekind
(F
) = E_In_Parameter
4167 and then Is_Entity_Name
(A
)
4168 and then Present
(Entity
(A
))
4169 and then Ekind
(Entity
(A
)) = E_Variable
4170 and then Has_Warnings_Off
(F_Typ
)
4172 Set_Never_Set_In_Source
(Entity
(A
), False);
4175 -- Perform error checks for IN and IN OUT parameters
4177 if Ekind
(F
) /= E_Out_Parameter
then
4179 -- Check unset reference. For scalar parameters, it is clearly
4180 -- wrong to pass an uninitialized value as either an IN or
4181 -- IN-OUT parameter. For composites, it is also clearly an
4182 -- error to pass a completely uninitialized value as an IN
4183 -- parameter, but the case of IN OUT is trickier. We prefer
4184 -- not to give a warning here. For example, suppose there is
4185 -- a routine that sets some component of a record to False.
4186 -- It is perfectly reasonable to make this IN-OUT and allow
4187 -- either initialized or uninitialized records to be passed
4190 -- For partially initialized composite values, we also avoid
4191 -- warnings, since it is quite likely that we are passing a
4192 -- partially initialized value and only the initialized fields
4193 -- will in fact be read in the subprogram.
4195 if Is_Scalar_Type
(A_Typ
)
4196 or else (Ekind
(F
) = E_In_Parameter
4197 and then not Is_Partially_Initialized_Type
(A_Typ
))
4199 Check_Unset_Reference
(A
);
4202 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4203 -- actual to a nested call, since this constitutes a reading of
4204 -- the parameter, which is not allowed.
4206 if Ada_Version
= Ada_83
4207 and then Is_Entity_Name
(A
)
4208 and then Ekind
(Entity
(A
)) = E_Out_Parameter
4210 Error_Msg_N
("(Ada 83) illegal reading of out parameter", A
);
4214 -- Case of OUT or IN OUT parameter
4216 if Ekind
(F
) /= E_In_Parameter
then
4218 -- For an Out parameter, check for useless assignment. Note
4219 -- that we can't set Last_Assignment this early, because we may
4220 -- kill current values in Resolve_Call, and that call would
4221 -- clobber the Last_Assignment field.
4223 -- Note: call Warn_On_Useless_Assignment before doing the check
4224 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4225 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4226 -- reflects the last assignment, not this one.
4228 if Ekind
(F
) = E_Out_Parameter
then
4229 if Warn_On_Modified_As_Out_Parameter
(F
)
4230 and then Is_Entity_Name
(A
)
4231 and then Present
(Entity
(A
))
4232 and then Comes_From_Source
(N
)
4234 Warn_On_Useless_Assignment
(Entity
(A
), A
);
4238 -- Validate the form of the actual. Note that the call to
4239 -- Is_OK_Variable_For_Out_Formal generates the required
4240 -- reference in this case.
4242 -- A call to an initialization procedure for an aggregate
4243 -- component may initialize a nested component of a constant
4244 -- designated object. In this context the object is variable.
4246 if not Is_OK_Variable_For_Out_Formal
(A
)
4247 and then not Is_Init_Proc
(Nam
)
4249 Error_Msg_NE
("actual for& must be a variable", A
, F
);
4251 if Is_Subprogram
(Current_Scope
) then
4252 if Is_Invariant_Procedure
(Current_Scope
)
4253 or else Is_Partial_Invariant_Procedure
(Current_Scope
)
4256 ("function used in invariant cannot modify its "
4259 elsif Is_Predicate_Function
(Current_Scope
) then
4261 ("function used in predicate cannot modify its "
4267 -- What's the following about???
4269 if Is_Entity_Name
(A
) then
4270 Kill_Checks
(Entity
(A
));
4276 if Etype
(A
) = Any_Type
then
4277 Set_Etype
(N
, Any_Type
);
4281 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4283 if Ekind_In
(F
, E_In_Parameter
, E_In_Out_Parameter
) then
4285 -- Apply predicate tests except in certain special cases. Note
4286 -- that it might be more consistent to apply these only when
4287 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4288 -- for the outbound predicate tests ??? In any case indicate
4289 -- the function being called, for better warnings if the call
4290 -- leads to an infinite recursion.
4292 if Predicate_Tests_On_Arguments
(Nam
) then
4293 Apply_Predicate_Check
(A
, F_Typ
, Nam
);
4296 -- Apply required constraint checks
4298 -- Gigi looks at the check flag and uses the appropriate types.
4299 -- For now since one flag is used there is an optimization
4300 -- which might not be done in the IN OUT case since Gigi does
4301 -- not do any analysis. More thought required about this ???
4303 -- In fact is this comment obsolete??? doesn't the expander now
4304 -- generate all these tests anyway???
4306 if Is_Scalar_Type
(Etype
(A
)) then
4307 Apply_Scalar_Range_Check
(A
, F_Typ
);
4309 elsif Is_Array_Type
(Etype
(A
)) then
4310 Apply_Length_Check
(A
, F_Typ
);
4312 elsif Is_Record_Type
(F_Typ
)
4313 and then Has_Discriminants
(F_Typ
)
4314 and then Is_Constrained
(F_Typ
)
4315 and then (not Is_Derived_Type
(F_Typ
)
4316 or else Comes_From_Source
(Nam
))
4318 Apply_Discriminant_Check
(A
, F_Typ
);
4320 -- For view conversions of a discriminated object, apply
4321 -- check to object itself, the conversion alreay has the
4324 if Nkind
(A
) = N_Type_Conversion
4325 and then Is_Constrained
(Etype
(Expression
(A
)))
4327 Apply_Discriminant_Check
(Expression
(A
), F_Typ
);
4330 elsif Is_Access_Type
(F_Typ
)
4331 and then Is_Array_Type
(Designated_Type
(F_Typ
))
4332 and then Is_Constrained
(Designated_Type
(F_Typ
))
4334 Apply_Length_Check
(A
, F_Typ
);
4336 elsif Is_Access_Type
(F_Typ
)
4337 and then Has_Discriminants
(Designated_Type
(F_Typ
))
4338 and then Is_Constrained
(Designated_Type
(F_Typ
))
4340 Apply_Discriminant_Check
(A
, F_Typ
);
4343 Apply_Range_Check
(A
, F_Typ
);
4346 -- Ada 2005 (AI-231): Note that the controlling parameter case
4347 -- already existed in Ada 95, which is partially checked
4348 -- elsewhere (see Checks), and we don't want the warning
4349 -- message to differ.
4351 if Is_Access_Type
(F_Typ
)
4352 and then Can_Never_Be_Null
(F_Typ
)
4353 and then Known_Null
(A
)
4355 if Is_Controlling_Formal
(F
) then
4356 Apply_Compile_Time_Constraint_Error
4358 Msg
=> "null value not allowed here??",
4359 Reason
=> CE_Access_Check_Failed
);
4361 elsif Ada_Version
>= Ada_2005
then
4362 Apply_Compile_Time_Constraint_Error
4364 Msg
=> "(Ada 2005) null not allowed in "
4365 & "null-excluding formal??",
4366 Reason
=> CE_Null_Not_Allowed
);
4371 -- Checks for OUT parameters and IN OUT parameters
4373 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
) then
4375 -- If there is a type conversion, make sure the return value
4376 -- meets the constraints of the variable before the conversion.
4378 if Nkind
(A
) = N_Type_Conversion
then
4379 if Is_Scalar_Type
(A_Typ
) then
4380 Apply_Scalar_Range_Check
4381 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4383 -- In addition, the returned value of the parameter must
4384 -- satisfy the bounds of the object type (see comment
4387 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
4391 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4394 -- If no conversion, apply scalar range checks and length check
4395 -- based on the subtype of the actual (NOT that of the formal).
4396 -- This indicates that the check takes place on return from the
4397 -- call. During expansion the required constraint checks are
4398 -- inserted. In GNATprove mode, in the absence of expansion,
4399 -- the flag indicates that the returned value is valid.
4402 if Is_Scalar_Type
(F_Typ
) then
4403 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
4405 elsif Is_Array_Type
(F_Typ
)
4406 and then Ekind
(F
) = E_Out_Parameter
4408 Apply_Length_Check
(A
, F_Typ
);
4410 Apply_Range_Check
(A
, A_Typ
, F_Typ
);
4414 -- Note: we do not apply the predicate checks for the case of
4415 -- OUT and IN OUT parameters. They are instead applied in the
4416 -- Expand_Actuals routine in Exp_Ch6.
4419 -- An actual associated with an access parameter is implicitly
4420 -- converted to the anonymous access type of the formal and must
4421 -- satisfy the legality checks for access conversions.
4423 if Ekind
(F_Typ
) = E_Anonymous_Access_Type
then
4424 if not Valid_Conversion
(A
, F_Typ
, A
) then
4426 ("invalid implicit conversion for access parameter", A
);
4429 -- If the actual is an access selected component of a variable,
4430 -- the call may modify its designated object. It is reasonable
4431 -- to treat this as a potential modification of the enclosing
4432 -- record, to prevent spurious warnings that it should be
4433 -- declared as a constant, because intuitively programmers
4434 -- regard the designated subcomponent as part of the record.
4436 if Nkind
(A
) = N_Selected_Component
4437 and then Is_Entity_Name
(Prefix
(A
))
4438 and then not Is_Constant_Object
(Entity
(Prefix
(A
)))
4440 Note_Possible_Modification
(A
, Sure
=> False);
4444 -- Check bad case of atomic/volatile argument (RM C.6(12))
4446 if Is_By_Reference_Type
(Etype
(F
))
4447 and then Comes_From_Source
(N
)
4449 if Is_Atomic_Object
(A
)
4450 and then not Is_Atomic
(Etype
(F
))
4453 ("cannot pass atomic argument to non-atomic formal&",
4456 elsif Is_Volatile_Object
(A
)
4457 and then not Is_Volatile
(Etype
(F
))
4460 ("cannot pass volatile argument to non-volatile formal&",
4465 -- Check that subprograms don't have improper controlling
4466 -- arguments (RM 3.9.2 (9)).
4468 -- A primitive operation may have an access parameter of an
4469 -- incomplete tagged type, but a dispatching call is illegal
4470 -- if the type is still incomplete.
4472 if Is_Controlling_Formal
(F
) then
4473 Set_Is_Controlling_Actual
(A
);
4475 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
4477 Desig
: constant Entity_Id
:= Designated_Type
(Etype
(F
));
4479 if Ekind
(Desig
) = E_Incomplete_Type
4480 and then No
(Full_View
(Desig
))
4481 and then No
(Non_Limited_View
(Desig
))
4484 ("premature use of incomplete type& "
4485 & "in dispatching call", A
, Desig
);
4490 elsif Nkind
(A
) = N_Explicit_Dereference
then
4491 Validate_Remote_Access_To_Class_Wide_Type
(A
);
4494 -- Apply legality rule 3.9.2 (9/1)
4496 if (Is_Class_Wide_Type
(A_Typ
) or else Is_Dynamically_Tagged
(A
))
4497 and then not Is_Class_Wide_Type
(F_Typ
)
4498 and then not Is_Controlling_Formal
(F
)
4499 and then not In_Instance
4501 Error_Msg_N
("class-wide argument not allowed here!", A
);
4503 if Is_Subprogram
(Nam
) and then Comes_From_Source
(Nam
) then
4504 Error_Msg_Node_2
:= F_Typ
;
4506 ("& is not a dispatching operation of &!", A
, Nam
);
4509 -- Apply the checks described in 3.10.2(27): if the context is a
4510 -- specific access-to-object, the actual cannot be class-wide.
4511 -- Use base type to exclude access_to_subprogram cases.
4513 elsif Is_Access_Type
(A_Typ
)
4514 and then Is_Access_Type
(F_Typ
)
4515 and then not Is_Access_Subprogram_Type
(Base_Type
(F_Typ
))
4516 and then (Is_Class_Wide_Type
(Designated_Type
(A_Typ
))
4517 or else (Nkind
(A
) = N_Attribute_Reference
4519 Is_Class_Wide_Type
(Etype
(Prefix
(A
)))))
4520 and then not Is_Class_Wide_Type
(Designated_Type
(F_Typ
))
4521 and then not Is_Controlling_Formal
(F
)
4523 -- Disable these checks for call to imported C++ subprograms
4526 (Is_Entity_Name
(Name
(N
))
4527 and then Is_Imported
(Entity
(Name
(N
)))
4528 and then Convention
(Entity
(Name
(N
))) = Convention_CPP
)
4531 ("access to class-wide argument not allowed here!", A
);
4533 if Is_Subprogram
(Nam
) and then Comes_From_Source
(Nam
) then
4534 Error_Msg_Node_2
:= Designated_Type
(F_Typ
);
4536 ("& is not a dispatching operation of &!", A
, Nam
);
4540 Check_Aliased_Parameter
;
4544 -- If it is a named association, treat the selector_name as a
4545 -- proper identifier, and mark the corresponding entity.
4547 if Nkind
(Parent
(A
)) = N_Parameter_Association
4549 -- Ignore reference in SPARK mode, as it refers to an entity not
4550 -- in scope at the point of reference, so the reference should
4551 -- be ignored for computing effects of subprograms.
4553 and then not GNATprove_Mode
4555 -- If subprogram is overridden, use name of formal that
4558 if Present
(Real_Subp
) then
4559 Set_Entity
(Selector_Name
(Parent
(A
)), Real_F
);
4560 Set_Etype
(Selector_Name
(Parent
(A
)), Etype
(Real_F
));
4563 Set_Entity
(Selector_Name
(Parent
(A
)), F
);
4564 Generate_Reference
(F
, Selector_Name
(Parent
(A
)));
4565 Set_Etype
(Selector_Name
(Parent
(A
)), F_Typ
);
4566 Generate_Reference
(F_Typ
, N
, ' ');
4572 if Ekind
(F
) /= E_Out_Parameter
then
4573 Check_Unset_Reference
(A
);
4576 -- The following checks are only relevant when SPARK_Mode is on as
4577 -- they are not standard Ada legality rule. Internally generated
4578 -- temporaries are ignored.
4580 if SPARK_Mode
= On
and then Comes_From_Source
(A
) then
4582 -- An effectively volatile object may act as an actual when the
4583 -- corresponding formal is of a non-scalar effectively volatile
4584 -- type (SPARK RM 7.1.3(11)).
4586 if not Is_Scalar_Type
(Etype
(F
))
4587 and then Is_Effectively_Volatile
(Etype
(F
))
4591 -- An effectively volatile object may act as an actual in a
4592 -- call to an instance of Unchecked_Conversion.
4593 -- (SPARK RM 7.1.3(11)).
4595 elsif Is_Unchecked_Conversion_Instance
(Nam
) then
4598 -- The actual denotes an object
4600 elsif Is_Effectively_Volatile_Object
(A
) then
4602 ("volatile object cannot act as actual in a call (SPARK "
4603 & "RM 7.1.3(11))", A
);
4605 -- Otherwise the actual denotes an expression. Inspect the
4606 -- expression and flag each effectively volatile object with
4607 -- enabled property Async_Writers or Effective_Reads as illegal
4608 -- because it apprears within an interfering context. Note that
4609 -- this is usually done in Resolve_Entity_Name, but when the
4610 -- effectively volatile object appears as an actual in a call,
4611 -- the call must be resolved first.
4614 Flag_Effectively_Volatile_Objects
(A
);
4617 -- Detect an external variable with an enabled property that
4618 -- does not match the mode of the corresponding formal in a
4619 -- procedure call. Functions are not considered because they
4620 -- cannot have effectively volatile formal parameters in the
4623 if Ekind
(Nam
) = E_Procedure
4624 and then Ekind
(F
) = E_In_Parameter
4625 and then Is_Entity_Name
(A
)
4626 and then Present
(Entity
(A
))
4627 and then Ekind
(Entity
(A
)) = E_Variable
4631 if Async_Readers_Enabled
(A_Id
) then
4632 Property_Error
(A
, A_Id
, Name_Async_Readers
);
4633 elsif Effective_Reads_Enabled
(A_Id
) then
4634 Property_Error
(A
, A_Id
, Name_Effective_Reads
);
4635 elsif Effective_Writes_Enabled
(A_Id
) then
4636 Property_Error
(A
, A_Id
, Name_Effective_Writes
);
4641 -- A formal parameter of a specific tagged type whose related
4642 -- subprogram is subject to pragma Extensions_Visible with value
4643 -- "False" cannot act as an actual in a subprogram with value
4644 -- "True" (SPARK RM 6.1.7(3)).
4646 if Is_EVF_Expression
(A
)
4647 and then Extensions_Visible_Status
(Nam
) =
4648 Extensions_Visible_True
4651 ("formal parameter cannot act as actual parameter when "
4652 & "Extensions_Visible is False", A
);
4654 ("\subprogram & has Extensions_Visible True", A
, Nam
);
4657 -- The actual parameter of a Ghost subprogram whose formal is of
4658 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(12)).
4660 if Comes_From_Source
(Nam
)
4661 and then Is_Ghost_Entity
(Nam
)
4662 and then Ekind_In
(F
, E_In_Out_Parameter
, E_Out_Parameter
)
4663 and then Is_Entity_Name
(A
)
4664 and then Present
(Entity
(A
))
4665 and then not Is_Ghost_Entity
(Entity
(A
))
4668 ("non-ghost variable & cannot appear as actual in call to "
4669 & "ghost procedure", A
, Entity
(A
));
4671 if Ekind
(F
) = E_In_Out_Parameter
then
4672 Error_Msg_N
("\corresponding formal has mode `IN OUT`", A
);
4674 Error_Msg_N
("\corresponding formal has mode OUT", A
);
4680 -- Case where actual is not present
4688 if Present
(Real_Subp
) then
4689 Next_Formal
(Real_F
);
4692 end Resolve_Actuals
;
4694 -----------------------
4695 -- Resolve_Allocator --
4696 -----------------------
4698 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
) is
4699 Desig_T
: constant Entity_Id
:= Designated_Type
(Typ
);
4700 E
: constant Node_Id
:= Expression
(N
);
4702 Discrim
: Entity_Id
;
4705 Assoc
: Node_Id
:= Empty
;
4708 procedure Check_Allocator_Discrim_Accessibility
4709 (Disc_Exp
: Node_Id
;
4710 Alloc_Typ
: Entity_Id
);
4711 -- Check that accessibility level associated with an access discriminant
4712 -- initialized in an allocator by the expression Disc_Exp is not deeper
4713 -- than the level of the allocator type Alloc_Typ. An error message is
4714 -- issued if this condition is violated. Specialized checks are done for
4715 -- the cases of a constraint expression which is an access attribute or
4716 -- an access discriminant.
4718 function In_Dispatching_Context
return Boolean;
4719 -- If the allocator is an actual in a call, it is allowed to be class-
4720 -- wide when the context is not because it is a controlling actual.
4722 -------------------------------------------
4723 -- Check_Allocator_Discrim_Accessibility --
4724 -------------------------------------------
4726 procedure Check_Allocator_Discrim_Accessibility
4727 (Disc_Exp
: Node_Id
;
4728 Alloc_Typ
: Entity_Id
)
4731 if Type_Access_Level
(Etype
(Disc_Exp
)) >
4732 Deepest_Type_Access_Level
(Alloc_Typ
)
4735 ("operand type has deeper level than allocator type", Disc_Exp
);
4737 -- When the expression is an Access attribute the level of the prefix
4738 -- object must not be deeper than that of the allocator's type.
4740 elsif Nkind
(Disc_Exp
) = N_Attribute_Reference
4741 and then Get_Attribute_Id
(Attribute_Name
(Disc_Exp
)) =
4743 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4744 Deepest_Type_Access_Level
(Alloc_Typ
)
4747 ("prefix of attribute has deeper level than allocator type",
4750 -- When the expression is an access discriminant the check is against
4751 -- the level of the prefix object.
4753 elsif Ekind
(Etype
(Disc_Exp
)) = E_Anonymous_Access_Type
4754 and then Nkind
(Disc_Exp
) = N_Selected_Component
4755 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4756 Deepest_Type_Access_Level
(Alloc_Typ
)
4759 ("access discriminant has deeper level than allocator type",
4762 -- All other cases are legal
4767 end Check_Allocator_Discrim_Accessibility
;
4769 ----------------------------
4770 -- In_Dispatching_Context --
4771 ----------------------------
4773 function In_Dispatching_Context
return Boolean is
4774 Par
: constant Node_Id
:= Parent
(N
);
4777 return Nkind
(Par
) in N_Subprogram_Call
4778 and then Is_Entity_Name
(Name
(Par
))
4779 and then Is_Dispatching_Operation
(Entity
(Name
(Par
)));
4780 end In_Dispatching_Context
;
4782 -- Start of processing for Resolve_Allocator
4785 -- Replace general access with specific type
4787 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
4788 Set_Etype
(N
, Base_Type
(Typ
));
4791 if Is_Abstract_Type
(Typ
) then
4792 Error_Msg_N
("type of allocator cannot be abstract", N
);
4795 -- For qualified expression, resolve the expression using the given
4796 -- subtype (nothing to do for type mark, subtype indication)
4798 if Nkind
(E
) = N_Qualified_Expression
then
4799 if Is_Class_Wide_Type
(Etype
(E
))
4800 and then not Is_Class_Wide_Type
(Desig_T
)
4801 and then not In_Dispatching_Context
4804 ("class-wide allocator not allowed for this access type", N
);
4807 Resolve
(Expression
(E
), Etype
(E
));
4808 Check_Non_Static_Context
(Expression
(E
));
4809 Check_Unset_Reference
(Expression
(E
));
4811 -- Allocators generated by the build-in-place expansion mechanism
4812 -- are explicitly marked as coming from source but do not need to be
4813 -- checked for limited initialization. To exclude this case, ensure
4814 -- that the parent of the allocator is a source node.
4816 if Is_Limited_Type
(Etype
(E
))
4817 and then Comes_From_Source
(N
)
4818 and then Comes_From_Source
(Parent
(N
))
4819 and then not In_Instance_Body
4821 if not OK_For_Limited_Init
(Etype
(E
), Expression
(E
)) then
4822 if Nkind
(Parent
(N
)) = N_Assignment_Statement
then
4824 ("illegal expression for initialized allocator of a "
4825 & "limited type (RM 7.5 (2.7/2))", N
);
4828 ("initialization not allowed for limited types", N
);
4831 Explain_Limited_Type
(Etype
(E
), N
);
4835 -- A qualified expression requires an exact match of the type. Class-
4836 -- wide matching is not allowed.
4838 if (Is_Class_Wide_Type
(Etype
(Expression
(E
)))
4839 or else Is_Class_Wide_Type
(Etype
(E
)))
4840 and then Base_Type
(Etype
(Expression
(E
))) /= Base_Type
(Etype
(E
))
4842 Wrong_Type
(Expression
(E
), Etype
(E
));
4845 -- Calls to build-in-place functions are not currently supported in
4846 -- allocators for access types associated with a simple storage pool.
4847 -- Supporting such allocators may require passing additional implicit
4848 -- parameters to build-in-place functions (or a significant revision
4849 -- of the current b-i-p implementation to unify the handling for
4850 -- multiple kinds of storage pools). ???
4852 if Is_Limited_View
(Desig_T
)
4853 and then Nkind
(Expression
(E
)) = N_Function_Call
4856 Pool
: constant Entity_Id
:=
4857 Associated_Storage_Pool
(Root_Type
(Typ
));
4861 Present
(Get_Rep_Pragma
4862 (Etype
(Pool
), Name_Simple_Storage_Pool_Type
))
4865 ("limited function calls not yet supported in simple "
4866 & "storage pool allocators", Expression
(E
));
4871 -- A special accessibility check is needed for allocators that
4872 -- constrain access discriminants. The level of the type of the
4873 -- expression used to constrain an access discriminant cannot be
4874 -- deeper than the type of the allocator (in contrast to access
4875 -- parameters, where the level of the actual can be arbitrary).
4877 -- We can't use Valid_Conversion to perform this check because in
4878 -- general the type of the allocator is unrelated to the type of
4879 -- the access discriminant.
4881 if Ekind
(Typ
) /= E_Anonymous_Access_Type
4882 or else Is_Local_Anonymous_Access
(Typ
)
4884 Subtyp
:= Entity
(Subtype_Mark
(E
));
4886 Aggr
:= Original_Node
(Expression
(E
));
4888 if Has_Discriminants
(Subtyp
)
4889 and then Nkind_In
(Aggr
, N_Aggregate
, N_Extension_Aggregate
)
4891 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4893 -- Get the first component expression of the aggregate
4895 if Present
(Expressions
(Aggr
)) then
4896 Disc_Exp
:= First
(Expressions
(Aggr
));
4898 elsif Present
(Component_Associations
(Aggr
)) then
4899 Assoc
:= First
(Component_Associations
(Aggr
));
4901 if Present
(Assoc
) then
4902 Disc_Exp
:= Expression
(Assoc
);
4911 while Present
(Discrim
) and then Present
(Disc_Exp
) loop
4912 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4913 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4916 Next_Discriminant
(Discrim
);
4918 if Present
(Discrim
) then
4919 if Present
(Assoc
) then
4921 Disc_Exp
:= Expression
(Assoc
);
4923 elsif Present
(Next
(Disc_Exp
)) then
4927 Assoc
:= First
(Component_Associations
(Aggr
));
4929 if Present
(Assoc
) then
4930 Disc_Exp
:= Expression
(Assoc
);
4940 -- For a subtype mark or subtype indication, freeze the subtype
4943 Freeze_Expression
(E
);
4945 if Is_Access_Constant
(Typ
) and then not No_Initialization
(N
) then
4947 ("initialization required for access-to-constant allocator", N
);
4950 -- A special accessibility check is needed for allocators that
4951 -- constrain access discriminants. The level of the type of the
4952 -- expression used to constrain an access discriminant cannot be
4953 -- deeper than the type of the allocator (in contrast to access
4954 -- parameters, where the level of the actual can be arbitrary).
4955 -- We can't use Valid_Conversion to perform this check because
4956 -- in general the type of the allocator is unrelated to the type
4957 -- of the access discriminant.
4959 if Nkind
(Original_Node
(E
)) = N_Subtype_Indication
4960 and then (Ekind
(Typ
) /= E_Anonymous_Access_Type
4961 or else Is_Local_Anonymous_Access
(Typ
))
4963 Subtyp
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4965 if Has_Discriminants
(Subtyp
) then
4966 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4967 Constr
:= First
(Constraints
(Constraint
(Original_Node
(E
))));
4968 while Present
(Discrim
) and then Present
(Constr
) loop
4969 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4970 if Nkind
(Constr
) = N_Discriminant_Association
then
4971 Disc_Exp
:= Original_Node
(Expression
(Constr
));
4973 Disc_Exp
:= Original_Node
(Constr
);
4976 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4979 Next_Discriminant
(Discrim
);
4986 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4987 -- check that the level of the type of the created object is not deeper
4988 -- than the level of the allocator's access type, since extensions can
4989 -- now occur at deeper levels than their ancestor types. This is a
4990 -- static accessibility level check; a run-time check is also needed in
4991 -- the case of an initialized allocator with a class-wide argument (see
4992 -- Expand_Allocator_Expression).
4994 if Ada_Version
>= Ada_2005
4995 and then Is_Class_Wide_Type
(Desig_T
)
4998 Exp_Typ
: Entity_Id
;
5001 if Nkind
(E
) = N_Qualified_Expression
then
5002 Exp_Typ
:= Etype
(E
);
5003 elsif Nkind
(E
) = N_Subtype_Indication
then
5004 Exp_Typ
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
5006 Exp_Typ
:= Entity
(E
);
5009 if Type_Access_Level
(Exp_Typ
) >
5010 Deepest_Type_Access_Level
(Typ
)
5012 if In_Instance_Body
then
5013 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5015 ("type in allocator has deeper level than "
5016 & "designated class-wide type<<", E
);
5017 Error_Msg_N
("\Program_Error [<<", E
);
5019 Make_Raise_Program_Error
(Sloc
(N
),
5020 Reason
=> PE_Accessibility_Check_Failed
));
5023 -- Do not apply Ada 2005 accessibility checks on a class-wide
5024 -- allocator if the type given in the allocator is a formal
5025 -- type. A run-time check will be performed in the instance.
5027 elsif not Is_Generic_Type
(Exp_Typ
) then
5028 Error_Msg_N
("type in allocator has deeper level than "
5029 & "designated class-wide type", E
);
5035 -- Check for allocation from an empty storage pool
5037 if No_Pool_Assigned
(Typ
) then
5038 Error_Msg_N
("allocation from empty storage pool!", N
);
5040 -- If the context is an unchecked conversion, as may happen within an
5041 -- inlined subprogram, the allocator is being resolved with its own
5042 -- anonymous type. In that case, if the target type has a specific
5043 -- storage pool, it must be inherited explicitly by the allocator type.
5045 elsif Nkind
(Parent
(N
)) = N_Unchecked_Type_Conversion
5046 and then No
(Associated_Storage_Pool
(Typ
))
5048 Set_Associated_Storage_Pool
5049 (Typ
, Associated_Storage_Pool
(Etype
(Parent
(N
))));
5052 if Ekind
(Etype
(N
)) = E_Anonymous_Access_Type
then
5053 Check_Restriction
(No_Anonymous_Allocators
, N
);
5056 -- Check that an allocator with task parts isn't for a nested access
5057 -- type when restriction No_Task_Hierarchy applies.
5059 if not Is_Library_Level_Entity
(Base_Type
(Typ
))
5060 and then Has_Task
(Base_Type
(Desig_T
))
5062 Check_Restriction
(No_Task_Hierarchy
, N
);
5065 -- An illegal allocator may be rewritten as a raise Program_Error
5068 if Nkind
(N
) = N_Allocator
then
5070 -- An anonymous access discriminant is the definition of a
5073 if Ekind
(Typ
) = E_Anonymous_Access_Type
5074 and then Nkind
(Associated_Node_For_Itype
(Typ
)) =
5075 N_Discriminant_Specification
5078 Discr
: constant Entity_Id
:=
5079 Defining_Identifier
(Associated_Node_For_Itype
(Typ
));
5082 Check_Restriction
(No_Coextensions
, N
);
5084 -- Ada 2012 AI05-0052: If the designated type of the allocator
5085 -- is limited, then the allocator shall not be used to define
5086 -- the value of an access discriminant unless the discriminated
5087 -- type is immutably limited.
5089 if Ada_Version
>= Ada_2012
5090 and then Is_Limited_Type
(Desig_T
)
5091 and then not Is_Limited_View
(Scope
(Discr
))
5094 ("only immutably limited types can have anonymous "
5095 & "access discriminants designating a limited type", N
);
5099 -- Avoid marking an allocator as a dynamic coextension if it is
5100 -- within a static construct.
5102 if not Is_Static_Coextension
(N
) then
5103 Set_Is_Dynamic_Coextension
(N
);
5106 -- Cleanup for potential static coextensions
5109 Set_Is_Dynamic_Coextension
(N
, False);
5110 Set_Is_Static_Coextension
(N
, False);
5114 -- Report a simple error: if the designated object is a local task,
5115 -- its body has not been seen yet, and its activation will fail an
5116 -- elaboration check.
5118 if Is_Task_Type
(Desig_T
)
5119 and then Scope
(Base_Type
(Desig_T
)) = Current_Scope
5120 and then Is_Compilation_Unit
(Current_Scope
)
5121 and then Ekind
(Current_Scope
) = E_Package
5122 and then not In_Package_Body
(Current_Scope
)
5124 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5125 Error_Msg_N
("cannot activate task before body seen<<", N
);
5126 Error_Msg_N
("\Program_Error [<<", N
);
5129 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5130 -- type with a task component on a subpool. This action must raise
5131 -- Program_Error at runtime.
5133 if Ada_Version
>= Ada_2012
5134 and then Nkind
(N
) = N_Allocator
5135 and then Present
(Subpool_Handle_Name
(N
))
5136 and then Has_Task
(Desig_T
)
5138 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5139 Error_Msg_N
("cannot allocate task on subpool<<", N
);
5140 Error_Msg_N
("\Program_Error [<<", N
);
5143 Make_Raise_Program_Error
(Sloc
(N
),
5144 Reason
=> PE_Explicit_Raise
));
5147 end Resolve_Allocator
;
5149 ---------------------------
5150 -- Resolve_Arithmetic_Op --
5151 ---------------------------
5153 -- Used for resolving all arithmetic operators except exponentiation
5155 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
5156 L
: constant Node_Id
:= Left_Opnd
(N
);
5157 R
: constant Node_Id
:= Right_Opnd
(N
);
5158 TL
: constant Entity_Id
:= Base_Type
(Etype
(L
));
5159 TR
: constant Entity_Id
:= Base_Type
(Etype
(R
));
5163 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
5164 -- We do the resolution using the base type, because intermediate values
5165 -- in expressions always are of the base type, not a subtype of it.
5167 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean;
5168 -- Returns True if N is in a context that expects "any real type"
5170 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean;
5171 -- Return True iff given type is Integer or universal real/integer
5173 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
);
5174 -- Choose type of integer literal in fixed-point operation to conform
5175 -- to available fixed-point type. T is the type of the other operand,
5176 -- which is needed to determine the expected type of N.
5178 procedure Set_Operand_Type
(N
: Node_Id
);
5179 -- Set operand type to T if universal
5181 -------------------------------
5182 -- Expected_Type_Is_Any_Real --
5183 -------------------------------
5185 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean is
5187 -- N is the expression after "delta" in a fixed_point_definition;
5190 return Nkind_In
(Parent
(N
), N_Ordinary_Fixed_Point_Definition
,
5191 N_Decimal_Fixed_Point_Definition
,
5193 -- N is one of the bounds in a real_range_specification;
5196 N_Real_Range_Specification
,
5198 -- N is the expression of a delta_constraint;
5201 N_Delta_Constraint
);
5202 end Expected_Type_Is_Any_Real
;
5204 -----------------------------
5205 -- Is_Integer_Or_Universal --
5206 -----------------------------
5208 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean is
5210 Index
: Interp_Index
;
5214 if not Is_Overloaded
(N
) then
5216 return Base_Type
(T
) = Base_Type
(Standard_Integer
)
5217 or else T
= Universal_Integer
5218 or else T
= Universal_Real
;
5220 Get_First_Interp
(N
, Index
, It
);
5221 while Present
(It
.Typ
) loop
5222 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
)
5223 or else It
.Typ
= Universal_Integer
5224 or else It
.Typ
= Universal_Real
5229 Get_Next_Interp
(Index
, It
);
5234 end Is_Integer_Or_Universal
;
5236 ----------------------------
5237 -- Set_Mixed_Mode_Operand --
5238 ----------------------------
5240 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
) is
5241 Index
: Interp_Index
;
5245 if Universal_Interpretation
(N
) = Universal_Integer
then
5247 -- A universal integer literal is resolved as standard integer
5248 -- except in the case of a fixed-point result, where we leave it
5249 -- as universal (to be handled by Exp_Fixd later on)
5251 if Is_Fixed_Point_Type
(T
) then
5252 Resolve
(N
, Universal_Integer
);
5254 Resolve
(N
, Standard_Integer
);
5257 elsif Universal_Interpretation
(N
) = Universal_Real
5258 and then (T
= Base_Type
(Standard_Integer
)
5259 or else T
= Universal_Integer
5260 or else T
= Universal_Real
)
5262 -- A universal real can appear in a fixed-type context. We resolve
5263 -- the literal with that context, even though this might raise an
5264 -- exception prematurely (the other operand may be zero).
5268 elsif Etype
(N
) = Base_Type
(Standard_Integer
)
5269 and then T
= Universal_Real
5270 and then Is_Overloaded
(N
)
5272 -- Integer arg in mixed-mode operation. Resolve with universal
5273 -- type, in case preference rule must be applied.
5275 Resolve
(N
, Universal_Integer
);
5278 and then B_Typ
/= Universal_Fixed
5280 -- Not a mixed-mode operation, resolve with context
5284 elsif Etype
(N
) = Any_Fixed
then
5286 -- N may itself be a mixed-mode operation, so use context type
5290 elsif Is_Fixed_Point_Type
(T
)
5291 and then B_Typ
= Universal_Fixed
5292 and then Is_Overloaded
(N
)
5294 -- Must be (fixed * fixed) operation, operand must have one
5295 -- compatible interpretation.
5297 Resolve
(N
, Any_Fixed
);
5299 elsif Is_Fixed_Point_Type
(B_Typ
)
5300 and then (T
= Universal_Real
or else Is_Fixed_Point_Type
(T
))
5301 and then Is_Overloaded
(N
)
5303 -- C * F(X) in a fixed context, where C is a real literal or a
5304 -- fixed-point expression. F must have either a fixed type
5305 -- interpretation or an integer interpretation, but not both.
5307 Get_First_Interp
(N
, Index
, It
);
5308 while Present
(It
.Typ
) loop
5309 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
) then
5310 if Analyzed
(N
) then
5311 Error_Msg_N
("ambiguous operand in fixed operation", N
);
5313 Resolve
(N
, Standard_Integer
);
5316 elsif Is_Fixed_Point_Type
(It
.Typ
) then
5317 if Analyzed
(N
) then
5318 Error_Msg_N
("ambiguous operand in fixed operation", N
);
5320 Resolve
(N
, It
.Typ
);
5324 Get_Next_Interp
(Index
, It
);
5327 -- Reanalyze the literal with the fixed type of the context. If
5328 -- context is Universal_Fixed, we are within a conversion, leave
5329 -- the literal as a universal real because there is no usable
5330 -- fixed type, and the target of the conversion plays no role in
5344 if B_Typ
= Universal_Fixed
5345 and then Nkind
(Op2
) = N_Real_Literal
5347 T2
:= Universal_Real
;
5352 Set_Analyzed
(Op2
, False);
5359 end Set_Mixed_Mode_Operand
;
5361 ----------------------
5362 -- Set_Operand_Type --
5363 ----------------------
5365 procedure Set_Operand_Type
(N
: Node_Id
) is
5367 if Etype
(N
) = Universal_Integer
5368 or else Etype
(N
) = Universal_Real
5372 end Set_Operand_Type
;
5374 -- Start of processing for Resolve_Arithmetic_Op
5377 if Comes_From_Source
(N
)
5378 and then Ekind
(Entity
(N
)) = E_Function
5379 and then Is_Imported
(Entity
(N
))
5380 and then Is_Intrinsic_Subprogram
(Entity
(N
))
5382 Resolve_Intrinsic_Operator
(N
, Typ
);
5385 -- Special-case for mixed-mode universal expressions or fixed point type
5386 -- operation: each argument is resolved separately. The same treatment
5387 -- is required if one of the operands of a fixed point operation is
5388 -- universal real, since in this case we don't do a conversion to a
5389 -- specific fixed-point type (instead the expander handles the case).
5391 -- Set the type of the node to its universal interpretation because
5392 -- legality checks on an exponentiation operand need the context.
5394 elsif (B_Typ
= Universal_Integer
or else B_Typ
= Universal_Real
)
5395 and then Present
(Universal_Interpretation
(L
))
5396 and then Present
(Universal_Interpretation
(R
))
5398 Set_Etype
(N
, B_Typ
);
5399 Resolve
(L
, Universal_Interpretation
(L
));
5400 Resolve
(R
, Universal_Interpretation
(R
));
5402 elsif (B_Typ
= Universal_Real
5403 or else Etype
(N
) = Universal_Fixed
5404 or else (Etype
(N
) = Any_Fixed
5405 and then Is_Fixed_Point_Type
(B_Typ
))
5406 or else (Is_Fixed_Point_Type
(B_Typ
)
5407 and then (Is_Integer_Or_Universal
(L
)
5409 Is_Integer_Or_Universal
(R
))))
5410 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
5412 if TL
= Universal_Integer
or else TR
= Universal_Integer
then
5413 Check_For_Visible_Operator
(N
, B_Typ
);
5416 -- If context is a fixed type and one operand is integer, the other
5417 -- is resolved with the type of the context.
5419 if Is_Fixed_Point_Type
(B_Typ
)
5420 and then (Base_Type
(TL
) = Base_Type
(Standard_Integer
)
5421 or else TL
= Universal_Integer
)
5426 elsif Is_Fixed_Point_Type
(B_Typ
)
5427 and then (Base_Type
(TR
) = Base_Type
(Standard_Integer
)
5428 or else TR
= Universal_Integer
)
5434 Set_Mixed_Mode_Operand
(L
, TR
);
5435 Set_Mixed_Mode_Operand
(R
, TL
);
5438 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5439 -- multiplying operators from being used when the expected type is
5440 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5441 -- some cases where the expected type is actually Any_Real;
5442 -- Expected_Type_Is_Any_Real takes care of that case.
5444 if Etype
(N
) = Universal_Fixed
5445 or else Etype
(N
) = Any_Fixed
5447 if B_Typ
= Universal_Fixed
5448 and then not Expected_Type_Is_Any_Real
(N
)
5449 and then not Nkind_In
(Parent
(N
), N_Type_Conversion
,
5450 N_Unchecked_Type_Conversion
)
5452 Error_Msg_N
("type cannot be determined from context!", N
);
5453 Error_Msg_N
("\explicit conversion to result type required", N
);
5455 Set_Etype
(L
, Any_Type
);
5456 Set_Etype
(R
, Any_Type
);
5459 if Ada_Version
= Ada_83
5460 and then Etype
(N
) = Universal_Fixed
5462 Nkind_In
(Parent
(N
), N_Type_Conversion
,
5463 N_Unchecked_Type_Conversion
)
5466 ("(Ada 83) fixed-point operation needs explicit "
5470 -- The expected type is "any real type" in contexts like
5472 -- type T is delta <universal_fixed-expression> ...
5474 -- in which case we need to set the type to Universal_Real
5475 -- so that static expression evaluation will work properly.
5477 if Expected_Type_Is_Any_Real
(N
) then
5478 Set_Etype
(N
, Universal_Real
);
5480 Set_Etype
(N
, B_Typ
);
5484 elsif Is_Fixed_Point_Type
(B_Typ
)
5485 and then (Is_Integer_Or_Universal
(L
)
5486 or else Nkind
(L
) = N_Real_Literal
5487 or else Nkind
(R
) = N_Real_Literal
5488 or else Is_Integer_Or_Universal
(R
))
5490 Set_Etype
(N
, B_Typ
);
5492 elsif Etype
(N
) = Any_Fixed
then
5494 -- If no previous errors, this is only possible if one operand is
5495 -- overloaded and the context is universal. Resolve as such.
5497 Set_Etype
(N
, B_Typ
);
5501 if (TL
= Universal_Integer
or else TL
= Universal_Real
)
5503 (TR
= Universal_Integer
or else TR
= Universal_Real
)
5505 Check_For_Visible_Operator
(N
, B_Typ
);
5508 -- If the context is Universal_Fixed and the operands are also
5509 -- universal fixed, this is an error, unless there is only one
5510 -- applicable fixed_point type (usually Duration).
5512 if B_Typ
= Universal_Fixed
and then Etype
(L
) = Universal_Fixed
then
5513 T
:= Unique_Fixed_Point_Type
(N
);
5515 if T
= Any_Type
then
5528 -- If one of the arguments was resolved to a non-universal type.
5529 -- label the result of the operation itself with the same type.
5530 -- Do the same for the universal argument, if any.
5532 T
:= Intersect_Types
(L
, R
);
5533 Set_Etype
(N
, Base_Type
(T
));
5534 Set_Operand_Type
(L
);
5535 Set_Operand_Type
(R
);
5538 Generate_Operator_Reference
(N
, Typ
);
5539 Analyze_Dimension
(N
);
5540 Eval_Arithmetic_Op
(N
);
5542 -- In SPARK, a multiplication or division with operands of fixed point
5543 -- types must be qualified or explicitly converted to identify the
5546 if (Is_Fixed_Point_Type
(Etype
(L
))
5547 or else Is_Fixed_Point_Type
(Etype
(R
)))
5548 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
5550 not Nkind_In
(Parent
(N
), N_Qualified_Expression
, N_Type_Conversion
)
5552 Check_SPARK_05_Restriction
5553 ("operation should be qualified or explicitly converted", N
);
5556 -- Set overflow and division checking bit
5558 if Nkind
(N
) in N_Op
then
5559 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
5560 Enable_Overflow_Check
(N
);
5563 -- Give warning if explicit division by zero
5565 if Nkind_In
(N
, N_Op_Divide
, N_Op_Rem
, N_Op_Mod
)
5566 and then not Division_Checks_Suppressed
(Etype
(N
))
5568 Rop
:= Right_Opnd
(N
);
5570 if Compile_Time_Known_Value
(Rop
)
5571 and then ((Is_Integer_Type
(Etype
(Rop
))
5572 and then Expr_Value
(Rop
) = Uint_0
)
5574 (Is_Real_Type
(Etype
(Rop
))
5575 and then Expr_Value_R
(Rop
) = Ureal_0
))
5577 -- Specialize the warning message according to the operation.
5578 -- When SPARK_Mode is On, force a warning instead of an error
5579 -- in that case, as this likely corresponds to deactivated
5580 -- code. The following warnings are for the case
5585 -- For division, we have two cases, for float division
5586 -- of an unconstrained float type, on a machine where
5587 -- Machine_Overflows is false, we don't get an exception
5588 -- at run-time, but rather an infinity or Nan. The Nan
5589 -- case is pretty obscure, so just warn about infinities.
5591 if Is_Floating_Point_Type
(Typ
)
5592 and then not Is_Constrained
(Typ
)
5593 and then not Machine_Overflows_On_Target
5596 ("float division by zero, may generate "
5597 & "'+'/'- infinity??", Right_Opnd
(N
));
5599 -- For all other cases, we get a Constraint_Error
5602 Apply_Compile_Time_Constraint_Error
5603 (N
, "division by zero??", CE_Divide_By_Zero
,
5604 Loc
=> Sloc
(Right_Opnd
(N
)),
5605 Warn
=> SPARK_Mode
= On
);
5609 Apply_Compile_Time_Constraint_Error
5610 (N
, "rem with zero divisor??", CE_Divide_By_Zero
,
5611 Loc
=> Sloc
(Right_Opnd
(N
)),
5612 Warn
=> SPARK_Mode
= On
);
5615 Apply_Compile_Time_Constraint_Error
5616 (N
, "mod with zero divisor??", CE_Divide_By_Zero
,
5617 Loc
=> Sloc
(Right_Opnd
(N
)),
5618 Warn
=> SPARK_Mode
= On
);
5620 -- Division by zero can only happen with division, rem,
5621 -- and mod operations.
5624 raise Program_Error
;
5627 -- In GNATprove mode, we enable the division check so that
5628 -- GNATprove will issue a message if it cannot be proved.
5630 if GNATprove_Mode
then
5631 Activate_Division_Check
(N
);
5634 -- Otherwise just set the flag to check at run time
5637 Activate_Division_Check
(N
);
5641 -- If Restriction No_Implicit_Conditionals is active, then it is
5642 -- violated if either operand can be negative for mod, or for rem
5643 -- if both operands can be negative.
5645 if Restriction_Check_Required
(No_Implicit_Conditionals
)
5646 and then Nkind_In
(N
, N_Op_Rem
, N_Op_Mod
)
5655 -- Set if corresponding operand might be negative
5659 (Left_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5660 LNeg
:= (not OK
) or else Lo
< 0;
5663 (Right_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5664 RNeg
:= (not OK
) or else Lo
< 0;
5666 -- Check if we will be generating conditionals. There are two
5667 -- cases where that can happen, first for REM, the only case
5668 -- is largest negative integer mod -1, where the division can
5669 -- overflow, but we still have to give the right result. The
5670 -- front end generates a test for this annoying case. Here we
5671 -- just test if both operands can be negative (that's what the
5672 -- expander does, so we match its logic here).
5674 -- The second case is mod where either operand can be negative.
5675 -- In this case, the back end has to generate additional tests.
5677 if (Nkind
(N
) = N_Op_Rem
and then (LNeg
and RNeg
))
5679 (Nkind
(N
) = N_Op_Mod
and then (LNeg
or RNeg
))
5681 Check_Restriction
(No_Implicit_Conditionals
, N
);
5687 Check_Unset_Reference
(L
);
5688 Check_Unset_Reference
(R
);
5689 end Resolve_Arithmetic_Op
;
5695 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
5696 function Same_Or_Aliased_Subprograms
5698 E
: Entity_Id
) return Boolean;
5699 -- Returns True if the subprogram entity S is the same as E or else
5700 -- S is an alias of E.
5702 ---------------------------------
5703 -- Same_Or_Aliased_Subprograms --
5704 ---------------------------------
5706 function Same_Or_Aliased_Subprograms
5708 E
: Entity_Id
) return Boolean
5710 Subp_Alias
: constant Entity_Id
:= Alias
(S
);
5712 return S
= E
or else (Present
(Subp_Alias
) and then Subp_Alias
= E
);
5713 end Same_Or_Aliased_Subprograms
;
5717 Loc
: constant Source_Ptr
:= Sloc
(N
);
5718 Subp
: constant Node_Id
:= Name
(N
);
5719 Body_Id
: Entity_Id
;
5729 -- Start of processing for Resolve_Call
5732 -- The context imposes a unique interpretation with type Typ on a
5733 -- procedure or function call. Find the entity of the subprogram that
5734 -- yields the expected type, and propagate the corresponding formal
5735 -- constraints on the actuals. The caller has established that an
5736 -- interpretation exists, and emitted an error if not unique.
5738 -- First deal with the case of a call to an access-to-subprogram,
5739 -- dereference made explicit in Analyze_Call.
5741 if Ekind
(Etype
(Subp
)) = E_Subprogram_Type
then
5742 if not Is_Overloaded
(Subp
) then
5743 Nam
:= Etype
(Subp
);
5746 -- Find the interpretation whose type (a subprogram type) has a
5747 -- return type that is compatible with the context. Analysis of
5748 -- the node has established that one exists.
5752 Get_First_Interp
(Subp
, I
, It
);
5753 while Present
(It
.Typ
) loop
5754 if Covers
(Typ
, Etype
(It
.Typ
)) then
5759 Get_Next_Interp
(I
, It
);
5763 raise Program_Error
;
5767 -- If the prefix is not an entity, then resolve it
5769 if not Is_Entity_Name
(Subp
) then
5770 Resolve
(Subp
, Nam
);
5773 -- For an indirect call, we always invalidate checks, since we do not
5774 -- know whether the subprogram is local or global. Yes we could do
5775 -- better here, e.g. by knowing that there are no local subprograms,
5776 -- but it does not seem worth the effort. Similarly, we kill all
5777 -- knowledge of current constant values.
5779 Kill_Current_Values
;
5781 -- If this is a procedure call which is really an entry call, do
5782 -- the conversion of the procedure call to an entry call. Protected
5783 -- operations use the same circuitry because the name in the call
5784 -- can be an arbitrary expression with special resolution rules.
5786 elsif Nkind_In
(Subp
, N_Selected_Component
, N_Indexed_Component
)
5787 or else (Is_Entity_Name
(Subp
)
5788 and then Ekind
(Entity
(Subp
)) = E_Entry
)
5790 Resolve_Entry_Call
(N
, Typ
);
5791 Check_Elab_Call
(N
);
5793 -- Kill checks and constant values, as above for indirect case
5794 -- Who knows what happens when another task is activated?
5796 Kill_Current_Values
;
5799 -- Normal subprogram call with name established in Resolve
5801 elsif not (Is_Type
(Entity
(Subp
))) then
5802 Nam
:= Entity
(Subp
);
5803 Set_Entity_With_Checks
(Subp
, Nam
);
5805 -- Otherwise we must have the case of an overloaded call
5808 pragma Assert
(Is_Overloaded
(Subp
));
5810 -- Initialize Nam to prevent warning (we know it will be assigned
5811 -- in the loop below, but the compiler does not know that).
5815 Get_First_Interp
(Subp
, I
, It
);
5816 while Present
(It
.Typ
) loop
5817 if Covers
(Typ
, It
.Typ
) then
5819 Set_Entity_With_Checks
(Subp
, Nam
);
5823 Get_Next_Interp
(I
, It
);
5827 if Is_Access_Subprogram_Type
(Base_Type
(Etype
(Nam
)))
5828 and then not Is_Access_Subprogram_Type
(Base_Type
(Typ
))
5829 and then Nkind
(Subp
) /= N_Explicit_Dereference
5830 and then Present
(Parameter_Associations
(N
))
5832 -- The prefix is a parameterless function call that returns an access
5833 -- to subprogram. If parameters are present in the current call, add
5834 -- add an explicit dereference. We use the base type here because
5835 -- within an instance these may be subtypes.
5837 -- The dereference is added either in Analyze_Call or here. Should
5838 -- be consolidated ???
5840 Set_Is_Overloaded
(Subp
, False);
5841 Set_Etype
(Subp
, Etype
(Nam
));
5842 Insert_Explicit_Dereference
(Subp
);
5843 Nam
:= Designated_Type
(Etype
(Nam
));
5844 Resolve
(Subp
, Nam
);
5847 -- Check that a call to Current_Task does not occur in an entry body
5849 if Is_RTE
(Nam
, RE_Current_Task
) then
5858 -- Exclude calls that occur within the default of a formal
5859 -- parameter of the entry, since those are evaluated outside
5862 exit when No
(P
) or else Nkind
(P
) = N_Parameter_Specification
;
5864 if Nkind
(P
) = N_Entry_Body
5865 or else (Nkind
(P
) = N_Subprogram_Body
5866 and then Is_Entry_Barrier_Function
(P
))
5869 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5871 ("& should not be used in entry body (RM C.7(17))<<",
5873 Error_Msg_NE
("\Program_Error [<<", N
, Nam
);
5875 Make_Raise_Program_Error
(Loc
,
5876 Reason
=> PE_Current_Task_In_Entry_Body
));
5877 Set_Etype
(N
, Rtype
);
5884 -- Check that a procedure call does not occur in the context of the
5885 -- entry call statement of a conditional or timed entry call. Note that
5886 -- the case of a call to a subprogram renaming of an entry will also be
5887 -- rejected. The test for N not being an N_Entry_Call_Statement is
5888 -- defensive, covering the possibility that the processing of entry
5889 -- calls might reach this point due to later modifications of the code
5892 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
5893 and then Nkind
(N
) /= N_Entry_Call_Statement
5894 and then Entry_Call_Statement
(Parent
(N
)) = N
5896 if Ada_Version
< Ada_2005
then
5897 Error_Msg_N
("entry call required in select statement", N
);
5899 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5900 -- for a procedure_or_entry_call, the procedure_name or
5901 -- procedure_prefix of the procedure_call_statement shall denote
5902 -- an entry renamed by a procedure, or (a view of) a primitive
5903 -- subprogram of a limited interface whose first parameter is
5904 -- a controlling parameter.
5906 elsif Nkind
(N
) = N_Procedure_Call_Statement
5907 and then not Is_Renamed_Entry
(Nam
)
5908 and then not Is_Controlling_Limited_Procedure
(Nam
)
5911 ("entry call or dispatching primitive of interface required", N
);
5915 -- If the SPARK_05 restriction is active, we are not allowed
5916 -- to have a call to a subprogram before we see its completion.
5918 if not Has_Completion
(Nam
)
5919 and then Restriction_Check_Required
(SPARK_05
)
5921 -- Don't flag strange internal calls
5923 and then Comes_From_Source
(N
)
5924 and then Comes_From_Source
(Nam
)
5926 -- Only flag calls in extended main source
5928 and then In_Extended_Main_Source_Unit
(Nam
)
5929 and then In_Extended_Main_Source_Unit
(N
)
5931 -- Exclude enumeration literals from this processing
5933 and then Ekind
(Nam
) /= E_Enumeration_Literal
5935 Check_SPARK_05_Restriction
5936 ("call to subprogram cannot appear before its body", N
);
5939 -- Check that this is not a call to a protected procedure or entry from
5940 -- within a protected function.
5942 Check_Internal_Protected_Use
(N
, Nam
);
5944 -- Freeze the subprogram name if not in a spec-expression. Note that
5945 -- we freeze procedure calls as well as function calls. Procedure calls
5946 -- are not frozen according to the rules (RM 13.14(14)) because it is
5947 -- impossible to have a procedure call to a non-frozen procedure in
5948 -- pure Ada, but in the code that we generate in the expander, this
5949 -- rule needs extending because we can generate procedure calls that
5952 -- In Ada 2012, expression functions may be called within pre/post
5953 -- conditions of subsequent functions or expression functions. Such
5954 -- calls do not freeze when they appear within generated bodies,
5955 -- (including the body of another expression function) which would
5956 -- place the freeze node in the wrong scope. An expression function
5957 -- is frozen in the usual fashion, by the appearance of a real body,
5958 -- or at the end of a declarative part.
5960 if Is_Entity_Name
(Subp
)
5961 and then not In_Spec_Expression
5962 and then not Is_Expression_Function_Or_Completion
(Current_Scope
)
5964 (not Is_Expression_Function_Or_Completion
(Entity
(Subp
))
5965 or else Scope
(Entity
(Subp
)) = Current_Scope
)
5967 Freeze_Expression
(Subp
);
5970 -- For a predefined operator, the type of the result is the type imposed
5971 -- by context, except for a predefined operation on universal fixed.
5972 -- Otherwise The type of the call is the type returned by the subprogram
5975 if Is_Predefined_Op
(Nam
) then
5976 if Etype
(N
) /= Universal_Fixed
then
5980 -- If the subprogram returns an array type, and the context requires the
5981 -- component type of that array type, the node is really an indexing of
5982 -- the parameterless call. Resolve as such. A pathological case occurs
5983 -- when the type of the component is an access to the array type. In
5984 -- this case the call is truly ambiguous. If the call is to an intrinsic
5985 -- subprogram, it can't be an indexed component. This check is necessary
5986 -- because if it's Unchecked_Conversion, and we have "type T_Ptr is
5987 -- access T;" and "type T is array (...) of T_Ptr;" (i.e. an array of
5988 -- pointers to the same array), the compiler gets confused and does an
5989 -- infinite recursion.
5991 elsif (Needs_No_Actuals
(Nam
) or else Needs_One_Actual
(Nam
))
5993 ((Is_Array_Type
(Etype
(Nam
))
5994 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
5996 (Is_Access_Type
(Etype
(Nam
))
5997 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
5999 Covers
(Typ
, Component_Type
(Designated_Type
(Etype
(Nam
))))
6000 and then not Is_Intrinsic_Subprogram
(Entity
(Subp
))))
6003 Index_Node
: Node_Id
;
6005 Ret_Type
: constant Entity_Id
:= Etype
(Nam
);
6008 if Is_Access_Type
(Ret_Type
)
6009 and then Ret_Type
= Component_Type
(Designated_Type
(Ret_Type
))
6012 ("cannot disambiguate function call and indexing", N
);
6014 New_Subp
:= Relocate_Node
(Subp
);
6016 -- The called entity may be an explicit dereference, in which
6017 -- case there is no entity to set.
6019 if Nkind
(New_Subp
) /= N_Explicit_Dereference
then
6020 Set_Entity
(Subp
, Nam
);
6023 if (Is_Array_Type
(Ret_Type
)
6024 and then Component_Type
(Ret_Type
) /= Any_Type
)
6026 (Is_Access_Type
(Ret_Type
)
6028 Component_Type
(Designated_Type
(Ret_Type
)) /= Any_Type
)
6030 if Needs_No_Actuals
(Nam
) then
6032 -- Indexed call to a parameterless function
6035 Make_Indexed_Component
(Loc
,
6037 Make_Function_Call
(Loc
, Name
=> New_Subp
),
6038 Expressions
=> Parameter_Associations
(N
));
6040 -- An Ada 2005 prefixed call to a primitive operation
6041 -- whose first parameter is the prefix. This prefix was
6042 -- prepended to the parameter list, which is actually a
6043 -- list of indexes. Remove the prefix in order to build
6044 -- the proper indexed component.
6047 Make_Indexed_Component
(Loc
,
6049 Make_Function_Call
(Loc
,
6051 Parameter_Associations
=>
6053 (Remove_Head
(Parameter_Associations
(N
)))),
6054 Expressions
=> Parameter_Associations
(N
));
6057 -- Preserve the parenthesis count of the node
6059 Set_Paren_Count
(Index_Node
, Paren_Count
(N
));
6061 -- Since we are correcting a node classification error made
6062 -- by the parser, we call Replace rather than Rewrite.
6064 Replace
(N
, Index_Node
);
6066 Set_Etype
(Prefix
(N
), Ret_Type
);
6068 Resolve_Indexed_Component
(N
, Typ
);
6069 Check_Elab_Call
(Prefix
(N
));
6077 -- If the called function is not declared in the main unit and it
6078 -- returns the limited view of type then use the available view (as
6079 -- is done in Try_Object_Operation) to prevent back-end confusion;
6080 -- the call must appear in a context where the nonlimited view is
6081 -- available. If the called function is in the extended main unit
6082 -- then no action is needed, because the back end handles this case.
6084 if not In_Extended_Main_Code_Unit
(Nam
)
6085 and then From_Limited_With
(Etype
(Nam
))
6087 Set_Etype
(Nam
, Available_View
(Etype
(Nam
)));
6090 Set_Etype
(N
, Etype
(Nam
));
6093 -- In the case where the call is to an overloaded subprogram, Analyze
6094 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6095 -- such a case Normalize_Actuals needs to be called once more to order
6096 -- the actuals correctly. Otherwise the call will have the ordering
6097 -- given by the last overloaded subprogram whether this is the correct
6098 -- one being called or not.
6100 if Is_Overloaded
(Subp
) then
6101 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
6102 pragma Assert
(Norm_OK
);
6105 -- In any case, call is fully resolved now. Reset Overload flag, to
6106 -- prevent subsequent overload resolution if node is analyzed again
6108 Set_Is_Overloaded
(Subp
, False);
6109 Set_Is_Overloaded
(N
, False);
6111 -- A Ghost entity must appear in a specific context
6113 if Is_Ghost_Entity
(Nam
) and then Comes_From_Source
(N
) then
6114 Check_Ghost_Context
(Nam
, N
);
6117 -- If we are calling the current subprogram from immediately within its
6118 -- body, then that is the case where we can sometimes detect cases of
6119 -- infinite recursion statically. Do not try this in case restriction
6120 -- No_Recursion is in effect anyway, and do it only for source calls.
6122 if Comes_From_Source
(N
) then
6123 Scop
:= Current_Scope
;
6125 -- Check violation of SPARK_05 restriction which does not permit
6126 -- a subprogram body to contain a call to the subprogram directly.
6128 if Restriction_Check_Required
(SPARK_05
)
6129 and then Same_Or_Aliased_Subprograms
(Nam
, Scop
)
6131 Check_SPARK_05_Restriction
6132 ("subprogram may not contain direct call to itself", N
);
6135 -- Issue warning for possible infinite recursion in the absence
6136 -- of the No_Recursion restriction.
6138 if Same_Or_Aliased_Subprograms
(Nam
, Scop
)
6139 and then not Restriction_Active
(No_Recursion
)
6140 and then Check_Infinite_Recursion
(N
)
6142 -- Here we detected and flagged an infinite recursion, so we do
6143 -- not need to test the case below for further warnings. Also we
6144 -- are all done if we now have a raise SE node.
6146 if Nkind
(N
) = N_Raise_Storage_Error
then
6150 -- If call is to immediately containing subprogram, then check for
6151 -- the case of a possible run-time detectable infinite recursion.
6154 Scope_Loop
: while Scop
/= Standard_Standard
loop
6155 if Same_Or_Aliased_Subprograms
(Nam
, Scop
) then
6157 -- Although in general case, recursion is not statically
6158 -- checkable, the case of calling an immediately containing
6159 -- subprogram is easy to catch.
6161 Check_Restriction
(No_Recursion
, N
);
6163 -- If the recursive call is to a parameterless subprogram,
6164 -- then even if we can't statically detect infinite
6165 -- recursion, this is pretty suspicious, and we output a
6166 -- warning. Furthermore, we will try later to detect some
6167 -- cases here at run time by expanding checking code (see
6168 -- Detect_Infinite_Recursion in package Exp_Ch6).
6170 -- If the recursive call is within a handler, do not emit a
6171 -- warning, because this is a common idiom: loop until input
6172 -- is correct, catch illegal input in handler and restart.
6174 if No
(First_Formal
(Nam
))
6175 and then Etype
(Nam
) = Standard_Void_Type
6176 and then not Error_Posted
(N
)
6177 and then Nkind
(Parent
(N
)) /= N_Exception_Handler
6179 -- For the case of a procedure call. We give the message
6180 -- only if the call is the first statement in a sequence
6181 -- of statements, or if all previous statements are
6182 -- simple assignments. This is simply a heuristic to
6183 -- decrease false positives, without losing too many good
6184 -- warnings. The idea is that these previous statements
6185 -- may affect global variables the procedure depends on.
6186 -- We also exclude raise statements, that may arise from
6187 -- constraint checks and are probably unrelated to the
6188 -- intended control flow.
6190 if Nkind
(N
) = N_Procedure_Call_Statement
6191 and then Is_List_Member
(N
)
6197 while Present
(P
) loop
6198 if not Nkind_In
(P
, N_Assignment_Statement
,
6199 N_Raise_Constraint_Error
)
6209 -- Do not give warning if we are in a conditional context
6212 K
: constant Node_Kind
:= Nkind
(Parent
(N
));
6214 if (K
= N_Loop_Statement
6215 and then Present
(Iteration_Scheme
(Parent
(N
))))
6216 or else K
= N_If_Statement
6217 or else K
= N_Elsif_Part
6218 or else K
= N_Case_Statement_Alternative
6224 -- Here warning is to be issued
6226 Set_Has_Recursive_Call
(Nam
);
6227 Error_Msg_Warn
:= SPARK_Mode
/= On
;
6228 Error_Msg_N
("possible infinite recursion<<!", N
);
6229 Error_Msg_N
("\Storage_Error ]<<!", N
);
6235 Scop
:= Scope
(Scop
);
6236 end loop Scope_Loop
;
6240 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6242 Check_Obsolescent_2005_Entity
(Nam
, Subp
);
6244 -- If subprogram name is a predefined operator, it was given in
6245 -- functional notation. Replace call node with operator node, so
6246 -- that actuals can be resolved appropriately.
6248 if Is_Predefined_Op
(Nam
) or else Ekind
(Nam
) = E_Operator
then
6249 Make_Call_Into_Operator
(N
, Typ
, Entity
(Name
(N
)));
6252 elsif Present
(Alias
(Nam
))
6253 and then Is_Predefined_Op
(Alias
(Nam
))
6255 Resolve_Actuals
(N
, Nam
);
6256 Make_Call_Into_Operator
(N
, Typ
, Alias
(Nam
));
6260 -- Create a transient scope if the resulting type requires it
6262 -- There are several notable exceptions:
6264 -- a) In init procs, the transient scope overhead is not needed, and is
6265 -- even incorrect when the call is a nested initialization call for a
6266 -- component whose expansion may generate adjust calls. However, if the
6267 -- call is some other procedure call within an initialization procedure
6268 -- (for example a call to Create_Task in the init_proc of the task
6269 -- run-time record) a transient scope must be created around this call.
6271 -- b) Enumeration literal pseudo-calls need no transient scope
6273 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6274 -- functions) do not use the secondary stack even though the return
6275 -- type may be unconstrained.
6277 -- d) Calls to a build-in-place function, since such functions may
6278 -- allocate their result directly in a target object, and cases where
6279 -- the result does get allocated in the secondary stack are checked for
6280 -- within the specialized Exp_Ch6 procedures for expanding those
6281 -- build-in-place calls.
6283 -- e) Calls to inlinable expression functions do not use the secondary
6284 -- stack (since the call will be replaced by its returned object).
6286 -- f) If the subprogram is marked Inline_Always, then even if it returns
6287 -- an unconstrained type the call does not require use of the secondary
6288 -- stack. However, inlining will only take place if the body to inline
6289 -- is already present. It may not be available if e.g. the subprogram is
6290 -- declared in a child instance.
6292 -- If this is an initialization call for a type whose construction
6293 -- uses the secondary stack, and it is not a nested call to initialize
6294 -- a component, we do need to create a transient scope for it. We
6295 -- check for this by traversing the type in Check_Initialization_Call.
6298 and then Has_Pragma_Inline
(Nam
)
6299 and then Nkind
(Unit_Declaration_Node
(Nam
)) = N_Subprogram_Declaration
6300 and then Present
(Body_To_Inline
(Unit_Declaration_Node
(Nam
)))
6304 elsif Ekind
(Nam
) = E_Enumeration_Literal
6305 or else Is_Build_In_Place_Function
(Nam
)
6306 or else Is_Intrinsic_Subprogram
(Nam
)
6307 or else Is_Inlinable_Expression_Function
(Nam
)
6311 elsif Expander_Active
6312 and then Is_Type
(Etype
(Nam
))
6313 and then Requires_Transient_Scope
(Etype
(Nam
))
6315 (not Within_Init_Proc
6317 (not Is_Init_Proc
(Nam
) and then Ekind
(Nam
) /= E_Function
))
6319 Establish_Transient_Scope
(N
, Sec_Stack
=> True);
6321 -- If the call appears within the bounds of a loop, it will
6322 -- be rewritten and reanalyzed, nothing left to do here.
6324 if Nkind
(N
) /= N_Function_Call
then
6328 elsif Is_Init_Proc
(Nam
)
6329 and then not Within_Init_Proc
6331 Check_Initialization_Call
(N
, Nam
);
6334 -- A protected function cannot be called within the definition of the
6335 -- enclosing protected type, unless it is part of a pre/postcondition
6336 -- on another protected operation. This may appear in the entry wrapper
6337 -- created for an entry with preconditions.
6339 if Is_Protected_Type
(Scope
(Nam
))
6340 and then In_Open_Scopes
(Scope
(Nam
))
6341 and then not Has_Completion
(Scope
(Nam
))
6342 and then not In_Spec_Expression
6343 and then not Is_Entry_Wrapper
(Current_Scope
)
6346 ("& cannot be called before end of protected definition", N
, Nam
);
6349 -- Propagate interpretation to actuals, and add default expressions
6352 if Present
(First_Formal
(Nam
)) then
6353 Resolve_Actuals
(N
, Nam
);
6355 -- Overloaded literals are rewritten as function calls, for purpose of
6356 -- resolution. After resolution, we can replace the call with the
6359 elsif Ekind
(Nam
) = E_Enumeration_Literal
then
6360 Copy_Node
(Subp
, N
);
6361 Resolve_Entity_Name
(N
, Typ
);
6363 -- Avoid validation, since it is a static function call
6365 Generate_Reference
(Nam
, Subp
);
6369 -- If the subprogram is not global, then kill all saved values and
6370 -- checks. This is a bit conservative, since in many cases we could do
6371 -- better, but it is not worth the effort. Similarly, we kill constant
6372 -- values. However we do not need to do this for internal entities
6373 -- (unless they are inherited user-defined subprograms), since they
6374 -- are not in the business of molesting local values.
6376 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6377 -- kill all checks and values for calls to global subprograms. This
6378 -- takes care of the case where an access to a local subprogram is
6379 -- taken, and could be passed directly or indirectly and then called
6380 -- from almost any context.
6382 -- Note: we do not do this step till after resolving the actuals. That
6383 -- way we still take advantage of the current value information while
6384 -- scanning the actuals.
6386 -- We suppress killing values if we are processing the nodes associated
6387 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6388 -- type kills all the values as part of analyzing the code that
6389 -- initializes the dispatch tables.
6391 if Inside_Freezing_Actions
= 0
6392 and then (not Is_Library_Level_Entity
(Nam
)
6393 or else Suppress_Value_Tracking_On_Call
6394 (Nearest_Dynamic_Scope
(Current_Scope
)))
6395 and then (Comes_From_Source
(Nam
)
6396 or else (Present
(Alias
(Nam
))
6397 and then Comes_From_Source
(Alias
(Nam
))))
6399 Kill_Current_Values
;
6402 -- If we are warning about unread OUT parameters, this is the place to
6403 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6404 -- after the above call to Kill_Current_Values (since that call clears
6405 -- the Last_Assignment field of all local variables).
6407 if (Warn_On_Modified_Unread
or Warn_On_All_Unread_Out_Parameters
)
6408 and then Comes_From_Source
(N
)
6409 and then In_Extended_Main_Source_Unit
(N
)
6416 F
:= First_Formal
(Nam
);
6417 A
:= First_Actual
(N
);
6418 while Present
(F
) and then Present
(A
) loop
6419 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
6420 and then Warn_On_Modified_As_Out_Parameter
(F
)
6421 and then Is_Entity_Name
(A
)
6422 and then Present
(Entity
(A
))
6423 and then Comes_From_Source
(N
)
6424 and then Safe_To_Capture_Value
(N
, Entity
(A
))
6426 Set_Last_Assignment
(Entity
(A
), A
);
6435 -- If the subprogram is a primitive operation, check whether or not
6436 -- it is a correct dispatching call.
6438 if Is_Overloadable
(Nam
)
6439 and then Is_Dispatching_Operation
(Nam
)
6441 Check_Dispatching_Call
(N
);
6443 elsif Ekind
(Nam
) /= E_Subprogram_Type
6444 and then Is_Abstract_Subprogram
(Nam
)
6445 and then not In_Instance
6447 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Nam
);
6450 -- If this is a dispatching call, generate the appropriate reference,
6451 -- for better source navigation in GPS.
6453 if Is_Overloadable
(Nam
)
6454 and then Present
(Controlling_Argument
(N
))
6456 Generate_Reference
(Nam
, Subp
, 'R');
6458 -- Normal case, not a dispatching call: generate a call reference
6461 Generate_Reference
(Nam
, Subp
, 's');
6464 if Is_Intrinsic_Subprogram
(Nam
) then
6465 Check_Intrinsic_Call
(N
);
6468 -- Check for violation of restriction No_Specific_Termination_Handlers
6469 -- and warn on a potentially blocking call to Abort_Task.
6471 if Restriction_Check_Required
(No_Specific_Termination_Handlers
)
6472 and then (Is_RTE
(Nam
, RE_Set_Specific_Handler
)
6474 Is_RTE
(Nam
, RE_Specific_Handler
))
6476 Check_Restriction
(No_Specific_Termination_Handlers
, N
);
6478 elsif Is_RTE
(Nam
, RE_Abort_Task
) then
6479 Check_Potentially_Blocking_Operation
(N
);
6482 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6483 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6484 -- need to check the second argument to determine whether it is an
6485 -- absolute or relative timing event.
6487 if Restriction_Check_Required
(No_Relative_Delay
)
6488 and then Is_RTE
(Nam
, RE_Set_Handler
)
6489 and then Is_RTE
(Etype
(Next_Actual
(First_Actual
(N
))), RE_Time_Span
)
6491 Check_Restriction
(No_Relative_Delay
, N
);
6494 -- Issue an error for a call to an eliminated subprogram. This routine
6495 -- will not perform the check if the call appears within a default
6498 Check_For_Eliminated_Subprogram
(Subp
, Nam
);
6500 -- In formal mode, the primitive operations of a tagged type or type
6501 -- extension do not include functions that return the tagged type.
6503 if Nkind
(N
) = N_Function_Call
6504 and then Is_Tagged_Type
(Etype
(N
))
6505 and then Is_Entity_Name
(Name
(N
))
6506 and then Is_Inherited_Operation_For_Type
(Entity
(Name
(N
)), Etype
(N
))
6508 Check_SPARK_05_Restriction
("function not inherited", N
);
6511 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6512 -- class-wide and the call dispatches on result in a context that does
6513 -- not provide a tag, the call raises Program_Error.
6515 if Nkind
(N
) = N_Function_Call
6516 and then In_Instance
6517 and then Is_Generic_Actual_Type
(Typ
)
6518 and then Is_Class_Wide_Type
(Typ
)
6519 and then Has_Controlling_Result
(Nam
)
6520 and then Nkind
(Parent
(N
)) = N_Object_Declaration
6522 -- Verify that none of the formals are controlling
6525 Call_OK
: Boolean := False;
6529 F
:= First_Formal
(Nam
);
6530 while Present
(F
) loop
6531 if Is_Controlling_Formal
(F
) then
6540 Error_Msg_Warn
:= SPARK_Mode
/= On
;
6541 Error_Msg_N
("!cannot determine tag of result<<", N
);
6542 Error_Msg_N
("\Program_Error [<<!", N
);
6544 Make_Raise_Program_Error
(Sloc
(N
),
6545 Reason
=> PE_Explicit_Raise
));
6550 -- Check for calling a function with OUT or IN OUT parameter when the
6551 -- calling context (us right now) is not Ada 2012, so does not allow
6552 -- OUT or IN OUT parameters in function calls. Functions declared in
6553 -- a predefined unit are OK, as they may be called indirectly from a
6554 -- user-declared instantiation.
6556 if Ada_Version
< Ada_2012
6557 and then Ekind
(Nam
) = E_Function
6558 and then Has_Out_Or_In_Out_Parameter
(Nam
)
6559 and then not In_Predefined_Unit
(Nam
)
6561 Error_Msg_NE
("& has at least one OUT or `IN OUT` parameter", N
, Nam
);
6562 Error_Msg_N
("\call to this function only allowed in Ada 2012", N
);
6565 -- Check the dimensions of the actuals in the call. For function calls,
6566 -- propagate the dimensions from the returned type to N.
6568 Analyze_Dimension_Call
(N
, Nam
);
6570 -- All done, evaluate call and deal with elaboration issues
6573 Check_Elab_Call
(N
);
6575 -- In GNATprove mode, expansion is disabled, but we want to inline some
6576 -- subprograms to facilitate formal verification. Indirect calls through
6577 -- a subprogram type or within a generic cannot be inlined. Inlining is
6578 -- performed only for calls subject to SPARK_Mode on.
6581 and then SPARK_Mode
= On
6582 and then Is_Overloadable
(Nam
)
6583 and then not Inside_A_Generic
6585 Nam_UA
:= Ultimate_Alias
(Nam
);
6586 Nam_Decl
:= Unit_Declaration_Node
(Nam_UA
);
6588 if Nkind
(Nam_Decl
) = N_Subprogram_Declaration
then
6589 Body_Id
:= Corresponding_Body
(Nam_Decl
);
6591 -- Nothing to do if the subprogram is not eligible for inlining in
6594 if not Is_Inlined_Always
(Nam_UA
)
6595 or else not Can_Be_Inlined_In_GNATprove_Mode
(Nam_UA
, Body_Id
)
6599 -- Calls cannot be inlined inside assertions, as GNATprove treats
6600 -- assertions as logic expressions.
6602 elsif In_Assertion_Expr
/= 0 then
6604 ("cannot inline & (in assertion expression)?", N
, Nam_UA
);
6606 -- Calls cannot be inlined inside default expressions
6608 elsif In_Default_Expr
then
6610 ("cannot inline & (in default expression)?", N
, Nam_UA
);
6612 -- Inlining should not be performed during pre-analysis
6614 elsif Full_Analysis
then
6616 -- With the one-pass inlining technique, a call cannot be
6617 -- inlined if the corresponding body has not been seen yet.
6619 if No
(Body_Id
) then
6621 ("cannot inline & (body not seen yet)?", N
, Nam_UA
);
6623 -- Nothing to do if there is no body to inline, indicating that
6624 -- the subprogram is not suitable for inlining in GNATprove
6627 elsif No
(Body_To_Inline
(Nam_Decl
)) then
6630 -- Do not inline calls inside expression functions, as this
6631 -- would prevent interpreting them as logical formulas in
6634 elsif Present
(Current_Subprogram
)
6636 Is_Expression_Function_Or_Completion
(Current_Subprogram
)
6639 ("cannot inline & (inside expression function)?",
6642 -- Calls cannot be inlined inside potentially unevaluated
6643 -- expressions, as this would create complex actions inside
6644 -- expressions, that are not handled by GNATprove.
6646 elsif Is_Potentially_Unevaluated
(N
) then
6648 ("cannot inline & (in potentially unevaluated context)?",
6651 -- Do not inline calls which would possibly lead to missing a
6652 -- type conversion check on an input parameter.
6654 elsif not Call_Can_Be_Inlined_In_GNATprove_Mode
(N
, Nam
) then
6656 ("cannot inline & (possible check on input parameters)?",
6659 -- Otherwise, inline the call
6662 Expand_Inlined_Call
(N
, Nam_UA
, Nam
);
6668 Warn_On_Overlapping_Actuals
(Nam
, N
);
6671 -----------------------------
6672 -- Resolve_Case_Expression --
6673 -----------------------------
6675 procedure Resolve_Case_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
6678 Alt_Typ
: Entity_Id
;
6682 Alt
:= First
(Alternatives
(N
));
6683 while Present
(Alt
) loop
6684 Alt_Expr
:= Expression
(Alt
);
6685 Resolve
(Alt_Expr
, Typ
);
6686 Alt_Typ
:= Etype
(Alt_Expr
);
6688 -- When the expression is of a scalar subtype different from the
6689 -- result subtype, then insert a conversion to ensure the generation
6690 -- of a constraint check.
6692 if Is_Scalar_Type
(Alt_Typ
) and then Alt_Typ
/= Typ
then
6693 Rewrite
(Alt_Expr
, Convert_To
(Typ
, Alt_Expr
));
6694 Analyze_And_Resolve
(Alt_Expr
, Typ
);
6700 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
6701 -- dynamically tagged must be known statically.
6703 if Is_Tagged_Type
(Typ
) and then not Is_Class_Wide_Type
(Typ
) then
6704 Alt
:= First
(Alternatives
(N
));
6705 Is_Dyn
:= Is_Dynamically_Tagged
(Expression
(Alt
));
6707 while Present
(Alt
) loop
6708 if Is_Dynamically_Tagged
(Expression
(Alt
)) /= Is_Dyn
then
6710 ("all or none of the dependent expressions can be "
6711 & "dynamically tagged", N
);
6719 Eval_Case_Expression
(N
);
6720 end Resolve_Case_Expression
;
6722 -------------------------------
6723 -- Resolve_Character_Literal --
6724 -------------------------------
6726 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
6727 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
6731 -- Verify that the character does belong to the type of the context
6733 Set_Etype
(N
, B_Typ
);
6734 Eval_Character_Literal
(N
);
6736 -- Wide_Wide_Character literals must always be defined, since the set
6737 -- of wide wide character literals is complete, i.e. if a character
6738 -- literal is accepted by the parser, then it is OK for wide wide
6739 -- character (out of range character literals are rejected).
6741 if Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
6744 -- Always accept character literal for type Any_Character, which
6745 -- occurs in error situations and in comparisons of literals, both
6746 -- of which should accept all literals.
6748 elsif B_Typ
= Any_Character
then
6751 -- For Standard.Character or a type derived from it, check that the
6752 -- literal is in range.
6754 elsif Root_Type
(B_Typ
) = Standard_Character
then
6755 if In_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6759 -- For Standard.Wide_Character or a type derived from it, check that the
6760 -- literal is in range.
6762 elsif Root_Type
(B_Typ
) = Standard_Wide_Character
then
6763 if In_Wide_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6767 -- For Standard.Wide_Wide_Character or a type derived from it, we
6768 -- know the literal is in range, since the parser checked.
6770 elsif Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
6773 -- If the entity is already set, this has already been resolved in a
6774 -- generic context, or comes from expansion. Nothing else to do.
6776 elsif Present
(Entity
(N
)) then
6779 -- Otherwise we have a user defined character type, and we can use the
6780 -- standard visibility mechanisms to locate the referenced entity.
6783 C
:= Current_Entity
(N
);
6784 while Present
(C
) loop
6785 if Etype
(C
) = B_Typ
then
6786 Set_Entity_With_Checks
(N
, C
);
6787 Generate_Reference
(C
, N
);
6795 -- If we fall through, then the literal does not match any of the
6796 -- entries of the enumeration type. This isn't just a constraint error
6797 -- situation, it is an illegality (see RM 4.2).
6800 ("character not defined for }", N
, First_Subtype
(B_Typ
));
6801 end Resolve_Character_Literal
;
6803 ---------------------------
6804 -- Resolve_Comparison_Op --
6805 ---------------------------
6807 -- Context requires a boolean type, and plays no role in resolution.
6808 -- Processing identical to that for equality operators. The result type is
6809 -- the base type, which matters when pathological subtypes of booleans with
6810 -- limited ranges are used.
6812 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
6813 L
: constant Node_Id
:= Left_Opnd
(N
);
6814 R
: constant Node_Id
:= Right_Opnd
(N
);
6818 -- If this is an intrinsic operation which is not predefined, use the
6819 -- types of its declared arguments to resolve the possibly overloaded
6820 -- operands. Otherwise the operands are unambiguous and specify the
6823 if Scope
(Entity
(N
)) /= Standard_Standard
then
6824 T
:= Etype
(First_Entity
(Entity
(N
)));
6827 T
:= Find_Unique_Type
(L
, R
);
6829 if T
= Any_Fixed
then
6830 T
:= Unique_Fixed_Point_Type
(L
);
6834 Set_Etype
(N
, Base_Type
(Typ
));
6835 Generate_Reference
(T
, N
, ' ');
6837 -- Skip remaining processing if already set to Any_Type
6839 if T
= Any_Type
then
6843 -- Deal with other error cases
6845 if T
= Any_String
or else
6846 T
= Any_Composite
or else
6849 if T
= Any_Character
then
6850 Ambiguous_Character
(L
);
6852 Error_Msg_N
("ambiguous operands for comparison", N
);
6855 Set_Etype
(N
, Any_Type
);
6859 -- Resolve the operands if types OK
6863 Check_Unset_Reference
(L
);
6864 Check_Unset_Reference
(R
);
6865 Generate_Operator_Reference
(N
, T
);
6866 Check_Low_Bound_Tested
(N
);
6868 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6869 -- types or array types except String.
6871 if Is_Boolean_Type
(T
) then
6872 Check_SPARK_05_Restriction
6873 ("comparison is not defined on Boolean type", N
);
6875 elsif Is_Array_Type
(T
)
6876 and then Base_Type
(T
) /= Standard_String
6878 Check_SPARK_05_Restriction
6879 ("comparison is not defined on array types other than String", N
);
6882 -- Check comparison on unordered enumeration
6884 if Bad_Unordered_Enumeration_Reference
(N
, Etype
(L
)) then
6885 Error_Msg_Sloc
:= Sloc
(Etype
(L
));
6887 ("comparison on unordered enumeration type& declared#?U?",
6891 -- Evaluate the relation (note we do this after the above check since
6892 -- this Eval call may change N to True/False.
6894 Analyze_Dimension
(N
);
6895 Eval_Relational_Op
(N
);
6896 end Resolve_Comparison_Op
;
6898 -----------------------------------------
6899 -- Resolve_Discrete_Subtype_Indication --
6900 -----------------------------------------
6902 procedure Resolve_Discrete_Subtype_Indication
6910 Analyze
(Subtype_Mark
(N
));
6911 S
:= Entity
(Subtype_Mark
(N
));
6913 if Nkind
(Constraint
(N
)) /= N_Range_Constraint
then
6914 Error_Msg_N
("expect range constraint for discrete type", N
);
6915 Set_Etype
(N
, Any_Type
);
6918 R
:= Range_Expression
(Constraint
(N
));
6926 if Base_Type
(S
) /= Base_Type
(Typ
) then
6928 ("expect subtype of }", N
, First_Subtype
(Typ
));
6930 -- Rewrite the constraint as a range of Typ
6931 -- to allow compilation to proceed further.
6934 Rewrite
(Low_Bound
(R
),
6935 Make_Attribute_Reference
(Sloc
(Low_Bound
(R
)),
6936 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
6937 Attribute_Name
=> Name_First
));
6938 Rewrite
(High_Bound
(R
),
6939 Make_Attribute_Reference
(Sloc
(High_Bound
(R
)),
6940 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
6941 Attribute_Name
=> Name_First
));
6945 Set_Etype
(N
, Etype
(R
));
6947 -- Additionally, we must check that the bounds are compatible
6948 -- with the given subtype, which might be different from the
6949 -- type of the context.
6951 Apply_Range_Check
(R
, S
);
6953 -- ??? If the above check statically detects a Constraint_Error
6954 -- it replaces the offending bound(s) of the range R with a
6955 -- Constraint_Error node. When the itype which uses these bounds
6956 -- is frozen the resulting call to Duplicate_Subexpr generates
6957 -- a new temporary for the bounds.
6959 -- Unfortunately there are other itypes that are also made depend
6960 -- on these bounds, so when Duplicate_Subexpr is called they get
6961 -- a forward reference to the newly created temporaries and Gigi
6962 -- aborts on such forward references. This is probably sign of a
6963 -- more fundamental problem somewhere else in either the order of
6964 -- itype freezing or the way certain itypes are constructed.
6966 -- To get around this problem we call Remove_Side_Effects right
6967 -- away if either bounds of R are a Constraint_Error.
6970 L
: constant Node_Id
:= Low_Bound
(R
);
6971 H
: constant Node_Id
:= High_Bound
(R
);
6974 if Nkind
(L
) = N_Raise_Constraint_Error
then
6975 Remove_Side_Effects
(L
);
6978 if Nkind
(H
) = N_Raise_Constraint_Error
then
6979 Remove_Side_Effects
(H
);
6983 Check_Unset_Reference
(Low_Bound
(R
));
6984 Check_Unset_Reference
(High_Bound
(R
));
6987 end Resolve_Discrete_Subtype_Indication
;
6989 -------------------------
6990 -- Resolve_Entity_Name --
6991 -------------------------
6993 -- Used to resolve identifiers and expanded names
6995 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
) is
6996 function Is_Assignment_Or_Object_Expression
6998 Expr
: Node_Id
) return Boolean;
6999 -- Determine whether node Context denotes an assignment statement or an
7000 -- object declaration whose expression is node Expr.
7002 ----------------------------------------
7003 -- Is_Assignment_Or_Object_Expression --
7004 ----------------------------------------
7006 function Is_Assignment_Or_Object_Expression
7008 Expr
: Node_Id
) return Boolean
7011 if Nkind_In
(Context
, N_Assignment_Statement
,
7012 N_Object_Declaration
)
7013 and then Expression
(Context
) = Expr
7017 -- Check whether a construct that yields a name is the expression of
7018 -- an assignment statement or an object declaration.
7020 elsif (Nkind_In
(Context
, N_Attribute_Reference
,
7021 N_Explicit_Dereference
,
7022 N_Indexed_Component
,
7023 N_Selected_Component
,
7025 and then Prefix
(Context
) = Expr
)
7027 (Nkind_In
(Context
, N_Type_Conversion
,
7028 N_Unchecked_Type_Conversion
)
7029 and then Expression
(Context
) = Expr
)
7032 Is_Assignment_Or_Object_Expression
7033 (Context
=> Parent
(Context
),
7036 -- Otherwise the context is not an assignment statement or an object
7042 end Is_Assignment_Or_Object_Expression
;
7046 E
: constant Entity_Id
:= Entity
(N
);
7049 -- Start of processing for Resolve_Entity_Name
7052 -- If garbage from errors, set to Any_Type and return
7054 if No
(E
) and then Total_Errors_Detected
/= 0 then
7055 Set_Etype
(N
, Any_Type
);
7059 -- Replace named numbers by corresponding literals. Note that this is
7060 -- the one case where Resolve_Entity_Name must reset the Etype, since
7061 -- it is currently marked as universal.
7063 if Ekind
(E
) = E_Named_Integer
then
7065 Eval_Named_Integer
(N
);
7067 elsif Ekind
(E
) = E_Named_Real
then
7069 Eval_Named_Real
(N
);
7071 -- For enumeration literals, we need to make sure that a proper style
7072 -- check is done, since such literals are overloaded, and thus we did
7073 -- not do a style check during the first phase of analysis.
7075 elsif Ekind
(E
) = E_Enumeration_Literal
then
7076 Set_Entity_With_Checks
(N
, E
);
7077 Eval_Entity_Name
(N
);
7079 -- Case of (sub)type name appearing in a context where an expression
7080 -- is expected. This is legal if occurrence is a current instance.
7081 -- See RM 8.6 (17/3).
7083 elsif Is_Type
(E
) then
7084 if Is_Current_Instance
(N
) then
7087 -- Any other use is an error
7091 ("invalid use of subtype mark in expression or call", N
);
7094 -- Check discriminant use if entity is discriminant in current scope,
7095 -- i.e. discriminant of record or concurrent type currently being
7096 -- analyzed. Uses in corresponding body are unrestricted.
7098 elsif Ekind
(E
) = E_Discriminant
7099 and then Scope
(E
) = Current_Scope
7100 and then not Has_Completion
(Current_Scope
)
7102 Check_Discriminant_Use
(N
);
7104 -- A parameterless generic function cannot appear in a context that
7105 -- requires resolution.
7107 elsif Ekind
(E
) = E_Generic_Function
then
7108 Error_Msg_N
("illegal use of generic function", N
);
7110 -- In Ada 83 an OUT parameter cannot be read
7112 elsif Ekind
(E
) = E_Out_Parameter
7113 and then (Nkind
(Parent
(N
)) in N_Op
7114 or else Nkind
(Parent
(N
)) = N_Explicit_Dereference
7115 or else Is_Assignment_Or_Object_Expression
7116 (Context
=> Parent
(N
),
7119 if Ada_Version
= Ada_83
then
7120 Error_Msg_N
("(Ada 83) illegal reading of out parameter", N
);
7123 -- In all other cases, just do the possible static evaluation
7126 -- A deferred constant that appears in an expression must have a
7127 -- completion, unless it has been removed by in-place expansion of
7128 -- an aggregate. A constant that is a renaming does not need
7131 if Ekind
(E
) = E_Constant
7132 and then Comes_From_Source
(E
)
7133 and then No
(Constant_Value
(E
))
7134 and then Is_Frozen
(Etype
(E
))
7135 and then not In_Spec_Expression
7136 and then not Is_Imported
(E
)
7137 and then Nkind
(Parent
(E
)) /= N_Object_Renaming_Declaration
7139 if No_Initialization
(Parent
(E
))
7140 or else (Present
(Full_View
(E
))
7141 and then No_Initialization
(Parent
(Full_View
(E
))))
7146 ("deferred constant is frozen before completion", N
);
7150 Eval_Entity_Name
(N
);
7155 -- When the entity appears in a parameter association, retrieve the
7156 -- related subprogram call.
7158 if Nkind
(Par
) = N_Parameter_Association
then
7159 Par
:= Parent
(Par
);
7162 if Comes_From_Source
(N
) then
7164 -- The following checks are only relevant when SPARK_Mode is on as
7165 -- they are not standard Ada legality rules.
7167 if SPARK_Mode
= On
then
7169 -- An effectively volatile object subject to enabled properties
7170 -- Async_Writers or Effective_Reads must appear in non-interfering
7171 -- context (SPARK RM 7.1.3(12)).
7174 and then Is_Effectively_Volatile
(E
)
7175 and then (Async_Writers_Enabled
(E
)
7176 or else Effective_Reads_Enabled
(E
))
7177 and then not Is_OK_Volatile_Context
(Par
, N
)
7180 ("volatile object cannot appear in this context "
7181 & "(SPARK RM 7.1.3(12))", N
);
7184 -- Check for possible elaboration issues with respect to reads of
7185 -- variables. The act of renaming the variable is not considered a
7186 -- read as it simply establishes an alias.
7188 if Ekind
(E
) = E_Variable
7189 and then Dynamic_Elaboration_Checks
7190 and then Nkind
(Par
) /= N_Object_Renaming_Declaration
7192 Check_Elab_Call
(N
);
7195 -- The variable may eventually become a constituent of a single
7196 -- protected/task type. Record the reference now and verify its
7197 -- legality when analyzing the contract of the variable
7200 if Ekind
(E
) = E_Variable
then
7201 Record_Possible_Part_Of_Reference
(E
, N
);
7205 -- A Ghost entity must appear in a specific context
7207 if Is_Ghost_Entity
(E
) then
7208 Check_Ghost_Context
(E
, N
);
7211 end Resolve_Entity_Name
;
7217 procedure Resolve_Entry
(Entry_Name
: Node_Id
) is
7218 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
7226 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
;
7227 -- If the bounds of the entry family being called depend on task
7228 -- discriminants, build a new index subtype where a discriminant is
7229 -- replaced with the value of the discriminant of the target task.
7230 -- The target task is the prefix of the entry name in the call.
7232 -----------------------
7233 -- Actual_Index_Type --
7234 -----------------------
7236 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
is
7237 Typ
: constant Entity_Id
:= Entry_Index_Type
(E
);
7238 Tsk
: constant Entity_Id
:= Scope
(E
);
7239 Lo
: constant Node_Id
:= Type_Low_Bound
(Typ
);
7240 Hi
: constant Node_Id
:= Type_High_Bound
(Typ
);
7243 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
;
7244 -- If the bound is given by a discriminant, replace with a reference
7245 -- to the discriminant of the same name in the target task. If the
7246 -- entry name is the target of a requeue statement and the entry is
7247 -- in the current protected object, the bound to be used is the
7248 -- discriminal of the object (see Apply_Range_Checks for details of
7249 -- the transformation).
7251 -----------------------------
7252 -- Actual_Discriminant_Ref --
7253 -----------------------------
7255 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
is
7256 Typ
: constant Entity_Id
:= Etype
(Bound
);
7260 Remove_Side_Effects
(Bound
);
7262 if not Is_Entity_Name
(Bound
)
7263 or else Ekind
(Entity
(Bound
)) /= E_Discriminant
7267 elsif Is_Protected_Type
(Tsk
)
7268 and then In_Open_Scopes
(Tsk
)
7269 and then Nkind
(Parent
(Entry_Name
)) = N_Requeue_Statement
7271 -- Note: here Bound denotes a discriminant of the corresponding
7272 -- record type tskV, whose discriminal is a formal of the
7273 -- init-proc tskVIP. What we want is the body discriminal,
7274 -- which is associated to the discriminant of the original
7275 -- concurrent type tsk.
7277 return New_Occurrence_Of
7278 (Find_Body_Discriminal
(Entity
(Bound
)), Loc
);
7282 Make_Selected_Component
(Loc
,
7283 Prefix
=> New_Copy_Tree
(Prefix
(Prefix
(Entry_Name
))),
7284 Selector_Name
=> New_Occurrence_Of
(Entity
(Bound
), Loc
));
7289 end Actual_Discriminant_Ref
;
7291 -- Start of processing for Actual_Index_Type
7294 if not Has_Discriminants
(Tsk
)
7295 or else (not Is_Entity_Name
(Lo
) and then not Is_Entity_Name
(Hi
))
7297 return Entry_Index_Type
(E
);
7300 New_T
:= Create_Itype
(Ekind
(Typ
), Parent
(Entry_Name
));
7301 Set_Etype
(New_T
, Base_Type
(Typ
));
7302 Set_Size_Info
(New_T
, Typ
);
7303 Set_RM_Size
(New_T
, RM_Size
(Typ
));
7304 Set_Scalar_Range
(New_T
,
7305 Make_Range
(Sloc
(Entry_Name
),
7306 Low_Bound
=> Actual_Discriminant_Ref
(Lo
),
7307 High_Bound
=> Actual_Discriminant_Ref
(Hi
)));
7311 end Actual_Index_Type
;
7313 -- Start of processing for Resolve_Entry
7316 -- Find name of entry being called, and resolve prefix of name with its
7317 -- own type. The prefix can be overloaded, and the name and signature of
7318 -- the entry must be taken into account.
7320 if Nkind
(Entry_Name
) = N_Indexed_Component
then
7322 -- Case of dealing with entry family within the current tasks
7324 E_Name
:= Prefix
(Entry_Name
);
7327 E_Name
:= Entry_Name
;
7330 if Is_Entity_Name
(E_Name
) then
7332 -- Entry call to an entry (or entry family) in the current task. This
7333 -- is legal even though the task will deadlock. Rewrite as call to
7336 -- This can also be a call to an entry in an enclosing task. If this
7337 -- is a single task, we have to retrieve its name, because the scope
7338 -- of the entry is the task type, not the object. If the enclosing
7339 -- task is a task type, the identity of the task is given by its own
7342 -- Finally this can be a requeue on an entry of the same task or
7343 -- protected object.
7345 S
:= Scope
(Entity
(E_Name
));
7347 for J
in reverse 0 .. Scope_Stack
.Last
loop
7348 if Is_Task_Type
(Scope_Stack
.Table
(J
).Entity
)
7349 and then not Comes_From_Source
(S
)
7351 -- S is an enclosing task or protected object. The concurrent
7352 -- declaration has been converted into a type declaration, and
7353 -- the object itself has an object declaration that follows
7354 -- the type in the same declarative part.
7356 Tsk
:= Next_Entity
(S
);
7357 while Etype
(Tsk
) /= S
loop
7364 elsif S
= Scope_Stack
.Table
(J
).Entity
then
7366 -- Call to current task. Will be transformed into call to Self
7374 Make_Selected_Component
(Loc
,
7375 Prefix
=> New_Occurrence_Of
(S
, Loc
),
7377 New_Occurrence_Of
(Entity
(E_Name
), Loc
));
7378 Rewrite
(E_Name
, New_N
);
7381 elsif Nkind
(Entry_Name
) = N_Selected_Component
7382 and then Is_Overloaded
(Prefix
(Entry_Name
))
7384 -- Use the entry name (which must be unique at this point) to find
7385 -- the prefix that returns the corresponding task/protected type.
7388 Pref
: constant Node_Id
:= Prefix
(Entry_Name
);
7389 Ent
: constant Entity_Id
:= Entity
(Selector_Name
(Entry_Name
));
7394 Get_First_Interp
(Pref
, I
, It
);
7395 while Present
(It
.Typ
) loop
7396 if Scope
(Ent
) = It
.Typ
then
7397 Set_Etype
(Pref
, It
.Typ
);
7401 Get_Next_Interp
(I
, It
);
7406 if Nkind
(Entry_Name
) = N_Selected_Component
then
7407 Resolve
(Prefix
(Entry_Name
));
7409 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7410 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
7411 Resolve
(Prefix
(Prefix
(Entry_Name
)));
7412 Index
:= First
(Expressions
(Entry_Name
));
7413 Resolve
(Index
, Entry_Index_Type
(Nam
));
7415 -- Up to this point the expression could have been the actual in a
7416 -- simple entry call, and be given by a named association.
7418 if Nkind
(Index
) = N_Parameter_Association
then
7419 Error_Msg_N
("expect expression for entry index", Index
);
7421 Apply_Range_Check
(Index
, Actual_Index_Type
(Nam
));
7426 ------------------------
7427 -- Resolve_Entry_Call --
7428 ------------------------
7430 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
7431 Entry_Name
: constant Node_Id
:= Name
(N
);
7432 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
7434 First_Named
: Node_Id
;
7441 -- We kill all checks here, because it does not seem worth the effort to
7442 -- do anything better, an entry call is a big operation.
7446 -- Processing of the name is similar for entry calls and protected
7447 -- operation calls. Once the entity is determined, we can complete
7448 -- the resolution of the actuals.
7450 -- The selector may be overloaded, in the case of a protected object
7451 -- with overloaded functions. The type of the context is used for
7454 if Nkind
(Entry_Name
) = N_Selected_Component
7455 and then Is_Overloaded
(Selector_Name
(Entry_Name
))
7456 and then Typ
/= Standard_Void_Type
7463 Get_First_Interp
(Selector_Name
(Entry_Name
), I
, It
);
7464 while Present
(It
.Typ
) loop
7465 if Covers
(Typ
, It
.Typ
) then
7466 Set_Entity
(Selector_Name
(Entry_Name
), It
.Nam
);
7467 Set_Etype
(Entry_Name
, It
.Typ
);
7469 Generate_Reference
(It
.Typ
, N
, ' ');
7472 Get_Next_Interp
(I
, It
);
7477 Resolve_Entry
(Entry_Name
);
7479 if Nkind
(Entry_Name
) = N_Selected_Component
then
7481 -- Simple entry call
7483 Nam
:= Entity
(Selector_Name
(Entry_Name
));
7484 Obj
:= Prefix
(Entry_Name
);
7485 Was_Over
:= Is_Overloaded
(Selector_Name
(Entry_Name
));
7487 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7489 -- Call to member of entry family
7491 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
7492 Obj
:= Prefix
(Prefix
(Entry_Name
));
7493 Was_Over
:= Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)));
7496 -- We cannot in general check the maximum depth of protected entry calls
7497 -- at compile time. But we can tell that any protected entry call at all
7498 -- violates a specified nesting depth of zero.
7500 if Is_Protected_Type
(Scope
(Nam
)) then
7501 Check_Restriction
(Max_Entry_Queue_Length
, N
);
7504 -- Use context type to disambiguate a protected function that can be
7505 -- called without actuals and that returns an array type, and where the
7506 -- argument list may be an indexing of the returned value.
7508 if Ekind
(Nam
) = E_Function
7509 and then Needs_No_Actuals
(Nam
)
7510 and then Present
(Parameter_Associations
(N
))
7512 ((Is_Array_Type
(Etype
(Nam
))
7513 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
7515 or else (Is_Access_Type
(Etype
(Nam
))
7516 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
7520 Component_Type
(Designated_Type
(Etype
(Nam
))))))
7523 Index_Node
: Node_Id
;
7527 Make_Indexed_Component
(Loc
,
7529 Make_Function_Call
(Loc
, Name
=> Relocate_Node
(Entry_Name
)),
7530 Expressions
=> Parameter_Associations
(N
));
7532 -- Since we are correcting a node classification error made by the
7533 -- parser, we call Replace rather than Rewrite.
7535 Replace
(N
, Index_Node
);
7536 Set_Etype
(Prefix
(N
), Etype
(Nam
));
7538 Resolve_Indexed_Component
(N
, Typ
);
7543 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
)
7544 and then Present
(Contract_Wrapper
(Nam
))
7545 and then Current_Scope
/= Contract_Wrapper
(Nam
)
7548 -- Note the entity being called before rewriting the call, so that
7549 -- it appears used at this point.
7551 Generate_Reference
(Nam
, Entry_Name
, 'r');
7553 -- Rewrite as call to the precondition wrapper, adding the task
7554 -- object to the list of actuals. If the call is to a member of an
7555 -- entry family, include the index as well.
7559 New_Actuals
: List_Id
;
7562 New_Actuals
:= New_List
(Obj
);
7564 if Nkind
(Entry_Name
) = N_Indexed_Component
then
7565 Append_To
(New_Actuals
,
7566 New_Copy_Tree
(First
(Expressions
(Entry_Name
))));
7569 Append_List
(Parameter_Associations
(N
), New_Actuals
);
7571 Make_Procedure_Call_Statement
(Loc
,
7573 New_Occurrence_Of
(Contract_Wrapper
(Nam
), Loc
),
7574 Parameter_Associations
=> New_Actuals
);
7575 Rewrite
(N
, New_Call
);
7577 -- Preanalyze and resolve new call. Current procedure is called
7578 -- from Resolve_Call, after which expansion will take place.
7580 Preanalyze_And_Resolve
(N
);
7585 -- The operation name may have been overloaded. Order the actuals
7586 -- according to the formals of the resolved entity, and set the return
7587 -- type to that of the operation.
7590 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
7591 pragma Assert
(Norm_OK
);
7592 Set_Etype
(N
, Etype
(Nam
));
7594 -- Reset the Is_Overloaded flag, since resolution is now completed
7596 -- Simple entry call
7598 if Nkind
(Entry_Name
) = N_Selected_Component
then
7599 Set_Is_Overloaded
(Selector_Name
(Entry_Name
), False);
7601 -- Call to a member of an entry family
7603 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7604 Set_Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)), False);
7608 Resolve_Actuals
(N
, Nam
);
7609 Check_Internal_Protected_Use
(N
, Nam
);
7611 -- Create a call reference to the entry
7613 Generate_Reference
(Nam
, Entry_Name
, 's');
7615 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
) then
7616 Check_Potentially_Blocking_Operation
(N
);
7619 -- Verify that a procedure call cannot masquerade as an entry
7620 -- call where an entry call is expected.
7622 if Ekind
(Nam
) = E_Procedure
then
7623 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
7624 and then N
= Entry_Call_Statement
(Parent
(N
))
7626 Error_Msg_N
("entry call required in select statement", N
);
7628 elsif Nkind
(Parent
(N
)) = N_Triggering_Alternative
7629 and then N
= Triggering_Statement
(Parent
(N
))
7631 Error_Msg_N
("triggering statement cannot be procedure call", N
);
7633 elsif Ekind
(Scope
(Nam
)) = E_Task_Type
7634 and then not In_Open_Scopes
(Scope
(Nam
))
7636 Error_Msg_N
("task has no entry with this name", Entry_Name
);
7640 -- After resolution, entry calls and protected procedure calls are
7641 -- changed into entry calls, for expansion. The structure of the node
7642 -- does not change, so it can safely be done in place. Protected
7643 -- function calls must keep their structure because they are
7646 if Ekind
(Nam
) /= E_Function
then
7648 -- A protected operation that is not a function may modify the
7649 -- corresponding object, and cannot apply to a constant. If this
7650 -- is an internal call, the prefix is the type itself.
7652 if Is_Protected_Type
(Scope
(Nam
))
7653 and then not Is_Variable
(Obj
)
7654 and then (not Is_Entity_Name
(Obj
)
7655 or else not Is_Type
(Entity
(Obj
)))
7658 ("prefix of protected procedure or entry call must be variable",
7662 Actuals
:= Parameter_Associations
(N
);
7663 First_Named
:= First_Named_Actual
(N
);
7666 Make_Entry_Call_Statement
(Loc
,
7668 Parameter_Associations
=> Actuals
));
7670 Set_First_Named_Actual
(N
, First_Named
);
7671 Set_Analyzed
(N
, True);
7673 -- Protected functions can return on the secondary stack, in which
7674 -- case we must trigger the transient scope mechanism.
7676 elsif Expander_Active
7677 and then Requires_Transient_Scope
(Etype
(Nam
))
7679 Establish_Transient_Scope
(N
, Sec_Stack
=> True);
7681 end Resolve_Entry_Call
;
7683 -------------------------
7684 -- Resolve_Equality_Op --
7685 -------------------------
7687 -- Both arguments must have the same type, and the boolean context does
7688 -- not participate in the resolution. The first pass verifies that the
7689 -- interpretation is not ambiguous, and the type of the left argument is
7690 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7691 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7692 -- though they carry a single (universal) type. Diagnose this case here.
7694 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
7695 L
: constant Node_Id
:= Left_Opnd
(N
);
7696 R
: constant Node_Id
:= Right_Opnd
(N
);
7697 T
: Entity_Id
:= Find_Unique_Type
(L
, R
);
7699 procedure Check_If_Expression
(Cond
: Node_Id
);
7700 -- The resolution rule for if expressions requires that each such must
7701 -- have a unique type. This means that if several dependent expressions
7702 -- are of a non-null anonymous access type, and the context does not
7703 -- impose an expected type (as can be the case in an equality operation)
7704 -- the expression must be rejected.
7706 procedure Explain_Redundancy
(N
: Node_Id
);
7707 -- Attempt to explain the nature of a redundant comparison with True. If
7708 -- the expression N is too complex, this routine issues a general error
7711 function Find_Unique_Access_Type
return Entity_Id
;
7712 -- In the case of allocators and access attributes, the context must
7713 -- provide an indication of the specific access type to be used. If
7714 -- one operand is of such a "generic" access type, check whether there
7715 -- is a specific visible access type that has the same designated type.
7716 -- This is semantically dubious, and of no interest to any real code,
7717 -- but c48008a makes it all worthwhile.
7719 -------------------------
7720 -- Check_If_Expression --
7721 -------------------------
7723 procedure Check_If_Expression
(Cond
: Node_Id
) is
7724 Then_Expr
: Node_Id
;
7725 Else_Expr
: Node_Id
;
7728 if Nkind
(Cond
) = N_If_Expression
then
7729 Then_Expr
:= Next
(First
(Expressions
(Cond
)));
7730 Else_Expr
:= Next
(Then_Expr
);
7732 if Nkind
(Then_Expr
) /= N_Null
7733 and then Nkind
(Else_Expr
) /= N_Null
7735 Error_Msg_N
("cannot determine type of if expression", Cond
);
7738 end Check_If_Expression
;
7740 ------------------------
7741 -- Explain_Redundancy --
7742 ------------------------
7744 procedure Explain_Redundancy
(N
: Node_Id
) is
7752 -- Strip the operand down to an entity
7755 if Nkind
(Val
) = N_Selected_Component
then
7756 Val
:= Selector_Name
(Val
);
7762 -- The construct denotes an entity
7764 if Is_Entity_Name
(Val
) and then Present
(Entity
(Val
)) then
7765 Val_Id
:= Entity
(Val
);
7767 -- Do not generate an error message when the comparison is done
7768 -- against the enumeration literal Standard.True.
7770 if Ekind
(Val_Id
) /= E_Enumeration_Literal
then
7772 -- Build a customized error message
7775 Add_Str_To_Name_Buffer
("?r?");
7777 if Ekind
(Val_Id
) = E_Component
then
7778 Add_Str_To_Name_Buffer
("component ");
7780 elsif Ekind
(Val_Id
) = E_Constant
then
7781 Add_Str_To_Name_Buffer
("constant ");
7783 elsif Ekind
(Val_Id
) = E_Discriminant
then
7784 Add_Str_To_Name_Buffer
("discriminant ");
7786 elsif Is_Formal
(Val_Id
) then
7787 Add_Str_To_Name_Buffer
("parameter ");
7789 elsif Ekind
(Val_Id
) = E_Variable
then
7790 Add_Str_To_Name_Buffer
("variable ");
7793 Add_Str_To_Name_Buffer
("& is always True!");
7796 Error_Msg_NE
(Get_Name_String
(Error
), Val
, Val_Id
);
7799 -- The construct is too complex to disect, issue a general message
7802 Error_Msg_N
("?r?expression is always True!", Val
);
7804 end Explain_Redundancy
;
7806 -----------------------------
7807 -- Find_Unique_Access_Type --
7808 -----------------------------
7810 function Find_Unique_Access_Type
return Entity_Id
is
7816 if Ekind_In
(Etype
(R
), E_Allocator_Type
,
7817 E_Access_Attribute_Type
)
7819 Acc
:= Designated_Type
(Etype
(R
));
7821 elsif Ekind_In
(Etype
(L
), E_Allocator_Type
,
7822 E_Access_Attribute_Type
)
7824 Acc
:= Designated_Type
(Etype
(L
));
7830 while S
/= Standard_Standard
loop
7831 E
:= First_Entity
(S
);
7832 while Present
(E
) loop
7834 and then Is_Access_Type
(E
)
7835 and then Ekind
(E
) /= E_Allocator_Type
7836 and then Designated_Type
(E
) = Base_Type
(Acc
)
7848 end Find_Unique_Access_Type
;
7850 -- Start of processing for Resolve_Equality_Op
7853 Set_Etype
(N
, Base_Type
(Typ
));
7854 Generate_Reference
(T
, N
, ' ');
7856 if T
= Any_Fixed
then
7857 T
:= Unique_Fixed_Point_Type
(L
);
7860 if T
/= Any_Type
then
7861 if T
= Any_String
or else
7862 T
= Any_Composite
or else
7865 if T
= Any_Character
then
7866 Ambiguous_Character
(L
);
7868 Error_Msg_N
("ambiguous operands for equality", N
);
7871 Set_Etype
(N
, Any_Type
);
7874 elsif T
= Any_Access
7875 or else Ekind_In
(T
, E_Allocator_Type
, E_Access_Attribute_Type
)
7877 T
:= Find_Unique_Access_Type
;
7880 Error_Msg_N
("ambiguous operands for equality", N
);
7881 Set_Etype
(N
, Any_Type
);
7885 -- If expressions must have a single type, and if the context does
7886 -- not impose one the dependent expressions cannot be anonymous
7889 -- Why no similar processing for case expressions???
7891 elsif Ada_Version
>= Ada_2012
7892 and then Ekind_In
(Etype
(L
), E_Anonymous_Access_Type
,
7893 E_Anonymous_Access_Subprogram_Type
)
7894 and then Ekind_In
(Etype
(R
), E_Anonymous_Access_Type
,
7895 E_Anonymous_Access_Subprogram_Type
)
7897 Check_If_Expression
(L
);
7898 Check_If_Expression
(R
);
7904 -- In SPARK, equality operators = and /= for array types other than
7905 -- String are only defined when, for each index position, the
7906 -- operands have equal static bounds.
7908 if Is_Array_Type
(T
) then
7910 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7911 -- operation if not needed.
7913 if Restriction_Check_Required
(SPARK_05
)
7914 and then Base_Type
(T
) /= Standard_String
7915 and then Base_Type
(Etype
(L
)) = Base_Type
(Etype
(R
))
7916 and then Etype
(L
) /= Any_Composite
-- or else L in error
7917 and then Etype
(R
) /= Any_Composite
-- or else R in error
7918 and then not Matching_Static_Array_Bounds
(Etype
(L
), Etype
(R
))
7920 Check_SPARK_05_Restriction
7921 ("array types should have matching static bounds", N
);
7925 -- If the unique type is a class-wide type then it will be expanded
7926 -- into a dispatching call to the predefined primitive. Therefore we
7927 -- check here for potential violation of such restriction.
7929 if Is_Class_Wide_Type
(T
) then
7930 Check_Restriction
(No_Dispatching_Calls
, N
);
7933 if Warn_On_Redundant_Constructs
7934 and then Comes_From_Source
(N
)
7935 and then Comes_From_Source
(R
)
7936 and then Is_Entity_Name
(R
)
7937 and then Entity
(R
) = Standard_True
7939 Error_Msg_N
-- CODEFIX
7940 ("?r?comparison with True is redundant!", N
);
7941 Explain_Redundancy
(Original_Node
(R
));
7944 Check_Unset_Reference
(L
);
7945 Check_Unset_Reference
(R
);
7946 Generate_Operator_Reference
(N
, T
);
7947 Check_Low_Bound_Tested
(N
);
7949 -- If this is an inequality, it may be the implicit inequality
7950 -- created for a user-defined operation, in which case the corres-
7951 -- ponding equality operation is not intrinsic, and the operation
7952 -- cannot be constant-folded. Else fold.
7954 if Nkind
(N
) = N_Op_Eq
7955 or else Comes_From_Source
(Entity
(N
))
7956 or else Ekind
(Entity
(N
)) = E_Operator
7957 or else Is_Intrinsic_Subprogram
7958 (Corresponding_Equality
(Entity
(N
)))
7960 Analyze_Dimension
(N
);
7961 Eval_Relational_Op
(N
);
7963 elsif Nkind
(N
) = N_Op_Ne
7964 and then Is_Abstract_Subprogram
(Entity
(N
))
7966 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Entity
(N
));
7969 -- Ada 2005: If one operand is an anonymous access type, convert the
7970 -- other operand to it, to ensure that the underlying types match in
7971 -- the back-end. Same for access_to_subprogram, and the conversion
7972 -- verifies that the types are subtype conformant.
7974 -- We apply the same conversion in the case one of the operands is a
7975 -- private subtype of the type of the other.
7977 -- Why the Expander_Active test here ???
7981 (Ekind_In
(T
, E_Anonymous_Access_Type
,
7982 E_Anonymous_Access_Subprogram_Type
)
7983 or else Is_Private_Type
(T
))
7985 if Etype
(L
) /= T
then
7987 Make_Unchecked_Type_Conversion
(Sloc
(L
),
7988 Subtype_Mark
=> New_Occurrence_Of
(T
, Sloc
(L
)),
7989 Expression
=> Relocate_Node
(L
)));
7990 Analyze_And_Resolve
(L
, T
);
7993 if (Etype
(R
)) /= T
then
7995 Make_Unchecked_Type_Conversion
(Sloc
(R
),
7996 Subtype_Mark
=> New_Occurrence_Of
(Etype
(L
), Sloc
(R
)),
7997 Expression
=> Relocate_Node
(R
)));
7998 Analyze_And_Resolve
(R
, T
);
8002 end Resolve_Equality_Op
;
8004 ----------------------------------
8005 -- Resolve_Explicit_Dereference --
8006 ----------------------------------
8008 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
) is
8009 Loc
: constant Source_Ptr
:= Sloc
(N
);
8011 P
: constant Node_Id
:= Prefix
(N
);
8014 -- The candidate prefix type, if overloaded
8020 Check_Fully_Declared_Prefix
(Typ
, P
);
8023 -- A useful optimization: check whether the dereference denotes an
8024 -- element of a container, and if so rewrite it as a call to the
8025 -- corresponding Element function.
8027 -- Disabled for now, on advice of ARG. A more restricted form of the
8028 -- predicate might be acceptable ???
8030 -- if Is_Container_Element (N) then
8034 if Is_Overloaded
(P
) then
8036 -- Use the context type to select the prefix that has the correct
8037 -- designated type. Keep the first match, which will be the inner-
8040 Get_First_Interp
(P
, I
, It
);
8042 while Present
(It
.Typ
) loop
8043 if Is_Access_Type
(It
.Typ
)
8044 and then Covers
(Typ
, Designated_Type
(It
.Typ
))
8050 -- Remove access types that do not match, but preserve access
8051 -- to subprogram interpretations, in case a further dereference
8052 -- is needed (see below).
8054 elsif Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
8058 Get_Next_Interp
(I
, It
);
8061 if Present
(P_Typ
) then
8063 Set_Etype
(N
, Designated_Type
(P_Typ
));
8066 -- If no interpretation covers the designated type of the prefix,
8067 -- this is the pathological case where not all implementations of
8068 -- the prefix allow the interpretation of the node as a call. Now
8069 -- that the expected type is known, Remove other interpretations
8070 -- from prefix, rewrite it as a call, and resolve again, so that
8071 -- the proper call node is generated.
8073 Get_First_Interp
(P
, I
, It
);
8074 while Present
(It
.Typ
) loop
8075 if Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
8079 Get_Next_Interp
(I
, It
);
8083 Make_Function_Call
(Loc
,
8085 Make_Explicit_Dereference
(Loc
,
8087 Parameter_Associations
=> New_List
);
8089 Save_Interps
(N
, New_N
);
8091 Analyze_And_Resolve
(N
, Typ
);
8095 -- If not overloaded, resolve P with its own type
8101 -- If the prefix might be null, add an access check
8103 if Is_Access_Type
(Etype
(P
))
8104 and then not Can_Never_Be_Null
(Etype
(P
))
8106 Apply_Access_Check
(N
);
8109 -- If the designated type is a packed unconstrained array type, and the
8110 -- explicit dereference is not in the context of an attribute reference,
8111 -- then we must compute and set the actual subtype, since it is needed
8112 -- by Gigi. The reason we exclude the attribute case is that this is
8113 -- handled fine by Gigi, and in fact we use such attributes to build the
8114 -- actual subtype. We also exclude generated code (which builds actual
8115 -- subtypes directly if they are needed).
8117 if Is_Array_Type
(Etype
(N
))
8118 and then Is_Packed
(Etype
(N
))
8119 and then not Is_Constrained
(Etype
(N
))
8120 and then Nkind
(Parent
(N
)) /= N_Attribute_Reference
8121 and then Comes_From_Source
(N
)
8123 Set_Etype
(N
, Get_Actual_Subtype
(N
));
8126 Analyze_Dimension
(N
);
8128 -- Note: No Eval processing is required for an explicit dereference,
8129 -- because such a name can never be static.
8131 end Resolve_Explicit_Dereference
;
8133 -------------------------------------
8134 -- Resolve_Expression_With_Actions --
8135 -------------------------------------
8137 procedure Resolve_Expression_With_Actions
(N
: Node_Id
; Typ
: Entity_Id
) is
8141 -- If N has no actions, and its expression has been constant folded,
8142 -- then rewrite N as just its expression. Note, we can't do this in
8143 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8144 -- Expression (N) to be expanded again.
8146 if Is_Empty_List
(Actions
(N
))
8147 and then Compile_Time_Known_Value
(Expression
(N
))
8149 Rewrite
(N
, Expression
(N
));
8151 end Resolve_Expression_With_Actions
;
8153 ----------------------------------
8154 -- Resolve_Generalized_Indexing --
8155 ----------------------------------
8157 procedure Resolve_Generalized_Indexing
(N
: Node_Id
; Typ
: Entity_Id
) is
8158 Indexing
: constant Node_Id
:= Generalized_Indexing
(N
);
8164 -- In ASIS mode, propagate the information about the indexes back to
8165 -- to the original indexing node. The generalized indexing is either
8166 -- a function call, or a dereference of one. The actuals include the
8167 -- prefix of the original node, which is the container expression.
8170 Resolve
(Indexing
, Typ
);
8171 Set_Etype
(N
, Etype
(Indexing
));
8172 Set_Is_Overloaded
(N
, False);
8175 while Nkind_In
(Call
, N_Explicit_Dereference
, N_Selected_Component
)
8177 Call
:= Prefix
(Call
);
8180 if Nkind
(Call
) = N_Function_Call
then
8181 Indexes
:= New_Copy_List
(Parameter_Associations
(Call
));
8182 Pref
:= Remove_Head
(Indexes
);
8183 Set_Expressions
(N
, Indexes
);
8185 -- If expression is to be reanalyzed, reset Generalized_Indexing
8186 -- to recreate call node, as is the case when the expression is
8187 -- part of an expression function.
8189 if In_Spec_Expression
then
8190 Set_Generalized_Indexing
(N
, Empty
);
8193 Set_Prefix
(N
, Pref
);
8197 Rewrite
(N
, Indexing
);
8200 end Resolve_Generalized_Indexing
;
8202 ---------------------------
8203 -- Resolve_If_Expression --
8204 ---------------------------
8206 procedure Resolve_If_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
8207 Condition
: constant Node_Id
:= First
(Expressions
(N
));
8208 Then_Expr
: constant Node_Id
:= Next
(Condition
);
8209 Else_Expr
: Node_Id
:= Next
(Then_Expr
);
8210 Else_Typ
: Entity_Id
;
8211 Then_Typ
: Entity_Id
;
8214 Resolve
(Condition
, Any_Boolean
);
8215 Resolve
(Then_Expr
, Typ
);
8216 Then_Typ
:= Etype
(Then_Expr
);
8218 -- When the "then" expression is of a scalar subtype different from the
8219 -- result subtype, then insert a conversion to ensure the generation of
8220 -- a constraint check. The same is done for the else part below, again
8221 -- comparing subtypes rather than base types.
8223 if Is_Scalar_Type
(Then_Typ
)
8224 and then Then_Typ
/= Typ
8226 Rewrite
(Then_Expr
, Convert_To
(Typ
, Then_Expr
));
8227 Analyze_And_Resolve
(Then_Expr
, Typ
);
8230 -- If ELSE expression present, just resolve using the determined type
8231 -- If type is universal, resolve to any member of the class.
8233 if Present
(Else_Expr
) then
8234 if Typ
= Universal_Integer
then
8235 Resolve
(Else_Expr
, Any_Integer
);
8237 elsif Typ
= Universal_Real
then
8238 Resolve
(Else_Expr
, Any_Real
);
8241 Resolve
(Else_Expr
, Typ
);
8244 Else_Typ
:= Etype
(Else_Expr
);
8246 if Is_Scalar_Type
(Else_Typ
) and then Else_Typ
/= Typ
then
8247 Rewrite
(Else_Expr
, Convert_To
(Typ
, Else_Expr
));
8248 Analyze_And_Resolve
(Else_Expr
, Typ
);
8250 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8251 -- dynamically tagged must be known statically.
8253 elsif Is_Tagged_Type
(Typ
) and then not Is_Class_Wide_Type
(Typ
) then
8254 if Is_Dynamically_Tagged
(Then_Expr
) /=
8255 Is_Dynamically_Tagged
(Else_Expr
)
8257 Error_Msg_N
("all or none of the dependent expressions "
8258 & "can be dynamically tagged", N
);
8262 -- If no ELSE expression is present, root type must be Standard.Boolean
8263 -- and we provide a Standard.True result converted to the appropriate
8264 -- Boolean type (in case it is a derived boolean type).
8266 elsif Root_Type
(Typ
) = Standard_Boolean
then
8268 Convert_To
(Typ
, New_Occurrence_Of
(Standard_True
, Sloc
(N
)));
8269 Analyze_And_Resolve
(Else_Expr
, Typ
);
8270 Append_To
(Expressions
(N
), Else_Expr
);
8273 Error_Msg_N
("can only omit ELSE expression in Boolean case", N
);
8274 Append_To
(Expressions
(N
), Error
);
8278 Eval_If_Expression
(N
);
8279 end Resolve_If_Expression
;
8281 -------------------------------
8282 -- Resolve_Indexed_Component --
8283 -------------------------------
8285 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
8286 Name
: constant Node_Id
:= Prefix
(N
);
8288 Array_Type
: Entity_Id
:= Empty
; -- to prevent junk warning
8292 if Present
(Generalized_Indexing
(N
)) then
8293 Resolve_Generalized_Indexing
(N
, Typ
);
8297 if Is_Overloaded
(Name
) then
8299 -- Use the context type to select the prefix that yields the correct
8305 I1
: Interp_Index
:= 0;
8306 P
: constant Node_Id
:= Prefix
(N
);
8307 Found
: Boolean := False;
8310 Get_First_Interp
(P
, I
, It
);
8311 while Present
(It
.Typ
) loop
8312 if (Is_Array_Type
(It
.Typ
)
8313 and then Covers
(Typ
, Component_Type
(It
.Typ
)))
8314 or else (Is_Access_Type
(It
.Typ
)
8315 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
8319 Component_Type
(Designated_Type
(It
.Typ
))))
8322 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
8324 if It
= No_Interp
then
8325 Error_Msg_N
("ambiguous prefix for indexing", N
);
8331 Array_Type
:= It
.Typ
;
8337 Array_Type
:= It
.Typ
;
8342 Get_Next_Interp
(I
, It
);
8347 Array_Type
:= Etype
(Name
);
8350 Resolve
(Name
, Array_Type
);
8351 Array_Type
:= Get_Actual_Subtype_If_Available
(Name
);
8353 -- If prefix is access type, dereference to get real array type.
8354 -- Note: we do not apply an access check because the expander always
8355 -- introduces an explicit dereference, and the check will happen there.
8357 if Is_Access_Type
(Array_Type
) then
8358 Array_Type
:= Designated_Type
(Array_Type
);
8361 -- If name was overloaded, set component type correctly now
8362 -- If a misplaced call to an entry family (which has no index types)
8363 -- return. Error will be diagnosed from calling context.
8365 if Is_Array_Type
(Array_Type
) then
8366 Set_Etype
(N
, Component_Type
(Array_Type
));
8371 Index
:= First_Index
(Array_Type
);
8372 Expr
:= First
(Expressions
(N
));
8374 -- The prefix may have resolved to a string literal, in which case its
8375 -- etype has a special representation. This is only possible currently
8376 -- if the prefix is a static concatenation, written in functional
8379 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
8380 Resolve
(Expr
, Standard_Positive
);
8383 while Present
(Index
) and Present
(Expr
) loop
8384 Resolve
(Expr
, Etype
(Index
));
8385 Check_Unset_Reference
(Expr
);
8387 if Is_Scalar_Type
(Etype
(Expr
)) then
8388 Apply_Scalar_Range_Check
(Expr
, Etype
(Index
));
8390 Apply_Range_Check
(Expr
, Get_Actual_Subtype
(Index
));
8398 Analyze_Dimension
(N
);
8400 -- Do not generate the warning on suspicious index if we are analyzing
8401 -- package Ada.Tags; otherwise we will report the warning with the
8402 -- Prims_Ptr field of the dispatch table.
8404 if Scope
(Etype
(Prefix
(N
))) = Standard_Standard
8406 Is_RTU
(Cunit_Entity
(Get_Source_Unit
(Etype
(Prefix
(N
)))),
8409 Warn_On_Suspicious_Index
(Name
, First
(Expressions
(N
)));
8410 Eval_Indexed_Component
(N
);
8413 -- If the array type is atomic, and the component is not atomic, then
8414 -- this is worth a warning, since we have a situation where the access
8415 -- to the component may cause extra read/writes of the atomic array
8416 -- object, or partial word accesses, which could be unexpected.
8418 if Nkind
(N
) = N_Indexed_Component
8419 and then Is_Atomic_Ref_With_Address
(N
)
8420 and then not (Has_Atomic_Components
(Array_Type
)
8421 or else (Is_Entity_Name
(Prefix
(N
))
8422 and then Has_Atomic_Components
8423 (Entity
(Prefix
(N
)))))
8424 and then not Is_Atomic
(Component_Type
(Array_Type
))
8427 ("??access to non-atomic component of atomic array", Prefix
(N
));
8429 ("??\may cause unexpected accesses to atomic object", Prefix
(N
));
8431 end Resolve_Indexed_Component
;
8433 -----------------------------
8434 -- Resolve_Integer_Literal --
8435 -----------------------------
8437 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
8440 Eval_Integer_Literal
(N
);
8441 end Resolve_Integer_Literal
;
8443 --------------------------------
8444 -- Resolve_Intrinsic_Operator --
8445 --------------------------------
8447 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
) is
8448 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
8453 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
;
8454 -- If the operand is a literal, it cannot be the expression in a
8455 -- conversion. Use a qualified expression instead.
8457 ---------------------
8458 -- Convert_Operand --
8459 ---------------------
8461 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
is
8462 Loc
: constant Source_Ptr
:= Sloc
(Opnd
);
8466 if Nkind_In
(Opnd
, N_Integer_Literal
, N_Real_Literal
) then
8468 Make_Qualified_Expression
(Loc
,
8469 Subtype_Mark
=> New_Occurrence_Of
(Btyp
, Loc
),
8470 Expression
=> Relocate_Node
(Opnd
));
8474 Res
:= Unchecked_Convert_To
(Btyp
, Opnd
);
8478 end Convert_Operand
;
8480 -- Start of processing for Resolve_Intrinsic_Operator
8483 -- We must preserve the original entity in a generic setting, so that
8484 -- the legality of the operation can be verified in an instance.
8486 if not Expander_Active
then
8491 while Scope
(Op
) /= Standard_Standard
loop
8493 pragma Assert
(Present
(Op
));
8497 Set_Is_Overloaded
(N
, False);
8499 -- If the result or operand types are private, rewrite with unchecked
8500 -- conversions on the operands and the result, to expose the proper
8501 -- underlying numeric type.
8503 if Is_Private_Type
(Typ
)
8504 or else Is_Private_Type
(Etype
(Left_Opnd
(N
)))
8505 or else Is_Private_Type
(Etype
(Right_Opnd
(N
)))
8507 Arg1
:= Convert_Operand
(Left_Opnd
(N
));
8509 if Nkind
(N
) = N_Op_Expon
then
8510 Arg2
:= Unchecked_Convert_To
(Standard_Integer
, Right_Opnd
(N
));
8512 Arg2
:= Convert_Operand
(Right_Opnd
(N
));
8515 if Nkind
(Arg1
) = N_Type_Conversion
then
8516 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
8519 if Nkind
(Arg2
) = N_Type_Conversion
then
8520 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8523 Set_Left_Opnd
(N
, Arg1
);
8524 Set_Right_Opnd
(N
, Arg2
);
8526 Set_Etype
(N
, Btyp
);
8527 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
8530 elsif Typ
/= Etype
(Left_Opnd
(N
))
8531 or else Typ
/= Etype
(Right_Opnd
(N
))
8533 -- Add explicit conversion where needed, and save interpretations in
8534 -- case operands are overloaded.
8536 Arg1
:= Convert_To
(Typ
, Left_Opnd
(N
));
8537 Arg2
:= Convert_To
(Typ
, Right_Opnd
(N
));
8539 if Nkind
(Arg1
) = N_Type_Conversion
then
8540 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
8542 Save_Interps
(Left_Opnd
(N
), Arg1
);
8545 if Nkind
(Arg2
) = N_Type_Conversion
then
8546 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8548 Save_Interps
(Right_Opnd
(N
), Arg2
);
8551 Rewrite
(Left_Opnd
(N
), Arg1
);
8552 Rewrite
(Right_Opnd
(N
), Arg2
);
8555 Resolve_Arithmetic_Op
(N
, Typ
);
8558 Resolve_Arithmetic_Op
(N
, Typ
);
8560 end Resolve_Intrinsic_Operator
;
8562 --------------------------------------
8563 -- Resolve_Intrinsic_Unary_Operator --
8564 --------------------------------------
8566 procedure Resolve_Intrinsic_Unary_Operator
8570 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
8576 while Scope
(Op
) /= Standard_Standard
loop
8578 pragma Assert
(Present
(Op
));
8583 if Is_Private_Type
(Typ
) then
8584 Arg2
:= Unchecked_Convert_To
(Btyp
, Right_Opnd
(N
));
8585 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8587 Set_Right_Opnd
(N
, Arg2
);
8589 Set_Etype
(N
, Btyp
);
8590 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
8594 Resolve_Unary_Op
(N
, Typ
);
8596 end Resolve_Intrinsic_Unary_Operator
;
8598 ------------------------
8599 -- Resolve_Logical_Op --
8600 ------------------------
8602 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
8606 Check_No_Direct_Boolean_Operators
(N
);
8608 -- Predefined operations on scalar types yield the base type. On the
8609 -- other hand, logical operations on arrays yield the type of the
8610 -- arguments (and the context).
8612 if Is_Array_Type
(Typ
) then
8615 B_Typ
:= Base_Type
(Typ
);
8618 -- The following test is required because the operands of the operation
8619 -- may be literals, in which case the resulting type appears to be
8620 -- compatible with a signed integer type, when in fact it is compatible
8621 -- only with modular types. If the context itself is universal, the
8622 -- operation is illegal.
8624 if not Valid_Boolean_Arg
(Typ
) then
8625 Error_Msg_N
("invalid context for logical operation", N
);
8626 Set_Etype
(N
, Any_Type
);
8629 elsif Typ
= Any_Modular
then
8631 ("no modular type available in this context", N
);
8632 Set_Etype
(N
, Any_Type
);
8635 elsif Is_Modular_Integer_Type
(Typ
)
8636 and then Etype
(Left_Opnd
(N
)) = Universal_Integer
8637 and then Etype
(Right_Opnd
(N
)) = Universal_Integer
8639 Check_For_Visible_Operator
(N
, B_Typ
);
8642 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8643 -- is active and the result type is standard Boolean (do not mess with
8644 -- ops that return a nonstandard Boolean type, because something strange
8647 -- Note: you might expect this replacement to be done during expansion,
8648 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8649 -- is used, no part of the right operand of an "and" or "or" operator
8650 -- should be executed if the left operand would short-circuit the
8651 -- evaluation of the corresponding "and then" or "or else". If we left
8652 -- the replacement to expansion time, then run-time checks associated
8653 -- with such operands would be evaluated unconditionally, due to being
8654 -- before the condition prior to the rewriting as short-circuit forms
8655 -- during expansion.
8657 if Short_Circuit_And_Or
8658 and then B_Typ
= Standard_Boolean
8659 and then Nkind_In
(N
, N_Op_And
, N_Op_Or
)
8661 -- Mark the corresponding putative SCO operator as truly a logical
8662 -- (and short-circuit) operator.
8664 if Generate_SCO
and then Comes_From_Source
(N
) then
8665 Set_SCO_Logical_Operator
(N
);
8668 if Nkind
(N
) = N_Op_And
then
8670 Make_And_Then
(Sloc
(N
),
8671 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
8672 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
8673 Analyze_And_Resolve
(N
, B_Typ
);
8675 -- Case of OR changed to OR ELSE
8679 Make_Or_Else
(Sloc
(N
),
8680 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
8681 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
8682 Analyze_And_Resolve
(N
, B_Typ
);
8685 -- Return now, since analysis of the rewritten ops will take care of
8686 -- other reference bookkeeping and expression folding.
8691 Resolve
(Left_Opnd
(N
), B_Typ
);
8692 Resolve
(Right_Opnd
(N
), B_Typ
);
8694 Check_Unset_Reference
(Left_Opnd
(N
));
8695 Check_Unset_Reference
(Right_Opnd
(N
));
8697 Set_Etype
(N
, B_Typ
);
8698 Generate_Operator_Reference
(N
, B_Typ
);
8699 Eval_Logical_Op
(N
);
8701 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8702 -- only when both operands have same static lower and higher bounds. Of
8703 -- course the types have to match, so only check if operands are
8704 -- compatible and the node itself has no errors.
8706 if Is_Array_Type
(B_Typ
)
8707 and then Nkind
(N
) in N_Binary_Op
8710 Left_Typ
: constant Node_Id
:= Etype
(Left_Opnd
(N
));
8711 Right_Typ
: constant Node_Id
:= Etype
(Right_Opnd
(N
));
8714 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8715 -- operation if not needed.
8717 if Restriction_Check_Required
(SPARK_05
)
8718 and then Base_Type
(Left_Typ
) = Base_Type
(Right_Typ
)
8719 and then Left_Typ
/= Any_Composite
-- or Left_Opnd in error
8720 and then Right_Typ
/= Any_Composite
-- or Right_Opnd in error
8721 and then not Matching_Static_Array_Bounds
(Left_Typ
, Right_Typ
)
8723 Check_SPARK_05_Restriction
8724 ("array types should have matching static bounds", N
);
8728 end Resolve_Logical_Op
;
8730 ---------------------------
8731 -- Resolve_Membership_Op --
8732 ---------------------------
8734 -- The context can only be a boolean type, and does not determine the
8735 -- arguments. Arguments should be unambiguous, but the preference rule for
8736 -- universal types applies.
8738 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
8739 pragma Warnings
(Off
, Typ
);
8741 L
: constant Node_Id
:= Left_Opnd
(N
);
8742 R
: constant Node_Id
:= Right_Opnd
(N
);
8745 procedure Resolve_Set_Membership
;
8746 -- Analysis has determined a unique type for the left operand. Use it to
8747 -- resolve the disjuncts.
8749 ----------------------------
8750 -- Resolve_Set_Membership --
8751 ----------------------------
8753 procedure Resolve_Set_Membership
is
8758 -- If the left operand is overloaded, find type compatible with not
8759 -- overloaded alternative of the right operand.
8761 if Is_Overloaded
(L
) then
8763 Alt
:= First
(Alternatives
(N
));
8764 while Present
(Alt
) loop
8765 if not Is_Overloaded
(Alt
) then
8766 Ltyp
:= Intersect_Types
(L
, Alt
);
8773 -- Unclear how to resolve expression if all alternatives are also
8777 Error_Msg_N
("ambiguous expression", N
);
8786 Alt
:= First
(Alternatives
(N
));
8787 while Present
(Alt
) loop
8789 -- Alternative is an expression, a range
8790 -- or a subtype mark.
8792 if not Is_Entity_Name
(Alt
)
8793 or else not Is_Type
(Entity
(Alt
))
8795 Resolve
(Alt
, Ltyp
);
8801 -- Check for duplicates for discrete case
8803 if Is_Discrete_Type
(Ltyp
) then
8810 Alts
: array (0 .. List_Length
(Alternatives
(N
))) of Ent
;
8814 -- Loop checking duplicates. This is quadratic, but giant sets
8815 -- are unlikely in this context so it's a reasonable choice.
8818 Alt
:= First
(Alternatives
(N
));
8819 while Present
(Alt
) loop
8820 if Is_OK_Static_Expression
(Alt
)
8821 and then (Nkind_In
(Alt
, N_Integer_Literal
,
8822 N_Character_Literal
)
8823 or else Nkind
(Alt
) in N_Has_Entity
)
8826 Alts
(Nalts
) := (Alt
, Expr_Value
(Alt
));
8828 for J
in 1 .. Nalts
- 1 loop
8829 if Alts
(J
).Val
= Alts
(Nalts
).Val
then
8830 Error_Msg_Sloc
:= Sloc
(Alts
(J
).Alt
);
8831 Error_Msg_N
("duplicate of value given#??", Alt
);
8840 end Resolve_Set_Membership
;
8842 -- Start of processing for Resolve_Membership_Op
8845 if L
= Error
or else R
= Error
then
8849 if Present
(Alternatives
(N
)) then
8850 Resolve_Set_Membership
;
8853 elsif not Is_Overloaded
(R
)
8855 (Etype
(R
) = Universal_Integer
8857 Etype
(R
) = Universal_Real
)
8858 and then Is_Overloaded
(L
)
8862 -- Ada 2005 (AI-251): Support the following case:
8864 -- type I is interface;
8865 -- type T is tagged ...
8867 -- function Test (O : I'Class) is
8869 -- return O in T'Class.
8872 -- In this case we have nothing else to do. The membership test will be
8873 -- done at run time.
8875 elsif Ada_Version
>= Ada_2005
8876 and then Is_Class_Wide_Type
(Etype
(L
))
8877 and then Is_Interface
(Etype
(L
))
8878 and then Is_Class_Wide_Type
(Etype
(R
))
8879 and then not Is_Interface
(Etype
(R
))
8883 T
:= Intersect_Types
(L
, R
);
8886 -- If mixed-mode operations are present and operands are all literal,
8887 -- the only interpretation involves Duration, which is probably not
8888 -- the intention of the programmer.
8890 if T
= Any_Fixed
then
8891 T
:= Unique_Fixed_Point_Type
(N
);
8893 if T
= Any_Type
then
8899 Check_Unset_Reference
(L
);
8901 if Nkind
(R
) = N_Range
8902 and then not Is_Scalar_Type
(T
)
8904 Error_Msg_N
("scalar type required for range", R
);
8907 if Is_Entity_Name
(R
) then
8908 Freeze_Expression
(R
);
8911 Check_Unset_Reference
(R
);
8914 -- Here after resolving membership operation
8918 Eval_Membership_Op
(N
);
8919 end Resolve_Membership_Op
;
8925 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
) is
8926 Loc
: constant Source_Ptr
:= Sloc
(N
);
8929 -- Handle restriction against anonymous null access values This
8930 -- restriction can be turned off using -gnatdj.
8932 -- Ada 2005 (AI-231): Remove restriction
8934 if Ada_Version
< Ada_2005
8935 and then not Debug_Flag_J
8936 and then Ekind
(Typ
) = E_Anonymous_Access_Type
8937 and then Comes_From_Source
(N
)
8939 -- In the common case of a call which uses an explicitly null value
8940 -- for an access parameter, give specialized error message.
8942 if Nkind
(Parent
(N
)) in N_Subprogram_Call
then
8944 ("null is not allowed as argument for an access parameter", N
);
8946 -- Standard message for all other cases (are there any?)
8950 ("null cannot be of an anonymous access type", N
);
8954 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
8955 -- assignment to a null-excluding object
8957 if Ada_Version
>= Ada_2005
8958 and then Can_Never_Be_Null
(Typ
)
8959 and then Nkind
(Parent
(N
)) = N_Assignment_Statement
8961 if not Inside_Init_Proc
then
8963 (Compile_Time_Constraint_Error
(N
,
8964 "(Ada 2005) null not allowed in null-excluding objects??"),
8965 Make_Raise_Constraint_Error
(Loc
,
8966 Reason
=> CE_Access_Check_Failed
));
8969 Make_Raise_Constraint_Error
(Loc
,
8970 Reason
=> CE_Access_Check_Failed
));
8974 -- In a distributed context, null for a remote access to subprogram may
8975 -- need to be replaced with a special record aggregate. In this case,
8976 -- return after having done the transformation.
8978 if (Ekind
(Typ
) = E_Record_Type
8979 or else Is_Remote_Access_To_Subprogram_Type
(Typ
))
8980 and then Remote_AST_Null_Value
(N
, Typ
)
8985 -- The null literal takes its type from the context
8990 -----------------------
8991 -- Resolve_Op_Concat --
8992 -----------------------
8994 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
) is
8996 -- We wish to avoid deep recursion, because concatenations are often
8997 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
8998 -- operands nonrecursively until we find something that is not a simple
8999 -- concatenation (A in this case). We resolve that, and then walk back
9000 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
9001 -- to do the rest of the work at each level. The Parent pointers allow
9002 -- us to avoid recursion, and thus avoid running out of memory. See also
9003 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
9009 -- The following code is equivalent to:
9011 -- Resolve_Op_Concat_First (NN, Typ);
9012 -- Resolve_Op_Concat_Arg (N, ...);
9013 -- Resolve_Op_Concat_Rest (N, Typ);
9015 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
9016 -- operand is a concatenation.
9018 -- Walk down left operands
9021 Resolve_Op_Concat_First
(NN
, Typ
);
9022 Op1
:= Left_Opnd
(NN
);
9023 exit when not (Nkind
(Op1
) = N_Op_Concat
9024 and then not Is_Array_Type
(Component_Type
(Typ
))
9025 and then Entity
(Op1
) = Entity
(NN
));
9029 -- Now (given the above example) NN is A&B and Op1 is A
9031 -- First resolve Op1 ...
9033 Resolve_Op_Concat_Arg
(NN
, Op1
, Typ
, Is_Component_Left_Opnd
(NN
));
9035 -- ... then walk NN back up until we reach N (where we started), calling
9036 -- Resolve_Op_Concat_Rest along the way.
9039 Resolve_Op_Concat_Rest
(NN
, Typ
);
9044 if Base_Type
(Etype
(N
)) /= Standard_String
then
9045 Check_SPARK_05_Restriction
9046 ("result of concatenation should have type String", N
);
9048 end Resolve_Op_Concat
;
9050 ---------------------------
9051 -- Resolve_Op_Concat_Arg --
9052 ---------------------------
9054 procedure Resolve_Op_Concat_Arg
9060 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
9061 Ctyp
: constant Entity_Id
:= Component_Type
(Typ
);
9066 or else (not Is_Overloaded
(Arg
)
9067 and then Etype
(Arg
) /= Any_Composite
9068 and then Covers
(Ctyp
, Etype
(Arg
)))
9070 Resolve
(Arg
, Ctyp
);
9072 Resolve
(Arg
, Btyp
);
9075 -- If both Array & Array and Array & Component are visible, there is a
9076 -- potential ambiguity that must be reported.
9078 elsif Has_Compatible_Type
(Arg
, Ctyp
) then
9079 if Nkind
(Arg
) = N_Aggregate
9080 and then Is_Composite_Type
(Ctyp
)
9082 if Is_Private_Type
(Ctyp
) then
9083 Resolve
(Arg
, Btyp
);
9085 -- If the operation is user-defined and not overloaded use its
9086 -- profile. The operation may be a renaming, in which case it has
9087 -- been rewritten, and we want the original profile.
9089 elsif not Is_Overloaded
(N
)
9090 and then Comes_From_Source
(Entity
(Original_Node
(N
)))
9091 and then Ekind
(Entity
(Original_Node
(N
))) = E_Function
9095 (Next_Formal
(First_Formal
(Entity
(Original_Node
(N
))))));
9098 -- Otherwise an aggregate may match both the array type and the
9102 Error_Msg_N
("ambiguous aggregate must be qualified", Arg
);
9103 Set_Etype
(Arg
, Any_Type
);
9107 if Is_Overloaded
(Arg
)
9108 and then Has_Compatible_Type
(Arg
, Typ
)
9109 and then Etype
(Arg
) /= Any_Type
9117 Get_First_Interp
(Arg
, I
, It
);
9119 Get_Next_Interp
(I
, It
);
9121 -- Special-case the error message when the overloading is
9122 -- caused by a function that yields an array and can be
9123 -- called without parameters.
9125 if It
.Nam
= Func
then
9126 Error_Msg_Sloc
:= Sloc
(Func
);
9127 Error_Msg_N
("ambiguous call to function#", Arg
);
9129 ("\\interpretation as call yields&", Arg
, Typ
);
9131 ("\\interpretation as indexing of call yields&",
9132 Arg
, Component_Type
(Typ
));
9135 Error_Msg_N
("ambiguous operand for concatenation!", Arg
);
9137 Get_First_Interp
(Arg
, I
, It
);
9138 while Present
(It
.Nam
) loop
9139 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
9141 if Base_Type
(It
.Typ
) = Btyp
9143 Base_Type
(It
.Typ
) = Base_Type
(Ctyp
)
9145 Error_Msg_N
-- CODEFIX
9146 ("\\possible interpretation#", Arg
);
9149 Get_Next_Interp
(I
, It
);
9155 Resolve
(Arg
, Component_Type
(Typ
));
9157 if Nkind
(Arg
) = N_String_Literal
then
9158 Set_Etype
(Arg
, Component_Type
(Typ
));
9161 if Arg
= Left_Opnd
(N
) then
9162 Set_Is_Component_Left_Opnd
(N
);
9164 Set_Is_Component_Right_Opnd
(N
);
9169 Resolve
(Arg
, Btyp
);
9172 -- Concatenation is restricted in SPARK: each operand must be either a
9173 -- string literal, the name of a string constant, a static character or
9174 -- string expression, or another concatenation. Arg cannot be a
9175 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9176 -- separately on each final operand, past concatenation operations.
9178 if Is_Character_Type
(Etype
(Arg
)) then
9179 if not Is_OK_Static_Expression
(Arg
) then
9180 Check_SPARK_05_Restriction
9181 ("character operand for concatenation should be static", Arg
);
9184 elsif Is_String_Type
(Etype
(Arg
)) then
9185 if not (Nkind_In
(Arg
, N_Identifier
, N_Expanded_Name
)
9186 and then Is_Constant_Object
(Entity
(Arg
)))
9187 and then not Is_OK_Static_Expression
(Arg
)
9189 Check_SPARK_05_Restriction
9190 ("string operand for concatenation should be static", Arg
);
9193 -- Do not issue error on an operand that is neither a character nor a
9194 -- string, as the error is issued in Resolve_Op_Concat.
9200 Check_Unset_Reference
(Arg
);
9201 end Resolve_Op_Concat_Arg
;
9203 -----------------------------
9204 -- Resolve_Op_Concat_First --
9205 -----------------------------
9207 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
) is
9208 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
9209 Op1
: constant Node_Id
:= Left_Opnd
(N
);
9210 Op2
: constant Node_Id
:= Right_Opnd
(N
);
9213 -- The parser folds an enormous sequence of concatenations of string
9214 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9215 -- in the right operand. If the expression resolves to a predefined "&"
9216 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9217 -- we give an error. See P_Simple_Expression in Par.Ch4.
9219 if Nkind
(Op2
) = N_String_Literal
9220 and then Is_Folded_In_Parser
(Op2
)
9221 and then Ekind
(Entity
(N
)) = E_Function
9223 pragma Assert
(Nkind
(Op1
) = N_String_Literal
-- should be ""
9224 and then String_Length
(Strval
(Op1
)) = 0);
9225 Error_Msg_N
("too many user-defined concatenations", N
);
9229 Set_Etype
(N
, Btyp
);
9231 if Is_Limited_Composite
(Btyp
) then
9232 Error_Msg_N
("concatenation not available for limited array", N
);
9233 Explain_Limited_Type
(Btyp
, N
);
9235 end Resolve_Op_Concat_First
;
9237 ----------------------------
9238 -- Resolve_Op_Concat_Rest --
9239 ----------------------------
9241 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
) is
9242 Op1
: constant Node_Id
:= Left_Opnd
(N
);
9243 Op2
: constant Node_Id
:= Right_Opnd
(N
);
9246 Resolve_Op_Concat_Arg
(N
, Op2
, Typ
, Is_Component_Right_Opnd
(N
));
9248 Generate_Operator_Reference
(N
, Typ
);
9250 if Is_String_Type
(Typ
) then
9251 Eval_Concatenation
(N
);
9254 -- If this is not a static concatenation, but the result is a string
9255 -- type (and not an array of strings) ensure that static string operands
9256 -- have their subtypes properly constructed.
9258 if Nkind
(N
) /= N_String_Literal
9259 and then Is_Character_Type
(Component_Type
(Typ
))
9261 Set_String_Literal_Subtype
(Op1
, Typ
);
9262 Set_String_Literal_Subtype
(Op2
, Typ
);
9264 end Resolve_Op_Concat_Rest
;
9266 ----------------------
9267 -- Resolve_Op_Expon --
9268 ----------------------
9270 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
) is
9271 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
9274 -- Catch attempts to do fixed-point exponentiation with universal
9275 -- operands, which is a case where the illegality is not caught during
9276 -- normal operator analysis. This is not done in preanalysis mode
9277 -- since the tree is not fully decorated during preanalysis.
9279 if Full_Analysis
then
9280 if Is_Fixed_Point_Type
(Typ
) and then Comes_From_Source
(N
) then
9281 Error_Msg_N
("exponentiation not available for fixed point", N
);
9284 elsif Nkind
(Parent
(N
)) in N_Op
9285 and then Is_Fixed_Point_Type
(Etype
(Parent
(N
)))
9286 and then Etype
(N
) = Universal_Real
9287 and then Comes_From_Source
(N
)
9289 Error_Msg_N
("exponentiation not available for fixed point", N
);
9294 if Comes_From_Source
(N
)
9295 and then Ekind
(Entity
(N
)) = E_Function
9296 and then Is_Imported
(Entity
(N
))
9297 and then Is_Intrinsic_Subprogram
(Entity
(N
))
9299 Resolve_Intrinsic_Operator
(N
, Typ
);
9303 if Etype
(Left_Opnd
(N
)) = Universal_Integer
9304 or else Etype
(Left_Opnd
(N
)) = Universal_Real
9306 Check_For_Visible_Operator
(N
, B_Typ
);
9309 -- We do the resolution using the base type, because intermediate values
9310 -- in expressions are always of the base type, not a subtype of it.
9312 Resolve
(Left_Opnd
(N
), B_Typ
);
9313 Resolve
(Right_Opnd
(N
), Standard_Integer
);
9315 -- For integer types, right argument must be in Natural range
9317 if Is_Integer_Type
(Typ
) then
9318 Apply_Scalar_Range_Check
(Right_Opnd
(N
), Standard_Natural
);
9321 Check_Unset_Reference
(Left_Opnd
(N
));
9322 Check_Unset_Reference
(Right_Opnd
(N
));
9324 Set_Etype
(N
, B_Typ
);
9325 Generate_Operator_Reference
(N
, B_Typ
);
9327 Analyze_Dimension
(N
);
9329 if Ada_Version
>= Ada_2012
and then Has_Dimension_System
(B_Typ
) then
9330 -- Evaluate the exponentiation operator for dimensioned type
9332 Eval_Op_Expon_For_Dimensioned_Type
(N
, B_Typ
);
9337 -- Set overflow checking bit. Much cleverer code needed here eventually
9338 -- and perhaps the Resolve routines should be separated for the various
9339 -- arithmetic operations, since they will need different processing. ???
9341 if Nkind
(N
) in N_Op
then
9342 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
9343 Enable_Overflow_Check
(N
);
9346 end Resolve_Op_Expon
;
9348 --------------------
9349 -- Resolve_Op_Not --
9350 --------------------
9352 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
) is
9355 function Parent_Is_Boolean
return Boolean;
9356 -- This function determines if the parent node is a boolean operator or
9357 -- operation (comparison op, membership test, or short circuit form) and
9358 -- the not in question is the left operand of this operation. Note that
9359 -- if the not is in parens, then false is returned.
9361 -----------------------
9362 -- Parent_Is_Boolean --
9363 -----------------------
9365 function Parent_Is_Boolean
return Boolean is
9367 if Paren_Count
(N
) /= 0 then
9371 case Nkind
(Parent
(N
)) is
9386 return Left_Opnd
(Parent
(N
)) = N
;
9392 end Parent_Is_Boolean
;
9394 -- Start of processing for Resolve_Op_Not
9397 -- Predefined operations on scalar types yield the base type. On the
9398 -- other hand, logical operations on arrays yield the type of the
9399 -- arguments (and the context).
9401 if Is_Array_Type
(Typ
) then
9404 B_Typ
:= Base_Type
(Typ
);
9407 -- Straightforward case of incorrect arguments
9409 if not Valid_Boolean_Arg
(Typ
) then
9410 Error_Msg_N
("invalid operand type for operator&", N
);
9411 Set_Etype
(N
, Any_Type
);
9414 -- Special case of probable missing parens
9416 elsif Typ
= Universal_Integer
or else Typ
= Any_Modular
then
9417 if Parent_Is_Boolean
then
9419 ("operand of not must be enclosed in parentheses",
9423 ("no modular type available in this context", N
);
9426 Set_Etype
(N
, Any_Type
);
9429 -- OK resolution of NOT
9432 -- Warn if non-boolean types involved. This is a case like not a < b
9433 -- where a and b are modular, where we will get (not a) < b and most
9434 -- likely not (a < b) was intended.
9436 if Warn_On_Questionable_Missing_Parens
9437 and then not Is_Boolean_Type
(Typ
)
9438 and then Parent_Is_Boolean
9440 Error_Msg_N
("?q?not expression should be parenthesized here!", N
);
9443 -- Warn on double negation if checking redundant constructs
9445 if Warn_On_Redundant_Constructs
9446 and then Comes_From_Source
(N
)
9447 and then Comes_From_Source
(Right_Opnd
(N
))
9448 and then Root_Type
(Typ
) = Standard_Boolean
9449 and then Nkind
(Right_Opnd
(N
)) = N_Op_Not
9451 Error_Msg_N
("redundant double negation?r?", N
);
9454 -- Complete resolution and evaluation of NOT
9456 Resolve
(Right_Opnd
(N
), B_Typ
);
9457 Check_Unset_Reference
(Right_Opnd
(N
));
9458 Set_Etype
(N
, B_Typ
);
9459 Generate_Operator_Reference
(N
, B_Typ
);
9464 -----------------------------
9465 -- Resolve_Operator_Symbol --
9466 -----------------------------
9468 -- Nothing to be done, all resolved already
9470 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
) is
9471 pragma Warnings
(Off
, N
);
9472 pragma Warnings
(Off
, Typ
);
9476 end Resolve_Operator_Symbol
;
9478 ----------------------------------
9479 -- Resolve_Qualified_Expression --
9480 ----------------------------------
9482 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
9483 pragma Warnings
(Off
, Typ
);
9485 Target_Typ
: constant Entity_Id
:= Entity
(Subtype_Mark
(N
));
9486 Expr
: constant Node_Id
:= Expression
(N
);
9489 Resolve
(Expr
, Target_Typ
);
9491 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9492 -- operation if not needed.
9494 if Restriction_Check_Required
(SPARK_05
)
9495 and then Is_Array_Type
(Target_Typ
)
9496 and then Is_Array_Type
(Etype
(Expr
))
9497 and then Etype
(Expr
) /= Any_Composite
-- or else Expr in error
9498 and then not Matching_Static_Array_Bounds
(Target_Typ
, Etype
(Expr
))
9500 Check_SPARK_05_Restriction
9501 ("array types should have matching static bounds", N
);
9504 -- A qualified expression requires an exact match of the type, class-
9505 -- wide matching is not allowed. However, if the qualifying type is
9506 -- specific and the expression has a class-wide type, it may still be
9507 -- okay, since it can be the result of the expansion of a call to a
9508 -- dispatching function, so we also have to check class-wideness of the
9509 -- type of the expression's original node.
9511 if (Is_Class_Wide_Type
(Target_Typ
)
9513 (Is_Class_Wide_Type
(Etype
(Expr
))
9514 and then Is_Class_Wide_Type
(Etype
(Original_Node
(Expr
)))))
9515 and then Base_Type
(Etype
(Expr
)) /= Base_Type
(Target_Typ
)
9517 Wrong_Type
(Expr
, Target_Typ
);
9520 -- If the target type is unconstrained, then we reset the type of the
9521 -- result from the type of the expression. For other cases, the actual
9522 -- subtype of the expression is the target type.
9524 if Is_Composite_Type
(Target_Typ
)
9525 and then not Is_Constrained
(Target_Typ
)
9527 Set_Etype
(N
, Etype
(Expr
));
9530 Analyze_Dimension
(N
);
9531 Eval_Qualified_Expression
(N
);
9533 -- If we still have a qualified expression after the static evaluation,
9534 -- then apply a scalar range check if needed. The reason that we do this
9535 -- after the Eval call is that otherwise, the application of the range
9536 -- check may convert an illegal static expression and result in warning
9537 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9539 if Nkind
(N
) = N_Qualified_Expression
and then Is_Scalar_Type
(Typ
) then
9540 Apply_Scalar_Range_Check
(Expr
, Typ
);
9543 -- Finally, check whether a predicate applies to the target type. This
9544 -- comes from AI12-0100. As for type conversions, check the enclosing
9545 -- context to prevent an infinite expansion.
9547 if Has_Predicates
(Target_Typ
) then
9548 if Nkind
(Parent
(N
)) = N_Function_Call
9549 and then Present
(Name
(Parent
(N
)))
9550 and then (Is_Predicate_Function
(Entity
(Name
(Parent
(N
))))
9552 Is_Predicate_Function_M
(Entity
(Name
(Parent
(N
)))))
9556 -- In the case of a qualified expression in an allocator, the check
9557 -- is applied when expanding the allocator, so avoid redundant check.
9559 elsif Nkind
(N
) = N_Qualified_Expression
9560 and then Nkind
(Parent
(N
)) /= N_Allocator
9562 Apply_Predicate_Check
(N
, Target_Typ
);
9565 end Resolve_Qualified_Expression
;
9567 ------------------------------
9568 -- Resolve_Raise_Expression --
9569 ------------------------------
9571 procedure Resolve_Raise_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
9573 if Typ
= Raise_Type
then
9574 Error_Msg_N
("cannot find unique type for raise expression", N
);
9575 Set_Etype
(N
, Any_Type
);
9579 end Resolve_Raise_Expression
;
9585 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
) is
9586 L
: constant Node_Id
:= Low_Bound
(N
);
9587 H
: constant Node_Id
:= High_Bound
(N
);
9589 function First_Last_Ref
return Boolean;
9590 -- Returns True if N is of the form X'First .. X'Last where X is the
9591 -- same entity for both attributes.
9593 --------------------
9594 -- First_Last_Ref --
9595 --------------------
9597 function First_Last_Ref
return Boolean is
9598 Lorig
: constant Node_Id
:= Original_Node
(L
);
9599 Horig
: constant Node_Id
:= Original_Node
(H
);
9602 if Nkind
(Lorig
) = N_Attribute_Reference
9603 and then Nkind
(Horig
) = N_Attribute_Reference
9604 and then Attribute_Name
(Lorig
) = Name_First
9605 and then Attribute_Name
(Horig
) = Name_Last
9608 PL
: constant Node_Id
:= Prefix
(Lorig
);
9609 PH
: constant Node_Id
:= Prefix
(Horig
);
9611 if Is_Entity_Name
(PL
)
9612 and then Is_Entity_Name
(PH
)
9613 and then Entity
(PL
) = Entity
(PH
)
9623 -- Start of processing for Resolve_Range
9628 -- The lower bound should be in Typ. The higher bound can be in Typ's
9629 -- base type if the range is null. It may still be invalid if it is
9630 -- higher than the lower bound. This is checked later in the context in
9631 -- which the range appears.
9634 Resolve
(H
, Base_Type
(Typ
));
9636 -- Check for inappropriate range on unordered enumeration type
9638 if Bad_Unordered_Enumeration_Reference
(N
, Typ
)
9640 -- Exclude X'First .. X'Last if X is the same entity for both
9642 and then not First_Last_Ref
9644 Error_Msg_Sloc
:= Sloc
(Typ
);
9646 ("subrange of unordered enumeration type& declared#?U?", N
, Typ
);
9649 Check_Unset_Reference
(L
);
9650 Check_Unset_Reference
(H
);
9652 -- We have to check the bounds for being within the base range as
9653 -- required for a non-static context. Normally this is automatic and
9654 -- done as part of evaluating expressions, but the N_Range node is an
9655 -- exception, since in GNAT we consider this node to be a subexpression,
9656 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9657 -- this, but that would put the test on the main evaluation path for
9660 Check_Non_Static_Context
(L
);
9661 Check_Non_Static_Context
(H
);
9663 -- Check for an ambiguous range over character literals. This will
9664 -- happen with a membership test involving only literals.
9666 if Typ
= Any_Character
then
9667 Ambiguous_Character
(L
);
9668 Set_Etype
(N
, Any_Type
);
9672 -- If bounds are static, constant-fold them, so size computations are
9673 -- identical between front-end and back-end. Do not perform this
9674 -- transformation while analyzing generic units, as type information
9675 -- would be lost when reanalyzing the constant node in the instance.
9677 if Is_Discrete_Type
(Typ
) and then Expander_Active
then
9678 if Is_OK_Static_Expression
(L
) then
9679 Fold_Uint
(L
, Expr_Value
(L
), Is_OK_Static_Expression
(L
));
9682 if Is_OK_Static_Expression
(H
) then
9683 Fold_Uint
(H
, Expr_Value
(H
), Is_OK_Static_Expression
(H
));
9688 --------------------------
9689 -- Resolve_Real_Literal --
9690 --------------------------
9692 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
9693 Actual_Typ
: constant Entity_Id
:= Etype
(N
);
9696 -- Special processing for fixed-point literals to make sure that the
9697 -- value is an exact multiple of small where this is required. We skip
9698 -- this for the universal real case, and also for generic types.
9700 if Is_Fixed_Point_Type
(Typ
)
9701 and then Typ
/= Universal_Fixed
9702 and then Typ
/= Any_Fixed
9703 and then not Is_Generic_Type
(Typ
)
9706 Val
: constant Ureal
:= Realval
(N
);
9707 Cintr
: constant Ureal
:= Val
/ Small_Value
(Typ
);
9708 Cint
: constant Uint
:= UR_Trunc
(Cintr
);
9709 Den
: constant Uint
:= Norm_Den
(Cintr
);
9713 -- Case of literal is not an exact multiple of the Small
9717 -- For a source program literal for a decimal fixed-point type,
9718 -- this is statically illegal (RM 4.9(36)).
9720 if Is_Decimal_Fixed_Point_Type
(Typ
)
9721 and then Actual_Typ
= Universal_Real
9722 and then Comes_From_Source
(N
)
9724 Error_Msg_N
("value has extraneous low order digits", N
);
9727 -- Generate a warning if literal from source
9729 if Is_OK_Static_Expression
(N
)
9730 and then Warn_On_Bad_Fixed_Value
9733 ("?b?static fixed-point value is not a multiple of Small!",
9737 -- Replace literal by a value that is the exact representation
9738 -- of a value of the type, i.e. a multiple of the small value,
9739 -- by truncation, since Machine_Rounds is false for all GNAT
9740 -- fixed-point types (RM 4.9(38)).
9742 Stat
:= Is_OK_Static_Expression
(N
);
9744 Make_Real_Literal
(Sloc
(N
),
9745 Realval
=> Small_Value
(Typ
) * Cint
));
9747 Set_Is_Static_Expression
(N
, Stat
);
9750 -- In all cases, set the corresponding integer field
9752 Set_Corresponding_Integer_Value
(N
, Cint
);
9756 -- Now replace the actual type by the expected type as usual
9759 Eval_Real_Literal
(N
);
9760 end Resolve_Real_Literal
;
9762 -----------------------
9763 -- Resolve_Reference --
9764 -----------------------
9766 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
) is
9767 P
: constant Node_Id
:= Prefix
(N
);
9770 -- Replace general access with specific type
9772 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
9773 Set_Etype
(N
, Base_Type
(Typ
));
9776 Resolve
(P
, Designated_Type
(Etype
(N
)));
9778 -- If we are taking the reference of a volatile entity, then treat it as
9779 -- a potential modification of this entity. This is too conservative,
9780 -- but necessary because remove side effects can cause transformations
9781 -- of normal assignments into reference sequences that otherwise fail to
9782 -- notice the modification.
9784 if Is_Entity_Name
(P
) and then Treat_As_Volatile
(Entity
(P
)) then
9785 Note_Possible_Modification
(P
, Sure
=> False);
9787 end Resolve_Reference
;
9789 --------------------------------
9790 -- Resolve_Selected_Component --
9791 --------------------------------
9793 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
9795 Comp1
: Entity_Id
:= Empty
; -- prevent junk warning
9796 P
: constant Node_Id
:= Prefix
(N
);
9797 S
: constant Node_Id
:= Selector_Name
(N
);
9798 T
: Entity_Id
:= Etype
(P
);
9800 I1
: Interp_Index
:= 0; -- prevent junk warning
9805 function Init_Component
return Boolean;
9806 -- Check whether this is the initialization of a component within an
9807 -- init proc (by assignment or call to another init proc). If true,
9808 -- there is no need for a discriminant check.
9810 --------------------
9811 -- Init_Component --
9812 --------------------
9814 function Init_Component
return Boolean is
9816 return Inside_Init_Proc
9817 and then Nkind
(Prefix
(N
)) = N_Identifier
9818 and then Chars
(Prefix
(N
)) = Name_uInit
9819 and then Nkind
(Parent
(Parent
(N
))) = N_Case_Statement_Alternative
;
9822 -- Start of processing for Resolve_Selected_Component
9825 if Is_Overloaded
(P
) then
9827 -- Use the context type to select the prefix that has a selector
9828 -- of the correct name and type.
9831 Get_First_Interp
(P
, I
, It
);
9833 Search
: while Present
(It
.Typ
) loop
9834 if Is_Access_Type
(It
.Typ
) then
9835 T
:= Designated_Type
(It
.Typ
);
9840 -- Locate selected component. For a private prefix the selector
9841 -- can denote a discriminant.
9843 if Is_Record_Type
(T
) or else Is_Private_Type
(T
) then
9845 -- The visible components of a class-wide type are those of
9848 if Is_Class_Wide_Type
(T
) then
9852 Comp
:= First_Entity
(T
);
9853 while Present
(Comp
) loop
9854 if Chars
(Comp
) = Chars
(S
)
9855 and then Covers
(Typ
, Etype
(Comp
))
9864 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
9866 if It
= No_Interp
then
9868 ("ambiguous prefix for selected component", N
);
9875 -- There may be an implicit dereference. Retrieve
9876 -- designated record type.
9878 if Is_Access_Type
(It1
.Typ
) then
9879 T
:= Designated_Type
(It1
.Typ
);
9884 if Scope
(Comp1
) /= T
then
9886 -- Resolution chooses the new interpretation.
9887 -- Find the component with the right name.
9889 Comp1
:= First_Entity
(T
);
9890 while Present
(Comp1
)
9891 and then Chars
(Comp1
) /= Chars
(S
)
9893 Comp1
:= Next_Entity
(Comp1
);
9902 Comp
:= Next_Entity
(Comp
);
9906 Get_Next_Interp
(I
, It
);
9909 -- There must be a legal interpretation at this point
9911 pragma Assert
(Found
);
9912 Resolve
(P
, It1
.Typ
);
9914 Set_Entity_With_Checks
(S
, Comp1
);
9917 -- Resolve prefix with its type
9922 -- Generate cross-reference. We needed to wait until full overloading
9923 -- resolution was complete to do this, since otherwise we can't tell if
9924 -- we are an lvalue or not.
9926 if May_Be_Lvalue
(N
) then
9927 Generate_Reference
(Entity
(S
), S
, 'm');
9929 Generate_Reference
(Entity
(S
), S
, 'r');
9932 -- If prefix is an access type, the node will be transformed into an
9933 -- explicit dereference during expansion. The type of the node is the
9934 -- designated type of that of the prefix.
9936 if Is_Access_Type
(Etype
(P
)) then
9937 T
:= Designated_Type
(Etype
(P
));
9938 Check_Fully_Declared_Prefix
(T
, P
);
9943 -- Set flag for expander if discriminant check required on a component
9944 -- appearing within a variant.
9946 if Has_Discriminants
(T
)
9947 and then Ekind
(Entity
(S
)) = E_Component
9948 and then Present
(Original_Record_Component
(Entity
(S
)))
9949 and then Ekind
(Original_Record_Component
(Entity
(S
))) = E_Component
9951 Is_Declared_Within_Variant
(Original_Record_Component
(Entity
(S
)))
9952 and then not Discriminant_Checks_Suppressed
(T
)
9953 and then not Init_Component
9955 Set_Do_Discriminant_Check
(N
);
9958 if Ekind
(Entity
(S
)) = E_Void
then
9959 Error_Msg_N
("premature use of component", S
);
9962 -- If the prefix is a record conversion, this may be a renamed
9963 -- discriminant whose bounds differ from those of the original
9964 -- one, so we must ensure that a range check is performed.
9966 if Nkind
(P
) = N_Type_Conversion
9967 and then Ekind
(Entity
(S
)) = E_Discriminant
9968 and then Is_Discrete_Type
(Typ
)
9970 Set_Etype
(N
, Base_Type
(Typ
));
9973 -- Note: No Eval processing is required, because the prefix is of a
9974 -- record type, or protected type, and neither can possibly be static.
9976 -- If the record type is atomic, and the component is non-atomic, then
9977 -- this is worth a warning, since we have a situation where the access
9978 -- to the component may cause extra read/writes of the atomic array
9979 -- object, or partial word accesses, both of which may be unexpected.
9981 if Nkind
(N
) = N_Selected_Component
9982 and then Is_Atomic_Ref_With_Address
(N
)
9983 and then not Is_Atomic
(Entity
(S
))
9984 and then not Is_Atomic
(Etype
(Entity
(S
)))
9987 ("??access to non-atomic component of atomic record",
9990 ("\??may cause unexpected accesses to atomic object",
9994 Analyze_Dimension
(N
);
9995 end Resolve_Selected_Component
;
10001 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
) is
10002 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
10003 L
: constant Node_Id
:= Left_Opnd
(N
);
10004 R
: constant Node_Id
:= Right_Opnd
(N
);
10007 -- We do the resolution using the base type, because intermediate values
10008 -- in expressions always are of the base type, not a subtype of it.
10010 Resolve
(L
, B_Typ
);
10011 Resolve
(R
, Standard_Natural
);
10013 Check_Unset_Reference
(L
);
10014 Check_Unset_Reference
(R
);
10016 Set_Etype
(N
, B_Typ
);
10017 Generate_Operator_Reference
(N
, B_Typ
);
10021 ---------------------------
10022 -- Resolve_Short_Circuit --
10023 ---------------------------
10025 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
) is
10026 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
10027 L
: constant Node_Id
:= Left_Opnd
(N
);
10028 R
: constant Node_Id
:= Right_Opnd
(N
);
10031 -- Ensure all actions associated with the left operand (e.g.
10032 -- finalization of transient objects) are fully evaluated locally within
10033 -- an expression with actions. This is particularly helpful for coverage
10034 -- analysis. However this should not happen in generics or if option
10035 -- Minimize_Expression_With_Actions is set.
10037 if Expander_Active
and not Minimize_Expression_With_Actions
then
10039 Reloc_L
: constant Node_Id
:= Relocate_Node
(L
);
10041 Save_Interps
(Old_N
=> L
, New_N
=> Reloc_L
);
10044 Make_Expression_With_Actions
(Sloc
(L
),
10045 Actions
=> New_List
,
10046 Expression
=> Reloc_L
));
10048 -- Set Comes_From_Source on L to preserve warnings for unset
10051 Set_Comes_From_Source
(L
, Comes_From_Source
(Reloc_L
));
10055 Resolve
(L
, B_Typ
);
10056 Resolve
(R
, B_Typ
);
10058 -- Check for issuing warning for always False assert/check, this happens
10059 -- when assertions are turned off, in which case the pragma Assert/Check
10060 -- was transformed into:
10062 -- if False and then <condition> then ...
10064 -- and we detect this pattern
10066 if Warn_On_Assertion_Failure
10067 and then Is_Entity_Name
(R
)
10068 and then Entity
(R
) = Standard_False
10069 and then Nkind
(Parent
(N
)) = N_If_Statement
10070 and then Nkind
(N
) = N_And_Then
10071 and then Is_Entity_Name
(L
)
10072 and then Entity
(L
) = Standard_False
10075 Orig
: constant Node_Id
:= Original_Node
(Parent
(N
));
10078 -- Special handling of Asssert pragma
10080 if Nkind
(Orig
) = N_Pragma
10081 and then Pragma_Name
(Orig
) = Name_Assert
10084 Expr
: constant Node_Id
:=
10087 (First
(Pragma_Argument_Associations
(Orig
))));
10090 -- Don't warn if original condition is explicit False,
10091 -- since obviously the failure is expected in this case.
10093 if Is_Entity_Name
(Expr
)
10094 and then Entity
(Expr
) = Standard_False
10098 -- Issue warning. We do not want the deletion of the
10099 -- IF/AND-THEN to take this message with it. We achieve this
10100 -- by making sure that the expanded code points to the Sloc
10101 -- of the expression, not the original pragma.
10104 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
10105 -- The source location of the expression is not usually
10106 -- the best choice here. For example, it gets located on
10107 -- the last AND keyword in a chain of boolean expressiond
10108 -- AND'ed together. It is best to put the message on the
10109 -- first character of the assertion, which is the effect
10110 -- of the First_Node call here.
10113 ("?A?assertion would fail at run time!",
10115 (First
(Pragma_Argument_Associations
(Orig
))));
10119 -- Similar processing for Check pragma
10121 elsif Nkind
(Orig
) = N_Pragma
10122 and then Pragma_Name
(Orig
) = Name_Check
10124 -- Don't want to warn if original condition is explicit False
10127 Expr
: constant Node_Id
:=
10130 (Next
(First
(Pragma_Argument_Associations
(Orig
)))));
10132 if Is_Entity_Name
(Expr
)
10133 and then Entity
(Expr
) = Standard_False
10140 -- Again use Error_Msg_F rather than Error_Msg_N, see
10141 -- comment above for an explanation of why we do this.
10144 ("?A?check would fail at run time!",
10146 (Last
(Pragma_Argument_Associations
(Orig
))));
10153 -- Continue with processing of short circuit
10155 Check_Unset_Reference
(L
);
10156 Check_Unset_Reference
(R
);
10158 Set_Etype
(N
, B_Typ
);
10159 Eval_Short_Circuit
(N
);
10160 end Resolve_Short_Circuit
;
10162 -------------------
10163 -- Resolve_Slice --
10164 -------------------
10166 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
) is
10167 Drange
: constant Node_Id
:= Discrete_Range
(N
);
10168 Name
: constant Node_Id
:= Prefix
(N
);
10169 Array_Type
: Entity_Id
:= Empty
;
10170 Dexpr
: Node_Id
:= Empty
;
10171 Index_Type
: Entity_Id
;
10174 if Is_Overloaded
(Name
) then
10176 -- Use the context type to select the prefix that yields the correct
10181 I1
: Interp_Index
:= 0;
10183 P
: constant Node_Id
:= Prefix
(N
);
10184 Found
: Boolean := False;
10187 Get_First_Interp
(P
, I
, It
);
10188 while Present
(It
.Typ
) loop
10189 if (Is_Array_Type
(It
.Typ
)
10190 and then Covers
(Typ
, It
.Typ
))
10191 or else (Is_Access_Type
(It
.Typ
)
10192 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
10193 and then Covers
(Typ
, Designated_Type
(It
.Typ
)))
10196 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
10198 if It
= No_Interp
then
10199 Error_Msg_N
("ambiguous prefix for slicing", N
);
10200 Set_Etype
(N
, Typ
);
10204 Array_Type
:= It
.Typ
;
10209 Array_Type
:= It
.Typ
;
10214 Get_Next_Interp
(I
, It
);
10219 Array_Type
:= Etype
(Name
);
10222 Resolve
(Name
, Array_Type
);
10224 if Is_Access_Type
(Array_Type
) then
10225 Apply_Access_Check
(N
);
10226 Array_Type
:= Designated_Type
(Array_Type
);
10228 -- If the prefix is an access to an unconstrained array, we must use
10229 -- the actual subtype of the object to perform the index checks. The
10230 -- object denoted by the prefix is implicit in the node, so we build
10231 -- an explicit representation for it in order to compute the actual
10234 if not Is_Constrained
(Array_Type
) then
10235 Remove_Side_Effects
(Prefix
(N
));
10238 Obj
: constant Node_Id
:=
10239 Make_Explicit_Dereference
(Sloc
(N
),
10240 Prefix
=> New_Copy_Tree
(Prefix
(N
)));
10242 Set_Etype
(Obj
, Array_Type
);
10243 Set_Parent
(Obj
, Parent
(N
));
10244 Array_Type
:= Get_Actual_Subtype
(Obj
);
10248 elsif Is_Entity_Name
(Name
)
10249 or else Nkind
(Name
) = N_Explicit_Dereference
10250 or else (Nkind
(Name
) = N_Function_Call
10251 and then not Is_Constrained
(Etype
(Name
)))
10253 Array_Type
:= Get_Actual_Subtype
(Name
);
10255 -- If the name is a selected component that depends on discriminants,
10256 -- build an actual subtype for it. This can happen only when the name
10257 -- itself is overloaded; otherwise the actual subtype is created when
10258 -- the selected component is analyzed.
10260 elsif Nkind
(Name
) = N_Selected_Component
10261 and then Full_Analysis
10262 and then Depends_On_Discriminant
(First_Index
(Array_Type
))
10265 Act_Decl
: constant Node_Id
:=
10266 Build_Actual_Subtype_Of_Component
(Array_Type
, Name
);
10268 Insert_Action
(N
, Act_Decl
);
10269 Array_Type
:= Defining_Identifier
(Act_Decl
);
10272 -- Maybe this should just be "else", instead of checking for the
10273 -- specific case of slice??? This is needed for the case where the
10274 -- prefix is an Image attribute, which gets expanded to a slice, and so
10275 -- has a constrained subtype which we want to use for the slice range
10276 -- check applied below (the range check won't get done if the
10277 -- unconstrained subtype of the 'Image is used).
10279 elsif Nkind
(Name
) = N_Slice
then
10280 Array_Type
:= Etype
(Name
);
10283 -- Obtain the type of the array index
10285 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
10286 Index_Type
:= Etype
(String_Literal_Low_Bound
(Array_Type
));
10288 Index_Type
:= Etype
(First_Index
(Array_Type
));
10291 -- If name was overloaded, set slice type correctly now
10293 Set_Etype
(N
, Array_Type
);
10295 -- Handle the generation of a range check that compares the array index
10296 -- against the discrete_range. The check is not applied to internally
10297 -- built nodes associated with the expansion of dispatch tables. Check
10298 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10301 if Tagged_Type_Expansion
10302 and then RTU_Loaded
(Ada_Tags
)
10303 and then Nkind
(Prefix
(N
)) = N_Selected_Component
10304 and then Present
(Entity
(Selector_Name
(Prefix
(N
))))
10305 and then Entity
(Selector_Name
(Prefix
(N
))) =
10306 RTE_Record_Component
(RE_Prims_Ptr
)
10310 -- The discrete_range is specified by a subtype indication. Create a
10311 -- shallow copy and inherit the type, parent and source location from
10312 -- the discrete_range. This ensures that the range check is inserted
10313 -- relative to the slice and that the runtime exception points to the
10314 -- proper construct.
10316 elsif Is_Entity_Name
(Drange
) then
10317 Dexpr
:= New_Copy
(Scalar_Range
(Entity
(Drange
)));
10319 Set_Etype
(Dexpr
, Etype
(Drange
));
10320 Set_Parent
(Dexpr
, Parent
(Drange
));
10321 Set_Sloc
(Dexpr
, Sloc
(Drange
));
10323 -- The discrete_range is a regular range. Resolve the bounds and remove
10324 -- their side effects.
10327 Resolve
(Drange
, Base_Type
(Index_Type
));
10329 if Nkind
(Drange
) = N_Range
then
10330 Force_Evaluation
(Low_Bound
(Drange
));
10331 Force_Evaluation
(High_Bound
(Drange
));
10337 if Present
(Dexpr
) then
10338 Apply_Range_Check
(Dexpr
, Index_Type
);
10341 Set_Slice_Subtype
(N
);
10343 -- Check bad use of type with predicates
10349 if Nkind
(Drange
) = N_Subtype_Indication
10350 and then Has_Predicates
(Entity
(Subtype_Mark
(Drange
)))
10352 Subt
:= Entity
(Subtype_Mark
(Drange
));
10354 Subt
:= Etype
(Drange
);
10357 if Has_Predicates
(Subt
) then
10358 Bad_Predicated_Subtype_Use
10359 ("subtype& has predicate, not allowed in slice", Drange
, Subt
);
10363 -- Otherwise here is where we check suspicious indexes
10365 if Nkind
(Drange
) = N_Range
then
10366 Warn_On_Suspicious_Index
(Name
, Low_Bound
(Drange
));
10367 Warn_On_Suspicious_Index
(Name
, High_Bound
(Drange
));
10370 Analyze_Dimension
(N
);
10374 ----------------------------
10375 -- Resolve_String_Literal --
10376 ----------------------------
10378 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
10379 C_Typ
: constant Entity_Id
:= Component_Type
(Typ
);
10380 R_Typ
: constant Entity_Id
:= Root_Type
(C_Typ
);
10381 Loc
: constant Source_Ptr
:= Sloc
(N
);
10382 Str
: constant String_Id
:= Strval
(N
);
10383 Strlen
: constant Nat
:= String_Length
(Str
);
10384 Subtype_Id
: Entity_Id
;
10385 Need_Check
: Boolean;
10388 -- For a string appearing in a concatenation, defer creation of the
10389 -- string_literal_subtype until the end of the resolution of the
10390 -- concatenation, because the literal may be constant-folded away. This
10391 -- is a useful optimization for long concatenation expressions.
10393 -- If the string is an aggregate built for a single character (which
10394 -- happens in a non-static context) or a is null string to which special
10395 -- checks may apply, we build the subtype. Wide strings must also get a
10396 -- string subtype if they come from a one character aggregate. Strings
10397 -- generated by attributes might be static, but it is often hard to
10398 -- determine whether the enclosing context is static, so we generate
10399 -- subtypes for them as well, thus losing some rarer optimizations ???
10400 -- Same for strings that come from a static conversion.
10403 (Strlen
= 0 and then Typ
/= Standard_String
)
10404 or else Nkind
(Parent
(N
)) /= N_Op_Concat
10405 or else (N
/= Left_Opnd
(Parent
(N
))
10406 and then N
/= Right_Opnd
(Parent
(N
)))
10407 or else ((Typ
= Standard_Wide_String
10408 or else Typ
= Standard_Wide_Wide_String
)
10409 and then Nkind
(Original_Node
(N
)) /= N_String_Literal
);
10411 -- If the resolving type is itself a string literal subtype, we can just
10412 -- reuse it, since there is no point in creating another.
10414 if Ekind
(Typ
) = E_String_Literal_Subtype
then
10417 elsif Nkind
(Parent
(N
)) = N_Op_Concat
10418 and then not Need_Check
10419 and then not Nkind_In
(Original_Node
(N
), N_Character_Literal
,
10420 N_Attribute_Reference
,
10421 N_Qualified_Expression
,
10426 -- Do not generate a string literal subtype for the default expression
10427 -- of a formal parameter in GNATprove mode. This is because the string
10428 -- subtype is associated with the freezing actions of the subprogram,
10429 -- however freezing is disabled in GNATprove mode and as a result the
10430 -- subtype is unavailable.
10432 elsif GNATprove_Mode
10433 and then Nkind
(Parent
(N
)) = N_Parameter_Specification
10437 -- Otherwise we must create a string literal subtype. Note that the
10438 -- whole idea of string literal subtypes is simply to avoid the need
10439 -- for building a full fledged array subtype for each literal.
10442 Set_String_Literal_Subtype
(N
, Typ
);
10443 Subtype_Id
:= Etype
(N
);
10446 if Nkind
(Parent
(N
)) /= N_Op_Concat
10449 Set_Etype
(N
, Subtype_Id
);
10450 Eval_String_Literal
(N
);
10453 if Is_Limited_Composite
(Typ
)
10454 or else Is_Private_Composite
(Typ
)
10456 Error_Msg_N
("string literal not available for private array", N
);
10457 Set_Etype
(N
, Any_Type
);
10461 -- The validity of a null string has been checked in the call to
10462 -- Eval_String_Literal.
10467 -- Always accept string literal with component type Any_Character, which
10468 -- occurs in error situations and in comparisons of literals, both of
10469 -- which should accept all literals.
10471 elsif R_Typ
= Any_Character
then
10474 -- If the type is bit-packed, then we always transform the string
10475 -- literal into a full fledged aggregate.
10477 elsif Is_Bit_Packed_Array
(Typ
) then
10480 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10483 -- For Standard.Wide_Wide_String, or any other type whose component
10484 -- type is Standard.Wide_Wide_Character, we know that all the
10485 -- characters in the string must be acceptable, since the parser
10486 -- accepted the characters as valid character literals.
10488 if R_Typ
= Standard_Wide_Wide_Character
then
10491 -- For the case of Standard.String, or any other type whose component
10492 -- type is Standard.Character, we must make sure that there are no
10493 -- wide characters in the string, i.e. that it is entirely composed
10494 -- of characters in range of type Character.
10496 -- If the string literal is the result of a static concatenation, the
10497 -- test has already been performed on the components, and need not be
10500 elsif R_Typ
= Standard_Character
10501 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
10503 for J
in 1 .. Strlen
loop
10504 if not In_Character_Range
(Get_String_Char
(Str
, J
)) then
10506 -- If we are out of range, post error. This is one of the
10507 -- very few places that we place the flag in the middle of
10508 -- a token, right under the offending wide character. Not
10509 -- quite clear if this is right wrt wide character encoding
10510 -- sequences, but it's only an error message.
10513 ("literal out of range of type Standard.Character",
10514 Source_Ptr
(Int
(Loc
) + J
));
10519 -- For the case of Standard.Wide_String, or any other type whose
10520 -- component type is Standard.Wide_Character, we must make sure that
10521 -- there are no wide characters in the string, i.e. that it is
10522 -- entirely composed of characters in range of type Wide_Character.
10524 -- If the string literal is the result of a static concatenation,
10525 -- the test has already been performed on the components, and need
10526 -- not be repeated.
10528 elsif R_Typ
= Standard_Wide_Character
10529 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
10531 for J
in 1 .. Strlen
loop
10532 if not In_Wide_Character_Range
(Get_String_Char
(Str
, J
)) then
10534 -- If we are out of range, post error. This is one of the
10535 -- very few places that we place the flag in the middle of
10536 -- a token, right under the offending wide character.
10538 -- This is not quite right, because characters in general
10539 -- will take more than one character position ???
10542 ("literal out of range of type Standard.Wide_Character",
10543 Source_Ptr
(Int
(Loc
) + J
));
10548 -- If the root type is not a standard character, then we will convert
10549 -- the string into an aggregate and will let the aggregate code do
10550 -- the checking. Standard Wide_Wide_Character is also OK here.
10556 -- See if the component type of the array corresponding to the string
10557 -- has compile time known bounds. If yes we can directly check
10558 -- whether the evaluation of the string will raise constraint error.
10559 -- Otherwise we need to transform the string literal into the
10560 -- corresponding character aggregate and let the aggregate code do
10563 if Is_Standard_Character_Type
(R_Typ
) then
10565 -- Check for the case of full range, where we are definitely OK
10567 if Component_Type
(Typ
) = Base_Type
(Component_Type
(Typ
)) then
10571 -- Here the range is not the complete base type range, so check
10574 Comp_Typ_Lo
: constant Node_Id
:=
10575 Type_Low_Bound
(Component_Type
(Typ
));
10576 Comp_Typ_Hi
: constant Node_Id
:=
10577 Type_High_Bound
(Component_Type
(Typ
));
10582 if Compile_Time_Known_Value
(Comp_Typ_Lo
)
10583 and then Compile_Time_Known_Value
(Comp_Typ_Hi
)
10585 for J
in 1 .. Strlen
loop
10586 Char_Val
:= UI_From_Int
(Int
(Get_String_Char
(Str
, J
)));
10588 if Char_Val
< Expr_Value
(Comp_Typ_Lo
)
10589 or else Char_Val
> Expr_Value
(Comp_Typ_Hi
)
10591 Apply_Compile_Time_Constraint_Error
10592 (N
, "character out of range??",
10593 CE_Range_Check_Failed
,
10594 Loc
=> Source_Ptr
(Int
(Loc
) + J
));
10604 -- If we got here we meed to transform the string literal into the
10605 -- equivalent qualified positional array aggregate. This is rather
10606 -- heavy artillery for this situation, but it is hard work to avoid.
10609 Lits
: constant List_Id
:= New_List
;
10610 P
: Source_Ptr
:= Loc
+ 1;
10614 -- Build the character literals, we give them source locations that
10615 -- correspond to the string positions, which is a bit tricky given
10616 -- the possible presence of wide character escape sequences.
10618 for J
in 1 .. Strlen
loop
10619 C
:= Get_String_Char
(Str
, J
);
10620 Set_Character_Literal_Name
(C
);
10623 Make_Character_Literal
(P
,
10624 Chars
=> Name_Find
,
10625 Char_Literal_Value
=> UI_From_CC
(C
)));
10627 if In_Character_Range
(C
) then
10630 -- Should we have a call to Skip_Wide here ???
10639 Make_Qualified_Expression
(Loc
,
10640 Subtype_Mark
=> New_Occurrence_Of
(Typ
, Loc
),
10642 Make_Aggregate
(Loc
, Expressions
=> Lits
)));
10644 Analyze_And_Resolve
(N
, Typ
);
10646 end Resolve_String_Literal
;
10648 -------------------------
10649 -- Resolve_Target_Name --
10650 -------------------------
10652 procedure Resolve_Target_Name
(N
: Node_Id
; Typ
: Entity_Id
) is
10654 Set_Etype
(N
, Typ
);
10655 end Resolve_Target_Name
;
10657 -----------------------------
10658 -- Resolve_Type_Conversion --
10659 -----------------------------
10661 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
) is
10662 Conv_OK
: constant Boolean := Conversion_OK
(N
);
10663 Operand
: constant Node_Id
:= Expression
(N
);
10664 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
10665 Target_Typ
: constant Entity_Id
:= Etype
(N
);
10670 Test_Redundant
: Boolean := Warn_On_Redundant_Constructs
;
10671 -- Set to False to suppress cases where we want to suppress the test
10672 -- for redundancy to avoid possible false positives on this warning.
10676 and then not Valid_Conversion
(N
, Target_Typ
, Operand
)
10681 -- If the Operand Etype is Universal_Fixed, then the conversion is
10682 -- never redundant. We need this check because by the time we have
10683 -- finished the rather complex transformation, the conversion looks
10684 -- redundant when it is not.
10686 if Operand_Typ
= Universal_Fixed
then
10687 Test_Redundant
:= False;
10689 -- If the operand is marked as Any_Fixed, then special processing is
10690 -- required. This is also a case where we suppress the test for a
10691 -- redundant conversion, since most certainly it is not redundant.
10693 elsif Operand_Typ
= Any_Fixed
then
10694 Test_Redundant
:= False;
10696 -- Mixed-mode operation involving a literal. Context must be a fixed
10697 -- type which is applied to the literal subsequently.
10699 if Is_Fixed_Point_Type
(Typ
) then
10700 Set_Etype
(Operand
, Universal_Real
);
10702 elsif Is_Numeric_Type
(Typ
)
10703 and then Nkind_In
(Operand
, N_Op_Multiply
, N_Op_Divide
)
10704 and then (Etype
(Right_Opnd
(Operand
)) = Universal_Real
10706 Etype
(Left_Opnd
(Operand
)) = Universal_Real
)
10708 -- Return if expression is ambiguous
10710 if Unique_Fixed_Point_Type
(N
) = Any_Type
then
10713 -- If nothing else, the available fixed type is Duration
10716 Set_Etype
(Operand
, Standard_Duration
);
10719 -- Resolve the real operand with largest available precision
10721 if Etype
(Right_Opnd
(Operand
)) = Universal_Real
then
10722 Rop
:= New_Copy_Tree
(Right_Opnd
(Operand
));
10724 Rop
:= New_Copy_Tree
(Left_Opnd
(Operand
));
10727 Resolve
(Rop
, Universal_Real
);
10729 -- If the operand is a literal (it could be a non-static and
10730 -- illegal exponentiation) check whether the use of Duration
10731 -- is potentially inaccurate.
10733 if Nkind
(Rop
) = N_Real_Literal
10734 and then Realval
(Rop
) /= Ureal_0
10735 and then abs (Realval
(Rop
)) < Delta_Value
(Standard_Duration
)
10738 ("??universal real operand can only "
10739 & "be interpreted as Duration!", Rop
);
10741 ("\??precision will be lost in the conversion!", Rop
);
10744 elsif Is_Numeric_Type
(Typ
)
10745 and then Nkind
(Operand
) in N_Op
10746 and then Unique_Fixed_Point_Type
(N
) /= Any_Type
10748 Set_Etype
(Operand
, Standard_Duration
);
10751 Error_Msg_N
("invalid context for mixed mode operation", N
);
10752 Set_Etype
(Operand
, Any_Type
);
10759 -- In SPARK, a type conversion between array types should be restricted
10760 -- to types which have matching static bounds.
10762 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10763 -- operation if not needed.
10765 if Restriction_Check_Required
(SPARK_05
)
10766 and then Is_Array_Type
(Target_Typ
)
10767 and then Is_Array_Type
(Operand_Typ
)
10768 and then Operand_Typ
/= Any_Composite
-- or else Operand in error
10769 and then not Matching_Static_Array_Bounds
(Target_Typ
, Operand_Typ
)
10771 Check_SPARK_05_Restriction
10772 ("array types should have matching static bounds", N
);
10775 -- In formal mode, the operand of an ancestor type conversion must be an
10776 -- object (not an expression).
10778 if Is_Tagged_Type
(Target_Typ
)
10779 and then not Is_Class_Wide_Type
(Target_Typ
)
10780 and then Is_Tagged_Type
(Operand_Typ
)
10781 and then not Is_Class_Wide_Type
(Operand_Typ
)
10782 and then Is_Ancestor
(Target_Typ
, Operand_Typ
)
10783 and then not Is_SPARK_05_Object_Reference
(Operand
)
10785 Check_SPARK_05_Restriction
("object required", Operand
);
10788 Analyze_Dimension
(N
);
10790 -- Note: we do the Eval_Type_Conversion call before applying the
10791 -- required checks for a subtype conversion. This is important, since
10792 -- both are prepared under certain circumstances to change the type
10793 -- conversion to a constraint error node, but in the case of
10794 -- Eval_Type_Conversion this may reflect an illegality in the static
10795 -- case, and we would miss the illegality (getting only a warning
10796 -- message), if we applied the type conversion checks first.
10798 Eval_Type_Conversion
(N
);
10800 -- Even when evaluation is not possible, we may be able to simplify the
10801 -- conversion or its expression. This needs to be done before applying
10802 -- checks, since otherwise the checks may use the original expression
10803 -- and defeat the simplifications. This is specifically the case for
10804 -- elimination of the floating-point Truncation attribute in
10805 -- float-to-int conversions.
10807 Simplify_Type_Conversion
(N
);
10809 -- If after evaluation we still have a type conversion, then we may need
10810 -- to apply checks required for a subtype conversion.
10812 -- Skip these type conversion checks if universal fixed operands
10813 -- operands involved, since range checks are handled separately for
10814 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10816 if Nkind
(N
) = N_Type_Conversion
10817 and then not Is_Generic_Type
(Root_Type
(Target_Typ
))
10818 and then Target_Typ
/= Universal_Fixed
10819 and then Operand_Typ
/= Universal_Fixed
10821 Apply_Type_Conversion_Checks
(N
);
10824 -- Issue warning for conversion of simple object to its own type. We
10825 -- have to test the original nodes, since they may have been rewritten
10826 -- by various optimizations.
10828 Orig_N
:= Original_Node
(N
);
10830 -- Here we test for a redundant conversion if the warning mode is
10831 -- active (and was not locally reset), and we have a type conversion
10832 -- from source not appearing in a generic instance.
10835 and then Nkind
(Orig_N
) = N_Type_Conversion
10836 and then Comes_From_Source
(Orig_N
)
10837 and then not In_Instance
10839 Orig_N
:= Original_Node
(Expression
(Orig_N
));
10840 Orig_T
:= Target_Typ
;
10842 -- If the node is part of a larger expression, the Target_Type
10843 -- may not be the original type of the node if the context is a
10844 -- condition. Recover original type to see if conversion is needed.
10846 if Is_Boolean_Type
(Orig_T
)
10847 and then Nkind
(Parent
(N
)) in N_Op
10849 Orig_T
:= Etype
(Parent
(N
));
10852 -- If we have an entity name, then give the warning if the entity
10853 -- is the right type, or if it is a loop parameter covered by the
10854 -- original type (that's needed because loop parameters have an
10855 -- odd subtype coming from the bounds).
10857 if (Is_Entity_Name
(Orig_N
)
10859 (Etype
(Entity
(Orig_N
)) = Orig_T
10861 (Ekind
(Entity
(Orig_N
)) = E_Loop_Parameter
10862 and then Covers
(Orig_T
, Etype
(Entity
(Orig_N
))))))
10864 -- If not an entity, then type of expression must match
10866 or else Etype
(Orig_N
) = Orig_T
10868 -- One more check, do not give warning if the analyzed conversion
10869 -- has an expression with non-static bounds, and the bounds of the
10870 -- target are static. This avoids junk warnings in cases where the
10871 -- conversion is necessary to establish staticness, for example in
10872 -- a case statement.
10874 if not Is_OK_Static_Subtype
(Operand_Typ
)
10875 and then Is_OK_Static_Subtype
(Target_Typ
)
10879 -- Finally, if this type conversion occurs in a context requiring
10880 -- a prefix, and the expression is a qualified expression then the
10881 -- type conversion is not redundant, since a qualified expression
10882 -- is not a prefix, whereas a type conversion is. For example, "X
10883 -- := T'(Funx(...)).Y;" is illegal because a selected component
10884 -- requires a prefix, but a type conversion makes it legal: "X :=
10885 -- T(T'(Funx(...))).Y;"
10887 -- In Ada 2012, a qualified expression is a name, so this idiom is
10888 -- no longer needed, but we still suppress the warning because it
10889 -- seems unfriendly for warnings to pop up when you switch to the
10890 -- newer language version.
10892 elsif Nkind
(Orig_N
) = N_Qualified_Expression
10893 and then Nkind_In
(Parent
(N
), N_Attribute_Reference
,
10894 N_Indexed_Component
,
10895 N_Selected_Component
,
10897 N_Explicit_Dereference
)
10901 -- Never warn on conversion to Long_Long_Integer'Base since
10902 -- that is most likely an artifact of the extended overflow
10903 -- checking and comes from complex expanded code.
10905 elsif Orig_T
= Base_Type
(Standard_Long_Long_Integer
) then
10908 -- Here we give the redundant conversion warning. If it is an
10909 -- entity, give the name of the entity in the message. If not,
10910 -- just mention the expression.
10912 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
10915 if Is_Entity_Name
(Orig_N
) then
10916 Error_Msg_Node_2
:= Orig_T
;
10917 Error_Msg_NE
-- CODEFIX
10918 ("??redundant conversion, & is of type &!",
10919 N
, Entity
(Orig_N
));
10922 ("??redundant conversion, expression is of type&!",
10929 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
10930 -- No need to perform any interface conversion if the type of the
10931 -- expression coincides with the target type.
10933 if Ada_Version
>= Ada_2005
10934 and then Expander_Active
10935 and then Operand_Typ
/= Target_Typ
10938 Opnd
: Entity_Id
:= Operand_Typ
;
10939 Target
: Entity_Id
:= Target_Typ
;
10942 -- If the type of the operand is a limited view, use nonlimited
10943 -- view when available. If it is a class-wide type, recover the
10944 -- class-wide type of the nonlimited view.
10946 if From_Limited_With
(Opnd
)
10947 and then Has_Non_Limited_View
(Opnd
)
10949 Opnd
:= Non_Limited_View
(Opnd
);
10950 Set_Etype
(Expression
(N
), Opnd
);
10953 if Is_Access_Type
(Opnd
) then
10954 Opnd
:= Designated_Type
(Opnd
);
10957 if Is_Access_Type
(Target_Typ
) then
10958 Target
:= Designated_Type
(Target
);
10961 if Opnd
= Target
then
10964 -- Conversion from interface type
10966 elsif Is_Interface
(Opnd
) then
10968 -- Ada 2005 (AI-217): Handle entities from limited views
10970 if From_Limited_With
(Opnd
) then
10971 Error_Msg_Qual_Level
:= 99;
10972 Error_Msg_NE
-- CODEFIX
10973 ("missing WITH clause on package &", N
,
10974 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Opnd
))));
10976 ("type conversions require visibility of the full view",
10979 elsif From_Limited_With
(Target
)
10981 (Is_Access_Type
(Target_Typ
)
10982 and then Present
(Non_Limited_View
(Etype
(Target
))))
10984 Error_Msg_Qual_Level
:= 99;
10985 Error_Msg_NE
-- CODEFIX
10986 ("missing WITH clause on package &", N
,
10987 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Target
))));
10989 ("type conversions require visibility of the full view",
10993 Expand_Interface_Conversion
(N
);
10996 -- Conversion to interface type
10998 elsif Is_Interface
(Target
) then
11002 if Ekind_In
(Opnd
, E_Protected_Subtype
, E_Task_Subtype
) then
11003 Opnd
:= Etype
(Opnd
);
11006 if Is_Class_Wide_Type
(Opnd
)
11007 or else Interface_Present_In_Ancestor
11011 Expand_Interface_Conversion
(N
);
11013 Error_Msg_Name_1
:= Chars
(Etype
(Target
));
11014 Error_Msg_Name_2
:= Chars
(Opnd
);
11016 ("wrong interface conversion (% is not a progenitor "
11023 -- Ada 2012: if target type has predicates, the result requires a
11024 -- predicate check. If the context is a call to another predicate
11025 -- check we must prevent infinite recursion.
11027 if Has_Predicates
(Target_Typ
) then
11028 if Nkind
(Parent
(N
)) = N_Function_Call
11029 and then Present
(Name
(Parent
(N
)))
11030 and then (Is_Predicate_Function
(Entity
(Name
(Parent
(N
))))
11032 Is_Predicate_Function_M
(Entity
(Name
(Parent
(N
)))))
11037 Apply_Predicate_Check
(N
, Target_Typ
);
11041 -- If at this stage we have a real to integer conversion, make sure
11042 -- that the Do_Range_Check flag is set, because such conversions in
11043 -- general need a range check. We only need this if expansion is off
11044 -- or we are in GNATProve mode.
11046 if Nkind
(N
) = N_Type_Conversion
11047 and then (GNATprove_Mode
or not Expander_Active
)
11048 and then Is_Integer_Type
(Target_Typ
)
11049 and then Is_Real_Type
(Operand_Typ
)
11051 Set_Do_Range_Check
(Operand
);
11054 -- Generating C code a type conversion of an access to constrained
11055 -- array type to access to unconstrained array type involves building
11056 -- a fat pointer which in general cannot be generated on the fly. We
11057 -- remove side effects in order to store the result of the conversion
11058 -- into a temporary.
11060 if Modify_Tree_For_C
11061 and then Nkind
(N
) = N_Type_Conversion
11062 and then Nkind
(Parent
(N
)) /= N_Object_Declaration
11063 and then Is_Access_Type
(Etype
(N
))
11064 and then Is_Array_Type
(Designated_Type
(Etype
(N
)))
11065 and then not Is_Constrained
(Designated_Type
(Etype
(N
)))
11066 and then Is_Constrained
(Designated_Type
(Etype
(Expression
(N
))))
11068 Remove_Side_Effects
(N
);
11070 end Resolve_Type_Conversion
;
11072 ----------------------
11073 -- Resolve_Unary_Op --
11074 ----------------------
11076 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
11077 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
11078 R
: constant Node_Id
:= Right_Opnd
(N
);
11084 if Is_Modular_Integer_Type
(Typ
) and then Nkind
(N
) /= N_Op_Not
then
11085 Error_Msg_Name_1
:= Chars
(Typ
);
11086 Check_SPARK_05_Restriction
11087 ("unary operator not defined for modular type%", N
);
11090 -- Deal with intrinsic unary operators
11092 if Comes_From_Source
(N
)
11093 and then Ekind
(Entity
(N
)) = E_Function
11094 and then Is_Imported
(Entity
(N
))
11095 and then Is_Intrinsic_Subprogram
(Entity
(N
))
11097 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
11101 -- Deal with universal cases
11103 if Etype
(R
) = Universal_Integer
11105 Etype
(R
) = Universal_Real
11107 Check_For_Visible_Operator
(N
, B_Typ
);
11110 Set_Etype
(N
, B_Typ
);
11111 Resolve
(R
, B_Typ
);
11113 -- Generate warning for expressions like abs (x mod 2)
11115 if Warn_On_Redundant_Constructs
11116 and then Nkind
(N
) = N_Op_Abs
11118 Determine_Range
(Right_Opnd
(N
), OK
, Lo
, Hi
);
11120 if OK
and then Hi
>= Lo
and then Lo
>= 0 then
11121 Error_Msg_N
-- CODEFIX
11122 ("?r?abs applied to known non-negative value has no effect", N
);
11126 -- Deal with reference generation
11128 Check_Unset_Reference
(R
);
11129 Generate_Operator_Reference
(N
, B_Typ
);
11130 Analyze_Dimension
(N
);
11133 -- Set overflow checking bit. Much cleverer code needed here eventually
11134 -- and perhaps the Resolve routines should be separated for the various
11135 -- arithmetic operations, since they will need different processing ???
11137 if Nkind
(N
) in N_Op
then
11138 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
11139 Enable_Overflow_Check
(N
);
11143 -- Generate warning for expressions like -5 mod 3 for integers. No need
11144 -- to worry in the floating-point case, since parens do not affect the
11145 -- result so there is no point in giving in a warning.
11148 Norig
: constant Node_Id
:= Original_Node
(N
);
11157 if Warn_On_Questionable_Missing_Parens
11158 and then Comes_From_Source
(Norig
)
11159 and then Is_Integer_Type
(Typ
)
11160 and then Nkind
(Norig
) = N_Op_Minus
11162 Rorig
:= Original_Node
(Right_Opnd
(Norig
));
11164 -- We are looking for cases where the right operand is not
11165 -- parenthesized, and is a binary operator, multiply, divide, or
11166 -- mod. These are the cases where the grouping can affect results.
11168 if Paren_Count
(Rorig
) = 0
11169 and then Nkind_In
(Rorig
, N_Op_Mod
, N_Op_Multiply
, N_Op_Divide
)
11171 -- For mod, we always give the warning, since the value is
11172 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11173 -- -(5 mod 315)). But for the other cases, the only concern is
11174 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11175 -- overflows, but (-2) * 64 does not). So we try to give the
11176 -- message only when overflow is possible.
11178 if Nkind
(Rorig
) /= N_Op_Mod
11179 and then Compile_Time_Known_Value
(R
)
11181 Val
:= Expr_Value
(R
);
11183 if Compile_Time_Known_Value
(Type_High_Bound
(Typ
)) then
11184 HB
:= Expr_Value
(Type_High_Bound
(Typ
));
11186 HB
:= Expr_Value
(Type_High_Bound
(Base_Type
(Typ
)));
11189 if Compile_Time_Known_Value
(Type_Low_Bound
(Typ
)) then
11190 LB
:= Expr_Value
(Type_Low_Bound
(Typ
));
11192 LB
:= Expr_Value
(Type_Low_Bound
(Base_Type
(Typ
)));
11195 -- Note that the test below is deliberately excluding the
11196 -- largest negative number, since that is a potentially
11197 -- troublesome case (e.g. -2 * x, where the result is the
11198 -- largest negative integer has an overflow with 2 * x).
11200 if Val
> LB
and then Val
<= HB
then
11205 -- For the multiplication case, the only case we have to worry
11206 -- about is when (-a)*b is exactly the largest negative number
11207 -- so that -(a*b) can cause overflow. This can only happen if
11208 -- a is a power of 2, and more generally if any operand is a
11209 -- constant that is not a power of 2, then the parentheses
11210 -- cannot affect whether overflow occurs. We only bother to
11211 -- test the left most operand
11213 -- Loop looking at left operands for one that has known value
11216 Opnd_Loop
: while Nkind
(Opnd
) = N_Op_Multiply
loop
11217 if Compile_Time_Known_Value
(Left_Opnd
(Opnd
)) then
11218 Lval
:= UI_Abs
(Expr_Value
(Left_Opnd
(Opnd
)));
11220 -- Operand value of 0 or 1 skips warning
11225 -- Otherwise check power of 2, if power of 2, warn, if
11226 -- anything else, skip warning.
11229 while Lval
/= 2 loop
11230 if Lval
mod 2 = 1 then
11241 -- Keep looking at left operands
11243 Opnd
:= Left_Opnd
(Opnd
);
11244 end loop Opnd_Loop
;
11246 -- For rem or "/" we can only have a problematic situation
11247 -- if the divisor has a value of minus one or one. Otherwise
11248 -- overflow is impossible (divisor > 1) or we have a case of
11249 -- division by zero in any case.
11251 if Nkind_In
(Rorig
, N_Op_Divide
, N_Op_Rem
)
11252 and then Compile_Time_Known_Value
(Right_Opnd
(Rorig
))
11253 and then UI_Abs
(Expr_Value
(Right_Opnd
(Rorig
))) /= 1
11258 -- If we fall through warning should be issued
11260 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11263 ("??unary minus expression should be parenthesized here!", N
);
11267 end Resolve_Unary_Op
;
11269 ----------------------------------
11270 -- Resolve_Unchecked_Expression --
11271 ----------------------------------
11273 procedure Resolve_Unchecked_Expression
11278 Resolve
(Expression
(N
), Typ
, Suppress
=> All_Checks
);
11279 Set_Etype
(N
, Typ
);
11280 end Resolve_Unchecked_Expression
;
11282 ---------------------------------------
11283 -- Resolve_Unchecked_Type_Conversion --
11284 ---------------------------------------
11286 procedure Resolve_Unchecked_Type_Conversion
11290 pragma Warnings
(Off
, Typ
);
11292 Operand
: constant Node_Id
:= Expression
(N
);
11293 Opnd_Type
: constant Entity_Id
:= Etype
(Operand
);
11296 -- Resolve operand using its own type
11298 Resolve
(Operand
, Opnd_Type
);
11300 -- In an inlined context, the unchecked conversion may be applied
11301 -- to a literal, in which case its type is the type of the context.
11302 -- (In other contexts conversions cannot apply to literals).
11305 and then (Opnd_Type
= Any_Character
or else
11306 Opnd_Type
= Any_Integer
or else
11307 Opnd_Type
= Any_Real
)
11309 Set_Etype
(Operand
, Typ
);
11312 Analyze_Dimension
(N
);
11313 Eval_Unchecked_Conversion
(N
);
11314 end Resolve_Unchecked_Type_Conversion
;
11316 ------------------------------
11317 -- Rewrite_Operator_As_Call --
11318 ------------------------------
11320 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
) is
11321 Loc
: constant Source_Ptr
:= Sloc
(N
);
11322 Actuals
: constant List_Id
:= New_List
;
11326 if Nkind
(N
) in N_Binary_Op
then
11327 Append
(Left_Opnd
(N
), Actuals
);
11330 Append
(Right_Opnd
(N
), Actuals
);
11333 Make_Function_Call
(Sloc
=> Loc
,
11334 Name
=> New_Occurrence_Of
(Nam
, Loc
),
11335 Parameter_Associations
=> Actuals
);
11337 Preserve_Comes_From_Source
(New_N
, N
);
11338 Preserve_Comes_From_Source
(Name
(New_N
), N
);
11339 Rewrite
(N
, New_N
);
11340 Set_Etype
(N
, Etype
(Nam
));
11341 end Rewrite_Operator_As_Call
;
11343 ------------------------------
11344 -- Rewrite_Renamed_Operator --
11345 ------------------------------
11347 procedure Rewrite_Renamed_Operator
11352 Nam
: constant Name_Id
:= Chars
(Op
);
11353 Is_Binary
: constant Boolean := Nkind
(N
) in N_Binary_Op
;
11357 -- Do not perform this transformation within a pre/postcondition,
11358 -- because the expression will be re-analyzed, and the transformation
11359 -- might affect the visibility of the operator, e.g. in an instance.
11360 -- Note that fully analyzed and expanded pre/postconditions appear as
11361 -- pragma Check equivalents.
11363 if In_Pre_Post_Condition
(N
) then
11367 -- Rewrite the operator node using the real operator, not its renaming.
11368 -- Exclude user-defined intrinsic operations of the same name, which are
11369 -- treated separately and rewritten as calls.
11371 if Ekind
(Op
) /= E_Function
or else Chars
(N
) /= Nam
then
11372 Op_Node
:= New_Node
(Operator_Kind
(Nam
, Is_Binary
), Sloc
(N
));
11373 Set_Chars
(Op_Node
, Nam
);
11374 Set_Etype
(Op_Node
, Etype
(N
));
11375 Set_Entity
(Op_Node
, Op
);
11376 Set_Right_Opnd
(Op_Node
, Right_Opnd
(N
));
11378 -- Indicate that both the original entity and its renaming are
11379 -- referenced at this point.
11381 Generate_Reference
(Entity
(N
), N
);
11382 Generate_Reference
(Op
, N
);
11385 Set_Left_Opnd
(Op_Node
, Left_Opnd
(N
));
11388 Rewrite
(N
, Op_Node
);
11390 -- If the context type is private, add the appropriate conversions so
11391 -- that the operator is applied to the full view. This is done in the
11392 -- routines that resolve intrinsic operators.
11394 if Is_Intrinsic_Subprogram
(Op
) and then Is_Private_Type
(Typ
) then
11404 Resolve_Intrinsic_Operator
(N
, Typ
);
11410 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
11417 elsif Ekind
(Op
) = E_Function
and then Is_Intrinsic_Subprogram
(Op
) then
11419 -- Operator renames a user-defined operator of the same name. Use the
11420 -- original operator in the node, which is the one Gigi knows about.
11422 Set_Entity
(N
, Op
);
11423 Set_Is_Overloaded
(N
, False);
11425 end Rewrite_Renamed_Operator
;
11427 -----------------------
11428 -- Set_Slice_Subtype --
11429 -----------------------
11431 -- Build an implicit subtype declaration to represent the type delivered by
11432 -- the slice. This is an abbreviated version of an array subtype. We define
11433 -- an index subtype for the slice, using either the subtype name or the
11434 -- discrete range of the slice. To be consistent with index usage elsewhere
11435 -- we create a list header to hold the single index. This list is not
11436 -- otherwise attached to the syntax tree.
11438 procedure Set_Slice_Subtype
(N
: Node_Id
) is
11439 Loc
: constant Source_Ptr
:= Sloc
(N
);
11440 Index_List
: constant List_Id
:= New_List
;
11442 Index_Subtype
: Entity_Id
;
11443 Index_Type
: Entity_Id
;
11444 Slice_Subtype
: Entity_Id
;
11445 Drange
: constant Node_Id
:= Discrete_Range
(N
);
11448 Index_Type
:= Base_Type
(Etype
(Drange
));
11450 if Is_Entity_Name
(Drange
) then
11451 Index_Subtype
:= Entity
(Drange
);
11454 -- We force the evaluation of a range. This is definitely needed in
11455 -- the renamed case, and seems safer to do unconditionally. Note in
11456 -- any case that since we will create and insert an Itype referring
11457 -- to this range, we must make sure any side effect removal actions
11458 -- are inserted before the Itype definition.
11460 if Nkind
(Drange
) = N_Range
then
11461 Force_Evaluation
(Low_Bound
(Drange
));
11462 Force_Evaluation
(High_Bound
(Drange
));
11464 -- If the discrete range is given by a subtype indication, the
11465 -- type of the slice is the base of the subtype mark.
11467 elsif Nkind
(Drange
) = N_Subtype_Indication
then
11469 R
: constant Node_Id
:= Range_Expression
(Constraint
(Drange
));
11471 Index_Type
:= Base_Type
(Entity
(Subtype_Mark
(Drange
)));
11472 Force_Evaluation
(Low_Bound
(R
));
11473 Force_Evaluation
(High_Bound
(R
));
11477 Index_Subtype
:= Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
11479 -- Take a new copy of Drange (where bounds have been rewritten to
11480 -- reference side-effect-free names). Using a separate tree ensures
11481 -- that further expansion (e.g. while rewriting a slice assignment
11482 -- into a FOR loop) does not attempt to remove side effects on the
11483 -- bounds again (which would cause the bounds in the index subtype
11484 -- definition to refer to temporaries before they are defined) (the
11485 -- reason is that some names are considered side effect free here
11486 -- for the subtype, but not in the context of a loop iteration
11489 Set_Scalar_Range
(Index_Subtype
, New_Copy_Tree
(Drange
));
11490 Set_Parent
(Scalar_Range
(Index_Subtype
), Index_Subtype
);
11491 Set_Etype
(Index_Subtype
, Index_Type
);
11492 Set_Size_Info
(Index_Subtype
, Index_Type
);
11493 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
11496 Slice_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
11498 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
11499 Set_Etype
(Index
, Index_Subtype
);
11500 Append
(Index
, Index_List
);
11502 Set_First_Index
(Slice_Subtype
, Index
);
11503 Set_Etype
(Slice_Subtype
, Base_Type
(Etype
(N
)));
11504 Set_Is_Constrained
(Slice_Subtype
, True);
11506 Check_Compile_Time_Size
(Slice_Subtype
);
11508 -- The Etype of the existing Slice node is reset to this slice subtype.
11509 -- Its bounds are obtained from its first index.
11511 Set_Etype
(N
, Slice_Subtype
);
11513 -- For packed slice subtypes, freeze immediately (except in the case of
11514 -- being in a "spec expression" where we never freeze when we first see
11515 -- the expression).
11517 if Is_Packed
(Slice_Subtype
) and not In_Spec_Expression
then
11518 Freeze_Itype
(Slice_Subtype
, N
);
11520 -- For all other cases insert an itype reference in the slice's actions
11521 -- so that the itype is frozen at the proper place in the tree (i.e. at
11522 -- the point where actions for the slice are analyzed). Note that this
11523 -- is different from freezing the itype immediately, which might be
11524 -- premature (e.g. if the slice is within a transient scope). This needs
11525 -- to be done only if expansion is enabled.
11527 elsif Expander_Active
then
11528 Ensure_Defined
(Typ
=> Slice_Subtype
, N
=> N
);
11530 end Set_Slice_Subtype
;
11532 --------------------------------
11533 -- Set_String_Literal_Subtype --
11534 --------------------------------
11536 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
) is
11537 Loc
: constant Source_Ptr
:= Sloc
(N
);
11538 Low_Bound
: constant Node_Id
:=
11539 Type_Low_Bound
(Etype
(First_Index
(Typ
)));
11540 Subtype_Id
: Entity_Id
;
11543 if Nkind
(N
) /= N_String_Literal
then
11547 Subtype_Id
:= Create_Itype
(E_String_Literal_Subtype
, N
);
11548 Set_String_Literal_Length
(Subtype_Id
, UI_From_Int
11549 (String_Length
(Strval
(N
))));
11550 Set_Etype
(Subtype_Id
, Base_Type
(Typ
));
11551 Set_Is_Constrained
(Subtype_Id
);
11552 Set_Etype
(N
, Subtype_Id
);
11554 -- The low bound is set from the low bound of the corresponding index
11555 -- type. Note that we do not store the high bound in the string literal
11556 -- subtype, but it can be deduced if necessary from the length and the
11559 if Is_OK_Static_Expression
(Low_Bound
) then
11560 Set_String_Literal_Low_Bound
(Subtype_Id
, Low_Bound
);
11562 -- If the lower bound is not static we create a range for the string
11563 -- literal, using the index type and the known length of the literal.
11564 -- The index type is not necessarily Positive, so the upper bound is
11565 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11569 Index_List
: constant List_Id
:= New_List
;
11570 Index_Type
: constant Entity_Id
:= Etype
(First_Index
(Typ
));
11571 High_Bound
: constant Node_Id
:=
11572 Make_Attribute_Reference
(Loc
,
11573 Attribute_Name
=> Name_Val
,
11575 New_Occurrence_Of
(Index_Type
, Loc
),
11576 Expressions
=> New_List
(
11579 Make_Attribute_Reference
(Loc
,
11580 Attribute_Name
=> Name_Pos
,
11582 New_Occurrence_Of
(Index_Type
, Loc
),
11584 New_List
(New_Copy_Tree
(Low_Bound
))),
11586 Make_Integer_Literal
(Loc
,
11587 String_Length
(Strval
(N
)) - 1))));
11589 Array_Subtype
: Entity_Id
;
11592 Index_Subtype
: Entity_Id
;
11595 if Is_Integer_Type
(Index_Type
) then
11596 Set_String_Literal_Low_Bound
11597 (Subtype_Id
, Make_Integer_Literal
(Loc
, 1));
11600 -- If the index type is an enumeration type, build bounds
11601 -- expression with attributes.
11603 Set_String_Literal_Low_Bound
11605 Make_Attribute_Reference
(Loc
,
11606 Attribute_Name
=> Name_First
,
11608 New_Occurrence_Of
(Base_Type
(Index_Type
), Loc
)));
11609 Set_Etype
(String_Literal_Low_Bound
(Subtype_Id
), Index_Type
);
11612 Analyze_And_Resolve
(String_Literal_Low_Bound
(Subtype_Id
));
11614 -- Build bona fide subtype for the string, and wrap it in an
11615 -- unchecked conversion, because the backend expects the
11616 -- String_Literal_Subtype to have a static lower bound.
11619 Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
11620 Drange
:= Make_Range
(Loc
, New_Copy_Tree
(Low_Bound
), High_Bound
);
11621 Set_Scalar_Range
(Index_Subtype
, Drange
);
11622 Set_Parent
(Drange
, N
);
11623 Analyze_And_Resolve
(Drange
, Index_Type
);
11625 -- In the context, the Index_Type may already have a constraint,
11626 -- so use common base type on string subtype. The base type may
11627 -- be used when generating attributes of the string, for example
11628 -- in the context of a slice assignment.
11630 Set_Etype
(Index_Subtype
, Base_Type
(Index_Type
));
11631 Set_Size_Info
(Index_Subtype
, Index_Type
);
11632 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
11634 Array_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
11636 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
11637 Set_Etype
(Index
, Index_Subtype
);
11638 Append
(Index
, Index_List
);
11640 Set_First_Index
(Array_Subtype
, Index
);
11641 Set_Etype
(Array_Subtype
, Base_Type
(Typ
));
11642 Set_Is_Constrained
(Array_Subtype
, True);
11645 Make_Unchecked_Type_Conversion
(Loc
,
11646 Subtype_Mark
=> New_Occurrence_Of
(Array_Subtype
, Loc
),
11647 Expression
=> Relocate_Node
(N
)));
11648 Set_Etype
(N
, Array_Subtype
);
11651 end Set_String_Literal_Subtype
;
11653 ------------------------------
11654 -- Simplify_Type_Conversion --
11655 ------------------------------
11657 procedure Simplify_Type_Conversion
(N
: Node_Id
) is
11659 if Nkind
(N
) = N_Type_Conversion
then
11661 Operand
: constant Node_Id
:= Expression
(N
);
11662 Target_Typ
: constant Entity_Id
:= Etype
(N
);
11663 Opnd_Typ
: constant Entity_Id
:= Etype
(Operand
);
11666 -- Special processing if the conversion is the expression of a
11667 -- Rounding or Truncation attribute reference. In this case we
11670 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11676 -- with the Float_Truncate flag set to False or True respectively,
11677 -- which is more efficient.
11679 if Is_Floating_Point_Type
(Opnd_Typ
)
11681 (Is_Integer_Type
(Target_Typ
)
11682 or else (Is_Fixed_Point_Type
(Target_Typ
)
11683 and then Conversion_OK
(N
)))
11684 and then Nkind
(Operand
) = N_Attribute_Reference
11685 and then Nam_In
(Attribute_Name
(Operand
), Name_Rounding
,
11689 Truncate
: constant Boolean :=
11690 Attribute_Name
(Operand
) = Name_Truncation
;
11693 Relocate_Node
(First
(Expressions
(Operand
))));
11694 Set_Float_Truncate
(N
, Truncate
);
11699 end Simplify_Type_Conversion
;
11701 -----------------------------
11702 -- Unique_Fixed_Point_Type --
11703 -----------------------------
11705 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
is
11706 T1
: Entity_Id
:= Empty
;
11711 procedure Fixed_Point_Error
;
11712 -- Give error messages for true ambiguity. Messages are posted on node
11713 -- N, and entities T1, T2 are the possible interpretations.
11715 -----------------------
11716 -- Fixed_Point_Error --
11717 -----------------------
11719 procedure Fixed_Point_Error
is
11721 Error_Msg_N
("ambiguous universal_fixed_expression", N
);
11722 Error_Msg_NE
("\\possible interpretation as}", N
, T1
);
11723 Error_Msg_NE
("\\possible interpretation as}", N
, T2
);
11724 end Fixed_Point_Error
;
11726 -- Start of processing for Unique_Fixed_Point_Type
11729 -- The operations on Duration are visible, so Duration is always a
11730 -- possible interpretation.
11732 T1
:= Standard_Duration
;
11734 -- Look for fixed-point types in enclosing scopes
11736 Scop
:= Current_Scope
;
11737 while Scop
/= Standard_Standard
loop
11738 T2
:= First_Entity
(Scop
);
11739 while Present
(T2
) loop
11740 if Is_Fixed_Point_Type
(T2
)
11741 and then Current_Entity
(T2
) = T2
11742 and then Scope
(Base_Type
(T2
)) = Scop
11744 if Present
(T1
) then
11755 Scop
:= Scope
(Scop
);
11758 -- Look for visible fixed type declarations in the context
11760 Item
:= First
(Context_Items
(Cunit
(Current_Sem_Unit
)));
11761 while Present
(Item
) loop
11762 if Nkind
(Item
) = N_With_Clause
then
11763 Scop
:= Entity
(Name
(Item
));
11764 T2
:= First_Entity
(Scop
);
11765 while Present
(T2
) loop
11766 if Is_Fixed_Point_Type
(T2
)
11767 and then Scope
(Base_Type
(T2
)) = Scop
11768 and then (Is_Potentially_Use_Visible
(T2
) or else In_Use
(T2
))
11770 if Present
(T1
) then
11785 if Nkind
(N
) = N_Real_Literal
then
11787 ("??real literal interpreted as }!", N
, T1
);
11790 ("??universal_fixed expression interpreted as }!", N
, T1
);
11794 end Unique_Fixed_Point_Type
;
11796 ----------------------
11797 -- Valid_Conversion --
11798 ----------------------
11800 function Valid_Conversion
11802 Target
: Entity_Id
;
11804 Report_Errs
: Boolean := True) return Boolean
11806 Target_Type
: constant Entity_Id
:= Base_Type
(Target
);
11807 Opnd_Type
: Entity_Id
:= Etype
(Operand
);
11808 Inc_Ancestor
: Entity_Id
;
11810 function Conversion_Check
11812 Msg
: String) return Boolean;
11813 -- Little routine to post Msg if Valid is False, returns Valid value
11815 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
);
11816 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
11818 procedure Conversion_Error_NE
11820 N
: Node_Or_Entity_Id
;
11821 E
: Node_Or_Entity_Id
);
11822 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
11824 function Valid_Tagged_Conversion
11825 (Target_Type
: Entity_Id
;
11826 Opnd_Type
: Entity_Id
) return Boolean;
11827 -- Specifically test for validity of tagged conversions
11829 function Valid_Array_Conversion
return Boolean;
11830 -- Check index and component conformance, and accessibility levels if
11831 -- the component types are anonymous access types (Ada 2005).
11833 ----------------------
11834 -- Conversion_Check --
11835 ----------------------
11837 function Conversion_Check
11839 Msg
: String) return Boolean
11844 -- A generic unit has already been analyzed and we have verified
11845 -- that a particular conversion is OK in that context. Since the
11846 -- instance is reanalyzed without relying on the relationships
11847 -- established during the analysis of the generic, it is possible
11848 -- to end up with inconsistent views of private types. Do not emit
11849 -- the error message in such cases. The rest of the machinery in
11850 -- Valid_Conversion still ensures the proper compatibility of
11851 -- target and operand types.
11853 and then not In_Instance
11855 Conversion_Error_N
(Msg
, Operand
);
11859 end Conversion_Check
;
11861 ------------------------
11862 -- Conversion_Error_N --
11863 ------------------------
11865 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
) is
11867 if Report_Errs
then
11868 Error_Msg_N
(Msg
, N
);
11870 end Conversion_Error_N
;
11872 -------------------------
11873 -- Conversion_Error_NE --
11874 -------------------------
11876 procedure Conversion_Error_NE
11878 N
: Node_Or_Entity_Id
;
11879 E
: Node_Or_Entity_Id
)
11882 if Report_Errs
then
11883 Error_Msg_NE
(Msg
, N
, E
);
11885 end Conversion_Error_NE
;
11887 ----------------------------
11888 -- Valid_Array_Conversion --
11889 ----------------------------
11891 function Valid_Array_Conversion
return Boolean is
11892 Opnd_Comp_Type
: constant Entity_Id
:= Component_Type
(Opnd_Type
);
11893 Opnd_Comp_Base
: constant Entity_Id
:= Base_Type
(Opnd_Comp_Type
);
11895 Opnd_Index
: Node_Id
;
11896 Opnd_Index_Type
: Entity_Id
;
11898 Target_Comp_Type
: constant Entity_Id
:=
11899 Component_Type
(Target_Type
);
11900 Target_Comp_Base
: constant Entity_Id
:=
11901 Base_Type
(Target_Comp_Type
);
11903 Target_Index
: Node_Id
;
11904 Target_Index_Type
: Entity_Id
;
11907 -- Error if wrong number of dimensions
11910 Number_Dimensions
(Target_Type
) /= Number_Dimensions
(Opnd_Type
)
11913 ("incompatible number of dimensions for conversion", Operand
);
11916 -- Number of dimensions matches
11919 -- Loop through indexes of the two arrays
11921 Target_Index
:= First_Index
(Target_Type
);
11922 Opnd_Index
:= First_Index
(Opnd_Type
);
11923 while Present
(Target_Index
) and then Present
(Opnd_Index
) loop
11924 Target_Index_Type
:= Etype
(Target_Index
);
11925 Opnd_Index_Type
:= Etype
(Opnd_Index
);
11927 -- Error if index types are incompatible
11929 if not (Is_Integer_Type
(Target_Index_Type
)
11930 and then Is_Integer_Type
(Opnd_Index_Type
))
11931 and then (Root_Type
(Target_Index_Type
)
11932 /= Root_Type
(Opnd_Index_Type
))
11935 ("incompatible index types for array conversion",
11940 Next_Index
(Target_Index
);
11941 Next_Index
(Opnd_Index
);
11944 -- If component types have same base type, all set
11946 if Target_Comp_Base
= Opnd_Comp_Base
then
11949 -- Here if base types of components are not the same. The only
11950 -- time this is allowed is if we have anonymous access types.
11952 -- The conversion of arrays of anonymous access types can lead
11953 -- to dangling pointers. AI-392 formalizes the accessibility
11954 -- checks that must be applied to such conversions to prevent
11955 -- out-of-scope references.
11958 (Target_Comp_Base
, E_Anonymous_Access_Type
,
11959 E_Anonymous_Access_Subprogram_Type
)
11960 and then Ekind
(Opnd_Comp_Base
) = Ekind
(Target_Comp_Base
)
11962 Subtypes_Statically_Match
(Target_Comp_Type
, Opnd_Comp_Type
)
11964 if Type_Access_Level
(Target_Type
) <
11965 Deepest_Type_Access_Level
(Opnd_Type
)
11967 if In_Instance_Body
then
11968 Error_Msg_Warn
:= SPARK_Mode
/= On
;
11970 ("source array type has deeper accessibility "
11971 & "level than target<<", Operand
);
11972 Conversion_Error_N
("\Program_Error [<<", Operand
);
11974 Make_Raise_Program_Error
(Sloc
(N
),
11975 Reason
=> PE_Accessibility_Check_Failed
));
11976 Set_Etype
(N
, Target_Type
);
11979 -- Conversion not allowed because of accessibility levels
11983 ("source array type has deeper accessibility "
11984 & "level than target", Operand
);
11992 -- All other cases where component base types do not match
11996 ("incompatible component types for array conversion",
12001 -- Check that component subtypes statically match. For numeric
12002 -- types this means that both must be either constrained or
12003 -- unconstrained. For enumeration types the bounds must match.
12004 -- All of this is checked in Subtypes_Statically_Match.
12006 if not Subtypes_Statically_Match
12007 (Target_Comp_Type
, Opnd_Comp_Type
)
12010 ("component subtypes must statically match", Operand
);
12016 end Valid_Array_Conversion
;
12018 -----------------------------
12019 -- Valid_Tagged_Conversion --
12020 -----------------------------
12022 function Valid_Tagged_Conversion
12023 (Target_Type
: Entity_Id
;
12024 Opnd_Type
: Entity_Id
) return Boolean
12027 -- Upward conversions are allowed (RM 4.6(22))
12029 if Covers
(Target_Type
, Opnd_Type
)
12030 or else Is_Ancestor
(Target_Type
, Opnd_Type
)
12034 -- Downward conversion are allowed if the operand is class-wide
12037 elsif Is_Class_Wide_Type
(Opnd_Type
)
12038 and then Covers
(Opnd_Type
, Target_Type
)
12042 elsif Covers
(Opnd_Type
, Target_Type
)
12043 or else Is_Ancestor
(Opnd_Type
, Target_Type
)
12046 Conversion_Check
(False,
12047 "downward conversion of tagged objects not allowed");
12049 -- Ada 2005 (AI-251): The conversion to/from interface types is
12050 -- always valid. The types involved may be class-wide (sub)types.
12052 elsif Is_Interface
(Etype
(Base_Type
(Target_Type
)))
12053 or else Is_Interface
(Etype
(Base_Type
(Opnd_Type
)))
12057 -- If the operand is a class-wide type obtained through a limited_
12058 -- with clause, and the context includes the nonlimited view, use
12059 -- it to determine whether the conversion is legal.
12061 elsif Is_Class_Wide_Type
(Opnd_Type
)
12062 and then From_Limited_With
(Opnd_Type
)
12063 and then Present
(Non_Limited_View
(Etype
(Opnd_Type
)))
12064 and then Is_Interface
(Non_Limited_View
(Etype
(Opnd_Type
)))
12068 elsif Is_Access_Type
(Opnd_Type
)
12069 and then Is_Interface
(Directly_Designated_Type
(Opnd_Type
))
12074 Conversion_Error_NE
12075 ("invalid tagged conversion, not compatible with}",
12076 N
, First_Subtype
(Opnd_Type
));
12079 end Valid_Tagged_Conversion
;
12081 -- Start of processing for Valid_Conversion
12084 Check_Parameterless_Call
(Operand
);
12086 if Is_Overloaded
(Operand
) then
12096 -- Remove procedure calls, which syntactically cannot appear in
12097 -- this context, but which cannot be removed by type checking,
12098 -- because the context does not impose a type.
12100 -- The node may be labelled overloaded, but still contain only one
12101 -- interpretation because others were discarded earlier. If this
12102 -- is the case, retain the single interpretation if legal.
12104 Get_First_Interp
(Operand
, I
, It
);
12105 Opnd_Type
:= It
.Typ
;
12106 Get_Next_Interp
(I
, It
);
12108 if Present
(It
.Typ
)
12109 and then Opnd_Type
/= Standard_Void_Type
12111 -- More than one candidate interpretation is available
12113 Get_First_Interp
(Operand
, I
, It
);
12114 while Present
(It
.Typ
) loop
12115 if It
.Typ
= Standard_Void_Type
then
12119 -- When compiling for a system where Address is of a visible
12120 -- integer type, spurious ambiguities can be produced when
12121 -- arithmetic operations have a literal operand and return
12122 -- System.Address or a descendant of it. These ambiguities
12123 -- are usually resolved by the context, but for conversions
12124 -- there is no context type and the removal of the spurious
12125 -- operations must be done explicitly here.
12127 if not Address_Is_Private
12128 and then Is_Descendant_Of_Address
(It
.Typ
)
12133 Get_Next_Interp
(I
, It
);
12137 Get_First_Interp
(Operand
, I
, It
);
12141 if No
(It
.Typ
) then
12142 Conversion_Error_N
("illegal operand in conversion", Operand
);
12146 Get_Next_Interp
(I
, It
);
12148 if Present
(It
.Typ
) then
12151 It1
:= Disambiguate
(Operand
, I1
, I
, Any_Type
);
12153 if It1
= No_Interp
then
12155 ("ambiguous operand in conversion", Operand
);
12157 -- If the interpretation involves a standard operator, use
12158 -- the location of the type, which may be user-defined.
12160 if Sloc
(It
.Nam
) = Standard_Location
then
12161 Error_Msg_Sloc
:= Sloc
(It
.Typ
);
12163 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
12166 Conversion_Error_N
-- CODEFIX
12167 ("\\possible interpretation#!", Operand
);
12169 if Sloc
(N1
) = Standard_Location
then
12170 Error_Msg_Sloc
:= Sloc
(T1
);
12172 Error_Msg_Sloc
:= Sloc
(N1
);
12175 Conversion_Error_N
-- CODEFIX
12176 ("\\possible interpretation#!", Operand
);
12182 Set_Etype
(Operand
, It1
.Typ
);
12183 Opnd_Type
:= It1
.Typ
;
12187 -- Deal with conversion of integer type to address if the pragma
12188 -- Allow_Integer_Address is in effect. We convert the conversion to
12189 -- an unchecked conversion in this case and we are all done.
12191 if Address_Integer_Convert_OK
(Opnd_Type
, Target_Type
) then
12192 Rewrite
(N
, Unchecked_Convert_To
(Target_Type
, Expression
(N
)));
12193 Analyze_And_Resolve
(N
, Target_Type
);
12197 -- If we are within a child unit, check whether the type of the
12198 -- expression has an ancestor in a parent unit, in which case it
12199 -- belongs to its derivation class even if the ancestor is private.
12200 -- See RM 7.3.1 (5.2/3).
12202 Inc_Ancestor
:= Get_Incomplete_View_Of_Ancestor
(Opnd_Type
);
12206 if Is_Numeric_Type
(Target_Type
) then
12208 -- A universal fixed expression can be converted to any numeric type
12210 if Opnd_Type
= Universal_Fixed
then
12213 -- Also no need to check when in an instance or inlined body, because
12214 -- the legality has been established when the template was analyzed.
12215 -- Furthermore, numeric conversions may occur where only a private
12216 -- view of the operand type is visible at the instantiation point.
12217 -- This results in a spurious error if we check that the operand type
12218 -- is a numeric type.
12220 -- Note: in a previous version of this unit, the following tests were
12221 -- applied only for generated code (Comes_From_Source set to False),
12222 -- but in fact the test is required for source code as well, since
12223 -- this situation can arise in source code.
12225 elsif In_Instance
or else In_Inlined_Body
then
12228 -- Otherwise we need the conversion check
12231 return Conversion_Check
12232 (Is_Numeric_Type
(Opnd_Type
)
12234 (Present
(Inc_Ancestor
)
12235 and then Is_Numeric_Type
(Inc_Ancestor
)),
12236 "illegal operand for numeric conversion");
12241 elsif Is_Array_Type
(Target_Type
) then
12242 if not Is_Array_Type
(Opnd_Type
)
12243 or else Opnd_Type
= Any_Composite
12244 or else Opnd_Type
= Any_String
12247 ("illegal operand for array conversion", Operand
);
12251 return Valid_Array_Conversion
;
12254 -- Ada 2005 (AI-251): Internally generated conversions of access to
12255 -- interface types added to force the displacement of the pointer to
12256 -- reference the corresponding dispatch table.
12258 elsif not Comes_From_Source
(N
)
12259 and then Is_Access_Type
(Target_Type
)
12260 and then Is_Interface
(Designated_Type
(Target_Type
))
12264 -- Ada 2005 (AI-251): Anonymous access types where target references an
12267 elsif Is_Access_Type
(Opnd_Type
)
12268 and then Ekind_In
(Target_Type
, E_General_Access_Type
,
12269 E_Anonymous_Access_Type
)
12270 and then Is_Interface
(Directly_Designated_Type
(Target_Type
))
12272 -- Check the static accessibility rule of 4.6(17). Note that the
12273 -- check is not enforced when within an instance body, since the
12274 -- RM requires such cases to be caught at run time.
12276 -- If the operand is a rewriting of an allocator no check is needed
12277 -- because there are no accessibility issues.
12279 if Nkind
(Original_Node
(N
)) = N_Allocator
then
12282 elsif Ekind
(Target_Type
) /= E_Anonymous_Access_Type
then
12283 if Type_Access_Level
(Opnd_Type
) >
12284 Deepest_Type_Access_Level
(Target_Type
)
12286 -- In an instance, this is a run-time check, but one we know
12287 -- will fail, so generate an appropriate warning. The raise
12288 -- will be generated by Expand_N_Type_Conversion.
12290 if In_Instance_Body
then
12291 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12293 ("cannot convert local pointer to non-local access type<<",
12295 Conversion_Error_N
("\Program_Error [<<", Operand
);
12299 ("cannot convert local pointer to non-local access type",
12304 -- Special accessibility checks are needed in the case of access
12305 -- discriminants declared for a limited type.
12307 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12308 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12310 -- When the operand is a selected access discriminant the check
12311 -- needs to be made against the level of the object denoted by
12312 -- the prefix of the selected name (Object_Access_Level handles
12313 -- checking the prefix of the operand for this case).
12315 if Nkind
(Operand
) = N_Selected_Component
12316 and then Object_Access_Level
(Operand
) >
12317 Deepest_Type_Access_Level
(Target_Type
)
12319 -- In an instance, this is a run-time check, but one we know
12320 -- will fail, so generate an appropriate warning. The raise
12321 -- will be generated by Expand_N_Type_Conversion.
12323 if In_Instance_Body
then
12324 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12326 ("cannot convert access discriminant to non-local "
12327 & "access type<<", Operand
);
12328 Conversion_Error_N
("\Program_Error [<<", Operand
);
12330 -- Real error if not in instance body
12334 ("cannot convert access discriminant to non-local "
12335 & "access type", Operand
);
12340 -- The case of a reference to an access discriminant from
12341 -- within a limited type declaration (which will appear as
12342 -- a discriminal) is always illegal because the level of the
12343 -- discriminant is considered to be deeper than any (nameable)
12346 if Is_Entity_Name
(Operand
)
12347 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12349 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
12350 and then Present
(Discriminal_Link
(Entity
(Operand
)))
12353 ("discriminant has deeper accessibility level than target",
12362 -- General and anonymous access types
12364 elsif Ekind_In
(Target_Type
, E_General_Access_Type
,
12365 E_Anonymous_Access_Type
)
12368 (Is_Access_Type
(Opnd_Type
)
12370 Ekind_In
(Opnd_Type
, E_Access_Subprogram_Type
,
12371 E_Access_Protected_Subprogram_Type
),
12372 "must be an access-to-object type")
12374 if Is_Access_Constant
(Opnd_Type
)
12375 and then not Is_Access_Constant
(Target_Type
)
12378 ("access-to-constant operand type not allowed", Operand
);
12382 -- Check the static accessibility rule of 4.6(17). Note that the
12383 -- check is not enforced when within an instance body, since the RM
12384 -- requires such cases to be caught at run time.
12386 if Ekind
(Target_Type
) /= E_Anonymous_Access_Type
12387 or else Is_Local_Anonymous_Access
(Target_Type
)
12388 or else Nkind
(Associated_Node_For_Itype
(Target_Type
)) =
12389 N_Object_Declaration
12391 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12392 -- conversions from an anonymous access type to a named general
12393 -- access type. Such conversions are not allowed in the case of
12394 -- access parameters and stand-alone objects of an anonymous
12395 -- access type. The implicit conversion case is recognized by
12396 -- testing that Comes_From_Source is False and that it's been
12397 -- rewritten. The Comes_From_Source test isn't sufficient because
12398 -- nodes in inlined calls to predefined library routines can have
12399 -- Comes_From_Source set to False. (Is there a better way to test
12400 -- for implicit conversions???)
12402 if Ada_Version
>= Ada_2012
12403 and then not Comes_From_Source
(N
)
12404 and then N
/= Original_Node
(N
)
12405 and then Ekind
(Target_Type
) = E_General_Access_Type
12406 and then Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12408 if Is_Itype
(Opnd_Type
) then
12410 -- Implicit conversions aren't allowed for objects of an
12411 -- anonymous access type, since such objects have nonstatic
12412 -- levels in Ada 2012.
12414 if Nkind
(Associated_Node_For_Itype
(Opnd_Type
)) =
12415 N_Object_Declaration
12418 ("implicit conversion of stand-alone anonymous "
12419 & "access object not allowed", Operand
);
12422 -- Implicit conversions aren't allowed for anonymous access
12423 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12424 -- is done to exclude anonymous access results.
12426 elsif not Is_Local_Anonymous_Access
(Opnd_Type
)
12427 and then Nkind_In
(Associated_Node_For_Itype
(Opnd_Type
),
12428 N_Function_Specification
,
12429 N_Procedure_Specification
)
12432 ("implicit conversion of anonymous access formal "
12433 & "not allowed", Operand
);
12436 -- This is a case where there's an enclosing object whose
12437 -- to which the "statically deeper than" relationship does
12438 -- not apply (such as an access discriminant selected from
12439 -- a dereference of an access parameter).
12441 elsif Object_Access_Level
(Operand
)
12442 = Scope_Depth
(Standard_Standard
)
12445 ("implicit conversion of anonymous access value "
12446 & "not allowed", Operand
);
12449 -- In other cases, the level of the operand's type must be
12450 -- statically less deep than that of the target type, else
12451 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12453 elsif Type_Access_Level
(Opnd_Type
) >
12454 Deepest_Type_Access_Level
(Target_Type
)
12457 ("implicit conversion of anonymous access value "
12458 & "violates accessibility", Operand
);
12463 elsif Type_Access_Level
(Opnd_Type
) >
12464 Deepest_Type_Access_Level
(Target_Type
)
12466 -- In an instance, this is a run-time check, but one we know
12467 -- will fail, so generate an appropriate warning. The raise
12468 -- will be generated by Expand_N_Type_Conversion.
12470 if In_Instance_Body
then
12471 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12473 ("cannot convert local pointer to non-local access type<<",
12475 Conversion_Error_N
("\Program_Error [<<", Operand
);
12477 -- If not in an instance body, this is a real error
12480 -- Avoid generation of spurious error message
12482 if not Error_Posted
(N
) then
12484 ("cannot convert local pointer to non-local access type",
12491 -- Special accessibility checks are needed in the case of access
12492 -- discriminants declared for a limited type.
12494 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12495 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12497 -- When the operand is a selected access discriminant the check
12498 -- needs to be made against the level of the object denoted by
12499 -- the prefix of the selected name (Object_Access_Level handles
12500 -- checking the prefix of the operand for this case).
12502 if Nkind
(Operand
) = N_Selected_Component
12503 and then Object_Access_Level
(Operand
) >
12504 Deepest_Type_Access_Level
(Target_Type
)
12506 -- In an instance, this is a run-time check, but one we know
12507 -- will fail, so generate an appropriate warning. The raise
12508 -- will be generated by Expand_N_Type_Conversion.
12510 if In_Instance_Body
then
12511 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12513 ("cannot convert access discriminant to non-local "
12514 & "access type<<", Operand
);
12515 Conversion_Error_N
("\Program_Error [<<", Operand
);
12517 -- If not in an instance body, this is a real error
12521 ("cannot convert access discriminant to non-local "
12522 & "access type", Operand
);
12527 -- The case of a reference to an access discriminant from
12528 -- within a limited type declaration (which will appear as
12529 -- a discriminal) is always illegal because the level of the
12530 -- discriminant is considered to be deeper than any (nameable)
12533 if Is_Entity_Name
(Operand
)
12535 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
12536 and then Present
(Discriminal_Link
(Entity
(Operand
)))
12539 ("discriminant has deeper accessibility level than target",
12546 -- In the presence of limited_with clauses we have to use nonlimited
12547 -- views, if available.
12549 Check_Limited
: declare
12550 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
;
12551 -- Helper function to handle limited views
12553 --------------------------
12554 -- Full_Designated_Type --
12555 --------------------------
12557 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
is
12558 Desig
: constant Entity_Id
:= Designated_Type
(T
);
12561 -- Handle the limited view of a type
12563 if From_Limited_With
(Desig
)
12564 and then Has_Non_Limited_View
(Desig
)
12566 return Available_View
(Desig
);
12570 end Full_Designated_Type
;
12572 -- Local Declarations
12574 Target
: constant Entity_Id
:= Full_Designated_Type
(Target_Type
);
12575 Opnd
: constant Entity_Id
:= Full_Designated_Type
(Opnd_Type
);
12577 Same_Base
: constant Boolean :=
12578 Base_Type
(Target
) = Base_Type
(Opnd
);
12580 -- Start of processing for Check_Limited
12583 if Is_Tagged_Type
(Target
) then
12584 return Valid_Tagged_Conversion
(Target
, Opnd
);
12587 if not Same_Base
then
12588 Conversion_Error_NE
12589 ("target designated type not compatible with }",
12590 N
, Base_Type
(Opnd
));
12593 -- Ada 2005 AI-384: legality rule is symmetric in both
12594 -- designated types. The conversion is legal (with possible
12595 -- constraint check) if either designated type is
12598 elsif Subtypes_Statically_Match
(Target
, Opnd
)
12600 (Has_Discriminants
(Target
)
12602 (not Is_Constrained
(Opnd
)
12603 or else not Is_Constrained
(Target
)))
12605 -- Special case, if Value_Size has been used to make the
12606 -- sizes different, the conversion is not allowed even
12607 -- though the subtypes statically match.
12609 if Known_Static_RM_Size
(Target
)
12610 and then Known_Static_RM_Size
(Opnd
)
12611 and then RM_Size
(Target
) /= RM_Size
(Opnd
)
12613 Conversion_Error_NE
12614 ("target designated subtype not compatible with }",
12616 Conversion_Error_NE
12617 ("\because sizes of the two designated subtypes differ",
12621 -- Normal case where conversion is allowed
12629 ("target designated subtype not compatible with }",
12636 -- Access to subprogram types. If the operand is an access parameter,
12637 -- the type has a deeper accessibility that any master, and cannot be
12638 -- assigned. We must make an exception if the conversion is part of an
12639 -- assignment and the target is the return object of an extended return
12640 -- statement, because in that case the accessibility check takes place
12641 -- after the return.
12643 elsif Is_Access_Subprogram_Type
(Target_Type
)
12645 -- Note: this test of Opnd_Type is there to prevent entering this
12646 -- branch in the case of a remote access to subprogram type, which
12647 -- is internally represented as an E_Record_Type.
12649 and then Is_Access_Type
(Opnd_Type
)
12651 if Ekind
(Base_Type
(Opnd_Type
)) = E_Anonymous_Access_Subprogram_Type
12652 and then Is_Entity_Name
(Operand
)
12653 and then Ekind
(Entity
(Operand
)) = E_In_Parameter
12655 (Nkind
(Parent
(N
)) /= N_Assignment_Statement
12656 or else not Is_Entity_Name
(Name
(Parent
(N
)))
12657 or else not Is_Return_Object
(Entity
(Name
(Parent
(N
)))))
12660 ("illegal attempt to store anonymous access to subprogram",
12663 ("\value has deeper accessibility than any master "
12664 & "(RM 3.10.2 (13))",
12668 ("\use named access type for& instead of access parameter",
12669 Operand
, Entity
(Operand
));
12672 -- Check that the designated types are subtype conformant
12674 Check_Subtype_Conformant
(New_Id
=> Designated_Type
(Target_Type
),
12675 Old_Id
=> Designated_Type
(Opnd_Type
),
12678 -- Check the static accessibility rule of 4.6(20)
12680 if Type_Access_Level
(Opnd_Type
) >
12681 Deepest_Type_Access_Level
(Target_Type
)
12684 ("operand type has deeper accessibility level than target",
12687 -- Check that if the operand type is declared in a generic body,
12688 -- then the target type must be declared within that same body
12689 -- (enforces last sentence of 4.6(20)).
12691 elsif Present
(Enclosing_Generic_Body
(Opnd_Type
)) then
12693 O_Gen
: constant Node_Id
:=
12694 Enclosing_Generic_Body
(Opnd_Type
);
12699 T_Gen
:= Enclosing_Generic_Body
(Target_Type
);
12700 while Present
(T_Gen
) and then T_Gen
/= O_Gen
loop
12701 T_Gen
:= Enclosing_Generic_Body
(T_Gen
);
12704 if T_Gen
/= O_Gen
then
12706 ("target type must be declared in same generic body "
12707 & "as operand type", N
);
12714 -- Remote access to subprogram types
12716 elsif Is_Remote_Access_To_Subprogram_Type
(Target_Type
)
12717 and then Is_Remote_Access_To_Subprogram_Type
(Opnd_Type
)
12719 -- It is valid to convert from one RAS type to another provided
12720 -- that their specification statically match.
12722 -- Note: at this point, remote access to subprogram types have been
12723 -- expanded to their E_Record_Type representation, and we need to
12724 -- go back to the original access type definition using the
12725 -- Corresponding_Remote_Type attribute in order to check that the
12726 -- designated profiles match.
12728 pragma Assert
(Ekind
(Target_Type
) = E_Record_Type
);
12729 pragma Assert
(Ekind
(Opnd_Type
) = E_Record_Type
);
12731 Check_Subtype_Conformant
12733 Designated_Type
(Corresponding_Remote_Type
(Target_Type
)),
12735 Designated_Type
(Corresponding_Remote_Type
(Opnd_Type
)),
12740 -- If it was legal in the generic, it's legal in the instance
12742 elsif In_Instance_Body
then
12745 -- If both are tagged types, check legality of view conversions
12747 elsif Is_Tagged_Type
(Target_Type
)
12749 Is_Tagged_Type
(Opnd_Type
)
12751 return Valid_Tagged_Conversion
(Target_Type
, Opnd_Type
);
12753 -- Types derived from the same root type are convertible
12755 elsif Root_Type
(Target_Type
) = Root_Type
(Opnd_Type
) then
12758 -- In an instance or an inlined body, there may be inconsistent views of
12759 -- the same type, or of types derived from a common root.
12761 elsif (In_Instance
or In_Inlined_Body
)
12763 Root_Type
(Underlying_Type
(Target_Type
)) =
12764 Root_Type
(Underlying_Type
(Opnd_Type
))
12768 -- Special check for common access type error case
12770 elsif Ekind
(Target_Type
) = E_Access_Type
12771 and then Is_Access_Type
(Opnd_Type
)
12773 Conversion_Error_N
("target type must be general access type!", N
);
12774 Conversion_Error_NE
-- CODEFIX
12775 ("add ALL to }!", N
, Target_Type
);
12778 -- Here we have a real conversion error
12781 Conversion_Error_NE
12782 ("invalid conversion, not compatible with }", N
, Opnd_Type
);
12785 end Valid_Conversion
;