1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2013, 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 Itypes
; use Itypes
;
42 with Lib
.Xref
; use Lib
.Xref
;
43 with Namet
; use Namet
;
44 with Nmake
; use Nmake
;
45 with Nlists
; use Nlists
;
47 with Output
; use Output
;
48 with Restrict
; use Restrict
;
49 with Rident
; use Rident
;
50 with Rtsfind
; use Rtsfind
;
52 with Sem_Aux
; use Sem_Aux
;
53 with Sem_Aggr
; use Sem_Aggr
;
54 with Sem_Attr
; use Sem_Attr
;
55 with Sem_Cat
; use Sem_Cat
;
56 with Sem_Ch4
; use Sem_Ch4
;
57 with Sem_Ch6
; use Sem_Ch6
;
58 with Sem_Ch8
; use Sem_Ch8
;
59 with Sem_Ch13
; use Sem_Ch13
;
60 with Sem_Dim
; use Sem_Dim
;
61 with Sem_Disp
; use Sem_Disp
;
62 with Sem_Dist
; use Sem_Dist
;
63 with Sem_Elim
; use Sem_Elim
;
64 with Sem_Elab
; use Sem_Elab
;
65 with Sem_Eval
; use Sem_Eval
;
66 with Sem_Intr
; use Sem_Intr
;
67 with Sem_Util
; use Sem_Util
;
68 with Targparm
; use Targparm
;
69 with Sem_Type
; use Sem_Type
;
70 with Sem_Warn
; use Sem_Warn
;
71 with Sinfo
; use Sinfo
;
72 with Sinfo
.CN
; use Sinfo
.CN
;
73 with Snames
; use Snames
;
74 with Stand
; use Stand
;
75 with Stringt
; use Stringt
;
76 with Style
; use Style
;
77 with Tbuild
; use Tbuild
;
78 with Uintp
; use Uintp
;
79 with Urealp
; use Urealp
;
81 package body Sem_Res
is
83 -----------------------
84 -- Local Subprograms --
85 -----------------------
87 -- Second pass (top-down) type checking and overload resolution procedures
88 -- Typ is the type required by context. These procedures propagate the type
89 -- information recursively to the descendants of N. If the node is not
90 -- overloaded, its Etype is established in the first pass. If overloaded,
91 -- the Resolve routines set the correct type. For arith. operators, the
92 -- Etype is the base type of the context.
94 -- Note that Resolve_Attribute is separated off in Sem_Attr
96 function Bad_Unordered_Enumeration_Reference
98 T
: Entity_Id
) return Boolean;
99 -- Node N contains a potentially dubious reference to type T, either an
100 -- explicit comparison, or an explicit range. This function returns True
101 -- if the type T is an enumeration type for which No pragma Order has been
102 -- given, and the reference N is not in the same extended source unit as
103 -- the declaration of T.
105 procedure Check_Discriminant_Use
(N
: Node_Id
);
106 -- Enforce the restrictions on the use of discriminants when constraining
107 -- a component of a discriminated type (record or concurrent type).
109 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
);
110 -- Given a node for an operator associated with type T, check that
111 -- the operator is visible. Operators all of whose operands are
112 -- universal must be checked for visibility during resolution
113 -- because their type is not determinable based on their operands.
115 procedure Check_Fully_Declared_Prefix
118 -- Check that the type of the prefix of a dereference is not incomplete
120 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean;
121 -- Given a call node, N, which is known to occur immediately within the
122 -- subprogram being called, determines whether it is a detectable case of
123 -- an infinite recursion, and if so, outputs appropriate messages. Returns
124 -- True if an infinite recursion is detected, and False otherwise.
126 procedure Check_Initialization_Call
(N
: Entity_Id
; Nam
: Entity_Id
);
127 -- If the type of the object being initialized uses the secondary stack
128 -- directly or indirectly, create a transient scope for the call to the
129 -- init proc. This is because we do not create transient scopes for the
130 -- initialization of individual components within the init proc itself.
131 -- Could be optimized away perhaps?
133 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
);
134 -- N is the node for a logical operator. If the operator is predefined, and
135 -- the root type of the operands is Standard.Boolean, then a check is made
136 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
137 -- the style check for Style_Check_Boolean_And_Or.
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_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
);
187 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
188 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
);
189 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
);
190 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
);
191 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
);
192 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
);
193 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
);
194 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
);
195 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
196 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
);
197 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
198 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
);
199 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
);
200 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
);
201 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
);
202 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
);
203 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
204 procedure Resolve_Subprogram_Info
(N
: Node_Id
; Typ
: Entity_Id
);
205 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
206 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
);
207 procedure Resolve_Unchecked_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
208 procedure Resolve_Unchecked_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
210 function Operator_Kind
212 Is_Binary
: Boolean) return Node_Kind
;
213 -- Utility to map the name of an operator into the corresponding Node. Used
214 -- by other node rewriting procedures.
216 procedure Resolve_Actuals
(N
: Node_Id
; Nam
: Entity_Id
);
217 -- Resolve actuals of call, and add default expressions for missing ones.
218 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
219 -- called subprogram.
221 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
);
222 -- Called from Resolve_Call, when the prefix denotes an entry or element
223 -- of entry family. Actuals are resolved as for subprograms, and the node
224 -- is rebuilt as an entry call. Also called for protected operations. Typ
225 -- is the context type, which is used when the operation is a protected
226 -- function with no arguments, and the return value is indexed.
228 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
229 -- A call to a user-defined intrinsic operator is rewritten as a call to
230 -- the corresponding predefined operator, with suitable conversions. Note
231 -- that this applies only for intrinsic operators that denote predefined
232 -- operators, not ones that are intrinsic imports of back-end builtins.
234 procedure Resolve_Intrinsic_Unary_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
235 -- Ditto, for unary operators (arithmetic ones and "not" on signed
236 -- integer types for VMS).
238 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
);
239 -- If an operator node resolves to a call to a user-defined operator,
240 -- rewrite the node as a function call.
242 procedure Make_Call_Into_Operator
246 -- Inverse transformation: if an operator is given in functional notation,
247 -- then after resolving the node, transform into an operator node, so
248 -- that operands are resolved properly. Recall that predefined operators
249 -- do not have a full signature and special resolution rules apply.
251 procedure Rewrite_Renamed_Operator
255 -- An operator can rename another, e.g. in an instantiation. In that
256 -- case, the proper operator node must be constructed and resolved.
258 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
);
259 -- The String_Literal_Subtype is built for all strings that are not
260 -- operands of a static concatenation operation. If the argument is
261 -- not a N_String_Literal node, then the call has no effect.
263 procedure Set_Slice_Subtype
(N
: Node_Id
);
264 -- Build subtype of array type, with the range specified by the slice
266 procedure Simplify_Type_Conversion
(N
: Node_Id
);
267 -- Called after N has been resolved and evaluated, but before range checks
268 -- have been applied. Currently simplifies a combination of floating-point
269 -- to integer conversion and Truncation attribute.
271 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
;
272 -- A universal_fixed expression in an universal context is unambiguous if
273 -- there is only one applicable fixed point type. Determining whether there
274 -- is only one requires a search over all visible entities, and happens
275 -- only in very pathological cases (see 6115-006).
277 -------------------------
278 -- Ambiguous_Character --
279 -------------------------
281 procedure Ambiguous_Character
(C
: Node_Id
) is
285 if Nkind
(C
) = N_Character_Literal
then
286 Error_Msg_N
("ambiguous character literal", C
);
288 -- First the ones in Standard
290 Error_Msg_N
("\\possible interpretation: Character!", C
);
291 Error_Msg_N
("\\possible interpretation: Wide_Character!", C
);
293 -- Include Wide_Wide_Character in Ada 2005 mode
295 if Ada_Version
>= Ada_2005
then
296 Error_Msg_N
("\\possible interpretation: Wide_Wide_Character!", C
);
299 -- Now any other types that match
301 E
:= Current_Entity
(C
);
302 while Present
(E
) loop
303 Error_Msg_NE
("\\possible interpretation:}!", C
, Etype
(E
));
307 end Ambiguous_Character
;
309 -------------------------
310 -- Analyze_And_Resolve --
311 -------------------------
313 procedure Analyze_And_Resolve
(N
: Node_Id
) is
317 end Analyze_And_Resolve
;
319 procedure Analyze_And_Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
323 end Analyze_And_Resolve
;
325 -- Versions with check(s) suppressed
327 procedure Analyze_And_Resolve
332 Scop
: constant Entity_Id
:= Current_Scope
;
335 if Suppress
= All_Checks
then
337 Sva
: constant Suppress_Array
:= Scope_Suppress
.Suppress
;
339 Scope_Suppress
.Suppress
:= (others => True);
340 Analyze_And_Resolve
(N
, Typ
);
341 Scope_Suppress
.Suppress
:= Sva
;
346 Svg
: constant Boolean := Scope_Suppress
.Suppress
(Suppress
);
348 Scope_Suppress
.Suppress
(Suppress
) := True;
349 Analyze_And_Resolve
(N
, Typ
);
350 Scope_Suppress
.Suppress
(Suppress
) := Svg
;
354 if Current_Scope
/= Scop
355 and then Scope_Is_Transient
357 -- This can only happen if a transient scope was created for an inner
358 -- expression, which will be removed upon completion of the analysis
359 -- of an enclosing construct. The transient scope must have the
360 -- suppress status of the enclosing environment, not of this Analyze
363 Scope_Stack
.Table
(Scope_Stack
.Last
).Save_Scope_Suppress
:=
366 end Analyze_And_Resolve
;
368 procedure Analyze_And_Resolve
372 Scop
: constant Entity_Id
:= Current_Scope
;
375 if Suppress
= All_Checks
then
377 Sva
: constant Suppress_Array
:= Scope_Suppress
.Suppress
;
379 Scope_Suppress
.Suppress
:= (others => True);
380 Analyze_And_Resolve
(N
);
381 Scope_Suppress
.Suppress
:= Sva
;
386 Svg
: constant Boolean := Scope_Suppress
.Suppress
(Suppress
);
388 Scope_Suppress
.Suppress
(Suppress
) := True;
389 Analyze_And_Resolve
(N
);
390 Scope_Suppress
.Suppress
(Suppress
) := Svg
;
394 if Current_Scope
/= Scop
and then Scope_Is_Transient
then
395 Scope_Stack
.Table
(Scope_Stack
.Last
).Save_Scope_Suppress
:=
398 end Analyze_And_Resolve
;
400 ----------------------------------------
401 -- Bad_Unordered_Enumeration_Reference --
402 ----------------------------------------
404 function Bad_Unordered_Enumeration_Reference
406 T
: Entity_Id
) return Boolean
409 return Is_Enumeration_Type
(T
)
410 and then Comes_From_Source
(N
)
411 and then Warn_On_Unordered_Enumeration_Type
412 and then not Has_Pragma_Ordered
(T
)
413 and then not In_Same_Extended_Unit
(N
, T
);
414 end Bad_Unordered_Enumeration_Reference
;
416 ----------------------------
417 -- Check_Discriminant_Use --
418 ----------------------------
420 procedure Check_Discriminant_Use
(N
: Node_Id
) is
421 PN
: constant Node_Id
:= Parent
(N
);
422 Disc
: constant Entity_Id
:= Entity
(N
);
427 -- Any use in a spec-expression is legal
429 if In_Spec_Expression
then
432 elsif Nkind
(PN
) = N_Range
then
434 -- Discriminant cannot be used to constrain a scalar type
438 if Nkind
(P
) = N_Range_Constraint
439 and then Nkind
(Parent
(P
)) = N_Subtype_Indication
440 and then Nkind
(Parent
(Parent
(P
))) = N_Component_Definition
442 Error_Msg_N
("discriminant cannot constrain scalar type", N
);
444 elsif Nkind
(P
) = N_Index_Or_Discriminant_Constraint
then
446 -- The following check catches the unusual case where a
447 -- discriminant appears within an index constraint that is part of
448 -- a larger expression within a constraint on a component, e.g. "C
449 -- : Int range 1 .. F (new A(1 .. D))". For now we only check case
450 -- of record components, and note that a similar check should also
451 -- apply in the case of discriminant constraints below. ???
453 -- Note that the check for N_Subtype_Declaration below is to
454 -- detect the valid use of discriminants in the constraints of a
455 -- subtype declaration when this subtype declaration appears
456 -- inside the scope of a record type (which is syntactically
457 -- illegal, but which may be created as part of derived type
458 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
461 if Ekind
(Current_Scope
) = E_Record_Type
462 and then Scope
(Disc
) = Current_Scope
464 (Nkind
(Parent
(P
)) = N_Subtype_Indication
466 Nkind_In
(Parent
(Parent
(P
)), N_Component_Definition
,
467 N_Subtype_Declaration
)
468 and then Paren_Count
(N
) = 0)
471 ("discriminant must appear alone in component constraint", N
);
475 -- Detect a common error:
477 -- type R (D : Positive := 100) is record
478 -- Name : String (1 .. D);
481 -- The default value causes an object of type R to be allocated
482 -- with room for Positive'Last characters. The RM does not mandate
483 -- the allocation of the maximum size, but that is what GNAT does
484 -- so we should warn the programmer that there is a problem.
486 Check_Large
: declare
492 function Large_Storage_Type
(T
: Entity_Id
) return Boolean;
493 -- Return True if type T has a large enough range that any
494 -- array whose index type covered the whole range of the type
495 -- would likely raise Storage_Error.
497 ------------------------
498 -- Large_Storage_Type --
499 ------------------------
501 function Large_Storage_Type
(T
: Entity_Id
) return Boolean is
503 -- The type is considered large if its bounds are known at
504 -- compile time and if it requires at least as many bits as
505 -- a Positive to store the possible values.
507 return Compile_Time_Known_Value
(Type_Low_Bound
(T
))
508 and then Compile_Time_Known_Value
(Type_High_Bound
(T
))
510 Minimum_Size
(T
, Biased
=> True) >=
511 RM_Size
(Standard_Positive
);
512 end Large_Storage_Type
;
514 -- Start of processing for Check_Large
517 -- Check that the Disc has a large range
519 if not Large_Storage_Type
(Etype
(Disc
)) then
523 -- If the enclosing type is limited, we allocate only the
524 -- default value, not the maximum, and there is no need for
527 if Is_Limited_Type
(Scope
(Disc
)) then
531 -- Check that it is the high bound
533 if N
/= High_Bound
(PN
)
534 or else No
(Discriminant_Default_Value
(Disc
))
539 -- Check the array allows a large range at this bound. First
544 if Nkind
(SI
) /= N_Subtype_Indication
then
548 T
:= Entity
(Subtype_Mark
(SI
));
550 if not Is_Array_Type
(T
) then
554 -- Next, find the dimension
556 TB
:= First_Index
(T
);
557 CB
:= First
(Constraints
(P
));
559 and then Present
(TB
)
560 and then Present
(CB
)
571 -- Now, check the dimension has a large range
573 if not Large_Storage_Type
(Etype
(TB
)) then
577 -- Warn about the danger
580 ("??creation of & object may raise Storage_Error!",
589 -- Legal case is in index or discriminant constraint
591 elsif Nkind_In
(PN
, N_Index_Or_Discriminant_Constraint
,
592 N_Discriminant_Association
)
594 if Paren_Count
(N
) > 0 then
596 ("discriminant in constraint must appear alone", N
);
598 elsif Nkind
(N
) = N_Expanded_Name
599 and then Comes_From_Source
(N
)
602 ("discriminant must appear alone as a direct name", N
);
607 -- Otherwise, context is an expression. It should not be within (i.e. a
608 -- subexpression of) a constraint for a component.
613 while not Nkind_In
(P
, N_Component_Declaration
,
614 N_Subtype_Indication
,
622 -- If the discriminant is used in an expression that is a bound of a
623 -- scalar type, an Itype is created and the bounds are attached to
624 -- its range, not to the original subtype indication. Such use is of
625 -- course a double fault.
627 if (Nkind
(P
) = N_Subtype_Indication
628 and then Nkind_In
(Parent
(P
), N_Component_Definition
,
629 N_Derived_Type_Definition
)
630 and then D
= Constraint
(P
))
632 -- The constraint itself may be given by a subtype indication,
633 -- rather than by a more common discrete range.
635 or else (Nkind
(P
) = N_Subtype_Indication
637 Nkind
(Parent
(P
)) = N_Index_Or_Discriminant_Constraint
)
638 or else Nkind
(P
) = N_Entry_Declaration
639 or else Nkind
(D
) = N_Defining_Identifier
642 ("discriminant in constraint must appear alone", N
);
645 end Check_Discriminant_Use
;
647 --------------------------------
648 -- Check_For_Visible_Operator --
649 --------------------------------
651 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
) is
653 if Is_Invisible_Operator
(N
, T
) then
654 Error_Msg_NE
-- CODEFIX
655 ("operator for} is not directly visible!", N
, First_Subtype
(T
));
656 Error_Msg_N
-- CODEFIX
657 ("use clause would make operation legal!", N
);
659 end Check_For_Visible_Operator
;
661 ----------------------------------
662 -- Check_Fully_Declared_Prefix --
663 ----------------------------------
665 procedure Check_Fully_Declared_Prefix
670 -- Check that the designated type of the prefix of a dereference is
671 -- not an incomplete type. This cannot be done unconditionally, because
672 -- dereferences of private types are legal in default expressions. This
673 -- case is taken care of in Check_Fully_Declared, called below. There
674 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
676 -- This consideration also applies to similar checks for allocators,
677 -- qualified expressions, and type conversions.
679 -- An additional exception concerns other per-object expressions that
680 -- are not directly related to component declarations, in particular
681 -- representation pragmas for tasks. These will be per-object
682 -- expressions if they depend on discriminants or some global entity.
683 -- If the task has access discriminants, the designated type may be
684 -- incomplete at the point the expression is resolved. This resolution
685 -- takes place within the body of the initialization procedure, where
686 -- the discriminant is replaced by its discriminal.
688 if Is_Entity_Name
(Pref
)
689 and then Ekind
(Entity
(Pref
)) = E_In_Parameter
693 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
694 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
695 -- Analyze_Object_Renaming, and Freeze_Entity.
697 elsif Ada_Version
>= Ada_2005
698 and then Is_Entity_Name
(Pref
)
699 and then Is_Access_Type
(Etype
(Pref
))
700 and then Ekind
(Directly_Designated_Type
(Etype
(Pref
))) =
702 and then Is_Tagged_Type
(Directly_Designated_Type
(Etype
(Pref
)))
706 Check_Fully_Declared
(Typ
, Parent
(Pref
));
708 end Check_Fully_Declared_Prefix
;
710 ------------------------------
711 -- Check_Infinite_Recursion --
712 ------------------------------
714 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean is
718 function Same_Argument_List
return Boolean;
719 -- Check whether list of actuals is identical to list of formals of
720 -- called function (which is also the enclosing scope).
722 ------------------------
723 -- Same_Argument_List --
724 ------------------------
726 function Same_Argument_List
return Boolean is
732 if not Is_Entity_Name
(Name
(N
)) then
735 Subp
:= Entity
(Name
(N
));
738 F
:= First_Formal
(Subp
);
739 A
:= First_Actual
(N
);
740 while Present
(F
) and then Present
(A
) loop
741 if not Is_Entity_Name
(A
)
742 or else Entity
(A
) /= F
752 end Same_Argument_List
;
754 -- Start of processing for Check_Infinite_Recursion
757 -- Special case, if this is a procedure call and is a call to the
758 -- current procedure with the same argument list, then this is for
759 -- sure an infinite recursion and we insert a call to raise SE.
761 if Is_List_Member
(N
)
762 and then List_Length
(List_Containing
(N
)) = 1
763 and then Same_Argument_List
766 P
: constant Node_Id
:= Parent
(N
);
768 if Nkind
(P
) = N_Handled_Sequence_Of_Statements
769 and then Nkind
(Parent
(P
)) = N_Subprogram_Body
770 and then Is_Empty_List
(Declarations
(Parent
(P
)))
772 Error_Msg_N
("!??infinite recursion", N
);
773 Error_Msg_N
("\!??Storage_Error will be raised at run time", N
);
775 Make_Raise_Storage_Error
(Sloc
(N
),
776 Reason
=> SE_Infinite_Recursion
));
782 -- If not that special case, search up tree, quitting if we reach a
783 -- construct (e.g. a conditional) that tells us that this is not a
784 -- case for an infinite recursion warning.
790 -- If no parent, then we were not inside a subprogram, this can for
791 -- example happen when processing certain pragmas in a spec. Just
792 -- return False in this case.
798 -- Done if we get to subprogram body, this is definitely an infinite
799 -- recursion case if we did not find anything to stop us.
801 exit when Nkind
(P
) = N_Subprogram_Body
;
803 -- If appearing in conditional, result is false
805 if Nkind_In
(P
, N_Or_Else
,
814 elsif Nkind
(P
) = N_Handled_Sequence_Of_Statements
815 and then C
/= First
(Statements
(P
))
817 -- If the call is the expression of a return statement and the
818 -- actuals are identical to the formals, it's worth a warning.
819 -- However, we skip this if there is an immediately preceding
820 -- raise statement, since the call is never executed.
822 -- Furthermore, this corresponds to a common idiom:
824 -- function F (L : Thing) return Boolean is
826 -- raise Program_Error;
830 -- for generating a stub function
832 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
833 and then Same_Argument_List
835 exit when not Is_List_Member
(Parent
(N
));
837 -- OK, return statement is in a statement list, look for raise
843 -- Skip past N_Freeze_Entity nodes generated by expansion
845 Nod
:= Prev
(Parent
(N
));
847 and then Nkind
(Nod
) = N_Freeze_Entity
852 -- If no raise statement, give warning. We look at the
853 -- original node, because in the case of "raise ... with
854 -- ...", the node has been transformed into a call.
856 exit when Nkind
(Original_Node
(Nod
)) /= N_Raise_Statement
858 (Nkind
(Nod
) not in N_Raise_xxx_Error
859 or else Present
(Condition
(Nod
)));
870 Error_Msg_N
("!??possible infinite recursion", N
);
871 Error_Msg_N
("\!??Storage_Error may be raised at run time", N
);
874 end Check_Infinite_Recursion
;
876 -------------------------------
877 -- Check_Initialization_Call --
878 -------------------------------
880 procedure Check_Initialization_Call
(N
: Entity_Id
; Nam
: Entity_Id
) is
881 Typ
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
883 function Uses_SS
(T
: Entity_Id
) return Boolean;
884 -- Check whether the creation of an object of the type will involve
885 -- use of the secondary stack. If T is a record type, this is true
886 -- if the expression for some component uses the secondary stack, e.g.
887 -- through a call to a function that returns an unconstrained value.
888 -- False if T is controlled, because cleanups occur elsewhere.
894 function Uses_SS
(T
: Entity_Id
) return Boolean is
897 Full_Type
: Entity_Id
:= Underlying_Type
(T
);
900 -- Normally we want to use the underlying type, but if it's not set
901 -- then continue with T.
903 if not Present
(Full_Type
) then
907 if Is_Controlled
(Full_Type
) then
910 elsif Is_Array_Type
(Full_Type
) then
911 return Uses_SS
(Component_Type
(Full_Type
));
913 elsif Is_Record_Type
(Full_Type
) then
914 Comp
:= First_Component
(Full_Type
);
915 while Present
(Comp
) loop
916 if Ekind
(Comp
) = E_Component
917 and then Nkind
(Parent
(Comp
)) = N_Component_Declaration
919 -- The expression for a dynamic component may be rewritten
920 -- as a dereference, so retrieve original node.
922 Expr
:= Original_Node
(Expression
(Parent
(Comp
)));
924 -- Return True if the expression is a call to a function
925 -- (including an attribute function such as Image, or a
926 -- user-defined operator) with a result that requires a
929 if (Nkind
(Expr
) = N_Function_Call
930 or else Nkind
(Expr
) in N_Op
931 or else (Nkind
(Expr
) = N_Attribute_Reference
932 and then Present
(Expressions
(Expr
))))
933 and then Requires_Transient_Scope
(Etype
(Expr
))
937 elsif Uses_SS
(Etype
(Comp
)) then
942 Next_Component
(Comp
);
952 -- Start of processing for Check_Initialization_Call
955 -- Establish a transient scope if the type needs it
957 if Uses_SS
(Typ
) then
958 Establish_Transient_Scope
(First_Actual
(N
), Sec_Stack
=> True);
960 end Check_Initialization_Call
;
962 ---------------------------------------
963 -- Check_No_Direct_Boolean_Operators --
964 ---------------------------------------
966 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
) is
968 if Scope
(Entity
(N
)) = Standard_Standard
969 and then Root_Type
(Etype
(Left_Opnd
(N
))) = Standard_Boolean
971 -- Restriction only applies to original source code
973 if Comes_From_Source
(N
) then
974 Check_Restriction
(No_Direct_Boolean_Operators
, N
);
979 Check_Boolean_Operator
(N
);
981 end Check_No_Direct_Boolean_Operators
;
983 ------------------------------
984 -- Check_Parameterless_Call --
985 ------------------------------
987 procedure Check_Parameterless_Call
(N
: Node_Id
) is
990 function Prefix_Is_Access_Subp
return Boolean;
991 -- If the prefix is of an access_to_subprogram type, the node must be
992 -- rewritten as a call. Ditto if the prefix is overloaded and all its
993 -- interpretations are access to subprograms.
995 ---------------------------
996 -- Prefix_Is_Access_Subp --
997 ---------------------------
999 function Prefix_Is_Access_Subp
return Boolean is
1004 -- If the context is an attribute reference that can apply to
1005 -- functions, this is never a parameterless call (RM 4.1.4(6)).
1007 if Nkind
(Parent
(N
)) = N_Attribute_Reference
1008 and then Nam_In
(Attribute_Name
(Parent
(N
)), Name_Address
,
1015 if not Is_Overloaded
(N
) then
1017 Ekind
(Etype
(N
)) = E_Subprogram_Type
1018 and then Base_Type
(Etype
(Etype
(N
))) /= Standard_Void_Type
;
1020 Get_First_Interp
(N
, I
, It
);
1021 while Present
(It
.Typ
) loop
1022 if Ekind
(It
.Typ
) /= E_Subprogram_Type
1023 or else Base_Type
(Etype
(It
.Typ
)) = Standard_Void_Type
1028 Get_Next_Interp
(I
, It
);
1033 end Prefix_Is_Access_Subp
;
1035 -- Start of processing for Check_Parameterless_Call
1038 -- Defend against junk stuff if errors already detected
1040 if Total_Errors_Detected
/= 0 then
1041 if Nkind
(N
) in N_Has_Etype
and then Etype
(N
) = Any_Type
then
1043 elsif Nkind
(N
) in N_Has_Chars
1044 and then Chars
(N
) in Error_Name_Or_No_Name
1052 -- If the context expects a value, and the name is a procedure, this is
1053 -- most likely a missing 'Access. Don't try to resolve the parameterless
1054 -- call, error will be caught when the outer call is analyzed.
1056 if Is_Entity_Name
(N
)
1057 and then Ekind
(Entity
(N
)) = E_Procedure
1058 and then not Is_Overloaded
(N
)
1060 Nkind_In
(Parent
(N
), N_Parameter_Association
,
1062 N_Procedure_Call_Statement
)
1067 -- Rewrite as call if overloadable entity that is (or could be, in the
1068 -- overloaded case) a function call. If we know for sure that the entity
1069 -- is an enumeration literal, we do not rewrite it.
1071 -- If the entity is the name of an operator, it cannot be a call because
1072 -- operators cannot have default parameters. In this case, this must be
1073 -- a string whose contents coincide with an operator name. Set the kind
1074 -- of the node appropriately.
1076 if (Is_Entity_Name
(N
)
1077 and then Nkind
(N
) /= N_Operator_Symbol
1078 and then Is_Overloadable
(Entity
(N
))
1079 and then (Ekind
(Entity
(N
)) /= E_Enumeration_Literal
1080 or else Is_Overloaded
(N
)))
1082 -- Rewrite as call if it is an explicit dereference of an expression of
1083 -- a subprogram access type, and the subprogram type is not that of a
1084 -- procedure or entry.
1087 (Nkind
(N
) = N_Explicit_Dereference
and then Prefix_Is_Access_Subp
)
1089 -- Rewrite as call if it is a selected component which is a function,
1090 -- this is the case of a call to a protected function (which may be
1091 -- overloaded with other protected operations).
1094 (Nkind
(N
) = N_Selected_Component
1095 and then (Ekind
(Entity
(Selector_Name
(N
))) = E_Function
1097 (Ekind_In
(Entity
(Selector_Name
(N
)), E_Entry
,
1099 and then Is_Overloaded
(Selector_Name
(N
)))))
1101 -- If one of the above three conditions is met, rewrite as call. Apply
1102 -- the rewriting only once.
1105 if Nkind
(Parent
(N
)) /= N_Function_Call
1106 or else N
/= Name
(Parent
(N
))
1109 -- This may be a prefixed call that was not fully analyzed, e.g.
1110 -- an actual in an instance.
1112 if Ada_Version
>= Ada_2005
1113 and then Nkind
(N
) = N_Selected_Component
1114 and then Is_Dispatching_Operation
(Entity
(Selector_Name
(N
)))
1116 Analyze_Selected_Component
(N
);
1118 if Nkind
(N
) /= N_Selected_Component
then
1123 Nam
:= New_Copy
(N
);
1125 -- If overloaded, overload set belongs to new copy
1127 Save_Interps
(N
, Nam
);
1129 -- Change node to parameterless function call (note that the
1130 -- Parameter_Associations associations field is left set to Empty,
1131 -- its normal default value since there are no parameters)
1133 Change_Node
(N
, N_Function_Call
);
1135 Set_Sloc
(N
, Sloc
(Nam
));
1139 elsif Nkind
(N
) = N_Parameter_Association
then
1140 Check_Parameterless_Call
(Explicit_Actual_Parameter
(N
));
1142 elsif Nkind
(N
) = N_Operator_Symbol
then
1143 Change_Operator_Symbol_To_String_Literal
(N
);
1144 Set_Is_Overloaded
(N
, False);
1145 Set_Etype
(N
, Any_String
);
1147 end Check_Parameterless_Call
;
1149 -----------------------------
1150 -- Is_Definite_Access_Type --
1151 -----------------------------
1153 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean is
1154 Btyp
: constant Entity_Id
:= Base_Type
(E
);
1156 return Ekind
(Btyp
) = E_Access_Type
1157 or else (Ekind
(Btyp
) = E_Access_Subprogram_Type
1158 and then Comes_From_Source
(Btyp
));
1159 end Is_Definite_Access_Type
;
1161 ----------------------
1162 -- Is_Predefined_Op --
1163 ----------------------
1165 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean is
1167 -- Predefined operators are intrinsic subprograms
1169 if not Is_Intrinsic_Subprogram
(Nam
) then
1173 -- A call to a back-end builtin is never a predefined operator
1175 if Is_Imported
(Nam
) and then Present
(Interface_Name
(Nam
)) then
1179 return not Is_Generic_Instance
(Nam
)
1180 and then Chars
(Nam
) in Any_Operator_Name
1181 and then (No
(Alias
(Nam
)) or else Is_Predefined_Op
(Alias
(Nam
)));
1182 end Is_Predefined_Op
;
1184 -----------------------------
1185 -- Make_Call_Into_Operator --
1186 -----------------------------
1188 procedure Make_Call_Into_Operator
1193 Op_Name
: constant Name_Id
:= Chars
(Op_Id
);
1194 Act1
: Node_Id
:= First_Actual
(N
);
1195 Act2
: Node_Id
:= Next_Actual
(Act1
);
1196 Error
: Boolean := False;
1197 Func
: constant Entity_Id
:= Entity
(Name
(N
));
1198 Is_Binary
: constant Boolean := Present
(Act2
);
1200 Opnd_Type
: Entity_Id
;
1201 Orig_Type
: Entity_Id
:= Empty
;
1204 type Kind_Test
is access function (E
: Entity_Id
) return Boolean;
1206 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean;
1207 -- If the operand is not universal, and the operator is given by an
1208 -- expanded name, verify that the operand has an interpretation with a
1209 -- type defined in the given scope of the operator.
1211 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
;
1212 -- Find a type of the given class in package Pack that contains the
1215 ---------------------------
1216 -- Operand_Type_In_Scope --
1217 ---------------------------
1219 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean is
1220 Nod
: constant Node_Id
:= Right_Opnd
(Op_Node
);
1225 if not Is_Overloaded
(Nod
) then
1226 return Scope
(Base_Type
(Etype
(Nod
))) = S
;
1229 Get_First_Interp
(Nod
, I
, It
);
1230 while Present
(It
.Typ
) loop
1231 if Scope
(Base_Type
(It
.Typ
)) = S
then
1235 Get_Next_Interp
(I
, It
);
1240 end Operand_Type_In_Scope
;
1246 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
is
1249 function In_Decl
return Boolean;
1250 -- Verify that node is not part of the type declaration for the
1251 -- candidate type, which would otherwise be invisible.
1257 function In_Decl
return Boolean is
1258 Decl_Node
: constant Node_Id
:= Parent
(E
);
1264 if Etype
(E
) = Any_Type
then
1267 elsif No
(Decl_Node
) then
1272 and then Nkind
(N2
) /= N_Compilation_Unit
1274 if N2
= Decl_Node
then
1285 -- Start of processing for Type_In_P
1288 -- If the context type is declared in the prefix package, this is the
1289 -- desired base type.
1291 if Scope
(Base_Type
(Typ
)) = Pack
and then Test
(Typ
) then
1292 return Base_Type
(Typ
);
1295 E
:= First_Entity
(Pack
);
1296 while Present
(E
) loop
1298 and then not In_Decl
1310 -- Start of processing for Make_Call_Into_Operator
1313 Op_Node
:= New_Node
(Operator_Kind
(Op_Name
, Is_Binary
), Sloc
(N
));
1318 Set_Left_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1319 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act2
));
1320 Save_Interps
(Act1
, Left_Opnd
(Op_Node
));
1321 Save_Interps
(Act2
, Right_Opnd
(Op_Node
));
1322 Act1
:= Left_Opnd
(Op_Node
);
1323 Act2
:= Right_Opnd
(Op_Node
);
1328 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1329 Save_Interps
(Act1
, Right_Opnd
(Op_Node
));
1330 Act1
:= Right_Opnd
(Op_Node
);
1333 -- If the operator is denoted by an expanded name, and the prefix is
1334 -- not Standard, but the operator is a predefined one whose scope is
1335 -- Standard, then this is an implicit_operator, inserted as an
1336 -- interpretation by the procedure of the same name. This procedure
1337 -- overestimates the presence of implicit operators, because it does
1338 -- not examine the type of the operands. Verify now that the operand
1339 -- type appears in the given scope. If right operand is universal,
1340 -- check the other operand. In the case of concatenation, either
1341 -- argument can be the component type, so check the type of the result.
1342 -- If both arguments are literals, look for a type of the right kind
1343 -- defined in the given scope. This elaborate nonsense is brought to
1344 -- you courtesy of b33302a. The type itself must be frozen, so we must
1345 -- find the type of the proper class in the given scope.
1347 -- A final wrinkle is the multiplication operator for fixed point types,
1348 -- which is defined in Standard only, and not in the scope of the
1349 -- fixed point type itself.
1351 if Nkind
(Name
(N
)) = N_Expanded_Name
then
1352 Pack
:= Entity
(Prefix
(Name
(N
)));
1354 -- If this is a package renaming, get renamed entity, which will be
1355 -- the scope of the operands if operaton is type-correct.
1357 if Present
(Renamed_Entity
(Pack
)) then
1358 Pack
:= Renamed_Entity
(Pack
);
1361 -- If the entity being called is defined in the given package, it is
1362 -- a renaming of a predefined operator, and known to be legal.
1364 if Scope
(Entity
(Name
(N
))) = Pack
1365 and then Pack
/= Standard_Standard
1369 -- Visibility does not need to be checked in an instance: if the
1370 -- operator was not visible in the generic it has been diagnosed
1371 -- already, else there is an implicit copy of it in the instance.
1373 elsif In_Instance
then
1376 elsif Nam_In
(Op_Name
, Name_Op_Multiply
, Name_Op_Divide
)
1377 and then Is_Fixed_Point_Type
(Etype
(Left_Opnd
(Op_Node
)))
1378 and then Is_Fixed_Point_Type
(Etype
(Right_Opnd
(Op_Node
)))
1380 if Pack
/= Standard_Standard
then
1384 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1387 elsif Ada_Version
>= Ada_2005
1388 and then Nam_In
(Op_Name
, Name_Op_Eq
, Name_Op_Ne
)
1389 and then Ekind
(Etype
(Act1
)) = E_Anonymous_Access_Type
1394 Opnd_Type
:= Base_Type
(Etype
(Right_Opnd
(Op_Node
)));
1396 if Op_Name
= Name_Op_Concat
then
1397 Opnd_Type
:= Base_Type
(Typ
);
1399 elsif (Scope
(Opnd_Type
) = Standard_Standard
1401 or else (Nkind
(Right_Opnd
(Op_Node
)) = N_Attribute_Reference
1403 and then not Comes_From_Source
(Opnd_Type
))
1405 Opnd_Type
:= Base_Type
(Etype
(Left_Opnd
(Op_Node
)));
1408 if Scope
(Opnd_Type
) = Standard_Standard
then
1410 -- Verify that the scope contains a type that corresponds to
1411 -- the given literal. Optimize the case where Pack is Standard.
1413 if Pack
/= Standard_Standard
then
1415 if Opnd_Type
= Universal_Integer
then
1416 Orig_Type
:= Type_In_P
(Is_Integer_Type
'Access);
1418 elsif Opnd_Type
= Universal_Real
then
1419 Orig_Type
:= Type_In_P
(Is_Real_Type
'Access);
1421 elsif Opnd_Type
= Any_String
then
1422 Orig_Type
:= Type_In_P
(Is_String_Type
'Access);
1424 elsif Opnd_Type
= Any_Access
then
1425 Orig_Type
:= Type_In_P
(Is_Definite_Access_Type
'Access);
1427 elsif Opnd_Type
= Any_Composite
then
1428 Orig_Type
:= Type_In_P
(Is_Composite_Type
'Access);
1430 if Present
(Orig_Type
) then
1431 if Has_Private_Component
(Orig_Type
) then
1434 Set_Etype
(Act1
, Orig_Type
);
1437 Set_Etype
(Act2
, Orig_Type
);
1446 Error
:= No
(Orig_Type
);
1449 elsif Ekind
(Opnd_Type
) = E_Allocator_Type
1450 and then No
(Type_In_P
(Is_Definite_Access_Type
'Access))
1454 -- If the type is defined elsewhere, and the operator is not
1455 -- defined in the given scope (by a renaming declaration, e.g.)
1456 -- then this is an error as well. If an extension of System is
1457 -- present, and the type may be defined there, Pack must be
1460 elsif Scope
(Opnd_Type
) /= Pack
1461 and then Scope
(Op_Id
) /= Pack
1462 and then (No
(System_Aux_Id
)
1463 or else Scope
(Opnd_Type
) /= System_Aux_Id
1464 or else Pack
/= Scope
(System_Aux_Id
))
1466 if not Is_Overloaded
(Right_Opnd
(Op_Node
)) then
1469 Error
:= not Operand_Type_In_Scope
(Pack
);
1472 elsif Pack
= Standard_Standard
1473 and then not Operand_Type_In_Scope
(Standard_Standard
)
1480 Error_Msg_Node_2
:= Pack
;
1482 ("& not declared in&", N
, Selector_Name
(Name
(N
)));
1483 Set_Etype
(N
, Any_Type
);
1486 -- Detect a mismatch between the context type and the result type
1487 -- in the named package, which is otherwise not detected if the
1488 -- operands are universal. Check is only needed if source entity is
1489 -- an operator, not a function that renames an operator.
1491 elsif Nkind
(Parent
(N
)) /= N_Type_Conversion
1492 and then Ekind
(Entity
(Name
(N
))) = E_Operator
1493 and then Is_Numeric_Type
(Typ
)
1494 and then not Is_Universal_Numeric_Type
(Typ
)
1495 and then Scope
(Base_Type
(Typ
)) /= Pack
1496 and then not In_Instance
1498 if Is_Fixed_Point_Type
(Typ
)
1499 and then Nam_In
(Op_Name
, Name_Op_Multiply
, Name_Op_Divide
)
1501 -- Already checked above
1505 -- Operator may be defined in an extension of System
1507 elsif Present
(System_Aux_Id
)
1508 and then Scope
(Opnd_Type
) = System_Aux_Id
1513 -- Could we use Wrong_Type here??? (this would require setting
1514 -- Etype (N) to the actual type found where Typ was expected).
1516 Error_Msg_NE
("expect }", N
, Typ
);
1521 Set_Chars
(Op_Node
, Op_Name
);
1523 if not Is_Private_Type
(Etype
(N
)) then
1524 Set_Etype
(Op_Node
, Base_Type
(Etype
(N
)));
1526 Set_Etype
(Op_Node
, Etype
(N
));
1529 -- If this is a call to a function that renames a predefined equality,
1530 -- the renaming declaration provides a type that must be used to
1531 -- resolve the operands. This must be done now because resolution of
1532 -- the equality node will not resolve any remaining ambiguity, and it
1533 -- assumes that the first operand is not overloaded.
1535 if Nam_In
(Op_Name
, Name_Op_Eq
, Name_Op_Ne
)
1536 and then Ekind
(Func
) = E_Function
1537 and then Is_Overloaded
(Act1
)
1539 Resolve
(Act1
, Base_Type
(Etype
(First_Formal
(Func
))));
1540 Resolve
(Act2
, Base_Type
(Etype
(First_Formal
(Func
))));
1543 Set_Entity
(Op_Node
, Op_Id
);
1544 Generate_Reference
(Op_Id
, N
, ' ');
1546 -- Do rewrite setting Comes_From_Source on the result if the original
1547 -- call came from source. Although it is not strictly the case that the
1548 -- operator as such comes from the source, logically it corresponds
1549 -- exactly to the function call in the source, so it should be marked
1550 -- this way (e.g. to make sure that validity checks work fine).
1553 CS
: constant Boolean := Comes_From_Source
(N
);
1555 Rewrite
(N
, Op_Node
);
1556 Set_Comes_From_Source
(N
, CS
);
1559 -- If this is an arithmetic operator and the result type is private,
1560 -- the operands and the result must be wrapped in conversion to
1561 -- expose the underlying numeric type and expand the proper checks,
1562 -- e.g. on division.
1564 if Is_Private_Type
(Typ
) then
1566 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1567 N_Op_Expon | N_Op_Mod | N_Op_Rem
=>
1568 Resolve_Intrinsic_Operator
(N
, Typ
);
1570 when N_Op_Plus | N_Op_Minus | N_Op_Abs
=>
1571 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
1580 -- If in ASIS_Mode, propagate operand types to original actuals of
1581 -- function call, which would otherwise not be fully resolved. If
1582 -- the call has already been constant-folded, nothing to do.
1584 if ASIS_Mode
and then Nkind
(N
) in N_Op
then
1586 Set_Parameter_Associations
1588 New_List
(New_Copy_Tree
(Left_Opnd
(N
)),
1589 New_Copy_Tree
(Right_Opnd
(N
))));
1591 Set_Parameter_Associations
1593 New_List
(New_Copy_Tree
(Right_Opnd
(N
))));
1596 end Make_Call_Into_Operator
;
1602 function Operator_Kind
1604 Is_Binary
: Boolean) return Node_Kind
1609 -- Use CASE statement or array???
1612 if Op_Name
= Name_Op_And
then
1614 elsif Op_Name
= Name_Op_Or
then
1616 elsif Op_Name
= Name_Op_Xor
then
1618 elsif Op_Name
= Name_Op_Eq
then
1620 elsif Op_Name
= Name_Op_Ne
then
1622 elsif Op_Name
= Name_Op_Lt
then
1624 elsif Op_Name
= Name_Op_Le
then
1626 elsif Op_Name
= Name_Op_Gt
then
1628 elsif Op_Name
= Name_Op_Ge
then
1630 elsif Op_Name
= Name_Op_Add
then
1632 elsif Op_Name
= Name_Op_Subtract
then
1633 Kind
:= N_Op_Subtract
;
1634 elsif Op_Name
= Name_Op_Concat
then
1635 Kind
:= N_Op_Concat
;
1636 elsif Op_Name
= Name_Op_Multiply
then
1637 Kind
:= N_Op_Multiply
;
1638 elsif Op_Name
= Name_Op_Divide
then
1639 Kind
:= N_Op_Divide
;
1640 elsif Op_Name
= Name_Op_Mod
then
1642 elsif Op_Name
= Name_Op_Rem
then
1644 elsif Op_Name
= Name_Op_Expon
then
1647 raise Program_Error
;
1653 if Op_Name
= Name_Op_Add
then
1655 elsif Op_Name
= Name_Op_Subtract
then
1657 elsif Op_Name
= Name_Op_Abs
then
1659 elsif Op_Name
= Name_Op_Not
then
1662 raise Program_Error
;
1669 ----------------------------
1670 -- Preanalyze_And_Resolve --
1671 ----------------------------
1673 procedure Preanalyze_And_Resolve
(N
: Node_Id
; T
: Entity_Id
) is
1674 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1677 Full_Analysis
:= False;
1678 Expander_Mode_Save_And_Set
(False);
1680 -- Normally, we suppress all checks for this preanalysis. There is no
1681 -- point in processing them now, since they will be applied properly
1682 -- and in the proper location when the default expressions reanalyzed
1683 -- and reexpanded later on. We will also have more information at that
1684 -- point for possible suppression of individual checks.
1686 -- However, in SPARK mode, most expansion is suppressed, and this
1687 -- later reanalysis and reexpansion may not occur. SPARK mode does
1688 -- require the setting of checking flags for proof purposes, so we
1689 -- do the SPARK preanalysis without suppressing checks.
1691 -- This special handling for SPARK mode is required for example in the
1692 -- case of Ada 2012 constructs such as quantified expressions, which are
1693 -- expanded in two separate steps.
1696 Analyze_And_Resolve
(N
, T
);
1698 Analyze_And_Resolve
(N
, T
, Suppress
=> All_Checks
);
1701 Expander_Mode_Restore
;
1702 Full_Analysis
:= Save_Full_Analysis
;
1703 end Preanalyze_And_Resolve
;
1705 -- Version without context type
1707 procedure Preanalyze_And_Resolve
(N
: Node_Id
) is
1708 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1711 Full_Analysis
:= False;
1712 Expander_Mode_Save_And_Set
(False);
1715 Resolve
(N
, Etype
(N
), Suppress
=> All_Checks
);
1717 Expander_Mode_Restore
;
1718 Full_Analysis
:= Save_Full_Analysis
;
1719 end Preanalyze_And_Resolve
;
1721 ----------------------------------
1722 -- Replace_Actual_Discriminants --
1723 ----------------------------------
1725 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
) is
1726 Loc
: constant Source_Ptr
:= Sloc
(N
);
1727 Tsk
: Node_Id
:= Empty
;
1729 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
;
1730 -- Comment needed???
1736 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
is
1740 if Nkind
(Nod
) = N_Identifier
then
1741 Ent
:= Entity
(Nod
);
1744 and then Ekind
(Ent
) = E_Discriminant
1747 Make_Selected_Component
(Loc
,
1748 Prefix
=> New_Copy_Tree
(Tsk
, New_Sloc
=> Loc
),
1749 Selector_Name
=> Make_Identifier
(Loc
, Chars
(Ent
))));
1751 Set_Etype
(Nod
, Etype
(Ent
));
1759 procedure Replace_Discrs
is new Traverse_Proc
(Process_Discr
);
1761 -- Start of processing for Replace_Actual_Discriminants
1764 if not Full_Expander_Active
then
1768 if Nkind
(Name
(N
)) = N_Selected_Component
then
1769 Tsk
:= Prefix
(Name
(N
));
1771 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
1772 Tsk
:= Prefix
(Prefix
(Name
(N
)));
1778 Replace_Discrs
(Default
);
1780 end Replace_Actual_Discriminants
;
1786 procedure Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
1787 Ambiguous
: Boolean := False;
1788 Ctx_Type
: Entity_Id
:= Typ
;
1789 Expr_Type
: Entity_Id
:= Empty
; -- prevent junk warning
1790 Err_Type
: Entity_Id
:= Empty
;
1791 Found
: Boolean := False;
1794 I1
: Interp_Index
:= 0; -- prevent junk warning
1797 Seen
: Entity_Id
:= Empty
; -- prevent junk warning
1799 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean;
1800 -- Determine whether a node comes from a predefined library unit or
1803 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
);
1804 -- Try and fix up a literal so that it matches its expected type. New
1805 -- literals are manufactured if necessary to avoid cascaded errors.
1807 function Proper_Current_Scope
return Entity_Id
;
1808 -- Return the current scope. Skip loop scopes created for the purpose of
1809 -- quantified expression analysis since those do not appear in the tree.
1811 procedure Report_Ambiguous_Argument
;
1812 -- Additional diagnostics when an ambiguous call has an ambiguous
1813 -- argument (typically a controlling actual).
1815 procedure Resolution_Failed
;
1816 -- Called when attempt at resolving current expression fails
1818 ------------------------------------
1819 -- Comes_From_Predefined_Lib_Unit --
1820 -------------------------------------
1822 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean is
1825 Sloc
(Nod
) = Standard_Location
1826 or else Is_Predefined_File_Name
1827 (Unit_File_Name
(Get_Source_Unit
(Sloc
(Nod
))));
1828 end Comes_From_Predefined_Lib_Unit
;
1830 --------------------
1831 -- Patch_Up_Value --
1832 --------------------
1834 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
) is
1836 if Nkind
(N
) = N_Integer_Literal
and then Is_Real_Type
(Typ
) then
1838 Make_Real_Literal
(Sloc
(N
),
1839 Realval
=> UR_From_Uint
(Intval
(N
))));
1840 Set_Etype
(N
, Universal_Real
);
1841 Set_Is_Static_Expression
(N
);
1843 elsif Nkind
(N
) = N_Real_Literal
and then Is_Integer_Type
(Typ
) then
1845 Make_Integer_Literal
(Sloc
(N
),
1846 Intval
=> UR_To_Uint
(Realval
(N
))));
1847 Set_Etype
(N
, Universal_Integer
);
1848 Set_Is_Static_Expression
(N
);
1850 elsif Nkind
(N
) = N_String_Literal
1851 and then Is_Character_Type
(Typ
)
1853 Set_Character_Literal_Name
(Char_Code
(Character'Pos ('A')));
1855 Make_Character_Literal
(Sloc
(N
),
1857 Char_Literal_Value
=>
1858 UI_From_Int
(Character'Pos ('A'))));
1859 Set_Etype
(N
, Any_Character
);
1860 Set_Is_Static_Expression
(N
);
1862 elsif Nkind
(N
) /= N_String_Literal
and then Is_String_Type
(Typ
) then
1864 Make_String_Literal
(Sloc
(N
),
1865 Strval
=> End_String
));
1867 elsif Nkind
(N
) = N_Range
then
1868 Patch_Up_Value
(Low_Bound
(N
), Typ
);
1869 Patch_Up_Value
(High_Bound
(N
), Typ
);
1873 --------------------------
1874 -- Proper_Current_Scope --
1875 --------------------------
1877 function Proper_Current_Scope
return Entity_Id
is
1878 S
: Entity_Id
:= Current_Scope
;
1881 while Present
(S
) loop
1883 -- Skip a loop scope created for quantified expression analysis
1885 if Ekind
(S
) = E_Loop
1886 and then Nkind
(Parent
(S
)) = N_Quantified_Expression
1895 end Proper_Current_Scope
;
1897 -------------------------------
1898 -- Report_Ambiguous_Argument --
1899 -------------------------------
1901 procedure Report_Ambiguous_Argument
is
1902 Arg
: constant Node_Id
:= First
(Parameter_Associations
(N
));
1907 if Nkind
(Arg
) = N_Function_Call
1908 and then Is_Entity_Name
(Name
(Arg
))
1909 and then Is_Overloaded
(Name
(Arg
))
1911 Error_Msg_NE
("ambiguous call to&", Arg
, Name
(Arg
));
1913 -- Could use comments on what is going on here???
1915 Get_First_Interp
(Name
(Arg
), I
, It
);
1916 while Present
(It
.Nam
) loop
1917 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
1919 if Nkind
(Parent
(It
.Nam
)) = N_Full_Type_Declaration
then
1920 Error_Msg_N
("interpretation (inherited) #!", Arg
);
1922 Error_Msg_N
("interpretation #!", Arg
);
1925 Get_Next_Interp
(I
, It
);
1928 end Report_Ambiguous_Argument
;
1930 -----------------------
1931 -- Resolution_Failed --
1932 -----------------------
1934 procedure Resolution_Failed
is
1936 Patch_Up_Value
(N
, Typ
);
1938 Debug_A_Exit
("resolving ", N
, " (done, resolution failed)");
1939 Set_Is_Overloaded
(N
, False);
1941 -- The caller will return without calling the expander, so we need
1942 -- to set the analyzed flag. Note that it is fine to set Analyzed
1943 -- to True even if we are in the middle of a shallow analysis,
1944 -- (see the spec of sem for more details) since this is an error
1945 -- situation anyway, and there is no point in repeating the
1946 -- analysis later (indeed it won't work to repeat it later, since
1947 -- we haven't got a clear resolution of which entity is being
1950 Set_Analyzed
(N
, True);
1952 end Resolution_Failed
;
1954 -- Start of processing for Resolve
1961 -- Access attribute on remote subprogram cannot be used for a non-remote
1962 -- access-to-subprogram type.
1964 if Nkind
(N
) = N_Attribute_Reference
1965 and then Nam_In
(Attribute_Name
(N
), Name_Access
,
1966 Name_Unrestricted_Access
,
1967 Name_Unchecked_Access
)
1968 and then Comes_From_Source
(N
)
1969 and then Is_Entity_Name
(Prefix
(N
))
1970 and then Is_Subprogram
(Entity
(Prefix
(N
)))
1971 and then Is_Remote_Call_Interface
(Entity
(Prefix
(N
)))
1972 and then not Is_Remote_Access_To_Subprogram_Type
(Typ
)
1975 ("prefix must statically denote a non-remote subprogram", N
);
1978 From_Lib
:= Comes_From_Predefined_Lib_Unit
(N
);
1980 -- If the context is a Remote_Access_To_Subprogram, access attributes
1981 -- must be resolved with the corresponding fat pointer. There is no need
1982 -- to check for the attribute name since the return type of an
1983 -- attribute is never a remote type.
1985 if Nkind
(N
) = N_Attribute_Reference
1986 and then Comes_From_Source
(N
)
1987 and then (Is_Remote_Call_Interface
(Typ
) or else Is_Remote_Types
(Typ
))
1990 Attr
: constant Attribute_Id
:=
1991 Get_Attribute_Id
(Attribute_Name
(N
));
1992 Pref
: constant Node_Id
:= Prefix
(N
);
1995 Is_Remote
: Boolean := True;
1998 -- Check that Typ is a remote access-to-subprogram type
2000 if Is_Remote_Access_To_Subprogram_Type
(Typ
) then
2002 -- Prefix (N) must statically denote a remote subprogram
2003 -- declared in a package specification.
2005 if Attr
= Attribute_Access
or else
2006 Attr
= Attribute_Unchecked_Access
or else
2007 Attr
= Attribute_Unrestricted_Access
2009 Decl
:= Unit_Declaration_Node
(Entity
(Pref
));
2011 if Nkind
(Decl
) = N_Subprogram_Body
then
2012 Spec
:= Corresponding_Spec
(Decl
);
2014 if not No
(Spec
) then
2015 Decl
:= Unit_Declaration_Node
(Spec
);
2019 Spec
:= Parent
(Decl
);
2021 if not Is_Entity_Name
(Prefix
(N
))
2022 or else Nkind
(Spec
) /= N_Package_Specification
2024 not Is_Remote_Call_Interface
(Defining_Entity
(Spec
))
2028 ("prefix must statically denote a remote subprogram ",
2032 -- If we are generating code in distributed mode, perform
2033 -- semantic checks against corresponding remote entities.
2035 if Full_Expander_Active
2036 and then Get_PCS_Name
/= Name_No_DSA
2038 Check_Subtype_Conformant
2039 (New_Id
=> Entity
(Prefix
(N
)),
2040 Old_Id
=> Designated_Type
2041 (Corresponding_Remote_Type
(Typ
)),
2045 Process_Remote_AST_Attribute
(N
, Typ
);
2053 Debug_A_Entry
("resolving ", N
);
2055 if Debug_Flag_V
then
2056 Write_Overloads
(N
);
2059 if Comes_From_Source
(N
) then
2060 if Is_Fixed_Point_Type
(Typ
) then
2061 Check_Restriction
(No_Fixed_Point
, N
);
2063 elsif Is_Floating_Point_Type
(Typ
)
2064 and then Typ
/= Universal_Real
2065 and then Typ
/= Any_Real
2067 Check_Restriction
(No_Floating_Point
, N
);
2071 -- Return if already analyzed
2073 if Analyzed
(N
) then
2074 Debug_A_Exit
("resolving ", N
, " (done, already analyzed)");
2075 Analyze_Dimension
(N
);
2078 -- A Raise_Expression takes its type from context. The Etype was set
2079 -- to Any_Type, reflecting the fact that the expression itself does
2080 -- not specify any possible interpretation. So we set the type to the
2081 -- resolution type here and now. We need to do this before Resolve sees
2082 -- the Any_Type value.
2084 elsif Nkind
(N
) = N_Raise_Expression
then
2087 -- Any other case of Any_Type as the Etype value means that we had
2088 -- a previous error.
2090 elsif Etype
(N
) = Any_Type
then
2091 Debug_A_Exit
("resolving ", N
, " (done, Etype = Any_Type)");
2095 Check_Parameterless_Call
(N
);
2097 -- If not overloaded, then we know the type, and all that needs doing
2098 -- is to check that this type is compatible with the context.
2100 if not Is_Overloaded
(N
) then
2101 Found
:= Covers
(Typ
, Etype
(N
));
2102 Expr_Type
:= Etype
(N
);
2104 -- In the overloaded case, we must select the interpretation that
2105 -- is compatible with the context (i.e. the type passed to Resolve)
2108 -- Loop through possible interpretations
2110 Get_First_Interp
(N
, I
, It
);
2111 Interp_Loop
: while Present
(It
.Typ
) loop
2113 if Debug_Flag_V
then
2114 Write_Str
("Interp: ");
2118 -- We are only interested in interpretations that are compatible
2119 -- with the expected type, any other interpretations are ignored.
2121 if not Covers
(Typ
, It
.Typ
) then
2122 if Debug_Flag_V
then
2123 Write_Str
(" interpretation incompatible with context");
2128 -- Skip the current interpretation if it is disabled by an
2129 -- abstract operator. This action is performed only when the
2130 -- type against which we are resolving is the same as the
2131 -- type of the interpretation.
2133 if Ada_Version
>= Ada_2005
2134 and then It
.Typ
= Typ
2135 and then Typ
/= Universal_Integer
2136 and then Typ
/= Universal_Real
2137 and then Present
(It
.Abstract_Op
)
2139 if Debug_Flag_V
then
2140 Write_Line
("Skip.");
2146 -- First matching interpretation
2152 Expr_Type
:= It
.Typ
;
2154 -- Matching interpretation that is not the first, maybe an
2155 -- error, but there are some cases where preference rules are
2156 -- used to choose between the two possibilities. These and
2157 -- some more obscure cases are handled in Disambiguate.
2160 -- If the current statement is part of a predefined library
2161 -- unit, then all interpretations which come from user level
2162 -- packages should not be considered.
2165 and then not Comes_From_Predefined_Lib_Unit
(It
.Nam
)
2170 Error_Msg_Sloc
:= Sloc
(Seen
);
2171 It1
:= Disambiguate
(N
, I1
, I
, Typ
);
2173 -- Disambiguation has succeeded. Skip the remaining
2176 if It1
/= No_Interp
then
2178 Expr_Type
:= It1
.Typ
;
2180 while Present
(It
.Typ
) loop
2181 Get_Next_Interp
(I
, It
);
2185 -- Before we issue an ambiguity complaint, check for
2186 -- the case of a subprogram call where at least one
2187 -- of the arguments is Any_Type, and if so, suppress
2188 -- the message, since it is a cascaded error.
2190 if Nkind
(N
) in N_Subprogram_Call
then
2196 A
:= First_Actual
(N
);
2197 while Present
(A
) loop
2200 if Nkind
(E
) = N_Parameter_Association
then
2201 E
:= Explicit_Actual_Parameter
(E
);
2204 if Etype
(E
) = Any_Type
then
2205 if Debug_Flag_V
then
2206 Write_Str
("Any_Type in call");
2217 elsif Nkind
(N
) in N_Binary_Op
2218 and then (Etype
(Left_Opnd
(N
)) = Any_Type
2219 or else Etype
(Right_Opnd
(N
)) = Any_Type
)
2223 elsif Nkind
(N
) in N_Unary_Op
2224 and then Etype
(Right_Opnd
(N
)) = Any_Type
2229 -- Not that special case, so issue message using the
2230 -- flag Ambiguous to control printing of the header
2231 -- message only at the start of an ambiguous set.
2233 if not Ambiguous
then
2234 if Nkind
(N
) = N_Function_Call
2235 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2238 ("ambiguous expression "
2239 & "(cannot resolve indirect call)!", N
);
2241 Error_Msg_NE
-- CODEFIX
2242 ("ambiguous expression (cannot resolve&)!",
2248 if Nkind
(Parent
(Seen
)) = N_Full_Type_Declaration
then
2250 ("\\possible interpretation (inherited)#!", N
);
2252 Error_Msg_N
-- CODEFIX
2253 ("\\possible interpretation#!", N
);
2256 if Nkind
(N
) in N_Subprogram_Call
2257 and then Present
(Parameter_Associations
(N
))
2259 Report_Ambiguous_Argument
;
2263 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2265 -- By default, the error message refers to the candidate
2266 -- interpretation. But if it is a predefined operator, it
2267 -- is implicitly declared at the declaration of the type
2268 -- of the operand. Recover the sloc of that declaration
2269 -- for the error message.
2271 if Nkind
(N
) in N_Op
2272 and then Scope
(It
.Nam
) = Standard_Standard
2273 and then not Is_Overloaded
(Right_Opnd
(N
))
2274 and then Scope
(Base_Type
(Etype
(Right_Opnd
(N
)))) /=
2277 Err_Type
:= First_Subtype
(Etype
(Right_Opnd
(N
)));
2279 if Comes_From_Source
(Err_Type
)
2280 and then Present
(Parent
(Err_Type
))
2282 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2285 elsif Nkind
(N
) in N_Binary_Op
2286 and then Scope
(It
.Nam
) = Standard_Standard
2287 and then not Is_Overloaded
(Left_Opnd
(N
))
2288 and then Scope
(Base_Type
(Etype
(Left_Opnd
(N
)))) /=
2291 Err_Type
:= First_Subtype
(Etype
(Left_Opnd
(N
)));
2293 if Comes_From_Source
(Err_Type
)
2294 and then Present
(Parent
(Err_Type
))
2296 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2299 -- If this is an indirect call, use the subprogram_type
2300 -- in the message, to have a meaningful location. Also
2301 -- indicate if this is an inherited operation, created
2302 -- by a type declaration.
2304 elsif Nkind
(N
) = N_Function_Call
2305 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2306 and then Is_Type
(It
.Nam
)
2310 Sloc
(Associated_Node_For_Itype
(Err_Type
));
2315 if Nkind
(N
) in N_Op
2316 and then Scope
(It
.Nam
) = Standard_Standard
2317 and then Present
(Err_Type
)
2319 -- Special-case the message for universal_fixed
2320 -- operators, which are not declared with the type
2321 -- of the operand, but appear forever in Standard.
2323 if It
.Typ
= Universal_Fixed
2324 and then Scope
(It
.Nam
) = Standard_Standard
2327 ("\\possible interpretation as universal_fixed "
2328 & "operation (RM 4.5.5 (19))", N
);
2331 ("\\possible interpretation (predefined)#!", N
);
2335 Nkind
(Parent
(It
.Nam
)) = N_Full_Type_Declaration
2338 ("\\possible interpretation (inherited)#!", N
);
2340 Error_Msg_N
-- CODEFIX
2341 ("\\possible interpretation#!", N
);
2347 -- We have a matching interpretation, Expr_Type is the type
2348 -- from this interpretation, and Seen is the entity.
2350 -- For an operator, just set the entity name. The type will be
2351 -- set by the specific operator resolution routine.
2353 if Nkind
(N
) in N_Op
then
2354 Set_Entity
(N
, Seen
);
2355 Generate_Reference
(Seen
, N
);
2357 elsif Nkind
(N
) = N_Case_Expression
then
2358 Set_Etype
(N
, Expr_Type
);
2360 elsif Nkind
(N
) = N_Character_Literal
then
2361 Set_Etype
(N
, Expr_Type
);
2363 elsif Nkind
(N
) = N_If_Expression
then
2364 Set_Etype
(N
, Expr_Type
);
2366 -- AI05-0139-2: Expression is overloaded because type has
2367 -- implicit dereference. If type matches context, no implicit
2368 -- dereference is involved.
2370 elsif Has_Implicit_Dereference
(Expr_Type
) then
2371 Set_Etype
(N
, Expr_Type
);
2372 Set_Is_Overloaded
(N
, False);
2375 elsif Is_Overloaded
(N
)
2376 and then Present
(It
.Nam
)
2377 and then Ekind
(It
.Nam
) = E_Discriminant
2378 and then Has_Implicit_Dereference
(It
.Nam
)
2380 Build_Explicit_Dereference
(N
, It
.Nam
);
2382 -- For an explicit dereference, attribute reference, range,
2383 -- short-circuit form (which is not an operator node), or call
2384 -- with a name that is an explicit dereference, there is
2385 -- nothing to be done at this point.
2387 elsif Nkind_In
(N
, N_Explicit_Dereference
,
2388 N_Attribute_Reference
,
2390 N_Indexed_Component
,
2393 N_Selected_Component
,
2395 or else Nkind
(Name
(N
)) = N_Explicit_Dereference
2399 -- For procedure or function calls, set the type of the name,
2400 -- and also the entity pointer for the prefix.
2402 elsif Nkind
(N
) in N_Subprogram_Call
2403 and then Is_Entity_Name
(Name
(N
))
2405 Set_Etype
(Name
(N
), Expr_Type
);
2406 Set_Entity
(Name
(N
), Seen
);
2407 Generate_Reference
(Seen
, Name
(N
));
2409 elsif Nkind
(N
) = N_Function_Call
2410 and then Nkind
(Name
(N
)) = N_Selected_Component
2412 Set_Etype
(Name
(N
), Expr_Type
);
2413 Set_Entity
(Selector_Name
(Name
(N
)), Seen
);
2414 Generate_Reference
(Seen
, Selector_Name
(Name
(N
)));
2416 -- For all other cases, just set the type of the Name
2419 Set_Etype
(Name
(N
), Expr_Type
);
2426 -- Move to next interpretation
2428 exit Interp_Loop
when No
(It
.Typ
);
2430 Get_Next_Interp
(I
, It
);
2431 end loop Interp_Loop
;
2434 -- At this stage Found indicates whether or not an acceptable
2435 -- interpretation exists. If not, then we have an error, except that if
2436 -- the context is Any_Type as a result of some other error, then we
2437 -- suppress the error report.
2440 if Typ
/= Any_Type
then
2442 -- If type we are looking for is Void, then this is the procedure
2443 -- call case, and the error is simply that what we gave is not a
2444 -- procedure name (we think of procedure calls as expressions with
2445 -- types internally, but the user doesn't think of them this way!)
2447 if Typ
= Standard_Void_Type
then
2449 -- Special case message if function used as a procedure
2451 if Nkind
(N
) = N_Procedure_Call_Statement
2452 and then Is_Entity_Name
(Name
(N
))
2453 and then Ekind
(Entity
(Name
(N
))) = E_Function
2456 ("cannot use function & in a procedure call",
2457 Name
(N
), Entity
(Name
(N
)));
2459 -- Otherwise give general message (not clear what cases this
2460 -- covers, but no harm in providing for them!)
2463 Error_Msg_N
("expect procedure name in procedure call", N
);
2468 -- Otherwise we do have a subexpression with the wrong type
2470 -- Check for the case of an allocator which uses an access type
2471 -- instead of the designated type. This is a common error and we
2472 -- specialize the message, posting an error on the operand of the
2473 -- allocator, complaining that we expected the designated type of
2476 elsif Nkind
(N
) = N_Allocator
2477 and then Ekind
(Typ
) in Access_Kind
2478 and then Ekind
(Etype
(N
)) in Access_Kind
2479 and then Designated_Type
(Etype
(N
)) = Typ
2481 Wrong_Type
(Expression
(N
), Designated_Type
(Typ
));
2484 -- Check for view mismatch on Null in instances, for which the
2485 -- view-swapping mechanism has no identifier.
2487 elsif (In_Instance
or else In_Inlined_Body
)
2488 and then (Nkind
(N
) = N_Null
)
2489 and then Is_Private_Type
(Typ
)
2490 and then Is_Access_Type
(Full_View
(Typ
))
2492 Resolve
(N
, Full_View
(Typ
));
2496 -- Check for an aggregate. Sometimes we can get bogus aggregates
2497 -- from misuse of parentheses, and we are about to complain about
2498 -- the aggregate without even looking inside it.
2500 -- Instead, if we have an aggregate of type Any_Composite, then
2501 -- analyze and resolve the component fields, and then only issue
2502 -- another message if we get no errors doing this (otherwise
2503 -- assume that the errors in the aggregate caused the problem).
2505 elsif Nkind
(N
) = N_Aggregate
2506 and then Etype
(N
) = Any_Composite
2508 -- Disable expansion in any case. If there is a type mismatch
2509 -- it may be fatal to try to expand the aggregate. The flag
2510 -- would otherwise be set to false when the error is posted.
2512 Expander_Active
:= False;
2515 procedure Check_Aggr
(Aggr
: Node_Id
);
2516 -- Check one aggregate, and set Found to True if we have a
2517 -- definite error in any of its elements
2519 procedure Check_Elmt
(Aelmt
: Node_Id
);
2520 -- Check one element of aggregate and set Found to True if
2521 -- we definitely have an error in the element.
2527 procedure Check_Aggr
(Aggr
: Node_Id
) is
2531 if Present
(Expressions
(Aggr
)) then
2532 Elmt
:= First
(Expressions
(Aggr
));
2533 while Present
(Elmt
) loop
2539 if Present
(Component_Associations
(Aggr
)) then
2540 Elmt
:= First
(Component_Associations
(Aggr
));
2541 while Present
(Elmt
) loop
2543 -- If this is a default-initialized component, then
2544 -- there is nothing to check. The box will be
2545 -- replaced by the appropriate call during late
2548 if not Box_Present
(Elmt
) then
2549 Check_Elmt
(Expression
(Elmt
));
2561 procedure Check_Elmt
(Aelmt
: Node_Id
) is
2563 -- If we have a nested aggregate, go inside it (to
2564 -- attempt a naked analyze-resolve of the aggregate can
2565 -- cause undesirable cascaded errors). Do not resolve
2566 -- expression if it needs a type from context, as for
2567 -- integer * fixed expression.
2569 if Nkind
(Aelmt
) = N_Aggregate
then
2575 if not Is_Overloaded
(Aelmt
)
2576 and then Etype
(Aelmt
) /= Any_Fixed
2581 if Etype
(Aelmt
) = Any_Type
then
2592 -- If an error message was issued already, Found got reset to
2593 -- True, so if it is still False, issue standard Wrong_Type msg.
2596 if Is_Overloaded
(N
)
2597 and then Nkind
(N
) = N_Function_Call
2600 Subp_Name
: Node_Id
;
2602 if Is_Entity_Name
(Name
(N
)) then
2603 Subp_Name
:= Name
(N
);
2605 elsif Nkind
(Name
(N
)) = N_Selected_Component
then
2607 -- Protected operation: retrieve operation name
2609 Subp_Name
:= Selector_Name
(Name
(N
));
2612 raise Program_Error
;
2615 Error_Msg_Node_2
:= Typ
;
2617 ("no visible interpretation of& "
2618 & "matches expected type&", N
, Subp_Name
);
2621 if All_Errors_Mode
then
2623 Index
: Interp_Index
;
2627 Error_Msg_N
("\\possible interpretations:", N
);
2629 Get_First_Interp
(Name
(N
), Index
, It
);
2630 while Present
(It
.Nam
) loop
2631 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2632 Error_Msg_Node_2
:= It
.Nam
;
2634 ("\\ type& for & declared#", N
, It
.Typ
);
2635 Get_Next_Interp
(Index
, It
);
2640 Error_Msg_N
("\use -gnatf for details", N
);
2644 Wrong_Type
(N
, Typ
);
2652 -- Test if we have more than one interpretation for the context
2654 elsif Ambiguous
then
2658 -- Only one intepretation
2661 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2662 -- the "+" on T is abstract, and the operands are of universal type,
2663 -- the above code will have (incorrectly) resolved the "+" to the
2664 -- universal one in Standard. Therefore check for this case and give
2665 -- an error. We can't do this earlier, because it would cause legal
2666 -- cases to get errors (when some other type has an abstract "+").
2668 if Ada_Version
>= Ada_2005
2669 and then Nkind
(N
) in N_Op
2670 and then Is_Overloaded
(N
)
2671 and then Is_Universal_Numeric_Type
(Etype
(Entity
(N
)))
2673 Get_First_Interp
(N
, I
, It
);
2674 while Present
(It
.Typ
) loop
2675 if Present
(It
.Abstract_Op
) and then
2676 Etype
(It
.Abstract_Op
) = Typ
2679 ("cannot call abstract subprogram &!", N
, It
.Abstract_Op
);
2683 Get_Next_Interp
(I
, It
);
2687 -- Here we have an acceptable interpretation for the context
2689 -- Propagate type information and normalize tree for various
2690 -- predefined operations. If the context only imposes a class of
2691 -- types, rather than a specific type, propagate the actual type
2694 if Typ
= Any_Integer
or else
2695 Typ
= Any_Boolean
or else
2696 Typ
= Any_Modular
or else
2697 Typ
= Any_Real
or else
2700 Ctx_Type
:= Expr_Type
;
2702 -- Any_Fixed is legal in a real context only if a specific fixed-
2703 -- point type is imposed. If Norman Cohen can be confused by this,
2704 -- it deserves a separate message.
2707 and then Expr_Type
= Any_Fixed
2709 Error_Msg_N
("illegal context for mixed mode operation", N
);
2710 Set_Etype
(N
, Universal_Real
);
2711 Ctx_Type
:= Universal_Real
;
2715 -- A user-defined operator is transformed into a function call at
2716 -- this point, so that further processing knows that operators are
2717 -- really operators (i.e. are predefined operators). User-defined
2718 -- operators that are intrinsic are just renamings of the predefined
2719 -- ones, and need not be turned into calls either, but if they rename
2720 -- a different operator, we must transform the node accordingly.
2721 -- Instantiations of Unchecked_Conversion are intrinsic but are
2722 -- treated as functions, even if given an operator designator.
2724 if Nkind
(N
) in N_Op
2725 and then Present
(Entity
(N
))
2726 and then Ekind
(Entity
(N
)) /= E_Operator
2729 if not Is_Predefined_Op
(Entity
(N
)) then
2730 Rewrite_Operator_As_Call
(N
, Entity
(N
));
2732 elsif Present
(Alias
(Entity
(N
)))
2734 Nkind
(Parent
(Parent
(Entity
(N
)))) =
2735 N_Subprogram_Renaming_Declaration
2737 Rewrite_Renamed_Operator
(N
, Alias
(Entity
(N
)), Typ
);
2739 -- If the node is rewritten, it will be fully resolved in
2740 -- Rewrite_Renamed_Operator.
2742 if Analyzed
(N
) then
2748 case N_Subexpr
'(Nkind (N)) is
2750 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2752 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2754 when N_Short_Circuit
2755 => Resolve_Short_Circuit (N, Ctx_Type);
2757 when N_Attribute_Reference
2758 => Resolve_Attribute (N, Ctx_Type);
2760 when N_Case_Expression
2761 => Resolve_Case_Expression (N, Ctx_Type);
2763 when N_Character_Literal
2764 => Resolve_Character_Literal (N, Ctx_Type);
2766 when N_Expanded_Name
2767 => Resolve_Entity_Name (N, Ctx_Type);
2769 when N_Explicit_Dereference
2770 => Resolve_Explicit_Dereference (N, Ctx_Type);
2772 when N_Expression_With_Actions
2773 => Resolve_Expression_With_Actions (N, Ctx_Type);
2775 when N_Extension_Aggregate
2776 => Resolve_Extension_Aggregate (N, Ctx_Type);
2778 when N_Function_Call
2779 => Resolve_Call (N, Ctx_Type);
2782 => Resolve_Entity_Name (N, Ctx_Type);
2784 when N_If_Expression
2785 => Resolve_If_Expression (N, Ctx_Type);
2787 when N_Indexed_Component
2788 => Resolve_Indexed_Component (N, Ctx_Type);
2790 when N_Integer_Literal
2791 => Resolve_Integer_Literal (N, Ctx_Type);
2793 when N_Membership_Test
2794 => Resolve_Membership_Op (N, Ctx_Type);
2796 when N_Null => Resolve_Null (N, Ctx_Type);
2798 when N_Op_And | N_Op_Or | N_Op_Xor
2799 => Resolve_Logical_Op (N, Ctx_Type);
2801 when N_Op_Eq | N_Op_Ne
2802 => Resolve_Equality_Op (N, Ctx_Type);
2804 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2805 => Resolve_Comparison_Op (N, Ctx_Type);
2807 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2809 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2810 N_Op_Divide | N_Op_Mod | N_Op_Rem
2812 => Resolve_Arithmetic_Op (N, Ctx_Type);
2814 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2816 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2818 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2819 => Resolve_Unary_Op (N, Ctx_Type);
2821 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2823 when N_Procedure_Call_Statement
2824 => Resolve_Call (N, Ctx_Type);
2826 when N_Operator_Symbol
2827 => Resolve_Operator_Symbol (N, Ctx_Type);
2829 when N_Qualified_Expression
2830 => Resolve_Qualified_Expression (N, Ctx_Type);
2832 -- Why is the following null, needs a comment ???
2834 when N_Quantified_Expression
2837 -- Nothing to do for Raise_Expression, since we took care of
2838 -- setting the Etype earlier, and no other processing is needed.
2840 when N_Raise_Expression
2843 when N_Raise_xxx_Error
2844 => Set_Etype (N, Ctx_Type);
2846 when N_Range => Resolve_Range (N, Ctx_Type);
2849 => Resolve_Real_Literal (N, Ctx_Type);
2851 when N_Reference => Resolve_Reference (N, Ctx_Type);
2853 when N_Selected_Component
2854 => Resolve_Selected_Component (N, Ctx_Type);
2856 when N_Slice => Resolve_Slice (N, Ctx_Type);
2858 when N_String_Literal
2859 => Resolve_String_Literal (N, Ctx_Type);
2861 when N_Subprogram_Info
2862 => Resolve_Subprogram_Info (N, Ctx_Type);
2864 when N_Type_Conversion
2865 => Resolve_Type_Conversion (N, Ctx_Type);
2867 when N_Unchecked_Expression =>
2868 Resolve_Unchecked_Expression (N, Ctx_Type);
2870 when N_Unchecked_Type_Conversion =>
2871 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2874 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2875 -- expression of an anonymous access type that occurs in the context
2876 -- of a named general access type, except when the expression is that
2877 -- of a membership test. This ensures proper legality checking in
2878 -- terms of allowed conversions (expressions that would be illegal to
2879 -- convert implicitly are allowed in membership tests).
2881 if Ada_Version >= Ada_2012
2882 and then Ekind (Ctx_Type) = E_General_Access_Type
2883 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
2884 and then Nkind (Parent (N)) not in N_Membership_Test
2886 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
2887 Analyze_And_Resolve (N, Ctx_Type);
2890 -- If the subexpression was replaced by a non-subexpression, then
2891 -- all we do is to expand it. The only legitimate case we know of
2892 -- is converting procedure call statement to entry call statements,
2893 -- but there may be others, so we are making this test general.
2895 if Nkind (N) not in N_Subexpr then
2896 Debug_A_Exit ("resolving ", N, " (done)");
2901 -- The expression is definitely NOT overloaded at this point, so
2902 -- we reset the Is_Overloaded flag to avoid any confusion when
2903 -- reanalyzing the node.
2905 Set_Is_Overloaded (N, False);
2907 -- Freeze expression type, entity if it is a name, and designated
2908 -- type if it is an allocator (RM 13.14(10,11,13)).
2910 -- Now that the resolution of the type of the node is complete, and
2911 -- we did not detect an error, we can expand this node. We skip the
2912 -- expand call if we are in a default expression, see section
2913 -- "Handling of Default Expressions" in Sem spec.
2915 Debug_A_Exit ("resolving ", N, " (done)");
2917 -- We unconditionally freeze the expression, even if we are in
2918 -- default expression mode (the Freeze_Expression routine tests this
2919 -- flag and only freezes static types if it is set).
2921 -- Ada 2012 (AI05-177): Expression functions do not freeze. Only
2922 -- their use (in an expanded call) freezes.
2924 if Ekind (Proper_Current_Scope) /= E_Function
2925 or else Nkind (Original_Node (Unit_Declaration_Node
2926 (Proper_Current_Scope))) /= N_Expression_Function
2928 Freeze_Expression (N);
2931 -- Now we can do the expansion
2941 -- Version with check(s) suppressed
2943 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2945 if Suppress = All_Checks then
2947 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
2949 Scope_Suppress.Suppress := (others => True);
2951 Scope_Suppress.Suppress := Sva;
2956 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
2958 Scope_Suppress.Suppress (Suppress) := True;
2960 Scope_Suppress.Suppress (Suppress) := Svg;
2969 -- Version with implicit type
2971 procedure Resolve (N : Node_Id) is
2973 Resolve (N, Etype (N));
2976 ---------------------
2977 -- Resolve_Actuals --
2978 ---------------------
2980 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2981 Loc : constant Source_Ptr := Sloc (N);
2986 Prev : Node_Id := Empty;
2989 procedure Check_Argument_Order;
2990 -- Performs a check for the case where the actuals are all simple
2991 -- identifiers that correspond to the formal names, but in the wrong
2992 -- order, which is considered suspicious and cause for a warning.
2994 procedure Check_Prefixed_Call;
2995 -- If the original node is an overloaded call in prefix notation,
2996 -- insert an 'Access or a dereference as needed over the first actual
.
2997 -- Try_Object_Operation has already verified that there is a valid
2998 -- interpretation, but the form of the actual can only be determined
2999 -- once the primitive operation is identified.
3001 procedure Insert_Default
;
3002 -- If the actual is missing in a call, insert in the actuals list
3003 -- an instance of the default expression. The insertion is always
3004 -- a named association.
3006 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean;
3007 -- Check whether T1 and T2, or their full views, are derived from a
3008 -- common type. Used to enforce the restrictions on array conversions
3011 function Static_Concatenation
(N
: Node_Id
) return Boolean;
3012 -- Predicate to determine whether an actual that is a concatenation
3013 -- will be evaluated statically and does not need a transient scope.
3014 -- This must be determined before the actual is resolved and expanded
3015 -- because if needed the transient scope must be introduced earlier.
3017 --------------------------
3018 -- Check_Argument_Order --
3019 --------------------------
3021 procedure Check_Argument_Order
is
3023 -- Nothing to do if no parameters, or original node is neither a
3024 -- function call nor a procedure call statement (happens in the
3025 -- operator-transformed-to-function call case), or the call does
3026 -- not come from source, or this warning is off.
3028 if not Warn_On_Parameter_Order
3029 or else No
(Parameter_Associations
(N
))
3030 or else Nkind
(Original_Node
(N
)) not in N_Subprogram_Call
3031 or else not Comes_From_Source
(N
)
3037 Nargs
: constant Nat
:= List_Length
(Parameter_Associations
(N
));
3040 -- Nothing to do if only one parameter
3046 -- Here if at least two arguments
3049 Actuals
: array (1 .. Nargs
) of Node_Id
;
3053 Wrong_Order
: Boolean := False;
3054 -- Set True if an out of order case is found
3057 -- Collect identifier names of actuals, fail if any actual is
3058 -- not a simple identifier, and record max length of name.
3060 Actual
:= First
(Parameter_Associations
(N
));
3061 for J
in Actuals
'Range loop
3062 if Nkind
(Actual
) /= N_Identifier
then
3065 Actuals
(J
) := Actual
;
3070 -- If we got this far, all actuals are identifiers and the list
3071 -- of their names is stored in the Actuals array.
3073 Formal
:= First_Formal
(Nam
);
3074 for J
in Actuals
'Range loop
3076 -- If we ran out of formals, that's odd, probably an error
3077 -- which will be detected elsewhere, but abandon the search.
3083 -- If name matches and is in order OK
3085 if Chars
(Formal
) = Chars
(Actuals
(J
)) then
3089 -- If no match, see if it is elsewhere in list and if so
3090 -- flag potential wrong order if type is compatible.
3092 for K
in Actuals
'Range loop
3093 if Chars
(Formal
) = Chars
(Actuals
(K
))
3095 Has_Compatible_Type
(Actuals
(K
), Etype
(Formal
))
3097 Wrong_Order
:= True;
3107 <<Continue
>> Next_Formal
(Formal
);
3110 -- If Formals left over, also probably an error, skip warning
3112 if Present
(Formal
) then
3116 -- Here we give the warning if something was out of order
3120 ("?P?actuals for this call may be in wrong order", N
);
3124 end Check_Argument_Order
;
3126 -------------------------
3127 -- Check_Prefixed_Call --
3128 -------------------------
3130 procedure Check_Prefixed_Call
is
3131 Act
: constant Node_Id
:= First_Actual
(N
);
3132 A_Type
: constant Entity_Id
:= Etype
(Act
);
3133 F_Type
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
3134 Orig
: constant Node_Id
:= Original_Node
(N
);
3138 -- Check whether the call is a prefixed call, with or without
3139 -- additional actuals.
3141 if Nkind
(Orig
) = N_Selected_Component
3143 (Nkind
(Orig
) = N_Indexed_Component
3144 and then Nkind
(Prefix
(Orig
)) = N_Selected_Component
3145 and then Is_Entity_Name
(Prefix
(Prefix
(Orig
)))
3146 and then Is_Entity_Name
(Act
)
3147 and then Chars
(Act
) = Chars
(Prefix
(Prefix
(Orig
))))
3149 if Is_Access_Type
(A_Type
)
3150 and then not Is_Access_Type
(F_Type
)
3152 -- Introduce dereference on object in prefix
3155 Make_Explicit_Dereference
(Sloc
(Act
),
3156 Prefix
=> Relocate_Node
(Act
));
3157 Rewrite
(Act
, New_A
);
3160 elsif Is_Access_Type
(F_Type
)
3161 and then not Is_Access_Type
(A_Type
)
3163 -- Introduce an implicit 'Access in prefix
3165 if not Is_Aliased_View
(Act
) then
3167 ("object in prefixed call to& must be aliased"
3168 & " (RM-2005 4.3.1 (13))",
3173 Make_Attribute_Reference
(Loc
,
3174 Attribute_Name
=> Name_Access
,
3175 Prefix
=> Relocate_Node
(Act
)));
3180 end Check_Prefixed_Call
;
3182 --------------------
3183 -- Insert_Default --
3184 --------------------
3186 procedure Insert_Default
is
3191 -- Missing argument in call, nothing to insert
3193 if No
(Default_Value
(F
)) then
3197 -- Note that we do a full New_Copy_Tree, so that any associated
3198 -- Itypes are properly copied. This may not be needed any more,
3199 -- but it does no harm as a safety measure! Defaults of a generic
3200 -- formal may be out of bounds of the corresponding actual (see
3201 -- cc1311b) and an additional check may be required.
3206 New_Scope
=> Current_Scope
,
3209 if Is_Concurrent_Type
(Scope
(Nam
))
3210 and then Has_Discriminants
(Scope
(Nam
))
3212 Replace_Actual_Discriminants
(N
, Actval
);
3215 if Is_Overloadable
(Nam
)
3216 and then Present
(Alias
(Nam
))
3218 if Base_Type
(Etype
(F
)) /= Base_Type
(Etype
(Actval
))
3219 and then not Is_Tagged_Type
(Etype
(F
))
3221 -- If default is a real literal, do not introduce a
3222 -- conversion whose effect may depend on the run-time
3223 -- size of universal real.
3225 if Nkind
(Actval
) = N_Real_Literal
then
3226 Set_Etype
(Actval
, Base_Type
(Etype
(F
)));
3228 Actval
:= Unchecked_Convert_To
(Etype
(F
), Actval
);
3232 if Is_Scalar_Type
(Etype
(F
)) then
3233 Enable_Range_Check
(Actval
);
3236 Set_Parent
(Actval
, N
);
3238 -- Resolve aggregates with their base type, to avoid scope
3239 -- anomalies: the subtype was first built in the subprogram
3240 -- declaration, and the current call may be nested.
3242 if Nkind
(Actval
) = N_Aggregate
then
3243 Analyze_And_Resolve
(Actval
, Etype
(F
));
3245 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3249 Set_Parent
(Actval
, N
);
3251 -- See note above concerning aggregates
3253 if Nkind
(Actval
) = N_Aggregate
3254 and then Has_Discriminants
(Etype
(Actval
))
3256 Analyze_And_Resolve
(Actval
, Base_Type
(Etype
(Actval
)));
3258 -- Resolve entities with their own type, which may differ from
3259 -- the type of a reference in a generic context (the view
3260 -- swapping mechanism did not anticipate the re-analysis of
3261 -- default values in calls).
3263 elsif Is_Entity_Name
(Actval
) then
3264 Analyze_And_Resolve
(Actval
, Etype
(Entity
(Actval
)));
3267 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3271 -- If default is a tag indeterminate function call, propagate tag
3272 -- to obtain proper dispatching.
3274 if Is_Controlling_Formal
(F
)
3275 and then Nkind
(Default_Value
(F
)) = N_Function_Call
3277 Set_Is_Controlling_Actual
(Actval
);
3282 -- If the default expression raises constraint error, then just
3283 -- silently replace it with an N_Raise_Constraint_Error node, since
3284 -- we already gave the warning on the subprogram spec. If node is
3285 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3286 -- the warnings removal machinery.
3288 if Raises_Constraint_Error
(Actval
)
3289 and then Nkind
(Actval
) /= N_Raise_Constraint_Error
3292 Make_Raise_Constraint_Error
(Loc
,
3293 Reason
=> CE_Range_Check_Failed
));
3294 Set_Raises_Constraint_Error
(Actval
);
3295 Set_Etype
(Actval
, Etype
(F
));
3299 Make_Parameter_Association
(Loc
,
3300 Explicit_Actual_Parameter
=> Actval
,
3301 Selector_Name
=> Make_Identifier
(Loc
, Chars
(F
)));
3303 -- Case of insertion is first named actual
3305 if No
(Prev
) or else
3306 Nkind
(Parent
(Prev
)) /= N_Parameter_Association
3308 Set_Next_Named_Actual
(Assoc
, First_Named_Actual
(N
));
3309 Set_First_Named_Actual
(N
, Actval
);
3312 if No
(Parameter_Associations
(N
)) then
3313 Set_Parameter_Associations
(N
, New_List
(Assoc
));
3315 Append
(Assoc
, Parameter_Associations
(N
));
3319 Insert_After
(Prev
, Assoc
);
3322 -- Case of insertion is not first named actual
3325 Set_Next_Named_Actual
3326 (Assoc
, Next_Named_Actual
(Parent
(Prev
)));
3327 Set_Next_Named_Actual
(Parent
(Prev
), Actval
);
3328 Append
(Assoc
, Parameter_Associations
(N
));
3331 Mark_Rewrite_Insertion
(Assoc
);
3332 Mark_Rewrite_Insertion
(Actval
);
3341 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean is
3342 FT1
: Entity_Id
:= T1
;
3343 FT2
: Entity_Id
:= T2
;
3346 if Is_Private_Type
(T1
)
3347 and then Present
(Full_View
(T1
))
3349 FT1
:= Full_View
(T1
);
3352 if Is_Private_Type
(T2
)
3353 and then Present
(Full_View
(T2
))
3355 FT2
:= Full_View
(T2
);
3358 return Root_Type
(Base_Type
(FT1
)) = Root_Type
(Base_Type
(FT2
));
3361 --------------------------
3362 -- Static_Concatenation --
3363 --------------------------
3365 function Static_Concatenation
(N
: Node_Id
) return Boolean is
3368 when N_String_Literal
=>
3373 -- Concatenation is static when both operands are static and
3374 -- the concatenation operator is a predefined one.
3376 return Scope
(Entity
(N
)) = Standard_Standard
3378 Static_Concatenation
(Left_Opnd
(N
))
3380 Static_Concatenation
(Right_Opnd
(N
));
3383 if Is_Entity_Name
(N
) then
3385 Ent
: constant Entity_Id
:= Entity
(N
);
3387 return Ekind
(Ent
) = E_Constant
3388 and then Present
(Constant_Value
(Ent
))
3390 Is_Static_Expression
(Constant_Value
(Ent
));
3397 end Static_Concatenation
;
3399 -- Start of processing for Resolve_Actuals
3402 Check_Argument_Order
;
3403 Check_Function_Writable_Actuals
(N
);
3405 if Present
(First_Actual
(N
)) then
3406 Check_Prefixed_Call
;
3409 A
:= First_Actual
(N
);
3410 F
:= First_Formal
(Nam
);
3411 while Present
(F
) loop
3412 if No
(A
) and then Needs_No_Actuals
(Nam
) then
3415 -- If we have an error in any actual or formal, indicated by a type
3416 -- of Any_Type, then abandon resolution attempt, and set result type
3419 elsif (Present
(A
) and then Etype
(A
) = Any_Type
)
3420 or else Etype
(F
) = Any_Type
3422 Set_Etype
(N
, Any_Type
);
3426 -- Case where actual is present
3428 -- If the actual is an entity, generate a reference to it now. We
3429 -- do this before the actual is resolved, because a formal of some
3430 -- protected subprogram, or a task discriminant, will be rewritten
3431 -- during expansion, and the source entity reference may be lost.
3434 and then Is_Entity_Name
(A
)
3435 and then Comes_From_Source
(N
)
3437 Orig_A
:= Entity
(A
);
3439 if Present
(Orig_A
) then
3440 if Is_Formal
(Orig_A
)
3441 and then Ekind
(F
) /= E_In_Parameter
3443 Generate_Reference
(Orig_A
, A
, 'm');
3445 elsif not Is_Overloaded
(A
) then
3446 if Ekind
(F
) /= E_Out_Parameter
then
3447 Generate_Reference
(Orig_A
, A
);
3449 -- RM 6.4.1(12): For an out parameter that is passed by
3450 -- copy, the formal parameter object is created, and:
3452 -- * For an access type, the formal parameter is initialized
3453 -- from the value of the actual, without checking that the
3454 -- value satisfies any constraint, any predicate, or any
3455 -- exclusion of the null value.
3457 -- * For a scalar type that has the Default_Value aspect
3458 -- specified, the formal parameter is initialized from the
3459 -- value of the actual, without checking that the value
3460 -- satisfies any constraint or any predicate.
3461 -- I do not understand why this case is included??? this is
3462 -- not a case where an OUT parameter is treated as IN OUT.
3464 -- * For a composite type with discriminants or that has
3465 -- implicit initial values for any subcomponents, the
3466 -- behavior is as for an in out parameter passed by copy.
3468 -- Hence for these cases we generate the read reference now
3469 -- (the write reference will be generated later by
3470 -- Note_Possible_Modification).
3472 elsif Is_By_Copy_Type
(Etype
(F
))
3474 (Is_Access_Type
(Etype
(F
))
3476 (Is_Scalar_Type
(Etype
(F
))
3478 Present
(Default_Aspect_Value
(Etype
(F
))))
3480 (Is_Composite_Type
(Etype
(F
))
3481 and then (Has_Discriminants
(Etype
(F
))
3482 or else Is_Partially_Initialized_Type
3485 Generate_Reference
(Orig_A
, A
);
3492 and then (Nkind
(Parent
(A
)) /= N_Parameter_Association
3493 or else Chars
(Selector_Name
(Parent
(A
))) = Chars
(F
))
3495 -- If style checking mode on, check match of formal name
3498 if Nkind
(Parent
(A
)) = N_Parameter_Association
then
3499 Check_Identifier
(Selector_Name
(Parent
(A
)), F
);
3503 -- If the formal is Out or In_Out, do not resolve and expand the
3504 -- conversion, because it is subsequently expanded into explicit
3505 -- temporaries and assignments. However, the object of the
3506 -- conversion can be resolved. An exception is the case of tagged
3507 -- type conversion with a class-wide actual. In that case we want
3508 -- the tag check to occur and no temporary will be needed (no
3509 -- representation change can occur) and the parameter is passed by
3510 -- reference, so we go ahead and resolve the type conversion.
3511 -- Another exception is the case of reference to component or
3512 -- subcomponent of a bit-packed array, in which case we want to
3513 -- defer expansion to the point the in and out assignments are
3516 if Ekind
(F
) /= E_In_Parameter
3517 and then Nkind
(A
) = N_Type_Conversion
3518 and then not Is_Class_Wide_Type
(Etype
(Expression
(A
)))
3520 if Ekind
(F
) = E_In_Out_Parameter
3521 and then Is_Array_Type
(Etype
(F
))
3523 -- In a view conversion, the conversion must be legal in
3524 -- both directions, and thus both component types must be
3525 -- aliased, or neither (4.6 (8)).
3527 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3528 -- the privacy requirement should not apply to generic
3529 -- types, and should be checked in an instance. ARG query
3532 if Has_Aliased_Components
(Etype
(Expression
(A
))) /=
3533 Has_Aliased_Components
(Etype
(F
))
3536 ("both component types in a view conversion must be"
3537 & " aliased, or neither", A
);
3539 -- Comment here??? what set of cases???
3542 not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3544 -- Check view conv between unrelated by ref array types
3546 if Is_By_Reference_Type
(Etype
(F
))
3547 or else Is_By_Reference_Type
(Etype
(Expression
(A
)))
3550 ("view conversion between unrelated by reference "
3551 & "array types not allowed (\'A'I-00246)", A
);
3553 -- In Ada 2005 mode, check view conversion component
3554 -- type cannot be private, tagged, or volatile. Note
3555 -- that we only apply this to source conversions. The
3556 -- generated code can contain conversions which are
3557 -- not subject to this test, and we cannot extract the
3558 -- component type in such cases since it is not present.
3560 elsif Comes_From_Source
(A
)
3561 and then Ada_Version
>= Ada_2005
3564 Comp_Type
: constant Entity_Id
:=
3566 (Etype
(Expression
(A
)));
3568 if (Is_Private_Type
(Comp_Type
)
3569 and then not Is_Generic_Type
(Comp_Type
))
3570 or else Is_Tagged_Type
(Comp_Type
)
3571 or else Is_Volatile
(Comp_Type
)
3574 ("component type of a view conversion cannot"
3575 & " be private, tagged, or volatile"
3584 -- Resolve expression if conversion is all OK
3586 if (Conversion_OK
(A
)
3587 or else Valid_Conversion
(A
, Etype
(A
), Expression
(A
)))
3588 and then not Is_Ref_To_Bit_Packed_Array
(Expression
(A
))
3590 Resolve
(Expression
(A
));
3593 -- If the actual is a function call that returns a limited
3594 -- unconstrained object that needs finalization, create a
3595 -- transient scope for it, so that it can receive the proper
3596 -- finalization list.
3598 elsif Nkind
(A
) = N_Function_Call
3599 and then Is_Limited_Record
(Etype
(F
))
3600 and then not Is_Constrained
(Etype
(F
))
3601 and then Full_Expander_Active
3602 and then (Is_Controlled
(Etype
(F
)) or else Has_Task
(Etype
(F
)))
3604 Establish_Transient_Scope
(A
, False);
3605 Resolve
(A
, Etype
(F
));
3607 -- A small optimization: if one of the actuals is a concatenation
3608 -- create a block around a procedure call to recover stack space.
3609 -- This alleviates stack usage when several procedure calls in
3610 -- the same statement list use concatenation. We do not perform
3611 -- this wrapping for code statements, where the argument is a
3612 -- static string, and we want to preserve warnings involving
3613 -- sequences of such statements.
3615 elsif Nkind
(A
) = N_Op_Concat
3616 and then Nkind
(N
) = N_Procedure_Call_Statement
3617 and then Full_Expander_Active
3619 not (Is_Intrinsic_Subprogram
(Nam
)
3620 and then Chars
(Nam
) = Name_Asm
)
3621 and then not Static_Concatenation
(A
)
3623 Establish_Transient_Scope
(A
, False);
3624 Resolve
(A
, Etype
(F
));
3627 if Nkind
(A
) = N_Type_Conversion
3628 and then Is_Array_Type
(Etype
(F
))
3629 and then not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3631 (Is_Limited_Type
(Etype
(F
))
3632 or else Is_Limited_Type
(Etype
(Expression
(A
))))
3635 ("conversion between unrelated limited array types "
3636 & "not allowed (\A\I-00246)", A
);
3638 if Is_Limited_Type
(Etype
(F
)) then
3639 Explain_Limited_Type
(Etype
(F
), A
);
3642 if Is_Limited_Type
(Etype
(Expression
(A
))) then
3643 Explain_Limited_Type
(Etype
(Expression
(A
)), A
);
3647 -- (Ada 2005: AI-251): If the actual is an allocator whose
3648 -- directly designated type is a class-wide interface, we build
3649 -- an anonymous access type to use it as the type of the
3650 -- allocator. Later, when the subprogram call is expanded, if
3651 -- the interface has a secondary dispatch table the expander
3652 -- will add a type conversion to force the correct displacement
3655 if Nkind
(A
) = N_Allocator
then
3657 DDT
: constant Entity_Id
:=
3658 Directly_Designated_Type
(Base_Type
(Etype
(F
)));
3660 New_Itype
: Entity_Id
;
3663 if Is_Class_Wide_Type
(DDT
)
3664 and then Is_Interface
(DDT
)
3666 New_Itype
:= Create_Itype
(E_Anonymous_Access_Type
, A
);
3667 Set_Etype
(New_Itype
, Etype
(A
));
3668 Set_Directly_Designated_Type
(New_Itype
,
3669 Directly_Designated_Type
(Etype
(A
)));
3670 Set_Etype
(A
, New_Itype
);
3673 -- Ada 2005, AI-162:If the actual is an allocator, the
3674 -- innermost enclosing statement is the master of the
3675 -- created object. This needs to be done with expansion
3676 -- enabled only, otherwise the transient scope will not
3677 -- be removed in the expansion of the wrapped construct.
3679 if (Is_Controlled
(DDT
) or else Has_Task
(DDT
))
3680 and then Full_Expander_Active
3682 Establish_Transient_Scope
(A
, False);
3686 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
3687 Check_Restriction
(No_Access_Parameter_Allocators
, A
);
3691 -- (Ada 2005): The call may be to a primitive operation of a
3692 -- tagged synchronized type, declared outside of the type. In
3693 -- this case the controlling actual must be converted to its
3694 -- corresponding record type, which is the formal type. The
3695 -- actual may be a subtype, either because of a constraint or
3696 -- because it is a generic actual, so use base type to locate
3699 F_Typ
:= Base_Type
(Etype
(F
));
3701 if Is_Tagged_Type
(F_Typ
)
3702 and then (Is_Concurrent_Type
(F_Typ
)
3703 or else Is_Concurrent_Record_Type
(F_Typ
))
3705 -- If the actual is overloaded, look for an interpretation
3706 -- that has a synchronized type.
3708 if not Is_Overloaded
(A
) then
3709 A_Typ
:= Base_Type
(Etype
(A
));
3713 Index
: Interp_Index
;
3717 Get_First_Interp
(A
, Index
, It
);
3718 while Present
(It
.Typ
) loop
3719 if Is_Concurrent_Type
(It
.Typ
)
3720 or else Is_Concurrent_Record_Type
(It
.Typ
)
3722 A_Typ
:= Base_Type
(It
.Typ
);
3726 Get_Next_Interp
(Index
, It
);
3732 Full_A_Typ
: Entity_Id
;
3735 if Present
(Full_View
(A_Typ
)) then
3736 Full_A_Typ
:= Base_Type
(Full_View
(A_Typ
));
3738 Full_A_Typ
:= A_Typ
;
3741 -- Tagged synchronized type (case 1): the actual is a
3744 if Is_Concurrent_Type
(A_Typ
)
3745 and then Corresponding_Record_Type
(A_Typ
) = F_Typ
3748 Unchecked_Convert_To
3749 (Corresponding_Record_Type
(A_Typ
), A
));
3750 Resolve
(A
, Etype
(F
));
3752 -- Tagged synchronized type (case 2): the formal is a
3755 elsif Ekind
(Full_A_Typ
) = E_Record_Type
3757 (Corresponding_Concurrent_Type
(Full_A_Typ
))
3758 and then Is_Concurrent_Type
(F_Typ
)
3759 and then Present
(Corresponding_Record_Type
(F_Typ
))
3760 and then Full_A_Typ
= Corresponding_Record_Type
(F_Typ
)
3762 Resolve
(A
, Corresponding_Record_Type
(F_Typ
));
3767 Resolve
(A
, Etype
(F
));
3772 -- not a synchronized operation.
3774 Resolve
(A
, Etype
(F
));
3781 if Comes_From_Source
(Original_Node
(N
))
3782 and then Nkind_In
(Original_Node
(N
), N_Function_Call
,
3783 N_Procedure_Call_Statement
)
3785 -- In formal mode, check that actual parameters matching
3786 -- formals of tagged types are objects (or ancestor type
3787 -- conversions of objects), not general expressions.
3789 if Is_Actual_Tagged_Parameter
(A
) then
3790 if Is_SPARK_Object_Reference
(A
) then
3793 elsif Nkind
(A
) = N_Type_Conversion
then
3795 Operand
: constant Node_Id
:= Expression
(A
);
3796 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
3797 Target_Typ
: constant Entity_Id
:= A_Typ
;
3800 if not Is_SPARK_Object_Reference
(Operand
) then
3801 Check_SPARK_Restriction
3802 ("object required", Operand
);
3804 -- In formal mode, the only view conversions are those
3805 -- involving ancestor conversion of an extended type.
3808 (Is_Tagged_Type
(Target_Typ
)
3809 and then not Is_Class_Wide_Type
(Target_Typ
)
3810 and then Is_Tagged_Type
(Operand_Typ
)
3811 and then not Is_Class_Wide_Type
(Operand_Typ
)
3812 and then Is_Ancestor
(Target_Typ
, Operand_Typ
))
3815 (F
, E_Out_Parameter
, E_In_Out_Parameter
)
3817 Check_SPARK_Restriction
3818 ("ancestor conversion is the only permitted "
3819 & "view conversion", A
);
3821 Check_SPARK_Restriction
3822 ("ancestor conversion required", A
);
3831 Check_SPARK_Restriction
("object required", A
);
3834 -- In formal mode, the only view conversions are those
3835 -- involving ancestor conversion of an extended type.
3837 elsif Nkind
(A
) = N_Type_Conversion
3838 and then Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
3840 Check_SPARK_Restriction
3841 ("ancestor conversion is the only permitted view "
3846 -- has warnings suppressed, then we reset Never_Set_In_Source for
3847 -- the calling entity. The reason for this is to catch cases like
3848 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3849 -- uses trickery to modify an IN parameter.
3851 if Ekind
(F
) = E_In_Parameter
3852 and then Is_Entity_Name
(A
)
3853 and then Present
(Entity
(A
))
3854 and then Ekind
(Entity
(A
)) = E_Variable
3855 and then Has_Warnings_Off
(F_Typ
)
3857 Set_Never_Set_In_Source
(Entity
(A
), False);
3860 -- Perform error checks for IN and IN OUT parameters
3862 if Ekind
(F
) /= E_Out_Parameter
then
3864 -- Check unset reference. For scalar parameters, it is clearly
3865 -- wrong to pass an uninitialized value as either an IN or
3866 -- IN-OUT parameter. For composites, it is also clearly an
3867 -- error to pass a completely uninitialized value as an IN
3868 -- parameter, but the case of IN OUT is trickier. We prefer
3869 -- not to give a warning here. For example, suppose there is
3870 -- a routine that sets some component of a record to False.
3871 -- It is perfectly reasonable to make this IN-OUT and allow
3872 -- either initialized or uninitialized records to be passed
3875 -- For partially initialized composite values, we also avoid
3876 -- warnings, since it is quite likely that we are passing a
3877 -- partially initialized value and only the initialized fields
3878 -- will in fact be read in the subprogram.
3880 if Is_Scalar_Type
(A_Typ
)
3881 or else (Ekind
(F
) = E_In_Parameter
3882 and then not Is_Partially_Initialized_Type
(A_Typ
))
3884 Check_Unset_Reference
(A
);
3887 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3888 -- actual to a nested call, since this is case of reading an
3889 -- out parameter, which is not allowed.
3891 if Ada_Version
= Ada_83
3892 and then Is_Entity_Name
(A
)
3893 and then Ekind
(Entity
(A
)) = E_Out_Parameter
3895 Error_Msg_N
("(Ada 83) illegal reading of out parameter", A
);
3899 -- Case of OUT or IN OUT parameter
3901 if Ekind
(F
) /= E_In_Parameter
then
3903 -- For an Out parameter, check for useless assignment. Note
3904 -- that we can't set Last_Assignment this early, because we may
3905 -- kill current values in Resolve_Call, and that call would
3906 -- clobber the Last_Assignment field.
3908 -- Note: call Warn_On_Useless_Assignment before doing the check
3909 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3910 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3911 -- reflects the last assignment, not this one!
3913 if Ekind
(F
) = E_Out_Parameter
then
3914 if Warn_On_Modified_As_Out_Parameter
(F
)
3915 and then Is_Entity_Name
(A
)
3916 and then Present
(Entity
(A
))
3917 and then Comes_From_Source
(N
)
3919 Warn_On_Useless_Assignment
(Entity
(A
), A
);
3923 -- Validate the form of the actual. Note that the call to
3924 -- Is_OK_Variable_For_Out_Formal generates the required
3925 -- reference in this case.
3927 -- A call to an initialization procedure for an aggregate
3928 -- component may initialize a nested component of a constant
3929 -- designated object. In this context the object is variable.
3931 if not Is_OK_Variable_For_Out_Formal
(A
)
3932 and then not Is_Init_Proc
(Nam
)
3934 Error_Msg_NE
("actual for& must be a variable", A
, F
);
3937 -- What's the following about???
3939 if Is_Entity_Name
(A
) then
3940 Kill_Checks
(Entity
(A
));
3946 if Etype
(A
) = Any_Type
then
3947 Set_Etype
(N
, Any_Type
);
3951 -- Apply appropriate range checks for in, out, and in-out
3952 -- parameters. Out and in-out parameters also need a separate
3953 -- check, if there is a type conversion, to make sure the return
3954 -- value meets the constraints of the variable before the
3957 -- Gigi looks at the check flag and uses the appropriate types.
3958 -- For now since one flag is used there is an optimization which
3959 -- might not be done in the In Out case since Gigi does not do
3960 -- any analysis. More thought required about this ???
3962 if Ekind_In
(F
, E_In_Parameter
, E_In_Out_Parameter
) then
3964 -- Apply predicate checks, unless this is a call to the
3965 -- predicate check function itself, which would cause an
3966 -- infinite recursion, or it is a call to an initialization
3967 -- procedure whose operand is of course an unfinished object.
3969 if not (Ekind
(Nam
) = E_Function
3970 and then (Is_Predicate_Function
(Nam
)
3972 Is_Predicate_Function_M
(Nam
)))
3973 and then not Is_Init_Proc
(Nam
)
3975 Apply_Predicate_Check
(A
, F_Typ
);
3978 -- Apply required constraint checks
3980 if Is_Scalar_Type
(Etype
(A
)) then
3981 Apply_Scalar_Range_Check
(A
, F_Typ
);
3983 elsif Is_Array_Type
(Etype
(A
)) then
3984 Apply_Length_Check
(A
, F_Typ
);
3986 elsif Is_Record_Type
(F_Typ
)
3987 and then Has_Discriminants
(F_Typ
)
3988 and then Is_Constrained
(F_Typ
)
3989 and then (not Is_Derived_Type
(F_Typ
)
3990 or else Comes_From_Source
(Nam
))
3992 Apply_Discriminant_Check
(A
, F_Typ
);
3994 elsif Is_Access_Type
(F_Typ
)
3995 and then Is_Array_Type
(Designated_Type
(F_Typ
))
3996 and then Is_Constrained
(Designated_Type
(F_Typ
))
3998 Apply_Length_Check
(A
, F_Typ
);
4000 elsif Is_Access_Type
(F_Typ
)
4001 and then Has_Discriminants
(Designated_Type
(F_Typ
))
4002 and then Is_Constrained
(Designated_Type
(F_Typ
))
4004 Apply_Discriminant_Check
(A
, F_Typ
);
4007 Apply_Range_Check
(A
, F_Typ
);
4010 -- Ada 2005 (AI-231): Note that the controlling parameter case
4011 -- already existed in Ada 95, which is partially checked
4012 -- elsewhere (see Checks), and we don't want the warning
4013 -- message to differ.
4015 if Is_Access_Type
(F_Typ
)
4016 and then Can_Never_Be_Null
(F_Typ
)
4017 and then Known_Null
(A
)
4019 if Is_Controlling_Formal
(F
) then
4020 Apply_Compile_Time_Constraint_Error
4022 Msg
=> "null value not allowed here??",
4023 Reason
=> CE_Access_Check_Failed
);
4025 elsif Ada_Version
>= Ada_2005
then
4026 Apply_Compile_Time_Constraint_Error
4028 Msg
=> "(Ada 2005) null not allowed in "
4029 & "null-excluding formal??",
4030 Reason
=> CE_Null_Not_Allowed
);
4035 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
) then
4036 if Nkind
(A
) = N_Type_Conversion
then
4037 if Is_Scalar_Type
(A_Typ
) then
4038 Apply_Scalar_Range_Check
4039 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4042 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4046 if Is_Scalar_Type
(F_Typ
) then
4047 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
4048 elsif Is_Array_Type
(F_Typ
)
4049 and then Ekind
(F
) = E_Out_Parameter
4051 Apply_Length_Check
(A
, F_Typ
);
4053 Apply_Range_Check
(A
, A_Typ
, F_Typ
);
4058 -- An actual associated with an access parameter is implicitly
4059 -- converted to the anonymous access type of the formal and must
4060 -- satisfy the legality checks for access conversions.
4062 if Ekind
(F_Typ
) = E_Anonymous_Access_Type
then
4063 if not Valid_Conversion
(A
, F_Typ
, A
) then
4065 ("invalid implicit conversion for access parameter", A
);
4068 -- If the actual is an access selected component of a variable,
4069 -- the call may modify its designated object. It is reasonable
4070 -- to treat this as a potential modification of the enclosing
4071 -- record, to prevent spurious warnings that it should be
4072 -- declared as a constant, because intuitively programmers
4073 -- regard the designated subcomponent as part of the record.
4075 if Nkind
(A
) = N_Selected_Component
4076 and then Is_Entity_Name
(Prefix
(A
))
4077 and then not Is_Constant_Object
(Entity
(Prefix
(A
)))
4079 Note_Possible_Modification
(A
, Sure
=> False);
4083 -- Check bad case of atomic/volatile argument (RM C.6(12))
4085 if Is_By_Reference_Type
(Etype
(F
))
4086 and then Comes_From_Source
(N
)
4088 if Is_Atomic_Object
(A
)
4089 and then not Is_Atomic
(Etype
(F
))
4092 ("cannot pass atomic argument to non-atomic formal&",
4095 elsif Is_Volatile_Object
(A
)
4096 and then not Is_Volatile
(Etype
(F
))
4099 ("cannot pass volatile argument to non-volatile formal&",
4104 -- Check that subprograms don't have improper controlling
4105 -- arguments (RM 3.9.2 (9)).
4107 -- A primitive operation may have an access parameter of an
4108 -- incomplete tagged type, but a dispatching call is illegal
4109 -- if the type is still incomplete.
4111 if Is_Controlling_Formal
(F
) then
4112 Set_Is_Controlling_Actual
(A
);
4114 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
4116 Desig
: constant Entity_Id
:= Designated_Type
(Etype
(F
));
4118 if Ekind
(Desig
) = E_Incomplete_Type
4119 and then No
(Full_View
(Desig
))
4120 and then No
(Non_Limited_View
(Desig
))
4123 ("premature use of incomplete type& "
4124 & "in dispatching call", A
, Desig
);
4129 elsif Nkind
(A
) = N_Explicit_Dereference
then
4130 Validate_Remote_Access_To_Class_Wide_Type
(A
);
4133 if (Is_Class_Wide_Type
(A_Typ
) or else Is_Dynamically_Tagged
(A
))
4134 and then not Is_Class_Wide_Type
(F_Typ
)
4135 and then not Is_Controlling_Formal
(F
)
4137 Error_Msg_N
("class-wide argument not allowed here!", A
);
4139 if Is_Subprogram
(Nam
)
4140 and then Comes_From_Source
(Nam
)
4142 Error_Msg_Node_2
:= F_Typ
;
4144 ("& is not a dispatching operation of &!", A
, Nam
);
4147 -- Apply the checks described in 3.10.2(27): if the context is a
4148 -- specific access-to-object, the actual cannot be class-wide.
4149 -- Use base type to exclude access_to_subprogram cases.
4151 elsif Is_Access_Type
(A_Typ
)
4152 and then Is_Access_Type
(F_Typ
)
4153 and then not Is_Access_Subprogram_Type
(Base_Type
(F_Typ
))
4154 and then (Is_Class_Wide_Type
(Designated_Type
(A_Typ
))
4155 or else (Nkind
(A
) = N_Attribute_Reference
4157 Is_Class_Wide_Type
(Etype
(Prefix
(A
)))))
4158 and then not Is_Class_Wide_Type
(Designated_Type
(F_Typ
))
4159 and then not Is_Controlling_Formal
(F
)
4161 -- Disable these checks for call to imported C++ subprograms
4164 (Is_Entity_Name
(Name
(N
))
4165 and then Is_Imported
(Entity
(Name
(N
)))
4166 and then Convention
(Entity
(Name
(N
))) = Convention_CPP
)
4169 ("access to class-wide argument not allowed here!", A
);
4171 if Is_Subprogram
(Nam
) and then Comes_From_Source
(Nam
) then
4172 Error_Msg_Node_2
:= Designated_Type
(F_Typ
);
4174 ("& is not a dispatching operation of &!", A
, Nam
);
4180 -- If it is a named association, treat the selector_name as a
4181 -- proper identifier, and mark the corresponding entity. Ignore
4182 -- this reference in SPARK mode, as it refers to an entity not in
4183 -- scope at the point of reference, so the reference should be
4184 -- ignored for computing effects of subprograms.
4186 if Nkind
(Parent
(A
)) = N_Parameter_Association
4187 and then not SPARK_Mode
4189 Set_Entity
(Selector_Name
(Parent
(A
)), F
);
4190 Generate_Reference
(F
, Selector_Name
(Parent
(A
)));
4191 Set_Etype
(Selector_Name
(Parent
(A
)), F_Typ
);
4192 Generate_Reference
(F_Typ
, N
, ' ');
4197 if Ekind
(F
) /= E_Out_Parameter
then
4198 Check_Unset_Reference
(A
);
4203 -- Case where actual is not present
4211 end Resolve_Actuals
;
4213 -----------------------
4214 -- Resolve_Allocator --
4215 -----------------------
4217 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
) is
4218 Desig_T
: constant Entity_Id
:= Designated_Type
(Typ
);
4219 E
: constant Node_Id
:= Expression
(N
);
4221 Discrim
: Entity_Id
;
4224 Assoc
: Node_Id
:= Empty
;
4227 procedure Check_Allocator_Discrim_Accessibility
4228 (Disc_Exp
: Node_Id
;
4229 Alloc_Typ
: Entity_Id
);
4230 -- Check that accessibility level associated with an access discriminant
4231 -- initialized in an allocator by the expression Disc_Exp is not deeper
4232 -- than the level of the allocator type Alloc_Typ. An error message is
4233 -- issued if this condition is violated. Specialized checks are done for
4234 -- the cases of a constraint expression which is an access attribute or
4235 -- an access discriminant.
4237 function In_Dispatching_Context
return Boolean;
4238 -- If the allocator is an actual in a call, it is allowed to be class-
4239 -- wide when the context is not because it is a controlling actual.
4241 -------------------------------------------
4242 -- Check_Allocator_Discrim_Accessibility --
4243 -------------------------------------------
4245 procedure Check_Allocator_Discrim_Accessibility
4246 (Disc_Exp
: Node_Id
;
4247 Alloc_Typ
: Entity_Id
)
4250 if Type_Access_Level
(Etype
(Disc_Exp
)) >
4251 Deepest_Type_Access_Level
(Alloc_Typ
)
4254 ("operand type has deeper level than allocator type", Disc_Exp
);
4256 -- When the expression is an Access attribute the level of the prefix
4257 -- object must not be deeper than that of the allocator's type.
4259 elsif Nkind
(Disc_Exp
) = N_Attribute_Reference
4260 and then Get_Attribute_Id
(Attribute_Name
(Disc_Exp
)) =
4262 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4263 Deepest_Type_Access_Level
(Alloc_Typ
)
4266 ("prefix of attribute has deeper level than allocator type",
4269 -- When the expression is an access discriminant the check is against
4270 -- the level of the prefix object.
4272 elsif Ekind
(Etype
(Disc_Exp
)) = E_Anonymous_Access_Type
4273 and then Nkind
(Disc_Exp
) = N_Selected_Component
4274 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4275 Deepest_Type_Access_Level
(Alloc_Typ
)
4278 ("access discriminant has deeper level than allocator type",
4281 -- All other cases are legal
4286 end Check_Allocator_Discrim_Accessibility
;
4288 ----------------------------
4289 -- In_Dispatching_Context --
4290 ----------------------------
4292 function In_Dispatching_Context
return Boolean is
4293 Par
: constant Node_Id
:= Parent
(N
);
4296 return Nkind
(Par
) in N_Subprogram_Call
4297 and then Is_Entity_Name
(Name
(Par
))
4298 and then Is_Dispatching_Operation
(Entity
(Name
(Par
)));
4299 end In_Dispatching_Context
;
4301 -- Start of processing for Resolve_Allocator
4304 -- Replace general access with specific type
4306 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
4307 Set_Etype
(N
, Base_Type
(Typ
));
4310 if Is_Abstract_Type
(Typ
) then
4311 Error_Msg_N
("type of allocator cannot be abstract", N
);
4314 -- For qualified expression, resolve the expression using the given
4315 -- subtype (nothing to do for type mark, subtype indication)
4317 if Nkind
(E
) = N_Qualified_Expression
then
4318 if Is_Class_Wide_Type
(Etype
(E
))
4319 and then not Is_Class_Wide_Type
(Desig_T
)
4320 and then not In_Dispatching_Context
4323 ("class-wide allocator not allowed for this access type", N
);
4326 Resolve
(Expression
(E
), Etype
(E
));
4327 Check_Unset_Reference
(Expression
(E
));
4329 -- A qualified expression requires an exact match of the type.
4330 -- Class-wide matching is not allowed.
4332 if (Is_Class_Wide_Type
(Etype
(Expression
(E
)))
4333 or else Is_Class_Wide_Type
(Etype
(E
)))
4334 and then Base_Type
(Etype
(Expression
(E
))) /= Base_Type
(Etype
(E
))
4336 Wrong_Type
(Expression
(E
), Etype
(E
));
4339 -- Calls to build-in-place functions are not currently supported in
4340 -- allocators for access types associated with a simple storage pool.
4341 -- Supporting such allocators may require passing additional implicit
4342 -- parameters to build-in-place functions (or a significant revision
4343 -- of the current b-i-p implementation to unify the handling for
4344 -- multiple kinds of storage pools). ???
4346 if Is_Immutably_Limited_Type
(Desig_T
)
4347 and then Nkind
(Expression
(E
)) = N_Function_Call
4350 Pool
: constant Entity_Id
:=
4351 Associated_Storage_Pool
(Root_Type
(Typ
));
4355 Present
(Get_Rep_Pragma
4356 (Etype
(Pool
), Name_Simple_Storage_Pool_Type
))
4359 ("limited function calls not yet supported in simple "
4360 & "storage pool allocators", Expression
(E
));
4365 -- A special accessibility check is needed for allocators that
4366 -- constrain access discriminants. The level of the type of the
4367 -- expression used to constrain an access discriminant cannot be
4368 -- deeper than the type of the allocator (in contrast to access
4369 -- parameters, where the level of the actual can be arbitrary).
4371 -- We can't use Valid_Conversion to perform this check because in
4372 -- general the type of the allocator is unrelated to the type of
4373 -- the access discriminant.
4375 if Ekind
(Typ
) /= E_Anonymous_Access_Type
4376 or else Is_Local_Anonymous_Access
(Typ
)
4378 Subtyp
:= Entity
(Subtype_Mark
(E
));
4380 Aggr
:= Original_Node
(Expression
(E
));
4382 if Has_Discriminants
(Subtyp
)
4383 and then Nkind_In
(Aggr
, N_Aggregate
, N_Extension_Aggregate
)
4385 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4387 -- Get the first component expression of the aggregate
4389 if Present
(Expressions
(Aggr
)) then
4390 Disc_Exp
:= First
(Expressions
(Aggr
));
4392 elsif Present
(Component_Associations
(Aggr
)) then
4393 Assoc
:= First
(Component_Associations
(Aggr
));
4395 if Present
(Assoc
) then
4396 Disc_Exp
:= Expression
(Assoc
);
4405 while Present
(Discrim
) and then Present
(Disc_Exp
) loop
4406 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4407 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4410 Next_Discriminant
(Discrim
);
4412 if Present
(Discrim
) then
4413 if Present
(Assoc
) then
4415 Disc_Exp
:= Expression
(Assoc
);
4417 elsif Present
(Next
(Disc_Exp
)) then
4421 Assoc
:= First
(Component_Associations
(Aggr
));
4423 if Present
(Assoc
) then
4424 Disc_Exp
:= Expression
(Assoc
);
4434 -- For a subtype mark or subtype indication, freeze the subtype
4437 Freeze_Expression
(E
);
4439 if Is_Access_Constant
(Typ
) and then not No_Initialization
(N
) then
4441 ("initialization required for access-to-constant allocator", N
);
4444 -- A special accessibility check is needed for allocators that
4445 -- constrain access discriminants. The level of the type of the
4446 -- expression used to constrain an access discriminant cannot be
4447 -- deeper than the type of the allocator (in contrast to access
4448 -- parameters, where the level of the actual can be arbitrary).
4449 -- We can't use Valid_Conversion to perform this check because
4450 -- in general the type of the allocator is unrelated to the type
4451 -- of the access discriminant.
4453 if Nkind
(Original_Node
(E
)) = N_Subtype_Indication
4454 and then (Ekind
(Typ
) /= E_Anonymous_Access_Type
4455 or else Is_Local_Anonymous_Access
(Typ
))
4457 Subtyp
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4459 if Has_Discriminants
(Subtyp
) then
4460 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4461 Constr
:= First
(Constraints
(Constraint
(Original_Node
(E
))));
4462 while Present
(Discrim
) and then Present
(Constr
) loop
4463 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4464 if Nkind
(Constr
) = N_Discriminant_Association
then
4465 Disc_Exp
:= Original_Node
(Expression
(Constr
));
4467 Disc_Exp
:= Original_Node
(Constr
);
4470 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4473 Next_Discriminant
(Discrim
);
4480 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4481 -- check that the level of the type of the created object is not deeper
4482 -- than the level of the allocator's access type, since extensions can
4483 -- now occur at deeper levels than their ancestor types. This is a
4484 -- static accessibility level check; a run-time check is also needed in
4485 -- the case of an initialized allocator with a class-wide argument (see
4486 -- Expand_Allocator_Expression).
4488 if Ada_Version
>= Ada_2005
4489 and then Is_Class_Wide_Type
(Desig_T
)
4492 Exp_Typ
: Entity_Id
;
4495 if Nkind
(E
) = N_Qualified_Expression
then
4496 Exp_Typ
:= Etype
(E
);
4497 elsif Nkind
(E
) = N_Subtype_Indication
then
4498 Exp_Typ
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4500 Exp_Typ
:= Entity
(E
);
4503 if Type_Access_Level
(Exp_Typ
) >
4504 Deepest_Type_Access_Level
(Typ
)
4506 if In_Instance_Body
then
4508 ("??type in allocator has deeper level than "
4509 & "designated class-wide type", E
);
4511 ("\??Program_Error will be raised at run time", E
);
4513 Make_Raise_Program_Error
(Sloc
(N
),
4514 Reason
=> PE_Accessibility_Check_Failed
));
4517 -- Do not apply Ada 2005 accessibility checks on a class-wide
4518 -- allocator if the type given in the allocator is a formal
4519 -- type. A run-time check will be performed in the instance.
4521 elsif not Is_Generic_Type
(Exp_Typ
) then
4522 Error_Msg_N
("type in allocator has deeper level than "
4523 & "designated class-wide type", E
);
4529 -- Check for allocation from an empty storage pool
4531 if No_Pool_Assigned
(Typ
) then
4532 Error_Msg_N
("allocation from empty storage pool!", N
);
4534 -- If the context is an unchecked conversion, as may happen within an
4535 -- inlined subprogram, the allocator is being resolved with its own
4536 -- anonymous type. In that case, if the target type has a specific
4537 -- storage pool, it must be inherited explicitly by the allocator type.
4539 elsif Nkind
(Parent
(N
)) = N_Unchecked_Type_Conversion
4540 and then No
(Associated_Storage_Pool
(Typ
))
4542 Set_Associated_Storage_Pool
4543 (Typ
, Associated_Storage_Pool
(Etype
(Parent
(N
))));
4546 if Ekind
(Etype
(N
)) = E_Anonymous_Access_Type
then
4547 Check_Restriction
(No_Anonymous_Allocators
, N
);
4550 -- Check that an allocator with task parts isn't for a nested access
4551 -- type when restriction No_Task_Hierarchy applies.
4553 if not Is_Library_Level_Entity
(Base_Type
(Typ
))
4554 and then Has_Task
(Base_Type
(Desig_T
))
4556 Check_Restriction
(No_Task_Hierarchy
, N
);
4559 -- An erroneous allocator may be rewritten as a raise Program_Error
4562 if Nkind
(N
) = N_Allocator
then
4564 -- An anonymous access discriminant is the definition of a
4567 if Ekind
(Typ
) = E_Anonymous_Access_Type
4568 and then Nkind
(Associated_Node_For_Itype
(Typ
)) =
4569 N_Discriminant_Specification
4572 Discr
: constant Entity_Id
:=
4573 Defining_Identifier
(Associated_Node_For_Itype
(Typ
));
4576 Check_Restriction
(No_Coextensions
, N
);
4578 -- Ada 2012 AI05-0052: If the designated type of the allocator
4579 -- is limited, then the allocator shall not be used to define
4580 -- the value of an access discriminant unless the discriminated
4581 -- type is immutably limited.
4583 if Ada_Version
>= Ada_2012
4584 and then Is_Limited_Type
(Desig_T
)
4585 and then not Is_Immutably_Limited_Type
(Scope
(Discr
))
4588 ("only immutably limited types can have anonymous "
4589 & "access discriminants designating a limited type", N
);
4593 -- Avoid marking an allocator as a dynamic coextension if it is
4594 -- within a static construct.
4596 if not Is_Static_Coextension
(N
) then
4597 Set_Is_Dynamic_Coextension
(N
);
4600 -- Cleanup for potential static coextensions
4603 Set_Is_Dynamic_Coextension
(N
, False);
4604 Set_Is_Static_Coextension
(N
, False);
4608 -- Report a simple error: if the designated object is a local task,
4609 -- its body has not been seen yet, and its activation will fail an
4610 -- elaboration check.
4612 if Is_Task_Type
(Desig_T
)
4613 and then Scope
(Base_Type
(Desig_T
)) = Current_Scope
4614 and then Is_Compilation_Unit
(Current_Scope
)
4615 and then Ekind
(Current_Scope
) = E_Package
4616 and then not In_Package_Body
(Current_Scope
)
4618 Error_Msg_N
("??cannot activate task before body seen", N
);
4619 Error_Msg_N
("\??Program_Error will be raised at run time", N
);
4622 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
4623 -- type with a task component on a subpool. This action must raise
4624 -- Program_Error at runtime.
4626 if Ada_Version
>= Ada_2012
4627 and then Nkind
(N
) = N_Allocator
4628 and then Present
(Subpool_Handle_Name
(N
))
4629 and then Has_Task
(Desig_T
)
4631 Error_Msg_N
("??cannot allocate task on subpool", N
);
4632 Error_Msg_N
("\??Program_Error will be raised at run time", N
);
4635 Make_Raise_Program_Error
(Sloc
(N
),
4636 Reason
=> PE_Explicit_Raise
));
4639 end Resolve_Allocator
;
4641 ---------------------------
4642 -- Resolve_Arithmetic_Op --
4643 ---------------------------
4645 -- Used for resolving all arithmetic operators except exponentiation
4647 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
4648 L
: constant Node_Id
:= Left_Opnd
(N
);
4649 R
: constant Node_Id
:= Right_Opnd
(N
);
4650 TL
: constant Entity_Id
:= Base_Type
(Etype
(L
));
4651 TR
: constant Entity_Id
:= Base_Type
(Etype
(R
));
4655 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
4656 -- We do the resolution using the base type, because intermediate values
4657 -- in expressions always are of the base type, not a subtype of it.
4659 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean;
4660 -- Returns True if N is in a context that expects "any real type"
4662 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean;
4663 -- Return True iff given type is Integer or universal real/integer
4665 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
);
4666 -- Choose type of integer literal in fixed-point operation to conform
4667 -- to available fixed-point type. T is the type of the other operand,
4668 -- which is needed to determine the expected type of N.
4670 procedure Set_Operand_Type
(N
: Node_Id
);
4671 -- Set operand type to T if universal
4673 -------------------------------
4674 -- Expected_Type_Is_Any_Real --
4675 -------------------------------
4677 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean is
4679 -- N is the expression after "delta" in a fixed_point_definition;
4682 return Nkind_In
(Parent
(N
), N_Ordinary_Fixed_Point_Definition
,
4683 N_Decimal_Fixed_Point_Definition
,
4685 -- N is one of the bounds in a real_range_specification;
4688 N_Real_Range_Specification
,
4690 -- N is the expression of a delta_constraint;
4693 N_Delta_Constraint
);
4694 end Expected_Type_Is_Any_Real
;
4696 -----------------------------
4697 -- Is_Integer_Or_Universal --
4698 -----------------------------
4700 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean is
4702 Index
: Interp_Index
;
4706 if not Is_Overloaded
(N
) then
4708 return Base_Type
(T
) = Base_Type
(Standard_Integer
)
4709 or else T
= Universal_Integer
4710 or else T
= Universal_Real
;
4712 Get_First_Interp
(N
, Index
, It
);
4713 while Present
(It
.Typ
) loop
4714 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
)
4715 or else It
.Typ
= Universal_Integer
4716 or else It
.Typ
= Universal_Real
4721 Get_Next_Interp
(Index
, It
);
4726 end Is_Integer_Or_Universal
;
4728 ----------------------------
4729 -- Set_Mixed_Mode_Operand --
4730 ----------------------------
4732 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
) is
4733 Index
: Interp_Index
;
4737 if Universal_Interpretation
(N
) = Universal_Integer
then
4739 -- A universal integer literal is resolved as standard integer
4740 -- except in the case of a fixed-point result, where we leave it
4741 -- as universal (to be handled by Exp_Fixd later on)
4743 if Is_Fixed_Point_Type
(T
) then
4744 Resolve
(N
, Universal_Integer
);
4746 Resolve
(N
, Standard_Integer
);
4749 elsif Universal_Interpretation
(N
) = Universal_Real
4750 and then (T
= Base_Type
(Standard_Integer
)
4751 or else T
= Universal_Integer
4752 or else T
= Universal_Real
)
4754 -- A universal real can appear in a fixed-type context. We resolve
4755 -- the literal with that context, even though this might raise an
4756 -- exception prematurely (the other operand may be zero).
4760 elsif Etype
(N
) = Base_Type
(Standard_Integer
)
4761 and then T
= Universal_Real
4762 and then Is_Overloaded
(N
)
4764 -- Integer arg in mixed-mode operation. Resolve with universal
4765 -- type, in case preference rule must be applied.
4767 Resolve
(N
, Universal_Integer
);
4770 and then B_Typ
/= Universal_Fixed
4772 -- Not a mixed-mode operation, resolve with context
4776 elsif Etype
(N
) = Any_Fixed
then
4778 -- N may itself be a mixed-mode operation, so use context type
4782 elsif Is_Fixed_Point_Type
(T
)
4783 and then B_Typ
= Universal_Fixed
4784 and then Is_Overloaded
(N
)
4786 -- Must be (fixed * fixed) operation, operand must have one
4787 -- compatible interpretation.
4789 Resolve
(N
, Any_Fixed
);
4791 elsif Is_Fixed_Point_Type
(B_Typ
)
4792 and then (T
= Universal_Real
or else Is_Fixed_Point_Type
(T
))
4793 and then Is_Overloaded
(N
)
4795 -- C * F(X) in a fixed context, where C is a real literal or a
4796 -- fixed-point expression. F must have either a fixed type
4797 -- interpretation or an integer interpretation, but not both.
4799 Get_First_Interp
(N
, Index
, It
);
4800 while Present
(It
.Typ
) loop
4801 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
) then
4802 if Analyzed
(N
) then
4803 Error_Msg_N
("ambiguous operand in fixed operation", N
);
4805 Resolve
(N
, Standard_Integer
);
4808 elsif Is_Fixed_Point_Type
(It
.Typ
) then
4809 if Analyzed
(N
) then
4810 Error_Msg_N
("ambiguous operand in fixed operation", N
);
4812 Resolve
(N
, It
.Typ
);
4816 Get_Next_Interp
(Index
, It
);
4819 -- Reanalyze the literal with the fixed type of the context. If
4820 -- context is Universal_Fixed, we are within a conversion, leave
4821 -- the literal as a universal real because there is no usable
4822 -- fixed type, and the target of the conversion plays no role in
4836 if B_Typ
= Universal_Fixed
4837 and then Nkind
(Op2
) = N_Real_Literal
4839 T2
:= Universal_Real
;
4844 Set_Analyzed
(Op2
, False);
4851 end Set_Mixed_Mode_Operand
;
4853 ----------------------
4854 -- Set_Operand_Type --
4855 ----------------------
4857 procedure Set_Operand_Type
(N
: Node_Id
) is
4859 if Etype
(N
) = Universal_Integer
4860 or else Etype
(N
) = Universal_Real
4864 end Set_Operand_Type
;
4866 -- Start of processing for Resolve_Arithmetic_Op
4869 if Comes_From_Source
(N
)
4870 and then Ekind
(Entity
(N
)) = E_Function
4871 and then Is_Imported
(Entity
(N
))
4872 and then Is_Intrinsic_Subprogram
(Entity
(N
))
4874 Resolve_Intrinsic_Operator
(N
, Typ
);
4877 -- Special-case for mixed-mode universal expressions or fixed point type
4878 -- operation: each argument is resolved separately. The same treatment
4879 -- is required if one of the operands of a fixed point operation is
4880 -- universal real, since in this case we don't do a conversion to a
4881 -- specific fixed-point type (instead the expander handles the case).
4883 -- Set the type of the node to its universal interpretation because
4884 -- legality checks on an exponentiation operand need the context.
4886 elsif (B_Typ
= Universal_Integer
or else B_Typ
= Universal_Real
)
4887 and then Present
(Universal_Interpretation
(L
))
4888 and then Present
(Universal_Interpretation
(R
))
4890 Set_Etype
(N
, B_Typ
);
4891 Resolve
(L
, Universal_Interpretation
(L
));
4892 Resolve
(R
, Universal_Interpretation
(R
));
4894 elsif (B_Typ
= Universal_Real
4895 or else Etype
(N
) = Universal_Fixed
4896 or else (Etype
(N
) = Any_Fixed
4897 and then Is_Fixed_Point_Type
(B_Typ
))
4898 or else (Is_Fixed_Point_Type
(B_Typ
)
4899 and then (Is_Integer_Or_Universal
(L
)
4901 Is_Integer_Or_Universal
(R
))))
4902 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
4904 if TL
= Universal_Integer
or else TR
= Universal_Integer
then
4905 Check_For_Visible_Operator
(N
, B_Typ
);
4908 -- If context is a fixed type and one operand is integer, the other
4909 -- is resolved with the type of the context.
4911 if Is_Fixed_Point_Type
(B_Typ
)
4912 and then (Base_Type
(TL
) = Base_Type
(Standard_Integer
)
4913 or else TL
= Universal_Integer
)
4918 elsif Is_Fixed_Point_Type
(B_Typ
)
4919 and then (Base_Type
(TR
) = Base_Type
(Standard_Integer
)
4920 or else TR
= Universal_Integer
)
4926 Set_Mixed_Mode_Operand
(L
, TR
);
4927 Set_Mixed_Mode_Operand
(R
, TL
);
4930 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4931 -- multiplying operators from being used when the expected type is
4932 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4933 -- some cases where the expected type is actually Any_Real;
4934 -- Expected_Type_Is_Any_Real takes care of that case.
4936 if Etype
(N
) = Universal_Fixed
4937 or else Etype
(N
) = Any_Fixed
4939 if B_Typ
= Universal_Fixed
4940 and then not Expected_Type_Is_Any_Real
(N
)
4941 and then not Nkind_In
(Parent
(N
), N_Type_Conversion
,
4942 N_Unchecked_Type_Conversion
)
4944 Error_Msg_N
("type cannot be determined from context!", N
);
4945 Error_Msg_N
("\explicit conversion to result type required", N
);
4947 Set_Etype
(L
, Any_Type
);
4948 Set_Etype
(R
, Any_Type
);
4951 if Ada_Version
= Ada_83
4952 and then Etype
(N
) = Universal_Fixed
4954 Nkind_In
(Parent
(N
), N_Type_Conversion
,
4955 N_Unchecked_Type_Conversion
)
4958 ("(Ada 83) fixed-point operation "
4959 & "needs explicit conversion", N
);
4962 -- The expected type is "any real type" in contexts like
4964 -- type T is delta <universal_fixed-expression> ...
4966 -- in which case we need to set the type to Universal_Real
4967 -- so that static expression evaluation will work properly.
4969 if Expected_Type_Is_Any_Real
(N
) then
4970 Set_Etype
(N
, Universal_Real
);
4972 Set_Etype
(N
, B_Typ
);
4976 elsif Is_Fixed_Point_Type
(B_Typ
)
4977 and then (Is_Integer_Or_Universal
(L
)
4978 or else Nkind
(L
) = N_Real_Literal
4979 or else Nkind
(R
) = N_Real_Literal
4980 or else Is_Integer_Or_Universal
(R
))
4982 Set_Etype
(N
, B_Typ
);
4984 elsif Etype
(N
) = Any_Fixed
then
4986 -- If no previous errors, this is only possible if one operand is
4987 -- overloaded and the context is universal. Resolve as such.
4989 Set_Etype
(N
, B_Typ
);
4993 if (TL
= Universal_Integer
or else TL
= Universal_Real
)
4995 (TR
= Universal_Integer
or else TR
= Universal_Real
)
4997 Check_For_Visible_Operator
(N
, B_Typ
);
5000 -- If the context is Universal_Fixed and the operands are also
5001 -- universal fixed, this is an error, unless there is only one
5002 -- applicable fixed_point type (usually Duration).
5004 if B_Typ
= Universal_Fixed
and then Etype
(L
) = Universal_Fixed
then
5005 T
:= Unique_Fixed_Point_Type
(N
);
5007 if T
= Any_Type
then
5020 -- If one of the arguments was resolved to a non-universal type.
5021 -- label the result of the operation itself with the same type.
5022 -- Do the same for the universal argument, if any.
5024 T
:= Intersect_Types
(L
, R
);
5025 Set_Etype
(N
, Base_Type
(T
));
5026 Set_Operand_Type
(L
);
5027 Set_Operand_Type
(R
);
5030 Generate_Operator_Reference
(N
, Typ
);
5031 Analyze_Dimension
(N
);
5032 Eval_Arithmetic_Op
(N
);
5034 -- In SPARK, a multiplication or division with operands of fixed point
5035 -- types shall be qualified or explicitly converted to identify the
5038 if (Is_Fixed_Point_Type
(Etype
(L
))
5039 or else Is_Fixed_Point_Type
(Etype
(R
)))
5040 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
5042 not Nkind_In
(Parent
(N
), N_Qualified_Expression
, N_Type_Conversion
)
5044 Check_SPARK_Restriction
5045 ("operation should be qualified or explicitly converted", N
);
5048 -- Set overflow and division checking bit
5050 if Nkind
(N
) in N_Op
then
5051 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
5052 Enable_Overflow_Check
(N
);
5055 -- Give warning if explicit division by zero
5057 if Nkind_In
(N
, N_Op_Divide
, N_Op_Rem
, N_Op_Mod
)
5058 and then not Division_Checks_Suppressed
(Etype
(N
))
5060 Rop
:= Right_Opnd
(N
);
5062 if Compile_Time_Known_Value
(Rop
)
5063 and then ((Is_Integer_Type
(Etype
(Rop
))
5064 and then Expr_Value
(Rop
) = Uint_0
)
5066 (Is_Real_Type
(Etype
(Rop
))
5067 and then Expr_Value_R
(Rop
) = Ureal_0
))
5069 -- Specialize the warning message according to the operation.
5070 -- The following warnings are for the case
5075 -- For division, we have two cases, for float division
5076 -- of an unconstrained float type, on a machine where
5077 -- Machine_Overflows is false, we don't get an exception
5078 -- at run-time, but rather an infinity or Nan. The Nan
5079 -- case is pretty obscure, so just warn about infinities.
5081 if Is_Floating_Point_Type
(Typ
)
5082 and then not Is_Constrained
(Typ
)
5083 and then not Machine_Overflows_On_Target
5086 ("float division by zero, may generate "
5087 & "'+'/'- infinity??", Right_Opnd
(N
));
5089 -- For all other cases, we get a Constraint_Error
5092 Apply_Compile_Time_Constraint_Error
5093 (N
, "division by zero??", CE_Divide_By_Zero
,
5094 Loc
=> Sloc
(Right_Opnd
(N
)));
5098 Apply_Compile_Time_Constraint_Error
5099 (N
, "rem with zero divisor??", CE_Divide_By_Zero
,
5100 Loc
=> Sloc
(Right_Opnd
(N
)));
5103 Apply_Compile_Time_Constraint_Error
5104 (N
, "mod with zero divisor??", CE_Divide_By_Zero
,
5105 Loc
=> Sloc
(Right_Opnd
(N
)));
5107 -- Division by zero can only happen with division, rem,
5108 -- and mod operations.
5111 raise Program_Error
;
5114 -- Otherwise just set the flag to check at run time
5117 Activate_Division_Check
(N
);
5121 -- If Restriction No_Implicit_Conditionals is active, then it is
5122 -- violated if either operand can be negative for mod, or for rem
5123 -- if both operands can be negative.
5125 if Restriction_Check_Required
(No_Implicit_Conditionals
)
5126 and then Nkind_In
(N
, N_Op_Rem
, N_Op_Mod
)
5135 -- Set if corresponding operand might be negative
5139 (Left_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5140 LNeg
:= (not OK
) or else Lo
< 0;
5143 (Right_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5144 RNeg
:= (not OK
) or else Lo
< 0;
5146 -- Check if we will be generating conditionals. There are two
5147 -- cases where that can happen, first for REM, the only case
5148 -- is largest negative integer mod -1, where the division can
5149 -- overflow, but we still have to give the right result. The
5150 -- front end generates a test for this annoying case. Here we
5151 -- just test if both operands can be negative (that's what the
5152 -- expander does, so we match its logic here).
5154 -- The second case is mod where either operand can be negative.
5155 -- In this case, the back end has to generate additional tests.
5157 if (Nkind
(N
) = N_Op_Rem
and then (LNeg
and RNeg
))
5159 (Nkind
(N
) = N_Op_Mod
and then (LNeg
or RNeg
))
5161 Check_Restriction
(No_Implicit_Conditionals
, N
);
5167 Check_Unset_Reference
(L
);
5168 Check_Unset_Reference
(R
);
5169 Check_Function_Writable_Actuals
(N
);
5170 end Resolve_Arithmetic_Op
;
5176 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
5177 Loc
: constant Source_Ptr
:= Sloc
(N
);
5178 Subp
: constant Node_Id
:= Name
(N
);
5186 function Same_Or_Aliased_Subprograms
5188 E
: Entity_Id
) return Boolean;
5189 -- Returns True if the subprogram entity S is the same as E or else
5190 -- S is an alias of E.
5192 ---------------------------------
5193 -- Same_Or_Aliased_Subprograms --
5194 ---------------------------------
5196 function Same_Or_Aliased_Subprograms
5198 E
: Entity_Id
) return Boolean
5200 Subp_Alias
: constant Entity_Id
:= Alias
(S
);
5203 or else (Present
(Subp_Alias
) and then Subp_Alias
= E
);
5204 end Same_Or_Aliased_Subprograms
;
5206 -- Start of processing for Resolve_Call
5209 -- The context imposes a unique interpretation with type Typ on a
5210 -- procedure or function call. Find the entity of the subprogram that
5211 -- yields the expected type, and propagate the corresponding formal
5212 -- constraints on the actuals. The caller has established that an
5213 -- interpretation exists, and emitted an error if not unique.
5215 -- First deal with the case of a call to an access-to-subprogram,
5216 -- dereference made explicit in Analyze_Call.
5218 if Ekind
(Etype
(Subp
)) = E_Subprogram_Type
then
5219 if not Is_Overloaded
(Subp
) then
5220 Nam
:= Etype
(Subp
);
5223 -- Find the interpretation whose type (a subprogram type) has a
5224 -- return type that is compatible with the context. Analysis of
5225 -- the node has established that one exists.
5229 Get_First_Interp
(Subp
, I
, It
);
5230 while Present
(It
.Typ
) loop
5231 if Covers
(Typ
, Etype
(It
.Typ
)) then
5236 Get_Next_Interp
(I
, It
);
5240 raise Program_Error
;
5244 -- If the prefix is not an entity, then resolve it
5246 if not Is_Entity_Name
(Subp
) then
5247 Resolve
(Subp
, Nam
);
5250 -- For an indirect call, we always invalidate checks, since we do not
5251 -- know whether the subprogram is local or global. Yes we could do
5252 -- better here, e.g. by knowing that there are no local subprograms,
5253 -- but it does not seem worth the effort. Similarly, we kill all
5254 -- knowledge of current constant values.
5256 Kill_Current_Values
;
5258 -- If this is a procedure call which is really an entry call, do
5259 -- the conversion of the procedure call to an entry call. Protected
5260 -- operations use the same circuitry because the name in the call
5261 -- can be an arbitrary expression with special resolution rules.
5263 elsif Nkind_In
(Subp
, N_Selected_Component
, N_Indexed_Component
)
5264 or else (Is_Entity_Name
(Subp
)
5265 and then Ekind
(Entity
(Subp
)) = E_Entry
)
5267 Resolve_Entry_Call
(N
, Typ
);
5268 Check_Elab_Call
(N
);
5270 -- Kill checks and constant values, as above for indirect case
5271 -- Who knows what happens when another task is activated?
5273 Kill_Current_Values
;
5276 -- Normal subprogram call with name established in Resolve
5278 elsif not (Is_Type
(Entity
(Subp
))) then
5279 Nam
:= Entity
(Subp
);
5280 Set_Entity_With_Style_Check
(Subp
, Nam
);
5282 -- Otherwise we must have the case of an overloaded call
5285 pragma Assert
(Is_Overloaded
(Subp
));
5287 -- Initialize Nam to prevent warning (we know it will be assigned
5288 -- in the loop below, but the compiler does not know that).
5292 Get_First_Interp
(Subp
, I
, It
);
5293 while Present
(It
.Typ
) loop
5294 if Covers
(Typ
, It
.Typ
) then
5296 Set_Entity_With_Style_Check
(Subp
, Nam
);
5300 Get_Next_Interp
(I
, It
);
5304 if Is_Access_Subprogram_Type
(Base_Type
(Etype
(Nam
)))
5305 and then not Is_Access_Subprogram_Type
(Base_Type
(Typ
))
5306 and then Nkind
(Subp
) /= N_Explicit_Dereference
5307 and then Present
(Parameter_Associations
(N
))
5309 -- The prefix is a parameterless function call that returns an access
5310 -- to subprogram. If parameters are present in the current call, add
5311 -- add an explicit dereference. We use the base type here because
5312 -- within an instance these may be subtypes.
5314 -- The dereference is added either in Analyze_Call or here. Should
5315 -- be consolidated ???
5317 Set_Is_Overloaded
(Subp
, False);
5318 Set_Etype
(Subp
, Etype
(Nam
));
5319 Insert_Explicit_Dereference
(Subp
);
5320 Nam
:= Designated_Type
(Etype
(Nam
));
5321 Resolve
(Subp
, Nam
);
5324 -- Check that a call to Current_Task does not occur in an entry body
5326 if Is_RTE
(Nam
, RE_Current_Task
) then
5335 -- Exclude calls that occur within the default of a formal
5336 -- parameter of the entry, since those are evaluated outside
5339 exit when No
(P
) or else Nkind
(P
) = N_Parameter_Specification
;
5341 if Nkind
(P
) = N_Entry_Body
5342 or else (Nkind
(P
) = N_Subprogram_Body
5343 and then Is_Entry_Barrier_Function
(P
))
5347 ("??& should not be used in entry body (RM C.7(17))",
5350 ("\Program_Error will be raised at run time??", N
, Nam
);
5352 Make_Raise_Program_Error
(Loc
,
5353 Reason
=> PE_Current_Task_In_Entry_Body
));
5354 Set_Etype
(N
, Rtype
);
5361 -- Check that a procedure call does not occur in the context of the
5362 -- entry call statement of a conditional or timed entry call. Note that
5363 -- the case of a call to a subprogram renaming of an entry will also be
5364 -- rejected. The test for N not being an N_Entry_Call_Statement is
5365 -- defensive, covering the possibility that the processing of entry
5366 -- calls might reach this point due to later modifications of the code
5369 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
5370 and then Nkind
(N
) /= N_Entry_Call_Statement
5371 and then Entry_Call_Statement
(Parent
(N
)) = N
5373 if Ada_Version
< Ada_2005
then
5374 Error_Msg_N
("entry call required in select statement", N
);
5376 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5377 -- for a procedure_or_entry_call, the procedure_name or
5378 -- procedure_prefix of the procedure_call_statement shall denote
5379 -- an entry renamed by a procedure, or (a view of) a primitive
5380 -- subprogram of a limited interface whose first parameter is
5381 -- a controlling parameter.
5383 elsif Nkind
(N
) = N_Procedure_Call_Statement
5384 and then not Is_Renamed_Entry
(Nam
)
5385 and then not Is_Controlling_Limited_Procedure
(Nam
)
5388 ("entry call or dispatching primitive of interface required", N
);
5392 -- Check that this is not a call to a protected procedure or entry from
5393 -- within a protected function.
5395 Check_Internal_Protected_Use
(N
, Nam
);
5397 -- Freeze the subprogram name if not in a spec-expression. Note that
5398 -- we freeze procedure calls as well as function calls. Procedure calls
5399 -- are not frozen according to the rules (RM 13.14(14)) because it is
5400 -- impossible to have a procedure call to a non-frozen procedure in
5401 -- pure Ada, but in the code that we generate in the expander, this
5402 -- rule needs extending because we can generate procedure calls that
5405 -- In Ada 2012, expression functions may be called within pre/post
5406 -- conditions of subsequent functions or expression functions. Such
5407 -- calls do not freeze when they appear within generated bodies,
5408 -- (including the body of another expression function) which would
5409 -- place the freeze node in the wrong scope. An expression function
5410 -- is frozen in the usual fashion, by the appearance of a real body,
5411 -- or at the end of a declarative part.
5413 if Is_Entity_Name
(Subp
) and then not In_Spec_Expression
5414 and then not Is_Expression_Function
(Current_Scope
)
5416 (not Is_Expression_Function
(Entity
(Subp
))
5417 or else Scope
(Entity
(Subp
)) = Current_Scope
)
5419 Freeze_Expression
(Subp
);
5422 -- For a predefined operator, the type of the result is the type imposed
5423 -- by context, except for a predefined operation on universal fixed.
5424 -- Otherwise The type of the call is the type returned by the subprogram
5427 if Is_Predefined_Op
(Nam
) then
5428 if Etype
(N
) /= Universal_Fixed
then
5432 -- If the subprogram returns an array type, and the context requires the
5433 -- component type of that array type, the node is really an indexing of
5434 -- the parameterless call. Resolve as such. A pathological case occurs
5435 -- when the type of the component is an access to the array type. In
5436 -- this case the call is truly ambiguous.
5438 elsif (Needs_No_Actuals
(Nam
) or else Needs_One_Actual
(Nam
))
5440 ((Is_Array_Type
(Etype
(Nam
))
5441 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
5442 or else (Is_Access_Type
(Etype
(Nam
))
5443 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
5447 Component_Type
(Designated_Type
(Etype
(Nam
))))))
5450 Index_Node
: Node_Id
;
5452 Ret_Type
: constant Entity_Id
:= Etype
(Nam
);
5455 if Is_Access_Type
(Ret_Type
)
5456 and then Ret_Type
= Component_Type
(Designated_Type
(Ret_Type
))
5459 ("cannot disambiguate function call and indexing", N
);
5461 New_Subp
:= Relocate_Node
(Subp
);
5462 Set_Entity
(Subp
, Nam
);
5464 if (Is_Array_Type
(Ret_Type
)
5465 and then Component_Type
(Ret_Type
) /= Any_Type
)
5467 (Is_Access_Type
(Ret_Type
)
5469 Component_Type
(Designated_Type
(Ret_Type
)) /= Any_Type
)
5471 if Needs_No_Actuals
(Nam
) then
5473 -- Indexed call to a parameterless function
5476 Make_Indexed_Component
(Loc
,
5478 Make_Function_Call
(Loc
,
5480 Expressions
=> Parameter_Associations
(N
));
5482 -- An Ada 2005 prefixed call to a primitive operation
5483 -- whose first parameter is the prefix. This prefix was
5484 -- prepended to the parameter list, which is actually a
5485 -- list of indexes. Remove the prefix in order to build
5486 -- the proper indexed component.
5489 Make_Indexed_Component
(Loc
,
5491 Make_Function_Call
(Loc
,
5493 Parameter_Associations
=>
5495 (Remove_Head
(Parameter_Associations
(N
)))),
5496 Expressions
=> Parameter_Associations
(N
));
5499 -- Preserve the parenthesis count of the node
5501 Set_Paren_Count
(Index_Node
, Paren_Count
(N
));
5503 -- Since we are correcting a node classification error made
5504 -- by the parser, we call Replace rather than Rewrite.
5506 Replace
(N
, Index_Node
);
5508 Set_Etype
(Prefix
(N
), Ret_Type
);
5510 Resolve_Indexed_Component
(N
, Typ
);
5511 Check_Elab_Call
(Prefix
(N
));
5519 Set_Etype
(N
, Etype
(Nam
));
5522 -- In the case where the call is to an overloaded subprogram, Analyze
5523 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5524 -- such a case Normalize_Actuals needs to be called once more to order
5525 -- the actuals correctly. Otherwise the call will have the ordering
5526 -- given by the last overloaded subprogram whether this is the correct
5527 -- one being called or not.
5529 if Is_Overloaded
(Subp
) then
5530 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
5531 pragma Assert
(Norm_OK
);
5534 -- In any case, call is fully resolved now. Reset Overload flag, to
5535 -- prevent subsequent overload resolution if node is analyzed again
5537 Set_Is_Overloaded
(Subp
, False);
5538 Set_Is_Overloaded
(N
, False);
5540 -- If we are calling the current subprogram from immediately within its
5541 -- body, then that is the case where we can sometimes detect cases of
5542 -- infinite recursion statically. Do not try this in case restriction
5543 -- No_Recursion is in effect anyway, and do it only for source calls.
5545 if Comes_From_Source
(N
) then
5546 Scop
:= Current_Scope
;
5548 -- Issue warning for possible infinite recursion in the absence
5549 -- of the No_Recursion restriction.
5551 if Same_Or_Aliased_Subprograms
(Nam
, Scop
)
5552 and then not Restriction_Active
(No_Recursion
)
5553 and then Check_Infinite_Recursion
(N
)
5555 -- Here we detected and flagged an infinite recursion, so we do
5556 -- not need to test the case below for further warnings. Also we
5557 -- are all done if we now have a raise SE node.
5559 if Nkind
(N
) = N_Raise_Storage_Error
then
5563 -- If call is to immediately containing subprogram, then check for
5564 -- the case of a possible run-time detectable infinite recursion.
5567 Scope_Loop
: while Scop
/= Standard_Standard
loop
5568 if Same_Or_Aliased_Subprograms
(Nam
, Scop
) then
5570 -- Although in general case, recursion is not statically
5571 -- checkable, the case of calling an immediately containing
5572 -- subprogram is easy to catch.
5574 Check_Restriction
(No_Recursion
, N
);
5576 -- If the recursive call is to a parameterless subprogram,
5577 -- then even if we can't statically detect infinite
5578 -- recursion, this is pretty suspicious, and we output a
5579 -- warning. Furthermore, we will try later to detect some
5580 -- cases here at run time by expanding checking code (see
5581 -- Detect_Infinite_Recursion in package Exp_Ch6).
5583 -- If the recursive call is within a handler, do not emit a
5584 -- warning, because this is a common idiom: loop until input
5585 -- is correct, catch illegal input in handler and restart.
5587 if No
(First_Formal
(Nam
))
5588 and then Etype
(Nam
) = Standard_Void_Type
5589 and then not Error_Posted
(N
)
5590 and then Nkind
(Parent
(N
)) /= N_Exception_Handler
5592 -- For the case of a procedure call. We give the message
5593 -- only if the call is the first statement in a sequence
5594 -- of statements, or if all previous statements are
5595 -- simple assignments. This is simply a heuristic to
5596 -- decrease false positives, without losing too many good
5597 -- warnings. The idea is that these previous statements
5598 -- may affect global variables the procedure depends on.
5599 -- We also exclude raise statements, that may arise from
5600 -- constraint checks and are probably unrelated to the
5601 -- intended control flow.
5603 if Nkind
(N
) = N_Procedure_Call_Statement
5604 and then Is_List_Member
(N
)
5610 while Present
(P
) loop
5612 N_Assignment_Statement
,
5613 N_Raise_Constraint_Error
)
5623 -- Do not give warning if we are in a conditional context
5626 K
: constant Node_Kind
:= Nkind
(Parent
(N
));
5628 if (K
= N_Loop_Statement
5629 and then Present
(Iteration_Scheme
(Parent
(N
))))
5630 or else K
= N_If_Statement
5631 or else K
= N_Elsif_Part
5632 or else K
= N_Case_Statement_Alternative
5638 -- Here warning is to be issued
5640 Set_Has_Recursive_Call
(Nam
);
5642 ("??possible infinite recursion!", N
);
5644 ("\??Storage_Error may be raised at run time!", N
);
5650 Scop
:= Scope
(Scop
);
5651 end loop Scope_Loop
;
5655 -- Check obsolescent reference to Ada.Characters.Handling subprogram
5657 Check_Obsolescent_2005_Entity
(Nam
, Subp
);
5659 -- If subprogram name is a predefined operator, it was given in
5660 -- functional notation. Replace call node with operator node, so
5661 -- that actuals can be resolved appropriately.
5663 if Is_Predefined_Op
(Nam
) or else Ekind
(Nam
) = E_Operator
then
5664 Make_Call_Into_Operator
(N
, Typ
, Entity
(Name
(N
)));
5667 elsif Present
(Alias
(Nam
))
5668 and then Is_Predefined_Op
(Alias
(Nam
))
5670 Resolve_Actuals
(N
, Nam
);
5671 Make_Call_Into_Operator
(N
, Typ
, Alias
(Nam
));
5675 -- Create a transient scope if the resulting type requires it
5677 -- There are several notable exceptions:
5679 -- a) In init procs, the transient scope overhead is not needed, and is
5680 -- even incorrect when the call is a nested initialization call for a
5681 -- component whose expansion may generate adjust calls. However, if the
5682 -- call is some other procedure call within an initialization procedure
5683 -- (for example a call to Create_Task in the init_proc of the task
5684 -- run-time record) a transient scope must be created around this call.
5686 -- b) Enumeration literal pseudo-calls need no transient scope
5688 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
5689 -- functions) do not use the secondary stack even though the return
5690 -- type may be unconstrained.
5692 -- d) Calls to a build-in-place function, since such functions may
5693 -- allocate their result directly in a target object, and cases where
5694 -- the result does get allocated in the secondary stack are checked for
5695 -- within the specialized Exp_Ch6 procedures for expanding those
5696 -- build-in-place calls.
5698 -- e) If the subprogram is marked Inline_Always, then even if it returns
5699 -- an unconstrained type the call does not require use of the secondary
5700 -- stack. However, inlining will only take place if the body to inline
5701 -- is already present. It may not be available if e.g. the subprogram is
5702 -- declared in a child instance.
5704 -- If this is an initialization call for a type whose construction
5705 -- uses the secondary stack, and it is not a nested call to initialize
5706 -- a component, we do need to create a transient scope for it. We
5707 -- check for this by traversing the type in Check_Initialization_Call.
5710 and then Has_Pragma_Inline_Always
(Nam
)
5711 and then Nkind
(Unit_Declaration_Node
(Nam
)) = N_Subprogram_Declaration
5712 and then Present
(Body_To_Inline
(Unit_Declaration_Node
(Nam
)))
5713 and then not Debug_Flag_Dot_K
5717 elsif Is_Inlined
(Nam
)
5718 and then Has_Pragma_Inline
(Nam
)
5719 and then Nkind
(Unit_Declaration_Node
(Nam
)) = N_Subprogram_Declaration
5720 and then Present
(Body_To_Inline
(Unit_Declaration_Node
(Nam
)))
5721 and then Debug_Flag_Dot_K
5725 elsif Ekind
(Nam
) = E_Enumeration_Literal
5726 or else Is_Build_In_Place_Function
(Nam
)
5727 or else Is_Intrinsic_Subprogram
(Nam
)
5731 elsif Full_Expander_Active
5732 and then Is_Type
(Etype
(Nam
))
5733 and then Requires_Transient_Scope
(Etype
(Nam
))
5735 (not Within_Init_Proc
5737 (not Is_Init_Proc
(Nam
) and then Ekind
(Nam
) /= E_Function
))
5739 Establish_Transient_Scope
(N
, Sec_Stack
=> True);
5741 -- If the call appears within the bounds of a loop, it will
5742 -- be rewritten and reanalyzed, nothing left to do here.
5744 if Nkind
(N
) /= N_Function_Call
then
5748 elsif Is_Init_Proc
(Nam
)
5749 and then not Within_Init_Proc
5751 Check_Initialization_Call
(N
, Nam
);
5754 -- A protected function cannot be called within the definition of the
5755 -- enclosing protected type.
5757 if Is_Protected_Type
(Scope
(Nam
))
5758 and then In_Open_Scopes
(Scope
(Nam
))
5759 and then not Has_Completion
(Scope
(Nam
))
5762 ("& cannot be called before end of protected definition", N
, Nam
);
5765 -- Propagate interpretation to actuals, and add default expressions
5768 if Present
(First_Formal
(Nam
)) then
5769 Resolve_Actuals
(N
, Nam
);
5771 -- Overloaded literals are rewritten as function calls, for purpose of
5772 -- resolution. After resolution, we can replace the call with the
5775 elsif Ekind
(Nam
) = E_Enumeration_Literal
then
5776 Copy_Node
(Subp
, N
);
5777 Resolve_Entity_Name
(N
, Typ
);
5779 -- Avoid validation, since it is a static function call
5781 Generate_Reference
(Nam
, Subp
);
5785 -- If the subprogram is not global, then kill all saved values and
5786 -- checks. This is a bit conservative, since in many cases we could do
5787 -- better, but it is not worth the effort. Similarly, we kill constant
5788 -- values. However we do not need to do this for internal entities
5789 -- (unless they are inherited user-defined subprograms), since they
5790 -- are not in the business of molesting local values.
5792 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5793 -- kill all checks and values for calls to global subprograms. This
5794 -- takes care of the case where an access to a local subprogram is
5795 -- taken, and could be passed directly or indirectly and then called
5796 -- from almost any context.
5798 -- Note: we do not do this step till after resolving the actuals. That
5799 -- way we still take advantage of the current value information while
5800 -- scanning the actuals.
5802 -- We suppress killing values if we are processing the nodes associated
5803 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5804 -- type kills all the values as part of analyzing the code that
5805 -- initializes the dispatch tables.
5807 if Inside_Freezing_Actions
= 0
5808 and then (not Is_Library_Level_Entity
(Nam
)
5809 or else Suppress_Value_Tracking_On_Call
5810 (Nearest_Dynamic_Scope
(Current_Scope
)))
5811 and then (Comes_From_Source
(Nam
)
5812 or else (Present
(Alias
(Nam
))
5813 and then Comes_From_Source
(Alias
(Nam
))))
5815 Kill_Current_Values
;
5818 -- If we are warning about unread OUT parameters, this is the place to
5819 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5820 -- after the above call to Kill_Current_Values (since that call clears
5821 -- the Last_Assignment field of all local variables).
5823 if (Warn_On_Modified_Unread
or Warn_On_All_Unread_Out_Parameters
)
5824 and then Comes_From_Source
(N
)
5825 and then In_Extended_Main_Source_Unit
(N
)
5832 F
:= First_Formal
(Nam
);
5833 A
:= First_Actual
(N
);
5834 while Present
(F
) and then Present
(A
) loop
5835 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
5836 and then Warn_On_Modified_As_Out_Parameter
(F
)
5837 and then Is_Entity_Name
(A
)
5838 and then Present
(Entity
(A
))
5839 and then Comes_From_Source
(N
)
5840 and then Safe_To_Capture_Value
(N
, Entity
(A
))
5842 Set_Last_Assignment
(Entity
(A
), A
);
5851 -- If the subprogram is a primitive operation, check whether or not
5852 -- it is a correct dispatching call.
5854 if Is_Overloadable
(Nam
)
5855 and then Is_Dispatching_Operation
(Nam
)
5857 Check_Dispatching_Call
(N
);
5859 elsif Ekind
(Nam
) /= E_Subprogram_Type
5860 and then Is_Abstract_Subprogram
(Nam
)
5861 and then not In_Instance
5863 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Nam
);
5866 -- If this is a dispatching call, generate the appropriate reference,
5867 -- for better source navigation in GPS.
5869 if Is_Overloadable
(Nam
)
5870 and then Present
(Controlling_Argument
(N
))
5872 Generate_Reference
(Nam
, Subp
, 'R');
5874 -- Normal case, not a dispatching call: generate a call reference
5877 Generate_Reference
(Nam
, Subp
, 's');
5880 if Is_Intrinsic_Subprogram
(Nam
) then
5881 Check_Intrinsic_Call
(N
);
5884 -- Check for violation of restriction No_Specific_Termination_Handlers
5885 -- and warn on a potentially blocking call to Abort_Task.
5887 if Restriction_Check_Required
(No_Specific_Termination_Handlers
)
5888 and then (Is_RTE
(Nam
, RE_Set_Specific_Handler
)
5890 Is_RTE
(Nam
, RE_Specific_Handler
))
5892 Check_Restriction
(No_Specific_Termination_Handlers
, N
);
5894 elsif Is_RTE
(Nam
, RE_Abort_Task
) then
5895 Check_Potentially_Blocking_Operation
(N
);
5898 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
5899 -- timing event violates restriction No_Relative_Delay (AI-0211). We
5900 -- need to check the second argument to determine whether it is an
5901 -- absolute or relative timing event.
5903 if Restriction_Check_Required
(No_Relative_Delay
)
5904 and then Is_RTE
(Nam
, RE_Set_Handler
)
5905 and then Is_RTE
(Etype
(Next_Actual
(First_Actual
(N
))), RE_Time_Span
)
5907 Check_Restriction
(No_Relative_Delay
, N
);
5910 -- Issue an error for a call to an eliminated subprogram. This routine
5911 -- will not perform the check if the call appears within a default
5914 Check_For_Eliminated_Subprogram
(Subp
, Nam
);
5916 -- In formal mode, the primitive operations of a tagged type or type
5917 -- extension do not include functions that return the tagged type.
5919 if Nkind
(N
) = N_Function_Call
5920 and then Is_Tagged_Type
(Etype
(N
))
5921 and then Is_Entity_Name
(Name
(N
))
5922 and then Is_Inherited_Operation_For_Type
(Entity
(Name
(N
)), Etype
(N
))
5924 Check_SPARK_Restriction
("function not inherited", N
);
5927 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
5928 -- class-wide and the call dispatches on result in a context that does
5929 -- not provide a tag, the call raises Program_Error.
5931 if Nkind
(N
) = N_Function_Call
5932 and then In_Instance
5933 and then Is_Generic_Actual_Type
(Typ
)
5934 and then Is_Class_Wide_Type
(Typ
)
5935 and then Has_Controlling_Result
(Nam
)
5936 and then Nkind
(Parent
(N
)) = N_Object_Declaration
5938 -- Verify that none of the formals are controlling
5941 Call_OK
: Boolean := False;
5945 F
:= First_Formal
(Nam
);
5946 while Present
(F
) loop
5947 if Is_Controlling_Formal
(F
) then
5956 Error_Msg_N
("!?? cannot determine tag of result", N
);
5957 Error_Msg_N
("!?? Program_Error will be raised", N
);
5959 Make_Raise_Program_Error
(Sloc
(N
),
5960 Reason
=> PE_Explicit_Raise
));
5965 -- Check the dimensions of the actuals in the call. For function calls,
5966 -- propagate the dimensions from the returned type to N.
5968 Analyze_Dimension_Call
(N
, Nam
);
5970 -- All done, evaluate call and deal with elaboration issues
5973 Check_Elab_Call
(N
);
5974 Warn_On_Overlapping_Actuals
(Nam
, N
);
5977 -----------------------------
5978 -- Resolve_Case_Expression --
5979 -----------------------------
5981 procedure Resolve_Case_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
5985 Alt
:= First
(Alternatives
(N
));
5986 while Present
(Alt
) loop
5987 Resolve
(Expression
(Alt
), Typ
);
5992 Eval_Case_Expression
(N
);
5993 end Resolve_Case_Expression
;
5995 -------------------------------
5996 -- Resolve_Character_Literal --
5997 -------------------------------
5999 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
6000 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
6004 -- Verify that the character does belong to the type of the context
6006 Set_Etype
(N
, B_Typ
);
6007 Eval_Character_Literal
(N
);
6009 -- Wide_Wide_Character literals must always be defined, since the set
6010 -- of wide wide character literals is complete, i.e. if a character
6011 -- literal is accepted by the parser, then it is OK for wide wide
6012 -- character (out of range character literals are rejected).
6014 if Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
6017 -- Always accept character literal for type Any_Character, which
6018 -- occurs in error situations and in comparisons of literals, both
6019 -- of which should accept all literals.
6021 elsif B_Typ
= Any_Character
then
6024 -- For Standard.Character or a type derived from it, check that the
6025 -- literal is in range.
6027 elsif Root_Type
(B_Typ
) = Standard_Character
then
6028 if In_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6032 -- For Standard.Wide_Character or a type derived from it, check that the
6033 -- literal is in range.
6035 elsif Root_Type
(B_Typ
) = Standard_Wide_Character
then
6036 if In_Wide_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6040 -- For Standard.Wide_Wide_Character or a type derived from it, we
6041 -- know the literal is in range, since the parser checked!
6043 elsif Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
6046 -- If the entity is already set, this has already been resolved in a
6047 -- generic context, or comes from expansion. Nothing else to do.
6049 elsif Present
(Entity
(N
)) then
6052 -- Otherwise we have a user defined character type, and we can use the
6053 -- standard visibility mechanisms to locate the referenced entity.
6056 C
:= Current_Entity
(N
);
6057 while Present
(C
) loop
6058 if Etype
(C
) = B_Typ
then
6059 Set_Entity_With_Style_Check
(N
, C
);
6060 Generate_Reference
(C
, N
);
6068 -- If we fall through, then the literal does not match any of the
6069 -- entries of the enumeration type. This isn't just a constraint error
6070 -- situation, it is an illegality (see RM 4.2).
6073 ("character not defined for }", N
, First_Subtype
(B_Typ
));
6074 end Resolve_Character_Literal
;
6076 ---------------------------
6077 -- Resolve_Comparison_Op --
6078 ---------------------------
6080 -- Context requires a boolean type, and plays no role in resolution.
6081 -- Processing identical to that for equality operators. The result type is
6082 -- the base type, which matters when pathological subtypes of booleans with
6083 -- limited ranges are used.
6085 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
6086 L
: constant Node_Id
:= Left_Opnd
(N
);
6087 R
: constant Node_Id
:= Right_Opnd
(N
);
6091 -- If this is an intrinsic operation which is not predefined, use the
6092 -- types of its declared arguments to resolve the possibly overloaded
6093 -- operands. Otherwise the operands are unambiguous and specify the
6096 if Scope
(Entity
(N
)) /= Standard_Standard
then
6097 T
:= Etype
(First_Entity
(Entity
(N
)));
6100 T
:= Find_Unique_Type
(L
, R
);
6102 if T
= Any_Fixed
then
6103 T
:= Unique_Fixed_Point_Type
(L
);
6107 Set_Etype
(N
, Base_Type
(Typ
));
6108 Generate_Reference
(T
, N
, ' ');
6110 -- Skip remaining processing if already set to Any_Type
6112 if T
= Any_Type
then
6116 -- Deal with other error cases
6118 if T
= Any_String
or else
6119 T
= Any_Composite
or else
6122 if T
= Any_Character
then
6123 Ambiguous_Character
(L
);
6125 Error_Msg_N
("ambiguous operands for comparison", N
);
6128 Set_Etype
(N
, Any_Type
);
6132 -- Resolve the operands if types OK
6136 Check_Unset_Reference
(L
);
6137 Check_Unset_Reference
(R
);
6138 Generate_Operator_Reference
(N
, T
);
6139 Check_Low_Bound_Tested
(N
);
6141 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6142 -- types or array types except String.
6144 if Is_Boolean_Type
(T
) then
6145 Check_SPARK_Restriction
6146 ("comparison is not defined on Boolean type", N
);
6148 elsif Is_Array_Type
(T
)
6149 and then Base_Type
(T
) /= Standard_String
6151 Check_SPARK_Restriction
6152 ("comparison is not defined on array types other than String", N
);
6155 -- Check comparison on unordered enumeration
6157 if Bad_Unordered_Enumeration_Reference
(N
, Etype
(L
)) then
6158 Error_Msg_N
("comparison on unordered enumeration type?U?", N
);
6161 -- Evaluate the relation (note we do this after the above check since
6162 -- this Eval call may change N to True/False.
6164 Analyze_Dimension
(N
);
6165 Eval_Relational_Op
(N
);
6166 end Resolve_Comparison_Op
;
6168 -----------------------------------------
6169 -- Resolve_Discrete_Subtype_Indication --
6170 -----------------------------------------
6172 procedure Resolve_Discrete_Subtype_Indication
6180 Analyze
(Subtype_Mark
(N
));
6181 S
:= Entity
(Subtype_Mark
(N
));
6183 if Nkind
(Constraint
(N
)) /= N_Range_Constraint
then
6184 Error_Msg_N
("expect range constraint for discrete type", N
);
6185 Set_Etype
(N
, Any_Type
);
6188 R
:= Range_Expression
(Constraint
(N
));
6196 if Base_Type
(S
) /= Base_Type
(Typ
) then
6198 ("expect subtype of }", N
, First_Subtype
(Typ
));
6200 -- Rewrite the constraint as a range of Typ
6201 -- to allow compilation to proceed further.
6204 Rewrite
(Low_Bound
(R
),
6205 Make_Attribute_Reference
(Sloc
(Low_Bound
(R
)),
6206 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
6207 Attribute_Name
=> Name_First
));
6208 Rewrite
(High_Bound
(R
),
6209 Make_Attribute_Reference
(Sloc
(High_Bound
(R
)),
6210 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
6211 Attribute_Name
=> Name_First
));
6215 Set_Etype
(N
, Etype
(R
));
6217 -- Additionally, we must check that the bounds are compatible
6218 -- with the given subtype, which might be different from the
6219 -- type of the context.
6221 Apply_Range_Check
(R
, S
);
6223 -- ??? If the above check statically detects a Constraint_Error
6224 -- it replaces the offending bound(s) of the range R with a
6225 -- Constraint_Error node. When the itype which uses these bounds
6226 -- is frozen the resulting call to Duplicate_Subexpr generates
6227 -- a new temporary for the bounds.
6229 -- Unfortunately there are other itypes that are also made depend
6230 -- on these bounds, so when Duplicate_Subexpr is called they get
6231 -- a forward reference to the newly created temporaries and Gigi
6232 -- aborts on such forward references. This is probably sign of a
6233 -- more fundamental problem somewhere else in either the order of
6234 -- itype freezing or the way certain itypes are constructed.
6236 -- To get around this problem we call Remove_Side_Effects right
6237 -- away if either bounds of R are a Constraint_Error.
6240 L
: constant Node_Id
:= Low_Bound
(R
);
6241 H
: constant Node_Id
:= High_Bound
(R
);
6244 if Nkind
(L
) = N_Raise_Constraint_Error
then
6245 Remove_Side_Effects
(L
);
6248 if Nkind
(H
) = N_Raise_Constraint_Error
then
6249 Remove_Side_Effects
(H
);
6253 Check_Unset_Reference
(Low_Bound
(R
));
6254 Check_Unset_Reference
(High_Bound
(R
));
6257 end Resolve_Discrete_Subtype_Indication
;
6259 -------------------------
6260 -- Resolve_Entity_Name --
6261 -------------------------
6263 -- Used to resolve identifiers and expanded names
6265 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
) is
6266 E
: constant Entity_Id
:= Entity
(N
);
6269 -- If garbage from errors, set to Any_Type and return
6271 if No
(E
) and then Total_Errors_Detected
/= 0 then
6272 Set_Etype
(N
, Any_Type
);
6276 -- Replace named numbers by corresponding literals. Note that this is
6277 -- the one case where Resolve_Entity_Name must reset the Etype, since
6278 -- it is currently marked as universal.
6280 if Ekind
(E
) = E_Named_Integer
then
6282 Eval_Named_Integer
(N
);
6284 elsif Ekind
(E
) = E_Named_Real
then
6286 Eval_Named_Real
(N
);
6288 -- For enumeration literals, we need to make sure that a proper style
6289 -- check is done, since such literals are overloaded, and thus we did
6290 -- not do a style check during the first phase of analysis.
6292 elsif Ekind
(E
) = E_Enumeration_Literal
then
6293 Set_Entity_With_Style_Check
(N
, E
);
6294 Eval_Entity_Name
(N
);
6296 -- Case of subtype name appearing as an operand in expression
6298 elsif Is_Type
(E
) then
6300 -- Allow use of subtype if it is a concurrent type where we are
6301 -- currently inside the body. This will eventually be expanded into a
6302 -- call to Self (for tasks) or _object (for protected objects). Any
6303 -- other use of a subtype is invalid.
6305 if Is_Concurrent_Type
(E
)
6306 and then In_Open_Scopes
(E
)
6310 -- Any other use is an error
6314 ("invalid use of subtype mark in expression or call", N
);
6317 -- Check discriminant use if entity is discriminant in current scope,
6318 -- i.e. discriminant of record or concurrent type currently being
6319 -- analyzed. Uses in corresponding body are unrestricted.
6321 elsif Ekind
(E
) = E_Discriminant
6322 and then Scope
(E
) = Current_Scope
6323 and then not Has_Completion
(Current_Scope
)
6325 Check_Discriminant_Use
(N
);
6327 -- A parameterless generic function cannot appear in a context that
6328 -- requires resolution.
6330 elsif Ekind
(E
) = E_Generic_Function
then
6331 Error_Msg_N
("illegal use of generic function", N
);
6333 elsif Ekind
(E
) = E_Out_Parameter
6334 and then Ada_Version
= Ada_83
6335 and then (Nkind
(Parent
(N
)) in N_Op
6336 or else (Nkind
(Parent
(N
)) = N_Assignment_Statement
6337 and then N
= Expression
(Parent
(N
)))
6338 or else Nkind
(Parent
(N
)) = N_Explicit_Dereference
)
6340 Error_Msg_N
("(Ada 83) illegal reading of out parameter", N
);
6342 -- In all other cases, just do the possible static evaluation
6345 -- A deferred constant that appears in an expression must have a
6346 -- completion, unless it has been removed by in-place expansion of
6349 if Ekind
(E
) = E_Constant
6350 and then Comes_From_Source
(E
)
6351 and then No
(Constant_Value
(E
))
6352 and then Is_Frozen
(Etype
(E
))
6353 and then not In_Spec_Expression
6354 and then not Is_Imported
(E
)
6356 if No_Initialization
(Parent
(E
))
6357 or else (Present
(Full_View
(E
))
6358 and then No_Initialization
(Parent
(Full_View
(E
))))
6363 "deferred constant is frozen before completion", N
);
6367 Eval_Entity_Name
(N
);
6369 end Resolve_Entity_Name
;
6375 procedure Resolve_Entry
(Entry_Name
: Node_Id
) is
6376 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
6384 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
;
6385 -- If the bounds of the entry family being called depend on task
6386 -- discriminants, build a new index subtype where a discriminant is
6387 -- replaced with the value of the discriminant of the target task.
6388 -- The target task is the prefix of the entry name in the call.
6390 -----------------------
6391 -- Actual_Index_Type --
6392 -----------------------
6394 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
is
6395 Typ
: constant Entity_Id
:= Entry_Index_Type
(E
);
6396 Tsk
: constant Entity_Id
:= Scope
(E
);
6397 Lo
: constant Node_Id
:= Type_Low_Bound
(Typ
);
6398 Hi
: constant Node_Id
:= Type_High_Bound
(Typ
);
6401 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
;
6402 -- If the bound is given by a discriminant, replace with a reference
6403 -- to the discriminant of the same name in the target task. If the
6404 -- entry name is the target of a requeue statement and the entry is
6405 -- in the current protected object, the bound to be used is the
6406 -- discriminal of the object (see Apply_Range_Checks for details of
6407 -- the transformation).
6409 -----------------------------
6410 -- Actual_Discriminant_Ref --
6411 -----------------------------
6413 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
is
6414 Typ
: constant Entity_Id
:= Etype
(Bound
);
6418 Remove_Side_Effects
(Bound
);
6420 if not Is_Entity_Name
(Bound
)
6421 or else Ekind
(Entity
(Bound
)) /= E_Discriminant
6425 elsif Is_Protected_Type
(Tsk
)
6426 and then In_Open_Scopes
(Tsk
)
6427 and then Nkind
(Parent
(Entry_Name
)) = N_Requeue_Statement
6429 -- Note: here Bound denotes a discriminant of the corresponding
6430 -- record type tskV, whose discriminal is a formal of the
6431 -- init-proc tskVIP. What we want is the body discriminal,
6432 -- which is associated to the discriminant of the original
6433 -- concurrent type tsk.
6435 return New_Occurrence_Of
6436 (Find_Body_Discriminal
(Entity
(Bound
)), Loc
);
6440 Make_Selected_Component
(Loc
,
6441 Prefix
=> New_Copy_Tree
(Prefix
(Prefix
(Entry_Name
))),
6442 Selector_Name
=> New_Occurrence_Of
(Entity
(Bound
), Loc
));
6447 end Actual_Discriminant_Ref
;
6449 -- Start of processing for Actual_Index_Type
6452 if not Has_Discriminants
(Tsk
)
6453 or else (not Is_Entity_Name
(Lo
) and then not Is_Entity_Name
(Hi
))
6455 return Entry_Index_Type
(E
);
6458 New_T
:= Create_Itype
(Ekind
(Typ
), Parent
(Entry_Name
));
6459 Set_Etype
(New_T
, Base_Type
(Typ
));
6460 Set_Size_Info
(New_T
, Typ
);
6461 Set_RM_Size
(New_T
, RM_Size
(Typ
));
6462 Set_Scalar_Range
(New_T
,
6463 Make_Range
(Sloc
(Entry_Name
),
6464 Low_Bound
=> Actual_Discriminant_Ref
(Lo
),
6465 High_Bound
=> Actual_Discriminant_Ref
(Hi
)));
6469 end Actual_Index_Type
;
6471 -- Start of processing of Resolve_Entry
6474 -- Find name of entry being called, and resolve prefix of name with its
6475 -- own type. The prefix can be overloaded, and the name and signature of
6476 -- the entry must be taken into account.
6478 if Nkind
(Entry_Name
) = N_Indexed_Component
then
6480 -- Case of dealing with entry family within the current tasks
6482 E_Name
:= Prefix
(Entry_Name
);
6485 E_Name
:= Entry_Name
;
6488 if Is_Entity_Name
(E_Name
) then
6490 -- Entry call to an entry (or entry family) in the current task. This
6491 -- is legal even though the task will deadlock. Rewrite as call to
6494 -- This can also be a call to an entry in an enclosing task. If this
6495 -- is a single task, we have to retrieve its name, because the scope
6496 -- of the entry is the task type, not the object. If the enclosing
6497 -- task is a task type, the identity of the task is given by its own
6500 -- Finally this can be a requeue on an entry of the same task or
6501 -- protected object.
6503 S
:= Scope
(Entity
(E_Name
));
6505 for J
in reverse 0 .. Scope_Stack
.Last
loop
6506 if Is_Task_Type
(Scope_Stack
.Table
(J
).Entity
)
6507 and then not Comes_From_Source
(S
)
6509 -- S is an enclosing task or protected object. The concurrent
6510 -- declaration has been converted into a type declaration, and
6511 -- the object itself has an object declaration that follows
6512 -- the type in the same declarative part.
6514 Tsk
:= Next_Entity
(S
);
6515 while Etype
(Tsk
) /= S
loop
6522 elsif S
= Scope_Stack
.Table
(J
).Entity
then
6524 -- Call to current task. Will be transformed into call to Self
6532 Make_Selected_Component
(Loc
,
6533 Prefix
=> New_Occurrence_Of
(S
, Loc
),
6535 New_Occurrence_Of
(Entity
(E_Name
), Loc
));
6536 Rewrite
(E_Name
, New_N
);
6539 elsif Nkind
(Entry_Name
) = N_Selected_Component
6540 and then Is_Overloaded
(Prefix
(Entry_Name
))
6542 -- Use the entry name (which must be unique at this point) to find
6543 -- the prefix that returns the corresponding task/protected type.
6546 Pref
: constant Node_Id
:= Prefix
(Entry_Name
);
6547 Ent
: constant Entity_Id
:= Entity
(Selector_Name
(Entry_Name
));
6552 Get_First_Interp
(Pref
, I
, It
);
6553 while Present
(It
.Typ
) loop
6554 if Scope
(Ent
) = It
.Typ
then
6555 Set_Etype
(Pref
, It
.Typ
);
6559 Get_Next_Interp
(I
, It
);
6564 if Nkind
(Entry_Name
) = N_Selected_Component
then
6565 Resolve
(Prefix
(Entry_Name
));
6567 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
6568 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
6569 Resolve
(Prefix
(Prefix
(Entry_Name
)));
6570 Index
:= First
(Expressions
(Entry_Name
));
6571 Resolve
(Index
, Entry_Index_Type
(Nam
));
6573 -- Up to this point the expression could have been the actual in a
6574 -- simple entry call, and be given by a named association.
6576 if Nkind
(Index
) = N_Parameter_Association
then
6577 Error_Msg_N
("expect expression for entry index", Index
);
6579 Apply_Range_Check
(Index
, Actual_Index_Type
(Nam
));
6584 ------------------------
6585 -- Resolve_Entry_Call --
6586 ------------------------
6588 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
6589 Entry_Name
: constant Node_Id
:= Name
(N
);
6590 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
6592 First_Named
: Node_Id
;
6599 -- We kill all checks here, because it does not seem worth the effort to
6600 -- do anything better, an entry call is a big operation.
6604 -- Processing of the name is similar for entry calls and protected
6605 -- operation calls. Once the entity is determined, we can complete
6606 -- the resolution of the actuals.
6608 -- The selector may be overloaded, in the case of a protected object
6609 -- with overloaded functions. The type of the context is used for
6612 if Nkind
(Entry_Name
) = N_Selected_Component
6613 and then Is_Overloaded
(Selector_Name
(Entry_Name
))
6614 and then Typ
/= Standard_Void_Type
6621 Get_First_Interp
(Selector_Name
(Entry_Name
), I
, It
);
6622 while Present
(It
.Typ
) loop
6623 if Covers
(Typ
, It
.Typ
) then
6624 Set_Entity
(Selector_Name
(Entry_Name
), It
.Nam
);
6625 Set_Etype
(Entry_Name
, It
.Typ
);
6627 Generate_Reference
(It
.Typ
, N
, ' ');
6630 Get_Next_Interp
(I
, It
);
6635 Resolve_Entry
(Entry_Name
);
6637 if Nkind
(Entry_Name
) = N_Selected_Component
then
6639 -- Simple entry call
6641 Nam
:= Entity
(Selector_Name
(Entry_Name
));
6642 Obj
:= Prefix
(Entry_Name
);
6643 Was_Over
:= Is_Overloaded
(Selector_Name
(Entry_Name
));
6645 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
6647 -- Call to member of entry family
6649 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
6650 Obj
:= Prefix
(Prefix
(Entry_Name
));
6651 Was_Over
:= Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)));
6654 -- We cannot in general check the maximum depth of protected entry calls
6655 -- at compile time. But we can tell that any protected entry call at all
6656 -- violates a specified nesting depth of zero.
6658 if Is_Protected_Type
(Scope
(Nam
)) then
6659 Check_Restriction
(Max_Entry_Queue_Length
, N
);
6662 -- Use context type to disambiguate a protected function that can be
6663 -- called without actuals and that returns an array type, and where the
6664 -- argument list may be an indexing of the returned value.
6666 if Ekind
(Nam
) = E_Function
6667 and then Needs_No_Actuals
(Nam
)
6668 and then Present
(Parameter_Associations
(N
))
6670 ((Is_Array_Type
(Etype
(Nam
))
6671 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
6673 or else (Is_Access_Type
(Etype
(Nam
))
6674 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
6678 Component_Type
(Designated_Type
(Etype
(Nam
))))))
6681 Index_Node
: Node_Id
;
6685 Make_Indexed_Component
(Loc
,
6687 Make_Function_Call
(Loc
, Name
=> Relocate_Node
(Entry_Name
)),
6688 Expressions
=> Parameter_Associations
(N
));
6690 -- Since we are correcting a node classification error made by the
6691 -- parser, we call Replace rather than Rewrite.
6693 Replace
(N
, Index_Node
);
6694 Set_Etype
(Prefix
(N
), Etype
(Nam
));
6696 Resolve_Indexed_Component
(N
, Typ
);
6701 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
)
6702 and then Present
(PPC_Wrapper
(Nam
))
6703 and then Current_Scope
/= PPC_Wrapper
(Nam
)
6705 -- Rewrite as call to the precondition wrapper, adding the task
6706 -- object to the list of actuals. If the call is to a member of an
6707 -- entry family, include the index as well.
6711 New_Actuals
: List_Id
;
6714 New_Actuals
:= New_List
(Obj
);
6716 if Nkind
(Entry_Name
) = N_Indexed_Component
then
6717 Append_To
(New_Actuals
,
6718 New_Copy_Tree
(First
(Expressions
(Entry_Name
))));
6721 Append_List
(Parameter_Associations
(N
), New_Actuals
);
6723 Make_Procedure_Call_Statement
(Loc
,
6725 New_Occurrence_Of
(PPC_Wrapper
(Nam
), Loc
),
6726 Parameter_Associations
=> New_Actuals
);
6727 Rewrite
(N
, New_Call
);
6728 Analyze_And_Resolve
(N
);
6733 -- The operation name may have been overloaded. Order the actuals
6734 -- according to the formals of the resolved entity, and set the return
6735 -- type to that of the operation.
6738 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
6739 pragma Assert
(Norm_OK
);
6740 Set_Etype
(N
, Etype
(Nam
));
6743 Resolve_Actuals
(N
, Nam
);
6744 Check_Internal_Protected_Use
(N
, Nam
);
6746 -- Create a call reference to the entry
6748 Generate_Reference
(Nam
, Entry_Name
, 's');
6750 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
) then
6751 Check_Potentially_Blocking_Operation
(N
);
6754 -- Verify that a procedure call cannot masquerade as an entry
6755 -- call where an entry call is expected.
6757 if Ekind
(Nam
) = E_Procedure
then
6758 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
6759 and then N
= Entry_Call_Statement
(Parent
(N
))
6761 Error_Msg_N
("entry call required in select statement", N
);
6763 elsif Nkind
(Parent
(N
)) = N_Triggering_Alternative
6764 and then N
= Triggering_Statement
(Parent
(N
))
6766 Error_Msg_N
("triggering statement cannot be procedure call", N
);
6768 elsif Ekind
(Scope
(Nam
)) = E_Task_Type
6769 and then not In_Open_Scopes
(Scope
(Nam
))
6771 Error_Msg_N
("task has no entry with this name", Entry_Name
);
6775 -- After resolution, entry calls and protected procedure calls are
6776 -- changed into entry calls, for expansion. The structure of the node
6777 -- does not change, so it can safely be done in place. Protected
6778 -- function calls must keep their structure because they are
6781 if Ekind
(Nam
) /= E_Function
then
6783 -- A protected operation that is not a function may modify the
6784 -- corresponding object, and cannot apply to a constant. If this
6785 -- is an internal call, the prefix is the type itself.
6787 if Is_Protected_Type
(Scope
(Nam
))
6788 and then not Is_Variable
(Obj
)
6789 and then (not Is_Entity_Name
(Obj
)
6790 or else not Is_Type
(Entity
(Obj
)))
6793 ("prefix of protected procedure or entry call must be variable",
6797 Actuals
:= Parameter_Associations
(N
);
6798 First_Named
:= First_Named_Actual
(N
);
6801 Make_Entry_Call_Statement
(Loc
,
6803 Parameter_Associations
=> Actuals
));
6805 Set_First_Named_Actual
(N
, First_Named
);
6806 Set_Analyzed
(N
, True);
6808 -- Protected functions can return on the secondary stack, in which
6809 -- case we must trigger the transient scope mechanism.
6811 elsif Full_Expander_Active
6812 and then Requires_Transient_Scope
(Etype
(Nam
))
6814 Establish_Transient_Scope
(N
, Sec_Stack
=> True);
6816 end Resolve_Entry_Call
;
6818 -------------------------
6819 -- Resolve_Equality_Op --
6820 -------------------------
6822 -- Both arguments must have the same type, and the boolean context does
6823 -- not participate in the resolution. The first pass verifies that the
6824 -- interpretation is not ambiguous, and the type of the left argument is
6825 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6826 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6827 -- though they carry a single (universal) type. Diagnose this case here.
6829 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
6830 L
: constant Node_Id
:= Left_Opnd
(N
);
6831 R
: constant Node_Id
:= Right_Opnd
(N
);
6832 T
: Entity_Id
:= Find_Unique_Type
(L
, R
);
6834 procedure Check_If_Expression
(Cond
: Node_Id
);
6835 -- The resolution rule for if expressions requires that each such must
6836 -- have a unique type. This means that if several dependent expressions
6837 -- are of a non-null anonymous access type, and the context does not
6838 -- impose an expected type (as can be the case in an equality operation)
6839 -- the expression must be rejected.
6841 procedure Explain_Redundancy
(N
: Node_Id
);
6842 -- Attempt to explain the nature of a redundant comparison with True. If
6843 -- the expression N is too complex, this routine issues a general error
6846 function Find_Unique_Access_Type
return Entity_Id
;
6847 -- In the case of allocators and access attributes, the context must
6848 -- provide an indication of the specific access type to be used. If
6849 -- one operand is of such a "generic" access type, check whether there
6850 -- is a specific visible access type that has the same designated type.
6851 -- This is semantically dubious, and of no interest to any real code,
6852 -- but c48008a makes it all worthwhile.
6854 -------------------------
6855 -- Check_If_Expression --
6856 -------------------------
6858 procedure Check_If_Expression
(Cond
: Node_Id
) is
6859 Then_Expr
: Node_Id
;
6860 Else_Expr
: Node_Id
;
6863 if Nkind
(Cond
) = N_If_Expression
then
6864 Then_Expr
:= Next
(First
(Expressions
(Cond
)));
6865 Else_Expr
:= Next
(Then_Expr
);
6867 if Nkind
(Then_Expr
) /= N_Null
6868 and then Nkind
(Else_Expr
) /= N_Null
6870 Error_Msg_N
("cannot determine type of if expression", Cond
);
6873 end Check_If_Expression
;
6875 ------------------------
6876 -- Explain_Redundancy --
6877 ------------------------
6879 procedure Explain_Redundancy
(N
: Node_Id
) is
6887 -- Strip the operand down to an entity
6890 if Nkind
(Val
) = N_Selected_Component
then
6891 Val
:= Selector_Name
(Val
);
6897 -- The construct denotes an entity
6899 if Is_Entity_Name
(Val
) and then Present
(Entity
(Val
)) then
6900 Val_Id
:= Entity
(Val
);
6902 -- Do not generate an error message when the comparison is done
6903 -- against the enumeration literal Standard.True.
6905 if Ekind
(Val_Id
) /= E_Enumeration_Literal
then
6907 -- Build a customized error message
6910 Add_Str_To_Name_Buffer
("?r?");
6912 if Ekind
(Val_Id
) = E_Component
then
6913 Add_Str_To_Name_Buffer
("component ");
6915 elsif Ekind
(Val_Id
) = E_Constant
then
6916 Add_Str_To_Name_Buffer
("constant ");
6918 elsif Ekind
(Val_Id
) = E_Discriminant
then
6919 Add_Str_To_Name_Buffer
("discriminant ");
6921 elsif Is_Formal
(Val_Id
) then
6922 Add_Str_To_Name_Buffer
("parameter ");
6924 elsif Ekind
(Val_Id
) = E_Variable
then
6925 Add_Str_To_Name_Buffer
("variable ");
6928 Add_Str_To_Name_Buffer
("& is always True!");
6931 Error_Msg_NE
(Get_Name_String
(Error
), Val
, Val_Id
);
6934 -- The construct is too complex to disect, issue a general message
6937 Error_Msg_N
("?r?expression is always True!", Val
);
6939 end Explain_Redundancy
;
6941 -----------------------------
6942 -- Find_Unique_Access_Type --
6943 -----------------------------
6945 function Find_Unique_Access_Type
return Entity_Id
is
6951 if Ekind_In
(Etype
(R
), E_Allocator_Type
,
6952 E_Access_Attribute_Type
)
6954 Acc
:= Designated_Type
(Etype
(R
));
6956 elsif Ekind_In
(Etype
(L
), E_Allocator_Type
,
6957 E_Access_Attribute_Type
)
6959 Acc
:= Designated_Type
(Etype
(L
));
6965 while S
/= Standard_Standard
loop
6966 E
:= First_Entity
(S
);
6967 while Present
(E
) loop
6969 and then Is_Access_Type
(E
)
6970 and then Ekind
(E
) /= E_Allocator_Type
6971 and then Designated_Type
(E
) = Base_Type
(Acc
)
6983 end Find_Unique_Access_Type
;
6985 -- Start of processing for Resolve_Equality_Op
6988 Set_Etype
(N
, Base_Type
(Typ
));
6989 Generate_Reference
(T
, N
, ' ');
6991 if T
= Any_Fixed
then
6992 T
:= Unique_Fixed_Point_Type
(L
);
6995 if T
/= Any_Type
then
6996 if T
= Any_String
or else
6997 T
= Any_Composite
or else
7000 if T
= Any_Character
then
7001 Ambiguous_Character
(L
);
7003 Error_Msg_N
("ambiguous operands for equality", N
);
7006 Set_Etype
(N
, Any_Type
);
7009 elsif T
= Any_Access
7010 or else Ekind_In
(T
, E_Allocator_Type
, E_Access_Attribute_Type
)
7012 T
:= Find_Unique_Access_Type
;
7015 Error_Msg_N
("ambiguous operands for equality", N
);
7016 Set_Etype
(N
, Any_Type
);
7020 -- If expressions must have a single type, and if the context does
7021 -- not impose one the dependent expressions cannot be anonymous
7024 -- Why no similar processing for case expressions???
7026 elsif Ada_Version
>= Ada_2012
7027 and then Ekind_In
(Etype
(L
), E_Anonymous_Access_Type
,
7028 E_Anonymous_Access_Subprogram_Type
)
7029 and then Ekind_In
(Etype
(R
), E_Anonymous_Access_Type
,
7030 E_Anonymous_Access_Subprogram_Type
)
7032 Check_If_Expression
(L
);
7033 Check_If_Expression
(R
);
7039 -- In SPARK, equality operators = and /= for array types other than
7040 -- String are only defined when, for each index position, the
7041 -- operands have equal static bounds.
7043 if Is_Array_Type
(T
) then
7045 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7046 -- operation if not needed.
7048 if Restriction_Check_Required
(SPARK_05
)
7049 and then Base_Type
(T
) /= Standard_String
7050 and then Base_Type
(Etype
(L
)) = Base_Type
(Etype
(R
))
7051 and then Etype
(L
) /= Any_Composite
-- or else L in error
7052 and then Etype
(R
) /= Any_Composite
-- or else R in error
7053 and then not Matching_Static_Array_Bounds
(Etype
(L
), Etype
(R
))
7055 Check_SPARK_Restriction
7056 ("array types should have matching static bounds", N
);
7060 -- If the unique type is a class-wide type then it will be expanded
7061 -- into a dispatching call to the predefined primitive. Therefore we
7062 -- check here for potential violation of such restriction.
7064 if Is_Class_Wide_Type
(T
) then
7065 Check_Restriction
(No_Dispatching_Calls
, N
);
7068 if Warn_On_Redundant_Constructs
7069 and then Comes_From_Source
(N
)
7070 and then Comes_From_Source
(R
)
7071 and then Is_Entity_Name
(R
)
7072 and then Entity
(R
) = Standard_True
7074 Error_Msg_N
-- CODEFIX
7075 ("?r?comparison with True is redundant!", N
);
7076 Explain_Redundancy
(Original_Node
(R
));
7079 Check_Unset_Reference
(L
);
7080 Check_Unset_Reference
(R
);
7081 Generate_Operator_Reference
(N
, T
);
7082 Check_Low_Bound_Tested
(N
);
7084 -- If this is an inequality, it may be the implicit inequality
7085 -- created for a user-defined operation, in which case the corres-
7086 -- ponding equality operation is not intrinsic, and the operation
7087 -- cannot be constant-folded. Else fold.
7089 if Nkind
(N
) = N_Op_Eq
7090 or else Comes_From_Source
(Entity
(N
))
7091 or else Ekind
(Entity
(N
)) = E_Operator
7092 or else Is_Intrinsic_Subprogram
7093 (Corresponding_Equality
(Entity
(N
)))
7095 Analyze_Dimension
(N
);
7096 Eval_Relational_Op
(N
);
7098 elsif Nkind
(N
) = N_Op_Ne
7099 and then Is_Abstract_Subprogram
(Entity
(N
))
7101 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Entity
(N
));
7104 -- Ada 2005: If one operand is an anonymous access type, convert the
7105 -- other operand to it, to ensure that the underlying types match in
7106 -- the back-end. Same for access_to_subprogram, and the conversion
7107 -- verifies that the types are subtype conformant.
7109 -- We apply the same conversion in the case one of the operands is a
7110 -- private subtype of the type of the other.
7112 -- Why the Expander_Active test here ???
7114 if Full_Expander_Active
7116 (Ekind_In
(T
, E_Anonymous_Access_Type
,
7117 E_Anonymous_Access_Subprogram_Type
)
7118 or else Is_Private_Type
(T
))
7120 if Etype
(L
) /= T
then
7122 Make_Unchecked_Type_Conversion
(Sloc
(L
),
7123 Subtype_Mark
=> New_Occurrence_Of
(T
, Sloc
(L
)),
7124 Expression
=> Relocate_Node
(L
)));
7125 Analyze_And_Resolve
(L
, T
);
7128 if (Etype
(R
)) /= T
then
7130 Make_Unchecked_Type_Conversion
(Sloc
(R
),
7131 Subtype_Mark
=> New_Occurrence_Of
(Etype
(L
), Sloc
(R
)),
7132 Expression
=> Relocate_Node
(R
)));
7133 Analyze_And_Resolve
(R
, T
);
7137 end Resolve_Equality_Op
;
7139 ----------------------------------
7140 -- Resolve_Explicit_Dereference --
7141 ----------------------------------
7143 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
) is
7144 Loc
: constant Source_Ptr
:= Sloc
(N
);
7146 P
: constant Node_Id
:= Prefix
(N
);
7149 -- The candidate prefix type, if overloaded
7155 Check_Fully_Declared_Prefix
(Typ
, P
);
7158 if Is_Overloaded
(P
) then
7160 -- Use the context type to select the prefix that has the correct
7161 -- designated type. Keep the first match, which will be the inner-
7164 Get_First_Interp
(P
, I
, It
);
7166 while Present
(It
.Typ
) loop
7167 if Is_Access_Type
(It
.Typ
)
7168 and then Covers
(Typ
, Designated_Type
(It
.Typ
))
7174 -- Remove access types that do not match, but preserve access
7175 -- to subprogram interpretations, in case a further dereference
7176 -- is needed (see below).
7178 elsif Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
7182 Get_Next_Interp
(I
, It
);
7185 if Present
(P_Typ
) then
7187 Set_Etype
(N
, Designated_Type
(P_Typ
));
7190 -- If no interpretation covers the designated type of the prefix,
7191 -- this is the pathological case where not all implementations of
7192 -- the prefix allow the interpretation of the node as a call. Now
7193 -- that the expected type is known, Remove other interpretations
7194 -- from prefix, rewrite it as a call, and resolve again, so that
7195 -- the proper call node is generated.
7197 Get_First_Interp
(P
, I
, It
);
7198 while Present
(It
.Typ
) loop
7199 if Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
7203 Get_Next_Interp
(I
, It
);
7207 Make_Function_Call
(Loc
,
7209 Make_Explicit_Dereference
(Loc
,
7211 Parameter_Associations
=> New_List
);
7213 Save_Interps
(N
, New_N
);
7215 Analyze_And_Resolve
(N
, Typ
);
7219 -- If not overloaded, resolve P with its own type
7225 if Is_Access_Type
(Etype
(P
)) then
7226 Apply_Access_Check
(N
);
7229 -- If the designated type is a packed unconstrained array type, and the
7230 -- explicit dereference is not in the context of an attribute reference,
7231 -- then we must compute and set the actual subtype, since it is needed
7232 -- by Gigi. The reason we exclude the attribute case is that this is
7233 -- handled fine by Gigi, and in fact we use such attributes to build the
7234 -- actual subtype. We also exclude generated code (which builds actual
7235 -- subtypes directly if they are needed).
7237 if Is_Array_Type
(Etype
(N
))
7238 and then Is_Packed
(Etype
(N
))
7239 and then not Is_Constrained
(Etype
(N
))
7240 and then Nkind
(Parent
(N
)) /= N_Attribute_Reference
7241 and then Comes_From_Source
(N
)
7243 Set_Etype
(N
, Get_Actual_Subtype
(N
));
7246 -- Note: No Eval processing is required for an explicit dereference,
7247 -- because such a name can never be static.
7249 end Resolve_Explicit_Dereference
;
7251 -------------------------------------
7252 -- Resolve_Expression_With_Actions --
7253 -------------------------------------
7255 procedure Resolve_Expression_With_Actions
(N
: Node_Id
; Typ
: Entity_Id
) is
7258 end Resolve_Expression_With_Actions
;
7260 ---------------------------
7261 -- Resolve_If_Expression --
7262 ---------------------------
7264 procedure Resolve_If_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
7265 Condition
: constant Node_Id
:= First
(Expressions
(N
));
7266 Then_Expr
: constant Node_Id
:= Next
(Condition
);
7267 Else_Expr
: Node_Id
:= Next
(Then_Expr
);
7268 Else_Typ
: Entity_Id
;
7269 Then_Typ
: Entity_Id
;
7272 Resolve
(Condition
, Any_Boolean
);
7273 Resolve
(Then_Expr
, Typ
);
7274 Then_Typ
:= Etype
(Then_Expr
);
7276 -- When the "then" expression is of a scalar subtype different from the
7277 -- result subtype, then insert a conversion to ensure the generation of
7278 -- a constraint check. The same is done for the else part below, again
7279 -- comparing subtypes rather than base types.
7281 if Is_Scalar_Type
(Then_Typ
)
7282 and then Then_Typ
/= Typ
7284 Rewrite
(Then_Expr
, Convert_To
(Typ
, Then_Expr
));
7285 Analyze_And_Resolve
(Then_Expr
, Typ
);
7288 -- If ELSE expression present, just resolve using the determined type
7290 if Present
(Else_Expr
) then
7291 Resolve
(Else_Expr
, Typ
);
7292 Else_Typ
:= Etype
(Else_Expr
);
7294 if Is_Scalar_Type
(Else_Typ
)
7295 and then Else_Typ
/= Typ
7297 Rewrite
(Else_Expr
, Convert_To
(Typ
, Else_Expr
));
7298 Analyze_And_Resolve
(Else_Expr
, Typ
);
7301 -- If no ELSE expression is present, root type must be Standard.Boolean
7302 -- and we provide a Standard.True result converted to the appropriate
7303 -- Boolean type (in case it is a derived boolean type).
7305 elsif Root_Type
(Typ
) = Standard_Boolean
then
7307 Convert_To
(Typ
, New_Occurrence_Of
(Standard_True
, Sloc
(N
)));
7308 Analyze_And_Resolve
(Else_Expr
, Typ
);
7309 Append_To
(Expressions
(N
), Else_Expr
);
7312 Error_Msg_N
("can only omit ELSE expression in Boolean case", N
);
7313 Append_To
(Expressions
(N
), Error
);
7317 Eval_If_Expression
(N
);
7318 end Resolve_If_Expression
;
7320 -------------------------------
7321 -- Resolve_Indexed_Component --
7322 -------------------------------
7324 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
7325 Name
: constant Node_Id
:= Prefix
(N
);
7327 Array_Type
: Entity_Id
:= Empty
; -- to prevent junk warning
7331 if Is_Overloaded
(Name
) then
7333 -- Use the context type to select the prefix that yields the correct
7339 I1
: Interp_Index
:= 0;
7340 P
: constant Node_Id
:= Prefix
(N
);
7341 Found
: Boolean := False;
7344 Get_First_Interp
(P
, I
, It
);
7345 while Present
(It
.Typ
) loop
7346 if (Is_Array_Type
(It
.Typ
)
7347 and then Covers
(Typ
, Component_Type
(It
.Typ
)))
7348 or else (Is_Access_Type
(It
.Typ
)
7349 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
7353 Component_Type
(Designated_Type
(It
.Typ
))))
7356 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
7358 if It
= No_Interp
then
7359 Error_Msg_N
("ambiguous prefix for indexing", N
);
7365 Array_Type
:= It
.Typ
;
7371 Array_Type
:= It
.Typ
;
7376 Get_Next_Interp
(I
, It
);
7381 Array_Type
:= Etype
(Name
);
7384 Resolve
(Name
, Array_Type
);
7385 Array_Type
:= Get_Actual_Subtype_If_Available
(Name
);
7387 -- If prefix is access type, dereference to get real array type.
7388 -- Note: we do not apply an access check because the expander always
7389 -- introduces an explicit dereference, and the check will happen there.
7391 if Is_Access_Type
(Array_Type
) then
7392 Array_Type
:= Designated_Type
(Array_Type
);
7395 -- If name was overloaded, set component type correctly now
7396 -- If a misplaced call to an entry family (which has no index types)
7397 -- return. Error will be diagnosed from calling context.
7399 if Is_Array_Type
(Array_Type
) then
7400 Set_Etype
(N
, Component_Type
(Array_Type
));
7405 Index
:= First_Index
(Array_Type
);
7406 Expr
:= First
(Expressions
(N
));
7408 -- The prefix may have resolved to a string literal, in which case its
7409 -- etype has a special representation. This is only possible currently
7410 -- if the prefix is a static concatenation, written in functional
7413 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
7414 Resolve
(Expr
, Standard_Positive
);
7417 while Present
(Index
) and Present
(Expr
) loop
7418 Resolve
(Expr
, Etype
(Index
));
7419 Check_Unset_Reference
(Expr
);
7421 if Is_Scalar_Type
(Etype
(Expr
)) then
7422 Apply_Scalar_Range_Check
(Expr
, Etype
(Index
));
7424 Apply_Range_Check
(Expr
, Get_Actual_Subtype
(Index
));
7432 Analyze_Dimension
(N
);
7434 -- Do not generate the warning on suspicious index if we are analyzing
7435 -- package Ada.Tags; otherwise we will report the warning with the
7436 -- Prims_Ptr field of the dispatch table.
7438 if Scope
(Etype
(Prefix
(N
))) = Standard_Standard
7440 Is_RTU
(Cunit_Entity
(Get_Source_Unit
(Etype
(Prefix
(N
)))),
7443 Warn_On_Suspicious_Index
(Name
, First
(Expressions
(N
)));
7444 Eval_Indexed_Component
(N
);
7447 -- If the array type is atomic, and is packed, and we are in a left side
7448 -- context, then this is worth a warning, since we have a situation
7449 -- where the access to the component may cause extra read/writes of
7450 -- the atomic array object, which could be considered unexpected.
7452 if Nkind
(N
) = N_Indexed_Component
7453 and then (Is_Atomic
(Array_Type
)
7454 or else (Is_Entity_Name
(Prefix
(N
))
7455 and then Is_Atomic
(Entity
(Prefix
(N
)))))
7456 and then Is_Bit_Packed_Array
(Array_Type
)
7459 Error_Msg_N
("??assignment to component of packed atomic array",
7461 Error_Msg_N
("??\may cause unexpected accesses to atomic object",
7464 end Resolve_Indexed_Component
;
7466 -----------------------------
7467 -- Resolve_Integer_Literal --
7468 -----------------------------
7470 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
7473 Eval_Integer_Literal
(N
);
7474 end Resolve_Integer_Literal
;
7476 --------------------------------
7477 -- Resolve_Intrinsic_Operator --
7478 --------------------------------
7480 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
) is
7481 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
7483 Orig_Op
: constant Entity_Id
:= Entity
(N
);
7487 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
;
7488 -- If the operand is a literal, it cannot be the expression in a
7489 -- conversion. Use a qualified expression instead.
7491 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
is
7492 Loc
: constant Source_Ptr
:= Sloc
(Opnd
);
7495 if Nkind_In
(Opnd
, N_Integer_Literal
, N_Real_Literal
) then
7497 Make_Qualified_Expression
(Loc
,
7498 Subtype_Mark
=> New_Occurrence_Of
(Btyp
, Loc
),
7499 Expression
=> Relocate_Node
(Opnd
));
7503 Res
:= Unchecked_Convert_To
(Btyp
, Opnd
);
7507 end Convert_Operand
;
7509 -- Start of processing for Resolve_Intrinsic_Operator
7512 -- We must preserve the original entity in a generic setting, so that
7513 -- the legality of the operation can be verified in an instance.
7515 if not Full_Expander_Active
then
7520 while Scope
(Op
) /= Standard_Standard
loop
7522 pragma Assert
(Present
(Op
));
7526 Set_Is_Overloaded
(N
, False);
7528 -- If the result or operand types are private, rewrite with unchecked
7529 -- conversions on the operands and the result, to expose the proper
7530 -- underlying numeric type.
7532 if Is_Private_Type
(Typ
)
7533 or else Is_Private_Type
(Etype
(Left_Opnd
(N
)))
7534 or else Is_Private_Type
(Etype
(Right_Opnd
(N
)))
7536 Arg1
:= Convert_Operand
(Left_Opnd
(N
));
7537 -- Unchecked_Convert_To (Btyp, Left_Opnd (N));
7538 -- What on earth is this commented out fragment of code???
7540 if Nkind
(N
) = N_Op_Expon
then
7541 Arg2
:= Unchecked_Convert_To
(Standard_Integer
, Right_Opnd
(N
));
7543 Arg2
:= Convert_Operand
(Right_Opnd
(N
));
7546 if Nkind
(Arg1
) = N_Type_Conversion
then
7547 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
7550 if Nkind
(Arg2
) = N_Type_Conversion
then
7551 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
7554 Set_Left_Opnd
(N
, Arg1
);
7555 Set_Right_Opnd
(N
, Arg2
);
7557 Set_Etype
(N
, Btyp
);
7558 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
7561 elsif Typ
/= Etype
(Left_Opnd
(N
))
7562 or else Typ
/= Etype
(Right_Opnd
(N
))
7564 -- Add explicit conversion where needed, and save interpretations in
7565 -- case operands are overloaded. If the context is a VMS operation,
7566 -- assert that the conversion is legal (the operands have the proper
7567 -- types to select the VMS intrinsic). Note that in rare cases the
7568 -- VMS operators may be visible, but the default System is being used
7569 -- and Address is a private type.
7571 Arg1
:= Convert_To
(Typ
, Left_Opnd
(N
));
7572 Arg2
:= Convert_To
(Typ
, Right_Opnd
(N
));
7574 if Nkind
(Arg1
) = N_Type_Conversion
then
7575 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
7577 if Is_VMS_Operator
(Orig_Op
) then
7578 Set_Conversion_OK
(Arg1
);
7581 Save_Interps
(Left_Opnd
(N
), Arg1
);
7584 if Nkind
(Arg2
) = N_Type_Conversion
then
7585 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
7587 if Is_VMS_Operator
(Orig_Op
) then
7588 Set_Conversion_OK
(Arg2
);
7591 Save_Interps
(Right_Opnd
(N
), Arg2
);
7594 Rewrite
(Left_Opnd
(N
), Arg1
);
7595 Rewrite
(Right_Opnd
(N
), Arg2
);
7598 Resolve_Arithmetic_Op
(N
, Typ
);
7601 Resolve_Arithmetic_Op
(N
, Typ
);
7603 end Resolve_Intrinsic_Operator
;
7605 --------------------------------------
7606 -- Resolve_Intrinsic_Unary_Operator --
7607 --------------------------------------
7609 procedure Resolve_Intrinsic_Unary_Operator
7613 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
7619 while Scope
(Op
) /= Standard_Standard
loop
7621 pragma Assert
(Present
(Op
));
7626 if Is_Private_Type
(Typ
) then
7627 Arg2
:= Unchecked_Convert_To
(Btyp
, Right_Opnd
(N
));
7628 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
7630 Set_Right_Opnd
(N
, Arg2
);
7632 Set_Etype
(N
, Btyp
);
7633 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
7637 Resolve_Unary_Op
(N
, Typ
);
7639 end Resolve_Intrinsic_Unary_Operator
;
7641 ------------------------
7642 -- Resolve_Logical_Op --
7643 ------------------------
7645 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
7649 Check_No_Direct_Boolean_Operators
(N
);
7651 -- Predefined operations on scalar types yield the base type. On the
7652 -- other hand, logical operations on arrays yield the type of the
7653 -- arguments (and the context).
7655 if Is_Array_Type
(Typ
) then
7658 B_Typ
:= Base_Type
(Typ
);
7661 -- OK if this is a VMS-specific intrinsic operation
7663 if Is_VMS_Operator
(Entity
(N
)) then
7666 -- The following test is required because the operands of the operation
7667 -- may be literals, in which case the resulting type appears to be
7668 -- compatible with a signed integer type, when in fact it is compatible
7669 -- only with modular types. If the context itself is universal, the
7670 -- operation is illegal.
7672 elsif not Valid_Boolean_Arg
(Typ
) then
7673 Error_Msg_N
("invalid context for logical operation", N
);
7674 Set_Etype
(N
, Any_Type
);
7677 elsif Typ
= Any_Modular
then
7679 ("no modular type available in this context", N
);
7680 Set_Etype
(N
, Any_Type
);
7683 elsif Is_Modular_Integer_Type
(Typ
)
7684 and then Etype
(Left_Opnd
(N
)) = Universal_Integer
7685 and then Etype
(Right_Opnd
(N
)) = Universal_Integer
7687 Check_For_Visible_Operator
(N
, B_Typ
);
7690 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
7691 -- is active and the result type is standard Boolean (do not mess with
7692 -- ops that return a nonstandard Boolean type, because something strange
7695 -- Note: you might expect this replacement to be done during expansion,
7696 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
7697 -- is used, no part of the right operand of an "and" or "or" operator
7698 -- should be executed if the left operand would short-circuit the
7699 -- evaluation of the corresponding "and then" or "or else". If we left
7700 -- the replacement to expansion time, then run-time checks associated
7701 -- with such operands would be evaluated unconditionally, due to being
7702 -- before the condition prior to the rewriting as short-circuit forms
7703 -- during expansion.
7705 if Short_Circuit_And_Or
7706 and then B_Typ
= Standard_Boolean
7707 and then Nkind_In
(N
, N_Op_And
, N_Op_Or
)
7709 if Nkind
(N
) = N_Op_And
then
7711 Make_And_Then
(Sloc
(N
),
7712 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
7713 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
7714 Analyze_And_Resolve
(N
, B_Typ
);
7716 -- Case of OR changed to OR ELSE
7720 Make_Or_Else
(Sloc
(N
),
7721 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
7722 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
7723 Analyze_And_Resolve
(N
, B_Typ
);
7726 -- Return now, since analysis of the rewritten ops will take care of
7727 -- other reference bookkeeping and expression folding.
7732 Resolve
(Left_Opnd
(N
), B_Typ
);
7733 Resolve
(Right_Opnd
(N
), B_Typ
);
7735 Check_Unset_Reference
(Left_Opnd
(N
));
7736 Check_Unset_Reference
(Right_Opnd
(N
));
7738 Set_Etype
(N
, B_Typ
);
7739 Generate_Operator_Reference
(N
, B_Typ
);
7740 Eval_Logical_Op
(N
);
7742 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
7743 -- only when both operands have same static lower and higher bounds. Of
7744 -- course the types have to match, so only check if operands are
7745 -- compatible and the node itself has no errors.
7747 if Is_Array_Type
(B_Typ
)
7748 and then Nkind
(N
) in N_Binary_Op
7751 Left_Typ
: constant Node_Id
:= Etype
(Left_Opnd
(N
));
7752 Right_Typ
: constant Node_Id
:= Etype
(Right_Opnd
(N
));
7755 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7756 -- operation if not needed.
7758 if Restriction_Check_Required
(SPARK_05
)
7759 and then Base_Type
(Left_Typ
) = Base_Type
(Right_Typ
)
7760 and then Left_Typ
/= Any_Composite
-- or Left_Opnd in error
7761 and then Right_Typ
/= Any_Composite
-- or Right_Opnd in error
7762 and then not Matching_Static_Array_Bounds
(Left_Typ
, Right_Typ
)
7764 Check_SPARK_Restriction
7765 ("array types should have matching static bounds", N
);
7770 Check_Function_Writable_Actuals
(N
);
7771 end Resolve_Logical_Op
;
7773 ---------------------------
7774 -- Resolve_Membership_Op --
7775 ---------------------------
7777 -- The context can only be a boolean type, and does not determine the
7778 -- arguments. Arguments should be unambiguous, but the preference rule for
7779 -- universal types applies.
7781 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
7782 pragma Warnings
(Off
, Typ
);
7784 L
: constant Node_Id
:= Left_Opnd
(N
);
7785 R
: constant Node_Id
:= Right_Opnd
(N
);
7788 procedure Resolve_Set_Membership
;
7789 -- Analysis has determined a unique type for the left operand. Use it to
7790 -- resolve the disjuncts.
7792 ----------------------------
7793 -- Resolve_Set_Membership --
7794 ----------------------------
7796 procedure Resolve_Set_Membership
is
7798 Ltyp
: constant Entity_Id
:= Etype
(L
);
7803 Alt
:= First
(Alternatives
(N
));
7804 while Present
(Alt
) loop
7806 -- Alternative is an expression, a range
7807 -- or a subtype mark.
7809 if not Is_Entity_Name
(Alt
)
7810 or else not Is_Type
(Entity
(Alt
))
7812 Resolve
(Alt
, Ltyp
);
7818 -- Check for duplicates for discrete case
7820 if Is_Discrete_Type
(Ltyp
) then
7827 Alts
: array (0 .. List_Length
(Alternatives
(N
))) of Ent
;
7831 -- Loop checking duplicates. This is quadratic, but giant sets
7832 -- are unlikely in this context so it's a reasonable choice.
7835 Alt
:= First
(Alternatives
(N
));
7836 while Present
(Alt
) loop
7837 if Is_Static_Expression
(Alt
)
7838 and then (Nkind_In
(Alt
, N_Integer_Literal
,
7839 N_Character_Literal
)
7840 or else Nkind
(Alt
) in N_Has_Entity
)
7843 Alts
(Nalts
) := (Alt
, Expr_Value
(Alt
));
7845 for J
in 1 .. Nalts
- 1 loop
7846 if Alts
(J
).Val
= Alts
(Nalts
).Val
then
7847 Error_Msg_Sloc
:= Sloc
(Alts
(J
).Alt
);
7848 Error_Msg_N
("duplicate of value given#??", Alt
);
7857 end Resolve_Set_Membership
;
7859 -- Start of processing for Resolve_Membership_Op
7862 if L
= Error
or else R
= Error
then
7866 if Present
(Alternatives
(N
)) then
7867 Resolve_Set_Membership
;
7868 Check_Function_Writable_Actuals
(N
);
7871 elsif not Is_Overloaded
(R
)
7873 (Etype
(R
) = Universal_Integer
7875 Etype
(R
) = Universal_Real
)
7876 and then Is_Overloaded
(L
)
7880 -- Ada 2005 (AI-251): Support the following case:
7882 -- type I is interface;
7883 -- type T is tagged ...
7885 -- function Test (O : I'Class) is
7887 -- return O in T'Class.
7890 -- In this case we have nothing else to do. The membership test will be
7891 -- done at run time.
7893 elsif Ada_Version
>= Ada_2005
7894 and then Is_Class_Wide_Type
(Etype
(L
))
7895 and then Is_Interface
(Etype
(L
))
7896 and then Is_Class_Wide_Type
(Etype
(R
))
7897 and then not Is_Interface
(Etype
(R
))
7901 T
:= Intersect_Types
(L
, R
);
7904 -- If mixed-mode operations are present and operands are all literal,
7905 -- the only interpretation involves Duration, which is probably not
7906 -- the intention of the programmer.
7908 if T
= Any_Fixed
then
7909 T
:= Unique_Fixed_Point_Type
(N
);
7911 if T
= Any_Type
then
7917 Check_Unset_Reference
(L
);
7919 if Nkind
(R
) = N_Range
7920 and then not Is_Scalar_Type
(T
)
7922 Error_Msg_N
("scalar type required for range", R
);
7925 if Is_Entity_Name
(R
) then
7926 Freeze_Expression
(R
);
7929 Check_Unset_Reference
(R
);
7932 Eval_Membership_Op
(N
);
7933 Check_Function_Writable_Actuals
(N
);
7934 end Resolve_Membership_Op
;
7940 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
) is
7941 Loc
: constant Source_Ptr
:= Sloc
(N
);
7944 -- Handle restriction against anonymous null access values This
7945 -- restriction can be turned off using -gnatdj.
7947 -- Ada 2005 (AI-231): Remove restriction
7949 if Ada_Version
< Ada_2005
7950 and then not Debug_Flag_J
7951 and then Ekind
(Typ
) = E_Anonymous_Access_Type
7952 and then Comes_From_Source
(N
)
7954 -- In the common case of a call which uses an explicitly null value
7955 -- for an access parameter, give specialized error message.
7957 if Nkind
(Parent
(N
)) in N_Subprogram_Call
then
7959 ("null is not allowed as argument for an access parameter", N
);
7961 -- Standard message for all other cases (are there any?)
7965 ("null cannot be of an anonymous access type", N
);
7969 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
7970 -- assignment to a null-excluding object
7972 if Ada_Version
>= Ada_2005
7973 and then Can_Never_Be_Null
(Typ
)
7974 and then Nkind
(Parent
(N
)) = N_Assignment_Statement
7976 if not Inside_Init_Proc
then
7978 (Compile_Time_Constraint_Error
(N
,
7979 "(Ada 2005) null not allowed in null-excluding objects??"),
7980 Make_Raise_Constraint_Error
(Loc
,
7981 Reason
=> CE_Access_Check_Failed
));
7984 Make_Raise_Constraint_Error
(Loc
,
7985 Reason
=> CE_Access_Check_Failed
));
7989 -- In a distributed context, null for a remote access to subprogram may
7990 -- need to be replaced with a special record aggregate. In this case,
7991 -- return after having done the transformation.
7993 if (Ekind
(Typ
) = E_Record_Type
7994 or else Is_Remote_Access_To_Subprogram_Type
(Typ
))
7995 and then Remote_AST_Null_Value
(N
, Typ
)
8000 -- The null literal takes its type from the context
8005 -----------------------
8006 -- Resolve_Op_Concat --
8007 -----------------------
8009 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
) is
8011 -- We wish to avoid deep recursion, because concatenations are often
8012 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
8013 -- operands nonrecursively until we find something that is not a simple
8014 -- concatenation (A in this case). We resolve that, and then walk back
8015 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
8016 -- to do the rest of the work at each level. The Parent pointers allow
8017 -- us to avoid recursion, and thus avoid running out of memory. See also
8018 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
8024 -- The following code is equivalent to:
8026 -- Resolve_Op_Concat_First (NN, Typ);
8027 -- Resolve_Op_Concat_Arg (N, ...);
8028 -- Resolve_Op_Concat_Rest (N, Typ);
8030 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
8031 -- operand is a concatenation.
8033 -- Walk down left operands
8036 Resolve_Op_Concat_First
(NN
, Typ
);
8037 Op1
:= Left_Opnd
(NN
);
8038 exit when not (Nkind
(Op1
) = N_Op_Concat
8039 and then not Is_Array_Type
(Component_Type
(Typ
))
8040 and then Entity
(Op1
) = Entity
(NN
));
8044 -- Now (given the above example) NN is A&B and Op1 is A
8046 -- First resolve Op1 ...
8048 Resolve_Op_Concat_Arg
(NN
, Op1
, Typ
, Is_Component_Left_Opnd
(NN
));
8050 -- ... then walk NN back up until we reach N (where we started), calling
8051 -- Resolve_Op_Concat_Rest along the way.
8054 Resolve_Op_Concat_Rest
(NN
, Typ
);
8059 if Base_Type
(Etype
(N
)) /= Standard_String
then
8060 Check_SPARK_Restriction
8061 ("result of concatenation should have type String", N
);
8063 end Resolve_Op_Concat
;
8065 ---------------------------
8066 -- Resolve_Op_Concat_Arg --
8067 ---------------------------
8069 procedure Resolve_Op_Concat_Arg
8075 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
8076 Ctyp
: constant Entity_Id
:= Component_Type
(Typ
);
8081 or else (not Is_Overloaded
(Arg
)
8082 and then Etype
(Arg
) /= Any_Composite
8083 and then Covers
(Ctyp
, Etype
(Arg
)))
8085 Resolve
(Arg
, Ctyp
);
8087 Resolve
(Arg
, Btyp
);
8090 -- If both Array & Array and Array & Component are visible, there is a
8091 -- potential ambiguity that must be reported.
8093 elsif Has_Compatible_Type
(Arg
, Ctyp
) then
8094 if Nkind
(Arg
) = N_Aggregate
8095 and then Is_Composite_Type
(Ctyp
)
8097 if Is_Private_Type
(Ctyp
) then
8098 Resolve
(Arg
, Btyp
);
8100 -- If the operation is user-defined and not overloaded use its
8101 -- profile. The operation may be a renaming, in which case it has
8102 -- been rewritten, and we want the original profile.
8104 elsif not Is_Overloaded
(N
)
8105 and then Comes_From_Source
(Entity
(Original_Node
(N
)))
8106 and then Ekind
(Entity
(Original_Node
(N
))) = E_Function
8110 (Next_Formal
(First_Formal
(Entity
(Original_Node
(N
))))));
8113 -- Otherwise an aggregate may match both the array type and the
8117 Error_Msg_N
("ambiguous aggregate must be qualified", Arg
);
8118 Set_Etype
(Arg
, Any_Type
);
8122 if Is_Overloaded
(Arg
)
8123 and then Has_Compatible_Type
(Arg
, Typ
)
8124 and then Etype
(Arg
) /= Any_Type
8132 Get_First_Interp
(Arg
, I
, It
);
8134 Get_Next_Interp
(I
, It
);
8136 -- Special-case the error message when the overloading is
8137 -- caused by a function that yields an array and can be
8138 -- called without parameters.
8140 if It
.Nam
= Func
then
8141 Error_Msg_Sloc
:= Sloc
(Func
);
8142 Error_Msg_N
("ambiguous call to function#", Arg
);
8144 ("\\interpretation as call yields&", Arg
, Typ
);
8146 ("\\interpretation as indexing of call yields&",
8147 Arg
, Component_Type
(Typ
));
8150 Error_Msg_N
("ambiguous operand for concatenation!", Arg
);
8152 Get_First_Interp
(Arg
, I
, It
);
8153 while Present
(It
.Nam
) loop
8154 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
8156 if Base_Type
(It
.Typ
) = Btyp
8158 Base_Type
(It
.Typ
) = Base_Type
(Ctyp
)
8160 Error_Msg_N
-- CODEFIX
8161 ("\\possible interpretation#", Arg
);
8164 Get_Next_Interp
(I
, It
);
8170 Resolve
(Arg
, Component_Type
(Typ
));
8172 if Nkind
(Arg
) = N_String_Literal
then
8173 Set_Etype
(Arg
, Component_Type
(Typ
));
8176 if Arg
= Left_Opnd
(N
) then
8177 Set_Is_Component_Left_Opnd
(N
);
8179 Set_Is_Component_Right_Opnd
(N
);
8184 Resolve
(Arg
, Btyp
);
8187 -- Concatenation is restricted in SPARK: each operand must be either a
8188 -- string literal, the name of a string constant, a static character or
8189 -- string expression, or another concatenation. Arg cannot be a
8190 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
8191 -- separately on each final operand, past concatenation operations.
8193 if Is_Character_Type
(Etype
(Arg
)) then
8194 if not Is_Static_Expression
(Arg
) then
8195 Check_SPARK_Restriction
8196 ("character operand for concatenation should be static", Arg
);
8199 elsif Is_String_Type
(Etype
(Arg
)) then
8200 if not (Nkind_In
(Arg
, N_Identifier
, N_Expanded_Name
)
8201 and then Is_Constant_Object
(Entity
(Arg
)))
8202 and then not Is_Static_Expression
(Arg
)
8204 Check_SPARK_Restriction
8205 ("string operand for concatenation should be static", Arg
);
8208 -- Do not issue error on an operand that is neither a character nor a
8209 -- string, as the error is issued in Resolve_Op_Concat.
8215 Check_Unset_Reference
(Arg
);
8216 end Resolve_Op_Concat_Arg
;
8218 -----------------------------
8219 -- Resolve_Op_Concat_First --
8220 -----------------------------
8222 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
) is
8223 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
8224 Op1
: constant Node_Id
:= Left_Opnd
(N
);
8225 Op2
: constant Node_Id
:= Right_Opnd
(N
);
8228 -- The parser folds an enormous sequence of concatenations of string
8229 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
8230 -- in the right operand. If the expression resolves to a predefined "&"
8231 -- operator, all is well. Otherwise, the parser's folding is wrong, so
8232 -- we give an error. See P_Simple_Expression in Par.Ch4.
8234 if Nkind
(Op2
) = N_String_Literal
8235 and then Is_Folded_In_Parser
(Op2
)
8236 and then Ekind
(Entity
(N
)) = E_Function
8238 pragma Assert
(Nkind
(Op1
) = N_String_Literal
-- should be ""
8239 and then String_Length
(Strval
(Op1
)) = 0);
8240 Error_Msg_N
("too many user-defined concatenations", N
);
8244 Set_Etype
(N
, Btyp
);
8246 if Is_Limited_Composite
(Btyp
) then
8247 Error_Msg_N
("concatenation not available for limited array", N
);
8248 Explain_Limited_Type
(Btyp
, N
);
8250 end Resolve_Op_Concat_First
;
8252 ----------------------------
8253 -- Resolve_Op_Concat_Rest --
8254 ----------------------------
8256 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
) is
8257 Op1
: constant Node_Id
:= Left_Opnd
(N
);
8258 Op2
: constant Node_Id
:= Right_Opnd
(N
);
8261 Resolve_Op_Concat_Arg
(N
, Op2
, Typ
, Is_Component_Right_Opnd
(N
));
8263 Generate_Operator_Reference
(N
, Typ
);
8265 if Is_String_Type
(Typ
) then
8266 Eval_Concatenation
(N
);
8269 -- If this is not a static concatenation, but the result is a string
8270 -- type (and not an array of strings) ensure that static string operands
8271 -- have their subtypes properly constructed.
8273 if Nkind
(N
) /= N_String_Literal
8274 and then Is_Character_Type
(Component_Type
(Typ
))
8276 Set_String_Literal_Subtype
(Op1
, Typ
);
8277 Set_String_Literal_Subtype
(Op2
, Typ
);
8279 end Resolve_Op_Concat_Rest
;
8281 ----------------------
8282 -- Resolve_Op_Expon --
8283 ----------------------
8285 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
) is
8286 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
8289 -- Catch attempts to do fixed-point exponentiation with universal
8290 -- operands, which is a case where the illegality is not caught during
8291 -- normal operator analysis.
8293 if Is_Fixed_Point_Type
(Typ
) and then Comes_From_Source
(N
) then
8294 Error_Msg_N
("exponentiation not available for fixed point", N
);
8297 elsif Nkind
(Parent
(N
)) in N_Op
8298 and then Is_Fixed_Point_Type
(Etype
(Parent
(N
)))
8299 and then Etype
(N
) = Universal_Real
8300 and then Comes_From_Source
(N
)
8302 Error_Msg_N
("exponentiation not available for fixed point", N
);
8306 if Comes_From_Source
(N
)
8307 and then Ekind
(Entity
(N
)) = E_Function
8308 and then Is_Imported
(Entity
(N
))
8309 and then Is_Intrinsic_Subprogram
(Entity
(N
))
8311 Resolve_Intrinsic_Operator
(N
, Typ
);
8315 if Etype
(Left_Opnd
(N
)) = Universal_Integer
8316 or else Etype
(Left_Opnd
(N
)) = Universal_Real
8318 Check_For_Visible_Operator
(N
, B_Typ
);
8321 -- We do the resolution using the base type, because intermediate values
8322 -- in expressions always are of the base type, not a subtype of it.
8324 Resolve
(Left_Opnd
(N
), B_Typ
);
8325 Resolve
(Right_Opnd
(N
), Standard_Integer
);
8327 Check_Unset_Reference
(Left_Opnd
(N
));
8328 Check_Unset_Reference
(Right_Opnd
(N
));
8330 Set_Etype
(N
, B_Typ
);
8331 Generate_Operator_Reference
(N
, B_Typ
);
8333 Analyze_Dimension
(N
);
8335 if Ada_Version
>= Ada_2012
and then Has_Dimension_System
(B_Typ
) then
8336 -- Evaluate the exponentiation operator for dimensioned type
8338 Eval_Op_Expon_For_Dimensioned_Type
(N
, B_Typ
);
8343 -- Set overflow checking bit. Much cleverer code needed here eventually
8344 -- and perhaps the Resolve routines should be separated for the various
8345 -- arithmetic operations, since they will need different processing. ???
8347 if Nkind
(N
) in N_Op
then
8348 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
8349 Enable_Overflow_Check
(N
);
8352 end Resolve_Op_Expon
;
8354 --------------------
8355 -- Resolve_Op_Not --
8356 --------------------
8358 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
) is
8361 function Parent_Is_Boolean
return Boolean;
8362 -- This function determines if the parent node is a boolean operator or
8363 -- operation (comparison op, membership test, or short circuit form) and
8364 -- the not in question is the left operand of this operation. Note that
8365 -- if the not is in parens, then false is returned.
8367 -----------------------
8368 -- Parent_Is_Boolean --
8369 -----------------------
8371 function Parent_Is_Boolean
return Boolean is
8373 if Paren_Count
(N
) /= 0 then
8377 case Nkind
(Parent
(N
)) is
8392 return Left_Opnd
(Parent
(N
)) = N
;
8398 end Parent_Is_Boolean
;
8400 -- Start of processing for Resolve_Op_Not
8403 -- Predefined operations on scalar types yield the base type. On the
8404 -- other hand, logical operations on arrays yield the type of the
8405 -- arguments (and the context).
8407 if Is_Array_Type
(Typ
) then
8410 B_Typ
:= Base_Type
(Typ
);
8413 if Is_VMS_Operator
(Entity
(N
)) then
8416 -- Straightforward case of incorrect arguments
8418 elsif not Valid_Boolean_Arg
(Typ
) then
8419 Error_Msg_N
("invalid operand type for operator&", N
);
8420 Set_Etype
(N
, Any_Type
);
8423 -- Special case of probable missing parens
8425 elsif Typ
= Universal_Integer
or else Typ
= Any_Modular
then
8426 if Parent_Is_Boolean
then
8428 ("operand of not must be enclosed in parentheses",
8432 ("no modular type available in this context", N
);
8435 Set_Etype
(N
, Any_Type
);
8438 -- OK resolution of NOT
8441 -- Warn if non-boolean types involved. This is a case like not a < b
8442 -- where a and b are modular, where we will get (not a) < b and most
8443 -- likely not (a < b) was intended.
8445 if Warn_On_Questionable_Missing_Parens
8446 and then not Is_Boolean_Type
(Typ
)
8447 and then Parent_Is_Boolean
8449 Error_Msg_N
("?q?not expression should be parenthesized here!", N
);
8452 -- Warn on double negation if checking redundant constructs
8454 if Warn_On_Redundant_Constructs
8455 and then Comes_From_Source
(N
)
8456 and then Comes_From_Source
(Right_Opnd
(N
))
8457 and then Root_Type
(Typ
) = Standard_Boolean
8458 and then Nkind
(Right_Opnd
(N
)) = N_Op_Not
8460 Error_Msg_N
("redundant double negation?r?", N
);
8463 -- Complete resolution and evaluation of NOT
8465 Resolve
(Right_Opnd
(N
), B_Typ
);
8466 Check_Unset_Reference
(Right_Opnd
(N
));
8467 Set_Etype
(N
, B_Typ
);
8468 Generate_Operator_Reference
(N
, B_Typ
);
8473 -----------------------------
8474 -- Resolve_Operator_Symbol --
8475 -----------------------------
8477 -- Nothing to be done, all resolved already
8479 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
) is
8480 pragma Warnings
(Off
, N
);
8481 pragma Warnings
(Off
, Typ
);
8485 end Resolve_Operator_Symbol
;
8487 ----------------------------------
8488 -- Resolve_Qualified_Expression --
8489 ----------------------------------
8491 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
8492 pragma Warnings
(Off
, Typ
);
8494 Target_Typ
: constant Entity_Id
:= Entity
(Subtype_Mark
(N
));
8495 Expr
: constant Node_Id
:= Expression
(N
);
8498 Resolve
(Expr
, Target_Typ
);
8500 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8501 -- operation if not needed.
8503 if Restriction_Check_Required
(SPARK_05
)
8504 and then Is_Array_Type
(Target_Typ
)
8505 and then Is_Array_Type
(Etype
(Expr
))
8506 and then Etype
(Expr
) /= Any_Composite
-- or else Expr in error
8507 and then not Matching_Static_Array_Bounds
(Target_Typ
, Etype
(Expr
))
8509 Check_SPARK_Restriction
8510 ("array types should have matching static bounds", N
);
8513 -- A qualified expression requires an exact match of the type, class-
8514 -- wide matching is not allowed. However, if the qualifying type is
8515 -- specific and the expression has a class-wide type, it may still be
8516 -- okay, since it can be the result of the expansion of a call to a
8517 -- dispatching function, so we also have to check class-wideness of the
8518 -- type of the expression's original node.
8520 if (Is_Class_Wide_Type
(Target_Typ
)
8522 (Is_Class_Wide_Type
(Etype
(Expr
))
8523 and then Is_Class_Wide_Type
(Etype
(Original_Node
(Expr
)))))
8524 and then Base_Type
(Etype
(Expr
)) /= Base_Type
(Target_Typ
)
8526 Wrong_Type
(Expr
, Target_Typ
);
8529 -- If the target type is unconstrained, then we reset the type of the
8530 -- result from the type of the expression. For other cases, the actual
8531 -- subtype of the expression is the target type.
8533 if Is_Composite_Type
(Target_Typ
)
8534 and then not Is_Constrained
(Target_Typ
)
8536 Set_Etype
(N
, Etype
(Expr
));
8539 Analyze_Dimension
(N
);
8540 Eval_Qualified_Expression
(N
);
8541 end Resolve_Qualified_Expression
;
8547 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
) is
8548 L
: constant Node_Id
:= Low_Bound
(N
);
8549 H
: constant Node_Id
:= High_Bound
(N
);
8551 function First_Last_Ref
return Boolean;
8552 -- Returns True if N is of the form X'First .. X'Last where X is the
8553 -- same entity for both attributes.
8555 --------------------
8556 -- First_Last_Ref --
8557 --------------------
8559 function First_Last_Ref
return Boolean is
8560 Lorig
: constant Node_Id
:= Original_Node
(L
);
8561 Horig
: constant Node_Id
:= Original_Node
(H
);
8564 if Nkind
(Lorig
) = N_Attribute_Reference
8565 and then Nkind
(Horig
) = N_Attribute_Reference
8566 and then Attribute_Name
(Lorig
) = Name_First
8567 and then Attribute_Name
(Horig
) = Name_Last
8570 PL
: constant Node_Id
:= Prefix
(Lorig
);
8571 PH
: constant Node_Id
:= Prefix
(Horig
);
8573 if Is_Entity_Name
(PL
)
8574 and then Is_Entity_Name
(PH
)
8575 and then Entity
(PL
) = Entity
(PH
)
8585 -- Start of processing for Resolve_Range
8592 -- Check for inappropriate range on unordered enumeration type
8594 if Bad_Unordered_Enumeration_Reference
(N
, Typ
)
8596 -- Exclude X'First .. X'Last if X is the same entity for both
8598 and then not First_Last_Ref
8600 Error_Msg
("subrange of unordered enumeration type?U?", Sloc
(N
));
8603 Check_Unset_Reference
(L
);
8604 Check_Unset_Reference
(H
);
8606 -- We have to check the bounds for being within the base range as
8607 -- required for a non-static context. Normally this is automatic and
8608 -- done as part of evaluating expressions, but the N_Range node is an
8609 -- exception, since in GNAT we consider this node to be a subexpression,
8610 -- even though in Ada it is not. The circuit in Sem_Eval could check for
8611 -- this, but that would put the test on the main evaluation path for
8614 Check_Non_Static_Context
(L
);
8615 Check_Non_Static_Context
(H
);
8617 -- Check for an ambiguous range over character literals. This will
8618 -- happen with a membership test involving only literals.
8620 if Typ
= Any_Character
then
8621 Ambiguous_Character
(L
);
8622 Set_Etype
(N
, Any_Type
);
8626 -- If bounds are static, constant-fold them, so size computations are
8627 -- identical between front-end and back-end. Do not perform this
8628 -- transformation while analyzing generic units, as type information
8629 -- would be lost when reanalyzing the constant node in the instance.
8631 if Is_Discrete_Type
(Typ
) and then Full_Expander_Active
then
8632 if Is_OK_Static_Expression
(L
) then
8633 Fold_Uint
(L
, Expr_Value
(L
), Is_Static_Expression
(L
));
8636 if Is_OK_Static_Expression
(H
) then
8637 Fold_Uint
(H
, Expr_Value
(H
), Is_Static_Expression
(H
));
8642 --------------------------
8643 -- Resolve_Real_Literal --
8644 --------------------------
8646 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
8647 Actual_Typ
: constant Entity_Id
:= Etype
(N
);
8650 -- Special processing for fixed-point literals to make sure that the
8651 -- value is an exact multiple of small where this is required. We skip
8652 -- this for the universal real case, and also for generic types.
8654 if Is_Fixed_Point_Type
(Typ
)
8655 and then Typ
/= Universal_Fixed
8656 and then Typ
/= Any_Fixed
8657 and then not Is_Generic_Type
(Typ
)
8660 Val
: constant Ureal
:= Realval
(N
);
8661 Cintr
: constant Ureal
:= Val
/ Small_Value
(Typ
);
8662 Cint
: constant Uint
:= UR_Trunc
(Cintr
);
8663 Den
: constant Uint
:= Norm_Den
(Cintr
);
8667 -- Case of literal is not an exact multiple of the Small
8671 -- For a source program literal for a decimal fixed-point type,
8672 -- this is statically illegal (RM 4.9(36)).
8674 if Is_Decimal_Fixed_Point_Type
(Typ
)
8675 and then Actual_Typ
= Universal_Real
8676 and then Comes_From_Source
(N
)
8678 Error_Msg_N
("value has extraneous low order digits", N
);
8681 -- Generate a warning if literal from source
8683 if Is_Static_Expression
(N
)
8684 and then Warn_On_Bad_Fixed_Value
8687 ("?b?static fixed-point value is not a multiple of Small!",
8691 -- Replace literal by a value that is the exact representation
8692 -- of a value of the type, i.e. a multiple of the small value,
8693 -- by truncation, since Machine_Rounds is false for all GNAT
8694 -- fixed-point types (RM 4.9(38)).
8696 Stat
:= Is_Static_Expression
(N
);
8698 Make_Real_Literal
(Sloc
(N
),
8699 Realval
=> Small_Value
(Typ
) * Cint
));
8701 Set_Is_Static_Expression
(N
, Stat
);
8704 -- In all cases, set the corresponding integer field
8706 Set_Corresponding_Integer_Value
(N
, Cint
);
8710 -- Now replace the actual type by the expected type as usual
8713 Eval_Real_Literal
(N
);
8714 end Resolve_Real_Literal
;
8716 -----------------------
8717 -- Resolve_Reference --
8718 -----------------------
8720 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
) is
8721 P
: constant Node_Id
:= Prefix
(N
);
8724 -- Replace general access with specific type
8726 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
8727 Set_Etype
(N
, Base_Type
(Typ
));
8730 Resolve
(P
, Designated_Type
(Etype
(N
)));
8732 -- If we are taking the reference of a volatile entity, then treat it as
8733 -- a potential modification of this entity. This is too conservative,
8734 -- but necessary because remove side effects can cause transformations
8735 -- of normal assignments into reference sequences that otherwise fail to
8736 -- notice the modification.
8738 if Is_Entity_Name
(P
) and then Treat_As_Volatile
(Entity
(P
)) then
8739 Note_Possible_Modification
(P
, Sure
=> False);
8741 end Resolve_Reference
;
8743 --------------------------------
8744 -- Resolve_Selected_Component --
8745 --------------------------------
8747 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
8749 Comp1
: Entity_Id
:= Empty
; -- prevent junk warning
8750 P
: constant Node_Id
:= Prefix
(N
);
8751 S
: constant Node_Id
:= Selector_Name
(N
);
8752 T
: Entity_Id
:= Etype
(P
);
8754 I1
: Interp_Index
:= 0; -- prevent junk warning
8759 function Init_Component
return Boolean;
8760 -- Check whether this is the initialization of a component within an
8761 -- init proc (by assignment or call to another init proc). If true,
8762 -- there is no need for a discriminant check.
8764 --------------------
8765 -- Init_Component --
8766 --------------------
8768 function Init_Component
return Boolean is
8770 return Inside_Init_Proc
8771 and then Nkind
(Prefix
(N
)) = N_Identifier
8772 and then Chars
(Prefix
(N
)) = Name_uInit
8773 and then Nkind
(Parent
(Parent
(N
))) = N_Case_Statement_Alternative
;
8776 -- Start of processing for Resolve_Selected_Component
8779 if Is_Overloaded
(P
) then
8781 -- Use the context type to select the prefix that has a selector
8782 -- of the correct name and type.
8785 Get_First_Interp
(P
, I
, It
);
8787 Search
: while Present
(It
.Typ
) loop
8788 if Is_Access_Type
(It
.Typ
) then
8789 T
:= Designated_Type
(It
.Typ
);
8794 -- Locate selected component. For a private prefix the selector
8795 -- can denote a discriminant.
8797 if Is_Record_Type
(T
) or else Is_Private_Type
(T
) then
8799 -- The visible components of a class-wide type are those of
8802 if Is_Class_Wide_Type
(T
) then
8806 Comp
:= First_Entity
(T
);
8807 while Present
(Comp
) loop
8808 if Chars
(Comp
) = Chars
(S
)
8809 and then Covers
(Etype
(Comp
), Typ
)
8818 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
8820 if It
= No_Interp
then
8822 ("ambiguous prefix for selected component", N
);
8829 -- There may be an implicit dereference. Retrieve
8830 -- designated record type.
8832 if Is_Access_Type
(It1
.Typ
) then
8833 T
:= Designated_Type
(It1
.Typ
);
8838 if Scope
(Comp1
) /= T
then
8840 -- Resolution chooses the new interpretation.
8841 -- Find the component with the right name.
8843 Comp1
:= First_Entity
(T
);
8844 while Present
(Comp1
)
8845 and then Chars
(Comp1
) /= Chars
(S
)
8847 Comp1
:= Next_Entity
(Comp1
);
8856 Comp
:= Next_Entity
(Comp
);
8860 Get_Next_Interp
(I
, It
);
8863 Resolve
(P
, It1
.Typ
);
8865 Set_Entity_With_Style_Check
(S
, Comp1
);
8868 -- Resolve prefix with its type
8873 -- Generate cross-reference. We needed to wait until full overloading
8874 -- resolution was complete to do this, since otherwise we can't tell if
8875 -- we are an lvalue or not.
8877 if May_Be_Lvalue
(N
) then
8878 Generate_Reference
(Entity
(S
), S
, 'm');
8880 Generate_Reference
(Entity
(S
), S
, 'r');
8883 -- If prefix is an access type, the node will be transformed into an
8884 -- explicit dereference during expansion. The type of the node is the
8885 -- designated type of that of the prefix.
8887 if Is_Access_Type
(Etype
(P
)) then
8888 T
:= Designated_Type
(Etype
(P
));
8889 Check_Fully_Declared_Prefix
(T
, P
);
8894 if Has_Discriminants
(T
)
8895 and then Ekind_In
(Entity
(S
), E_Component
, E_Discriminant
)
8896 and then Present
(Original_Record_Component
(Entity
(S
)))
8897 and then Ekind
(Original_Record_Component
(Entity
(S
))) = E_Component
8898 and then not Discriminant_Checks_Suppressed
(T
)
8899 and then not Init_Component
8901 Set_Do_Discriminant_Check
(N
);
8904 if Ekind
(Entity
(S
)) = E_Void
then
8905 Error_Msg_N
("premature use of component", S
);
8908 -- If the prefix is a record conversion, this may be a renamed
8909 -- discriminant whose bounds differ from those of the original
8910 -- one, so we must ensure that a range check is performed.
8912 if Nkind
(P
) = N_Type_Conversion
8913 and then Ekind
(Entity
(S
)) = E_Discriminant
8914 and then Is_Discrete_Type
(Typ
)
8916 Set_Etype
(N
, Base_Type
(Typ
));
8919 -- Note: No Eval processing is required, because the prefix is of a
8920 -- record type, or protected type, and neither can possibly be static.
8922 -- If the array type is atomic, and is packed, and we are in a left side
8923 -- context, then this is worth a warning, since we have a situation
8924 -- where the access to the component may cause extra read/writes of the
8925 -- atomic array object, which could be considered unexpected.
8927 if Nkind
(N
) = N_Selected_Component
8928 and then (Is_Atomic
(T
)
8929 or else (Is_Entity_Name
(Prefix
(N
))
8930 and then Is_Atomic
(Entity
(Prefix
(N
)))))
8931 and then Is_Packed
(T
)
8935 ("??assignment to component of packed atomic record", Prefix
(N
));
8937 ("\??may cause unexpected accesses to atomic object", Prefix
(N
));
8940 Analyze_Dimension
(N
);
8941 end Resolve_Selected_Component
;
8947 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
) is
8948 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
8949 L
: constant Node_Id
:= Left_Opnd
(N
);
8950 R
: constant Node_Id
:= Right_Opnd
(N
);
8953 -- We do the resolution using the base type, because intermediate values
8954 -- in expressions always are of the base type, not a subtype of it.
8957 Resolve
(R
, Standard_Natural
);
8959 Check_Unset_Reference
(L
);
8960 Check_Unset_Reference
(R
);
8962 Set_Etype
(N
, B_Typ
);
8963 Generate_Operator_Reference
(N
, B_Typ
);
8967 ---------------------------
8968 -- Resolve_Short_Circuit --
8969 ---------------------------
8971 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
) is
8972 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
8973 L
: constant Node_Id
:= Left_Opnd
(N
);
8974 R
: constant Node_Id
:= Right_Opnd
(N
);
8980 -- Check for issuing warning for always False assert/check, this happens
8981 -- when assertions are turned off, in which case the pragma Assert/Check
8982 -- was transformed into:
8984 -- if False and then <condition> then ...
8986 -- and we detect this pattern
8988 if Warn_On_Assertion_Failure
8989 and then Is_Entity_Name
(R
)
8990 and then Entity
(R
) = Standard_False
8991 and then Nkind
(Parent
(N
)) = N_If_Statement
8992 and then Nkind
(N
) = N_And_Then
8993 and then Is_Entity_Name
(L
)
8994 and then Entity
(L
) = Standard_False
8997 Orig
: constant Node_Id
:= Original_Node
(Parent
(N
));
9000 -- Special handling of Asssert pragma
9002 if Nkind
(Orig
) = N_Pragma
9003 and then Pragma_Name
(Orig
) = Name_Assert
9006 Expr
: constant Node_Id
:=
9009 (First
(Pragma_Argument_Associations
(Orig
))));
9012 -- Don't warn if original condition is explicit False,
9013 -- since obviously the failure is expected in this case.
9015 if Is_Entity_Name
(Expr
)
9016 and then Entity
(Expr
) = Standard_False
9020 -- Issue warning. We do not want the deletion of the
9021 -- IF/AND-THEN to take this message with it. We achieve this
9022 -- by making sure that the expanded code points to the Sloc
9023 -- of the expression, not the original pragma.
9026 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
9027 -- The source location of the expression is not usually
9028 -- the best choice here. For example, it gets located on
9029 -- the last AND keyword in a chain of boolean expressiond
9030 -- AND'ed together. It is best to put the message on the
9031 -- first character of the assertion, which is the effect
9032 -- of the First_Node call here.
9035 ("?A?assertion would fail at run time!",
9037 (First
(Pragma_Argument_Associations
(Orig
))));
9041 -- Similar processing for Check pragma
9043 elsif Nkind
(Orig
) = N_Pragma
9044 and then Pragma_Name
(Orig
) = Name_Check
9046 -- Don't want to warn if original condition is explicit False
9049 Expr
: constant Node_Id
:=
9052 (Next
(First
(Pragma_Argument_Associations
(Orig
)))));
9054 if Is_Entity_Name
(Expr
)
9055 and then Entity
(Expr
) = Standard_False
9062 -- Again use Error_Msg_F rather than Error_Msg_N, see
9063 -- comment above for an explanation of why we do this.
9066 ("?A?check would fail at run time!",
9068 (Last
(Pragma_Argument_Associations
(Orig
))));
9075 -- Continue with processing of short circuit
9077 Check_Unset_Reference
(L
);
9078 Check_Unset_Reference
(R
);
9080 Set_Etype
(N
, B_Typ
);
9081 Eval_Short_Circuit
(N
);
9082 end Resolve_Short_Circuit
;
9088 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
) is
9089 Drange
: constant Node_Id
:= Discrete_Range
(N
);
9090 Name
: constant Node_Id
:= Prefix
(N
);
9091 Array_Type
: Entity_Id
:= Empty
;
9092 Index_Type
: Entity_Id
;
9095 if Is_Overloaded
(Name
) then
9097 -- Use the context type to select the prefix that yields the correct
9102 I1
: Interp_Index
:= 0;
9104 P
: constant Node_Id
:= Prefix
(N
);
9105 Found
: Boolean := False;
9108 Get_First_Interp
(P
, I
, It
);
9109 while Present
(It
.Typ
) loop
9110 if (Is_Array_Type
(It
.Typ
)
9111 and then Covers
(Typ
, It
.Typ
))
9112 or else (Is_Access_Type
(It
.Typ
)
9113 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
9114 and then Covers
(Typ
, Designated_Type
(It
.Typ
)))
9117 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
9119 if It
= No_Interp
then
9120 Error_Msg_N
("ambiguous prefix for slicing", N
);
9125 Array_Type
:= It
.Typ
;
9130 Array_Type
:= It
.Typ
;
9135 Get_Next_Interp
(I
, It
);
9140 Array_Type
:= Etype
(Name
);
9143 Resolve
(Name
, Array_Type
);
9145 if Is_Access_Type
(Array_Type
) then
9146 Apply_Access_Check
(N
);
9147 Array_Type
:= Designated_Type
(Array_Type
);
9149 -- If the prefix is an access to an unconstrained array, we must use
9150 -- the actual subtype of the object to perform the index checks. The
9151 -- object denoted by the prefix is implicit in the node, so we build
9152 -- an explicit representation for it in order to compute the actual
9155 if not Is_Constrained
(Array_Type
) then
9156 Remove_Side_Effects
(Prefix
(N
));
9159 Obj
: constant Node_Id
:=
9160 Make_Explicit_Dereference
(Sloc
(N
),
9161 Prefix
=> New_Copy_Tree
(Prefix
(N
)));
9163 Set_Etype
(Obj
, Array_Type
);
9164 Set_Parent
(Obj
, Parent
(N
));
9165 Array_Type
:= Get_Actual_Subtype
(Obj
);
9169 elsif Is_Entity_Name
(Name
)
9170 or else Nkind
(Name
) = N_Explicit_Dereference
9171 or else (Nkind
(Name
) = N_Function_Call
9172 and then not Is_Constrained
(Etype
(Name
)))
9174 Array_Type
:= Get_Actual_Subtype
(Name
);
9176 -- If the name is a selected component that depends on discriminants,
9177 -- build an actual subtype for it. This can happen only when the name
9178 -- itself is overloaded; otherwise the actual subtype is created when
9179 -- the selected component is analyzed.
9181 elsif Nkind
(Name
) = N_Selected_Component
9182 and then Full_Analysis
9183 and then Depends_On_Discriminant
(First_Index
(Array_Type
))
9186 Act_Decl
: constant Node_Id
:=
9187 Build_Actual_Subtype_Of_Component
(Array_Type
, Name
);
9189 Insert_Action
(N
, Act_Decl
);
9190 Array_Type
:= Defining_Identifier
(Act_Decl
);
9193 -- Maybe this should just be "else", instead of checking for the
9194 -- specific case of slice??? This is needed for the case where the
9195 -- prefix is an Image attribute, which gets expanded to a slice, and so
9196 -- has a constrained subtype which we want to use for the slice range
9197 -- check applied below (the range check won't get done if the
9198 -- unconstrained subtype of the 'Image is used).
9200 elsif Nkind
(Name
) = N_Slice
then
9201 Array_Type
:= Etype
(Name
);
9204 -- If name was overloaded, set slice type correctly now
9206 Set_Etype
(N
, Array_Type
);
9208 -- If the range is specified by a subtype mark, no resolution is
9209 -- necessary. Else resolve the bounds, and apply needed checks.
9211 if not Is_Entity_Name
(Drange
) then
9212 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
9213 Index_Type
:= Etype
(String_Literal_Low_Bound
(Array_Type
));
9215 Index_Type
:= Etype
(First_Index
(Array_Type
));
9218 Resolve
(Drange
, Base_Type
(Index_Type
));
9220 if Nkind
(Drange
) = N_Range
then
9222 -- Ensure that side effects in the bounds are properly handled
9224 Force_Evaluation
(Low_Bound
(Drange
));
9225 Force_Evaluation
(High_Bound
(Drange
));
9227 -- Do not apply the range check to nodes associated with the
9228 -- frontend expansion of the dispatch table. We first check
9229 -- if Ada.Tags is already loaded to avoid the addition of an
9230 -- undesired dependence on such run-time unit.
9232 if not Tagged_Type_Expansion
9234 (RTU_Loaded
(Ada_Tags
)
9235 and then Nkind
(Prefix
(N
)) = N_Selected_Component
9236 and then Present
(Entity
(Selector_Name
(Prefix
(N
))))
9237 and then Entity
(Selector_Name
(Prefix
(N
))) =
9238 RTE_Record_Component
(RE_Prims_Ptr
))
9240 Apply_Range_Check
(Drange
, Index_Type
);
9245 Set_Slice_Subtype
(N
);
9247 -- Check bad use of type with predicates
9249 if Has_Predicates
(Etype
(Drange
)) then
9250 Bad_Predicated_Subtype_Use
9251 ("subtype& has predicate, not allowed in slice",
9252 Drange
, Etype
(Drange
));
9254 -- Otherwise here is where we check suspicious indexes
9256 elsif Nkind
(Drange
) = N_Range
then
9257 Warn_On_Suspicious_Index
(Name
, Low_Bound
(Drange
));
9258 Warn_On_Suspicious_Index
(Name
, High_Bound
(Drange
));
9261 Analyze_Dimension
(N
);
9265 ----------------------------
9266 -- Resolve_String_Literal --
9267 ----------------------------
9269 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
9270 C_Typ
: constant Entity_Id
:= Component_Type
(Typ
);
9271 R_Typ
: constant Entity_Id
:= Root_Type
(C_Typ
);
9272 Loc
: constant Source_Ptr
:= Sloc
(N
);
9273 Str
: constant String_Id
:= Strval
(N
);
9274 Strlen
: constant Nat
:= String_Length
(Str
);
9275 Subtype_Id
: Entity_Id
;
9276 Need_Check
: Boolean;
9279 -- For a string appearing in a concatenation, defer creation of the
9280 -- string_literal_subtype until the end of the resolution of the
9281 -- concatenation, because the literal may be constant-folded away. This
9282 -- is a useful optimization for long concatenation expressions.
9284 -- If the string is an aggregate built for a single character (which
9285 -- happens in a non-static context) or a is null string to which special
9286 -- checks may apply, we build the subtype. Wide strings must also get a
9287 -- string subtype if they come from a one character aggregate. Strings
9288 -- generated by attributes might be static, but it is often hard to
9289 -- determine whether the enclosing context is static, so we generate
9290 -- subtypes for them as well, thus losing some rarer optimizations ???
9291 -- Same for strings that come from a static conversion.
9294 (Strlen
= 0 and then Typ
/= Standard_String
)
9295 or else Nkind
(Parent
(N
)) /= N_Op_Concat
9296 or else (N
/= Left_Opnd
(Parent
(N
))
9297 and then N
/= Right_Opnd
(Parent
(N
)))
9298 or else ((Typ
= Standard_Wide_String
9299 or else Typ
= Standard_Wide_Wide_String
)
9300 and then Nkind
(Original_Node
(N
)) /= N_String_Literal
);
9302 -- If the resolving type is itself a string literal subtype, we can just
9303 -- reuse it, since there is no point in creating another.
9305 if Ekind
(Typ
) = E_String_Literal_Subtype
then
9308 elsif Nkind
(Parent
(N
)) = N_Op_Concat
9309 and then not Need_Check
9310 and then not Nkind_In
(Original_Node
(N
), N_Character_Literal
,
9311 N_Attribute_Reference
,
9312 N_Qualified_Expression
,
9317 -- Otherwise we must create a string literal subtype. Note that the
9318 -- whole idea of string literal subtypes is simply to avoid the need
9319 -- for building a full fledged array subtype for each literal.
9322 Set_String_Literal_Subtype
(N
, Typ
);
9323 Subtype_Id
:= Etype
(N
);
9326 if Nkind
(Parent
(N
)) /= N_Op_Concat
9329 Set_Etype
(N
, Subtype_Id
);
9330 Eval_String_Literal
(N
);
9333 if Is_Limited_Composite
(Typ
)
9334 or else Is_Private_Composite
(Typ
)
9336 Error_Msg_N
("string literal not available for private array", N
);
9337 Set_Etype
(N
, Any_Type
);
9341 -- The validity of a null string has been checked in the call to
9342 -- Eval_String_Literal.
9347 -- Always accept string literal with component type Any_Character, which
9348 -- occurs in error situations and in comparisons of literals, both of
9349 -- which should accept all literals.
9351 elsif R_Typ
= Any_Character
then
9354 -- If the type is bit-packed, then we always transform the string
9355 -- literal into a full fledged aggregate.
9357 elsif Is_Bit_Packed_Array
(Typ
) then
9360 -- Deal with cases of Wide_Wide_String, Wide_String, and String
9363 -- For Standard.Wide_Wide_String, or any other type whose component
9364 -- type is Standard.Wide_Wide_Character, we know that all the
9365 -- characters in the string must be acceptable, since the parser
9366 -- accepted the characters as valid character literals.
9368 if R_Typ
= Standard_Wide_Wide_Character
then
9371 -- For the case of Standard.String, or any other type whose component
9372 -- type is Standard.Character, we must make sure that there are no
9373 -- wide characters in the string, i.e. that it is entirely composed
9374 -- of characters in range of type Character.
9376 -- If the string literal is the result of a static concatenation, the
9377 -- test has already been performed on the components, and need not be
9380 elsif R_Typ
= Standard_Character
9381 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
9383 for J
in 1 .. Strlen
loop
9384 if not In_Character_Range
(Get_String_Char
(Str
, J
)) then
9386 -- If we are out of range, post error. This is one of the
9387 -- very few places that we place the flag in the middle of
9388 -- a token, right under the offending wide character. Not
9389 -- quite clear if this is right wrt wide character encoding
9390 -- sequences, but it's only an error message!
9393 ("literal out of range of type Standard.Character",
9394 Source_Ptr
(Int
(Loc
) + J
));
9399 -- For the case of Standard.Wide_String, or any other type whose
9400 -- component type is Standard.Wide_Character, we must make sure that
9401 -- there are no wide characters in the string, i.e. that it is
9402 -- entirely composed of characters in range of type Wide_Character.
9404 -- If the string literal is the result of a static concatenation,
9405 -- the test has already been performed on the components, and need
9408 elsif R_Typ
= Standard_Wide_Character
9409 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
9411 for J
in 1 .. Strlen
loop
9412 if not In_Wide_Character_Range
(Get_String_Char
(Str
, J
)) then
9414 -- If we are out of range, post error. This is one of the
9415 -- very few places that we place the flag in the middle of
9416 -- a token, right under the offending wide character.
9418 -- This is not quite right, because characters in general
9419 -- will take more than one character position ???
9422 ("literal out of range of type Standard.Wide_Character",
9423 Source_Ptr
(Int
(Loc
) + J
));
9428 -- If the root type is not a standard character, then we will convert
9429 -- the string into an aggregate and will let the aggregate code do
9430 -- the checking. Standard Wide_Wide_Character is also OK here.
9436 -- See if the component type of the array corresponding to the string
9437 -- has compile time known bounds. If yes we can directly check
9438 -- whether the evaluation of the string will raise constraint error.
9439 -- Otherwise we need to transform the string literal into the
9440 -- corresponding character aggregate and let the aggregate code do
9443 if Is_Standard_Character_Type
(R_Typ
) then
9445 -- Check for the case of full range, where we are definitely OK
9447 if Component_Type
(Typ
) = Base_Type
(Component_Type
(Typ
)) then
9451 -- Here the range is not the complete base type range, so check
9454 Comp_Typ_Lo
: constant Node_Id
:=
9455 Type_Low_Bound
(Component_Type
(Typ
));
9456 Comp_Typ_Hi
: constant Node_Id
:=
9457 Type_High_Bound
(Component_Type
(Typ
));
9462 if Compile_Time_Known_Value
(Comp_Typ_Lo
)
9463 and then Compile_Time_Known_Value
(Comp_Typ_Hi
)
9465 for J
in 1 .. Strlen
loop
9466 Char_Val
:= UI_From_Int
(Int
(Get_String_Char
(Str
, J
)));
9468 if Char_Val
< Expr_Value
(Comp_Typ_Lo
)
9469 or else Char_Val
> Expr_Value
(Comp_Typ_Hi
)
9471 Apply_Compile_Time_Constraint_Error
9472 (N
, "character out of range??",
9473 CE_Range_Check_Failed
,
9474 Loc
=> Source_Ptr
(Int
(Loc
) + J
));
9484 -- If we got here we meed to transform the string literal into the
9485 -- equivalent qualified positional array aggregate. This is rather
9486 -- heavy artillery for this situation, but it is hard work to avoid.
9489 Lits
: constant List_Id
:= New_List
;
9490 P
: Source_Ptr
:= Loc
+ 1;
9494 -- Build the character literals, we give them source locations that
9495 -- correspond to the string positions, which is a bit tricky given
9496 -- the possible presence of wide character escape sequences.
9498 for J
in 1 .. Strlen
loop
9499 C
:= Get_String_Char
(Str
, J
);
9500 Set_Character_Literal_Name
(C
);
9503 Make_Character_Literal
(P
,
9505 Char_Literal_Value
=> UI_From_CC
(C
)));
9507 if In_Character_Range
(C
) then
9510 -- Should we have a call to Skip_Wide here ???
9519 Make_Qualified_Expression
(Loc
,
9520 Subtype_Mark
=> New_Reference_To
(Typ
, Loc
),
9522 Make_Aggregate
(Loc
, Expressions
=> Lits
)));
9524 Analyze_And_Resolve
(N
, Typ
);
9526 end Resolve_String_Literal
;
9528 -----------------------------
9529 -- Resolve_Subprogram_Info --
9530 -----------------------------
9532 procedure Resolve_Subprogram_Info
(N
: Node_Id
; Typ
: Entity_Id
) is
9535 end Resolve_Subprogram_Info
;
9537 -----------------------------
9538 -- Resolve_Type_Conversion --
9539 -----------------------------
9541 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
) is
9542 Conv_OK
: constant Boolean := Conversion_OK
(N
);
9543 Operand
: constant Node_Id
:= Expression
(N
);
9544 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
9545 Target_Typ
: constant Entity_Id
:= Etype
(N
);
9550 Test_Redundant
: Boolean := Warn_On_Redundant_Constructs
;
9551 -- Set to False to suppress cases where we want to suppress the test
9552 -- for redundancy to avoid possible false positives on this warning.
9556 and then not Valid_Conversion
(N
, Target_Typ
, Operand
)
9561 -- If the Operand Etype is Universal_Fixed, then the conversion is
9562 -- never redundant. We need this check because by the time we have
9563 -- finished the rather complex transformation, the conversion looks
9564 -- redundant when it is not.
9566 if Operand_Typ
= Universal_Fixed
then
9567 Test_Redundant
:= False;
9569 -- If the operand is marked as Any_Fixed, then special processing is
9570 -- required. This is also a case where we suppress the test for a
9571 -- redundant conversion, since most certainly it is not redundant.
9573 elsif Operand_Typ
= Any_Fixed
then
9574 Test_Redundant
:= False;
9576 -- Mixed-mode operation involving a literal. Context must be a fixed
9577 -- type which is applied to the literal subsequently.
9579 if Is_Fixed_Point_Type
(Typ
) then
9580 Set_Etype
(Operand
, Universal_Real
);
9582 elsif Is_Numeric_Type
(Typ
)
9583 and then Nkind_In
(Operand
, N_Op_Multiply
, N_Op_Divide
)
9584 and then (Etype
(Right_Opnd
(Operand
)) = Universal_Real
9586 Etype
(Left_Opnd
(Operand
)) = Universal_Real
)
9588 -- Return if expression is ambiguous
9590 if Unique_Fixed_Point_Type
(N
) = Any_Type
then
9593 -- If nothing else, the available fixed type is Duration
9596 Set_Etype
(Operand
, Standard_Duration
);
9599 -- Resolve the real operand with largest available precision
9601 if Etype
(Right_Opnd
(Operand
)) = Universal_Real
then
9602 Rop
:= New_Copy_Tree
(Right_Opnd
(Operand
));
9604 Rop
:= New_Copy_Tree
(Left_Opnd
(Operand
));
9607 Resolve
(Rop
, Universal_Real
);
9609 -- If the operand is a literal (it could be a non-static and
9610 -- illegal exponentiation) check whether the use of Duration
9611 -- is potentially inaccurate.
9613 if Nkind
(Rop
) = N_Real_Literal
9614 and then Realval
(Rop
) /= Ureal_0
9615 and then abs (Realval
(Rop
)) < Delta_Value
(Standard_Duration
)
9618 ("??universal real operand can only "
9619 & "be interpreted as Duration!", Rop
);
9621 ("\??precision will be lost in the conversion!", Rop
);
9624 elsif Is_Numeric_Type
(Typ
)
9625 and then Nkind
(Operand
) in N_Op
9626 and then Unique_Fixed_Point_Type
(N
) /= Any_Type
9628 Set_Etype
(Operand
, Standard_Duration
);
9631 Error_Msg_N
("invalid context for mixed mode operation", N
);
9632 Set_Etype
(Operand
, Any_Type
);
9639 -- In SPARK, a type conversion between array types should be restricted
9640 -- to types which have matching static bounds.
9642 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9643 -- operation if not needed.
9645 if Restriction_Check_Required
(SPARK_05
)
9646 and then Is_Array_Type
(Target_Typ
)
9647 and then Is_Array_Type
(Operand_Typ
)
9648 and then Operand_Typ
/= Any_Composite
-- or else Operand in error
9649 and then not Matching_Static_Array_Bounds
(Target_Typ
, Operand_Typ
)
9651 Check_SPARK_Restriction
9652 ("array types should have matching static bounds", N
);
9655 -- In formal mode, the operand of an ancestor type conversion must be an
9656 -- object (not an expression).
9658 if Is_Tagged_Type
(Target_Typ
)
9659 and then not Is_Class_Wide_Type
(Target_Typ
)
9660 and then Is_Tagged_Type
(Operand_Typ
)
9661 and then not Is_Class_Wide_Type
(Operand_Typ
)
9662 and then Is_Ancestor
(Target_Typ
, Operand_Typ
)
9663 and then not Is_SPARK_Object_Reference
(Operand
)
9665 Check_SPARK_Restriction
("object required", Operand
);
9668 Analyze_Dimension
(N
);
9670 -- Note: we do the Eval_Type_Conversion call before applying the
9671 -- required checks for a subtype conversion. This is important, since
9672 -- both are prepared under certain circumstances to change the type
9673 -- conversion to a constraint error node, but in the case of
9674 -- Eval_Type_Conversion this may reflect an illegality in the static
9675 -- case, and we would miss the illegality (getting only a warning
9676 -- message), if we applied the type conversion checks first.
9678 Eval_Type_Conversion
(N
);
9680 -- Even when evaluation is not possible, we may be able to simplify the
9681 -- conversion or its expression. This needs to be done before applying
9682 -- checks, since otherwise the checks may use the original expression
9683 -- and defeat the simplifications. This is specifically the case for
9684 -- elimination of the floating-point Truncation attribute in
9685 -- float-to-int conversions.
9687 Simplify_Type_Conversion
(N
);
9689 -- If after evaluation we still have a type conversion, then we may need
9690 -- to apply checks required for a subtype conversion.
9692 -- Skip these type conversion checks if universal fixed operands
9693 -- operands involved, since range checks are handled separately for
9694 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
9696 if Nkind
(N
) = N_Type_Conversion
9697 and then not Is_Generic_Type
(Root_Type
(Target_Typ
))
9698 and then Target_Typ
/= Universal_Fixed
9699 and then Operand_Typ
/= Universal_Fixed
9701 Apply_Type_Conversion_Checks
(N
);
9704 -- Issue warning for conversion of simple object to its own type. We
9705 -- have to test the original nodes, since they may have been rewritten
9706 -- by various optimizations.
9708 Orig_N
:= Original_Node
(N
);
9710 -- Here we test for a redundant conversion if the warning mode is
9711 -- active (and was not locally reset), and we have a type conversion
9712 -- from source not appearing in a generic instance.
9715 and then Nkind
(Orig_N
) = N_Type_Conversion
9716 and then Comes_From_Source
(Orig_N
)
9717 and then not In_Instance
9719 Orig_N
:= Original_Node
(Expression
(Orig_N
));
9720 Orig_T
:= Target_Typ
;
9722 -- If the node is part of a larger expression, the Target_Type
9723 -- may not be the original type of the node if the context is a
9724 -- condition. Recover original type to see if conversion is needed.
9726 if Is_Boolean_Type
(Orig_T
)
9727 and then Nkind
(Parent
(N
)) in N_Op
9729 Orig_T
:= Etype
(Parent
(N
));
9732 -- If we have an entity name, then give the warning if the entity
9733 -- is the right type, or if it is a loop parameter covered by the
9734 -- original type (that's needed because loop parameters have an
9735 -- odd subtype coming from the bounds).
9737 if (Is_Entity_Name
(Orig_N
)
9739 (Etype
(Entity
(Orig_N
)) = Orig_T
9741 (Ekind
(Entity
(Orig_N
)) = E_Loop_Parameter
9742 and then Covers
(Orig_T
, Etype
(Entity
(Orig_N
))))))
9744 -- If not an entity, then type of expression must match
9746 or else Etype
(Orig_N
) = Orig_T
9748 -- One more check, do not give warning if the analyzed conversion
9749 -- has an expression with non-static bounds, and the bounds of the
9750 -- target are static. This avoids junk warnings in cases where the
9751 -- conversion is necessary to establish staticness, for example in
9752 -- a case statement.
9754 if not Is_OK_Static_Subtype
(Operand_Typ
)
9755 and then Is_OK_Static_Subtype
(Target_Typ
)
9759 -- Finally, if this type conversion occurs in a context requiring
9760 -- a prefix, and the expression is a qualified expression then the
9761 -- type conversion is not redundant, since a qualified expression
9762 -- is not a prefix, whereas a type conversion is. For example, "X
9763 -- := T'(Funx(...)).Y;" is illegal because a selected component
9764 -- requires a prefix, but a type conversion makes it legal: "X :=
9765 -- T(T'(Funx(...))).Y;"
9767 -- In Ada 2012, a qualified expression is a name, so this idiom is
9768 -- no longer needed, but we still suppress the warning because it
9769 -- seems unfriendly for warnings to pop up when you switch to the
9770 -- newer language version.
9772 elsif Nkind
(Orig_N
) = N_Qualified_Expression
9773 and then Nkind_In
(Parent
(N
), N_Attribute_Reference
,
9774 N_Indexed_Component
,
9775 N_Selected_Component
,
9777 N_Explicit_Dereference
)
9781 -- Never warn on conversion to Long_Long_Integer'Base since
9782 -- that is most likely an artifact of the extended overflow
9783 -- checking and comes from complex expanded code.
9785 elsif Orig_T
= Base_Type
(Standard_Long_Long_Integer
) then
9788 -- Here we give the redundant conversion warning. If it is an
9789 -- entity, give the name of the entity in the message. If not,
9790 -- just mention the expression.
9792 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
9795 if Is_Entity_Name
(Orig_N
) then
9796 Error_Msg_Node_2
:= Orig_T
;
9797 Error_Msg_NE
-- CODEFIX
9798 ("??redundant conversion, & is of type &!",
9799 N
, Entity
(Orig_N
));
9802 ("??redundant conversion, expression is of type&!",
9809 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
9810 -- No need to perform any interface conversion if the type of the
9811 -- expression coincides with the target type.
9813 if Ada_Version
>= Ada_2005
9814 and then Full_Expander_Active
9815 and then Operand_Typ
/= Target_Typ
9818 Opnd
: Entity_Id
:= Operand_Typ
;
9819 Target
: Entity_Id
:= Target_Typ
;
9822 if Is_Access_Type
(Opnd
) then
9823 Opnd
:= Designated_Type
(Opnd
);
9826 if Is_Access_Type
(Target_Typ
) then
9827 Target
:= Designated_Type
(Target
);
9830 if Opnd
= Target
then
9833 -- Conversion from interface type
9835 elsif Is_Interface
(Opnd
) then
9837 -- Ada 2005 (AI-217): Handle entities from limited views
9839 if From_With_Type
(Opnd
) then
9840 Error_Msg_Qual_Level
:= 99;
9841 Error_Msg_NE
-- CODEFIX
9842 ("missing WITH clause on package &", N
,
9843 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Opnd
))));
9845 ("type conversions require visibility of the full view",
9848 elsif From_With_Type
(Target
)
9850 (Is_Access_Type
(Target_Typ
)
9851 and then Present
(Non_Limited_View
(Etype
(Target
))))
9853 Error_Msg_Qual_Level
:= 99;
9854 Error_Msg_NE
-- CODEFIX
9855 ("missing WITH clause on package &", N
,
9856 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Target
))));
9858 ("type conversions require visibility of the full view",
9862 Expand_Interface_Conversion
(N
);
9865 -- Conversion to interface type
9867 elsif Is_Interface
(Target
) then
9871 if Ekind_In
(Opnd
, E_Protected_Subtype
, E_Task_Subtype
) then
9872 Opnd
:= Etype
(Opnd
);
9875 if Is_Class_Wide_Type
(Opnd
)
9876 or else Interface_Present_In_Ancestor
9880 Expand_Interface_Conversion
(N
);
9882 Error_Msg_Name_1
:= Chars
(Etype
(Target
));
9883 Error_Msg_Name_2
:= Chars
(Opnd
);
9885 ("wrong interface conversion (% is not a progenitor "
9892 -- Ada 2012: if target type has predicates, the result requires a
9893 -- predicate check. If the context is a call to another predicate
9894 -- check we must prevent infinite recursion.
9896 if Has_Predicates
(Target_Typ
) then
9897 if Nkind
(Parent
(N
)) = N_Function_Call
9898 and then Present
(Name
(Parent
(N
)))
9899 and then (Is_Predicate_Function
(Entity
(Name
(Parent
(N
))))
9901 Is_Predicate_Function_M
(Entity
(Name
(Parent
(N
)))))
9906 Apply_Predicate_Check
(N
, Target_Typ
);
9909 end Resolve_Type_Conversion
;
9911 ----------------------
9912 -- Resolve_Unary_Op --
9913 ----------------------
9915 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
9916 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
9917 R
: constant Node_Id
:= Right_Opnd
(N
);
9923 if Is_Modular_Integer_Type
(Typ
) and then Nkind
(N
) /= N_Op_Not
then
9924 Error_Msg_Name_1
:= Chars
(Typ
);
9925 Check_SPARK_Restriction
9926 ("unary operator not defined for modular type%", N
);
9929 -- Deal with intrinsic unary operators
9931 if Comes_From_Source
(N
)
9932 and then Ekind
(Entity
(N
)) = E_Function
9933 and then Is_Imported
(Entity
(N
))
9934 and then Is_Intrinsic_Subprogram
(Entity
(N
))
9936 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
9940 -- Deal with universal cases
9942 if Etype
(R
) = Universal_Integer
9944 Etype
(R
) = Universal_Real
9946 Check_For_Visible_Operator
(N
, B_Typ
);
9949 Set_Etype
(N
, B_Typ
);
9952 -- Generate warning for expressions like abs (x mod 2)
9954 if Warn_On_Redundant_Constructs
9955 and then Nkind
(N
) = N_Op_Abs
9957 Determine_Range
(Right_Opnd
(N
), OK
, Lo
, Hi
);
9959 if OK
and then Hi
>= Lo
and then Lo
>= 0 then
9960 Error_Msg_N
-- CODEFIX
9961 ("?r?abs applied to known non-negative value has no effect", N
);
9965 -- Deal with reference generation
9967 Check_Unset_Reference
(R
);
9968 Generate_Operator_Reference
(N
, B_Typ
);
9969 Analyze_Dimension
(N
);
9972 -- Set overflow checking bit. Much cleverer code needed here eventually
9973 -- and perhaps the Resolve routines should be separated for the various
9974 -- arithmetic operations, since they will need different processing ???
9976 if Nkind
(N
) in N_Op
then
9977 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
9978 Enable_Overflow_Check
(N
);
9982 -- Generate warning for expressions like -5 mod 3 for integers. No need
9983 -- to worry in the floating-point case, since parens do not affect the
9984 -- result so there is no point in giving in a warning.
9987 Norig
: constant Node_Id
:= Original_Node
(N
);
9996 if Warn_On_Questionable_Missing_Parens
9997 and then Comes_From_Source
(Norig
)
9998 and then Is_Integer_Type
(Typ
)
9999 and then Nkind
(Norig
) = N_Op_Minus
10001 Rorig
:= Original_Node
(Right_Opnd
(Norig
));
10003 -- We are looking for cases where the right operand is not
10004 -- parenthesized, and is a binary operator, multiply, divide, or
10005 -- mod. These are the cases where the grouping can affect results.
10007 if Paren_Count
(Rorig
) = 0
10008 and then Nkind_In
(Rorig
, N_Op_Mod
, N_Op_Multiply
, N_Op_Divide
)
10010 -- For mod, we always give the warning, since the value is
10011 -- affected by the parenthesization (e.g. (-5) mod 315 /=
10012 -- -(5 mod 315)). But for the other cases, the only concern is
10013 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
10014 -- overflows, but (-2) * 64 does not). So we try to give the
10015 -- message only when overflow is possible.
10017 if Nkind
(Rorig
) /= N_Op_Mod
10018 and then Compile_Time_Known_Value
(R
)
10020 Val
:= Expr_Value
(R
);
10022 if Compile_Time_Known_Value
(Type_High_Bound
(Typ
)) then
10023 HB
:= Expr_Value
(Type_High_Bound
(Typ
));
10025 HB
:= Expr_Value
(Type_High_Bound
(Base_Type
(Typ
)));
10028 if Compile_Time_Known_Value
(Type_Low_Bound
(Typ
)) then
10029 LB
:= Expr_Value
(Type_Low_Bound
(Typ
));
10031 LB
:= Expr_Value
(Type_Low_Bound
(Base_Type
(Typ
)));
10034 -- Note that the test below is deliberately excluding the
10035 -- largest negative number, since that is a potentially
10036 -- troublesome case (e.g. -2 * x, where the result is the
10037 -- largest negative integer has an overflow with 2 * x).
10039 if Val
> LB
and then Val
<= HB
then
10044 -- For the multiplication case, the only case we have to worry
10045 -- about is when (-a)*b is exactly the largest negative number
10046 -- so that -(a*b) can cause overflow. This can only happen if
10047 -- a is a power of 2, and more generally if any operand is a
10048 -- constant that is not a power of 2, then the parentheses
10049 -- cannot affect whether overflow occurs. We only bother to
10050 -- test the left most operand
10052 -- Loop looking at left operands for one that has known value
10055 Opnd_Loop
: while Nkind
(Opnd
) = N_Op_Multiply
loop
10056 if Compile_Time_Known_Value
(Left_Opnd
(Opnd
)) then
10057 Lval
:= UI_Abs
(Expr_Value
(Left_Opnd
(Opnd
)));
10059 -- Operand value of 0 or 1 skips warning
10064 -- Otherwise check power of 2, if power of 2, warn, if
10065 -- anything else, skip warning.
10068 while Lval
/= 2 loop
10069 if Lval
mod 2 = 1 then
10080 -- Keep looking at left operands
10082 Opnd
:= Left_Opnd
(Opnd
);
10083 end loop Opnd_Loop
;
10085 -- For rem or "/" we can only have a problematic situation
10086 -- if the divisor has a value of minus one or one. Otherwise
10087 -- overflow is impossible (divisor > 1) or we have a case of
10088 -- division by zero in any case.
10090 if Nkind_In
(Rorig
, N_Op_Divide
, N_Op_Rem
)
10091 and then Compile_Time_Known_Value
(Right_Opnd
(Rorig
))
10092 and then UI_Abs
(Expr_Value
(Right_Opnd
(Rorig
))) /= 1
10097 -- If we fall through warning should be issued
10099 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
10102 ("??unary minus expression should be parenthesized here!", N
);
10106 end Resolve_Unary_Op
;
10108 ----------------------------------
10109 -- Resolve_Unchecked_Expression --
10110 ----------------------------------
10112 procedure Resolve_Unchecked_Expression
10117 Resolve
(Expression
(N
), Typ
, Suppress
=> All_Checks
);
10118 Set_Etype
(N
, Typ
);
10119 end Resolve_Unchecked_Expression
;
10121 ---------------------------------------
10122 -- Resolve_Unchecked_Type_Conversion --
10123 ---------------------------------------
10125 procedure Resolve_Unchecked_Type_Conversion
10129 pragma Warnings
(Off
, Typ
);
10131 Operand
: constant Node_Id
:= Expression
(N
);
10132 Opnd_Type
: constant Entity_Id
:= Etype
(Operand
);
10135 -- Resolve operand using its own type
10137 Resolve
(Operand
, Opnd_Type
);
10138 Analyze_Dimension
(N
);
10139 Eval_Unchecked_Conversion
(N
);
10140 end Resolve_Unchecked_Type_Conversion
;
10142 ------------------------------
10143 -- Rewrite_Operator_As_Call --
10144 ------------------------------
10146 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
) is
10147 Loc
: constant Source_Ptr
:= Sloc
(N
);
10148 Actuals
: constant List_Id
:= New_List
;
10152 if Nkind
(N
) in N_Binary_Op
then
10153 Append
(Left_Opnd
(N
), Actuals
);
10156 Append
(Right_Opnd
(N
), Actuals
);
10159 Make_Function_Call
(Sloc
=> Loc
,
10160 Name
=> New_Occurrence_Of
(Nam
, Loc
),
10161 Parameter_Associations
=> Actuals
);
10163 Preserve_Comes_From_Source
(New_N
, N
);
10164 Preserve_Comes_From_Source
(Name
(New_N
), N
);
10165 Rewrite
(N
, New_N
);
10166 Set_Etype
(N
, Etype
(Nam
));
10167 end Rewrite_Operator_As_Call
;
10169 ------------------------------
10170 -- Rewrite_Renamed_Operator --
10171 ------------------------------
10173 procedure Rewrite_Renamed_Operator
10178 Nam
: constant Name_Id
:= Chars
(Op
);
10179 Is_Binary
: constant Boolean := Nkind
(N
) in N_Binary_Op
;
10183 -- Rewrite the operator node using the real operator, not its renaming.
10184 -- Exclude user-defined intrinsic operations of the same name, which are
10185 -- treated separately and rewritten as calls.
10187 if Ekind
(Op
) /= E_Function
or else Chars
(N
) /= Nam
then
10188 Op_Node
:= New_Node
(Operator_Kind
(Nam
, Is_Binary
), Sloc
(N
));
10189 Set_Chars
(Op_Node
, Nam
);
10190 Set_Etype
(Op_Node
, Etype
(N
));
10191 Set_Entity
(Op_Node
, Op
);
10192 Set_Right_Opnd
(Op_Node
, Right_Opnd
(N
));
10194 -- Indicate that both the original entity and its renaming are
10195 -- referenced at this point.
10197 Generate_Reference
(Entity
(N
), N
);
10198 Generate_Reference
(Op
, N
);
10201 Set_Left_Opnd
(Op_Node
, Left_Opnd
(N
));
10204 Rewrite
(N
, Op_Node
);
10206 -- If the context type is private, add the appropriate conversions so
10207 -- that the operator is applied to the full view. This is done in the
10208 -- routines that resolve intrinsic operators.
10210 if Is_Intrinsic_Subprogram
(Op
)
10211 and then Is_Private_Type
(Typ
)
10214 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
10215 N_Op_Expon | N_Op_Mod | N_Op_Rem
=>
10216 Resolve_Intrinsic_Operator
(N
, Typ
);
10218 when N_Op_Plus | N_Op_Minus | N_Op_Abs
=>
10219 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
10226 elsif Ekind
(Op
) = E_Function
and then Is_Intrinsic_Subprogram
(Op
) then
10228 -- Operator renames a user-defined operator of the same name. Use the
10229 -- original operator in the node, which is the one Gigi knows about.
10231 Set_Entity
(N
, Op
);
10232 Set_Is_Overloaded
(N
, False);
10234 end Rewrite_Renamed_Operator
;
10236 -----------------------
10237 -- Set_Slice_Subtype --
10238 -----------------------
10240 -- Build an implicit subtype declaration to represent the type delivered by
10241 -- the slice. This is an abbreviated version of an array subtype. We define
10242 -- an index subtype for the slice, using either the subtype name or the
10243 -- discrete range of the slice. To be consistent with index usage elsewhere
10244 -- we create a list header to hold the single index. This list is not
10245 -- otherwise attached to the syntax tree.
10247 procedure Set_Slice_Subtype
(N
: Node_Id
) is
10248 Loc
: constant Source_Ptr
:= Sloc
(N
);
10249 Index_List
: constant List_Id
:= New_List
;
10251 Index_Subtype
: Entity_Id
;
10252 Index_Type
: Entity_Id
;
10253 Slice_Subtype
: Entity_Id
;
10254 Drange
: constant Node_Id
:= Discrete_Range
(N
);
10257 if Is_Entity_Name
(Drange
) then
10258 Index_Subtype
:= Entity
(Drange
);
10261 -- We force the evaluation of a range. This is definitely needed in
10262 -- the renamed case, and seems safer to do unconditionally. Note in
10263 -- any case that since we will create and insert an Itype referring
10264 -- to this range, we must make sure any side effect removal actions
10265 -- are inserted before the Itype definition.
10267 if Nkind
(Drange
) = N_Range
then
10268 Force_Evaluation
(Low_Bound
(Drange
));
10269 Force_Evaluation
(High_Bound
(Drange
));
10272 Index_Type
:= Base_Type
(Etype
(Drange
));
10274 Index_Subtype
:= Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
10276 -- Take a new copy of Drange (where bounds have been rewritten to
10277 -- reference side-effect-free names). Using a separate tree ensures
10278 -- that further expansion (e.g. while rewriting a slice assignment
10279 -- into a FOR loop) does not attempt to remove side effects on the
10280 -- bounds again (which would cause the bounds in the index subtype
10281 -- definition to refer to temporaries before they are defined) (the
10282 -- reason is that some names are considered side effect free here
10283 -- for the subtype, but not in the context of a loop iteration
10286 Set_Scalar_Range
(Index_Subtype
, New_Copy_Tree
(Drange
));
10287 Set_Parent
(Scalar_Range
(Index_Subtype
), Index_Subtype
);
10288 Set_Etype
(Index_Subtype
, Index_Type
);
10289 Set_Size_Info
(Index_Subtype
, Index_Type
);
10290 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
10293 Slice_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
10295 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
10296 Set_Etype
(Index
, Index_Subtype
);
10297 Append
(Index
, Index_List
);
10299 Set_First_Index
(Slice_Subtype
, Index
);
10300 Set_Etype
(Slice_Subtype
, Base_Type
(Etype
(N
)));
10301 Set_Is_Constrained
(Slice_Subtype
, True);
10303 Check_Compile_Time_Size
(Slice_Subtype
);
10305 -- The Etype of the existing Slice node is reset to this slice subtype.
10306 -- Its bounds are obtained from its first index.
10308 Set_Etype
(N
, Slice_Subtype
);
10310 -- For packed slice subtypes, freeze immediately (except in the case of
10311 -- being in a "spec expression" where we never freeze when we first see
10312 -- the expression).
10314 if Is_Packed
(Slice_Subtype
) and not In_Spec_Expression
then
10315 Freeze_Itype
(Slice_Subtype
, N
);
10317 -- For all other cases insert an itype reference in the slice's actions
10318 -- so that the itype is frozen at the proper place in the tree (i.e. at
10319 -- the point where actions for the slice are analyzed). Note that this
10320 -- is different from freezing the itype immediately, which might be
10321 -- premature (e.g. if the slice is within a transient scope). This needs
10322 -- to be done only if expansion is enabled.
10324 elsif Full_Expander_Active
then
10325 Ensure_Defined
(Typ
=> Slice_Subtype
, N
=> N
);
10327 end Set_Slice_Subtype
;
10329 --------------------------------
10330 -- Set_String_Literal_Subtype --
10331 --------------------------------
10333 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
) is
10334 Loc
: constant Source_Ptr
:= Sloc
(N
);
10335 Low_Bound
: constant Node_Id
:=
10336 Type_Low_Bound
(Etype
(First_Index
(Typ
)));
10337 Subtype_Id
: Entity_Id
;
10340 if Nkind
(N
) /= N_String_Literal
then
10344 Subtype_Id
:= Create_Itype
(E_String_Literal_Subtype
, N
);
10345 Set_String_Literal_Length
(Subtype_Id
, UI_From_Int
10346 (String_Length
(Strval
(N
))));
10347 Set_Etype
(Subtype_Id
, Base_Type
(Typ
));
10348 Set_Is_Constrained
(Subtype_Id
);
10349 Set_Etype
(N
, Subtype_Id
);
10351 -- The low bound is set from the low bound of the corresponding index
10352 -- type. Note that we do not store the high bound in the string literal
10353 -- subtype, but it can be deduced if necessary from the length and the
10356 if Is_OK_Static_Expression
(Low_Bound
) then
10357 Set_String_Literal_Low_Bound
(Subtype_Id
, Low_Bound
);
10359 -- If the lower bound is not static we create a range for the string
10360 -- literal, using the index type and the known length of the literal.
10361 -- The index type is not necessarily Positive, so the upper bound is
10362 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
10366 Index_List
: constant List_Id
:= New_List
;
10367 Index_Type
: constant Entity_Id
:= Etype
(First_Index
(Typ
));
10368 High_Bound
: constant Node_Id
:=
10369 Make_Attribute_Reference
(Loc
,
10370 Attribute_Name
=> Name_Val
,
10372 New_Occurrence_Of
(Index_Type
, Loc
),
10373 Expressions
=> New_List
(
10376 Make_Attribute_Reference
(Loc
,
10377 Attribute_Name
=> Name_Pos
,
10379 New_Occurrence_Of
(Index_Type
, Loc
),
10381 New_List
(New_Copy_Tree
(Low_Bound
))),
10383 Make_Integer_Literal
(Loc
,
10384 String_Length
(Strval
(N
)) - 1))));
10386 Array_Subtype
: Entity_Id
;
10389 Index_Subtype
: Entity_Id
;
10392 if Is_Integer_Type
(Index_Type
) then
10393 Set_String_Literal_Low_Bound
10394 (Subtype_Id
, Make_Integer_Literal
(Loc
, 1));
10397 -- If the index type is an enumeration type, build bounds
10398 -- expression with attributes.
10400 Set_String_Literal_Low_Bound
10402 Make_Attribute_Reference
(Loc
,
10403 Attribute_Name
=> Name_First
,
10405 New_Occurrence_Of
(Base_Type
(Index_Type
), Loc
)));
10406 Set_Etype
(String_Literal_Low_Bound
(Subtype_Id
), Index_Type
);
10409 Analyze_And_Resolve
(String_Literal_Low_Bound
(Subtype_Id
));
10411 -- Build bona fide subtype for the string, and wrap it in an
10412 -- unchecked conversion, because the backend expects the
10413 -- String_Literal_Subtype to have a static lower bound.
10416 Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
10417 Drange
:= Make_Range
(Loc
, New_Copy_Tree
(Low_Bound
), High_Bound
);
10418 Set_Scalar_Range
(Index_Subtype
, Drange
);
10419 Set_Parent
(Drange
, N
);
10420 Analyze_And_Resolve
(Drange
, Index_Type
);
10422 -- In the context, the Index_Type may already have a constraint,
10423 -- so use common base type on string subtype. The base type may
10424 -- be used when generating attributes of the string, for example
10425 -- in the context of a slice assignment.
10427 Set_Etype
(Index_Subtype
, Base_Type
(Index_Type
));
10428 Set_Size_Info
(Index_Subtype
, Index_Type
);
10429 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
10431 Array_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
10433 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
10434 Set_Etype
(Index
, Index_Subtype
);
10435 Append
(Index
, Index_List
);
10437 Set_First_Index
(Array_Subtype
, Index
);
10438 Set_Etype
(Array_Subtype
, Base_Type
(Typ
));
10439 Set_Is_Constrained
(Array_Subtype
, True);
10442 Make_Unchecked_Type_Conversion
(Loc
,
10443 Subtype_Mark
=> New_Occurrence_Of
(Array_Subtype
, Loc
),
10444 Expression
=> Relocate_Node
(N
)));
10445 Set_Etype
(N
, Array_Subtype
);
10448 end Set_String_Literal_Subtype
;
10450 ------------------------------
10451 -- Simplify_Type_Conversion --
10452 ------------------------------
10454 procedure Simplify_Type_Conversion
(N
: Node_Id
) is
10456 if Nkind
(N
) = N_Type_Conversion
then
10458 Operand
: constant Node_Id
:= Expression
(N
);
10459 Target_Typ
: constant Entity_Id
:= Etype
(N
);
10460 Opnd_Typ
: constant Entity_Id
:= Etype
(Operand
);
10463 if Is_Floating_Point_Type
(Opnd_Typ
)
10465 (Is_Integer_Type
(Target_Typ
)
10466 or else (Is_Fixed_Point_Type
(Target_Typ
)
10467 and then Conversion_OK
(N
)))
10468 and then Nkind
(Operand
) = N_Attribute_Reference
10469 and then Attribute_Name
(Operand
) = Name_Truncation
10471 -- Special processing required if the conversion is the expression
10472 -- of a Truncation attribute reference. In this case we replace:
10474 -- ityp (ftyp'Truncation (x))
10480 -- with the Float_Truncate flag set, which is more efficient.
10484 Relocate_Node
(First
(Expressions
(Operand
))));
10485 Set_Float_Truncate
(N
, True);
10489 end Simplify_Type_Conversion
;
10491 -----------------------------
10492 -- Unique_Fixed_Point_Type --
10493 -----------------------------
10495 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
is
10496 T1
: Entity_Id
:= Empty
;
10501 procedure Fixed_Point_Error
;
10502 -- Give error messages for true ambiguity. Messages are posted on node
10503 -- N, and entities T1, T2 are the possible interpretations.
10505 -----------------------
10506 -- Fixed_Point_Error --
10507 -----------------------
10509 procedure Fixed_Point_Error
is
10511 Error_Msg_N
("ambiguous universal_fixed_expression", N
);
10512 Error_Msg_NE
("\\possible interpretation as}", N
, T1
);
10513 Error_Msg_NE
("\\possible interpretation as}", N
, T2
);
10514 end Fixed_Point_Error
;
10516 -- Start of processing for Unique_Fixed_Point_Type
10519 -- The operations on Duration are visible, so Duration is always a
10520 -- possible interpretation.
10522 T1
:= Standard_Duration
;
10524 -- Look for fixed-point types in enclosing scopes
10526 Scop
:= Current_Scope
;
10527 while Scop
/= Standard_Standard
loop
10528 T2
:= First_Entity
(Scop
);
10529 while Present
(T2
) loop
10530 if Is_Fixed_Point_Type
(T2
)
10531 and then Current_Entity
(T2
) = T2
10532 and then Scope
(Base_Type
(T2
)) = Scop
10534 if Present
(T1
) then
10545 Scop
:= Scope
(Scop
);
10548 -- Look for visible fixed type declarations in the context
10550 Item
:= First
(Context_Items
(Cunit
(Current_Sem_Unit
)));
10551 while Present
(Item
) loop
10552 if Nkind
(Item
) = N_With_Clause
then
10553 Scop
:= Entity
(Name
(Item
));
10554 T2
:= First_Entity
(Scop
);
10555 while Present
(T2
) loop
10556 if Is_Fixed_Point_Type
(T2
)
10557 and then Scope
(Base_Type
(T2
)) = Scop
10558 and then (Is_Potentially_Use_Visible
(T2
) or else In_Use
(T2
))
10560 if Present
(T1
) then
10575 if Nkind
(N
) = N_Real_Literal
then
10577 ("??real literal interpreted as }!", N
, T1
);
10580 ("??universal_fixed expression interpreted as }!", N
, T1
);
10584 end Unique_Fixed_Point_Type
;
10586 ----------------------
10587 -- Valid_Conversion --
10588 ----------------------
10590 function Valid_Conversion
10592 Target
: Entity_Id
;
10594 Report_Errs
: Boolean := True) return Boolean
10596 Target_Type
: constant Entity_Id
:= Base_Type
(Target
);
10597 Opnd_Type
: Entity_Id
:= Etype
(Operand
);
10598 Inc_Ancestor
: Entity_Id
;
10600 function Conversion_Check
10602 Msg
: String) return Boolean;
10603 -- Little routine to post Msg if Valid is False, returns Valid value
10605 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
);
10606 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
10608 procedure Conversion_Error_NE
10610 N
: Node_Or_Entity_Id
;
10611 E
: Node_Or_Entity_Id
);
10612 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
10614 function Valid_Tagged_Conversion
10615 (Target_Type
: Entity_Id
;
10616 Opnd_Type
: Entity_Id
) return Boolean;
10617 -- Specifically test for validity of tagged conversions
10619 function Valid_Array_Conversion
return Boolean;
10620 -- Check index and component conformance, and accessibility levels if
10621 -- the component types are anonymous access types (Ada 2005).
10623 ----------------------
10624 -- Conversion_Check --
10625 ----------------------
10627 function Conversion_Check
10629 Msg
: String) return Boolean
10634 -- A generic unit has already been analyzed and we have verified
10635 -- that a particular conversion is OK in that context. Since the
10636 -- instance is reanalyzed without relying on the relationships
10637 -- established during the analysis of the generic, it is possible
10638 -- to end up with inconsistent views of private types. Do not emit
10639 -- the error message in such cases. The rest of the machinery in
10640 -- Valid_Conversion still ensures the proper compatibility of
10641 -- target and operand types.
10643 and then not In_Instance
10645 Conversion_Error_N
(Msg
, Operand
);
10649 end Conversion_Check
;
10651 ------------------------
10652 -- Conversion_Error_N --
10653 ------------------------
10655 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
) is
10657 if Report_Errs
then
10658 Error_Msg_N
(Msg
, N
);
10660 end Conversion_Error_N
;
10662 -------------------------
10663 -- Conversion_Error_NE --
10664 -------------------------
10666 procedure Conversion_Error_NE
10668 N
: Node_Or_Entity_Id
;
10669 E
: Node_Or_Entity_Id
)
10672 if Report_Errs
then
10673 Error_Msg_NE
(Msg
, N
, E
);
10675 end Conversion_Error_NE
;
10677 ----------------------------
10678 -- Valid_Array_Conversion --
10679 ----------------------------
10681 function Valid_Array_Conversion
return Boolean
10683 Opnd_Comp_Type
: constant Entity_Id
:= Component_Type
(Opnd_Type
);
10684 Opnd_Comp_Base
: constant Entity_Id
:= Base_Type
(Opnd_Comp_Type
);
10686 Opnd_Index
: Node_Id
;
10687 Opnd_Index_Type
: Entity_Id
;
10689 Target_Comp_Type
: constant Entity_Id
:=
10690 Component_Type
(Target_Type
);
10691 Target_Comp_Base
: constant Entity_Id
:=
10692 Base_Type
(Target_Comp_Type
);
10694 Target_Index
: Node_Id
;
10695 Target_Index_Type
: Entity_Id
;
10698 -- Error if wrong number of dimensions
10701 Number_Dimensions
(Target_Type
) /= Number_Dimensions
(Opnd_Type
)
10704 ("incompatible number of dimensions for conversion", Operand
);
10707 -- Number of dimensions matches
10710 -- Loop through indexes of the two arrays
10712 Target_Index
:= First_Index
(Target_Type
);
10713 Opnd_Index
:= First_Index
(Opnd_Type
);
10714 while Present
(Target_Index
) and then Present
(Opnd_Index
) loop
10715 Target_Index_Type
:= Etype
(Target_Index
);
10716 Opnd_Index_Type
:= Etype
(Opnd_Index
);
10718 -- Error if index types are incompatible
10720 if not (Is_Integer_Type
(Target_Index_Type
)
10721 and then Is_Integer_Type
(Opnd_Index_Type
))
10722 and then (Root_Type
(Target_Index_Type
)
10723 /= Root_Type
(Opnd_Index_Type
))
10726 ("incompatible index types for array conversion",
10731 Next_Index
(Target_Index
);
10732 Next_Index
(Opnd_Index
);
10735 -- If component types have same base type, all set
10737 if Target_Comp_Base
= Opnd_Comp_Base
then
10740 -- Here if base types of components are not the same. The only
10741 -- time this is allowed is if we have anonymous access types.
10743 -- The conversion of arrays of anonymous access types can lead
10744 -- to dangling pointers. AI-392 formalizes the accessibility
10745 -- checks that must be applied to such conversions to prevent
10746 -- out-of-scope references.
10749 (Target_Comp_Base
, E_Anonymous_Access_Type
,
10750 E_Anonymous_Access_Subprogram_Type
)
10751 and then Ekind
(Opnd_Comp_Base
) = Ekind
(Target_Comp_Base
)
10753 Subtypes_Statically_Match
(Target_Comp_Type
, Opnd_Comp_Type
)
10755 if Type_Access_Level
(Target_Type
) <
10756 Deepest_Type_Access_Level
(Opnd_Type
)
10758 if In_Instance_Body
then
10760 ("??source array type has deeper accessibility "
10761 & "level than target", Operand
);
10763 ("\??Program_Error will be raised at run time",
10766 Make_Raise_Program_Error
(Sloc
(N
),
10767 Reason
=> PE_Accessibility_Check_Failed
));
10768 Set_Etype
(N
, Target_Type
);
10771 -- Conversion not allowed because of accessibility levels
10775 ("source array type has deeper accessibility "
10776 & "level than target", Operand
);
10784 -- All other cases where component base types do not match
10788 ("incompatible component types for array conversion",
10793 -- Check that component subtypes statically match. For numeric
10794 -- types this means that both must be either constrained or
10795 -- unconstrained. For enumeration types the bounds must match.
10796 -- All of this is checked in Subtypes_Statically_Match.
10798 if not Subtypes_Statically_Match
10799 (Target_Comp_Type
, Opnd_Comp_Type
)
10802 ("component subtypes must statically match", Operand
);
10808 end Valid_Array_Conversion
;
10810 -----------------------------
10811 -- Valid_Tagged_Conversion --
10812 -----------------------------
10814 function Valid_Tagged_Conversion
10815 (Target_Type
: Entity_Id
;
10816 Opnd_Type
: Entity_Id
) return Boolean
10819 -- Upward conversions are allowed (RM 4.6(22))
10821 if Covers
(Target_Type
, Opnd_Type
)
10822 or else Is_Ancestor
(Target_Type
, Opnd_Type
)
10826 -- Downward conversion are allowed if the operand is class-wide
10829 elsif Is_Class_Wide_Type
(Opnd_Type
)
10830 and then Covers
(Opnd_Type
, Target_Type
)
10834 elsif Covers
(Opnd_Type
, Target_Type
)
10835 or else Is_Ancestor
(Opnd_Type
, Target_Type
)
10838 Conversion_Check
(False,
10839 "downward conversion of tagged objects not allowed");
10841 -- Ada 2005 (AI-251): The conversion to/from interface types is
10844 elsif Is_Interface
(Target_Type
) or else Is_Interface
(Opnd_Type
) then
10847 -- If the operand is a class-wide type obtained through a limited_
10848 -- with clause, and the context includes the non-limited view, use
10849 -- it to determine whether the conversion is legal.
10851 elsif Is_Class_Wide_Type
(Opnd_Type
)
10852 and then From_With_Type
(Opnd_Type
)
10853 and then Present
(Non_Limited_View
(Etype
(Opnd_Type
)))
10854 and then Is_Interface
(Non_Limited_View
(Etype
(Opnd_Type
)))
10858 elsif Is_Access_Type
(Opnd_Type
)
10859 and then Is_Interface
(Directly_Designated_Type
(Opnd_Type
))
10864 Conversion_Error_NE
10865 ("invalid tagged conversion, not compatible with}",
10866 N
, First_Subtype
(Opnd_Type
));
10869 end Valid_Tagged_Conversion
;
10871 -- Start of processing for Valid_Conversion
10874 Check_Parameterless_Call
(Operand
);
10876 if Is_Overloaded
(Operand
) then
10886 -- Remove procedure calls, which syntactically cannot appear in
10887 -- this context, but which cannot be removed by type checking,
10888 -- because the context does not impose a type.
10890 -- When compiling for VMS, spurious ambiguities can be produced
10891 -- when arithmetic operations have a literal operand and return
10892 -- System.Address or a descendant of it. These ambiguities are
10893 -- otherwise resolved by the context, but for conversions there
10894 -- is no context type and the removal of the spurious operations
10895 -- must be done explicitly here.
10897 -- The node may be labelled overloaded, but still contain only one
10898 -- interpretation because others were discarded earlier. If this
10899 -- is the case, retain the single interpretation if legal.
10901 Get_First_Interp
(Operand
, I
, It
);
10902 Opnd_Type
:= It
.Typ
;
10903 Get_Next_Interp
(I
, It
);
10905 if Present
(It
.Typ
)
10906 and then Opnd_Type
/= Standard_Void_Type
10908 -- More than one candidate interpretation is available
10910 Get_First_Interp
(Operand
, I
, It
);
10911 while Present
(It
.Typ
) loop
10912 if It
.Typ
= Standard_Void_Type
then
10916 if Present
(System_Aux_Id
)
10917 and then Is_Descendent_Of_Address
(It
.Typ
)
10922 Get_Next_Interp
(I
, It
);
10926 Get_First_Interp
(Operand
, I
, It
);
10930 if No
(It
.Typ
) then
10931 Conversion_Error_N
("illegal operand in conversion", Operand
);
10935 Get_Next_Interp
(I
, It
);
10937 if Present
(It
.Typ
) then
10940 It1
:= Disambiguate
(Operand
, I1
, I
, Any_Type
);
10942 if It1
= No_Interp
then
10944 ("ambiguous operand in conversion", Operand
);
10946 -- If the interpretation involves a standard operator, use
10947 -- the location of the type, which may be user-defined.
10949 if Sloc
(It
.Nam
) = Standard_Location
then
10950 Error_Msg_Sloc
:= Sloc
(It
.Typ
);
10952 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
10955 Conversion_Error_N
-- CODEFIX
10956 ("\\possible interpretation#!", Operand
);
10958 if Sloc
(N1
) = Standard_Location
then
10959 Error_Msg_Sloc
:= Sloc
(T1
);
10961 Error_Msg_Sloc
:= Sloc
(N1
);
10964 Conversion_Error_N
-- CODEFIX
10965 ("\\possible interpretation#!", Operand
);
10971 Set_Etype
(Operand
, It1
.Typ
);
10972 Opnd_Type
:= It1
.Typ
;
10976 -- If we are within a child unit, check whether the type of the
10977 -- expression has an ancestor in a parent unit, in which case it
10978 -- belongs to its derivation class even if the ancestor is private.
10979 -- See RM 7.3.1 (5.2/3).
10981 Inc_Ancestor
:= Get_Incomplete_View_Of_Ancestor
(Opnd_Type
);
10985 if Is_Numeric_Type
(Target_Type
) then
10987 -- A universal fixed expression can be converted to any numeric type
10989 if Opnd_Type
= Universal_Fixed
then
10992 -- Also no need to check when in an instance or inlined body, because
10993 -- the legality has been established when the template was analyzed.
10994 -- Furthermore, numeric conversions may occur where only a private
10995 -- view of the operand type is visible at the instantiation point.
10996 -- This results in a spurious error if we check that the operand type
10997 -- is a numeric type.
10999 -- Note: in a previous version of this unit, the following tests were
11000 -- applied only for generated code (Comes_From_Source set to False),
11001 -- but in fact the test is required for source code as well, since
11002 -- this situation can arise in source code.
11004 elsif In_Instance
or else In_Inlined_Body
then
11007 -- Otherwise we need the conversion check
11010 return Conversion_Check
11011 (Is_Numeric_Type
(Opnd_Type
)
11013 (Present
(Inc_Ancestor
)
11014 and then Is_Numeric_Type
(Inc_Ancestor
)),
11015 "illegal operand for numeric conversion");
11020 elsif Is_Array_Type
(Target_Type
) then
11021 if not Is_Array_Type
(Opnd_Type
)
11022 or else Opnd_Type
= Any_Composite
11023 or else Opnd_Type
= Any_String
11026 ("illegal operand for array conversion", Operand
);
11030 return Valid_Array_Conversion
;
11033 -- Ada 2005 (AI-251): Anonymous access types where target references an
11036 elsif Ekind_In
(Target_Type
, E_General_Access_Type
,
11037 E_Anonymous_Access_Type
)
11038 and then Is_Interface
(Directly_Designated_Type
(Target_Type
))
11040 -- Check the static accessibility rule of 4.6(17). Note that the
11041 -- check is not enforced when within an instance body, since the
11042 -- RM requires such cases to be caught at run time.
11044 -- If the operand is a rewriting of an allocator no check is needed
11045 -- because there are no accessibility issues.
11047 if Nkind
(Original_Node
(N
)) = N_Allocator
then
11050 elsif Ekind
(Target_Type
) /= E_Anonymous_Access_Type
then
11051 if Type_Access_Level
(Opnd_Type
) >
11052 Deepest_Type_Access_Level
(Target_Type
)
11054 -- In an instance, this is a run-time check, but one we know
11055 -- will fail, so generate an appropriate warning. The raise
11056 -- will be generated by Expand_N_Type_Conversion.
11058 if In_Instance_Body
then
11060 ("??cannot convert local pointer to non-local access type",
11063 ("\??Program_Error will be raised at run time", Operand
);
11067 ("cannot convert local pointer to non-local access type",
11072 -- Special accessibility checks are needed in the case of access
11073 -- discriminants declared for a limited type.
11075 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
11076 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
11078 -- When the operand is a selected access discriminant the check
11079 -- needs to be made against the level of the object denoted by
11080 -- the prefix of the selected name (Object_Access_Level handles
11081 -- checking the prefix of the operand for this case).
11083 if Nkind
(Operand
) = N_Selected_Component
11084 and then Object_Access_Level
(Operand
) >
11085 Deepest_Type_Access_Level
(Target_Type
)
11087 -- In an instance, this is a run-time check, but one we know
11088 -- will fail, so generate an appropriate warning. The raise
11089 -- will be generated by Expand_N_Type_Conversion.
11091 if In_Instance_Body
then
11093 ("??cannot convert access discriminant to non-local "
11094 & "access type", Operand
);
11096 ("\??Program_Error will be raised at run time",
11100 ("cannot convert access discriminant to non-local "
11101 & "access type", Operand
);
11106 -- The case of a reference to an access discriminant from
11107 -- within a limited type declaration (which will appear as
11108 -- a discriminal) is always illegal because the level of the
11109 -- discriminant is considered to be deeper than any (nameable)
11112 if Is_Entity_Name
(Operand
)
11113 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
11115 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
11116 and then Present
(Discriminal_Link
(Entity
(Operand
)))
11119 ("discriminant has deeper accessibility level than target",
11128 -- General and anonymous access types
11130 elsif Ekind_In
(Target_Type
, E_General_Access_Type
,
11131 E_Anonymous_Access_Type
)
11134 (Is_Access_Type
(Opnd_Type
)
11136 Ekind_In
(Opnd_Type
, E_Access_Subprogram_Type
,
11137 E_Access_Protected_Subprogram_Type
),
11138 "must be an access-to-object type")
11140 if Is_Access_Constant
(Opnd_Type
)
11141 and then not Is_Access_Constant
(Target_Type
)
11144 ("access-to-constant operand type not allowed", Operand
);
11148 -- Check the static accessibility rule of 4.6(17). Note that the
11149 -- check is not enforced when within an instance body, since the RM
11150 -- requires such cases to be caught at run time.
11152 if Ekind
(Target_Type
) /= E_Anonymous_Access_Type
11153 or else Is_Local_Anonymous_Access
(Target_Type
)
11154 or else Nkind
(Associated_Node_For_Itype
(Target_Type
)) =
11155 N_Object_Declaration
11157 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
11158 -- conversions from an anonymous access type to a named general
11159 -- access type. Such conversions are not allowed in the case of
11160 -- access parameters and stand-alone objects of an anonymous
11161 -- access type. The implicit conversion case is recognized by
11162 -- testing that Comes_From_Source is False and that it's been
11163 -- rewritten. The Comes_From_Source test isn't sufficient because
11164 -- nodes in inlined calls to predefined library routines can have
11165 -- Comes_From_Source set to False. (Is there a better way to test
11166 -- for implicit conversions???)
11168 if Ada_Version
>= Ada_2012
11169 and then not Comes_From_Source
(N
)
11170 and then N
/= Original_Node
(N
)
11171 and then Ekind
(Target_Type
) = E_General_Access_Type
11172 and then Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
11174 if Is_Itype
(Opnd_Type
) then
11176 -- Implicit conversions aren't allowed for objects of an
11177 -- anonymous access type, since such objects have nonstatic
11178 -- levels in Ada 2012.
11180 if Nkind
(Associated_Node_For_Itype
(Opnd_Type
)) =
11181 N_Object_Declaration
11184 ("implicit conversion of stand-alone anonymous "
11185 & "access object not allowed", Operand
);
11188 -- Implicit conversions aren't allowed for anonymous access
11189 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
11190 -- is done to exclude anonymous access results.
11192 elsif not Is_Local_Anonymous_Access
(Opnd_Type
)
11193 and then Nkind_In
(Associated_Node_For_Itype
(Opnd_Type
),
11194 N_Function_Specification
,
11195 N_Procedure_Specification
)
11198 ("implicit conversion of anonymous access formal "
11199 & "not allowed", Operand
);
11202 -- This is a case where there's an enclosing object whose
11203 -- to which the "statically deeper than" relationship does
11204 -- not apply (such as an access discriminant selected from
11205 -- a dereference of an access parameter).
11207 elsif Object_Access_Level
(Operand
)
11208 = Scope_Depth
(Standard_Standard
)
11211 ("implicit conversion of anonymous access value "
11212 & "not allowed", Operand
);
11215 -- In other cases, the level of the operand's type must be
11216 -- statically less deep than that of the target type, else
11217 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
11219 elsif Type_Access_Level
(Opnd_Type
) >
11220 Deepest_Type_Access_Level
(Target_Type
)
11223 ("implicit conversion of anonymous access value "
11224 & "violates accessibility", Operand
);
11229 elsif Type_Access_Level
(Opnd_Type
) >
11230 Deepest_Type_Access_Level
(Target_Type
)
11232 -- In an instance, this is a run-time check, but one we know
11233 -- will fail, so generate an appropriate warning. The raise
11234 -- will be generated by Expand_N_Type_Conversion.
11236 if In_Instance_Body
then
11238 ("??cannot convert local pointer to non-local access type",
11241 ("\??Program_Error will be raised at run time", Operand
);
11244 -- Avoid generation of spurious error message
11246 if not Error_Posted
(N
) then
11248 ("cannot convert local pointer to non-local access type",
11255 -- Special accessibility checks are needed in the case of access
11256 -- discriminants declared for a limited type.
11258 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
11259 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
11261 -- When the operand is a selected access discriminant the check
11262 -- needs to be made against the level of the object denoted by
11263 -- the prefix of the selected name (Object_Access_Level handles
11264 -- checking the prefix of the operand for this case).
11266 if Nkind
(Operand
) = N_Selected_Component
11267 and then Object_Access_Level
(Operand
) >
11268 Deepest_Type_Access_Level
(Target_Type
)
11270 -- In an instance, this is a run-time check, but one we know
11271 -- will fail, so generate an appropriate warning. The raise
11272 -- will be generated by Expand_N_Type_Conversion.
11274 if In_Instance_Body
then
11276 ("??cannot convert access discriminant to non-local "
11277 & "access type", Operand
);
11279 ("\??Program_Error will be raised at run time",
11284 ("cannot convert access discriminant to non-local "
11285 & "access type", Operand
);
11290 -- The case of a reference to an access discriminant from
11291 -- within a limited type declaration (which will appear as
11292 -- a discriminal) is always illegal because the level of the
11293 -- discriminant is considered to be deeper than any (nameable)
11296 if Is_Entity_Name
(Operand
)
11298 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
11299 and then Present
(Discriminal_Link
(Entity
(Operand
)))
11302 ("discriminant has deeper accessibility level than target",
11309 -- In the presence of limited_with clauses we have to use non-limited
11310 -- views, if available.
11312 Check_Limited
: declare
11313 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
;
11314 -- Helper function to handle limited views
11316 --------------------------
11317 -- Full_Designated_Type --
11318 --------------------------
11320 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
is
11321 Desig
: constant Entity_Id
:= Designated_Type
(T
);
11324 -- Handle the limited view of a type
11326 if Is_Incomplete_Type
(Desig
)
11327 and then From_With_Type
(Desig
)
11328 and then Present
(Non_Limited_View
(Desig
))
11330 return Available_View
(Desig
);
11334 end Full_Designated_Type
;
11336 -- Local Declarations
11338 Target
: constant Entity_Id
:= Full_Designated_Type
(Target_Type
);
11339 Opnd
: constant Entity_Id
:= Full_Designated_Type
(Opnd_Type
);
11341 Same_Base
: constant Boolean :=
11342 Base_Type
(Target
) = Base_Type
(Opnd
);
11344 -- Start of processing for Check_Limited
11347 if Is_Tagged_Type
(Target
) then
11348 return Valid_Tagged_Conversion
(Target
, Opnd
);
11351 if not Same_Base
then
11352 Conversion_Error_NE
11353 ("target designated type not compatible with }",
11354 N
, Base_Type
(Opnd
));
11357 -- Ada 2005 AI-384: legality rule is symmetric in both
11358 -- designated types. The conversion is legal (with possible
11359 -- constraint check) if either designated type is
11362 elsif Subtypes_Statically_Match
(Target
, Opnd
)
11364 (Has_Discriminants
(Target
)
11366 (not Is_Constrained
(Opnd
)
11367 or else not Is_Constrained
(Target
)))
11369 -- Special case, if Value_Size has been used to make the
11370 -- sizes different, the conversion is not allowed even
11371 -- though the subtypes statically match.
11373 if Known_Static_RM_Size
(Target
)
11374 and then Known_Static_RM_Size
(Opnd
)
11375 and then RM_Size
(Target
) /= RM_Size
(Opnd
)
11377 Conversion_Error_NE
11378 ("target designated subtype not compatible with }",
11380 Conversion_Error_NE
11381 ("\because sizes of the two designated subtypes differ",
11385 -- Normal case where conversion is allowed
11393 ("target designated subtype not compatible with }",
11400 -- Access to subprogram types. If the operand is an access parameter,
11401 -- the type has a deeper accessibility that any master, and cannot be
11402 -- assigned. We must make an exception if the conversion is part of an
11403 -- assignment and the target is the return object of an extended return
11404 -- statement, because in that case the accessibility check takes place
11405 -- after the return.
11407 elsif Is_Access_Subprogram_Type
(Target_Type
)
11408 and then No
(Corresponding_Remote_Type
(Opnd_Type
))
11410 if Ekind
(Base_Type
(Opnd_Type
)) = E_Anonymous_Access_Subprogram_Type
11411 and then Is_Entity_Name
(Operand
)
11412 and then Ekind
(Entity
(Operand
)) = E_In_Parameter
11414 (Nkind
(Parent
(N
)) /= N_Assignment_Statement
11415 or else not Is_Entity_Name
(Name
(Parent
(N
)))
11416 or else not Is_Return_Object
(Entity
(Name
(Parent
(N
)))))
11419 ("illegal attempt to store anonymous access to subprogram",
11422 ("\value has deeper accessibility than any master "
11423 & "(RM 3.10.2 (13))",
11427 ("\use named access type for& instead of access parameter",
11428 Operand
, Entity
(Operand
));
11431 -- Check that the designated types are subtype conformant
11433 Check_Subtype_Conformant
(New_Id
=> Designated_Type
(Target_Type
),
11434 Old_Id
=> Designated_Type
(Opnd_Type
),
11437 -- Check the static accessibility rule of 4.6(20)
11439 if Type_Access_Level
(Opnd_Type
) >
11440 Deepest_Type_Access_Level
(Target_Type
)
11443 ("operand type has deeper accessibility level than target",
11446 -- Check that if the operand type is declared in a generic body,
11447 -- then the target type must be declared within that same body
11448 -- (enforces last sentence of 4.6(20)).
11450 elsif Present
(Enclosing_Generic_Body
(Opnd_Type
)) then
11452 O_Gen
: constant Node_Id
:=
11453 Enclosing_Generic_Body
(Opnd_Type
);
11458 T_Gen
:= Enclosing_Generic_Body
(Target_Type
);
11459 while Present
(T_Gen
) and then T_Gen
/= O_Gen
loop
11460 T_Gen
:= Enclosing_Generic_Body
(T_Gen
);
11463 if T_Gen
/= O_Gen
then
11465 ("target type must be declared in same generic body "
11466 & "as operand type", N
);
11473 -- Remote subprogram access types
11475 elsif Is_Remote_Access_To_Subprogram_Type
(Target_Type
)
11476 and then Is_Remote_Access_To_Subprogram_Type
(Opnd_Type
)
11478 -- It is valid to convert from one RAS type to another provided
11479 -- that their specification statically match.
11481 Check_Subtype_Conformant
11483 Designated_Type
(Corresponding_Remote_Type
(Target_Type
)),
11485 Designated_Type
(Corresponding_Remote_Type
(Opnd_Type
)),
11490 -- If it was legal in the generic, it's legal in the instance
11492 elsif In_Instance_Body
then
11495 -- If both are tagged types, check legality of view conversions
11497 elsif Is_Tagged_Type
(Target_Type
)
11499 Is_Tagged_Type
(Opnd_Type
)
11501 return Valid_Tagged_Conversion
(Target_Type
, Opnd_Type
);
11503 -- Types derived from the same root type are convertible
11505 elsif Root_Type
(Target_Type
) = Root_Type
(Opnd_Type
) then
11508 -- In an instance or an inlined body, there may be inconsistent views of
11509 -- the same type, or of types derived from a common root.
11511 elsif (In_Instance
or In_Inlined_Body
)
11513 Root_Type
(Underlying_Type
(Target_Type
)) =
11514 Root_Type
(Underlying_Type
(Opnd_Type
))
11518 -- Special check for common access type error case
11520 elsif Ekind
(Target_Type
) = E_Access_Type
11521 and then Is_Access_Type
(Opnd_Type
)
11523 Conversion_Error_N
("target type must be general access type!", N
);
11524 Conversion_Error_NE
-- CODEFIX
11525 ("add ALL to }!", N
, Target_Type
);
11529 Conversion_Error_NE
11530 ("invalid conversion, not compatible with }", N
, Opnd_Type
);
11533 end Valid_Conversion
;