1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree
; use Atree
;
27 with Checks
; use Checks
;
28 with Debug
; use Debug
;
29 with Debug_A
; use Debug_A
;
30 with Einfo
; use Einfo
;
31 with Errout
; use Errout
;
32 with Expander
; use Expander
;
33 with Exp_Disp
; use Exp_Disp
;
34 with Exp_Ch6
; use Exp_Ch6
;
35 with Exp_Ch7
; use Exp_Ch7
;
36 with Exp_Tss
; use Exp_Tss
;
37 with Exp_Util
; use Exp_Util
;
38 with Fname
; use Fname
;
39 with Freeze
; use Freeze
;
40 with Ghost
; use Ghost
;
41 with Inline
; use Inline
;
42 with Itypes
; use Itypes
;
44 with Lib
.Xref
; use Lib
.Xref
;
45 with Namet
; use Namet
;
46 with Nmake
; use Nmake
;
47 with Nlists
; use Nlists
;
49 with Output
; use Output
;
50 with Par_SCO
; use Par_SCO
;
51 with Restrict
; use Restrict
;
52 with Rident
; use Rident
;
53 with Rtsfind
; use Rtsfind
;
55 with Sem_Aux
; use Sem_Aux
;
56 with Sem_Aggr
; use Sem_Aggr
;
57 with Sem_Attr
; use Sem_Attr
;
58 with Sem_Cat
; use Sem_Cat
;
59 with Sem_Ch4
; use Sem_Ch4
;
60 with Sem_Ch3
; use Sem_Ch3
;
61 with Sem_Ch6
; use Sem_Ch6
;
62 with Sem_Ch8
; use Sem_Ch8
;
63 with Sem_Ch13
; use Sem_Ch13
;
64 with Sem_Dim
; use Sem_Dim
;
65 with Sem_Disp
; use Sem_Disp
;
66 with Sem_Dist
; use Sem_Dist
;
67 with Sem_Elim
; use Sem_Elim
;
68 with Sem_Elab
; use Sem_Elab
;
69 with Sem_Eval
; use Sem_Eval
;
70 with Sem_Intr
; use Sem_Intr
;
71 with Sem_Util
; use Sem_Util
;
72 with Targparm
; use Targparm
;
73 with Sem_Type
; use Sem_Type
;
74 with Sem_Warn
; use Sem_Warn
;
75 with Sinfo
; use Sinfo
;
76 with Sinfo
.CN
; use Sinfo
.CN
;
77 with Snames
; use Snames
;
78 with Stand
; use Stand
;
79 with Stringt
; use Stringt
;
80 with Style
; use Style
;
81 with Tbuild
; use Tbuild
;
82 with Uintp
; use Uintp
;
83 with Urealp
; use Urealp
;
85 package body Sem_Res
is
87 -----------------------
88 -- Local Subprograms --
89 -----------------------
91 -- Second pass (top-down) type checking and overload resolution procedures
92 -- Typ is the type required by context. These procedures propagate the
93 -- type information recursively to the descendants of N. If the node is not
94 -- overloaded, its Etype is established in the first pass. If overloaded,
95 -- the Resolve routines set the correct type. For arithmetic operators, the
96 -- Etype is the base type of the context.
98 -- Note that Resolve_Attribute is separated off in Sem_Attr
100 procedure Check_Discriminant_Use
(N
: Node_Id
);
101 -- Enforce the restrictions on the use of discriminants when constraining
102 -- a component of a discriminated type (record or concurrent type).
104 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
);
105 -- Given a node for an operator associated with type T, check that the
106 -- operator is visible. Operators all of whose operands are universal must
107 -- be checked for visibility during resolution because their type is not
108 -- determinable based on their operands.
110 procedure Check_Fully_Declared_Prefix
113 -- Check that the type of the prefix of a dereference is not incomplete
115 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean;
116 -- Given a call node, N, which is known to occur immediately within the
117 -- subprogram being called, determines whether it is a detectable case of
118 -- an infinite recursion, and if so, outputs appropriate messages. Returns
119 -- True if an infinite recursion is detected, and False otherwise.
121 procedure Check_Initialization_Call
(N
: Entity_Id
; Nam
: Entity_Id
);
122 -- If the type of the object being initialized uses the secondary stack
123 -- directly or indirectly, create a transient scope for the call to the
124 -- init proc. This is because we do not create transient scopes for the
125 -- initialization of individual components within the init proc itself.
126 -- Could be optimized away perhaps?
128 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
);
129 -- N is the node for a logical operator. If the operator is predefined, and
130 -- the root type of the operands is Standard.Boolean, then a check is made
131 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
132 -- the style check for Style_Check_Boolean_And_Or.
134 function Is_Atomic_Ref_With_Address
(N
: Node_Id
) return Boolean;
135 -- N is either an indexed component or a selected component. This function
136 -- returns true if the prefix refers to an object that has an address
137 -- clause (the case in which we may want to issue a warning).
139 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean;
140 -- Determine whether E is an access type declared by an access declaration,
141 -- and not an (anonymous) allocator type.
143 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean;
144 -- Utility to check whether the entity for an operator is a predefined
145 -- operator, in which case the expression is left as an operator in the
146 -- tree (else it is rewritten into a call). An instance of an intrinsic
147 -- conversion operation may be given an operator name, but is not treated
148 -- like an operator. Note that an operator that is an imported back-end
149 -- builtin has convention Intrinsic, but is expected to be rewritten into
150 -- a call, so such an operator is not treated as predefined by this
153 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
);
154 -- If a default expression in entry call N depends on the discriminants
155 -- of the task, it must be replaced with a reference to the discriminant
156 -- of the task being called.
158 procedure Resolve_Op_Concat_Arg
163 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
164 -- concatenation operator. The operand is either of the array type or of
165 -- the component type. If the operand is an aggregate, and the component
166 -- type is composite, this is ambiguous if component type has aggregates.
168 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
);
169 -- Does the first part of the work of Resolve_Op_Concat
171 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
);
172 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
173 -- has been resolved. See Resolve_Op_Concat for details.
175 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
);
176 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
);
177 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
);
178 procedure Resolve_Case_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
179 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
180 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
);
181 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
);
182 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
);
183 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
);
184 procedure Resolve_Expression_With_Actions
(N
: Node_Id
; Typ
: Entity_Id
);
185 procedure Resolve_If_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
186 procedure Resolve_Generalized_Indexing
(N
: Node_Id
; Typ
: Entity_Id
);
187 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
);
188 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
189 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
);
190 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
);
191 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
);
192 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
);
193 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
);
194 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
);
195 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
);
196 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
197 procedure Resolve_Raise_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
198 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
);
199 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
200 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
);
201 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
);
202 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
);
203 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
);
204 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
);
205 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
);
206 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
207 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
);
208 procedure Resolve_Unchecked_Expression
(N
: Node_Id
; Typ
: Entity_Id
);
209 procedure Resolve_Unchecked_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
);
211 function Operator_Kind
213 Is_Binary
: Boolean) return Node_Kind
;
214 -- Utility to map the name of an operator into the corresponding Node. Used
215 -- by other node rewriting procedures.
217 procedure Resolve_Actuals
(N
: Node_Id
; Nam
: Entity_Id
);
218 -- Resolve actuals of call, and add default expressions for missing ones.
219 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
220 -- called subprogram.
222 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
);
223 -- Called from Resolve_Call, when the prefix denotes an entry or element
224 -- of entry family. Actuals are resolved as for subprograms, and the node
225 -- is rebuilt as an entry call. Also called for protected operations. Typ
226 -- is the context type, which is used when the operation is a protected
227 -- function with no arguments, and the return value is indexed.
229 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
230 -- A call to a user-defined intrinsic operator is rewritten as a call to
231 -- the corresponding predefined operator, with suitable conversions. Note
232 -- that this applies only for intrinsic operators that denote predefined
233 -- operators, not ones that are intrinsic imports of back-end builtins.
235 procedure Resolve_Intrinsic_Unary_Operator
(N
: Node_Id
; Typ
: Entity_Id
);
236 -- Ditto, for arithmetic unary operators
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 that
248 -- operands are resolved properly. Recall that predefined operators do not
249 -- 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 not
261 -- 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 Rounding or 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 -- Check_Discriminant_Use --
402 ----------------------------
404 procedure Check_Discriminant_Use
(N
: Node_Id
) is
405 PN
: constant Node_Id
:= Parent
(N
);
406 Disc
: constant Entity_Id
:= Entity
(N
);
411 -- Any use in a spec-expression is legal
413 if In_Spec_Expression
then
416 elsif Nkind
(PN
) = N_Range
then
418 -- Discriminant cannot be used to constrain a scalar type
422 if Nkind
(P
) = N_Range_Constraint
423 and then Nkind
(Parent
(P
)) = N_Subtype_Indication
424 and then Nkind
(Parent
(Parent
(P
))) = N_Component_Definition
426 Error_Msg_N
("discriminant cannot constrain scalar type", N
);
428 elsif Nkind
(P
) = N_Index_Or_Discriminant_Constraint
then
430 -- The following check catches the unusual case where a
431 -- discriminant appears within an index constraint that is part
432 -- of a larger expression within a constraint on a component,
433 -- e.g. "C : Int range 1 .. F (new A(1 .. D))". For now we only
434 -- check case of record components, and note that a similar check
435 -- should also apply in the case of discriminant constraints
438 -- Note that the check for N_Subtype_Declaration below is to
439 -- detect the valid use of discriminants in the constraints of a
440 -- subtype declaration when this subtype declaration appears
441 -- inside the scope of a record type (which is syntactically
442 -- illegal, but which may be created as part of derived type
443 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
446 if Ekind
(Current_Scope
) = E_Record_Type
447 and then Scope
(Disc
) = Current_Scope
449 (Nkind
(Parent
(P
)) = N_Subtype_Indication
451 Nkind_In
(Parent
(Parent
(P
)), N_Component_Definition
,
452 N_Subtype_Declaration
)
453 and then Paren_Count
(N
) = 0)
456 ("discriminant must appear alone in component constraint", N
);
460 -- Detect a common error:
462 -- type R (D : Positive := 100) is record
463 -- Name : String (1 .. D);
466 -- The default value causes an object of type R to be allocated
467 -- with room for Positive'Last characters. The RM does not mandate
468 -- the allocation of the maximum size, but that is what GNAT does
469 -- so we should warn the programmer that there is a problem.
471 Check_Large
: declare
477 function Large_Storage_Type
(T
: Entity_Id
) return Boolean;
478 -- Return True if type T has a large enough range that any
479 -- array whose index type covered the whole range of the type
480 -- would likely raise Storage_Error.
482 ------------------------
483 -- Large_Storage_Type --
484 ------------------------
486 function Large_Storage_Type
(T
: Entity_Id
) return Boolean is
488 -- The type is considered large if its bounds are known at
489 -- compile time and if it requires at least as many bits as
490 -- a Positive to store the possible values.
492 return Compile_Time_Known_Value
(Type_Low_Bound
(T
))
493 and then Compile_Time_Known_Value
(Type_High_Bound
(T
))
495 Minimum_Size
(T
, Biased
=> True) >=
496 RM_Size
(Standard_Positive
);
497 end Large_Storage_Type
;
499 -- Start of processing for Check_Large
502 -- Check that the Disc has a large range
504 if not Large_Storage_Type
(Etype
(Disc
)) then
508 -- If the enclosing type is limited, we allocate only the
509 -- default value, not the maximum, and there is no need for
512 if Is_Limited_Type
(Scope
(Disc
)) then
516 -- Check that it is the high bound
518 if N
/= High_Bound
(PN
)
519 or else No
(Discriminant_Default_Value
(Disc
))
524 -- Check the array allows a large range at this bound. First
529 if Nkind
(SI
) /= N_Subtype_Indication
then
533 T
:= Entity
(Subtype_Mark
(SI
));
535 if not Is_Array_Type
(T
) then
539 -- Next, find the dimension
541 TB
:= First_Index
(T
);
542 CB
:= First
(Constraints
(P
));
544 and then Present
(TB
)
545 and then Present
(CB
)
556 -- Now, check the dimension has a large range
558 if not Large_Storage_Type
(Etype
(TB
)) then
562 -- Warn about the danger
565 ("??creation of & object may raise Storage_Error!",
574 -- Legal case is in index or discriminant constraint
576 elsif Nkind_In
(PN
, N_Index_Or_Discriminant_Constraint
,
577 N_Discriminant_Association
)
579 if Paren_Count
(N
) > 0 then
581 ("discriminant in constraint must appear alone", N
);
583 elsif Nkind
(N
) = N_Expanded_Name
584 and then Comes_From_Source
(N
)
587 ("discriminant must appear alone as a direct name", N
);
592 -- Otherwise, context is an expression. It should not be within (i.e. a
593 -- subexpression of) a constraint for a component.
598 while not Nkind_In
(P
, N_Component_Declaration
,
599 N_Subtype_Indication
,
607 -- If the discriminant is used in an expression that is a bound of a
608 -- scalar type, an Itype is created and the bounds are attached to
609 -- its range, not to the original subtype indication. Such use is of
610 -- course a double fault.
612 if (Nkind
(P
) = N_Subtype_Indication
613 and then Nkind_In
(Parent
(P
), N_Component_Definition
,
614 N_Derived_Type_Definition
)
615 and then D
= Constraint
(P
))
617 -- The constraint itself may be given by a subtype indication,
618 -- rather than by a more common discrete range.
620 or else (Nkind
(P
) = N_Subtype_Indication
622 Nkind
(Parent
(P
)) = N_Index_Or_Discriminant_Constraint
)
623 or else Nkind
(P
) = N_Entry_Declaration
624 or else Nkind
(D
) = N_Defining_Identifier
627 ("discriminant in constraint must appear alone", N
);
630 end Check_Discriminant_Use
;
632 --------------------------------
633 -- Check_For_Visible_Operator --
634 --------------------------------
636 procedure Check_For_Visible_Operator
(N
: Node_Id
; T
: Entity_Id
) is
638 if Is_Invisible_Operator
(N
, T
) then
639 Error_Msg_NE
-- CODEFIX
640 ("operator for} is not directly visible!", N
, First_Subtype
(T
));
641 Error_Msg_N
-- CODEFIX
642 ("use clause would make operation legal!", N
);
644 end Check_For_Visible_Operator
;
646 ----------------------------------
647 -- Check_Fully_Declared_Prefix --
648 ----------------------------------
650 procedure Check_Fully_Declared_Prefix
655 -- Check that the designated type of the prefix of a dereference is
656 -- not an incomplete type. This cannot be done unconditionally, because
657 -- dereferences of private types are legal in default expressions. This
658 -- case is taken care of in Check_Fully_Declared, called below. There
659 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
661 -- This consideration also applies to similar checks for allocators,
662 -- qualified expressions, and type conversions.
664 -- An additional exception concerns other per-object expressions that
665 -- are not directly related to component declarations, in particular
666 -- representation pragmas for tasks. These will be per-object
667 -- expressions if they depend on discriminants or some global entity.
668 -- If the task has access discriminants, the designated type may be
669 -- incomplete at the point the expression is resolved. This resolution
670 -- takes place within the body of the initialization procedure, where
671 -- the discriminant is replaced by its discriminal.
673 if Is_Entity_Name
(Pref
)
674 and then Ekind
(Entity
(Pref
)) = E_In_Parameter
678 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
679 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
680 -- Analyze_Object_Renaming, and Freeze_Entity.
682 elsif Ada_Version
>= Ada_2005
683 and then Is_Entity_Name
(Pref
)
684 and then Is_Access_Type
(Etype
(Pref
))
685 and then Ekind
(Directly_Designated_Type
(Etype
(Pref
))) =
687 and then Is_Tagged_Type
(Directly_Designated_Type
(Etype
(Pref
)))
691 Check_Fully_Declared
(Typ
, Parent
(Pref
));
693 end Check_Fully_Declared_Prefix
;
695 ------------------------------
696 -- Check_Infinite_Recursion --
697 ------------------------------
699 function Check_Infinite_Recursion
(N
: Node_Id
) return Boolean is
703 function Same_Argument_List
return Boolean;
704 -- Check whether list of actuals is identical to list of formals of
705 -- called function (which is also the enclosing scope).
707 ------------------------
708 -- Same_Argument_List --
709 ------------------------
711 function Same_Argument_List
return Boolean is
717 if not Is_Entity_Name
(Name
(N
)) then
720 Subp
:= Entity
(Name
(N
));
723 F
:= First_Formal
(Subp
);
724 A
:= First_Actual
(N
);
725 while Present
(F
) and then Present
(A
) loop
726 if not Is_Entity_Name
(A
) or else Entity
(A
) /= F
then
735 end Same_Argument_List
;
737 -- Start of processing for Check_Infinite_Recursion
740 -- Special case, if this is a procedure call and is a call to the
741 -- current procedure with the same argument list, then this is for
742 -- sure an infinite recursion and we insert a call to raise SE.
744 if Is_List_Member
(N
)
745 and then List_Length
(List_Containing
(N
)) = 1
746 and then Same_Argument_List
749 P
: constant Node_Id
:= Parent
(N
);
751 if Nkind
(P
) = N_Handled_Sequence_Of_Statements
752 and then Nkind
(Parent
(P
)) = N_Subprogram_Body
753 and then Is_Empty_List
(Declarations
(Parent
(P
)))
755 Error_Msg_Warn
:= SPARK_Mode
/= On
;
756 Error_Msg_N
("!infinite recursion<<", N
);
757 Error_Msg_N
("\!Storage_Error [<<", N
);
759 Make_Raise_Storage_Error
(Sloc
(N
),
760 Reason
=> SE_Infinite_Recursion
));
766 -- If not that special case, search up tree, quitting if we reach a
767 -- construct (e.g. a conditional) that tells us that this is not a
768 -- case for an infinite recursion warning.
774 -- If no parent, then we were not inside a subprogram, this can for
775 -- example happen when processing certain pragmas in a spec. Just
776 -- return False in this case.
782 -- Done if we get to subprogram body, this is definitely an infinite
783 -- recursion case if we did not find anything to stop us.
785 exit when Nkind
(P
) = N_Subprogram_Body
;
787 -- If appearing in conditional, result is false
789 if Nkind_In
(P
, N_Or_Else
,
798 elsif Nkind
(P
) = N_Handled_Sequence_Of_Statements
799 and then C
/= First
(Statements
(P
))
801 -- If the call is the expression of a return statement and the
802 -- actuals are identical to the formals, it's worth a warning.
803 -- However, we skip this if there is an immediately preceding
804 -- raise statement, since the call is never executed.
806 -- Furthermore, this corresponds to a common idiom:
808 -- function F (L : Thing) return Boolean is
810 -- raise Program_Error;
814 -- for generating a stub function
816 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
817 and then Same_Argument_List
819 exit when not Is_List_Member
(Parent
(N
));
821 -- OK, return statement is in a statement list, look for raise
827 -- Skip past N_Freeze_Entity nodes generated by expansion
829 Nod
:= Prev
(Parent
(N
));
831 and then Nkind
(Nod
) = N_Freeze_Entity
836 -- If no raise statement, give warning. We look at the
837 -- original node, because in the case of "raise ... with
838 -- ...", the node has been transformed into a call.
840 exit when Nkind
(Original_Node
(Nod
)) /= N_Raise_Statement
842 (Nkind
(Nod
) not in N_Raise_xxx_Error
843 or else Present
(Condition
(Nod
)));
854 Error_Msg_Warn
:= SPARK_Mode
/= On
;
855 Error_Msg_N
("!possible infinite recursion<<", N
);
856 Error_Msg_N
("\!??Storage_Error ]<<", N
);
859 end Check_Infinite_Recursion
;
861 -------------------------------
862 -- Check_Initialization_Call --
863 -------------------------------
865 procedure Check_Initialization_Call
(N
: Entity_Id
; Nam
: Entity_Id
) is
866 Typ
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
868 function Uses_SS
(T
: Entity_Id
) return Boolean;
869 -- Check whether the creation of an object of the type will involve
870 -- use of the secondary stack. If T is a record type, this is true
871 -- if the expression for some component uses the secondary stack, e.g.
872 -- through a call to a function that returns an unconstrained value.
873 -- False if T is controlled, because cleanups occur elsewhere.
879 function Uses_SS
(T
: Entity_Id
) return Boolean is
882 Full_Type
: Entity_Id
:= Underlying_Type
(T
);
885 -- Normally we want to use the underlying type, but if it's not set
886 -- then continue with T.
888 if not Present
(Full_Type
) then
892 if Is_Controlled
(Full_Type
) then
895 elsif Is_Array_Type
(Full_Type
) then
896 return Uses_SS
(Component_Type
(Full_Type
));
898 elsif Is_Record_Type
(Full_Type
) then
899 Comp
:= First_Component
(Full_Type
);
900 while Present
(Comp
) loop
901 if Ekind
(Comp
) = E_Component
902 and then Nkind
(Parent
(Comp
)) = N_Component_Declaration
904 -- The expression for a dynamic component may be rewritten
905 -- as a dereference, so retrieve original node.
907 Expr
:= Original_Node
(Expression
(Parent
(Comp
)));
909 -- Return True if the expression is a call to a function
910 -- (including an attribute function such as Image, or a
911 -- user-defined operator) with a result that requires a
914 if (Nkind
(Expr
) = N_Function_Call
915 or else Nkind
(Expr
) in N_Op
916 or else (Nkind
(Expr
) = N_Attribute_Reference
917 and then Present
(Expressions
(Expr
))))
918 and then Requires_Transient_Scope
(Etype
(Expr
))
922 elsif Uses_SS
(Etype
(Comp
)) then
927 Next_Component
(Comp
);
937 -- Start of processing for Check_Initialization_Call
940 -- Establish a transient scope if the type needs it
942 if Uses_SS
(Typ
) then
943 Establish_Transient_Scope
(First_Actual
(N
), Sec_Stack
=> True);
945 end Check_Initialization_Call
;
947 ---------------------------------------
948 -- Check_No_Direct_Boolean_Operators --
949 ---------------------------------------
951 procedure Check_No_Direct_Boolean_Operators
(N
: Node_Id
) is
953 if Scope
(Entity
(N
)) = Standard_Standard
954 and then Root_Type
(Etype
(Left_Opnd
(N
))) = Standard_Boolean
956 -- Restriction only applies to original source code
958 if Comes_From_Source
(N
) then
959 Check_Restriction
(No_Direct_Boolean_Operators
, N
);
963 -- Do style check (but skip if in instance, error is on template)
966 if not In_Instance
then
967 Check_Boolean_Operator
(N
);
970 end Check_No_Direct_Boolean_Operators
;
972 ------------------------------
973 -- Check_Parameterless_Call --
974 ------------------------------
976 procedure Check_Parameterless_Call
(N
: Node_Id
) is
979 function Prefix_Is_Access_Subp
return Boolean;
980 -- If the prefix is of an access_to_subprogram type, the node must be
981 -- rewritten as a call. Ditto if the prefix is overloaded and all its
982 -- interpretations are access to subprograms.
984 ---------------------------
985 -- Prefix_Is_Access_Subp --
986 ---------------------------
988 function Prefix_Is_Access_Subp
return Boolean is
993 -- If the context is an attribute reference that can apply to
994 -- functions, this is never a parameterless call (RM 4.1.4(6)).
996 if Nkind
(Parent
(N
)) = N_Attribute_Reference
997 and then Nam_In
(Attribute_Name
(Parent
(N
)), Name_Address
,
1004 if not Is_Overloaded
(N
) then
1006 Ekind
(Etype
(N
)) = E_Subprogram_Type
1007 and then Base_Type
(Etype
(Etype
(N
))) /= Standard_Void_Type
;
1009 Get_First_Interp
(N
, I
, It
);
1010 while Present
(It
.Typ
) loop
1011 if Ekind
(It
.Typ
) /= E_Subprogram_Type
1012 or else Base_Type
(Etype
(It
.Typ
)) = Standard_Void_Type
1017 Get_Next_Interp
(I
, It
);
1022 end Prefix_Is_Access_Subp
;
1024 -- Start of processing for Check_Parameterless_Call
1027 -- Defend against junk stuff if errors already detected
1029 if Total_Errors_Detected
/= 0 then
1030 if Nkind
(N
) in N_Has_Etype
and then Etype
(N
) = Any_Type
then
1032 elsif Nkind
(N
) in N_Has_Chars
1033 and then Chars
(N
) in Error_Name_Or_No_Name
1041 -- If the context expects a value, and the name is a procedure, this is
1042 -- most likely a missing 'Access. Don't try to resolve the parameterless
1043 -- call, error will be caught when the outer call is analyzed.
1045 if Is_Entity_Name
(N
)
1046 and then Ekind
(Entity
(N
)) = E_Procedure
1047 and then not Is_Overloaded
(N
)
1049 Nkind_In
(Parent
(N
), N_Parameter_Association
,
1051 N_Procedure_Call_Statement
)
1056 -- Rewrite as call if overloadable entity that is (or could be, in the
1057 -- overloaded case) a function call. If we know for sure that the entity
1058 -- is an enumeration literal, we do not rewrite it.
1060 -- If the entity is the name of an operator, it cannot be a call because
1061 -- operators cannot have default parameters. In this case, this must be
1062 -- a string whose contents coincide with an operator name. Set the kind
1063 -- of the node appropriately.
1065 if (Is_Entity_Name
(N
)
1066 and then Nkind
(N
) /= N_Operator_Symbol
1067 and then Is_Overloadable
(Entity
(N
))
1068 and then (Ekind
(Entity
(N
)) /= E_Enumeration_Literal
1069 or else Is_Overloaded
(N
)))
1071 -- Rewrite as call if it is an explicit dereference of an expression of
1072 -- a subprogram access type, and the subprogram type is not that of a
1073 -- procedure or entry.
1076 (Nkind
(N
) = N_Explicit_Dereference
and then Prefix_Is_Access_Subp
)
1078 -- Rewrite as call if it is a selected component which is a function,
1079 -- this is the case of a call to a protected function (which may be
1080 -- overloaded with other protected operations).
1083 (Nkind
(N
) = N_Selected_Component
1084 and then (Ekind
(Entity
(Selector_Name
(N
))) = E_Function
1086 (Ekind_In
(Entity
(Selector_Name
(N
)), E_Entry
,
1088 and then Is_Overloaded
(Selector_Name
(N
)))))
1090 -- If one of the above three conditions is met, rewrite as call. Apply
1091 -- the rewriting only once.
1094 if Nkind
(Parent
(N
)) /= N_Function_Call
1095 or else N
/= Name
(Parent
(N
))
1098 -- This may be a prefixed call that was not fully analyzed, e.g.
1099 -- an actual in an instance.
1101 if Ada_Version
>= Ada_2005
1102 and then Nkind
(N
) = N_Selected_Component
1103 and then Is_Dispatching_Operation
(Entity
(Selector_Name
(N
)))
1105 Analyze_Selected_Component
(N
);
1107 if Nkind
(N
) /= N_Selected_Component
then
1112 -- The node is the name of the parameterless call. Preserve its
1113 -- descendants, which may be complex expressions.
1115 Nam
:= Relocate_Node
(N
);
1117 -- If overloaded, overload set belongs to new copy
1119 Save_Interps
(N
, Nam
);
1121 -- Change node to parameterless function call (note that the
1122 -- Parameter_Associations associations field is left set to Empty,
1123 -- its normal default value since there are no parameters)
1125 Change_Node
(N
, N_Function_Call
);
1127 Set_Sloc
(N
, Sloc
(Nam
));
1131 elsif Nkind
(N
) = N_Parameter_Association
then
1132 Check_Parameterless_Call
(Explicit_Actual_Parameter
(N
));
1134 elsif Nkind
(N
) = N_Operator_Symbol
then
1135 Change_Operator_Symbol_To_String_Literal
(N
);
1136 Set_Is_Overloaded
(N
, False);
1137 Set_Etype
(N
, Any_String
);
1139 end Check_Parameterless_Call
;
1141 --------------------------------
1142 -- Is_Atomic_Ref_With_Address --
1143 --------------------------------
1145 function Is_Atomic_Ref_With_Address
(N
: Node_Id
) return Boolean is
1146 Pref
: constant Node_Id
:= Prefix
(N
);
1149 if not Is_Entity_Name
(Pref
) then
1154 Pent
: constant Entity_Id
:= Entity
(Pref
);
1155 Ptyp
: constant Entity_Id
:= Etype
(Pent
);
1157 return not Is_Access_Type
(Ptyp
)
1158 and then (Is_Atomic
(Ptyp
) or else Is_Atomic
(Pent
))
1159 and then Present
(Address_Clause
(Pent
));
1162 end Is_Atomic_Ref_With_Address
;
1164 -----------------------------
1165 -- Is_Definite_Access_Type --
1166 -----------------------------
1168 function Is_Definite_Access_Type
(E
: Entity_Id
) return Boolean is
1169 Btyp
: constant Entity_Id
:= Base_Type
(E
);
1171 return Ekind
(Btyp
) = E_Access_Type
1172 or else (Ekind
(Btyp
) = E_Access_Subprogram_Type
1173 and then Comes_From_Source
(Btyp
));
1174 end Is_Definite_Access_Type
;
1176 ----------------------
1177 -- Is_Predefined_Op --
1178 ----------------------
1180 function Is_Predefined_Op
(Nam
: Entity_Id
) return Boolean is
1182 -- Predefined operators are intrinsic subprograms
1184 if not Is_Intrinsic_Subprogram
(Nam
) then
1188 -- A call to a back-end builtin is never a predefined operator
1190 if Is_Imported
(Nam
) and then Present
(Interface_Name
(Nam
)) then
1194 return not Is_Generic_Instance
(Nam
)
1195 and then Chars
(Nam
) in Any_Operator_Name
1196 and then (No
(Alias
(Nam
)) or else Is_Predefined_Op
(Alias
(Nam
)));
1197 end Is_Predefined_Op
;
1199 -----------------------------
1200 -- Make_Call_Into_Operator --
1201 -----------------------------
1203 procedure Make_Call_Into_Operator
1208 Op_Name
: constant Name_Id
:= Chars
(Op_Id
);
1209 Act1
: Node_Id
:= First_Actual
(N
);
1210 Act2
: Node_Id
:= Next_Actual
(Act1
);
1211 Error
: Boolean := False;
1212 Func
: constant Entity_Id
:= Entity
(Name
(N
));
1213 Is_Binary
: constant Boolean := Present
(Act2
);
1215 Opnd_Type
: Entity_Id
;
1216 Orig_Type
: Entity_Id
:= Empty
;
1219 type Kind_Test
is access function (E
: Entity_Id
) return Boolean;
1221 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean;
1222 -- If the operand is not universal, and the operator is given by an
1223 -- expanded name, verify that the operand has an interpretation with a
1224 -- type defined in the given scope of the operator.
1226 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
;
1227 -- Find a type of the given class in package Pack that contains the
1230 ---------------------------
1231 -- Operand_Type_In_Scope --
1232 ---------------------------
1234 function Operand_Type_In_Scope
(S
: Entity_Id
) return Boolean is
1235 Nod
: constant Node_Id
:= Right_Opnd
(Op_Node
);
1240 if not Is_Overloaded
(Nod
) then
1241 return Scope
(Base_Type
(Etype
(Nod
))) = S
;
1244 Get_First_Interp
(Nod
, I
, It
);
1245 while Present
(It
.Typ
) loop
1246 if Scope
(Base_Type
(It
.Typ
)) = S
then
1250 Get_Next_Interp
(I
, It
);
1255 end Operand_Type_In_Scope
;
1261 function Type_In_P
(Test
: Kind_Test
) return Entity_Id
is
1264 function In_Decl
return Boolean;
1265 -- Verify that node is not part of the type declaration for the
1266 -- candidate type, which would otherwise be invisible.
1272 function In_Decl
return Boolean is
1273 Decl_Node
: constant Node_Id
:= Parent
(E
);
1279 if Etype
(E
) = Any_Type
then
1282 elsif No
(Decl_Node
) then
1287 and then Nkind
(N2
) /= N_Compilation_Unit
1289 if N2
= Decl_Node
then
1300 -- Start of processing for Type_In_P
1303 -- If the context type is declared in the prefix package, this is the
1304 -- desired base type.
1306 if Scope
(Base_Type
(Typ
)) = Pack
and then Test
(Typ
) then
1307 return Base_Type
(Typ
);
1310 E
:= First_Entity
(Pack
);
1311 while Present
(E
) loop
1312 if Test
(E
) and then not In_Decl
then
1323 -- Start of processing for Make_Call_Into_Operator
1326 Op_Node
:= New_Node
(Operator_Kind
(Op_Name
, Is_Binary
), Sloc
(N
));
1331 Set_Left_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1332 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act2
));
1333 Save_Interps
(Act1
, Left_Opnd
(Op_Node
));
1334 Save_Interps
(Act2
, Right_Opnd
(Op_Node
));
1335 Act1
:= Left_Opnd
(Op_Node
);
1336 Act2
:= Right_Opnd
(Op_Node
);
1341 Set_Right_Opnd
(Op_Node
, Relocate_Node
(Act1
));
1342 Save_Interps
(Act1
, Right_Opnd
(Op_Node
));
1343 Act1
:= Right_Opnd
(Op_Node
);
1346 -- If the operator is denoted by an expanded name, and the prefix is
1347 -- not Standard, but the operator is a predefined one whose scope is
1348 -- Standard, then this is an implicit_operator, inserted as an
1349 -- interpretation by the procedure of the same name. This procedure
1350 -- overestimates the presence of implicit operators, because it does
1351 -- not examine the type of the operands. Verify now that the operand
1352 -- type appears in the given scope. If right operand is universal,
1353 -- check the other operand. In the case of concatenation, either
1354 -- argument can be the component type, so check the type of the result.
1355 -- If both arguments are literals, look for a type of the right kind
1356 -- defined in the given scope. This elaborate nonsense is brought to
1357 -- you courtesy of b33302a. The type itself must be frozen, so we must
1358 -- find the type of the proper class in the given scope.
1360 -- A final wrinkle is the multiplication operator for fixed point types,
1361 -- which is defined in Standard only, and not in the scope of the
1362 -- fixed point type itself.
1364 if Nkind
(Name
(N
)) = N_Expanded_Name
then
1365 Pack
:= Entity
(Prefix
(Name
(N
)));
1367 -- If this is a package renaming, get renamed entity, which will be
1368 -- the scope of the operands if operaton is type-correct.
1370 if Present
(Renamed_Entity
(Pack
)) then
1371 Pack
:= Renamed_Entity
(Pack
);
1374 -- If the entity being called is defined in the given package, it is
1375 -- a renaming of a predefined operator, and known to be legal.
1377 if Scope
(Entity
(Name
(N
))) = Pack
1378 and then Pack
/= Standard_Standard
1382 -- Visibility does not need to be checked in an instance: if the
1383 -- operator was not visible in the generic it has been diagnosed
1384 -- already, else there is an implicit copy of it in the instance.
1386 elsif In_Instance
then
1389 elsif Nam_In
(Op_Name
, Name_Op_Multiply
, Name_Op_Divide
)
1390 and then Is_Fixed_Point_Type
(Etype
(Left_Opnd
(Op_Node
)))
1391 and then Is_Fixed_Point_Type
(Etype
(Right_Opnd
(Op_Node
)))
1393 if Pack
/= Standard_Standard
then
1397 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
1400 elsif Ada_Version
>= Ada_2005
1401 and then Nam_In
(Op_Name
, Name_Op_Eq
, Name_Op_Ne
)
1402 and then Ekind
(Etype
(Act1
)) = E_Anonymous_Access_Type
1407 Opnd_Type
:= Base_Type
(Etype
(Right_Opnd
(Op_Node
)));
1409 if Op_Name
= Name_Op_Concat
then
1410 Opnd_Type
:= Base_Type
(Typ
);
1412 elsif (Scope
(Opnd_Type
) = Standard_Standard
1414 or else (Nkind
(Right_Opnd
(Op_Node
)) = N_Attribute_Reference
1416 and then not Comes_From_Source
(Opnd_Type
))
1418 Opnd_Type
:= Base_Type
(Etype
(Left_Opnd
(Op_Node
)));
1421 if Scope
(Opnd_Type
) = Standard_Standard
then
1423 -- Verify that the scope contains a type that corresponds to
1424 -- the given literal. Optimize the case where Pack is Standard.
1426 if Pack
/= Standard_Standard
then
1427 if Opnd_Type
= Universal_Integer
then
1428 Orig_Type
:= Type_In_P
(Is_Integer_Type
'Access);
1430 elsif Opnd_Type
= Universal_Real
then
1431 Orig_Type
:= Type_In_P
(Is_Real_Type
'Access);
1433 elsif Opnd_Type
= Any_String
then
1434 Orig_Type
:= Type_In_P
(Is_String_Type
'Access);
1436 elsif Opnd_Type
= Any_Access
then
1437 Orig_Type
:= Type_In_P
(Is_Definite_Access_Type
'Access);
1439 elsif Opnd_Type
= Any_Composite
then
1440 Orig_Type
:= Type_In_P
(Is_Composite_Type
'Access);
1442 if Present
(Orig_Type
) then
1443 if Has_Private_Component
(Orig_Type
) then
1446 Set_Etype
(Act1
, Orig_Type
);
1449 Set_Etype
(Act2
, Orig_Type
);
1458 Error
:= No
(Orig_Type
);
1461 elsif Ekind
(Opnd_Type
) = E_Allocator_Type
1462 and then No
(Type_In_P
(Is_Definite_Access_Type
'Access))
1466 -- If the type is defined elsewhere, and the operator is not
1467 -- defined in the given scope (by a renaming declaration, e.g.)
1468 -- then this is an error as well. If an extension of System is
1469 -- present, and the type may be defined there, Pack must be
1472 elsif Scope
(Opnd_Type
) /= Pack
1473 and then Scope
(Op_Id
) /= Pack
1474 and then (No
(System_Aux_Id
)
1475 or else Scope
(Opnd_Type
) /= System_Aux_Id
1476 or else Pack
/= Scope
(System_Aux_Id
))
1478 if not Is_Overloaded
(Right_Opnd
(Op_Node
)) then
1481 Error
:= not Operand_Type_In_Scope
(Pack
);
1484 elsif Pack
= Standard_Standard
1485 and then not Operand_Type_In_Scope
(Standard_Standard
)
1492 Error_Msg_Node_2
:= Pack
;
1494 ("& not declared in&", N
, Selector_Name
(Name
(N
)));
1495 Set_Etype
(N
, Any_Type
);
1498 -- Detect a mismatch between the context type and the result type
1499 -- in the named package, which is otherwise not detected if the
1500 -- operands are universal. Check is only needed if source entity is
1501 -- an operator, not a function that renames an operator.
1503 elsif Nkind
(Parent
(N
)) /= N_Type_Conversion
1504 and then Ekind
(Entity
(Name
(N
))) = E_Operator
1505 and then Is_Numeric_Type
(Typ
)
1506 and then not Is_Universal_Numeric_Type
(Typ
)
1507 and then Scope
(Base_Type
(Typ
)) /= Pack
1508 and then not In_Instance
1510 if Is_Fixed_Point_Type
(Typ
)
1511 and then Nam_In
(Op_Name
, Name_Op_Multiply
, Name_Op_Divide
)
1513 -- Already checked above
1517 -- Operator may be defined in an extension of System
1519 elsif Present
(System_Aux_Id
)
1520 and then Scope
(Opnd_Type
) = System_Aux_Id
1525 -- Could we use Wrong_Type here??? (this would require setting
1526 -- Etype (N) to the actual type found where Typ was expected).
1528 Error_Msg_NE
("expect }", N
, Typ
);
1533 Set_Chars
(Op_Node
, Op_Name
);
1535 if not Is_Private_Type
(Etype
(N
)) then
1536 Set_Etype
(Op_Node
, Base_Type
(Etype
(N
)));
1538 Set_Etype
(Op_Node
, Etype
(N
));
1541 -- If this is a call to a function that renames a predefined equality,
1542 -- the renaming declaration provides a type that must be used to
1543 -- resolve the operands. This must be done now because resolution of
1544 -- the equality node will not resolve any remaining ambiguity, and it
1545 -- assumes that the first operand is not overloaded.
1547 if Nam_In
(Op_Name
, Name_Op_Eq
, Name_Op_Ne
)
1548 and then Ekind
(Func
) = E_Function
1549 and then Is_Overloaded
(Act1
)
1551 Resolve
(Act1
, Base_Type
(Etype
(First_Formal
(Func
))));
1552 Resolve
(Act2
, Base_Type
(Etype
(First_Formal
(Func
))));
1555 Set_Entity
(Op_Node
, Op_Id
);
1556 Generate_Reference
(Op_Id
, N
, ' ');
1558 -- Do rewrite setting Comes_From_Source on the result if the original
1559 -- call came from source. Although it is not strictly the case that the
1560 -- operator as such comes from the source, logically it corresponds
1561 -- exactly to the function call in the source, so it should be marked
1562 -- this way (e.g. to make sure that validity checks work fine).
1565 CS
: constant Boolean := Comes_From_Source
(N
);
1567 Rewrite
(N
, Op_Node
);
1568 Set_Comes_From_Source
(N
, CS
);
1571 -- If this is an arithmetic operator and the result type is private,
1572 -- the operands and the result must be wrapped in conversion to
1573 -- expose the underlying numeric type and expand the proper checks,
1574 -- e.g. on division.
1576 if Is_Private_Type
(Typ
) then
1586 Resolve_Intrinsic_Operator
(N
, Typ
);
1592 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
1601 -- If in ASIS_Mode, propagate operand types to original actuals of
1602 -- function call, which would otherwise not be fully resolved. If
1603 -- the call has already been constant-folded, nothing to do. We
1604 -- relocate the operand nodes rather than copy them, to preserve
1605 -- original_node pointers, given that the operands themselves may
1606 -- have been rewritten. If the call was itself a rewriting of an
1607 -- operator node, nothing to do.
1610 and then Nkind
(N
) in N_Op
1611 and then Nkind
(Original_Node
(N
)) = N_Function_Call
1615 R
: constant Node_Id
:= Right_Opnd
(N
);
1617 Old_First
: constant Node_Id
:=
1618 First
(Parameter_Associations
(Original_Node
(N
)));
1624 Old_Sec
:= Next
(Old_First
);
1626 -- If the original call has named associations, replace the
1627 -- explicit actual parameter in the association with the proper
1628 -- resolved operand.
1630 if Nkind
(Old_First
) = N_Parameter_Association
then
1631 if Chars
(Selector_Name
(Old_First
)) =
1632 Chars
(First_Entity
(Op_Id
))
1634 Rewrite
(Explicit_Actual_Parameter
(Old_First
),
1637 Rewrite
(Explicit_Actual_Parameter
(Old_First
),
1642 Rewrite
(Old_First
, Relocate_Node
(L
));
1645 if Nkind
(Old_Sec
) = N_Parameter_Association
then
1646 if Chars
(Selector_Name
(Old_Sec
)) =
1647 Chars
(First_Entity
(Op_Id
))
1649 Rewrite
(Explicit_Actual_Parameter
(Old_Sec
),
1652 Rewrite
(Explicit_Actual_Parameter
(Old_Sec
),
1657 Rewrite
(Old_Sec
, Relocate_Node
(R
));
1661 if Nkind
(Old_First
) = N_Parameter_Association
then
1662 Rewrite
(Explicit_Actual_Parameter
(Old_First
),
1665 Rewrite
(Old_First
, Relocate_Node
(R
));
1670 Set_Parent
(Original_Node
(N
), Parent
(N
));
1672 end Make_Call_Into_Operator
;
1678 function Operator_Kind
1680 Is_Binary
: Boolean) return Node_Kind
1685 -- Use CASE statement or array???
1688 if Op_Name
= Name_Op_And
then
1690 elsif Op_Name
= Name_Op_Or
then
1692 elsif Op_Name
= Name_Op_Xor
then
1694 elsif Op_Name
= Name_Op_Eq
then
1696 elsif Op_Name
= Name_Op_Ne
then
1698 elsif Op_Name
= Name_Op_Lt
then
1700 elsif Op_Name
= Name_Op_Le
then
1702 elsif Op_Name
= Name_Op_Gt
then
1704 elsif Op_Name
= Name_Op_Ge
then
1706 elsif Op_Name
= Name_Op_Add
then
1708 elsif Op_Name
= Name_Op_Subtract
then
1709 Kind
:= N_Op_Subtract
;
1710 elsif Op_Name
= Name_Op_Concat
then
1711 Kind
:= N_Op_Concat
;
1712 elsif Op_Name
= Name_Op_Multiply
then
1713 Kind
:= N_Op_Multiply
;
1714 elsif Op_Name
= Name_Op_Divide
then
1715 Kind
:= N_Op_Divide
;
1716 elsif Op_Name
= Name_Op_Mod
then
1718 elsif Op_Name
= Name_Op_Rem
then
1720 elsif Op_Name
= Name_Op_Expon
then
1723 raise Program_Error
;
1729 if Op_Name
= Name_Op_Add
then
1731 elsif Op_Name
= Name_Op_Subtract
then
1733 elsif Op_Name
= Name_Op_Abs
then
1735 elsif Op_Name
= Name_Op_Not
then
1738 raise Program_Error
;
1745 ----------------------------
1746 -- Preanalyze_And_Resolve --
1747 ----------------------------
1749 procedure Preanalyze_And_Resolve
(N
: Node_Id
; T
: Entity_Id
) is
1750 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1753 Full_Analysis
:= False;
1754 Expander_Mode_Save_And_Set
(False);
1756 -- Normally, we suppress all checks for this preanalysis. There is no
1757 -- point in processing them now, since they will be applied properly
1758 -- and in the proper location when the default expressions reanalyzed
1759 -- and reexpanded later on. We will also have more information at that
1760 -- point for possible suppression of individual checks.
1762 -- However, in SPARK mode, most expansion is suppressed, and this
1763 -- later reanalysis and reexpansion may not occur. SPARK mode does
1764 -- require the setting of checking flags for proof purposes, so we
1765 -- do the SPARK preanalysis without suppressing checks.
1767 -- This special handling for SPARK mode is required for example in the
1768 -- case of Ada 2012 constructs such as quantified expressions, which are
1769 -- expanded in two separate steps.
1771 if GNATprove_Mode
then
1772 Analyze_And_Resolve
(N
, T
);
1774 Analyze_And_Resolve
(N
, T
, Suppress
=> All_Checks
);
1777 Expander_Mode_Restore
;
1778 Full_Analysis
:= Save_Full_Analysis
;
1779 end Preanalyze_And_Resolve
;
1781 -- Version without context type
1783 procedure Preanalyze_And_Resolve
(N
: Node_Id
) is
1784 Save_Full_Analysis
: constant Boolean := Full_Analysis
;
1787 Full_Analysis
:= False;
1788 Expander_Mode_Save_And_Set
(False);
1791 Resolve
(N
, Etype
(N
), Suppress
=> All_Checks
);
1793 Expander_Mode_Restore
;
1794 Full_Analysis
:= Save_Full_Analysis
;
1795 end Preanalyze_And_Resolve
;
1797 ----------------------------------
1798 -- Replace_Actual_Discriminants --
1799 ----------------------------------
1801 procedure Replace_Actual_Discriminants
(N
: Node_Id
; Default
: Node_Id
) is
1802 Loc
: constant Source_Ptr
:= Sloc
(N
);
1803 Tsk
: Node_Id
:= Empty
;
1805 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
;
1806 -- Comment needed???
1812 function Process_Discr
(Nod
: Node_Id
) return Traverse_Result
is
1816 if Nkind
(Nod
) = N_Identifier
then
1817 Ent
:= Entity
(Nod
);
1820 and then Ekind
(Ent
) = E_Discriminant
1823 Make_Selected_Component
(Loc
,
1824 Prefix
=> New_Copy_Tree
(Tsk
, New_Sloc
=> Loc
),
1825 Selector_Name
=> Make_Identifier
(Loc
, Chars
(Ent
))));
1827 Set_Etype
(Nod
, Etype
(Ent
));
1835 procedure Replace_Discrs
is new Traverse_Proc
(Process_Discr
);
1837 -- Start of processing for Replace_Actual_Discriminants
1840 if not Expander_Active
then
1844 if Nkind
(Name
(N
)) = N_Selected_Component
then
1845 Tsk
:= Prefix
(Name
(N
));
1847 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
1848 Tsk
:= Prefix
(Prefix
(Name
(N
)));
1854 Replace_Discrs
(Default
);
1856 end Replace_Actual_Discriminants
;
1862 procedure Resolve
(N
: Node_Id
; Typ
: Entity_Id
) is
1863 Ambiguous
: Boolean := False;
1864 Ctx_Type
: Entity_Id
:= Typ
;
1865 Expr_Type
: Entity_Id
:= Empty
; -- prevent junk warning
1866 Err_Type
: Entity_Id
:= Empty
;
1867 Found
: Boolean := False;
1870 I1
: Interp_Index
:= 0; -- prevent junk warning
1873 Seen
: Entity_Id
:= Empty
; -- prevent junk warning
1875 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean;
1876 -- Determine whether a node comes from a predefined library unit or
1879 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
);
1880 -- Try and fix up a literal so that it matches its expected type. New
1881 -- literals are manufactured if necessary to avoid cascaded errors.
1883 procedure Report_Ambiguous_Argument
;
1884 -- Additional diagnostics when an ambiguous call has an ambiguous
1885 -- argument (typically a controlling actual).
1887 procedure Resolution_Failed
;
1888 -- Called when attempt at resolving current expression fails
1890 ------------------------------------
1891 -- Comes_From_Predefined_Lib_Unit --
1892 -------------------------------------
1894 function Comes_From_Predefined_Lib_Unit
(Nod
: Node_Id
) return Boolean is
1897 Sloc
(Nod
) = Standard_Location
1898 or else Is_Predefined_File_Name
1899 (Unit_File_Name
(Get_Source_Unit
(Sloc
(Nod
))));
1900 end Comes_From_Predefined_Lib_Unit
;
1902 --------------------
1903 -- Patch_Up_Value --
1904 --------------------
1906 procedure Patch_Up_Value
(N
: Node_Id
; Typ
: Entity_Id
) is
1908 if Nkind
(N
) = N_Integer_Literal
and then Is_Real_Type
(Typ
) then
1910 Make_Real_Literal
(Sloc
(N
),
1911 Realval
=> UR_From_Uint
(Intval
(N
))));
1912 Set_Etype
(N
, Universal_Real
);
1913 Set_Is_Static_Expression
(N
);
1915 elsif Nkind
(N
) = N_Real_Literal
and then Is_Integer_Type
(Typ
) then
1917 Make_Integer_Literal
(Sloc
(N
),
1918 Intval
=> UR_To_Uint
(Realval
(N
))));
1919 Set_Etype
(N
, Universal_Integer
);
1920 Set_Is_Static_Expression
(N
);
1922 elsif Nkind
(N
) = N_String_Literal
1923 and then Is_Character_Type
(Typ
)
1925 Set_Character_Literal_Name
(Char_Code
(Character'Pos ('A')));
1927 Make_Character_Literal
(Sloc
(N
),
1929 Char_Literal_Value
=>
1930 UI_From_Int
(Character'Pos ('A'))));
1931 Set_Etype
(N
, Any_Character
);
1932 Set_Is_Static_Expression
(N
);
1934 elsif Nkind
(N
) /= N_String_Literal
and then Is_String_Type
(Typ
) then
1936 Make_String_Literal
(Sloc
(N
),
1937 Strval
=> End_String
));
1939 elsif Nkind
(N
) = N_Range
then
1940 Patch_Up_Value
(Low_Bound
(N
), Typ
);
1941 Patch_Up_Value
(High_Bound
(N
), Typ
);
1945 -------------------------------
1946 -- Report_Ambiguous_Argument --
1947 -------------------------------
1949 procedure Report_Ambiguous_Argument
is
1950 Arg
: constant Node_Id
:= First
(Parameter_Associations
(N
));
1955 if Nkind
(Arg
) = N_Function_Call
1956 and then Is_Entity_Name
(Name
(Arg
))
1957 and then Is_Overloaded
(Name
(Arg
))
1959 Error_Msg_NE
("ambiguous call to&", Arg
, Name
(Arg
));
1961 -- Could use comments on what is going on here???
1963 Get_First_Interp
(Name
(Arg
), I
, It
);
1964 while Present
(It
.Nam
) loop
1965 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
1967 if Nkind
(Parent
(It
.Nam
)) = N_Full_Type_Declaration
then
1968 Error_Msg_N
("interpretation (inherited) #!", Arg
);
1970 Error_Msg_N
("interpretation #!", Arg
);
1973 Get_Next_Interp
(I
, It
);
1976 end Report_Ambiguous_Argument
;
1978 -----------------------
1979 -- Resolution_Failed --
1980 -----------------------
1982 procedure Resolution_Failed
is
1984 Patch_Up_Value
(N
, Typ
);
1986 -- Set the type to the desired one to minimize cascaded errors. Note
1987 -- that this is an approximation and does not work in all cases.
1991 Debug_A_Exit
("resolving ", N
, " (done, resolution failed)");
1992 Set_Is_Overloaded
(N
, False);
1994 -- The caller will return without calling the expander, so we need
1995 -- to set the analyzed flag. Note that it is fine to set Analyzed
1996 -- to True even if we are in the middle of a shallow analysis,
1997 -- (see the spec of sem for more details) since this is an error
1998 -- situation anyway, and there is no point in repeating the
1999 -- analysis later (indeed it won't work to repeat it later, since
2000 -- we haven't got a clear resolution of which entity is being
2003 Set_Analyzed
(N
, True);
2005 end Resolution_Failed
;
2007 -- Start of processing for Resolve
2014 -- Access attribute on remote subprogram cannot be used for a non-remote
2015 -- access-to-subprogram type.
2017 if Nkind
(N
) = N_Attribute_Reference
2018 and then Nam_In
(Attribute_Name
(N
), Name_Access
,
2019 Name_Unrestricted_Access
,
2020 Name_Unchecked_Access
)
2021 and then Comes_From_Source
(N
)
2022 and then Is_Entity_Name
(Prefix
(N
))
2023 and then Is_Subprogram
(Entity
(Prefix
(N
)))
2024 and then Is_Remote_Call_Interface
(Entity
(Prefix
(N
)))
2025 and then not Is_Remote_Access_To_Subprogram_Type
(Typ
)
2028 ("prefix must statically denote a non-remote subprogram", N
);
2031 From_Lib
:= Comes_From_Predefined_Lib_Unit
(N
);
2033 -- If the context is a Remote_Access_To_Subprogram, access attributes
2034 -- must be resolved with the corresponding fat pointer. There is no need
2035 -- to check for the attribute name since the return type of an
2036 -- attribute is never a remote type.
2038 if Nkind
(N
) = N_Attribute_Reference
2039 and then Comes_From_Source
(N
)
2040 and then (Is_Remote_Call_Interface
(Typ
) or else Is_Remote_Types
(Typ
))
2043 Attr
: constant Attribute_Id
:=
2044 Get_Attribute_Id
(Attribute_Name
(N
));
2045 Pref
: constant Node_Id
:= Prefix
(N
);
2048 Is_Remote
: Boolean := True;
2051 -- Check that Typ is a remote access-to-subprogram type
2053 if Is_Remote_Access_To_Subprogram_Type
(Typ
) then
2055 -- Prefix (N) must statically denote a remote subprogram
2056 -- declared in a package specification.
2058 if Attr
= Attribute_Access
or else
2059 Attr
= Attribute_Unchecked_Access
or else
2060 Attr
= Attribute_Unrestricted_Access
2062 Decl
:= Unit_Declaration_Node
(Entity
(Pref
));
2064 if Nkind
(Decl
) = N_Subprogram_Body
then
2065 Spec
:= Corresponding_Spec
(Decl
);
2067 if Present
(Spec
) then
2068 Decl
:= Unit_Declaration_Node
(Spec
);
2072 Spec
:= Parent
(Decl
);
2074 if not Is_Entity_Name
(Prefix
(N
))
2075 or else Nkind
(Spec
) /= N_Package_Specification
2077 not Is_Remote_Call_Interface
(Defining_Entity
(Spec
))
2081 ("prefix must statically denote a remote subprogram ",
2085 -- If we are generating code in distributed mode, perform
2086 -- semantic checks against corresponding remote entities.
2089 and then Get_PCS_Name
/= Name_No_DSA
2091 Check_Subtype_Conformant
2092 (New_Id
=> Entity
(Prefix
(N
)),
2093 Old_Id
=> Designated_Type
2094 (Corresponding_Remote_Type
(Typ
)),
2098 Process_Remote_AST_Attribute
(N
, Typ
);
2106 Debug_A_Entry
("resolving ", N
);
2108 if Debug_Flag_V
then
2109 Write_Overloads
(N
);
2112 if Comes_From_Source
(N
) then
2113 if Is_Fixed_Point_Type
(Typ
) then
2114 Check_Restriction
(No_Fixed_Point
, N
);
2116 elsif Is_Floating_Point_Type
(Typ
)
2117 and then Typ
/= Universal_Real
2118 and then Typ
/= Any_Real
2120 Check_Restriction
(No_Floating_Point
, N
);
2124 -- Return if already analyzed
2126 if Analyzed
(N
) then
2127 Debug_A_Exit
("resolving ", N
, " (done, already analyzed)");
2128 Analyze_Dimension
(N
);
2131 -- Any case of Any_Type as the Etype value means that we had a
2134 elsif Etype
(N
) = Any_Type
then
2135 Debug_A_Exit
("resolving ", N
, " (done, Etype = Any_Type)");
2139 Check_Parameterless_Call
(N
);
2141 -- The resolution of an Expression_With_Actions is determined by
2144 if Nkind
(N
) = N_Expression_With_Actions
then
2145 Resolve
(Expression
(N
), Typ
);
2148 Expr_Type
:= Etype
(Expression
(N
));
2150 -- If not overloaded, then we know the type, and all that needs doing
2151 -- is to check that this type is compatible with the context.
2153 elsif not Is_Overloaded
(N
) then
2154 Found
:= Covers
(Typ
, Etype
(N
));
2155 Expr_Type
:= Etype
(N
);
2157 -- In the overloaded case, we must select the interpretation that
2158 -- is compatible with the context (i.e. the type passed to Resolve)
2161 -- Loop through possible interpretations
2163 Get_First_Interp
(N
, I
, It
);
2164 Interp_Loop
: while Present
(It
.Typ
) loop
2165 if Debug_Flag_V
then
2166 Write_Str
("Interp: ");
2170 -- We are only interested in interpretations that are compatible
2171 -- with the expected type, any other interpretations are ignored.
2173 if not Covers
(Typ
, It
.Typ
) then
2174 if Debug_Flag_V
then
2175 Write_Str
(" interpretation incompatible with context");
2180 -- Skip the current interpretation if it is disabled by an
2181 -- abstract operator. This action is performed only when the
2182 -- type against which we are resolving is the same as the
2183 -- type of the interpretation.
2185 if Ada_Version
>= Ada_2005
2186 and then It
.Typ
= Typ
2187 and then Typ
/= Universal_Integer
2188 and then Typ
/= Universal_Real
2189 and then Present
(It
.Abstract_Op
)
2191 if Debug_Flag_V
then
2192 Write_Line
("Skip.");
2198 -- First matching interpretation
2204 Expr_Type
:= It
.Typ
;
2206 -- Matching interpretation that is not the first, maybe an
2207 -- error, but there are some cases where preference rules are
2208 -- used to choose between the two possibilities. These and
2209 -- some more obscure cases are handled in Disambiguate.
2212 -- If the current statement is part of a predefined library
2213 -- unit, then all interpretations which come from user level
2214 -- packages should not be considered. Check previous and
2218 if not Comes_From_Predefined_Lib_Unit
(It
.Nam
) then
2221 elsif not Comes_From_Predefined_Lib_Unit
(Seen
) then
2223 -- Previous interpretation must be discarded
2227 Expr_Type
:= It
.Typ
;
2228 Set_Entity
(N
, Seen
);
2233 -- Otherwise apply further disambiguation steps
2235 Error_Msg_Sloc
:= Sloc
(Seen
);
2236 It1
:= Disambiguate
(N
, I1
, I
, Typ
);
2238 -- Disambiguation has succeeded. Skip the remaining
2241 if It1
/= No_Interp
then
2243 Expr_Type
:= It1
.Typ
;
2245 while Present
(It
.Typ
) loop
2246 Get_Next_Interp
(I
, It
);
2250 -- Before we issue an ambiguity complaint, check for the
2251 -- case of a subprogram call where at least one of the
2252 -- arguments is Any_Type, and if so suppress the message,
2253 -- since it is a cascaded error. This can also happen for
2254 -- a generalized indexing operation.
2256 if Nkind
(N
) in N_Subprogram_Call
2257 or else (Nkind
(N
) = N_Indexed_Component
2258 and then Present
(Generalized_Indexing
(N
)))
2265 if Nkind
(N
) = N_Indexed_Component
then
2266 Rewrite
(N
, Generalized_Indexing
(N
));
2269 A
:= First_Actual
(N
);
2270 while Present
(A
) loop
2273 if Nkind
(E
) = N_Parameter_Association
then
2274 E
:= Explicit_Actual_Parameter
(E
);
2277 if Etype
(E
) = Any_Type
then
2278 if Debug_Flag_V
then
2279 Write_Str
("Any_Type in call");
2290 elsif Nkind
(N
) in N_Binary_Op
2291 and then (Etype
(Left_Opnd
(N
)) = Any_Type
2292 or else Etype
(Right_Opnd
(N
)) = Any_Type
)
2296 elsif Nkind
(N
) in N_Unary_Op
2297 and then Etype
(Right_Opnd
(N
)) = Any_Type
2302 -- Not that special case, so issue message using the flag
2303 -- Ambiguous to control printing of the header message
2304 -- only at the start of an ambiguous set.
2306 if not Ambiguous
then
2307 if Nkind
(N
) = N_Function_Call
2308 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2311 ("ambiguous expression (cannot resolve indirect "
2314 Error_Msg_NE
-- CODEFIX
2315 ("ambiguous expression (cannot resolve&)!",
2321 if Nkind
(Parent
(Seen
)) = N_Full_Type_Declaration
then
2323 ("\\possible interpretation (inherited)#!", N
);
2325 Error_Msg_N
-- CODEFIX
2326 ("\\possible interpretation#!", N
);
2329 if Nkind
(N
) in N_Subprogram_Call
2330 and then Present
(Parameter_Associations
(N
))
2332 Report_Ambiguous_Argument
;
2336 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2338 -- By default, the error message refers to the candidate
2339 -- interpretation. But if it is a predefined operator, it
2340 -- is implicitly declared at the declaration of the type
2341 -- of the operand. Recover the sloc of that declaration
2342 -- for the error message.
2344 if Nkind
(N
) in N_Op
2345 and then Scope
(It
.Nam
) = Standard_Standard
2346 and then not Is_Overloaded
(Right_Opnd
(N
))
2347 and then Scope
(Base_Type
(Etype
(Right_Opnd
(N
)))) /=
2350 Err_Type
:= First_Subtype
(Etype
(Right_Opnd
(N
)));
2352 if Comes_From_Source
(Err_Type
)
2353 and then Present
(Parent
(Err_Type
))
2355 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2358 elsif Nkind
(N
) in N_Binary_Op
2359 and then Scope
(It
.Nam
) = Standard_Standard
2360 and then not Is_Overloaded
(Left_Opnd
(N
))
2361 and then Scope
(Base_Type
(Etype
(Left_Opnd
(N
)))) /=
2364 Err_Type
:= First_Subtype
(Etype
(Left_Opnd
(N
)));
2366 if Comes_From_Source
(Err_Type
)
2367 and then Present
(Parent
(Err_Type
))
2369 Error_Msg_Sloc
:= Sloc
(Parent
(Err_Type
));
2372 -- If this is an indirect call, use the subprogram_type
2373 -- in the message, to have a meaningful location. Also
2374 -- indicate if this is an inherited operation, created
2375 -- by a type declaration.
2377 elsif Nkind
(N
) = N_Function_Call
2378 and then Nkind
(Name
(N
)) = N_Explicit_Dereference
2379 and then Is_Type
(It
.Nam
)
2383 Sloc
(Associated_Node_For_Itype
(Err_Type
));
2388 if Nkind
(N
) in N_Op
2389 and then Scope
(It
.Nam
) = Standard_Standard
2390 and then Present
(Err_Type
)
2392 -- Special-case the message for universal_fixed
2393 -- operators, which are not declared with the type
2394 -- of the operand, but appear forever in Standard.
2396 if It
.Typ
= Universal_Fixed
2397 and then Scope
(It
.Nam
) = Standard_Standard
2400 ("\\possible interpretation as universal_fixed "
2401 & "operation (RM 4.5.5 (19))", N
);
2404 ("\\possible interpretation (predefined)#!", N
);
2408 Nkind
(Parent
(It
.Nam
)) = N_Full_Type_Declaration
2411 ("\\possible interpretation (inherited)#!", N
);
2413 Error_Msg_N
-- CODEFIX
2414 ("\\possible interpretation#!", N
);
2420 -- We have a matching interpretation, Expr_Type is the type
2421 -- from this interpretation, and Seen is the entity.
2423 -- For an operator, just set the entity name. The type will be
2424 -- set by the specific operator resolution routine.
2426 if Nkind
(N
) in N_Op
then
2427 Set_Entity
(N
, Seen
);
2428 Generate_Reference
(Seen
, N
);
2430 elsif Nkind
(N
) = N_Case_Expression
then
2431 Set_Etype
(N
, Expr_Type
);
2433 elsif Nkind
(N
) = N_Character_Literal
then
2434 Set_Etype
(N
, Expr_Type
);
2436 elsif Nkind
(N
) = N_If_Expression
then
2437 Set_Etype
(N
, Expr_Type
);
2439 -- AI05-0139-2: Expression is overloaded because type has
2440 -- implicit dereference. If type matches context, no implicit
2441 -- dereference is involved.
2443 elsif Has_Implicit_Dereference
(Expr_Type
) then
2444 Set_Etype
(N
, Expr_Type
);
2445 Set_Is_Overloaded
(N
, False);
2448 elsif Is_Overloaded
(N
)
2449 and then Present
(It
.Nam
)
2450 and then Ekind
(It
.Nam
) = E_Discriminant
2451 and then Has_Implicit_Dereference
(It
.Nam
)
2453 -- If the node is a general indexing, the dereference is
2454 -- is inserted when resolving the rewritten form, else
2457 if Nkind
(N
) /= N_Indexed_Component
2458 or else No
(Generalized_Indexing
(N
))
2460 Build_Explicit_Dereference
(N
, It
.Nam
);
2463 -- For an explicit dereference, attribute reference, range,
2464 -- short-circuit form (which is not an operator node), or call
2465 -- with a name that is an explicit dereference, there is
2466 -- nothing to be done at this point.
2468 elsif Nkind_In
(N
, N_Attribute_Reference
,
2470 N_Explicit_Dereference
,
2472 N_Indexed_Component
,
2475 N_Selected_Component
,
2477 or else Nkind
(Name
(N
)) = N_Explicit_Dereference
2481 -- For procedure or function calls, set the type of the name,
2482 -- and also the entity pointer for the prefix.
2484 elsif Nkind
(N
) in N_Subprogram_Call
2485 and then Is_Entity_Name
(Name
(N
))
2487 Set_Etype
(Name
(N
), Expr_Type
);
2488 Set_Entity
(Name
(N
), Seen
);
2489 Generate_Reference
(Seen
, Name
(N
));
2491 elsif Nkind
(N
) = N_Function_Call
2492 and then Nkind
(Name
(N
)) = N_Selected_Component
2494 Set_Etype
(Name
(N
), Expr_Type
);
2495 Set_Entity
(Selector_Name
(Name
(N
)), Seen
);
2496 Generate_Reference
(Seen
, Selector_Name
(Name
(N
)));
2498 -- For all other cases, just set the type of the Name
2501 Set_Etype
(Name
(N
), Expr_Type
);
2508 -- Move to next interpretation
2510 exit Interp_Loop
when No
(It
.Typ
);
2512 Get_Next_Interp
(I
, It
);
2513 end loop Interp_Loop
;
2516 -- At this stage Found indicates whether or not an acceptable
2517 -- interpretation exists. If not, then we have an error, except that if
2518 -- the context is Any_Type as a result of some other error, then we
2519 -- suppress the error report.
2522 if Typ
/= Any_Type
then
2524 -- If type we are looking for is Void, then this is the procedure
2525 -- call case, and the error is simply that what we gave is not a
2526 -- procedure name (we think of procedure calls as expressions with
2527 -- types internally, but the user doesn't think of them this way).
2529 if Typ
= Standard_Void_Type
then
2531 -- Special case message if function used as a procedure
2533 if Nkind
(N
) = N_Procedure_Call_Statement
2534 and then Is_Entity_Name
(Name
(N
))
2535 and then Ekind
(Entity
(Name
(N
))) = E_Function
2538 ("cannot use function & in a procedure call",
2539 Name
(N
), Entity
(Name
(N
)));
2541 -- Otherwise give general message (not clear what cases this
2542 -- covers, but no harm in providing for them).
2545 Error_Msg_N
("expect procedure name in procedure call", N
);
2550 -- Otherwise we do have a subexpression with the wrong type
2552 -- Check for the case of an allocator which uses an access type
2553 -- instead of the designated type. This is a common error and we
2554 -- specialize the message, posting an error on the operand of the
2555 -- allocator, complaining that we expected the designated type of
2558 elsif Nkind
(N
) = N_Allocator
2559 and then Is_Access_Type
(Typ
)
2560 and then Is_Access_Type
(Etype
(N
))
2561 and then Designated_Type
(Etype
(N
)) = Typ
2563 Wrong_Type
(Expression
(N
), Designated_Type
(Typ
));
2566 -- Check for view mismatch on Null in instances, for which the
2567 -- view-swapping mechanism has no identifier.
2569 elsif (In_Instance
or else In_Inlined_Body
)
2570 and then (Nkind
(N
) = N_Null
)
2571 and then Is_Private_Type
(Typ
)
2572 and then Is_Access_Type
(Full_View
(Typ
))
2574 Resolve
(N
, Full_View
(Typ
));
2578 -- Check for an aggregate. Sometimes we can get bogus aggregates
2579 -- from misuse of parentheses, and we are about to complain about
2580 -- the aggregate without even looking inside it.
2582 -- Instead, if we have an aggregate of type Any_Composite, then
2583 -- analyze and resolve the component fields, and then only issue
2584 -- another message if we get no errors doing this (otherwise
2585 -- assume that the errors in the aggregate caused the problem).
2587 elsif Nkind
(N
) = N_Aggregate
2588 and then Etype
(N
) = Any_Composite
2590 -- Disable expansion in any case. If there is a type mismatch
2591 -- it may be fatal to try to expand the aggregate. The flag
2592 -- would otherwise be set to false when the error is posted.
2594 Expander_Active
:= False;
2597 procedure Check_Aggr
(Aggr
: Node_Id
);
2598 -- Check one aggregate, and set Found to True if we have a
2599 -- definite error in any of its elements
2601 procedure Check_Elmt
(Aelmt
: Node_Id
);
2602 -- Check one element of aggregate and set Found to True if
2603 -- we definitely have an error in the element.
2609 procedure Check_Aggr
(Aggr
: Node_Id
) is
2613 if Present
(Expressions
(Aggr
)) then
2614 Elmt
:= First
(Expressions
(Aggr
));
2615 while Present
(Elmt
) loop
2621 if Present
(Component_Associations
(Aggr
)) then
2622 Elmt
:= First
(Component_Associations
(Aggr
));
2623 while Present
(Elmt
) loop
2625 -- If this is a default-initialized component, then
2626 -- there is nothing to check. The box will be
2627 -- replaced by the appropriate call during late
2630 if Nkind
(Elmt
) /= N_Iterated_Component_Association
2631 and then not Box_Present
(Elmt
)
2633 Check_Elmt
(Expression
(Elmt
));
2645 procedure Check_Elmt
(Aelmt
: Node_Id
) is
2647 -- If we have a nested aggregate, go inside it (to
2648 -- attempt a naked analyze-resolve of the aggregate can
2649 -- cause undesirable cascaded errors). Do not resolve
2650 -- expression if it needs a type from context, as for
2651 -- integer * fixed expression.
2653 if Nkind
(Aelmt
) = N_Aggregate
then
2659 if not Is_Overloaded
(Aelmt
)
2660 and then Etype
(Aelmt
) /= Any_Fixed
2665 if Etype
(Aelmt
) = Any_Type
then
2676 -- Looks like we have a type error, but check for special case
2677 -- of Address wanted, integer found, with the configuration pragma
2678 -- Allow_Integer_Address active. If we have this case, introduce
2679 -- an unchecked conversion to allow the integer expression to be
2680 -- treated as an Address. The reverse case of integer wanted,
2681 -- Address found, is treated in an analogous manner.
2683 if Address_Integer_Convert_OK
(Typ
, Etype
(N
)) then
2684 Rewrite
(N
, Unchecked_Convert_To
(Typ
, Relocate_Node
(N
)));
2685 Analyze_And_Resolve
(N
, Typ
);
2688 -- Under relaxed RM semantics silently replace occurrences of null
2689 -- by System.Address_Null.
2691 elsif Null_To_Null_Address_Convert_OK
(N
, Typ
) then
2692 Replace_Null_By_Null_Address
(N
);
2693 Analyze_And_Resolve
(N
, Typ
);
2697 -- That special Allow_Integer_Address check did not apply, so we
2698 -- have a real type error. If an error message was issued already,
2699 -- Found got reset to True, so if it's still False, issue standard
2700 -- Wrong_Type message.
2703 if Is_Overloaded
(N
) and then Nkind
(N
) = N_Function_Call
then
2705 Subp_Name
: Node_Id
;
2708 if Is_Entity_Name
(Name
(N
)) then
2709 Subp_Name
:= Name
(N
);
2711 elsif Nkind
(Name
(N
)) = N_Selected_Component
then
2713 -- Protected operation: retrieve operation name
2715 Subp_Name
:= Selector_Name
(Name
(N
));
2718 raise Program_Error
;
2721 Error_Msg_Node_2
:= Typ
;
2723 ("no visible interpretation of& matches expected type&",
2727 if All_Errors_Mode
then
2729 Index
: Interp_Index
;
2733 Error_Msg_N
("\\possible interpretations:", N
);
2735 Get_First_Interp
(Name
(N
), Index
, It
);
2736 while Present
(It
.Nam
) loop
2737 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
2738 Error_Msg_Node_2
:= It
.Nam
;
2740 ("\\ type& for & declared#", N
, It
.Typ
);
2741 Get_Next_Interp
(Index
, It
);
2746 Error_Msg_N
("\use -gnatf for details", N
);
2750 Wrong_Type
(N
, Typ
);
2758 -- Test if we have more than one interpretation for the context
2760 elsif Ambiguous
then
2764 -- Only one intepretation
2767 -- In Ada 2005, if we have something like "X : T := 2 + 2;", where
2768 -- the "+" on T is abstract, and the operands are of universal type,
2769 -- the above code will have (incorrectly) resolved the "+" to the
2770 -- universal one in Standard. Therefore check for this case and give
2771 -- an error. We can't do this earlier, because it would cause legal
2772 -- cases to get errors (when some other type has an abstract "+").
2774 if Ada_Version
>= Ada_2005
2775 and then Nkind
(N
) in N_Op
2776 and then Is_Overloaded
(N
)
2777 and then Is_Universal_Numeric_Type
(Etype
(Entity
(N
)))
2779 Get_First_Interp
(N
, I
, It
);
2780 while Present
(It
.Typ
) loop
2781 if Present
(It
.Abstract_Op
) and then
2782 Etype
(It
.Abstract_Op
) = Typ
2785 ("cannot call abstract subprogram &!", N
, It
.Abstract_Op
);
2789 Get_Next_Interp
(I
, It
);
2793 -- Here we have an acceptable interpretation for the context
2795 -- Propagate type information and normalize tree for various
2796 -- predefined operations. If the context only imposes a class of
2797 -- types, rather than a specific type, propagate the actual type
2800 if Typ
= Any_Integer
or else
2801 Typ
= Any_Boolean
or else
2802 Typ
= Any_Modular
or else
2803 Typ
= Any_Real
or else
2806 Ctx_Type
:= Expr_Type
;
2808 -- Any_Fixed is legal in a real context only if a specific fixed-
2809 -- point type is imposed. If Norman Cohen can be confused by this,
2810 -- it deserves a separate message.
2813 and then Expr_Type
= Any_Fixed
2815 Error_Msg_N
("illegal context for mixed mode operation", N
);
2816 Set_Etype
(N
, Universal_Real
);
2817 Ctx_Type
:= Universal_Real
;
2821 -- A user-defined operator is transformed into a function call at
2822 -- this point, so that further processing knows that operators are
2823 -- really operators (i.e. are predefined operators). User-defined
2824 -- operators that are intrinsic are just renamings of the predefined
2825 -- ones, and need not be turned into calls either, but if they rename
2826 -- a different operator, we must transform the node accordingly.
2827 -- Instantiations of Unchecked_Conversion are intrinsic but are
2828 -- treated as functions, even if given an operator designator.
2830 if Nkind
(N
) in N_Op
2831 and then Present
(Entity
(N
))
2832 and then Ekind
(Entity
(N
)) /= E_Operator
2834 if not Is_Predefined_Op
(Entity
(N
)) then
2835 Rewrite_Operator_As_Call
(N
, Entity
(N
));
2837 elsif Present
(Alias
(Entity
(N
)))
2839 Nkind
(Parent
(Parent
(Entity
(N
)))) =
2840 N_Subprogram_Renaming_Declaration
2842 Rewrite_Renamed_Operator
(N
, Alias
(Entity
(N
)), Typ
);
2844 -- If the node is rewritten, it will be fully resolved in
2845 -- Rewrite_Renamed_Operator.
2847 if Analyzed
(N
) then
2853 case N_Subexpr
'(Nkind (N)) is
2855 Resolve_Aggregate (N, Ctx_Type);
2858 Resolve_Allocator (N, Ctx_Type);
2860 when N_Short_Circuit =>
2861 Resolve_Short_Circuit (N, Ctx_Type);
2863 when N_Attribute_Reference =>
2864 Resolve_Attribute (N, Ctx_Type);
2866 when N_Case_Expression =>
2867 Resolve_Case_Expression (N, Ctx_Type);
2869 when N_Character_Literal =>
2870 Resolve_Character_Literal (N, Ctx_Type);
2872 when N_Expanded_Name =>
2873 Resolve_Entity_Name (N, Ctx_Type);
2875 when N_Explicit_Dereference =>
2876 Resolve_Explicit_Dereference (N, Ctx_Type);
2878 when N_Expression_With_Actions =>
2879 Resolve_Expression_With_Actions (N, Ctx_Type);
2881 when N_Extension_Aggregate =>
2882 Resolve_Extension_Aggregate (N, Ctx_Type);
2884 when N_Function_Call =>
2885 Resolve_Call (N, Ctx_Type);
2887 when N_Identifier =>
2888 Resolve_Entity_Name (N, Ctx_Type);
2890 when N_If_Expression =>
2891 Resolve_If_Expression (N, Ctx_Type);
2893 when N_Indexed_Component =>
2894 Resolve_Indexed_Component (N, Ctx_Type);
2896 when N_Integer_Literal =>
2897 Resolve_Integer_Literal (N, Ctx_Type);
2899 when N_Membership_Test =>
2900 Resolve_Membership_Op (N, Ctx_Type);
2903 Resolve_Null (N, Ctx_Type);
2909 Resolve_Logical_Op (N, Ctx_Type);
2914 Resolve_Equality_Op (N, Ctx_Type);
2921 Resolve_Comparison_Op (N, Ctx_Type);
2924 Resolve_Op_Not (N, Ctx_Type);
2933 Resolve_Arithmetic_Op (N, Ctx_Type);
2936 Resolve_Op_Concat (N, Ctx_Type);
2939 Resolve_Op_Expon (N, Ctx_Type);
2945 Resolve_Unary_Op (N, Ctx_Type);
2948 Resolve_Shift (N, Ctx_Type);
2950 when N_Procedure_Call_Statement =>
2951 Resolve_Call (N, Ctx_Type);
2953 when N_Operator_Symbol =>
2954 Resolve_Operator_Symbol (N, Ctx_Type);
2956 when N_Qualified_Expression =>
2957 Resolve_Qualified_Expression (N, Ctx_Type);
2959 -- Why is the following null, needs a comment ???
2961 when N_Quantified_Expression =>
2964 when N_Raise_Expression =>
2965 Resolve_Raise_Expression (N, Ctx_Type);
2967 when N_Raise_xxx_Error =>
2968 Set_Etype (N, Ctx_Type);
2971 Resolve_Range (N, Ctx_Type);
2973 when N_Real_Literal =>
2974 Resolve_Real_Literal (N, Ctx_Type);
2977 Resolve_Reference (N, Ctx_Type);
2979 when N_Selected_Component =>
2980 Resolve_Selected_Component (N, Ctx_Type);
2983 Resolve_Slice (N, Ctx_Type);
2985 when N_String_Literal =>
2986 Resolve_String_Literal (N, Ctx_Type);
2988 when N_Type_Conversion =>
2989 Resolve_Type_Conversion (N, Ctx_Type);
2991 when N_Unchecked_Expression =>
2992 Resolve_Unchecked_Expression (N, Ctx_Type);
2994 when N_Unchecked_Type_Conversion =>
2995 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
2998 -- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
2999 -- expression of an anonymous access type that occurs in the context
3000 -- of a named general access type, except when the expression is that
3001 -- of a membership test. This ensures proper legality checking in
3002 -- terms of allowed conversions (expressions that would be illegal to
3003 -- convert implicitly are allowed in membership tests).
3005 if Ada_Version >= Ada_2012
3006 and then Ekind (Ctx_Type) = E_General_Access_Type
3007 and then Ekind (Etype (N)) = E_Anonymous_Access_Type
3008 and then Nkind (Parent (N)) not in N_Membership_Test
3010 Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
3011 Analyze_And_Resolve (N, Ctx_Type);
3014 -- If the subexpression was replaced by a non-subexpression, then
3015 -- all we do is to expand it. The only legitimate case we know of
3016 -- is converting procedure call statement to entry call statements,
3017 -- but there may be others, so we are making this test general.
3019 if Nkind (N) not in N_Subexpr then
3020 Debug_A_Exit ("resolving ", N, " (done)");
3025 -- The expression is definitely NOT overloaded at this point, so
3026 -- we reset the Is_Overloaded flag to avoid any confusion when
3027 -- reanalyzing the node.
3029 Set_Is_Overloaded (N, False);
3031 -- Freeze expression type, entity if it is a name, and designated
3032 -- type if it is an allocator (RM 13.14(10,11,13)).
3034 -- Now that the resolution of the type of the node is complete, and
3035 -- we did not detect an error, we can expand this node. We skip the
3036 -- expand call if we are in a default expression, see section
3037 -- "Handling of Default Expressions" in Sem spec.
3039 Debug_A_Exit ("resolving ", N, " (done)");
3041 -- We unconditionally freeze the expression, even if we are in
3042 -- default expression mode (the Freeze_Expression routine tests this
3043 -- flag and only freezes static types if it is set).
3045 -- Ada 2012 (AI05-177): The declaration of an expression function
3046 -- does not cause freezing, but we never reach here in that case.
3047 -- Here we are resolving the corresponding expanded body, so we do
3048 -- need to perform normal freezing.
3050 Freeze_Expression (N);
3052 -- Now we can do the expansion
3062 -- Version with check(s) suppressed
3064 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
3066 if Suppress = All_Checks then
3068 Sva : constant Suppress_Array := Scope_Suppress.Suppress;
3070 Scope_Suppress.Suppress := (others => True);
3072 Scope_Suppress.Suppress := Sva;
3077 Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
3079 Scope_Suppress.Suppress (Suppress) := True;
3081 Scope_Suppress.Suppress (Suppress) := Svg;
3090 -- Version with implicit type
3092 procedure Resolve (N : Node_Id) is
3094 Resolve (N, Etype (N));
3097 ---------------------
3098 -- Resolve_Actuals --
3099 ---------------------
3101 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
3102 Loc : constant Source_Ptr := Sloc (N);
3108 Prev : Node_Id := Empty;
3112 Real_Subp : Entity_Id;
3113 -- If the subprogram being called is an inherited operation for
3114 -- a formal derived type in an instance, Real_Subp is the subprogram
3115 -- that will be called. It may have different formal names than the
3116 -- operation of the formal in the generic, so after actual is resolved
3117 -- the name of the actual in a named association must carry the name
3118 -- of the actual of the subprogram being called.
3120 procedure Check_Aliased_Parameter;
3121 -- Check rules on aliased parameters and related accessibility rules
3122 -- in (RM 3.10.2 (10.2-10.4)).
3124 procedure Check_Argument_Order;
3125 -- Performs a check for the case where the actuals are all simple
3126 -- identifiers that correspond to the formal names, but in the wrong
3127 -- order, which is considered suspicious and cause for a warning.
3129 procedure Check_Prefixed_Call;
3130 -- If the original node is an overloaded call in prefix notation,
3131 -- insert an 'Access or a dereference as needed over the first actual
.
3132 -- Try_Object_Operation has already verified that there is a valid
3133 -- interpretation, but the form of the actual can only be determined
3134 -- once the primitive operation is identified.
3136 procedure Flag_Effectively_Volatile_Objects
(Expr
: Node_Id
);
3137 -- Emit an error concerning the illegal usage of an effectively volatile
3138 -- object in interfering context (SPARK RM 7.13(12)).
3140 procedure Insert_Default
;
3141 -- If the actual is missing in a call, insert in the actuals list
3142 -- an instance of the default expression. The insertion is always
3143 -- a named association.
3145 procedure Property_Error
3148 Prop_Nam
: Name_Id
);
3149 -- Emit an error concerning variable Var with entity Var_Id that has
3150 -- enabled property Prop_Nam when it acts as an actual parameter in a
3151 -- call and the corresponding formal parameter is of mode IN.
3153 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean;
3154 -- Check whether T1 and T2, or their full views, are derived from a
3155 -- common type. Used to enforce the restrictions on array conversions
3158 function Static_Concatenation
(N
: Node_Id
) return Boolean;
3159 -- Predicate to determine whether an actual that is a concatenation
3160 -- will be evaluated statically and does not need a transient scope.
3161 -- This must be determined before the actual is resolved and expanded
3162 -- because if needed the transient scope must be introduced earlier.
3164 -----------------------------
3165 -- Check_Aliased_Parameter --
3166 -----------------------------
3168 procedure Check_Aliased_Parameter
is
3169 Nominal_Subt
: Entity_Id
;
3172 if Is_Aliased
(F
) then
3173 if Is_Tagged_Type
(A_Typ
) then
3176 elsif Is_Aliased_View
(A
) then
3177 if Is_Constr_Subt_For_U_Nominal
(A_Typ
) then
3178 Nominal_Subt
:= Base_Type
(A_Typ
);
3180 Nominal_Subt
:= A_Typ
;
3183 if Subtypes_Statically_Match
(F_Typ
, Nominal_Subt
) then
3186 -- In a generic body assume the worst for generic formals:
3187 -- they can have a constrained partial view (AI05-041).
3189 elsif Has_Discriminants
(F_Typ
)
3190 and then not Is_Constrained
(F_Typ
)
3191 and then not Has_Constrained_Partial_View
(F_Typ
)
3192 and then not Is_Generic_Type
(F_Typ
)
3197 Error_Msg_NE
("untagged actual does not match "
3198 & "aliased formal&", A
, F
);
3202 Error_Msg_NE
("actual for aliased formal& must be "
3203 & "aliased object", A
, F
);
3206 if Ekind
(Nam
) = E_Procedure
then
3209 elsif Ekind
(Etype
(Nam
)) = E_Anonymous_Access_Type
then
3210 if Nkind
(Parent
(N
)) = N_Type_Conversion
3211 and then Type_Access_Level
(Etype
(Parent
(N
))) <
3212 Object_Access_Level
(A
)
3214 Error_Msg_N
("aliased actual has wrong accessibility", A
);
3217 elsif Nkind
(Parent
(N
)) = N_Qualified_Expression
3218 and then Nkind
(Parent
(Parent
(N
))) = N_Allocator
3219 and then Type_Access_Level
(Etype
(Parent
(Parent
(N
)))) <
3220 Object_Access_Level
(A
)
3223 ("aliased actual in allocator has wrong accessibility", A
);
3226 end Check_Aliased_Parameter
;
3228 --------------------------
3229 -- Check_Argument_Order --
3230 --------------------------
3232 procedure Check_Argument_Order
is
3234 -- Nothing to do if no parameters, or original node is neither a
3235 -- function call nor a procedure call statement (happens in the
3236 -- operator-transformed-to-function call case), or the call does
3237 -- not come from source, or this warning is off.
3239 if not Warn_On_Parameter_Order
3240 or else No
(Parameter_Associations
(N
))
3241 or else Nkind
(Original_Node
(N
)) not in N_Subprogram_Call
3242 or else not Comes_From_Source
(N
)
3248 Nargs
: constant Nat
:= List_Length
(Parameter_Associations
(N
));
3251 -- Nothing to do if only one parameter
3257 -- Here if at least two arguments
3260 Actuals
: array (1 .. Nargs
) of Node_Id
;
3264 Wrong_Order
: Boolean := False;
3265 -- Set True if an out of order case is found
3268 -- Collect identifier names of actuals, fail if any actual is
3269 -- not a simple identifier, and record max length of name.
3271 Actual
:= First
(Parameter_Associations
(N
));
3272 for J
in Actuals
'Range loop
3273 if Nkind
(Actual
) /= N_Identifier
then
3276 Actuals
(J
) := Actual
;
3281 -- If we got this far, all actuals are identifiers and the list
3282 -- of their names is stored in the Actuals array.
3284 Formal
:= First_Formal
(Nam
);
3285 for J
in Actuals
'Range loop
3287 -- If we ran out of formals, that's odd, probably an error
3288 -- which will be detected elsewhere, but abandon the search.
3294 -- If name matches and is in order OK
3296 if Chars
(Formal
) = Chars
(Actuals
(J
)) then
3300 -- If no match, see if it is elsewhere in list and if so
3301 -- flag potential wrong order if type is compatible.
3303 for K
in Actuals
'Range loop
3304 if Chars
(Formal
) = Chars
(Actuals
(K
))
3306 Has_Compatible_Type
(Actuals
(K
), Etype
(Formal
))
3308 Wrong_Order
:= True;
3318 <<Continue
>> Next_Formal
(Formal
);
3321 -- If Formals left over, also probably an error, skip warning
3323 if Present
(Formal
) then
3327 -- Here we give the warning if something was out of order
3331 ("?P?actuals for this call may be in wrong order", N
);
3335 end Check_Argument_Order
;
3337 -------------------------
3338 -- Check_Prefixed_Call --
3339 -------------------------
3341 procedure Check_Prefixed_Call
is
3342 Act
: constant Node_Id
:= First_Actual
(N
);
3343 A_Type
: constant Entity_Id
:= Etype
(Act
);
3344 F_Type
: constant Entity_Id
:= Etype
(First_Formal
(Nam
));
3345 Orig
: constant Node_Id
:= Original_Node
(N
);
3349 -- Check whether the call is a prefixed call, with or without
3350 -- additional actuals.
3352 if Nkind
(Orig
) = N_Selected_Component
3354 (Nkind
(Orig
) = N_Indexed_Component
3355 and then Nkind
(Prefix
(Orig
)) = N_Selected_Component
3356 and then Is_Entity_Name
(Prefix
(Prefix
(Orig
)))
3357 and then Is_Entity_Name
(Act
)
3358 and then Chars
(Act
) = Chars
(Prefix
(Prefix
(Orig
))))
3360 if Is_Access_Type
(A_Type
)
3361 and then not Is_Access_Type
(F_Type
)
3363 -- Introduce dereference on object in prefix
3366 Make_Explicit_Dereference
(Sloc
(Act
),
3367 Prefix
=> Relocate_Node
(Act
));
3368 Rewrite
(Act
, New_A
);
3371 elsif Is_Access_Type
(F_Type
)
3372 and then not Is_Access_Type
(A_Type
)
3374 -- Introduce an implicit 'Access in prefix
3376 if not Is_Aliased_View
(Act
) then
3378 ("object in prefixed call to& must be aliased "
3379 & "(RM 4.1.3 (13 1/2))",
3384 Make_Attribute_Reference
(Loc
,
3385 Attribute_Name
=> Name_Access
,
3386 Prefix
=> Relocate_Node
(Act
)));
3391 end Check_Prefixed_Call
;
3393 ---------------------------------------
3394 -- Flag_Effectively_Volatile_Objects --
3395 ---------------------------------------
3397 procedure Flag_Effectively_Volatile_Objects
(Expr
: Node_Id
) is
3398 function Flag_Object
(N
: Node_Id
) return Traverse_Result
;
3399 -- Determine whether arbitrary node N denotes an effectively volatile
3400 -- object and if it does, emit an error.
3406 function Flag_Object
(N
: Node_Id
) return Traverse_Result
is
3410 -- Do not consider nested function calls because they have already
3411 -- been processed during their own resolution.
3413 if Nkind
(N
) = N_Function_Call
then
3416 elsif Is_Entity_Name
(N
) and then Present
(Entity
(N
)) then
3420 and then Is_Effectively_Volatile
(Id
)
3421 and then (Async_Writers_Enabled
(Id
)
3422 or else Effective_Reads_Enabled
(Id
))
3425 ("volatile object cannot appear in this context (SPARK "
3426 & "RM 7.1.3(11))", N
);
3434 procedure Flag_Objects
is new Traverse_Proc
(Flag_Object
);
3436 -- Start of processing for Flag_Effectively_Volatile_Objects
3439 Flag_Objects
(Expr
);
3440 end Flag_Effectively_Volatile_Objects
;
3442 --------------------
3443 -- Insert_Default --
3444 --------------------
3446 procedure Insert_Default
is
3451 -- Missing argument in call, nothing to insert
3453 if No
(Default_Value
(F
)) then
3457 -- Note that we do a full New_Copy_Tree, so that any associated
3458 -- Itypes are properly copied. This may not be needed any more,
3459 -- but it does no harm as a safety measure. Defaults of a generic
3460 -- formal may be out of bounds of the corresponding actual (see
3461 -- cc1311b) and an additional check may be required.
3466 New_Scope
=> Current_Scope
,
3469 -- Propagate dimension information, if any.
3471 Copy_Dimensions
(Default_Value
(F
), Actval
);
3473 if Is_Concurrent_Type
(Scope
(Nam
))
3474 and then Has_Discriminants
(Scope
(Nam
))
3476 Replace_Actual_Discriminants
(N
, Actval
);
3479 if Is_Overloadable
(Nam
)
3480 and then Present
(Alias
(Nam
))
3482 if Base_Type
(Etype
(F
)) /= Base_Type
(Etype
(Actval
))
3483 and then not Is_Tagged_Type
(Etype
(F
))
3485 -- If default is a real literal, do not introduce a
3486 -- conversion whose effect may depend on the run-time
3487 -- size of universal real.
3489 if Nkind
(Actval
) = N_Real_Literal
then
3490 Set_Etype
(Actval
, Base_Type
(Etype
(F
)));
3492 Actval
:= Unchecked_Convert_To
(Etype
(F
), Actval
);
3496 if Is_Scalar_Type
(Etype
(F
)) then
3497 Enable_Range_Check
(Actval
);
3500 Set_Parent
(Actval
, N
);
3502 -- Resolve aggregates with their base type, to avoid scope
3503 -- anomalies: the subtype was first built in the subprogram
3504 -- declaration, and the current call may be nested.
3506 if Nkind
(Actval
) = N_Aggregate
then
3507 Analyze_And_Resolve
(Actval
, Etype
(F
));
3509 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3513 Set_Parent
(Actval
, N
);
3515 -- See note above concerning aggregates
3517 if Nkind
(Actval
) = N_Aggregate
3518 and then Has_Discriminants
(Etype
(Actval
))
3520 Analyze_And_Resolve
(Actval
, Base_Type
(Etype
(Actval
)));
3522 -- Resolve entities with their own type, which may differ from
3523 -- the type of a reference in a generic context (the view
3524 -- swapping mechanism did not anticipate the re-analysis of
3525 -- default values in calls).
3527 elsif Is_Entity_Name
(Actval
) then
3528 Analyze_And_Resolve
(Actval
, Etype
(Entity
(Actval
)));
3531 Analyze_And_Resolve
(Actval
, Etype
(Actval
));
3535 -- If default is a tag indeterminate function call, propagate tag
3536 -- to obtain proper dispatching.
3538 if Is_Controlling_Formal
(F
)
3539 and then Nkind
(Default_Value
(F
)) = N_Function_Call
3541 Set_Is_Controlling_Actual
(Actval
);
3545 -- If the default expression raises constraint error, then just
3546 -- silently replace it with an N_Raise_Constraint_Error node, since
3547 -- we already gave the warning on the subprogram spec. If node is
3548 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3549 -- the warnings removal machinery.
3551 if Raises_Constraint_Error
(Actval
)
3552 and then Nkind
(Actval
) /= N_Raise_Constraint_Error
3555 Make_Raise_Constraint_Error
(Loc
,
3556 Reason
=> CE_Range_Check_Failed
));
3557 Set_Raises_Constraint_Error
(Actval
);
3558 Set_Etype
(Actval
, Etype
(F
));
3562 Make_Parameter_Association
(Loc
,
3563 Explicit_Actual_Parameter
=> Actval
,
3564 Selector_Name
=> Make_Identifier
(Loc
, Chars
(F
)));
3566 -- Case of insertion is first named actual
3568 if No
(Prev
) or else
3569 Nkind
(Parent
(Prev
)) /= N_Parameter_Association
3571 Set_Next_Named_Actual
(Assoc
, First_Named_Actual
(N
));
3572 Set_First_Named_Actual
(N
, Actval
);
3575 if No
(Parameter_Associations
(N
)) then
3576 Set_Parameter_Associations
(N
, New_List
(Assoc
));
3578 Append
(Assoc
, Parameter_Associations
(N
));
3582 Insert_After
(Prev
, Assoc
);
3585 -- Case of insertion is not first named actual
3588 Set_Next_Named_Actual
3589 (Assoc
, Next_Named_Actual
(Parent
(Prev
)));
3590 Set_Next_Named_Actual
(Parent
(Prev
), Actval
);
3591 Append
(Assoc
, Parameter_Associations
(N
));
3594 Mark_Rewrite_Insertion
(Assoc
);
3595 Mark_Rewrite_Insertion
(Actval
);
3600 --------------------
3601 -- Property_Error --
3602 --------------------
3604 procedure Property_Error
3610 Error_Msg_Name_1
:= Prop_Nam
;
3612 ("external variable & with enabled property % cannot appear as "
3613 & "actual in procedure call (SPARK RM 7.1.3(10))", Var
, Var_Id
);
3614 Error_Msg_N
("\\corresponding formal parameter has mode In", Var
);
3621 function Same_Ancestor
(T1
, T2
: Entity_Id
) return Boolean is
3622 FT1
: Entity_Id
:= T1
;
3623 FT2
: Entity_Id
:= T2
;
3626 if Is_Private_Type
(T1
)
3627 and then Present
(Full_View
(T1
))
3629 FT1
:= Full_View
(T1
);
3632 if Is_Private_Type
(T2
)
3633 and then Present
(Full_View
(T2
))
3635 FT2
:= Full_View
(T2
);
3638 return Root_Type
(Base_Type
(FT1
)) = Root_Type
(Base_Type
(FT2
));
3641 --------------------------
3642 -- Static_Concatenation --
3643 --------------------------
3645 function Static_Concatenation
(N
: Node_Id
) return Boolean is
3648 when N_String_Literal
=>
3653 -- Concatenation is static when both operands are static and
3654 -- the concatenation operator is a predefined one.
3656 return Scope
(Entity
(N
)) = Standard_Standard
3658 Static_Concatenation
(Left_Opnd
(N
))
3660 Static_Concatenation
(Right_Opnd
(N
));
3663 if Is_Entity_Name
(N
) then
3665 Ent
: constant Entity_Id
:= Entity
(N
);
3667 return Ekind
(Ent
) = E_Constant
3668 and then Present
(Constant_Value
(Ent
))
3670 Is_OK_Static_Expression
(Constant_Value
(Ent
));
3677 end Static_Concatenation
;
3679 -- Start of processing for Resolve_Actuals
3682 Check_Argument_Order
;
3684 if Is_Overloadable
(Nam
)
3685 and then Is_Inherited_Operation
(Nam
)
3686 and then In_Instance
3687 and then Present
(Alias
(Nam
))
3688 and then Present
(Overridden_Operation
(Alias
(Nam
)))
3690 Real_Subp
:= Alias
(Nam
);
3695 if Present
(First_Actual
(N
)) then
3696 Check_Prefixed_Call
;
3699 A
:= First_Actual
(N
);
3700 F
:= First_Formal
(Nam
);
3702 if Present
(Real_Subp
) then
3703 Real_F
:= First_Formal
(Real_Subp
);
3706 while Present
(F
) loop
3707 if No
(A
) and then Needs_No_Actuals
(Nam
) then
3710 -- If we have an error in any actual or formal, indicated by a type
3711 -- of Any_Type, then abandon resolution attempt, and set result type
3712 -- to Any_Type. Skip this if the actual is a Raise_Expression, whose
3713 -- type is imposed from context.
3715 elsif (Present
(A
) and then Etype
(A
) = Any_Type
)
3716 or else Etype
(F
) = Any_Type
3718 if Nkind
(A
) /= N_Raise_Expression
then
3719 Set_Etype
(N
, Any_Type
);
3724 -- Case where actual is present
3726 -- If the actual is an entity, generate a reference to it now. We
3727 -- do this before the actual is resolved, because a formal of some
3728 -- protected subprogram, or a task discriminant, will be rewritten
3729 -- during expansion, and the source entity reference may be lost.
3732 and then Is_Entity_Name
(A
)
3733 and then Comes_From_Source
(A
)
3735 Orig_A
:= Entity
(A
);
3737 if Present
(Orig_A
) then
3738 if Is_Formal
(Orig_A
)
3739 and then Ekind
(F
) /= E_In_Parameter
3741 Generate_Reference
(Orig_A
, A
, 'm');
3743 elsif not Is_Overloaded
(A
) then
3744 if Ekind
(F
) /= E_Out_Parameter
then
3745 Generate_Reference
(Orig_A
, A
);
3747 -- RM 6.4.1(12): For an out parameter that is passed by
3748 -- copy, the formal parameter object is created, and:
3750 -- * For an access type, the formal parameter is initialized
3751 -- from the value of the actual, without checking that the
3752 -- value satisfies any constraint, any predicate, or any
3753 -- exclusion of the null value.
3755 -- * For a scalar type that has the Default_Value aspect
3756 -- specified, the formal parameter is initialized from the
3757 -- value of the actual, without checking that the value
3758 -- satisfies any constraint or any predicate.
3759 -- I do not understand why this case is included??? this is
3760 -- not a case where an OUT parameter is treated as IN OUT.
3762 -- * For a composite type with discriminants or that has
3763 -- implicit initial values for any subcomponents, the
3764 -- behavior is as for an in out parameter passed by copy.
3766 -- Hence for these cases we generate the read reference now
3767 -- (the write reference will be generated later by
3768 -- Note_Possible_Modification).
3770 elsif Is_By_Copy_Type
(Etype
(F
))
3772 (Is_Access_Type
(Etype
(F
))
3774 (Is_Scalar_Type
(Etype
(F
))
3776 Present
(Default_Aspect_Value
(Etype
(F
))))
3778 (Is_Composite_Type
(Etype
(F
))
3779 and then (Has_Discriminants
(Etype
(F
))
3780 or else Is_Partially_Initialized_Type
3783 Generate_Reference
(Orig_A
, A
);
3790 and then (Nkind
(Parent
(A
)) /= N_Parameter_Association
3791 or else Chars
(Selector_Name
(Parent
(A
))) = Chars
(F
))
3793 -- If style checking mode on, check match of formal name
3796 if Nkind
(Parent
(A
)) = N_Parameter_Association
then
3797 Check_Identifier
(Selector_Name
(Parent
(A
)), F
);
3801 -- If the formal is Out or In_Out, do not resolve and expand the
3802 -- conversion, because it is subsequently expanded into explicit
3803 -- temporaries and assignments. However, the object of the
3804 -- conversion can be resolved. An exception is the case of tagged
3805 -- type conversion with a class-wide actual. In that case we want
3806 -- the tag check to occur and no temporary will be needed (no
3807 -- representation change can occur) and the parameter is passed by
3808 -- reference, so we go ahead and resolve the type conversion.
3809 -- Another exception is the case of reference to component or
3810 -- subcomponent of a bit-packed array, in which case we want to
3811 -- defer expansion to the point the in and out assignments are
3814 if Ekind
(F
) /= E_In_Parameter
3815 and then Nkind
(A
) = N_Type_Conversion
3816 and then not Is_Class_Wide_Type
(Etype
(Expression
(A
)))
3818 if Ekind
(F
) = E_In_Out_Parameter
3819 and then Is_Array_Type
(Etype
(F
))
3821 -- In a view conversion, the conversion must be legal in
3822 -- both directions, and thus both component types must be
3823 -- aliased, or neither (4.6 (8)).
3825 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3826 -- the privacy requirement should not apply to generic
3827 -- types, and should be checked in an instance. ARG query
3830 if Has_Aliased_Components
(Etype
(Expression
(A
))) /=
3831 Has_Aliased_Components
(Etype
(F
))
3834 ("both component types in a view conversion must be"
3835 & " aliased, or neither", A
);
3837 -- Comment here??? what set of cases???
3840 not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3842 -- Check view conv between unrelated by ref array types
3844 if Is_By_Reference_Type
(Etype
(F
))
3845 or else Is_By_Reference_Type
(Etype
(Expression
(A
)))
3848 ("view conversion between unrelated by reference "
3849 & "array types not allowed (\'A'I-00246)", A
);
3851 -- In Ada 2005 mode, check view conversion component
3852 -- type cannot be private, tagged, or volatile. Note
3853 -- that we only apply this to source conversions. The
3854 -- generated code can contain conversions which are
3855 -- not subject to this test, and we cannot extract the
3856 -- component type in such cases since it is not present.
3858 elsif Comes_From_Source
(A
)
3859 and then Ada_Version
>= Ada_2005
3862 Comp_Type
: constant Entity_Id
:=
3864 (Etype
(Expression
(A
)));
3866 if (Is_Private_Type
(Comp_Type
)
3867 and then not Is_Generic_Type
(Comp_Type
))
3868 or else Is_Tagged_Type
(Comp_Type
)
3869 or else Is_Volatile
(Comp_Type
)
3872 ("component type of a view conversion cannot"
3873 & " be private, tagged, or volatile"
3882 -- Resolve expression if conversion is all OK
3884 if (Conversion_OK
(A
)
3885 or else Valid_Conversion
(A
, Etype
(A
), Expression
(A
)))
3886 and then not Is_Ref_To_Bit_Packed_Array
(Expression
(A
))
3888 Resolve
(Expression
(A
));
3891 -- If the actual is a function call that returns a limited
3892 -- unconstrained object that needs finalization, create a
3893 -- transient scope for it, so that it can receive the proper
3894 -- finalization list.
3896 elsif Nkind
(A
) = N_Function_Call
3897 and then Is_Limited_Record
(Etype
(F
))
3898 and then not Is_Constrained
(Etype
(F
))
3899 and then Expander_Active
3900 and then (Is_Controlled
(Etype
(F
)) or else Has_Task
(Etype
(F
)))
3902 Establish_Transient_Scope
(A
, Sec_Stack
=> False);
3903 Resolve
(A
, Etype
(F
));
3905 -- A small optimization: if one of the actuals is a concatenation
3906 -- create a block around a procedure call to recover stack space.
3907 -- This alleviates stack usage when several procedure calls in
3908 -- the same statement list use concatenation. We do not perform
3909 -- this wrapping for code statements, where the argument is a
3910 -- static string, and we want to preserve warnings involving
3911 -- sequences of such statements.
3913 elsif Nkind
(A
) = N_Op_Concat
3914 and then Nkind
(N
) = N_Procedure_Call_Statement
3915 and then Expander_Active
3917 not (Is_Intrinsic_Subprogram
(Nam
)
3918 and then Chars
(Nam
) = Name_Asm
)
3919 and then not Static_Concatenation
(A
)
3921 Establish_Transient_Scope
(A
, Sec_Stack
=> False);
3922 Resolve
(A
, Etype
(F
));
3925 if Nkind
(A
) = N_Type_Conversion
3926 and then Is_Array_Type
(Etype
(F
))
3927 and then not Same_Ancestor
(Etype
(F
), Etype
(Expression
(A
)))
3929 (Is_Limited_Type
(Etype
(F
))
3930 or else Is_Limited_Type
(Etype
(Expression
(A
))))
3933 ("conversion between unrelated limited array types "
3934 & "not allowed ('A'I-00246)", A
);
3936 if Is_Limited_Type
(Etype
(F
)) then
3937 Explain_Limited_Type
(Etype
(F
), A
);
3940 if Is_Limited_Type
(Etype
(Expression
(A
))) then
3941 Explain_Limited_Type
(Etype
(Expression
(A
)), A
);
3945 -- (Ada 2005: AI-251): If the actual is an allocator whose
3946 -- directly designated type is a class-wide interface, we build
3947 -- an anonymous access type to use it as the type of the
3948 -- allocator. Later, when the subprogram call is expanded, if
3949 -- the interface has a secondary dispatch table the expander
3950 -- will add a type conversion to force the correct displacement
3953 if Nkind
(A
) = N_Allocator
then
3955 DDT
: constant Entity_Id
:=
3956 Directly_Designated_Type
(Base_Type
(Etype
(F
)));
3958 New_Itype
: Entity_Id
;
3961 if Is_Class_Wide_Type
(DDT
)
3962 and then Is_Interface
(DDT
)
3964 New_Itype
:= Create_Itype
(E_Anonymous_Access_Type
, A
);
3965 Set_Etype
(New_Itype
, Etype
(A
));
3966 Set_Directly_Designated_Type
3967 (New_Itype
, Directly_Designated_Type
(Etype
(A
)));
3968 Set_Etype
(A
, New_Itype
);
3971 -- Ada 2005, AI-162:If the actual is an allocator, the
3972 -- innermost enclosing statement is the master of the
3973 -- created object. This needs to be done with expansion
3974 -- enabled only, otherwise the transient scope will not
3975 -- be removed in the expansion of the wrapped construct.
3977 if (Is_Controlled
(DDT
) or else Has_Task
(DDT
))
3978 and then Expander_Active
3980 Establish_Transient_Scope
(A
, Sec_Stack
=> False);
3984 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
3985 Check_Restriction
(No_Access_Parameter_Allocators
, A
);
3989 -- (Ada 2005): The call may be to a primitive operation of a
3990 -- tagged synchronized type, declared outside of the type. In
3991 -- this case the controlling actual must be converted to its
3992 -- corresponding record type, which is the formal type. The
3993 -- actual may be a subtype, either because of a constraint or
3994 -- because it is a generic actual, so use base type to locate
3997 F_Typ
:= Base_Type
(Etype
(F
));
3999 if Is_Tagged_Type
(F_Typ
)
4000 and then (Is_Concurrent_Type
(F_Typ
)
4001 or else Is_Concurrent_Record_Type
(F_Typ
))
4003 -- If the actual is overloaded, look for an interpretation
4004 -- that has a synchronized type.
4006 if not Is_Overloaded
(A
) then
4007 A_Typ
:= Base_Type
(Etype
(A
));
4011 Index
: Interp_Index
;
4015 Get_First_Interp
(A
, Index
, It
);
4016 while Present
(It
.Typ
) loop
4017 if Is_Concurrent_Type
(It
.Typ
)
4018 or else Is_Concurrent_Record_Type
(It
.Typ
)
4020 A_Typ
:= Base_Type
(It
.Typ
);
4024 Get_Next_Interp
(Index
, It
);
4030 Full_A_Typ
: Entity_Id
;
4033 if Present
(Full_View
(A_Typ
)) then
4034 Full_A_Typ
:= Base_Type
(Full_View
(A_Typ
));
4036 Full_A_Typ
:= A_Typ
;
4039 -- Tagged synchronized type (case 1): the actual is a
4042 if Is_Concurrent_Type
(A_Typ
)
4043 and then Corresponding_Record_Type
(A_Typ
) = F_Typ
4046 Unchecked_Convert_To
4047 (Corresponding_Record_Type
(A_Typ
), A
));
4048 Resolve
(A
, Etype
(F
));
4050 -- Tagged synchronized type (case 2): the formal is a
4053 elsif Ekind
(Full_A_Typ
) = E_Record_Type
4055 (Corresponding_Concurrent_Type
(Full_A_Typ
))
4056 and then Is_Concurrent_Type
(F_Typ
)
4057 and then Present
(Corresponding_Record_Type
(F_Typ
))
4058 and then Full_A_Typ
= Corresponding_Record_Type
(F_Typ
)
4060 Resolve
(A
, Corresponding_Record_Type
(F_Typ
));
4065 Resolve
(A
, Etype
(F
));
4069 -- Not a synchronized operation
4072 Resolve
(A
, Etype
(F
));
4079 -- An actual cannot be an untagged formal incomplete type
4081 if Ekind
(A_Typ
) = E_Incomplete_Type
4082 and then not Is_Tagged_Type
(A_Typ
)
4083 and then Is_Generic_Type
(A_Typ
)
4086 ("invalid use of untagged formal incomplete type", A
);
4089 if Comes_From_Source
(Original_Node
(N
))
4090 and then Nkind_In
(Original_Node
(N
), N_Function_Call
,
4091 N_Procedure_Call_Statement
)
4093 -- In formal mode, check that actual parameters matching
4094 -- formals of tagged types are objects (or ancestor type
4095 -- conversions of objects), not general expressions.
4097 if Is_Actual_Tagged_Parameter
(A
) then
4098 if Is_SPARK_05_Object_Reference
(A
) then
4101 elsif Nkind
(A
) = N_Type_Conversion
then
4103 Operand
: constant Node_Id
:= Expression
(A
);
4104 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
4105 Target_Typ
: constant Entity_Id
:= A_Typ
;
4108 if not Is_SPARK_05_Object_Reference
(Operand
) then
4109 Check_SPARK_05_Restriction
4110 ("object required", Operand
);
4112 -- In formal mode, the only view conversions are those
4113 -- involving ancestor conversion of an extended type.
4116 (Is_Tagged_Type
(Target_Typ
)
4117 and then not Is_Class_Wide_Type
(Target_Typ
)
4118 and then Is_Tagged_Type
(Operand_Typ
)
4119 and then not Is_Class_Wide_Type
(Operand_Typ
)
4120 and then Is_Ancestor
(Target_Typ
, Operand_Typ
))
4123 (F
, E_Out_Parameter
, E_In_Out_Parameter
)
4125 Check_SPARK_05_Restriction
4126 ("ancestor conversion is the only permitted "
4127 & "view conversion", A
);
4129 Check_SPARK_05_Restriction
4130 ("ancestor conversion required", A
);
4139 Check_SPARK_05_Restriction
("object required", A
);
4142 -- In formal mode, the only view conversions are those
4143 -- involving ancestor conversion of an extended type.
4145 elsif Nkind
(A
) = N_Type_Conversion
4146 and then Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
4148 Check_SPARK_05_Restriction
4149 ("ancestor conversion is the only permitted view "
4154 -- has warnings suppressed, then we reset Never_Set_In_Source for
4155 -- the calling entity. The reason for this is to catch cases like
4156 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
4157 -- uses trickery to modify an IN parameter.
4159 if Ekind
(F
) = E_In_Parameter
4160 and then Is_Entity_Name
(A
)
4161 and then Present
(Entity
(A
))
4162 and then Ekind
(Entity
(A
)) = E_Variable
4163 and then Has_Warnings_Off
(F_Typ
)
4165 Set_Never_Set_In_Source
(Entity
(A
), False);
4168 -- Perform error checks for IN and IN OUT parameters
4170 if Ekind
(F
) /= E_Out_Parameter
then
4172 -- Check unset reference. For scalar parameters, it is clearly
4173 -- wrong to pass an uninitialized value as either an IN or
4174 -- IN-OUT parameter. For composites, it is also clearly an
4175 -- error to pass a completely uninitialized value as an IN
4176 -- parameter, but the case of IN OUT is trickier. We prefer
4177 -- not to give a warning here. For example, suppose there is
4178 -- a routine that sets some component of a record to False.
4179 -- It is perfectly reasonable to make this IN-OUT and allow
4180 -- either initialized or uninitialized records to be passed
4183 -- For partially initialized composite values, we also avoid
4184 -- warnings, since it is quite likely that we are passing a
4185 -- partially initialized value and only the initialized fields
4186 -- will in fact be read in the subprogram.
4188 if Is_Scalar_Type
(A_Typ
)
4189 or else (Ekind
(F
) = E_In_Parameter
4190 and then not Is_Partially_Initialized_Type
(A_Typ
))
4192 Check_Unset_Reference
(A
);
4195 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
4196 -- actual to a nested call, since this constitutes a reading of
4197 -- the parameter, which is not allowed.
4199 if Ada_Version
= Ada_83
4200 and then Is_Entity_Name
(A
)
4201 and then Ekind
(Entity
(A
)) = E_Out_Parameter
4203 Error_Msg_N
("(Ada 83) illegal reading of out parameter", A
);
4207 -- Case of OUT or IN OUT parameter
4209 if Ekind
(F
) /= E_In_Parameter
then
4211 -- For an Out parameter, check for useless assignment. Note
4212 -- that we can't set Last_Assignment this early, because we may
4213 -- kill current values in Resolve_Call, and that call would
4214 -- clobber the Last_Assignment field.
4216 -- Note: call Warn_On_Useless_Assignment before doing the check
4217 -- below for Is_OK_Variable_For_Out_Formal so that the setting
4218 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
4219 -- reflects the last assignment, not this one.
4221 if Ekind
(F
) = E_Out_Parameter
then
4222 if Warn_On_Modified_As_Out_Parameter
(F
)
4223 and then Is_Entity_Name
(A
)
4224 and then Present
(Entity
(A
))
4225 and then Comes_From_Source
(N
)
4227 Warn_On_Useless_Assignment
(Entity
(A
), A
);
4231 -- Validate the form of the actual. Note that the call to
4232 -- Is_OK_Variable_For_Out_Formal generates the required
4233 -- reference in this case.
4235 -- A call to an initialization procedure for an aggregate
4236 -- component may initialize a nested component of a constant
4237 -- designated object. In this context the object is variable.
4239 if not Is_OK_Variable_For_Out_Formal
(A
)
4240 and then not Is_Init_Proc
(Nam
)
4242 Error_Msg_NE
("actual for& must be a variable", A
, F
);
4244 if Is_Subprogram
(Current_Scope
) then
4245 if Is_Invariant_Procedure
(Current_Scope
)
4246 or else Is_Partial_Invariant_Procedure
(Current_Scope
)
4249 ("function used in invariant cannot modify its "
4252 elsif Is_Predicate_Function
(Current_Scope
) then
4254 ("function used in predicate cannot modify its "
4260 -- What's the following about???
4262 if Is_Entity_Name
(A
) then
4263 Kill_Checks
(Entity
(A
));
4269 if Etype
(A
) = Any_Type
then
4270 Set_Etype
(N
, Any_Type
);
4274 -- Apply appropriate constraint/predicate checks for IN [OUT] case
4276 if Ekind_In
(F
, E_In_Parameter
, E_In_Out_Parameter
) then
4278 -- Apply predicate tests except in certain special cases. Note
4279 -- that it might be more consistent to apply these only when
4280 -- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
4281 -- for the outbound predicate tests ??? In any case indicate
4282 -- the function being called, for better warnings if the call
4283 -- leads to an infinite recursion.
4285 if Predicate_Tests_On_Arguments
(Nam
) then
4286 Apply_Predicate_Check
(A
, F_Typ
, Nam
);
4289 -- Apply required constraint checks
4291 -- Gigi looks at the check flag and uses the appropriate types.
4292 -- For now since one flag is used there is an optimization
4293 -- which might not be done in the IN OUT case since Gigi does
4294 -- not do any analysis. More thought required about this ???
4296 -- In fact is this comment obsolete??? doesn't the expander now
4297 -- generate all these tests anyway???
4299 if Is_Scalar_Type
(Etype
(A
)) then
4300 Apply_Scalar_Range_Check
(A
, F_Typ
);
4302 elsif Is_Array_Type
(Etype
(A
)) then
4303 Apply_Length_Check
(A
, F_Typ
);
4305 elsif Is_Record_Type
(F_Typ
)
4306 and then Has_Discriminants
(F_Typ
)
4307 and then Is_Constrained
(F_Typ
)
4308 and then (not Is_Derived_Type
(F_Typ
)
4309 or else Comes_From_Source
(Nam
))
4311 Apply_Discriminant_Check
(A
, F_Typ
);
4313 -- For view conversions of a discriminated object, apply
4314 -- check to object itself, the conversion alreay has the
4317 if Nkind
(A
) = N_Type_Conversion
4318 and then Is_Constrained
(Etype
(Expression
(A
)))
4320 Apply_Discriminant_Check
(Expression
(A
), F_Typ
);
4323 elsif Is_Access_Type
(F_Typ
)
4324 and then Is_Array_Type
(Designated_Type
(F_Typ
))
4325 and then Is_Constrained
(Designated_Type
(F_Typ
))
4327 Apply_Length_Check
(A
, F_Typ
);
4329 elsif Is_Access_Type
(F_Typ
)
4330 and then Has_Discriminants
(Designated_Type
(F_Typ
))
4331 and then Is_Constrained
(Designated_Type
(F_Typ
))
4333 Apply_Discriminant_Check
(A
, F_Typ
);
4336 Apply_Range_Check
(A
, F_Typ
);
4339 -- Ada 2005 (AI-231): Note that the controlling parameter case
4340 -- already existed in Ada 95, which is partially checked
4341 -- elsewhere (see Checks), and we don't want the warning
4342 -- message to differ.
4344 if Is_Access_Type
(F_Typ
)
4345 and then Can_Never_Be_Null
(F_Typ
)
4346 and then Known_Null
(A
)
4348 if Is_Controlling_Formal
(F
) then
4349 Apply_Compile_Time_Constraint_Error
4351 Msg
=> "null value not allowed here??",
4352 Reason
=> CE_Access_Check_Failed
);
4354 elsif Ada_Version
>= Ada_2005
then
4355 Apply_Compile_Time_Constraint_Error
4357 Msg
=> "(Ada 2005) null not allowed in "
4358 & "null-excluding formal??",
4359 Reason
=> CE_Null_Not_Allowed
);
4364 -- Checks for OUT parameters and IN OUT parameters
4366 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
) then
4368 -- If there is a type conversion, make sure the return value
4369 -- meets the constraints of the variable before the conversion.
4371 if Nkind
(A
) = N_Type_Conversion
then
4372 if Is_Scalar_Type
(A_Typ
) then
4373 Apply_Scalar_Range_Check
4374 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4376 -- In addition, the returned value of the parameter must
4377 -- satisfy the bounds of the object type (see comment
4380 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
4384 (Expression
(A
), Etype
(Expression
(A
)), A_Typ
);
4387 -- If no conversion, apply scalar range checks and length check
4388 -- based on the subtype of the actual (NOT that of the formal).
4389 -- This indicates that the check takes place on return from the
4390 -- call. During expansion the required constraint checks are
4391 -- inserted. In GNATprove mode, in the absence of expansion,
4392 -- the flag indicates that the returned value is valid.
4395 if Is_Scalar_Type
(F_Typ
) then
4396 Apply_Scalar_Range_Check
(A
, A_Typ
, F_Typ
);
4398 elsif Is_Array_Type
(F_Typ
)
4399 and then Ekind
(F
) = E_Out_Parameter
4401 Apply_Length_Check
(A
, F_Typ
);
4403 Apply_Range_Check
(A
, A_Typ
, F_Typ
);
4407 -- Note: we do not apply the predicate checks for the case of
4408 -- OUT and IN OUT parameters. They are instead applied in the
4409 -- Expand_Actuals routine in Exp_Ch6.
4412 -- An actual associated with an access parameter is implicitly
4413 -- converted to the anonymous access type of the formal and must
4414 -- satisfy the legality checks for access conversions.
4416 if Ekind
(F_Typ
) = E_Anonymous_Access_Type
then
4417 if not Valid_Conversion
(A
, F_Typ
, A
) then
4419 ("invalid implicit conversion for access parameter", A
);
4422 -- If the actual is an access selected component of a variable,
4423 -- the call may modify its designated object. It is reasonable
4424 -- to treat this as a potential modification of the enclosing
4425 -- record, to prevent spurious warnings that it should be
4426 -- declared as a constant, because intuitively programmers
4427 -- regard the designated subcomponent as part of the record.
4429 if Nkind
(A
) = N_Selected_Component
4430 and then Is_Entity_Name
(Prefix
(A
))
4431 and then not Is_Constant_Object
(Entity
(Prefix
(A
)))
4433 Note_Possible_Modification
(A
, Sure
=> False);
4437 -- Check bad case of atomic/volatile argument (RM C.6(12))
4439 if Is_By_Reference_Type
(Etype
(F
))
4440 and then Comes_From_Source
(N
)
4442 if Is_Atomic_Object
(A
)
4443 and then not Is_Atomic
(Etype
(F
))
4446 ("cannot pass atomic argument to non-atomic formal&",
4449 elsif Is_Volatile_Object
(A
)
4450 and then not Is_Volatile
(Etype
(F
))
4453 ("cannot pass volatile argument to non-volatile formal&",
4458 -- Check that subprograms don't have improper controlling
4459 -- arguments (RM 3.9.2 (9)).
4461 -- A primitive operation may have an access parameter of an
4462 -- incomplete tagged type, but a dispatching call is illegal
4463 -- if the type is still incomplete.
4465 if Is_Controlling_Formal
(F
) then
4466 Set_Is_Controlling_Actual
(A
);
4468 if Ekind
(Etype
(F
)) = E_Anonymous_Access_Type
then
4470 Desig
: constant Entity_Id
:= Designated_Type
(Etype
(F
));
4472 if Ekind
(Desig
) = E_Incomplete_Type
4473 and then No
(Full_View
(Desig
))
4474 and then No
(Non_Limited_View
(Desig
))
4477 ("premature use of incomplete type& "
4478 & "in dispatching call", A
, Desig
);
4483 elsif Nkind
(A
) = N_Explicit_Dereference
then
4484 Validate_Remote_Access_To_Class_Wide_Type
(A
);
4487 -- Apply legality rule 3.9.2 (9/1)
4489 if (Is_Class_Wide_Type
(A_Typ
) or else Is_Dynamically_Tagged
(A
))
4490 and then not Is_Class_Wide_Type
(F_Typ
)
4491 and then not Is_Controlling_Formal
(F
)
4492 and then not In_Instance
4494 Error_Msg_N
("class-wide argument not allowed here!", A
);
4496 if Is_Subprogram
(Nam
) and then Comes_From_Source
(Nam
) then
4497 Error_Msg_Node_2
:= F_Typ
;
4499 ("& is not a dispatching operation of &!", A
, Nam
);
4502 -- Apply the checks described in 3.10.2(27): if the context is a
4503 -- specific access-to-object, the actual cannot be class-wide.
4504 -- Use base type to exclude access_to_subprogram cases.
4506 elsif Is_Access_Type
(A_Typ
)
4507 and then Is_Access_Type
(F_Typ
)
4508 and then not Is_Access_Subprogram_Type
(Base_Type
(F_Typ
))
4509 and then (Is_Class_Wide_Type
(Designated_Type
(A_Typ
))
4510 or else (Nkind
(A
) = N_Attribute_Reference
4512 Is_Class_Wide_Type
(Etype
(Prefix
(A
)))))
4513 and then not Is_Class_Wide_Type
(Designated_Type
(F_Typ
))
4514 and then not Is_Controlling_Formal
(F
)
4516 -- Disable these checks for call to imported C++ subprograms
4519 (Is_Entity_Name
(Name
(N
))
4520 and then Is_Imported
(Entity
(Name
(N
)))
4521 and then Convention
(Entity
(Name
(N
))) = Convention_CPP
)
4524 ("access to class-wide argument not allowed here!", A
);
4526 if Is_Subprogram
(Nam
) and then Comes_From_Source
(Nam
) then
4527 Error_Msg_Node_2
:= Designated_Type
(F_Typ
);
4529 ("& is not a dispatching operation of &!", A
, Nam
);
4533 Check_Aliased_Parameter
;
4537 -- If it is a named association, treat the selector_name as a
4538 -- proper identifier, and mark the corresponding entity.
4540 if Nkind
(Parent
(A
)) = N_Parameter_Association
4542 -- Ignore reference in SPARK mode, as it refers to an entity not
4543 -- in scope at the point of reference, so the reference should
4544 -- be ignored for computing effects of subprograms.
4546 and then not GNATprove_Mode
4548 -- If subprogram is overridden, use name of formal that
4551 if Present
(Real_Subp
) then
4552 Set_Entity
(Selector_Name
(Parent
(A
)), Real_F
);
4553 Set_Etype
(Selector_Name
(Parent
(A
)), Etype
(Real_F
));
4556 Set_Entity
(Selector_Name
(Parent
(A
)), F
);
4557 Generate_Reference
(F
, Selector_Name
(Parent
(A
)));
4558 Set_Etype
(Selector_Name
(Parent
(A
)), F_Typ
);
4559 Generate_Reference
(F_Typ
, N
, ' ');
4565 if Ekind
(F
) /= E_Out_Parameter
then
4566 Check_Unset_Reference
(A
);
4569 -- The following checks are only relevant when SPARK_Mode is on as
4570 -- they are not standard Ada legality rule. Internally generated
4571 -- temporaries are ignored.
4573 if SPARK_Mode
= On
and then Comes_From_Source
(A
) then
4575 -- An effectively volatile object may act as an actual when the
4576 -- corresponding formal is of a non-scalar effectively volatile
4577 -- type (SPARK RM 7.1.3(11)).
4579 if not Is_Scalar_Type
(Etype
(F
))
4580 and then Is_Effectively_Volatile
(Etype
(F
))
4584 -- An effectively volatile object may act as an actual in a
4585 -- call to an instance of Unchecked_Conversion.
4586 -- (SPARK RM 7.1.3(11)).
4588 elsif Is_Unchecked_Conversion_Instance
(Nam
) then
4591 -- The actual denotes an object
4593 elsif Is_Effectively_Volatile_Object
(A
) then
4595 ("volatile object cannot act as actual in a call (SPARK "
4596 & "RM 7.1.3(11))", A
);
4598 -- Otherwise the actual denotes an expression. Inspect the
4599 -- expression and flag each effectively volatile object with
4600 -- enabled property Async_Writers or Effective_Reads as illegal
4601 -- because it apprears within an interfering context. Note that
4602 -- this is usually done in Resolve_Entity_Name, but when the
4603 -- effectively volatile object appears as an actual in a call,
4604 -- the call must be resolved first.
4607 Flag_Effectively_Volatile_Objects
(A
);
4610 -- Detect an external variable with an enabled property that
4611 -- does not match the mode of the corresponding formal in a
4612 -- procedure call. Functions are not considered because they
4613 -- cannot have effectively volatile formal parameters in the
4616 if Ekind
(Nam
) = E_Procedure
4617 and then Ekind
(F
) = E_In_Parameter
4618 and then Is_Entity_Name
(A
)
4619 and then Present
(Entity
(A
))
4620 and then Ekind
(Entity
(A
)) = E_Variable
4624 if Async_Readers_Enabled
(A_Id
) then
4625 Property_Error
(A
, A_Id
, Name_Async_Readers
);
4626 elsif Effective_Reads_Enabled
(A_Id
) then
4627 Property_Error
(A
, A_Id
, Name_Effective_Reads
);
4628 elsif Effective_Writes_Enabled
(A_Id
) then
4629 Property_Error
(A
, A_Id
, Name_Effective_Writes
);
4634 -- A formal parameter of a specific tagged type whose related
4635 -- subprogram is subject to pragma Extensions_Visible with value
4636 -- "False" cannot act as an actual in a subprogram with value
4637 -- "True" (SPARK RM 6.1.7(3)).
4639 if Is_EVF_Expression
(A
)
4640 and then Extensions_Visible_Status
(Nam
) =
4641 Extensions_Visible_True
4644 ("formal parameter cannot act as actual parameter when "
4645 & "Extensions_Visible is False", A
);
4647 ("\subprogram & has Extensions_Visible True", A
, Nam
);
4650 -- The actual parameter of a Ghost subprogram whose formal is of
4651 -- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(12)).
4653 if Comes_From_Source
(Nam
)
4654 and then Is_Ghost_Entity
(Nam
)
4655 and then Ekind_In
(F
, E_In_Out_Parameter
, E_Out_Parameter
)
4656 and then Is_Entity_Name
(A
)
4657 and then Present
(Entity
(A
))
4658 and then not Is_Ghost_Entity
(Entity
(A
))
4661 ("non-ghost variable & cannot appear as actual in call to "
4662 & "ghost procedure", A
, Entity
(A
));
4664 if Ekind
(F
) = E_In_Out_Parameter
then
4665 Error_Msg_N
("\corresponding formal has mode `IN OUT`", A
);
4667 Error_Msg_N
("\corresponding formal has mode OUT", A
);
4673 -- Case where actual is not present
4681 if Present
(Real_Subp
) then
4682 Next_Formal
(Real_F
);
4685 end Resolve_Actuals
;
4687 -----------------------
4688 -- Resolve_Allocator --
4689 -----------------------
4691 procedure Resolve_Allocator
(N
: Node_Id
; Typ
: Entity_Id
) is
4692 Desig_T
: constant Entity_Id
:= Designated_Type
(Typ
);
4693 E
: constant Node_Id
:= Expression
(N
);
4695 Discrim
: Entity_Id
;
4698 Assoc
: Node_Id
:= Empty
;
4701 procedure Check_Allocator_Discrim_Accessibility
4702 (Disc_Exp
: Node_Id
;
4703 Alloc_Typ
: Entity_Id
);
4704 -- Check that accessibility level associated with an access discriminant
4705 -- initialized in an allocator by the expression Disc_Exp is not deeper
4706 -- than the level of the allocator type Alloc_Typ. An error message is
4707 -- issued if this condition is violated. Specialized checks are done for
4708 -- the cases of a constraint expression which is an access attribute or
4709 -- an access discriminant.
4711 function In_Dispatching_Context
return Boolean;
4712 -- If the allocator is an actual in a call, it is allowed to be class-
4713 -- wide when the context is not because it is a controlling actual.
4715 -------------------------------------------
4716 -- Check_Allocator_Discrim_Accessibility --
4717 -------------------------------------------
4719 procedure Check_Allocator_Discrim_Accessibility
4720 (Disc_Exp
: Node_Id
;
4721 Alloc_Typ
: Entity_Id
)
4724 if Type_Access_Level
(Etype
(Disc_Exp
)) >
4725 Deepest_Type_Access_Level
(Alloc_Typ
)
4728 ("operand type has deeper level than allocator type", Disc_Exp
);
4730 -- When the expression is an Access attribute the level of the prefix
4731 -- object must not be deeper than that of the allocator's type.
4733 elsif Nkind
(Disc_Exp
) = N_Attribute_Reference
4734 and then Get_Attribute_Id
(Attribute_Name
(Disc_Exp
)) =
4736 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4737 Deepest_Type_Access_Level
(Alloc_Typ
)
4740 ("prefix of attribute has deeper level than allocator type",
4743 -- When the expression is an access discriminant the check is against
4744 -- the level of the prefix object.
4746 elsif Ekind
(Etype
(Disc_Exp
)) = E_Anonymous_Access_Type
4747 and then Nkind
(Disc_Exp
) = N_Selected_Component
4748 and then Object_Access_Level
(Prefix
(Disc_Exp
)) >
4749 Deepest_Type_Access_Level
(Alloc_Typ
)
4752 ("access discriminant has deeper level than allocator type",
4755 -- All other cases are legal
4760 end Check_Allocator_Discrim_Accessibility
;
4762 ----------------------------
4763 -- In_Dispatching_Context --
4764 ----------------------------
4766 function In_Dispatching_Context
return Boolean is
4767 Par
: constant Node_Id
:= Parent
(N
);
4770 return Nkind
(Par
) in N_Subprogram_Call
4771 and then Is_Entity_Name
(Name
(Par
))
4772 and then Is_Dispatching_Operation
(Entity
(Name
(Par
)));
4773 end In_Dispatching_Context
;
4775 -- Start of processing for Resolve_Allocator
4778 -- Replace general access with specific type
4780 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
4781 Set_Etype
(N
, Base_Type
(Typ
));
4784 if Is_Abstract_Type
(Typ
) then
4785 Error_Msg_N
("type of allocator cannot be abstract", N
);
4788 -- For qualified expression, resolve the expression using the given
4789 -- subtype (nothing to do for type mark, subtype indication)
4791 if Nkind
(E
) = N_Qualified_Expression
then
4792 if Is_Class_Wide_Type
(Etype
(E
))
4793 and then not Is_Class_Wide_Type
(Desig_T
)
4794 and then not In_Dispatching_Context
4797 ("class-wide allocator not allowed for this access type", N
);
4800 Resolve
(Expression
(E
), Etype
(E
));
4801 Check_Non_Static_Context
(Expression
(E
));
4802 Check_Unset_Reference
(Expression
(E
));
4804 -- Allocators generated by the build-in-place expansion mechanism
4805 -- are explicitly marked as coming from source but do not need to be
4806 -- checked for limited initialization. To exclude this case, ensure
4807 -- that the parent of the allocator is a source node.
4809 if Is_Limited_Type
(Etype
(E
))
4810 and then Comes_From_Source
(N
)
4811 and then Comes_From_Source
(Parent
(N
))
4812 and then not In_Instance_Body
4814 if not OK_For_Limited_Init
(Etype
(E
), Expression
(E
)) then
4815 if Nkind
(Parent
(N
)) = N_Assignment_Statement
then
4817 ("illegal expression for initialized allocator of a "
4818 & "limited type (RM 7.5 (2.7/2))", N
);
4821 ("initialization not allowed for limited types", N
);
4824 Explain_Limited_Type
(Etype
(E
), N
);
4828 -- A qualified expression requires an exact match of the type. Class-
4829 -- wide matching is not allowed.
4831 if (Is_Class_Wide_Type
(Etype
(Expression
(E
)))
4832 or else Is_Class_Wide_Type
(Etype
(E
)))
4833 and then Base_Type
(Etype
(Expression
(E
))) /= Base_Type
(Etype
(E
))
4835 Wrong_Type
(Expression
(E
), Etype
(E
));
4838 -- Calls to build-in-place functions are not currently supported in
4839 -- allocators for access types associated with a simple storage pool.
4840 -- Supporting such allocators may require passing additional implicit
4841 -- parameters to build-in-place functions (or a significant revision
4842 -- of the current b-i-p implementation to unify the handling for
4843 -- multiple kinds of storage pools). ???
4845 if Is_Limited_View
(Desig_T
)
4846 and then Nkind
(Expression
(E
)) = N_Function_Call
4849 Pool
: constant Entity_Id
:=
4850 Associated_Storage_Pool
(Root_Type
(Typ
));
4854 Present
(Get_Rep_Pragma
4855 (Etype
(Pool
), Name_Simple_Storage_Pool_Type
))
4858 ("limited function calls not yet supported in simple "
4859 & "storage pool allocators", Expression
(E
));
4864 -- A special accessibility check is needed for allocators that
4865 -- constrain access discriminants. The level of the type of the
4866 -- expression used to constrain an access discriminant cannot be
4867 -- deeper than the type of the allocator (in contrast to access
4868 -- parameters, where the level of the actual can be arbitrary).
4870 -- We can't use Valid_Conversion to perform this check because in
4871 -- general the type of the allocator is unrelated to the type of
4872 -- the access discriminant.
4874 if Ekind
(Typ
) /= E_Anonymous_Access_Type
4875 or else Is_Local_Anonymous_Access
(Typ
)
4877 Subtyp
:= Entity
(Subtype_Mark
(E
));
4879 Aggr
:= Original_Node
(Expression
(E
));
4881 if Has_Discriminants
(Subtyp
)
4882 and then Nkind_In
(Aggr
, N_Aggregate
, N_Extension_Aggregate
)
4884 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4886 -- Get the first component expression of the aggregate
4888 if Present
(Expressions
(Aggr
)) then
4889 Disc_Exp
:= First
(Expressions
(Aggr
));
4891 elsif Present
(Component_Associations
(Aggr
)) then
4892 Assoc
:= First
(Component_Associations
(Aggr
));
4894 if Present
(Assoc
) then
4895 Disc_Exp
:= Expression
(Assoc
);
4904 while Present
(Discrim
) and then Present
(Disc_Exp
) loop
4905 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4906 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4909 Next_Discriminant
(Discrim
);
4911 if Present
(Discrim
) then
4912 if Present
(Assoc
) then
4914 Disc_Exp
:= Expression
(Assoc
);
4916 elsif Present
(Next
(Disc_Exp
)) then
4920 Assoc
:= First
(Component_Associations
(Aggr
));
4922 if Present
(Assoc
) then
4923 Disc_Exp
:= Expression
(Assoc
);
4933 -- For a subtype mark or subtype indication, freeze the subtype
4936 Freeze_Expression
(E
);
4938 if Is_Access_Constant
(Typ
) and then not No_Initialization
(N
) then
4940 ("initialization required for access-to-constant allocator", N
);
4943 -- A special accessibility check is needed for allocators that
4944 -- constrain access discriminants. The level of the type of the
4945 -- expression used to constrain an access discriminant cannot be
4946 -- deeper than the type of the allocator (in contrast to access
4947 -- parameters, where the level of the actual can be arbitrary).
4948 -- We can't use Valid_Conversion to perform this check because
4949 -- in general the type of the allocator is unrelated to the type
4950 -- of the access discriminant.
4952 if Nkind
(Original_Node
(E
)) = N_Subtype_Indication
4953 and then (Ekind
(Typ
) /= E_Anonymous_Access_Type
4954 or else Is_Local_Anonymous_Access
(Typ
))
4956 Subtyp
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4958 if Has_Discriminants
(Subtyp
) then
4959 Discrim
:= First_Discriminant
(Base_Type
(Subtyp
));
4960 Constr
:= First
(Constraints
(Constraint
(Original_Node
(E
))));
4961 while Present
(Discrim
) and then Present
(Constr
) loop
4962 if Ekind
(Etype
(Discrim
)) = E_Anonymous_Access_Type
then
4963 if Nkind
(Constr
) = N_Discriminant_Association
then
4964 Disc_Exp
:= Original_Node
(Expression
(Constr
));
4966 Disc_Exp
:= Original_Node
(Constr
);
4969 Check_Allocator_Discrim_Accessibility
(Disc_Exp
, Typ
);
4972 Next_Discriminant
(Discrim
);
4979 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4980 -- check that the level of the type of the created object is not deeper
4981 -- than the level of the allocator's access type, since extensions can
4982 -- now occur at deeper levels than their ancestor types. This is a
4983 -- static accessibility level check; a run-time check is also needed in
4984 -- the case of an initialized allocator with a class-wide argument (see
4985 -- Expand_Allocator_Expression).
4987 if Ada_Version
>= Ada_2005
4988 and then Is_Class_Wide_Type
(Desig_T
)
4991 Exp_Typ
: Entity_Id
;
4994 if Nkind
(E
) = N_Qualified_Expression
then
4995 Exp_Typ
:= Etype
(E
);
4996 elsif Nkind
(E
) = N_Subtype_Indication
then
4997 Exp_Typ
:= Entity
(Subtype_Mark
(Original_Node
(E
)));
4999 Exp_Typ
:= Entity
(E
);
5002 if Type_Access_Level
(Exp_Typ
) >
5003 Deepest_Type_Access_Level
(Typ
)
5005 if In_Instance_Body
then
5006 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5008 ("type in allocator has deeper level than "
5009 & "designated class-wide type<<", E
);
5010 Error_Msg_N
("\Program_Error [<<", E
);
5012 Make_Raise_Program_Error
(Sloc
(N
),
5013 Reason
=> PE_Accessibility_Check_Failed
));
5016 -- Do not apply Ada 2005 accessibility checks on a class-wide
5017 -- allocator if the type given in the allocator is a formal
5018 -- type. A run-time check will be performed in the instance.
5020 elsif not Is_Generic_Type
(Exp_Typ
) then
5021 Error_Msg_N
("type in allocator has deeper level than "
5022 & "designated class-wide type", E
);
5028 -- Check for allocation from an empty storage pool
5030 if No_Pool_Assigned
(Typ
) then
5031 Error_Msg_N
("allocation from empty storage pool!", N
);
5033 -- If the context is an unchecked conversion, as may happen within an
5034 -- inlined subprogram, the allocator is being resolved with its own
5035 -- anonymous type. In that case, if the target type has a specific
5036 -- storage pool, it must be inherited explicitly by the allocator type.
5038 elsif Nkind
(Parent
(N
)) = N_Unchecked_Type_Conversion
5039 and then No
(Associated_Storage_Pool
(Typ
))
5041 Set_Associated_Storage_Pool
5042 (Typ
, Associated_Storage_Pool
(Etype
(Parent
(N
))));
5045 if Ekind
(Etype
(N
)) = E_Anonymous_Access_Type
then
5046 Check_Restriction
(No_Anonymous_Allocators
, N
);
5049 -- Check that an allocator with task parts isn't for a nested access
5050 -- type when restriction No_Task_Hierarchy applies.
5052 if not Is_Library_Level_Entity
(Base_Type
(Typ
))
5053 and then Has_Task
(Base_Type
(Desig_T
))
5055 Check_Restriction
(No_Task_Hierarchy
, N
);
5058 -- An illegal allocator may be rewritten as a raise Program_Error
5061 if Nkind
(N
) = N_Allocator
then
5063 -- An anonymous access discriminant is the definition of a
5066 if Ekind
(Typ
) = E_Anonymous_Access_Type
5067 and then Nkind
(Associated_Node_For_Itype
(Typ
)) =
5068 N_Discriminant_Specification
5071 Discr
: constant Entity_Id
:=
5072 Defining_Identifier
(Associated_Node_For_Itype
(Typ
));
5075 Check_Restriction
(No_Coextensions
, N
);
5077 -- Ada 2012 AI05-0052: If the designated type of the allocator
5078 -- is limited, then the allocator shall not be used to define
5079 -- the value of an access discriminant unless the discriminated
5080 -- type is immutably limited.
5082 if Ada_Version
>= Ada_2012
5083 and then Is_Limited_Type
(Desig_T
)
5084 and then not Is_Limited_View
(Scope
(Discr
))
5087 ("only immutably limited types can have anonymous "
5088 & "access discriminants designating a limited type", N
);
5092 -- Avoid marking an allocator as a dynamic coextension if it is
5093 -- within a static construct.
5095 if not Is_Static_Coextension
(N
) then
5096 Set_Is_Dynamic_Coextension
(N
);
5099 -- Cleanup for potential static coextensions
5102 Set_Is_Dynamic_Coextension
(N
, False);
5103 Set_Is_Static_Coextension
(N
, False);
5107 -- Report a simple error: if the designated object is a local task,
5108 -- its body has not been seen yet, and its activation will fail an
5109 -- elaboration check.
5111 if Is_Task_Type
(Desig_T
)
5112 and then Scope
(Base_Type
(Desig_T
)) = Current_Scope
5113 and then Is_Compilation_Unit
(Current_Scope
)
5114 and then Ekind
(Current_Scope
) = E_Package
5115 and then not In_Package_Body
(Current_Scope
)
5117 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5118 Error_Msg_N
("cannot activate task before body seen<<", N
);
5119 Error_Msg_N
("\Program_Error [<<", N
);
5122 -- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
5123 -- type with a task component on a subpool. This action must raise
5124 -- Program_Error at runtime.
5126 if Ada_Version
>= Ada_2012
5127 and then Nkind
(N
) = N_Allocator
5128 and then Present
(Subpool_Handle_Name
(N
))
5129 and then Has_Task
(Desig_T
)
5131 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5132 Error_Msg_N
("cannot allocate task on subpool<<", N
);
5133 Error_Msg_N
("\Program_Error [<<", N
);
5136 Make_Raise_Program_Error
(Sloc
(N
),
5137 Reason
=> PE_Explicit_Raise
));
5140 end Resolve_Allocator
;
5142 ---------------------------
5143 -- Resolve_Arithmetic_Op --
5144 ---------------------------
5146 -- Used for resolving all arithmetic operators except exponentiation
5148 procedure Resolve_Arithmetic_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
5149 L
: constant Node_Id
:= Left_Opnd
(N
);
5150 R
: constant Node_Id
:= Right_Opnd
(N
);
5151 TL
: constant Entity_Id
:= Base_Type
(Etype
(L
));
5152 TR
: constant Entity_Id
:= Base_Type
(Etype
(R
));
5156 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
5157 -- We do the resolution using the base type, because intermediate values
5158 -- in expressions always are of the base type, not a subtype of it.
5160 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean;
5161 -- Returns True if N is in a context that expects "any real type"
5163 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean;
5164 -- Return True iff given type is Integer or universal real/integer
5166 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
);
5167 -- Choose type of integer literal in fixed-point operation to conform
5168 -- to available fixed-point type. T is the type of the other operand,
5169 -- which is needed to determine the expected type of N.
5171 procedure Set_Operand_Type
(N
: Node_Id
);
5172 -- Set operand type to T if universal
5174 -------------------------------
5175 -- Expected_Type_Is_Any_Real --
5176 -------------------------------
5178 function Expected_Type_Is_Any_Real
(N
: Node_Id
) return Boolean is
5180 -- N is the expression after "delta" in a fixed_point_definition;
5183 return Nkind_In
(Parent
(N
), N_Ordinary_Fixed_Point_Definition
,
5184 N_Decimal_Fixed_Point_Definition
,
5186 -- N is one of the bounds in a real_range_specification;
5189 N_Real_Range_Specification
,
5191 -- N is the expression of a delta_constraint;
5194 N_Delta_Constraint
);
5195 end Expected_Type_Is_Any_Real
;
5197 -----------------------------
5198 -- Is_Integer_Or_Universal --
5199 -----------------------------
5201 function Is_Integer_Or_Universal
(N
: Node_Id
) return Boolean is
5203 Index
: Interp_Index
;
5207 if not Is_Overloaded
(N
) then
5209 return Base_Type
(T
) = Base_Type
(Standard_Integer
)
5210 or else T
= Universal_Integer
5211 or else T
= Universal_Real
;
5213 Get_First_Interp
(N
, Index
, It
);
5214 while Present
(It
.Typ
) loop
5215 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
)
5216 or else It
.Typ
= Universal_Integer
5217 or else It
.Typ
= Universal_Real
5222 Get_Next_Interp
(Index
, It
);
5227 end Is_Integer_Or_Universal
;
5229 ----------------------------
5230 -- Set_Mixed_Mode_Operand --
5231 ----------------------------
5233 procedure Set_Mixed_Mode_Operand
(N
: Node_Id
; T
: Entity_Id
) is
5234 Index
: Interp_Index
;
5238 if Universal_Interpretation
(N
) = Universal_Integer
then
5240 -- A universal integer literal is resolved as standard integer
5241 -- except in the case of a fixed-point result, where we leave it
5242 -- as universal (to be handled by Exp_Fixd later on)
5244 if Is_Fixed_Point_Type
(T
) then
5245 Resolve
(N
, Universal_Integer
);
5247 Resolve
(N
, Standard_Integer
);
5250 elsif Universal_Interpretation
(N
) = Universal_Real
5251 and then (T
= Base_Type
(Standard_Integer
)
5252 or else T
= Universal_Integer
5253 or else T
= Universal_Real
)
5255 -- A universal real can appear in a fixed-type context. We resolve
5256 -- the literal with that context, even though this might raise an
5257 -- exception prematurely (the other operand may be zero).
5261 elsif Etype
(N
) = Base_Type
(Standard_Integer
)
5262 and then T
= Universal_Real
5263 and then Is_Overloaded
(N
)
5265 -- Integer arg in mixed-mode operation. Resolve with universal
5266 -- type, in case preference rule must be applied.
5268 Resolve
(N
, Universal_Integer
);
5271 and then B_Typ
/= Universal_Fixed
5273 -- Not a mixed-mode operation, resolve with context
5277 elsif Etype
(N
) = Any_Fixed
then
5279 -- N may itself be a mixed-mode operation, so use context type
5283 elsif Is_Fixed_Point_Type
(T
)
5284 and then B_Typ
= Universal_Fixed
5285 and then Is_Overloaded
(N
)
5287 -- Must be (fixed * fixed) operation, operand must have one
5288 -- compatible interpretation.
5290 Resolve
(N
, Any_Fixed
);
5292 elsif Is_Fixed_Point_Type
(B_Typ
)
5293 and then (T
= Universal_Real
or else Is_Fixed_Point_Type
(T
))
5294 and then Is_Overloaded
(N
)
5296 -- C * F(X) in a fixed context, where C is a real literal or a
5297 -- fixed-point expression. F must have either a fixed type
5298 -- interpretation or an integer interpretation, but not both.
5300 Get_First_Interp
(N
, Index
, It
);
5301 while Present
(It
.Typ
) loop
5302 if Base_Type
(It
.Typ
) = Base_Type
(Standard_Integer
) then
5303 if Analyzed
(N
) then
5304 Error_Msg_N
("ambiguous operand in fixed operation", N
);
5306 Resolve
(N
, Standard_Integer
);
5309 elsif Is_Fixed_Point_Type
(It
.Typ
) then
5310 if Analyzed
(N
) then
5311 Error_Msg_N
("ambiguous operand in fixed operation", N
);
5313 Resolve
(N
, It
.Typ
);
5317 Get_Next_Interp
(Index
, It
);
5320 -- Reanalyze the literal with the fixed type of the context. If
5321 -- context is Universal_Fixed, we are within a conversion, leave
5322 -- the literal as a universal real because there is no usable
5323 -- fixed type, and the target of the conversion plays no role in
5337 if B_Typ
= Universal_Fixed
5338 and then Nkind
(Op2
) = N_Real_Literal
5340 T2
:= Universal_Real
;
5345 Set_Analyzed
(Op2
, False);
5352 end Set_Mixed_Mode_Operand
;
5354 ----------------------
5355 -- Set_Operand_Type --
5356 ----------------------
5358 procedure Set_Operand_Type
(N
: Node_Id
) is
5360 if Etype
(N
) = Universal_Integer
5361 or else Etype
(N
) = Universal_Real
5365 end Set_Operand_Type
;
5367 -- Start of processing for Resolve_Arithmetic_Op
5370 if Comes_From_Source
(N
)
5371 and then Ekind
(Entity
(N
)) = E_Function
5372 and then Is_Imported
(Entity
(N
))
5373 and then Is_Intrinsic_Subprogram
(Entity
(N
))
5375 Resolve_Intrinsic_Operator
(N
, Typ
);
5378 -- Special-case for mixed-mode universal expressions or fixed point type
5379 -- operation: each argument is resolved separately. The same treatment
5380 -- is required if one of the operands of a fixed point operation is
5381 -- universal real, since in this case we don't do a conversion to a
5382 -- specific fixed-point type (instead the expander handles the case).
5384 -- Set the type of the node to its universal interpretation because
5385 -- legality checks on an exponentiation operand need the context.
5387 elsif (B_Typ
= Universal_Integer
or else B_Typ
= Universal_Real
)
5388 and then Present
(Universal_Interpretation
(L
))
5389 and then Present
(Universal_Interpretation
(R
))
5391 Set_Etype
(N
, B_Typ
);
5392 Resolve
(L
, Universal_Interpretation
(L
));
5393 Resolve
(R
, Universal_Interpretation
(R
));
5395 elsif (B_Typ
= Universal_Real
5396 or else Etype
(N
) = Universal_Fixed
5397 or else (Etype
(N
) = Any_Fixed
5398 and then Is_Fixed_Point_Type
(B_Typ
))
5399 or else (Is_Fixed_Point_Type
(B_Typ
)
5400 and then (Is_Integer_Or_Universal
(L
)
5402 Is_Integer_Or_Universal
(R
))))
5403 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
5405 if TL
= Universal_Integer
or else TR
= Universal_Integer
then
5406 Check_For_Visible_Operator
(N
, B_Typ
);
5409 -- If context is a fixed type and one operand is integer, the other
5410 -- is resolved with the type of the context.
5412 if Is_Fixed_Point_Type
(B_Typ
)
5413 and then (Base_Type
(TL
) = Base_Type
(Standard_Integer
)
5414 or else TL
= Universal_Integer
)
5419 elsif Is_Fixed_Point_Type
(B_Typ
)
5420 and then (Base_Type
(TR
) = Base_Type
(Standard_Integer
)
5421 or else TR
= Universal_Integer
)
5427 Set_Mixed_Mode_Operand
(L
, TR
);
5428 Set_Mixed_Mode_Operand
(R
, TL
);
5431 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
5432 -- multiplying operators from being used when the expected type is
5433 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
5434 -- some cases where the expected type is actually Any_Real;
5435 -- Expected_Type_Is_Any_Real takes care of that case.
5437 if Etype
(N
) = Universal_Fixed
5438 or else Etype
(N
) = Any_Fixed
5440 if B_Typ
= Universal_Fixed
5441 and then not Expected_Type_Is_Any_Real
(N
)
5442 and then not Nkind_In
(Parent
(N
), N_Type_Conversion
,
5443 N_Unchecked_Type_Conversion
)
5445 Error_Msg_N
("type cannot be determined from context!", N
);
5446 Error_Msg_N
("\explicit conversion to result type required", N
);
5448 Set_Etype
(L
, Any_Type
);
5449 Set_Etype
(R
, Any_Type
);
5452 if Ada_Version
= Ada_83
5453 and then Etype
(N
) = Universal_Fixed
5455 Nkind_In
(Parent
(N
), N_Type_Conversion
,
5456 N_Unchecked_Type_Conversion
)
5459 ("(Ada 83) fixed-point operation needs explicit "
5463 -- The expected type is "any real type" in contexts like
5465 -- type T is delta <universal_fixed-expression> ...
5467 -- in which case we need to set the type to Universal_Real
5468 -- so that static expression evaluation will work properly.
5470 if Expected_Type_Is_Any_Real
(N
) then
5471 Set_Etype
(N
, Universal_Real
);
5473 Set_Etype
(N
, B_Typ
);
5477 elsif Is_Fixed_Point_Type
(B_Typ
)
5478 and then (Is_Integer_Or_Universal
(L
)
5479 or else Nkind
(L
) = N_Real_Literal
5480 or else Nkind
(R
) = N_Real_Literal
5481 or else Is_Integer_Or_Universal
(R
))
5483 Set_Etype
(N
, B_Typ
);
5485 elsif Etype
(N
) = Any_Fixed
then
5487 -- If no previous errors, this is only possible if one operand is
5488 -- overloaded and the context is universal. Resolve as such.
5490 Set_Etype
(N
, B_Typ
);
5494 if (TL
= Universal_Integer
or else TL
= Universal_Real
)
5496 (TR
= Universal_Integer
or else TR
= Universal_Real
)
5498 Check_For_Visible_Operator
(N
, B_Typ
);
5501 -- If the context is Universal_Fixed and the operands are also
5502 -- universal fixed, this is an error, unless there is only one
5503 -- applicable fixed_point type (usually Duration).
5505 if B_Typ
= Universal_Fixed
and then Etype
(L
) = Universal_Fixed
then
5506 T
:= Unique_Fixed_Point_Type
(N
);
5508 if T
= Any_Type
then
5521 -- If one of the arguments was resolved to a non-universal type.
5522 -- label the result of the operation itself with the same type.
5523 -- Do the same for the universal argument, if any.
5525 T
:= Intersect_Types
(L
, R
);
5526 Set_Etype
(N
, Base_Type
(T
));
5527 Set_Operand_Type
(L
);
5528 Set_Operand_Type
(R
);
5531 Generate_Operator_Reference
(N
, Typ
);
5532 Analyze_Dimension
(N
);
5533 Eval_Arithmetic_Op
(N
);
5535 -- In SPARK, a multiplication or division with operands of fixed point
5536 -- types must be qualified or explicitly converted to identify the
5539 if (Is_Fixed_Point_Type
(Etype
(L
))
5540 or else Is_Fixed_Point_Type
(Etype
(R
)))
5541 and then Nkind_In
(N
, N_Op_Multiply
, N_Op_Divide
)
5543 not Nkind_In
(Parent
(N
), N_Qualified_Expression
, N_Type_Conversion
)
5545 Check_SPARK_05_Restriction
5546 ("operation should be qualified or explicitly converted", N
);
5549 -- Set overflow and division checking bit
5551 if Nkind
(N
) in N_Op
then
5552 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
5553 Enable_Overflow_Check
(N
);
5556 -- Give warning if explicit division by zero
5558 if Nkind_In
(N
, N_Op_Divide
, N_Op_Rem
, N_Op_Mod
)
5559 and then not Division_Checks_Suppressed
(Etype
(N
))
5561 Rop
:= Right_Opnd
(N
);
5563 if Compile_Time_Known_Value
(Rop
)
5564 and then ((Is_Integer_Type
(Etype
(Rop
))
5565 and then Expr_Value
(Rop
) = Uint_0
)
5567 (Is_Real_Type
(Etype
(Rop
))
5568 and then Expr_Value_R
(Rop
) = Ureal_0
))
5570 -- Specialize the warning message according to the operation.
5571 -- When SPARK_Mode is On, force a warning instead of an error
5572 -- in that case, as this likely corresponds to deactivated
5573 -- code. The following warnings are for the case
5578 -- For division, we have two cases, for float division
5579 -- of an unconstrained float type, on a machine where
5580 -- Machine_Overflows is false, we don't get an exception
5581 -- at run-time, but rather an infinity or Nan. The Nan
5582 -- case is pretty obscure, so just warn about infinities.
5584 if Is_Floating_Point_Type
(Typ
)
5585 and then not Is_Constrained
(Typ
)
5586 and then not Machine_Overflows_On_Target
5589 ("float division by zero, may generate "
5590 & "'+'/'- infinity??", Right_Opnd
(N
));
5592 -- For all other cases, we get a Constraint_Error
5595 Apply_Compile_Time_Constraint_Error
5596 (N
, "division by zero??", CE_Divide_By_Zero
,
5597 Loc
=> Sloc
(Right_Opnd
(N
)),
5598 Warn
=> SPARK_Mode
= On
);
5602 Apply_Compile_Time_Constraint_Error
5603 (N
, "rem with zero divisor??", CE_Divide_By_Zero
,
5604 Loc
=> Sloc
(Right_Opnd
(N
)),
5605 Warn
=> SPARK_Mode
= On
);
5608 Apply_Compile_Time_Constraint_Error
5609 (N
, "mod with zero divisor??", CE_Divide_By_Zero
,
5610 Loc
=> Sloc
(Right_Opnd
(N
)),
5611 Warn
=> SPARK_Mode
= On
);
5613 -- Division by zero can only happen with division, rem,
5614 -- and mod operations.
5617 raise Program_Error
;
5620 -- In GNATprove mode, we enable the division check so that
5621 -- GNATprove will issue a message if it cannot be proved.
5623 if GNATprove_Mode
then
5624 Activate_Division_Check
(N
);
5627 -- Otherwise just set the flag to check at run time
5630 Activate_Division_Check
(N
);
5634 -- If Restriction No_Implicit_Conditionals is active, then it is
5635 -- violated if either operand can be negative for mod, or for rem
5636 -- if both operands can be negative.
5638 if Restriction_Check_Required
(No_Implicit_Conditionals
)
5639 and then Nkind_In
(N
, N_Op_Rem
, N_Op_Mod
)
5648 -- Set if corresponding operand might be negative
5652 (Left_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5653 LNeg
:= (not OK
) or else Lo
< 0;
5656 (Right_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
5657 RNeg
:= (not OK
) or else Lo
< 0;
5659 -- Check if we will be generating conditionals. There are two
5660 -- cases where that can happen, first for REM, the only case
5661 -- is largest negative integer mod -1, where the division can
5662 -- overflow, but we still have to give the right result. The
5663 -- front end generates a test for this annoying case. Here we
5664 -- just test if both operands can be negative (that's what the
5665 -- expander does, so we match its logic here).
5667 -- The second case is mod where either operand can be negative.
5668 -- In this case, the back end has to generate additional tests.
5670 if (Nkind
(N
) = N_Op_Rem
and then (LNeg
and RNeg
))
5672 (Nkind
(N
) = N_Op_Mod
and then (LNeg
or RNeg
))
5674 Check_Restriction
(No_Implicit_Conditionals
, N
);
5680 Check_Unset_Reference
(L
);
5681 Check_Unset_Reference
(R
);
5682 end Resolve_Arithmetic_Op
;
5688 procedure Resolve_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
5689 function Same_Or_Aliased_Subprograms
5691 E
: Entity_Id
) return Boolean;
5692 -- Returns True if the subprogram entity S is the same as E or else
5693 -- S is an alias of E.
5695 ---------------------------------
5696 -- Same_Or_Aliased_Subprograms --
5697 ---------------------------------
5699 function Same_Or_Aliased_Subprograms
5701 E
: Entity_Id
) return Boolean
5703 Subp_Alias
: constant Entity_Id
:= Alias
(S
);
5705 return S
= E
or else (Present
(Subp_Alias
) and then Subp_Alias
= E
);
5706 end Same_Or_Aliased_Subprograms
;
5710 Loc
: constant Source_Ptr
:= Sloc
(N
);
5711 Subp
: constant Node_Id
:= Name
(N
);
5712 Body_Id
: Entity_Id
;
5722 -- Start of processing for Resolve_Call
5725 -- The context imposes a unique interpretation with type Typ on a
5726 -- procedure or function call. Find the entity of the subprogram that
5727 -- yields the expected type, and propagate the corresponding formal
5728 -- constraints on the actuals. The caller has established that an
5729 -- interpretation exists, and emitted an error if not unique.
5731 -- First deal with the case of a call to an access-to-subprogram,
5732 -- dereference made explicit in Analyze_Call.
5734 if Ekind
(Etype
(Subp
)) = E_Subprogram_Type
then
5735 if not Is_Overloaded
(Subp
) then
5736 Nam
:= Etype
(Subp
);
5739 -- Find the interpretation whose type (a subprogram type) has a
5740 -- return type that is compatible with the context. Analysis of
5741 -- the node has established that one exists.
5745 Get_First_Interp
(Subp
, I
, It
);
5746 while Present
(It
.Typ
) loop
5747 if Covers
(Typ
, Etype
(It
.Typ
)) then
5752 Get_Next_Interp
(I
, It
);
5756 raise Program_Error
;
5760 -- If the prefix is not an entity, then resolve it
5762 if not Is_Entity_Name
(Subp
) then
5763 Resolve
(Subp
, Nam
);
5766 -- For an indirect call, we always invalidate checks, since we do not
5767 -- know whether the subprogram is local or global. Yes we could do
5768 -- better here, e.g. by knowing that there are no local subprograms,
5769 -- but it does not seem worth the effort. Similarly, we kill all
5770 -- knowledge of current constant values.
5772 Kill_Current_Values
;
5774 -- If this is a procedure call which is really an entry call, do
5775 -- the conversion of the procedure call to an entry call. Protected
5776 -- operations use the same circuitry because the name in the call
5777 -- can be an arbitrary expression with special resolution rules.
5779 elsif Nkind_In
(Subp
, N_Selected_Component
, N_Indexed_Component
)
5780 or else (Is_Entity_Name
(Subp
)
5781 and then Ekind
(Entity
(Subp
)) = E_Entry
)
5783 Resolve_Entry_Call
(N
, Typ
);
5784 Check_Elab_Call
(N
);
5786 -- Kill checks and constant values, as above for indirect case
5787 -- Who knows what happens when another task is activated?
5789 Kill_Current_Values
;
5792 -- Normal subprogram call with name established in Resolve
5794 elsif not (Is_Type
(Entity
(Subp
))) then
5795 Nam
:= Entity
(Subp
);
5796 Set_Entity_With_Checks
(Subp
, Nam
);
5798 -- Otherwise we must have the case of an overloaded call
5801 pragma Assert
(Is_Overloaded
(Subp
));
5803 -- Initialize Nam to prevent warning (we know it will be assigned
5804 -- in the loop below, but the compiler does not know that).
5808 Get_First_Interp
(Subp
, I
, It
);
5809 while Present
(It
.Typ
) loop
5810 if Covers
(Typ
, It
.Typ
) then
5812 Set_Entity_With_Checks
(Subp
, Nam
);
5816 Get_Next_Interp
(I
, It
);
5820 if Is_Access_Subprogram_Type
(Base_Type
(Etype
(Nam
)))
5821 and then not Is_Access_Subprogram_Type
(Base_Type
(Typ
))
5822 and then Nkind
(Subp
) /= N_Explicit_Dereference
5823 and then Present
(Parameter_Associations
(N
))
5825 -- The prefix is a parameterless function call that returns an access
5826 -- to subprogram. If parameters are present in the current call, add
5827 -- add an explicit dereference. We use the base type here because
5828 -- within an instance these may be subtypes.
5830 -- The dereference is added either in Analyze_Call or here. Should
5831 -- be consolidated ???
5833 Set_Is_Overloaded
(Subp
, False);
5834 Set_Etype
(Subp
, Etype
(Nam
));
5835 Insert_Explicit_Dereference
(Subp
);
5836 Nam
:= Designated_Type
(Etype
(Nam
));
5837 Resolve
(Subp
, Nam
);
5840 -- Check that a call to Current_Task does not occur in an entry body
5842 if Is_RTE
(Nam
, RE_Current_Task
) then
5851 -- Exclude calls that occur within the default of a formal
5852 -- parameter of the entry, since those are evaluated outside
5855 exit when No
(P
) or else Nkind
(P
) = N_Parameter_Specification
;
5857 if Nkind
(P
) = N_Entry_Body
5858 or else (Nkind
(P
) = N_Subprogram_Body
5859 and then Is_Entry_Barrier_Function
(P
))
5862 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5864 ("& should not be used in entry body (RM C.7(17))<<",
5866 Error_Msg_NE
("\Program_Error [<<", N
, Nam
);
5868 Make_Raise_Program_Error
(Loc
,
5869 Reason
=> PE_Current_Task_In_Entry_Body
));
5870 Set_Etype
(N
, Rtype
);
5877 -- Check that a procedure call does not occur in the context of the
5878 -- entry call statement of a conditional or timed entry call. Note that
5879 -- the case of a call to a subprogram renaming of an entry will also be
5880 -- rejected. The test for N not being an N_Entry_Call_Statement is
5881 -- defensive, covering the possibility that the processing of entry
5882 -- calls might reach this point due to later modifications of the code
5885 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
5886 and then Nkind
(N
) /= N_Entry_Call_Statement
5887 and then Entry_Call_Statement
(Parent
(N
)) = N
5889 if Ada_Version
< Ada_2005
then
5890 Error_Msg_N
("entry call required in select statement", N
);
5892 -- Ada 2005 (AI-345): If a procedure_call_statement is used
5893 -- for a procedure_or_entry_call, the procedure_name or
5894 -- procedure_prefix of the procedure_call_statement shall denote
5895 -- an entry renamed by a procedure, or (a view of) a primitive
5896 -- subprogram of a limited interface whose first parameter is
5897 -- a controlling parameter.
5899 elsif Nkind
(N
) = N_Procedure_Call_Statement
5900 and then not Is_Renamed_Entry
(Nam
)
5901 and then not Is_Controlling_Limited_Procedure
(Nam
)
5904 ("entry call or dispatching primitive of interface required", N
);
5908 -- If the SPARK_05 restriction is active, we are not allowed
5909 -- to have a call to a subprogram before we see its completion.
5911 if not Has_Completion
(Nam
)
5912 and then Restriction_Check_Required
(SPARK_05
)
5914 -- Don't flag strange internal calls
5916 and then Comes_From_Source
(N
)
5917 and then Comes_From_Source
(Nam
)
5919 -- Only flag calls in extended main source
5921 and then In_Extended_Main_Source_Unit
(Nam
)
5922 and then In_Extended_Main_Source_Unit
(N
)
5924 -- Exclude enumeration literals from this processing
5926 and then Ekind
(Nam
) /= E_Enumeration_Literal
5928 Check_SPARK_05_Restriction
5929 ("call to subprogram cannot appear before its body", N
);
5932 -- Check that this is not a call to a protected procedure or entry from
5933 -- within a protected function.
5935 Check_Internal_Protected_Use
(N
, Nam
);
5937 -- Freeze the subprogram name if not in a spec-expression. Note that
5938 -- we freeze procedure calls as well as function calls. Procedure calls
5939 -- are not frozen according to the rules (RM 13.14(14)) because it is
5940 -- impossible to have a procedure call to a non-frozen procedure in
5941 -- pure Ada, but in the code that we generate in the expander, this
5942 -- rule needs extending because we can generate procedure calls that
5945 -- In Ada 2012, expression functions may be called within pre/post
5946 -- conditions of subsequent functions or expression functions. Such
5947 -- calls do not freeze when they appear within generated bodies,
5948 -- (including the body of another expression function) which would
5949 -- place the freeze node in the wrong scope. An expression function
5950 -- is frozen in the usual fashion, by the appearance of a real body,
5951 -- or at the end of a declarative part.
5953 if Is_Entity_Name
(Subp
)
5954 and then not In_Spec_Expression
5955 and then not Is_Expression_Function_Or_Completion
(Current_Scope
)
5957 (not Is_Expression_Function_Or_Completion
(Entity
(Subp
))
5958 or else Scope
(Entity
(Subp
)) = Current_Scope
)
5960 Freeze_Expression
(Subp
);
5963 -- For a predefined operator, the type of the result is the type imposed
5964 -- by context, except for a predefined operation on universal fixed.
5965 -- Otherwise The type of the call is the type returned by the subprogram
5968 if Is_Predefined_Op
(Nam
) then
5969 if Etype
(N
) /= Universal_Fixed
then
5973 -- If the subprogram returns an array type, and the context requires the
5974 -- component type of that array type, the node is really an indexing of
5975 -- the parameterless call. Resolve as such. A pathological case occurs
5976 -- when the type of the component is an access to the array type. In
5977 -- this case the call is truly ambiguous. If the call is to an intrinsic
5978 -- subprogram, it can't be an indexed component. This check is necessary
5979 -- because if it's Unchecked_Conversion, and we have "type T_Ptr is
5980 -- access T;" and "type T is array (...) of T_Ptr;" (i.e. an array of
5981 -- pointers to the same array), the compiler gets confused and does an
5982 -- infinite recursion.
5984 elsif (Needs_No_Actuals
(Nam
) or else Needs_One_Actual
(Nam
))
5986 ((Is_Array_Type
(Etype
(Nam
))
5987 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
5989 (Is_Access_Type
(Etype
(Nam
))
5990 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
5992 Covers
(Typ
, Component_Type
(Designated_Type
(Etype
(Nam
))))
5993 and then not Is_Intrinsic_Subprogram
(Entity
(Subp
))))
5996 Index_Node
: Node_Id
;
5998 Ret_Type
: constant Entity_Id
:= Etype
(Nam
);
6001 if Is_Access_Type
(Ret_Type
)
6002 and then Ret_Type
= Component_Type
(Designated_Type
(Ret_Type
))
6005 ("cannot disambiguate function call and indexing", N
);
6007 New_Subp
:= Relocate_Node
(Subp
);
6009 -- The called entity may be an explicit dereference, in which
6010 -- case there is no entity to set.
6012 if Nkind
(New_Subp
) /= N_Explicit_Dereference
then
6013 Set_Entity
(Subp
, Nam
);
6016 if (Is_Array_Type
(Ret_Type
)
6017 and then Component_Type
(Ret_Type
) /= Any_Type
)
6019 (Is_Access_Type
(Ret_Type
)
6021 Component_Type
(Designated_Type
(Ret_Type
)) /= Any_Type
)
6023 if Needs_No_Actuals
(Nam
) then
6025 -- Indexed call to a parameterless function
6028 Make_Indexed_Component
(Loc
,
6030 Make_Function_Call
(Loc
, Name
=> New_Subp
),
6031 Expressions
=> Parameter_Associations
(N
));
6033 -- An Ada 2005 prefixed call to a primitive operation
6034 -- whose first parameter is the prefix. This prefix was
6035 -- prepended to the parameter list, which is actually a
6036 -- list of indexes. Remove the prefix in order to build
6037 -- the proper indexed component.
6040 Make_Indexed_Component
(Loc
,
6042 Make_Function_Call
(Loc
,
6044 Parameter_Associations
=>
6046 (Remove_Head
(Parameter_Associations
(N
)))),
6047 Expressions
=> Parameter_Associations
(N
));
6050 -- Preserve the parenthesis count of the node
6052 Set_Paren_Count
(Index_Node
, Paren_Count
(N
));
6054 -- Since we are correcting a node classification error made
6055 -- by the parser, we call Replace rather than Rewrite.
6057 Replace
(N
, Index_Node
);
6059 Set_Etype
(Prefix
(N
), Ret_Type
);
6061 Resolve_Indexed_Component
(N
, Typ
);
6062 Check_Elab_Call
(Prefix
(N
));
6070 -- If the called function is not declared in the main unit and it
6071 -- returns the limited view of type then use the available view (as
6072 -- is done in Try_Object_Operation) to prevent back-end confusion;
6073 -- the call must appear in a context where the nonlimited view is
6074 -- available. If the called function is in the extended main unit
6075 -- then no action is needed, because the back end handles this case.
6077 if not In_Extended_Main_Code_Unit
(Nam
)
6078 and then From_Limited_With
(Etype
(Nam
))
6080 Set_Etype
(Nam
, Available_View
(Etype
(Nam
)));
6083 Set_Etype
(N
, Etype
(Nam
));
6086 -- In the case where the call is to an overloaded subprogram, Analyze
6087 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
6088 -- such a case Normalize_Actuals needs to be called once more to order
6089 -- the actuals correctly. Otherwise the call will have the ordering
6090 -- given by the last overloaded subprogram whether this is the correct
6091 -- one being called or not.
6093 if Is_Overloaded
(Subp
) then
6094 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
6095 pragma Assert
(Norm_OK
);
6098 -- In any case, call is fully resolved now. Reset Overload flag, to
6099 -- prevent subsequent overload resolution if node is analyzed again
6101 Set_Is_Overloaded
(Subp
, False);
6102 Set_Is_Overloaded
(N
, False);
6104 -- A Ghost entity must appear in a specific context
6106 if Is_Ghost_Entity
(Nam
) and then Comes_From_Source
(N
) then
6107 Check_Ghost_Context
(Nam
, N
);
6110 -- If we are calling the current subprogram from immediately within its
6111 -- body, then that is the case where we can sometimes detect cases of
6112 -- infinite recursion statically. Do not try this in case restriction
6113 -- No_Recursion is in effect anyway, and do it only for source calls.
6115 if Comes_From_Source
(N
) then
6116 Scop
:= Current_Scope
;
6118 -- Check violation of SPARK_05 restriction which does not permit
6119 -- a subprogram body to contain a call to the subprogram directly.
6121 if Restriction_Check_Required
(SPARK_05
)
6122 and then Same_Or_Aliased_Subprograms
(Nam
, Scop
)
6124 Check_SPARK_05_Restriction
6125 ("subprogram may not contain direct call to itself", N
);
6128 -- Issue warning for possible infinite recursion in the absence
6129 -- of the No_Recursion restriction.
6131 if Same_Or_Aliased_Subprograms
(Nam
, Scop
)
6132 and then not Restriction_Active
(No_Recursion
)
6133 and then Check_Infinite_Recursion
(N
)
6135 -- Here we detected and flagged an infinite recursion, so we do
6136 -- not need to test the case below for further warnings. Also we
6137 -- are all done if we now have a raise SE node.
6139 if Nkind
(N
) = N_Raise_Storage_Error
then
6143 -- If call is to immediately containing subprogram, then check for
6144 -- the case of a possible run-time detectable infinite recursion.
6147 Scope_Loop
: while Scop
/= Standard_Standard
loop
6148 if Same_Or_Aliased_Subprograms
(Nam
, Scop
) then
6150 -- Although in general case, recursion is not statically
6151 -- checkable, the case of calling an immediately containing
6152 -- subprogram is easy to catch.
6154 Check_Restriction
(No_Recursion
, N
);
6156 -- If the recursive call is to a parameterless subprogram,
6157 -- then even if we can't statically detect infinite
6158 -- recursion, this is pretty suspicious, and we output a
6159 -- warning. Furthermore, we will try later to detect some
6160 -- cases here at run time by expanding checking code (see
6161 -- Detect_Infinite_Recursion in package Exp_Ch6).
6163 -- If the recursive call is within a handler, do not emit a
6164 -- warning, because this is a common idiom: loop until input
6165 -- is correct, catch illegal input in handler and restart.
6167 if No
(First_Formal
(Nam
))
6168 and then Etype
(Nam
) = Standard_Void_Type
6169 and then not Error_Posted
(N
)
6170 and then Nkind
(Parent
(N
)) /= N_Exception_Handler
6172 -- For the case of a procedure call. We give the message
6173 -- only if the call is the first statement in a sequence
6174 -- of statements, or if all previous statements are
6175 -- simple assignments. This is simply a heuristic to
6176 -- decrease false positives, without losing too many good
6177 -- warnings. The idea is that these previous statements
6178 -- may affect global variables the procedure depends on.
6179 -- We also exclude raise statements, that may arise from
6180 -- constraint checks and are probably unrelated to the
6181 -- intended control flow.
6183 if Nkind
(N
) = N_Procedure_Call_Statement
6184 and then Is_List_Member
(N
)
6190 while Present
(P
) loop
6191 if not Nkind_In
(P
, N_Assignment_Statement
,
6192 N_Raise_Constraint_Error
)
6202 -- Do not give warning if we are in a conditional context
6205 K
: constant Node_Kind
:= Nkind
(Parent
(N
));
6207 if (K
= N_Loop_Statement
6208 and then Present
(Iteration_Scheme
(Parent
(N
))))
6209 or else K
= N_If_Statement
6210 or else K
= N_Elsif_Part
6211 or else K
= N_Case_Statement_Alternative
6217 -- Here warning is to be issued
6219 Set_Has_Recursive_Call
(Nam
);
6220 Error_Msg_Warn
:= SPARK_Mode
/= On
;
6221 Error_Msg_N
("possible infinite recursion<<!", N
);
6222 Error_Msg_N
("\Storage_Error ]<<!", N
);
6228 Scop
:= Scope
(Scop
);
6229 end loop Scope_Loop
;
6233 -- Check obsolescent reference to Ada.Characters.Handling subprogram
6235 Check_Obsolescent_2005_Entity
(Nam
, Subp
);
6237 -- If subprogram name is a predefined operator, it was given in
6238 -- functional notation. Replace call node with operator node, so
6239 -- that actuals can be resolved appropriately.
6241 if Is_Predefined_Op
(Nam
) or else Ekind
(Nam
) = E_Operator
then
6242 Make_Call_Into_Operator
(N
, Typ
, Entity
(Name
(N
)));
6245 elsif Present
(Alias
(Nam
))
6246 and then Is_Predefined_Op
(Alias
(Nam
))
6248 Resolve_Actuals
(N
, Nam
);
6249 Make_Call_Into_Operator
(N
, Typ
, Alias
(Nam
));
6253 -- Create a transient scope if the resulting type requires it
6255 -- There are several notable exceptions:
6257 -- a) In init procs, the transient scope overhead is not needed, and is
6258 -- even incorrect when the call is a nested initialization call for a
6259 -- component whose expansion may generate adjust calls. However, if the
6260 -- call is some other procedure call within an initialization procedure
6261 -- (for example a call to Create_Task in the init_proc of the task
6262 -- run-time record) a transient scope must be created around this call.
6264 -- b) Enumeration literal pseudo-calls need no transient scope
6266 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
6267 -- functions) do not use the secondary stack even though the return
6268 -- type may be unconstrained.
6270 -- d) Calls to a build-in-place function, since such functions may
6271 -- allocate their result directly in a target object, and cases where
6272 -- the result does get allocated in the secondary stack are checked for
6273 -- within the specialized Exp_Ch6 procedures for expanding those
6274 -- build-in-place calls.
6276 -- e) Calls to inlinable expression functions do not use the secondary
6277 -- stack (since the call will be replaced by its returned object).
6279 -- f) If the subprogram is marked Inline_Always, then even if it returns
6280 -- an unconstrained type the call does not require use of the secondary
6281 -- stack. However, inlining will only take place if the body to inline
6282 -- is already present. It may not be available if e.g. the subprogram is
6283 -- declared in a child instance.
6285 -- If this is an initialization call for a type whose construction
6286 -- uses the secondary stack, and it is not a nested call to initialize
6287 -- a component, we do need to create a transient scope for it. We
6288 -- check for this by traversing the type in Check_Initialization_Call.
6291 and then Has_Pragma_Inline
(Nam
)
6292 and then Nkind
(Unit_Declaration_Node
(Nam
)) = N_Subprogram_Declaration
6293 and then Present
(Body_To_Inline
(Unit_Declaration_Node
(Nam
)))
6297 elsif Ekind
(Nam
) = E_Enumeration_Literal
6298 or else Is_Build_In_Place_Function
(Nam
)
6299 or else Is_Intrinsic_Subprogram
(Nam
)
6300 or else Is_Inlinable_Expression_Function
(Nam
)
6304 elsif Expander_Active
6305 and then Is_Type
(Etype
(Nam
))
6306 and then Requires_Transient_Scope
(Etype
(Nam
))
6308 (not Within_Init_Proc
6310 (not Is_Init_Proc
(Nam
) and then Ekind
(Nam
) /= E_Function
))
6312 Establish_Transient_Scope
(N
, Sec_Stack
=> True);
6314 -- If the call appears within the bounds of a loop, it will
6315 -- be rewritten and reanalyzed, nothing left to do here.
6317 if Nkind
(N
) /= N_Function_Call
then
6321 elsif Is_Init_Proc
(Nam
)
6322 and then not Within_Init_Proc
6324 Check_Initialization_Call
(N
, Nam
);
6327 -- A protected function cannot be called within the definition of the
6328 -- enclosing protected type, unless it is part of a pre/postcondition
6329 -- on another protected operation. This may appear in the entry wrapper
6330 -- created for an entry with preconditions.
6332 if Is_Protected_Type
(Scope
(Nam
))
6333 and then In_Open_Scopes
(Scope
(Nam
))
6334 and then not Has_Completion
(Scope
(Nam
))
6335 and then not In_Spec_Expression
6336 and then not Is_Entry_Wrapper
(Current_Scope
)
6339 ("& cannot be called before end of protected definition", N
, Nam
);
6342 -- Propagate interpretation to actuals, and add default expressions
6345 if Present
(First_Formal
(Nam
)) then
6346 Resolve_Actuals
(N
, Nam
);
6348 -- Overloaded literals are rewritten as function calls, for purpose of
6349 -- resolution. After resolution, we can replace the call with the
6352 elsif Ekind
(Nam
) = E_Enumeration_Literal
then
6353 Copy_Node
(Subp
, N
);
6354 Resolve_Entity_Name
(N
, Typ
);
6356 -- Avoid validation, since it is a static function call
6358 Generate_Reference
(Nam
, Subp
);
6362 -- If the subprogram is not global, then kill all saved values and
6363 -- checks. This is a bit conservative, since in many cases we could do
6364 -- better, but it is not worth the effort. Similarly, we kill constant
6365 -- values. However we do not need to do this for internal entities
6366 -- (unless they are inherited user-defined subprograms), since they
6367 -- are not in the business of molesting local values.
6369 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
6370 -- kill all checks and values for calls to global subprograms. This
6371 -- takes care of the case where an access to a local subprogram is
6372 -- taken, and could be passed directly or indirectly and then called
6373 -- from almost any context.
6375 -- Note: we do not do this step till after resolving the actuals. That
6376 -- way we still take advantage of the current value information while
6377 -- scanning the actuals.
6379 -- We suppress killing values if we are processing the nodes associated
6380 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
6381 -- type kills all the values as part of analyzing the code that
6382 -- initializes the dispatch tables.
6384 if Inside_Freezing_Actions
= 0
6385 and then (not Is_Library_Level_Entity
(Nam
)
6386 or else Suppress_Value_Tracking_On_Call
6387 (Nearest_Dynamic_Scope
(Current_Scope
)))
6388 and then (Comes_From_Source
(Nam
)
6389 or else (Present
(Alias
(Nam
))
6390 and then Comes_From_Source
(Alias
(Nam
))))
6392 Kill_Current_Values
;
6395 -- If we are warning about unread OUT parameters, this is the place to
6396 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
6397 -- after the above call to Kill_Current_Values (since that call clears
6398 -- the Last_Assignment field of all local variables).
6400 if (Warn_On_Modified_Unread
or Warn_On_All_Unread_Out_Parameters
)
6401 and then Comes_From_Source
(N
)
6402 and then In_Extended_Main_Source_Unit
(N
)
6409 F
:= First_Formal
(Nam
);
6410 A
:= First_Actual
(N
);
6411 while Present
(F
) and then Present
(A
) loop
6412 if Ekind_In
(F
, E_Out_Parameter
, E_In_Out_Parameter
)
6413 and then Warn_On_Modified_As_Out_Parameter
(F
)
6414 and then Is_Entity_Name
(A
)
6415 and then Present
(Entity
(A
))
6416 and then Comes_From_Source
(N
)
6417 and then Safe_To_Capture_Value
(N
, Entity
(A
))
6419 Set_Last_Assignment
(Entity
(A
), A
);
6428 -- If the subprogram is a primitive operation, check whether or not
6429 -- it is a correct dispatching call.
6431 if Is_Overloadable
(Nam
)
6432 and then Is_Dispatching_Operation
(Nam
)
6434 Check_Dispatching_Call
(N
);
6436 elsif Ekind
(Nam
) /= E_Subprogram_Type
6437 and then Is_Abstract_Subprogram
(Nam
)
6438 and then not In_Instance
6440 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Nam
);
6443 -- If this is a dispatching call, generate the appropriate reference,
6444 -- for better source navigation in GPS.
6446 if Is_Overloadable
(Nam
)
6447 and then Present
(Controlling_Argument
(N
))
6449 Generate_Reference
(Nam
, Subp
, 'R');
6451 -- Normal case, not a dispatching call: generate a call reference
6454 Generate_Reference
(Nam
, Subp
, 's');
6457 if Is_Intrinsic_Subprogram
(Nam
) then
6458 Check_Intrinsic_Call
(N
);
6461 -- Check for violation of restriction No_Specific_Termination_Handlers
6462 -- and warn on a potentially blocking call to Abort_Task.
6464 if Restriction_Check_Required
(No_Specific_Termination_Handlers
)
6465 and then (Is_RTE
(Nam
, RE_Set_Specific_Handler
)
6467 Is_RTE
(Nam
, RE_Specific_Handler
))
6469 Check_Restriction
(No_Specific_Termination_Handlers
, N
);
6471 elsif Is_RTE
(Nam
, RE_Abort_Task
) then
6472 Check_Potentially_Blocking_Operation
(N
);
6475 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
6476 -- timing event violates restriction No_Relative_Delay (AI-0211). We
6477 -- need to check the second argument to determine whether it is an
6478 -- absolute or relative timing event.
6480 if Restriction_Check_Required
(No_Relative_Delay
)
6481 and then Is_RTE
(Nam
, RE_Set_Handler
)
6482 and then Is_RTE
(Etype
(Next_Actual
(First_Actual
(N
))), RE_Time_Span
)
6484 Check_Restriction
(No_Relative_Delay
, N
);
6487 -- Issue an error for a call to an eliminated subprogram. This routine
6488 -- will not perform the check if the call appears within a default
6491 Check_For_Eliminated_Subprogram
(Subp
, Nam
);
6493 -- In formal mode, the primitive operations of a tagged type or type
6494 -- extension do not include functions that return the tagged type.
6496 if Nkind
(N
) = N_Function_Call
6497 and then Is_Tagged_Type
(Etype
(N
))
6498 and then Is_Entity_Name
(Name
(N
))
6499 and then Is_Inherited_Operation_For_Type
(Entity
(Name
(N
)), Etype
(N
))
6501 Check_SPARK_05_Restriction
("function not inherited", N
);
6504 -- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
6505 -- class-wide and the call dispatches on result in a context that does
6506 -- not provide a tag, the call raises Program_Error.
6508 if Nkind
(N
) = N_Function_Call
6509 and then In_Instance
6510 and then Is_Generic_Actual_Type
(Typ
)
6511 and then Is_Class_Wide_Type
(Typ
)
6512 and then Has_Controlling_Result
(Nam
)
6513 and then Nkind
(Parent
(N
)) = N_Object_Declaration
6515 -- Verify that none of the formals are controlling
6518 Call_OK
: Boolean := False;
6522 F
:= First_Formal
(Nam
);
6523 while Present
(F
) loop
6524 if Is_Controlling_Formal
(F
) then
6533 Error_Msg_Warn
:= SPARK_Mode
/= On
;
6534 Error_Msg_N
("!cannot determine tag of result<<", N
);
6535 Error_Msg_N
("\Program_Error [<<!", N
);
6537 Make_Raise_Program_Error
(Sloc
(N
),
6538 Reason
=> PE_Explicit_Raise
));
6543 -- Check for calling a function with OUT or IN OUT parameter when the
6544 -- calling context (us right now) is not Ada 2012, so does not allow
6545 -- OUT or IN OUT parameters in function calls. Functions declared in
6546 -- a predefined unit are OK, as they may be called indirectly from a
6547 -- user-declared instantiation.
6549 if Ada_Version
< Ada_2012
6550 and then Ekind
(Nam
) = E_Function
6551 and then Has_Out_Or_In_Out_Parameter
(Nam
)
6552 and then not In_Predefined_Unit
(Nam
)
6554 Error_Msg_NE
("& has at least one OUT or `IN OUT` parameter", N
, Nam
);
6555 Error_Msg_N
("\call to this function only allowed in Ada 2012", N
);
6558 -- Check the dimensions of the actuals in the call. For function calls,
6559 -- propagate the dimensions from the returned type to N.
6561 Analyze_Dimension_Call
(N
, Nam
);
6563 -- All done, evaluate call and deal with elaboration issues
6566 Check_Elab_Call
(N
);
6568 -- In GNATprove mode, expansion is disabled, but we want to inline some
6569 -- subprograms to facilitate formal verification. Indirect calls through
6570 -- a subprogram type or within a generic cannot be inlined. Inlining is
6571 -- performed only for calls subject to SPARK_Mode on.
6574 and then SPARK_Mode
= On
6575 and then Is_Overloadable
(Nam
)
6576 and then not Inside_A_Generic
6578 Nam_UA
:= Ultimate_Alias
(Nam
);
6579 Nam_Decl
:= Unit_Declaration_Node
(Nam_UA
);
6581 if Nkind
(Nam_Decl
) = N_Subprogram_Declaration
then
6582 Body_Id
:= Corresponding_Body
(Nam_Decl
);
6584 -- Nothing to do if the subprogram is not eligible for inlining in
6587 if not Is_Inlined_Always
(Nam_UA
)
6588 or else not Can_Be_Inlined_In_GNATprove_Mode
(Nam_UA
, Body_Id
)
6592 -- Calls cannot be inlined inside assertions, as GNATprove treats
6593 -- assertions as logic expressions.
6595 elsif In_Assertion_Expr
/= 0 then
6597 ("cannot inline & (in assertion expression)?", N
, Nam_UA
);
6599 -- Calls cannot be inlined inside default expressions
6601 elsif In_Default_Expr
then
6603 ("cannot inline & (in default expression)?", N
, Nam_UA
);
6605 -- Inlining should not be performed during pre-analysis
6607 elsif Full_Analysis
then
6609 -- With the one-pass inlining technique, a call cannot be
6610 -- inlined if the corresponding body has not been seen yet.
6612 if No
(Body_Id
) then
6614 ("cannot inline & (body not seen yet)?", N
, Nam_UA
);
6616 -- Nothing to do if there is no body to inline, indicating that
6617 -- the subprogram is not suitable for inlining in GNATprove
6620 elsif No
(Body_To_Inline
(Nam_Decl
)) then
6623 -- Do not inline calls inside expression functions, as this
6624 -- would prevent interpreting them as logical formulas in
6627 elsif Present
(Current_Subprogram
)
6629 Is_Expression_Function_Or_Completion
(Current_Subprogram
)
6632 ("cannot inline & (inside expression function)?",
6635 -- Calls cannot be inlined inside potentially unevaluated
6636 -- expressions, as this would create complex actions inside
6637 -- expressions, that are not handled by GNATprove.
6639 elsif Is_Potentially_Unevaluated
(N
) then
6641 ("cannot inline & (in potentially unevaluated context)?",
6644 -- Do not inline calls which would possibly lead to missing a
6645 -- type conversion check on an input parameter.
6647 elsif not Call_Can_Be_Inlined_In_GNATprove_Mode
(N
, Nam
) then
6649 ("cannot inline & (possible check on input parameters)?",
6652 -- Otherwise, inline the call
6655 Expand_Inlined_Call
(N
, Nam_UA
, Nam
);
6661 Warn_On_Overlapping_Actuals
(Nam
, N
);
6664 -----------------------------
6665 -- Resolve_Case_Expression --
6666 -----------------------------
6668 procedure Resolve_Case_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
6671 Alt_Typ
: Entity_Id
;
6675 Alt
:= First
(Alternatives
(N
));
6676 while Present
(Alt
) loop
6677 Alt_Expr
:= Expression
(Alt
);
6678 Resolve
(Alt_Expr
, Typ
);
6679 Alt_Typ
:= Etype
(Alt_Expr
);
6681 -- When the expression is of a scalar subtype different from the
6682 -- result subtype, then insert a conversion to ensure the generation
6683 -- of a constraint check.
6685 if Is_Scalar_Type
(Alt_Typ
) and then Alt_Typ
/= Typ
then
6686 Rewrite
(Alt_Expr
, Convert_To
(Typ
, Alt_Expr
));
6687 Analyze_And_Resolve
(Alt_Expr
, Typ
);
6693 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
6694 -- dynamically tagged must be known statically.
6696 if Is_Tagged_Type
(Typ
) and then not Is_Class_Wide_Type
(Typ
) then
6697 Alt
:= First
(Alternatives
(N
));
6698 Is_Dyn
:= Is_Dynamically_Tagged
(Expression
(Alt
));
6700 while Present
(Alt
) loop
6701 if Is_Dynamically_Tagged
(Expression
(Alt
)) /= Is_Dyn
then
6703 ("all or none of the dependent expressions can be "
6704 & "dynamically tagged", N
);
6712 Eval_Case_Expression
(N
);
6713 end Resolve_Case_Expression
;
6715 -------------------------------
6716 -- Resolve_Character_Literal --
6717 -------------------------------
6719 procedure Resolve_Character_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
6720 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
6724 -- Verify that the character does belong to the type of the context
6726 Set_Etype
(N
, B_Typ
);
6727 Eval_Character_Literal
(N
);
6729 -- Wide_Wide_Character literals must always be defined, since the set
6730 -- of wide wide character literals is complete, i.e. if a character
6731 -- literal is accepted by the parser, then it is OK for wide wide
6732 -- character (out of range character literals are rejected).
6734 if Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
6737 -- Always accept character literal for type Any_Character, which
6738 -- occurs in error situations and in comparisons of literals, both
6739 -- of which should accept all literals.
6741 elsif B_Typ
= Any_Character
then
6744 -- For Standard.Character or a type derived from it, check that the
6745 -- literal is in range.
6747 elsif Root_Type
(B_Typ
) = Standard_Character
then
6748 if In_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6752 -- For Standard.Wide_Character or a type derived from it, check that the
6753 -- literal is in range.
6755 elsif Root_Type
(B_Typ
) = Standard_Wide_Character
then
6756 if In_Wide_Character_Range
(UI_To_CC
(Char_Literal_Value
(N
))) then
6760 -- For Standard.Wide_Wide_Character or a type derived from it, we
6761 -- know the literal is in range, since the parser checked.
6763 elsif Root_Type
(B_Typ
) = Standard_Wide_Wide_Character
then
6766 -- If the entity is already set, this has already been resolved in a
6767 -- generic context, or comes from expansion. Nothing else to do.
6769 elsif Present
(Entity
(N
)) then
6772 -- Otherwise we have a user defined character type, and we can use the
6773 -- standard visibility mechanisms to locate the referenced entity.
6776 C
:= Current_Entity
(N
);
6777 while Present
(C
) loop
6778 if Etype
(C
) = B_Typ
then
6779 Set_Entity_With_Checks
(N
, C
);
6780 Generate_Reference
(C
, N
);
6788 -- If we fall through, then the literal does not match any of the
6789 -- entries of the enumeration type. This isn't just a constraint error
6790 -- situation, it is an illegality (see RM 4.2).
6793 ("character not defined for }", N
, First_Subtype
(B_Typ
));
6794 end Resolve_Character_Literal
;
6796 ---------------------------
6797 -- Resolve_Comparison_Op --
6798 ---------------------------
6800 -- Context requires a boolean type, and plays no role in resolution.
6801 -- Processing identical to that for equality operators. The result type is
6802 -- the base type, which matters when pathological subtypes of booleans with
6803 -- limited ranges are used.
6805 procedure Resolve_Comparison_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
6806 L
: constant Node_Id
:= Left_Opnd
(N
);
6807 R
: constant Node_Id
:= Right_Opnd
(N
);
6811 -- If this is an intrinsic operation which is not predefined, use the
6812 -- types of its declared arguments to resolve the possibly overloaded
6813 -- operands. Otherwise the operands are unambiguous and specify the
6816 if Scope
(Entity
(N
)) /= Standard_Standard
then
6817 T
:= Etype
(First_Entity
(Entity
(N
)));
6820 T
:= Find_Unique_Type
(L
, R
);
6822 if T
= Any_Fixed
then
6823 T
:= Unique_Fixed_Point_Type
(L
);
6827 Set_Etype
(N
, Base_Type
(Typ
));
6828 Generate_Reference
(T
, N
, ' ');
6830 -- Skip remaining processing if already set to Any_Type
6832 if T
= Any_Type
then
6836 -- Deal with other error cases
6838 if T
= Any_String
or else
6839 T
= Any_Composite
or else
6842 if T
= Any_Character
then
6843 Ambiguous_Character
(L
);
6845 Error_Msg_N
("ambiguous operands for comparison", N
);
6848 Set_Etype
(N
, Any_Type
);
6852 -- Resolve the operands if types OK
6856 Check_Unset_Reference
(L
);
6857 Check_Unset_Reference
(R
);
6858 Generate_Operator_Reference
(N
, T
);
6859 Check_Low_Bound_Tested
(N
);
6861 -- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
6862 -- types or array types except String.
6864 if Is_Boolean_Type
(T
) then
6865 Check_SPARK_05_Restriction
6866 ("comparison is not defined on Boolean type", N
);
6868 elsif Is_Array_Type
(T
)
6869 and then Base_Type
(T
) /= Standard_String
6871 Check_SPARK_05_Restriction
6872 ("comparison is not defined on array types other than String", N
);
6875 -- Check comparison on unordered enumeration
6877 if Bad_Unordered_Enumeration_Reference
(N
, Etype
(L
)) then
6878 Error_Msg_Sloc
:= Sloc
(Etype
(L
));
6880 ("comparison on unordered enumeration type& declared#?U?",
6884 -- Evaluate the relation (note we do this after the above check since
6885 -- this Eval call may change N to True/False.
6887 Analyze_Dimension
(N
);
6888 Eval_Relational_Op
(N
);
6889 end Resolve_Comparison_Op
;
6891 -----------------------------------------
6892 -- Resolve_Discrete_Subtype_Indication --
6893 -----------------------------------------
6895 procedure Resolve_Discrete_Subtype_Indication
6903 Analyze
(Subtype_Mark
(N
));
6904 S
:= Entity
(Subtype_Mark
(N
));
6906 if Nkind
(Constraint
(N
)) /= N_Range_Constraint
then
6907 Error_Msg_N
("expect range constraint for discrete type", N
);
6908 Set_Etype
(N
, Any_Type
);
6911 R
:= Range_Expression
(Constraint
(N
));
6919 if Base_Type
(S
) /= Base_Type
(Typ
) then
6921 ("expect subtype of }", N
, First_Subtype
(Typ
));
6923 -- Rewrite the constraint as a range of Typ
6924 -- to allow compilation to proceed further.
6927 Rewrite
(Low_Bound
(R
),
6928 Make_Attribute_Reference
(Sloc
(Low_Bound
(R
)),
6929 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
6930 Attribute_Name
=> Name_First
));
6931 Rewrite
(High_Bound
(R
),
6932 Make_Attribute_Reference
(Sloc
(High_Bound
(R
)),
6933 Prefix
=> New_Occurrence_Of
(Typ
, Sloc
(R
)),
6934 Attribute_Name
=> Name_First
));
6938 Set_Etype
(N
, Etype
(R
));
6940 -- Additionally, we must check that the bounds are compatible
6941 -- with the given subtype, which might be different from the
6942 -- type of the context.
6944 Apply_Range_Check
(R
, S
);
6946 -- ??? If the above check statically detects a Constraint_Error
6947 -- it replaces the offending bound(s) of the range R with a
6948 -- Constraint_Error node. When the itype which uses these bounds
6949 -- is frozen the resulting call to Duplicate_Subexpr generates
6950 -- a new temporary for the bounds.
6952 -- Unfortunately there are other itypes that are also made depend
6953 -- on these bounds, so when Duplicate_Subexpr is called they get
6954 -- a forward reference to the newly created temporaries and Gigi
6955 -- aborts on such forward references. This is probably sign of a
6956 -- more fundamental problem somewhere else in either the order of
6957 -- itype freezing or the way certain itypes are constructed.
6959 -- To get around this problem we call Remove_Side_Effects right
6960 -- away if either bounds of R are a Constraint_Error.
6963 L
: constant Node_Id
:= Low_Bound
(R
);
6964 H
: constant Node_Id
:= High_Bound
(R
);
6967 if Nkind
(L
) = N_Raise_Constraint_Error
then
6968 Remove_Side_Effects
(L
);
6971 if Nkind
(H
) = N_Raise_Constraint_Error
then
6972 Remove_Side_Effects
(H
);
6976 Check_Unset_Reference
(Low_Bound
(R
));
6977 Check_Unset_Reference
(High_Bound
(R
));
6980 end Resolve_Discrete_Subtype_Indication
;
6982 -------------------------
6983 -- Resolve_Entity_Name --
6984 -------------------------
6986 -- Used to resolve identifiers and expanded names
6988 procedure Resolve_Entity_Name
(N
: Node_Id
; Typ
: Entity_Id
) is
6989 function Is_Assignment_Or_Object_Expression
6991 Expr
: Node_Id
) return Boolean;
6992 -- Determine whether node Context denotes an assignment statement or an
6993 -- object declaration whose expression is node Expr.
6995 ----------------------------------------
6996 -- Is_Assignment_Or_Object_Expression --
6997 ----------------------------------------
6999 function Is_Assignment_Or_Object_Expression
7001 Expr
: Node_Id
) return Boolean
7004 if Nkind_In
(Context
, N_Assignment_Statement
,
7005 N_Object_Declaration
)
7006 and then Expression
(Context
) = Expr
7010 -- Check whether a construct that yields a name is the expression of
7011 -- an assignment statement or an object declaration.
7013 elsif (Nkind_In
(Context
, N_Attribute_Reference
,
7014 N_Explicit_Dereference
,
7015 N_Indexed_Component
,
7016 N_Selected_Component
,
7018 and then Prefix
(Context
) = Expr
)
7020 (Nkind_In
(Context
, N_Type_Conversion
,
7021 N_Unchecked_Type_Conversion
)
7022 and then Expression
(Context
) = Expr
)
7025 Is_Assignment_Or_Object_Expression
7026 (Context
=> Parent
(Context
),
7029 -- Otherwise the context is not an assignment statement or an object
7035 end Is_Assignment_Or_Object_Expression
;
7039 E
: constant Entity_Id
:= Entity
(N
);
7042 -- Start of processing for Resolve_Entity_Name
7045 -- If garbage from errors, set to Any_Type and return
7047 if No
(E
) and then Total_Errors_Detected
/= 0 then
7048 Set_Etype
(N
, Any_Type
);
7052 -- Replace named numbers by corresponding literals. Note that this is
7053 -- the one case where Resolve_Entity_Name must reset the Etype, since
7054 -- it is currently marked as universal.
7056 if Ekind
(E
) = E_Named_Integer
then
7058 Eval_Named_Integer
(N
);
7060 elsif Ekind
(E
) = E_Named_Real
then
7062 Eval_Named_Real
(N
);
7064 -- For enumeration literals, we need to make sure that a proper style
7065 -- check is done, since such literals are overloaded, and thus we did
7066 -- not do a style check during the first phase of analysis.
7068 elsif Ekind
(E
) = E_Enumeration_Literal
then
7069 Set_Entity_With_Checks
(N
, E
);
7070 Eval_Entity_Name
(N
);
7072 -- Case of (sub)type name appearing in a context where an expression
7073 -- is expected. This is legal if occurrence is a current instance.
7074 -- See RM 8.6 (17/3).
7076 elsif Is_Type
(E
) then
7077 if Is_Current_Instance
(N
) then
7080 -- Any other use is an error
7084 ("invalid use of subtype mark in expression or call", N
);
7087 -- Check discriminant use if entity is discriminant in current scope,
7088 -- i.e. discriminant of record or concurrent type currently being
7089 -- analyzed. Uses in corresponding body are unrestricted.
7091 elsif Ekind
(E
) = E_Discriminant
7092 and then Scope
(E
) = Current_Scope
7093 and then not Has_Completion
(Current_Scope
)
7095 Check_Discriminant_Use
(N
);
7097 -- A parameterless generic function cannot appear in a context that
7098 -- requires resolution.
7100 elsif Ekind
(E
) = E_Generic_Function
then
7101 Error_Msg_N
("illegal use of generic function", N
);
7103 -- In Ada 83 an OUT parameter cannot be read
7105 elsif Ekind
(E
) = E_Out_Parameter
7106 and then (Nkind
(Parent
(N
)) in N_Op
7107 or else Nkind
(Parent
(N
)) = N_Explicit_Dereference
7108 or else Is_Assignment_Or_Object_Expression
7109 (Context
=> Parent
(N
),
7112 if Ada_Version
= Ada_83
then
7113 Error_Msg_N
("(Ada 83) illegal reading of out parameter", N
);
7116 -- In all other cases, just do the possible static evaluation
7119 -- A deferred constant that appears in an expression must have a
7120 -- completion, unless it has been removed by in-place expansion of
7121 -- an aggregate. A constant that is a renaming does not need
7124 if Ekind
(E
) = E_Constant
7125 and then Comes_From_Source
(E
)
7126 and then No
(Constant_Value
(E
))
7127 and then Is_Frozen
(Etype
(E
))
7128 and then not In_Spec_Expression
7129 and then not Is_Imported
(E
)
7130 and then Nkind
(Parent
(E
)) /= N_Object_Renaming_Declaration
7132 if No_Initialization
(Parent
(E
))
7133 or else (Present
(Full_View
(E
))
7134 and then No_Initialization
(Parent
(Full_View
(E
))))
7139 ("deferred constant is frozen before completion", N
);
7143 Eval_Entity_Name
(N
);
7148 -- When the entity appears in a parameter association, retrieve the
7149 -- related subprogram call.
7151 if Nkind
(Par
) = N_Parameter_Association
then
7152 Par
:= Parent
(Par
);
7155 if Comes_From_Source
(N
) then
7157 -- The following checks are only relevant when SPARK_Mode is on as
7158 -- they are not standard Ada legality rules.
7160 if SPARK_Mode
= On
then
7162 -- An effectively volatile object subject to enabled properties
7163 -- Async_Writers or Effective_Reads must appear in non-interfering
7164 -- context (SPARK RM 7.1.3(12)).
7167 and then Is_Effectively_Volatile
(E
)
7168 and then (Async_Writers_Enabled
(E
)
7169 or else Effective_Reads_Enabled
(E
))
7170 and then not Is_OK_Volatile_Context
(Par
, N
)
7173 ("volatile object cannot appear in this context "
7174 & "(SPARK RM 7.1.3(12))", N
);
7177 -- Check for possible elaboration issues with respect to reads of
7178 -- variables. The act of renaming the variable is not considered a
7179 -- read as it simply establishes an alias.
7181 if Ekind
(E
) = E_Variable
7182 and then Dynamic_Elaboration_Checks
7183 and then Nkind
(Par
) /= N_Object_Renaming_Declaration
7185 Check_Elab_Call
(N
);
7188 -- The variable may eventually become a constituent of a single
7189 -- protected/task type. Record the reference now and verify its
7190 -- legality when analyzing the contract of the variable
7193 if Ekind
(E
) = E_Variable
then
7194 Record_Possible_Part_Of_Reference
(E
, N
);
7198 -- A Ghost entity must appear in a specific context
7200 if Is_Ghost_Entity
(E
) then
7201 Check_Ghost_Context
(E
, N
);
7204 end Resolve_Entity_Name
;
7210 procedure Resolve_Entry
(Entry_Name
: Node_Id
) is
7211 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
7219 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
;
7220 -- If the bounds of the entry family being called depend on task
7221 -- discriminants, build a new index subtype where a discriminant is
7222 -- replaced with the value of the discriminant of the target task.
7223 -- The target task is the prefix of the entry name in the call.
7225 -----------------------
7226 -- Actual_Index_Type --
7227 -----------------------
7229 function Actual_Index_Type
(E
: Entity_Id
) return Entity_Id
is
7230 Typ
: constant Entity_Id
:= Entry_Index_Type
(E
);
7231 Tsk
: constant Entity_Id
:= Scope
(E
);
7232 Lo
: constant Node_Id
:= Type_Low_Bound
(Typ
);
7233 Hi
: constant Node_Id
:= Type_High_Bound
(Typ
);
7236 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
;
7237 -- If the bound is given by a discriminant, replace with a reference
7238 -- to the discriminant of the same name in the target task. If the
7239 -- entry name is the target of a requeue statement and the entry is
7240 -- in the current protected object, the bound to be used is the
7241 -- discriminal of the object (see Apply_Range_Checks for details of
7242 -- the transformation).
7244 -----------------------------
7245 -- Actual_Discriminant_Ref --
7246 -----------------------------
7248 function Actual_Discriminant_Ref
(Bound
: Node_Id
) return Node_Id
is
7249 Typ
: constant Entity_Id
:= Etype
(Bound
);
7253 Remove_Side_Effects
(Bound
);
7255 if not Is_Entity_Name
(Bound
)
7256 or else Ekind
(Entity
(Bound
)) /= E_Discriminant
7260 elsif Is_Protected_Type
(Tsk
)
7261 and then In_Open_Scopes
(Tsk
)
7262 and then Nkind
(Parent
(Entry_Name
)) = N_Requeue_Statement
7264 -- Note: here Bound denotes a discriminant of the corresponding
7265 -- record type tskV, whose discriminal is a formal of the
7266 -- init-proc tskVIP. What we want is the body discriminal,
7267 -- which is associated to the discriminant of the original
7268 -- concurrent type tsk.
7270 return New_Occurrence_Of
7271 (Find_Body_Discriminal
(Entity
(Bound
)), Loc
);
7275 Make_Selected_Component
(Loc
,
7276 Prefix
=> New_Copy_Tree
(Prefix
(Prefix
(Entry_Name
))),
7277 Selector_Name
=> New_Occurrence_Of
(Entity
(Bound
), Loc
));
7282 end Actual_Discriminant_Ref
;
7284 -- Start of processing for Actual_Index_Type
7287 if not Has_Discriminants
(Tsk
)
7288 or else (not Is_Entity_Name
(Lo
) and then not Is_Entity_Name
(Hi
))
7290 return Entry_Index_Type
(E
);
7293 New_T
:= Create_Itype
(Ekind
(Typ
), Parent
(Entry_Name
));
7294 Set_Etype
(New_T
, Base_Type
(Typ
));
7295 Set_Size_Info
(New_T
, Typ
);
7296 Set_RM_Size
(New_T
, RM_Size
(Typ
));
7297 Set_Scalar_Range
(New_T
,
7298 Make_Range
(Sloc
(Entry_Name
),
7299 Low_Bound
=> Actual_Discriminant_Ref
(Lo
),
7300 High_Bound
=> Actual_Discriminant_Ref
(Hi
)));
7304 end Actual_Index_Type
;
7306 -- Start of processing for Resolve_Entry
7309 -- Find name of entry being called, and resolve prefix of name with its
7310 -- own type. The prefix can be overloaded, and the name and signature of
7311 -- the entry must be taken into account.
7313 if Nkind
(Entry_Name
) = N_Indexed_Component
then
7315 -- Case of dealing with entry family within the current tasks
7317 E_Name
:= Prefix
(Entry_Name
);
7320 E_Name
:= Entry_Name
;
7323 if Is_Entity_Name
(E_Name
) then
7325 -- Entry call to an entry (or entry family) in the current task. This
7326 -- is legal even though the task will deadlock. Rewrite as call to
7329 -- This can also be a call to an entry in an enclosing task. If this
7330 -- is a single task, we have to retrieve its name, because the scope
7331 -- of the entry is the task type, not the object. If the enclosing
7332 -- task is a task type, the identity of the task is given by its own
7335 -- Finally this can be a requeue on an entry of the same task or
7336 -- protected object.
7338 S
:= Scope
(Entity
(E_Name
));
7340 for J
in reverse 0 .. Scope_Stack
.Last
loop
7341 if Is_Task_Type
(Scope_Stack
.Table
(J
).Entity
)
7342 and then not Comes_From_Source
(S
)
7344 -- S is an enclosing task or protected object. The concurrent
7345 -- declaration has been converted into a type declaration, and
7346 -- the object itself has an object declaration that follows
7347 -- the type in the same declarative part.
7349 Tsk
:= Next_Entity
(S
);
7350 while Etype
(Tsk
) /= S
loop
7357 elsif S
= Scope_Stack
.Table
(J
).Entity
then
7359 -- Call to current task. Will be transformed into call to Self
7367 Make_Selected_Component
(Loc
,
7368 Prefix
=> New_Occurrence_Of
(S
, Loc
),
7370 New_Occurrence_Of
(Entity
(E_Name
), Loc
));
7371 Rewrite
(E_Name
, New_N
);
7374 elsif Nkind
(Entry_Name
) = N_Selected_Component
7375 and then Is_Overloaded
(Prefix
(Entry_Name
))
7377 -- Use the entry name (which must be unique at this point) to find
7378 -- the prefix that returns the corresponding task/protected type.
7381 Pref
: constant Node_Id
:= Prefix
(Entry_Name
);
7382 Ent
: constant Entity_Id
:= Entity
(Selector_Name
(Entry_Name
));
7387 Get_First_Interp
(Pref
, I
, It
);
7388 while Present
(It
.Typ
) loop
7389 if Scope
(Ent
) = It
.Typ
then
7390 Set_Etype
(Pref
, It
.Typ
);
7394 Get_Next_Interp
(I
, It
);
7399 if Nkind
(Entry_Name
) = N_Selected_Component
then
7400 Resolve
(Prefix
(Entry_Name
));
7402 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7403 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
7404 Resolve
(Prefix
(Prefix
(Entry_Name
)));
7405 Index
:= First
(Expressions
(Entry_Name
));
7406 Resolve
(Index
, Entry_Index_Type
(Nam
));
7408 -- Up to this point the expression could have been the actual in a
7409 -- simple entry call, and be given by a named association.
7411 if Nkind
(Index
) = N_Parameter_Association
then
7412 Error_Msg_N
("expect expression for entry index", Index
);
7414 Apply_Range_Check
(Index
, Actual_Index_Type
(Nam
));
7419 ------------------------
7420 -- Resolve_Entry_Call --
7421 ------------------------
7423 procedure Resolve_Entry_Call
(N
: Node_Id
; Typ
: Entity_Id
) is
7424 Entry_Name
: constant Node_Id
:= Name
(N
);
7425 Loc
: constant Source_Ptr
:= Sloc
(Entry_Name
);
7427 First_Named
: Node_Id
;
7434 -- We kill all checks here, because it does not seem worth the effort to
7435 -- do anything better, an entry call is a big operation.
7439 -- Processing of the name is similar for entry calls and protected
7440 -- operation calls. Once the entity is determined, we can complete
7441 -- the resolution of the actuals.
7443 -- The selector may be overloaded, in the case of a protected object
7444 -- with overloaded functions. The type of the context is used for
7447 if Nkind
(Entry_Name
) = N_Selected_Component
7448 and then Is_Overloaded
(Selector_Name
(Entry_Name
))
7449 and then Typ
/= Standard_Void_Type
7456 Get_First_Interp
(Selector_Name
(Entry_Name
), I
, It
);
7457 while Present
(It
.Typ
) loop
7458 if Covers
(Typ
, It
.Typ
) then
7459 Set_Entity
(Selector_Name
(Entry_Name
), It
.Nam
);
7460 Set_Etype
(Entry_Name
, It
.Typ
);
7462 Generate_Reference
(It
.Typ
, N
, ' ');
7465 Get_Next_Interp
(I
, It
);
7470 Resolve_Entry
(Entry_Name
);
7472 if Nkind
(Entry_Name
) = N_Selected_Component
then
7474 -- Simple entry call
7476 Nam
:= Entity
(Selector_Name
(Entry_Name
));
7477 Obj
:= Prefix
(Entry_Name
);
7478 Was_Over
:= Is_Overloaded
(Selector_Name
(Entry_Name
));
7480 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7482 -- Call to member of entry family
7484 Nam
:= Entity
(Selector_Name
(Prefix
(Entry_Name
)));
7485 Obj
:= Prefix
(Prefix
(Entry_Name
));
7486 Was_Over
:= Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)));
7489 -- We cannot in general check the maximum depth of protected entry calls
7490 -- at compile time. But we can tell that any protected entry call at all
7491 -- violates a specified nesting depth of zero.
7493 if Is_Protected_Type
(Scope
(Nam
)) then
7494 Check_Restriction
(Max_Entry_Queue_Length
, N
);
7497 -- Use context type to disambiguate a protected function that can be
7498 -- called without actuals and that returns an array type, and where the
7499 -- argument list may be an indexing of the returned value.
7501 if Ekind
(Nam
) = E_Function
7502 and then Needs_No_Actuals
(Nam
)
7503 and then Present
(Parameter_Associations
(N
))
7505 ((Is_Array_Type
(Etype
(Nam
))
7506 and then Covers
(Typ
, Component_Type
(Etype
(Nam
))))
7508 or else (Is_Access_Type
(Etype
(Nam
))
7509 and then Is_Array_Type
(Designated_Type
(Etype
(Nam
)))
7513 Component_Type
(Designated_Type
(Etype
(Nam
))))))
7516 Index_Node
: Node_Id
;
7520 Make_Indexed_Component
(Loc
,
7522 Make_Function_Call
(Loc
, Name
=> Relocate_Node
(Entry_Name
)),
7523 Expressions
=> Parameter_Associations
(N
));
7525 -- Since we are correcting a node classification error made by the
7526 -- parser, we call Replace rather than Rewrite.
7528 Replace
(N
, Index_Node
);
7529 Set_Etype
(Prefix
(N
), Etype
(Nam
));
7531 Resolve_Indexed_Component
(N
, Typ
);
7536 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
)
7537 and then Present
(Contract_Wrapper
(Nam
))
7538 and then Current_Scope
/= Contract_Wrapper
(Nam
)
7541 -- Note the entity being called before rewriting the call, so that
7542 -- it appears used at this point.
7544 Generate_Reference
(Nam
, Entry_Name
, 'r');
7546 -- Rewrite as call to the precondition wrapper, adding the task
7547 -- object to the list of actuals. If the call is to a member of an
7548 -- entry family, include the index as well.
7552 New_Actuals
: List_Id
;
7555 New_Actuals
:= New_List
(Obj
);
7557 if Nkind
(Entry_Name
) = N_Indexed_Component
then
7558 Append_To
(New_Actuals
,
7559 New_Copy_Tree
(First
(Expressions
(Entry_Name
))));
7562 Append_List
(Parameter_Associations
(N
), New_Actuals
);
7564 Make_Procedure_Call_Statement
(Loc
,
7566 New_Occurrence_Of
(Contract_Wrapper
(Nam
), Loc
),
7567 Parameter_Associations
=> New_Actuals
);
7568 Rewrite
(N
, New_Call
);
7570 -- Preanalyze and resolve new call. Current procedure is called
7571 -- from Resolve_Call, after which expansion will take place.
7573 Preanalyze_And_Resolve
(N
);
7578 -- The operation name may have been overloaded. Order the actuals
7579 -- according to the formals of the resolved entity, and set the return
7580 -- type to that of the operation.
7583 Normalize_Actuals
(N
, Nam
, False, Norm_OK
);
7584 pragma Assert
(Norm_OK
);
7585 Set_Etype
(N
, Etype
(Nam
));
7587 -- Reset the Is_Overloaded flag, since resolution is now completed
7589 -- Simple entry call
7591 if Nkind
(Entry_Name
) = N_Selected_Component
then
7592 Set_Is_Overloaded
(Selector_Name
(Entry_Name
), False);
7594 -- Call to a member of an entry family
7596 else pragma Assert
(Nkind
(Entry_Name
) = N_Indexed_Component
);
7597 Set_Is_Overloaded
(Selector_Name
(Prefix
(Entry_Name
)), False);
7601 Resolve_Actuals
(N
, Nam
);
7602 Check_Internal_Protected_Use
(N
, Nam
);
7604 -- Create a call reference to the entry
7606 Generate_Reference
(Nam
, Entry_Name
, 's');
7608 if Ekind_In
(Nam
, E_Entry
, E_Entry_Family
) then
7609 Check_Potentially_Blocking_Operation
(N
);
7612 -- Verify that a procedure call cannot masquerade as an entry
7613 -- call where an entry call is expected.
7615 if Ekind
(Nam
) = E_Procedure
then
7616 if Nkind
(Parent
(N
)) = N_Entry_Call_Alternative
7617 and then N
= Entry_Call_Statement
(Parent
(N
))
7619 Error_Msg_N
("entry call required in select statement", N
);
7621 elsif Nkind
(Parent
(N
)) = N_Triggering_Alternative
7622 and then N
= Triggering_Statement
(Parent
(N
))
7624 Error_Msg_N
("triggering statement cannot be procedure call", N
);
7626 elsif Ekind
(Scope
(Nam
)) = E_Task_Type
7627 and then not In_Open_Scopes
(Scope
(Nam
))
7629 Error_Msg_N
("task has no entry with this name", Entry_Name
);
7633 -- After resolution, entry calls and protected procedure calls are
7634 -- changed into entry calls, for expansion. The structure of the node
7635 -- does not change, so it can safely be done in place. Protected
7636 -- function calls must keep their structure because they are
7639 if Ekind
(Nam
) /= E_Function
then
7641 -- A protected operation that is not a function may modify the
7642 -- corresponding object, and cannot apply to a constant. If this
7643 -- is an internal call, the prefix is the type itself.
7645 if Is_Protected_Type
(Scope
(Nam
))
7646 and then not Is_Variable
(Obj
)
7647 and then (not Is_Entity_Name
(Obj
)
7648 or else not Is_Type
(Entity
(Obj
)))
7651 ("prefix of protected procedure or entry call must be variable",
7655 Actuals
:= Parameter_Associations
(N
);
7656 First_Named
:= First_Named_Actual
(N
);
7659 Make_Entry_Call_Statement
(Loc
,
7661 Parameter_Associations
=> Actuals
));
7663 Set_First_Named_Actual
(N
, First_Named
);
7664 Set_Analyzed
(N
, True);
7666 -- Protected functions can return on the secondary stack, in which
7667 -- case we must trigger the transient scope mechanism.
7669 elsif Expander_Active
7670 and then Requires_Transient_Scope
(Etype
(Nam
))
7672 Establish_Transient_Scope
(N
, Sec_Stack
=> True);
7674 end Resolve_Entry_Call
;
7676 -------------------------
7677 -- Resolve_Equality_Op --
7678 -------------------------
7680 -- Both arguments must have the same type, and the boolean context does
7681 -- not participate in the resolution. The first pass verifies that the
7682 -- interpretation is not ambiguous, and the type of the left argument is
7683 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
7684 -- are strings or aggregates, allocators, or Null, they are ambiguous even
7685 -- though they carry a single (universal) type. Diagnose this case here.
7687 procedure Resolve_Equality_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
7688 L
: constant Node_Id
:= Left_Opnd
(N
);
7689 R
: constant Node_Id
:= Right_Opnd
(N
);
7690 T
: Entity_Id
:= Find_Unique_Type
(L
, R
);
7692 procedure Check_If_Expression
(Cond
: Node_Id
);
7693 -- The resolution rule for if expressions requires that each such must
7694 -- have a unique type. This means that if several dependent expressions
7695 -- are of a non-null anonymous access type, and the context does not
7696 -- impose an expected type (as can be the case in an equality operation)
7697 -- the expression must be rejected.
7699 procedure Explain_Redundancy
(N
: Node_Id
);
7700 -- Attempt to explain the nature of a redundant comparison with True. If
7701 -- the expression N is too complex, this routine issues a general error
7704 function Find_Unique_Access_Type
return Entity_Id
;
7705 -- In the case of allocators and access attributes, the context must
7706 -- provide an indication of the specific access type to be used. If
7707 -- one operand is of such a "generic" access type, check whether there
7708 -- is a specific visible access type that has the same designated type.
7709 -- This is semantically dubious, and of no interest to any real code,
7710 -- but c48008a makes it all worthwhile.
7712 -------------------------
7713 -- Check_If_Expression --
7714 -------------------------
7716 procedure Check_If_Expression
(Cond
: Node_Id
) is
7717 Then_Expr
: Node_Id
;
7718 Else_Expr
: Node_Id
;
7721 if Nkind
(Cond
) = N_If_Expression
then
7722 Then_Expr
:= Next
(First
(Expressions
(Cond
)));
7723 Else_Expr
:= Next
(Then_Expr
);
7725 if Nkind
(Then_Expr
) /= N_Null
7726 and then Nkind
(Else_Expr
) /= N_Null
7728 Error_Msg_N
("cannot determine type of if expression", Cond
);
7731 end Check_If_Expression
;
7733 ------------------------
7734 -- Explain_Redundancy --
7735 ------------------------
7737 procedure Explain_Redundancy
(N
: Node_Id
) is
7745 -- Strip the operand down to an entity
7748 if Nkind
(Val
) = N_Selected_Component
then
7749 Val
:= Selector_Name
(Val
);
7755 -- The construct denotes an entity
7757 if Is_Entity_Name
(Val
) and then Present
(Entity
(Val
)) then
7758 Val_Id
:= Entity
(Val
);
7760 -- Do not generate an error message when the comparison is done
7761 -- against the enumeration literal Standard.True.
7763 if Ekind
(Val_Id
) /= E_Enumeration_Literal
then
7765 -- Build a customized error message
7768 Add_Str_To_Name_Buffer
("?r?");
7770 if Ekind
(Val_Id
) = E_Component
then
7771 Add_Str_To_Name_Buffer
("component ");
7773 elsif Ekind
(Val_Id
) = E_Constant
then
7774 Add_Str_To_Name_Buffer
("constant ");
7776 elsif Ekind
(Val_Id
) = E_Discriminant
then
7777 Add_Str_To_Name_Buffer
("discriminant ");
7779 elsif Is_Formal
(Val_Id
) then
7780 Add_Str_To_Name_Buffer
("parameter ");
7782 elsif Ekind
(Val_Id
) = E_Variable
then
7783 Add_Str_To_Name_Buffer
("variable ");
7786 Add_Str_To_Name_Buffer
("& is always True!");
7789 Error_Msg_NE
(Get_Name_String
(Error
), Val
, Val_Id
);
7792 -- The construct is too complex to disect, issue a general message
7795 Error_Msg_N
("?r?expression is always True!", Val
);
7797 end Explain_Redundancy
;
7799 -----------------------------
7800 -- Find_Unique_Access_Type --
7801 -----------------------------
7803 function Find_Unique_Access_Type
return Entity_Id
is
7809 if Ekind_In
(Etype
(R
), E_Allocator_Type
,
7810 E_Access_Attribute_Type
)
7812 Acc
:= Designated_Type
(Etype
(R
));
7814 elsif Ekind_In
(Etype
(L
), E_Allocator_Type
,
7815 E_Access_Attribute_Type
)
7817 Acc
:= Designated_Type
(Etype
(L
));
7823 while S
/= Standard_Standard
loop
7824 E
:= First_Entity
(S
);
7825 while Present
(E
) loop
7827 and then Is_Access_Type
(E
)
7828 and then Ekind
(E
) /= E_Allocator_Type
7829 and then Designated_Type
(E
) = Base_Type
(Acc
)
7841 end Find_Unique_Access_Type
;
7843 -- Start of processing for Resolve_Equality_Op
7846 Set_Etype
(N
, Base_Type
(Typ
));
7847 Generate_Reference
(T
, N
, ' ');
7849 if T
= Any_Fixed
then
7850 T
:= Unique_Fixed_Point_Type
(L
);
7853 if T
/= Any_Type
then
7854 if T
= Any_String
or else
7855 T
= Any_Composite
or else
7858 if T
= Any_Character
then
7859 Ambiguous_Character
(L
);
7861 Error_Msg_N
("ambiguous operands for equality", N
);
7864 Set_Etype
(N
, Any_Type
);
7867 elsif T
= Any_Access
7868 or else Ekind_In
(T
, E_Allocator_Type
, E_Access_Attribute_Type
)
7870 T
:= Find_Unique_Access_Type
;
7873 Error_Msg_N
("ambiguous operands for equality", N
);
7874 Set_Etype
(N
, Any_Type
);
7878 -- If expressions must have a single type, and if the context does
7879 -- not impose one the dependent expressions cannot be anonymous
7882 -- Why no similar processing for case expressions???
7884 elsif Ada_Version
>= Ada_2012
7885 and then Ekind_In
(Etype
(L
), E_Anonymous_Access_Type
,
7886 E_Anonymous_Access_Subprogram_Type
)
7887 and then Ekind_In
(Etype
(R
), E_Anonymous_Access_Type
,
7888 E_Anonymous_Access_Subprogram_Type
)
7890 Check_If_Expression
(L
);
7891 Check_If_Expression
(R
);
7897 -- In SPARK, equality operators = and /= for array types other than
7898 -- String are only defined when, for each index position, the
7899 -- operands have equal static bounds.
7901 if Is_Array_Type
(T
) then
7903 -- Protect call to Matching_Static_Array_Bounds to avoid costly
7904 -- operation if not needed.
7906 if Restriction_Check_Required
(SPARK_05
)
7907 and then Base_Type
(T
) /= Standard_String
7908 and then Base_Type
(Etype
(L
)) = Base_Type
(Etype
(R
))
7909 and then Etype
(L
) /= Any_Composite
-- or else L in error
7910 and then Etype
(R
) /= Any_Composite
-- or else R in error
7911 and then not Matching_Static_Array_Bounds
(Etype
(L
), Etype
(R
))
7913 Check_SPARK_05_Restriction
7914 ("array types should have matching static bounds", N
);
7918 -- If the unique type is a class-wide type then it will be expanded
7919 -- into a dispatching call to the predefined primitive. Therefore we
7920 -- check here for potential violation of such restriction.
7922 if Is_Class_Wide_Type
(T
) then
7923 Check_Restriction
(No_Dispatching_Calls
, N
);
7926 if Warn_On_Redundant_Constructs
7927 and then Comes_From_Source
(N
)
7928 and then Comes_From_Source
(R
)
7929 and then Is_Entity_Name
(R
)
7930 and then Entity
(R
) = Standard_True
7932 Error_Msg_N
-- CODEFIX
7933 ("?r?comparison with True is redundant!", N
);
7934 Explain_Redundancy
(Original_Node
(R
));
7937 Check_Unset_Reference
(L
);
7938 Check_Unset_Reference
(R
);
7939 Generate_Operator_Reference
(N
, T
);
7940 Check_Low_Bound_Tested
(N
);
7942 -- If this is an inequality, it may be the implicit inequality
7943 -- created for a user-defined operation, in which case the corres-
7944 -- ponding equality operation is not intrinsic, and the operation
7945 -- cannot be constant-folded. Else fold.
7947 if Nkind
(N
) = N_Op_Eq
7948 or else Comes_From_Source
(Entity
(N
))
7949 or else Ekind
(Entity
(N
)) = E_Operator
7950 or else Is_Intrinsic_Subprogram
7951 (Corresponding_Equality
(Entity
(N
)))
7953 Analyze_Dimension
(N
);
7954 Eval_Relational_Op
(N
);
7956 elsif Nkind
(N
) = N_Op_Ne
7957 and then Is_Abstract_Subprogram
(Entity
(N
))
7959 Error_Msg_NE
("cannot call abstract subprogram &!", N
, Entity
(N
));
7962 -- Ada 2005: If one operand is an anonymous access type, convert the
7963 -- other operand to it, to ensure that the underlying types match in
7964 -- the back-end. Same for access_to_subprogram, and the conversion
7965 -- verifies that the types are subtype conformant.
7967 -- We apply the same conversion in the case one of the operands is a
7968 -- private subtype of the type of the other.
7970 -- Why the Expander_Active test here ???
7974 (Ekind_In
(T
, E_Anonymous_Access_Type
,
7975 E_Anonymous_Access_Subprogram_Type
)
7976 or else Is_Private_Type
(T
))
7978 if Etype
(L
) /= T
then
7980 Make_Unchecked_Type_Conversion
(Sloc
(L
),
7981 Subtype_Mark
=> New_Occurrence_Of
(T
, Sloc
(L
)),
7982 Expression
=> Relocate_Node
(L
)));
7983 Analyze_And_Resolve
(L
, T
);
7986 if (Etype
(R
)) /= T
then
7988 Make_Unchecked_Type_Conversion
(Sloc
(R
),
7989 Subtype_Mark
=> New_Occurrence_Of
(Etype
(L
), Sloc
(R
)),
7990 Expression
=> Relocate_Node
(R
)));
7991 Analyze_And_Resolve
(R
, T
);
7995 end Resolve_Equality_Op
;
7997 ----------------------------------
7998 -- Resolve_Explicit_Dereference --
7999 ----------------------------------
8001 procedure Resolve_Explicit_Dereference
(N
: Node_Id
; Typ
: Entity_Id
) is
8002 Loc
: constant Source_Ptr
:= Sloc
(N
);
8004 P
: constant Node_Id
:= Prefix
(N
);
8007 -- The candidate prefix type, if overloaded
8013 Check_Fully_Declared_Prefix
(Typ
, P
);
8016 -- A useful optimization: check whether the dereference denotes an
8017 -- element of a container, and if so rewrite it as a call to the
8018 -- corresponding Element function.
8020 -- Disabled for now, on advice of ARG. A more restricted form of the
8021 -- predicate might be acceptable ???
8023 -- if Is_Container_Element (N) then
8027 if Is_Overloaded
(P
) then
8029 -- Use the context type to select the prefix that has the correct
8030 -- designated type. Keep the first match, which will be the inner-
8033 Get_First_Interp
(P
, I
, It
);
8035 while Present
(It
.Typ
) loop
8036 if Is_Access_Type
(It
.Typ
)
8037 and then Covers
(Typ
, Designated_Type
(It
.Typ
))
8043 -- Remove access types that do not match, but preserve access
8044 -- to subprogram interpretations, in case a further dereference
8045 -- is needed (see below).
8047 elsif Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
8051 Get_Next_Interp
(I
, It
);
8054 if Present
(P_Typ
) then
8056 Set_Etype
(N
, Designated_Type
(P_Typ
));
8059 -- If no interpretation covers the designated type of the prefix,
8060 -- this is the pathological case where not all implementations of
8061 -- the prefix allow the interpretation of the node as a call. Now
8062 -- that the expected type is known, Remove other interpretations
8063 -- from prefix, rewrite it as a call, and resolve again, so that
8064 -- the proper call node is generated.
8066 Get_First_Interp
(P
, I
, It
);
8067 while Present
(It
.Typ
) loop
8068 if Ekind
(It
.Typ
) /= E_Access_Subprogram_Type
then
8072 Get_Next_Interp
(I
, It
);
8076 Make_Function_Call
(Loc
,
8078 Make_Explicit_Dereference
(Loc
,
8080 Parameter_Associations
=> New_List
);
8082 Save_Interps
(N
, New_N
);
8084 Analyze_And_Resolve
(N
, Typ
);
8088 -- If not overloaded, resolve P with its own type
8094 -- If the prefix might be null, add an access check
8096 if Is_Access_Type
(Etype
(P
))
8097 and then not Can_Never_Be_Null
(Etype
(P
))
8099 Apply_Access_Check
(N
);
8102 -- If the designated type is a packed unconstrained array type, and the
8103 -- explicit dereference is not in the context of an attribute reference,
8104 -- then we must compute and set the actual subtype, since it is needed
8105 -- by Gigi. The reason we exclude the attribute case is that this is
8106 -- handled fine by Gigi, and in fact we use such attributes to build the
8107 -- actual subtype. We also exclude generated code (which builds actual
8108 -- subtypes directly if they are needed).
8110 if Is_Array_Type
(Etype
(N
))
8111 and then Is_Packed
(Etype
(N
))
8112 and then not Is_Constrained
(Etype
(N
))
8113 and then Nkind
(Parent
(N
)) /= N_Attribute_Reference
8114 and then Comes_From_Source
(N
)
8116 Set_Etype
(N
, Get_Actual_Subtype
(N
));
8119 Analyze_Dimension
(N
);
8121 -- Note: No Eval processing is required for an explicit dereference,
8122 -- because such a name can never be static.
8124 end Resolve_Explicit_Dereference
;
8126 -------------------------------------
8127 -- Resolve_Expression_With_Actions --
8128 -------------------------------------
8130 procedure Resolve_Expression_With_Actions
(N
: Node_Id
; Typ
: Entity_Id
) is
8134 -- If N has no actions, and its expression has been constant folded,
8135 -- then rewrite N as just its expression. Note, we can't do this in
8136 -- the general case of Is_Empty_List (Actions (N)) as this would cause
8137 -- Expression (N) to be expanded again.
8139 if Is_Empty_List
(Actions
(N
))
8140 and then Compile_Time_Known_Value
(Expression
(N
))
8142 Rewrite
(N
, Expression
(N
));
8144 end Resolve_Expression_With_Actions
;
8146 ----------------------------------
8147 -- Resolve_Generalized_Indexing --
8148 ----------------------------------
8150 procedure Resolve_Generalized_Indexing
(N
: Node_Id
; Typ
: Entity_Id
) is
8151 Indexing
: constant Node_Id
:= Generalized_Indexing
(N
);
8157 -- In ASIS mode, propagate the information about the indexes back to
8158 -- to the original indexing node. The generalized indexing is either
8159 -- a function call, or a dereference of one. The actuals include the
8160 -- prefix of the original node, which is the container expression.
8163 Resolve
(Indexing
, Typ
);
8164 Set_Etype
(N
, Etype
(Indexing
));
8165 Set_Is_Overloaded
(N
, False);
8168 while Nkind_In
(Call
, N_Explicit_Dereference
, N_Selected_Component
)
8170 Call
:= Prefix
(Call
);
8173 if Nkind
(Call
) = N_Function_Call
then
8174 Indexes
:= New_Copy_List
(Parameter_Associations
(Call
));
8175 Pref
:= Remove_Head
(Indexes
);
8176 Set_Expressions
(N
, Indexes
);
8178 -- If expression is to be reanalyzed, reset Generalized_Indexing
8179 -- to recreate call node, as is the case when the expression is
8180 -- part of an expression function.
8182 if In_Spec_Expression
then
8183 Set_Generalized_Indexing
(N
, Empty
);
8186 Set_Prefix
(N
, Pref
);
8190 Rewrite
(N
, Indexing
);
8193 end Resolve_Generalized_Indexing
;
8195 ---------------------------
8196 -- Resolve_If_Expression --
8197 ---------------------------
8199 procedure Resolve_If_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
8200 Condition
: constant Node_Id
:= First
(Expressions
(N
));
8201 Then_Expr
: constant Node_Id
:= Next
(Condition
);
8202 Else_Expr
: Node_Id
:= Next
(Then_Expr
);
8203 Else_Typ
: Entity_Id
;
8204 Then_Typ
: Entity_Id
;
8207 Resolve
(Condition
, Any_Boolean
);
8208 Resolve
(Then_Expr
, Typ
);
8209 Then_Typ
:= Etype
(Then_Expr
);
8211 -- When the "then" expression is of a scalar subtype different from the
8212 -- result subtype, then insert a conversion to ensure the generation of
8213 -- a constraint check. The same is done for the else part below, again
8214 -- comparing subtypes rather than base types.
8216 if Is_Scalar_Type
(Then_Typ
)
8217 and then Then_Typ
/= Typ
8219 Rewrite
(Then_Expr
, Convert_To
(Typ
, Then_Expr
));
8220 Analyze_And_Resolve
(Then_Expr
, Typ
);
8223 -- If ELSE expression present, just resolve using the determined type
8224 -- If type is universal, resolve to any member of the class.
8226 if Present
(Else_Expr
) then
8227 if Typ
= Universal_Integer
then
8228 Resolve
(Else_Expr
, Any_Integer
);
8230 elsif Typ
= Universal_Real
then
8231 Resolve
(Else_Expr
, Any_Real
);
8234 Resolve
(Else_Expr
, Typ
);
8237 Else_Typ
:= Etype
(Else_Expr
);
8239 if Is_Scalar_Type
(Else_Typ
) and then Else_Typ
/= Typ
then
8240 Rewrite
(Else_Expr
, Convert_To
(Typ
, Else_Expr
));
8241 Analyze_And_Resolve
(Else_Expr
, Typ
);
8243 -- Apply RM 4.5.7 (17/3): whether the expression is statically or
8244 -- dynamically tagged must be known statically.
8246 elsif Is_Tagged_Type
(Typ
) and then not Is_Class_Wide_Type
(Typ
) then
8247 if Is_Dynamically_Tagged
(Then_Expr
) /=
8248 Is_Dynamically_Tagged
(Else_Expr
)
8250 Error_Msg_N
("all or none of the dependent expressions "
8251 & "can be dynamically tagged", N
);
8255 -- If no ELSE expression is present, root type must be Standard.Boolean
8256 -- and we provide a Standard.True result converted to the appropriate
8257 -- Boolean type (in case it is a derived boolean type).
8259 elsif Root_Type
(Typ
) = Standard_Boolean
then
8261 Convert_To
(Typ
, New_Occurrence_Of
(Standard_True
, Sloc
(N
)));
8262 Analyze_And_Resolve
(Else_Expr
, Typ
);
8263 Append_To
(Expressions
(N
), Else_Expr
);
8266 Error_Msg_N
("can only omit ELSE expression in Boolean case", N
);
8267 Append_To
(Expressions
(N
), Error
);
8271 Eval_If_Expression
(N
);
8272 end Resolve_If_Expression
;
8274 -------------------------------
8275 -- Resolve_Indexed_Component --
8276 -------------------------------
8278 procedure Resolve_Indexed_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
8279 Name
: constant Node_Id
:= Prefix
(N
);
8281 Array_Type
: Entity_Id
:= Empty
; -- to prevent junk warning
8285 if Present
(Generalized_Indexing
(N
)) then
8286 Resolve_Generalized_Indexing
(N
, Typ
);
8290 if Is_Overloaded
(Name
) then
8292 -- Use the context type to select the prefix that yields the correct
8298 I1
: Interp_Index
:= 0;
8299 P
: constant Node_Id
:= Prefix
(N
);
8300 Found
: Boolean := False;
8303 Get_First_Interp
(P
, I
, It
);
8304 while Present
(It
.Typ
) loop
8305 if (Is_Array_Type
(It
.Typ
)
8306 and then Covers
(Typ
, Component_Type
(It
.Typ
)))
8307 or else (Is_Access_Type
(It
.Typ
)
8308 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
8312 Component_Type
(Designated_Type
(It
.Typ
))))
8315 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
8317 if It
= No_Interp
then
8318 Error_Msg_N
("ambiguous prefix for indexing", N
);
8324 Array_Type
:= It
.Typ
;
8330 Array_Type
:= It
.Typ
;
8335 Get_Next_Interp
(I
, It
);
8340 Array_Type
:= Etype
(Name
);
8343 Resolve
(Name
, Array_Type
);
8344 Array_Type
:= Get_Actual_Subtype_If_Available
(Name
);
8346 -- If prefix is access type, dereference to get real array type.
8347 -- Note: we do not apply an access check because the expander always
8348 -- introduces an explicit dereference, and the check will happen there.
8350 if Is_Access_Type
(Array_Type
) then
8351 Array_Type
:= Designated_Type
(Array_Type
);
8354 -- If name was overloaded, set component type correctly now
8355 -- If a misplaced call to an entry family (which has no index types)
8356 -- return. Error will be diagnosed from calling context.
8358 if Is_Array_Type
(Array_Type
) then
8359 Set_Etype
(N
, Component_Type
(Array_Type
));
8364 Index
:= First_Index
(Array_Type
);
8365 Expr
:= First
(Expressions
(N
));
8367 -- The prefix may have resolved to a string literal, in which case its
8368 -- etype has a special representation. This is only possible currently
8369 -- if the prefix is a static concatenation, written in functional
8372 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
8373 Resolve
(Expr
, Standard_Positive
);
8376 while Present
(Index
) and Present
(Expr
) loop
8377 Resolve
(Expr
, Etype
(Index
));
8378 Check_Unset_Reference
(Expr
);
8380 if Is_Scalar_Type
(Etype
(Expr
)) then
8381 Apply_Scalar_Range_Check
(Expr
, Etype
(Index
));
8383 Apply_Range_Check
(Expr
, Get_Actual_Subtype
(Index
));
8391 Analyze_Dimension
(N
);
8393 -- Do not generate the warning on suspicious index if we are analyzing
8394 -- package Ada.Tags; otherwise we will report the warning with the
8395 -- Prims_Ptr field of the dispatch table.
8397 if Scope
(Etype
(Prefix
(N
))) = Standard_Standard
8399 Is_RTU
(Cunit_Entity
(Get_Source_Unit
(Etype
(Prefix
(N
)))),
8402 Warn_On_Suspicious_Index
(Name
, First
(Expressions
(N
)));
8403 Eval_Indexed_Component
(N
);
8406 -- If the array type is atomic, and the component is not atomic, then
8407 -- this is worth a warning, since we have a situation where the access
8408 -- to the component may cause extra read/writes of the atomic array
8409 -- object, or partial word accesses, which could be unexpected.
8411 if Nkind
(N
) = N_Indexed_Component
8412 and then Is_Atomic_Ref_With_Address
(N
)
8413 and then not (Has_Atomic_Components
(Array_Type
)
8414 or else (Is_Entity_Name
(Prefix
(N
))
8415 and then Has_Atomic_Components
8416 (Entity
(Prefix
(N
)))))
8417 and then not Is_Atomic
(Component_Type
(Array_Type
))
8420 ("??access to non-atomic component of atomic array", Prefix
(N
));
8422 ("??\may cause unexpected accesses to atomic object", Prefix
(N
));
8424 end Resolve_Indexed_Component
;
8426 -----------------------------
8427 -- Resolve_Integer_Literal --
8428 -----------------------------
8430 procedure Resolve_Integer_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
8433 Eval_Integer_Literal
(N
);
8434 end Resolve_Integer_Literal
;
8436 --------------------------------
8437 -- Resolve_Intrinsic_Operator --
8438 --------------------------------
8440 procedure Resolve_Intrinsic_Operator
(N
: Node_Id
; Typ
: Entity_Id
) is
8441 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
8446 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
;
8447 -- If the operand is a literal, it cannot be the expression in a
8448 -- conversion. Use a qualified expression instead.
8450 ---------------------
8451 -- Convert_Operand --
8452 ---------------------
8454 function Convert_Operand
(Opnd
: Node_Id
) return Node_Id
is
8455 Loc
: constant Source_Ptr
:= Sloc
(Opnd
);
8459 if Nkind_In
(Opnd
, N_Integer_Literal
, N_Real_Literal
) then
8461 Make_Qualified_Expression
(Loc
,
8462 Subtype_Mark
=> New_Occurrence_Of
(Btyp
, Loc
),
8463 Expression
=> Relocate_Node
(Opnd
));
8467 Res
:= Unchecked_Convert_To
(Btyp
, Opnd
);
8471 end Convert_Operand
;
8473 -- Start of processing for Resolve_Intrinsic_Operator
8476 -- We must preserve the original entity in a generic setting, so that
8477 -- the legality of the operation can be verified in an instance.
8479 if not Expander_Active
then
8484 while Scope
(Op
) /= Standard_Standard
loop
8486 pragma Assert
(Present
(Op
));
8490 Set_Is_Overloaded
(N
, False);
8492 -- If the result or operand types are private, rewrite with unchecked
8493 -- conversions on the operands and the result, to expose the proper
8494 -- underlying numeric type.
8496 if Is_Private_Type
(Typ
)
8497 or else Is_Private_Type
(Etype
(Left_Opnd
(N
)))
8498 or else Is_Private_Type
(Etype
(Right_Opnd
(N
)))
8500 Arg1
:= Convert_Operand
(Left_Opnd
(N
));
8502 if Nkind
(N
) = N_Op_Expon
then
8503 Arg2
:= Unchecked_Convert_To
(Standard_Integer
, Right_Opnd
(N
));
8505 Arg2
:= Convert_Operand
(Right_Opnd
(N
));
8508 if Nkind
(Arg1
) = N_Type_Conversion
then
8509 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
8512 if Nkind
(Arg2
) = N_Type_Conversion
then
8513 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8516 Set_Left_Opnd
(N
, Arg1
);
8517 Set_Right_Opnd
(N
, Arg2
);
8519 Set_Etype
(N
, Btyp
);
8520 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
8523 elsif Typ
/= Etype
(Left_Opnd
(N
))
8524 or else Typ
/= Etype
(Right_Opnd
(N
))
8526 -- Add explicit conversion where needed, and save interpretations in
8527 -- case operands are overloaded.
8529 Arg1
:= Convert_To
(Typ
, Left_Opnd
(N
));
8530 Arg2
:= Convert_To
(Typ
, Right_Opnd
(N
));
8532 if Nkind
(Arg1
) = N_Type_Conversion
then
8533 Save_Interps
(Left_Opnd
(N
), Expression
(Arg1
));
8535 Save_Interps
(Left_Opnd
(N
), Arg1
);
8538 if Nkind
(Arg2
) = N_Type_Conversion
then
8539 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8541 Save_Interps
(Right_Opnd
(N
), Arg2
);
8544 Rewrite
(Left_Opnd
(N
), Arg1
);
8545 Rewrite
(Right_Opnd
(N
), Arg2
);
8548 Resolve_Arithmetic_Op
(N
, Typ
);
8551 Resolve_Arithmetic_Op
(N
, Typ
);
8553 end Resolve_Intrinsic_Operator
;
8555 --------------------------------------
8556 -- Resolve_Intrinsic_Unary_Operator --
8557 --------------------------------------
8559 procedure Resolve_Intrinsic_Unary_Operator
8563 Btyp
: constant Entity_Id
:= Base_Type
(Underlying_Type
(Typ
));
8569 while Scope
(Op
) /= Standard_Standard
loop
8571 pragma Assert
(Present
(Op
));
8576 if Is_Private_Type
(Typ
) then
8577 Arg2
:= Unchecked_Convert_To
(Btyp
, Right_Opnd
(N
));
8578 Save_Interps
(Right_Opnd
(N
), Expression
(Arg2
));
8580 Set_Right_Opnd
(N
, Arg2
);
8582 Set_Etype
(N
, Btyp
);
8583 Rewrite
(N
, Unchecked_Convert_To
(Typ
, N
));
8587 Resolve_Unary_Op
(N
, Typ
);
8589 end Resolve_Intrinsic_Unary_Operator
;
8591 ------------------------
8592 -- Resolve_Logical_Op --
8593 ------------------------
8595 procedure Resolve_Logical_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
8599 Check_No_Direct_Boolean_Operators
(N
);
8601 -- Predefined operations on scalar types yield the base type. On the
8602 -- other hand, logical operations on arrays yield the type of the
8603 -- arguments (and the context).
8605 if Is_Array_Type
(Typ
) then
8608 B_Typ
:= Base_Type
(Typ
);
8611 -- The following test is required because the operands of the operation
8612 -- may be literals, in which case the resulting type appears to be
8613 -- compatible with a signed integer type, when in fact it is compatible
8614 -- only with modular types. If the context itself is universal, the
8615 -- operation is illegal.
8617 if not Valid_Boolean_Arg
(Typ
) then
8618 Error_Msg_N
("invalid context for logical operation", N
);
8619 Set_Etype
(N
, Any_Type
);
8622 elsif Typ
= Any_Modular
then
8624 ("no modular type available in this context", N
);
8625 Set_Etype
(N
, Any_Type
);
8628 elsif Is_Modular_Integer_Type
(Typ
)
8629 and then Etype
(Left_Opnd
(N
)) = Universal_Integer
8630 and then Etype
(Right_Opnd
(N
)) = Universal_Integer
8632 Check_For_Visible_Operator
(N
, B_Typ
);
8635 -- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
8636 -- is active and the result type is standard Boolean (do not mess with
8637 -- ops that return a nonstandard Boolean type, because something strange
8640 -- Note: you might expect this replacement to be done during expansion,
8641 -- but that doesn't work, because when the pragma Short_Circuit_And_Or
8642 -- is used, no part of the right operand of an "and" or "or" operator
8643 -- should be executed if the left operand would short-circuit the
8644 -- evaluation of the corresponding "and then" or "or else". If we left
8645 -- the replacement to expansion time, then run-time checks associated
8646 -- with such operands would be evaluated unconditionally, due to being
8647 -- before the condition prior to the rewriting as short-circuit forms
8648 -- during expansion.
8650 if Short_Circuit_And_Or
8651 and then B_Typ
= Standard_Boolean
8652 and then Nkind_In
(N
, N_Op_And
, N_Op_Or
)
8654 -- Mark the corresponding putative SCO operator as truly a logical
8655 -- (and short-circuit) operator.
8657 if Generate_SCO
and then Comes_From_Source
(N
) then
8658 Set_SCO_Logical_Operator
(N
);
8661 if Nkind
(N
) = N_Op_And
then
8663 Make_And_Then
(Sloc
(N
),
8664 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
8665 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
8666 Analyze_And_Resolve
(N
, B_Typ
);
8668 -- Case of OR changed to OR ELSE
8672 Make_Or_Else
(Sloc
(N
),
8673 Left_Opnd
=> Relocate_Node
(Left_Opnd
(N
)),
8674 Right_Opnd
=> Relocate_Node
(Right_Opnd
(N
))));
8675 Analyze_And_Resolve
(N
, B_Typ
);
8678 -- Return now, since analysis of the rewritten ops will take care of
8679 -- other reference bookkeeping and expression folding.
8684 Resolve
(Left_Opnd
(N
), B_Typ
);
8685 Resolve
(Right_Opnd
(N
), B_Typ
);
8687 Check_Unset_Reference
(Left_Opnd
(N
));
8688 Check_Unset_Reference
(Right_Opnd
(N
));
8690 Set_Etype
(N
, B_Typ
);
8691 Generate_Operator_Reference
(N
, B_Typ
);
8692 Eval_Logical_Op
(N
);
8694 -- In SPARK, logical operations AND, OR and XOR for arrays are defined
8695 -- only when both operands have same static lower and higher bounds. Of
8696 -- course the types have to match, so only check if operands are
8697 -- compatible and the node itself has no errors.
8699 if Is_Array_Type
(B_Typ
)
8700 and then Nkind
(N
) in N_Binary_Op
8703 Left_Typ
: constant Node_Id
:= Etype
(Left_Opnd
(N
));
8704 Right_Typ
: constant Node_Id
:= Etype
(Right_Opnd
(N
));
8707 -- Protect call to Matching_Static_Array_Bounds to avoid costly
8708 -- operation if not needed.
8710 if Restriction_Check_Required
(SPARK_05
)
8711 and then Base_Type
(Left_Typ
) = Base_Type
(Right_Typ
)
8712 and then Left_Typ
/= Any_Composite
-- or Left_Opnd in error
8713 and then Right_Typ
/= Any_Composite
-- or Right_Opnd in error
8714 and then not Matching_Static_Array_Bounds
(Left_Typ
, Right_Typ
)
8716 Check_SPARK_05_Restriction
8717 ("array types should have matching static bounds", N
);
8721 end Resolve_Logical_Op
;
8723 ---------------------------
8724 -- Resolve_Membership_Op --
8725 ---------------------------
8727 -- The context can only be a boolean type, and does not determine the
8728 -- arguments. Arguments should be unambiguous, but the preference rule for
8729 -- universal types applies.
8731 procedure Resolve_Membership_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
8732 pragma Warnings
(Off
, Typ
);
8734 L
: constant Node_Id
:= Left_Opnd
(N
);
8735 R
: constant Node_Id
:= Right_Opnd
(N
);
8738 procedure Resolve_Set_Membership
;
8739 -- Analysis has determined a unique type for the left operand. Use it to
8740 -- resolve the disjuncts.
8742 ----------------------------
8743 -- Resolve_Set_Membership --
8744 ----------------------------
8746 procedure Resolve_Set_Membership
is
8751 -- If the left operand is overloaded, find type compatible with not
8752 -- overloaded alternative of the right operand.
8754 if Is_Overloaded
(L
) then
8756 Alt
:= First
(Alternatives
(N
));
8757 while Present
(Alt
) loop
8758 if not Is_Overloaded
(Alt
) then
8759 Ltyp
:= Intersect_Types
(L
, Alt
);
8766 -- Unclear how to resolve expression if all alternatives are also
8770 Error_Msg_N
("ambiguous expression", N
);
8779 Alt
:= First
(Alternatives
(N
));
8780 while Present
(Alt
) loop
8782 -- Alternative is an expression, a range
8783 -- or a subtype mark.
8785 if not Is_Entity_Name
(Alt
)
8786 or else not Is_Type
(Entity
(Alt
))
8788 Resolve
(Alt
, Ltyp
);
8794 -- Check for duplicates for discrete case
8796 if Is_Discrete_Type
(Ltyp
) then
8803 Alts
: array (0 .. List_Length
(Alternatives
(N
))) of Ent
;
8807 -- Loop checking duplicates. This is quadratic, but giant sets
8808 -- are unlikely in this context so it's a reasonable choice.
8811 Alt
:= First
(Alternatives
(N
));
8812 while Present
(Alt
) loop
8813 if Is_OK_Static_Expression
(Alt
)
8814 and then (Nkind_In
(Alt
, N_Integer_Literal
,
8815 N_Character_Literal
)
8816 or else Nkind
(Alt
) in N_Has_Entity
)
8819 Alts
(Nalts
) := (Alt
, Expr_Value
(Alt
));
8821 for J
in 1 .. Nalts
- 1 loop
8822 if Alts
(J
).Val
= Alts
(Nalts
).Val
then
8823 Error_Msg_Sloc
:= Sloc
(Alts
(J
).Alt
);
8824 Error_Msg_N
("duplicate of value given#??", Alt
);
8833 end Resolve_Set_Membership
;
8835 -- Start of processing for Resolve_Membership_Op
8838 if L
= Error
or else R
= Error
then
8842 if Present
(Alternatives
(N
)) then
8843 Resolve_Set_Membership
;
8846 elsif not Is_Overloaded
(R
)
8848 (Etype
(R
) = Universal_Integer
8850 Etype
(R
) = Universal_Real
)
8851 and then Is_Overloaded
(L
)
8855 -- Ada 2005 (AI-251): Support the following case:
8857 -- type I is interface;
8858 -- type T is tagged ...
8860 -- function Test (O : I'Class) is
8862 -- return O in T'Class.
8865 -- In this case we have nothing else to do. The membership test will be
8866 -- done at run time.
8868 elsif Ada_Version
>= Ada_2005
8869 and then Is_Class_Wide_Type
(Etype
(L
))
8870 and then Is_Interface
(Etype
(L
))
8871 and then Is_Class_Wide_Type
(Etype
(R
))
8872 and then not Is_Interface
(Etype
(R
))
8876 T
:= Intersect_Types
(L
, R
);
8879 -- If mixed-mode operations are present and operands are all literal,
8880 -- the only interpretation involves Duration, which is probably not
8881 -- the intention of the programmer.
8883 if T
= Any_Fixed
then
8884 T
:= Unique_Fixed_Point_Type
(N
);
8886 if T
= Any_Type
then
8892 Check_Unset_Reference
(L
);
8894 if Nkind
(R
) = N_Range
8895 and then not Is_Scalar_Type
(T
)
8897 Error_Msg_N
("scalar type required for range", R
);
8900 if Is_Entity_Name
(R
) then
8901 Freeze_Expression
(R
);
8904 Check_Unset_Reference
(R
);
8907 -- Here after resolving membership operation
8911 Eval_Membership_Op
(N
);
8912 end Resolve_Membership_Op
;
8918 procedure Resolve_Null
(N
: Node_Id
; Typ
: Entity_Id
) is
8919 Loc
: constant Source_Ptr
:= Sloc
(N
);
8922 -- Handle restriction against anonymous null access values This
8923 -- restriction can be turned off using -gnatdj.
8925 -- Ada 2005 (AI-231): Remove restriction
8927 if Ada_Version
< Ada_2005
8928 and then not Debug_Flag_J
8929 and then Ekind
(Typ
) = E_Anonymous_Access_Type
8930 and then Comes_From_Source
(N
)
8932 -- In the common case of a call which uses an explicitly null value
8933 -- for an access parameter, give specialized error message.
8935 if Nkind
(Parent
(N
)) in N_Subprogram_Call
then
8937 ("null is not allowed as argument for an access parameter", N
);
8939 -- Standard message for all other cases (are there any?)
8943 ("null cannot be of an anonymous access type", N
);
8947 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
8948 -- assignment to a null-excluding object
8950 if Ada_Version
>= Ada_2005
8951 and then Can_Never_Be_Null
(Typ
)
8952 and then Nkind
(Parent
(N
)) = N_Assignment_Statement
8954 if not Inside_Init_Proc
then
8956 (Compile_Time_Constraint_Error
(N
,
8957 "(Ada 2005) null not allowed in null-excluding objects??"),
8958 Make_Raise_Constraint_Error
(Loc
,
8959 Reason
=> CE_Access_Check_Failed
));
8962 Make_Raise_Constraint_Error
(Loc
,
8963 Reason
=> CE_Access_Check_Failed
));
8967 -- In a distributed context, null for a remote access to subprogram may
8968 -- need to be replaced with a special record aggregate. In this case,
8969 -- return after having done the transformation.
8971 if (Ekind
(Typ
) = E_Record_Type
8972 or else Is_Remote_Access_To_Subprogram_Type
(Typ
))
8973 and then Remote_AST_Null_Value
(N
, Typ
)
8978 -- The null literal takes its type from the context
8983 -----------------------
8984 -- Resolve_Op_Concat --
8985 -----------------------
8987 procedure Resolve_Op_Concat
(N
: Node_Id
; Typ
: Entity_Id
) is
8989 -- We wish to avoid deep recursion, because concatenations are often
8990 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
8991 -- operands nonrecursively until we find something that is not a simple
8992 -- concatenation (A in this case). We resolve that, and then walk back
8993 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
8994 -- to do the rest of the work at each level. The Parent pointers allow
8995 -- us to avoid recursion, and thus avoid running out of memory. See also
8996 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
9002 -- The following code is equivalent to:
9004 -- Resolve_Op_Concat_First (NN, Typ);
9005 -- Resolve_Op_Concat_Arg (N, ...);
9006 -- Resolve_Op_Concat_Rest (N, Typ);
9008 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
9009 -- operand is a concatenation.
9011 -- Walk down left operands
9014 Resolve_Op_Concat_First
(NN
, Typ
);
9015 Op1
:= Left_Opnd
(NN
);
9016 exit when not (Nkind
(Op1
) = N_Op_Concat
9017 and then not Is_Array_Type
(Component_Type
(Typ
))
9018 and then Entity
(Op1
) = Entity
(NN
));
9022 -- Now (given the above example) NN is A&B and Op1 is A
9024 -- First resolve Op1 ...
9026 Resolve_Op_Concat_Arg
(NN
, Op1
, Typ
, Is_Component_Left_Opnd
(NN
));
9028 -- ... then walk NN back up until we reach N (where we started), calling
9029 -- Resolve_Op_Concat_Rest along the way.
9032 Resolve_Op_Concat_Rest
(NN
, Typ
);
9037 if Base_Type
(Etype
(N
)) /= Standard_String
then
9038 Check_SPARK_05_Restriction
9039 ("result of concatenation should have type String", N
);
9041 end Resolve_Op_Concat
;
9043 ---------------------------
9044 -- Resolve_Op_Concat_Arg --
9045 ---------------------------
9047 procedure Resolve_Op_Concat_Arg
9053 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
9054 Ctyp
: constant Entity_Id
:= Component_Type
(Typ
);
9059 or else (not Is_Overloaded
(Arg
)
9060 and then Etype
(Arg
) /= Any_Composite
9061 and then Covers
(Ctyp
, Etype
(Arg
)))
9063 Resolve
(Arg
, Ctyp
);
9065 Resolve
(Arg
, Btyp
);
9068 -- If both Array & Array and Array & Component are visible, there is a
9069 -- potential ambiguity that must be reported.
9071 elsif Has_Compatible_Type
(Arg
, Ctyp
) then
9072 if Nkind
(Arg
) = N_Aggregate
9073 and then Is_Composite_Type
(Ctyp
)
9075 if Is_Private_Type
(Ctyp
) then
9076 Resolve
(Arg
, Btyp
);
9078 -- If the operation is user-defined and not overloaded use its
9079 -- profile. The operation may be a renaming, in which case it has
9080 -- been rewritten, and we want the original profile.
9082 elsif not Is_Overloaded
(N
)
9083 and then Comes_From_Source
(Entity
(Original_Node
(N
)))
9084 and then Ekind
(Entity
(Original_Node
(N
))) = E_Function
9088 (Next_Formal
(First_Formal
(Entity
(Original_Node
(N
))))));
9091 -- Otherwise an aggregate may match both the array type and the
9095 Error_Msg_N
("ambiguous aggregate must be qualified", Arg
);
9096 Set_Etype
(Arg
, Any_Type
);
9100 if Is_Overloaded
(Arg
)
9101 and then Has_Compatible_Type
(Arg
, Typ
)
9102 and then Etype
(Arg
) /= Any_Type
9110 Get_First_Interp
(Arg
, I
, It
);
9112 Get_Next_Interp
(I
, It
);
9114 -- Special-case the error message when the overloading is
9115 -- caused by a function that yields an array and can be
9116 -- called without parameters.
9118 if It
.Nam
= Func
then
9119 Error_Msg_Sloc
:= Sloc
(Func
);
9120 Error_Msg_N
("ambiguous call to function#", Arg
);
9122 ("\\interpretation as call yields&", Arg
, Typ
);
9124 ("\\interpretation as indexing of call yields&",
9125 Arg
, Component_Type
(Typ
));
9128 Error_Msg_N
("ambiguous operand for concatenation!", Arg
);
9130 Get_First_Interp
(Arg
, I
, It
);
9131 while Present
(It
.Nam
) loop
9132 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
9134 if Base_Type
(It
.Typ
) = Btyp
9136 Base_Type
(It
.Typ
) = Base_Type
(Ctyp
)
9138 Error_Msg_N
-- CODEFIX
9139 ("\\possible interpretation#", Arg
);
9142 Get_Next_Interp
(I
, It
);
9148 Resolve
(Arg
, Component_Type
(Typ
));
9150 if Nkind
(Arg
) = N_String_Literal
then
9151 Set_Etype
(Arg
, Component_Type
(Typ
));
9154 if Arg
= Left_Opnd
(N
) then
9155 Set_Is_Component_Left_Opnd
(N
);
9157 Set_Is_Component_Right_Opnd
(N
);
9162 Resolve
(Arg
, Btyp
);
9165 -- Concatenation is restricted in SPARK: each operand must be either a
9166 -- string literal, the name of a string constant, a static character or
9167 -- string expression, or another concatenation. Arg cannot be a
9168 -- concatenation here as callers of Resolve_Op_Concat_Arg call it
9169 -- separately on each final operand, past concatenation operations.
9171 if Is_Character_Type
(Etype
(Arg
)) then
9172 if not Is_OK_Static_Expression
(Arg
) then
9173 Check_SPARK_05_Restriction
9174 ("character operand for concatenation should be static", Arg
);
9177 elsif Is_String_Type
(Etype
(Arg
)) then
9178 if not (Nkind_In
(Arg
, N_Identifier
, N_Expanded_Name
)
9179 and then Is_Constant_Object
(Entity
(Arg
)))
9180 and then not Is_OK_Static_Expression
(Arg
)
9182 Check_SPARK_05_Restriction
9183 ("string operand for concatenation should be static", Arg
);
9186 -- Do not issue error on an operand that is neither a character nor a
9187 -- string, as the error is issued in Resolve_Op_Concat.
9193 Check_Unset_Reference
(Arg
);
9194 end Resolve_Op_Concat_Arg
;
9196 -----------------------------
9197 -- Resolve_Op_Concat_First --
9198 -----------------------------
9200 procedure Resolve_Op_Concat_First
(N
: Node_Id
; Typ
: Entity_Id
) is
9201 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
9202 Op1
: constant Node_Id
:= Left_Opnd
(N
);
9203 Op2
: constant Node_Id
:= Right_Opnd
(N
);
9206 -- The parser folds an enormous sequence of concatenations of string
9207 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
9208 -- in the right operand. If the expression resolves to a predefined "&"
9209 -- operator, all is well. Otherwise, the parser's folding is wrong, so
9210 -- we give an error. See P_Simple_Expression in Par.Ch4.
9212 if Nkind
(Op2
) = N_String_Literal
9213 and then Is_Folded_In_Parser
(Op2
)
9214 and then Ekind
(Entity
(N
)) = E_Function
9216 pragma Assert
(Nkind
(Op1
) = N_String_Literal
-- should be ""
9217 and then String_Length
(Strval
(Op1
)) = 0);
9218 Error_Msg_N
("too many user-defined concatenations", N
);
9222 Set_Etype
(N
, Btyp
);
9224 if Is_Limited_Composite
(Btyp
) then
9225 Error_Msg_N
("concatenation not available for limited array", N
);
9226 Explain_Limited_Type
(Btyp
, N
);
9228 end Resolve_Op_Concat_First
;
9230 ----------------------------
9231 -- Resolve_Op_Concat_Rest --
9232 ----------------------------
9234 procedure Resolve_Op_Concat_Rest
(N
: Node_Id
; Typ
: Entity_Id
) is
9235 Op1
: constant Node_Id
:= Left_Opnd
(N
);
9236 Op2
: constant Node_Id
:= Right_Opnd
(N
);
9239 Resolve_Op_Concat_Arg
(N
, Op2
, Typ
, Is_Component_Right_Opnd
(N
));
9241 Generate_Operator_Reference
(N
, Typ
);
9243 if Is_String_Type
(Typ
) then
9244 Eval_Concatenation
(N
);
9247 -- If this is not a static concatenation, but the result is a string
9248 -- type (and not an array of strings) ensure that static string operands
9249 -- have their subtypes properly constructed.
9251 if Nkind
(N
) /= N_String_Literal
9252 and then Is_Character_Type
(Component_Type
(Typ
))
9254 Set_String_Literal_Subtype
(Op1
, Typ
);
9255 Set_String_Literal_Subtype
(Op2
, Typ
);
9257 end Resolve_Op_Concat_Rest
;
9259 ----------------------
9260 -- Resolve_Op_Expon --
9261 ----------------------
9263 procedure Resolve_Op_Expon
(N
: Node_Id
; Typ
: Entity_Id
) is
9264 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
9267 -- Catch attempts to do fixed-point exponentiation with universal
9268 -- operands, which is a case where the illegality is not caught during
9269 -- normal operator analysis. This is not done in preanalysis mode
9270 -- since the tree is not fully decorated during preanalysis.
9272 if Full_Analysis
then
9273 if Is_Fixed_Point_Type
(Typ
) and then Comes_From_Source
(N
) then
9274 Error_Msg_N
("exponentiation not available for fixed point", N
);
9277 elsif Nkind
(Parent
(N
)) in N_Op
9278 and then Is_Fixed_Point_Type
(Etype
(Parent
(N
)))
9279 and then Etype
(N
) = Universal_Real
9280 and then Comes_From_Source
(N
)
9282 Error_Msg_N
("exponentiation not available for fixed point", N
);
9287 if Comes_From_Source
(N
)
9288 and then Ekind
(Entity
(N
)) = E_Function
9289 and then Is_Imported
(Entity
(N
))
9290 and then Is_Intrinsic_Subprogram
(Entity
(N
))
9292 Resolve_Intrinsic_Operator
(N
, Typ
);
9296 if Etype
(Left_Opnd
(N
)) = Universal_Integer
9297 or else Etype
(Left_Opnd
(N
)) = Universal_Real
9299 Check_For_Visible_Operator
(N
, B_Typ
);
9302 -- We do the resolution using the base type, because intermediate values
9303 -- in expressions are always of the base type, not a subtype of it.
9305 Resolve
(Left_Opnd
(N
), B_Typ
);
9306 Resolve
(Right_Opnd
(N
), Standard_Integer
);
9308 -- For integer types, right argument must be in Natural range
9310 if Is_Integer_Type
(Typ
) then
9311 Apply_Scalar_Range_Check
(Right_Opnd
(N
), Standard_Natural
);
9314 Check_Unset_Reference
(Left_Opnd
(N
));
9315 Check_Unset_Reference
(Right_Opnd
(N
));
9317 Set_Etype
(N
, B_Typ
);
9318 Generate_Operator_Reference
(N
, B_Typ
);
9320 Analyze_Dimension
(N
);
9322 if Ada_Version
>= Ada_2012
and then Has_Dimension_System
(B_Typ
) then
9323 -- Evaluate the exponentiation operator for dimensioned type
9325 Eval_Op_Expon_For_Dimensioned_Type
(N
, B_Typ
);
9330 -- Set overflow checking bit. Much cleverer code needed here eventually
9331 -- and perhaps the Resolve routines should be separated for the various
9332 -- arithmetic operations, since they will need different processing. ???
9334 if Nkind
(N
) in N_Op
then
9335 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
9336 Enable_Overflow_Check
(N
);
9339 end Resolve_Op_Expon
;
9341 --------------------
9342 -- Resolve_Op_Not --
9343 --------------------
9345 procedure Resolve_Op_Not
(N
: Node_Id
; Typ
: Entity_Id
) is
9348 function Parent_Is_Boolean
return Boolean;
9349 -- This function determines if the parent node is a boolean operator or
9350 -- operation (comparison op, membership test, or short circuit form) and
9351 -- the not in question is the left operand of this operation. Note that
9352 -- if the not is in parens, then false is returned.
9354 -----------------------
9355 -- Parent_Is_Boolean --
9356 -----------------------
9358 function Parent_Is_Boolean
return Boolean is
9360 if Paren_Count
(N
) /= 0 then
9364 case Nkind
(Parent
(N
)) is
9379 return Left_Opnd
(Parent
(N
)) = N
;
9385 end Parent_Is_Boolean
;
9387 -- Start of processing for Resolve_Op_Not
9390 -- Predefined operations on scalar types yield the base type. On the
9391 -- other hand, logical operations on arrays yield the type of the
9392 -- arguments (and the context).
9394 if Is_Array_Type
(Typ
) then
9397 B_Typ
:= Base_Type
(Typ
);
9400 -- Straightforward case of incorrect arguments
9402 if not Valid_Boolean_Arg
(Typ
) then
9403 Error_Msg_N
("invalid operand type for operator&", N
);
9404 Set_Etype
(N
, Any_Type
);
9407 -- Special case of probable missing parens
9409 elsif Typ
= Universal_Integer
or else Typ
= Any_Modular
then
9410 if Parent_Is_Boolean
then
9412 ("operand of not must be enclosed in parentheses",
9416 ("no modular type available in this context", N
);
9419 Set_Etype
(N
, Any_Type
);
9422 -- OK resolution of NOT
9425 -- Warn if non-boolean types involved. This is a case like not a < b
9426 -- where a and b are modular, where we will get (not a) < b and most
9427 -- likely not (a < b) was intended.
9429 if Warn_On_Questionable_Missing_Parens
9430 and then not Is_Boolean_Type
(Typ
)
9431 and then Parent_Is_Boolean
9433 Error_Msg_N
("?q?not expression should be parenthesized here!", N
);
9436 -- Warn on double negation if checking redundant constructs
9438 if Warn_On_Redundant_Constructs
9439 and then Comes_From_Source
(N
)
9440 and then Comes_From_Source
(Right_Opnd
(N
))
9441 and then Root_Type
(Typ
) = Standard_Boolean
9442 and then Nkind
(Right_Opnd
(N
)) = N_Op_Not
9444 Error_Msg_N
("redundant double negation?r?", N
);
9447 -- Complete resolution and evaluation of NOT
9449 Resolve
(Right_Opnd
(N
), B_Typ
);
9450 Check_Unset_Reference
(Right_Opnd
(N
));
9451 Set_Etype
(N
, B_Typ
);
9452 Generate_Operator_Reference
(N
, B_Typ
);
9457 -----------------------------
9458 -- Resolve_Operator_Symbol --
9459 -----------------------------
9461 -- Nothing to be done, all resolved already
9463 procedure Resolve_Operator_Symbol
(N
: Node_Id
; Typ
: Entity_Id
) is
9464 pragma Warnings
(Off
, N
);
9465 pragma Warnings
(Off
, Typ
);
9469 end Resolve_Operator_Symbol
;
9471 ----------------------------------
9472 -- Resolve_Qualified_Expression --
9473 ----------------------------------
9475 procedure Resolve_Qualified_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
9476 pragma Warnings
(Off
, Typ
);
9478 Target_Typ
: constant Entity_Id
:= Entity
(Subtype_Mark
(N
));
9479 Expr
: constant Node_Id
:= Expression
(N
);
9482 Resolve
(Expr
, Target_Typ
);
9484 -- Protect call to Matching_Static_Array_Bounds to avoid costly
9485 -- operation if not needed.
9487 if Restriction_Check_Required
(SPARK_05
)
9488 and then Is_Array_Type
(Target_Typ
)
9489 and then Is_Array_Type
(Etype
(Expr
))
9490 and then Etype
(Expr
) /= Any_Composite
-- or else Expr in error
9491 and then not Matching_Static_Array_Bounds
(Target_Typ
, Etype
(Expr
))
9493 Check_SPARK_05_Restriction
9494 ("array types should have matching static bounds", N
);
9497 -- A qualified expression requires an exact match of the type, class-
9498 -- wide matching is not allowed. However, if the qualifying type is
9499 -- specific and the expression has a class-wide type, it may still be
9500 -- okay, since it can be the result of the expansion of a call to a
9501 -- dispatching function, so we also have to check class-wideness of the
9502 -- type of the expression's original node.
9504 if (Is_Class_Wide_Type
(Target_Typ
)
9506 (Is_Class_Wide_Type
(Etype
(Expr
))
9507 and then Is_Class_Wide_Type
(Etype
(Original_Node
(Expr
)))))
9508 and then Base_Type
(Etype
(Expr
)) /= Base_Type
(Target_Typ
)
9510 Wrong_Type
(Expr
, Target_Typ
);
9513 -- If the target type is unconstrained, then we reset the type of the
9514 -- result from the type of the expression. For other cases, the actual
9515 -- subtype of the expression is the target type.
9517 if Is_Composite_Type
(Target_Typ
)
9518 and then not Is_Constrained
(Target_Typ
)
9520 Set_Etype
(N
, Etype
(Expr
));
9523 Analyze_Dimension
(N
);
9524 Eval_Qualified_Expression
(N
);
9526 -- If we still have a qualified expression after the static evaluation,
9527 -- then apply a scalar range check if needed. The reason that we do this
9528 -- after the Eval call is that otherwise, the application of the range
9529 -- check may convert an illegal static expression and result in warning
9530 -- rather than giving an error (e.g Integer'(Integer'Last + 1)).
9532 if Nkind
(N
) = N_Qualified_Expression
and then Is_Scalar_Type
(Typ
) then
9533 Apply_Scalar_Range_Check
(Expr
, Typ
);
9536 -- Finally, check whether a predicate applies to the target type. This
9537 -- comes from AI12-0100. As for type conversions, check the enclosing
9538 -- context to prevent an infinite expansion.
9540 if Has_Predicates
(Target_Typ
) then
9541 if Nkind
(Parent
(N
)) = N_Function_Call
9542 and then Present
(Name
(Parent
(N
)))
9543 and then (Is_Predicate_Function
(Entity
(Name
(Parent
(N
))))
9545 Is_Predicate_Function_M
(Entity
(Name
(Parent
(N
)))))
9549 -- In the case of a qualified expression in an allocator, the check
9550 -- is applied when expanding the allocator, so avoid redundant check.
9552 elsif Nkind
(N
) = N_Qualified_Expression
9553 and then Nkind
(Parent
(N
)) /= N_Allocator
9555 Apply_Predicate_Check
(N
, Target_Typ
);
9558 end Resolve_Qualified_Expression
;
9560 ------------------------------
9561 -- Resolve_Raise_Expression --
9562 ------------------------------
9564 procedure Resolve_Raise_Expression
(N
: Node_Id
; Typ
: Entity_Id
) is
9566 if Typ
= Raise_Type
then
9567 Error_Msg_N
("cannot find unique type for raise expression", N
);
9568 Set_Etype
(N
, Any_Type
);
9572 end Resolve_Raise_Expression
;
9578 procedure Resolve_Range
(N
: Node_Id
; Typ
: Entity_Id
) is
9579 L
: constant Node_Id
:= Low_Bound
(N
);
9580 H
: constant Node_Id
:= High_Bound
(N
);
9582 function First_Last_Ref
return Boolean;
9583 -- Returns True if N is of the form X'First .. X'Last where X is the
9584 -- same entity for both attributes.
9586 --------------------
9587 -- First_Last_Ref --
9588 --------------------
9590 function First_Last_Ref
return Boolean is
9591 Lorig
: constant Node_Id
:= Original_Node
(L
);
9592 Horig
: constant Node_Id
:= Original_Node
(H
);
9595 if Nkind
(Lorig
) = N_Attribute_Reference
9596 and then Nkind
(Horig
) = N_Attribute_Reference
9597 and then Attribute_Name
(Lorig
) = Name_First
9598 and then Attribute_Name
(Horig
) = Name_Last
9601 PL
: constant Node_Id
:= Prefix
(Lorig
);
9602 PH
: constant Node_Id
:= Prefix
(Horig
);
9604 if Is_Entity_Name
(PL
)
9605 and then Is_Entity_Name
(PH
)
9606 and then Entity
(PL
) = Entity
(PH
)
9616 -- Start of processing for Resolve_Range
9623 -- Check for inappropriate range on unordered enumeration type
9625 if Bad_Unordered_Enumeration_Reference
(N
, Typ
)
9627 -- Exclude X'First .. X'Last if X is the same entity for both
9629 and then not First_Last_Ref
9631 Error_Msg_Sloc
:= Sloc
(Typ
);
9633 ("subrange of unordered enumeration type& declared#?U?", N
, Typ
);
9636 Check_Unset_Reference
(L
);
9637 Check_Unset_Reference
(H
);
9639 -- We have to check the bounds for being within the base range as
9640 -- required for a non-static context. Normally this is automatic and
9641 -- done as part of evaluating expressions, but the N_Range node is an
9642 -- exception, since in GNAT we consider this node to be a subexpression,
9643 -- even though in Ada it is not. The circuit in Sem_Eval could check for
9644 -- this, but that would put the test on the main evaluation path for
9647 Check_Non_Static_Context
(L
);
9648 Check_Non_Static_Context
(H
);
9650 -- Check for an ambiguous range over character literals. This will
9651 -- happen with a membership test involving only literals.
9653 if Typ
= Any_Character
then
9654 Ambiguous_Character
(L
);
9655 Set_Etype
(N
, Any_Type
);
9659 -- If bounds are static, constant-fold them, so size computations are
9660 -- identical between front-end and back-end. Do not perform this
9661 -- transformation while analyzing generic units, as type information
9662 -- would be lost when reanalyzing the constant node in the instance.
9664 if Is_Discrete_Type
(Typ
) and then Expander_Active
then
9665 if Is_OK_Static_Expression
(L
) then
9666 Fold_Uint
(L
, Expr_Value
(L
), Is_OK_Static_Expression
(L
));
9669 if Is_OK_Static_Expression
(H
) then
9670 Fold_Uint
(H
, Expr_Value
(H
), Is_OK_Static_Expression
(H
));
9675 --------------------------
9676 -- Resolve_Real_Literal --
9677 --------------------------
9679 procedure Resolve_Real_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
9680 Actual_Typ
: constant Entity_Id
:= Etype
(N
);
9683 -- Special processing for fixed-point literals to make sure that the
9684 -- value is an exact multiple of small where this is required. We skip
9685 -- this for the universal real case, and also for generic types.
9687 if Is_Fixed_Point_Type
(Typ
)
9688 and then Typ
/= Universal_Fixed
9689 and then Typ
/= Any_Fixed
9690 and then not Is_Generic_Type
(Typ
)
9693 Val
: constant Ureal
:= Realval
(N
);
9694 Cintr
: constant Ureal
:= Val
/ Small_Value
(Typ
);
9695 Cint
: constant Uint
:= UR_Trunc
(Cintr
);
9696 Den
: constant Uint
:= Norm_Den
(Cintr
);
9700 -- Case of literal is not an exact multiple of the Small
9704 -- For a source program literal for a decimal fixed-point type,
9705 -- this is statically illegal (RM 4.9(36)).
9707 if Is_Decimal_Fixed_Point_Type
(Typ
)
9708 and then Actual_Typ
= Universal_Real
9709 and then Comes_From_Source
(N
)
9711 Error_Msg_N
("value has extraneous low order digits", N
);
9714 -- Generate a warning if literal from source
9716 if Is_OK_Static_Expression
(N
)
9717 and then Warn_On_Bad_Fixed_Value
9720 ("?b?static fixed-point value is not a multiple of Small!",
9724 -- Replace literal by a value that is the exact representation
9725 -- of a value of the type, i.e. a multiple of the small value,
9726 -- by truncation, since Machine_Rounds is false for all GNAT
9727 -- fixed-point types (RM 4.9(38)).
9729 Stat
:= Is_OK_Static_Expression
(N
);
9731 Make_Real_Literal
(Sloc
(N
),
9732 Realval
=> Small_Value
(Typ
) * Cint
));
9734 Set_Is_Static_Expression
(N
, Stat
);
9737 -- In all cases, set the corresponding integer field
9739 Set_Corresponding_Integer_Value
(N
, Cint
);
9743 -- Now replace the actual type by the expected type as usual
9746 Eval_Real_Literal
(N
);
9747 end Resolve_Real_Literal
;
9749 -----------------------
9750 -- Resolve_Reference --
9751 -----------------------
9753 procedure Resolve_Reference
(N
: Node_Id
; Typ
: Entity_Id
) is
9754 P
: constant Node_Id
:= Prefix
(N
);
9757 -- Replace general access with specific type
9759 if Ekind
(Etype
(N
)) = E_Allocator_Type
then
9760 Set_Etype
(N
, Base_Type
(Typ
));
9763 Resolve
(P
, Designated_Type
(Etype
(N
)));
9765 -- If we are taking the reference of a volatile entity, then treat it as
9766 -- a potential modification of this entity. This is too conservative,
9767 -- but necessary because remove side effects can cause transformations
9768 -- of normal assignments into reference sequences that otherwise fail to
9769 -- notice the modification.
9771 if Is_Entity_Name
(P
) and then Treat_As_Volatile
(Entity
(P
)) then
9772 Note_Possible_Modification
(P
, Sure
=> False);
9774 end Resolve_Reference
;
9776 --------------------------------
9777 -- Resolve_Selected_Component --
9778 --------------------------------
9780 procedure Resolve_Selected_Component
(N
: Node_Id
; Typ
: Entity_Id
) is
9782 Comp1
: Entity_Id
:= Empty
; -- prevent junk warning
9783 P
: constant Node_Id
:= Prefix
(N
);
9784 S
: constant Node_Id
:= Selector_Name
(N
);
9785 T
: Entity_Id
:= Etype
(P
);
9787 I1
: Interp_Index
:= 0; -- prevent junk warning
9792 function Init_Component
return Boolean;
9793 -- Check whether this is the initialization of a component within an
9794 -- init proc (by assignment or call to another init proc). If true,
9795 -- there is no need for a discriminant check.
9797 --------------------
9798 -- Init_Component --
9799 --------------------
9801 function Init_Component
return Boolean is
9803 return Inside_Init_Proc
9804 and then Nkind
(Prefix
(N
)) = N_Identifier
9805 and then Chars
(Prefix
(N
)) = Name_uInit
9806 and then Nkind
(Parent
(Parent
(N
))) = N_Case_Statement_Alternative
;
9809 -- Start of processing for Resolve_Selected_Component
9812 if Is_Overloaded
(P
) then
9814 -- Use the context type to select the prefix that has a selector
9815 -- of the correct name and type.
9818 Get_First_Interp
(P
, I
, It
);
9820 Search
: while Present
(It
.Typ
) loop
9821 if Is_Access_Type
(It
.Typ
) then
9822 T
:= Designated_Type
(It
.Typ
);
9827 -- Locate selected component. For a private prefix the selector
9828 -- can denote a discriminant.
9830 if Is_Record_Type
(T
) or else Is_Private_Type
(T
) then
9832 -- The visible components of a class-wide type are those of
9835 if Is_Class_Wide_Type
(T
) then
9839 Comp
:= First_Entity
(T
);
9840 while Present
(Comp
) loop
9841 if Chars
(Comp
) = Chars
(S
)
9842 and then Covers
(Typ
, Etype
(Comp
))
9851 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
9853 if It
= No_Interp
then
9855 ("ambiguous prefix for selected component", N
);
9862 -- There may be an implicit dereference. Retrieve
9863 -- designated record type.
9865 if Is_Access_Type
(It1
.Typ
) then
9866 T
:= Designated_Type
(It1
.Typ
);
9871 if Scope
(Comp1
) /= T
then
9873 -- Resolution chooses the new interpretation.
9874 -- Find the component with the right name.
9876 Comp1
:= First_Entity
(T
);
9877 while Present
(Comp1
)
9878 and then Chars
(Comp1
) /= Chars
(S
)
9880 Comp1
:= Next_Entity
(Comp1
);
9889 Comp
:= Next_Entity
(Comp
);
9893 Get_Next_Interp
(I
, It
);
9896 -- There must be a legal interpretation at this point
9898 pragma Assert
(Found
);
9899 Resolve
(P
, It1
.Typ
);
9901 Set_Entity_With_Checks
(S
, Comp1
);
9904 -- Resolve prefix with its type
9909 -- Generate cross-reference. We needed to wait until full overloading
9910 -- resolution was complete to do this, since otherwise we can't tell if
9911 -- we are an lvalue or not.
9913 if May_Be_Lvalue
(N
) then
9914 Generate_Reference
(Entity
(S
), S
, 'm');
9916 Generate_Reference
(Entity
(S
), S
, 'r');
9919 -- If prefix is an access type, the node will be transformed into an
9920 -- explicit dereference during expansion. The type of the node is the
9921 -- designated type of that of the prefix.
9923 if Is_Access_Type
(Etype
(P
)) then
9924 T
:= Designated_Type
(Etype
(P
));
9925 Check_Fully_Declared_Prefix
(T
, P
);
9930 -- Set flag for expander if discriminant check required on a component
9931 -- appearing within a variant.
9933 if Has_Discriminants
(T
)
9934 and then Ekind
(Entity
(S
)) = E_Component
9935 and then Present
(Original_Record_Component
(Entity
(S
)))
9936 and then Ekind
(Original_Record_Component
(Entity
(S
))) = E_Component
9938 Is_Declared_Within_Variant
(Original_Record_Component
(Entity
(S
)))
9939 and then not Discriminant_Checks_Suppressed
(T
)
9940 and then not Init_Component
9942 Set_Do_Discriminant_Check
(N
);
9945 if Ekind
(Entity
(S
)) = E_Void
then
9946 Error_Msg_N
("premature use of component", S
);
9949 -- If the prefix is a record conversion, this may be a renamed
9950 -- discriminant whose bounds differ from those of the original
9951 -- one, so we must ensure that a range check is performed.
9953 if Nkind
(P
) = N_Type_Conversion
9954 and then Ekind
(Entity
(S
)) = E_Discriminant
9955 and then Is_Discrete_Type
(Typ
)
9957 Set_Etype
(N
, Base_Type
(Typ
));
9960 -- Note: No Eval processing is required, because the prefix is of a
9961 -- record type, or protected type, and neither can possibly be static.
9963 -- If the record type is atomic, and the component is non-atomic, then
9964 -- this is worth a warning, since we have a situation where the access
9965 -- to the component may cause extra read/writes of the atomic array
9966 -- object, or partial word accesses, both of which may be unexpected.
9968 if Nkind
(N
) = N_Selected_Component
9969 and then Is_Atomic_Ref_With_Address
(N
)
9970 and then not Is_Atomic
(Entity
(S
))
9971 and then not Is_Atomic
(Etype
(Entity
(S
)))
9974 ("??access to non-atomic component of atomic record",
9977 ("\??may cause unexpected accesses to atomic object",
9981 Analyze_Dimension
(N
);
9982 end Resolve_Selected_Component
;
9988 procedure Resolve_Shift
(N
: Node_Id
; Typ
: Entity_Id
) is
9989 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
9990 L
: constant Node_Id
:= Left_Opnd
(N
);
9991 R
: constant Node_Id
:= Right_Opnd
(N
);
9994 -- We do the resolution using the base type, because intermediate values
9995 -- in expressions always are of the base type, not a subtype of it.
9998 Resolve
(R
, Standard_Natural
);
10000 Check_Unset_Reference
(L
);
10001 Check_Unset_Reference
(R
);
10003 Set_Etype
(N
, B_Typ
);
10004 Generate_Operator_Reference
(N
, B_Typ
);
10008 ---------------------------
10009 -- Resolve_Short_Circuit --
10010 ---------------------------
10012 procedure Resolve_Short_Circuit
(N
: Node_Id
; Typ
: Entity_Id
) is
10013 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
10014 L
: constant Node_Id
:= Left_Opnd
(N
);
10015 R
: constant Node_Id
:= Right_Opnd
(N
);
10018 -- Ensure all actions associated with the left operand (e.g.
10019 -- finalization of transient objects) are fully evaluated locally within
10020 -- an expression with actions. This is particularly helpful for coverage
10021 -- analysis. However this should not happen in generics or if option
10022 -- Minimize_Expression_With_Actions is set.
10024 if Expander_Active
and not Minimize_Expression_With_Actions
then
10026 Reloc_L
: constant Node_Id
:= Relocate_Node
(L
);
10028 Save_Interps
(Old_N
=> L
, New_N
=> Reloc_L
);
10031 Make_Expression_With_Actions
(Sloc
(L
),
10032 Actions
=> New_List
,
10033 Expression
=> Reloc_L
));
10035 -- Set Comes_From_Source on L to preserve warnings for unset
10038 Set_Comes_From_Source
(L
, Comes_From_Source
(Reloc_L
));
10042 Resolve
(L
, B_Typ
);
10043 Resolve
(R
, B_Typ
);
10045 -- Check for issuing warning for always False assert/check, this happens
10046 -- when assertions are turned off, in which case the pragma Assert/Check
10047 -- was transformed into:
10049 -- if False and then <condition> then ...
10051 -- and we detect this pattern
10053 if Warn_On_Assertion_Failure
10054 and then Is_Entity_Name
(R
)
10055 and then Entity
(R
) = Standard_False
10056 and then Nkind
(Parent
(N
)) = N_If_Statement
10057 and then Nkind
(N
) = N_And_Then
10058 and then Is_Entity_Name
(L
)
10059 and then Entity
(L
) = Standard_False
10062 Orig
: constant Node_Id
:= Original_Node
(Parent
(N
));
10065 -- Special handling of Asssert pragma
10067 if Nkind
(Orig
) = N_Pragma
10068 and then Pragma_Name
(Orig
) = Name_Assert
10071 Expr
: constant Node_Id
:=
10074 (First
(Pragma_Argument_Associations
(Orig
))));
10077 -- Don't warn if original condition is explicit False,
10078 -- since obviously the failure is expected in this case.
10080 if Is_Entity_Name
(Expr
)
10081 and then Entity
(Expr
) = Standard_False
10085 -- Issue warning. We do not want the deletion of the
10086 -- IF/AND-THEN to take this message with it. We achieve this
10087 -- by making sure that the expanded code points to the Sloc
10088 -- of the expression, not the original pragma.
10091 -- Note: Use Error_Msg_F here rather than Error_Msg_N.
10092 -- The source location of the expression is not usually
10093 -- the best choice here. For example, it gets located on
10094 -- the last AND keyword in a chain of boolean expressiond
10095 -- AND'ed together. It is best to put the message on the
10096 -- first character of the assertion, which is the effect
10097 -- of the First_Node call here.
10100 ("?A?assertion would fail at run time!",
10102 (First
(Pragma_Argument_Associations
(Orig
))));
10106 -- Similar processing for Check pragma
10108 elsif Nkind
(Orig
) = N_Pragma
10109 and then Pragma_Name
(Orig
) = Name_Check
10111 -- Don't want to warn if original condition is explicit False
10114 Expr
: constant Node_Id
:=
10117 (Next
(First
(Pragma_Argument_Associations
(Orig
)))));
10119 if Is_Entity_Name
(Expr
)
10120 and then Entity
(Expr
) = Standard_False
10127 -- Again use Error_Msg_F rather than Error_Msg_N, see
10128 -- comment above for an explanation of why we do this.
10131 ("?A?check would fail at run time!",
10133 (Last
(Pragma_Argument_Associations
(Orig
))));
10140 -- Continue with processing of short circuit
10142 Check_Unset_Reference
(L
);
10143 Check_Unset_Reference
(R
);
10145 Set_Etype
(N
, B_Typ
);
10146 Eval_Short_Circuit
(N
);
10147 end Resolve_Short_Circuit
;
10149 -------------------
10150 -- Resolve_Slice --
10151 -------------------
10153 procedure Resolve_Slice
(N
: Node_Id
; Typ
: Entity_Id
) is
10154 Drange
: constant Node_Id
:= Discrete_Range
(N
);
10155 Name
: constant Node_Id
:= Prefix
(N
);
10156 Array_Type
: Entity_Id
:= Empty
;
10157 Dexpr
: Node_Id
:= Empty
;
10158 Index_Type
: Entity_Id
;
10161 if Is_Overloaded
(Name
) then
10163 -- Use the context type to select the prefix that yields the correct
10168 I1
: Interp_Index
:= 0;
10170 P
: constant Node_Id
:= Prefix
(N
);
10171 Found
: Boolean := False;
10174 Get_First_Interp
(P
, I
, It
);
10175 while Present
(It
.Typ
) loop
10176 if (Is_Array_Type
(It
.Typ
)
10177 and then Covers
(Typ
, It
.Typ
))
10178 or else (Is_Access_Type
(It
.Typ
)
10179 and then Is_Array_Type
(Designated_Type
(It
.Typ
))
10180 and then Covers
(Typ
, Designated_Type
(It
.Typ
)))
10183 It
:= Disambiguate
(P
, I1
, I
, Any_Type
);
10185 if It
= No_Interp
then
10186 Error_Msg_N
("ambiguous prefix for slicing", N
);
10187 Set_Etype
(N
, Typ
);
10191 Array_Type
:= It
.Typ
;
10196 Array_Type
:= It
.Typ
;
10201 Get_Next_Interp
(I
, It
);
10206 Array_Type
:= Etype
(Name
);
10209 Resolve
(Name
, Array_Type
);
10211 if Is_Access_Type
(Array_Type
) then
10212 Apply_Access_Check
(N
);
10213 Array_Type
:= Designated_Type
(Array_Type
);
10215 -- If the prefix is an access to an unconstrained array, we must use
10216 -- the actual subtype of the object to perform the index checks. The
10217 -- object denoted by the prefix is implicit in the node, so we build
10218 -- an explicit representation for it in order to compute the actual
10221 if not Is_Constrained
(Array_Type
) then
10222 Remove_Side_Effects
(Prefix
(N
));
10225 Obj
: constant Node_Id
:=
10226 Make_Explicit_Dereference
(Sloc
(N
),
10227 Prefix
=> New_Copy_Tree
(Prefix
(N
)));
10229 Set_Etype
(Obj
, Array_Type
);
10230 Set_Parent
(Obj
, Parent
(N
));
10231 Array_Type
:= Get_Actual_Subtype
(Obj
);
10235 elsif Is_Entity_Name
(Name
)
10236 or else Nkind
(Name
) = N_Explicit_Dereference
10237 or else (Nkind
(Name
) = N_Function_Call
10238 and then not Is_Constrained
(Etype
(Name
)))
10240 Array_Type
:= Get_Actual_Subtype
(Name
);
10242 -- If the name is a selected component that depends on discriminants,
10243 -- build an actual subtype for it. This can happen only when the name
10244 -- itself is overloaded; otherwise the actual subtype is created when
10245 -- the selected component is analyzed.
10247 elsif Nkind
(Name
) = N_Selected_Component
10248 and then Full_Analysis
10249 and then Depends_On_Discriminant
(First_Index
(Array_Type
))
10252 Act_Decl
: constant Node_Id
:=
10253 Build_Actual_Subtype_Of_Component
(Array_Type
, Name
);
10255 Insert_Action
(N
, Act_Decl
);
10256 Array_Type
:= Defining_Identifier
(Act_Decl
);
10259 -- Maybe this should just be "else", instead of checking for the
10260 -- specific case of slice??? This is needed for the case where the
10261 -- prefix is an Image attribute, which gets expanded to a slice, and so
10262 -- has a constrained subtype which we want to use for the slice range
10263 -- check applied below (the range check won't get done if the
10264 -- unconstrained subtype of the 'Image is used).
10266 elsif Nkind
(Name
) = N_Slice
then
10267 Array_Type
:= Etype
(Name
);
10270 -- Obtain the type of the array index
10272 if Ekind
(Array_Type
) = E_String_Literal_Subtype
then
10273 Index_Type
:= Etype
(String_Literal_Low_Bound
(Array_Type
));
10275 Index_Type
:= Etype
(First_Index
(Array_Type
));
10278 -- If name was overloaded, set slice type correctly now
10280 Set_Etype
(N
, Array_Type
);
10282 -- Handle the generation of a range check that compares the array index
10283 -- against the discrete_range. The check is not applied to internally
10284 -- built nodes associated with the expansion of dispatch tables. Check
10285 -- that Ada.Tags has already been loaded to avoid extra dependencies on
10288 if Tagged_Type_Expansion
10289 and then RTU_Loaded
(Ada_Tags
)
10290 and then Nkind
(Prefix
(N
)) = N_Selected_Component
10291 and then Present
(Entity
(Selector_Name
(Prefix
(N
))))
10292 and then Entity
(Selector_Name
(Prefix
(N
))) =
10293 RTE_Record_Component
(RE_Prims_Ptr
)
10297 -- The discrete_range is specified by a subtype indication. Create a
10298 -- shallow copy and inherit the type, parent and source location from
10299 -- the discrete_range. This ensures that the range check is inserted
10300 -- relative to the slice and that the runtime exception points to the
10301 -- proper construct.
10303 elsif Is_Entity_Name
(Drange
) then
10304 Dexpr
:= New_Copy
(Scalar_Range
(Entity
(Drange
)));
10306 Set_Etype
(Dexpr
, Etype
(Drange
));
10307 Set_Parent
(Dexpr
, Parent
(Drange
));
10308 Set_Sloc
(Dexpr
, Sloc
(Drange
));
10310 -- The discrete_range is a regular range. Resolve the bounds and remove
10311 -- their side effects.
10314 Resolve
(Drange
, Base_Type
(Index_Type
));
10316 if Nkind
(Drange
) = N_Range
then
10317 Force_Evaluation
(Low_Bound
(Drange
));
10318 Force_Evaluation
(High_Bound
(Drange
));
10324 if Present
(Dexpr
) then
10325 Apply_Range_Check
(Dexpr
, Index_Type
);
10328 Set_Slice_Subtype
(N
);
10330 -- Check bad use of type with predicates
10336 if Nkind
(Drange
) = N_Subtype_Indication
10337 and then Has_Predicates
(Entity
(Subtype_Mark
(Drange
)))
10339 Subt
:= Entity
(Subtype_Mark
(Drange
));
10341 Subt
:= Etype
(Drange
);
10344 if Has_Predicates
(Subt
) then
10345 Bad_Predicated_Subtype_Use
10346 ("subtype& has predicate, not allowed in slice", Drange
, Subt
);
10350 -- Otherwise here is where we check suspicious indexes
10352 if Nkind
(Drange
) = N_Range
then
10353 Warn_On_Suspicious_Index
(Name
, Low_Bound
(Drange
));
10354 Warn_On_Suspicious_Index
(Name
, High_Bound
(Drange
));
10357 Analyze_Dimension
(N
);
10361 ----------------------------
10362 -- Resolve_String_Literal --
10363 ----------------------------
10365 procedure Resolve_String_Literal
(N
: Node_Id
; Typ
: Entity_Id
) is
10366 C_Typ
: constant Entity_Id
:= Component_Type
(Typ
);
10367 R_Typ
: constant Entity_Id
:= Root_Type
(C_Typ
);
10368 Loc
: constant Source_Ptr
:= Sloc
(N
);
10369 Str
: constant String_Id
:= Strval
(N
);
10370 Strlen
: constant Nat
:= String_Length
(Str
);
10371 Subtype_Id
: Entity_Id
;
10372 Need_Check
: Boolean;
10375 -- For a string appearing in a concatenation, defer creation of the
10376 -- string_literal_subtype until the end of the resolution of the
10377 -- concatenation, because the literal may be constant-folded away. This
10378 -- is a useful optimization for long concatenation expressions.
10380 -- If the string is an aggregate built for a single character (which
10381 -- happens in a non-static context) or a is null string to which special
10382 -- checks may apply, we build the subtype. Wide strings must also get a
10383 -- string subtype if they come from a one character aggregate. Strings
10384 -- generated by attributes might be static, but it is often hard to
10385 -- determine whether the enclosing context is static, so we generate
10386 -- subtypes for them as well, thus losing some rarer optimizations ???
10387 -- Same for strings that come from a static conversion.
10390 (Strlen
= 0 and then Typ
/= Standard_String
)
10391 or else Nkind
(Parent
(N
)) /= N_Op_Concat
10392 or else (N
/= Left_Opnd
(Parent
(N
))
10393 and then N
/= Right_Opnd
(Parent
(N
)))
10394 or else ((Typ
= Standard_Wide_String
10395 or else Typ
= Standard_Wide_Wide_String
)
10396 and then Nkind
(Original_Node
(N
)) /= N_String_Literal
);
10398 -- If the resolving type is itself a string literal subtype, we can just
10399 -- reuse it, since there is no point in creating another.
10401 if Ekind
(Typ
) = E_String_Literal_Subtype
then
10404 elsif Nkind
(Parent
(N
)) = N_Op_Concat
10405 and then not Need_Check
10406 and then not Nkind_In
(Original_Node
(N
), N_Character_Literal
,
10407 N_Attribute_Reference
,
10408 N_Qualified_Expression
,
10413 -- Do not generate a string literal subtype for the default expression
10414 -- of a formal parameter in GNATprove mode. This is because the string
10415 -- subtype is associated with the freezing actions of the subprogram,
10416 -- however freezing is disabled in GNATprove mode and as a result the
10417 -- subtype is unavailable.
10419 elsif GNATprove_Mode
10420 and then Nkind
(Parent
(N
)) = N_Parameter_Specification
10424 -- Otherwise we must create a string literal subtype. Note that the
10425 -- whole idea of string literal subtypes is simply to avoid the need
10426 -- for building a full fledged array subtype for each literal.
10429 Set_String_Literal_Subtype
(N
, Typ
);
10430 Subtype_Id
:= Etype
(N
);
10433 if Nkind
(Parent
(N
)) /= N_Op_Concat
10436 Set_Etype
(N
, Subtype_Id
);
10437 Eval_String_Literal
(N
);
10440 if Is_Limited_Composite
(Typ
)
10441 or else Is_Private_Composite
(Typ
)
10443 Error_Msg_N
("string literal not available for private array", N
);
10444 Set_Etype
(N
, Any_Type
);
10448 -- The validity of a null string has been checked in the call to
10449 -- Eval_String_Literal.
10454 -- Always accept string literal with component type Any_Character, which
10455 -- occurs in error situations and in comparisons of literals, both of
10456 -- which should accept all literals.
10458 elsif R_Typ
= Any_Character
then
10461 -- If the type is bit-packed, then we always transform the string
10462 -- literal into a full fledged aggregate.
10464 elsif Is_Bit_Packed_Array
(Typ
) then
10467 -- Deal with cases of Wide_Wide_String, Wide_String, and String
10470 -- For Standard.Wide_Wide_String, or any other type whose component
10471 -- type is Standard.Wide_Wide_Character, we know that all the
10472 -- characters in the string must be acceptable, since the parser
10473 -- accepted the characters as valid character literals.
10475 if R_Typ
= Standard_Wide_Wide_Character
then
10478 -- For the case of Standard.String, or any other type whose component
10479 -- type is Standard.Character, we must make sure that there are no
10480 -- wide characters in the string, i.e. that it is entirely composed
10481 -- of characters in range of type Character.
10483 -- If the string literal is the result of a static concatenation, the
10484 -- test has already been performed on the components, and need not be
10487 elsif R_Typ
= Standard_Character
10488 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
10490 for J
in 1 .. Strlen
loop
10491 if not In_Character_Range
(Get_String_Char
(Str
, J
)) then
10493 -- If we are out of range, post error. This is one of the
10494 -- very few places that we place the flag in the middle of
10495 -- a token, right under the offending wide character. Not
10496 -- quite clear if this is right wrt wide character encoding
10497 -- sequences, but it's only an error message.
10500 ("literal out of range of type Standard.Character",
10501 Source_Ptr
(Int
(Loc
) + J
));
10506 -- For the case of Standard.Wide_String, or any other type whose
10507 -- component type is Standard.Wide_Character, we must make sure that
10508 -- there are no wide characters in the string, i.e. that it is
10509 -- entirely composed of characters in range of type Wide_Character.
10511 -- If the string literal is the result of a static concatenation,
10512 -- the test has already been performed on the components, and need
10513 -- not be repeated.
10515 elsif R_Typ
= Standard_Wide_Character
10516 and then Nkind
(Original_Node
(N
)) /= N_Op_Concat
10518 for J
in 1 .. Strlen
loop
10519 if not In_Wide_Character_Range
(Get_String_Char
(Str
, J
)) then
10521 -- If we are out of range, post error. This is one of the
10522 -- very few places that we place the flag in the middle of
10523 -- a token, right under the offending wide character.
10525 -- This is not quite right, because characters in general
10526 -- will take more than one character position ???
10529 ("literal out of range of type Standard.Wide_Character",
10530 Source_Ptr
(Int
(Loc
) + J
));
10535 -- If the root type is not a standard character, then we will convert
10536 -- the string into an aggregate and will let the aggregate code do
10537 -- the checking. Standard Wide_Wide_Character is also OK here.
10543 -- See if the component type of the array corresponding to the string
10544 -- has compile time known bounds. If yes we can directly check
10545 -- whether the evaluation of the string will raise constraint error.
10546 -- Otherwise we need to transform the string literal into the
10547 -- corresponding character aggregate and let the aggregate code do
10550 if Is_Standard_Character_Type
(R_Typ
) then
10552 -- Check for the case of full range, where we are definitely OK
10554 if Component_Type
(Typ
) = Base_Type
(Component_Type
(Typ
)) then
10558 -- Here the range is not the complete base type range, so check
10561 Comp_Typ_Lo
: constant Node_Id
:=
10562 Type_Low_Bound
(Component_Type
(Typ
));
10563 Comp_Typ_Hi
: constant Node_Id
:=
10564 Type_High_Bound
(Component_Type
(Typ
));
10569 if Compile_Time_Known_Value
(Comp_Typ_Lo
)
10570 and then Compile_Time_Known_Value
(Comp_Typ_Hi
)
10572 for J
in 1 .. Strlen
loop
10573 Char_Val
:= UI_From_Int
(Int
(Get_String_Char
(Str
, J
)));
10575 if Char_Val
< Expr_Value
(Comp_Typ_Lo
)
10576 or else Char_Val
> Expr_Value
(Comp_Typ_Hi
)
10578 Apply_Compile_Time_Constraint_Error
10579 (N
, "character out of range??",
10580 CE_Range_Check_Failed
,
10581 Loc
=> Source_Ptr
(Int
(Loc
) + J
));
10591 -- If we got here we meed to transform the string literal into the
10592 -- equivalent qualified positional array aggregate. This is rather
10593 -- heavy artillery for this situation, but it is hard work to avoid.
10596 Lits
: constant List_Id
:= New_List
;
10597 P
: Source_Ptr
:= Loc
+ 1;
10601 -- Build the character literals, we give them source locations that
10602 -- correspond to the string positions, which is a bit tricky given
10603 -- the possible presence of wide character escape sequences.
10605 for J
in 1 .. Strlen
loop
10606 C
:= Get_String_Char
(Str
, J
);
10607 Set_Character_Literal_Name
(C
);
10610 Make_Character_Literal
(P
,
10611 Chars
=> Name_Find
,
10612 Char_Literal_Value
=> UI_From_CC
(C
)));
10614 if In_Character_Range
(C
) then
10617 -- Should we have a call to Skip_Wide here ???
10626 Make_Qualified_Expression
(Loc
,
10627 Subtype_Mark
=> New_Occurrence_Of
(Typ
, Loc
),
10629 Make_Aggregate
(Loc
, Expressions
=> Lits
)));
10631 Analyze_And_Resolve
(N
, Typ
);
10633 end Resolve_String_Literal
;
10635 -----------------------------
10636 -- Resolve_Type_Conversion --
10637 -----------------------------
10639 procedure Resolve_Type_Conversion
(N
: Node_Id
; Typ
: Entity_Id
) is
10640 Conv_OK
: constant Boolean := Conversion_OK
(N
);
10641 Operand
: constant Node_Id
:= Expression
(N
);
10642 Operand_Typ
: constant Entity_Id
:= Etype
(Operand
);
10643 Target_Typ
: constant Entity_Id
:= Etype
(N
);
10648 Test_Redundant
: Boolean := Warn_On_Redundant_Constructs
;
10649 -- Set to False to suppress cases where we want to suppress the test
10650 -- for redundancy to avoid possible false positives on this warning.
10654 and then not Valid_Conversion
(N
, Target_Typ
, Operand
)
10659 -- If the Operand Etype is Universal_Fixed, then the conversion is
10660 -- never redundant. We need this check because by the time we have
10661 -- finished the rather complex transformation, the conversion looks
10662 -- redundant when it is not.
10664 if Operand_Typ
= Universal_Fixed
then
10665 Test_Redundant
:= False;
10667 -- If the operand is marked as Any_Fixed, then special processing is
10668 -- required. This is also a case where we suppress the test for a
10669 -- redundant conversion, since most certainly it is not redundant.
10671 elsif Operand_Typ
= Any_Fixed
then
10672 Test_Redundant
:= False;
10674 -- Mixed-mode operation involving a literal. Context must be a fixed
10675 -- type which is applied to the literal subsequently.
10677 if Is_Fixed_Point_Type
(Typ
) then
10678 Set_Etype
(Operand
, Universal_Real
);
10680 elsif Is_Numeric_Type
(Typ
)
10681 and then Nkind_In
(Operand
, N_Op_Multiply
, N_Op_Divide
)
10682 and then (Etype
(Right_Opnd
(Operand
)) = Universal_Real
10684 Etype
(Left_Opnd
(Operand
)) = Universal_Real
)
10686 -- Return if expression is ambiguous
10688 if Unique_Fixed_Point_Type
(N
) = Any_Type
then
10691 -- If nothing else, the available fixed type is Duration
10694 Set_Etype
(Operand
, Standard_Duration
);
10697 -- Resolve the real operand with largest available precision
10699 if Etype
(Right_Opnd
(Operand
)) = Universal_Real
then
10700 Rop
:= New_Copy_Tree
(Right_Opnd
(Operand
));
10702 Rop
:= New_Copy_Tree
(Left_Opnd
(Operand
));
10705 Resolve
(Rop
, Universal_Real
);
10707 -- If the operand is a literal (it could be a non-static and
10708 -- illegal exponentiation) check whether the use of Duration
10709 -- is potentially inaccurate.
10711 if Nkind
(Rop
) = N_Real_Literal
10712 and then Realval
(Rop
) /= Ureal_0
10713 and then abs (Realval
(Rop
)) < Delta_Value
(Standard_Duration
)
10716 ("??universal real operand can only "
10717 & "be interpreted as Duration!", Rop
);
10719 ("\??precision will be lost in the conversion!", Rop
);
10722 elsif Is_Numeric_Type
(Typ
)
10723 and then Nkind
(Operand
) in N_Op
10724 and then Unique_Fixed_Point_Type
(N
) /= Any_Type
10726 Set_Etype
(Operand
, Standard_Duration
);
10729 Error_Msg_N
("invalid context for mixed mode operation", N
);
10730 Set_Etype
(Operand
, Any_Type
);
10737 -- In SPARK, a type conversion between array types should be restricted
10738 -- to types which have matching static bounds.
10740 -- Protect call to Matching_Static_Array_Bounds to avoid costly
10741 -- operation if not needed.
10743 if Restriction_Check_Required
(SPARK_05
)
10744 and then Is_Array_Type
(Target_Typ
)
10745 and then Is_Array_Type
(Operand_Typ
)
10746 and then Operand_Typ
/= Any_Composite
-- or else Operand in error
10747 and then not Matching_Static_Array_Bounds
(Target_Typ
, Operand_Typ
)
10749 Check_SPARK_05_Restriction
10750 ("array types should have matching static bounds", N
);
10753 -- In formal mode, the operand of an ancestor type conversion must be an
10754 -- object (not an expression).
10756 if Is_Tagged_Type
(Target_Typ
)
10757 and then not Is_Class_Wide_Type
(Target_Typ
)
10758 and then Is_Tagged_Type
(Operand_Typ
)
10759 and then not Is_Class_Wide_Type
(Operand_Typ
)
10760 and then Is_Ancestor
(Target_Typ
, Operand_Typ
)
10761 and then not Is_SPARK_05_Object_Reference
(Operand
)
10763 Check_SPARK_05_Restriction
("object required", Operand
);
10766 Analyze_Dimension
(N
);
10768 -- Note: we do the Eval_Type_Conversion call before applying the
10769 -- required checks for a subtype conversion. This is important, since
10770 -- both are prepared under certain circumstances to change the type
10771 -- conversion to a constraint error node, but in the case of
10772 -- Eval_Type_Conversion this may reflect an illegality in the static
10773 -- case, and we would miss the illegality (getting only a warning
10774 -- message), if we applied the type conversion checks first.
10776 Eval_Type_Conversion
(N
);
10778 -- Even when evaluation is not possible, we may be able to simplify the
10779 -- conversion or its expression. This needs to be done before applying
10780 -- checks, since otherwise the checks may use the original expression
10781 -- and defeat the simplifications. This is specifically the case for
10782 -- elimination of the floating-point Truncation attribute in
10783 -- float-to-int conversions.
10785 Simplify_Type_Conversion
(N
);
10787 -- If after evaluation we still have a type conversion, then we may need
10788 -- to apply checks required for a subtype conversion.
10790 -- Skip these type conversion checks if universal fixed operands
10791 -- operands involved, since range checks are handled separately for
10792 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
10794 if Nkind
(N
) = N_Type_Conversion
10795 and then not Is_Generic_Type
(Root_Type
(Target_Typ
))
10796 and then Target_Typ
/= Universal_Fixed
10797 and then Operand_Typ
/= Universal_Fixed
10799 Apply_Type_Conversion_Checks
(N
);
10802 -- Issue warning for conversion of simple object to its own type. We
10803 -- have to test the original nodes, since they may have been rewritten
10804 -- by various optimizations.
10806 Orig_N
:= Original_Node
(N
);
10808 -- Here we test for a redundant conversion if the warning mode is
10809 -- active (and was not locally reset), and we have a type conversion
10810 -- from source not appearing in a generic instance.
10813 and then Nkind
(Orig_N
) = N_Type_Conversion
10814 and then Comes_From_Source
(Orig_N
)
10815 and then not In_Instance
10817 Orig_N
:= Original_Node
(Expression
(Orig_N
));
10818 Orig_T
:= Target_Typ
;
10820 -- If the node is part of a larger expression, the Target_Type
10821 -- may not be the original type of the node if the context is a
10822 -- condition. Recover original type to see if conversion is needed.
10824 if Is_Boolean_Type
(Orig_T
)
10825 and then Nkind
(Parent
(N
)) in N_Op
10827 Orig_T
:= Etype
(Parent
(N
));
10830 -- If we have an entity name, then give the warning if the entity
10831 -- is the right type, or if it is a loop parameter covered by the
10832 -- original type (that's needed because loop parameters have an
10833 -- odd subtype coming from the bounds).
10835 if (Is_Entity_Name
(Orig_N
)
10837 (Etype
(Entity
(Orig_N
)) = Orig_T
10839 (Ekind
(Entity
(Orig_N
)) = E_Loop_Parameter
10840 and then Covers
(Orig_T
, Etype
(Entity
(Orig_N
))))))
10842 -- If not an entity, then type of expression must match
10844 or else Etype
(Orig_N
) = Orig_T
10846 -- One more check, do not give warning if the analyzed conversion
10847 -- has an expression with non-static bounds, and the bounds of the
10848 -- target are static. This avoids junk warnings in cases where the
10849 -- conversion is necessary to establish staticness, for example in
10850 -- a case statement.
10852 if not Is_OK_Static_Subtype
(Operand_Typ
)
10853 and then Is_OK_Static_Subtype
(Target_Typ
)
10857 -- Finally, if this type conversion occurs in a context requiring
10858 -- a prefix, and the expression is a qualified expression then the
10859 -- type conversion is not redundant, since a qualified expression
10860 -- is not a prefix, whereas a type conversion is. For example, "X
10861 -- := T'(Funx(...)).Y;" is illegal because a selected component
10862 -- requires a prefix, but a type conversion makes it legal: "X :=
10863 -- T(T'(Funx(...))).Y;"
10865 -- In Ada 2012, a qualified expression is a name, so this idiom is
10866 -- no longer needed, but we still suppress the warning because it
10867 -- seems unfriendly for warnings to pop up when you switch to the
10868 -- newer language version.
10870 elsif Nkind
(Orig_N
) = N_Qualified_Expression
10871 and then Nkind_In
(Parent
(N
), N_Attribute_Reference
,
10872 N_Indexed_Component
,
10873 N_Selected_Component
,
10875 N_Explicit_Dereference
)
10879 -- Never warn on conversion to Long_Long_Integer'Base since
10880 -- that is most likely an artifact of the extended overflow
10881 -- checking and comes from complex expanded code.
10883 elsif Orig_T
= Base_Type
(Standard_Long_Long_Integer
) then
10886 -- Here we give the redundant conversion warning. If it is an
10887 -- entity, give the name of the entity in the message. If not,
10888 -- just mention the expression.
10890 -- Shoudn't we test Warn_On_Redundant_Constructs here ???
10893 if Is_Entity_Name
(Orig_N
) then
10894 Error_Msg_Node_2
:= Orig_T
;
10895 Error_Msg_NE
-- CODEFIX
10896 ("??redundant conversion, & is of type &!",
10897 N
, Entity
(Orig_N
));
10900 ("??redundant conversion, expression is of type&!",
10907 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
10908 -- No need to perform any interface conversion if the type of the
10909 -- expression coincides with the target type.
10911 if Ada_Version
>= Ada_2005
10912 and then Expander_Active
10913 and then Operand_Typ
/= Target_Typ
10916 Opnd
: Entity_Id
:= Operand_Typ
;
10917 Target
: Entity_Id
:= Target_Typ
;
10920 -- If the type of the operand is a limited view, use nonlimited
10921 -- view when available. If it is a class-wide type, recover the
10922 -- class-wide type of the nonlimited view.
10924 if From_Limited_With
(Opnd
)
10925 and then Has_Non_Limited_View
(Opnd
)
10927 Opnd
:= Non_Limited_View
(Opnd
);
10928 Set_Etype
(Expression
(N
), Opnd
);
10931 if Is_Access_Type
(Opnd
) then
10932 Opnd
:= Designated_Type
(Opnd
);
10935 if Is_Access_Type
(Target_Typ
) then
10936 Target
:= Designated_Type
(Target
);
10939 if Opnd
= Target
then
10942 -- Conversion from interface type
10944 elsif Is_Interface
(Opnd
) then
10946 -- Ada 2005 (AI-217): Handle entities from limited views
10948 if From_Limited_With
(Opnd
) then
10949 Error_Msg_Qual_Level
:= 99;
10950 Error_Msg_NE
-- CODEFIX
10951 ("missing WITH clause on package &", N
,
10952 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Opnd
))));
10954 ("type conversions require visibility of the full view",
10957 elsif From_Limited_With
(Target
)
10959 (Is_Access_Type
(Target_Typ
)
10960 and then Present
(Non_Limited_View
(Etype
(Target
))))
10962 Error_Msg_Qual_Level
:= 99;
10963 Error_Msg_NE
-- CODEFIX
10964 ("missing WITH clause on package &", N
,
10965 Cunit_Entity
(Get_Source_Unit
(Base_Type
(Target
))));
10967 ("type conversions require visibility of the full view",
10971 Expand_Interface_Conversion
(N
);
10974 -- Conversion to interface type
10976 elsif Is_Interface
(Target
) then
10980 if Ekind_In
(Opnd
, E_Protected_Subtype
, E_Task_Subtype
) then
10981 Opnd
:= Etype
(Opnd
);
10984 if Is_Class_Wide_Type
(Opnd
)
10985 or else Interface_Present_In_Ancestor
10989 Expand_Interface_Conversion
(N
);
10991 Error_Msg_Name_1
:= Chars
(Etype
(Target
));
10992 Error_Msg_Name_2
:= Chars
(Opnd
);
10994 ("wrong interface conversion (% is not a progenitor "
11001 -- Ada 2012: if target type has predicates, the result requires a
11002 -- predicate check. If the context is a call to another predicate
11003 -- check we must prevent infinite recursion.
11005 if Has_Predicates
(Target_Typ
) then
11006 if Nkind
(Parent
(N
)) = N_Function_Call
11007 and then Present
(Name
(Parent
(N
)))
11008 and then (Is_Predicate_Function
(Entity
(Name
(Parent
(N
))))
11010 Is_Predicate_Function_M
(Entity
(Name
(Parent
(N
)))))
11015 Apply_Predicate_Check
(N
, Target_Typ
);
11019 -- If at this stage we have a real to integer conversion, make sure
11020 -- that the Do_Range_Check flag is set, because such conversions in
11021 -- general need a range check. We only need this if expansion is off
11022 -- or we are in GNATProve mode.
11024 if Nkind
(N
) = N_Type_Conversion
11025 and then (GNATprove_Mode
or not Expander_Active
)
11026 and then Is_Integer_Type
(Target_Typ
)
11027 and then Is_Real_Type
(Operand_Typ
)
11029 Set_Do_Range_Check
(Operand
);
11032 -- Generating C code a type conversion of an access to constrained
11033 -- array type to access to unconstrained array type involves building
11034 -- a fat pointer which in general cannot be generated on the fly. We
11035 -- remove side effects in order to store the result of the conversion
11036 -- into a temporary.
11038 if Modify_Tree_For_C
11039 and then Nkind
(N
) = N_Type_Conversion
11040 and then Nkind
(Parent
(N
)) /= N_Object_Declaration
11041 and then Is_Access_Type
(Etype
(N
))
11042 and then Is_Array_Type
(Designated_Type
(Etype
(N
)))
11043 and then not Is_Constrained
(Designated_Type
(Etype
(N
)))
11044 and then Is_Constrained
(Designated_Type
(Etype
(Expression
(N
))))
11046 Remove_Side_Effects
(N
);
11048 end Resolve_Type_Conversion
;
11050 ----------------------
11051 -- Resolve_Unary_Op --
11052 ----------------------
11054 procedure Resolve_Unary_Op
(N
: Node_Id
; Typ
: Entity_Id
) is
11055 B_Typ
: constant Entity_Id
:= Base_Type
(Typ
);
11056 R
: constant Node_Id
:= Right_Opnd
(N
);
11062 if Is_Modular_Integer_Type
(Typ
) and then Nkind
(N
) /= N_Op_Not
then
11063 Error_Msg_Name_1
:= Chars
(Typ
);
11064 Check_SPARK_05_Restriction
11065 ("unary operator not defined for modular type%", N
);
11068 -- Deal with intrinsic unary operators
11070 if Comes_From_Source
(N
)
11071 and then Ekind
(Entity
(N
)) = E_Function
11072 and then Is_Imported
(Entity
(N
))
11073 and then Is_Intrinsic_Subprogram
(Entity
(N
))
11075 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
11079 -- Deal with universal cases
11081 if Etype
(R
) = Universal_Integer
11083 Etype
(R
) = Universal_Real
11085 Check_For_Visible_Operator
(N
, B_Typ
);
11088 Set_Etype
(N
, B_Typ
);
11089 Resolve
(R
, B_Typ
);
11091 -- Generate warning for expressions like abs (x mod 2)
11093 if Warn_On_Redundant_Constructs
11094 and then Nkind
(N
) = N_Op_Abs
11096 Determine_Range
(Right_Opnd
(N
), OK
, Lo
, Hi
);
11098 if OK
and then Hi
>= Lo
and then Lo
>= 0 then
11099 Error_Msg_N
-- CODEFIX
11100 ("?r?abs applied to known non-negative value has no effect", N
);
11104 -- Deal with reference generation
11106 Check_Unset_Reference
(R
);
11107 Generate_Operator_Reference
(N
, B_Typ
);
11108 Analyze_Dimension
(N
);
11111 -- Set overflow checking bit. Much cleverer code needed here eventually
11112 -- and perhaps the Resolve routines should be separated for the various
11113 -- arithmetic operations, since they will need different processing ???
11115 if Nkind
(N
) in N_Op
then
11116 if not Overflow_Checks_Suppressed
(Etype
(N
)) then
11117 Enable_Overflow_Check
(N
);
11121 -- Generate warning for expressions like -5 mod 3 for integers. No need
11122 -- to worry in the floating-point case, since parens do not affect the
11123 -- result so there is no point in giving in a warning.
11126 Norig
: constant Node_Id
:= Original_Node
(N
);
11135 if Warn_On_Questionable_Missing_Parens
11136 and then Comes_From_Source
(Norig
)
11137 and then Is_Integer_Type
(Typ
)
11138 and then Nkind
(Norig
) = N_Op_Minus
11140 Rorig
:= Original_Node
(Right_Opnd
(Norig
));
11142 -- We are looking for cases where the right operand is not
11143 -- parenthesized, and is a binary operator, multiply, divide, or
11144 -- mod. These are the cases where the grouping can affect results.
11146 if Paren_Count
(Rorig
) = 0
11147 and then Nkind_In
(Rorig
, N_Op_Mod
, N_Op_Multiply
, N_Op_Divide
)
11149 -- For mod, we always give the warning, since the value is
11150 -- affected by the parenthesization (e.g. (-5) mod 315 /=
11151 -- -(5 mod 315)). But for the other cases, the only concern is
11152 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
11153 -- overflows, but (-2) * 64 does not). So we try to give the
11154 -- message only when overflow is possible.
11156 if Nkind
(Rorig
) /= N_Op_Mod
11157 and then Compile_Time_Known_Value
(R
)
11159 Val
:= Expr_Value
(R
);
11161 if Compile_Time_Known_Value
(Type_High_Bound
(Typ
)) then
11162 HB
:= Expr_Value
(Type_High_Bound
(Typ
));
11164 HB
:= Expr_Value
(Type_High_Bound
(Base_Type
(Typ
)));
11167 if Compile_Time_Known_Value
(Type_Low_Bound
(Typ
)) then
11168 LB
:= Expr_Value
(Type_Low_Bound
(Typ
));
11170 LB
:= Expr_Value
(Type_Low_Bound
(Base_Type
(Typ
)));
11173 -- Note that the test below is deliberately excluding the
11174 -- largest negative number, since that is a potentially
11175 -- troublesome case (e.g. -2 * x, where the result is the
11176 -- largest negative integer has an overflow with 2 * x).
11178 if Val
> LB
and then Val
<= HB
then
11183 -- For the multiplication case, the only case we have to worry
11184 -- about is when (-a)*b is exactly the largest negative number
11185 -- so that -(a*b) can cause overflow. This can only happen if
11186 -- a is a power of 2, and more generally if any operand is a
11187 -- constant that is not a power of 2, then the parentheses
11188 -- cannot affect whether overflow occurs. We only bother to
11189 -- test the left most operand
11191 -- Loop looking at left operands for one that has known value
11194 Opnd_Loop
: while Nkind
(Opnd
) = N_Op_Multiply
loop
11195 if Compile_Time_Known_Value
(Left_Opnd
(Opnd
)) then
11196 Lval
:= UI_Abs
(Expr_Value
(Left_Opnd
(Opnd
)));
11198 -- Operand value of 0 or 1 skips warning
11203 -- Otherwise check power of 2, if power of 2, warn, if
11204 -- anything else, skip warning.
11207 while Lval
/= 2 loop
11208 if Lval
mod 2 = 1 then
11219 -- Keep looking at left operands
11221 Opnd
:= Left_Opnd
(Opnd
);
11222 end loop Opnd_Loop
;
11224 -- For rem or "/" we can only have a problematic situation
11225 -- if the divisor has a value of minus one or one. Otherwise
11226 -- overflow is impossible (divisor > 1) or we have a case of
11227 -- division by zero in any case.
11229 if Nkind_In
(Rorig
, N_Op_Divide
, N_Op_Rem
)
11230 and then Compile_Time_Known_Value
(Right_Opnd
(Rorig
))
11231 and then UI_Abs
(Expr_Value
(Right_Opnd
(Rorig
))) /= 1
11236 -- If we fall through warning should be issued
11238 -- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
11241 ("??unary minus expression should be parenthesized here!", N
);
11245 end Resolve_Unary_Op
;
11247 ----------------------------------
11248 -- Resolve_Unchecked_Expression --
11249 ----------------------------------
11251 procedure Resolve_Unchecked_Expression
11256 Resolve
(Expression
(N
), Typ
, Suppress
=> All_Checks
);
11257 Set_Etype
(N
, Typ
);
11258 end Resolve_Unchecked_Expression
;
11260 ---------------------------------------
11261 -- Resolve_Unchecked_Type_Conversion --
11262 ---------------------------------------
11264 procedure Resolve_Unchecked_Type_Conversion
11268 pragma Warnings
(Off
, Typ
);
11270 Operand
: constant Node_Id
:= Expression
(N
);
11271 Opnd_Type
: constant Entity_Id
:= Etype
(Operand
);
11274 -- Resolve operand using its own type
11276 Resolve
(Operand
, Opnd_Type
);
11278 -- In an inlined context, the unchecked conversion may be applied
11279 -- to a literal, in which case its type is the type of the context.
11280 -- (In other contexts conversions cannot apply to literals).
11283 and then (Opnd_Type
= Any_Character
or else
11284 Opnd_Type
= Any_Integer
or else
11285 Opnd_Type
= Any_Real
)
11287 Set_Etype
(Operand
, Typ
);
11290 Analyze_Dimension
(N
);
11291 Eval_Unchecked_Conversion
(N
);
11292 end Resolve_Unchecked_Type_Conversion
;
11294 ------------------------------
11295 -- Rewrite_Operator_As_Call --
11296 ------------------------------
11298 procedure Rewrite_Operator_As_Call
(N
: Node_Id
; Nam
: Entity_Id
) is
11299 Loc
: constant Source_Ptr
:= Sloc
(N
);
11300 Actuals
: constant List_Id
:= New_List
;
11304 if Nkind
(N
) in N_Binary_Op
then
11305 Append
(Left_Opnd
(N
), Actuals
);
11308 Append
(Right_Opnd
(N
), Actuals
);
11311 Make_Function_Call
(Sloc
=> Loc
,
11312 Name
=> New_Occurrence_Of
(Nam
, Loc
),
11313 Parameter_Associations
=> Actuals
);
11315 Preserve_Comes_From_Source
(New_N
, N
);
11316 Preserve_Comes_From_Source
(Name
(New_N
), N
);
11317 Rewrite
(N
, New_N
);
11318 Set_Etype
(N
, Etype
(Nam
));
11319 end Rewrite_Operator_As_Call
;
11321 ------------------------------
11322 -- Rewrite_Renamed_Operator --
11323 ------------------------------
11325 procedure Rewrite_Renamed_Operator
11330 Nam
: constant Name_Id
:= Chars
(Op
);
11331 Is_Binary
: constant Boolean := Nkind
(N
) in N_Binary_Op
;
11335 -- Do not perform this transformation within a pre/postcondition,
11336 -- because the expression will be re-analyzed, and the transformation
11337 -- might affect the visibility of the operator, e.g. in an instance.
11338 -- Note that fully analyzed and expanded pre/postconditions appear as
11339 -- pragma Check equivalents.
11341 if In_Pre_Post_Condition
(N
) then
11345 -- Rewrite the operator node using the real operator, not its renaming.
11346 -- Exclude user-defined intrinsic operations of the same name, which are
11347 -- treated separately and rewritten as calls.
11349 if Ekind
(Op
) /= E_Function
or else Chars
(N
) /= Nam
then
11350 Op_Node
:= New_Node
(Operator_Kind
(Nam
, Is_Binary
), Sloc
(N
));
11351 Set_Chars
(Op_Node
, Nam
);
11352 Set_Etype
(Op_Node
, Etype
(N
));
11353 Set_Entity
(Op_Node
, Op
);
11354 Set_Right_Opnd
(Op_Node
, Right_Opnd
(N
));
11356 -- Indicate that both the original entity and its renaming are
11357 -- referenced at this point.
11359 Generate_Reference
(Entity
(N
), N
);
11360 Generate_Reference
(Op
, N
);
11363 Set_Left_Opnd
(Op_Node
, Left_Opnd
(N
));
11366 Rewrite
(N
, Op_Node
);
11368 -- If the context type is private, add the appropriate conversions so
11369 -- that the operator is applied to the full view. This is done in the
11370 -- routines that resolve intrinsic operators.
11372 if Is_Intrinsic_Subprogram
(Op
) and then Is_Private_Type
(Typ
) then
11382 Resolve_Intrinsic_Operator
(N
, Typ
);
11388 Resolve_Intrinsic_Unary_Operator
(N
, Typ
);
11395 elsif Ekind
(Op
) = E_Function
and then Is_Intrinsic_Subprogram
(Op
) then
11397 -- Operator renames a user-defined operator of the same name. Use the
11398 -- original operator in the node, which is the one Gigi knows about.
11400 Set_Entity
(N
, Op
);
11401 Set_Is_Overloaded
(N
, False);
11403 end Rewrite_Renamed_Operator
;
11405 -----------------------
11406 -- Set_Slice_Subtype --
11407 -----------------------
11409 -- Build an implicit subtype declaration to represent the type delivered by
11410 -- the slice. This is an abbreviated version of an array subtype. We define
11411 -- an index subtype for the slice, using either the subtype name or the
11412 -- discrete range of the slice. To be consistent with index usage elsewhere
11413 -- we create a list header to hold the single index. This list is not
11414 -- otherwise attached to the syntax tree.
11416 procedure Set_Slice_Subtype
(N
: Node_Id
) is
11417 Loc
: constant Source_Ptr
:= Sloc
(N
);
11418 Index_List
: constant List_Id
:= New_List
;
11420 Index_Subtype
: Entity_Id
;
11421 Index_Type
: Entity_Id
;
11422 Slice_Subtype
: Entity_Id
;
11423 Drange
: constant Node_Id
:= Discrete_Range
(N
);
11426 Index_Type
:= Base_Type
(Etype
(Drange
));
11428 if Is_Entity_Name
(Drange
) then
11429 Index_Subtype
:= Entity
(Drange
);
11432 -- We force the evaluation of a range. This is definitely needed in
11433 -- the renamed case, and seems safer to do unconditionally. Note in
11434 -- any case that since we will create and insert an Itype referring
11435 -- to this range, we must make sure any side effect removal actions
11436 -- are inserted before the Itype definition.
11438 if Nkind
(Drange
) = N_Range
then
11439 Force_Evaluation
(Low_Bound
(Drange
));
11440 Force_Evaluation
(High_Bound
(Drange
));
11442 -- If the discrete range is given by a subtype indication, the
11443 -- type of the slice is the base of the subtype mark.
11445 elsif Nkind
(Drange
) = N_Subtype_Indication
then
11447 R
: constant Node_Id
:= Range_Expression
(Constraint
(Drange
));
11449 Index_Type
:= Base_Type
(Entity
(Subtype_Mark
(Drange
)));
11450 Force_Evaluation
(Low_Bound
(R
));
11451 Force_Evaluation
(High_Bound
(R
));
11455 Index_Subtype
:= Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
11457 -- Take a new copy of Drange (where bounds have been rewritten to
11458 -- reference side-effect-free names). Using a separate tree ensures
11459 -- that further expansion (e.g. while rewriting a slice assignment
11460 -- into a FOR loop) does not attempt to remove side effects on the
11461 -- bounds again (which would cause the bounds in the index subtype
11462 -- definition to refer to temporaries before they are defined) (the
11463 -- reason is that some names are considered side effect free here
11464 -- for the subtype, but not in the context of a loop iteration
11467 Set_Scalar_Range
(Index_Subtype
, New_Copy_Tree
(Drange
));
11468 Set_Parent
(Scalar_Range
(Index_Subtype
), Index_Subtype
);
11469 Set_Etype
(Index_Subtype
, Index_Type
);
11470 Set_Size_Info
(Index_Subtype
, Index_Type
);
11471 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
11474 Slice_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
11476 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
11477 Set_Etype
(Index
, Index_Subtype
);
11478 Append
(Index
, Index_List
);
11480 Set_First_Index
(Slice_Subtype
, Index
);
11481 Set_Etype
(Slice_Subtype
, Base_Type
(Etype
(N
)));
11482 Set_Is_Constrained
(Slice_Subtype
, True);
11484 Check_Compile_Time_Size
(Slice_Subtype
);
11486 -- The Etype of the existing Slice node is reset to this slice subtype.
11487 -- Its bounds are obtained from its first index.
11489 Set_Etype
(N
, Slice_Subtype
);
11491 -- For packed slice subtypes, freeze immediately (except in the case of
11492 -- being in a "spec expression" where we never freeze when we first see
11493 -- the expression).
11495 if Is_Packed
(Slice_Subtype
) and not In_Spec_Expression
then
11496 Freeze_Itype
(Slice_Subtype
, N
);
11498 -- For all other cases insert an itype reference in the slice's actions
11499 -- so that the itype is frozen at the proper place in the tree (i.e. at
11500 -- the point where actions for the slice are analyzed). Note that this
11501 -- is different from freezing the itype immediately, which might be
11502 -- premature (e.g. if the slice is within a transient scope). This needs
11503 -- to be done only if expansion is enabled.
11505 elsif Expander_Active
then
11506 Ensure_Defined
(Typ
=> Slice_Subtype
, N
=> N
);
11508 end Set_Slice_Subtype
;
11510 --------------------------------
11511 -- Set_String_Literal_Subtype --
11512 --------------------------------
11514 procedure Set_String_Literal_Subtype
(N
: Node_Id
; Typ
: Entity_Id
) is
11515 Loc
: constant Source_Ptr
:= Sloc
(N
);
11516 Low_Bound
: constant Node_Id
:=
11517 Type_Low_Bound
(Etype
(First_Index
(Typ
)));
11518 Subtype_Id
: Entity_Id
;
11521 if Nkind
(N
) /= N_String_Literal
then
11525 Subtype_Id
:= Create_Itype
(E_String_Literal_Subtype
, N
);
11526 Set_String_Literal_Length
(Subtype_Id
, UI_From_Int
11527 (String_Length
(Strval
(N
))));
11528 Set_Etype
(Subtype_Id
, Base_Type
(Typ
));
11529 Set_Is_Constrained
(Subtype_Id
);
11530 Set_Etype
(N
, Subtype_Id
);
11532 -- The low bound is set from the low bound of the corresponding index
11533 -- type. Note that we do not store the high bound in the string literal
11534 -- subtype, but it can be deduced if necessary from the length and the
11537 if Is_OK_Static_Expression
(Low_Bound
) then
11538 Set_String_Literal_Low_Bound
(Subtype_Id
, Low_Bound
);
11540 -- If the lower bound is not static we create a range for the string
11541 -- literal, using the index type and the known length of the literal.
11542 -- The index type is not necessarily Positive, so the upper bound is
11543 -- computed as T'Val (T'Pos (Low_Bound) + L - 1).
11547 Index_List
: constant List_Id
:= New_List
;
11548 Index_Type
: constant Entity_Id
:= Etype
(First_Index
(Typ
));
11549 High_Bound
: constant Node_Id
:=
11550 Make_Attribute_Reference
(Loc
,
11551 Attribute_Name
=> Name_Val
,
11553 New_Occurrence_Of
(Index_Type
, Loc
),
11554 Expressions
=> New_List
(
11557 Make_Attribute_Reference
(Loc
,
11558 Attribute_Name
=> Name_Pos
,
11560 New_Occurrence_Of
(Index_Type
, Loc
),
11562 New_List
(New_Copy_Tree
(Low_Bound
))),
11564 Make_Integer_Literal
(Loc
,
11565 String_Length
(Strval
(N
)) - 1))));
11567 Array_Subtype
: Entity_Id
;
11570 Index_Subtype
: Entity_Id
;
11573 if Is_Integer_Type
(Index_Type
) then
11574 Set_String_Literal_Low_Bound
11575 (Subtype_Id
, Make_Integer_Literal
(Loc
, 1));
11578 -- If the index type is an enumeration type, build bounds
11579 -- expression with attributes.
11581 Set_String_Literal_Low_Bound
11583 Make_Attribute_Reference
(Loc
,
11584 Attribute_Name
=> Name_First
,
11586 New_Occurrence_Of
(Base_Type
(Index_Type
), Loc
)));
11587 Set_Etype
(String_Literal_Low_Bound
(Subtype_Id
), Index_Type
);
11590 Analyze_And_Resolve
(String_Literal_Low_Bound
(Subtype_Id
));
11592 -- Build bona fide subtype for the string, and wrap it in an
11593 -- unchecked conversion, because the backend expects the
11594 -- String_Literal_Subtype to have a static lower bound.
11597 Create_Itype
(Subtype_Kind
(Ekind
(Index_Type
)), N
);
11598 Drange
:= Make_Range
(Loc
, New_Copy_Tree
(Low_Bound
), High_Bound
);
11599 Set_Scalar_Range
(Index_Subtype
, Drange
);
11600 Set_Parent
(Drange
, N
);
11601 Analyze_And_Resolve
(Drange
, Index_Type
);
11603 -- In the context, the Index_Type may already have a constraint,
11604 -- so use common base type on string subtype. The base type may
11605 -- be used when generating attributes of the string, for example
11606 -- in the context of a slice assignment.
11608 Set_Etype
(Index_Subtype
, Base_Type
(Index_Type
));
11609 Set_Size_Info
(Index_Subtype
, Index_Type
);
11610 Set_RM_Size
(Index_Subtype
, RM_Size
(Index_Type
));
11612 Array_Subtype
:= Create_Itype
(E_Array_Subtype
, N
);
11614 Index
:= New_Occurrence_Of
(Index_Subtype
, Loc
);
11615 Set_Etype
(Index
, Index_Subtype
);
11616 Append
(Index
, Index_List
);
11618 Set_First_Index
(Array_Subtype
, Index
);
11619 Set_Etype
(Array_Subtype
, Base_Type
(Typ
));
11620 Set_Is_Constrained
(Array_Subtype
, True);
11623 Make_Unchecked_Type_Conversion
(Loc
,
11624 Subtype_Mark
=> New_Occurrence_Of
(Array_Subtype
, Loc
),
11625 Expression
=> Relocate_Node
(N
)));
11626 Set_Etype
(N
, Array_Subtype
);
11629 end Set_String_Literal_Subtype
;
11631 ------------------------------
11632 -- Simplify_Type_Conversion --
11633 ------------------------------
11635 procedure Simplify_Type_Conversion
(N
: Node_Id
) is
11637 if Nkind
(N
) = N_Type_Conversion
then
11639 Operand
: constant Node_Id
:= Expression
(N
);
11640 Target_Typ
: constant Entity_Id
:= Etype
(N
);
11641 Opnd_Typ
: constant Entity_Id
:= Etype
(Operand
);
11644 -- Special processing if the conversion is the expression of a
11645 -- Rounding or Truncation attribute reference. In this case we
11648 -- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
11654 -- with the Float_Truncate flag set to False or True respectively,
11655 -- which is more efficient.
11657 if Is_Floating_Point_Type
(Opnd_Typ
)
11659 (Is_Integer_Type
(Target_Typ
)
11660 or else (Is_Fixed_Point_Type
(Target_Typ
)
11661 and then Conversion_OK
(N
)))
11662 and then Nkind
(Operand
) = N_Attribute_Reference
11663 and then Nam_In
(Attribute_Name
(Operand
), Name_Rounding
,
11667 Truncate
: constant Boolean :=
11668 Attribute_Name
(Operand
) = Name_Truncation
;
11671 Relocate_Node
(First
(Expressions
(Operand
))));
11672 Set_Float_Truncate
(N
, Truncate
);
11677 end Simplify_Type_Conversion
;
11679 -----------------------------
11680 -- Unique_Fixed_Point_Type --
11681 -----------------------------
11683 function Unique_Fixed_Point_Type
(N
: Node_Id
) return Entity_Id
is
11684 T1
: Entity_Id
:= Empty
;
11689 procedure Fixed_Point_Error
;
11690 -- Give error messages for true ambiguity. Messages are posted on node
11691 -- N, and entities T1, T2 are the possible interpretations.
11693 -----------------------
11694 -- Fixed_Point_Error --
11695 -----------------------
11697 procedure Fixed_Point_Error
is
11699 Error_Msg_N
("ambiguous universal_fixed_expression", N
);
11700 Error_Msg_NE
("\\possible interpretation as}", N
, T1
);
11701 Error_Msg_NE
("\\possible interpretation as}", N
, T2
);
11702 end Fixed_Point_Error
;
11704 -- Start of processing for Unique_Fixed_Point_Type
11707 -- The operations on Duration are visible, so Duration is always a
11708 -- possible interpretation.
11710 T1
:= Standard_Duration
;
11712 -- Look for fixed-point types in enclosing scopes
11714 Scop
:= Current_Scope
;
11715 while Scop
/= Standard_Standard
loop
11716 T2
:= First_Entity
(Scop
);
11717 while Present
(T2
) loop
11718 if Is_Fixed_Point_Type
(T2
)
11719 and then Current_Entity
(T2
) = T2
11720 and then Scope
(Base_Type
(T2
)) = Scop
11722 if Present
(T1
) then
11733 Scop
:= Scope
(Scop
);
11736 -- Look for visible fixed type declarations in the context
11738 Item
:= First
(Context_Items
(Cunit
(Current_Sem_Unit
)));
11739 while Present
(Item
) loop
11740 if Nkind
(Item
) = N_With_Clause
then
11741 Scop
:= Entity
(Name
(Item
));
11742 T2
:= First_Entity
(Scop
);
11743 while Present
(T2
) loop
11744 if Is_Fixed_Point_Type
(T2
)
11745 and then Scope
(Base_Type
(T2
)) = Scop
11746 and then (Is_Potentially_Use_Visible
(T2
) or else In_Use
(T2
))
11748 if Present
(T1
) then
11763 if Nkind
(N
) = N_Real_Literal
then
11765 ("??real literal interpreted as }!", N
, T1
);
11768 ("??universal_fixed expression interpreted as }!", N
, T1
);
11772 end Unique_Fixed_Point_Type
;
11774 ----------------------
11775 -- Valid_Conversion --
11776 ----------------------
11778 function Valid_Conversion
11780 Target
: Entity_Id
;
11782 Report_Errs
: Boolean := True) return Boolean
11784 Target_Type
: constant Entity_Id
:= Base_Type
(Target
);
11785 Opnd_Type
: Entity_Id
:= Etype
(Operand
);
11786 Inc_Ancestor
: Entity_Id
;
11788 function Conversion_Check
11790 Msg
: String) return Boolean;
11791 -- Little routine to post Msg if Valid is False, returns Valid value
11793 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
);
11794 -- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
11796 procedure Conversion_Error_NE
11798 N
: Node_Or_Entity_Id
;
11799 E
: Node_Or_Entity_Id
);
11800 -- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
11802 function Valid_Tagged_Conversion
11803 (Target_Type
: Entity_Id
;
11804 Opnd_Type
: Entity_Id
) return Boolean;
11805 -- Specifically test for validity of tagged conversions
11807 function Valid_Array_Conversion
return Boolean;
11808 -- Check index and component conformance, and accessibility levels if
11809 -- the component types are anonymous access types (Ada 2005).
11811 ----------------------
11812 -- Conversion_Check --
11813 ----------------------
11815 function Conversion_Check
11817 Msg
: String) return Boolean
11822 -- A generic unit has already been analyzed and we have verified
11823 -- that a particular conversion is OK in that context. Since the
11824 -- instance is reanalyzed without relying on the relationships
11825 -- established during the analysis of the generic, it is possible
11826 -- to end up with inconsistent views of private types. Do not emit
11827 -- the error message in such cases. The rest of the machinery in
11828 -- Valid_Conversion still ensures the proper compatibility of
11829 -- target and operand types.
11831 and then not In_Instance
11833 Conversion_Error_N
(Msg
, Operand
);
11837 end Conversion_Check
;
11839 ------------------------
11840 -- Conversion_Error_N --
11841 ------------------------
11843 procedure Conversion_Error_N
(Msg
: String; N
: Node_Or_Entity_Id
) is
11845 if Report_Errs
then
11846 Error_Msg_N
(Msg
, N
);
11848 end Conversion_Error_N
;
11850 -------------------------
11851 -- Conversion_Error_NE --
11852 -------------------------
11854 procedure Conversion_Error_NE
11856 N
: Node_Or_Entity_Id
;
11857 E
: Node_Or_Entity_Id
)
11860 if Report_Errs
then
11861 Error_Msg_NE
(Msg
, N
, E
);
11863 end Conversion_Error_NE
;
11865 ----------------------------
11866 -- Valid_Array_Conversion --
11867 ----------------------------
11869 function Valid_Array_Conversion
return Boolean is
11870 Opnd_Comp_Type
: constant Entity_Id
:= Component_Type
(Opnd_Type
);
11871 Opnd_Comp_Base
: constant Entity_Id
:= Base_Type
(Opnd_Comp_Type
);
11873 Opnd_Index
: Node_Id
;
11874 Opnd_Index_Type
: Entity_Id
;
11876 Target_Comp_Type
: constant Entity_Id
:=
11877 Component_Type
(Target_Type
);
11878 Target_Comp_Base
: constant Entity_Id
:=
11879 Base_Type
(Target_Comp_Type
);
11881 Target_Index
: Node_Id
;
11882 Target_Index_Type
: Entity_Id
;
11885 -- Error if wrong number of dimensions
11888 Number_Dimensions
(Target_Type
) /= Number_Dimensions
(Opnd_Type
)
11891 ("incompatible number of dimensions for conversion", Operand
);
11894 -- Number of dimensions matches
11897 -- Loop through indexes of the two arrays
11899 Target_Index
:= First_Index
(Target_Type
);
11900 Opnd_Index
:= First_Index
(Opnd_Type
);
11901 while Present
(Target_Index
) and then Present
(Opnd_Index
) loop
11902 Target_Index_Type
:= Etype
(Target_Index
);
11903 Opnd_Index_Type
:= Etype
(Opnd_Index
);
11905 -- Error if index types are incompatible
11907 if not (Is_Integer_Type
(Target_Index_Type
)
11908 and then Is_Integer_Type
(Opnd_Index_Type
))
11909 and then (Root_Type
(Target_Index_Type
)
11910 /= Root_Type
(Opnd_Index_Type
))
11913 ("incompatible index types for array conversion",
11918 Next_Index
(Target_Index
);
11919 Next_Index
(Opnd_Index
);
11922 -- If component types have same base type, all set
11924 if Target_Comp_Base
= Opnd_Comp_Base
then
11927 -- Here if base types of components are not the same. The only
11928 -- time this is allowed is if we have anonymous access types.
11930 -- The conversion of arrays of anonymous access types can lead
11931 -- to dangling pointers. AI-392 formalizes the accessibility
11932 -- checks that must be applied to such conversions to prevent
11933 -- out-of-scope references.
11936 (Target_Comp_Base
, E_Anonymous_Access_Type
,
11937 E_Anonymous_Access_Subprogram_Type
)
11938 and then Ekind
(Opnd_Comp_Base
) = Ekind
(Target_Comp_Base
)
11940 Subtypes_Statically_Match
(Target_Comp_Type
, Opnd_Comp_Type
)
11942 if Type_Access_Level
(Target_Type
) <
11943 Deepest_Type_Access_Level
(Opnd_Type
)
11945 if In_Instance_Body
then
11946 Error_Msg_Warn
:= SPARK_Mode
/= On
;
11948 ("source array type has deeper accessibility "
11949 & "level than target<<", Operand
);
11950 Conversion_Error_N
("\Program_Error [<<", Operand
);
11952 Make_Raise_Program_Error
(Sloc
(N
),
11953 Reason
=> PE_Accessibility_Check_Failed
));
11954 Set_Etype
(N
, Target_Type
);
11957 -- Conversion not allowed because of accessibility levels
11961 ("source array type has deeper accessibility "
11962 & "level than target", Operand
);
11970 -- All other cases where component base types do not match
11974 ("incompatible component types for array conversion",
11979 -- Check that component subtypes statically match. For numeric
11980 -- types this means that both must be either constrained or
11981 -- unconstrained. For enumeration types the bounds must match.
11982 -- All of this is checked in Subtypes_Statically_Match.
11984 if not Subtypes_Statically_Match
11985 (Target_Comp_Type
, Opnd_Comp_Type
)
11988 ("component subtypes must statically match", Operand
);
11994 end Valid_Array_Conversion
;
11996 -----------------------------
11997 -- Valid_Tagged_Conversion --
11998 -----------------------------
12000 function Valid_Tagged_Conversion
12001 (Target_Type
: Entity_Id
;
12002 Opnd_Type
: Entity_Id
) return Boolean
12005 -- Upward conversions are allowed (RM 4.6(22))
12007 if Covers
(Target_Type
, Opnd_Type
)
12008 or else Is_Ancestor
(Target_Type
, Opnd_Type
)
12012 -- Downward conversion are allowed if the operand is class-wide
12015 elsif Is_Class_Wide_Type
(Opnd_Type
)
12016 and then Covers
(Opnd_Type
, Target_Type
)
12020 elsif Covers
(Opnd_Type
, Target_Type
)
12021 or else Is_Ancestor
(Opnd_Type
, Target_Type
)
12024 Conversion_Check
(False,
12025 "downward conversion of tagged objects not allowed");
12027 -- Ada 2005 (AI-251): The conversion to/from interface types is
12028 -- always valid. The types involved may be class-wide (sub)types.
12030 elsif Is_Interface
(Etype
(Base_Type
(Target_Type
)))
12031 or else Is_Interface
(Etype
(Base_Type
(Opnd_Type
)))
12035 -- If the operand is a class-wide type obtained through a limited_
12036 -- with clause, and the context includes the nonlimited view, use
12037 -- it to determine whether the conversion is legal.
12039 elsif Is_Class_Wide_Type
(Opnd_Type
)
12040 and then From_Limited_With
(Opnd_Type
)
12041 and then Present
(Non_Limited_View
(Etype
(Opnd_Type
)))
12042 and then Is_Interface
(Non_Limited_View
(Etype
(Opnd_Type
)))
12046 elsif Is_Access_Type
(Opnd_Type
)
12047 and then Is_Interface
(Directly_Designated_Type
(Opnd_Type
))
12052 Conversion_Error_NE
12053 ("invalid tagged conversion, not compatible with}",
12054 N
, First_Subtype
(Opnd_Type
));
12057 end Valid_Tagged_Conversion
;
12059 -- Start of processing for Valid_Conversion
12062 Check_Parameterless_Call
(Operand
);
12064 if Is_Overloaded
(Operand
) then
12074 -- Remove procedure calls, which syntactically cannot appear in
12075 -- this context, but which cannot be removed by type checking,
12076 -- because the context does not impose a type.
12078 -- The node may be labelled overloaded, but still contain only one
12079 -- interpretation because others were discarded earlier. If this
12080 -- is the case, retain the single interpretation if legal.
12082 Get_First_Interp
(Operand
, I
, It
);
12083 Opnd_Type
:= It
.Typ
;
12084 Get_Next_Interp
(I
, It
);
12086 if Present
(It
.Typ
)
12087 and then Opnd_Type
/= Standard_Void_Type
12089 -- More than one candidate interpretation is available
12091 Get_First_Interp
(Operand
, I
, It
);
12092 while Present
(It
.Typ
) loop
12093 if It
.Typ
= Standard_Void_Type
then
12097 -- When compiling for a system where Address is of a visible
12098 -- integer type, spurious ambiguities can be produced when
12099 -- arithmetic operations have a literal operand and return
12100 -- System.Address or a descendant of it. These ambiguities
12101 -- are usually resolved by the context, but for conversions
12102 -- there is no context type and the removal of the spurious
12103 -- operations must be done explicitly here.
12105 if not Address_Is_Private
12106 and then Is_Descendant_Of_Address
(It
.Typ
)
12111 Get_Next_Interp
(I
, It
);
12115 Get_First_Interp
(Operand
, I
, It
);
12119 if No
(It
.Typ
) then
12120 Conversion_Error_N
("illegal operand in conversion", Operand
);
12124 Get_Next_Interp
(I
, It
);
12126 if Present
(It
.Typ
) then
12129 It1
:= Disambiguate
(Operand
, I1
, I
, Any_Type
);
12131 if It1
= No_Interp
then
12133 ("ambiguous operand in conversion", Operand
);
12135 -- If the interpretation involves a standard operator, use
12136 -- the location of the type, which may be user-defined.
12138 if Sloc
(It
.Nam
) = Standard_Location
then
12139 Error_Msg_Sloc
:= Sloc
(It
.Typ
);
12141 Error_Msg_Sloc
:= Sloc
(It
.Nam
);
12144 Conversion_Error_N
-- CODEFIX
12145 ("\\possible interpretation#!", Operand
);
12147 if Sloc
(N1
) = Standard_Location
then
12148 Error_Msg_Sloc
:= Sloc
(T1
);
12150 Error_Msg_Sloc
:= Sloc
(N1
);
12153 Conversion_Error_N
-- CODEFIX
12154 ("\\possible interpretation#!", Operand
);
12160 Set_Etype
(Operand
, It1
.Typ
);
12161 Opnd_Type
:= It1
.Typ
;
12165 -- Deal with conversion of integer type to address if the pragma
12166 -- Allow_Integer_Address is in effect. We convert the conversion to
12167 -- an unchecked conversion in this case and we are all done.
12169 if Address_Integer_Convert_OK
(Opnd_Type
, Target_Type
) then
12170 Rewrite
(N
, Unchecked_Convert_To
(Target_Type
, Expression
(N
)));
12171 Analyze_And_Resolve
(N
, Target_Type
);
12175 -- If we are within a child unit, check whether the type of the
12176 -- expression has an ancestor in a parent unit, in which case it
12177 -- belongs to its derivation class even if the ancestor is private.
12178 -- See RM 7.3.1 (5.2/3).
12180 Inc_Ancestor
:= Get_Incomplete_View_Of_Ancestor
(Opnd_Type
);
12184 if Is_Numeric_Type
(Target_Type
) then
12186 -- A universal fixed expression can be converted to any numeric type
12188 if Opnd_Type
= Universal_Fixed
then
12191 -- Also no need to check when in an instance or inlined body, because
12192 -- the legality has been established when the template was analyzed.
12193 -- Furthermore, numeric conversions may occur where only a private
12194 -- view of the operand type is visible at the instantiation point.
12195 -- This results in a spurious error if we check that the operand type
12196 -- is a numeric type.
12198 -- Note: in a previous version of this unit, the following tests were
12199 -- applied only for generated code (Comes_From_Source set to False),
12200 -- but in fact the test is required for source code as well, since
12201 -- this situation can arise in source code.
12203 elsif In_Instance
or else In_Inlined_Body
then
12206 -- Otherwise we need the conversion check
12209 return Conversion_Check
12210 (Is_Numeric_Type
(Opnd_Type
)
12212 (Present
(Inc_Ancestor
)
12213 and then Is_Numeric_Type
(Inc_Ancestor
)),
12214 "illegal operand for numeric conversion");
12219 elsif Is_Array_Type
(Target_Type
) then
12220 if not Is_Array_Type
(Opnd_Type
)
12221 or else Opnd_Type
= Any_Composite
12222 or else Opnd_Type
= Any_String
12225 ("illegal operand for array conversion", Operand
);
12229 return Valid_Array_Conversion
;
12232 -- Ada 2005 (AI-251): Internally generated conversions of access to
12233 -- interface types added to force the displacement of the pointer to
12234 -- reference the corresponding dispatch table.
12236 elsif not Comes_From_Source
(N
)
12237 and then Is_Access_Type
(Target_Type
)
12238 and then Is_Interface
(Designated_Type
(Target_Type
))
12242 -- Ada 2005 (AI-251): Anonymous access types where target references an
12245 elsif Is_Access_Type
(Opnd_Type
)
12246 and then Ekind_In
(Target_Type
, E_General_Access_Type
,
12247 E_Anonymous_Access_Type
)
12248 and then Is_Interface
(Directly_Designated_Type
(Target_Type
))
12250 -- Check the static accessibility rule of 4.6(17). Note that the
12251 -- check is not enforced when within an instance body, since the
12252 -- RM requires such cases to be caught at run time.
12254 -- If the operand is a rewriting of an allocator no check is needed
12255 -- because there are no accessibility issues.
12257 if Nkind
(Original_Node
(N
)) = N_Allocator
then
12260 elsif Ekind
(Target_Type
) /= E_Anonymous_Access_Type
then
12261 if Type_Access_Level
(Opnd_Type
) >
12262 Deepest_Type_Access_Level
(Target_Type
)
12264 -- In an instance, this is a run-time check, but one we know
12265 -- will fail, so generate an appropriate warning. The raise
12266 -- will be generated by Expand_N_Type_Conversion.
12268 if In_Instance_Body
then
12269 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12271 ("cannot convert local pointer to non-local access type<<",
12273 Conversion_Error_N
("\Program_Error [<<", Operand
);
12277 ("cannot convert local pointer to non-local access type",
12282 -- Special accessibility checks are needed in the case of access
12283 -- discriminants declared for a limited type.
12285 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12286 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12288 -- When the operand is a selected access discriminant the check
12289 -- needs to be made against the level of the object denoted by
12290 -- the prefix of the selected name (Object_Access_Level handles
12291 -- checking the prefix of the operand for this case).
12293 if Nkind
(Operand
) = N_Selected_Component
12294 and then Object_Access_Level
(Operand
) >
12295 Deepest_Type_Access_Level
(Target_Type
)
12297 -- In an instance, this is a run-time check, but one we know
12298 -- will fail, so generate an appropriate warning. The raise
12299 -- will be generated by Expand_N_Type_Conversion.
12301 if In_Instance_Body
then
12302 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12304 ("cannot convert access discriminant to non-local "
12305 & "access type<<", Operand
);
12306 Conversion_Error_N
("\Program_Error [<<", Operand
);
12308 -- Real error if not in instance body
12312 ("cannot convert access discriminant to non-local "
12313 & "access type", Operand
);
12318 -- The case of a reference to an access discriminant from
12319 -- within a limited type declaration (which will appear as
12320 -- a discriminal) is always illegal because the level of the
12321 -- discriminant is considered to be deeper than any (nameable)
12324 if Is_Entity_Name
(Operand
)
12325 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12327 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
12328 and then Present
(Discriminal_Link
(Entity
(Operand
)))
12331 ("discriminant has deeper accessibility level than target",
12340 -- General and anonymous access types
12342 elsif Ekind_In
(Target_Type
, E_General_Access_Type
,
12343 E_Anonymous_Access_Type
)
12346 (Is_Access_Type
(Opnd_Type
)
12348 Ekind_In
(Opnd_Type
, E_Access_Subprogram_Type
,
12349 E_Access_Protected_Subprogram_Type
),
12350 "must be an access-to-object type")
12352 if Is_Access_Constant
(Opnd_Type
)
12353 and then not Is_Access_Constant
(Target_Type
)
12356 ("access-to-constant operand type not allowed", Operand
);
12360 -- Check the static accessibility rule of 4.6(17). Note that the
12361 -- check is not enforced when within an instance body, since the RM
12362 -- requires such cases to be caught at run time.
12364 if Ekind
(Target_Type
) /= E_Anonymous_Access_Type
12365 or else Is_Local_Anonymous_Access
(Target_Type
)
12366 or else Nkind
(Associated_Node_For_Itype
(Target_Type
)) =
12367 N_Object_Declaration
12369 -- Ada 2012 (AI05-0149): Perform legality checking on implicit
12370 -- conversions from an anonymous access type to a named general
12371 -- access type. Such conversions are not allowed in the case of
12372 -- access parameters and stand-alone objects of an anonymous
12373 -- access type. The implicit conversion case is recognized by
12374 -- testing that Comes_From_Source is False and that it's been
12375 -- rewritten. The Comes_From_Source test isn't sufficient because
12376 -- nodes in inlined calls to predefined library routines can have
12377 -- Comes_From_Source set to False. (Is there a better way to test
12378 -- for implicit conversions???)
12380 if Ada_Version
>= Ada_2012
12381 and then not Comes_From_Source
(N
)
12382 and then N
/= Original_Node
(N
)
12383 and then Ekind
(Target_Type
) = E_General_Access_Type
12384 and then Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12386 if Is_Itype
(Opnd_Type
) then
12388 -- Implicit conversions aren't allowed for objects of an
12389 -- anonymous access type, since such objects have nonstatic
12390 -- levels in Ada 2012.
12392 if Nkind
(Associated_Node_For_Itype
(Opnd_Type
)) =
12393 N_Object_Declaration
12396 ("implicit conversion of stand-alone anonymous "
12397 & "access object not allowed", Operand
);
12400 -- Implicit conversions aren't allowed for anonymous access
12401 -- parameters. The "not Is_Local_Anonymous_Access_Type" test
12402 -- is done to exclude anonymous access results.
12404 elsif not Is_Local_Anonymous_Access
(Opnd_Type
)
12405 and then Nkind_In
(Associated_Node_For_Itype
(Opnd_Type
),
12406 N_Function_Specification
,
12407 N_Procedure_Specification
)
12410 ("implicit conversion of anonymous access formal "
12411 & "not allowed", Operand
);
12414 -- This is a case where there's an enclosing object whose
12415 -- to which the "statically deeper than" relationship does
12416 -- not apply (such as an access discriminant selected from
12417 -- a dereference of an access parameter).
12419 elsif Object_Access_Level
(Operand
)
12420 = Scope_Depth
(Standard_Standard
)
12423 ("implicit conversion of anonymous access value "
12424 & "not allowed", Operand
);
12427 -- In other cases, the level of the operand's type must be
12428 -- statically less deep than that of the target type, else
12429 -- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
12431 elsif Type_Access_Level
(Opnd_Type
) >
12432 Deepest_Type_Access_Level
(Target_Type
)
12435 ("implicit conversion of anonymous access value "
12436 & "violates accessibility", Operand
);
12441 elsif Type_Access_Level
(Opnd_Type
) >
12442 Deepest_Type_Access_Level
(Target_Type
)
12444 -- In an instance, this is a run-time check, but one we know
12445 -- will fail, so generate an appropriate warning. The raise
12446 -- will be generated by Expand_N_Type_Conversion.
12448 if In_Instance_Body
then
12449 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12451 ("cannot convert local pointer to non-local access type<<",
12453 Conversion_Error_N
("\Program_Error [<<", Operand
);
12455 -- If not in an instance body, this is a real error
12458 -- Avoid generation of spurious error message
12460 if not Error_Posted
(N
) then
12462 ("cannot convert local pointer to non-local access type",
12469 -- Special accessibility checks are needed in the case of access
12470 -- discriminants declared for a limited type.
12472 elsif Ekind
(Opnd_Type
) = E_Anonymous_Access_Type
12473 and then not Is_Local_Anonymous_Access
(Opnd_Type
)
12475 -- When the operand is a selected access discriminant the check
12476 -- needs to be made against the level of the object denoted by
12477 -- the prefix of the selected name (Object_Access_Level handles
12478 -- checking the prefix of the operand for this case).
12480 if Nkind
(Operand
) = N_Selected_Component
12481 and then Object_Access_Level
(Operand
) >
12482 Deepest_Type_Access_Level
(Target_Type
)
12484 -- In an instance, this is a run-time check, but one we know
12485 -- will fail, so generate an appropriate warning. The raise
12486 -- will be generated by Expand_N_Type_Conversion.
12488 if In_Instance_Body
then
12489 Error_Msg_Warn
:= SPARK_Mode
/= On
;
12491 ("cannot convert access discriminant to non-local "
12492 & "access type<<", Operand
);
12493 Conversion_Error_N
("\Program_Error [<<", Operand
);
12495 -- If not in an instance body, this is a real error
12499 ("cannot convert access discriminant to non-local "
12500 & "access type", Operand
);
12505 -- The case of a reference to an access discriminant from
12506 -- within a limited type declaration (which will appear as
12507 -- a discriminal) is always illegal because the level of the
12508 -- discriminant is considered to be deeper than any (nameable)
12511 if Is_Entity_Name
(Operand
)
12513 Ekind_In
(Entity
(Operand
), E_In_Parameter
, E_Constant
)
12514 and then Present
(Discriminal_Link
(Entity
(Operand
)))
12517 ("discriminant has deeper accessibility level than target",
12524 -- In the presence of limited_with clauses we have to use nonlimited
12525 -- views, if available.
12527 Check_Limited
: declare
12528 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
;
12529 -- Helper function to handle limited views
12531 --------------------------
12532 -- Full_Designated_Type --
12533 --------------------------
12535 function Full_Designated_Type
(T
: Entity_Id
) return Entity_Id
is
12536 Desig
: constant Entity_Id
:= Designated_Type
(T
);
12539 -- Handle the limited view of a type
12541 if From_Limited_With
(Desig
)
12542 and then Has_Non_Limited_View
(Desig
)
12544 return Available_View
(Desig
);
12548 end Full_Designated_Type
;
12550 -- Local Declarations
12552 Target
: constant Entity_Id
:= Full_Designated_Type
(Target_Type
);
12553 Opnd
: constant Entity_Id
:= Full_Designated_Type
(Opnd_Type
);
12555 Same_Base
: constant Boolean :=
12556 Base_Type
(Target
) = Base_Type
(Opnd
);
12558 -- Start of processing for Check_Limited
12561 if Is_Tagged_Type
(Target
) then
12562 return Valid_Tagged_Conversion
(Target
, Opnd
);
12565 if not Same_Base
then
12566 Conversion_Error_NE
12567 ("target designated type not compatible with }",
12568 N
, Base_Type
(Opnd
));
12571 -- Ada 2005 AI-384: legality rule is symmetric in both
12572 -- designated types. The conversion is legal (with possible
12573 -- constraint check) if either designated type is
12576 elsif Subtypes_Statically_Match
(Target
, Opnd
)
12578 (Has_Discriminants
(Target
)
12580 (not Is_Constrained
(Opnd
)
12581 or else not Is_Constrained
(Target
)))
12583 -- Special case, if Value_Size has been used to make the
12584 -- sizes different, the conversion is not allowed even
12585 -- though the subtypes statically match.
12587 if Known_Static_RM_Size
(Target
)
12588 and then Known_Static_RM_Size
(Opnd
)
12589 and then RM_Size
(Target
) /= RM_Size
(Opnd
)
12591 Conversion_Error_NE
12592 ("target designated subtype not compatible with }",
12594 Conversion_Error_NE
12595 ("\because sizes of the two designated subtypes differ",
12599 -- Normal case where conversion is allowed
12607 ("target designated subtype not compatible with }",
12614 -- Access to subprogram types. If the operand is an access parameter,
12615 -- the type has a deeper accessibility that any master, and cannot be
12616 -- assigned. We must make an exception if the conversion is part of an
12617 -- assignment and the target is the return object of an extended return
12618 -- statement, because in that case the accessibility check takes place
12619 -- after the return.
12621 elsif Is_Access_Subprogram_Type
(Target_Type
)
12623 -- Note: this test of Opnd_Type is there to prevent entering this
12624 -- branch in the case of a remote access to subprogram type, which
12625 -- is internally represented as an E_Record_Type.
12627 and then Is_Access_Type
(Opnd_Type
)
12629 if Ekind
(Base_Type
(Opnd_Type
)) = E_Anonymous_Access_Subprogram_Type
12630 and then Is_Entity_Name
(Operand
)
12631 and then Ekind
(Entity
(Operand
)) = E_In_Parameter
12633 (Nkind
(Parent
(N
)) /= N_Assignment_Statement
12634 or else not Is_Entity_Name
(Name
(Parent
(N
)))
12635 or else not Is_Return_Object
(Entity
(Name
(Parent
(N
)))))
12638 ("illegal attempt to store anonymous access to subprogram",
12641 ("\value has deeper accessibility than any master "
12642 & "(RM 3.10.2 (13))",
12646 ("\use named access type for& instead of access parameter",
12647 Operand
, Entity
(Operand
));
12650 -- Check that the designated types are subtype conformant
12652 Check_Subtype_Conformant
(New_Id
=> Designated_Type
(Target_Type
),
12653 Old_Id
=> Designated_Type
(Opnd_Type
),
12656 -- Check the static accessibility rule of 4.6(20)
12658 if Type_Access_Level
(Opnd_Type
) >
12659 Deepest_Type_Access_Level
(Target_Type
)
12662 ("operand type has deeper accessibility level than target",
12665 -- Check that if the operand type is declared in a generic body,
12666 -- then the target type must be declared within that same body
12667 -- (enforces last sentence of 4.6(20)).
12669 elsif Present
(Enclosing_Generic_Body
(Opnd_Type
)) then
12671 O_Gen
: constant Node_Id
:=
12672 Enclosing_Generic_Body
(Opnd_Type
);
12677 T_Gen
:= Enclosing_Generic_Body
(Target_Type
);
12678 while Present
(T_Gen
) and then T_Gen
/= O_Gen
loop
12679 T_Gen
:= Enclosing_Generic_Body
(T_Gen
);
12682 if T_Gen
/= O_Gen
then
12684 ("target type must be declared in same generic body "
12685 & "as operand type", N
);
12692 -- Remote access to subprogram types
12694 elsif Is_Remote_Access_To_Subprogram_Type
(Target_Type
)
12695 and then Is_Remote_Access_To_Subprogram_Type
(Opnd_Type
)
12697 -- It is valid to convert from one RAS type to another provided
12698 -- that their specification statically match.
12700 -- Note: at this point, remote access to subprogram types have been
12701 -- expanded to their E_Record_Type representation, and we need to
12702 -- go back to the original access type definition using the
12703 -- Corresponding_Remote_Type attribute in order to check that the
12704 -- designated profiles match.
12706 pragma Assert
(Ekind
(Target_Type
) = E_Record_Type
);
12707 pragma Assert
(Ekind
(Opnd_Type
) = E_Record_Type
);
12709 Check_Subtype_Conformant
12711 Designated_Type
(Corresponding_Remote_Type
(Target_Type
)),
12713 Designated_Type
(Corresponding_Remote_Type
(Opnd_Type
)),
12718 -- If it was legal in the generic, it's legal in the instance
12720 elsif In_Instance_Body
then
12723 -- If both are tagged types, check legality of view conversions
12725 elsif Is_Tagged_Type
(Target_Type
)
12727 Is_Tagged_Type
(Opnd_Type
)
12729 return Valid_Tagged_Conversion
(Target_Type
, Opnd_Type
);
12731 -- Types derived from the same root type are convertible
12733 elsif Root_Type
(Target_Type
) = Root_Type
(Opnd_Type
) then
12736 -- In an instance or an inlined body, there may be inconsistent views of
12737 -- the same type, or of types derived from a common root.
12739 elsif (In_Instance
or In_Inlined_Body
)
12741 Root_Type
(Underlying_Type
(Target_Type
)) =
12742 Root_Type
(Underlying_Type
(Opnd_Type
))
12746 -- Special check for common access type error case
12748 elsif Ekind
(Target_Type
) = E_Access_Type
12749 and then Is_Access_Type
(Opnd_Type
)
12751 Conversion_Error_N
("target type must be general access type!", N
);
12752 Conversion_Error_NE
-- CODEFIX
12753 ("add ALL to }!", N
, Target_Type
);
12756 -- Here we have a real conversion error
12759 Conversion_Error_NE
12760 ("invalid conversion, not compatible with }", N
, Opnd_Type
);
12763 end Valid_Conversion
;