1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2024, 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 Aspects
; use Aspects
;
27 with Atree
; use Atree
;
28 with Checks
; use Checks
;
29 with Debug
; use Debug
;
30 with Einfo
; use Einfo
;
31 with Einfo
.Entities
; use Einfo
.Entities
;
32 with Einfo
.Utils
; use Einfo
.Utils
;
33 with Errout
; use Errout
;
34 with Expander
; use Expander
;
35 with Exp_Ch6
; use Exp_Ch6
;
36 with Exp_Tss
; use Exp_Tss
;
37 with Exp_Util
; use Exp_Util
;
38 with Freeze
; use Freeze
;
39 with Ghost
; use Ghost
;
41 with Lib
.Xref
; use Lib
.Xref
;
42 with Mutably_Tagged
; use Mutably_Tagged
;
43 with Namet
; use Namet
;
44 with Nlists
; use Nlists
;
45 with Nmake
; use Nmake
;
48 with Sem_Aux
; use Sem_Aux
;
49 with Sem_Case
; use Sem_Case
;
50 with Sem_Ch3
; use Sem_Ch3
;
51 with Sem_Ch6
; use Sem_Ch6
;
52 with Sem_Ch8
; use Sem_Ch8
;
53 with Sem_Dim
; use Sem_Dim
;
54 with Sem_Disp
; use Sem_Disp
;
55 with Sem_Elab
; use Sem_Elab
;
56 with Sem_Eval
; use Sem_Eval
;
57 with Sem_Res
; use Sem_Res
;
58 with Sem_Type
; use Sem_Type
;
59 with Sem_Util
; use Sem_Util
;
60 with Sem_Warn
; use Sem_Warn
;
61 with Snames
; use Snames
;
62 with Stand
; use Stand
;
63 with Sinfo
; use Sinfo
;
64 with Sinfo
.Nodes
; use Sinfo
.Nodes
;
65 with Sinfo
.Utils
; use Sinfo
.Utils
;
66 with Targparm
; use Targparm
;
67 with Tbuild
; use Tbuild
;
68 with Ttypes
; use Ttypes
;
69 with Uintp
; use Uintp
;
70 with Warnsw
; use Warnsw
;
72 package body Sem_Ch5
is
74 Current_Assignment
: Node_Id
:= Empty
;
75 -- This variable holds the node for an assignment that contains target
76 -- names. The corresponding flag has been set by the parser, and when
77 -- set the analysis of the RHS must be done with all expansion disabled,
78 -- because the assignment is reanalyzed after expansion has replaced all
79 -- occurrences of the target name appropriately.
81 Unblocked_Exit_Count
: Nat
:= 0;
82 -- This variable is used when processing if statements, case statements,
83 -- and block statements. It counts the number of exit points that are not
84 -- blocked by unconditional transfer instructions: for IF and CASE, these
85 -- are the branches of the conditional; for a block, they are the statement
86 -- sequence of the block, and the statement sequences of any exception
87 -- handlers that are part of the block. When processing is complete, if
88 -- this count is zero, it means that control cannot fall through the IF,
89 -- CASE or block statement. This is used for the generation of warning
90 -- messages. This variable is recursively saved on entry to processing the
91 -- construct, and restored on exit.
93 function Has_Sec_Stack_Call
(N
: Node_Id
) return Boolean;
94 -- N is the node for an arbitrary construct. This function searches the
95 -- construct N to see if it contains a function call that returns on the
96 -- secondary stack, returning True if any such call is found, and False
99 -- ??? The implementation invokes Sem_Util.Requires_Transient_Scope so it
100 -- will return True if N contains a function call that needs finalization,
101 -- in addition to the above specification. See Analyze_Loop_Statement for
102 -- a similar comment about this entanglement.
104 procedure Preanalyze_Range
(R_Copy
: Node_Id
);
105 -- Determine expected type of range or domain of iteration of Ada 2012
106 -- loop by analyzing separate copy. Do the analysis and resolution of the
107 -- copy of the bound(s) with expansion disabled, to prevent the generation
108 -- of finalization actions. This prevents memory leaks when the bounds
109 -- contain calls to functions returning controlled arrays or when the
110 -- domain of iteration is a container.
112 ------------------------
113 -- Analyze_Assignment --
114 ------------------------
116 -- WARNING: This routine manages Ghost regions. Return statements must be
117 -- replaced by gotos which jump to the end of the routine and restore the
120 procedure Analyze_Assignment
(N
: Node_Id
) is
121 Lhs
: constant Node_Id
:= Name
(N
);
122 Rhs
: constant Node_Id
:= Expression
(N
);
124 procedure Diagnose_Non_Variable_Lhs
(N
: Node_Id
);
125 -- N is the node for the left hand side of an assignment, and it is not
126 -- a variable. This routine issues an appropriate diagnostic.
128 function Is_Protected_Part_Of_Constituent
129 (Nod
: Node_Id
) return Boolean;
130 -- Determine whether arbitrary node Nod denotes a Part_Of constituent of
131 -- a single protected type.
134 -- This is called to kill current value settings of a simple variable
135 -- on the left hand side. We call it if we find any error in analyzing
136 -- the assignment, and at the end of processing before setting any new
137 -- current values in place.
139 procedure Set_Assignment_Type
141 Opnd_Type
: in out Entity_Id
);
142 -- Opnd is either the Lhs or Rhs of the assignment, and Opnd_Type is the
143 -- nominal subtype. This procedure is used to deal with cases where the
144 -- nominal subtype must be replaced by the actual subtype.
146 function Within_Function
return Boolean;
147 -- Determine whether the current scope is a function or appears within
150 -------------------------------
151 -- Diagnose_Non_Variable_Lhs --
152 -------------------------------
154 procedure Diagnose_Non_Variable_Lhs
(N
: Node_Id
) is
156 -- Not worth posting another error if left hand side already flagged
157 -- as being illegal in some respect.
159 if Error_Posted
(N
) then
162 -- Some special bad cases of entity names
164 elsif Is_Entity_Name
(N
) then
166 Ent
: constant Entity_Id
:= Entity
(N
);
169 if Ekind
(Ent
) = E_Loop_Parameter
170 or else Is_Loop_Parameter
(Ent
)
172 Error_Msg_N
("assignment to loop parameter not allowed", N
);
175 elsif Ekind
(Ent
) = E_In_Parameter
then
177 ("assignment to IN mode parameter not allowed", N
);
180 -- Renamings of protected private components are turned into
181 -- constants when compiling a protected function. In the case
182 -- of single protected types, the private component appears
185 elsif (Is_Prival
(Ent
) and then Within_Function
)
186 or else Is_Protected_Component
(Ent
)
189 ("protected function cannot modify its protected object",
195 -- For indexed components, test prefix if it is in array. We do not
196 -- want to recurse for cases where the prefix is a pointer, since we
197 -- may get a message confusing the pointer and what it references.
199 elsif Nkind
(N
) = N_Indexed_Component
200 and then Is_Array_Type
(Etype
(Prefix
(N
)))
202 Diagnose_Non_Variable_Lhs
(Prefix
(N
));
205 -- Another special case for assignment to discriminant
207 elsif Nkind
(N
) = N_Selected_Component
then
208 if Present
(Entity
(Selector_Name
(N
)))
209 and then Ekind
(Entity
(Selector_Name
(N
))) = E_Discriminant
211 Error_Msg_N
("assignment to discriminant not allowed", N
);
214 -- For selection from record, diagnose prefix, but note that again
215 -- we only do this for a record, not e.g. for a pointer.
217 elsif Is_Record_Type
(Etype
(Prefix
(N
))) then
218 Diagnose_Non_Variable_Lhs
(Prefix
(N
));
223 -- If we fall through, we have no special message to issue
225 Error_Msg_N
("left hand side of assignment must be a variable", N
);
226 end Diagnose_Non_Variable_Lhs
;
228 --------------------------------------
229 -- Is_Protected_Part_Of_Constituent --
230 --------------------------------------
232 function Is_Protected_Part_Of_Constituent
233 (Nod
: Node_Id
) return Boolean
235 Encap_Id
: Entity_Id
;
239 -- Abstract states and variables may act as Part_Of constituents of
240 -- single protected types, however only variables can be modified by
243 if Is_Entity_Name
(Nod
) then
244 Var_Id
:= Entity
(Nod
);
246 if Present
(Var_Id
) and then Ekind
(Var_Id
) = E_Variable
then
247 Encap_Id
:= Encapsulating_State
(Var_Id
);
249 -- To qualify, the node must denote a reference to a variable
250 -- whose encapsulating state is a single protected object.
254 and then Is_Single_Protected_Object
(Encap_Id
);
259 end Is_Protected_Part_Of_Constituent
;
265 procedure Kill_Lhs
is
267 if Is_Entity_Name
(Lhs
) then
269 Ent
: constant Entity_Id
:= Entity
(Lhs
);
271 if Present
(Ent
) then
272 Kill_Current_Values
(Ent
);
278 -------------------------
279 -- Set_Assignment_Type --
280 -------------------------
282 procedure Set_Assignment_Type
284 Opnd_Type
: in out Entity_Id
)
289 Require_Entity
(Opnd
);
291 -- If the assignment operand is an in-out or out parameter, then we
292 -- get the actual subtype (needed for the unconstrained case). If the
293 -- operand is the actual in an entry declaration, then within the
294 -- accept statement it is replaced with a local renaming, which may
295 -- also have an actual subtype. Likewise for a return object that
296 -- lives on the secondary stack.
298 if Is_Entity_Name
(Opnd
)
299 and then (Ekind
(Entity
(Opnd
)) in E_Out_Parameter
301 | E_Generic_In_Out_Parameter
303 (Ekind
(Entity
(Opnd
)) = E_Variable
304 and then Nkind
(Parent
(Entity
(Opnd
))) =
305 N_Object_Renaming_Declaration
306 and then Nkind
(Parent
(Parent
(Entity
(Opnd
)))) =
308 or else Is_Secondary_Stack_Return_Object
(Entity
(Opnd
)))
310 Opnd_Type
:= Get_Actual_Subtype
(Opnd
);
312 -- If the assignment operand is a component reference, then we build
313 -- the actual subtype of the component for the unconstrained case,
314 -- unless there is already one or the type is an unchecked union.
316 elsif (Nkind
(Opnd
) = N_Selected_Component
317 or else (Nkind
(Opnd
) = N_Explicit_Dereference
318 and then No
(Actual_Designated_Subtype
(Opnd
))))
319 and then not Is_Unchecked_Union
(Opnd_Type
)
321 Decl
:= Build_Actual_Subtype_Of_Component
(Opnd_Type
, Opnd
);
323 if Present
(Decl
) then
324 Insert_Action
(N
, Decl
);
325 Mark_Rewrite_Insertion
(Decl
);
327 Opnd_Type
:= Defining_Identifier
(Decl
);
328 Set_Etype
(Opnd
, Opnd_Type
);
329 Freeze_Itype
(Opnd_Type
, N
);
331 elsif Is_Constrained
(Etype
(Opnd
)) then
332 Opnd_Type
:= Etype
(Opnd
);
335 -- For slice, use the constrained subtype created for the slice
337 elsif Nkind
(Opnd
) = N_Slice
then
338 Opnd_Type
:= Etype
(Opnd
);
340 end Set_Assignment_Type
;
342 ---------------------
343 -- Within_Function --
344 ---------------------
346 function Within_Function
return Boolean is
347 Scop_Id
: constant Entity_Id
:= Current_Scope
;
350 if Ekind
(Scop_Id
) = E_Function
then
353 elsif Ekind
(Enclosing_Dynamic_Scope
(Scop_Id
)) = E_Function
then
362 Saved_GM
: constant Ghost_Mode_Type
:= Ghost_Mode
;
363 Saved_IGR
: constant Node_Id
:= Ignored_Ghost_Region
;
364 -- Save the Ghost-related attributes to restore on exit
369 Save_Full_Analysis
: Boolean := False;
370 -- Force initialization to facilitate static analysis
372 -- Start of processing for Analyze_Assignment
375 Mark_Coextensions
(N
, Rhs
);
377 -- Preserve relevant elaboration-related attributes of the context which
378 -- are no longer available or very expensive to recompute once analysis,
379 -- resolution, and expansion are over.
381 Mark_Elaboration_Attributes
386 -- An assignment statement is Ghost when the left hand side denotes a
387 -- Ghost entity. Set the mode now to ensure that any nodes generated
388 -- during analysis and expansion are properly marked as Ghost.
390 Mark_And_Set_Ghost_Assignment
(N
);
392 if Has_Target_Names
(N
) then
393 pragma Assert
(No
(Current_Assignment
));
394 Current_Assignment
:= N
;
395 Expander_Mode_Save_And_Set
(False);
396 Save_Full_Analysis
:= Full_Analysis
;
397 Full_Analysis
:= False;
403 -- Ensure that we never do an assignment on a variable marked as
404 -- Is_Safe_To_Reevaluate.
407 (not Is_Entity_Name
(Lhs
)
408 or else Ekind
(Entity
(Lhs
)) /= E_Variable
409 or else not Is_Safe_To_Reevaluate
(Entity
(Lhs
)));
411 -- Start type analysis for assignment
415 -- In the most general case, both Lhs and Rhs can be overloaded, and we
416 -- must compute the intersection of the possible types on each side.
418 if Is_Overloaded
(Lhs
) then
425 Get_First_Interp
(Lhs
, I
, It
);
427 while Present
(It
.Typ
) loop
429 -- An indexed component with generalized indexing is always
430 -- overloaded with the corresponding dereference. Discard the
431 -- interpretation that yields a reference type, which is not
434 if Nkind
(Lhs
) = N_Indexed_Component
435 and then Present
(Generalized_Indexing
(Lhs
))
436 and then Has_Implicit_Dereference
(It
.Typ
)
440 -- This may be a call to a parameterless function through an
441 -- implicit dereference, so discard interpretation as well.
443 elsif Is_Entity_Name
(Lhs
)
444 and then Has_Implicit_Dereference
(It
.Typ
)
448 elsif Has_Compatible_Type
(Rhs
, It
.Typ
) then
449 if T1
= Any_Type
then
452 -- An explicit dereference is overloaded if the prefix
453 -- is. Try to remove the ambiguity on the prefix, the
454 -- error will be posted there if the ambiguity is real.
456 if Nkind
(Lhs
) = N_Explicit_Dereference
then
459 PI1
: Interp_Index
:= 0;
465 Get_First_Interp
(Prefix
(Lhs
), PI
, PIt
);
467 while Present
(PIt
.Typ
) loop
468 if Is_Access_Type
(PIt
.Typ
)
469 and then Has_Compatible_Type
470 (Rhs
, Designated_Type
(PIt
.Typ
))
474 Disambiguate
(Prefix
(Lhs
),
477 if PIt
= No_Interp
then
479 ("ambiguous left-hand side in "
480 & "assignment", Lhs
);
483 Resolve
(Prefix
(Lhs
), PIt
.Typ
);
493 Get_Next_Interp
(PI
, PIt
);
499 ("ambiguous left-hand side in assignment", Lhs
);
505 Get_Next_Interp
(I
, It
);
509 if T1
= Any_Type
then
511 ("no valid types for left-hand side for assignment", Lhs
);
517 -- The resulting assignment type is T1, so now we will resolve the left
518 -- hand side of the assignment using this determined type.
522 -- Cases where Lhs is not a variable. In an instance or an inlined body
523 -- no need for further check because assignment was legal in template.
525 if In_Inlined_Body
then
528 elsif not Is_Variable
(Lhs
) then
530 -- Ada 2005 (AI-327): Check assignment to the attribute Priority of a
538 if Ada_Version
>= Ada_2005
then
540 -- Handle chains of renamings
543 while Nkind
(Ent
) in N_Has_Entity
544 and then Present
(Entity
(Ent
))
545 and then Is_Object
(Entity
(Ent
))
546 and then Present
(Renamed_Object
(Entity
(Ent
)))
548 Ent
:= Renamed_Object
(Entity
(Ent
));
551 if (Nkind
(Ent
) = N_Attribute_Reference
552 and then Attribute_Name
(Ent
) = Name_Priority
)
554 -- Renamings of the attribute Priority applied to protected
555 -- objects have been previously expanded into calls to the
556 -- Get_Ceiling run-time subprogram.
558 or else Is_Expanded_Priority_Attribute
(Ent
)
560 -- The enclosing subprogram cannot be a protected function
563 while not (Is_Subprogram
(S
)
564 and then Convention
(S
) = Convention_Protected
)
565 and then S
/= Standard_Standard
570 if Ekind
(S
) = E_Function
571 and then Convention
(S
) = Convention_Protected
574 ("protected function cannot modify its protected " &
579 -- Changes of the ceiling priority of the protected object
580 -- are only effective if the Ceiling_Locking policy is in
581 -- effect (AARM D.5.2 (5/2)).
583 if Locking_Policy
/= 'C' then
585 ("assignment to the attribute PRIORITY has no effect??",
588 ("\since no Locking_Policy has been specified??", Lhs
);
596 Diagnose_Non_Variable_Lhs
(Lhs
);
599 -- Error of assigning to limited type. We do however allow this in
600 -- certain cases where the front end generates the assignments.
601 -- Comes_From_Source test is needed to allow compiler-generated
602 -- streaming/put_image subprograms, which may ignore privacy.
604 elsif Is_Limited_Type
(T1
)
605 and then not Assignment_OK
(Lhs
)
606 and then not Assignment_OK
(Original_Node
(Lhs
))
607 and then (Comes_From_Source
(N
) or Is_Immutably_Limited_Type
(T1
))
609 -- CPP constructors can only be called in declarations
611 if Is_CPP_Constructor_Call
(Rhs
) then
612 Error_Msg_N
("invalid use of 'C'P'P constructor", Rhs
);
615 ("left hand of assignment must not be limited type", Lhs
);
616 Explain_Limited_Type
(T1
, Lhs
);
621 -- A class-wide type may be a limited view. This illegal case is not
622 -- caught by previous checks.
624 elsif Ekind
(T1
) = E_Class_Wide_Type
and then From_Limited_With
(T1
) then
625 Error_Msg_NE
("invalid use of limited view of&", Lhs
, T1
);
628 -- Enforce RM 3.9.3 (8): the target of an assignment operation cannot be
629 -- abstract. This is only checked when the assignment Comes_From_Source,
630 -- because in some cases the expander generates such assignments (such
631 -- in the _assign operation for an abstract type).
633 elsif Is_Abstract_Type
(T1
) and then Comes_From_Source
(N
) then
635 ("target of assignment operation must not be abstract", Lhs
);
638 -- Variables which are Part_Of constituents of single protected types
639 -- behave in similar fashion to protected components. Such variables
640 -- cannot be modified by protected functions.
642 if Is_Protected_Part_Of_Constituent
(Lhs
) and then Within_Function
then
644 ("protected function cannot modify its protected object", Lhs
);
647 -- Resolution may have updated the subtype, in case the left-hand side
648 -- is a private protected component. Use the correct subtype to avoid
649 -- scoping issues in the back-end.
653 -- Ada 2005 (AI-50217, AI-326): Check wrong dereference of incomplete
654 -- type. For example:
658 -- type Acc is access P.T;
661 -- with Pkg; use Acc;
662 -- procedure Example is
665 -- A.all := B.all; -- ERROR
668 if Nkind
(Lhs
) = N_Explicit_Dereference
669 and then Ekind
(T1
) = E_Incomplete_Type
671 Error_Msg_N
("invalid use of incomplete type", Lhs
);
676 -- Now we can complete the resolution of the right hand side
678 Set_Assignment_Type
(Lhs
, T1
);
680 -- When analyzing a mutably tagged class-wide equivalent type pretend we
681 -- are actually looking at the mutably tagged type itself for proper
684 T1
:= Get_Corresponding_Mutably_Tagged_Type_If_Present
(T1
);
686 -- If the target of the assignment is an entity of a mutably tagged type
687 -- and the expression is a conditional expression, its alternatives can
688 -- be of different subtypes of the nominal type of the LHS, so they must
689 -- be resolved with the base type, given that their subtype may differ
690 -- from that of the target mutable object.
692 if Is_Entity_Name
(Lhs
)
693 and then Is_Assignable
(Entity
(Lhs
))
694 and then Is_Composite_Type
(T1
)
695 and then not Is_Constrained
(Etype
(Entity
(Lhs
)))
696 and then Nkind
(Rhs
) in N_If_Expression | N_Case_Expression
698 Resolve
(Rhs
, Base_Type
(T1
));
704 -- This is the point at which we check for an unset reference
706 Check_Unset_Reference
(Rhs
);
707 Check_Unprotected_Access
(Lhs
, Rhs
);
709 -- Remaining steps are skipped if Rhs was syntactically in error
718 if not Covers
(T1
, T2
) then
719 Wrong_Type
(Rhs
, Etype
(Lhs
));
724 -- Ada 2005 (AI-326): In case of explicit dereference of incomplete
725 -- types, use the non-limited view if available
727 if Nkind
(Rhs
) = N_Explicit_Dereference
728 and then Is_Tagged_Type
(T2
)
729 and then Has_Non_Limited_View
(T2
)
731 T2
:= Non_Limited_View
(T2
);
734 Set_Assignment_Type
(Rhs
, T2
);
736 if Total_Errors_Detected
/= 0 then
746 if T1
= Any_Type
or else T2
= Any_Type
then
751 -- If the rhs is class-wide or dynamically tagged, then require the lhs
752 -- to be class-wide. The case where the rhs is a dynamically tagged call
753 -- to a dispatching operation with a controlling access result is
754 -- excluded from this check, since the target has an access type (and
755 -- no tag propagation occurs in that case).
757 if (Is_Class_Wide_Type
(T2
)
758 or else (Is_Dynamically_Tagged
(Rhs
)
759 and then not Is_Access_Type
(T1
)))
760 and then not Is_Class_Wide_Type
(T1
)
762 Error_Msg_N
("dynamically tagged expression not allowed!", Rhs
);
764 elsif Is_Class_Wide_Type
(T1
)
765 and then not Is_Class_Wide_Type
(T2
)
766 and then not Is_Tag_Indeterminate
(Rhs
)
767 and then not Is_Dynamically_Tagged
(Rhs
)
769 Error_Msg_N
("dynamically tagged expression required!", Rhs
);
772 -- Propagate the tag from a class-wide target to the rhs when the rhs
773 -- is a tag-indeterminate call.
775 if Is_Tag_Indeterminate
(Rhs
) then
776 if Is_Class_Wide_Type
(T1
) then
777 Propagate_Tag
(Lhs
, Rhs
);
779 elsif Nkind
(Rhs
) = N_Function_Call
780 and then Is_Entity_Name
(Name
(Rhs
))
781 and then Is_Abstract_Subprogram
(Entity
(Name
(Rhs
)))
784 ("call to abstract function must be dispatching", Name
(Rhs
));
786 elsif Nkind
(Rhs
) = N_Qualified_Expression
787 and then Nkind
(Expression
(Rhs
)) = N_Function_Call
788 and then Is_Entity_Name
(Name
(Expression
(Rhs
)))
790 Is_Abstract_Subprogram
(Entity
(Name
(Expression
(Rhs
))))
793 ("call to abstract function must be dispatching",
794 Name
(Expression
(Rhs
)));
798 -- Ada 2005 (AI-385): When the lhs type is an anonymous access type,
799 -- apply an implicit conversion of the rhs to that type to force
800 -- appropriate static and run-time accessibility checks. This applies
801 -- as well to anonymous access-to-subprogram types that are component
802 -- subtypes or formal parameters.
804 if Ada_Version
>= Ada_2005
and then Is_Access_Type
(T1
) then
805 if Is_Local_Anonymous_Access
(T1
)
806 or else Ekind
(T2
) = E_Anonymous_Access_Subprogram_Type
808 -- Handle assignment to an Ada 2012 stand-alone object
809 -- of an anonymous access type.
811 or else (Ekind
(T1
) = E_Anonymous_Access_Type
812 and then Nkind
(Associated_Node_For_Itype
(T1
)) =
813 N_Object_Declaration
)
816 Rewrite
(Rhs
, Convert_To
(T1
, Relocate_Node
(Rhs
)));
817 Analyze_And_Resolve
(Rhs
, T1
);
821 -- Ada 2005 (AI-231): Assignment to not null variable
823 if Ada_Version
>= Ada_2005
824 and then Can_Never_Be_Null
(T1
)
825 and then not Assignment_OK
(Lhs
)
827 -- Case where we know the right hand side is null
829 if Known_Null
(Rhs
) then
830 Apply_Compile_Time_Constraint_Error
833 "(Ada 2005) NULL not allowed in null-excluding objects??",
834 Reason
=> CE_Null_Not_Allowed
);
836 -- We still mark this as a possible modification, that's necessary
837 -- to reset Is_True_Constant, and desirable for xref purposes.
839 Note_Possible_Modification
(Lhs
, Sure
=> True);
842 -- If we know the right hand side is non-null, then we convert to the
843 -- target type, since we don't need a run time check in that case.
845 elsif not Can_Never_Be_Null
(T2
) then
846 Rewrite
(Rhs
, Convert_To
(T1
, Relocate_Node
(Rhs
)));
847 Analyze_And_Resolve
(Rhs
, T1
);
851 if Is_Scalar_Type
(T1
) then
854 function Omit_Range_Check_For_Streaming
return Boolean;
855 -- Return True if this assignment statement is the expansion of
856 -- a Some_Scalar_Type'Read procedure call such that all conditions
857 -- of 13.3.2(35)'s "no check is made" rule are met.
859 ------------------------------------
860 -- Omit_Range_Check_For_Streaming --
861 ------------------------------------
863 function Omit_Range_Check_For_Streaming
return Boolean is
865 -- Have we got an implicitly generated assignment to a
866 -- component of a composite object? If not, return False.
868 if Comes_From_Source
(N
)
869 or else Serious_Errors_Detected
> 0
871 not in N_Selected_Component | N_Indexed_Component
877 Pref
: constant Node_Id
:= Prefix
(Lhs
);
879 -- Are we in the implicitly-defined Read subprogram
880 -- for a composite type, reading the value of a scalar
881 -- component from the stream? If not, return False.
883 if Nkind
(Pref
) /= N_Identifier
884 or else not Is_TSS
(Scope
(Entity
(Pref
)), TSS_Stream_Read
)
889 -- Return False if Default_Value or Default_Component_Value
892 if Has_Default_Aspect
(Etype
(Lhs
))
893 or else Has_Default_Aspect
(Etype
(Pref
))
897 -- Are we assigning to a record component (as opposed to
898 -- an array component)?
900 elsif Nkind
(Lhs
) = N_Selected_Component
then
902 -- Are we assigning to a nondiscriminant component
903 -- that lacks a default initial value expression?
904 -- If so, return True.
907 Comp_Id
: constant Entity_Id
:=
908 Original_Record_Component
909 (Entity
(Selector_Name
(Lhs
)));
911 if Ekind
(Comp_Id
) = E_Component
912 and then Nkind
(Parent
(Comp_Id
))
913 = N_Component_Declaration
914 and then No
(Expression
(Parent
(Comp_Id
)))
921 -- We are assigning to a component of an array
922 -- (and we tested for both Default_Value and
923 -- Default_Component_Value above), so return True.
926 pragma Assert
(Nkind
(Lhs
) = N_Indexed_Component
);
930 end Omit_Range_Check_For_Streaming
;
933 if not Omit_Range_Check_For_Streaming
then
934 Apply_Scalar_Range_Check
(Rhs
, Etype
(Lhs
));
938 -- For array types, verify that lengths match. If the right hand side
939 -- is a function call that has been inlined, the assignment has been
940 -- rewritten as a block, and the constraint check will be applied to the
941 -- assignment within the block.
943 elsif Is_Array_Type
(T1
)
944 and then (Nkind
(Rhs
) /= N_Type_Conversion
945 or else Is_Constrained
(Etype
(Rhs
)))
946 and then (Nkind
(Rhs
) /= N_Function_Call
947 or else Nkind
(N
) /= N_Block_Statement
)
949 -- Assignment verifies that the length of the Lhs and Rhs are equal,
950 -- but of course the indexes do not have to match. If the right-hand
951 -- side is a type conversion to an unconstrained type, a length check
952 -- is performed on the expression itself during expansion. In rare
953 -- cases, the redundant length check is computed on an index type
954 -- with a different representation, triggering incorrect code in the
957 Apply_Length_Check_On_Assignment
(Rhs
, Etype
(Lhs
), Lhs
);
960 -- Discriminant checks are applied in the course of expansion
965 -- Note: modifications of the Lhs may only be recorded after
966 -- checks have been applied.
968 Note_Possible_Modification
(Lhs
, Sure
=> True);
970 -- ??? a real accessibility check is needed when ???
972 -- Post warning for redundant assignment or variable to itself
974 if Warn_On_Redundant_Constructs
976 -- We only warn for source constructs
978 and then Comes_From_Source
(N
)
980 -- Where the object is the same on both sides
982 and then Same_Object
(Lhs
, Rhs
)
984 -- But exclude the case where the right side was an operation that
985 -- got rewritten (e.g. JUNK + K, where K was known to be zero). We
986 -- don't want to warn in such a case, since it is reasonable to write
987 -- such expressions especially when K is defined symbolically in some
990 and then Nkind
(Original_Node
(Rhs
)) not in N_Op
992 if Nkind
(Lhs
) in N_Has_Entity
then
993 Error_Msg_NE
-- CODEFIX
994 ("?r?useless assignment of & to itself!", N
, Entity
(Lhs
));
996 Error_Msg_N
-- CODEFIX
997 ("?r?useless assignment of object to itself!", N
);
1001 -- Check for non-allowed composite assignment
1003 if not Support_Composite_Assign_On_Target
1004 and then (Is_Array_Type
(T1
) or else Is_Record_Type
(T1
))
1005 and then (not Has_Size_Clause
(T1
)
1006 or else Esize
(T1
) > Ttypes
.System_Max_Integer_Size
)
1008 Error_Msg_CRT
("composite assignment", N
);
1011 -- Check elaboration warning for left side if not in elab code
1013 if Legacy_Elaboration_Checks
1014 and not In_Subprogram_Or_Concurrent_Unit
1016 Check_Elab_Assign
(Lhs
);
1019 -- Save the scenario for later examination by the ABE Processing phase
1021 Record_Elaboration_Scenario
(N
);
1023 -- Set Referenced_As_LHS if appropriate. We are not interested in
1024 -- compiler-generated assignment statements, nor in references outside
1025 -- the extended main source unit. We check whether the Original_Node is
1026 -- in the extended main source unit because in the case of a renaming of
1027 -- a component of a packed array, the Lhs itself has a Sloc from the
1028 -- place of the renaming.
1030 if Comes_From_Source
(N
)
1031 and then (In_Extended_Main_Source_Unit
(Lhs
)
1032 or else In_Extended_Main_Source_Unit
(Original_Node
(Lhs
)))
1034 Set_Referenced_Modified
(Lhs
, Out_Param
=> False);
1037 -- RM 7.3.2 (12/3): An assignment to a view conversion (from a type to
1038 -- one of its ancestors) requires an invariant check. Apply check only
1039 -- if expression comes from source, otherwise it will be applied when
1040 -- value is assigned to source entity. This is not done in GNATprove
1041 -- mode, as GNATprove handles invariant checks itself.
1043 if Nkind
(Lhs
) = N_Type_Conversion
1044 and then Has_Invariants
(Etype
(Expression
(Lhs
)))
1045 and then Comes_From_Source
(Expression
(Lhs
))
1046 and then not GNATprove_Mode
1048 Insert_After
(N
, Make_Invariant_Call
(Expression
(Lhs
)));
1051 -- Final step. If left side is an entity, then we may be able to reset
1052 -- the current tracked values to new safe values. We only have something
1053 -- to do if the left side is an entity name, and expansion has not
1054 -- modified the node into something other than an assignment, and of
1055 -- course we only capture values if it is safe to do so.
1057 if Is_Entity_Name
(Lhs
)
1058 and then Nkind
(N
) = N_Assignment_Statement
1061 Ent
: constant Entity_Id
:= Entity
(Lhs
);
1064 if Safe_To_Capture_Value
(N
, Ent
) then
1066 -- If simple variable on left side, warn if this assignment
1067 -- blots out another one (rendering it useless). We only do
1068 -- this for source assignments, otherwise we can generate bogus
1069 -- warnings when an assignment is rewritten as another
1070 -- assignment, and gets tied up with itself.
1072 -- We also omit the warning if the RHS includes target names,
1073 -- that is to say the Ada 2022 "@" that denotes an instance of
1074 -- the LHS, which indicates that the current value is being
1075 -- used. Note that this implicit reference to the entity on
1076 -- the RHS is not treated as a source reference.
1078 -- There may have been a previous reference to a component of
1079 -- the variable, which in general removes the Last_Assignment
1080 -- field of the variable to indicate a relevant use of the
1081 -- previous assignment.
1083 if Warn_On_Modified_Unread
1084 and then Is_Assignable
(Ent
)
1085 and then Comes_From_Source
(N
)
1086 and then In_Extended_Main_Source_Unit
(Ent
)
1087 and then not Has_Target_Names
(N
)
1089 Warn_On_Useless_Assignment
(Ent
, N
);
1092 -- If we are assigning an access type and the left side is an
1093 -- entity, then make sure that the Is_Known_[Non_]Null flags
1094 -- properly reflect the state of the entity after assignment.
1096 if Is_Access_Type
(T1
) then
1097 if Known_Non_Null
(Rhs
) then
1098 Set_Is_Known_Non_Null
(Ent
, True);
1100 elsif Known_Null
(Rhs
)
1101 and then not Can_Never_Be_Null
(Ent
)
1103 Set_Is_Known_Null
(Ent
, True);
1106 Set_Is_Known_Null
(Ent
, False);
1108 if not Can_Never_Be_Null
(Ent
) then
1109 Set_Is_Known_Non_Null
(Ent
, False);
1113 -- For discrete types, we may be able to set the current value
1114 -- if the value is known at compile time.
1116 elsif Is_Discrete_Type
(T1
)
1117 and then Compile_Time_Known_Value
(Rhs
)
1119 Set_Current_Value
(Ent
, Rhs
);
1121 Set_Current_Value
(Ent
, Empty
);
1124 -- If not safe to capture values, kill them
1132 -- If assigning to an object in whole or in part, note location of
1133 -- assignment in case no one references value. We only do this for
1134 -- source assignments, otherwise we can generate bogus warnings when an
1135 -- assignment is rewritten as another assignment, and gets tied up with
1139 Ent
: constant Entity_Id
:= Get_Enclosing_Object
(Lhs
);
1142 and then Safe_To_Capture_Value
(N
, Ent
)
1143 and then Nkind
(N
) = N_Assignment_Statement
1144 and then Warn_On_Modified_Unread
1145 and then Is_Assignable
(Ent
)
1146 and then Comes_From_Source
(N
)
1147 and then In_Extended_Main_Source_Unit
(Ent
)
1149 Set_Last_Assignment
(Ent
, Lhs
);
1153 Analyze_Dimension
(N
);
1156 Restore_Ghost_Region
(Saved_GM
, Saved_IGR
);
1158 -- If the right-hand side contains target names, expansion has been
1159 -- disabled to prevent expansion that might move target names out of
1160 -- the context of the assignment statement. Restore the expander mode
1161 -- now so that assignment statement can be properly expanded.
1163 if Nkind
(N
) = N_Assignment_Statement
then
1164 if Has_Target_Names
(N
) then
1165 Expander_Mode_Restore
;
1166 Full_Analysis
:= Save_Full_Analysis
;
1167 Current_Assignment
:= Empty
;
1170 end Analyze_Assignment
;
1172 -----------------------------
1173 -- Analyze_Block_Statement --
1174 -----------------------------
1176 procedure Analyze_Block_Statement
(N
: Node_Id
) is
1177 procedure Install_Return_Entities
(Scop
: Entity_Id
);
1178 -- Install all entities of return statement scope Scop in the visibility
1179 -- chain except for the return object since its entity is reused in a
1182 -----------------------------
1183 -- Install_Return_Entities --
1184 -----------------------------
1186 procedure Install_Return_Entities
(Scop
: Entity_Id
) is
1190 Id
:= First_Entity
(Scop
);
1191 while Present
(Id
) loop
1193 -- Do not install the return object
1195 if Ekind
(Id
) not in E_Constant | E_Variable
1196 or else not Is_Return_Object
(Id
)
1198 Install_Entity
(Id
);
1203 end Install_Return_Entities
;
1205 -- Local constants and variables
1207 Decls
: constant List_Id
:= Declarations
(N
);
1208 Id
: constant Node_Id
:= Identifier
(N
);
1209 HSS
: constant Node_Id
:= Handled_Statement_Sequence
(N
);
1211 Is_BIP_Return_Statement
: Boolean;
1213 -- Start of processing for Analyze_Block_Statement
1216 -- If no handled statement sequence is present, things are really messed
1217 -- up, and we just return immediately (defence against previous errors).
1220 Check_Error_Detected
;
1224 -- Detect whether the block is actually a rewritten return statement of
1225 -- a build-in-place function.
1227 Is_BIP_Return_Statement
:=
1229 and then Present
(Entity
(Id
))
1230 and then Ekind
(Entity
(Id
)) = E_Return_Statement
1231 and then Is_Build_In_Place_Function
1232 (Return_Applies_To
(Entity
(Id
)));
1234 -- Normal processing with HSS present
1237 EH
: constant List_Id
:= Exception_Handlers
(HSS
);
1238 Ent
: Entity_Id
:= Empty
;
1241 Save_Unblocked_Exit_Count
: constant Nat
:= Unblocked_Exit_Count
;
1242 -- Recursively save value of this global, will be restored on exit
1245 -- Initialize unblocked exit count for statements of begin block
1246 -- plus one for each exception handler that is present.
1248 Unblocked_Exit_Count
:= 1 + List_Length
(EH
);
1250 -- If a label is present analyze it and mark it as referenced
1252 if Present
(Id
) then
1256 -- An error defense. If we have an identifier, but no entity, then
1257 -- something is wrong. If previous errors, then just remove the
1258 -- identifier and continue, otherwise raise an exception.
1261 Check_Error_Detected
;
1262 Set_Identifier
(N
, Empty
);
1265 if Ekind
(Ent
) = E_Label
then
1266 Reinit_Field_To_Zero
(Ent
, F_Enclosing_Scope
);
1269 Mutate_Ekind
(Ent
, E_Block
);
1270 Generate_Reference
(Ent
, N
, ' ');
1271 Generate_Definition
(Ent
);
1273 if Nkind
(Parent
(Ent
)) = N_Implicit_Label_Declaration
then
1274 Set_Label_Construct
(Parent
(Ent
), N
);
1279 -- If no entity set, create a label entity
1282 Ent
:= New_Internal_Entity
(E_Block
, Current_Scope
, Sloc
(N
), 'B');
1283 Set_Identifier
(N
, New_Occurrence_Of
(Ent
, Sloc
(N
)));
1284 Set_Parent
(Ent
, N
);
1287 Set_Etype
(Ent
, Standard_Void_Type
);
1288 Set_Block_Node
(Ent
, Identifier
(N
));
1291 -- The block served as an extended return statement. Ensure that any
1292 -- entities created during the analysis and expansion of the return
1293 -- object declaration are once again visible.
1295 if Is_BIP_Return_Statement
then
1296 Install_Return_Entities
(Ent
);
1299 if Present
(Decls
) then
1300 Analyze_Declarations
(Decls
);
1302 Inspect_Deferred_Constant_Completion
(Decls
);
1306 Process_End_Label
(HSS
, 'e', Ent
);
1308 -- If exception handlers are present, then we indicate that enclosing
1309 -- scopes contain a block with handlers. We only need to mark non-
1312 if Present
(EH
) then
1315 Set_Has_Nested_Block_With_Handler
(S
);
1316 exit when Is_Overloadable
(S
)
1317 or else Ekind
(S
) = E_Package
1318 or else Is_Generic_Unit
(S
);
1323 Check_References
(Ent
);
1324 Update_Use_Clause_Chain
;
1327 if Unblocked_Exit_Count
= 0 then
1328 Unblocked_Exit_Count
:= Save_Unblocked_Exit_Count
;
1329 Check_Unreachable_Code
(N
);
1331 Unblocked_Exit_Count
:= Save_Unblocked_Exit_Count
;
1334 end Analyze_Block_Statement
;
1336 --------------------------------
1337 -- Analyze_Compound_Statement --
1338 --------------------------------
1340 procedure Analyze_Compound_Statement
(N
: Node_Id
) is
1342 Analyze_List
(Actions
(N
));
1343 end Analyze_Compound_Statement
;
1345 ----------------------------
1346 -- Analyze_Case_Statement --
1347 ----------------------------
1349 procedure Analyze_Case_Statement
(N
: Node_Id
) is
1350 Exp
: constant Node_Id
:= Expression
(N
);
1352 Statements_Analyzed
: Boolean := False;
1353 -- Set True if at least some statement sequences get analyzed. If False
1354 -- on exit, means we had a serious error that prevented full analysis of
1355 -- the case statement, and as a result it is not a good idea to output
1356 -- warning messages about unreachable code.
1358 Is_General_Case_Statement
: Boolean := False;
1359 -- Set True (later) if type of case expression is not discrete
1361 procedure Non_Static_Choice_Error
(Choice
: Node_Id
);
1362 -- Error routine invoked by the generic instantiation below when the
1363 -- case statement has a non static choice.
1365 procedure Process_Statements
(Alternative
: Node_Id
);
1366 -- Analyzes the statements associated with a case alternative. Needed
1367 -- by instantiation below.
1369 package Analyze_Case_Choices
is new
1370 Generic_Analyze_Choices
1371 (Process_Associated_Node
=> Process_Statements
);
1372 use Analyze_Case_Choices
;
1373 -- Instantiation of the generic choice analysis package
1375 package Check_Case_Choices
is new
1376 Generic_Check_Choices
1377 (Process_Empty_Choice
=> No_OP
,
1378 Process_Non_Static_Choice
=> Non_Static_Choice_Error
,
1379 Process_Associated_Node
=> No_OP
);
1380 use Check_Case_Choices
;
1381 -- Instantiation of the generic choice processing package
1383 -----------------------------
1384 -- Non_Static_Choice_Error --
1385 -----------------------------
1387 procedure Non_Static_Choice_Error
(Choice
: Node_Id
) is
1389 Flag_Non_Static_Expr
1390 ("choice given in case statement is not static!", Choice
);
1391 end Non_Static_Choice_Error
;
1393 ------------------------
1394 -- Process_Statements --
1395 ------------------------
1397 procedure Process_Statements
(Alternative
: Node_Id
) is
1398 Choices
: constant List_Id
:= Discrete_Choices
(Alternative
);
1402 if Is_General_Case_Statement
then
1404 -- Processing deferred in this case; decls associated with
1405 -- pattern match bindings don't exist yet.
1408 Unblocked_Exit_Count
:= Unblocked_Exit_Count
+ 1;
1409 Statements_Analyzed
:= True;
1411 -- An interesting optimization. If the case statement expression
1412 -- is a simple entity, then we can set the current value within an
1413 -- alternative if the alternative has one possible value.
1417 -- when 2 | 3 => beta
1418 -- when others => gamma
1420 -- Here we know that N is initially 1 within alpha, but for beta and
1421 -- gamma, we do not know anything more about the initial value.
1423 if Is_Entity_Name
(Exp
) then
1424 Ent
:= Entity
(Exp
);
1426 if Is_Object
(Ent
) then
1427 if List_Length
(Choices
) = 1
1428 and then Nkind
(First
(Choices
)) in N_Subexpr
1429 and then Compile_Time_Known_Value
(First
(Choices
))
1431 Set_Current_Value
(Entity
(Exp
), First
(Choices
));
1434 Analyze_Statements
(Statements
(Alternative
));
1436 -- After analyzing the case, set the current value to empty
1437 -- since we won't know what it is for the next alternative
1438 -- (unless reset by this same circuit), or after the case.
1440 Set_Current_Value
(Entity
(Exp
), Empty
);
1445 -- Case where expression is not an entity name of an object
1447 Analyze_Statements
(Statements
(Alternative
));
1448 end Process_Statements
;
1452 Exp_Type
: Entity_Id
;
1453 Exp_Btype
: Entity_Id
;
1455 Others_Present
: Boolean;
1456 -- Indicates if Others was present
1458 Save_Unblocked_Exit_Count
: constant Nat
:= Unblocked_Exit_Count
;
1459 -- Recursively save value of this global, will be restored on exit
1461 -- Start of processing for Analyze_Case_Statement
1466 -- The expression must be of any discrete type. In rare cases, the
1467 -- expander constructs a case statement whose expression has a private
1468 -- type whose full view is discrete. This can happen when generating
1469 -- a stream operation for a variant type after the type is frozen,
1470 -- when the partial of view of the type of the discriminant is private.
1471 -- In that case, use the full view to analyze case alternatives.
1473 if not Is_Overloaded
(Exp
)
1474 and then not Comes_From_Source
(N
)
1475 and then Is_Private_Type
(Etype
(Exp
))
1476 and then Present
(Full_View
(Etype
(Exp
)))
1477 and then Is_Discrete_Type
(Full_View
(Etype
(Exp
)))
1480 Exp_Type
:= Full_View
(Etype
(Exp
));
1482 -- For Ada, overloading might be ok because subsequently filtering
1483 -- out non-discretes may resolve the ambiguity.
1484 -- But GNAT extensions allow casing on non-discretes.
1486 elsif All_Extensions_Allowed
and then Is_Overloaded
(Exp
) then
1488 -- It would be nice if we could generate all the right error
1489 -- messages by calling "Resolve (Exp, Any_Type);" in the
1490 -- same way that they are generated a few lines below by the
1491 -- call "Analyze_And_Resolve (Exp, Any_Discrete);".
1492 -- Unfortunately, Any_Type and Any_Discrete are not treated
1493 -- consistently (specifically, by Sem_Type.Covers), so that
1497 ("selecting expression of general case statement is ambiguous",
1501 -- Check for a GNAT-extension "general" case statement (i.e., one where
1502 -- the type of the selecting expression is not discrete).
1504 elsif All_Extensions_Allowed
1505 and then not Is_Discrete_Type
(Etype
(Exp
))
1507 Resolve
(Exp
, Etype
(Exp
));
1508 Exp_Type
:= Etype
(Exp
);
1509 Is_General_Case_Statement
:= True;
1510 if not (Is_Record_Type
(Exp_Type
) or Is_Array_Type
(Exp_Type
)) then
1512 ("selecting expression of general case statement " &
1513 "must be a record or an array",
1516 -- Avoid cascading errors
1520 Analyze_And_Resolve
(Exp
, Any_Discrete
);
1521 Exp_Type
:= Etype
(Exp
);
1524 Check_Unset_Reference
(Exp
);
1525 Exp_Btype
:= Base_Type
(Exp_Type
);
1527 -- The expression must be of a discrete type which must be determinable
1528 -- independently of the context in which the expression occurs, but
1529 -- using the fact that the expression must be of a discrete type.
1530 -- Moreover, the type this expression must not be a character literal
1531 -- (which is always ambiguous) or, for Ada-83, a generic formal type.
1533 -- If error already reported by Resolve, nothing more to do
1535 if Exp_Btype
= Any_Discrete
or else Exp_Btype
= Any_Type
then
1538 elsif Exp_Btype
= Any_Character
then
1540 ("character literal as case expression is ambiguous", Exp
);
1543 elsif Ada_Version
= Ada_83
1544 and then (Is_Generic_Type
(Exp_Btype
)
1545 or else Is_Generic_Type
(Root_Type
(Exp_Btype
)))
1548 ("(Ada 83) case expression cannot be of a generic type", Exp
);
1551 elsif not All_Extensions_Allowed
1552 and then not Is_Discrete_Type
(Exp_Type
)
1555 ("expression in case statement must be of a discrete_Type", Exp
);
1559 -- If the case expression is a formal object of mode in out, then treat
1560 -- it as having a nonstatic subtype by forcing use of the base type
1561 -- (which has to get passed to Check_Case_Choices below). Also use base
1562 -- type when the case expression is parenthesized.
1564 if Paren_Count
(Exp
) > 0
1565 or else (Is_Entity_Name
(Exp
)
1566 and then Ekind
(Entity
(Exp
)) = E_Generic_In_Out_Parameter
)
1568 Exp_Type
:= Exp_Btype
;
1571 -- Call instantiated procedures to analyze and check discrete choices
1573 Unblocked_Exit_Count
:= 0;
1575 Analyze_Choices
(Alternatives
(N
), Exp_Type
);
1576 Check_Choices
(N
, Alternatives
(N
), Exp_Type
, Others_Present
);
1578 if Is_General_Case_Statement
then
1579 -- Work normally done in Process_Statements was deferred; do that
1580 -- deferred work now that Check_Choices has had a chance to create
1581 -- any needed pattern-match-binding declarations.
1583 Alt
: Node_Id
:= First
(Alternatives
(N
));
1585 while Present
(Alt
) loop
1586 Unblocked_Exit_Count
:= Unblocked_Exit_Count
+ 1;
1587 Analyze_Statements
(Statements
(Alt
));
1593 if Exp_Type
= Universal_Integer
and then not Others_Present
then
1594 Error_Msg_N
("case on universal integer requires OTHERS choice", Exp
);
1597 -- If all our exits were blocked by unconditional transfers of control,
1598 -- then the entire CASE statement acts as an unconditional transfer of
1599 -- control, so treat it like one, and check unreachable code. Skip this
1600 -- test if we had serious errors preventing any statement analysis.
1602 if Unblocked_Exit_Count
= 0 and then Statements_Analyzed
then
1603 Unblocked_Exit_Count
:= Save_Unblocked_Exit_Count
;
1604 Check_Unreachable_Code
(N
);
1606 Unblocked_Exit_Count
:= Save_Unblocked_Exit_Count
;
1609 -- If the expander is active it will detect the case of a statically
1610 -- determined single alternative and remove warnings for the case, but
1611 -- if we are not doing expansion, that circuit won't be active. Here we
1612 -- duplicate the effect of removing warnings in the same way, so that
1613 -- we will get the same set of warnings in -gnatc mode.
1615 if not Expander_Active
1616 and then Compile_Time_Known_Value
(Expression
(N
))
1617 and then Serious_Errors_Detected
= 0
1620 Chosen
: constant Node_Id
:= Find_Static_Alternative
(N
);
1624 Alt
:= First
(Alternatives
(N
));
1625 while Present
(Alt
) loop
1626 if Alt
/= Chosen
then
1627 Remove_Warning_Messages
(Statements
(Alt
));
1634 end Analyze_Case_Statement
;
1636 ----------------------------
1637 -- Analyze_Exit_Statement --
1638 ----------------------------
1640 -- If the exit includes a name, it must be the name of a currently open
1641 -- loop. Otherwise there must be an innermost open loop on the stack, to
1642 -- which the statement implicitly refers.
1644 -- Additionally, in SPARK mode:
1646 -- The exit can only name the closest enclosing loop;
1648 -- An exit with a when clause must be directly contained in a loop;
1650 -- An exit without a when clause must be directly contained in an
1651 -- if-statement with no elsif or else, which is itself directly contained
1652 -- in a loop. The exit must be the last statement in the if-statement.
1654 procedure Analyze_Exit_Statement
(N
: Node_Id
) is
1655 Target
: constant Node_Id
:= Name
(N
);
1656 Cond
: constant Node_Id
:= Condition
(N
);
1657 Scope_Id
: Entity_Id
:= Empty
; -- initialize to prevent warning
1663 Check_Unreachable_Code
(N
);
1666 if Present
(Target
) then
1668 U_Name
:= Entity
(Target
);
1670 if not In_Open_Scopes
(U_Name
) or else Ekind
(U_Name
) /= E_Loop
then
1671 Error_Msg_N
("invalid loop name in exit statement", N
);
1675 Set_Has_Exit
(U_Name
);
1682 for J
in reverse 0 .. Scope_Stack
.Last
loop
1683 Scope_Id
:= Scope_Stack
.Table
(J
).Entity
;
1684 Kind
:= Ekind
(Scope_Id
);
1686 if Kind
= E_Loop
and then (No
(Target
) or else Scope_Id
= U_Name
) then
1687 Set_Has_Exit
(Scope_Id
);
1690 elsif Kind
= E_Block
1691 or else Kind
= E_Loop
1692 or else Kind
= E_Return_Statement
1698 ("cannot exit from program unit or accept statement", N
);
1703 -- Verify that if present the condition is a Boolean expression
1705 if Present
(Cond
) then
1706 Analyze_And_Resolve
(Cond
, Any_Boolean
);
1707 Check_Unset_Reference
(Cond
);
1710 -- Chain exit statement to associated loop entity
1712 Set_Next_Exit_Statement
(N
, First_Exit_Statement
(Scope_Id
));
1713 Set_First_Exit_Statement
(Scope_Id
, N
);
1715 -- Since the exit may take us out of a loop, any previous assignment
1716 -- statement is not useless, so clear last assignment indications. It
1717 -- is OK to keep other current values, since if the exit statement
1718 -- does not exit, then the current values are still valid.
1720 Kill_Current_Values
(Last_Assignment_Only
=> True);
1721 end Analyze_Exit_Statement
;
1723 ----------------------------
1724 -- Analyze_Goto_Statement --
1725 ----------------------------
1727 procedure Analyze_Goto_Statement
(N
: Node_Id
) is
1728 Label
: constant Node_Id
:= Name
(N
);
1729 Scope_Id
: Entity_Id
;
1730 Label_Scope
: Entity_Id
;
1731 Label_Ent
: Entity_Id
;
1734 -- Actual semantic checks
1736 Check_Unreachable_Code
(N
);
1737 Kill_Current_Values
(Last_Assignment_Only
=> True);
1740 Label_Ent
:= Entity
(Label
);
1742 -- Ignore previous error
1744 if Label_Ent
= Any_Id
then
1745 Check_Error_Detected
;
1748 -- We just have a label as the target of a goto
1750 elsif Ekind
(Label_Ent
) /= E_Label
then
1751 Error_Msg_N
("target of goto statement must be a label", Label
);
1754 -- Check that the target of the goto is reachable according to Ada
1755 -- scoping rules. Note: the special gotos we generate for optimizing
1756 -- local handling of exceptions would violate these rules, but we mark
1757 -- such gotos as analyzed when built, so this code is never entered.
1759 elsif not Reachable
(Label_Ent
) then
1760 Error_Msg_N
("target of goto statement is not reachable", Label
);
1764 -- Here if goto passes initial validity checks
1766 Label_Scope
:= Enclosing_Scope
(Label_Ent
);
1768 for J
in reverse 0 .. Scope_Stack
.Last
loop
1769 Scope_Id
:= Scope_Stack
.Table
(J
).Entity
;
1771 if Label_Scope
= Scope_Id
1772 or else Ekind
(Scope_Id
) not in
1773 E_Block | E_Loop | E_Return_Statement
1775 if Scope_Id
/= Label_Scope
then
1777 ("cannot exit from program unit or accept statement", N
);
1784 raise Program_Error
;
1785 end Analyze_Goto_Statement
;
1787 ---------------------------------
1788 -- Analyze_Goto_When_Statement --
1789 ---------------------------------
1791 procedure Analyze_Goto_When_Statement
(N
: Node_Id
) is
1793 -- Verify the condition is a Boolean expression
1795 Analyze_And_Resolve
(Condition
(N
), Any_Boolean
);
1796 Check_Unset_Reference
(Condition
(N
));
1797 end Analyze_Goto_When_Statement
;
1799 --------------------------
1800 -- Analyze_If_Statement --
1801 --------------------------
1803 -- A special complication arises in the analysis of if statements
1805 -- The expander has circuitry to completely delete code that it can tell
1806 -- will not be executed (as a result of compile time known conditions). In
1807 -- the analyzer, we ensure that code that will be deleted in this manner
1808 -- is analyzed but not expanded. This is obviously more efficient, but
1809 -- more significantly, difficulties arise if code is expanded and then
1810 -- eliminated (e.g. exception table entries disappear). Similarly, itypes
1811 -- generated in deleted code must be frozen from start, because the nodes
1812 -- on which they depend will not be available at the freeze point.
1814 procedure Analyze_If_Statement
(N
: Node_Id
) is
1815 Save_Unblocked_Exit_Count
: constant Nat
:= Unblocked_Exit_Count
;
1816 -- Recursively save value of this global, will be restored on exit
1818 Save_In_Deleted_Code
: Boolean := In_Deleted_Code
;
1820 Del
: Boolean := False;
1821 -- This flag gets set True if a True condition has been found, which
1822 -- means that remaining ELSE/ELSIF parts are deleted.
1824 procedure Analyze_Cond_Then
(Cnode
: Node_Id
);
1825 -- This is applied to either the N_If_Statement node itself or to an
1826 -- N_Elsif_Part node. It deals with analyzing the condition and the THEN
1827 -- statements associated with it.
1829 -----------------------
1830 -- Analyze_Cond_Then --
1831 -----------------------
1833 procedure Analyze_Cond_Then
(Cnode
: Node_Id
) is
1834 Cond
: constant Node_Id
:= Condition
(Cnode
);
1835 Tstm
: constant List_Id
:= Then_Statements
(Cnode
);
1838 Unblocked_Exit_Count
:= Unblocked_Exit_Count
+ 1;
1839 Analyze_And_Resolve
(Cond
, Any_Boolean
);
1840 Check_Unset_Reference
(Cond
);
1841 Set_Current_Value_Condition
(Cnode
);
1843 -- If already deleting, then just analyze then statements
1846 Analyze_Statements
(Tstm
);
1848 -- Compile time known value, not deleting yet
1850 elsif Compile_Time_Known_Value
(Cond
) then
1851 Save_In_Deleted_Code
:= In_Deleted_Code
;
1853 -- If condition is True, then analyze the THEN statements and set
1854 -- no expansion for ELSE and ELSIF parts.
1856 if Is_True
(Expr_Value
(Cond
)) then
1857 Analyze_Statements
(Tstm
);
1859 Expander_Mode_Save_And_Set
(False);
1860 In_Deleted_Code
:= True;
1862 -- If condition is False, analyze THEN with expansion off
1864 else pragma Assert
(Is_False
(Expr_Value
(Cond
)));
1865 Expander_Mode_Save_And_Set
(False);
1866 In_Deleted_Code
:= True;
1867 Analyze_Statements
(Tstm
);
1868 Expander_Mode_Restore
;
1869 In_Deleted_Code
:= Save_In_Deleted_Code
;
1872 -- Not known at compile time, not deleting, normal analysis
1875 Analyze_Statements
(Tstm
);
1877 end Analyze_Cond_Then
;
1882 -- For iterating over elsif parts
1884 -- Start of processing for Analyze_If_Statement
1887 -- Initialize exit count for else statements. If there is no else part,
1888 -- this count will stay non-zero reflecting the fact that the uncovered
1889 -- else case is an unblocked exit.
1891 Unblocked_Exit_Count
:= 1;
1892 Analyze_Cond_Then
(N
);
1894 -- Now to analyze the elsif parts if any are present
1896 E
:= First
(Elsif_Parts
(N
));
1897 while Present
(E
) loop
1898 Analyze_Cond_Then
(E
);
1902 if Present
(Else_Statements
(N
)) then
1903 Analyze_Statements
(Else_Statements
(N
));
1906 -- If all our exits were blocked by unconditional transfers of control,
1907 -- then the entire IF statement acts as an unconditional transfer of
1908 -- control, so treat it like one, and check unreachable code.
1910 if Unblocked_Exit_Count
= 0 then
1911 Unblocked_Exit_Count
:= Save_Unblocked_Exit_Count
;
1912 Check_Unreachable_Code
(N
);
1914 Unblocked_Exit_Count
:= Save_Unblocked_Exit_Count
;
1918 Expander_Mode_Restore
;
1919 In_Deleted_Code
:= Save_In_Deleted_Code
;
1922 if not Expander_Active
1923 and then Compile_Time_Known_Value
(Condition
(N
))
1924 and then Serious_Errors_Detected
= 0
1926 if Is_True
(Expr_Value
(Condition
(N
))) then
1927 Remove_Warning_Messages
(Else_Statements
(N
));
1929 E
:= First
(Elsif_Parts
(N
));
1930 while Present
(E
) loop
1931 Remove_Warning_Messages
(Then_Statements
(E
));
1936 Remove_Warning_Messages
(Then_Statements
(N
));
1940 -- Warn on redundant if statement that has no effect
1942 -- Note, we could also check empty ELSIF parts ???
1944 if Warn_On_Redundant_Constructs
1946 -- If statement must be from source
1948 and then Comes_From_Source
(N
)
1950 -- Condition must not have obvious side effect
1952 and then Has_No_Obvious_Side_Effects
(Condition
(N
))
1954 -- No elsif parts of else part
1956 and then No
(Elsif_Parts
(N
))
1957 and then No
(Else_Statements
(N
))
1959 -- Then must be a single null statement
1961 and then List_Length
(Then_Statements
(N
)) = 1
1963 -- Go to original node, since we may have rewritten something as
1964 -- a null statement (e.g. a case we could figure the outcome of).
1967 T
: constant Node_Id
:= First
(Then_Statements
(N
));
1968 S
: constant Node_Id
:= Original_Node
(T
);
1971 if Comes_From_Source
(S
) and then Nkind
(S
) = N_Null_Statement
then
1972 Error_Msg_N
("if statement has no effect?r?", N
);
1976 end Analyze_If_Statement
;
1978 ----------------------------------------
1979 -- Analyze_Implicit_Label_Declaration --
1980 ----------------------------------------
1982 -- An implicit label declaration is generated in the innermost enclosing
1983 -- declarative part. This is done for labels, and block and loop names.
1985 procedure Analyze_Implicit_Label_Declaration
(N
: Node_Id
) is
1986 Id
: constant Node_Id
:= Defining_Identifier
(N
);
1989 Mutate_Ekind
(Id
, E_Label
);
1990 Set_Etype
(Id
, Standard_Void_Type
);
1991 Set_Enclosing_Scope
(Id
, Current_Scope
);
1993 -- A label declared within a Ghost region becomes Ghost (SPARK RM
1996 if Ghost_Mode
> None
then
1997 Set_Is_Ghost_Entity
(Id
);
1999 end Analyze_Implicit_Label_Declaration
;
2001 ------------------------------
2002 -- Analyze_Iteration_Scheme --
2003 ------------------------------
2005 procedure Analyze_Iteration_Scheme
(N
: Node_Id
) is
2007 Iter_Spec
: Node_Id
;
2008 Loop_Spec
: Node_Id
;
2011 -- For an infinite loop, there is no iteration scheme
2017 Cond
:= Condition
(N
);
2018 Iter_Spec
:= Iterator_Specification
(N
);
2019 Loop_Spec
:= Loop_Parameter_Specification
(N
);
2021 if Present
(Cond
) then
2022 Analyze_And_Resolve
(Cond
, Any_Boolean
);
2023 Check_Unset_Reference
(Cond
);
2024 Set_Current_Value_Condition
(N
);
2026 elsif Present
(Iter_Spec
) then
2027 Analyze_Iterator_Specification
(Iter_Spec
);
2030 Analyze_Loop_Parameter_Specification
(Loop_Spec
);
2032 end Analyze_Iteration_Scheme
;
2034 ------------------------------------
2035 -- Analyze_Iterator_Specification --
2036 ------------------------------------
2038 procedure Analyze_Iterator_Specification
(N
: Node_Id
) is
2039 Def_Id
: constant Node_Id
:= Defining_Identifier
(N
);
2040 Iter_Name
: constant Node_Id
:= Name
(N
);
2041 Loc
: constant Source_Ptr
:= Sloc
(N
);
2042 Subt
: constant Node_Id
:= Subtype_Indication
(N
);
2044 Bas
: Entity_Id
:= Empty
; -- initialize to prevent warning
2047 procedure Check_Reverse_Iteration
(Typ
: Entity_Id
);
2048 -- For an iteration over a container, if the loop carries the Reverse
2049 -- indicator, verify that the container type has an Iterate aspect that
2050 -- implements the reversible iterator interface.
2052 procedure Check_Subtype_Definition
(Comp_Type
: Entity_Id
);
2053 -- If a subtype indication is present, verify that it is consistent
2054 -- with the component type of the array or container name.
2055 -- In Ada 2022, the subtype indication may be an access definition,
2056 -- if the array or container has elements of an anonymous access type.
2058 function Get_Cursor_Type
(Typ
: Entity_Id
) return Entity_Id
;
2059 -- For containers with Iterator and related aspects, the cursor is
2060 -- obtained by locating an entity with the proper name in the scope
2063 -----------------------------
2064 -- Check_Reverse_Iteration --
2065 -----------------------------
2067 procedure Check_Reverse_Iteration
(Typ
: Entity_Id
) is
2069 if Reverse_Present
(N
) then
2070 if Is_Array_Type
(Typ
)
2071 or else Is_Reversible_Iterator
(Typ
)
2073 (Has_Aspect
(Typ
, Aspect_Iterable
)
2076 (Get_Iterable_Type_Primitive
(Typ
, Name_Previous
)))
2081 ("container type does not support reverse iteration", N
);
2084 end Check_Reverse_Iteration
;
2086 -------------------------------
2087 -- Check_Subtype_Definition --
2088 -------------------------------
2090 procedure Check_Subtype_Definition
(Comp_Type
: Entity_Id
) is
2096 if Is_Anonymous_Access_Type
(Entity
(Subt
)) then
2097 if not Is_Anonymous_Access_Type
(Comp_Type
) then
2099 ("component type& is not an anonymous access",
2102 elsif not Conforming_Types
2103 (Designated_Type
(Entity
(Subt
)),
2104 Designated_Type
(Comp_Type
),
2108 ("subtype indication does not match component type&",
2112 elsif not Covers
(Base_Type
(Bas
), Comp_Type
)
2113 or else not Subtypes_Statically_Match
(Bas
, Comp_Type
)
2115 if Is_Array_Type
(Typ
) then
2117 ("subtype indication does not match component type&",
2121 ("subtype indication does not match element type&",
2125 end Check_Subtype_Definition
;
2127 ---------------------
2128 -- Get_Cursor_Type --
2129 ---------------------
2131 function Get_Cursor_Type
(Typ
: Entity_Id
) return Entity_Id
is
2135 -- If the iterator type is derived and it has an iterator interface
2136 -- type as an ancestor, then the cursor type is declared in the scope
2137 -- of that interface type.
2139 if Is_Derived_Type
(Typ
) then
2141 Iter_Iface
: constant Entity_Id
:=
2142 Iterator_Interface_Ancestor
(Typ
);
2145 if Present
(Iter_Iface
) then
2146 Ent
:= First_Entity
(Scope
(Iter_Iface
));
2148 -- If there's not an iterator interface, then retrieve the
2149 -- scope associated with the parent type and start from its
2153 Ent
:= First_Entity
(Scope
(Etype
(Typ
)));
2158 Ent
:= First_Entity
(Scope
(Typ
));
2161 while Present
(Ent
) loop
2162 exit when Chars
(Ent
) = Name_Cursor
;
2170 -- The cursor is the target of generated assignments in the
2171 -- loop, and cannot have a limited type.
2173 if Is_Limited_Type
(Etype
(Ent
)) then
2174 Error_Msg_N
("cursor type cannot be limited", N
);
2178 end Get_Cursor_Type
;
2180 -- Start of processing for Analyze_Iterator_Specification
2183 Enter_Name
(Def_Id
);
2185 -- AI12-0151 specifies that when the subtype indication is present, it
2186 -- must statically match the type of the array or container element.
2187 -- To simplify this check, we introduce a subtype declaration with the
2188 -- given subtype indication when it carries a constraint, and rewrite
2189 -- the original as a reference to the created subtype entity.
2191 if Present
(Subt
) then
2192 if Nkind
(Subt
) = N_Subtype_Indication
then
2194 S
: constant Entity_Id
:= Make_Temporary
(Sloc
(Subt
), 'S');
2195 Decl
: constant Node_Id
:=
2196 Make_Subtype_Declaration
(Loc
,
2197 Defining_Identifier
=> S
,
2198 Subtype_Indication
=> New_Copy_Tree
(Subt
));
2200 Insert_Action
(N
, Decl
);
2202 Rewrite
(Subt
, New_Occurrence_Of
(S
, Sloc
(Subt
)));
2205 -- Ada 2022: the subtype definition may be for an anonymous
2208 elsif Nkind
(Subt
) = N_Access_Definition
then
2210 S
: constant Entity_Id
:= Make_Temporary
(Sloc
(Subt
), 'S');
2213 if Present
(Subtype_Mark
(Subt
)) then
2215 Make_Full_Type_Declaration
(Loc
,
2216 Defining_Identifier
=> S
,
2218 Make_Access_To_Object_Definition
(Loc
,
2219 All_Present
=> True,
2220 Subtype_Indication
=>
2221 New_Copy_Tree
(Subtype_Mark
(Subt
))));
2225 Make_Full_Type_Declaration
(Loc
,
2226 Defining_Identifier
=> S
,
2229 (Access_To_Subprogram_Definition
(Subt
)));
2232 Insert_Before
(Parent
(Parent
(N
)), Decl
);
2234 Freeze_Before
(First
(Statements
(Parent
(Parent
(N
)))), S
);
2235 Rewrite
(Subt
, New_Occurrence_Of
(S
, Sloc
(Subt
)));
2241 -- Save entity of subtype indication for subsequent check
2243 Bas
:= Entity
(Subt
);
2246 Preanalyze_Range
(Iter_Name
);
2248 -- If the domain of iteration is a function call, make sure the function
2249 -- itself is frozen. This is an issue if this is a local expression
2252 if Nkind
(Iter_Name
) = N_Function_Call
2253 and then Is_Entity_Name
(Name
(Iter_Name
))
2254 and then Full_Analysis
2255 and then (In_Assertion_Expr
= 0 or else Assertions_Enabled
)
2257 Freeze_Before
(N
, Entity
(Name
(Iter_Name
)));
2260 -- Set the kind of the loop variable, which is not visible within the
2263 Mutate_Ekind
(Def_Id
, E_Variable
);
2264 Set_Is_Not_Self_Hidden
(Def_Id
);
2266 -- Provide a link between the iterator variable and the container, for
2267 -- subsequent use in cross-reference and modification information.
2269 if Of_Present
(N
) then
2270 Set_Related_Expression
(Def_Id
, Iter_Name
);
2272 -- For a container, the iterator is specified through the aspect
2274 if not Is_Array_Type
(Etype
(Iter_Name
)) then
2276 Iterator
: constant Entity_Id
:=
2277 Find_Value_Of_Aspect
2278 (Etype
(Iter_Name
), Aspect_Default_Iterator
);
2284 -- The domain of iteration must implement either the RM
2285 -- iterator interface, or the SPARK Iterable aspect.
2287 if No
(Iterator
) then
2288 if No
(Find_Aspect
(Etype
(Iter_Name
), Aspect_Iterable
)) then
2290 ("cannot iterate over&",
2291 N
, Base_Type
(Etype
(Iter_Name
)));
2295 elsif not Is_Overloaded
(Iterator
) then
2296 Check_Reverse_Iteration
(Etype
(Iterator
));
2298 -- If Iterator is overloaded, use reversible iterator if one is
2301 elsif Is_Overloaded
(Iterator
) then
2302 Get_First_Interp
(Iterator
, I
, It
);
2303 while Present
(It
.Nam
) loop
2304 if Ekind
(It
.Nam
) = E_Function
2305 and then Is_Reversible_Iterator
(Etype
(It
.Nam
))
2307 Set_Etype
(Iterator
, It
.Typ
);
2308 Set_Entity
(Iterator
, It
.Nam
);
2312 Get_Next_Interp
(I
, It
);
2315 Check_Reverse_Iteration
(Etype
(Iterator
));
2321 -- If the domain of iteration is an expression, create a declaration for
2322 -- it, so that finalization actions are introduced outside of the loop.
2323 -- The declaration must be a renaming (both in GNAT and GNATprove
2324 -- modes), because the body of the loop may assign to elements.
2326 if not Is_Entity_Name
(Iter_Name
)
2328 -- Do not perform this expansion in preanalysis
2330 and then Full_Analysis
2332 -- Do not perform this expansion when expansion is disabled, where the
2333 -- temporary may hide the transformation of a selected component into
2334 -- a prefixed function call, and references need to see the original
2337 and then (Expander_Active
or GNATprove_Mode
)
2340 Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'R', Iter_Name
);
2346 -- If the domain of iteration is an array component that depends
2347 -- on a discriminant, create actual subtype for it. Preanalysis
2348 -- does not generate the actual subtype of a selected component.
2350 if Nkind
(Iter_Name
) = N_Selected_Component
2351 and then Is_Array_Type
(Etype
(Iter_Name
))
2354 Build_Actual_Subtype_Of_Component
2355 (Etype
(Selector_Name
(Iter_Name
)), Iter_Name
);
2356 Insert_Action
(N
, Act_S
);
2358 if Present
(Act_S
) then
2359 Typ
:= Defining_Identifier
(Act_S
);
2361 Typ
:= Etype
(Iter_Name
);
2365 Typ
:= Etype
(Iter_Name
);
2367 -- Verify that the expression produces an iterator
2369 if not Of_Present
(N
) and then not Is_Iterator
(Typ
)
2370 and then not Is_Array_Type
(Typ
)
2371 and then No
(Find_Aspect
(Typ
, Aspect_Iterable
))
2374 ("expect object that implements iterator interface",
2379 -- Protect against malformed iterator
2381 if Typ
= Any_Type
then
2382 Error_Msg_N
("invalid expression in loop iterator", Iter_Name
);
2386 if not Of_Present
(N
) then
2387 Check_Reverse_Iteration
(Typ
);
2390 -- For an element iteration over a slice, we must complete
2391 -- the resolution and expansion of the slice bounds. These
2392 -- can be arbitrary expressions, and the preanalysis that
2393 -- was performed in preparation for the iteration may have
2394 -- generated an itype whose bounds must be fully expanded.
2395 -- We set the parent node to provide a proper insertion
2396 -- point for generated actions, if any.
2398 if Nkind
(Iter_Name
) = N_Slice
2399 and then Nkind
(Discrete_Range
(Iter_Name
)) = N_Range
2400 and then not Analyzed
(Discrete_Range
(Iter_Name
))
2403 Indx
: constant Node_Id
:=
2404 Entity
(First_Index
(Etype
(Iter_Name
)));
2406 Set_Parent
(Indx
, Iter_Name
);
2407 Resolve
(Scalar_Range
(Indx
), Etype
(Indx
));
2411 -- The name in the renaming declaration may be a function call.
2412 -- Indicate that it does not come from source, to suppress
2413 -- spurious warnings on renamings of parameterless functions,
2414 -- a common enough idiom in user-defined iterators.
2417 Make_Object_Renaming_Declaration
(Loc
,
2418 Defining_Identifier
=> Id
,
2419 Subtype_Mark
=> New_Occurrence_Of
(Typ
, Loc
),
2421 New_Copy_Tree
(Iter_Name
, New_Sloc
=> Loc
));
2422 Set_Comes_From_Iterator
(Decl
);
2424 Insert_Actions
(Parent
(Parent
(N
)), New_List
(Decl
));
2425 Rewrite
(Name
(N
), New_Occurrence_Of
(Id
, Loc
));
2427 Set_Etype
(Id
, Typ
);
2428 Set_Etype
(Name
(N
), Typ
);
2431 -- Container is an entity or an array with uncontrolled components, or
2432 -- else it is a container iterator given by a function call, typically
2433 -- called Iterate in the case of predefined containers, even though
2434 -- Iterate is not a reserved name. What matters is that the return type
2435 -- of the function is an iterator type.
2437 elsif Is_Entity_Name
(Iter_Name
) then
2438 Analyze
(Iter_Name
);
2440 if Nkind
(Iter_Name
) = N_Function_Call
then
2442 C
: constant Node_Id
:= Name
(Iter_Name
);
2447 if not Is_Overloaded
(Iter_Name
) then
2448 Resolve
(Iter_Name
, Etype
(C
));
2451 Get_First_Interp
(C
, I
, It
);
2452 while It
.Typ
/= Empty
loop
2453 if Reverse_Present
(N
) then
2454 if Is_Reversible_Iterator
(It
.Typ
) then
2455 Resolve
(Iter_Name
, It
.Typ
);
2459 elsif Is_Iterator
(It
.Typ
) then
2460 Resolve
(Iter_Name
, It
.Typ
);
2464 Get_Next_Interp
(I
, It
);
2469 -- Domain of iteration is not overloaded
2472 Resolve
(Iter_Name
);
2475 if not Of_Present
(N
) then
2476 Check_Reverse_Iteration
(Etype
(Iter_Name
));
2480 -- Get base type of container, for proper retrieval of Cursor type
2481 -- and primitive operations.
2483 Typ
:= Base_Type
(Etype
(Iter_Name
));
2485 if Is_Array_Type
(Typ
) then
2486 if Of_Present
(N
) then
2487 Set_Etype
(Def_Id
, Component_Type
(Typ
));
2489 -- The loop variable is aliased if the array components are
2490 -- aliased. Likewise for the independent aspect.
2492 Set_Is_Aliased
(Def_Id
, Has_Aliased_Components
(Typ
));
2493 Set_Is_Independent
(Def_Id
, Has_Independent_Components
(Typ
));
2495 -- AI12-0047 stipulates that the domain (array or container)
2496 -- cannot be a component that depends on a discriminant if the
2497 -- enclosing object is mutable, to prevent a modification of the
2498 -- domain of iteration in the course of an iteration.
2500 -- If the object is an expression it has been captured in a
2501 -- temporary, so examine original node.
2503 if Nkind
(Original_Node
(Iter_Name
)) = N_Selected_Component
2504 and then Is_Dependent_Component_Of_Mutable_Object
2505 (Original_Node
(Iter_Name
))
2508 ("iterable name cannot be a discriminant-dependent "
2509 & "component of a mutable object", N
);
2511 elsif Depends_On_Mutably_Tagged_Ext_Comp
2512 (Original_Node
(Iter_Name
))
2515 ("iterable name cannot depend on a mutably tagged component",
2519 Check_Subtype_Definition
(Component_Type
(Typ
));
2521 -- Here we have a missing Range attribute
2525 ("missing Range attribute in iteration over an array", N
);
2527 -- In Ada 2012 mode, this may be an attempt at an iterator
2529 if Ada_Version
>= Ada_2012
then
2531 ("\if& is meant to designate an element of the array, use OF",
2535 -- Prevent cascaded errors
2537 Mutate_Ekind
(Def_Id
, E_Loop_Parameter
);
2538 Set_Etype
(Def_Id
, Etype
(First_Index
(Typ
)));
2541 -- Check for type error in iterator
2543 elsif Typ
= Any_Type
then
2546 -- Iteration over a container
2549 Mutate_Ekind
(Def_Id
, E_Loop_Parameter
);
2550 Set_Is_Not_Self_Hidden
(Def_Id
);
2551 Error_Msg_Ada_2012_Feature
("container iterator", Sloc
(N
));
2555 if Of_Present
(N
) then
2556 if Has_Aspect
(Typ
, Aspect_Iterable
) then
2558 Elt
: constant Entity_Id
:=
2559 Get_Iterable_Type_Primitive
(Typ
, Name_Element
);
2563 ("missing Element primitive for iteration", N
);
2565 Set_Etype
(Def_Id
, Etype
(Elt
));
2566 Check_Reverse_Iteration
(Typ
);
2570 Check_Subtype_Definition
(Etype
(Def_Id
));
2572 -- For a predefined container, the type of the loop variable is
2573 -- the Iterator_Element aspect of the container type.
2577 Element
: constant Entity_Id
:=
2578 Find_Value_Of_Aspect
2579 (Typ
, Aspect_Iterator_Element
);
2580 Iterator
: constant Entity_Id
:=
2581 Find_Value_Of_Aspect
2582 (Typ
, Aspect_Default_Iterator
);
2583 Orig_Iter_Name
: constant Node_Id
:=
2584 Original_Node
(Iter_Name
);
2585 Cursor_Type
: Entity_Id
;
2588 if No
(Element
) then
2589 Error_Msg_NE
("cannot iterate over&", N
, Typ
);
2593 Set_Etype
(Def_Id
, Entity
(Element
));
2594 Cursor_Type
:= Get_Cursor_Type
(Typ
);
2595 pragma Assert
(Present
(Cursor_Type
));
2597 Check_Subtype_Definition
(Etype
(Def_Id
));
2599 -- If the container has a variable indexing aspect, the
2600 -- element is a variable and is modifiable in the loop.
2602 if Has_Aspect
(Typ
, Aspect_Variable_Indexing
) then
2603 Mutate_Ekind
(Def_Id
, E_Variable
);
2604 Set_Is_Not_Self_Hidden
(Def_Id
);
2607 -- If the container is a constant, iterating over it
2608 -- requires a Constant_Indexing operation.
2610 if not Is_Variable
(Iter_Name
)
2611 and then not Has_Aspect
(Typ
, Aspect_Constant_Indexing
)
2614 ("iteration over constant container require "
2615 & "constant_indexing aspect", N
);
2617 -- The Iterate function may have an in_out parameter,
2618 -- and a constant container is thus illegal.
2620 elsif Present
(Iterator
)
2621 and then Ekind
(Entity
(Iterator
)) = E_Function
2622 and then Ekind
(First_Formal
(Entity
(Iterator
))) /=
2624 and then not Is_Variable
(Iter_Name
)
2626 Error_Msg_N
("variable container expected", N
);
2629 -- Detect a case where the iterator denotes a component
2630 -- of a mutable object which depends on a discriminant.
2631 -- Note that the iterator may denote a function call in
2632 -- qualified form, in which case this check should not
2635 if Nkind
(Orig_Iter_Name
) = N_Selected_Component
2637 Present
(Entity
(Selector_Name
(Orig_Iter_Name
)))
2639 Ekind
(Entity
(Selector_Name
(Orig_Iter_Name
))) in
2640 E_Component | E_Discriminant
2641 and then Is_Dependent_Component_Of_Mutable_Object
2645 ("container cannot be a discriminant-dependent "
2646 & "component of a mutable object", N
);
2648 elsif Depends_On_Mutably_Tagged_Ext_Comp
2652 ("container cannot depend on a mutably tagged "
2659 -- IN iterator, domain is a range, a call to Iterate function,
2660 -- or an object/actual parameter of an iterator type.
2663 -- If the type of the name is class-wide and its root type is a
2664 -- derived type, the primitive operations (First, Next, etc.) are
2665 -- those inherited by its specific type. Calls to these primitives
2666 -- will be dispatching.
2668 if Is_Class_Wide_Type
(Typ
)
2669 and then Is_Derived_Type
(Etype
(Typ
))
2674 -- For an iteration of the form IN, the name must denote an
2675 -- iterator, typically the result of a call to Iterate. Give a
2676 -- useful error message when the name is a container by itself.
2678 -- The type may be a formal container type, which has to have
2679 -- an Iterable aspect detailing the required primitives.
2681 if Is_Entity_Name
(Original_Node
(Name
(N
)))
2682 and then not Is_Iterator
(Typ
)
2684 if Has_Aspect
(Typ
, Aspect_Iterable
) then
2687 elsif not Has_Aspect
(Typ
, Aspect_Iterator_Element
) then
2689 ("cannot iterate over&", Name
(N
), Typ
);
2692 ("name must be an iterator, not a container", Name
(N
));
2695 if Has_Aspect
(Typ
, Aspect_Iterable
) then
2699 ("\to iterate directly over the elements of a container, "
2700 & "write `of &`", Name
(N
), Original_Node
(Name
(N
)));
2702 -- No point in continuing analysis of iterator spec
2708 -- If the name is a call (typically prefixed) to some Iterate
2709 -- function, it has been rewritten as an object declaration.
2710 -- If that object is a selected component, verify that it is not
2711 -- a component of an unconstrained mutable object.
2713 if Nkind
(Iter_Name
) = N_Identifier
2714 or else (not Expander_Active
and Comes_From_Source
(Iter_Name
))
2717 Orig_Node
: constant Node_Id
:= Original_Node
(Iter_Name
);
2718 Iter_Kind
: constant Node_Kind
:= Nkind
(Orig_Node
);
2722 if Iter_Kind
= N_Selected_Component
then
2723 Obj
:= Prefix
(Orig_Node
);
2725 elsif Iter_Kind
= N_Function_Call
then
2726 Obj
:= First_Actual
(Orig_Node
);
2728 -- If neither, the name comes from source
2734 if Nkind
(Obj
) = N_Selected_Component
2735 and then Is_Dependent_Component_Of_Mutable_Object
(Obj
)
2738 ("container cannot be a discriminant-dependent "
2739 & "component of a mutable object", N
);
2741 elsif Depends_On_Mutably_Tagged_Ext_Comp
(Obj
) then
2743 ("container cannot depend on a mutably tagged"
2749 -- The result type of Iterate function is the classwide type of
2750 -- the interface parent. We need the specific Cursor type defined
2751 -- in the container package. We obtain it by name for a predefined
2752 -- container, or through the Iterable aspect for a formal one.
2754 if Has_Aspect
(Typ
, Aspect_Iterable
) then
2757 (Parent
(Find_Value_Of_Aspect
(Typ
, Aspect_Iterable
)),
2761 Set_Etype
(Def_Id
, Get_Cursor_Type
(Typ
));
2762 Check_Reverse_Iteration
(Etype
(Iter_Name
));
2768 -- Preanalyze the filter. Expansion will take place when enclosing
2769 -- loop is expanded.
2771 if Present
(Iterator_Filter
(N
)) then
2772 Preanalyze_And_Resolve
(Iterator_Filter
(N
), Standard_Boolean
);
2774 end Analyze_Iterator_Specification
;
2780 -- Note: the semantic work required for analyzing labels (setting them as
2781 -- reachable) was done in a prepass through the statements in the block,
2782 -- so that forward gotos would be properly handled. See Analyze_Statements
2783 -- for further details. The only processing required here is to deal with
2784 -- optimizations that depend on an assumption of sequential control flow,
2785 -- since of course the occurrence of a label breaks this assumption.
2787 procedure Analyze_Label
(N
: Node_Id
) is
2788 pragma Warnings
(Off
, N
);
2790 Kill_Current_Values
;
2793 ------------------------------------------
2794 -- Analyze_Loop_Parameter_Specification --
2795 ------------------------------------------
2797 procedure Analyze_Loop_Parameter_Specification
(N
: Node_Id
) is
2798 Loop_Nod
: constant Node_Id
:= Parent
(Parent
(N
));
2800 procedure Check_Controlled_Array_Attribute
(DS
: Node_Id
);
2801 -- If the bounds are given by a 'Range reference on a function call
2802 -- that returns a controlled array, introduce an explicit declaration
2803 -- to capture the bounds, so that the function result can be finalized
2804 -- in timely fashion.
2806 procedure Check_Predicate_Use
(T
: Entity_Id
);
2807 -- Diagnose Attempt to iterate through non-static predicate. Note that
2808 -- a type with inherited predicates may have both static and dynamic
2809 -- forms. In this case it is not sufficient to check the static
2810 -- predicate function only, look for a dynamic predicate aspect as well.
2812 procedure Process_Bounds
(R
: Node_Id
);
2813 -- If the iteration is given by a range, create temporaries and
2814 -- assignment statements block to capture the bounds and perform
2815 -- required finalization actions in case a bound includes a function
2816 -- call that uses the temporary stack. We first preanalyze a copy of
2817 -- the range in order to determine the expected type, and analyze and
2818 -- resolve the original bounds.
2820 --------------------------------------
2821 -- Check_Controlled_Array_Attribute --
2822 --------------------------------------
2824 procedure Check_Controlled_Array_Attribute
(DS
: Node_Id
) is
2826 if Nkind
(DS
) = N_Attribute_Reference
2827 and then Is_Entity_Name
(Prefix
(DS
))
2828 and then Ekind
(Entity
(Prefix
(DS
))) = E_Function
2829 and then Is_Array_Type
(Etype
(Entity
(Prefix
(DS
))))
2831 Is_Controlled
(Component_Type
(Etype
(Entity
(Prefix
(DS
)))))
2832 and then Expander_Active
2835 Loc
: constant Source_Ptr
:= Sloc
(N
);
2836 Arr
: constant Entity_Id
:= Etype
(Entity
(Prefix
(DS
)));
2837 Indx
: constant Entity_Id
:=
2838 Base_Type
(Etype
(First_Index
(Arr
)));
2839 Subt
: constant Entity_Id
:= Make_Temporary
(Loc
, 'S');
2844 Make_Subtype_Declaration
(Loc
,
2845 Defining_Identifier
=> Subt
,
2846 Subtype_Indication
=>
2847 Make_Subtype_Indication
(Loc
,
2848 Subtype_Mark
=> New_Occurrence_Of
(Indx
, Loc
),
2850 Make_Range_Constraint
(Loc
, Relocate_Node
(DS
))));
2851 Insert_Before
(Loop_Nod
, Decl
);
2855 Make_Attribute_Reference
(Loc
,
2856 Prefix
=> New_Occurrence_Of
(Subt
, Loc
),
2857 Attribute_Name
=> Attribute_Name
(DS
)));
2862 end Check_Controlled_Array_Attribute
;
2864 -------------------------
2865 -- Check_Predicate_Use --
2866 -------------------------
2868 procedure Check_Predicate_Use
(T
: Entity_Id
) is
2870 -- A predicated subtype is illegal in loops and related constructs
2871 -- if the predicate is not static, or if it is a non-static subtype
2872 -- of a statically predicated subtype.
2874 if Is_Discrete_Type
(T
)
2875 and then Has_Predicates
(T
)
2876 and then (not Has_Static_Predicate
(T
)
2877 or else not Is_Static_Subtype
(T
)
2878 or else Has_Dynamic_Predicate_Aspect
(T
)
2879 or else Has_Ghost_Predicate_Aspect
(T
))
2881 -- Seems a confusing message for the case of a static predicate
2882 -- with a non-static subtype???
2884 Bad_Predicated_Subtype_Use
2885 ("cannot use subtype& with non-static predicate for loop "
2886 & "iteration", Discrete_Subtype_Definition
(N
),
2887 T
, Suggest_Static
=> True);
2889 elsif Inside_A_Generic
2890 and then Is_Generic_Formal
(T
)
2891 and then Is_Discrete_Type
(T
)
2893 Set_No_Dynamic_Predicate_On_Actual
(T
);
2895 end Check_Predicate_Use
;
2897 --------------------
2898 -- Process_Bounds --
2899 --------------------
2901 procedure Process_Bounds
(R
: Node_Id
) is
2902 Loc
: constant Source_Ptr
:= Sloc
(N
);
2905 (Original_Bound
: Node_Id
;
2906 Analyzed_Bound
: Node_Id
;
2907 Typ
: Entity_Id
) return Node_Id
;
2908 -- Capture value of bound and return captured value
2915 (Original_Bound
: Node_Id
;
2916 Analyzed_Bound
: Node_Id
;
2917 Typ
: Entity_Id
) return Node_Id
2924 -- If the bound is a constant or an object, no need for a separate
2925 -- declaration. If the bound is the result of previous expansion
2926 -- it is already analyzed and should not be modified. Note that
2927 -- the Bound will be resolved later, if needed, as part of the
2928 -- call to Make_Index (literal bounds may need to be resolved to
2931 if Analyzed
(Original_Bound
) then
2932 return Original_Bound
;
2934 elsif Nkind
(Analyzed_Bound
) in
2935 N_Integer_Literal | N_Character_Literal
2936 or else Is_Entity_Name
(Analyzed_Bound
)
2938 Analyze_And_Resolve
(Original_Bound
, Typ
);
2939 return Original_Bound
;
2941 elsif Inside_Class_Condition_Preanalysis
then
2942 Analyze_And_Resolve
(Original_Bound
, Typ
);
2943 return Original_Bound
;
2946 -- Normally, the best approach is simply to generate a constant
2947 -- declaration that captures the bound. However, there is a nasty
2948 -- case where this is wrong. If the bound is complex, and has a
2949 -- possible use of the secondary stack, we need to generate a
2950 -- separate assignment statement to ensure the creation of a block
2951 -- which will release the secondary stack.
2953 -- We prefer the constant declaration, since it leaves us with a
2954 -- proper trace of the value, useful in optimizations that get rid
2955 -- of junk range checks.
2957 if not Has_Sec_Stack_Call
(Analyzed_Bound
) then
2958 Analyze_And_Resolve
(Original_Bound
, Typ
);
2960 -- Ensure that the bound is valid. This check should not be
2961 -- generated when the range belongs to a quantified expression
2962 -- as the construct is still not expanded into its final form.
2964 if Nkind
(Parent
(R
)) /= N_Loop_Parameter_Specification
2965 or else Nkind
(Parent
(Parent
(R
))) /= N_Quantified_Expression
2967 Ensure_Valid
(Original_Bound
);
2970 Force_Evaluation
(Original_Bound
);
2971 return Original_Bound
;
2974 Id
:= Make_Temporary
(Loc
, 'R', Original_Bound
);
2976 -- Here we make a declaration with a separate assignment
2977 -- statement, and insert before loop header.
2980 Make_Object_Declaration
(Loc
,
2981 Defining_Identifier
=> Id
,
2982 Object_Definition
=> New_Occurrence_Of
(Typ
, Loc
));
2985 Make_Assignment_Statement
(Loc
,
2986 Name
=> New_Occurrence_Of
(Id
, Loc
),
2987 Expression
=> Relocate_Node
(Original_Bound
));
2989 Insert_Actions
(Loop_Nod
, New_List
(Decl
, Assign
));
2991 -- Now that this temporary variable is initialized we decorate it
2992 -- as safe-to-reevaluate to inform to the backend that no further
2993 -- asignment will be issued and hence it can be handled as side
2994 -- effect free. Note that this decoration must be done when the
2995 -- assignment has been analyzed because otherwise it will be
2996 -- rejected (see Analyze_Assignment).
2998 Set_Is_Safe_To_Reevaluate
(Id
);
3000 Rewrite
(Original_Bound
, New_Occurrence_Of
(Id
, Loc
));
3002 if Nkind
(Assign
) = N_Assignment_Statement
then
3003 return Expression
(Assign
);
3005 return Original_Bound
;
3009 Hi
: constant Node_Id
:= High_Bound
(R
);
3010 Lo
: constant Node_Id
:= Low_Bound
(R
);
3011 R_Copy
: constant Node_Id
:= New_Copy_Tree
(R
);
3016 -- Start of processing for Process_Bounds
3019 Set_Parent
(R_Copy
, Parent
(R
));
3020 Preanalyze_Range
(R_Copy
);
3021 Typ
:= Etype
(R_Copy
);
3023 -- If the type of the discrete range is Universal_Integer, then the
3024 -- bound's type must be resolved to Integer, and any object used to
3025 -- hold the bound must also have type Integer, unless the literal
3026 -- bounds are constant-folded expressions with a user-defined type.
3028 if Typ
= Universal_Integer
then
3029 if Nkind
(Lo
) = N_Integer_Literal
3030 and then Present
(Etype
(Lo
))
3031 and then Scope
(Etype
(Lo
)) /= Standard_Standard
3035 elsif Nkind
(Hi
) = N_Integer_Literal
3036 and then Present
(Etype
(Hi
))
3037 and then Scope
(Etype
(Hi
)) /= Standard_Standard
3042 Typ
:= Standard_Integer
;
3048 New_Lo
:= One_Bound
(Lo
, Low_Bound
(R_Copy
), Typ
);
3049 New_Hi
:= One_Bound
(Hi
, High_Bound
(R_Copy
), Typ
);
3051 -- Propagate staticness to loop range itself, in case the
3052 -- corresponding subtype is static.
3054 if New_Lo
/= Lo
and then Is_OK_Static_Expression
(New_Lo
) then
3055 Rewrite
(Low_Bound
(R
), New_Copy
(New_Lo
));
3058 if New_Hi
/= Hi
and then Is_OK_Static_Expression
(New_Hi
) then
3059 Rewrite
(High_Bound
(R
), New_Copy
(New_Hi
));
3065 DS
: constant Node_Id
:= Discrete_Subtype_Definition
(N
);
3066 Id
: constant Entity_Id
:= Defining_Identifier
(N
);
3070 -- Start of processing for Analyze_Loop_Parameter_Specification
3075 -- We always consider the loop variable to be referenced, since the loop
3076 -- may be used just for counting purposes.
3078 Generate_Reference
(Id
, N
, ' ');
3080 -- Check for the case of loop variable hiding a local variable (used
3081 -- later on to give a nice warning if the hidden variable is never
3085 H
: constant Entity_Id
:= Homonym
(Id
);
3088 and then Ekind
(H
) = E_Variable
3089 and then Is_Discrete_Type
(Etype
(H
))
3090 and then Enclosing_Dynamic_Scope
(H
) = Enclosing_Dynamic_Scope
(Id
)
3092 Set_Hiding_Loop_Variable
(H
, Id
);
3096 -- Analyze the subtype definition and create temporaries for the bounds.
3097 -- Do not evaluate the range when preanalyzing a quantified expression
3098 -- because bounds expressed as function calls with side effects will be
3099 -- incorrectly replicated.
3101 if Nkind
(DS
) = N_Range
3102 and then Expander_Active
3103 and then Nkind
(Parent
(N
)) /= N_Quantified_Expression
3105 Process_Bounds
(DS
);
3107 -- Either the expander not active or the range of iteration is a subtype
3108 -- indication, an entity, or a function call that yields an aggregate or
3112 DS_Copy
:= New_Copy_Tree
(DS
);
3113 Set_Parent
(DS_Copy
, Parent
(DS
));
3114 Preanalyze_Range
(DS_Copy
);
3116 -- Ada 2012: If the domain of iteration is:
3118 -- a) a function call,
3119 -- b) an identifier that is not a type,
3120 -- c) an attribute reference 'Old (within a postcondition),
3121 -- d) an unchecked conversion or a qualified expression with
3122 -- the proper iterator type.
3124 -- then it is an iteration over a container. It was classified as
3125 -- a loop specification by the parser, and must be rewritten now
3126 -- to activate container iteration. The last case will occur within
3127 -- an expanded inlined call, where the expansion wraps an actual in
3128 -- an unchecked conversion when needed. The expression of the
3129 -- conversion is always an object.
3131 if Nkind
(DS_Copy
) = N_Function_Call
3133 or else (Is_Entity_Name
(DS_Copy
)
3134 and then not Is_Type
(Entity
(DS_Copy
)))
3136 or else (Nkind
(DS_Copy
) = N_Attribute_Reference
3137 and then Attribute_Name
(DS_Copy
) in
3138 Name_Loop_Entry | Name_Old
)
3140 or else Has_Aspect
(Etype
(DS_Copy
), Aspect_Iterable
)
3142 or else Nkind
(DS_Copy
) = N_Unchecked_Type_Conversion
3143 or else (Nkind
(DS_Copy
) = N_Qualified_Expression
3144 and then Is_Iterator
(Etype
(DS_Copy
)))
3146 -- This is an iterator specification. Rewrite it as such and
3147 -- analyze it to capture function calls that may require
3148 -- finalization actions.
3151 I_Spec
: constant Node_Id
:=
3152 Make_Iterator_Specification
(Sloc
(N
),
3153 Defining_Identifier
=> Relocate_Node
(Id
),
3155 Subtype_Indication
=> Empty
,
3156 Reverse_Present
=> Reverse_Present
(N
));
3157 Scheme
: constant Node_Id
:= Parent
(N
);
3160 Set_Iterator_Specification
(Scheme
, I_Spec
);
3161 Set_Loop_Parameter_Specification
(Scheme
, Empty
);
3162 Set_Iterator_Filter
(I_Spec
,
3163 Relocate_Node
(Iterator_Filter
(N
)));
3165 Analyze_Iterator_Specification
(I_Spec
);
3167 -- In a generic context, analyze the original domain of
3168 -- iteration, for name capture.
3170 if not Expander_Active
then
3174 -- Set kind of loop parameter, which may be used in the
3175 -- subsequent analysis of the condition in a quantified
3178 Mutate_Ekind
(Id
, E_Loop_Parameter
);
3182 -- Domain of iteration is not a function call, and is side-effect
3186 -- A quantified expression that appears in a pre/post condition
3187 -- is preanalyzed several times. If the range is given by an
3188 -- attribute reference it is rewritten as a range, and this is
3189 -- done even with expansion disabled. If the type is already set
3190 -- do not reanalyze, because a range with static bounds may be
3191 -- typed Integer by default.
3193 if Nkind
(Parent
(N
)) = N_Quantified_Expression
3194 and then Present
(Etype
(DS
))
3207 -- Some additional checks if we are iterating through a type
3209 if Is_Entity_Name
(DS
)
3210 and then Present
(Entity
(DS
))
3211 and then Is_Type
(Entity
(DS
))
3213 -- The subtype indication may denote the completion of an incomplete
3214 -- type declaration.
3216 if Ekind
(Entity
(DS
)) = E_Incomplete_Type
then
3217 Set_Entity
(DS
, Get_Full_View
(Entity
(DS
)));
3218 Set_Etype
(DS
, Entity
(DS
));
3221 Check_Predicate_Use
(Entity
(DS
));
3224 -- Error if not discrete type
3226 if not Is_Discrete_Type
(Etype
(DS
)) then
3227 Wrong_Type
(DS
, Any_Discrete
);
3228 Set_Etype
(DS
, Any_Type
);
3231 Check_Controlled_Array_Attribute
(DS
);
3233 if Nkind
(DS
) = N_Subtype_Indication
then
3234 Check_Predicate_Use
(Entity
(Subtype_Mark
(DS
)));
3237 if Nkind
(DS
) not in N_Raise_xxx_Error
then
3241 Mutate_Ekind
(Id
, E_Loop_Parameter
);
3242 Set_Is_Not_Self_Hidden
(Id
);
3244 -- A quantified expression which appears in a pre- or post-condition may
3245 -- be analyzed multiple times. The analysis of the range creates several
3246 -- itypes which reside in different scopes depending on whether the pre-
3247 -- or post-condition has been expanded. Update the type of the loop
3248 -- variable to reflect the proper itype at each stage of analysis.
3250 -- Loop_Nod might not be present when we are preanalyzing a class-wide
3251 -- pre/postcondition since preanalysis occurs in a place unrelated to
3252 -- the actual code and the quantified expression may be the outermost
3253 -- expression of the class-wide condition.
3256 or else Etype
(Id
) = Any_Type
3258 (Present
(Etype
(Id
))
3259 and then Is_Itype
(Etype
(Id
))
3260 and then Present
(Loop_Nod
)
3261 and then Nkind
(Parent
(Loop_Nod
)) = N_Expression_With_Actions
3262 and then Nkind
(Original_Node
(Parent
(Loop_Nod
))) =
3263 N_Quantified_Expression
)
3265 Set_Etype
(Id
, Etype
(DS
));
3268 -- Treat a range as an implicit reference to the type, to inhibit
3269 -- spurious warnings.
3271 Generate_Reference
(Base_Type
(Etype
(DS
)), N
, ' ');
3272 Set_Is_Known_Valid
(Id
, True);
3274 -- The loop is not a declarative part, so the loop variable must be
3275 -- frozen explicitly. Do not freeze while preanalyzing a quantified
3276 -- expression because the freeze node will not be inserted into the
3277 -- tree due to flag Is_Spec_Expression being set.
3279 if Nkind
(Parent
(N
)) /= N_Quantified_Expression
then
3281 Flist
: constant List_Id
:= Freeze_Entity
(Id
, N
);
3283 Insert_Actions
(N
, Flist
);
3287 -- Case where we have a range or a subtype, get type bounds
3289 if Nkind
(DS
) in N_Range | N_Subtype_Indication
3290 and then not Error_Posted
(DS
)
3291 and then Etype
(DS
) /= Any_Type
3292 and then Is_Discrete_Type
(Etype
(DS
))
3297 Null_Range
: Boolean := False;
3300 if Nkind
(DS
) = N_Range
then
3301 L
:= Low_Bound
(DS
);
3302 H
:= High_Bound
(DS
);
3305 Type_Low_Bound
(Underlying_Type
(Etype
(Subtype_Mark
(DS
))));
3307 Type_High_Bound
(Underlying_Type
(Etype
(Subtype_Mark
(DS
))));
3310 -- Check for null or possibly null range and issue warning. We
3311 -- suppress such messages in generic templates and instances,
3312 -- because in practice they tend to be dubious in these cases. The
3313 -- check applies as well to rewritten array element loops where a
3314 -- null range may be detected statically.
3316 if Compile_Time_Compare
(L
, H
, Assume_Valid
=> True) = GT
then
3317 if Compile_Time_Compare
(L
, H
, Assume_Valid
=> False) = GT
then
3318 -- Since we know the range of the loop is always null,
3319 -- set the appropriate flag to remove the loop entirely
3320 -- during expansion.
3322 Set_Is_Null_Loop
(Loop_Nod
);
3326 -- Suppress the warning if inside a generic template or
3327 -- instance, since in practice they tend to be dubious in these
3328 -- cases since they can result from intended parameterization.
3330 if not Inside_A_Generic
and then not In_Instance
then
3332 -- Specialize msg if invalid values could make the loop
3333 -- non-null after all.
3336 if Comes_From_Source
(N
) then
3338 ("??loop range is null, loop will not execute", DS
);
3341 -- Here is where the loop could execute because of
3342 -- invalid values, so issue appropriate message.
3344 elsif Comes_From_Source
(N
) then
3346 ("??loop range may be null, loop may not execute",
3349 ("??can only execute if invalid values are present",
3354 -- In either case, suppress warnings in the body of the loop,
3355 -- since it is likely that these warnings will be inappropriate
3356 -- if the loop never actually executes, which is likely.
3358 Set_Suppress_Loop_Warnings
(Loop_Nod
);
3360 -- The other case for a warning is a reverse loop where the
3361 -- upper bound is the integer literal zero or one, and the
3362 -- lower bound may exceed this value.
3364 -- For example, we have
3366 -- for J in reverse N .. 1 loop
3368 -- In practice, this is very likely to be a case of reversing
3369 -- the bounds incorrectly in the range.
3371 elsif Reverse_Present
(N
)
3372 and then Nkind
(Original_Node
(H
)) = N_Integer_Literal
3374 (Intval
(Original_Node
(H
)) = Uint_0
3376 Intval
(Original_Node
(H
)) = Uint_1
)
3378 -- Lower bound may in fact be known and known not to exceed
3379 -- upper bound (e.g. reverse 0 .. 1) and that's OK.
3381 if Compile_Time_Known_Value
(L
)
3382 and then Expr_Value
(L
) <= Expr_Value
(H
)
3386 -- Otherwise warning is warranted
3389 Error_Msg_N
("??loop range may be null", DS
);
3390 Error_Msg_N
("\??bounds may be wrong way round", DS
);
3394 -- Check if either bound is known to be outside the range of the
3395 -- loop parameter type, this is e.g. the case of a loop from
3396 -- 20..X where the type is 1..19.
3398 -- Such a loop is dubious since either it raises CE or it executes
3399 -- zero times, and that cannot be useful!
3401 if Etype
(DS
) /= Any_Type
3402 and then not Error_Posted
(DS
)
3403 and then Nkind
(DS
) = N_Subtype_Indication
3404 and then Nkind
(Constraint
(DS
)) = N_Range_Constraint
3407 LLo
: constant Node_Id
:=
3408 Low_Bound
(Range_Expression
(Constraint
(DS
)));
3409 LHi
: constant Node_Id
:=
3410 High_Bound
(Range_Expression
(Constraint
(DS
)));
3412 Bad_Bound
: Node_Id
:= Empty
;
3413 -- Suspicious loop bound
3416 -- At this stage L, H are the bounds of the type, and LLo
3417 -- Lhi are the low bound and high bound of the loop.
3419 if Compile_Time_Compare
(LLo
, L
, Assume_Valid
=> True) = LT
3421 Compile_Time_Compare
(LLo
, H
, Assume_Valid
=> True) = GT
3426 if Compile_Time_Compare
(LHi
, L
, Assume_Valid
=> True) = LT
3428 Compile_Time_Compare
(LHi
, H
, Assume_Valid
=> True) = GT
3433 if Present
(Bad_Bound
) then
3435 ("suspicious loop bound out of range of "
3436 & "loop subtype??", Bad_Bound
);
3438 ("\loop executes zero times or raises "
3439 & "Constraint_Error??", Bad_Bound
);
3442 if Compile_Time_Compare
(LLo
, LHi
, Assume_Valid
=> False)
3445 Error_Msg_N
("??constrained range is null",
3448 -- Additional constraints on modular types can be
3449 -- confusing, add more information.
3451 if Ekind
(Etype
(DS
)) = E_Modular_Integer_Subtype
then
3452 Error_Msg_Uint_1
:= Intval
(LLo
);
3453 Error_Msg_Uint_2
:= Intval
(LHi
);
3454 Error_Msg_NE
("\iterator has modular type &, " &
3455 "so the loop has bounds ^ ..^",
3460 Set_Is_Null_Loop
(Loop_Nod
);
3463 -- Suppress other warnings about the body of the loop, as
3464 -- it will never execute.
3465 Set_Suppress_Loop_Warnings
(Loop_Nod
);
3470 -- This declare block is about warnings, if we get an exception while
3471 -- testing for warnings, we simply abandon the attempt silently. This
3472 -- most likely occurs as the result of a previous error, but might
3473 -- just be an obscure case we have missed. In either case, not giving
3474 -- the warning is perfectly acceptable.
3478 -- With debug flag K we will get an exception unless an error
3479 -- has already occurred (useful for debugging).
3481 if Debug_Flag_K
then
3482 Check_Error_Detected
;
3487 -- Preanalyze the filter. Expansion will take place when enclosing
3488 -- loop is expanded.
3490 if Present
(Iterator_Filter
(N
)) then
3491 Preanalyze_And_Resolve
(Iterator_Filter
(N
), Standard_Boolean
);
3493 end Analyze_Loop_Parameter_Specification
;
3495 ----------------------------
3496 -- Analyze_Loop_Statement --
3497 ----------------------------
3499 procedure Analyze_Loop_Statement
(N
: Node_Id
) is
3501 -- The following exception is raised by routine Prepare_Loop_Statement
3502 -- to avoid further analysis of a transformed loop.
3504 procedure Prepare_Loop_Statement
3506 Stop_Processing
: out Boolean);
3507 -- Determine whether loop statement N with iteration scheme Iter must be
3508 -- transformed prior to analysis, and if so, perform it.
3509 -- If Stop_Processing is set to True, should stop further processing.
3511 ----------------------------
3512 -- Prepare_Loop_Statement --
3513 ----------------------------
3515 procedure Prepare_Loop_Statement
3517 Stop_Processing
: out Boolean)
3519 function Has_Sec_Stack_Default_Iterator
3520 (Cont_Typ
: Entity_Id
) return Boolean;
3521 pragma Inline
(Has_Sec_Stack_Default_Iterator
);
3522 -- Determine whether container type Cont_Typ has a default iterator
3523 -- that requires secondary stack management.
3525 function Is_Sec_Stack_Iteration_Primitive
3526 (Cont_Typ
: Entity_Id
;
3527 Iter_Prim_Nam
: Name_Id
) return Boolean;
3528 pragma Inline
(Is_Sec_Stack_Iteration_Primitive
);
3529 -- Determine whether container type Cont_Typ has an iteration routine
3530 -- described by its name Iter_Prim_Nam that requires secondary stack
3533 function Is_Wrapped_In_Block
(Stmt
: Node_Id
) return Boolean;
3534 pragma Inline
(Is_Wrapped_In_Block
);
3535 -- Determine whether arbitrary statement Stmt is the sole statement
3536 -- wrapped within some block, excluding pragmas.
3538 procedure Prepare_Iterator_Loop
3539 (Iter_Spec
: Node_Id
;
3540 Stop_Processing
: out Boolean);
3541 pragma Inline
(Prepare_Iterator_Loop
);
3542 -- Prepare an iterator loop with iteration specification Iter_Spec
3543 -- for transformation if needed.
3544 -- If Stop_Processing is set to True, should stop further processing.
3546 procedure Prepare_Param_Spec_Loop
3547 (Param_Spec
: Node_Id
;
3548 Stop_Processing
: out Boolean);
3549 pragma Inline
(Prepare_Param_Spec_Loop
);
3550 -- Prepare a discrete loop with parameter specification Param_Spec
3551 -- for transformation if needed.
3552 -- If Stop_Processing is set to True, should stop further processing.
3554 procedure Wrap_Loop_Statement
(Manage_Sec_Stack
: Boolean);
3555 pragma Inline
(Wrap_Loop_Statement
);
3556 -- Wrap loop statement N within a block. Flag Manage_Sec_Stack must
3557 -- be set when the block must mark and release the secondary stack.
3558 -- Should stop further processing after calling this procedure.
3560 ------------------------------------
3561 -- Has_Sec_Stack_Default_Iterator --
3562 ------------------------------------
3564 function Has_Sec_Stack_Default_Iterator
3565 (Cont_Typ
: Entity_Id
) return Boolean
3567 Def_Iter
: constant Node_Id
:=
3568 Find_Value_Of_Aspect
3569 (Cont_Typ
, Aspect_Default_Iterator
);
3573 and then Present
(Etype
(Def_Iter
))
3574 and then Requires_Transient_Scope
(Etype
(Def_Iter
));
3575 end Has_Sec_Stack_Default_Iterator
;
3577 --------------------------------------
3578 -- Is_Sec_Stack_Iteration_Primitive --
3579 --------------------------------------
3581 function Is_Sec_Stack_Iteration_Primitive
3582 (Cont_Typ
: Entity_Id
;
3583 Iter_Prim_Nam
: Name_Id
) return Boolean
3585 Iter_Prim
: constant Entity_Id
:=
3586 Get_Iterable_Type_Primitive
3587 (Cont_Typ
, Iter_Prim_Nam
);
3591 and then Requires_Transient_Scope
(Etype
(Iter_Prim
));
3592 end Is_Sec_Stack_Iteration_Primitive
;
3594 -------------------------
3595 -- Is_Wrapped_In_Block --
3596 -------------------------
3598 function Is_Wrapped_In_Block
(Stmt
: Node_Id
) return Boolean is
3604 Blk_Id
:= Current_Scope
;
3606 -- The current context is a block. Inspect the statements of the
3607 -- block to determine whether it wraps Stmt.
3609 if Ekind
(Blk_Id
) = E_Block
3610 and then Present
(Block_Node
(Blk_Id
))
3613 Handled_Statement_Sequence
(Parent
(Block_Node
(Blk_Id
)));
3615 -- Skip leading pragmas introduced for invariant and predicate
3618 Blk_Stmt
:= First
(Statements
(Blk_HSS
));
3619 while Present
(Blk_Stmt
)
3620 and then Nkind
(Blk_Stmt
) = N_Pragma
3625 return Blk_Stmt
= Stmt
and then No
(Next
(Blk_Stmt
));
3629 end Is_Wrapped_In_Block
;
3631 ---------------------------
3632 -- Prepare_Iterator_Loop --
3633 ---------------------------
3635 procedure Prepare_Iterator_Loop
3636 (Iter_Spec
: Node_Id
;
3637 Stop_Processing
: out Boolean)
3639 Cont_Typ
: Entity_Id
;
3644 Stop_Processing
:= False;
3646 -- The iterator specification has syntactic errors. Transform the
3647 -- loop into an infinite loop in order to safely perform at least
3648 -- some minor analysis. This check must come first.
3650 if Error_Posted
(Iter_Spec
) then
3651 Set_Iteration_Scheme
(N
, Empty
);
3653 Stop_Processing
:= True;
3655 -- Nothing to do when the loop is already wrapped in a block
3657 elsif Is_Wrapped_In_Block
(N
) then
3660 -- Otherwise the iterator loop traverses an array or a container
3661 -- and appears in the form
3663 -- for Def_Id in [reverse] Iterator_Name loop
3664 -- for Def_Id [: Subtyp_Indic] of [reverse] Iterable_Name loop
3667 -- Prepare a copy of the iterated name for preanalysis. The
3668 -- copy is semi inserted into the tree by setting its Parent
3671 Nam
:= Name
(Iter_Spec
);
3672 Nam_Copy
:= New_Copy_Tree
(Nam
);
3673 Set_Parent
(Nam_Copy
, Parent
(Nam
));
3675 -- Determine what the loop is iterating on
3677 Preanalyze_Range
(Nam_Copy
);
3678 Cont_Typ
:= Etype
(Nam_Copy
);
3680 -- The iterator loop is traversing an array. This case does not
3681 -- require any transformation, unless the name contains a call
3682 -- that returns on the secondary stack since we need to release
3683 -- the space allocated there.
3685 if Is_Array_Type
(Cont_Typ
)
3686 and then not Has_Sec_Stack_Call
(Nam_Copy
)
3690 -- Otherwise unconditionally wrap the loop statement within
3691 -- a block. The expansion of iterator loops may relocate the
3692 -- iterator outside the loop, thus "leaking" its entity into
3693 -- the enclosing scope. Wrapping the loop statement allows
3694 -- for multiple iterator loops using the same iterator name
3695 -- to coexist within the same scope.
3697 -- The block must manage the secondary stack when the iterator
3698 -- loop is traversing a container using either
3700 -- * A default iterator obtained on the secondary stack
3702 -- * Call to Iterate where the iterator is returned on the
3705 -- * Combination of First, Next, and Has_Element where the
3706 -- first two return a cursor on the secondary stack.
3710 (Manage_Sec_Stack
=>
3711 Has_Sec_Stack_Default_Iterator
(Cont_Typ
)
3712 or else Has_Sec_Stack_Call
(Nam_Copy
)
3713 or else Is_Sec_Stack_Iteration_Primitive
3714 (Cont_Typ
, Name_First
)
3715 or else Is_Sec_Stack_Iteration_Primitive
3716 (Cont_Typ
, Name_Next
));
3717 Stop_Processing
:= True;
3720 end Prepare_Iterator_Loop
;
3722 -----------------------------
3723 -- Prepare_Param_Spec_Loop --
3724 -----------------------------
3726 procedure Prepare_Param_Spec_Loop
3727 (Param_Spec
: Node_Id
;
3728 Stop_Processing
: out Boolean)
3734 Rng_Typ
: Entity_Id
;
3737 Stop_Processing
:= False;
3738 Rng
:= Discrete_Subtype_Definition
(Param_Spec
);
3740 -- Nothing to do when the loop is already wrapped in a block
3742 if Is_Wrapped_In_Block
(N
) then
3745 -- The parameter specification appears in the form
3747 -- for Def_Id in Subtype_Mark Constraint loop
3749 elsif Nkind
(Rng
) = N_Subtype_Indication
3750 and then Nkind
(Range_Expression
(Constraint
(Rng
))) = N_Range
3752 Rng
:= Range_Expression
(Constraint
(Rng
));
3754 -- Preanalyze the bounds of the range constraint, setting
3755 -- parent fields to associate the copied bounds with the range,
3756 -- allowing proper tree climbing during preanalysis.
3758 Low
:= New_Copy_Tree
(Low_Bound
(Rng
));
3759 High
:= New_Copy_Tree
(High_Bound
(Rng
));
3761 Set_Parent
(Low
, Rng
);
3762 Set_Parent
(High
, Rng
);
3767 -- The bounds contain at least one function call that returns
3768 -- on the secondary stack. Note that the loop must be wrapped
3769 -- only when such a call exists.
3771 if Has_Sec_Stack_Call
(Low
) or else Has_Sec_Stack_Call
(High
)
3773 Wrap_Loop_Statement
(Manage_Sec_Stack
=> True);
3774 Stop_Processing
:= True;
3777 -- Otherwise the parameter specification appears in the form
3779 -- for Def_Id in Range loop
3782 -- Prepare a copy of the discrete range for preanalysis. The
3783 -- copy is semi inserted into the tree by setting its Parent
3786 Rng_Copy
:= New_Copy_Tree
(Rng
);
3787 Set_Parent
(Rng_Copy
, Parent
(Rng
));
3789 -- Determine what the loop is iterating on
3791 Preanalyze_Range
(Rng_Copy
);
3792 Rng_Typ
:= Etype
(Rng_Copy
);
3794 -- Wrap the loop statement within a block in order to manage
3795 -- the secondary stack when the discrete range is
3797 -- * Either a Forward_Iterator or a Reverse_Iterator
3799 -- * Function call whose return type requires finalization
3802 -- ??? it is unclear why using Has_Sec_Stack_Call directly on
3803 -- the discrete range causes the freeze node of an itype to be
3804 -- in the wrong scope in complex assertion expressions.
3806 if Is_Iterator
(Rng_Typ
)
3807 or else (Nkind
(Rng_Copy
) = N_Function_Call
3808 and then Needs_Finalization
(Rng_Typ
))
3810 Wrap_Loop_Statement
(Manage_Sec_Stack
=> True);
3811 Stop_Processing
:= True;
3814 end Prepare_Param_Spec_Loop
;
3816 -------------------------
3817 -- Wrap_Loop_Statement --
3818 -------------------------
3820 procedure Wrap_Loop_Statement
(Manage_Sec_Stack
: Boolean) is
3821 Loc
: constant Source_Ptr
:= Sloc
(N
);
3828 Make_Block_Statement
(Loc
,
3829 Declarations
=> New_List
,
3830 Handled_Statement_Sequence
=>
3831 Make_Handled_Sequence_Of_Statements
(Loc
,
3832 Statements
=> New_List
(Relocate_Node
(N
))));
3834 Add_Block_Identifier
(Blk
, Blk_Id
);
3835 Set_Uses_Sec_Stack
(Blk_Id
, Manage_Sec_Stack
);
3839 end Wrap_Loop_Statement
;
3843 Iter_Spec
: constant Node_Id
:= Iterator_Specification
(Iter
);
3844 Param_Spec
: constant Node_Id
:= Loop_Parameter_Specification
(Iter
);
3846 -- Start of processing for Prepare_Loop_Statement
3849 Stop_Processing
:= False;
3851 if Present
(Iter_Spec
) then
3852 Prepare_Iterator_Loop
(Iter_Spec
, Stop_Processing
);
3854 elsif Present
(Param_Spec
) then
3855 Prepare_Param_Spec_Loop
(Param_Spec
, Stop_Processing
);
3857 end Prepare_Loop_Statement
;
3859 -- Local declarations
3861 Id
: constant Node_Id
:= Identifier
(N
);
3862 Iter
: constant Node_Id
:= Iteration_Scheme
(N
);
3863 Loc
: constant Source_Ptr
:= Sloc
(N
);
3867 -- Start of processing for Analyze_Loop_Statement
3870 if Present
(Id
) then
3872 -- Make name visible, e.g. for use in exit statements. Loop labels
3873 -- are always considered to be referenced.
3878 -- Guard against serious error (typically, a scope mismatch when
3879 -- semantic analysis is requested) by creating loop entity to
3880 -- continue analysis.
3883 if Total_Errors_Detected
/= 0 then
3884 Ent
:= New_Internal_Entity
(E_Loop
, Current_Scope
, Loc
, 'L');
3886 raise Program_Error
;
3889 -- Verify that the loop name is hot hidden by an unrelated
3890 -- declaration in an inner scope.
3892 elsif Ekind
(Ent
) /= E_Label
and then Ekind
(Ent
) /= E_Loop
then
3893 Error_Msg_Sloc
:= Sloc
(Ent
);
3894 Error_Msg_N
("implicit label declaration for & is hidden#", Id
);
3896 if Present
(Homonym
(Ent
))
3897 and then Ekind
(Homonym
(Ent
)) = E_Label
3899 Set_Entity
(Id
, Ent
);
3900 Mutate_Ekind
(Ent
, E_Loop
);
3904 Generate_Reference
(Ent
, N
, ' ');
3905 Generate_Definition
(Ent
);
3907 -- If we found a label, mark its type. If not, ignore it, since it
3908 -- means we have a conflicting declaration, which would already
3909 -- have been diagnosed at declaration time. Set Label_Construct
3910 -- of the implicit label declaration, which is not created by the
3911 -- parser for generic units.
3913 if Ekind
(Ent
) = E_Label
then
3914 Reinit_Field_To_Zero
(Ent
, F_Enclosing_Scope
);
3915 Reinit_Field_To_Zero
(Ent
, F_Reachable
);
3916 Mutate_Ekind
(Ent
, E_Loop
);
3918 if Nkind
(Parent
(Ent
)) = N_Implicit_Label_Declaration
then
3919 Set_Label_Construct
(Parent
(Ent
), N
);
3924 -- Case of no identifier present. Create one and attach it to the
3925 -- loop statement for use as a scope and as a reference for later
3926 -- expansions. Indicate that the label does not come from source,
3927 -- and attach it to the loop statement so it is part of the tree,
3928 -- even without a full declaration.
3931 Ent
:= New_Internal_Entity
(E_Loop
, Current_Scope
, Loc
, 'L');
3932 Set_Etype
(Ent
, Standard_Void_Type
);
3933 Set_Identifier
(N
, New_Occurrence_Of
(Ent
, Loc
));
3934 Set_Parent
(Ent
, N
);
3935 Set_Has_Created_Identifier
(N
);
3938 -- Determine whether the loop statement must be transformed prior to
3939 -- analysis, and if so, perform it. This early modification is needed
3942 -- * The loop has an erroneous iteration scheme. In this case the
3943 -- loop is converted into an infinite loop in order to perform
3946 -- * The loop is an Ada 2012 iterator loop. In this case the loop is
3947 -- wrapped within a block to provide a local scope for the iterator.
3948 -- If the iterator specification requires the secondary stack in any
3949 -- way, the block is marked in order to manage it.
3951 -- * The loop is using a parameter specification where the discrete
3952 -- range requires the secondary stack. In this case the loop is
3953 -- wrapped within a block in order to manage the secondary stack.
3955 -- ??? This overlooks finalization: the loop may leave the secondary
3956 -- stack untouched, but its iterator or discrete range may need
3957 -- finalization, in which case the block is also required. Therefore
3958 -- the criterion must be based on Sem_Util.Requires_Transient_Scope,
3959 -- which happens to be what is currently implemented.
3961 if Present
(Iter
) then
3963 Stop_Processing
: Boolean;
3965 Prepare_Loop_Statement
(Iter
, Stop_Processing
);
3967 if Stop_Processing
then
3973 -- Kill current values on entry to loop, since statements in the body of
3974 -- the loop may have been executed before the loop is entered. Similarly
3975 -- we kill values after the loop, since we do not know that the body of
3976 -- the loop was executed.
3978 Kill_Current_Values
;
3980 Analyze_Iteration_Scheme
(Iter
);
3982 -- Check for following case which merits a warning if the type E of is
3983 -- a multi-dimensional array (and no explicit subscript ranges present).
3989 and then Present
(Loop_Parameter_Specification
(Iter
))
3992 LPS
: constant Node_Id
:= Loop_Parameter_Specification
(Iter
);
3993 DSD
: constant Node_Id
:=
3994 Original_Node
(Discrete_Subtype_Definition
(LPS
));
3996 if Nkind
(DSD
) = N_Attribute_Reference
3997 and then Attribute_Name
(DSD
) = Name_Range
3998 and then No
(Expressions
(DSD
))
4001 Typ
: constant Entity_Id
:= Etype
(Prefix
(DSD
));
4003 if Is_Array_Type
(Typ
)
4004 and then Number_Dimensions
(Typ
) > 1
4005 and then Nkind
(Parent
(N
)) = N_Loop_Statement
4006 and then Present
(Iteration_Scheme
(Parent
(N
)))
4009 OIter
: constant Node_Id
:=
4010 Iteration_Scheme
(Parent
(N
));
4011 OLPS
: constant Node_Id
:=
4012 Loop_Parameter_Specification
(OIter
);
4013 ODSD
: constant Node_Id
:=
4014 Original_Node
(Discrete_Subtype_Definition
(OLPS
));
4016 if Nkind
(ODSD
) = N_Attribute_Reference
4017 and then Attribute_Name
(ODSD
) = Name_Range
4018 and then No
(Expressions
(ODSD
))
4019 and then Etype
(Prefix
(ODSD
)) = Typ
4021 Error_Msg_Sloc
:= Sloc
(ODSD
);
4023 ("inner range same as outer range#??", DSD
);
4032 -- Analyze the statements of the body except in the case of an Ada 2012
4033 -- iterator with the expander active. In this case the expander will do
4034 -- a rewrite of the loop into a while loop. We will then analyze the
4035 -- loop body when we analyze this while loop.
4037 -- We need to do this delay because if the container is for indefinite
4038 -- types the actual subtype of the components will only be determined
4039 -- when the cursor declaration is analyzed.
4041 -- If the expander is not active then we want to analyze the loop body
4042 -- now even in the Ada 2012 iterator case, since the rewriting will not
4043 -- be done. Insert the loop variable in the current scope, if not done
4044 -- when analysing the iteration scheme. Set its kind properly to detect
4045 -- improper uses in the loop body.
4047 -- In GNATprove mode, we do one of the above depending on the kind of
4048 -- loop. If it is an iterator over an array, then we do not analyze the
4049 -- loop now. We will analyze it after it has been rewritten by the
4050 -- special SPARK expansion which is activated in GNATprove mode. We need
4051 -- to do this so that other expansions that should occur in GNATprove
4052 -- mode take into account the specificities of the rewritten loop, in
4053 -- particular the introduction of a renaming (which needs to be
4056 -- In other cases in GNATprove mode then we want to analyze the loop
4057 -- body now, since no rewriting will occur. Within a generic the
4058 -- GNATprove mode is irrelevant, we must analyze the generic for
4059 -- non-local name capture.
4062 and then Present
(Iterator_Specification
(Iter
))
4065 and then Is_Iterator_Over_Array
(Iterator_Specification
(Iter
))
4066 and then not Inside_A_Generic
4070 elsif not Expander_Active
then
4072 I_Spec
: constant Node_Id
:= Iterator_Specification
(Iter
);
4073 Id
: constant Entity_Id
:= Defining_Identifier
(I_Spec
);
4076 if Scope
(Id
) /= Current_Scope
then
4080 -- In an element iterator, the loop parameter is a variable if
4081 -- the domain of iteration (container or array) is a variable.
4083 if not Of_Present
(I_Spec
)
4084 or else not Is_Variable
(Name
(I_Spec
))
4086 Mutate_Ekind
(Id
, E_Loop_Parameter
);
4090 Analyze_Statements
(Statements
(N
));
4094 -- Pre-Ada2012 for-loops and while loops
4096 Analyze_Statements
(Statements
(N
));
4099 -- If the loop has no side effects, mark it for removal.
4101 if Side_Effect_Free_Loop
(N
) then
4102 Set_Is_Null_Loop
(N
);
4105 -- When the iteration scheme of a loop contains attribute 'Loop_Entry,
4106 -- the loop is transformed into a conditional block. Retrieve the loop.
4110 if Subject_To_Loop_Entry_Attributes
(Stmt
) then
4111 Stmt
:= Find_Loop_In_Conditional_Block
(Stmt
);
4114 -- Finish up processing for the loop. We kill all current values, since
4115 -- in general we don't know if the statements in the loop have been
4116 -- executed. We could do a bit better than this with a loop that we
4117 -- know will execute at least once, but it's not worth the trouble and
4118 -- the front end is not in the business of flow tracing.
4120 Process_End_Label
(Stmt
, 'e', Ent
);
4122 Kill_Current_Values
;
4124 -- Check for infinite loop. Skip check for generated code, since it
4125 -- justs waste time and makes debugging the routine called harder.
4127 -- Note that we have to wait till the body of the loop is fully analyzed
4128 -- before making this call, since Check_Infinite_Loop_Warning relies on
4129 -- being able to use semantic visibility information to find references.
4131 if Comes_From_Source
(Stmt
) then
4132 Check_Infinite_Loop_Warning
(Stmt
);
4135 -- Code after loop is unreachable if the loop has no WHILE or FOR and
4136 -- contains no EXIT statements within the body of the loop.
4138 if No
(Iter
) and then not Has_Exit
(Ent
) then
4139 Check_Unreachable_Code
(Stmt
);
4141 end Analyze_Loop_Statement
;
4143 ----------------------------
4144 -- Analyze_Null_Statement --
4145 ----------------------------
4147 -- Note: the semantics of the null statement is implemented by a single
4148 -- null statement, too bad everything isn't as simple as this.
4150 procedure Analyze_Null_Statement
(N
: Node_Id
) is
4151 pragma Warnings
(Off
, N
);
4154 end Analyze_Null_Statement
;
4156 -------------------------
4157 -- Analyze_Target_Name --
4158 -------------------------
4160 procedure Analyze_Target_Name
(N
: Node_Id
) is
4161 procedure Report_Error
;
4162 -- Complain about illegal use of target_name and rewrite it into unknown
4169 procedure Report_Error
is
4172 ("must appear in the right-hand side of an assignment statement",
4174 Rewrite
(N
, New_Occurrence_Of
(Any_Id
, Sloc
(N
)));
4177 -- Start of processing for Analyze_Target_Name
4180 -- A target name has the type of the left-hand side of the enclosing
4183 -- First, verify that the context is the right-hand side of an
4184 -- assignment statement.
4186 if No
(Current_Assignment
) then
4192 Current
: Node_Id
:= N
;
4193 Context
: Node_Id
:= Parent
(N
);
4195 while Present
(Context
) loop
4197 -- Check if target_name appears in the expression of the enclosing
4200 if Nkind
(Context
) = N_Assignment_Statement
then
4201 if Current
= Expression
(Context
) then
4202 pragma Assert
(Context
= Current_Assignment
);
4203 Set_Etype
(N
, Etype
(Name
(Current_Assignment
)));
4209 -- Prevent the search from going too far
4211 elsif Is_Body_Or_Package_Declaration
(Context
) then
4217 Context
:= Parent
(Context
);
4222 end Analyze_Target_Name
;
4224 ------------------------
4225 -- Analyze_Statements --
4226 ------------------------
4228 procedure Analyze_Statements
(L
: List_Id
) is
4233 -- The labels declared in the statement list are reachable from
4234 -- statements in the list. We do this as a prepass so that any goto
4235 -- statement will be properly flagged if its target is not reachable.
4236 -- This is not required, but is nice behavior.
4239 while Present
(S
) loop
4240 if Nkind
(S
) = N_Label
then
4241 Analyze
(Identifier
(S
));
4242 Lab
:= Entity
(Identifier
(S
));
4244 -- If we found a label mark it as reachable
4246 if Ekind
(Lab
) = E_Label
then
4247 Generate_Definition
(Lab
);
4248 Set_Reachable
(Lab
);
4250 if Nkind
(Parent
(Lab
)) = N_Implicit_Label_Declaration
then
4251 Set_Label_Construct
(Parent
(Lab
), S
);
4254 -- If we failed to find a label, it means the implicit declaration
4255 -- of the label was hidden. A for-loop parameter can do this to
4256 -- a label with the same name inside the loop, since the implicit
4257 -- label declaration is in the innermost enclosing body or block
4261 Error_Msg_Sloc
:= Sloc
(Lab
);
4263 ("implicit label declaration for & is hidden#",
4271 -- Perform semantic analysis on all statements
4273 Conditional_Statements_Begin
;
4276 while Present
(S
) loop
4279 -- Remove dimension in all statements
4281 Remove_Dimension_In_Statement
(S
);
4285 Conditional_Statements_End
;
4287 -- Make labels unreachable. Visibility is not sufficient, because labels
4288 -- in one if-branch for example are not reachable from the other branch,
4289 -- even though their declarations are in the enclosing declarative part.
4292 while Present
(S
) loop
4293 if Nkind
(S
) = N_Label
4294 and then Ekind
(Entity
(Identifier
(S
))) = E_Label
4296 Set_Reachable
(Entity
(Identifier
(S
)), False);
4301 end Analyze_Statements
;
4303 ----------------------------
4304 -- Check_Unreachable_Code --
4305 ----------------------------
4307 procedure Check_Unreachable_Code
(N
: Node_Id
) is
4309 function Is_Simple_Case
(N
: Node_Id
) return Boolean;
4310 -- N is the condition of an if statement. True if N is simple enough
4311 -- that we should not set Unblocked_Exit_Count in the special case
4314 --------------------
4315 -- Is_Simple_Case --
4316 --------------------
4318 function Is_Simple_Case
(N
: Node_Id
) return Boolean is
4321 Is_Trivial_Boolean
(N
)
4323 (Comes_From_Source
(N
)
4324 and then Is_Static_Expression
(N
)
4325 and then Nkind
(N
) in N_Identifier | N_Expanded_Name
4326 and then Ekind
(Entity
(N
)) = E_Constant
)
4329 and then Nkind
(Original_Node
(N
)) = N_Op_Not
4330 and then Is_Simple_Case
(Right_Opnd
(Original_Node
(N
))));
4333 Error_Node
: Node_Id
;
4338 if Comes_From_Source
(N
) then
4339 Nxt
:= Original_Node
(Next
(N
));
4341 -- Skip past pragmas
4343 while Nkind
(Nxt
) = N_Pragma
loop
4344 Nxt
:= Original_Node
(Next
(Nxt
));
4347 -- If a label follows us, then we never have dead code, since someone
4348 -- could branch to the label, so we just ignore it.
4350 if Nkind
(Nxt
) = N_Label
then
4353 -- Otherwise see if we have a real statement following us
4355 elsif Comes_From_Source
(Nxt
)
4356 and then Is_Statement
(Nxt
)
4358 -- Special very annoying exception. Ada RM 6.5(5) annoyingly
4359 -- requires functions to have at least one return statement, so
4360 -- don't complain about a simple return that follows a raise or a
4361 -- call to procedure with No_Return.
4363 if not (Present
(Current_Subprogram
)
4364 and then Ekind
(Current_Subprogram
) = E_Function
4365 and then (Nkind
(N
) in N_Raise_Statement
4367 (Nkind
(N
) = N_Procedure_Call_Statement
4368 and then Is_Entity_Name
(Name
(N
))
4369 and then Present
(Entity
(Name
(N
)))
4370 and then No_Return
(Entity
(Name
(N
)))))
4371 and then Nkind
(Nxt
) = N_Simple_Return_Statement
)
4373 -- The rather strange shenanigans with the warning message
4374 -- here reflects the fact that Kill_Dead_Code is very good at
4375 -- removing warnings in deleted code, and this is one warning
4376 -- we would prefer NOT to have removed.
4380 -- If we have unreachable code, analyze and remove the
4381 -- unreachable code, since it is useless and we don't want
4382 -- to generate junk warnings.
4384 -- We skip this step if we are not in code generation mode.
4386 -- This is the one case where we remove dead code in the
4387 -- semantics as opposed to the expander, and we do not want
4388 -- to remove code if we are not in code generation mode, since
4389 -- this messes up the tree or loses useful information for
4390 -- analysis tools such as CodePeer.
4392 -- Note that one might react by moving the whole circuit to
4393 -- exp_ch5, but then we lose the warning in -gnatc mode.
4395 if Operating_Mode
= Generate_Code
then
4398 Del
: constant Node_Id
:= Next
(N
);
4399 -- Node to be possibly deleted
4401 -- Quit deleting when we have nothing more to delete
4402 -- or if we hit a label (since someone could transfer
4403 -- control to a label, so we should not delete it).
4405 exit when No
(Del
) or else Nkind
(Del
) = N_Label
;
4407 -- Statement/declaration is to be deleted
4410 Kill_Dead_Code
(Del
);
4415 -- If this is a function, we add "raise Program_Error;",
4416 -- because otherwise, we will get incorrect warnings about
4417 -- falling off the end of the function.
4420 Subp
: constant Entity_Id
:= Current_Subprogram
;
4422 if Present
(Subp
) and then Ekind
(Subp
) = E_Function
then
4423 Insert_After_And_Analyze
(N
,
4424 Make_Raise_Program_Error
(Sloc
(Error_Node
),
4425 Reason
=> PE_Missing_Return
));
4431 -- Suppress the warning in instances, because a statement can
4432 -- be unreachable in some instances but not others.
4434 if not In_Instance
then
4435 Error_Msg_N
("??unreachable code!", Error_Node
);
4439 -- If the unconditional transfer of control instruction is the
4440 -- last statement of a sequence, then see if our parent is one of
4441 -- the constructs for which we count unblocked exits, and if so,
4442 -- adjust the count.
4447 -- Statements in THEN part or ELSE part of IF statement
4449 if Nkind
(P
) = N_If_Statement
then
4452 -- Statements in ELSIF part of an IF statement
4454 elsif Nkind
(P
) = N_Elsif_Part
then
4456 pragma Assert
(Nkind
(P
) = N_If_Statement
);
4458 -- Statements in CASE statement alternative
4460 elsif Nkind
(P
) = N_Case_Statement_Alternative
then
4462 pragma Assert
(Nkind
(P
) = N_Case_Statement
);
4464 -- Statements in body of block
4466 elsif Nkind
(P
) = N_Handled_Sequence_Of_Statements
4467 and then Nkind
(Parent
(P
)) = N_Block_Statement
4469 -- The original loop is now placed inside a block statement
4470 -- due to the expansion of attribute 'Loop_Entry. Return as
4471 -- this is not a "real" block for the purposes of exit
4474 if Nkind
(N
) = N_Loop_Statement
4475 and then Subject_To_Loop_Entry_Attributes
(N
)
4480 -- Statements in exception handler in a block
4482 elsif Nkind
(P
) = N_Exception_Handler
4483 and then Nkind
(Parent
(P
)) = N_Handled_Sequence_Of_Statements
4484 and then Nkind
(Parent
(Parent
(P
))) = N_Block_Statement
4488 -- None of these cases, so return
4494 -- This was one of the cases we are looking for (i.e. the parent
4495 -- construct was IF, CASE or block). In most cases, we simply
4496 -- decrement the count. However, if the parent is something like:
4499 -- raise ...; -- or some other jump
4502 -- where cond is an expression that is known-true at compile time,
4503 -- we can treat that as just the jump -- i.e. anything following
4504 -- the if statement is unreachable. We don't do this for simple
4505 -- cases like "if True" or "if Debug_Flag", because that causes
4506 -- too many warnings.
4508 if Nkind
(P
) = N_If_Statement
4509 and then Present
(Then_Statements
(P
))
4510 and then No
(Elsif_Parts
(P
))
4511 and then No
(Else_Statements
(P
))
4512 and then Is_OK_Static_Expression
(Condition
(P
))
4513 and then Is_True
(Expr_Value
(Condition
(P
)))
4514 and then not Is_Simple_Case
(Condition
(P
))
4516 pragma Assert
(Unblocked_Exit_Count
= 2);
4517 Unblocked_Exit_Count
:= 0;
4519 Unblocked_Exit_Count
:= Unblocked_Exit_Count
- 1;
4523 end Check_Unreachable_Code
;
4525 ------------------------
4526 -- Has_Sec_Stack_Call --
4527 ------------------------
4529 function Has_Sec_Stack_Call
(N
: Node_Id
) return Boolean is
4530 function Check_Call
(N
: Node_Id
) return Traverse_Result
;
4531 -- Check if N is a function call which uses the secondary stack
4537 function Check_Call
(N
: Node_Id
) return Traverse_Result
is
4543 if Nkind
(N
) = N_Function_Call
then
4546 -- Obtain the subprogram being invoked
4549 if Nkind
(Nam
) = N_Explicit_Dereference
then
4550 Nam
:= Prefix
(Nam
);
4552 elsif Nkind
(Nam
) = N_Selected_Component
then
4553 Nam
:= Selector_Name
(Nam
);
4560 Subp
:= Entity
(Nam
);
4562 if Present
(Subp
) then
4563 Typ
:= Etype
(Subp
);
4565 if Requires_Transient_Scope
(Typ
) then
4568 elsif Sec_Stack_Needed_For_Return
(Subp
) then
4574 -- Continue traversing the tree
4579 function Check_Calls
is new Traverse_Func
(Check_Call
);
4581 -- Start of processing for Has_Sec_Stack_Call
4584 return Check_Calls
(N
) = Abandon
;
4585 end Has_Sec_Stack_Call
;
4587 ----------------------
4588 -- Preanalyze_Range --
4589 ----------------------
4591 procedure Preanalyze_Range
(R_Copy
: Node_Id
) is
4592 Save_Analysis
: constant Boolean := Full_Analysis
;
4596 Full_Analysis
:= False;
4597 Expander_Mode_Save_And_Set
(False);
4599 -- In addition to the above we must explicitly suppress the generation
4600 -- of freeze nodes that might otherwise be generated during resolution
4601 -- of the range (e.g. if given by an attribute that will freeze its
4604 Set_Must_Not_Freeze
(R_Copy
);
4606 if Nkind
(R_Copy
) = N_Attribute_Reference
then
4607 Set_Must_Not_Freeze
(Prefix
(R_Copy
));
4612 if Nkind
(R_Copy
) in N_Subexpr
and then Is_Overloaded
(R_Copy
) then
4614 -- Apply preference rules for range of predefined integer types, or
4615 -- check for array or iterable construct for "of" iterator, or
4616 -- diagnose true ambiguity.
4621 Found
: Entity_Id
:= Empty
;
4624 Get_First_Interp
(R_Copy
, I
, It
);
4625 while Present
(It
.Typ
) loop
4626 if Is_Discrete_Type
(It
.Typ
) then
4630 if Scope
(Found
) = Standard_Standard
then
4633 elsif Scope
(It
.Typ
) = Standard_Standard
then
4637 -- Both of them are user-defined
4640 ("ambiguous bounds in range of iteration", R_Copy
);
4641 Error_Msg_N
("\possible interpretations:", R_Copy
);
4642 Error_Msg_NE
("\\}", R_Copy
, Found
);
4643 Error_Msg_NE
("\\}", R_Copy
, It
.Typ
);
4648 elsif Nkind
(Parent
(R_Copy
)) = N_Iterator_Specification
4649 and then Of_Present
(Parent
(R_Copy
))
4651 if Is_Array_Type
(It
.Typ
)
4652 or else Has_Aspect
(It
.Typ
, Aspect_Iterator_Element
)
4653 or else Has_Aspect
(It
.Typ
, Aspect_Constant_Indexing
)
4654 or else Has_Aspect
(It
.Typ
, Aspect_Variable_Indexing
)
4658 Set_Etype
(R_Copy
, It
.Typ
);
4661 Error_Msg_N
("ambiguous domain of iteration", R_Copy
);
4666 Get_Next_Interp
(I
, It
);
4671 -- Subtype mark in iteration scheme
4673 if Is_Entity_Name
(R_Copy
) and then Is_Type
(Entity
(R_Copy
)) then
4676 -- Expression in range, or Ada 2012 iterator
4678 elsif Nkind
(R_Copy
) in N_Subexpr
then
4680 Typ
:= Etype
(R_Copy
);
4682 if Is_Discrete_Type
(Typ
) then
4685 -- Check that the resulting object is an iterable container
4687 elsif Has_Aspect
(Typ
, Aspect_Iterator_Element
)
4688 or else Has_Aspect
(Typ
, Aspect_Constant_Indexing
)
4689 or else Has_Aspect
(Typ
, Aspect_Variable_Indexing
)
4693 -- The expression may yield an implicit reference to an iterable
4694 -- container. Insert explicit dereference so that proper type is
4695 -- visible in the loop.
4697 elsif Has_Implicit_Dereference
(Etype
(R_Copy
)) then
4698 Build_Explicit_Dereference
4699 (R_Copy
, Get_Reference_Discriminant
(Etype
(R_Copy
)));
4703 Expander_Mode_Restore
;
4704 Full_Analysis
:= Save_Analysis
;
4705 end Preanalyze_Range
;