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-------------------------------------------------------------------------------
-- (C) Altran Praxis Limited
-------------------------------------------------------------------------------
--
-- The SPARK toolset is free software; you can redistribute it and/or modify it
-- under terms of the GNU General Public License as published by the Free
-- Software Foundation; either version 3, or (at your option) any later
-- version. The SPARK toolset is distributed in the hope that it will be
-- useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
-- Public License for more details. You should have received a copy of the GNU
-- General Public License distributed with the SPARK toolset; see file
-- COPYING3. If not, go to http://www.gnu.org/licenses for a complete copy of
-- the license.
--
--=============================================================================
with SystemErrors;
with Debug;
package body StmtStack is
EmptyStack : constant StmtStacks :=
StmtStacks'(Vector => StmtVector'(others => StmtRecord'(StmtNmbr => 0,
Kind => ArcKind'First)),
Pointer => 0);
S : StmtStacks;
function IsEmpty return Boolean is
begin
return S.Pointer = 0;
end IsEmpty;
function Top return StmtRecord
-- pre not IsEmpty (S);
is
begin
--# accept Flow, 10, "Expected ineffective statement";
if S.Pointer = 0 then
--# end accept;
SystemErrors.Fatal_Error (Sys_Err => SystemErrors.Statement_Stack_Underflow,
Msg => "");
end if;
return S.Vector (S.Pointer);
end Top;
procedure Clear is
begin
S := EmptyStack;
end Clear;
procedure Pop
-- pre not IsEmpty (S);
is
begin
if S.Pointer = 0 then
SystemErrors.Fatal_Error (Sys_Err => SystemErrors.Statement_Stack_Underflow,
Msg => "");
end if;
S.Pointer := S.Pointer - 1;
end Pop;
procedure Push (R : in StmtRecord) is
begin
if S.Pointer = StmtRange'Last then
SystemErrors.Fatal_Error (Sys_Err => SystemErrors.Statement_Stack_Overflow,
Msg => "");
end if;
S.Pointer := S.Pointer + 1;
S.Vector (S.Pointer) := R;
end Push;
procedure Dump_Stack (Msg : in String) is
--# hide Dump_Stack;
begin
Debug.PrintMsg (Msg, True);
if S.Pointer = 0 then
Debug.PrintMsg ("Empty", True);
else
Debug.PrintMsg ("Top", True);
for I in reverse StmtRange range 1 .. S.Pointer loop
Debug.PrintMsg (ArcKind'Image (S.Vector (I).Kind), False);
Debug.PrintMsg (Integer'Image (S.Vector (I).StmtNmbr), True);
end loop;
Debug.PrintMsg ("Bottom", True);
end if;
end Dump_Stack;
begin
S := EmptyStack;
end StmtStack;
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