1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
-------------------------------------------------------------------------------
-- (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 CStacks;
package body Structures is
procedure CopyStructure (Heap : in out Cells.Heap_Record;
Root : in Cells.Cell;
RootCopy : out Cells.Cell) is
CopiedCellStack, UnexploredCellStack : CStacks.Stack;
TopCell, TopCellCopy : Cells.Cell;
-------------------------------------------
procedure Mark (C : in Cells.Cell)
--# global in out CopiedCellStack;
--# in out Heap;
--# in out Statistics.TableUsage;
--# in out UnexploredCellStack;
--# derives CopiedCellStack,
--# UnexploredCellStack from *,
--# C,
--# CopiedCellStack,
--# Heap &
--# Heap,
--# Statistics.TableUsage from *,
--# C,
--# CopiedCellStack,
--# Heap,
--# UnexploredCellStack;
is
begin
if not Cells.Is_Null_Cell (C) then
if not Cells.Is_Marked (Heap, C) then
Cells.Mark_Cell (Heap, C);
CStacks.Push (Heap, C, CopiedCellStack);
CStacks.Push (Heap, C, UnexploredCellStack);
Cells.Create_Copy (Heap, C);
end if;
end if;
end Mark;
----------------------------------------------
begin -- CopyStructure;
CStacks.CreateStack (UnexploredCellStack);
CStacks.CreateStack (CopiedCellStack);
Mark (Root);
RootCopy := Cells.Get_Copy (Heap, Root);
loop
exit when CStacks.IsEmpty (UnexploredCellStack);
TopCell := CStacks.Top (Heap, UnexploredCellStack);
CStacks.Pop (Heap, UnexploredCellStack);
Mark (Cells.Get_A_Ptr (Heap, TopCell));
Mark (Cells.Get_B_Ptr (Heap, TopCell));
Mark (Cells.Get_C_Ptr (Heap, TopCell));
end loop;
loop
exit when CStacks.IsEmpty (CopiedCellStack);
TopCell := CStacks.Top (Heap, CopiedCellStack);
TopCellCopy := Cells.Get_Copy (Heap, TopCell);
if not Cells.Is_Null_Cell (Cells.Get_A_Ptr (Heap, TopCell)) then
Cells.Set_A_Ptr (Heap, TopCellCopy, Cells.Get_Copy (Heap, Cells.Get_A_Ptr (Heap, TopCell)));
end if;
if not Cells.Is_Null_Cell (Cells.Get_B_Ptr (Heap, TopCell)) then
Cells.Set_B_Ptr (Heap, TopCellCopy, Cells.Get_Copy (Heap, Cells.Get_B_Ptr (Heap, TopCell)));
end if;
if not Cells.Is_Null_Cell (Cells.Get_C_Ptr (Heap, TopCell)) then
Cells.Set_C_Ptr (Heap, TopCellCopy, Cells.Get_Copy (Heap, Cells.Get_C_Ptr (Heap, TopCell)));
end if;
Cells.UnMark_Cell (Heap, TopCell);
CStacks.Pop (Heap, CopiedCellStack);
end loop;
end CopyStructure;
--------------------------------------------------------------------------
procedure DisposeOfStructure (Heap : in out Cells.Heap_Record;
Root : in Cells.Cell) is
DefunctCellStack, UnexploredCellStack : CStacks.Stack;
TopCell : Cells.Cell;
-----------------------------------------------
procedure MarkAndPush (C : in Cells.Cell)
--# global in out DefunctCellStack;
--# in out Heap;
--# in out Statistics.TableUsage;
--# in out UnexploredCellStack;
--# derives DefunctCellStack,
--# Statistics.TableUsage,
--# UnexploredCellStack from *,
--# C,
--# DefunctCellStack,
--# Heap &
--# Heap from *,
--# C,
--# DefunctCellStack,
--# UnexploredCellStack;
is
begin
if not Cells.Is_Null_Cell (C) then
if not Cells.Is_Marked (Heap, C) then
Cells.Mark_Cell (Heap, C);
CStacks.Push (Heap, C, DefunctCellStack);
CStacks.Push (Heap, C, UnexploredCellStack);
end if;
end if;
end MarkAndPush;
---------------------------------------------------
begin -- DisposeOfStructure;
CStacks.CreateStack (UnexploredCellStack);
CStacks.CreateStack (DefunctCellStack);
MarkAndPush (Root);
loop
exit when CStacks.IsEmpty (UnexploredCellStack);
TopCell := CStacks.Top (Heap, UnexploredCellStack);
CStacks.Pop (Heap, UnexploredCellStack);
MarkAndPush (Cells.Get_A_Ptr (Heap, TopCell));
MarkAndPush (Cells.Get_B_Ptr (Heap, TopCell));
MarkAndPush (Cells.Get_C_Ptr (Heap, TopCell));
end loop;
loop
exit when CStacks.IsEmpty (DefunctCellStack);
Cells.Dispose_Of_Cell (Heap, CStacks.Top (Heap, DefunctCellStack));
CStacks.Pop (Heap, DefunctCellStack);
end loop;
end DisposeOfStructure;
end Structures;
|
