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
|
// RUN: %boogie -noinfer -typeEncoding:m -useArrayTheory "%s" > "%t"
// RUN: %diff "%s.expect" "%t"
// XFAIL: *
type Node;
type lmap;
function {:linear "Node"} dom(lmap): [Node]bool;
function map(lmap): [Node]Node;
procedure {:yields} Load(i:Node) returns(v:Node);
requires dom(stack)[i];
ensures {:atomic 0} v == map(stack)[i];
procedure {:yields} Store({:linear "Node"} l_in:lmap, i:Node, v:Node) returns({:linear "Node"} l_out:lmap);
requires dom(l_in)[i];
ensures {:atomic 0} dom(l_out) == dom(l_in) && map(l_out) == map(l_in)[i := v];
procedure {:yields} TransferToStack(oldVal: Node, newVal: Node, {:linear "Node"} l_in:lmap) returns (r: bool, {:linear "Node"} l_out:lmap);
requires dom(l_in)[newVal];
modifies stack, TOP;
ensures {:atomic 0} if oldVal == old(TOP)
then newVal == TOP && dom(stack) == dom(old(stack))[newVal := true] && map(stack) == map(old(stack))[newVal := map(l_in)[newVal]]
else TOP == old(TOP) && stack == old(stack) && l_out == l_in;
procedure {:yields} TransferFromStack(oldVal: Node, newVal: Node) returns (r: bool, {:linear "Node"} l_out:lmap);
requires dom(stack)[oldVal];
modifies stack, TOP;
ensures {:atomic 0} if oldVal == old(TOP)
then dom(stack) == dom(old(stack))[oldVal := false] && map(stack) == map(old(stack)) && dom(l_out)[oldVal] && map(l_out)[oldVal] == map(old(stack))[oldVal]
else TOP == old(TOP) && stack == old(stack);
procedure Alloc() returns (d: Node, {:linear "Node"} l: lmap);
ensures dom(l)[d];
procedure Free(d: Node, {:linear "Node"} l: lmap);
const unique null: Node;
var {:qed} TOP: Node;
var {:qed} {:linear "Node"} stack: lmap;
procedure {:yields} push()
{
var t, x: Node;
var g: bool;
var {:linear "Node"} x_lmap: lmap;
call x, x_lmap := Alloc();
while(true)
{
t := TOP;
call x_lmap := Store(x_lmap, x, t);
call g, x_lmap := TransferToStack(t, x, x_lmap);
if (g) {
break;
}
}
}
procedure {:yields} pop()
{
var t, x: Node;
var g: bool;
var {:linear "Node"} t_lmap: lmap;
while(true)
{
t := TOP;
if (t == null)
{
return;
}
call x := Load(t);
call g, t_lmap := TransferFromStack(t, x);
if (g) {
call Free(t, t_lmap);
break;
}
}
}
|
