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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity 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
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libsolidity/formal/Z3Interface.h>
#include <liblangutil/Exceptions.h>
#include <libdevcore/CommonIO.h>
using namespace std;
using namespace dev;
using namespace dev::solidity::smt;
Z3Interface::Z3Interface():
m_solver(m_context)
{
// This needs to be set globally.
z3::set_param("rewriter.pull_cheap_ite", true);
// This needs to be set in the context.
m_context.set("timeout", queryTimeout);
}
void Z3Interface::reset()
{
m_constants.clear();
m_functions.clear();
m_solver.reset();
}
void Z3Interface::push()
{
m_solver.push();
}
void Z3Interface::pop()
{
m_solver.pop();
}
void Z3Interface::declareFunction(string _name, vector<SortPointer> const& _domain, Sort const& _codomain)
{
if (!m_functions.count(_name))
m_functions.insert({_name, m_context.function(_name.c_str(), z3Sort(_domain), z3Sort(_codomain))});
}
void Z3Interface::declareInteger(string _name)
{
if (!m_constants.count(_name))
m_constants.insert({_name, m_context.int_const(_name.c_str())});
}
void Z3Interface::declareBool(string _name)
{
if (!m_constants.count(_name))
m_constants.insert({_name, m_context.bool_const(_name.c_str())});
}
void Z3Interface::addAssertion(Expression const& _expr)
{
m_solver.add(toZ3Expr(_expr));
}
pair<CheckResult, vector<string>> Z3Interface::check(vector<Expression> const& _expressionsToEvaluate)
{
CheckResult result;
vector<string> values;
try
{
switch (m_solver.check())
{
case z3::check_result::sat:
result = CheckResult::SATISFIABLE;
break;
case z3::check_result::unsat:
result = CheckResult::UNSATISFIABLE;
break;
case z3::check_result::unknown:
result = CheckResult::UNKNOWN;
break;
}
if (result == CheckResult::SATISFIABLE && !_expressionsToEvaluate.empty())
{
z3::model m = m_solver.get_model();
for (Expression const& e: _expressionsToEvaluate)
values.push_back(toString(m.eval(toZ3Expr(e))));
}
}
catch (z3::exception const&)
{
result = CheckResult::ERROR;
values.clear();
}
return make_pair(result, values);
}
z3::expr Z3Interface::toZ3Expr(Expression const& _expr)
{
if (_expr.arguments.empty() && m_constants.count(_expr.name))
return m_constants.at(_expr.name);
z3::expr_vector arguments(m_context);
for (auto const& arg: _expr.arguments)
arguments.push_back(toZ3Expr(arg));
string const& n = _expr.name;
if (m_functions.count(n))
return m_functions.at(n)(arguments);
else if (m_constants.count(n))
{
solAssert(arguments.empty(), "");
return m_constants.at(n);
}
else if (arguments.empty())
{
if (n == "true")
return m_context.bool_val(true);
else if (n == "false")
return m_context.bool_val(false);
else
// We assume it is an integer...
return m_context.int_val(n.c_str());
}
solAssert(_expr.hasCorrectArity(), "");
if (n == "ite")
return z3::ite(arguments[0], arguments[1], arguments[2]);
else if (n == "not")
return !arguments[0];
else if (n == "and")
return arguments[0] && arguments[1];
else if (n == "or")
return arguments[0] || arguments[1];
else if (n == "=")
return arguments[0] == arguments[1];
else if (n == "<")
return arguments[0] < arguments[1];
else if (n == "<=")
return arguments[0] <= arguments[1];
else if (n == ">")
return arguments[0] > arguments[1];
else if (n == ">=")
return arguments[0] >= arguments[1];
else if (n == "+")
return arguments[0] + arguments[1];
else if (n == "-")
return arguments[0] - arguments[1];
else if (n == "*")
return arguments[0] * arguments[1];
else if (n == "/")
return arguments[0] / arguments[1];
// Cannot reach here.
solAssert(false, "");
return arguments[0];
}
z3::sort Z3Interface::z3Sort(Sort const& _sort)
{
switch (_sort.kind)
{
case Kind::Bool:
return m_context.bool_sort();
case Kind::Int:
return m_context.int_sort();
default:
break;
}
solAssert(false, "");
// Cannot be reached.
return m_context.int_sort();
}
z3::sort_vector Z3Interface::z3Sort(vector<SortPointer> const& _sorts)
{
z3::sort_vector z3Sorts(m_context);
for (auto const& _sort: _sorts)
z3Sorts.push_back(z3Sort(*_sort));
return z3Sorts;
}
|
