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/*
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::declareVariable(string const& _name, Sort const& _sort)
{
if (_sort.kind == Kind::Function)
declareFunction(_name, _sort);
else if (!m_constants.count(_name))
m_constants.insert({_name, m_context.constant(_name.c_str(), z3Sort(_sort))});
}
void Z3Interface::declareFunction(string const& _name, Sort const& _sort)
{
solAssert(_sort.kind == smt::Kind::Function, "");
if (!m_functions.count(_name))
{
FunctionSort fSort = dynamic_cast<FunctionSort const&>(_sort);
m_functions.insert({_name, m_context.function(_name.c_str(), z3Sort(fSort.domain), z3Sort(*fSort.codomain))});
}
}
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];
else if (n == "select")
return z3::select(arguments[0], arguments[1]);
else if (n == "store")
return z3::store(arguments[0], arguments[1], arguments[2]);
// 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();
case Kind::Array:
{
auto const& arraySort = dynamic_cast<ArraySort const&>(_sort);
return m_context.array_sort(z3Sort(*arraySort.domain), z3Sort(*arraySort.range));
}
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;
}
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