solidity/libsolidity/formal/Z3CHCInterface.cpp
2019-09-13 12:40:53 +02:00

112 lines
3.0 KiB
C++

/*
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/Z3CHCInterface.h>
#include <liblangutil/Exceptions.h>
#include <libdevcore/CommonIO.h>
using namespace std;
using namespace dev;
using namespace dev::solidity::smt;
Z3CHCInterface::Z3CHCInterface():
m_z3Interface(make_shared<Z3Interface>()),
m_context(m_z3Interface->context()),
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);
// Spacer options.
// These needs to be set in the solver.
// https://github.com/Z3Prover/z3/blob/master/src/muz/base/fp_params.pyg
z3::params p(*m_context);
// These are useful for solving problems with arrays and loops.
// Use quantified lemma generalizer.
p.set("fp.spacer.q3.use_qgen", true);
p.set("fp.spacer.mbqi", false);
// Ground pobs by using values from a model.
p.set("fp.spacer.ground_pobs", false);
m_solver.set(p);
}
void Z3CHCInterface::declareVariable(string const& _name, Sort const& _sort)
{
m_z3Interface->declareVariable(_name, _sort);
}
void Z3CHCInterface::registerRelation(Expression const& _expr)
{
m_solver.register_relation(m_z3Interface->functions().at(_expr.name));
}
void Z3CHCInterface::addRule(Expression const& _expr, string const& _name)
{
z3::expr rule = m_z3Interface->toZ3Expr(_expr);
if (m_z3Interface->constants().empty())
m_solver.add_rule(rule, m_context->str_symbol(_name.c_str()));
else
{
z3::expr_vector variables(*m_context);
for (auto const& var: m_z3Interface->constants())
variables.push_back(var.second);
z3::expr boundRule = z3::forall(variables, rule);
m_solver.add_rule(boundRule, m_context->str_symbol(_name.c_str()));
}
}
pair<CheckResult, vector<string>> Z3CHCInterface::query(Expression const& _expr)
{
CheckResult result;
vector<string> values;
try
{
z3::expr z3Expr = m_z3Interface->toZ3Expr(_expr);
switch (m_solver.query(z3Expr))
{
case z3::check_result::sat:
{
result = CheckResult::SATISFIABLE;
// TODO retrieve model.
break;
}
case z3::check_result::unsat:
{
result = CheckResult::UNSATISFIABLE;
// TODO retrieve invariants.
break;
}
case z3::check_result::unknown:
{
result = CheckResult::UNKNOWN;
break;
}
}
// TODO retrieve model / invariants
}
catch (z3::exception const&)
{
result = CheckResult::ERROR;
values.clear();
}
return make_pair(result, values);
}