solidity/libsmtutil/CVC4Interface.cpp
2020-09-09 19:47:52 +02:00

330 lines
9.9 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/>.
*/
// SPDX-License-Identifier: GPL-3.0
#include <libsmtutil/CVC4Interface.h>
#include <libsolutil/CommonIO.h>
#include <cvc4/util/bitvector.h>
using namespace std;
using namespace solidity;
using namespace solidity::util;
using namespace solidity::smtutil;
CVC4Interface::CVC4Interface():
m_solver(&m_context)
{
reset();
}
void CVC4Interface::reset()
{
m_variables.clear();
m_solver.reset();
m_solver.setOption("produce-models", true);
m_solver.setResourceLimit(resourceLimit);
}
void CVC4Interface::push()
{
m_solver.push();
}
void CVC4Interface::pop()
{
m_solver.pop();
}
void CVC4Interface::declareVariable(string const& _name, SortPointer const& _sort)
{
smtAssert(_sort, "");
m_variables[_name] = m_context.mkVar(_name.c_str(), cvc4Sort(*_sort));
}
void CVC4Interface::addAssertion(Expression const& _expr)
{
try
{
m_solver.assertFormula(toCVC4Expr(_expr));
}
catch (CVC4::TypeCheckingException const& _e)
{
smtAssert(false, _e.what());
}
catch (CVC4::LogicException const& _e)
{
smtAssert(false, _e.what());
}
catch (CVC4::UnsafeInterruptException const& _e)
{
smtAssert(false, _e.what());
}
catch (CVC4::Exception const& _e)
{
smtAssert(false, _e.what());
}
}
pair<CheckResult, vector<string>> CVC4Interface::check(vector<Expression> const& _expressionsToEvaluate)
{
CheckResult result;
vector<string> values;
try
{
switch (m_solver.checkSat().isSat())
{
case CVC4::Result::SAT:
result = CheckResult::SATISFIABLE;
break;
case CVC4::Result::UNSAT:
result = CheckResult::UNSATISFIABLE;
break;
case CVC4::Result::SAT_UNKNOWN:
result = CheckResult::UNKNOWN;
break;
default:
smtAssert(false, "");
}
if (result == CheckResult::SATISFIABLE && !_expressionsToEvaluate.empty())
{
for (Expression const& e: _expressionsToEvaluate)
values.push_back(toString(m_solver.getValue(toCVC4Expr(e))));
}
}
catch (CVC4::Exception const&)
{
result = CheckResult::ERROR;
values.clear();
}
return make_pair(result, values);
}
CVC4::Expr CVC4Interface::toCVC4Expr(Expression const& _expr)
{
// Variable
if (_expr.arguments.empty() && m_variables.count(_expr.name))
return m_variables.at(_expr.name);
vector<CVC4::Expr> arguments;
for (auto const& arg: _expr.arguments)
arguments.push_back(toCVC4Expr(arg));
try
{
string const& n = _expr.name;
// Function application
if (!arguments.empty() && m_variables.count(_expr.name))
return m_context.mkExpr(CVC4::kind::APPLY_UF, m_variables.at(n), arguments);
// Literal
else if (arguments.empty())
{
if (n == "true")
return m_context.mkConst(true);
else if (n == "false")
return m_context.mkConst(false);
else if (auto sortSort = dynamic_pointer_cast<SortSort>(_expr.sort))
return m_context.mkVar(n, cvc4Sort(*sortSort->inner));
else
try
{
return m_context.mkConst(CVC4::Rational(n));
}
catch (CVC4::TypeCheckingException const& _e)
{
smtAssert(false, _e.what());
}
catch (CVC4::Exception const& _e)
{
smtAssert(false, _e.what());
}
}
smtAssert(_expr.hasCorrectArity(), "");
if (n == "ite")
return arguments[0].iteExpr(arguments[1], arguments[2]);
else if (n == "not")
return arguments[0].notExpr();
else if (n == "and")
return arguments[0].andExpr(arguments[1]);
else if (n == "or")
return arguments[0].orExpr(arguments[1]);
else if (n == "implies")
return m_context.mkExpr(CVC4::kind::IMPLIES, arguments[0], arguments[1]);
else if (n == "=")
return m_context.mkExpr(CVC4::kind::EQUAL, arguments[0], arguments[1]);
else if (n == "<")
return m_context.mkExpr(CVC4::kind::LT, arguments[0], arguments[1]);
else if (n == "<=")
return m_context.mkExpr(CVC4::kind::LEQ, arguments[0], arguments[1]);
else if (n == ">")
return m_context.mkExpr(CVC4::kind::GT, arguments[0], arguments[1]);
else if (n == ">=")
return m_context.mkExpr(CVC4::kind::GEQ, arguments[0], arguments[1]);
else if (n == "+")
return m_context.mkExpr(CVC4::kind::PLUS, arguments[0], arguments[1]);
else if (n == "-")
return m_context.mkExpr(CVC4::kind::MINUS, arguments[0], arguments[1]);
else if (n == "*")
return m_context.mkExpr(CVC4::kind::MULT, arguments[0], arguments[1]);
else if (n == "/")
return m_context.mkExpr(CVC4::kind::INTS_DIVISION_TOTAL, arguments[0], arguments[1]);
else if (n == "mod")
return m_context.mkExpr(CVC4::kind::INTS_MODULUS, arguments[0], arguments[1]);
else if (n == "bvnot")
return m_context.mkExpr(CVC4::kind::BITVECTOR_NOT, arguments[0]);
else if (n == "bvand")
return m_context.mkExpr(CVC4::kind::BITVECTOR_AND, arguments[0], arguments[1]);
else if (n == "bvor")
return m_context.mkExpr(CVC4::kind::BITVECTOR_OR, arguments[0], arguments[1]);
else if (n == "bvxor")
return m_context.mkExpr(CVC4::kind::BITVECTOR_XOR, arguments[0], arguments[1]);
else if (n == "bvshl")
return m_context.mkExpr(CVC4::kind::BITVECTOR_SHL, arguments[0], arguments[1]);
else if (n == "bvlshr")
return m_context.mkExpr(CVC4::kind::BITVECTOR_LSHR, arguments[0], arguments[1]);
else if (n == "bvashr")
return m_context.mkExpr(CVC4::kind::BITVECTOR_ASHR, arguments[0], arguments[1]);
else if (n == "int2bv")
{
size_t size = std::stoul(_expr.arguments[1].name);
auto i2bvOp = m_context.mkConst(CVC4::IntToBitVector(size));
// CVC4 treats all BVs as unsigned, so we need to manually apply 2's complement if needed.
return m_context.mkExpr(
CVC4::kind::ITE,
m_context.mkExpr(CVC4::kind::GEQ, arguments[0], m_context.mkConst(CVC4::Rational(0))),
m_context.mkExpr(CVC4::kind::INT_TO_BITVECTOR, i2bvOp, arguments[0]),
m_context.mkExpr(
CVC4::kind::BITVECTOR_NEG,
m_context.mkExpr(CVC4::kind::INT_TO_BITVECTOR, i2bvOp, m_context.mkExpr(CVC4::kind::UMINUS, arguments[0]))
)
);
}
else if (n == "bv2int")
{
auto intSort = dynamic_pointer_cast<IntSort>(_expr.sort);
smtAssert(intSort, "");
auto nat = m_context.mkExpr(CVC4::kind::BITVECTOR_TO_NAT, arguments[0]);
if (!intSort->isSigned)
return nat;
auto type = arguments[0].getType();
smtAssert(type.isBitVector(), "");
auto size = CVC4::BitVectorType(type).getSize();
// CVC4 treats all BVs as unsigned, so we need to manually apply 2's complement if needed.
auto extractOp = m_context.mkConst(CVC4::BitVectorExtract(size - 1, size - 1));
return m_context.mkExpr(CVC4::kind::ITE,
m_context.mkExpr(
CVC4::kind::EQUAL,
m_context.mkExpr(CVC4::kind::BITVECTOR_EXTRACT, extractOp, arguments[0]),
m_context.mkConst(CVC4::BitVector(1, size_t(0)))
),
nat,
m_context.mkExpr(
CVC4::kind::UMINUS,
m_context.mkExpr(CVC4::kind::BITVECTOR_TO_NAT, m_context.mkExpr(CVC4::kind::BITVECTOR_NEG, arguments[0]))
)
);
}
else if (n == "select")
return m_context.mkExpr(CVC4::kind::SELECT, arguments[0], arguments[1]);
else if (n == "store")
return m_context.mkExpr(CVC4::kind::STORE, arguments[0], arguments[1], arguments[2]);
else if (n == "const_array")
{
shared_ptr<SortSort> sortSort = std::dynamic_pointer_cast<SortSort>(_expr.arguments[0].sort);
smtAssert(sortSort, "");
return m_context.mkConst(CVC4::ArrayStoreAll(cvc4Sort(*sortSort->inner), arguments[1]));
}
else if (n == "tuple_get")
{
shared_ptr<TupleSort> tupleSort = std::dynamic_pointer_cast<TupleSort>(_expr.arguments[0].sort);
smtAssert(tupleSort, "");
CVC4::DatatypeType tt = m_context.mkTupleType(cvc4Sort(tupleSort->components));
CVC4::Datatype const& dt = tt.getDatatype();
size_t index = std::stoul(_expr.arguments[1].name);
CVC4::Expr s = dt[0][index].getSelector();
return m_context.mkExpr(CVC4::kind::APPLY_SELECTOR, s, arguments[0]);
}
else if (n == "tuple_constructor")
{
shared_ptr<TupleSort> tupleSort = std::dynamic_pointer_cast<TupleSort>(_expr.sort);
smtAssert(tupleSort, "");
CVC4::DatatypeType tt = m_context.mkTupleType(cvc4Sort(tupleSort->components));
CVC4::Datatype const& dt = tt.getDatatype();
CVC4::Expr c = dt[0].getConstructor();
return m_context.mkExpr(CVC4::kind::APPLY_CONSTRUCTOR, c, arguments);
}
smtAssert(false, "");
}
catch (CVC4::TypeCheckingException const& _e)
{
smtAssert(false, _e.what());
}
catch (CVC4::Exception const& _e)
{
smtAssert(false, _e.what());
}
smtAssert(false, "");
}
CVC4::Type CVC4Interface::cvc4Sort(Sort const& _sort)
{
switch (_sort.kind)
{
case Kind::Bool:
return m_context.booleanType();
case Kind::Int:
return m_context.integerType();
case Kind::BitVector:
return m_context.mkBitVectorType(dynamic_cast<BitVectorSort const&>(_sort).size);
case Kind::Function:
{
FunctionSort const& fSort = dynamic_cast<FunctionSort const&>(_sort);
return m_context.mkFunctionType(cvc4Sort(fSort.domain), cvc4Sort(*fSort.codomain));
}
case Kind::Array:
{
auto const& arraySort = dynamic_cast<ArraySort const&>(_sort);
return m_context.mkArrayType(cvc4Sort(*arraySort.domain), cvc4Sort(*arraySort.range));
}
case Kind::Tuple:
{
auto const& tupleSort = dynamic_cast<TupleSort const&>(_sort);
return m_context.mkTupleType(cvc4Sort(tupleSort.components));
}
default:
break;
}
smtAssert(false, "");
// Cannot be reached.
return m_context.integerType();
}
vector<CVC4::Type> CVC4Interface::cvc4Sort(vector<SortPointer> const& _sorts)
{
vector<CVC4::Type> cvc4Sorts;
for (auto const& _sort: _sorts)
cvc4Sorts.push_back(cvc4Sort(*_sort));
return cvc4Sorts;
}