path: root/libsolidity/formal/SolverInterface.h

/*
    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/>.
*/

#pragma once

#include <libsolidity/interface/Exceptions.h>
#include <libsolidity/interface/ReadFile.h>

#include <libdevcore/Common.h>
#include <libdevcore/Exceptions.h>

#include <boost/noncopyable.hpp>

#include <map>
#include <string>
#include <vector>
#include <cstdio>

namespace dev
{
namespace solidity
{
namespace smt
{

enum class CheckResult
{
    SAT, UNSAT, UNKNOWN, ERROR
};

enum class Sort
{
    Int, Bool
};

/// C++ representation of an SMTLIB2 expression.
class Expression
{
    friend class SolverInterface;
public:
    Expression(size_t _number): name(std::to_string(_number)) {}
    Expression(u256 const& _number): name(_number.str()) {}
    Expression(bigint const& _number): name(_number.str()) {}

    Expression(Expression const& _other) = default;
    Expression(Expression&& _other) = default;
    Expression& operator=(Expression const& _other) = default;
    Expression& operator=(Expression&& _other) = default;

    static Expression ite(Expression _condition, Expression _trueValue, Expression _falseValue)
    {
        return Expression("ite", std::vector<Expression>{
            std::move(_condition), std::move(_trueValue), std::move(_falseValue)
        });
    }

    friend Expression operator!(Expression _a)
    {
        return Expression("not", std::move(_a));
    }
    friend Expression operator&&(Expression _a, Expression _b)
    {
        return Expression("and", std::move(_a), std::move(_b));
    }
    friend Expression operator||(Expression _a, Expression _b)
    {
        return Expression("or", std::move(_a), std::move(_b));
    }
    friend Expression operator==(Expression _a, Expression _b)
    {
        return Expression("=", std::move(_a), std::move(_b));
    }
    friend Expression operator!=(Expression _a, Expression _b)
    {
        return !(std::move(_a) == std::move(_b));
    }
    friend Expression operator<(Expression _a, Expression _b)
    {
        return Expression("<", std::move(_a), std::move(_b));
    }
    friend Expression operator<=(Expression _a, Expression _b)
    {
        return Expression("<=", std::move(_a), std::move(_b));
    }
    friend Expression operator>(Expression _a, Expression _b)
    {
        return Expression(">", std::move(_a), std::move(_b));
    }
    friend Expression operator>=(Expression _a, Expression _b)
    {
        return Expression(">=", std::move(_a), std::move(_b));
    }
    friend Expression operator+(Expression _a, Expression _b)
    {
        return Expression("+", std::move(_a), std::move(_b));
    }
    friend Expression operator-(Expression _a, Expression _b)
    {
        return Expression("-", std::move(_a), std::move(_b));
    }
    friend Expression operator*(Expression _a, Expression _b)
    {
        return Expression("*", std::move(_a), std::move(_b));
    }
    Expression operator()(Expression _a) const
    {
        solAssert(arguments.empty(), "Attempted function application to non-function.");
        return Expression(name, _a);
    }

    std::string const name;
    std::vector<Expression> const arguments;

private:
    /// Manual constructor, should only be used by SolverInterface and this class itself.
    Expression(std::string _name, std::vector<Expression> _arguments):
        name(std::move(_name)), arguments(std::move(_arguments)) {}

    explicit Expression(std::string _name):
        Expression(std::move(_name), std::vector<Expression>{}) {}
    Expression(std::string _name, Expression _arg):
        Expression(std::move(_name), std::vector<Expression>{std::move(_arg)}) {}
    Expression(std::string _name, Expression _arg1, Expression _arg2):
        Expression(std::move(_name), std::vector<Expression>{std::move(_arg1), std::move(_arg2)}) {}
};

DEV_SIMPLE_EXCEPTION(SolverError);

class SolverInterface
{
public:
    virtual void reset() = 0;

    virtual void push() = 0;
    virtual void pop() = 0;

    virtual Expression newFunction(std::string _name, Sort /*_domain*/, Sort /*_codomain*/)
    {
        // Subclasses should do something here
        return Expression(std::move(_name), {});
    }
    virtual Expression newInteger(std::string _name)
    {
        // Subclasses should do something here
        return Expression(std::move(_name), {});
    }
    virtual Expression newBool(std::string _name)
    {
        // Subclasses should do something here
        return Expression(std::move(_name), {});
    }

    virtual void addAssertion(Expression const& _expr) = 0;

    /// Checks for satisfiability, evaluates the expressions if a model
    /// is available. Throws SMTSolverError on error.
    virtual std::pair<CheckResult, std::vector<std::string>>
    check(std::vector<Expression> const& _expressionsToEvaluate) = 0;
};


}
}
}