path: root/libsolidity/formal/SSAVariable.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 <memory>

namespace dev
{
namespace solidity
{

/**
 * This class represents the SSA representation of a program variable.
 */
class SSAVariable
{
public:
    SSAVariable();
    void resetIndex();

    /// This function returns the current index of this SSA variable.
    unsigned index() const { return m_currentIndex; }
    unsigned& index() { return m_currentIndex; }

    unsigned operator++()
    {
        return m_currentIndex = (*m_nextFreeIndex)++;
    }

private:
    unsigned m_currentIndex;
    /// The next free index is a shared pointer because we want
    /// the copy and the copied to share it.
    std::shared_ptr<unsigned> m_nextFreeIndex;
};

}
}