path: root/libyul/optimiser/ExpressionInliner.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/>.
*/
/**
 * Optimiser component that performs function inlining.
 */
#pragma once

#include <libyul/optimiser/ASTWalker.h>

#include <libyul/ASTDataForward.h>

#include <boost/variant.hpp>
#include <boost/optional.hpp>

#include <set>

namespace dev
{
namespace yul
{

/**
 * Optimiser component that modifies an AST in place, inlining functions that can be
 * inlined inside functional expressions, i.e. functions that
 *  - return a single value
 *  - have a body like r := <functional expression>
 *  - neither reference themselves nor r in the right hand side
 *
 * Furthermore, the arguments of the function call cannot have any side-effects.
 *
 * This component can only be used on sources with unique names.
 */
class ExpressionInliner: public ASTModifier
{
public:
    ExpressionInliner(Block& _block):
        m_block(_block)
    {}

    void run();

    using ASTModifier::operator();
    virtual void operator()(FunctionDefinition& _fun) override;

    virtual void visit(Expression& _expression) override;

private:
    std::map<YulString, FunctionDefinition const*> m_inlinableFunctions;
    std::map<YulString, YulString> m_varReplacements;
    /// Set of functions we are currently visiting inside.
    std::set<YulString> m_currentFunctions;

    Block& m_block;
};


}
}