/*

  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

/**

 * Optimiser component that combines syntactically equivalent functions.

 */

#pragma once

#include <libyul/optimiser/ASTWalker.h>

#include <libyul/optimiser/BlockHasher.h>

#include <libyul/ASTForward.h>

namespace solidity::yul

{

/**

 * Optimiser component that detects syntactically equivalent functions.

 *

 * Prerequisite: Disambiguator, ForLoopInitRewriter

 */

class EquivalentFunctionDetector: public ASTWalker

{

public:

  static std::map<YulString, FunctionDefinition const*> run(Block& _block)

  {

    EquivalentFunctionDetector detector{BlockHasher::run(_block)};

    detector(_block);

    return std::move(detector.m_duplicates);

  }

  using ASTWalker::operator();

  void operator()(FunctionDefinition const& _fun) override;

private:

  EquivalentFunctionDetector(std::map<Block const*, uint64_t> _blockHashes): m_blockHashes(std::move(_blockHashes)) {}

  std::map<Block const*, uint64_t> m_blockHashes;

  std::map<uint64_t, std::vector<FunctionDefinition const*>> m_candidates;

  std::map<YulString, FunctionDefinition const*> m_duplicates;

};

}