/*

  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 changes the code of a block so that all non-function definition

 * statements are moved to a block of their own followed by all function definitions.

 */

#include <libyul/optimiser/FunctionGrouper.h>

#include <libyul/AST.h>

using namespace solidity;

using namespace solidity::yul;

void FunctionGrouper::operator()(Block& _block)

{

  if (alreadyGrouped(_block))

    return;

  std::vector<Statement> reordered;

  reordered.emplace_back(Block{_block.debugData, {}});

  for (auto&& statement: _block.statements)

  {

    if (std::holds_alternative<FunctionDefinition>(statement))

      reordered.emplace_back(std::move(statement));

    else

      std::get<Block>(reordered.front()).statements.emplace_back(std::move(statement));

  }

  _block.statements = std::move(reordered);

}

bool FunctionGrouper::alreadyGrouped(Block const& _block)

{

  if (_block.statements.empty())

    return false;

  if (!std::holds_alternative<Block>(_block.statements.front()))

    return false;

  for (size_t i = 1; i < _block.statements.size(); ++i)

    if (!std::holds_alternative<FunctionDefinition>(_block.statements.at(i)))

      return false;

  return true;

}