/*

  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

#pragma once

#include <libyul/optimiser/ASTWalker.h>

#include <libyul/Dialect.h>

namespace solidity::yul

{

struct OptimiserStepContext;

/**

 * Rewrites ForLoop by moving iteration condition into the ForLoop body.

 * For example, `for {} lt(a, b) {} { mstore(1, 2) }` will become

 * `for {} 1 {} { if iszero(lt(a, b)) { break } mstore(1, 2) }`

 *

 * By moving the iteration check part into the ForLoop body, we can apply expression splitter

 * to the condition expression.

 *

 * This rewriter will skip loops that already have literal constant as iteration condition.

 *

 * Requirements:

 * - The Disambiguator must be run upfront.

 * - To avoid unnecessary rewrite, it is recommended to run this rewriter after StructuralSimplifier.

 * - Only works for dialects with a builtin boolean negation function.

 */

class ForLoopConditionIntoBody: public ASTModifier

{

public:

  static constexpr char const* name{"ForLoopConditionIntoBody"};

  static void run(OptimiserStepContext&, Block& _ast);

  using ASTModifier::operator();

  void operator()(ForLoop& _forLoop) override;

private:

  ForLoopConditionIntoBody(Dialect const& _dialect): m_dialect(_dialect) {}

  Dialect const& m_dialect;

};

}