/*

  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 renames identifiers to free up certain names.

 */

#pragma once

#include <libyul/optimiser/ASTWalker.h>

#include <libyul/optimiser/NameDispenser.h>

#include <set>

#include <map>

namespace solidity::yul

{

class Dialect;

/**

 * Optimiser component that renames identifiers to free up certain names.

 *

 * Only replaces names that have been defined inside the code. If the code uses

 * names to be freed but does not define them, they remain unchanged.

 *

 * Prerequisites: Disambiguator

 */

class NameDisplacer: public ASTModifier

{

public:

  explicit NameDisplacer(

    NameDispenser& _dispenser,

    std::set<YulName> const& _namesToFree

  ):

    m_nameDispenser(_dispenser),

    m_namesToFree(_namesToFree)

  {

    for (YulName n: _namesToFree)

      m_nameDispenser.markUsed(n);

  }

  using ASTModifier::operator();

  void operator()(Identifier& _identifier) override;

  void operator()(VariableDeclaration& _varDecl) override;

  void operator()(FunctionDefinition& _function) override;

  void operator()(FunctionCall& _funCall) override;

  void operator()(Block& _block) override;

  std::map<YulName, YulName> const& translations() const { return m_translations; }

protected:

  /// Check if the newly introduced identifier @a _name has to be replaced.

  void checkAndReplaceNew(YulName& _name);

  /// Replace the identifier @a _name if it is in the translation map.

  void checkAndReplace(YulName& _name) const;

  NameDispenser& m_nameDispenser;

  std::set<YulName> const& m_namesToFree;

  std::map<YulName, YulName> m_translations;

};

}