mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
66 lines
1.8 KiB
C++
66 lines
1.8 KiB
C++
/*
|
|
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/>.
|
|
*/
|
|
/**
|
|
* Optimisation stage that removes unused variables and functions.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <libyul/optimiser/ASTWalker.h>
|
|
#include <libyul/YulString.h>
|
|
|
|
#include <map>
|
|
#include <set>
|
|
|
|
namespace dev
|
|
{
|
|
namespace yul
|
|
{
|
|
|
|
/**
|
|
* Optimisation stage that removes unused variables and functions and also
|
|
* removes movable expression statements.
|
|
*
|
|
* Note that this does not remove circular references.
|
|
*
|
|
* Prerequisite: Disambiguator
|
|
*/
|
|
class UnusedPruner: public ASTModifier
|
|
{
|
|
public:
|
|
explicit UnusedPruner(Block& _ast, std::set<YulString> const& _externallyUsedFunctions = {});
|
|
|
|
using ASTModifier::operator();
|
|
void operator()(Block& _block) override;
|
|
|
|
// @returns true iff the code changed in the previous run.
|
|
bool shouldRunAgain() const { return m_shouldRunAgain; }
|
|
|
|
// Run the pruner until the code does not change anymore.
|
|
static void runUntilStabilised(Block& _ast, std::set<YulString> const& _externallyUsedFunctions = {});
|
|
|
|
private:
|
|
bool used(YulString _name) const;
|
|
void subtractReferences(std::map<YulString, size_t> const& _subtrahend);
|
|
|
|
bool m_shouldRunAgain = false;
|
|
std::map<YulString, size_t> m_references;
|
|
};
|
|
|
|
}
|
|
}
|