mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
61 lines
1.7 KiB
C++
61 lines
1.7 KiB
C++
/*
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This file is part of solidity.
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solidity is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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solidity is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with solidity. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* Specific AST walkers that collect semantical facts.
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*/
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#pragma once
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#include <libyul/optimiser/ASTWalker.h>
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#include <set>
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namespace dev
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{
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namespace yul
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{
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/**
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* Specific AST walker that determines whether an expression is movable.
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*/
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class MovableChecker: public ASTWalker
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{
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public:
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MovableChecker() = default;
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explicit MovableChecker(Expression const& _expression);
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virtual void operator()(Identifier const& _identifier) override;
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virtual void operator()(FunctionalInstruction const& _functionalInstruction) override;
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virtual void operator()(FunctionCall const& _functionCall) override;
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/// Disallow visiting anything apart from Expressions (this throws).
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virtual void visit(Statement const&) override;
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using ASTWalker::visit;
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bool movable() const { return m_movable; }
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std::set<YulString> const& referencedVariables() const { return m_variableReferences; }
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private:
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/// Which variables the current expression references.
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std::set<YulString> m_variableReferences;
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/// Is the current expression movable or not.
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bool m_movable = true;
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};
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}
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}
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