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			69 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			69 lines
		
	
	
		
			2.1 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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// SPDX-License-Identifier: GPL-3.0
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/**
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 * Counts the number of references to a variable.
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 */
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#pragma once
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#include <libyul/optimiser/ASTWalker.h>
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#include <libyul/Scope.h>
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namespace solidity::yul
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{
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struct AsmAnalysisInfo;
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/**
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 * Counts the number of references to a variable. This includes actual (read) references
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 * but also assignments to the variable. It does not include the declaration itself or
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 * function parameters, but it does include function return parameters.
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 *
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 * This component can handle multiple variables of the same name.
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 *
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 * Can only be applied to strict assembly.
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 */
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struct VariableReferenceCounter: public yul::ASTWalker
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{
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public:
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	static std::map<Scope::Variable const*, unsigned> run(AsmAnalysisInfo const& _assemblyInfo, Block const& _block)
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	{
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		VariableReferenceCounter variableReferenceCounter(_assemblyInfo);
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		variableReferenceCounter(_block);
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		return std::move(variableReferenceCounter.m_variableReferences);
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	}
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protected:
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	void operator()(Block const& _block) override;
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	void operator()(Identifier const& _identifier) override;
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	void operator()(FunctionDefinition const&) override;
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	void operator()(ForLoop const&) override;
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private:
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	explicit VariableReferenceCounter(
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		AsmAnalysisInfo const& _assemblyInfo
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	): m_info(_assemblyInfo)
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	{}
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	void increaseRefIfFound(YulString _variableName);
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	AsmAnalysisInfo const& m_info;
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	Scope* m_scope = nullptr;
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	std::map<Scope::Variable const*, unsigned> m_variableReferences;
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};
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}
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