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			63 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			63 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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#include <libsolidity/formal/EncodingContext.h>
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#include <libsolidity/formal/Predicate.h>
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#include <libsolidity/formal/SymbolicVariables.h>
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#include <libsmtutil/Sorts.h>
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#include <vector>
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namespace solidity::frontend
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{
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/**
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 * Contains the set of rules to compute an array slice.
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 * Rules:
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 * 1. end > start => ArraySliceHeader(a, b, start, end, 0)
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 * 2. ArraySliceHeader(a, b, start, end, i) && i >= (end - start) => ArraySlice(a, b, start, end)
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 * 3. ArraySliceHeader(a, b, start, end, i) && i >= 0 && i < (end - start) => ArraySliceLoop(a, b, start, end, i)
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 * 4. ArraySliceLoop(a, b, start, end, i) && b[i] = a[start + i] => ArraySliceHeader(a, b, start, end, i + 1)
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 *
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 * The rule to be used by CHC is ArraySlice(a, b, start, end).
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 */
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struct ArraySlicePredicate
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{
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	/// Contains the predicates and rules created to compute
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	/// array slices for a given sort.
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	struct SliceData
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	{
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		std::vector<Predicate const*> predicates;
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		std::vector<smtutil::Expression> rules;
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	};
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	/// @returns a flag representing whether the array slice predicates had already been created before for this sort,
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	/// and the corresponding slice data.
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	static std::pair<bool, SliceData const&> create(smtutil::SortPointer _sort, smt::EncodingContext& _context);
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	static void reset() { m_slicePredicates.clear(); }
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private:
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	/// Maps a unique sort name to its slice data.
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	static std::map<std::string, SliceData> m_slicePredicates;
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};
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}
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