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			86 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			86 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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| 	This file is part of solidity.
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| 
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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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| 
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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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| 
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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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| #include <libsolidity/formal/EncodingContext.h>
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| 
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| #include <libsolidity/formal/SymbolicTypes.h>
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| 
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| using namespace std;
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| using namespace dev;
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| using namespace dev::solidity;
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| using namespace dev::solidity::smt;
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| 
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| EncodingContext::EncodingContext(SolverInterface& _solver):
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| 	m_solver(_solver),
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| 	m_thisAddress(make_unique<SymbolicAddressVariable>("this", m_solver))
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| {
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| 	auto sort = make_shared<smt::ArraySort>(
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| 		make_shared<smt::Sort>(smt::Kind::Int),
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| 		make_shared<smt::Sort>(smt::Kind::Int)
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| 	);
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| 	m_balances = make_unique<SymbolicVariable>(sort, "balances", m_solver);
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| }
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| 
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| void EncodingContext::reset()
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| {
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| 	m_thisAddress->increaseIndex();
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| 	m_balances->increaseIndex();
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| }
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| 
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| smt::Expression EncodingContext::thisAddress()
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| {
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| 	return m_thisAddress->currentValue();
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| }
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| 
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| smt::Expression EncodingContext::balance()
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| {
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| 	return balance(m_thisAddress->currentValue());
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| }
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| 
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| smt::Expression EncodingContext::balance(smt::Expression _address)
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| {
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| 	return smt::Expression::select(m_balances->currentValue(), move(_address));
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| }
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| 
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| void EncodingContext::transfer(smt::Expression _from, smt::Expression _to, smt::Expression _value)
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| {
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| 	unsigned indexBefore = m_balances->index();
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| 	addBalance(_from, 0 - _value);
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| 	addBalance(_to, move(_value));
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| 	unsigned indexAfter = m_balances->index();
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| 	solAssert(indexAfter > indexBefore, "");
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| 	m_balances->increaseIndex();
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| 	/// Do not apply the transfer operation if _from == _to.
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| 	auto newBalances = smt::Expression::ite(
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| 		move(_from) == move(_to),
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| 		m_balances->valueAtIndex(indexBefore),
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| 		m_balances->valueAtIndex(indexAfter)
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| 	);
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| 	m_solver.addAssertion(m_balances->currentValue() == newBalances);
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| }
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| 
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| void EncodingContext::addBalance(smt::Expression _address, smt::Expression _value)
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| {
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| 	auto newBalances = smt::Expression::store(
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| 		m_balances->currentValue(),
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| 		_address,
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| 		balance(_address) + move(_value)
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| 	);
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| 	m_balances->increaseIndex();
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| 	m_solver.addAssertion(newBalances == m_balances->currentValue());
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| }
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