mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
86 lines
2.4 KiB
C++
86 lines
2.4 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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#include <libsolidity/formal/SymbolicState.h>
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#include <libsolidity/formal/EncodingContext.h>
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using namespace std;
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using namespace solidity;
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using namespace solidity::frontend::smt;
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SymbolicState::SymbolicState(EncodingContext& _context):
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m_context(_context)
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{
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}
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void SymbolicState::reset()
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{
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m_thisAddress.resetIndex();
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m_balances.resetIndex();
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}
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// Blockchain
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smtutil::Expression SymbolicState::thisAddress()
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{
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return m_thisAddress.currentValue();
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}
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smtutil::Expression SymbolicState::balance()
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{
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return balance(m_thisAddress.currentValue());
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}
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smtutil::Expression SymbolicState::balance(smtutil::Expression _address)
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{
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return smtutil::Expression::select(m_balances.elements(), move(_address));
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}
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void SymbolicState::transfer(smtutil::Expression _from, smtutil::Expression _to, smtutil::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 = smtutil::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_context.addAssertion(m_balances.currentValue() == newBalances);
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}
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/// Private helpers.
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void SymbolicState::addBalance(smtutil::Expression _address, smtutil::Expression _value)
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{
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auto newBalances = smtutil::Expression::store(
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m_balances.elements(),
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_address,
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balance(_address) + move(_value)
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);
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auto oldLength = m_balances.length();
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m_balances.increaseIndex();
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m_context.addAssertion(m_balances.elements() == newBalances);
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m_context.addAssertion(m_balances.length() == oldLength);
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}
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