solidity/libsolidity/formal/SSAVariable.h
2018-02-28 18:31:11 +01:00

89 lines
2.2 KiB
C++

/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <libsolidity/formal/SymbolicVariable.h>
#include <memory>
namespace dev
{
namespace solidity
{
class Declaration;
/**
* This class represents the SSA representation of a program variable.
*/
class SSAVariable
{
public:
/// @param _decl Used to determine the type and forwarded to the symbolic var.
/// @param _interface Forwarded to the symbolic var such that it can give constraints to the solver.
SSAVariable(
Declaration const* _decl,
smt::SolverInterface& _interface
);
void resetIndex();
/// This function returns the current index of this SSA variable.
int index() const;
/// This function returns the next free index of this SSA variable.
int next() const;
int operator++()
{
return m_currentSequenceCounter = (*m_nextFreeSequenceCounter)++;
}
smt::Expression operator()() const
{
return valueAtSequence(index());
}
smt::Expression operator()(int _seq) const
{
return valueAtSequence(_seq);
}
/// These two functions forward the call to the symbolic var
/// which generates the constraints according to the type.
void setZeroValue();
void setUnknownValue();
/// So far Int is supported.
static bool supportedType(Type const* _decl);
private:
smt::Expression valueAtSequence(int _seq) const
{
return (*m_symbolicVar)(_seq);
}
std::shared_ptr<SymbolicVariable> m_symbolicVar = nullptr;
int m_currentSequenceCounter;
/// The next free sequence counter is a shared pointer because we want
/// the copy and the copied to share it.
std::shared_ptr<int> m_nextFreeSequenceCounter;
};
}
}