[SMTChecker] Support this as address

libsolidity/formal/EncodingContext.cpp

@@ -0,0 +1,41 @@
+/*
+	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/>.
+*/
+
+#include <libsolidity/formal/EncodingContext.h>
+
+#include <libsolidity/formal/SymbolicTypes.h>
+
+using namespace std;
+using namespace dev;
+using namespace dev::solidity;
+using namespace dev::solidity::smt;
+
+EncodingContext::EncodingContext(SolverInterface& _solver):
+	m_solver(_solver),
+	m_thisAddress(make_unique<SymbolicAddressVariable>("this", m_solver))
+{
+}
+
+void EncodingContext::reset()
+{
+	m_thisAddress->increaseIndex();
+}
+
+smt::Expression EncodingContext::thisAddress()
+{
+	return m_thisAddress->currentValue();
+}