Merge pull request #461 from chriseth/sol_contractCompiler

Solidity contract compiler

3 files changed, 736 insertions, 152 deletions

diff --git a/solidityCompiler.cpp b/solidityCompiler.cpp
index e024043e..17de9af5 100644
--- a/solidityCompiler.cpp
+++ b/solidityCompiler.cpp
@@ -1,4 +1,3 @@
-
 /*
 	This file is part of cpp-ethereum.
 
@@ -18,18 +17,21 @@
 /**
  * @author Christian <c@ethdev.com>
  * @date 2014
- * Unit tests for the name and type resolution of the solidity parser.
+ * Unit tests for the solidity compiler.
  */
 
 #include <string>
-
+#include <iostream>
+#include <boost/test/unit_test.hpp>
 #include <libdevcore/Log.h>
 #include <libsolidity/Scanner.h>
 #include <libsolidity/Parser.h>
 #include <libsolidity/NameAndTypeResolver.h>
 #include <libsolidity/Compiler.h>
 #include <libsolidity/AST.h>
-#include <boost/test/unit_test.hpp>
+
+using namespace std;
+using namespace dev::eth;
 
 namespace dev
 {
@@ -41,186 +43,187 @@ namespace test
 namespace
 {
 
-/**
- * Helper class that extracts the first expression in an AST.
- */
-class FirstExpressionExtractor: private ASTVisitor
-{
-public:
-	FirstExpressionExtractor(ASTNode& _node): m_expression(nullptr) { _node.accept(*this); }
-	Expression* getExpression() const { return m_expression; }
-private:
-	virtual bool visit(Expression& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(Assignment& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(UnaryOperation& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(BinaryOperation& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(FunctionCall& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(MemberAccess& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(IndexAccess& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(PrimaryExpression& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(Identifier& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(ElementaryTypeNameExpression& _expression) override { return checkExpression(_expression); }
-	virtual bool visit(Literal& _expression) override { return checkExpression(_expression); }
-	bool checkExpression(Expression& _expression)
-	{
-		if (m_expression == nullptr)
-			m_expression = &_expression;
-		return false;
-	}
-private:
-	Expression* m_expression;
-};
-
-bytes compileFirstExpression(std::string const& _sourceCode)
+bytes compileContract(const string& _sourceCode)
 {
 	Parser parser;
 	ASTPointer<ContractDefinition> contract;
-	BOOST_REQUIRE_NO_THROW(contract = parser.parse(std::make_shared<Scanner>(CharStream(_sourceCode))));
+	BOOST_REQUIRE_NO_THROW(contract = parser.parse(make_shared<Scanner>(CharStream(_sourceCode))));
 	NameAndTypeResolver resolver;
 	BOOST_REQUIRE_NO_THROW(resolver.resolveNamesAndTypes(*contract));
-	FirstExpressionExtractor extractor(*contract);
-	BOOST_REQUIRE(extractor.getExpression() != nullptr);
 
-	CompilerContext context;
-	ExpressionCompiler compiler(context);
-	compiler.compile(*extractor.getExpression());
-	bytes instructions = compiler.getAssembledBytecode();
+	Compiler compiler;
+	compiler.compileContract(*contract);
 	// debug
-	//std::cout << eth::disassemble(instructions) << std::endl;
-	return instructions;
+	//compiler.streamAssembly(cout);
+	return compiler.getAssembledBytecode();
 }
 
-} // end anonymous namespace
-
-BOOST_AUTO_TEST_SUITE(SolidityExpressionCompiler)
-
-BOOST_AUTO_TEST_CASE(literal_true)
+/// Checks that @a _compiledCode is present starting from offset @a _offset in @a _expectation.
+/// This is necessary since the compiler will add boilerplate add the beginning that is not
+/// tested here.
+void checkCodePresentAt(bytes const& _compiledCode, bytes const& _expectation, unsigned _offset)
 {
-	char const* sourceCode = "contract test {\n"
-							 "  function f() { var x = true; }"
-							 "}\n";
-	bytes code = compileFirstExpression(sourceCode);
-
-	bytes expectation({byte(eth::Instruction::PUSH1), 0x1});
-	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
-}
-
-BOOST_AUTO_TEST_CASE(literal_false)
-{
-	char const* sourceCode = "contract test {\n"
-							 "  function f() { var x = false; }"
-							 "}\n";
-	bytes code = compileFirstExpression(sourceCode);
-
-	bytes expectation({byte(eth::Instruction::PUSH1), 0x0});
-	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+	BOOST_REQUIRE(_compiledCode.size() >= _offset + _expectation.size());
+	auto checkStart = _compiledCode.begin() + _offset;
+	BOOST_CHECK_EQUAL_COLLECTIONS(checkStart, checkStart + _expectation.size(),
+								  _expectation.begin(), _expectation.end());
 }
 
-BOOST_AUTO_TEST_CASE(int_literal)
-{
-	char const* sourceCode = "contract test {\n"
-							 "  function f() { var x = 0x12345678901234567890; }"
-							 "}\n";
-	bytes code = compileFirstExpression(sourceCode);
+} // end anonymous namespace
 
-	bytes expectation({byte(eth::Instruction::PUSH10), 0x12, 0x34, 0x56, 0x78, 0x90,
-													   0x12, 0x34, 0x56, 0x78, 0x90});
-	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
-}
+BOOST_AUTO_TEST_SUITE(SolidityCompiler)
 
-BOOST_AUTO_TEST_CASE(comparison)
+BOOST_AUTO_TEST_CASE(smoke_test)
 {
 	char const* sourceCode = "contract test {\n"
-							 "  function f() { var x = (0x10aa < 0x11aa) != true; }"
+							 "  function f() { var x = 2; }\n"
 							 "}\n";
-	bytes code = compileFirstExpression(sourceCode);
-
-	bytes expectation({byte(eth::Instruction::PUSH2), 0x10, 0xaa,
-					   byte(eth::Instruction::PUSH2), 0x11, 0xaa,
-					   byte(eth::Instruction::GT),
-					   byte(eth::Instruction::PUSH1), 0x1,
-					   byte(eth::Instruction::EQ),
-					   byte(eth::Instruction::NOT)});
-	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+	bytes code = compileContract(sourceCode);
+
+	unsigned boilerplateSize = 51;
+	bytes expectation({byte(Instruction::JUMPDEST),
+					   byte(Instruction::PUSH1), 0x0, // initialize local variable x
+					   byte(Instruction::PUSH1), 0x2,
+					   byte(Instruction::SWAP1),
+					   byte(Instruction::POP),
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::POP),
+					   byte(Instruction::JUMP)});
+	checkCodePresentAt(code, expectation, boilerplateSize);
 }
 
-BOOST_AUTO_TEST_CASE(short_circuiting)
+BOOST_AUTO_TEST_CASE(different_argument_numbers)
 {
 	char const* sourceCode = "contract test {\n"
-							 "  function f() { var x = (10 + 8 >= 4 || 2 != 9) != true; }"
+							 "  function f(uint a, uint b, uint c) returns(uint d) { return b; }\n"
+							 "  function g() returns (uint e, uint h) { h = f(1, 2, 3); }\n"
 							 "}\n";
-	bytes code = compileFirstExpression(sourceCode);
-
-	bytes expectation({byte(eth::Instruction::PUSH1), 0xa,
-					   byte(eth::Instruction::PUSH1), 0x8,
-					   byte(eth::Instruction::ADD),
-					   byte(eth::Instruction::PUSH1), 0x4,
-					   byte(eth::Instruction::GT),
-					   byte(eth::Instruction::NOT), // after this we have 10 + 8 >= 4
-					   byte(eth::Instruction::DUP1),
-					   byte(eth::Instruction::PUSH1), 0x14,
-					   byte(eth::Instruction::JUMPI), // short-circuit if it is true
-					   byte(eth::Instruction::PUSH1), 0x2,
-					   byte(eth::Instruction::PUSH1), 0x9,
-					   byte(eth::Instruction::EQ),
-					   byte(eth::Instruction::NOT), // after this we have 2 != 9
-					   byte(eth::Instruction::JUMPDEST),
-					   byte(eth::Instruction::PUSH1), 0x1,
-					   byte(eth::Instruction::EQ),
-					   byte(eth::Instruction::NOT)});
-	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+	bytes code = compileContract(sourceCode);
+
+	unsigned shift = 75;
+	unsigned boilerplateSize = 88;
+	bytes expectation({byte(Instruction::JUMPDEST),
+					   byte(Instruction::PUSH1), 0x0, // initialize return variable d
+					   byte(Instruction::DUP3),
+					   byte(Instruction::SWAP1), // assign b to d
+					   byte(Instruction::POP),
+					   byte(Instruction::PUSH1), 0xa + shift, // jump to return
+					   byte(Instruction::JUMP),
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::SWAP4), // store d and fetch return address
+					   byte(Instruction::SWAP3), // store return address
+					   byte(Instruction::POP),
+					   byte(Instruction::POP),
+					   byte(Instruction::POP),
+					   byte(Instruction::JUMP), // end of f
+					   byte(Instruction::JUMPDEST), // beginning of g
+					   byte(Instruction::PUSH1), 0x0,
+					   byte(Instruction::DUP1), // initialized e and h
+					   byte(Instruction::PUSH1), 0x20 + shift, // ret address
+					   byte(Instruction::PUSH1), 0x1,
+					   byte(Instruction::PUSH1), 0x2,
+					   byte(Instruction::PUSH1), 0x3,
+					   byte(Instruction::PUSH1), 0x1 + shift,
+					   // stack here: ret e h 0x20 1 2 3 0x1
+					   byte(Instruction::JUMP),
+					   byte(Instruction::JUMPDEST),
+					   // stack here: ret e h f(1,2,3)
+					   byte(Instruction::DUP2),
+					   byte(Instruction::POP),
+					   byte(Instruction::SWAP1),
+					   // stack here: ret e f(1,2,3) h
+					   byte(Instruction::POP),
+					   byte(Instruction::DUP1), // retrieve it again as "value of expression"
+					   byte(Instruction::POP), // end of assignment
+					   // stack here: ret e f(1,2,3)
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::SWAP1),
+					   // ret e f(1,2,3)
+					   byte(Instruction::SWAP2),
+					   // f(1,2,3) e ret
+					   byte(Instruction::JUMP) // end of g
+					   });
+	checkCodePresentAt(code, expectation, boilerplateSize);
 }
 
-BOOST_AUTO_TEST_CASE(arithmetics)
+BOOST_AUTO_TEST_CASE(ifStatement)
 {
 	char const* sourceCode = "contract test {\n"
-							 "  function f() { var x = (1 * (2 / (3 % (4 + (5 - (6 | (7 & (8 ^ 9)))))))); }"
+							 "  function f() { bool x; if (x) 77; else if (!x) 78; else 79; }"
 							 "}\n";
-	bytes code = compileFirstExpression(sourceCode);
-
-	bytes expectation({byte(eth::Instruction::PUSH1), 0x1,
-					   byte(eth::Instruction::PUSH1), 0x2,
-					   byte(eth::Instruction::PUSH1), 0x3,
-					   byte(eth::Instruction::PUSH1), 0x4,
-					   byte(eth::Instruction::PUSH1), 0x5,
-					   byte(eth::Instruction::PUSH1), 0x6,
-					   byte(eth::Instruction::PUSH1), 0x7,
-					   byte(eth::Instruction::PUSH1), 0x8,
-					   byte(eth::Instruction::PUSH1), 0x9,
-					   byte(eth::Instruction::XOR),
-					   byte(eth::Instruction::AND),
-					   byte(eth::Instruction::OR),
-					   byte(eth::Instruction::SWAP1),
-					   byte(eth::Instruction::SUB),
-					   byte(eth::Instruction::ADD),
-					   byte(eth::Instruction::SWAP1),
-					   byte(eth::Instruction::MOD),
-					   byte(eth::Instruction::SWAP1),
-					   byte(eth::Instruction::DIV),
-					   byte(eth::Instruction::MUL)});
-	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+	bytes code = compileContract(sourceCode);
+
+	unsigned shift = 38;
+	unsigned boilerplateSize = 51;
+	bytes expectation({byte(Instruction::JUMPDEST),
+					   byte(Instruction::PUSH1), 0x0,
+					   byte(Instruction::DUP1),
+					   byte(Instruction::PUSH1), 0x1b + shift, // "true" target
+					   byte(Instruction::JUMPI),
+					   // new check "else if" condition
+					   byte(Instruction::DUP1),
+					   byte(Instruction::ISZERO),
+					   byte(Instruction::PUSH1), 0x13 + shift,
+					   byte(Instruction::JUMPI),
+					   // "else" body
+					   byte(Instruction::PUSH1), 0x4f,
+					   byte(Instruction::POP),
+					   byte(Instruction::PUSH1), 0x17 + shift, // exit path of second part
+					   byte(Instruction::JUMP),
+					   // "else if" body
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::PUSH1), 0x4e,
+					   byte(Instruction::POP),
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::PUSH1), 0x1f + shift,
+					   byte(Instruction::JUMP),
+					   // "if" body
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::PUSH1), 0x4d,
+					   byte(Instruction::POP),
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::POP),
+					   byte(Instruction::JUMP)});
+	checkCodePresentAt(code, expectation, boilerplateSize);
 }
 
-BOOST_AUTO_TEST_CASE(unary_operators)
+BOOST_AUTO_TEST_CASE(loops)
 {
 	char const* sourceCode = "contract test {\n"
-							 "  function f() { var x = !(~+-(--(++1++)--) == 2); }"
+							 "  function f() { while(true){1;break;2;continue;3;return;4;} }"
 							 "}\n";
-	bytes code = compileFirstExpression(sourceCode);
-
-	bytes expectation({byte(eth::Instruction::PUSH1), 0x1,
-					   byte(eth::Instruction::PUSH1), 0x1,
-					   byte(eth::Instruction::ADD),
-					   byte(eth::Instruction::PUSH1), 0x1,
-					   byte(eth::Instruction::SWAP1),
-					   byte(eth::Instruction::SUB),
-					   byte(eth::Instruction::PUSH1), 0x0,
-					   byte(eth::Instruction::SUB),
-					   byte(eth::Instruction::NOT),
-					   byte(eth::Instruction::PUSH1), 0x2,
-					   byte(eth::Instruction::EQ),
-					   byte(eth::Instruction::ISZERO)});
-	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+	bytes code = compileContract(sourceCode);
+
+	unsigned shift = 38;
+	unsigned boilerplateSize = 51;
+	bytes expectation({byte(Instruction::JUMPDEST),
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::PUSH1), 0x1,
+					   byte(Instruction::ISZERO),
+					   byte(Instruction::PUSH1), 0x21 + shift,
+					   byte(Instruction::JUMPI),
+					   byte(Instruction::PUSH1), 0x1,
+					   byte(Instruction::POP),
+					   byte(Instruction::PUSH1), 0x21 + shift,
+					   byte(Instruction::JUMP), // break
+					   byte(Instruction::PUSH1), 0x2,
+					   byte(Instruction::POP),
+					   byte(Instruction::PUSH1), 0x2 + shift,
+					   byte(Instruction::JUMP), // continue
+					   byte(Instruction::PUSH1), 0x3,
+					   byte(Instruction::POP),
+					   byte(Instruction::PUSH1), 0x22 + shift,
+					   byte(Instruction::JUMP), // return
+					   byte(Instruction::PUSH1), 0x4,
+					   byte(Instruction::POP),
+					   byte(Instruction::PUSH1), 0x2 + shift,
+					   byte(Instruction::JUMP),
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::JUMPDEST),
+					   byte(Instruction::JUMP)});
+
+	checkCodePresentAt(code, expectation, boilerplateSize);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/solidityEndToEndTest.cpp b/solidityEndToEndTest.cpp
new file mode 100644
index 00000000..b28b8499
--- /dev/null
+++ b/solidityEndToEndTest.cpp
@@ -0,0 +1,229 @@
+
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum 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.
+
+	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @author Christian <c@ethdev.com>
+ * @date 2014
+ * Unit tests for the solidity expression compiler, testing the behaviour of the code.
+ */
+
+#include <string>
+#include <boost/test/unit_test.hpp>
+#include <libethereum/State.h>
+#include <libethereum/Executive.h>
+#include <libsolidity/CompilerStack.h>
+
+using namespace std;
+
+namespace dev
+{
+namespace solidity
+{
+namespace test
+{
+
+class ExecutionFramework
+{
+public:
+	ExecutionFramework() { g_logVerbosity = 0; }
+
+	bytes compileAndRun(std::string const& _sourceCode)
+	{
+		bytes code = dev::solidity::CompilerStack::compile(_sourceCode);
+		sendMessage(code, true);
+		return m_output;
+	}
+
+	bytes callFunction(byte _index, bytes const& _data)
+	{
+		sendMessage(bytes(1, _index) + _data, false);
+		return m_output;
+	}
+
+	bytes callFunction(byte _index, u256 const& _argument1)
+	{
+		callFunction(_index, toBigEndian(_argument1));
+		return m_output;
+	}
+
+private:
+	void sendMessage(bytes const& _data, bool _isCreation)
+	{
+		eth::Executive executive(m_state);
+		eth::Transaction t = _isCreation ? eth::Transaction(0, m_gasPrice, m_gas, _data)
+										 : eth::Transaction(0, m_gasPrice, m_gas, m_contractAddress, _data);
+		bytes transactionRLP = t.rlp();
+		try
+		{
+			// this will throw since the transaction is invalid, but it should nevertheless store the transaction
+			executive.setup(&transactionRLP);
+		}
+		catch (...) {}
+		if (_isCreation)
+		{
+			BOOST_REQUIRE(!executive.create(Address(), 0, m_gasPrice, m_gas, &_data, Address()));
+			m_contractAddress = executive.newAddress();
+			BOOST_REQUIRE(m_state.addressHasCode(m_contractAddress));
+		}
+		else
+			BOOST_REQUIRE(!executive.call(m_contractAddress, Address(), 0, m_gasPrice, &_data, m_gas, Address()));
+		BOOST_REQUIRE(executive.go());
+		executive.finalize();
+		m_output = executive.out().toBytes();
+	}
+
+	Address m_contractAddress;
+	eth::State m_state;
+	u256 const m_gasPrice = 100 * eth::szabo;
+	u256 const m_gas = 1000000;
+	bytes m_output;
+};
+
+BOOST_AUTO_TEST_SUITE(SolidityCompilerEndToEndTest)
+
+BOOST_AUTO_TEST_CASE(smoke_test)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f(uint a) returns(uint d) { return a * 7; }\n"
+							 "}\n";
+	ExecutionFramework framework;
+	framework.compileAndRun(sourceCode);
+	u256 a = 0x200030004;
+	bytes result = framework.callFunction(0, a);
+	BOOST_CHECK(result == toBigEndian(a * 7));
+}
+
+BOOST_AUTO_TEST_CASE(empty_contract)
+{
+	char const* sourceCode = "contract test {\n"
+							 "}\n";
+	ExecutionFramework framework;
+	framework.compileAndRun(sourceCode);
+	BOOST_CHECK(framework.callFunction(0, bytes()).empty());
+}
+
+BOOST_AUTO_TEST_CASE(recursive_calls)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f(uint n) returns(uint nfac) {\n"
+							 "    if (n <= 1) return 1;\n"
+							 "    else return n * f(n - 1);\n"
+							 "  }\n"
+							 "}\n";
+	ExecutionFramework framework;
+	framework.compileAndRun(sourceCode);
+	BOOST_CHECK(framework.callFunction(0, u256(0)) == toBigEndian(u256(1)));
+	BOOST_CHECK(framework.callFunction(0, u256(1)) == toBigEndian(u256(1)));
+	BOOST_CHECK(framework.callFunction(0, u256(2)) == toBigEndian(u256(2)));
+	BOOST_CHECK(framework.callFunction(0, u256(3)) == toBigEndian(u256(6)));
+	BOOST_CHECK(framework.callFunction(0, u256(4)) == toBigEndian(u256(24)));
+}
+
+BOOST_AUTO_TEST_CASE(while_loop)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f(uint n) returns(uint nfac) {\n"
+							 "    nfac = 1;\n"
+							 "    var i = 2;\n"
+							 "    while (i <= n) nfac *= i++;\n"
+							 "  }\n"
+							 "}\n";
+	ExecutionFramework framework;
+	framework.compileAndRun(sourceCode);
+	BOOST_CHECK(framework.callFunction(0, u256(0)) == toBigEndian(u256(1)));
+	BOOST_CHECK(framework.callFunction(0, u256(1)) == toBigEndian(u256(1)));
+	BOOST_CHECK(framework.callFunction(0, u256(2)) == toBigEndian(u256(2)));
+	BOOST_CHECK(framework.callFunction(0, u256(3)) == toBigEndian(u256(6)));
+	BOOST_CHECK(framework.callFunction(0, u256(4)) == toBigEndian(u256(24)));
+}
+
+BOOST_AUTO_TEST_CASE(calling_other_functions)
+{
+	// note that the index of a function is its index in the sorted sequence of functions
+	char const* sourceCode = "contract collatz {\n"
+							 "  function run(uint x) returns(uint y) {\n"
+							 "    while ((y = x) > 1) {\n"
+							 "      if (x % 2 == 0) x = evenStep(x);\n"
+							 "      else x = oddStep(x);\n"
+							 "    }\n"
+							 "  }\n"
+							 "  function evenStep(uint x) returns(uint y) {\n"
+							 "    return x / 2;\n"
+							 "  }\n"
+							 "  function oddStep(uint x) returns(uint y) {\n"
+							 "    return 3 * x + 1;\n"
+							 "  }\n"
+							 "}\n";
+	ExecutionFramework framework;
+	framework.compileAndRun(sourceCode);
+	BOOST_CHECK(framework.callFunction(2, u256(0)) == toBigEndian(u256(0)));
+	BOOST_CHECK(framework.callFunction(2, u256(1)) == toBigEndian(u256(1)));
+	BOOST_CHECK(framework.callFunction(2, u256(2)) == toBigEndian(u256(1)));
+	BOOST_CHECK(framework.callFunction(2, u256(8)) == toBigEndian(u256(1)));
+	BOOST_CHECK(framework.callFunction(2, u256(127)) == toBigEndian(u256(1)));
+}
+
+BOOST_AUTO_TEST_CASE(many_local_variables)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function run(uint x1, uint x2, uint x3) returns(uint y) {\n"
+							 "    var a = 0x1; var b = 0x10; var c = 0x100;\n"
+							 "    y = a + b + c + x1 + x2 + x3;\n"
+							 "    y += b + x2;\n"
+							 "  }\n"
+							 "}\n";
+	ExecutionFramework framework;
+	framework.compileAndRun(sourceCode);
+	BOOST_CHECK(framework.callFunction(0, toBigEndian(u256(0x1000)) + toBigEndian(u256(0x10000)) + toBigEndian(u256(0x100000)))
+				== toBigEndian(u256(0x121121)));
+}
+
+BOOST_AUTO_TEST_CASE(multiple_return_values)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function run(bool x1, uint x2) returns(uint y1, bool y2, uint y3) {\n"
+							 "    y1 = x2; y2 = x1;\n"
+							 "  }\n"
+							 "}\n";
+	ExecutionFramework framework;
+	framework.compileAndRun(sourceCode);
+	BOOST_CHECK(framework.callFunction(0, bytes(1, 1) + toBigEndian(u256(0xcd)))
+				== toBigEndian(u256(0xcd)) + bytes(1, 1) + toBigEndian(u256(0)));
+}
+
+BOOST_AUTO_TEST_CASE(short_circuiting)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function run(uint x) returns(uint y) {\n"
+							 "    x == 0 || ((x = 8) > 0);\n"
+							 "    return x;"
+							 "  }\n"
+							 "}\n";
+	ExecutionFramework framework;
+	framework.compileAndRun(sourceCode);
+	BOOST_CHECK(framework.callFunction(0, u256(0)) == toBigEndian(u256(0)));
+	BOOST_CHECK(framework.callFunction(0, u256(1)) == toBigEndian(u256(8)));
+}
+
+//@todo test smaller types
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}
+}
+} // end namespaces
+
diff --git a/solidityExpressionCompiler.cpp b/solidityExpressionCompiler.cpp
new file mode 100644
index 00000000..561cc3bd
--- /dev/null
+++ b/solidityExpressionCompiler.cpp
@@ -0,0 +1,352 @@
+
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum 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.
+
+	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @author Christian <c@ethdev.com>
+ * @date 2014
+ * Unit tests for the solidity expression compiler.
+ */
+
+#include <string>
+
+#include <libdevcore/Log.h>
+#include <libsolidity/Scanner.h>
+#include <libsolidity/Parser.h>
+#include <libsolidity/NameAndTypeResolver.h>
+#include <libsolidity/CompilerContext.h>
+#include <libsolidity/ExpressionCompiler.h>
+#include <libsolidity/AST.h>
+#include <boost/test/unit_test.hpp>
+
+using namespace std;
+
+namespace dev
+{
+namespace solidity
+{
+namespace test
+{
+
+namespace
+{
+
+/// Helper class that extracts the first expression in an AST.
+class FirstExpressionExtractor: private ASTVisitor
+{
+public:
+	FirstExpressionExtractor(ASTNode& _node): m_expression(nullptr) { _node.accept(*this); }
+	Expression* getExpression() const { return m_expression; }
+private:
+	virtual bool visit(Expression& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(Assignment& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(UnaryOperation& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(BinaryOperation& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(FunctionCall& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(MemberAccess& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(IndexAccess& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(PrimaryExpression& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(Identifier& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(ElementaryTypeNameExpression& _expression) override { return checkExpression(_expression); }
+	virtual bool visit(Literal& _expression) override { return checkExpression(_expression); }
+	bool checkExpression(Expression& _expression)
+	{
+		if (m_expression == nullptr)
+			m_expression = &_expression;
+		return false;
+	}
+private:
+	Expression* m_expression;
+};
+
+Declaration const& resolveDeclaration(vector<string> const& _namespacedName,
+											  NameAndTypeResolver const& _resolver)
+{
+	Declaration const* declaration = nullptr;
+	for (string const& namePart: _namespacedName)
+		BOOST_REQUIRE(declaration = _resolver.resolveName(namePart, declaration));
+	BOOST_REQUIRE(declaration);
+	return *declaration;
+}
+
+bytes compileFirstExpression(const string& _sourceCode, vector<vector<string>> _functions = {},
+							 vector<vector<string>> _localVariables = {})
+{
+	Parser parser;
+	ASTPointer<ContractDefinition> contract;
+	BOOST_REQUIRE_NO_THROW(contract = parser.parse(make_shared<Scanner>(CharStream(_sourceCode))));
+	NameAndTypeResolver resolver;
+	BOOST_REQUIRE_NO_THROW(resolver.resolveNamesAndTypes(*contract));
+	FirstExpressionExtractor extractor(*contract);
+	BOOST_REQUIRE(extractor.getExpression() != nullptr);
+
+	CompilerContext context;
+	for (vector<string> const& function: _functions)
+		context.addFunction(dynamic_cast<FunctionDefinition const&>(resolveDeclaration(function, resolver)));
+	for (vector<string> const& variable: _localVariables)
+		context.addVariable(dynamic_cast<VariableDeclaration const&>(resolveDeclaration(variable, resolver)));
+
+	ExpressionCompiler::compileExpression(context, *extractor.getExpression());
+
+	for (vector<string> const& function: _functions)
+		context << context.getFunctionEntryLabel(dynamic_cast<FunctionDefinition const&>(resolveDeclaration(function, resolver)));
+	bytes instructions = context.getAssembledBytecode();
+	// debug
+	// cout << eth::disassemble(instructions) << endl;
+	return instructions;
+}
+
+} // end anonymous namespace
+
+BOOST_AUTO_TEST_SUITE(SolidityExpressionCompiler)
+
+BOOST_AUTO_TEST_CASE(literal_true)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f() { var x = true; }"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode);
+
+	bytes expectation({byte(eth::Instruction::PUSH1), 0x1});
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_CASE(literal_false)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f() { var x = false; }"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode);
+
+	bytes expectation({byte(eth::Instruction::PUSH1), 0x0});
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_CASE(int_literal)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f() { var x = 0x12345678901234567890; }"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode);
+
+	bytes expectation({byte(eth::Instruction::PUSH10), 0x12, 0x34, 0x56, 0x78, 0x90,
+													   0x12, 0x34, 0x56, 0x78, 0x90});
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_CASE(comparison)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f() { var x = (0x10aa < 0x11aa) != true; }"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode);
+
+	bytes expectation({byte(eth::Instruction::PUSH2), 0x10, 0xaa,
+					   byte(eth::Instruction::PUSH2), 0x11, 0xaa,
+					   byte(eth::Instruction::GT),
+					   byte(eth::Instruction::PUSH1), 0x1,
+					   byte(eth::Instruction::EQ),
+					   byte(eth::Instruction::ISZERO)});
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_CASE(short_circuiting)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f() { var x = (10 + 8 >= 4 || 2 != 9) != true; }"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode);
+
+	bytes expectation({byte(eth::Instruction::PUSH1), 0xa,
+					   byte(eth::Instruction::PUSH1), 0x8,
+					   byte(eth::Instruction::ADD),
+					   byte(eth::Instruction::PUSH1), 0x4,
+					   byte(eth::Instruction::GT),
+					   byte(eth::Instruction::ISZERO), // after this we have 10 + 8 >= 4
+					   byte(eth::Instruction::DUP1),
+					   byte(eth::Instruction::PUSH1), 0x14,
+					   byte(eth::Instruction::JUMPI), // short-circuit if it is true
+					   byte(eth::Instruction::POP),
+					   byte(eth::Instruction::PUSH1), 0x2,
+					   byte(eth::Instruction::PUSH1), 0x9,
+					   byte(eth::Instruction::EQ),
+					   byte(eth::Instruction::ISZERO), // after this we have 2 != 9
+					   byte(eth::Instruction::JUMPDEST),
+					   byte(eth::Instruction::PUSH1), 0x1,
+					   byte(eth::Instruction::EQ),
+					   byte(eth::Instruction::ISZERO)});
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_CASE(arithmetics)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f() { var x = (1 * (2 / (3 % (4 + (5 - (6 | (7 & (8 ^ 9)))))))); }"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode);
+
+	bytes expectation({byte(eth::Instruction::PUSH1), 0x1,
+					   byte(eth::Instruction::PUSH1), 0x2,
+					   byte(eth::Instruction::PUSH1), 0x3,
+					   byte(eth::Instruction::PUSH1), 0x4,
+					   byte(eth::Instruction::PUSH1), 0x5,
+					   byte(eth::Instruction::PUSH1), 0x6,
+					   byte(eth::Instruction::PUSH1), 0x7,
+					   byte(eth::Instruction::PUSH1), 0x8,
+					   byte(eth::Instruction::PUSH1), 0x9,
+					   byte(eth::Instruction::XOR),
+					   byte(eth::Instruction::AND),
+					   byte(eth::Instruction::OR),
+					   byte(eth::Instruction::SWAP1),
+					   byte(eth::Instruction::SUB),
+					   byte(eth::Instruction::ADD),
+					   byte(eth::Instruction::SWAP1),
+					   byte(eth::Instruction::MOD),
+					   byte(eth::Instruction::SWAP1),
+					   byte(eth::Instruction::DIV),
+					   byte(eth::Instruction::MUL)});
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_CASE(unary_operators)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f() { var x = !(~+-1 == 2); }"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode);
+
+	bytes expectation({byte(eth::Instruction::PUSH1), 0x1,
+					   byte(eth::Instruction::PUSH1), 0x0,
+					   byte(eth::Instruction::SUB),
+					   byte(eth::Instruction::NOT),
+					   byte(eth::Instruction::PUSH1), 0x2,
+					   byte(eth::Instruction::EQ),
+					   byte(eth::Instruction::ISZERO)});
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_CASE(unary_inc_dec)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f(uint a) { var x = ((a++ ^ ++a) ^ a--) ^ --a; }"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode, {}, {{"test", "f", "a"}, {"test", "f", "x"}});
+
+	// Stack: a, x
+	bytes expectation({byte(eth::Instruction::DUP2),
+					   byte(eth::Instruction::DUP1),
+					   byte(eth::Instruction::PUSH1), 0x1,
+					   byte(eth::Instruction::ADD),
+					   // Stack here: a x a (a+1)
+					   byte(eth::Instruction::SWAP3),
+					   byte(eth::Instruction::POP), // first ++
+					   // Stack here: (a+1) x a
+					   byte(eth::Instruction::DUP3),
+					   byte(eth::Instruction::PUSH1), 0x1,
+					   byte(eth::Instruction::ADD),
+					   // Stack here: (a+1) x a (a+2)
+					   byte(eth::Instruction::SWAP3),
+					   byte(eth::Instruction::POP),
+					   // Stack here: (a+2) x a
+					   byte(eth::Instruction::DUP3), // second ++
+					   byte(eth::Instruction::XOR),
+					   // Stack here: (a+2) x a^(a+2)
+					   byte(eth::Instruction::DUP3),
+					   byte(eth::Instruction::DUP1),
+					   byte(eth::Instruction::PUSH1), 0x1,
+					   byte(eth::Instruction::SWAP1),
+					   byte(eth::Instruction::SUB),
+					   // Stack here: (a+2) x a^(a+2) (a+2) (a+1)
+					   byte(eth::Instruction::SWAP4),
+					   byte(eth::Instruction::POP), // first --
+					   byte(eth::Instruction::XOR),
+					   // Stack here: (a+1) x a^(a+2)^(a+2)
+					   byte(eth::Instruction::DUP3),
+					   byte(eth::Instruction::PUSH1), 0x1,
+					   byte(eth::Instruction::SWAP1),
+					   byte(eth::Instruction::SUB),
+					   // Stack here: (a+1) x a^(a+2)^(a+2) a
+					   byte(eth::Instruction::SWAP3),
+					   byte(eth::Instruction::POP), // second ++
+					   // Stack here: a x a^(a+2)^(a+2)
+					   byte(eth::Instruction::DUP3), // will change
+					   byte(eth::Instruction::XOR)});
+					   // Stack here: a x a^(a+2)^(a+2)^a
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_CASE(assignment)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f(uint a, uint b) { (a += b) * 2; }"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode, {}, {{"test", "f", "a"}, {"test", "f", "b"}});
+
+	// Stack: a, b
+	bytes expectation({byte(eth::Instruction::DUP1),
+					   byte(eth::Instruction::DUP3),
+					   byte(eth::Instruction::SWAP1),
+					   byte(eth::Instruction::ADD),
+					   // Stack here: a b a+b
+					   byte(eth::Instruction::SWAP2),
+					   byte(eth::Instruction::POP),
+					   byte(eth::Instruction::DUP2),
+					   // Stack here: a+b b a+b
+					   byte(eth::Instruction::PUSH1), 0x2,
+					   byte(eth::Instruction::MUL)});
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_CASE(function_call)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function f(uint a, uint b) { a += g(a + 1, b) * 2; }\n"
+							 "  function g(uint a, uint b) returns (uint c) {}\n"
+							 "}\n";
+	bytes code = compileFirstExpression(sourceCode, {{"test", "g"}},
+										{{"test", "f", "a"}, {"test", "f", "b"}});
+
+	// Stack: a, b
+	bytes expectation({byte(eth::Instruction::PUSH1), 0x0a,
+					   byte(eth::Instruction::DUP3),
+					   byte(eth::Instruction::PUSH1), 0x01,
+					   byte(eth::Instruction::ADD),
+					   // Stack here: a b <ret label> (a+1)
+					   byte(eth::Instruction::DUP3),
+					   byte(eth::Instruction::PUSH1), 0x14,
+					   byte(eth::Instruction::JUMP),
+					   byte(eth::Instruction::JUMPDEST),
+					   // Stack here: a b g(a+1, b)
+					   byte(eth::Instruction::PUSH1), 0x02,
+					   byte(eth::Instruction::MUL),
+					   // Stack here: a b g(a+1, b)*2
+					   byte(eth::Instruction::DUP3),
+					   byte(eth::Instruction::SWAP1),
+					   byte(eth::Instruction::ADD),
+					   // Stack here: a b a+g(a+1, b)*2
+					   byte(eth::Instruction::SWAP2),
+					   byte(eth::Instruction::POP),
+					   byte(eth::Instruction::DUP2),
+					   byte(eth::Instruction::JUMPDEST)});
+	BOOST_CHECK_EQUAL_COLLECTIONS(code.begin(), code.end(), expectation.begin(), expectation.end());
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}
+}
+} // end namespaces
+