Merge pull request #4887 from ethereum/addressSplit

Split IntegerType into IntegerType and AddressType.

12 files changed, 174 insertions, 102 deletions

diff --git a/Changelog.md b/Changelog.md
index 8760b818..14a362be 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -86,6 +86,7 @@ Compiler Features:
  * C API (``libsolc``): Export the ``solidity_license``, ``solidity_version`` and ``solidity_compile`` methods.
  * Type Checker: Nicer error message when trying to reference overloaded identifiers in inline assembly.
  * Type Checker: Show named argument in case of error.
+ * Type System: IntegerType is split into IntegerType and AddressType internally.
  * Tests: Determine transaction status during IPC calls.
  * Code Generator: Allocate and free local variables according to their scope.
  * Removed ``pragma experimental "v0.5.0";``.
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index a2b72896..a3f4459e 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -2103,7 +2103,7 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 				"after argument-dependent lookup in " + exprType->toString() +
 				(memberName == "value" ? " - did you forget the \"payable\" modifier?" : ".");
 		if (exprType->category() == Type::Category::Contract)
-			for (auto const& addressMember: IntegerType(160, IntegerType::Modifier::Address).nativeMembers(nullptr))
+			for (auto const& addressMember: AddressType().nativeMembers(nullptr))
 				if (addressMember.name == memberName)
 				{
 					Identifier const* var = dynamic_cast<Identifier const*>(&_memberAccess.expression());
@@ -2353,7 +2353,7 @@ void TypeChecker::endVisit(Literal const& _literal)
 	if (_literal.looksLikeAddress())
 	{
 		// Assign type here if it even looks like an address. This prevents double errors for invalid addresses
-		_literal.annotation().type = make_shared<IntegerType>(160, IntegerType::Modifier::Address);
+		_literal.annotation().type = make_shared<AddressType>();
 
 		string msg;
 		if (_literal.value().length() != 42) // "0x" + 40 hex digits
diff --git a/libsolidity/analysis/ViewPureChecker.cpp b/libsolidity/analysis/ViewPureChecker.cpp
index be6b7ef7..113a3177 100644
--- a/libsolidity/analysis/ViewPureChecker.cpp
+++ b/libsolidity/analysis/ViewPureChecker.cpp
@@ -323,7 +323,7 @@ void ViewPureChecker::endVisit(MemberAccess const& _memberAccess)
 	ASTString const& member = _memberAccess.memberName();
 	switch (_memberAccess.expression().annotation().type->category())
 	{
-	case Type::Category::Integer:
+	case Type::Category::Address:
 		if (member == "balance")
 			mutability = StateMutability::View;
 		break;
diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index a6867dcb..a302203b 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -299,7 +299,7 @@ TypePointer Type::fromElementaryTypeName(ElementaryTypeNameToken const& _type)
 	case Token::Byte:
 		return make_shared<FixedBytesType>(1);
 	case Token::Address:
-		return make_shared<IntegerType>(160, IntegerType::Modifier::Address);
+		return make_shared<AddressType>();
 	case Token::Bool:
 		return make_shared<BoolType>();
 	case Token::Bytes:
@@ -439,6 +439,59 @@ MemberList::MemberMap Type::boundFunctions(Type const& _type, ContractDefinition
 	return members;
 }
 
+string AddressType::richIdentifier() const
+{
+	return "t_address";
+}
+
+bool AddressType::isExplicitlyConvertibleTo(Type const& _convertTo) const
+{
+	return isImplicitlyConvertibleTo(_convertTo) ||
+		   _convertTo.category() == Category::Contract ||
+		   _convertTo.category() == Category::Integer ||
+		   (_convertTo.category() == Category::FixedBytes && 160 == dynamic_cast<FixedBytesType const&>(_convertTo).numBytes() * 8);
+}
+
+string AddressType::toString(bool) const
+{
+	return "address";
+}
+
+u256 AddressType::literalValue(Literal const* _literal) const
+{
+	solAssert(_literal, "");
+	solAssert(_literal->value().substr(0, 2) == "0x", "");
+	return u256(_literal->value());
+}
+
+TypePointer AddressType::unaryOperatorResult(Token::Value _operator) const
+{
+	return _operator == Token::Delete ? make_shared<TupleType>() : TypePointer();
+}
+
+
+TypePointer AddressType::binaryOperatorResult(Token::Value _operator, TypePointer const& _other) const
+{
+	// Addresses can only be compared.
+	if (!Token::isCompareOp(_operator))
+		return TypePointer();
+
+	return Type::commonType(shared_from_this(), _other);
+}
+
+MemberList::MemberMap AddressType::nativeMembers(ContractDefinition const*) const
+{
+	return {
+		{"balance", make_shared<IntegerType>(256)},
+		{"call", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bool", "bytes memory"}, FunctionType::Kind::BareCall, false, StateMutability::Payable)},
+		{"callcode", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bool", "bytes memory"}, FunctionType::Kind::BareCallCode, false, StateMutability::Payable)},
+		{"delegatecall", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bool", "bytes memory"}, FunctionType::Kind::BareDelegateCall, false)},
+		{"send", make_shared<FunctionType>(strings{"uint"}, strings{"bool"}, FunctionType::Kind::Send)},
+		{"staticcall", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bool", "bytes memory"}, FunctionType::Kind::BareStaticCall, false, StateMutability::View)},
+		{"transfer", make_shared<FunctionType>(strings{"uint"}, strings(), FunctionType::Kind::Transfer)}
+	};
+}
+
 namespace
 {
 
@@ -448,7 +501,7 @@ bool isValidShiftAndAmountType(Token::Value _operator, Type const& _shiftAmountT
 	if (_operator == Token::SHR)
 		return false;
 	else if (IntegerType const* otherInt = dynamic_cast<decltype(otherInt)>(&_shiftAmountType))
-		return !otherInt->isAddress();
+		return true;
 	else if (RationalNumberType const* otherRat = dynamic_cast<decltype(otherRat)>(&_shiftAmountType))
 		return !otherRat->isFractional() && otherRat->integerType() && !otherRat->integerType()->isSigned();
 	else
@@ -460,8 +513,6 @@ bool isValidShiftAndAmountType(Token::Value _operator, Type const& _shiftAmountT
 IntegerType::IntegerType(unsigned _bits, IntegerType::Modifier _modifier):
 	m_bits(_bits), m_modifier(_modifier)
 {
-	if (isAddress())
-		solAssert(m_bits == 160, "");
 	solAssert(
 		m_bits > 0 && m_bits <= 256 && m_bits % 8 == 0,
 		"Invalid bit number for integer type: " + dev::toString(m_bits)
@@ -470,10 +521,7 @@ IntegerType::IntegerType(unsigned _bits, IntegerType::Modifier _modifier):
 
 string IntegerType::richIdentifier() const
 {
-	if (isAddress())
-		return "t_address";
-	else
-		return "t_" + string(isSigned() ? "" : "u") + "int" + to_string(numBits());
+	return "t_" + string(isSigned() ? "" : "u") + "int" + to_string(numBits());
 }
 
 bool IntegerType::isImplicitlyConvertibleTo(Type const& _convertTo) const
@@ -483,8 +531,6 @@ bool IntegerType::isImplicitlyConvertibleTo(Type const& _convertTo) const
 		IntegerType const& convertTo = dynamic_cast<IntegerType const&>(_convertTo);
 		if (convertTo.m_bits < m_bits)
 			return false;
-		if (isAddress())
-			return convertTo.isAddress();
 		else if (isSigned())
 			return convertTo.isSigned();
 		else
@@ -493,11 +539,7 @@ bool IntegerType::isImplicitlyConvertibleTo(Type const& _convertTo) const
 	else if (_convertTo.category() == Category::FixedPoint)
 	{
 		FixedPointType const& convertTo = dynamic_cast<FixedPointType const&>(_convertTo);
-
-		if (isAddress())
-			return false;
-		else
-			return maxValue() <= convertTo.maxIntegerValue() && minValue() >= convertTo.minIntegerValue();
+		return maxValue() <= convertTo.maxIntegerValue() && minValue() >= convertTo.minIntegerValue();
 	}
 	else
 		return false;
@@ -506,6 +548,7 @@ bool IntegerType::isImplicitlyConvertibleTo(Type const& _convertTo) const
 bool IntegerType::isExplicitlyConvertibleTo(Type const& _convertTo) const
 {
 	return _convertTo.category() == category() ||
+		_convertTo.category() == Category::Address ||
 		_convertTo.category() == Category::Contract ||
 		_convertTo.category() == Category::Enum ||
 		(_convertTo.category() == Category::FixedBytes && numBits() == dynamic_cast<FixedBytesType const&>(_convertTo).numBytes() * 8) ||
@@ -517,10 +560,7 @@ TypePointer IntegerType::unaryOperatorResult(Token::Value _operator) const
 	// "delete" is ok for all integer types
 	if (_operator == Token::Delete)
 		return make_shared<TupleType>();
-	// no further unary operators for addresses
-	else if (isAddress())
-		return TypePointer();
-	// for non-address integers, we allow +, -, ++ and --
+	// we allow +, -, ++ and --
 	else if (_operator == Token::Add || _operator == Token::Sub ||
 			_operator == Token::Inc || _operator == Token::Dec ||
 			_operator == Token::BitNot)
@@ -539,20 +579,10 @@ bool IntegerType::operator==(Type const& _other) const
 
 string IntegerType::toString(bool) const
 {
-	if (isAddress())
-		return "address";
 	string prefix = isSigned() ? "int" : "uint";
 	return prefix + dev::toString(m_bits);
 }
 
-u256 IntegerType::literalValue(Literal const* _literal) const
-{
-	solAssert(m_modifier == Modifier::Address, "");
-	solAssert(_literal, "");
-	solAssert(_literal->value().substr(0, 2) == "0x", "");
-	return u256(_literal->value());
-}
-
 bigint IntegerType::minValue() const
 {
 	if (isSigned())
@@ -580,8 +610,6 @@ TypePointer IntegerType::binaryOperatorResult(Token::Value _operator, TypePointe
 	if (Token::isShiftOp(_operator))
 	{
 		// Shifts are not symmetric with respect to the type
-		if (isAddress())
-			return TypePointer();
 		if (isValidShiftAndAmountType(_operator, *_other))
 			return shared_from_this();
 		else
@@ -599,9 +627,6 @@ TypePointer IntegerType::binaryOperatorResult(Token::Value _operator, TypePointe
 		return TypePointer();
 	if (auto intType = dynamic_pointer_cast<IntegerType const>(commonType))
 	{
-		// Nothing else can be done with addresses
-		if (intType->isAddress())
-			return TypePointer();
 		// Signed EXP is not allowed
 		if (Token::Exp == _operator && intType->isSigned())
 			return TypePointer();
@@ -612,22 +637,6 @@ TypePointer IntegerType::binaryOperatorResult(Token::Value _operator, TypePointe
 	return commonType;
 }
 
-MemberList::MemberMap IntegerType::nativeMembers(ContractDefinition const*) const
-{
-	if (isAddress())
-		return {
-			{"balance", make_shared<IntegerType>(256)},
-			{"call", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bool", "bytes memory"}, FunctionType::Kind::BareCall, false, StateMutability::Payable)},
-			{"callcode", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bool", "bytes memory"}, FunctionType::Kind::BareCallCode, false, StateMutability::Payable)},
-			{"delegatecall", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bool", "bytes memory"}, FunctionType::Kind::BareDelegateCall, false)},
-			{"send", make_shared<FunctionType>(strings{"uint"}, strings{"bool"}, FunctionType::Kind::Send)},
-			{"staticcall", make_shared<FunctionType>(strings{"bytes memory"}, strings{"bool", "bytes memory"}, FunctionType::Kind::BareStaticCall, false, StateMutability::View)},
-			{"transfer", make_shared<FunctionType>(strings{"uint"}, strings(), FunctionType::Kind::Transfer)}
-		};
-	else
-		return MemberList::MemberMap();
-}
-
 FixedPointType::FixedPointType(unsigned _totalBits, unsigned _fractionalDigits, FixedPointType::Modifier _modifier):
 	m_totalBits(_totalBits), m_fractionalDigits(_fractionalDigits), m_modifier(_modifier)
 {
@@ -658,8 +667,7 @@ bool FixedPointType::isImplicitlyConvertibleTo(Type const& _convertTo) const
 
 bool FixedPointType::isExplicitlyConvertibleTo(Type const& _convertTo) const
 {
-	return _convertTo.category() == category() ||
-		(_convertTo.category() == Category::Integer && !dynamic_cast<IntegerType const&>(_convertTo).isAddress());
+	return _convertTo.category() == category() || _convertTo.category() == Category::Integer;
 }
 
 TypePointer FixedPointType::unaryOperatorResult(Token::Value _operator) const
@@ -912,8 +920,6 @@ bool RationalNumberType::isImplicitlyConvertibleTo(Type const& _convertTo) const
 		if (isFractional())
 			return false;
 		IntegerType const& targetType = dynamic_cast<IntegerType const&>(_convertTo);
-		if (targetType.isAddress())
-			return false;
 		if (m_value == rational(0))
 			return true;
 		unsigned forSignBit = (targetType.isSigned() ? 1 : 0);
@@ -1368,6 +1374,7 @@ bool FixedBytesType::isImplicitlyConvertibleTo(Type const& _convertTo) const
 bool FixedBytesType::isExplicitlyConvertibleTo(Type const& _convertTo) const
 {
 	return (_convertTo.category() == Category::Integer && numBytes() * 8 == dynamic_cast<IntegerType const&>(_convertTo).numBits()) ||
+		(_convertTo.category() == Category::Address && numBytes() == 20) ||
 		_convertTo.category() == Category::FixedPoint ||
 		_convertTo.category() == category();
 }
@@ -1469,9 +1476,7 @@ bool ContractType::isImplicitlyConvertibleTo(Type const& _convertTo) const
 
 bool ContractType::isExplicitlyConvertibleTo(Type const& _convertTo) const
 {
-	return
-		isImplicitlyConvertibleTo(_convertTo) ||
-		_convertTo == IntegerType(160, IntegerType::Modifier::Address);
+	return isImplicitlyConvertibleTo(_convertTo) || _convertTo.category() == Category::Address;
 }
 
 bool ContractType::isPayable() const
@@ -2584,12 +2589,8 @@ bool FunctionType::operator==(Type const& _other) const
 
 bool FunctionType::isExplicitlyConvertibleTo(Type const& _convertTo) const
 {
-	if (m_kind == Kind::External && _convertTo.category() == Category::Integer)
-	{
-		IntegerType const& convertTo = dynamic_cast<IntegerType const&>(_convertTo);
-		if (convertTo.isAddress())
+	if (m_kind == Kind::External && _convertTo.category() == Category::Address)
 			return true;
-	}
 	return _convertTo.category() == category();
 }
 
@@ -3274,7 +3275,7 @@ MemberList::MemberMap MagicType::nativeMembers(ContractDefinition const*) const
 	{
 	case Kind::Block:
 		return MemberList::MemberMap({
-			{"coinbase", make_shared<IntegerType>(160, IntegerType::Modifier::Address)},
+			{"coinbase", make_shared<AddressType>()},
 			{"timestamp", make_shared<IntegerType>(256)},
 			{"blockhash", make_shared<FunctionType>(strings{"uint"}, strings{"bytes32"}, FunctionType::Kind::BlockHash, false, StateMutability::View)},
 			{"difficulty", make_shared<IntegerType>(256)},
@@ -3283,7 +3284,7 @@ MemberList::MemberMap MagicType::nativeMembers(ContractDefinition const*) const
 		});
 	case Kind::Message:
 		return MemberList::MemberMap({
-			{"sender", make_shared<IntegerType>(160, IntegerType::Modifier::Address)},
+			{"sender", make_shared<AddressType>()},
 			{"gas", make_shared<IntegerType>(256)},
 			{"value", make_shared<IntegerType>(256)},
 			{"data", make_shared<ArrayType>(DataLocation::CallData)},
@@ -3291,7 +3292,7 @@ MemberList::MemberMap MagicType::nativeMembers(ContractDefinition const*) const
 		});
 	case Kind::Transaction:
 		return MemberList::MemberMap({
-			{"origin", make_shared<IntegerType>(160, IntegerType::Modifier::Address)},
+			{"origin", make_shared<AddressType>()},
 			{"gasprice", make_shared<IntegerType>(256)}
 		});
 	case Kind::ABI:
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index b860bf6a..7ee66838 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -141,7 +141,7 @@ public:
 	virtual ~Type() = default;
 	enum class Category
 	{
-		Integer, RationalNumber, StringLiteral, Bool, FixedPoint, Array,
+		Address, Integer, RationalNumber, StringLiteral, Bool, FixedPoint, Array,
 		FixedBytes, Contract, Struct, Function, Enum, Tuple,
 		Mapping, TypeType, Modifier, Magic, Module,
 		InaccessibleDynamic
@@ -314,14 +314,45 @@ protected:
 };
 
 /**
- * Any kind of integer type (signed, unsigned, address).
+ * Type for addresses.
+ */
+class AddressType: public Type
+{
+public:
+	virtual Category category() const override { return Category::Address; }
+
+	explicit AddressType()
+	{
+	}
+
+	virtual std::string richIdentifier() const override;
+	virtual bool isExplicitlyConvertibleTo(Type const& _convertTo) const override;
+	virtual TypePointer unaryOperatorResult(Token::Value _operator) const override;
+	virtual TypePointer binaryOperatorResult(Token::Value _operator, TypePointer const& _other) const override;
+
+	virtual unsigned calldataEncodedSize(bool _padded = true) const override { return _padded ? 32 : 160 / 8; }
+	virtual unsigned storageBytes() const override { return 160 / 8; }
+	virtual bool isValueType() const override { return true; }
+
+	virtual MemberList::MemberMap nativeMembers(ContractDefinition const*) const override;
+
+	virtual std::string toString(bool _short) const override;
+
+	virtual u256 literalValue(Literal const* _literal) const override;
+
+	virtual TypePointer encodingType() const override { return shared_from_this(); }
+	virtual TypePointer interfaceType(bool) const override { return shared_from_this(); }
+};
+
+/**
+ * Any kind of integer type (signed, unsigned).
  */
 class IntegerType: public Type
 {
 public:
 	enum class Modifier
 	{
-		Unsigned, Signed, Address
+		Unsigned, Signed
 	};
 	virtual Category category() const override { return Category::Integer; }
 
@@ -339,17 +370,12 @@ public:
 	virtual unsigned storageBytes() const override { return m_bits / 8; }
 	virtual bool isValueType() const override { return true; }
 
-	virtual MemberList::MemberMap nativeMembers(ContractDefinition const*) const override;
-
 	virtual std::string toString(bool _short) const override;
 
-	virtual u256 literalValue(Literal const* _literal) const override;
-
 	virtual TypePointer encodingType() const override { return shared_from_this(); }
 	virtual TypePointer interfaceType(bool) const override { return shared_from_this(); }
 
 	unsigned numBits() const { return m_bits; }
-	bool isAddress() const { return m_modifier == Modifier::Address; }
 	bool isSigned() const { return m_modifier == Modifier::Signed; }
 
 	bigint minValue() const;
@@ -729,7 +755,7 @@ public:
 	{
 		if (isSuper())
 			return TypePointer{};
-		return std::make_shared<IntegerType>(160, IntegerType::Modifier::Address);
+		return std::make_shared<AddressType>();
 	}
 	virtual TypePointer interfaceType(bool _inLibrary) const override
 	{
diff --git a/libsolidity/codegen/ABIFunctions.cpp b/libsolidity/codegen/ABIFunctions.cpp
index dda77958..5e5fe84a 100644
--- a/libsolidity/codegen/ABIFunctions.cpp
+++ b/libsolidity/codegen/ABIFunctions.cpp
@@ -197,6 +197,9 @@ string ABIFunctions::cleanupFunction(Type const& _type, bool _revertOnFailure)
 		templ("functionName", functionName);
 		switch (_type.category())
 		{
+		case Type::Category::Address:
+			templ("body", "cleaned := " + cleanupFunction(IntegerType(160)) + "(value)");
+			break;
 		case Type::Category::Integer:
 		{
 			IntegerType const& type = dynamic_cast<IntegerType const&>(_type);
@@ -239,7 +242,7 @@ string ABIFunctions::cleanupFunction(Type const& _type, bool _revertOnFailure)
 			break;
 		}
 		case Type::Category::Contract:
-			templ("body", "cleaned := " + cleanupFunction(IntegerType(160, IntegerType::Modifier::Address)) + "(value)");
+			templ("body", "cleaned := " + cleanupFunction(AddressType()) + "(value)");
 			break;
 		case Type::Category::Enum:
 		{
@@ -284,6 +287,12 @@ string ABIFunctions::conversionFunction(Type const& _from, Type const& _to)
 		auto fromCategory = _from.category();
 		switch (fromCategory)
 		{
+		case Type::Category::Address:
+			body =
+				Whiskers("converted := <convert>(value)")
+					("convert", conversionFunction(IntegerType(160), _to))
+					.render();
+			break;
 		case Type::Category::Integer:
 		case Type::Category::RationalNumber:
 		case Type::Category::Contract:
@@ -314,16 +323,19 @@ string ABIFunctions::conversionFunction(Type const& _from, Type const& _to)
 					.render();
 			}
 			else if (toCategory == Type::Category::FixedPoint)
-			{
 				solUnimplemented("Not yet implemented - FixedPointType.");
-			}
+			else if (toCategory == Type::Category::Address)
+				body =
+					Whiskers("converted := <convert>(value)")
+						("convert", conversionFunction(_from, IntegerType(160)))
+						.render();
 			else
 			{
 				solAssert(
 					toCategory == Type::Category::Integer ||
 					toCategory == Type::Category::Contract,
 				"");
-				IntegerType const addressType(160, IntegerType::Modifier::Address);
+				IntegerType const addressType(160);
 				IntegerType const& to =
 					toCategory == Type::Category::Integer ?
 					dynamic_cast<IntegerType const&>(_to) :
@@ -375,6 +387,11 @@ string ABIFunctions::conversionFunction(Type const& _from, Type const& _to)
 					("shift", shiftRightFunction(256 - from.numBytes() * 8))
 					("convert", conversionFunction(IntegerType(from.numBytes() * 8), _to))
 					.render();
+			else if (toCategory == Type::Category::Address)
+				body =
+					Whiskers("converted := <convert>(value)")
+						("convert", conversionFunction(_from, IntegerType(160)))
+						.render();
 			else
 			{
 				// clear for conversion to longer bytes
@@ -410,7 +427,7 @@ string ABIFunctions::conversionFunction(Type const& _from, Type const& _to)
 			solAssert(false, "");
 		}
 
-		solAssert(!body.empty(), "");
+		solAssert(!body.empty(), _from.canonicalName() + " to " + _to.canonicalName());
 		templ("body", body);
 		return templ.render();
 	});
diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp
index b30851fb..e6ad6d9c 100644
--- a/libsolidity/codegen/CompilerUtils.cpp
+++ b/libsolidity/codegen/CompilerUtils.cpp
@@ -657,6 +657,11 @@ void CompilerUtils::convertType(
 			if (targetIntegerType.numBits() < typeOnStack.numBytes() * 8)
 				convertType(IntegerType(typeOnStack.numBytes() * 8), _targetType, _cleanupNeeded);
 		}
+		else if (targetTypeCategory == Type::Category::Address)
+		{
+			solAssert(typeOnStack.numBytes() * 8 == 160, "");
+			rightShiftNumberOnStack(256 - 160);
+		}
 		else
 		{
 			// clear for conversion to longer bytes
@@ -690,23 +695,33 @@ void CompilerUtils::convertType(
 		break;
 	case Type::Category::FixedPoint:
 		solUnimplemented("Not yet implemented - FixedPointType.");
+	case Type::Category::Address:
 	case Type::Category::Integer:
 	case Type::Category::Contract:
 	case Type::Category::RationalNumber:
 		if (targetTypeCategory == Type::Category::FixedBytes)
 		{
-			solAssert(stackTypeCategory == Type::Category::Integer || stackTypeCategory == Type::Category::RationalNumber,
-				"Invalid conversion to FixedBytesType requested.");
+			solAssert(
+				stackTypeCategory == Type::Category::Address ||
+				stackTypeCategory == Type::Category::Integer ||
+				stackTypeCategory == Type::Category::RationalNumber,
+				"Invalid conversion to FixedBytesType requested."
+			);
 			// conversion from bytes to string. no need to clean the high bit
 			// only to shift left because of opposite alignment
 			FixedBytesType const& targetBytesType = dynamic_cast<FixedBytesType const&>(_targetType);
 			if (auto typeOnStack = dynamic_cast<IntegerType const*>(&_typeOnStack))
+			{
 				if (targetBytesType.numBytes() * 8 > typeOnStack->numBits())
 					cleanHigherOrderBits(*typeOnStack);
+			}
+			else if (stackTypeCategory == Type::Category::Address)
+				solAssert(targetBytesType.numBytes() * 8 == 160, "");
 			leftShiftNumberOnStack(256 - targetBytesType.numBytes() * 8);
 		}
 		else if (targetTypeCategory == Type::Category::Enum)
 		{
+			solAssert(stackTypeCategory != Type::Category::Address, "Invalid conversion to EnumType requested.");
 			solAssert(_typeOnStack.mobileType(), "");
 			// just clean
 			convertType(_typeOnStack, *_typeOnStack.mobileType(), true);
@@ -733,8 +748,8 @@ void CompilerUtils::convertType(
 		}
 		else
 		{
-			solAssert(targetTypeCategory == Type::Category::Integer || targetTypeCategory == Type::Category::Contract, "");
-			IntegerType addressType(160, IntegerType::Modifier::Address);
+			solAssert(targetTypeCategory == Type::Category::Integer || targetTypeCategory == Type::Category::Contract || targetTypeCategory == Type::Category::Address, "");
+			IntegerType addressType(160);
 			IntegerType const& targetType = targetTypeCategory == Type::Category::Integer
 				? dynamic_cast<IntegerType const&>(_targetType) : addressType;
 			if (stackTypeCategory == Type::Category::RationalNumber)
@@ -996,10 +1011,8 @@ void CompilerUtils::convertType(
 			m_context << Instruction::ISZERO << Instruction::ISZERO;
 		break;
 	default:
-		if (stackTypeCategory == Type::Category::Function && targetTypeCategory == Type::Category::Integer)
+		if (stackTypeCategory == Type::Category::Function && targetTypeCategory == Type::Category::Address)
 		{
-			IntegerType const& targetType = dynamic_cast<IntegerType const&>(_targetType);
-			solAssert(targetType.isAddress(), "Function type can only be converted to address.");
 			FunctionType const& typeOnStack = dynamic_cast<FunctionType const&>(_typeOnStack);
 			solAssert(typeOnStack.kind() == FunctionType::Kind::External, "Only external function type can be converted.");
 
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index 4cc4ba53..4150bc11 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -1259,7 +1259,7 @@ bool ExpressionCompiler::visit(MemberAccess const& _memberAccess)
 				identifier = FunctionType(*function).externalIdentifier();
 			else
 				solAssert(false, "Contract member is neither variable nor function.");
-			utils().convertType(type, IntegerType(160, IntegerType::Modifier::Address), true);
+			utils().convertType(type, AddressType(), true);
 			m_context << identifier;
 		}
 		else
@@ -1268,11 +1268,16 @@ bool ExpressionCompiler::visit(MemberAccess const& _memberAccess)
 	}
 	case Type::Category::Integer:
 	{
+		solAssert(false, "Invalid member access to integer");
+		break;
+	}
+	case Type::Category::Address:
+	{
 		if (member == "balance")
 		{
 			utils().convertType(
 				*_memberAccess.expression().annotation().type,
-				IntegerType(160, IntegerType::Modifier::Address),
+				AddressType(),
 				true
 			);
 			m_context << Instruction::BALANCE;
@@ -1280,11 +1285,11 @@ bool ExpressionCompiler::visit(MemberAccess const& _memberAccess)
 		else if ((set<string>{"send", "transfer", "call", "callcode", "delegatecall", "staticcall"}).count(member))
 			utils().convertType(
 				*_memberAccess.expression().annotation().type,
-				IntegerType(160, IntegerType::Modifier::Address),
+				AddressType(),
 				true
 			);
 		else
-			solAssert(false, "Invalid member access to integer");
+			solAssert(false, "Invalid member access to address");
 		break;
 	}
 	case Type::Category::Function:
@@ -1578,7 +1583,7 @@ void ExpressionCompiler::endVisit(Literal const& _literal)
 	{
 	case Type::Category::RationalNumber:
 	case Type::Category::Bool:
-	case Type::Category::Integer:
+	case Type::Category::Address:
 		m_context << type->literalValue(&_literal);
 		break;
 	case Type::Category::StringLiteral:
diff --git a/libsolidity/formal/SMTChecker.cpp b/libsolidity/formal/SMTChecker.cpp
index 88c1e56a..49c90405 100644
--- a/libsolidity/formal/SMTChecker.cpp
+++ b/libsolidity/formal/SMTChecker.cpp
@@ -394,7 +394,7 @@ void SMTChecker::endVisit(Identifier const& _identifier)
 void SMTChecker::endVisit(Literal const& _literal)
 {
 	Type const& type = *_literal.annotation().type;
-	if (type.category() == Type::Category::Integer || type.category() == Type::Category::RationalNumber)
+	if (type.category() == Type::Category::Integer || type.category() == Type::Category::Address || type.category() == Type::Category::RationalNumber)
 	{
 		if (RationalNumberType const* rational = dynamic_cast<RationalNumberType const*>(&type))
 			solAssert(!rational->isFractional(), "");
@@ -540,6 +540,8 @@ void SMTChecker::assignment(VariableDeclaration const& _variable, smt::Expressio
 	TypePointer type = _variable.type();
 	if (auto const* intType = dynamic_cast<IntegerType const*>(type.get()))
 		checkUnderOverflow(_value, *intType, _location);
+	else if (dynamic_cast<AddressType const*>(type.get()))
+		checkUnderOverflow(_value, IntegerType(160), _location);
 	m_interface->addAssertion(newValue(_variable) == _value);
 }
 
@@ -862,6 +864,7 @@ void SMTChecker::createExpr(Expression const& _e)
 			m_expressions.emplace(&_e, m_interface->newInteger(uniqueSymbol(_e)));
 			break;
 		}
+		case Type::Category::Address:
 		case Type::Category::Integer:
 			m_expressions.emplace(&_e, m_interface->newInteger(uniqueSymbol(_e)));
 			break;
diff --git a/libsolidity/formal/SSAVariable.cpp b/libsolidity/formal/SSAVariable.cpp
index f3213e03..4fc2dd45 100644
--- a/libsolidity/formal/SSAVariable.cpp
+++ b/libsolidity/formal/SSAVariable.cpp
@@ -50,7 +50,7 @@ bool SSAVariable::isSupportedType(Type::Category _category)
 
 bool SSAVariable::isInteger(Type::Category _category)
 {
-	return _category == Type::Category::Integer;
+	return _category == Type::Category::Integer || _category == Type::Category::Address;
 }
 
 bool SSAVariable::isBool(Type::Category _category)
diff --git a/libsolidity/formal/SymbolicIntVariable.cpp b/libsolidity/formal/SymbolicIntVariable.cpp
index 5e71fdcc..4f65b1fd 100644
--- a/libsolidity/formal/SymbolicIntVariable.cpp
+++ b/libsolidity/formal/SymbolicIntVariable.cpp
@@ -29,7 +29,11 @@ SymbolicIntVariable::SymbolicIntVariable(
 ):
 	SymbolicVariable(_decl, _interface)
 {
-	solAssert(m_declaration.type()->category() == Type::Category::Integer, "");
+	solAssert(
+		m_declaration.type()->category() == Type::Category::Integer ||
+		m_declaration.type()->category() == Type::Category::Address,
+		""
+	);
 }
 
 smt::Expression SymbolicIntVariable::valueAtSequence(int _seq) const
@@ -44,9 +48,11 @@ void SymbolicIntVariable::setZeroValue(int _seq)
 
 void SymbolicIntVariable::setUnknownValue(int _seq)
 {
-	auto const& intType = dynamic_cast<IntegerType const&>(*m_declaration.type());
-	m_interface.addAssertion(valueAtSequence(_seq) >= minValue(intType));
-	m_interface.addAssertion(valueAtSequence(_seq) <= maxValue(intType));
+	auto intType = dynamic_pointer_cast<IntegerType const>(m_declaration.type());
+	if (!intType)
+		intType = make_shared<IntegerType>(160);
+	m_interface.addAssertion(valueAtSequence(_seq) >= minValue(*intType));
+	m_interface.addAssertion(valueAtSequence(_seq) <= maxValue(*intType));
 }
 
 smt::Expression SymbolicIntVariable::minValue(IntegerType const& _t)
diff --git a/test/compilationTests/zeppelin/token/VestedToken.sol b/test/compilationTests/zeppelin/token/VestedToken.sol
index 7edc7d16..2cd607bc 100644
--- a/test/compilationTests/zeppelin/token/VestedToken.sol
+++ b/test/compilationTests/zeppelin/token/VestedToken.sol
@@ -53,7 +53,7 @@ contract VestedToken is StandardToken, LimitedTransferToken {
 
     uint256 count = grants[_to].push(
                 TokenGrant(
-                  _revokable ? msg.sender : 0, // avoid storing an extra 20 bytes when it is non-revokable
+                  _revokable ? msg.sender : 0x0000000000000000000000000000000000000000, // avoid storing an extra 20 bytes when it is non-revokable
                   _value,
                   _cliff,
                   _vesting,
@@ -84,7 +84,7 @@ contract VestedToken is StandardToken, LimitedTransferToken {
       revert();
     }
 
-    address receiver = grant.burnsOnRevoke ? 0xdead : msg.sender;
+    address receiver = grant.burnsOnRevoke ? 0x000000000000000000000000000000000000dEaD : msg.sender;
 
     uint256 nonVested = nonVestedTokens(grant, uint64(now));