length member for byte arrays.

libsolidity/ExpressionCompiler.cpp

@@ -504,6 +504,12 @@ void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
 		}
 		BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Invalid member access to " + type.toString()));
 	}
+	case Type::Category::ByteArray:
+	{
+		solAssert(member == "length", "Illegal bytearray member.");
+		m_context << eth::Instruction::SLOAD;
+		break;
+	}
 	default:
 		BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Member access to unknown type."));
 	}

libsolidity/Types.cpp

@@ -541,6 +541,8 @@ unsigned ByteArrayType::getSizeOnStack() const
 		return 1;
 }
 
+const MemberList ByteArrayType::s_byteArrayMemberList = MemberList({{"length", make_shared<IntegerType >(256)}});
+
 bool ContractType::operator==(Type const& _other) const
 {
 	if (_other.getCategory() != getCategory())

libsolidity/Types.h

@@ -292,11 +292,13 @@ public:
 	virtual bool operator==(const Type& _other) const override;
 	virtual unsigned getSizeOnStack() const override;
 	virtual std::string toString() const override { return "bytes"; }
+	virtual MemberList const& getMembers() const override { return s_byteArrayMemberList; }
 
 	Location getLocation() const { return m_location; }
 
 private:
 	Location m_location;
+	static const MemberList s_byteArrayMemberList;
 };
 
 /**

test/SolidityEndToEndTest.cpp

@@ -2409,6 +2409,21 @@ BOOST_AUTO_TEST_CASE(bytes_inside_mappings)
 	BOOST_CHECK(m_state.storage(m_contractAddress).empty());
 }
 
+BOOST_AUTO_TEST_CASE(bytes_length_member)
+{
+	char const* sourceCode = R"(
+		contract c {
+			function set() returns (bool) { data = msg.data; return true; }
+			function getLength() returns (uint) { return data.length; }
+			bytes data;
+		}
+	)";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction("getLength()") == encodeArgs(0));
+	BOOST_CHECK(callContractFunction("set()", 1, 2) == encodeArgs(true));
+	BOOST_CHECK(callContractFunction("getLength()") == encodeArgs(4+32+32));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }