Fix overload resolution when conflict is with members of address (balance, transfer, etc)

Changelog.md

@@ -5,6 +5,8 @@ Features:
 
 Bugfixes:
  * Parser: Fix source location of VariableDeclarationStatement.
+ * Type Checker: Properly support overwriting members inherited from ``address`` in a contract
+   (such as ``balance``, ``transfer``, etc.)
 
 ### 0.4.17 (2017-09-21)
 

libsolidity/analysis/TypeChecker.cpp

@@ -1720,12 +1720,34 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 		);
 	}
 	else if (possibleMembers.size() > 1)
-		m_errorReporter.fatalTypeError(
-			_memberAccess.location(),
-			"Member \"" + memberName + "\" not unique "
-			"after argument-dependent lookup in " + exprType->toString() +
-			(memberName == "value" ? " - did you forget the \"payable\" modifier?" : "")
-		);
+	{
+		// Remove builtins (i.e. not having a declaration) first
+		for (auto it = possibleMembers.begin(); it != possibleMembers.end();)
+			if (
+				(
+					// Overloaded functions without declaration (e.g. transfer(), send(), call(), etc.)
+					it->type->category() == Type::Category::Function &&
+					!dynamic_cast<FunctionType const&>(*it->type).hasDeclaration()
+				)
+				||
+				(
+					// Overloaded members (e.g. balance)
+					it->type->category() == Type::Category::Integer &&
+					memberName == "balance"
+				)
+			)
+				it = possibleMembers.erase(it);
+			else
+				++it;
+
+		if (possibleMembers.size() > 1)
+			m_errorReporter.fatalTypeError(
+				_memberAccess.location(),
+				"Member \"" + memberName + "\" not unique "
+				"after argument-dependent lookup in " + exprType->toString() +
+				(memberName == "value" ? " - did you forget the \"payable\" modifier?" : "")
+			);
+	}
 
 	auto& annotation = _memberAccess.annotation();
 	annotation.referencedDeclaration = possibleMembers.front().declaration;

test/libsolidity/SolidityEndToEndTest.cpp

@@ -10151,6 +10151,31 @@ BOOST_AUTO_TEST_CASE(constant_string)
 	ABI_CHECK(callContractFunction("h()"), encodeDyn(string("hello")));
 }
 
+BOOST_AUTO_TEST_CASE(address_overload_resolution)
+{
+	char const* sourceCode = R"(
+		contract C {
+			function balance() returns (uint) {
+				return 1;
+			}
+			function transfer(uint amount) returns (uint) {
+				return amount;
+			}
+		}
+		contract D {
+			function f() returns (uint) {
+				return (new C()).balance();
+			}
+			function g() returns (uint) {
+				return (new C()).transfer(5);
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "D");
+	BOOST_CHECK(callContractFunction("f()") == encodeArgs(u256(1)));
+	BOOST_CHECK(callContractFunction("g()") == encodeArgs(u256(5)));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }

test/libsolidity/SolidityNameAndTypeResolution.cpp

@@ -6953,6 +6953,29 @@ BOOST_AUTO_TEST_CASE(warn_about_suicide)
 	CHECK_WARNING(text, "\"suicide\" has been deprecated in favour of \"selfdestruct\"");
 }
 
+BOOST_AUTO_TEST_CASE(address_overload_resolution)
+{
+	char const* text = R"(
+		contract C {
+			function balance() returns (uint) {
+				this.balance; // to avoid pureness warning
+				return 1;
+			}
+			function transfer(uint amount) {
+				address(this).transfer(amount); // to avoid pureness warning
+			}
+		}
+		contract D {
+			function f() {
+				var x = (new C()).balance();
+				x;
+				(new C()).transfer(5);
+			}
+		}
+	)";
+	CHECK_SUCCESS(text);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }