From 10a9960eb3de40e3d99db5306981215fa72952a0 Mon Sep 17 00:00:00 2001
From: Mathias Baumann <marenz@supradigital.org>
Date: Tue, 12 Feb 2019 16:56:22 +0100
Subject: [PATCH] Fix error msg hint for non-payable contracts

---
 libsolidity/analysis/TypeChecker.cpp          | 38 +++++++++----------
 .../contract_not_payable_send.sol             |  8 ++++
 .../contract_not_payable_transfer.sol         |  8 ++++
 3 files changed, 33 insertions(+), 21 deletions(-)
 create mode 100644 test/libsolidity/syntaxTests/memberLookup/contract_not_payable_send.sol
 create mode 100644 test/libsolidity/syntaxTests/memberLookup/contract_not_payable_transfer.sol

diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 1bc89ce17..1d30a1910 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -2064,7 +2064,8 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 						errorMsg += " Did you intend to call the function?";
 			}
 		}
-		if (exprType->category() == Type::Category::Contract)
+		else if (exprType->category() == Type::Category::Contract)
+		{
 			for (auto const& addressMember: AddressType::addressPayable().nativeMembers(nullptr))
 				if (addressMember.name == memberName)
 				{
@@ -2073,6 +2074,21 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 					errorMsg += " Use \"address(" + varName + ")." + memberName + "\" to access this address member.";
 					break;
 				}
+		}
+		else if (auto addressType = dynamic_cast<AddressType const*>(exprType.get()))
+		{
+			// Trigger error when using send or transfer with a non-payable fallback function.
+			if (memberName == "send" || memberName == "transfer")
+			{
+				solAssert(
+					addressType->stateMutability() != StateMutability::Payable,
+					"Expected address not-payable as members were not found"
+				);
+
+				errorMsg = "\"send\" and \"transfer\" are only available for objects of type \"address payable\", not \"" + exprType->toString() + "\".";
+			}
+		}
+
 		m_errorReporter.fatalTypeError(
 			_memberAccess.location(),
 			errorMsg
@@ -2115,26 +2131,6 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 			annotation.isLValue = annotation.referencedDeclaration->isLValue();
 	}
 
-	if (exprType->category() == Type::Category::Contract)
-	{
-		// Warn about using send or transfer with a non-payable fallback function.
-		if (auto callType = dynamic_cast<FunctionType const*>(type(_memberAccess).get()))
-		{
-			auto kind = callType->kind();
-			auto contractType = dynamic_cast<ContractType const*>(exprType.get());
-			solAssert(!!contractType, "Should be contract type.");
-
-			if (
-				(kind == FunctionType::Kind::Send || kind == FunctionType::Kind::Transfer) &&
-				!contractType->isPayable()
-			)
-				m_errorReporter.typeError(
-					_memberAccess.location(),
-					"Value transfer to a contract without a payable fallback function."
-				);
-		}
-	}
-
 	// TODO some members might be pure, but for example `address(0x123).balance` is not pure
 	// although every subexpression is, so leaving this limited for now.
 	if (auto tt = dynamic_cast<TypeType const*>(exprType.get()))
diff --git a/test/libsolidity/syntaxTests/memberLookup/contract_not_payable_send.sol b/test/libsolidity/syntaxTests/memberLookup/contract_not_payable_send.sol
new file mode 100644
index 000000000..56ad89286
--- /dev/null
+++ b/test/libsolidity/syntaxTests/memberLookup/contract_not_payable_send.sol
@@ -0,0 +1,8 @@
+contract C {
+    function f() public {
+        address(this).send(10);
+    }
+}
+
+// ----
+// TypeError: (47-65): "send" and "transfer" are only available for objects of type "address payable", not "address".
diff --git a/test/libsolidity/syntaxTests/memberLookup/contract_not_payable_transfer.sol b/test/libsolidity/syntaxTests/memberLookup/contract_not_payable_transfer.sol
new file mode 100644
index 000000000..21d792ee4
--- /dev/null
+++ b/test/libsolidity/syntaxTests/memberLookup/contract_not_payable_transfer.sol
@@ -0,0 +1,8 @@
+contract C {
+    function f() public {
+        address(this).transfer(10);
+    }
+}
+
+// ----
+// TypeError: (47-69): "send" and "transfer" are only available for objects of type "address payable", not "address".