Merge pull request #3932 from ethereum/betterErrorForFailedLookup

Better error for failed lookup

Changelog.md

@@ -6,6 +6,7 @@ Features:
  * Syntax Checker: Warn about functions named "constructor".
 
 Bugfixes:
+ * Type Checker: Improve error message for failed function overload resolution.
  * Type Checker: Do not complain about new-style constructor and fallback function to have the same name.
  * Type Checker: Detect multiple constructor declarations in the new syntax and old syntax.
 

libsolidity/analysis/TypeChecker.cpp

@@ -1904,7 +1904,8 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 	// Retrieve the types of the arguments if this is used to call a function.
 	auto const& argumentTypes = _memberAccess.annotation().argumentTypes;
 	MemberList::MemberMap possibleMembers = exprType->members(m_scope).membersByName(memberName);
-	if (possibleMembers.size() > 1 && argumentTypes)
+	size_t const initialMemberCount = possibleMembers.size();
+	if (initialMemberCount > 1 && argumentTypes)
 	{
 		// do overload resolution
 		for (auto it = possibleMembers.begin(); it != possibleMembers.end();)
@@ -1918,17 +1919,21 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 	}
 	if (possibleMembers.size() == 0)
 	{
-		auto storageType = ReferenceType::copyForLocationIfReference(
-			DataLocation::Storage,
-			exprType
-		);
-		if (!storageType->members(m_scope).membersByName(memberName).empty())
-			m_errorReporter.fatalTypeError(
-				_memberAccess.location(),
-				"Member \"" + memberName + "\" is not available in " +
-				exprType->toString() +
-				" outside of storage."
+		if (initialMemberCount == 0)
+		{
+			// Try to see if the member was removed because it is only available for storage types.
+			auto storageType = ReferenceType::copyForLocationIfReference(
+				DataLocation::Storage,
+				exprType
 			);
+			if (!storageType->members(m_scope).membersByName(memberName).empty())
+				m_errorReporter.fatalTypeError(
+					_memberAccess.location(),
+					"Member \"" + memberName + "\" is not available in " +
+					exprType->toString() +
+					" outside of storage."
+				);
+		}
 		m_errorReporter.fatalTypeError(
 			_memberAccess.location(),
 			"Member \"" + memberName + "\" not found or not visible "

test/libsolidity/SolidityNameAndTypeResolution.cpp

@@ -2993,21 +2993,6 @@ BOOST_AUTO_TEST_CASE(literal_strings)
 	CHECK_SUCCESS(text);
 }
 
-BOOST_AUTO_TEST_CASE(memory_structs_with_mappings)
-{
-	char const* text = R"(
-		contract Test {
-			struct S { uint8 a; mapping(uint => uint) b; uint8 c; }
-			S s;
-			function f() public {
-				S memory x;
-				x.b[1];
-			}
-		}
-	)";
-	CHECK_ERROR(text, TypeError, "Member \"b\" is not available in struct Test.S memory outside of storage.");
-}
-
 BOOST_AUTO_TEST_CASE(string_bytes_conversion)
 {
 	char const* text = R"(

test/libsolidity/syntaxTests/memberLookup/failed_function_lookup.sol

@@ -0,0 +1,7 @@
+contract C {
+  function f(uint, uint) {}
+  function f(uint) {}
+  function g() { f(1, 2, 3); }
+}
+// ----
+// TypeError: (80-81): No matching declaration found after argument-dependent lookup.

test/libsolidity/syntaxTests/memberLookup/failed_function_lookup_in_library.sol

@@ -0,0 +1,9 @@
+library L {
+  function f(uint, uint) {}
+  function f(uint) {}
+}
+contract C {
+  function g() { L.f(1, 2, 3); }
+}
+// ----
+// TypeError: (94-97): Member "f" not found or not visible after argument-dependent lookup in type(library L)

test/libsolidity/syntaxTests/memberLookup/memory_structs_with_mappings.sol

@@ -0,0 +1,10 @@
+contract Test {
+	struct S { uint8 a; mapping(uint => uint) b; uint8 c; }
+	S s;
+	function f() public {
+		S memory x;
+		x.b[1];
+	}
+}
+// ----
+// TypeError: (118-121): Member "b" is not available in struct Test.S memory outside of storage.

test/libsolidity/syntaxTests/memberLookup/push_on_memory_types.sol

@@ -0,0 +1,8 @@
+contract Test {
+	function f() public pure {
+        uint[] memory x;
+        x.push(1);
+	}
+}
+// ----
+// TypeError: (77-83): Member "push" is not available in uint256[] memory outside of storage.