From a94945dfe40c879b6c3762620987a235582ccecf Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Wed, 18 Apr 2018 20:40:46 +0200
Subject: [PATCH] Improve error message for failed member lookup.

---
 Changelog.md                                  |  1 +
 libsolidity/analysis/TypeChecker.cpp          | 27 +++++++++++--------
 .../memberLookup/failed_function_lookup.sol   |  7 +++++
 .../failed_function_lookup_in_library.sol     |  9 +++++++
 .../memberLookup/push_on_memory_types.sol     |  8 ++++++
 5 files changed, 41 insertions(+), 11 deletions(-)
 create mode 100644 test/libsolidity/syntaxTests/memberLookup/failed_function_lookup.sol
 create mode 100644 test/libsolidity/syntaxTests/memberLookup/failed_function_lookup_in_library.sol
 create mode 100644 test/libsolidity/syntaxTests/memberLookup/push_on_memory_types.sol

diff --git a/Changelog.md b/Changelog.md
index 8812bacef..3922c641d 100644
--- a/Changelog.md
+++ b/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.
 
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 87d69d97f..72d297621 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/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 "
diff --git a/test/libsolidity/syntaxTests/memberLookup/failed_function_lookup.sol b/test/libsolidity/syntaxTests/memberLookup/failed_function_lookup.sol
new file mode 100644
index 000000000..c23992e99
--- /dev/null
+++ b/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.
diff --git a/test/libsolidity/syntaxTests/memberLookup/failed_function_lookup_in_library.sol b/test/libsolidity/syntaxTests/memberLookup/failed_function_lookup_in_library.sol
new file mode 100644
index 000000000..310c4a103
--- /dev/null
+++ b/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)
diff --git a/test/libsolidity/syntaxTests/memberLookup/push_on_memory_types.sol b/test/libsolidity/syntaxTests/memberLookup/push_on_memory_types.sol
new file mode 100644
index 000000000..310c073f5
--- /dev/null
+++ b/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.