Merge pull request #2528 from ethereum/warnNoStorage

Warn if local storage reference variable does not use "storage" explicitly.

2 files changed, 20 insertions, 5 deletions

diff --git a/libsolidity/analysis/ReferencesResolver.cpp b/libsolidity/analysis/ReferencesResolver.cpp
index 2a5f27df..cc95c294 100644
--- a/libsolidity/analysis/ReferencesResolver.cpp
+++ b/libsolidity/analysis/ReferencesResolver.cpp
@@ -289,7 +289,20 @@ void ReferencesResolver::endVisit(VariableDeclaration const& _variable)
 					typeLoc = DataLocation::Memory;
 				}
 				else if (varLoc == Location::Default)
-					typeLoc = _variable.isCallableParameter() ? DataLocation::Memory : DataLocation::Storage;
+				{
+					if (_variable.isCallableParameter())
+						typeLoc = DataLocation::Memory;
+					else
+					{
+						typeLoc = DataLocation::Storage;
+						if (!_variable.isStateVariable())
+							m_errorReporter.warning(
+								_variable.location(),
+								"Variable is declared as a storage pointer. "
+								"Use an explicit \"storage\" keyword to silence this warning."
+							);
+					}
+				}
 				else
 					typeLoc = varLoc == Location::Memory ? DataLocation::Memory : DataLocation::Storage;
 				isPointer = !_variable.isStateVariable();
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 1563467c..7306a36d 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -854,10 +854,12 @@ bool TypeChecker::visit(VariableDeclarationStatement const& _statement)
 		if (auto ref = dynamic_cast<ReferenceType const*>(type(varDecl).get()))
 		{
 			if (ref->dataStoredIn(DataLocation::Storage))
-				m_errorReporter.warning(
-					varDecl.location(),
-					"Uninitialized storage pointer. Did you mean '<type> memory " + varDecl.name() + "'?"
-				);
+			{
+				string errorText{"Uninitialized storage pointer."};
+				if (varDecl.referenceLocation() == VariableDeclaration::Location::Default)
+					errorText += " Did you mean '<type> memory " + varDecl.name() + "'?";
+				m_errorReporter.warning(varDecl.location(), errorText);
+			}
 		}
 		else if (dynamic_cast<MappingType const*>(type(varDecl).get()))
 			m_errorReporter.typeError(