diff --git a/include/llvm/Metadata.h b/include/llvm/Metadata.h
index 49c5b3c87a1..3cb34f9ec6e 100644
--- a/include/llvm/Metadata.h
+++ b/include/llvm/Metadata.h
@@ -287,14 +287,14 @@ private:
 public:
   /// registerMDKind - Register a new metadata kind and return its ID.
   /// A metadata kind can be registered only once. 
-  unsigned registerMDKind(const char *Name);
+  unsigned registerMDKind(const StringRef Name);
 
   /// getMDKind - Return metadata kind. If the requested metadata kind
   /// is not registered then return 0.
-  unsigned getMDKind(const char *Name);
+  unsigned getMDKind(const StringRef Name) const;
 
   /// isValidName - Return true if Name is a valid custom metadata handler name.
-  bool isValidName(const char *Name);
+  static bool isValidName(const StringRef Name);
 
   /// getMD - Get the metadata of given kind attached to an Instruction.
   /// If the metadata is not found then return 0.
diff --git a/lib/VMCore/Metadata.cpp b/lib/VMCore/Metadata.cpp
index 6da3ec1a5d7..ce5cc7eed14 100644
--- a/lib/VMCore/Metadata.cpp
+++ b/lib/VMCore/Metadata.cpp
@@ -250,7 +250,7 @@ NamedMDNode::~NamedMDNode() {
 
 /// registerMDKind - Register a new metadata kind and return its ID.
 /// A metadata kind can be registered only once. 
-unsigned MetadataContext::registerMDKind(const char *Name) {
+unsigned MetadataContext::registerMDKind(const StringRef Name) {
   assert(isValidName(Name) && "Invalid custome metadata name!");
   unsigned Count = MDHandlerNames.size();
   assert(MDHandlerNames.count(Name) == 0 && "Already registered MDKind!");
@@ -258,7 +258,8 @@ unsigned MetadataContext::registerMDKind(const char *Name) {
 }
 
 /// isValidName - Return true if Name is a valid custom metadata handler name.
-bool MetadataContext::isValidName(const char *Name) {
+bool MetadataContext::isValidName(const StringRef MDName) {
+  const char *Name = MDName.data();
   if (!Name)
     return false;
 
@@ -280,8 +281,8 @@ bool MetadataContext::isValidName(const char *Name) {
 
 /// getMDKind - Return metadata kind. If the requested metadata kind
 /// is not registered then return 0.
-unsigned MetadataContext::getMDKind(const char *Name) {
-  StringMap<unsigned>::iterator I = MDHandlerNames.find(Name);
+unsigned MetadataContext::getMDKind(const StringRef Name) const {
+  StringMap<unsigned>::const_iterator I = MDHandlerNames.find(Name);
   if (I == MDHandlerNames.end()) {
     assert(isValidName(Name) && "Invalid custome metadata name!");
     return 0;