Index: clang-tools-extra/trunk/clang-tidy/ClangTidyDiagnosticConsumer.h
===================================================================
--- clang-tools-extra/trunk/clang-tidy/ClangTidyDiagnosticConsumer.h
+++ clang-tools-extra/trunk/clang-tidy/ClangTidyDiagnosticConsumer.h
@@ -138,7 +138,7 @@
 
   /// \brief Returns the name of the clang-tidy check which produced this
   /// diagnostic ID.
-  StringRef getCheckName(unsigned DiagnosticID) const;
+  std::string getCheckName(unsigned DiagnosticID) const;
 
   /// \brief Returns \c true if the check is enabled for the \c CurrentFile.
   ///
Index: clang-tools-extra/trunk/clang-tidy/ClangTidyDiagnosticConsumer.cpp
===================================================================
--- clang-tools-extra/trunk/clang-tidy/ClangTidyDiagnosticConsumer.cpp
+++ clang-tools-extra/trunk/clang-tidy/ClangTidyDiagnosticConsumer.cpp
@@ -254,7 +254,11 @@
   return WarningAsErrorFilter->contains(CheckName);
 }
 
-StringRef ClangTidyContext::getCheckName(unsigned DiagnosticID) const {
+std::string ClangTidyContext::getCheckName(unsigned DiagnosticID) const {
+  std::string ClangWarningOption =
+      DiagEngine->getDiagnosticIDs()->getWarningOptionForDiag(DiagnosticID);
+  if (!ClangWarningOption.empty())
+    return "clang-diagnostic-" + ClangWarningOption;
   llvm::DenseMap<unsigned, std::string>::const_iterator I =
       CheckNamesByDiagnosticID.find(DiagnosticID);
   if (I != CheckNamesByDiagnosticID.end())
@@ -305,7 +309,7 @@
           Line.substr(BracketIndex, BracketEndIndex - BracketIndex);
       // Allow disabling all the checks with "*".
       if (ChecksStr != "*") {
-        StringRef CheckName = Context.getCheckName(DiagID);
+        std::string CheckName = Context.getCheckName(DiagID);
         // Allow specifying a few check names, delimited with comma.
         SmallVector<StringRef, 1> Checks;
         ChecksStr.split(Checks, ',', -1, false);
@@ -402,13 +406,7 @@
            "A diagnostic note can only be appended to a message.");
   } else {
     finalizeLastError();
-    StringRef WarningOption =
-        Context.DiagEngine->getDiagnosticIDs()->getWarningOptionForDiag(
-            Info.getID());
-    std::string CheckName = !WarningOption.empty()
-                                ? ("clang-diagnostic-" + WarningOption).str()
-                                : Context.getCheckName(Info.getID()).str();
-
+    std::string CheckName = Context.getCheckName(Info.getID());
     if (CheckName.empty()) {
       // This is a compiler diagnostic without a warning option. Assign check
       // name based on its level.
Index: clang-tools-extra/trunk/test/clang-tidy/nolint.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/nolint.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/nolint.cpp
@@ -31,6 +31,7 @@
   int i;
 // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: unused variable 'i' [clang-diagnostic-unused-variable]
   int j; // NOLINT
+  int k; // NOLINT(clang-diagnostic-unused-variable)
 }
 
 #define MACRO(X) class X { X(int i); };
@@ -47,4 +48,4 @@
 #define DOUBLE_MACRO MACRO(H) // NOLINT
 DOUBLE_MACRO
 
-// CHECK-MESSAGES: Suppressed 12 warnings (12 NOLINT)
+// CHECK-MESSAGES: Suppressed 13 warnings (13 NOLINT)