diff --git a/clang/include/clang/Basic/Diagnostic.h b/clang/include/clang/Basic/Diagnostic.h
index 71240f4fdcd8..4136b5cc0598 100644
--- a/clang/include/clang/Basic/Diagnostic.h
+++ b/clang/include/clang/Basic/Diagnostic.h
@@ -563,15 +563,6 @@ private:
   /// \brief Report the delayed diagnostic.
   void ReportDelayed();
 
-
-  /// getDiagnosticMappingInfo - Return the mapping info currently set for the
-  /// specified builtin diagnostic.  This returns the high bit encoding, or zero
-  /// if the field is completely uninitialized.
-  diag::Mapping getDiagnosticMappingInfo(diag::kind Diag,
-                                         DiagState *State) const {
-    return State->getMapping(Diag);
-  }
-
   void setDiagnosticMappingInternal(unsigned DiagId, unsigned Map,
                                     DiagState *State,
                                     bool isUser, bool isPragma) const {
diff --git a/clang/lib/Basic/DiagnosticIDs.cpp b/clang/lib/Basic/DiagnosticIDs.cpp
index 1e76a26de729..d8a0afc1cc57 100644
--- a/clang/lib/Basic/DiagnosticIDs.cpp
+++ b/clang/lib/Basic/DiagnosticIDs.cpp
@@ -507,8 +507,7 @@ DiagnosticIDs::getDiagnosticLevel(unsigned DiagID, unsigned DiagClass,
   DiagnosticsEngine::DiagState *State = Pos->State;
 
   // Get the mapping information, if unset, compute it lazily.
-  unsigned MappingInfo = Diag.getDiagnosticMappingInfo((diag::kind)DiagID,
-                                                       State);
+  unsigned MappingInfo = State->getMapping((diag::kind) DiagID);
   if (MappingInfo == 0) {
     MappingInfo = GetDefaultDiagMapping(DiagID);
     Diag.setDiagnosticMappingInternal(DiagID, MappingInfo, State, false, false);