diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index 7905246..268b024 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -243,6 +243,24 @@
   return false;
 }
 
+void DiagnosticsEngine::setDiagnosticWarningAsError(diag::kind Diag,
+                                                    bool Enabled) {
+  // If we are enabling this feature, just set the diagnostic mappings to map to
+  // errors.
+  if (Enabled) 
+    setDiagnosticMapping(Diag, diag::MAP_ERROR, SourceLocation());
+
+  // Otherwise, we want to set the diagnostic mapping's "no Werror" bit, and
+  // potentially downgrade anything already mapped to be a warning.
+  DiagnosticMappingInfo &Info = GetCurDiagState()->getOrAddMappingInfo(Diag);
+
+  if (Info.getMapping() == diag::MAP_ERROR ||
+      Info.getMapping() == diag::MAP_FATAL)
+    Info.setMapping(diag::MAP_WARNING);
+
+  Info.setNoWarningAsError(true);
+}
+
 bool DiagnosticsEngine::setDiagnosticGroupWarningAsError(StringRef Group,
                                                          bool Enabled) {
   // If we are enabling this feature, just set the diagnostic mappings to map to
@@ -273,6 +291,23 @@
   return false;
 }
 
+void DiagnosticsEngine::setDiagnosticErrorAsFatal(diag::kind Diag,
+                                                  bool Enabled) {
+  // If we are enabling this feature, just set the diagnostic mappings to map to
+  // errors.
+  if (Enabled)
+    setDiagnosticMapping(Diag, diag::MAP_FATAL, SourceLocation());
+  
+  // Otherwise, we want to set the diagnostic mapping's "no Werror" bit, and
+  // potentially downgrade anything already mapped to be a warning.
+  DiagnosticMappingInfo &Info = GetCurDiagState()->getOrAddMappingInfo(Diag);
+  
+  if (Info.getMapping() == diag::MAP_FATAL)
+    Info.setMapping(diag::MAP_ERROR);
+  
+  Info.setNoErrorAsFatal(true);
+}
+
 bool DiagnosticsEngine::setDiagnosticGroupErrorAsFatal(StringRef Group,
                                                        bool Enabled) {
   // If we are enabling this feature, just set the diagnostic mappings to map to