diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index 81d19cc..19f43e3 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -196,6 +196,7 @@
   IgnoreAllWarnings = false;
   WarningsAsErrors = false;
   SuppressSystemWarnings = false;
+  SuppressAllDiagnostics = false;
   ExtBehavior = Ext_Ignore;
 
   ErrorOccurred = false;
@@ -424,6 +425,9 @@
 bool Diagnostic::ProcessDiag() {
   DiagnosticInfo Info(this);
 
+  if (SuppressAllDiagnostics)
+    return false;
+  
   // Figure out the diagnostic level of this message.
   Diagnostic::Level DiagLevel;
   unsigned DiagID = Info.getID();