Index: cfe/trunk/lib/Basic/DiagnosticIDs.cpp
===================================================================
--- cfe/trunk/lib/Basic/DiagnosticIDs.cpp
+++ cfe/trunk/lib/Basic/DiagnosticIDs.cpp
@@ -516,7 +516,7 @@
     std::string Diag(DiagGroupNames + I + 1, DiagGroupNames[I]);
     I += DiagGroupNames[I] + 1;
     Res.push_back("-W" + Diag);
-    Res.push_back("-Wno" + Diag);
+    Res.push_back("-Wno-" + Diag);
   }
 
   return Res;
Index: cfe/trunk/test/Driver/autocomplete.c
===================================================================
--- cfe/trunk/test/Driver/autocomplete.c
+++ cfe/trunk/test/Driver/autocomplete.c
@@ -42,5 +42,5 @@
 // MRELOCMODEL_CC1: -mrelocation-model
 // RUN: %clang --autocomplete=-Wma | FileCheck %s -check-prefix=WARNING
 // WARNING: -Wmacro-redefined -Wmain -Wmain-return-type -Wmalformed-warning-check -Wmany-braces-around-scalar-init -Wmax-unsigned-zero
-// RUN: %clang --autocomplete=-Wnoinvalid-pp- | FileCheck %s -check-prefix=NOWARNING
-// NOWARNING: -Wnoinvalid-pp-token
+// RUN: %clang --autocomplete=-Wno-invalid-pp- | FileCheck %s -check-prefix=NOWARNING
+// NOWARNING: -Wno-invalid-pp-token