diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index 1ffa9b7b7d..0d105ac0d0 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -379,7 +379,7 @@ void Driver::generateCompilationDiagnostics(Compilation &C,
     return;  
 
   // Don't try to generate diagnostics for link jobs.
-  if (FailingCommand->getCreator().isLinkJob())
+  if (FailingCommand && FailingCommand->getCreator().isLinkJob())
     return;
 
   Diag(clang::diag::note_drv_command_failed_diag_msg)
diff --git a/tools/driver/driver.cpp b/tools/driver/driver.cpp
index 8c05fff4de..a07738458a 100644
--- a/tools/driver/driver.cpp
+++ b/tools/driver/driver.cpp
@@ -475,6 +475,10 @@ int main(int argc_, const char **argv_) {
   if (C.get())
     Res = TheDriver.ExecuteCompilation(*C, FailingCommand);
 
+  // Force a crash to test the diagnostics.
+  if(::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH"))
+     Res = -1;
+
   // If result status is < 0, then the driver command signalled an error.
   // In this case, generate additional diagnostic information if possible.
   if (Res < 0)