Index: lib/Frontend/DiagnosticRenderer.cpp
===================================================================
--- lib/Frontend/DiagnosticRenderer.cpp
+++ lib/Frontend/DiagnosticRenderer.cpp
@@ -618,7 +618,7 @@
   // Generate a note indicating the include location.
   SmallString<200> MessageStorage;
   llvm::raw_svector_ostream Message(MessageStorage);
-  if (PLoc.getFilename())
+  if (PLoc.isValid())
     Message << "while building module '" << ModuleName << "' imported from "
             << PLoc.getFilename() << ':' << PLoc.getLine() << ":";
   else