diff --git a/lib/Basic/SourceLocation.cpp b/lib/Basic/SourceLocation.cpp
index c014475..83c264a 100644
--- a/lib/Basic/SourceLocation.cpp
+++ b/lib/Basic/SourceLocation.cpp
@@ -88,3 +88,7 @@
   assert (isValid());
   return SrcMgr->getBuffer(Loc.getFileID());
 }
+
+unsigned FullSourceLoc::getCanonicalFileID() const {
+  return SrcMgr->getCanonicalFileID(Loc);
+}