Index: clang/lib/Lex/PPDirectives.cpp
===================================================================
--- clang/lib/Lex/PPDirectives.cpp
+++ clang/lib/Lex/PPDirectives.cpp
@@ -547,7 +547,7 @@
   } SkippingRangeState(*this);
 
   while (true) {
-    if (CurLexer->isDependencyDirectivesLexer()) {
+    if (CurLexer && CurLexer->isDependencyDirectivesLexer()) {
       CurLexer->LexDependencyDirectiveTokenWhileSkipping(Tok);
     } else {
       SkippingRangeState.beginLexPass();