1 files changed, 6 insertions, 0 deletions
diff --git a/clang/lib/Parse/ParseAST.cpp b/clang/lib/Parse/ParseAST.cpp
index 354b3800791..696506099e5 100644
--- a/clang/lib/Parse/ParseAST.cpp
+++ b/clang/lib/Parse/ParseAST.cpp
@@ -141,6 +141,12 @@ void clang::ParseAST(Sema &S, bool PrintStats, bool SkipFunctionBodies) {
     CleanupParser(ParseOP.get());
 
   S.getPreprocessor().EnterMainSourceFile();
+  if (!S.getPreprocessor().getCurrentLexer()) {
+    // If a PCH through header is specified that does not have an include in
+    // the source, there won't be any tokens or a Lexer.
+    return;
+  }
+
   P.Initialize();
 
   Parser::DeclGroupPtrTy ADecl;