Check in LLVM r95781.
diff --git a/lib/Lex/PreprocessorLexer.cpp b/lib/Lex/PreprocessorLexer.cpp
new file mode 100644
index 0000000..e005c49
--- /dev/null
+++ b/lib/Lex/PreprocessorLexer.cpp
@@ -0,0 +1,45 @@
+//===--- PreprocessorLexer.cpp - C Language Family Lexer ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements the PreprocessorLexer and Token interfaces.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Lex/PreprocessorLexer.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/LexDiagnostic.h"
+#include "clang/Basic/SourceManager.h"
+using namespace clang;
+
+/// LexIncludeFilename - After the preprocessor has parsed a #include, lex and
+/// (potentially) macro expand the filename.
+void PreprocessorLexer::LexIncludeFilename(Token &FilenameTok) {
+  assert(ParsingPreprocessorDirective &&
+         ParsingFilename == false &&
+         "Must be in a preprocessing directive!");
+
+  // We are now parsing a filename!
+  ParsingFilename = true;
+
+  // Lex the filename.
+  IndirectLex(FilenameTok);
+
+  // We should have obtained the filename now.
+  ParsingFilename = false;
+
+  // No filename?
+  if (FilenameTok.is(tok::eom))
+    PP->Diag(FilenameTok.getLocation(), diag::err_pp_expects_filename);
+}
+
+/// getFileEntry - Return the FileEntry corresponding to this FileID.  Like
+/// getFileID(), this only works for lexers with attached preprocessors.
+const FileEntry *PreprocessorLexer::getFileEntry() const {
+  return PP->getSourceManager().getFileEntryForID(getFileID());
+}