Move LexIncludeFilename from Lexer to PreprocessorLexer.
PreprocessorLexer now has a virtual method "IndirectLex" which allows it to call the lex method of its subclasses.  This is not for performance intensive operations.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59185 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PreprocessorLexer.cpp b/lib/Lex/PreprocessorLexer.cpp
new file mode 100644
index 0000000..cbda79f
--- /dev/null
+++ b/lib/Lex/PreprocessorLexer.cpp
@@ -0,0 +1,40 @@
+//===--- 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/Basic/Diagnostic.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))
+    Diag(FilenameTok.getLocation(), diag::err_pp_expects_filename);
+}