diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
index fc092e14e942..36027157e3f9 100644
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -348,6 +348,9 @@ class Preprocessor : public RefCountedBase<Preprocessor> {
   /// should use from the command line etc.
   std::string Predefines;
 
+  /// \brief The file ID for the preprocessor predefines.
+  FileID PredefinesFileID;
+
   /// TokenLexerCache - Cache macro expanders to reduce malloc traffic.
   enum { TokenLexerCacheSize = 8 };
   unsigned NumCachedTokenLexers;
@@ -503,6 +506,9 @@ public:
   /// expansions going on at the time.
   PreprocessorLexer *getCurrentFileLexer() const;
 
+  /// \brief Returns the file ID for the preprocessor predefines.
+  FileID getPredefinesFileID() { return PredefinesFileID; }
+
   /// getPPCallbacks/addPPCallbacks - Accessors for preprocessor callbacks.
   /// Note that this class takes ownership of any PPCallbacks object given to
   /// it.
@@ -1357,6 +1363,12 @@ private:
   /// start getting tokens from it using the PTH cache.
   void EnterSourceFileWithPTH(PTHLexer *PL, const DirectoryLookup *Dir);
 
+  /// \brief Set the file ID for the preprocessor predefines.
+  void setPredefinesFileID(FileID FID) {
+    assert(PredefinesFileID.isInvalid() && "PredefinesFileID already set!");
+    PredefinesFileID = FID;
+  }
+
   /// IsFileLexer - Returns true if we are lexing from a file and not a
   ///  pragma or a macro.
   static bool IsFileLexer(const Lexer* L, const PreprocessorLexer* P) {
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index eb498dbfd286..155074c9f812 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -483,6 +483,7 @@ void Preprocessor::EnterMainSourceFile() {
   assert(SB && "Cannot create predefined source buffer");
   FileID FID = SourceMgr.createFileIDForMemBuffer(SB);
   assert(!FID.isInvalid() && "Could not create FileID for predefines?");
+  setPredefinesFileID(FID);
 
   // Start parsing the predefines.
   EnterSourceFile(FID, 0, SourceLocation());