Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -825,6 +825,12 @@
   Group<f_Group>, Flags<[DriverOption, CC1Option]>;
 def fretain_comments_from_system_headers : Flag<["-"], "fretain-comments-from-system-headers">, Group<f_Group>, Flags<[CC1Option]>;
 
+def FILE_prefix_to_remove : Joined<["-"], "ffile-macro-prefix-to-remove=">,
+  Group<f_Group>, Flags<[DriverOption, CC1Option]>,
+  HelpText<"prefix to be removed from expanded string of __FILE__ macro">;
+def FILE_basename_only : Flag <["-"], "ffile-macro-basename-only">,
+  Group<f_Group>, Flags<[DriverOption, CC1Option]>,
+  HelpText<"only expand the basename of __FILE__ macro.">;
 def fmudflapth : Flag<["-"], "fmudflapth">, Group<f_Group>;
 def fmudflap : Flag<["-"], "fmudflap">, Group<f_Group>;
 def fnested_functions : Flag<["-"], "fnested-functions">, Group<f_Group>;
Index: include/clang/Lex/PreprocessorOptions.h
===================================================================
--- include/clang/Lex/PreprocessorOptions.h
+++ include/clang/Lex/PreprocessorOptions.h
@@ -108,15 +108,23 @@
   /// the buffers associated with remapped files.
   ///
   /// This flag defaults to false; it can be set true only through direct
-  /// manipulation of the compiler invocation object, in cases where the 
+  /// manipulation of the compiler invocation object, in cases where the
   /// compiler invocation and its buffers will be reused.
   bool RetainRemappedFileBuffers;
-  
+
   /// \brief The Objective-C++ ARC standard library that we should support,
   /// by providing appropriate definitions to retrofit the standard library
   /// with support for lifetime-qualified pointers.
   ObjCXXARCStandardLibraryKind ObjCXXARCStandardLibrary;
-    
+
+  /// \brief This string will be used in expanding __FILE__ macro. If it
+  /// matches the prefix of __FILE__, the matched part won't be expanded.
+  std::string __FILE__PrefixToRemove;
+
+  /// \brief This falgs defaults to false; If it is set to true, only the
+  /// basename part of __FILE__ will be expanded.
+  bool __FILE__BasenameOnly;
+
   /// \brief Records the set of modules
   class FailedModulesSet : public RefCountedBase<FailedModulesSet> {
     llvm::StringSet<> Failed;
@@ -130,7 +138,7 @@
       Failed.insert(module);
     }
   };
-  
+
   /// \brief The set of modules that failed to build.
   ///
   /// This pointer will be shared among all of the compiler instances created
@@ -140,14 +148,12 @@
   IntrusiveRefCntPtr<FailedModulesSet> FailedModules;
 
 public:
-  PreprocessorOptions() : UsePredefines(true), DetailedRecord(false),
-                          DisablePCHValidation(false),
-                          AllowPCHWithCompilerErrors(false),
-                          DumpDeserializedPCHDecls(false),
-                          PrecompiledPreambleBytes(0, true),
-                          RemappedFilesKeepOriginalName(true),
-                          RetainRemappedFileBuffers(false),
-                          ObjCXXARCStandardLibrary(ARCXX_nolib) { }
+  PreprocessorOptions()
+      : UsePredefines(true), DetailedRecord(false), DisablePCHValidation(false),
+        AllowPCHWithCompilerErrors(false), DumpDeserializedPCHDecls(false),
+        PrecompiledPreambleBytes(0, true), RemappedFilesKeepOriginalName(true),
+        RetainRemappedFileBuffers(false), ObjCXXARCStandardLibrary(ARCXX_nolib),
+        __FILE__PrefixToRemove(""), __FILE__BasenameOnly(false) {}
 
   void addMacroDef(StringRef Name) { Macros.emplace_back(Name, false); }
   void addMacroUndef(StringRef Name) { Macros.emplace_back(Name, true); }
@@ -163,7 +169,7 @@
     RemappedFiles.clear();
     RemappedFileBuffers.clear();
   }
-  
+
   /// \brief Reset any options that are not considered when building a
   /// module.
   void resetNonModularOptions() {
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -570,6 +570,16 @@
   // Add CUDA include arguments, if needed.
   if (types::isCuda(Inputs[0].getType()))
     getToolChain().AddCudaIncludeArgs(Args, CmdArgs);
+
+  // Add FILE macro prefix removing arguments or basename only flags.
+  if (const Arg *A = Args.getLastArg(options::OPT_FILE_prefix_to_remove,
+                                     options::OPT_FILE_basename_only)) {
+    if (A->getOption().matches(options::OPT_FILE_basename_only))
+      CmdArgs.push_back(Args.MakeArgString("-ffile-macro-basename-only"));
+    else if (!StringRef(A->getValue()).empty())
+      CmdArgs.push_back(Args.MakeArgString(
+          Twine("-ffile-macro-prefix-to-remove=") + A->getValue()));
+  }
 }
 
 // FIXME: Move to target hook.
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -2010,6 +2010,14 @@
     else
       Opts.ObjCXXARCStandardLibrary = (ObjCXXARCStandardLibraryKind)Library;
   }
+
+  if (Arg *A =
+          Args.getLastArg(OPT_FILE_prefix_to_remove, OPT_FILE_basename_only)) {
+    if (A->getOption().matches(options::OPT_FILE_basename_only))
+      Opts.__FILE__BasenameOnly = true;
+    else
+      Opts.__FILE__PrefixToRemove = A->getValue();
+  }
 }
 
 static void ParsePreprocessorOutputArgs(PreprocessorOutputOptions &Opts,
Index: lib/Lex/PPMacroExpansion.cpp
===================================================================
--- lib/Lex/PPMacroExpansion.cpp
+++ lib/Lex/PPMacroExpansion.cpp
@@ -12,7 +12,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/Lex/Preprocessor.h"
 #include "clang/Basic/Attributes.h"
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/SourceManager.h"
@@ -22,12 +21,15 @@
 #include "clang/Lex/LexDiagnostic.h"
 #include "clang/Lex/MacroArgs.h"
 #include "clang/Lex/MacroInfo.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/PreprocessorOptions.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Config/llvm-config.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstdio>
 #include <ctime>
@@ -1595,7 +1597,7 @@
         PLoc = SourceMgr.getPresumedLoc(NextLoc);
         if (PLoc.isInvalid())
           break;
-        
+
         NextLoc = PLoc.getIncludeLoc();
       }
     }
@@ -1603,7 +1605,18 @@
     // Escape this filename.  Turn '\' -> '\\' '"' -> '\"'
     SmallString<128> FN;
     if (PLoc.isValid()) {
-      FN += PLoc.getFilename();
+      StringRef Filename(PLoc.getFilename());
+      if (II == Ident__FILE__) {
+        const std::string &PrefixToRemove =
+            getPreprocessorOpts().__FILE__PrefixToRemove;
+        if (getPreprocessorOpts().__FILE__BasenameOnly)
+          FN += llvm::sys::path::filename(Filename);
+        else if (!PrefixToRemove.empty() && Filename.startswith(PrefixToRemove))
+          FN += Filename.substr(PrefixToRemove.size());
+        else
+          FN += Filename;
+      } else
+        FN += Filename;
       Lexer::Stringify(FN);
       OS << '"' << FN << '"';
     }