diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index f4a4432..52a7a04 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -95,13 +95,11 @@
 /// with the specified preprocessor managing the lexing process.  This lexer
 /// assumes that the associated file buffer and Preprocessor objects will
 /// outlive it, so it doesn't take ownership of either of them.
-Lexer::Lexer(FileID FID, Preprocessor &PP)
+Lexer::Lexer(FileID FID, const llvm::MemoryBuffer *InputFile, Preprocessor &PP)
   : PreprocessorLexer(&PP, FID),
     FileLoc(PP.getSourceManager().getLocForStartOfFile(FID)),
     Features(PP.getLangOptions()) {
 
-  const llvm::MemoryBuffer *InputFile = PP.getSourceManager().getBuffer(FID);
-  
   InitLexer(InputFile->getBufferStart(), InputFile->getBufferStart(),
             InputFile->getBufferEnd());
 
@@ -129,9 +127,9 @@
 /// Lexer constructor - Create a new raw lexer object.  This object is only
 /// suitable for calls to 'LexRawToken'.  This lexer assumes that the text
 /// range will outlive it, so it doesn't take ownership of it.
-Lexer::Lexer(FileID FID, const SourceManager &SM, const LangOptions &features)
+Lexer::Lexer(FileID FID, const llvm::MemoryBuffer *FromFile,
+             const SourceManager &SM, const LangOptions &features)
   : FileLoc(SM.getLocForStartOfFile(FID)), Features(features) {
-  const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
 
   InitLexer(FromFile->getBufferStart(), FromFile->getBufferStart(),
             FromFile->getBufferEnd());
@@ -163,7 +161,8 @@
 
   // Create the lexer as if we were going to lex the file normally.
   FileID SpellingFID = SM.getFileID(SpellingLoc);
-  Lexer *L = new Lexer(SpellingFID, PP);
+  const llvm::MemoryBuffer *InputFile = SM.getBuffer(SpellingFID);
+  Lexer *L = new Lexer(SpellingFID, InputFile, PP);
 
   // Now that the lexer is created, change the start/end locations so that we
   // just lex the subsection of the file that we want.  This is lexing from a
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index dc7d95e..9caca33 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -16,6 +16,7 @@
 #include "clang/Lex/HeaderSearch.h"
 #include "clang/Lex/MacroInfo.h"
 #include "clang/Lex/LexDiagnostic.h"
+#include "clang/Basic/FileManager.h"
 #include "clang/Basic/SourceManager.h"
 #include "llvm/ADT/APInt.h"
 using namespace clang;
@@ -1111,7 +1112,9 @@
   }
 
   // Finally, if all is good, enter the new file!
-  EnterSourceFile(FID, CurDir);
+  if (EnterSourceFile(FID, CurDir))
+    Diag(FilenameTok, diag::err_pp_error_opening_file)
+      << std::string(SourceMgr.getFileEntryForID(FID)->getName());
 }
 
 /// HandleIncludeNextDirective - Implements #include_next.
diff --git a/lib/Lex/PPLexerChange.cpp b/lib/Lex/PPLexerChange.cpp
index d5d6a6e..8a61d7b 100644
--- a/lib/Lex/PPLexerChange.cpp
+++ b/lib/Lex/PPLexerChange.cpp
@@ -64,7 +64,7 @@
 
 /// EnterSourceFile - Add a source file to the top of the include stack and
 /// start lexing tokens from it instead of the current buffer.
-void Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir) {
+bool Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir) {
   assert(CurTokenLexer == 0 && "Cannot #include a file inside a macro!");
   ++NumEnteredSourceFiles;
 
@@ -72,10 +72,19 @@
     MaxIncludeStackDepth = IncludeMacroStack.size();
 
   if (PTH) {
-    if (PTHLexer *PL = PTH->CreateLexer(FID))
-      return EnterSourceFileWithPTH(PL, CurDir);
+    if (PTHLexer *PL = PTH->CreateLexer(FID)) {
+      EnterSourceFileWithPTH(PL, CurDir);
+      return false;
+    }
   }
-  EnterSourceFileWithLexer(new Lexer(FID, *this), CurDir);
+  
+  // Get the MemoryBuffer for this FID, if it fails, we fail.
+  const llvm::MemoryBuffer *InputFile = getSourceManager().getBuffer(FID);
+  if (InputFile == 0)
+    return true;
+  
+  EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir);
+  return false;
 }
 
 /// EnterSourceFileWithLexer - Add a source file to the top of the include stack