diff --git a/clang/lib/Format/FormatTokenLexer.cpp b/clang/lib/Format/FormatTokenLexer.cpp
--- a/clang/lib/Format/FormatTokenLexer.cpp
+++ b/clang/lib/Format/FormatTokenLexer.cpp
@@ -763,7 +763,7 @@
   unsigned FirstInLineOffset;
   std::tie(ID, FirstInLineOffset) = SourceMgr.getDecomposedLoc(
       Tokens[FirstInLineIndex]->getStartOfNonWhitespace());
-  StringRef Buffer = SourceMgr.getBuffer(ID)->getBuffer();
+  StringRef Buffer = SourceMgr.getBufferOrFake(ID).getBuffer();
   // Calculate the offset of the start of the current line.
   auto LineOffset = Buffer.rfind('\n', FirstInLineOffset);
   if (LineOffset == StringRef::npos) {
diff --git a/clang/lib/Rewrite/HTMLRewrite.cpp b/clang/lib/Rewrite/HTMLRewrite.cpp
--- a/clang/lib/Rewrite/HTMLRewrite.cpp
+++ b/clang/lib/Rewrite/HTMLRewrite.cpp
@@ -107,9 +107,9 @@
 void html::EscapeText(Rewriter &R, FileID FID,
                       bool EscapeSpaces, bool ReplaceTabs) {
 
-  const llvm::MemoryBuffer *Buf = R.getSourceMgr().getBuffer(FID);
-  const char* C = Buf->getBufferStart();
-  const char* FileEnd = Buf->getBufferEnd();
+  llvm::MemoryBufferRef Buf = R.getSourceMgr().getBufferOrFake(FID);
+  const char* C = Buf.getBufferStart();
+  const char* FileEnd = Buf.getBufferEnd();
 
   assert (C <= FileEnd);
 
@@ -226,9 +226,9 @@
 
 void html::AddLineNumbers(Rewriter& R, FileID FID) {
 
-  const llvm::MemoryBuffer *Buf = R.getSourceMgr().getBuffer(FID);
-  const char* FileBeg = Buf->getBufferStart();
-  const char* FileEnd = Buf->getBufferEnd();
+  llvm::MemoryBufferRef Buf = R.getSourceMgr().getBufferOrFake(FID);
+  const char* FileBeg = Buf.getBufferStart();
+  const char* FileEnd = Buf.getBufferEnd();
   const char* C = FileBeg;
   RewriteBuffer &RB = R.getEditBuffer(FID);
 
@@ -274,9 +274,9 @@
 void html::AddHeaderFooterInternalBuiltinCSS(Rewriter &R, FileID FID,
                                              StringRef title) {
 
-  const llvm::MemoryBuffer *Buf = R.getSourceMgr().getBuffer(FID);
-  const char* FileStart = Buf->getBufferStart();
-  const char* FileEnd = Buf->getBufferEnd();
+  llvm::MemoryBufferRef Buf = R.getSourceMgr().getBufferOrFake(FID);
+  const char* FileStart = Buf.getBufferStart();
+  const char* FileEnd = Buf.getBufferEnd();
 
   SourceLocation StartLoc = R.getSourceMgr().getLocForStartOfFile(FID);
   SourceLocation EndLoc = StartLoc.getLocWithOffset(FileEnd-FileStart);