Index: clang/tools/clang-format/ClangFormat.cpp
===================================================================
--- clang/tools/clang-format/ClangFormat.cpp
+++ clang/tools/clang-format/ClangFormat.cpp
@@ -174,7 +174,7 @@
 namespace clang {
 namespace format {
 
-static FileID createInMemoryFile(StringRef FileName, MemoryBuffer *Source,
+static FileID createInMemoryFile(StringRef FileName, MemoryBufferRef Source,
                                  SourceManager &Sources, FileManager &Files,
                                  llvm::vfs::InMemoryFileSystem *MemFS) {
   MemFS->addFileNoOwn(FileName, 0, Source);
@@ -201,7 +201,7 @@
       IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
       new DiagnosticOptions);
   SourceManager Sources(Diagnostics, Files);
-  FileID ID = createInMemoryFile("<irrelevant>", Code, Sources, Files,
+  FileID ID = createInMemoryFile("<irrelevant>", *Code, Sources, Files,
                                  InMemoryFileSystem.get());
   if (!LineRanges.empty()) {
     if (!Offsets.empty() || !Lengths.empty()) {
@@ -427,7 +427,7 @@
         IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
         new DiagnosticOptions);
     SourceManager Sources(Diagnostics, Files);
-    FileID ID = createInMemoryFile(AssumedFileName, Code.get(), Sources, Files,
+    FileID ID = createInMemoryFile(AssumedFileName, *Code, Sources, Files,
                                    InMemoryFileSystem.get());
     Rewriter Rewrite(Sources, LangOptions());
     tooling::applyAllReplacements(Replaces, Rewrite);
Index: llvm/include/llvm/Support/VirtualFileSystem.h
===================================================================
--- llvm/include/llvm/Support/VirtualFileSystem.h
+++ llvm/include/llvm/Support/VirtualFileSystem.h
@@ -37,6 +37,7 @@
 namespace llvm {
 
 class MemoryBuffer;
+class MemoryBufferRef;
 class Twine;
 
 namespace vfs {
@@ -463,7 +464,8 @@
   /// false if the file or directory already exists in the file system with
   /// different contents.
   bool addFileNoOwn(const Twine &Path, time_t ModificationTime,
-                    llvm::MemoryBuffer *Buffer, Optional<uint32_t> User = None,
+                    const llvm::MemoryBufferRef &Buffer,
+                    Optional<uint32_t> User = None,
                     Optional<uint32_t> Group = None,
                     Optional<llvm::sys::fs::file_type> Type = None,
                     Optional<llvm::sys::fs::perms> Perms = None);
Index: llvm/lib/Support/VirtualFileSystem.cpp
===================================================================
--- llvm/lib/Support/VirtualFileSystem.cpp
+++ llvm/lib/Support/VirtualFileSystem.cpp
@@ -792,14 +792,12 @@
 }
 
 bool InMemoryFileSystem::addFileNoOwn(const Twine &P, time_t ModificationTime,
-                                      llvm::MemoryBuffer *Buffer,
+                                      const llvm::MemoryBufferRef &Buffer,
                                       Optional<uint32_t> User,
                                       Optional<uint32_t> Group,
                                       Optional<llvm::sys::fs::file_type> Type,
                                       Optional<llvm::sys::fs::perms> Perms) {
-  return addFile(P, ModificationTime,
-                 llvm::MemoryBuffer::getMemBuffer(
-                     Buffer->getBuffer(), Buffer->getBufferIdentifier()),
+  return addFile(P, ModificationTime, llvm::MemoryBuffer::getMemBuffer(Buffer),
                  std::move(User), std::move(Group), std::move(Type),
                  std::move(Perms));
 }
Index: llvm/unittests/Support/VirtualFileSystemTest.cpp
===================================================================
--- llvm/unittests/Support/VirtualFileSystemTest.cpp
+++ llvm/unittests/Support/VirtualFileSystemTest.cpp
@@ -939,7 +939,7 @@
 
 TEST_F(InMemoryFileSystemTest, OverlayFileNoOwn) {
   auto Buf = MemoryBuffer::getMemBuffer("a");
-  FS.addFileNoOwn("/a", 0, Buf.get());
+  FS.addFileNoOwn("/a", 0, *Buf);
   auto Stat = FS.status("/a");
   ASSERT_FALSE(Stat.getError()) << Stat.getError() << "\n" << FS.toString();
   ASSERT_EQ("/a", Stat->getName());