Index: clang-tools-extra/clangd/Preamble.cpp
===================================================================
--- clang-tools-extra/clangd/Preamble.cpp
+++ clang-tools-extra/clangd/Preamble.cpp
@@ -378,8 +378,7 @@
   auto VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
   return compileCommandsAreEqual(Inputs.CompileCommand,
                                  Preamble.CompileCommand) &&
-         Preamble.Preamble.CanReuse(CI, ContentsBuffer.get(), Bounds,
-                                    VFS.get());
+         Preamble.Preamble.CanReuse(CI, *ContentsBuffer, Bounds, *VFS);
 }
 
 void escapeBackslashAndQuotes(llvm::StringRef Text, llvm::raw_ostream &OS) {
Index: clang/include/clang/Frontend/PrecompiledPreamble.h
===================================================================
--- clang/include/clang/Frontend/PrecompiledPreamble.h
+++ clang/include/clang/Frontend/PrecompiledPreamble.h
@@ -105,8 +105,8 @@
   /// Check whether PrecompiledPreamble can be reused for the new contents(\p
   /// MainFileBuffer) of the main file.
   bool CanReuse(const CompilerInvocation &Invocation,
-                const llvm::MemoryBuffer *MainFileBuffer, PreambleBounds Bounds,
-                llvm::vfs::FileSystem *VFS) const;
+                const llvm::MemoryBufferRef &MainFileBuffer,
+                PreambleBounds Bounds, llvm::vfs::FileSystem &VFS) const;
 
   /// Changes options inside \p CI to use PCH from this preamble. Also remaps
   /// main file to \p MainFileBuffer and updates \p VFS to ensure the preamble
Index: clang/lib/Frontend/ASTUnit.cpp
===================================================================
--- clang/lib/Frontend/ASTUnit.cpp
+++ clang/lib/Frontend/ASTUnit.cpp
@@ -1316,8 +1316,8 @@
     return nullptr;
 
   if (Preamble) {
-    if (Preamble->CanReuse(PreambleInvocationIn, MainFileBuffer.get(), Bounds,
-                           VFS.get())) {
+    if (Preamble->CanReuse(PreambleInvocationIn, *MainFileBuffer, Bounds,
+                           *VFS)) {
       // Okay! We can re-use the precompiled preamble.
 
       // Set the state of the diagnostic object to mimic its state
Index: clang/lib/Frontend/PrecompiledPreamble.cpp
===================================================================
--- clang/lib/Frontend/PrecompiledPreamble.cpp
+++ clang/lib/Frontend/PrecompiledPreamble.cpp
@@ -501,12 +501,12 @@
 }
 
 bool PrecompiledPreamble::CanReuse(const CompilerInvocation &Invocation,
-                                   const llvm::MemoryBuffer *MainFileBuffer,
+                                   const llvm::MemoryBufferRef &MainFileBuffer,
                                    PreambleBounds Bounds,
-                                   llvm::vfs::FileSystem *VFS) const {
+                                   llvm::vfs::FileSystem &VFS) const {
 
   assert(
-      Bounds.Size <= MainFileBuffer->getBufferSize() &&
+      Bounds.Size <= MainFileBuffer.getBufferSize() &&
       "Buffer is too large. Bounds were calculated from a different buffer?");
 
   auto PreambleInvocation = std::make_shared<CompilerInvocation>(Invocation);
@@ -520,7 +520,7 @@
   if (PreambleBytes.size() != Bounds.Size ||
       PreambleEndsAtStartOfLine != Bounds.PreambleEndsAtStartOfLine ||
       !std::equal(PreambleBytes.begin(), PreambleBytes.end(),
-                  MainFileBuffer->getBuffer().begin()))
+                  MainFileBuffer.getBuffer().begin()))
     return false;
   // The preamble has not changed. We may be able to re-use the precompiled
   // preamble.
@@ -532,14 +532,14 @@
   llvm::StringSet<> OverriddenAbsPaths; // Either by buffers or files.
   for (const auto &R : PreprocessorOpts.RemappedFiles) {
     llvm::vfs::Status Status;
-    if (!moveOnNoError(VFS->status(R.second), Status)) {
+    if (!moveOnNoError(VFS.status(R.second), Status)) {
       // If we can't stat the file we're remapping to, assume that something
       // horrible happened.
       return false;
     }
     // If a mapped file was previously missing, then it has changed.
     llvm::SmallString<128> MappedPath(R.first);
-    if (!VFS->makeAbsolute(MappedPath))
+    if (!VFS.makeAbsolute(MappedPath))
       OverriddenAbsPaths.insert(MappedPath);
 
     OverriddenFiles[Status.getUniqueID()] = PreambleFileHash::createForFile(
@@ -552,13 +552,13 @@
     const PrecompiledPreamble::PreambleFileHash PreambleHash =
         PreambleFileHash::createForMemoryBuffer(RB.second->getMemBufferRef());
     llvm::vfs::Status Status;
-    if (moveOnNoError(VFS->status(RB.first), Status))
+    if (moveOnNoError(VFS.status(RB.first), Status))
       OverriddenFiles[Status.getUniqueID()] = PreambleHash;
     else
       OverridenFileBuffers[RB.first] = PreambleHash;
 
     llvm::SmallString<128> MappedPath(RB.first);
-    if (!VFS->makeAbsolute(MappedPath))
+    if (!VFS.makeAbsolute(MappedPath))
       OverriddenAbsPaths.insert(MappedPath);
   }
 
@@ -574,7 +574,7 @@
     }
 
     llvm::vfs::Status Status;
-    if (!moveOnNoError(VFS->status(F.first()), Status)) {
+    if (!moveOnNoError(VFS.status(F.first()), Status)) {
       // If the file's buffer is not remapped and we can't stat it,
       // assume that something horrible happened.
       return false;
@@ -603,7 +603,7 @@
       return false;
     // If a file previously recorded as missing exists as a regular file, then
     // consider the preamble out-of-date.
-    if (auto Status = VFS->status(F.getKey())) {
+    if (auto Status = VFS.status(F.getKey())) {
       if (Status->isRegularFile())
         return false;
     }