diff --git a/clang/include/clang/Basic/FileManager.h b/clang/include/clang/Basic/FileManager.h
--- a/clang/include/clang/Basic/FileManager.h
+++ b/clang/include/clang/Basic/FileManager.h
@@ -311,9 +311,9 @@
   bool makeAbsolutePath(SmallVectorImpl<char> &Path) const;
 
   /// Produce an array mapping from the unique IDs assigned to each
-  /// file to the corresponding FileEntry pointer.
-  void GetUniqueIDMapping(
-                    SmallVectorImpl<const FileEntry *> &UIDToFiles) const;
+  /// file to the corresponding FileEntryRef.
+  void
+  getUniqueIDMapping(SmallVectorImpl<OptionalFileEntryRef> &UIDToFiles) const;
 
   /// Retrieve the canonical name for a given directory.
   ///
diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -611,25 +611,15 @@
   return std::error_code();
 }
 
-void FileManager::GetUniqueIDMapping(
-    SmallVectorImpl<const FileEntry *> &UIDToFiles) const {
+void FileManager::getUniqueIDMapping(
+    SmallVectorImpl<OptionalFileEntryRef> &UIDToFiles) const {
   UIDToFiles.clear();
   UIDToFiles.resize(NextFileUID);
 
-  // Map file entries
-  for (llvm::StringMap<llvm::ErrorOr<FileEntryRef::MapValue>,
-                       llvm::BumpPtrAllocator>::const_iterator
-           FE = SeenFileEntries.begin(),
-           FEEnd = SeenFileEntries.end();
-       FE != FEEnd; ++FE)
-    if (llvm::ErrorOr<FileEntryRef::MapValue> Entry = FE->getValue()) {
-      if (const auto *FE = Entry->V.dyn_cast<FileEntry *>())
-        UIDToFiles[FE->getUID()] = FE;
-    }
-
-  // Map virtual file entries
-  for (const auto &VFE : VirtualFileEntries)
-    UIDToFiles[VFE->getUID()] = VFE;
+  for (const auto &Entry : SeenFileEntries)
+    if (llvm::ErrorOr<FileEntryRef::MapValue> Value = Entry.getValue())
+      if (const auto *FE = Value->V.dyn_cast<FileEntry *>())
+        UIDToFiles[FE->getUID()] = FileEntryRef(Entry);
 }
 
 StringRef FileManager::getCanonicalName(const DirectoryEntry *Dir) {
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -169,23 +169,23 @@
 
   const HeaderSearch &HS = PP.getHeaderSearchInfo();
 
-  SmallVector<const FileEntry *, 16> FilesByUID;
-  HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
+  SmallVector<OptionalFileEntryRef, 16> FilesByUID;
+  HS.getFileMgr().getUniqueIDMapping(FilesByUID);
 
   if (FilesByUID.size() > HS.header_file_size())
     FilesByUID.resize(HS.header_file_size());
 
   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
-    const FileEntry *File = FilesByUID[UID];
+    OptionalFileEntryRef File = FilesByUID[UID];
     if (!File)
       continue;
 
     const HeaderFileInfo *HFI =
-        HS.getExistingFileInfo(File, /*WantExternal*/ false);
+        HS.getExistingFileInfo(*File, /*WantExternal=*/false);
     if (!HFI || (HFI->isModuleHeader && !HFI->isCompilingModuleHeader))
       continue;
 
-    for (const auto &KH : HS.findAllModulesForHeader(File)) {
+    for (const auto &KH : HS.findAllModulesForHeader(*File)) {
       if (!KH.getModule())
         continue;
       ModulesToProcess.push_back(KH.getModule());
@@ -1918,14 +1918,14 @@
     }
   }
 
-  SmallVector<const FileEntry *, 16> FilesByUID;
-  HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
+  SmallVector<OptionalFileEntryRef, 16> FilesByUID;
+  HS.getFileMgr().getUniqueIDMapping(FilesByUID);
 
   if (FilesByUID.size() > HS.header_file_size())
     FilesByUID.resize(HS.header_file_size());
 
   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
-    const FileEntry *File = FilesByUID[UID];
+    OptionalFileEntryRef File = FilesByUID[UID];
     if (!File)
       continue;
 
@@ -1936,7 +1936,7 @@
     // from a different module; in that case, we rely on the module(s)
     // containing the header to provide this information.
     const HeaderFileInfo *HFI =
-        HS.getExistingFileInfo(File, /*WantExternal*/!Chain);
+        HS.getExistingFileInfo(*File, /*WantExternal=*/!Chain);
     if (!HFI || (HFI->isModuleHeader && !HFI->isCompilingModuleHeader))
       continue;
 
@@ -1951,10 +1951,10 @@
     }
 
     HeaderFileInfoTrait::key_type Key = {
-      Filename, File->getSize(), getTimestampForOutput(File)
+      Filename, File->getSize(), getTimestampForOutput(*File)
     };
     HeaderFileInfoTrait::data_type Data = {
-      *HFI, HS.getModuleMap().findResolvedModulesForHeader(File), {}
+      *HFI, HS.getModuleMap().findResolvedModulesForHeader(*File), {}
     };
     Generator.insert(Key, Data, GeneratorTrait);
     ++NumHeaderSearchEntries;