diff --git a/clang-tools-extra/clang-move/Move.cpp b/clang-tools-extra/clang-move/Move.cpp
--- a/clang-tools-extra/clang-move/Move.cpp
+++ b/clang-tools-extra/clang-move/Move.cpp
@@ -131,7 +131,7 @@
   void InclusionDirective(SourceLocation HashLoc, const Token & /*IncludeTok*/,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          const FileEntry * /*File*/, StringRef SearchPath,
+                          Optional<FileEntryRef> /*File*/, StringRef SearchPath,
                           StringRef /*RelativePath*/,
                           const Module * /*Imported*/,
                           SrcMgr::CharacteristicKind /*FileType*/) override {
diff --git a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h
--- a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h
+++ b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h
@@ -69,8 +69,9 @@
   void InclusionDirective(SourceLocation DirectiveLoc,
                           const Token &IncludeToken, StringRef IncludedFilename,
                           bool IsAngled, CharSourceRange FilenameRange,
-                          const FileEntry *IncludedFile, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          Optional<FileEntryRef> IncludedFile,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
   void EndOfMainFile() override;
diff --git a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp
--- a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp
+++ b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp
@@ -162,8 +162,9 @@
 void ExpandModularHeadersPPCallbacks::InclusionDirective(
     SourceLocation DirectiveLoc, const Token &IncludeToken,
     StringRef IncludedFilename, bool IsAngled, CharSourceRange FilenameRange,
-    const FileEntry *IncludedFile, StringRef SearchPath, StringRef RelativePath,
-    const Module *Imported, SrcMgr::CharacteristicKind FileType) {
+    Optional<FileEntryRef> IncludedFile, StringRef SearchPath,
+    StringRef RelativePath, const Module *Imported,
+    SrcMgr::CharacteristicKind FileType) {
   if (Imported) {
     serialization::ModuleFile *MF =
         Compiler.getASTReader()->getModuleManager().lookup(
diff --git a/clang-tools-extra/clang-tidy/altera/KernelNameRestrictionCheck.cpp b/clang-tools-extra/clang-tidy/altera/KernelNameRestrictionCheck.cpp
--- a/clang-tools-extra/clang-tidy/altera/KernelNameRestrictionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/altera/KernelNameRestrictionCheck.cpp
@@ -29,9 +29,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FileNameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FileNameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
   void EndOfMainFile() override;
@@ -62,8 +62,8 @@
 
 void KernelNameRestrictionPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &, StringRef FileName, bool,
-    CharSourceRange, const FileEntry *, StringRef, StringRef, const Module *,
-    SrcMgr::CharacteristicKind) {
+    CharSourceRange, Optional<FileEntryRef>, StringRef, StringRef,
+    const Module *, SrcMgr::CharacteristicKind) {
   IncludeDirective ID = {HashLoc, FileName};
   IncludeDirectives.push_back(std::move(ID));
 }
diff --git a/clang-tools-extra/clang-tidy/bugprone/SuspiciousIncludeCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/SuspiciousIncludeCheck.cpp
--- a/clang-tools-extra/clang-tidy/bugprone/SuspiciousIncludeCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousIncludeCheck.cpp
@@ -24,9 +24,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
 private:
@@ -72,7 +72,7 @@
 
 void SuspiciousIncludePPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   if (IncludeTok.getIdentifierInfo()->getPPKeywordID() == tok::pp_import)
diff --git a/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp b/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp
--- a/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp
+++ b/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp
@@ -26,9 +26,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
   void EndOfMainFile() override;
 
@@ -81,7 +81,7 @@
 
 void IncludeOrderPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   // We recognize the first include as a special main module header and want
diff --git a/clang-tools-extra/clang-tidy/llvmlibc/RestrictSystemLibcHeadersCheck.cpp b/clang-tools-extra/clang-tidy/llvmlibc/RestrictSystemLibcHeadersCheck.cpp
--- a/clang-tools-extra/clang-tidy/llvmlibc/RestrictSystemLibcHeadersCheck.cpp
+++ b/clang-tools-extra/clang-tidy/llvmlibc/RestrictSystemLibcHeadersCheck.cpp
@@ -33,9 +33,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
 private:
@@ -46,7 +46,7 @@
 
 void RestrictedIncludesPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   // Compiler provided headers are allowed (e.g stddef.h).
diff --git a/clang-tools-extra/clang-tidy/modernize/DeprecatedHeadersCheck.cpp b/clang-tools-extra/clang-tidy/modernize/DeprecatedHeadersCheck.cpp
--- a/clang-tools-extra/clang-tidy/modernize/DeprecatedHeadersCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/DeprecatedHeadersCheck.cpp
@@ -27,9 +27,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
 private:
@@ -91,7 +91,7 @@
 
 void IncludeModernizePPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   // FIXME: Take care of library symbols from the global namespace.
diff --git a/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp b/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp
--- a/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp
@@ -133,9 +133,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
     clearCurrentEnum(HashLoc);
   }
diff --git a/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.h b/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.h
--- a/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.h
+++ b/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.h
@@ -50,9 +50,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
   void EndOfMainFile() override;
 
diff --git a/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.cpp b/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.cpp
--- a/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.cpp
+++ b/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.cpp
@@ -22,7 +22,7 @@
 
 void RestrictedIncludesPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   if (!Check.contains(FileName) && SrcMgr::isSystem(FileType)) {
diff --git a/clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp b/clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp
--- a/clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp
@@ -47,9 +47,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
   void MacroDefined(const Token &MacroNameTok,
@@ -77,7 +77,7 @@
 
 void DuplicateIncludeCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   if (llvm::find(Files.back(), FileName) != Files.back().end()) {
diff --git a/clang-tools-extra/clang-tidy/utils/IncludeInserter.cpp b/clang-tools-extra/clang-tidy/utils/IncludeInserter.cpp
--- a/clang-tools-extra/clang-tidy/utils/IncludeInserter.cpp
+++ b/clang-tools-extra/clang-tidy/utils/IncludeInserter.cpp
@@ -24,7 +24,7 @@
   void InclusionDirective(SourceLocation HashLocation,
                           const Token &IncludeToken, StringRef FileNameRef,
                           bool IsAngled, CharSourceRange FileNameRange,
-                          const FileEntry * /*IncludedFile*/,
+                          Optional<FileEntryRef> /*IncludedFile*/,
                           StringRef /*SearchPath*/, StringRef /*RelativePath*/,
                           const Module * /*ImportedModule*/,
                           SrcMgr::CharacteristicKind /*FileType*/) override {
diff --git a/clang-tools-extra/clangd/Headers.h b/clang-tools-extra/clangd/Headers.h
--- a/clang-tools-extra/clangd/Headers.h
+++ b/clang-tools-extra/clangd/Headers.h
@@ -134,7 +134,7 @@
   enum class HeaderID : unsigned {};
 
   llvm::Optional<HeaderID> getID(const FileEntry *Entry) const;
-  HeaderID getOrCreateID(const FileEntry *Entry);
+  HeaderID getOrCreateID(FileEntryRef Entry);
 
   StringRef getRealPath(HeaderID ID) const {
     assert(static_cast<unsigned>(ID) <= RealPathNames.size());
diff --git a/clang-tools-extra/clangd/Headers.cpp b/clang-tools-extra/clangd/Headers.cpp
--- a/clang-tools-extra/clangd/Headers.cpp
+++ b/clang-tools-extra/clangd/Headers.cpp
@@ -35,7 +35,8 @@
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           llvm::StringRef FileName, bool IsAngled,
                           CharSourceRange /*FilenameRange*/,
-                          const FileEntry *File, llvm::StringRef /*SearchPath*/,
+                          Optional<FileEntryRef> File,
+                          llvm::StringRef /*SearchPath*/,
                           llvm::StringRef /*RelativePath*/,
                           const clang::Module * /*Imported*/,
                           SrcMgr::CharacteristicKind FileKind) override {
@@ -51,7 +52,8 @@
       auto &Inc = Out->MainFileIncludes.back();
       Inc.Written =
           (IsAngled ? "<" + FileName + ">" : "\"" + FileName + "\"").str();
-      Inc.Resolved = std::string(File ? File->tryGetRealPathName() : "");
+      Inc.Resolved =
+          std::string(File ? File->getFileEntry().tryGetRealPathName() : "");
       Inc.HashOffset = SM.getFileOffset(HashLoc);
       Inc.HashLine =
           SM.getLineNumber(SM.getFileID(HashLoc), Inc.HashOffset) - 1;
@@ -60,7 +62,7 @@
       if (LastPragmaKeepInMainFileLine == Inc.HashLine)
         Inc.BehindPragmaKeep = true;
       if (File) {
-        IncludeStructure::HeaderID HID = Out->getOrCreateID(File);
+        IncludeStructure::HeaderID HID = Out->getOrCreateID(*File);
         Inc.HeaderID = static_cast<unsigned>(HID);
         if (IsAngled)
           if (auto StdlibHeader = tooling::stdlib::Header::named(Inc.Written)) {
@@ -74,15 +76,15 @@
 
     // Record include graph (not just for main-file includes)
     if (File) {
-      auto *IncludingFileEntry = SM.getFileEntryForID(SM.getFileID(HashLoc));
+      auto IncludingFileEntry = SM.getFileEntryRefForID(SM.getFileID(HashLoc));
       if (!IncludingFileEntry) {
         assert(SM.getBufferName(HashLoc).startswith("<") &&
                "Expected #include location to be a file or <built-in>");
         // Treat as if included from the main file.
-        IncludingFileEntry = SM.getFileEntryForID(MainFID);
+        IncludingFileEntry = SM.getFileEntryRefForID(MainFID);
       }
-      auto IncludingID = Out->getOrCreateID(IncludingFileEntry),
-           IncludedID = Out->getOrCreateID(File);
+      auto IncludingID = Out->getOrCreateID(*IncludingFileEntry),
+           IncludedID = Out->getOrCreateID(*File);
       Out->IncludeChildren[IncludingID].push_back(IncludedID);
     }
   }
@@ -226,22 +228,22 @@
 }
 
 IncludeStructure::HeaderID
-IncludeStructure::getOrCreateID(const FileEntry *Entry) {
+IncludeStructure::getOrCreateID(FileEntryRef Entry) {
   // Main file's FileEntry was not known at IncludeStructure creation time.
-  if (Entry == MainFileEntry) {
+  if (&Entry.getFileEntry() == MainFileEntry) {
     if (RealPathNames.front().empty())
       RealPathNames.front() = MainFileEntry->tryGetRealPathName().str();
     return MainFileID;
   }
   auto R = UIDToIndex.try_emplace(
-      Entry->getUniqueID(),
+      Entry.getUniqueID(),
       static_cast<IncludeStructure::HeaderID>(RealPathNames.size()));
   if (R.second)
     RealPathNames.emplace_back();
   IncludeStructure::HeaderID Result = R.first->getSecond();
   std::string &RealPathName = RealPathNames[static_cast<unsigned>(Result)];
   if (RealPathName.empty())
-    RealPathName = Entry->tryGetRealPathName().str();
+    RealPathName = Entry.getFileEntry().tryGetRealPathName().str();
   return Result;
 }
 
diff --git a/clang-tools-extra/clangd/ParsedAST.cpp b/clang-tools-extra/clangd/ParsedAST.cpp
--- a/clang-tools-extra/clangd/ParsedAST.cpp
+++ b/clang-tools-extra/clangd/ParsedAST.cpp
@@ -211,7 +211,6 @@
       SynthesizedFilenameTok.setKind(tok::header_name);
       SynthesizedFilenameTok.setLiteralData(Inc.Written.data());
 
-      const FileEntry *FE = File ? &File->getFileEntry() : nullptr;
       llvm::StringRef WrittenFilename =
           llvm::StringRef(Inc.Written).drop_front().drop_back();
       Delegate->InclusionDirective(
@@ -220,7 +219,7 @@
           syntax::FileRange(SM, SynthesizedFilenameTok.getLocation(),
                             SynthesizedFilenameTok.getEndLoc())
               .toCharRange(SM),
-          FE, "SearchPath", "RelPath",
+          File, "SearchPath", "RelPath",
           /*Imported=*/nullptr, Inc.FileKind);
       if (File)
         Delegate->FileSkipped(*File, SynthesizedFilenameTok, Inc.FileKind);
diff --git a/clang-tools-extra/clangd/index/IndexAction.cpp b/clang-tools-extra/clangd/index/IndexAction.cpp
--- a/clang-tools-extra/clangd/index/IndexAction.cpp
+++ b/clang-tools-extra/clangd/index/IndexAction.cpp
@@ -28,10 +28,10 @@
 namespace clangd {
 namespace {
 
-llvm::Optional<std::string> toURI(const FileEntry *File) {
+llvm::Optional<std::string> toURI(Optional<FileEntryRef> File) {
   if (!File)
     return llvm::None;
-  auto AbsolutePath = File->tryGetRealPathName();
+  auto AbsolutePath = File->getFileEntry().tryGetRealPathName();
   if (AbsolutePath.empty())
     return llvm::None;
   return URI::create(AbsolutePath).toString();
@@ -58,7 +58,7 @@
       return;
 
     const auto FileID = SM.getFileID(Loc);
-    const auto *File = SM.getFileEntryForID(FileID);
+    auto File = SM.getFileEntryRefForID(FileID);
     auto URI = toURI(File);
     if (!URI)
       return;
@@ -84,7 +84,8 @@
   // Add edges from including files to includes.
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           llvm::StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File,
                           llvm::StringRef SearchPath,
                           llvm::StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
@@ -92,7 +93,7 @@
     if (!IncludeURI)
       return;
 
-    auto IncludingURI = toURI(SM.getFileEntryForID(SM.getFileID(HashLoc)));
+    auto IncludingURI = toURI(SM.getFileEntryRefForID(SM.getFileID(HashLoc)));
     if (!IncludingURI)
       return;
 
@@ -106,7 +107,7 @@
   void FileSkipped(const FileEntryRef &SkippedFile, const Token &FilenameTok,
                    SrcMgr::CharacteristicKind FileType) override {
 #ifndef NDEBUG
-    auto URI = toURI(&SkippedFile.getFileEntry());
+    auto URI = toURI(SkippedFile);
     if (!URI)
       return;
     auto I = IG.try_emplace(*URI);
diff --git a/clang-tools-extra/clangd/unittests/HeadersTests.cpp b/clang-tools-extra/clangd/unittests/HeadersTests.cpp
--- a/clang-tools-extra/clangd/unittests/HeadersTests.cpp
+++ b/clang-tools-extra/clangd/unittests/HeadersTests.cpp
@@ -19,6 +19,7 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Testing/Support/Error.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
@@ -68,8 +69,8 @@
   IncludeStructure::HeaderID getID(StringRef Filename,
                                    IncludeStructure &Includes) {
     auto &SM = Clang->getSourceManager();
-    auto Entry = SM.getFileManager().getFile(Filename);
-    EXPECT_TRUE(Entry);
+    auto Entry = SM.getFileManager().getFileRef(Filename);
+    EXPECT_THAT_EXPECTED(Entry, llvm::Succeeded());
     return Includes.getOrCreateID(*Entry);
   }
 
diff --git a/clang-tools-extra/clangd/unittests/ParsedASTTests.cpp b/clang-tools-extra/clangd/unittests/ParsedASTTests.cpp
--- a/clang-tools-extra/clangd/unittests/ParsedASTTests.cpp
+++ b/clang-tools-extra/clangd/unittests/ParsedASTTests.cpp
@@ -33,6 +33,7 @@
 #include "clang/Lex/Token.h"
 #include "clang/Tooling/Syntax/Tokens.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Testing/Support/Error.h"
 #include "gmock/gmock-matchers.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
@@ -379,8 +380,9 @@
 
     void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                             StringRef FileName, bool IsAngled,
-                            CharSourceRange FilenameRange, const FileEntry *,
-                            StringRef, StringRef, const clang::Module *,
+                            CharSourceRange FilenameRange,
+                            Optional<FileEntryRef>, StringRef, StringRef,
+                            const clang::Module *,
                             SrcMgr::CharacteristicKind) override {
       Includes.emplace_back(SM, HashLoc, IncludeTok, FileName, IsAngled,
                             FilenameRange);
@@ -560,13 +562,13 @@
   auto &FM = SM.getFileManager();
   // Copy so that we can getOrCreateID().
   IncludeStructure Includes = ExpectedAST.getIncludeStructure();
-  auto MainFE = FM.getFile(testPath("foo.cpp"));
-  ASSERT_TRUE(MainFE);
+  auto MainFE = FM.getFileRef(testPath("foo.cpp"));
+  ASSERT_THAT_EXPECTED(MainFE, llvm::Succeeded());
   auto MainID = Includes.getOrCreateID(*MainFE);
   auto &PatchedFM = PatchedAST->getSourceManager().getFileManager();
   IncludeStructure PatchedIncludes = PatchedAST->getIncludeStructure();
-  auto PatchedMainFE = PatchedFM.getFile(testPath("foo.cpp"));
-  ASSERT_TRUE(PatchedMainFE);
+  auto PatchedMainFE = PatchedFM.getFileRef(testPath("foo.cpp"));
+  ASSERT_THAT_EXPECTED(PatchedMainFE, llvm::Succeeded());
   auto PatchedMainID = PatchedIncludes.getOrCreateID(*PatchedMainFE);
   EXPECT_EQ(Includes.includeDepth(MainID)[MainID],
             PatchedIncludes.includeDepth(PatchedMainID)[PatchedMainID]);
diff --git a/clang-tools-extra/modularize/CoverageChecker.cpp b/clang-tools-extra/modularize/CoverageChecker.cpp
--- a/clang-tools-extra/modularize/CoverageChecker.cpp
+++ b/clang-tools-extra/modularize/CoverageChecker.cpp
@@ -88,9 +88,9 @@
   // Include directive callback.
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
     Checker.collectUmbrellaHeaderHeader(File->getName());
   }
diff --git a/clang-tools-extra/modularize/PreprocessorTracker.cpp b/clang-tools-extra/modularize/PreprocessorTracker.cpp
--- a/clang-tools-extra/modularize/PreprocessorTracker.cpp
+++ b/clang-tools-extra/modularize/PreprocessorTracker.cpp
@@ -734,7 +734,7 @@
                           const clang::Token &IncludeTok,
                           llvm::StringRef FileName, bool IsAngled,
                           clang::CharSourceRange FilenameRange,
-                          const clang::FileEntry *File,
+                          llvm::Optional<clang::FileEntryRef> File,
                           llvm::StringRef SearchPath,
                           llvm::StringRef RelativePath,
                           const clang::Module *Imported,
@@ -1277,9 +1277,10 @@
 void PreprocessorCallbacks::InclusionDirective(
     clang::SourceLocation HashLoc, const clang::Token &IncludeTok,
     llvm::StringRef FileName, bool IsAngled,
-    clang::CharSourceRange FilenameRange, const clang::FileEntry *File,
-    llvm::StringRef SearchPath, llvm::StringRef RelativePath,
-    const clang::Module *Imported, clang::SrcMgr::CharacteristicKind FileType) {
+    clang::CharSourceRange FilenameRange,
+    llvm::Optional<clang::FileEntryRef> File, llvm::StringRef SearchPath,
+    llvm::StringRef RelativePath, const clang::Module *Imported,
+    clang::SrcMgr::CharacteristicKind FileType) {
   int DirectiveLine, DirectiveColumn;
   std::string HeaderPath = getSourceLocationFile(PP, HashLoc);
   getSourceLocationLineAndColumn(PP, HashLoc, DirectiveLine, DirectiveColumn);
diff --git a/clang-tools-extra/pp-trace/PPCallbacksTracker.h b/clang-tools-extra/pp-trace/PPCallbacksTracker.h
--- a/clang-tools-extra/pp-trace/PPCallbacksTracker.h
+++ b/clang-tools-extra/pp-trace/PPCallbacksTracker.h
@@ -93,7 +93,8 @@
                    SrcMgr::CharacteristicKind FileType) override;
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           llvm::StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File,
                           llvm::StringRef SearchPath,
                           llvm::StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
@@ -177,8 +178,9 @@
   /// Append a FileID argument to the top trace item.
   void appendArgument(const char *Name, FileID Value);
 
-  /// Append a FileEntry argument to the top trace item.
-  void appendArgument(const char *Name, const FileEntry *Value);
+  /// Append a FileEntryRef argument to the top trace item.
+  void appendArgument(const char *Name, Optional<FileEntryRef> Value);
+  void appendArgument(const char *Name, FileEntryRef Value);
 
   /// Append a SourceLocation argument to the top trace item.
   void appendArgument(const char *Name, SourceLocation Value);
diff --git a/clang-tools-extra/pp-trace/PPCallbacksTracker.cpp b/clang-tools-extra/pp-trace/PPCallbacksTracker.cpp
--- a/clang-tools-extra/pp-trace/PPCallbacksTracker.cpp
+++ b/clang-tools-extra/pp-trace/PPCallbacksTracker.cpp
@@ -123,7 +123,7 @@
                                      const Token &FilenameTok,
                                      SrcMgr::CharacteristicKind FileType) {
   beginCallback("FileSkipped");
-  appendArgument("ParentFile", &SkippedFile.getFileEntry());
+  appendArgument("ParentFile", SkippedFile);
   appendArgument("FilenameTok", FilenameTok);
   appendArgument("FileType", FileType, CharacteristicKindStrings);
 }
@@ -133,7 +133,7 @@
 // of whether the inclusion will actually result in an inclusion.
 void PPCallbacksTracker::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, llvm::StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
     llvm::StringRef SearchPath, llvm::StringRef RelativePath,
     const Module *Imported, SrcMgr::CharacteristicKind FileType) {
   beginCallback("InclusionDirective");
@@ -485,12 +485,16 @@
 
 // Append a FileEntry argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
-                                        const FileEntry *Value) {
+                                        Optional<FileEntryRef> Value) {
   if (!Value) {
     appendArgument(Name, "(null)");
     return;
   }
-  appendFilePathArgument(Name, Value->getName());
+  appendArgument(Name, *Value);
+}
+
+void PPCallbacksTracker::appendArgument(const char *Name, FileEntryRef Value) {
+  appendFilePathArgument(Name, Value.getName());
 }
 
 // Append a SourceLocation argument to the top trace item.
diff --git a/clang/include/clang/Lex/PPCallbacks.h b/clang/include/clang/Lex/PPCallbacks.h
--- a/clang/include/clang/Lex/PPCallbacks.h
+++ b/clang/include/clang/Lex/PPCallbacks.h
@@ -107,7 +107,7 @@
                                   StringRef FileName,
                                   bool IsAngled,
                                   CharSourceRange FilenameRange,
-                                  const FileEntry *File,
+                                  Optional<FileEntryRef> File,
                                   StringRef SearchPath,
                                   StringRef RelativePath,
                                   const Module *Imported,
@@ -428,9 +428,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
     First->InclusionDirective(HashLoc, IncludeTok, FileName, IsAngled,
                               FilenameRange, File, SearchPath, RelativePath,
diff --git a/clang/include/clang/Lex/PreprocessingRecord.h b/clang/include/clang/Lex/PreprocessingRecord.h
--- a/clang/include/clang/Lex/PreprocessingRecord.h
+++ b/clang/include/clang/Lex/PreprocessingRecord.h
@@ -242,13 +242,12 @@
     unsigned ImportedModule : 1;
 
     /// The file that was included.
-    const FileEntry *File;
+    Optional<FileEntryRef> File;
 
   public:
-    InclusionDirective(PreprocessingRecord &PPRec,
-                       InclusionKind Kind, StringRef FileName,
-                       bool InQuotes, bool ImportedModule,
-                       const FileEntry *File, SourceRange Range);
+    InclusionDirective(PreprocessingRecord &PPRec, InclusionKind Kind,
+                       StringRef FileName, bool InQuotes, bool ImportedModule,
+                       Optional<FileEntryRef> File, SourceRange Range);
 
     /// Determine what kind of inclusion directive this is.
     InclusionKind getKind() const { return static_cast<InclusionKind>(Kind); }
@@ -266,7 +265,7 @@
 
     /// Retrieve the file entry for the actual file that was included
     /// by this directive.
-    const FileEntry *getFile() const { return File; }
+    Optional<FileEntryRef> getFile() const { return File; }
 
     // Implement isa/cast/dyncast/etc.
     static bool classof(const PreprocessedEntity *PE) {
@@ -531,7 +530,7 @@
     void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                             StringRef FileName, bool IsAngled,
                             CharSourceRange FilenameRange,
-                            const FileEntry *File, StringRef SearchPath,
+                            Optional<FileEntryRef> File, StringRef SearchPath,
                             StringRef RelativePath, const Module *Imported,
                             SrcMgr::CharacteristicKind FileType) override;
     void Ifdef(SourceLocation Loc, const Token &MacroNameTok,
diff --git a/clang/include/clang/Tooling/DependencyScanning/ModuleDepCollector.h b/clang/include/clang/Tooling/DependencyScanning/ModuleDepCollector.h
--- a/clang/include/clang/Tooling/DependencyScanning/ModuleDepCollector.h
+++ b/clang/include/clang/Tooling/DependencyScanning/ModuleDepCollector.h
@@ -136,9 +136,9 @@
                    FileID PrevFID) override;
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
   void moduleImport(SourceLocation ImportLoc, ModuleIdPath Path,
                     const Module *Imported) override;
diff --git a/clang/lib/CodeGen/MacroPPCallbacks.h b/clang/lib/CodeGen/MacroPPCallbacks.h
--- a/clang/lib/CodeGen/MacroPPCallbacks.h
+++ b/clang/lib/CodeGen/MacroPPCallbacks.h
@@ -100,9 +100,9 @@
   /// Callback invoked whenever a directive (#xxx) is processed.
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
   /// Hook called whenever a macro definition is seen.
diff --git a/clang/lib/CodeGen/MacroPPCallbacks.cpp b/clang/lib/CodeGen/MacroPPCallbacks.cpp
--- a/clang/lib/CodeGen/MacroPPCallbacks.cpp
+++ b/clang/lib/CodeGen/MacroPPCallbacks.cpp
@@ -167,7 +167,7 @@
 
 void MacroPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
 
diff --git a/clang/lib/Frontend/DependencyFile.cpp b/clang/lib/Frontend/DependencyFile.cpp
--- a/clang/lib/Frontend/DependencyFile.cpp
+++ b/clang/lib/Frontend/DependencyFile.cpp
@@ -66,9 +66,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
     if (!File)
       DepCollector.maybeAddDependency(FileName, /*FromModule*/false,
diff --git a/clang/lib/Frontend/DependencyGraph.cpp b/clang/lib/Frontend/DependencyGraph.cpp
--- a/clang/lib/Frontend/DependencyGraph.cpp
+++ b/clang/lib/Frontend/DependencyGraph.cpp
@@ -29,9 +29,9 @@
   const Preprocessor *PP;
   std::string OutputFile;
   std::string SysRoot;
-  llvm::SetVector<const FileEntry *> AllFiles;
-  typedef llvm::DenseMap<const FileEntry *,
-                         SmallVector<const FileEntry *, 2> > DependencyMap;
+  llvm::SetVector<FileEntryRef> AllFiles;
+  using DependencyMap =
+      llvm::DenseMap<FileEntryRef, SmallVector<FileEntryRef, 2>>;
 
   DependencyMap Dependencies;
 
@@ -47,9 +47,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
   void EndOfMainFile() override {
@@ -71,7 +71,7 @@
     StringRef FileName,
     bool IsAngled,
     CharSourceRange FilenameRange,
-    const FileEntry *File,
+    Optional<FileEntryRef> File,
     StringRef SearchPath,
     StringRef RelativePath,
     const Module *Imported,
@@ -80,15 +80,15 @@
     return;
 
   SourceManager &SM = PP->getSourceManager();
-  const FileEntry *FromFile
-    = SM.getFileEntryForID(SM.getFileID(SM.getExpansionLoc(HashLoc)));
+  Optional<FileEntryRef> FromFile =
+      SM.getFileEntryRefForID(SM.getFileID(SM.getExpansionLoc(HashLoc)));
   if (!FromFile)
     return;
 
-  Dependencies[FromFile].push_back(File);
+  Dependencies[*FromFile].push_back(*File);
 
-  AllFiles.insert(File);
-  AllFiles.insert(FromFile);
+  AllFiles.insert(*File);
+  AllFiles.insert(*FromFile);
 }
 
 raw_ostream &
@@ -115,7 +115,7 @@
     OS.indent(2);
     writeNodeReference(OS, AllFiles[I]);
     OS << " [ shape=\"box\", label=\"";
-    StringRef FileName = AllFiles[I]->getName();
+    StringRef FileName = AllFiles[I].getName();
     if (FileName.startswith(SysRoot))
       FileName = FileName.substr(SysRoot.size());
 
diff --git a/clang/lib/Frontend/ModuleDependencyCollector.cpp b/clang/lib/Frontend/ModuleDependencyCollector.cpp
--- a/clang/lib/Frontend/ModuleDependencyCollector.cpp
+++ b/clang/lib/Frontend/ModuleDependencyCollector.cpp
@@ -47,9 +47,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
     if (!File)
       return;
diff --git a/clang/lib/Frontend/PrecompiledPreamble.cpp b/clang/lib/Frontend/PrecompiledPreamble.cpp
--- a/clang/lib/Frontend/PrecompiledPreamble.cpp
+++ b/clang/lib/Frontend/PrecompiledPreamble.cpp
@@ -99,13 +99,13 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
-    // File is null if it wasn't found.
+    // File is None if it wasn't found.
     // (We have some false negatives if PP recovered e.g. <foo> -> "foo")
-    if (File != nullptr)
+    if (File)
       return;
 
     // If it's a rare absolute include, we know the full path already.
diff --git a/clang/lib/Frontend/PrintPreprocessedOutput.cpp b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
--- a/clang/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/clang/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -145,9 +145,9 @@
                    FileID PrevFID) override;
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
   void Ident(SourceLocation Loc, StringRef str) override;
   void PragmaMessage(SourceLocation Loc, StringRef Namespace,
@@ -394,7 +394,7 @@
     StringRef FileName,
     bool IsAngled,
     CharSourceRange FilenameRange,
-    const FileEntry *File,
+    Optional<FileEntryRef> File,
     StringRef SearchPath,
     StringRef RelativePath,
     const Module *Imported,
diff --git a/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp b/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
--- a/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
+++ b/clang/lib/Frontend/Rewrite/InclusionRewriter.cpp
@@ -72,9 +72,9 @@
                    SrcMgr::CharacteristicKind FileType) override;
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
   void If(SourceLocation Loc, SourceRange ConditionRange,
           ConditionValueKind ConditionValue) override;
@@ -186,7 +186,7 @@
                                            StringRef /*FileName*/,
                                            bool /*IsAngled*/,
                                            CharSourceRange /*FilenameRange*/,
-                                           const FileEntry * /*File*/,
+                                           Optional<FileEntryRef> /*File*/,
                                            StringRef /*SearchPath*/,
                                            StringRef /*RelativePath*/,
                                            const Module *Imported,
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -2192,11 +2192,11 @@
   if (Callbacks && !IsImportDecl) {
     // Notify the callback object that we've seen an inclusion directive.
     // FIXME: Use a different callback for a pp-import?
-    Callbacks->InclusionDirective(
-        HashLoc, IncludeTok, LookupFilename, isAngled, FilenameRange,
-        File ? &File->getFileEntry() : nullptr, SearchPath, RelativePath,
-        Action == Import ? SuggestedModule.getModule() : nullptr,
-        FileCharacter);
+    Callbacks->InclusionDirective(HashLoc, IncludeTok, LookupFilename, isAngled,
+                                  FilenameRange, File, SearchPath, RelativePath,
+                                  Action == Import ? SuggestedModule.getModule()
+                                                   : nullptr,
+                                  FileCharacter);
     if (Action == Skip && File)
       Callbacks->FileSkipped(*File, FilenameTok, FileCharacter);
   }
diff --git a/clang/lib/Lex/PreprocessingRecord.cpp b/clang/lib/Lex/PreprocessingRecord.cpp
--- a/clang/lib/Lex/PreprocessingRecord.cpp
+++ b/clang/lib/Lex/PreprocessingRecord.cpp
@@ -42,7 +42,8 @@
 InclusionDirective::InclusionDirective(PreprocessingRecord &PPRec,
                                        InclusionKind Kind, StringRef FileName,
                                        bool InQuotes, bool ImportedModule,
-                                       const FileEntry *File, SourceRange Range)
+                                       Optional<FileEntryRef> File,
+                                       SourceRange Range)
     : PreprocessingDirective(InclusionDirectiveKind, Range), InQuotes(InQuotes),
       Kind(Kind), ImportedModule(ImportedModule), File(File) {
   char *Memory = (char *)PPRec.Allocate(FileName.size() + 1, alignof(char));
@@ -480,7 +481,7 @@
     StringRef FileName,
     bool IsAngled,
     CharSourceRange FilenameRange,
-    const FileEntry *File,
+    Optional<FileEntryRef> File,
     StringRef SearchPath,
     StringRef RelativePath,
     const Module *Imported,
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -6043,10 +6043,9 @@
   case PPD_INCLUSION_DIRECTIVE: {
     const char *FullFileNameStart = Blob.data() + Record[0];
     StringRef FullFileName(FullFileNameStart, Blob.size() - Record[0]);
-    const FileEntry *File = nullptr;
+    Optional<FileEntryRef> File;
     if (!FullFileName.empty())
-      if (auto FE = PP.getFileManager().getFile(FullFileName))
-        File = *FE;
+      File = PP.getFileManager().getOptionalFileRef(FullFileName);
 
     // FIXME: Stable encoding
     InclusionDirective::InclusionKind Kind
diff --git a/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp b/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
--- a/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
+++ b/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
@@ -147,7 +147,7 @@
 
 void ModuleDepCollectorPP::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, const FileEntry *File,
+    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   if (!File && !Imported) {
diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -8298,7 +8298,8 @@
     return nullptr;
 
   const InclusionDirective *ID = getCursorInclusionDirective(cursor);
-  return const_cast<FileEntry *>(ID->getFile());
+  Optional<FileEntryRef> File = ID->getFile();
+  return const_cast<FileEntry *>(File ? &File->getFileEntry() : nullptr);
 }
 
 unsigned clang_Cursor_getObjCPropertyAttributes(CXCursor C, unsigned reserved) {
diff --git a/clang/tools/libclang/CXIndexDataConsumer.h b/clang/tools/libclang/CXIndexDataConsumer.h
--- a/clang/tools/libclang/CXIndexDataConsumer.h
+++ b/clang/tools/libclang/CXIndexDataConsumer.h
@@ -362,9 +362,9 @@
 
   void enteredMainFile(const FileEntry *File);
 
-  void ppIncludedFile(SourceLocation hashLoc,
-                      StringRef filename, const FileEntry *File,
-                      bool isImport, bool isAngled, bool isModuleImport);
+  void ppIncludedFile(SourceLocation hashLoc, StringRef filename,
+                      Optional<FileEntryRef> File, bool isImport, bool isAngled,
+                      bool isModuleImport);
 
   void importedModule(const ImportDecl *ImportD);
   void importedPCH(const FileEntry *File);
diff --git a/clang/tools/libclang/CXIndexDataConsumer.cpp b/clang/tools/libclang/CXIndexDataConsumer.cpp
--- a/clang/tools/libclang/CXIndexDataConsumer.cpp
+++ b/clang/tools/libclang/CXIndexDataConsumer.cpp
@@ -459,20 +459,22 @@
 
 void CXIndexDataConsumer::ppIncludedFile(SourceLocation hashLoc,
                                      StringRef filename,
-                                     const FileEntry *File,
+                                     Optional<FileEntryRef> File,
                                      bool isImport, bool isAngled,
                                      bool isModuleImport) {
   if (!CB.ppIncludedFile)
     return;
 
+  const FileEntry *FE = File ? &File->getFileEntry() : nullptr;
+
   ScratchAlloc SA(*this);
   CXIdxIncludedFileInfo Info = { getIndexLoc(hashLoc),
                                  SA.toCStr(filename),
                                  static_cast<CXFile>(
-                                   const_cast<FileEntry *>(File)),
+                                   const_cast<FileEntry *>(FE)),
                                  isImport, isAngled, isModuleImport };
   CXIdxClientFile idxFile = CB.ppIncludedFile(ClientData, &Info);
-  FileMap[File] = idxFile;
+  FileMap[FE] = idxFile;
 }
 
 void CXIndexDataConsumer::importedModule(const ImportDecl *ImportD) {
diff --git a/clang/tools/libclang/Indexing.cpp b/clang/tools/libclang/Indexing.cpp
--- a/clang/tools/libclang/Indexing.cpp
+++ b/clang/tools/libclang/Indexing.cpp
@@ -261,9 +261,9 @@
 
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
     bool isImport = (IncludeTok.is(tok::identifier) &&
             IncludeTok.getIdentifierInfo()->getPPKeywordID() == tok::pp_import);
diff --git a/clang/unittests/Lex/PPCallbacksTest.cpp b/clang/unittests/Lex/PPCallbacksTest.cpp
--- a/clang/unittests/Lex/PPCallbacksTest.cpp
+++ b/clang/unittests/Lex/PPCallbacksTest.cpp
@@ -35,9 +35,9 @@
 public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
-                          CharSourceRange FilenameRange, const FileEntry *File,
-                          StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
+                          CharSourceRange FilenameRange,
+                          Optional<FileEntryRef> File, StringRef SearchPath,
+                          StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
     this->HashLoc = HashLoc;
     this->IncludeTok = IncludeTok;
@@ -56,7 +56,7 @@
   SmallString<16> FileName;
   bool IsAngled;
   CharSourceRange FilenameRange;
-  const FileEntry* File;
+  Optional<FileEntryRef> File;
   SmallString<16> SearchPath;
   SmallString<16> RelativePath;
   const Module* Imported;