[clang] Convert OptionalFileEntryRefDegradesToFileEntryPtr to std::optional

22 files changed, 98 insertions, 57 deletions

diff --git a/clang-tools-extra/clang-move/Move.cpp b/clang-tools-extra/clang-move/Move.cpp
index 9e44fe1..8fe1a99 100644
--- a/clang-tools-extra/clang-move/Move.cpp
+++ b/clang-tools-extra/clang-move/Move.cpp
@@ -18,6 +18,7 @@
 #include "clang/Tooling/Core/Replacement.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Path.h"
+#include <optional>
 
 #define DEBUG_TYPE "clang-move"
 
@@ -131,8 +132,8 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token & /*IncludeTok*/,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> /*File*/, StringRef SearchPath,
-                          StringRef /*RelativePath*/,
+                          std::optional<FileEntryRef> /*File*/,
+                          StringRef SearchPath, StringRef /*RelativePath*/,
                           const Module * /*Imported*/,
                           SrcMgr::CharacteristicKind /*FileType*/) override {
     if (const auto *FileEntry = SM.getFileEntryForID(SM.getFileID(HashLoc)))
diff --git a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp
index f88e24c..62a1700 100644
--- a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp
+++ b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.cpp
@@ -12,6 +12,7 @@
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Lex/PreprocessorOptions.h"
 #include "clang/Serialization/ASTReader.h"
+#include <optional>
 
 #define DEBUG_TYPE "clang-tidy"
 
@@ -162,7 +163,7 @@ void ExpandModularHeadersPPCallbacks::FileChanged(
 void ExpandModularHeadersPPCallbacks::InclusionDirective(
     SourceLocation DirectiveLoc, const Token &IncludeToken,
     StringRef IncludedFilename, bool IsAngled, CharSourceRange FilenameRange,
-    Optional<FileEntryRef> IncludedFile, StringRef SearchPath,
+    std::optional<FileEntryRef> IncludedFile, StringRef SearchPath,
     StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   if (Imported) {
@@ -224,7 +225,8 @@ void ExpandModularHeadersPPCallbacks::PragmaDiagnostic(SourceLocation Loc,
   parseToLocation(Loc);
 }
 void ExpandModularHeadersPPCallbacks::HasInclude(SourceLocation Loc, StringRef,
-                                                 bool, Optional<FileEntryRef>,
+                                                 bool,
+                                                 std::optional<FileEntryRef>,
                                                  SrcMgr::CharacteristicKind) {
   parseToLocation(Loc);
 }
diff --git a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h
index 29f0605..7e616dc 100644
--- a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h
+++ b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h
@@ -12,6 +12,7 @@
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
 #include "llvm/ADT/DenseSet.h"
+#include <optional>
 
 namespace llvm {
 namespace vfs {
@@ -69,7 +70,7 @@ private:
   void InclusionDirective(SourceLocation DirectiveLoc,
                           const Token &IncludeToken, StringRef IncludedFilename,
                           bool IsAngled, CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> IncludedFile,
+                          std::optional<FileEntryRef> IncludedFile,
                           StringRef SearchPath, StringRef RelativePath,
                           const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
@@ -91,7 +92,8 @@ private:
   void PragmaDiagnosticPop(SourceLocation Loc, StringRef) override;
   void PragmaDiagnostic(SourceLocation Loc, StringRef, diag::Severity,
                         StringRef) override;
-  void HasInclude(SourceLocation Loc, StringRef, bool, Optional<FileEntryRef> ,
+  void HasInclude(SourceLocation Loc, StringRef, bool,
+                  std::optional<FileEntryRef>,
                   SrcMgr::CharacteristicKind) override;
   void PragmaOpenCLExtension(SourceLocation NameLoc, const IdentifierInfo *,
                              SourceLocation StateLoc, unsigned) override;
diff --git a/clang-tools-extra/clang-tidy/altera/KernelNameRestrictionCheck.cpp b/clang-tools-extra/clang-tidy/altera/KernelNameRestrictionCheck.cpp
index c51fd53..6a8214c 100644
--- a/clang-tools-extra/clang-tidy/altera/KernelNameRestrictionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/altera/KernelNameRestrictionCheck.cpp
@@ -10,6 +10,7 @@
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -30,8 +31,9 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FileNameRange,
-                          Optional<FileEntryRef> File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          std::optional<FileEntryRef> File,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
   void EndOfMainFile() override;
@@ -62,7 +64,7 @@ void KernelNameRestrictionCheck::registerPPCallbacks(const SourceManager &SM,
 
 void KernelNameRestrictionPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &, StringRef FileName, bool,
-    CharSourceRange, Optional<FileEntryRef>, StringRef, StringRef,
+    CharSourceRange, std::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
index b8fbc6e..08d2cf1 100644
--- a/clang-tools-extra/clang-tidy/bugprone/SuspiciousIncludeCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/SuspiciousIncludeCheck.cpp
@@ -9,6 +9,7 @@
 #include "SuspiciousIncludeCheck.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/Lex/Preprocessor.h"
+#include <optional>
 
 namespace clang {
 namespace tidy {
@@ -25,8 +26,9 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          std::optional<FileEntryRef> File,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
 private:
@@ -72,8 +74,9 @@ void SuspiciousIncludeCheck::registerPPCallbacks(
 
 void SuspiciousIncludePPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
-    StringRef SearchPath, StringRef RelativePath, const Module *Imported,
+    bool IsAngled, CharSourceRange FilenameRange,
+    std::optional<FileEntryRef> File, StringRef SearchPath,
+    StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   if (IncludeTok.getIdentifierInfo()->getPPKeywordID() == tok::pp_import)
     return;
@@ -93,7 +96,7 @@ void SuspiciousIncludePPCallbacks::InclusionDirective(
     llvm::sys::path::replace_extension(GuessedFileName,
                                        (HFE.size() ? "." : "") + HFE);
 
-    Optional<FileEntryRef> File =
+    std::optional<FileEntryRef> File =
         PP->LookupFile(DiagLoc, GuessedFileName, IsAngled, nullptr, nullptr,
                        nullptr, nullptr, nullptr, nullptr, nullptr, nullptr);
     if (File) {
diff --git a/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp b/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp
index f701bd1..617dfb6 100644
--- a/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp
+++ b/clang-tools-extra/clang-tidy/llvm/IncludeOrderCheck.cpp
@@ -13,6 +13,7 @@
 #include "llvm/ADT/STLExtras.h"
 
 #include <map>
+#include <optional>
 
 namespace clang {
 namespace tidy {
@@ -28,8 +29,9 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          std::optional<FileEntryRef> File,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
   void EndOfMainFile() override;
 
@@ -82,8 +84,9 @@ static int getPriority(StringRef Filename, bool IsAngled, bool IsMainModule) {
 
 void IncludeOrderPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
-    StringRef SearchPath, StringRef RelativePath, const Module *Imported,
+    bool IsAngled, CharSourceRange FilenameRange,
+    std::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
   // to leave it in the top position.
diff --git a/clang-tools-extra/clang-tidy/llvmlibc/RestrictSystemLibcHeadersCheck.cpp b/clang-tools-extra/clang-tidy/llvmlibc/RestrictSystemLibcHeadersCheck.cpp
index 62379f1..97b5bae 100644
--- a/clang-tools-extra/clang-tidy/llvmlibc/RestrictSystemLibcHeadersCheck.cpp
+++ b/clang-tools-extra/clang-tidy/llvmlibc/RestrictSystemLibcHeadersCheck.cpp
@@ -12,6 +12,7 @@
 #include "clang/Lex/HeaderSearch.h"
 #include "clang/Lex/HeaderSearchOptions.h"
 #include "clang/Lex/Preprocessor.h"
+#include <optional>
 
 // FixItHint - Hint to check documentation script to mark this check as
 // providing a FixIt.
@@ -34,8 +35,9 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          std::optional<FileEntryRef> File,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
 private:
@@ -46,8 +48,9 @@ private:
 
 void RestrictedIncludesPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
-    StringRef SearchPath, StringRef RelativePath, const Module *Imported,
+    bool IsAngled, CharSourceRange FilenameRange,
+    std::optional<FileEntryRef> File, StringRef SearchPath,
+    StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   // Compiler provided headers are allowed (e.g stddef.h).
   if (SrcMgr::isSystem(FileType) && SearchPath == CompilerIncudeDir)
diff --git a/clang-tools-extra/clang-tidy/modernize/DeprecatedHeadersCheck.cpp b/clang-tools-extra/clang-tidy/modernize/DeprecatedHeadersCheck.cpp
index 64e70ad..ea3e84d 100644
--- a/clang-tools-extra/clang-tidy/modernize/DeprecatedHeadersCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/DeprecatedHeadersCheck.cpp
@@ -15,6 +15,7 @@
 #include "llvm/ADT/StringSet.h"
 
 #include <algorithm>
+#include <optional>
 #include <vector>
 
 using IncludeMarker =
@@ -33,8 +34,9 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          std::optional<FileEntryRef> File,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
 private:
@@ -179,8 +181,9 @@ IncludeModernizePPCallbacks::IncludeModernizePPCallbacks(
 
 void IncludeModernizePPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
-    StringRef SearchPath, StringRef RelativePath, const Module *Imported,
+    bool IsAngled, CharSourceRange FilenameRange,
+    std::optional<FileEntryRef> File, StringRef SearchPath,
+    StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
 
   // If we don't want to warn for non-main file reports and this is one, skip
diff --git a/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp b/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp
index 1c196a9..32489e0 100644
--- a/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp
@@ -16,6 +16,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cctype>
+#include <optional>
 #include <string>
 
 namespace clang {
@@ -119,8 +120,9 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          std::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.cpp b/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.cpp
index 7faf7cc..c914d9c 100644
--- a/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.cpp
+++ b/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.cpp
@@ -15,6 +15,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/Path.h"
 #include <cstring>
+#include <optional>
 
 namespace clang {
 namespace tidy {
@@ -22,8 +23,9 @@ namespace portability {
 
 void RestrictedIncludesPPCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
-    StringRef SearchPath, StringRef RelativePath, const Module *Imported,
+    bool IsAngled, CharSourceRange FilenameRange,
+    std::optional<FileEntryRef> File, StringRef SearchPath,
+    StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   if (!Check.contains(FileName) && SrcMgr::isSystem(FileType)) {
     SmallString<256> FullPath;
diff --git a/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.h b/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.h
index 2919b06..165aadb 100644
--- a/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.h
+++ b/clang-tools-extra/clang-tidy/portability/RestrictSystemIncludesCheck.h
@@ -12,6 +12,7 @@
 #include "../ClangTidyCheck.h"
 #include "../GlobList.h"
 #include "clang/Lex/PPCallbacks.h"
+#include <optional>
 
 namespace clang {
 namespace tidy {
@@ -51,8 +52,9 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          std::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/readability/DuplicateIncludeCheck.cpp b/clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp
index 22a4e4e..84b97d1 100644
--- a/clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/DuplicateIncludeCheck.cpp
@@ -12,6 +12,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
 #include <memory>
+#include <optional>
 
 namespace clang {
 namespace tidy {
@@ -48,8 +49,9 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          std::optional<FileEntryRef> File,
+                          StringRef SearchPath, StringRef RelativePath,
+                          const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
 
   void MacroDefined(const Token &MacroNameTok,
@@ -77,8 +79,9 @@ void DuplicateIncludeCallbacks::FileChanged(SourceLocation Loc,
 
 void DuplicateIncludeCallbacks::InclusionDirective(
     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
-    bool IsAngled, CharSourceRange FilenameRange, Optional<FileEntryRef> File,
-    StringRef SearchPath, StringRef RelativePath, const Module *Imported,
+    bool IsAngled, CharSourceRange FilenameRange,
+    std::optional<FileEntryRef> File, StringRef SearchPath,
+    StringRef RelativePath, const Module *Imported,
     SrcMgr::CharacteristicKind FileType) {
   if (llvm::is_contained(Files.back(), FileName)) {
     // We want to delete the entire line, so make sure that [Start,End] covers
diff --git a/clang-tools-extra/clang-tidy/utils/IncludeInserter.cpp b/clang-tools-extra/clang-tidy/utils/IncludeInserter.cpp
index 08bbe9d..f497f79 100644
--- a/clang-tools-extra/clang-tidy/utils/IncludeInserter.cpp
+++ b/clang-tools-extra/clang-tidy/utils/IncludeInserter.cpp
@@ -10,6 +10,7 @@
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Lex/Token.h"
+#include <optional>
 
 namespace clang {
 namespace tidy {
@@ -24,7 +25,7 @@ public:
   void InclusionDirective(SourceLocation HashLocation,
                           const Token &IncludeToken, StringRef FileNameRef,
                           bool IsAngled, CharSourceRange FileNameRange,
-                          Optional<FileEntryRef> /*IncludedFile*/,
+                          std::optional<FileEntryRef> /*IncludedFile*/,
                           StringRef /*SearchPath*/, StringRef /*RelativePath*/,
                           const Module * /*ImportedModule*/,
                           SrcMgr::CharacteristicKind /*FileType*/) override {
diff --git a/clang-tools-extra/clangd/Headers.cpp b/clang-tools-extra/clangd/Headers.cpp
index 4314ef1..a4647b3 100644
--- a/clang-tools-extra/clangd/Headers.cpp
+++ b/clang-tools-extra/clangd/Headers.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Path.h"
 #include <cstring>
+#include <optional>
 
 namespace clang {
 namespace clangd {
@@ -35,7 +36,7 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           llvm::StringRef FileName, bool IsAngled,
                           CharSourceRange /*FilenameRange*/,
-                          Optional<FileEntryRef> File,
+                          std::optional<FileEntryRef> File,
                           llvm::StringRef /*SearchPath*/,
                           llvm::StringRef /*RelativePath*/,
                           const clang::Module * /*Imported*/,
diff --git a/clang-tools-extra/clangd/ParsedAST.cpp b/clang-tools-extra/clangd/ParsedAST.cpp
index 4e99365..edb46cf 100644
--- a/clang-tools-extra/clangd/ParsedAST.cpp
+++ b/clang-tools-extra/clangd/ParsedAST.cpp
@@ -50,6 +50,7 @@
 #include "llvm/ADT/StringRef.h"
 #include <algorithm>
 #include <memory>
+#include <optional>
 #include <vector>
 
 // Force the linker to link in Clang-tidy modules.
@@ -171,9 +172,10 @@ private:
 
   void replay() {
     for (const auto &Inc : Includes) {
-      llvm::Optional<FileEntryRef> File;
+      std::optional<FileEntryRef> File;
       if (Inc.Resolved != "")
-        File = expectedToOptional(SM.getFileManager().getFileRef(Inc.Resolved));
+        File =
+            expectedToStdOptional(SM.getFileManager().getFileRef(Inc.Resolved));
 
       // Re-lex the #include directive to find its interesting parts.
       auto HashLoc = SM.getComposedLoc(SM.getMainFileID(), Inc.HashOffset);
diff --git a/clang-tools-extra/clangd/index/IndexAction.cpp b/clang-tools-extra/clangd/index/IndexAction.cpp
index aaba2c9..9041c79 100644
--- a/clang-tools-extra/clangd/index/IndexAction.cpp
+++ b/clang-tools-extra/clangd/index/IndexAction.cpp
@@ -22,13 +22,14 @@
 #include <cstddef>
 #include <functional>
 #include <memory>
+#include <optional>
 #include <utility>
 
 namespace clang {
 namespace clangd {
 namespace {
 
-llvm::Optional<std::string> toURI(Optional<FileEntryRef> File) {
+std::optional<std::string> toURI(std::optional<FileEntryRef> File) {
   if (!File)
     return std::nullopt;
   auto AbsolutePath = File->getFileEntry().tryGetRealPathName();
@@ -85,7 +86,7 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           llvm::StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File,
+                          std::optional<FileEntryRef> File,
                           llvm::StringRef SearchPath,
                           llvm::StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override {
diff --git a/clang-tools-extra/clangd/unittests/ParsedASTTests.cpp b/clang-tools-extra/clangd/unittests/ParsedASTTests.cpp
index 8167413..52f7ded 100644
--- a/clang-tools-extra/clangd/unittests/ParsedASTTests.cpp
+++ b/clang-tools-extra/clangd/unittests/ParsedASTTests.cpp
@@ -37,6 +37,7 @@
 #include "gmock/gmock-matchers.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 namespace clang {
 namespace clangd {
@@ -381,7 +382,7 @@ TEST(ParsedASTTest, ReplayPreambleForTidyCheckers) {
     void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                             StringRef FileName, bool IsAngled,
                             CharSourceRange FilenameRange,
-                            Optional<FileEntryRef>, StringRef, StringRef,
+                            std::optional<FileEntryRef>, StringRef, StringRef,
                             const clang::Module *,
                             SrcMgr::CharacteristicKind) override {
       Includes.emplace_back(SM, HashLoc, IncludeTok, FileName, IsAngled,
diff --git a/clang-tools-extra/include-cleaner/lib/Record.cpp b/clang-tools-extra/include-cleaner/lib/Record.cpp
index e16be12..efdacc7 100644
--- a/clang-tools-extra/include-cleaner/lib/Record.cpp
+++ b/clang-tools-extra/include-cleaner/lib/Record.cpp
@@ -17,6 +17,7 @@
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Tooling/Inclusions/HeaderAnalysis.h"
+#include <optional>
 
 namespace clang::include_cleaner {
 namespace {
@@ -35,7 +36,7 @@ public:
   void InclusionDirective(SourceLocation Hash, const Token &IncludeTok,
                           StringRef SpelledFilename, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          llvm::Optional<FileEntryRef> File,
+                          std::optional<FileEntryRef> File,
                           StringRef SearchPath, StringRef RelativePath,
                           const Module *, SrcMgr::CharacteristicKind) override {
     if (!Active)
@@ -180,7 +181,7 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           llvm::StringRef FileName, bool IsAngled,
                           CharSourceRange /*FilenameRange*/,
-                          Optional<FileEntryRef> File,
+                          std::optional<FileEntryRef> File,
                           llvm::StringRef /*SearchPath*/,
                           llvm::StringRef /*RelativePath*/,
                           const clang::Module * /*Imported*/,
diff --git a/clang-tools-extra/modularize/CoverageChecker.cpp b/clang-tools-extra/modularize/CoverageChecker.cpp
index 610fb59..d1c0cf8 100644
--- a/clang-tools-extra/modularize/CoverageChecker.cpp
+++ b/clang-tools-extra/modularize/CoverageChecker.cpp
@@ -50,9 +50,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "CoverageChecker.h"
 #include "ModularizeUtilities.h"
 #include "clang/AST/ASTConsumer.h"
-#include "CoverageChecker.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/Basic/SourceManager.h"
@@ -69,6 +69,7 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace Modularize;
 using namespace clang;
@@ -89,8 +90,9 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File, StringRef SearchPath,
-                          StringRef RelativePath, const Module *Imported,
+                          std::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
index 171a938..f697288 100644
--- a/clang-tools-extra/modularize/PreprocessorTracker.cpp
+++ b/clang-tools-extra/modularize/PreprocessorTracker.cpp
@@ -251,6 +251,7 @@
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 namespace Modularize {
 
@@ -734,7 +735,7 @@ public:
                           const clang::Token &IncludeTok,
                           llvm::StringRef FileName, bool IsAngled,
                           clang::CharSourceRange FilenameRange,
-                          llvm::Optional<clang::FileEntryRef> File,
+                          std::optional<clang::FileEntryRef> File,
                           llvm::StringRef SearchPath,
                           llvm::StringRef RelativePath,
                           const clang::Module *Imported,
@@ -1278,7 +1279,7 @@ void PreprocessorCallbacks::InclusionDirective(
     clang::SourceLocation HashLoc, const clang::Token &IncludeTok,
     llvm::StringRef FileName, bool IsAngled,
     clang::CharSourceRange FilenameRange,
-    llvm::Optional<clang::FileEntryRef> File, llvm::StringRef SearchPath,
+    std::optional<clang::FileEntryRef> File, llvm::StringRef SearchPath,
     llvm::StringRef RelativePath, const clang::Module *Imported,
     clang::SrcMgr::CharacteristicKind FileType) {
   int DirectiveLine, DirectiveColumn;
diff --git a/clang-tools-extra/pp-trace/PPCallbacksTracker.cpp b/clang-tools-extra/pp-trace/PPCallbacksTracker.cpp
index c143455..1f2eeda 100644
--- a/clang-tools-extra/pp-trace/PPCallbacksTracker.cpp
+++ b/clang-tools-extra/pp-trace/PPCallbacksTracker.cpp
@@ -17,6 +17,7 @@
 #include "clang/Basic/FileManager.h"
 #include "clang/Lex/MacroArgs.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 namespace clang {
 namespace pp_trace {
@@ -133,9 +134,10 @@ void PPCallbacksTracker::FileSkipped(const FileEntryRef &SkippedFile,
 // 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, Optional<FileEntryRef> File,
-    llvm::StringRef SearchPath, llvm::StringRef RelativePath,
-    const Module *Imported, SrcMgr::CharacteristicKind FileType) {
+    bool IsAngled, CharSourceRange FilenameRange,
+    std::optional<FileEntryRef> File, llvm::StringRef SearchPath,
+    llvm::StringRef RelativePath, const Module *Imported,
+    SrcMgr::CharacteristicKind FileType) {
   beginCallback("InclusionDirective");
   appendArgument("HashLoc", HashLoc);
   appendArgument("IncludeTok", IncludeTok);
@@ -486,7 +488,7 @@ void PPCallbacksTracker::appendArgument(const char *Name, FileID Value) {
 
 // Append a FileEntry argument to the top trace item.
 void PPCallbacksTracker::appendArgument(const char *Name,
-                                        Optional<FileEntryRef> Value) {
+                                        std::optional<FileEntryRef> Value) {
   if (!Value) {
     appendArgument(Name, "(null)");
     return;
diff --git a/clang-tools-extra/pp-trace/PPCallbacksTracker.h b/clang-tools-extra/pp-trace/PPCallbacksTracker.h
index 8640146..c494556 100644
--- a/clang-tools-extra/pp-trace/PPCallbacksTracker.h
+++ b/clang-tools-extra/pp-trace/PPCallbacksTracker.h
@@ -21,14 +21,15 @@
 #ifndef PPTRACE_PPCALLBACKSTRACKER_H
 #define PPTRACE_PPCALLBACKSTRACKER_H
 
+#include "clang/Basic/SourceManager.h"
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
-#include "clang/Basic/SourceManager.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/GlobPattern.h"
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -94,7 +95,7 @@ public:
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           llvm::StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange,
-                          Optional<FileEntryRef> File,
+                          std::optional<FileEntryRef> File,
                           llvm::StringRef SearchPath,
                           llvm::StringRef RelativePath, const Module *Imported,
                           SrcMgr::CharacteristicKind FileType) override;
@@ -179,7 +180,7 @@ public:
   void appendArgument(const char *Name, FileID Value);
 
   /// Append a FileEntryRef argument to the top trace item.
-  void appendArgument(const char *Name, Optional<FileEntryRef> Value);
+  void appendArgument(const char *Name, std::optional<FileEntryRef> Value);
   void appendArgument(const char *Name, FileEntryRef Value);
 
   /// Append a SourceLocation argument to the top trace item.