[tools] Use std::nullopt instead of None (NFC)

This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

36 files changed, 82 insertions, 78 deletions

diff --git a/llvm/tools/bugpoint/ToolRunner.cpp b/llvm/tools/bugpoint/ToolRunner.cpp
index 3f4c6a6..352588f0 100644
--- a/llvm/tools/bugpoint/ToolRunner.cpp
+++ b/llvm/tools/bugpoint/ToolRunner.cpp
@@ -59,8 +59,8 @@ static int RunProgramWithTimeout(StringRef ProgramPath,
                                  unsigned MemoryLimit = 0,
                                  std::string *ErrMsg = nullptr) {
   std::optional<StringRef> Redirects[3] = {StdInFile, StdOutFile, StdErrFile};
-  return sys::ExecuteAndWait(ProgramPath, Args, None, Redirects, NumSeconds,
-                             MemoryLimit, ErrMsg);
+  return sys::ExecuteAndWait(ProgramPath, Args, std::nullopt, Redirects,
+                             NumSeconds, MemoryLimit, ErrMsg);
 }
 
 /// RunProgramRemotelyWithTimeout - This function runs the given program
@@ -76,8 +76,8 @@ static int RunProgramRemotelyWithTimeout(
   std::optional<StringRef> Redirects[3] = {StdInFile, StdOutFile, StdErrFile};
 
   // Run the program remotely with the remote client
-  int ReturnCode = sys::ExecuteAndWait(RemoteClientPath, Args, None, Redirects,
-                                       NumSeconds, MemoryLimit);
+  int ReturnCode = sys::ExecuteAndWait(RemoteClientPath, Args, std::nullopt,
+                                       Redirects, NumSeconds, MemoryLimit);
 
   // Has the remote client fail?
   if (255 == ReturnCode) {
diff --git a/llvm/tools/dsymutil/MachODebugMapParser.cpp b/llvm/tools/dsymutil/MachODebugMapParser.cpp
index 955272b..26aeb39 100644
--- a/llvm/tools/dsymutil/MachODebugMapParser.cpp
+++ b/llvm/tools/dsymutil/MachODebugMapParser.cpp
@@ -151,7 +151,8 @@ void MachODebugMapParser::addCommonSymbols() {
       // The main binary doesn't have an address for the given symbol.
       continue;
     }
-    if (!CurrentDebugMapObject->addSymbol(CommonSymbol, None /*ObjectAddress*/,
+    if (!CurrentDebugMapObject->addSymbol(CommonSymbol,
+                                          std::nullopt /*ObjectAddress*/,
                                           CommonAddr, 0 /*size*/)) {
       // The symbol is already present.
       continue;
@@ -533,9 +534,9 @@ void MachODebugMapParser::loadCurrentObjectFileSymbols(
     // in the DebugMap, leave it unassigned for these symbols.
     uint32_t Flags = cantFail(Sym.getFlags());
     if (Flags & SymbolRef::SF_Absolute) {
-      CurrentObjectAddresses[*Name] = None;
+      CurrentObjectAddresses[*Name] = std::nullopt;
     } else if (Flags & SymbolRef::SF_Common) {
-      CurrentObjectAddresses[*Name] = None;
+      CurrentObjectAddresses[*Name] = std::nullopt;
       CommonSymbols.push_back(std::string(*Name));
     } else {
       CurrentObjectAddresses[*Name] = Addr;
diff --git a/llvm/tools/dsymutil/MachOUtils.cpp b/llvm/tools/dsymutil/MachOUtils.cpp
index a239ed2..3ab748c 100644
--- a/llvm/tools/dsymutil/MachOUtils.cpp
+++ b/llvm/tools/dsymutil/MachOUtils.cpp
@@ -66,7 +66,8 @@ static bool runLipo(StringRef SDKPath, SmallVectorImpl<StringRef> &Args) {
   }
 
   std::string ErrMsg;
-  int result = sys::ExecuteAndWait(*Path, Args, None, {}, 0, 0, &ErrMsg);
+  int result =
+      sys::ExecuteAndWait(*Path, Args, std::nullopt, {}, 0, 0, &ErrMsg);
   if (result) {
     WithColor::error() << "lipo: " << ErrMsg << "\n";
     return false;
diff --git a/llvm/tools/llvm-as/llvm-as.cpp b/llvm/tools/llvm-as/llvm-as.cpp
index b777f72..e74c202 100644
--- a/llvm/tools/llvm-as/llvm-as.cpp
+++ b/llvm/tools/llvm-as/llvm-as.cpp
@@ -122,7 +122,7 @@ int main(int argc, char **argv) {
   SMDiagnostic Err;
   auto SetDataLayout = [](StringRef) -> Optional<std::string> {
     if (ClDataLayout.empty())
-      return None;
+      return std::nullopt;
     return ClDataLayout;
   };
   ParsedModuleAndIndex ModuleAndIndex;
diff --git a/llvm/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp b/llvm/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
index cb86d3c..78c4251 100644
--- a/llvm/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
+++ b/llvm/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
@@ -114,7 +114,7 @@ int main(int argc, char **argv) {
 
   BitcodeAnalyzer BA(MB->getBuffer(),
                      BlockInfoMB ? Optional<StringRef>(BlockInfoMB->getBuffer())
-                                 : None);
+                                 : std::nullopt);
 
   BCDumpOptions O(outs());
   O.Histogram = !NoHistogram;
@@ -124,7 +124,7 @@ int main(int argc, char **argv) {
 
   ExitOnErr(BA.analyze(
       Dump ? Optional<BCDumpOptions>(O) : Optional<BCDumpOptions>(),
-      CheckHash.empty() ? None : Optional<StringRef>(CheckHash)));
+      CheckHash.empty() ? std::nullopt : Optional<StringRef>(CheckHash)));
 
   if (Dump)
     outs() << "\n\n";
diff --git a/llvm/tools/llvm-cov/CodeCoverage.cpp b/llvm/tools/llvm-cov/CodeCoverage.cpp
index fe35d89..63732fa 100644
--- a/llvm/tools/llvm-cov/CodeCoverage.cpp
+++ b/llvm/tools/llvm-cov/CodeCoverage.cpp
@@ -559,9 +559,10 @@ void CodeCoverageTool::demangleSymbols(const CoverageMapping &Coverage) {
   std::optional<StringRef> Redirects[] = {
       InputPath.str(), OutputPath.str(), {""}};
   std::string ErrMsg;
-  int RC = sys::ExecuteAndWait(ViewOpts.DemanglerOpts[0], ArgsV,
-                               /*env=*/None, Redirects, /*secondsToWait=*/0,
-                               /*memoryLimit=*/0, &ErrMsg);
+  int RC =
+      sys::ExecuteAndWait(ViewOpts.DemanglerOpts[0], ArgsV,
+                          /*env=*/std::nullopt, Redirects, /*secondsToWait=*/0,
+                          /*memoryLimit=*/0, &ErrMsg);
   if (RC) {
     error(ErrMsg, ViewOpts.DemanglerOpts[0]);
     return;
diff --git a/llvm/tools/llvm-cov/SourceCoverageViewHTML.cpp b/llvm/tools/llvm-cov/SourceCoverageViewHTML.cpp
index 03f1107..48082cb 100644
--- a/llvm/tools/llvm-cov/SourceCoverageViewHTML.cpp
+++ b/llvm/tools/llvm-cov/SourceCoverageViewHTML.cpp
@@ -560,7 +560,7 @@ void SourceCoverageViewHTML::renderLine(raw_ostream &OS, LineRef L,
     else if (CurSeg->Col == ExpansionCol)
       Color = "cyan";
     else
-      Color = None;
+      Color = std::nullopt;
 
     if (Color)
       Snippets[I + 1] = Highlight(Snippets[I + 1], CurSeg->Col,
diff --git a/llvm/tools/llvm-cov/SourceCoverageViewText.cpp b/llvm/tools/llvm-cov/SourceCoverageViewText.cpp
index 5f3eca3..6755619 100644
--- a/llvm/tools/llvm-cov/SourceCoverageViewText.cpp
+++ b/llvm/tools/llvm-cov/SourceCoverageViewText.cpp
@@ -128,7 +128,7 @@ void SourceCoverageViewText::renderLine(raw_ostream &OS, LineRef L,
     else if (Col == ExpansionCol)
       Highlight = raw_ostream::CYAN;
     else
-      Highlight = None;
+      Highlight = std::nullopt;
   }
 
   // Show the rest of the line.
diff --git a/llvm/tools/llvm-dwarfdump/Statistics.cpp b/llvm/tools/llvm-dwarfdump/Statistics.cpp
index ed92665..a967abf 100644
--- a/llvm/tools/llvm-dwarfdump/Statistics.cpp
+++ b/llvm/tools/llvm-dwarfdump/Statistics.cpp
@@ -500,7 +500,8 @@ static void collectStatsRecursive(
     return;
 
   // Handle any kind of lexical scope.
-  const bool HasAbstractOrigin = Die.find(dwarf::DW_AT_abstract_origin) != None;
+  const bool HasAbstractOrigin =
+      Die.find(dwarf::DW_AT_abstract_origin) != std::nullopt;
   const bool IsFunction = Tag == dwarf::DW_TAG_subprogram;
   const bool IsBlock = Tag == dwarf::DW_TAG_lexical_block;
   const bool IsInlinedFunction = Tag == dwarf::DW_TAG_inlined_subroutine;
diff --git a/llvm/tools/llvm-dwarfutil/DebugInfoLinker.cpp b/llvm/tools/llvm-dwarfutil/DebugInfoLinker.cpp
index 5b1ded8..3dafb62 100644
--- a/llvm/tools/llvm-dwarfutil/DebugInfoLinker.cpp
+++ b/llvm/tools/llvm-dwarfutil/DebugInfoLinker.cpp
@@ -222,7 +222,8 @@ protected:
 
   bool isDeadAddress(uint64_t LowPC, uint16_t Version, TombstoneKind Tombstone,
                      uint8_t AddressByteSize) {
-    return isDeadAddressRange(LowPC, None, Version, Tombstone, AddressByteSize);
+    return isDeadAddressRange(LowPC, std::nullopt, Version, Tombstone,
+                              AddressByteSize);
   }
 
 private:
diff --git a/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp b/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp
index 698c77d5..99c6567 100644
--- a/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp
+++ b/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp
@@ -102,7 +102,7 @@ struct YamlContext {
     if (Iter != RegNameToRegNo.end())
       return Iter->second;
     ErrorStream << "No register with name '" << RegName << "'\n";
-    return None;
+    return std::nullopt;
   }
 
 private:
diff --git a/llvm/tools/llvm-gsymutil/llvm-gsymutil.cpp b/llvm/tools/llvm-gsymutil/llvm-gsymutil.cpp
index 4769546..be131d4 100644
--- a/llvm/tools/llvm-gsymutil/llvm-gsymutil.cpp
+++ b/llvm/tools/llvm-gsymutil/llvm-gsymutil.cpp
@@ -191,12 +191,12 @@ getImageBaseAddress(const object::ELFFile<ELFT> &ELFFile) {
   auto PhdrRangeOrErr = ELFFile.program_headers();
   if (!PhdrRangeOrErr) {
     consumeError(PhdrRangeOrErr.takeError());
-    return llvm::None;
+    return std::nullopt;
   }
   for (const typename ELFT::Phdr &Phdr : *PhdrRangeOrErr)
     if (Phdr.p_type == ELF::PT_LOAD)
       return (uint64_t)Phdr.p_vaddr;
-  return llvm::None;
+  return std::nullopt;
 }
 
 /// Determine the virtual address that is considered the base address of mach-o
@@ -222,7 +222,7 @@ getImageBaseAddress(const object::MachOObjectFile *MachO) {
         return SLC.vmaddr;
     }
   }
-  return llvm::None;
+  return std::nullopt;
 }
 
 /// Determine the virtual address that is considered the base address of an
@@ -248,7 +248,7 @@ static llvm::Optional<uint64_t> getImageBaseAddress(object::ObjectFile &Obj) {
     return getImageBaseAddress(ELFObj->getELFFile());
   else if (const auto *ELFObj = dyn_cast<object::ELF64BEObjectFile>(&Obj))
     return getImageBaseAddress(ELFObj->getELFFile());
-  return llvm::None;
+  return std::nullopt;
 }
 
 static llvm::Error handleObjectFile(ObjectFile &Obj,
diff --git a/llvm/tools/llvm-ifs/llvm-ifs.cpp b/llvm/tools/llvm-ifs/llvm-ifs.cpp
index 646d4df..d704422 100644
--- a/llvm/tools/llvm-ifs/llvm-ifs.cpp
+++ b/llvm/tools/llvm-ifs/llvm-ifs.cpp
@@ -309,7 +309,7 @@ static DriverConfig parseArgs(int argc, char *const *argv) {
     Config.InputFormat = StringSwitch<Optional<FileFormat>>(A->getValue())
                              .Case("IFS", FileFormat::IFS)
                              .Case("ELF", FileFormat::ELF)
-                             .Default(None);
+                             .Default(std::nullopt);
     if (!Config.InputFormat)
       fatalError(Twine("invalid argument '") + A->getValue());
   }
@@ -323,7 +323,7 @@ static DriverConfig parseArgs(int argc, char *const *argv) {
                               .Case("IFS", FileFormat::IFS)
                               .Case("ELF", FileFormat::ELF)
                               .Case("TBD", FileFormat::TBD)
-                              .Default(None);
+                              .Default(std::nullopt);
     if (!Config.OutputFormat)
       OptionNotFound("--output-format", A->getValue());
   }
@@ -344,7 +344,7 @@ static DriverConfig parseArgs(int argc, char *const *argv) {
         StringSwitch<Optional<IFSEndiannessType>>(A->getValue())
             .Case("little", IFSEndiannessType::Little)
             .Case("big", IFSEndiannessType::Big)
-            .Default(None);
+            .Default(std::nullopt);
     if (!Config.OverrideEndianness)
       OptionNotFound("--endianness", A->getValue());
   }
diff --git a/llvm/tools/llvm-libtool-darwin/llvm-libtool-darwin.cpp b/llvm/tools/llvm-libtool-darwin/llvm-libtool-darwin.cpp
index d3760a9a..9870bf2 100644
--- a/llvm/tools/llvm-libtool-darwin/llvm-libtool-darwin.cpp
+++ b/llvm/tools/llvm-libtool-darwin/llvm-libtool-darwin.cpp
@@ -136,7 +136,7 @@ static Expected<std::string> searchForFile(const Twine &FileName) {
 
       GlobalDependencyInfo->addMissingInput(Path);
     }
-    return None;
+    return std::nullopt;
   };
 
   Optional<std::string> Found = FindLib(LibrarySearchDirs);
diff --git a/llvm/tools/llvm-lipo/llvm-lipo.cpp b/llvm/tools/llvm-lipo/llvm-lipo.cpp
index c1eef69..0537f07 100644
--- a/llvm/tools/llvm-lipo/llvm-lipo.cpp
+++ b/llvm/tools/llvm-lipo/llvm-lipo.cpp
@@ -182,7 +182,7 @@ static Config parseLipoOptions(ArrayRef<const char *> ArgsArr) {
     reportError("unknown argument '" + Arg->getAsString(InputArgs) + "'");
 
   for (auto *Arg : InputArgs.filtered(LIPO_INPUT))
-    C.InputFiles.push_back({None, Arg->getValue()});
+    C.InputFiles.push_back({std::nullopt, Arg->getValue()});
   for (auto *Arg : InputArgs.filtered(LIPO_arch)) {
     validateArchitectureName(Arg->getValue(0));
     assert(Arg->getValue(1) && "file_name is missing");
diff --git a/llvm/tools/llvm-nm/llvm-nm.cpp b/llvm/tools/llvm-nm/llvm-nm.cpp
index d2c90dd..b19f9ee 100644
--- a/llvm/tools/llvm-nm/llvm-nm.cpp
+++ b/llvm/tools/llvm-nm/llvm-nm.cpp
@@ -651,7 +651,7 @@ static Optional<std::string> demangle(StringRef Name) {
   std::string Demangled;
   if (nonMicrosoftDemangle(Name.str().c_str(), Demangled))
     return Demangled;
-  return None;
+  return std::nullopt;
 }
 
 static Optional<std::string> demangleXCOFF(StringRef Name) {
@@ -662,7 +662,7 @@ static Optional<std::string> demangleXCOFF(StringRef Name) {
   Optional<std::string> DemangledName = demangle(Name);
   if (DemangledName)
     return "." + *DemangledName;
-  return None;
+  return std::nullopt;
 }
 
 static Optional<std::string> demangleMachO(StringRef Name) {
diff --git a/llvm/tools/llvm-objdump/SourcePrinter.cpp b/llvm/tools/llvm-objdump/SourcePrinter.cpp
index c8ea6b5..d0b80fd 100644
--- a/llvm/tools/llvm-objdump/SourcePrinter.cpp
+++ b/llvm/tools/llvm-objdump/SourcePrinter.cpp
@@ -31,7 +31,7 @@ unsigned getInstStartColumn(const MCSubtargetInfo &STI) {
 }
 
 bool LiveVariable::liveAtAddress(object::SectionedAddress Addr) {
-  if (LocExpr.Range == None)
+  if (LocExpr.Range == std::nullopt)
     return false;
   return LocExpr.Range->SectionIndex == Addr.SectionIndex &&
          LocExpr.Range->LowPC <= Addr.Address &&
diff --git a/llvm/tools/llvm-objdump/XCOFFDump.cpp b/llvm/tools/llvm-objdump/XCOFFDump.cpp
index dd1570e..1169532 100644
--- a/llvm/tools/llvm-objdump/XCOFFDump.cpp
+++ b/llvm/tools/llvm-objdump/XCOFFDump.cpp
@@ -49,11 +49,11 @@ objdump::getXCOFFSymbolCsectSMC(const XCOFFObjectFile &Obj,
   const XCOFFSymbolRef SymRef = Obj.toSymbolRef(Sym.getRawDataRefImpl());
 
   if (!SymRef.isCsectSymbol())
-    return None;
+    return std::nullopt;
 
   auto CsectAuxEntOrErr = SymRef.getXCOFFCsectAuxRef();
   if (!CsectAuxEntOrErr)
-    return None;
+    return std::nullopt;
 
   return CsectAuxEntOrErr.get().getStorageMappingClass();
 }
@@ -63,11 +63,11 @@ objdump::getXCOFFSymbolContainingSymbolRef(const XCOFFObjectFile &Obj,
                                            const SymbolRef &Sym) {
   const XCOFFSymbolRef SymRef = Obj.toSymbolRef(Sym.getRawDataRefImpl());
   if (!SymRef.isCsectSymbol())
-    return None;
+    return std::nullopt;
 
   Expected<XCOFFCsectAuxRef> CsectAuxEntOrErr = SymRef.getXCOFFCsectAuxRef();
   if (!CsectAuxEntOrErr || !CsectAuxEntOrErr.get().isLabel())
-    return None;
+    return std::nullopt;
   uint32_t Idx =
       static_cast<uint32_t>(CsectAuxEntOrErr.get().getSectionOrLength());
   DataRefImpl DRI;
diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 0757e3b..7b95642 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -869,7 +869,7 @@ static Optional<SectionRef> getWasmCodeSection(const WasmObjectFile &Obj) {
     if (Section.Type == wasm::WASM_SEC_CODE)
       return SecI;
   }
-  return None;
+  return std::nullopt;
 }
 
 static void
@@ -1101,7 +1101,7 @@ static SymbolInfoTy createDummySymbolInfo(const ObjectFile &Obj,
                                           const uint64_t Addr, StringRef &Name,
                                           uint8_t Type) {
   if (Obj.isXCOFF() && SymbolDescription)
-    return SymbolInfoTy(Addr, Name, None, None, false);
+    return SymbolInfoTy(Addr, Name, std::nullopt, std::nullopt, false);
   else
     return SymbolInfoTy(Addr, Name, Type);
 }
@@ -1276,14 +1276,14 @@ static Optional<OwningBinary<Binary>>
 fetchBinaryByBuildID(const ObjectFile &Obj) {
   Optional<object::BuildIDRef> BuildID = getBuildID(&Obj);
   if (!BuildID)
-    return None;
+    return std::nullopt;
   Optional<std::string> Path = BIDFetcher->fetch(*BuildID);
   if (!Path)
-    return None;
+    return std::nullopt;
   Expected<OwningBinary<Binary>> DebugBinary = createBinary(*Path);
   if (!DebugBinary) {
     reportWarning(toString(DebugBinary.takeError()), *Path);
-    return None;
+    return std::nullopt;
   }
   return std::move(*DebugBinary);
 }
@@ -1423,13 +1423,12 @@ static void disassembleObject(const Target *TheTarget, ObjectFile &Obj,
   LLVM_DEBUG(LVP.dump());
 
   std::unordered_map<uint64_t, BBAddrMap> AddrToBBAddrMap;
-  auto ReadBBAddrMap = [&](Optional<unsigned> SectionIndex = None) {
+  auto ReadBBAddrMap = [&](Optional<unsigned> SectionIndex = std::nullopt) {
     AddrToBBAddrMap.clear();
     if (const auto *Elf = dyn_cast<ELFObjectFileBase>(&Obj)) {
       auto BBAddrMapsOrErr = Elf->readBBAddrMap(SectionIndex);
       if (!BBAddrMapsOrErr)
-          reportWarning(toString(BBAddrMapsOrErr.takeError()),
-                        Obj.getFileName());
+        reportWarning(toString(BBAddrMapsOrErr.takeError()), Obj.getFileName());
       for (auto &FunctionBBAddrMap : *BBAddrMapsOrErr)
         AddrToBBAddrMap.emplace(FunctionBBAddrMap.Addr,
                                 std::move(FunctionBBAddrMap));
diff --git a/llvm/tools/llvm-pdbutil/ExplainOutputStyle.cpp b/llvm/tools/llvm-pdbutil/ExplainOutputStyle.cpp
index 13a5f6e..ef9eb29 100644
--- a/llvm/tools/llvm-pdbutil/ExplainOutputStyle.cpp
+++ b/llvm/tools/llvm-pdbutil/ExplainOutputStyle.cpp
@@ -131,7 +131,7 @@ Optional<uint32_t> ExplainOutputStyle::getPdbBlockStreamIndex() const {
       continue;
     return Entry.index();
   }
-  return None;
+  return std::nullopt;
 }
 
 bool ExplainOutputStyle::explainPdbBlockStatus() {
diff --git a/llvm/tools/llvm-pdbutil/llvm-pdbutil.cpp b/llvm/tools/llvm-pdbutil/llvm-pdbutil.cpp
index 3859558..214cc07 100644
--- a/llvm/tools/llvm-pdbutil/llvm-pdbutil.cpp
+++ b/llvm/tools/llvm-pdbutil/llvm-pdbutil.cpp
@@ -865,7 +865,7 @@ static void yamlToPdb(StringRef Path) {
   AppendingTypeTableBuilder TS(Allocator);
   for (const auto &R : Tpi.Records) {
     CVType Type = R.toCodeViewRecord(TS);
-    TpiBuilder.addTypeRecord(Type.RecordData, None);
+    TpiBuilder.addTypeRecord(Type.RecordData, std::nullopt);
   }
 
   const auto &Ipi = YamlObj.IpiStream.value_or(DefaultIpiStream);
@@ -873,7 +873,7 @@ static void yamlToPdb(StringRef Path) {
   IpiBuilder.setVersionHeader(Ipi.Version);
   for (const auto &R : Ipi.Records) {
     CVType Type = R.toCodeViewRecord(TS);
-    IpiBuilder.addTypeRecord(Type.RecordData, None);
+    IpiBuilder.addTypeRecord(Type.RecordData, std::nullopt);
   }
 
   Builder.getStringTableBuilder().setStrings(*Strings.strings());
@@ -1353,10 +1353,10 @@ static void mergePdbs() {
   auto &DestTpi = Builder.getTpiBuilder();
   auto &DestIpi = Builder.getIpiBuilder();
   MergedTpi.ForEachRecord([&DestTpi](TypeIndex TI, const CVType &Type) {
-    DestTpi.addTypeRecord(Type.RecordData, None);
+    DestTpi.addTypeRecord(Type.RecordData, std::nullopt);
   });
   MergedIpi.ForEachRecord([&DestIpi](TypeIndex TI, const CVType &Type) {
-    DestIpi.addTypeRecord(Type.RecordData, None);
+    DestIpi.addTypeRecord(Type.RecordData, std::nullopt);
   });
   Builder.getInfoBuilder().addFeature(PdbRaw_FeatureSig::VC140);
 
diff --git a/llvm/tools/llvm-profgen/PerfReader.cpp b/llvm/tools/llvm-profgen/PerfReader.cpp
index 0f27429..14bc04b 100644
--- a/llvm/tools/llvm-profgen/PerfReader.cpp
+++ b/llvm/tools/llvm-profgen/PerfReader.cpp
@@ -396,7 +396,7 @@ PerfInputFile PerfScriptReader::convertPerfDataToTrace(
   StringRef ScriptSampleArgs[] = {PerfPath, "script",     "--show-mmap-events",
                                   "-F",     "ip,brstack", "--pid",
                                   PIDs,     "-i",         PerfData};
-  sys::ExecuteAndWait(PerfPath, ScriptSampleArgs, llvm::None, Redirects);
+  sys::ExecuteAndWait(PerfPath, ScriptSampleArgs, std::nullopt, Redirects);
 
   return {PerfTraceFile, PerfFormat::PerfScript, PerfContent::UnknownContent};
 }
diff --git a/llvm/tools/llvm-readobj/ARMEHABIPrinter.h b/llvm/tools/llvm-readobj/ARMEHABIPrinter.h
index d641b17..609104a 100644
--- a/llvm/tools/llvm-readobj/ARMEHABIPrinter.h
+++ b/llvm/tools/llvm-readobj/ARMEHABIPrinter.h
@@ -502,7 +502,7 @@ void PrinterContext<ET>::PrintExceptionTable(const Elf_Shdr &EHT,
                            : PREL31(Word, EHT.sh_addr + TableEntryOffset);
     SW.printHex("PersonalityRoutineAddress", Address);
     Optional<unsigned> SecIndex =
-        IsRelocatable ? Optional<unsigned>(EHT.sh_link) : None;
+        IsRelocatable ? Optional<unsigned>(EHT.sh_link) : std::nullopt;
     if (ErrorOr<StringRef> Name = FunctionAtAddress(Address, SecIndex))
       SW.printString("PersonalityRoutineName", *Name);
   }
@@ -575,7 +575,7 @@ void PrinterContext<ET>::PrintIndexTable(unsigned SectionIndex,
     // the sh_link field is not reliable, because we have one .ARM.exidx section
     // normally, but might have many code sections.
     Optional<unsigned> SecIndex =
-        IsRelocatable ? Optional<unsigned>(IT->sh_link) : None;
+        IsRelocatable ? Optional<unsigned>(IT->sh_link) : std::nullopt;
     if (ErrorOr<StringRef> Name = FunctionAtAddress(Address, SecIndex))
       SW.printString("FunctionName", *Name);
 
diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index 7f66266..4ed62f6 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -942,7 +942,7 @@ ELFDumper<ELFT>::getSymbolSectionIndex(const Elf_Sym &Symbol, unsigned SymIndex,
     return Ndx;
 
   auto CreateErr = [&](const Twine &Name,
-                       std::optional<unsigned> Offset = None) {
+                       std::optional<unsigned> Offset = std::nullopt) {
     std::string Desc;
     if (Offset)
       Desc = (Name + "+0x" + Twine::utohexstr(*Offset)).str();
@@ -4640,7 +4640,7 @@ void GNUELFDumper<ELFT>::printVersionSymbolSection(const Elf_Shdr *Sec) {
 
     bool IsDefault;
     Expected<StringRef> NameOrErr = this->Obj.getSymbolVersionByIndex(
-        Ndx, IsDefault, *VersionMap, /*IsSymHidden=*/None);
+        Ndx, IsDefault, *VersionMap, /*IsSymHidden=*/std::nullopt);
     if (!NameOrErr) {
       this->reportUniqueWarning("unable to get a version for entry " +
                                 Twine(I) + " of " + this->describe(*Sec) +
@@ -5233,11 +5233,11 @@ template <typename ELFT>
 static Optional<FreeBSDNote>
 getFreeBSDNote(uint32_t NoteType, ArrayRef<uint8_t> Desc, bool IsCore) {
   if (IsCore)
-    return None; // No pretty-printing yet.
+    return std::nullopt; // No pretty-printing yet.
   switch (NoteType) {
   case ELF::NT_FREEBSD_ABI_TAG:
     if (Desc.size() != 4)
-      return None;
+      return std::nullopt;
     return FreeBSDNote{
         "ABI tag",
         utostr(support::endian::read32<ELFT::TargetEndianness>(Desc.data()))};
@@ -5245,7 +5245,7 @@ getFreeBSDNote(uint32_t NoteType, ArrayRef<uint8_t> Desc, bool IsCore) {
     return FreeBSDNote{"Arch tag", toStringRef(Desc).str()};
   case ELF::NT_FREEBSD_FEATURE_CTL: {
     if (Desc.size() != 4)
-      return None;
+      return std::nullopt;
     unsigned Value =
         support::endian::read32<ELFT::TargetEndianness>(Desc.data());
     std::string FlagsStr;
@@ -5258,7 +5258,7 @@ getFreeBSDNote(uint32_t NoteType, ArrayRef<uint8_t> Desc, bool IsCore) {
     return FreeBSDNote{"Feature flags", OS.str()};
   }
   default:
-    return None;
+    return std::nullopt;
   }
 }
 
@@ -5725,7 +5725,7 @@ static void printNotesHelper(
     const typename ELFT::Phdr &P = (*PhdrsOrErr)[I];
     if (P.p_type != PT_NOTE)
       continue;
-    StartNotesFn(/*SecName=*/None, P.p_offset, P.p_filesz);
+    StartNotesFn(/*SecName=*/std::nullopt, P.p_offset, P.p_filesz);
     Error Err = Error::success();
     size_t Index = 0;
     for (const typename ELFT::Note Note : Obj.notes(P, Err)) {
@@ -6186,8 +6186,8 @@ void ELFDumper<ELFT>::printNonRelocatableStackSizes(
         break;
       }
       uint64_t SymValue = Data.getAddress(&Offset);
-      if (!printFunctionStackSize(SymValue, /*FunctionSec=*/None, Sec, Data,
-                                  &Offset))
+      if (!printFunctionStackSize(SymValue, /*FunctionSec=*/std::nullopt, Sec,
+                                  Data, &Offset))
         break;
     }
   }
@@ -6742,7 +6742,7 @@ void LLVMELFDumper<ELFT>::printSymbolSection(
       return StringRef("Common");
     if (Symbol.isReserved() && Symbol.st_shndx != SHN_XINDEX)
       return StringRef("Reserved");
-    return None;
+    return std::nullopt;
   };
 
   if (Optional<StringRef> Type = GetSectionSpecialType()) {
diff --git a/llvm/tools/llvm-readobj/MachODumper.cpp b/llvm/tools/llvm-readobj/MachODumper.cpp
index 4931ab5..6ea1c50 100644
--- a/llvm/tools/llvm-readobj/MachODumper.cpp
+++ b/llvm/tools/llvm-readobj/MachODumper.cpp
@@ -634,7 +634,7 @@ bool MachODumper::compareSymbolsByType(SymbolRef LHS, SymbolRef RHS) const {
   return getSymbolType(LHS) < getSymbolType(RHS);
 }
 
-void MachODumper::printSymbols() { printSymbols(None); }
+void MachODumper::printSymbols() { printSymbols(std::nullopt); }
 
 void MachODumper::printSymbols(Optional<SymbolComparator> SymComp) {
   ListScope Group(W, "Symbols");
diff --git a/llvm/tools/llvm-readobj/XCOFFDumper.cpp b/llvm/tools/llvm-readobj/XCOFFDumper.cpp
index fa9b5fe..2556f86 100644
--- a/llvm/tools/llvm-readobj/XCOFFDumper.cpp
+++ b/llvm/tools/llvm-readobj/XCOFFDumper.cpp
@@ -601,7 +601,7 @@ static void printUnexpectedRawAuxEnt(ScopedPrinter &W, uintptr_t AuxAddress) {
                        ArrayRef<uint8_t>(
                            reinterpret_cast<const uint8_t *>(AuxAddress),
                            XCOFF::SymbolTableEntrySize),
-                       None, XCOFF::SymbolTableEntrySize)
+                       std::nullopt, XCOFF::SymbolTableEntrySize)
                 << "\n";
 }
 
diff --git a/llvm/tools/llvm-reduce/TestRunner.cpp b/llvm/tools/llvm-reduce/TestRunner.cpp
index e413f58..fe905b3 100644
--- a/llvm/tools/llvm-reduce/TestRunner.cpp
+++ b/llvm/tools/llvm-reduce/TestRunner.cpp
@@ -49,9 +49,9 @@ int TestRunner::run(StringRef Filename) const {
     for (int i = 0; i < 3; ++i)
       Redirects.push_back(Empty);
   }
-  int Result =
-      sys::ExecuteAndWait(TestName, ProgramArgs, /*Env=*/None, Redirects,
-                          /*SecondsToWait=*/0, /*MemoryLimit=*/0, &ErrMsg);
+  int Result = sys::ExecuteAndWait(
+      TestName, ProgramArgs, /*Env=*/std::nullopt, Redirects,
+      /*SecondsToWait=*/0, /*MemoryLimit=*/0, &ErrMsg);
 
   if (Result < 0) {
     Error E = make_error<StringError>("Error running interesting-ness test: " +
diff --git a/llvm/tools/llvm-reduce/deltas/ReduceOpcodes.cpp b/llvm/tools/llvm-reduce/deltas/ReduceOpcodes.cpp
index 75a00ae..4acc77bb 100644
--- a/llvm/tools/llvm-reduce/deltas/ReduceOpcodes.cpp
+++ b/llvm/tools/llvm-reduce/deltas/ReduceOpcodes.cpp
@@ -27,7 +27,7 @@ static bool shouldIgnoreArgument(const Value *V) {
 
 static Value *replaceIntrinsic(Module &M, IntrinsicInst *II,
                                Intrinsic::ID NewIID,
-                               ArrayRef<Type *> Tys = None) {
+                               ArrayRef<Type *> Tys = std::nullopt) {
   Function *NewFunc = Intrinsic::getDeclaration(&M, NewIID, Tys);
   II->setCalledFunction(NewFunc);
   return II;
diff --git a/llvm/tools/llvm-reduce/deltas/RunIRPasses.cpp b/llvm/tools/llvm-reduce/deltas/RunIRPasses.cpp
index 0071047..5186239 100644
--- a/llvm/tools/llvm-reduce/deltas/RunIRPasses.cpp
+++ b/llvm/tools/llvm-reduce/deltas/RunIRPasses.cpp
@@ -30,7 +30,7 @@ static void runPasses(Oracle &O, Module &Program) {
   PassInstrumentationCallbacks PIC;
   PIC.registerShouldRunOptionalPassCallback(
       [&](StringRef, Any) { return !O.shouldKeep(); });
-  PassBuilder PB(nullptr, PipelineTuningOptions(), None, &PIC);
+  PassBuilder PB(nullptr, PipelineTuningOptions(), std::nullopt, &PIC);
 
   PB.registerModuleAnalyses(MAM);
   PB.registerCGSCCAnalyses(CGAM);
diff --git a/llvm/tools/llvm-sim/llvm-sim.cpp b/llvm/tools/llvm-sim/llvm-sim.cpp
index 2b717d7..7b61ad7 100644
--- a/llvm/tools/llvm-sim/llvm-sim.cpp
+++ b/llvm/tools/llvm-sim/llvm-sim.cpp
@@ -47,7 +47,7 @@ getPositionInModule(const Instruction *I,
   assert(I && "Instruction is nullptr!");
   DenseMap<Instruction *, unsigned>::const_iterator It = LLVMInstNum.find(I);
   if (It == LLVMInstNum.end())
-    return None;
+    return std::nullopt;
   return It->second;
 }
 
diff --git a/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp b/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp
index a59364a..73750c2 100644
--- a/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp
+++ b/llvm/tools/llvm-symbolizer/llvm-symbolizer.cpp
@@ -260,7 +260,7 @@ static void symbolizeInput(const opt::InputArgList &Args,
   uint64_t Offset = 0;
   if (!parseCommand(Args.getLastArgValue(OPT_obj_EQ), IsAddr2Line,
                     StringRef(InputString), Cmd, ModuleName, BuildID, Offset)) {
-    Printer.printInvalidCommand({ModuleName, None}, InputString);
+    Printer.printInvalidCommand({ModuleName, std::nullopt}, InputString);
     return;
   }
   bool ShouldInline = Args.hasFlag(OPT_inlines, OPT_no_inlines, !IsAddr2Line);
@@ -348,8 +348,8 @@ static Optional<bool> parseColorArg(const opt::InputArgList &Args) {
     return StringSwitch<Optional<bool>>(A->getValue())
         .Case("always", true)
         .Case("never", false)
-        .Case("auto", None);
-  return None;
+        .Case("auto", std::nullopt);
+  return std::nullopt;
 }
 
 static object::BuildID parseBuildIDArg(const opt::InputArgList &Args, int ID) {
diff --git a/llvm/tools/lto/lto.cpp b/llvm/tools/lto/lto.cpp
index 1402565..f50b6ac 100644
--- a/llvm/tools/lto/lto.cpp
+++ b/llvm/tools/lto/lto.cpp
@@ -396,7 +396,7 @@ bool lto_codegen_set_pic_model(lto_code_gen_t cg, lto_codegen_model model) {
     unwrap(cg)->setCodePICModel(Reloc::DynamicNoPIC);
     return false;
   case LTO_CODEGEN_PIC_MODEL_DEFAULT:
-    unwrap(cg)->setCodePICModel(None);
+    unwrap(cg)->setCodePICModel(std::nullopt);
     return false;
   }
   sLastErrorString = "Unknown PIC model";
@@ -673,7 +673,7 @@ lto_bool_t thinlto_codegen_set_pic_model(thinlto_code_gen_t cg,
     unwrap(cg)->setCodePICModel(Reloc::DynamicNoPIC);
     return false;
   case LTO_CODEGEN_PIC_MODEL_DEFAULT:
-    unwrap(cg)->setCodePICModel(None);
+    unwrap(cg)->setCodePICModel(std::nullopt);
     return false;
   }
   sLastErrorString = "Unknown PIC model";
diff --git a/llvm/tools/obj2yaml/dwarf2yaml.cpp b/llvm/tools/obj2yaml/dwarf2yaml.cpp
index 2426705..347fb3d 100644
--- a/llvm/tools/obj2yaml/dwarf2yaml.cpp
+++ b/llvm/tools/obj2yaml/dwarf2yaml.cpp
@@ -178,7 +178,7 @@ dumpPubSection(const DWARFContext &DCtx, const DWARFSection &Section,
                 [](Error Err) { consumeError(std::move(Err)); });
   ArrayRef<DWARFDebugPubTable::Set> Sets = Table.getData();
   if (Sets.empty())
-    return None;
+    return std::nullopt;
 
   // FIXME: Currently, obj2yaml only supports dumping the first pubtable.
   Y.Format = Sets[0].Format;
diff --git a/llvm/tools/obj2yaml/elf2yaml.cpp b/llvm/tools/obj2yaml/elf2yaml.cpp
index e4def74..f64e479 100644
--- a/llvm/tools/obj2yaml/elf2yaml.cpp
+++ b/llvm/tools/obj2yaml/elf2yaml.cpp
@@ -550,7 +550,7 @@ Optional<DWARFYAML::Data> ELFDumper<ELFT>::dumpDWARFSections(
   }
 
   if (DWARF.getNonEmptySectionNames().empty())
-    return None;
+    return std::nullopt;
   return DWARF;
 }
 
diff --git a/llvm/tools/opt/NewPMDriver.cpp b/llvm/tools/opt/NewPMDriver.cpp
index 769ed96..39a998e 100644
--- a/llvm/tools/opt/NewPMDriver.cpp
+++ b/llvm/tools/opt/NewPMDriver.cpp
@@ -350,7 +350,7 @@ bool llvm::runPassPipeline(StringRef Arg0, Module &M, TargetMachine *TM,
       P = PGOOptions("", "", "", PGOOptions::NoAction, PGOOptions::NoCSAction,
                      DebugInfoForProfiling, PseudoProbeForProfiling);
     else
-      P = None;
+      P = std::nullopt;
   }
   if (CSPGOKindFlag != NoCSPGO) {
     if (P && (P->Action == PGOOptions::IRInstr ||
diff --git a/llvm/tools/opt/opt.cpp b/llvm/tools/opt/opt.cpp
index e06481d..5563442 100644
--- a/llvm/tools/opt/opt.cpp
+++ b/llvm/tools/opt/opt.cpp
@@ -515,7 +515,7 @@ int main(int argc, char **argv) {
   // Load the input module...
   auto SetDataLayout = [](StringRef) -> Optional<std::string> {
     if (ClDataLayout.empty())
-      return None;
+      return std::nullopt;
     return ClDataLayout;
   };
   std::unique_ptr<Module> M;