Import LLVM 10.0.0 release including clang, lld and lldb.

ok hackroom
tested by plenty

1 files changed, 1095 insertions, 0 deletions

diff --git a/gnu/llvm/clang/lib/Driver/ToolChain.cpp b/gnu/llvm/clang/lib/Driver/ToolChain.cpp
new file mode 100644
index 00000000000..cab97b1a601
--- /dev/null
+++ b/gnu/llvm/clang/lib/Driver/ToolChain.cpp
@@ -0,0 +1,1095 @@
+//===- ToolChain.cpp - Collections of tools for one platform --------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Driver/ToolChain.h"
+#include "InputInfo.h"
+#include "ToolChains/Arch/ARM.h"
+#include "ToolChains/Clang.h"
+#include "ToolChains/InterfaceStubs.h"
+#include "ToolChains/Flang.h"
+#include "clang/Basic/ObjCRuntime.h"
+#include "clang/Basic/Sanitizers.h"
+#include "clang/Config/config.h"
+#include "clang/Driver/Action.h"
+#include "clang/Driver/Driver.h"
+#include "clang/Driver/DriverDiagnostic.h"
+#include "clang/Driver/Job.h"
+#include "clang/Driver/Options.h"
+#include "clang/Driver/SanitizerArgs.h"
+#include "clang/Driver/XRayArgs.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Config/llvm-config.h"
+#include "llvm/MC/MCTargetOptions.h"
+#include "llvm/Option/Arg.h"
+#include "llvm/Option/ArgList.h"
+#include "llvm/Option/OptTable.h"
+#include "llvm/Option/Option.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/TargetParser.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/VersionTuple.h"
+#include "llvm/Support/VirtualFileSystem.h"
+#include <cassert>
+#include <cstddef>
+#include <cstring>
+#include <string>
+
+using namespace clang;
+using namespace driver;
+using namespace tools;
+using namespace llvm;
+using namespace llvm::opt;
+
+static llvm::opt::Arg *GetRTTIArgument(const ArgList &Args) {
+  return Args.getLastArg(options::OPT_mkernel, options::OPT_fapple_kext,
+                         options::OPT_fno_rtti, options::OPT_frtti);
+}
+
+static ToolChain::RTTIMode CalculateRTTIMode(const ArgList &Args,
+                                             const llvm::Triple &Triple,
+                                             const Arg *CachedRTTIArg) {
+  // Explicit rtti/no-rtti args
+  if (CachedRTTIArg) {
+    if (CachedRTTIArg->getOption().matches(options::OPT_frtti))
+      return ToolChain::RM_Enabled;
+    else
+      return ToolChain::RM_Disabled;
+  }
+
+  // -frtti is default, except for the PS4 CPU.
+  return (Triple.isPS4CPU()) ? ToolChain::RM_Disabled : ToolChain::RM_Enabled;
+}
+
+ToolChain::ToolChain(const Driver &D, const llvm::Triple &T,
+                     const ArgList &Args)
+    : D(D), Triple(T), Args(Args), CachedRTTIArg(GetRTTIArgument(Args)),
+      CachedRTTIMode(CalculateRTTIMode(Args, Triple, CachedRTTIArg)) {
+  if (D.CCCIsCXX()) {
+    if (auto CXXStdlibPath = getCXXStdlibPath())
+      getFilePaths().push_back(*CXXStdlibPath);
+  }
+
+  if (auto RuntimePath = getRuntimePath())
+    getLibraryPaths().push_back(*RuntimePath);
+
+  std::string CandidateLibPath = getArchSpecificLibPath();
+  if (getVFS().exists(CandidateLibPath))
+    getFilePaths().push_back(CandidateLibPath);
+}
+
+void ToolChain::setTripleEnvironment(llvm::Triple::EnvironmentType Env) {
+  Triple.setEnvironment(Env);
+  if (EffectiveTriple != llvm::Triple())
+    EffectiveTriple.setEnvironment(Env);
+}
+
+ToolChain::~ToolChain() = default;
+
+llvm::vfs::FileSystem &ToolChain::getVFS() const {
+  return getDriver().getVFS();
+}
+
+bool ToolChain::useIntegratedAs() const {
+  return Args.hasFlag(options::OPT_fintegrated_as,
+                      options::OPT_fno_integrated_as,
+                      IsIntegratedAssemblerDefault());
+}
+
+bool ToolChain::useRelaxRelocations() const {
+  return ENABLE_X86_RELAX_RELOCATIONS;
+}
+
+bool ToolChain::isNoExecStackDefault() const {
+    return false;
+}
+
+const SanitizerArgs& ToolChain::getSanitizerArgs() const {
+  if (!SanitizerArguments.get())
+    SanitizerArguments.reset(new SanitizerArgs(*this, Args));
+  return *SanitizerArguments.get();
+}
+
+const XRayArgs& ToolChain::getXRayArgs() const {
+  if (!XRayArguments.get())
+    XRayArguments.reset(new XRayArgs(*this, Args));
+  return *XRayArguments.get();
+}
+
+namespace {
+
+struct DriverSuffix {
+  const char *Suffix;
+  const char *ModeFlag;
+};
+
+} // namespace
+
+static const DriverSuffix *FindDriverSuffix(StringRef ProgName, size_t &Pos) {
+  // A list of known driver suffixes. Suffixes are compared against the
+  // program name in order. If there is a match, the frontend type is updated as
+  // necessary by applying the ModeFlag.
+  static const DriverSuffix DriverSuffixes[] = {
+      {"clang", nullptr},
+      {"clang++", "--driver-mode=g++"},
+      {"clang-c++", "--driver-mode=g++"},
+      {"clang-cc", nullptr},
+      {"clang-cpp", "--driver-mode=cpp"},
+      {"clang-g++", "--driver-mode=g++"},
+      {"clang-gcc", nullptr},
+      {"clang-cl", "--driver-mode=cl"},
+      {"cc", nullptr},
+      {"cpp", "--driver-mode=cpp"},
+      {"cl", "--driver-mode=cl"},
+      {"++", "--driver-mode=g++"},
+      {"flang", "--driver-mode=flang"},
+  };
+
+  for (size_t i = 0; i < llvm::array_lengthof(DriverSuffixes); ++i) {
+    StringRef Suffix(DriverSuffixes[i].Suffix);
+    if (ProgName.endswith(Suffix)) {
+      Pos = ProgName.size() - Suffix.size();
+      return &DriverSuffixes[i];
+    }
+  }
+  return nullptr;
+}
+
+/// Normalize the program name from argv[0] by stripping the file extension if
+/// present and lower-casing the string on Windows.
+static std::string normalizeProgramName(llvm::StringRef Argv0) {
+  std::string ProgName = llvm::sys::path::stem(Argv0);
+#ifdef _WIN32
+  // Transform to lowercase for case insensitive file systems.
+  std::transform(ProgName.begin(), ProgName.end(), ProgName.begin(), ::tolower);
+#endif
+  return ProgName;
+}
+
+static const DriverSuffix *parseDriverSuffix(StringRef ProgName, size_t &Pos) {
+  // Try to infer frontend type and default target from the program name by
+  // comparing it against DriverSuffixes in order.
+
+  // If there is a match, the function tries to identify a target as prefix.
+  // E.g. "x86_64-linux-clang" as interpreted as suffix "clang" with target
+  // prefix "x86_64-linux". If such a target prefix is found, it may be
+  // added via -target as implicit first argument.
+  const DriverSuffix *DS = FindDriverSuffix(ProgName, Pos);
+
+  if (!DS) {
+    // Try again after stripping any trailing version number:
+    // clang++3.5 -> clang++
+    ProgName = ProgName.rtrim("0123456789.");
+    DS = FindDriverSuffix(ProgName, Pos);
+  }
+
+  if (!DS) {
+    // Try again after stripping trailing -component.
+    // clang++-tot -> clang++
+    ProgName = ProgName.slice(0, ProgName.rfind('-'));
+    DS = FindDriverSuffix(ProgName, Pos);
+  }
+  return DS;
+}
+
+ParsedClangName
+ToolChain::getTargetAndModeFromProgramName(StringRef PN) {
+  std::string ProgName = normalizeProgramName(PN);
+  size_t SuffixPos;
+  const DriverSuffix *DS = parseDriverSuffix(ProgName, SuffixPos);
+  if (!DS)
+    return {};
+  size_t SuffixEnd = SuffixPos + strlen(DS->Suffix);
+
+  size_t LastComponent = ProgName.rfind('-', SuffixPos);
+  if (LastComponent == std::string::npos)
+    return ParsedClangName(ProgName.substr(0, SuffixEnd), DS->ModeFlag);
+  std::string ModeSuffix = ProgName.substr(LastComponent + 1,
+                                           SuffixEnd - LastComponent - 1);
+
+  // Infer target from the prefix.
+  StringRef Prefix(ProgName);
+  Prefix = Prefix.slice(0, LastComponent);
+  std::string IgnoredError;
+  bool IsRegistered = llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError);
+  return ParsedClangName{Prefix, ModeSuffix, DS->ModeFlag, IsRegistered};
+}
+
+StringRef ToolChain::getDefaultUniversalArchName() const {
+  // In universal driver terms, the arch name accepted by -arch isn't exactly
+  // the same as the ones that appear in the triple. Roughly speaking, this is
+  // an inverse of the darwin::getArchTypeForDarwinArchName() function, but the
+  // only interesting special case is powerpc.
+  switch (Triple.getArch()) {
+  case llvm::Triple::ppc:
+    return "ppc";
+  case llvm::Triple::ppc64:
+    return "ppc64";
+  case llvm::Triple::ppc64le:
+    return "ppc64le";
+  default:
+    return Triple.getArchName();
+  }
+}
+
+std::string ToolChain::getInputFilename(const InputInfo &Input) const {
+  return Input.getFilename();
+}
+
+bool ToolChain::IsUnwindTablesDefault(const ArgList &Args) const {
+  return false;
+}
+
+Tool *ToolChain::getClang() const {
+  if (!Clang)
+    Clang.reset(new tools::Clang(*this));
+  return Clang.get();
+}
+
+Tool *ToolChain::getFlang() const {
+  if (!Flang)
+    Flang.reset(new tools::Flang(*this));
+  return Flang.get();
+}
+
+Tool *ToolChain::buildAssembler() const {
+  return new tools::ClangAs(*this);
+}
+
+Tool *ToolChain::buildLinker() const {
+  llvm_unreachable("Linking is not supported by this toolchain");
+}
+
+Tool *ToolChain::getAssemble() const {
+  if (!Assemble)
+    Assemble.reset(buildAssembler());
+  return Assemble.get();
+}
+
+Tool *ToolChain::getClangAs() const {
+  if (!Assemble)
+    Assemble.reset(new tools::ClangAs(*this));
+  return Assemble.get();
+}
+
+Tool *ToolChain::getLink() const {
+  if (!Link)
+    Link.reset(buildLinker());
+  return Link.get();
+}
+
+Tool *ToolChain::getIfsMerge() const {
+  if (!IfsMerge)
+    IfsMerge.reset(new tools::ifstool::Merger(*this));
+  return IfsMerge.get();
+}
+
+Tool *ToolChain::getOffloadBundler() const {
+  if (!OffloadBundler)
+    OffloadBundler.reset(new tools::OffloadBundler(*this));
+  return OffloadBundler.get();
+}
+
+Tool *ToolChain::getOffloadWrapper() const {
+  if (!OffloadWrapper)
+    OffloadWrapper.reset(new tools::OffloadWrapper(*this));
+  return OffloadWrapper.get();
+}
+
+Tool *ToolChain::getTool(Action::ActionClass AC) const {
+  switch (AC) {
+  case Action::AssembleJobClass:
+    return getAssemble();
+
+  case Action::IfsMergeJobClass:
+    return getIfsMerge();
+
+  case Action::LinkJobClass:
+    return getLink();
+
+  case Action::InputClass:
+  case Action::BindArchClass:
+  case Action::OffloadClass:
+  case Action::LipoJobClass:
+  case Action::DsymutilJobClass:
+  case Action::VerifyDebugInfoJobClass:
+    llvm_unreachable("Invalid tool kind.");
+
+  case Action::CompileJobClass:
+  case Action::PrecompileJobClass:
+  case Action::HeaderModulePrecompileJobClass:
+  case Action::PreprocessJobClass:
+  case Action::AnalyzeJobClass:
+  case Action::MigrateJobClass:
+  case Action::VerifyPCHJobClass:
+  case Action::BackendJobClass:
+    return getClang();
+
+  case Action::OffloadBundlingJobClass:
+  case Action::OffloadUnbundlingJobClass:
+    return getOffloadBundler();
+
+  case Action::OffloadWrapperJobClass:
+    return getOffloadWrapper();
+  }
+
+  llvm_unreachable("Invalid tool kind.");
+}
+
+static StringRef getArchNameForCompilerRTLib(const ToolChain &TC,
+                                             const ArgList &Args) {
+  const llvm::Triple &Triple = TC.getTriple();
+  bool IsWindows = Triple.isOSWindows();
+
+  if (TC.getArch() == llvm::Triple::arm || TC.getArch() == llvm::Triple::armeb)
+    return (arm::getARMFloatABI(TC, Args) == arm::FloatABI::Hard && !IsWindows)
+               ? "armhf"
+               : "arm";
+
+  // For historic reasons, Android library is using i686 instead of i386.
+  if (TC.getArch() == llvm::Triple::x86 && Triple.isAndroid())
+    return "i686";
+
+  return llvm::Triple::getArchTypeName(TC.getArch());
+}
+
+StringRef ToolChain::getOSLibName() const {
+  switch (Triple.getOS()) {
+  case llvm::Triple::FreeBSD:
+    return "freebsd";
+  case llvm::Triple::NetBSD:
+    return "netbsd";
+  case llvm::Triple::OpenBSD:
+    return "openbsd";
+  case llvm::Triple::Solaris:
+    return "sunos";
+  default:
+    return getOS();
+  }
+}
+
+std::string ToolChain::getCompilerRTPath() const {
+  SmallString<128> Path(getDriver().ResourceDir);
+  if (Triple.isOSUnknown()) {
+    llvm::sys::path::append(Path, "lib");
+  } else {
+    llvm::sys::path::append(Path, "lib", getOSLibName());
+  }
+  return Path.str();
+}
+
+std::string ToolChain::getCompilerRT(const ArgList &Args, StringRef Component,
+                                     FileType Type) const {
+  const llvm::Triple &TT = getTriple();
+  bool IsITANMSVCWindows =
+      TT.isWindowsMSVCEnvironment() || TT.isWindowsItaniumEnvironment();
+
+  const char *Prefix =
+      IsITANMSVCWindows || Type == ToolChain::FT_Object ? "" : "lib";
+  const char *Suffix;
+  switch (Type) {
+  case ToolChain::FT_Object:
+    Suffix = IsITANMSVCWindows ? ".obj" : ".o";
+    break;
+  case ToolChain::FT_Static:
+    Suffix = IsITANMSVCWindows ? ".lib" : ".a";
+    break;
+  case ToolChain::FT_Shared:
+    Suffix = Triple.isOSWindows()
+                 ? (Triple.isWindowsGNUEnvironment() ? ".dll.a" : ".lib")
+                 : ".so";
+    break;
+  }
+
+  for (const auto &LibPath : getLibraryPaths()) {
+    SmallString<128> P(LibPath);
+    llvm::sys::path::append(P, Prefix + Twine("clang_rt.") + Component + Suffix);
+    if (getVFS().exists(P))
+      return P.str();
+  }
+
+  StringRef Arch = getArchNameForCompilerRTLib(*this, Args);
+  const char *Env = TT.isAndroid() ? "-android" : "";
+  SmallString<128> Path(getCompilerRTPath());
+  llvm::sys::path::append(Path, Prefix + Twine("clang_rt.") + Component + "-" +
+                                    Arch + Env + Suffix);
+  return Path.str();
+}
+
+const char *ToolChain::getCompilerRTArgString(const llvm::opt::ArgList &Args,
+                                              StringRef Component,
+                                              FileType Type) const {
+  return Args.MakeArgString(getCompilerRT(Args, Component, Type));
+}
+
+
+Optional<std::string> ToolChain::getRuntimePath() const {
+  SmallString<128> P;
+
+  // First try the triple passed to driver as --target=<triple>.
+  P.assign(D.ResourceDir);
+  llvm::sys::path::append(P, "lib", D.getTargetTriple());
+  if (getVFS().exists(P))
+    return llvm::Optional<std::string>(P.str());
+
+  // Second try the normalized triple.
+  P.assign(D.ResourceDir);
+  llvm::sys::path::append(P, "lib", Triple.str());
+  if (getVFS().exists(P))
+    return llvm::Optional<std::string>(P.str());
+
+  return None;
+}
+
+Optional<std::string> ToolChain::getCXXStdlibPath() const {
+  SmallString<128> P;
+
+  // First try the triple passed to driver as --target=<triple>.
+  P.assign(D.Dir);
+  llvm::sys::path::append(P, "..", "lib", D.getTargetTriple(), "c++");
+  if (getVFS().exists(P))
+    return llvm::Optional<std::string>(P.str());
+
+  // Second try the normalized triple.
+  P.assign(D.Dir);
+  llvm::sys::path::append(P, "..", "lib", Triple.str(), "c++");
+  if (getVFS().exists(P))
+    return llvm::Optional<std::string>(P.str());
+
+  return None;
+}
+
+std::string ToolChain::getArchSpecificLibPath() const {
+  SmallString<128> Path(getDriver().ResourceDir);
+  llvm::sys::path::append(Path, "lib", getOSLibName(),
+                          llvm::Triple::getArchTypeName(getArch()));
+  return Path.str();
+}
+
+bool ToolChain::needsProfileRT(const ArgList &Args) {
+  if (Args.hasArg(options::OPT_noprofilelib))
+    return false;
+
+  if (needsGCovInstrumentation(Args) ||
+      Args.hasArg(options::OPT_fprofile_generate) ||
+      Args.hasArg(options::OPT_fprofile_generate_EQ) ||
+      Args.hasArg(options::OPT_fcs_profile_generate) ||
+      Args.hasArg(options::OPT_fcs_profile_generate_EQ) ||
+      Args.hasArg(options::OPT_fprofile_instr_generate) ||
+      Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
+      Args.hasArg(options::OPT_fcreate_profile) ||
+      Args.hasArg(options::OPT_forder_file_instrumentation))
+    return true;
+
+  return false;
+}
+
+bool ToolChain::needsGCovInstrumentation(const llvm::opt::ArgList &Args) {
+  return Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
+                      false) ||
+         Args.hasArg(options::OPT_coverage);
+}
+
+Tool *ToolChain::SelectTool(const JobAction &JA) const {
+  if (D.IsFlangMode() && getDriver().ShouldUseFlangCompiler(JA)) return getFlang();
+  if (getDriver().ShouldUseClangCompiler(JA)) return getClang();
+  Action::ActionClass AC = JA.getKind();
+  if (AC == Action::AssembleJobClass && useIntegratedAs())
+    return getClangAs();
+  return getTool(AC);
+}
+
+std::string ToolChain::GetFilePath(const char *Name) const {
+  return D.GetFilePath(Name, *this);
+}
+
+std::string ToolChain::GetProgramPath(const char *Name) const {
+  return D.GetProgramPath(Name, *this);
+}
+
+std::string ToolChain::GetLinkerPath() const {
+  const Arg* A = Args.getLastArg(options::OPT_fuse_ld_EQ);
+  StringRef UseLinker = A ? A->getValue() : CLANG_DEFAULT_LINKER;
+
+  if (llvm::sys::path::is_absolute(UseLinker)) {
+    // If we're passed what looks like an absolute path, don't attempt to
+    // second-guess that.
+    if (llvm::sys::fs::can_execute(UseLinker))
+      return UseLinker;
+  } else if (UseLinker.empty() || UseLinker == "ld") {
+    // If we're passed -fuse-ld= with no argument, or with the argument ld,
+    // then use whatever the default system linker is.
+    return GetProgramPath(getDefaultLinker());
+  } else {
+    llvm::SmallString<8> LinkerName;
+    if (Triple.isOSDarwin())
+      LinkerName.append("ld64.");
+    else
+      LinkerName.append("ld.");
+    LinkerName.append(UseLinker);
+
+    std::string LinkerPath(GetProgramPath(LinkerName.c_str()));
+    if (llvm::sys::fs::can_execute(LinkerPath))
+      return LinkerPath;
+  }
+
+  if (A)
+    getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
+
+  return GetProgramPath(getDefaultLinker());
+}
+
+types::ID ToolChain::LookupTypeForExtension(StringRef Ext) const {
+  types::ID id = types::lookupTypeForExtension(Ext);
+
+  // Flang always runs the preprocessor and has no notion of "preprocessed
+  // fortran". Here, TY_PP_Fortran is coerced to TY_Fortran to avoid treating
+  // them differently.
+  if (D.IsFlangMode() && id == types::TY_PP_Fortran)
+    id = types::TY_Fortran;
+
+  return id;
+}
+
+bool ToolChain::HasNativeLLVMSupport() const {
+  return false;
+}
+
+bool ToolChain::isCrossCompiling() const {
+  llvm::Triple HostTriple(LLVM_HOST_TRIPLE);
+  switch (HostTriple.getArch()) {
+  // The A32/T32/T16 instruction sets are not separate architectures in this
+  // context.
+  case llvm::Triple::arm:
+  case llvm::Triple::armeb:
+  case llvm::Triple::thumb:
+  case llvm::Triple::thumbeb:
+    return getArch() != llvm::Triple::arm && getArch() != llvm::Triple::thumb &&
+           getArch() != llvm::Triple::armeb && getArch() != llvm::Triple::thumbeb;
+  default:
+    return HostTriple.getArch() != getArch();
+  }
+}
+
+ObjCRuntime ToolChain::getDefaultObjCRuntime(bool isNonFragile) const {
+  return ObjCRuntime(isNonFragile ? ObjCRuntime::GNUstep : ObjCRuntime::GCC,
+                     VersionTuple());
+}
+
+llvm::ExceptionHandling
+ToolChain::GetExceptionModel(const llvm::opt::ArgList &Args) const {
+  return llvm::ExceptionHandling::None;
+}
+
+bool ToolChain::isThreadModelSupported(const StringRef Model) const {
+  if (Model == "single") {
+    // FIXME: 'single' is only supported on ARM and WebAssembly so far.
+    return Triple.getArch() == llvm::Triple::arm ||
+           Triple.getArch() == llvm::Triple::armeb ||
+           Triple.getArch() == llvm::Triple::thumb ||
+           Triple.getArch() == llvm::Triple::thumbeb ||
+           Triple.getArch() == llvm::Triple::wasm32 ||
+           Triple.getArch() == llvm::Triple::wasm64;
+  } else if (Model == "posix")
+    return true;
+
+  return false;
+}
+
+std::string ToolChain::ComputeLLVMTriple(const ArgList &Args,
+                                         types::ID InputType) const {
+  switch (getTriple().getArch()) {
+  default:
+    return getTripleString();
+
+  case llvm::Triple::x86_64: {
+    llvm::Triple Triple = getTriple();
+    if (!Triple.isOSBinFormatMachO())
+      return getTripleString();
+
+    if (Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
+      // x86_64h goes in the triple. Other -march options just use the
+      // vanilla triple we already have.
+      StringRef MArch = A->getValue();
+      if (MArch == "x86_64h")
+        Triple.setArchName(MArch);
+    }
+    return Triple.getTriple();
+  }
+  case llvm::Triple::aarch64: {
+    llvm::Triple Triple = getTriple();
+    if (!Triple.isOSBinFormatMachO())
+      return getTripleString();
+
+    // FIXME: older versions of ld64 expect the "arm64" component in the actual
+    // triple string and query it to determine whether an LTO file can be
+    // handled. Remove this when we don't care any more.
+    Triple.setArchName("arm64");
+    return Triple.getTriple();
+  }
+  case llvm::Triple::aarch64_32:
+    return getTripleString();
+  case llvm::Triple::arm:
+  case llvm::Triple::armeb:
+  case llvm::Triple::thumb:
+  case llvm::Triple::thumbeb: {
+    // FIXME: Factor into subclasses.
+    llvm::Triple Triple = getTriple();
+    bool IsBigEndian = getTriple().getArch() == llvm::Triple::armeb ||
+                       getTriple().getArch() == llvm::Triple::thumbeb;
+
+    // Handle pseudo-target flags '-mlittle-endian'/'-EL' and
+    // '-mbig-endian'/'-EB'.
+    if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
+                                 options::OPT_mbig_endian)) {
+      IsBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
+    }
+
+    // Thumb2 is the default for V7 on Darwin.
+    //
+    // FIXME: Thumb should just be another -target-feaure, not in the triple.
+    StringRef MCPU, MArch;
+    if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
+      MCPU = A->getValue();
+    if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
+      MArch = A->getValue();
+    std::string CPU =
+        Triple.isOSBinFormatMachO()
+            ? tools::arm::getARMCPUForMArch(MArch, Triple).str()
+            : tools::arm::getARMTargetCPU(MCPU, MArch, Triple);
+    StringRef Suffix =
+      tools::arm::getLLVMArchSuffixForARM(CPU, MArch, Triple);
+    bool IsMProfile = ARM::parseArchProfile(Suffix) == ARM::ProfileKind::M;
+    bool ThumbDefault = IsMProfile || (ARM::parseArchVersion(Suffix) == 7 &&
+                                       getTriple().isOSBinFormatMachO());
+    // FIXME: this is invalid for WindowsCE
+    if (getTriple().isOSWindows())
+      ThumbDefault = true;
+    std::string ArchName;
+    if (IsBigEndian)
+      ArchName = "armeb";
+    else
+      ArchName = "arm";
+
+    // Check if ARM ISA was explicitly selected (using -mno-thumb or -marm) for
+    // M-Class CPUs/architecture variants, which is not supported.
+    bool ARMModeRequested = !Args.hasFlag(options::OPT_mthumb,
+                                          options::OPT_mno_thumb, ThumbDefault);
+    if (IsMProfile && ARMModeRequested) {
+      if (!MCPU.empty())
+        getDriver().Diag(diag::err_cpu_unsupported_isa) << CPU << "ARM";
+       else
+        getDriver().Diag(diag::err_arch_unsupported_isa)
+          << tools::arm::getARMArch(MArch, getTriple()) << "ARM";
+    }
+
+    // Check to see if an explicit choice to use thumb has been made via
+    // -mthumb. For assembler files we must check for -mthumb in the options
+    // passed to the assembler via -Wa or -Xassembler.
+    bool IsThumb = false;
+    if (InputType != types::TY_PP_Asm)
+      IsThumb = Args.hasFlag(options::OPT_mthumb, options::OPT_mno_thumb,
+                              ThumbDefault);
+    else {
+      // Ideally we would check for these flags in
+      // CollectArgsForIntegratedAssembler but we can't change the ArchName at
+      // that point. There is no assembler equivalent of -mno-thumb, -marm, or
+      // -mno-arm.
+      for (const auto *A :
+           Args.filtered(options::OPT_Wa_COMMA, options::OPT_Xassembler)) {
+        for (StringRef Value : A->getValues()) {
+          if (Value == "-mthumb")
+            IsThumb = true;
+        }
+      }
+    }
+    // Assembly files should start in ARM mode, unless arch is M-profile, or
+    // -mthumb has been passed explicitly to the assembler. Windows is always
+    // thumb.
+    if (IsThumb || IsMProfile || getTriple().isOSWindows()) {
+      if (IsBigEndian)
+        ArchName = "thumbeb";
+      else
+        ArchName = "thumb";
+    }
+    Triple.setArchName(ArchName + Suffix.str());
+
+    return Triple.getTriple();
+  }
+  }
+}
+
+std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args,
+                                                   types::ID InputType) const {
+  return ComputeLLVMTriple(Args, InputType);
+}
+
+void ToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
+                                          ArgStringList &CC1Args) const {
+  // Each toolchain should provide the appropriate include flags.
+}
+
+void ToolChain::addClangTargetOptions(
+    const ArgList &DriverArgs, ArgStringList &CC1Args,
+    Action::OffloadKind DeviceOffloadKind) const {}
+
+void ToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {}
+
+void ToolChain::addProfileRTLibs(const llvm::opt::ArgList &Args,
+                                 llvm::opt::ArgStringList &CmdArgs) const {
+  if (!needsProfileRT(Args)) return;
+
+  CmdArgs.push_back(getCompilerRTArgString(Args, "profile"));
+}
+
+ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
+    const ArgList &Args) const {
+  const Arg* A = Args.getLastArg(options::OPT_rtlib_EQ);
+  StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_RTLIB;
+
+  // Only use "platform" in tests to override CLANG_DEFAULT_RTLIB!
+  if (LibName == "compiler-rt")
+    return ToolChain::RLT_CompilerRT;
+  else if (LibName == "libgcc")
+    return ToolChain::RLT_Libgcc;
+  else if (LibName == "platform")
+    return GetDefaultRuntimeLibType();
+
+  if (A)
+    getDriver().Diag(diag::err_drv_invalid_rtlib_name) << A->getAsString(Args);
+
+  return GetDefaultRuntimeLibType();
+}
+
+ToolChain::UnwindLibType ToolChain::GetUnwindLibType(
+    const ArgList &Args) const {
+  const Arg *A = Args.getLastArg(options::OPT_unwindlib_EQ);
+  StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_UNWINDLIB;
+
+  if (LibName == "none")
+    return ToolChain::UNW_None;
+  else if (LibName == "platform" || LibName == "") {
+    ToolChain::RuntimeLibType RtLibType = GetRuntimeLibType(Args);
+    if (RtLibType == ToolChain::RLT_CompilerRT)
+      return ToolChain::UNW_None;
+    else if (RtLibType == ToolChain::RLT_Libgcc)
+      return ToolChain::UNW_Libgcc;
+  } else if (LibName == "libunwind") {
+    if (GetRuntimeLibType(Args) == RLT_Libgcc)
+      getDriver().Diag(diag::err_drv_incompatible_unwindlib);
+    return ToolChain::UNW_CompilerRT;
+  } else if (LibName == "libgcc")
+    return ToolChain::UNW_Libgcc;
+
+  if (A)
+    getDriver().Diag(diag::err_drv_invalid_unwindlib_name)
+        << A->getAsString(Args);
+
+  return GetDefaultUnwindLibType();
+}
+
+ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
+  const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
+  StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_CXX_STDLIB;
+
+  // Only use "platform" in tests to override CLANG_DEFAULT_CXX_STDLIB!
+  if (LibName == "libc++")
+    return ToolChain::CST_Libcxx;
+  else if (LibName == "libstdc++")
+    return ToolChain::CST_Libstdcxx;
+  else if (LibName == "platform")
+    return GetDefaultCXXStdlibType();
+
+  if (A)
+    getDriver().Diag(diag::err_drv_invalid_stdlib_name) << A->getAsString(Args);
+
+  return GetDefaultCXXStdlibType();
+}
+
+/// Utility function to add a system include directory to CC1 arguments.
+/*static*/ void ToolChain::addSystemInclude(const ArgList &DriverArgs,
+                                            ArgStringList &CC1Args,
+                                            const Twine &Path) {
+  CC1Args.push_back("-internal-isystem");
+  CC1Args.push_back(DriverArgs.MakeArgString(Path));
+}
+
+/// Utility function to add a system include directory with extern "C"
+/// semantics to CC1 arguments.
+///
+/// Note that this should be used rarely, and only for directories that
+/// historically and for legacy reasons are treated as having implicit extern
+/// "C" semantics. These semantics are *ignored* by and large today, but its
+/// important to preserve the preprocessor changes resulting from the
+/// classification.
+/*static*/ void ToolChain::addExternCSystemInclude(const ArgList &DriverArgs,
+                                                   ArgStringList &CC1Args,
+                                                   const Twine &Path) {
+  CC1Args.push_back("-internal-externc-isystem");
+  CC1Args.push_back(DriverArgs.MakeArgString(Path));
+}
+
+void ToolChain::addExternCSystemIncludeIfExists(const ArgList &DriverArgs,
+                                                ArgStringList &CC1Args,
+                                                const Twine &Path) {
+  if (llvm::sys::fs::exists(Path))
+    addExternCSystemInclude(DriverArgs, CC1Args, Path);
+}
+
+/// Utility function to add a list of system include directories to CC1.
+/*static*/ void ToolChain::addSystemIncludes(const ArgList &DriverArgs,
+                                             ArgStringList &CC1Args,
+                                             ArrayRef<StringRef> Paths) {
+  for (const auto &Path : Paths) {
+    CC1Args.push_back("-internal-isystem");
+    CC1Args.push_back(DriverArgs.MakeArgString(Path));
+  }
+}
+
+void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
+                                             ArgStringList &CC1Args) const {
+  // Header search paths should be handled by each of the subclasses.
+  // Historically, they have not been, and instead have been handled inside of
+  // the CC1-layer frontend. As the logic is hoisted out, this generic function
+  // will slowly stop being called.
+  //
+  // While it is being called, replicate a bit of a hack to propagate the
+  // '-stdlib=' flag down to CC1 so that it can in turn customize the C++
+  // header search paths with it. Once all systems are overriding this
+  // function, the CC1 flag and this line can be removed.
+  DriverArgs.AddAllArgs(CC1Args, options::OPT_stdlib_EQ);
+}
+
+void ToolChain::AddClangCXXStdlibIsystemArgs(
+    const llvm::opt::ArgList &DriverArgs,
+    llvm::opt::ArgStringList &CC1Args) const {
+  DriverArgs.ClaimAllArgs(options::OPT_stdlibxx_isystem);
+  if (!DriverArgs.hasArg(options::OPT_nostdincxx))
+    for (const auto &P :
+         DriverArgs.getAllArgValues(options::OPT_stdlibxx_isystem))
+      addSystemInclude(DriverArgs, CC1Args, P);
+}
+
+bool ToolChain::ShouldLinkCXXStdlib(const llvm::opt::ArgList &Args) const {
+  return getDriver().CCCIsCXX() &&
+         !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
+                      options::OPT_nostdlibxx);
+}
+
+void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
+                                    ArgStringList &CmdArgs) const {
+  assert(!Args.hasArg(options::OPT_nostdlibxx) &&
+         "should not have called this");
+  CXXStdlibType Type = GetCXXStdlibType(Args);
+
+  switch (Type) {
+  case ToolChain::CST_Libcxx:
+    CmdArgs.push_back("-lc++");
+    break;
+
+  case ToolChain::CST_Libstdcxx:
+    CmdArgs.push_back("-lstdc++");
+    break;
+  }
+}
+
+void ToolChain::AddFilePathLibArgs(const ArgList &Args,
+                                   ArgStringList &CmdArgs) const {
+  for (const auto &LibPath : getFilePaths())
+    if(LibPath.length() > 0)
+      CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
+}
+
+void ToolChain::AddCCKextLibArgs(const ArgList &Args,
+                                 ArgStringList &CmdArgs) const {
+  CmdArgs.push_back("-lcc_kext");
+}
+
+bool ToolChain::AddFastMathRuntimeIfAvailable(const ArgList &Args,
+                                              ArgStringList &CmdArgs) const {
+  // Do not check for -fno-fast-math or -fno-unsafe-math when -Ofast passed
+  // (to keep the linker options consistent with gcc and clang itself).
+  if (!isOptimizationLevelFast(Args)) {
+    // Check if -ffast-math or -funsafe-math.
+    Arg *A =
+        Args.getLastArg(options::OPT_ffast_math, options::OPT_fno_fast_math,
+                        options::OPT_funsafe_math_optimizations,
+                        options::OPT_fno_unsafe_math_optimizations);
+
+    if (!A || A->getOption().getID() == options::OPT_fno_fast_math ||
+        A->getOption().getID() == options::OPT_fno_unsafe_math_optimizations)
+      return false;
+  }
+  // If crtfastmath.o exists add it to the arguments.
+  std::string Path = GetFilePath("crtfastmath.o");
+  if (Path == "crtfastmath.o") // Not found.
+    return false;
+
+  CmdArgs.push_back(Args.MakeArgString(Path));
+  return true;
+}
+
+SanitizerMask ToolChain::getSupportedSanitizers() const {
+  // Return sanitizers which don't require runtime support and are not
+  // platform dependent.
+
+  SanitizerMask Res = (SanitizerKind::Undefined & ~SanitizerKind::Vptr &
+                       ~SanitizerKind::Function) |
+                      (SanitizerKind::CFI & ~SanitizerKind::CFIICall) |
+                      SanitizerKind::CFICastStrict |
+                      SanitizerKind::FloatDivideByZero |
+                      SanitizerKind::UnsignedIntegerOverflow |
+                      SanitizerKind::ImplicitConversion |
+                      SanitizerKind::Nullability | SanitizerKind::LocalBounds;
+  if (getTriple().getArch() == llvm::Triple::x86 ||
+      getTriple().getArch() == llvm::Triple::x86_64 ||
+      getTriple().getArch() == llvm::Triple::arm ||
+      getTriple().getArch() == llvm::Triple::aarch64 ||
+      getTriple().getArch() == llvm::Triple::wasm32 ||
+      getTriple().getArch() == llvm::Triple::wasm64)
+    Res |= SanitizerKind::CFIICall;
+  if (getTriple().getArch() == llvm::Triple::x86_64 ||
+      getTriple().getArch() == llvm::Triple::aarch64)
+    Res |= SanitizerKind::ShadowCallStack;
+  if (getTriple().getArch() == llvm::Triple::aarch64 ||
+      getTriple().getArch() == llvm::Triple::aarch64_be)
+    Res |= SanitizerKind::MemTag;
+  return Res;
+}
+
+void ToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
+                                   ArgStringList &CC1Args) const {}
+
+void ToolChain::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
+                                    ArgStringList &CC1Args) const {}
+
+static VersionTuple separateMSVCFullVersion(unsigned Version) {
+  if (Version < 100)
+    return VersionTuple(Version);
+
+  if (Version < 10000)
+    return VersionTuple(Version / 100, Version % 100);
+
+  unsigned Build = 0, Factor = 1;
+  for (; Version > 10000; Version = Version / 10, Factor = Factor * 10)
+    Build = Build + (Version % 10) * Factor;
+  return VersionTuple(Version / 100, Version % 100, Build);
+}
+
+VersionTuple
+ToolChain::computeMSVCVersion(const Driver *D,
+                              const llvm::opt::ArgList &Args) const {
+  const Arg *MSCVersion = Args.getLastArg(options::OPT_fmsc_version);
+  const Arg *MSCompatibilityVersion =
+      Args.getLastArg(options::OPT_fms_compatibility_version);
+
+  if (MSCVersion && MSCompatibilityVersion) {
+    if (D)
+      D->Diag(diag::err_drv_argument_not_allowed_with)
+          << MSCVersion->getAsString(Args)
+          << MSCompatibilityVersion->getAsString(Args);
+    return VersionTuple();
+  }
+
+  if (MSCompatibilityVersion) {
+    VersionTuple MSVT;
+    if (MSVT.tryParse(MSCompatibilityVersion->getValue())) {
+      if (D)
+        D->Diag(diag::err_drv_invalid_value)
+            << MSCompatibilityVersion->getAsString(Args)
+            << MSCompatibilityVersion->getValue();
+    } else {
+      return MSVT;
+    }
+  }
+
+  if (MSCVersion) {
+    unsigned Version = 0;
+    if (StringRef(MSCVersion->getValue()).getAsInteger(10, Version)) {
+      if (D)
+        D->Diag(diag::err_drv_invalid_value)
+            << MSCVersion->getAsString(Args) << MSCVersion->getValue();
+    } else {
+      return separateMSVCFullVersion(Version);
+    }
+  }
+
+  return VersionTuple();
+}
+
+llvm::opt::DerivedArgList *ToolChain::TranslateOpenMPTargetArgs(
+    const llvm::opt::DerivedArgList &Args, bool SameTripleAsHost,
+    SmallVectorImpl<llvm::opt::Arg *> &AllocatedArgs) const {
+  DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
+  const OptTable &Opts = getDriver().getOpts();
+  bool Modified = false;
+
+  // Handle -Xopenmp-target flags
+  for (auto *A : Args) {
+    // Exclude flags which may only apply to the host toolchain.
+    // Do not exclude flags when the host triple (AuxTriple)
+    // matches the current toolchain triple. If it is not present
+    // at all, target and host share a toolchain.
+    if (A->getOption().matches(options::OPT_m_Group)) {
+      if (SameTripleAsHost)
+        DAL->append(A);
+      else
+        Modified = true;
+      continue;
+    }
+
+    unsigned Index;
+    unsigned Prev;
+    bool XOpenMPTargetNoTriple =
+        A->getOption().matches(options::OPT_Xopenmp_target);
+
+    if (A->getOption().matches(options::OPT_Xopenmp_target_EQ)) {
+      // Passing device args: -Xopenmp-target=<triple> -opt=val.
+      if (A->getValue(0) == getTripleString())
+        Index = Args.getBaseArgs().MakeIndex(A->getValue(1));
+      else
+        continue;
+    } else if (XOpenMPTargetNoTriple) {
+      // Passing device args: -Xopenmp-target -opt=val.
+      Index = Args.getBaseArgs().MakeIndex(A->getValue(0));
+    } else {
+      DAL->append(A);
+      continue;
+    }
+
+    // Parse the argument to -Xopenmp-target.
+    Prev = Index;
+    std::unique_ptr<Arg> XOpenMPTargetArg(Opts.ParseOneArg(Args, Index));
+    if (!XOpenMPTargetArg || Index > Prev + 1) {
+      getDriver().Diag(diag::err_drv_invalid_Xopenmp_target_with_args)
+          << A->getAsString(Args);
+      continue;
+    }
+    if (XOpenMPTargetNoTriple && XOpenMPTargetArg &&
+        Args.getAllArgValues(options::OPT_fopenmp_targets_EQ).size() != 1) {
+      getDriver().Diag(diag::err_drv_Xopenmp_target_missing_triple);
+      continue;
+    }
+    XOpenMPTargetArg->setBaseArg(A);
+    A = XOpenMPTargetArg.release();
+    AllocatedArgs.push_back(A);
+    DAL->append(A);
+    Modified = true;
+  }
+
+  if (Modified)
+    return DAL;
+
+  delete DAL;
+  return nullptr;
+}