text: //===--- Driver.cpp - Clang GCC Compatible Driver -------------------------===//
  //
  // 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/Driver.h"
  #include "ToolChains/AIX.h"
  #include "ToolChains/AMDGPU.h"
  #include "ToolChains/AMDGPUOpenMP.h"
  #include "ToolChains/AVR.h"
  #include "ToolChains/Ananas.h"
  #include "ToolChains/BareMetal.h"
  #include "ToolChains/Clang.h"
  #include "ToolChains/CloudABI.h"
  #include "ToolChains/Contiki.h"
  #include "ToolChains/CrossWindows.h"
  #include "ToolChains/Cuda.h"
  #include "ToolChains/Darwin.h"
  #include "ToolChains/DragonFly.h"
  #include "ToolChains/FreeBSD.h"
  #include "ToolChains/Fuchsia.h"
  #include "ToolChains/Gnu.h"
  #include "ToolChains/HIPAMD.h"
  #include "ToolChains/HIPSPV.h"
  #include "ToolChains/Haiku.h"
  #include "ToolChains/Hexagon.h"
  #include "ToolChains/Hurd.h"
  #include "ToolChains/Lanai.h"
  #include "ToolChains/Linux.h"
  #include "ToolChains/MSP430.h"
  #include "ToolChains/MSVC.h"
  #include "ToolChains/MinGW.h"
  #include "ToolChains/Minix.h"
  #include "ToolChains/MipsLinux.h"
  #include "ToolChains/Myriad.h"
  #include "ToolChains/NaCl.h"
  #include "ToolChains/NetBSD.h"
  #include "ToolChains/OpenBSD.h"
  #include "ToolChains/PPCFreeBSD.h"
  #include "ToolChains/PPCLinux.h"
  #include "ToolChains/PS4CPU.h"
  #include "ToolChains/RISCVToolchain.h"
  #include "ToolChains/SPIRV.h"
  #include "ToolChains/Solaris.h"
  #include "ToolChains/TCE.h"
  #include "ToolChains/VEToolchain.h"
  #include "ToolChains/WebAssembly.h"
  #include "ToolChains/XCore.h"
  #include "ToolChains/ZOS.h"
  #include "clang/Basic/TargetID.h"
  #include "clang/Basic/Version.h"
  #include "clang/Config/config.h"
  #include "clang/Driver/Action.h"
  #include "clang/Driver/Compilation.h"
  #include "clang/Driver/DriverDiagnostic.h"
  #include "clang/Driver/InputInfo.h"
  #include "clang/Driver/Job.h"
  #include "clang/Driver/Options.h"
  #include "clang/Driver/SanitizerArgs.h"
  #include "clang/Driver/Tool.h"
  #include "clang/Driver/ToolChain.h"
  #include "llvm/ADT/ArrayRef.h"
  #include "llvm/ADT/STLExtras.h"
  #include "llvm/ADT/SmallSet.h"
  #include "llvm/ADT/StringExtras.h"
  #include "llvm/ADT/StringRef.h"
  #include "llvm/ADT/StringSet.h"
  #include "llvm/ADT/StringSwitch.h"
  #include "llvm/Config/llvm-config.h"
  #include "llvm/MC/TargetRegistry.h"
  #include "llvm/Option/Arg.h"
  #include "llvm/Option/ArgList.h"
  #include "llvm/Option/OptSpecifier.h"
  #include "llvm/Option/OptTable.h"
  #include "llvm/Option/Option.h"
  #include "llvm/Support/CommandLine.h"
  #include "llvm/Support/ErrorHandling.h"
  #include "llvm/Support/ExitCodes.h"
  #include "llvm/Support/FileSystem.h"
  #include "llvm/Support/FormatVariadic.h"
  #include "llvm/Support/Host.h"
  #include "llvm/Support/MD5.h"
  #include "llvm/Support/Path.h"
  #include "llvm/Support/PrettyStackTrace.h"
  #include "llvm/Support/Process.h"
  #include "llvm/Support/Program.h"
  #include "llvm/Support/StringSaver.h"
  #include "llvm/Support/VirtualFileSystem.h"
  #include "llvm/Support/raw_ostream.h"
  #include <map>
  #include <memory>
  #include <utility>
  #if LLVM_ON_UNIX
  #include <unistd.h> // getpid
  #endif
  
  using namespace clang::driver;
  using namespace clang;
  using namespace llvm::opt;
  
  static llvm::Optional<llvm::Triple>
  getHIPOffloadTargetTriple(const Driver &D, const ArgList &Args) {
    if (Args.hasArg(options::OPT_offload_EQ)) {
      auto HIPOffloadTargets = Args.getAllArgValues(options::OPT_offload_EQ);
  
      // HIP compilation flow does not support multiple targets for now. We need
      // the HIPActionBuilder (and possibly the CudaActionBuilder{,Base}too) to
      // support multiple tool chains first.
      switch (HIPOffloadTargets.size()) {
      default:
        D.Diag(diag::err_drv_only_one_offload_target_supported_in) << "HIP";
        return llvm::None;
      case 0:
        D.Diag(diag::err_drv_invalid_or_unsupported_offload_target) << "";
        return llvm::None;
      case 1:
        break;
      }
      llvm::Triple TT(HIPOffloadTargets[0]);
      if (TT.getArch() == llvm::Triple::amdgcn &&
          TT.getVendor() == llvm::Triple::AMD &&
          TT.getOS() == llvm::Triple::AMDHSA)
        return TT;
      if (TT.getArch() == llvm::Triple::spirv64 &&
          TT.getVendor() == llvm::Triple::UnknownVendor &&
          TT.getOS() == llvm::Triple::UnknownOS)
        return TT;
      D.Diag(diag::err_drv_invalid_or_unsupported_offload_target)
          << HIPOffloadTargets[0];
      return llvm::None;
    }
  
    static const llvm::Triple T("amdgcn-amd-amdhsa"); // Default HIP triple.
    return T;
  }
  
  // static
  std::string Driver::GetResourcesPath(StringRef BinaryPath,
                                       StringRef CustomResourceDir) {
    // Since the resource directory is embedded in the module hash, it's important
    // that all places that need it call this function, so that they get the
    // exact same string ("a/../b/" and "b/" get different hashes, for example).
  
    // Dir is bin/ or lib/, depending on where BinaryPath is.
    std::string Dir = std::string(llvm::sys::path::parent_path(BinaryPath));
  
    SmallString<128> P(Dir);
    if (CustomResourceDir != "") {
      llvm::sys::path::append(P, CustomResourceDir);
    } else {
      // On Windows, libclang.dll is in bin/.
      // On non-Windows, libclang.so/.dylib is in lib/.
      // With a static-library build of libclang, LibClangPath will contain the
      // path of the embedding binary, which for LLVM binaries will be in bin/.
      // ../lib gets us to lib/ in both cases.
      P = llvm::sys::path::parent_path(Dir);
      llvm::sys::path::append(P, Twine("lib") + CLANG_LIBDIR_SUFFIX, "clang",
                              CLANG_VERSION_STRING);
    }
  
    return std::string(P.str());
  }
  
  Driver::Driver(StringRef ClangExecutable, StringRef TargetTriple,
                 DiagnosticsEngine &Diags, std::string Title,
                 IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS)
      : Diags(Diags), VFS(std::move(VFS)), Mode(GCCMode),
        SaveTemps(SaveTempsNone), BitcodeEmbed(EmbedNone), LTOMode(LTOK_None),
        ClangExecutable(ClangExecutable), SysRoot(DEFAULT_SYSROOT),
        DriverTitle(Title), CCCPrintBindings(false), CCPrintOptions(false),
        CCPrintHeaders(false), CCLogDiagnostics(false), CCGenDiagnostics(false),
        CCPrintProcessStats(false), TargetTriple(TargetTriple), Saver(Alloc),
        CheckInputsExist(true), GenReproducer(false),
        SuppressMissingInputWarning(false) {
    // Provide a sane fallback if no VFS is specified.
    if (!this->VFS)
      this->VFS = llvm::vfs::getRealFileSystem();
  
    Name = std::string(llvm::sys::path::filename(ClangExecutable));
    Dir = std::string(llvm::sys::path::parent_path(ClangExecutable));
    InstalledDir = Dir; // Provide a sensible default installed dir.
  
    if ((!SysRoot.empty()) && llvm::sys::path::is_relative(SysRoot)) {
      // Prepend InstalledDir if SysRoot is relative
      SmallString<128> P(InstalledDir);
      llvm::sys::path::append(P, SysRoot);
      SysRoot = std::string(P);
    }
  
  #if defined(CLANG_CONFIG_FILE_SYSTEM_DIR)
    SystemConfigDir = CLANG_CONFIG_FILE_SYSTEM_DIR;
  #endif
  #if defined(CLANG_CONFIG_FILE_USER_DIR)
    UserConfigDir = CLANG_CONFIG_FILE_USER_DIR;
  #endif
  
    // Compute the path to the resource directory.
    ResourceDir = GetResourcesPath(ClangExecutable, CLANG_RESOURCE_DIR);
  }
  
  void Driver::setDriverMode(StringRef Value) {
    static const std::string OptName =
        getOpts().getOption(options::OPT_driver_mode).getPrefixedName();
    if (auto M = llvm::StringSwitch<llvm::Optional<DriverMode>>(Value)
                     .Case("gcc", GCCMode)
                     .Case("g++", GXXMode)
                     .Case("cpp", CPPMode)
                     .Case("cl", CLMode)
                     .Case("flang", FlangMode)
                     .Default(None))
      Mode = *M;
    else
      Diag(diag::err_drv_unsupported_option_argument) << OptName << Value;
  }
  
  InputArgList Driver::ParseArgStrings(ArrayRef<const char *> ArgStrings,
                                       bool IsClCompatMode,
                                       bool &ContainsError) {
    llvm::PrettyStackTraceString CrashInfo("Command line argument parsing");
    ContainsError = false;
  
    unsigned IncludedFlagsBitmask;
    unsigned ExcludedFlagsBitmask;
    std::tie(IncludedFlagsBitmask, ExcludedFlagsBitmask) =
        getIncludeExcludeOptionFlagMasks(IsClCompatMode);
  
    // Make sure that Flang-only options don't pollute the Clang output
    // TODO: Make sure that Clang-only options don't pollute Flang output
    if (!IsFlangMode())
      ExcludedFlagsBitmask |= options::FlangOnlyOption;
  
    unsigned MissingArgIndex, MissingArgCount;
    InputArgList Args =
        getOpts().ParseArgs(ArgStrings, MissingArgIndex, MissingArgCount,
                            IncludedFlagsBitmask, ExcludedFlagsBitmask);
  
    // Check for missing argument error.
    if (MissingArgCount) {
      Diag(diag::err_drv_missing_argument)
          << Args.getArgString(MissingArgIndex) << MissingArgCount;
      ContainsError |=
          Diags.getDiagnosticLevel(diag::err_drv_missing_argument,
                                   SourceLocation()) > DiagnosticsEngine::Warning;
    }
  
    // Check for unsupported options.
    for (const Arg *A : Args) {
      if (A->getOption().hasFlag(options::Unsupported)) {
        unsigned DiagID;
        auto ArgString = A->getAsString(Args);
        std::string Nearest;
        if (getOpts().findNearest(
              ArgString, Nearest, IncludedFlagsBitmask,
              ExcludedFlagsBitmask | options::Unsupported) > 1) {
          DiagID = diag::err_drv_unsupported_opt;
          Diag(DiagID) << ArgString;
        } else {
          DiagID = diag::err_drv_unsupported_opt_with_suggestion;
          Diag(DiagID) << ArgString << Nearest;
        }
        ContainsError |= Diags.getDiagnosticLevel(DiagID, SourceLocation()) >
                         DiagnosticsEngine::Warning;
        continue;
      }
  
      // Warn about -mcpu= without an argument.
      if (A->getOption().matches(options::OPT_mcpu_EQ) && A->containsValue("")) {
        Diag(diag::warn_drv_empty_joined_argument) << A->getAsString(Args);
        ContainsError |= Diags.getDiagnosticLevel(
                             diag::warn_drv_empty_joined_argument,
                             SourceLocation()) > DiagnosticsEngine::Warning;
      }
    }
  
    for (const Arg *A : Args.filtered(options::OPT_UNKNOWN)) {
      unsigned DiagID;
      auto ArgString = A->getAsString(Args);
      std::string Nearest;
      if (getOpts().findNearest(
            ArgString, Nearest, IncludedFlagsBitmask, ExcludedFlagsBitmask) > 1) {
        DiagID = IsCLMode() ? diag::warn_drv_unknown_argument_clang_cl
                            : diag::err_drv_unknown_argument;
        Diags.Report(DiagID) << ArgString;
      } else {
        DiagID = IsCLMode()
                     ? diag::warn_drv_unknown_argument_clang_cl_with_suggestion
                     : diag::err_drv_unknown_argument_with_suggestion;
        Diags.Report(DiagID) << ArgString << Nearest;
      }
      ContainsError |= Diags.getDiagnosticLevel(DiagID, SourceLocation()) >
                       DiagnosticsEngine::Warning;
    }
  
    return Args;
  }
  
  // Determine which compilation mode we are in. We look for options which
  // affect the phase, starting with the earliest phases, and record which
  // option we used to determine the final phase.
  phases::ID Driver::getFinalPhase(const DerivedArgList &DAL,
                                   Arg **FinalPhaseArg) const {
    Arg *PhaseArg = nullptr;
    phases::ID FinalPhase;
  
    // -{E,EP,P,M,MM} only run the preprocessor.
    if (CCCIsCPP() || (PhaseArg = DAL.getLastArg(options::OPT_E)) ||
        (PhaseArg = DAL.getLastArg(options::OPT__SLASH_EP)) ||
        (PhaseArg = DAL.getLastArg(options::OPT_M, options::OPT_MM)) ||
        (PhaseArg = DAL.getLastArg(options::OPT__SLASH_P)) ||
        CCGenDiagnostics) {
      FinalPhase = phases::Preprocess;
  
    // --precompile only runs up to precompilation.
    } else if ((PhaseArg = DAL.getLastArg(options::OPT__precompile))) {
      FinalPhase = phases::Precompile;
  
    // -{fsyntax-only,-analyze,emit-ast} only run up to the compiler.
    } else if ((PhaseArg = DAL.getLastArg(options::OPT_fsyntax_only)) ||
               (PhaseArg = DAL.getLastArg(options::OPT_print_supported_cpus)) ||
               (PhaseArg = DAL.getLastArg(options::OPT_module_file_info)) ||
               (PhaseArg = DAL.getLastArg(options::OPT_verify_pch)) ||
               (PhaseArg = DAL.getLastArg(options::OPT_rewrite_objc)) ||
               (PhaseArg = DAL.getLastArg(options::OPT_rewrite_legacy_objc)) ||
               (PhaseArg = DAL.getLastArg(options::OPT__migrate)) ||
               (PhaseArg = DAL.getLastArg(options::OPT__analyze)) ||
               (PhaseArg = DAL.getLastArg(options::OPT_emit_ast))) {
      FinalPhase = phases::Compile;
  
    // -S only runs up to the backend.
    } else if ((PhaseArg = DAL.getLastArg(options::OPT_S))) {
      FinalPhase = phases::Backend;
  
    // -c compilation only runs up to the assembler.
    } else if ((PhaseArg = DAL.getLastArg(options::OPT_c))) {
      FinalPhase = phases::Assemble;
  
    } else if ((PhaseArg = DAL.getLastArg(options::OPT_emit_interface_stubs))) {
      FinalPhase = phases::IfsMerge;
  
    // Otherwise do everything.
    } else
      FinalPhase = phases::Link;
  
    if (FinalPhaseArg)
      *FinalPhaseArg = PhaseArg;
  
    return FinalPhase;
  }
  
  static Arg *MakeInputArg(DerivedArgList &Args, const OptTable &Opts,
                           StringRef Value, bool Claim = true) {
    Arg *A = new Arg(Opts.getOption(options::OPT_INPUT), Value,
                     Args.getBaseArgs().MakeIndex(Value), Value.data());
    Args.AddSynthesizedArg(A);
    if (Claim)
      A->claim();
    return A;
  }
  
  DerivedArgList *Driver::TranslateInputArgs(const InputArgList &Args) const {
    const llvm::opt::OptTable &Opts = getOpts();
    DerivedArgList *DAL = new DerivedArgList(Args);
  
    bool HasNostdlib = Args.hasArg(options::OPT_nostdlib);
    bool HasNostdlibxx = Args.hasArg(options::OPT_nostdlibxx);
    bool HasNodefaultlib = Args.hasArg(options::OPT_nodefaultlibs);
    bool IgnoreUnused = false;
    for (Arg *A : Args) {
      if (IgnoreUnused)
        A->claim();
  
      if (A->getOption().matches(options::OPT_start_no_unused_arguments)) {
        IgnoreUnused = true;
        continue;
      }
      if (A->getOption().matches(options::OPT_end_no_unused_arguments)) {
        IgnoreUnused = false;
        continue;
      }
  
      // Unfortunately, we have to parse some forwarding options (-Xassembler,
      // -Xlinker, -Xpreprocessor) because we either integrate their functionality
      // (assembler and preprocessor), or bypass a previous driver ('collect2').
  
      // Rewrite linker options, to replace --no-demangle with a custom internal
      // option.
      if ((A->getOption().matches(options::OPT_Wl_COMMA) ||
           A->getOption().matches(options::OPT_Xlinker)) &&
          A->containsValue("--no-demangle")) {
        // Add the rewritten no-demangle argument.
        DAL->AddFlagArg(A, Opts.getOption(options::OPT_Z_Xlinker__no_demangle));
  
        // Add the remaining values as Xlinker arguments.
        for (StringRef Val : A->getValues())
          if (Val != "--no-demangle")
            DAL->AddSeparateArg(A, Opts.getOption(options::OPT_Xlinker), Val);
  
        continue;
      }
  
      // Rewrite preprocessor options, to replace -Wp,-MD,FOO which is used by
      // some build systems. We don't try to be complete here because we don't
      // care to encourage this usage model.
      if (A->getOption().matches(options::OPT_Wp_COMMA) &&
          (A->getValue(0) == StringRef("-MD") ||
           A->getValue(0) == StringRef("-MMD"))) {
        // Rewrite to -MD/-MMD along with -MF.
        if (A->getValue(0) == StringRef("-MD"))
          DAL->AddFlagArg(A, Opts.getOption(options::OPT_MD));
        else
          DAL->AddFlagArg(A, Opts.getOption(options::OPT_MMD));
        if (A->getNumValues() == 2)
          DAL->AddSeparateArg(A, Opts.getOption(options::OPT_MF), A->getValue(1));
        continue;
      }
  
      // Rewrite reserved library names.
      if (A->getOption().matches(options::OPT_l)) {
        StringRef Value = A->getValue();
  
        // Rewrite unless -nostdlib is present.
        if (!HasNostdlib && !HasNodefaultlib && !HasNostdlibxx &&
            Value == "stdc++") {
          DAL->AddFlagArg(A, Opts.getOption(options::OPT_Z_reserved_lib_stdcxx));
          continue;
        }
  
        // Rewrite unconditionally.
        if (Value == "cc_kext") {
          DAL->AddFlagArg(A, Opts.getOption(options::OPT_Z_reserved_lib_cckext));
          continue;
        }
      }
  
      // Pick up inputs via the -- option.
      if (A->getOption().matches(options::OPT__DASH_DASH)) {
        A->claim();
        for (StringRef Val : A->getValues())
          DAL->append(MakeInputArg(*DAL, Opts, Val, false));
        continue;
      }
  
      DAL->append(A);
    }
  
    // Enforce -static if -miamcu is present.
    if (Args.hasFlag(options::OPT_miamcu, options::OPT_mno_iamcu, false))
      DAL->AddFlagArg(nullptr, Opts.getOption(options::OPT_static));
  
  // Add a default value of -mlinker-version=, if one was given and the user
  // didn't specify one.
  #if defined(HOST_LINK_VERSION)
    if (!Args.hasArg(options::OPT_mlinker_version_EQ) &&
        strlen(HOST_LINK_VERSION) > 0) {
      DAL->AddJoinedArg(0, Opts.getOption(options::OPT_mlinker_version_EQ),
                        HOST_LINK_VERSION);
      DAL->getLastArg(options::OPT_mlinker_version_EQ)->claim();
    }
  #endif
  
    return DAL;
  }
  
  /// Compute target triple from args.
  ///
  /// This routine provides the logic to compute a target triple from various
  /// args passed to the driver and the default triple string.
  static llvm::Triple computeTargetTriple(const Driver &D,
                                          StringRef TargetTriple,
                                          const ArgList &Args,
                                          StringRef DarwinArchName = "") {
    // FIXME: Already done in Compilation *Driver::BuildCompilation
    if (const Arg *A = Args.getLastArg(options::OPT_target))
      TargetTriple = A->getValue();
  
    llvm::Triple Target(llvm::Triple::normalize(TargetTriple));
  
    // GNU/Hurd's triples should have been -hurd-gnu*, but were historically made
    // -gnu* only, and we can not change this, so we have to detect that case as
    // being the Hurd OS.
    if (TargetTriple.contains("-unknown-gnu") || TargetTriple.contains("-pc-gnu"))
      Target.setOSName("hurd");
  
    // Handle Apple-specific options available here.
    if (Target.isOSBinFormatMachO()) {
      // If an explicit Darwin arch name is given, that trumps all.
      if (!DarwinArchName.empty()) {
        tools::darwin::setTripleTypeForMachOArchName(Target, DarwinArchName);
        return Target;
      }
  
      // Handle the Darwin '-arch' flag.
      if (Arg *A = Args.getLastArg(options::OPT_arch)) {
        StringRef ArchName = A->getValue();
        tools::darwin::setTripleTypeForMachOArchName(Target, ArchName);
      }
    }
  
    // Handle pseudo-target flags '-mlittle-endian'/'-EL' and
    // '-mbig-endian'/'-EB'.
    if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
                                 options::OPT_mbig_endian)) {
      if (A->getOption().matches(options::OPT_mlittle_endian)) {
        llvm::Triple LE = Target.getLittleEndianArchVariant();
        if (LE.getArch() != llvm::Triple::UnknownArch)
          Target = std::move(LE);
      } else {
        llvm::Triple BE = Target.getBigEndianArchVariant();
        if (BE.getArch() != llvm::Triple::UnknownArch)
          Target = std::move(BE);
      }
    }
  
    // Skip further flag support on OSes which don't support '-m32' or '-m64'.
    if (Target.getArch() == llvm::Triple::tce ||
        Target.getOS() == llvm::Triple::Minix)
      return Target;
  
    // On AIX, the env OBJECT_MODE may affect the resulting arch variant.
    if (Target.isOSAIX()) {
      if (Optional<std::string> ObjectModeValue =
              llvm::sys::Process::GetEnv("OBJECT_MODE")) {
        StringRef ObjectMode = *ObjectModeValue;
        llvm::Triple::ArchType AT = llvm::Triple::UnknownArch;
  
        if (ObjectMode.equals("64")) {
          AT = Target.get64BitArchVariant().getArch();
        } else if (ObjectMode.equals("32")) {
          AT = Target.get32BitArchVariant().getArch();
        } else {
          D.Diag(diag::err_drv_invalid_object_mode) << ObjectMode;
        }
  
        if (AT != llvm::Triple::UnknownArch && AT != Target.getArch())
          Target.setArch(AT);
      }
    }
  
    // Handle pseudo-target flags '-m64', '-mx32', '-m32' and '-m16'.
    Arg *A = Args.getLastArg(options::OPT_m64, options::OPT_mx32,
                             options::OPT_m32, options::OPT_m16);
    if (A) {
      llvm::Triple::ArchType AT = llvm::Triple::UnknownArch;
  
      if (A->getOption().matches(options::OPT_m64)) {
        AT = Target.get64BitArchVariant().getArch();
        if (Target.getEnvironment() == llvm::Triple::GNUX32)
          Target.setEnvironment(llvm::Triple::GNU);
        else if (Target.getEnvironment() == llvm::Triple::MuslX32)
          Target.setEnvironment(llvm::Triple::Musl);
      } else if (A->getOption().matches(options::OPT_mx32) &&
                 Target.get64BitArchVariant().getArch() == llvm::Triple::x86_64) {
        AT = llvm::Triple::x86_64;
        if (Target.getEnvironment() == llvm::Triple::Musl)
          Target.setEnvironment(llvm::Triple::MuslX32);
        else
          Target.setEnvironment(llvm::Triple::GNUX32);
      } else if (A->getOption().matches(options::OPT_m32)) {
        AT = Target.get32BitArchVariant().getArch();
        if (Target.getEnvironment() == llvm::Triple::GNUX32)
          Target.setEnvironment(llvm::Triple::GNU);
        else if (Target.getEnvironment() == llvm::Triple::MuslX32)
          Target.setEnvironment(llvm::Triple::Musl);
      } else if (A->getOption().matches(options::OPT_m16) &&
                 Target.get32BitArchVariant().getArch() == llvm::Triple::x86) {
        AT = llvm::Triple::x86;
        Target.setEnvironment(llvm::Triple::CODE16);
      }
  
      if (AT != llvm::Triple::UnknownArch && AT != Target.getArch()) {
        Target.setArch(AT);
        if (Target.isWindowsGNUEnvironment())
          toolchains::MinGW::fixTripleArch(D, Target, Args);
      }
    }
  
    // Handle -miamcu flag.
    if (Args.hasFlag(options::OPT_miamcu, options::OPT_mno_iamcu, false)) {
      if (Target.get32BitArchVariant().getArch() != llvm::Triple::x86)
        D.Diag(diag::err_drv_unsupported_opt_for_target) << "-miamcu"
                                                         << Target.str();
  
      if (A && !A->getOption().matches(options::OPT_m32))
        D.Diag(diag::err_drv_argument_not_allowed_with)
            << "-miamcu" << A->getBaseArg().getAsString(Args);
  
      Target.setArch(llvm::Triple::x86);
      Target.setArchName("i586");
      Target.setEnvironment(llvm::Triple::UnknownEnvironment);
      Target.setEnvironmentName("");
      Target.setOS(llvm::Triple::ELFIAMCU);
      Target.setVendor(llvm::Triple::UnknownVendor);
      Target.setVendorName("intel");
    }
  
    // If target is MIPS adjust the target triple
    // accordingly to provided ABI name.
    A = Args.getLastArg(options::OPT_mabi_EQ);
    if (A && Target.isMIPS()) {
      StringRef ABIName = A->getValue();
      if (ABIName == "32") {
        Target = Target.get32BitArchVariant();
        if (Target.getEnvironment() == llvm::Triple::GNUABI64 ||
            Target.getEnvironment() == llvm::Triple::GNUABIN32)
          Target.setEnvironment(llvm::Triple::GNU);
      } else if (ABIName == "n32") {
        Target = Target.get64BitArchVariant();
        if (Target.getEnvironment() == llvm::Triple::GNU ||
            Target.getEnvironment() == llvm::Triple::GNUABI64)
          Target.setEnvironment(llvm::Triple::GNUABIN32);
      } else if (ABIName == "64") {
        Target = Target.get64BitArchVariant();
        if (Target.getEnvironment() == llvm::Triple::GNU ||
            Target.getEnvironment() == llvm::Triple::GNUABIN32)
          Target.setEnvironment(llvm::Triple::GNUABI64);
      }
    }
  
    // If target is RISC-V adjust the target triple according to
    // provided architecture name
    A = Args.getLastArg(options::OPT_march_EQ);
    if (A && Target.isRISCV()) {
      StringRef ArchName = A->getValue();
      if (ArchName.startswith_insensitive("rv32"))
        Target.setArch(llvm::Triple::riscv32);
      else if (ArchName.startswith_insensitive("rv64"))
        Target.setArch(llvm::Triple::riscv64);
    }
  
    return Target;
  }
  
  // Parse the LTO options and record the type of LTO compilation
  // based on which -f(no-)?lto(=.*)? or -f(no-)?offload-lto(=.*)?
  // option occurs last.
  static driver::LTOKind parseLTOMode(Driver &D, const llvm::opt::ArgList &Args,
                                      OptSpecifier OptEq, OptSpecifier OptNeg) {
    if (!Args.hasFlag(OptEq, OptNeg, false))
      return LTOK_None;
  
    const Arg *A = Args.getLastArg(OptEq);
    StringRef LTOName = A->getValue();
  
    driver::LTOKind LTOMode = llvm::StringSwitch<LTOKind>(LTOName)
                                  .Case("full", LTOK_Full)
                                  .Case("thin", LTOK_Thin)
                                  .Default(LTOK_Unknown);
  
    if (LTOMode == LTOK_Unknown) {
      D.Diag(diag::err_drv_unsupported_option_argument)
          << A->getOption().getName() << A->getValue();
      return LTOK_None;
    }
    return LTOMode;
  }
  
  // Parse the LTO options.
  void Driver::setLTOMode(const llvm::opt::ArgList &Args) {
    LTOMode =
        parseLTOMode(*this, Args, options::OPT_flto_EQ, options::OPT_fno_lto);
  
    OffloadLTOMode = parseLTOMode(*this, Args, options::OPT_foffload_lto_EQ,
                                  options::OPT_fno_offload_lto);
  }
  
  /// Compute the desired OpenMP runtime from the flags provided.
  Driver::OpenMPRuntimeKind Driver::getOpenMPRuntime(const ArgList &Args) const {
    StringRef RuntimeName(CLANG_DEFAULT_OPENMP_RUNTIME);
  
    const Arg *A = Args.getLastArg(options::OPT_fopenmp_EQ);
    if (A)
      RuntimeName = A->getValue();
  
    auto RT = llvm::StringSwitch<OpenMPRuntimeKind>(RuntimeName)
                  .Case("libomp", OMPRT_OMP)
                  .Case("libgomp", OMPRT_GOMP)
                  .Case("libiomp5", OMPRT_IOMP5)
                  .Default(OMPRT_Unknown);
  
    if (RT == OMPRT_Unknown) {
      if (A)
        Diag(diag::err_drv_unsupported_option_argument)
            << A->getOption().getName() << A->getValue();
      else
        // FIXME: We could use a nicer diagnostic here.
        Diag(diag::err_drv_unsupported_opt) << "-fopenmp";
    }
  
    return RT;
  }
  
  void Driver::CreateOffloadingDeviceToolChains(Compilation &C,
                                                InputList &Inputs) {
  
    //
    // CUDA/HIP
    //
    // We need to generate a CUDA/HIP toolchain if any of the inputs has a CUDA
    // or HIP type. However, mixed CUDA/HIP compilation is not supported.
    bool IsCuda =
        llvm::any_of(Inputs, [](std::pair<types::ID, const llvm::opt::Arg *> &I) {
          return types::isCuda(I.first);
        });
    bool IsHIP =
        llvm::any_of(Inputs,
                     [](std::pair<types::ID, const llvm::opt::Arg *> &I) {
                       return types::isHIP(I.first);
                     }) ||
        C.getInputArgs().hasArg(options::OPT_hip_link);
    if (IsCuda && IsHIP) {
      Diag(clang::diag::err_drv_mix_cuda_hip);
      return;
    }
    if (IsCuda) {
      const ToolChain *HostTC = C.getSingleOffloadToolChain<Action::OFK_Host>();
      const llvm::Triple &HostTriple = HostTC->getTriple();
      StringRef DeviceTripleStr;
      auto OFK = Action::OFK_Cuda;
      DeviceTripleStr =
          HostTriple.isArch64Bit() ? "nvptx64-nvidia-cuda" : "nvptx-nvidia-cuda";
      llvm::Triple CudaTriple(DeviceTripleStr);
      // Use the CUDA and host triples as the key into the ToolChains map,
      // because the device toolchain we create depends on both.
      auto &CudaTC = ToolChains[CudaTriple.str() + "/" + HostTriple.str()];
      if (!CudaTC) {
        CudaTC = std::make_unique<toolchains::CudaToolChain>(
            *this, CudaTriple, *HostTC, C.getInputArgs(), OFK);
      }
      C.addOffloadDeviceToolChain(CudaTC.get(), OFK);
    } else if (IsHIP) {
      if (auto *OMPTargetArg =
              C.getInputArgs().getLastArg(options::OPT_fopenmp_targets_EQ)) {
        Diag(clang::diag::err_drv_unsupported_opt_for_language_mode)
            << OMPTargetArg->getSpelling() << "HIP";
        return;
      }
      const ToolChain *HostTC = C.getSingleOffloadToolChain<Action::OFK_Host>();
      auto OFK = Action::OFK_HIP;
      auto HIPTriple = getHIPOffloadTargetTriple(*this, C.getInputArgs());
      if (!HIPTriple)
        return;
      auto *HIPTC = &getOffloadingDeviceToolChain(C.getInputArgs(), *HIPTriple,
                                                  *HostTC, OFK);
      assert(HIPTC && "Could not create offloading device tool chain.");
      C.addOffloadDeviceToolChain(HIPTC, OFK);
    }
  
    //
    // OpenMP
    //
    // We need to generate an OpenMP toolchain if the user specified targets with
    // the -fopenmp-targets option.
    if (Arg *OpenMPTargets =
            C.getInputArgs().getLastArg(options::OPT_fopenmp_targets_EQ)) {
      if (OpenMPTargets->getNumValues()) {
        // We expect that -fopenmp-targets is always used in conjunction with the
        // option -fopenmp specifying a valid runtime with offloading support,
        // i.e. libomp or libiomp.
        bool HasValidOpenMPRuntime = C.getInputArgs().hasFlag(
            options::OPT_fopenmp, options::OPT_fopenmp_EQ,
            options::OPT_fno_openmp, false);
        if (HasValidOpenMPRuntime) {
          OpenMPRuntimeKind OpenMPKind = getOpenMPRuntime(C.getInputArgs());
          HasValidOpenMPRuntime =
              OpenMPKind == OMPRT_OMP || OpenMPKind == OMPRT_IOMP5;
        }
  
        if (HasValidOpenMPRuntime) {
          llvm::StringMap<const char *> FoundNormalizedTriples;
          for (const char *Val : OpenMPTargets->getValues()) {
            llvm::Triple TT(Val);
            std::string NormalizedName = TT.normalize();
  
            // Make sure we don't have a duplicate triple.
            auto Duplicate = FoundNormalizedTriples.find(NormalizedName);
            if (Duplicate != FoundNormalizedTriples.end()) {
              Diag(clang::diag::warn_drv_omp_offload_target_duplicate)
                  << Val << Duplicate->second;
              continue;
            }
  
            // Store the current triple so that we can check for duplicates in the
            // following iterations.
            FoundNormalizedTriples[NormalizedName] = Val;
  
            // If the specified target is invalid, emit a diagnostic.
            if (TT.getArch() == llvm::Triple::UnknownArch)
              Diag(clang::diag::err_drv_invalid_omp_target) << Val;
            else {
              const ToolChain *TC;
              // Device toolchains have to be selected differently. They pair host
              // and device in their implementation.
              if (TT.isNVPTX() || TT.isAMDGCN()) {
                const ToolChain *HostTC =
                    C.getSingleOffloadToolChain<Action::OFK_Host>();
                assert(HostTC && "Host toolchain should be always defined.");
                auto &DeviceTC =
                    ToolChains[TT.str() + "/" + HostTC->getTriple().normalize()];
                if (!DeviceTC) {
                  if (TT.isNVPTX())
                    DeviceTC = std::make_unique<toolchains::CudaToolChain>(
                        *this, TT, *HostTC, C.getInputArgs(), Action::OFK_OpenMP);
                  else if (TT.isAMDGCN())
                    DeviceTC =
                        std::make_unique<toolchains::AMDGPUOpenMPToolChain>(
                            *this, TT, *HostTC, C.getInputArgs());
                  else
                    assert(DeviceTC && "Device toolchain not defined.");
                }
  
                TC = DeviceTC.get();
              } else
                TC = &getToolChain(C.getInputArgs(), TT);
              C.addOffloadDeviceToolChain(TC, Action::OFK_OpenMP);
            }
          }
        } else
          Diag(clang::diag::err_drv_expecting_fopenmp_with_fopenmp_targets);
      } else
        Diag(clang::diag::warn_drv_empty_joined_argument)
            << OpenMPTargets->getAsString(C.getInputArgs());
    }
  
    //
    // TODO: Add support for other offloading programming models here.
    //
  }
  
  /// Looks the given directories for the specified file.
  ///
  /// \param[out] FilePath File path, if the file was found.
  /// \param[in]  Dirs Directories used for the search.
  /// \param[in]  FileName Name of the file to search for.
  /// \return True if file was found.
  ///
  /// Looks for file specified by FileName sequentially in directories specified
  /// by Dirs.
  ///
  static bool searchForFile(SmallVectorImpl<char> &FilePath,
                            ArrayRef<StringRef> Dirs, StringRef FileName) {
    SmallString<128> WPath;
    for (const StringRef &Dir : Dirs) {
      if (Dir.empty())
        continue;
      WPath.clear();
      llvm::sys::path::append(WPath, Dir, FileName);
      llvm::sys::path::native(WPath);
      if (llvm::sys::fs::is_regular_file(WPath)) {
        FilePath = std::move(WPath);
        return true;
      }
    }
    return false;
  }
  
  bool Driver::readConfigFile(StringRef FileName) {
    // Try reading the given file.
    SmallVector<const char *, 32> NewCfgArgs;
    if (!llvm::cl::readConfigFile(FileName, Saver, NewCfgArgs)) {
      Diag(diag::err_drv_cannot_read_config_file) << FileName;
      return true;
    }
  
    // Read options from config file.
    llvm::SmallString<128> CfgFileName(FileName);
    llvm::sys::path::native(CfgFileName);
    ConfigFile = std::string(CfgFileName);
    bool ContainErrors;
    CfgOptions = std::make_unique<InputArgList>(
        ParseArgStrings(NewCfgArgs, IsCLMode(), ContainErrors));
    if (ContainErrors) {
      CfgOptions.reset();
      return true;
    }
  
    if (CfgOptions->hasArg(options::OPT_config)) {
      CfgOptions.reset();
      Diag(diag::err_drv_nested_config_file);
      return true;
    }
  
    // Claim all arguments that come from a configuration file so that the driver
    // does not warn on any that is unused.
    for (Arg *A : *CfgOptions)
      A->claim();
    return false;
  }
  
  bool Driver::loadConfigFile() {
    std::string CfgFileName;
    bool FileSpecifiedExplicitly = false;
  
    // Process options that change search path for config files.
    if (CLOptions) {
      if (CLOptions->hasArg(options::OPT_config_system_dir_EQ)) {
        SmallString<128> CfgDir;
        CfgDir.append(
            CLOptions->getLastArgValue(options::OPT_config_system_dir_EQ));
        if (!CfgDir.empty()) {
          if (llvm::sys::fs::make_absolute(CfgDir).value() != 0)
            SystemConfigDir.clear();
          else
            SystemConfigDir = std::string(CfgDir.begin(), CfgDir.end());
        }
      }
      if (CLOptions->hasArg(options::OPT_config_user_dir_EQ)) {
        SmallString<128> CfgDir;
        CfgDir.append(
            CLOptions->getLastArgValue(options::OPT_config_user_dir_EQ));
        if (!CfgDir.empty()) {
          if (llvm::sys::fs::make_absolute(CfgDir).value() != 0)
            UserConfigDir.clear();
          else
            UserConfigDir = std::string(CfgDir.begin(), CfgDir.end());
        }
      }
    }
  
    // First try to find config file specified in command line.
    if (CLOptions) {
      std::vector<std::string> ConfigFiles =
          CLOptions->getAllArgValues(options::OPT_config);
      if (ConfigFiles.size() > 1) {
        if (!llvm::all_of(ConfigFiles, [ConfigFiles](const std::string &s) {
              return s == ConfigFiles[0];
            })) {
          Diag(diag::err_drv_duplicate_config);
          return true;
        }
      }
  
      if (!ConfigFiles.empty()) {
        CfgFileName = ConfigFiles.front();
        assert(!CfgFileName.empty());
  
        // If argument contains directory separator, treat it as a path to
        // configuration file.
        if (llvm::sys::path::has_parent_path(CfgFileName)) {
          SmallString<128> CfgFilePath;
          if (llvm::sys::path::is_relative(CfgFileName))
            llvm::sys::fs::current_path(CfgFilePath);
          llvm::sys::path::append(CfgFilePath, CfgFileName);
          if (!llvm::sys::fs::is_regular_file(CfgFilePath)) {
            Diag(diag::err_drv_config_file_not_exist) << CfgFilePath;
            return true;
          }
          return readConfigFile(CfgFilePath);
        }
  
        FileSpecifiedExplicitly = true;
      }
    }
  
    // If config file is not specified explicitly, try to deduce configuration
    // from executable name. For instance, an executable 'armv7l-clang' will
    // search for config file 'armv7l-clang.cfg'.
    if (CfgFileName.empty() && !ClangNameParts.TargetPrefix.empty())
      CfgFileName = ClangNameParts.TargetPrefix + '-' + ClangNameParts.ModeSuffix;
  
    if (CfgFileName.empty())
      return false;
  
    // Determine architecture part of the file name, if it is present.
    StringRef CfgFileArch = CfgFileName;
    size_t ArchPrefixLen = CfgFileArch.find('-');
    if (ArchPrefixLen == StringRef::npos)
      ArchPrefixLen = CfgFileArch.size();
    llvm::Triple CfgTriple;
    CfgFileArch = CfgFileArch.take_front(ArchPrefixLen);
    CfgTriple = llvm::Triple(llvm::Triple::normalize(CfgFileArch));
    if (CfgTriple.getArch() == llvm::Triple::ArchType::UnknownArch)
      ArchPrefixLen = 0;
  
    if (!StringRef(CfgFileName).endswith(".cfg"))
      CfgFileName += ".cfg";
  
    // If config file starts with architecture name and command line options
    // redefine architecture (with options like -m32 -LE etc), try finding new
    // config file with that architecture.
    SmallString<128> FixedConfigFile;
    size_t FixedArchPrefixLen = 0;
    if (ArchPrefixLen) {
      // Get architecture name from config file name like 'i386.cfg' or
      // 'armv7l-clang.cfg'.
      // Check if command line options changes effective triple.
      llvm::Triple EffectiveTriple = computeTargetTriple(*this,
                                               CfgTriple.getTriple(), *CLOptions);
      if (CfgTriple.getArch() != EffectiveTriple.getArch()) {
        FixedConfigFile = EffectiveTriple.getArchName();
        FixedArchPrefixLen = FixedConfigFile.size();
        // Append the rest of original file name so that file name transforms
        // like: i386-clang.cfg -> x86_64-clang.cfg.
        if (ArchPrefixLen < CfgFileName.size())
          FixedConfigFile += CfgFileName.substr(ArchPrefixLen);
      }
    }
  
    // Prepare list of directories where config file is searched for.
    StringRef CfgFileSearchDirs[] = {UserConfigDir, SystemConfigDir, Dir};
  
    // Try to find config file. First try file with corrected architecture.
    llvm::SmallString<128> CfgFilePath;
    if (!FixedConfigFile.empty()) {
      if (searchForFile(CfgFilePath, CfgFileSearchDirs, FixedConfigFile))
        return readConfigFile(CfgFilePath);
      // If 'x86_64-clang.cfg' was not found, try 'x86_64.cfg'.
      FixedConfigFile.resize(FixedArchPrefixLen);
      FixedConfigFile.append(".cfg");
      if (searchForFile(CfgFilePath, CfgFileSearchDirs, FixedConfigFile))
        return readConfigFile(CfgFilePath);
    }
  
    // Then try original file name.
    if (searchForFile(CfgFilePath, CfgFileSearchDirs, CfgFileName))
      return readConfigFile(CfgFilePath);
  
    // Finally try removing driver mode part: 'x86_64-clang.cfg' -> 'x86_64.cfg'.
    if (!ClangNameParts.ModeSuffix.empty() &&
        !ClangNameParts.TargetPrefix.empty()) {
      CfgFileName.assign(ClangNameParts.TargetPrefix);
      CfgFileName.append(".cfg");
      if (searchForFile(CfgFilePath, CfgFileSearchDirs, CfgFileName))
        return readConfigFile(CfgFilePath);
    }
  
    // Report error but only if config file was specified explicitly, by option
    // --config. If it was deduced from executable name, it is not an error.
    if (FileSpecifiedExplicitly) {
      Diag(diag::err_drv_config_file_not_found) << CfgFileName;
      for (const StringRef &SearchDir : CfgFileSearchDirs)
        if (!SearchDir.empty())
          Diag(diag::note_drv_config_file_searched_in) << SearchDir;
      return true;
    }
  
    return false;
  }
  
  Compilation *Driver::BuildCompilation(ArrayRef<const char *> ArgList) {
    llvm::PrettyStackTraceString CrashInfo("Compilation construction");
  
    // FIXME: Handle environment options which affect driver behavior, somewhere
    // (client?). GCC_EXEC_PREFIX, LPATH, CC_PRINT_OPTIONS.
  
    // We look for the driver mode option early, because the mode can affect
    // how other options are parsed.
  
    auto DriverMode = getDriverMode(ClangExecutable, ArgList.slice(1));
    if (!DriverMode.empty())
      setDriverMode(DriverMode);
  
    // FIXME: What are we going to do with -V and -b?
  
    // Arguments specified in command line.
    bool ContainsError;
    CLOptions = std::make_unique<InputArgList>(
        ParseArgStrings(ArgList.slice(1), IsCLMode(), ContainsError));
  
    // Try parsing configuration file.
    if (!ContainsError)
      ContainsError = loadConfigFile();
    bool HasConfigFile = !ContainsError && (CfgOptions.get() != nullptr);
  
    // All arguments, from both config file and command line.
    InputArgList Args = std::move(HasConfigFile ? std::move(*CfgOptions)
                                                : std::move(*CLOptions));
  
    // The args for config files or /clang: flags belong to different InputArgList
    // objects than Args. This copies an Arg from one of those other InputArgLists
    // to the ownership of Args.
    auto appendOneArg = [&Args](const Arg *Opt, const Arg *BaseArg) {
      unsigned Index = Args.MakeIndex(Opt->getSpelling());
      Arg *Copy = new llvm::opt::Arg(Opt->getOption(), Args.getArgString(Index),
                                     Index, BaseArg);
      Copy->getValues() = Opt->getValues();
      if (Opt->isClaimed())
        Copy->claim();
      Copy->setOwnsValues(Opt->getOwnsValues());
      Opt->setOwnsValues(false);
      Args.append(Copy);
    };
  
    if (HasConfigFile)
      for (auto *Opt : *CLOptions) {
        if (Opt->getOption().matches(options::OPT_config))
          continue;
        const Arg *BaseArg = &Opt->getBaseArg();
        if (BaseArg == Opt)
          BaseArg = nullptr;
        appendOneArg(Opt, BaseArg);
      }
  
    // In CL mode, look for any pass-through arguments
    if (IsCLMode() && !ContainsError) {
      SmallVector<const char *, 16> CLModePassThroughArgList;
      for (const auto *A : Args.filtered(options::OPT__SLASH_clang)) {
        A->claim();
        CLModePassThroughArgList.push_back(A->getValue());
      }
  
      if (!CLModePassThroughArgList.empty()) {
        // Parse any pass through args using default clang processing rather
        // than clang-cl processing.
        auto CLModePassThroughOptions = std::make_unique<InputArgList>(
            ParseArgStrings(CLModePassThroughArgList, false, ContainsError));
  
        if (!ContainsError)
          for (auto *Opt : *CLModePassThroughOptions) {
            appendOneArg(Opt, nullptr);
          }
      }
    }
  
    // Check for working directory option before accessing any files
    if (Arg *WD = Args.getLastArg(options::OPT_working_directory))
      if (VFS->setCurrentWorkingDirectory(WD->getValue()))
        Diag(diag::err_drv_unable_to_set_working_directory) << WD->getValue();
  
    // FIXME: This stuff needs to go into the Compilation, not the driver.
    bool CCCPrintPhases;
  
    // Silence driver warnings if requested
    Diags.setIgnoreAllWarnings(Args.hasArg(options::OPT_w));
  
    // -canonical-prefixes, -no-canonical-prefixes are used very early in main.
    Args.ClaimAllArgs(options::OPT_canonical_prefixes);
    Args.ClaimAllArgs(options::OPT_no_canonical_prefixes);
  
    // f(no-)integated-cc1 is also used very early in main.
    Args.ClaimAllArgs(options::OPT_fintegrated_cc1);
    Args.ClaimAllArgs(options::OPT_fno_integrated_cc1);
  
    // Ignore -pipe.
    Args.ClaimAllArgs(options::OPT_pipe);
  
    // Extract -ccc args.
    //
    // FIXME: We need to figure out where this behavior should live. Most of it
    // should be outside in the client; the parts that aren't should have proper
    // options, either by introducing new ones or by overloading gcc ones like -V
    // or -b.
    CCCPrintPhases = Args.hasArg(options::OPT_ccc_print_phases);
    CCCPrintBindings = Args.hasArg(options::OPT_ccc_print_bindings);
    if (const Arg *A = Args.getLastArg(options::OPT_ccc_gcc_name))
      CCCGenericGCCName = A->getValue();
    GenReproducer = Args.hasFlag(options::OPT_gen_reproducer,
                                 options::OPT_fno_crash_diagnostics,
                                 !!::getenv("FORCE_CLANG_DIAGNOSTICS_CRASH"));
  
    // Process -fproc-stat-report options.
    if (const Arg *A = Args.getLastArg(options::OPT_fproc_stat_report_EQ)) {
      CCPrintProcessStats = true;
      CCPrintStatReportFilename = A->getValue();
    }
    if (Args.hasArg(options::OPT_fproc_stat_report))
      CCPrintProcessStats = true;
  
    // FIXME: TargetTriple is used by the target-prefixed calls to as/ld
    // and getToolChain is const.
    if (IsCLMode()) {
      // clang-cl targets MSVC-style Win32.
      llvm::Triple T(TargetTriple);
      T.setOS(llvm::Triple::Win32);
      T.setVendor(llvm::Triple::PC);
      T.setEnvironment(llvm::Triple::MSVC);
      T.setObjectFormat(llvm::Triple::COFF);
      TargetTriple = T.str();
    }
    if (const Arg *A = Args.getLastArg(options::OPT_target))
      TargetTriple = A->getValue();
    if (const Arg *A = Args.getLastArg(options::OPT_ccc_install_dir))
      Dir = InstalledDir = A->getValue();
    for (const Arg *A : Args.filtered(options::OPT_B)) {
      A->claim();
      PrefixDirs.push_back(A->getValue(0));
    }
    if (Optional<std::string> CompilerPathValue =
            llvm::sys::Process::GetEnv("COMPILER_PATH")) {
      StringRef CompilerPath = *CompilerPathValue;
      while (!CompilerPath.empty()) {
        std::pair<StringRef, StringRef> Split =
            CompilerPath.split(llvm::sys::EnvPathSeparator);
        PrefixDirs.push_back(std::string(Split.first));
        CompilerPath = Split.second;
      }
    }
    if (const Arg *A = Args.getLastArg(options::OPT__sysroot_EQ))
      SysRoot = A->getValue();
    if (const Arg *A = Args.getLastArg(options::OPT__dyld_prefix_EQ))
      DyldPrefix = A->getValue();
  
    if (const Arg *A = Args.getLastArg(options::OPT_resource_dir))
      ResourceDir = A->getValue();
  
    if (const Arg *A = Args.getLastArg(options::OPT_save_temps_EQ)) {
      SaveTemps = llvm::StringSwitch<SaveTempsMode>(A->getValue())
                      .Case("cwd", SaveTempsCwd)
                      .Case("obj", SaveTempsObj)
                      .Default(SaveTempsCwd);
    }
  
    setLTOMode(Args);
  
    // Process -fembed-bitcode= flags.
    if (Arg *A = Args.getLastArg(options::OPT_fembed_bitcode_EQ)) {
      StringRef Name = A->getValue();
      unsigned Model = llvm::StringSwitch<unsigned>(Name)
          .Case("off", EmbedNone)
          .Case("all", EmbedBitcode)
          .Case("bitcode", EmbedBitcode)
          .Case("marker", EmbedMarker)
          .Default(~0U);
      if (Model == ~0U) {
        Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args)
                                                  << Name;
      } else
        BitcodeEmbed = static_cast<BitcodeEmbedMode>(Model);
    }
  
    std::unique_ptr<llvm::opt::InputArgList> UArgs =
        std::make_unique<InputArgList>(std::move(Args));
  
    // Perform the default argument translations.
    DerivedArgList *TranslatedArgs = TranslateInputArgs(*UArgs);
  
    // Owned by the host.
    const ToolChain &TC = getToolChain(
        *UArgs, computeTargetTriple(*this, TargetTriple, *UArgs));
  
    // The compilation takes ownership of Args.
    Compilation *C = new Compilation(*this, TC, UArgs.release(), TranslatedArgs,
                                     ContainsError);
  
    if (!HandleImmediateArgs(*C))
      return C;
  
    // Construct the list of inputs.
    InputList Inputs;
    BuildInputs(C->getDefaultToolChain(), *TranslatedArgs, Inputs);
  
    // Populate the tool chains for the offloading devices, if any.
    CreateOffloadingDeviceToolChains(*C, Inputs);
  
    // Construct the list of abstract actions to perform for this compilation. On
    // MachO targets this uses the driver-driver and universal actions.
    if (TC.getTriple().isOSBinFormatMachO())
      BuildUniversalActions(*C, C->getDefaultToolChain(), Inputs);
    else
      BuildActions(*C, C->getArgs(), Inputs, C->getActions());
  
    if (CCCPrintPhases) {
      PrintActions(*C);
      return C;
    }
  
    BuildJobs(*C);
  
    return C;
  }
  
  static void printArgList(raw_ostream &OS, const llvm::opt::ArgList &Args) {
    llvm::opt::ArgStringList ASL;
    for (const auto *A : Args) {
      // Use user's original spelling of flags. For example, use
      // `/source-charset:utf-8` instead of `-finput-charset=utf-8` if the user
      // wrote the former.
      while (A->getAlias())
        A = A->getAlias();
      A->render(Args, ASL);
    }
  
    for (auto I = ASL.begin(), E = ASL.end(); I != E; ++I) {
      if (I != ASL.begin())
        OS << ' ';
      llvm::sys::printArg(OS, *I, true);
    }
    OS << '\n';
  }
  
  bool Driver::getCrashDiagnosticFile(StringRef ReproCrashFilename,
                                      SmallString<128> &CrashDiagDir) {
    using namespace llvm::sys;
    assert(llvm::Triple(llvm::sys::getProcessTriple()).isOSDarwin() &&
           "Only knows about .crash files on Darwin");
  
    // The .crash file can be found on at ~/Library/Logs/DiagnosticReports/
    // (or /Library/Logs/DiagnosticReports for root) and has the filename pattern
    // clang-<VERSION>_<YYYY-MM-DD-HHMMSS>_<hostname>.crash.
    path::home_directory(CrashDiagDir);
    if (CrashDiagDir.startswith("/var/root"))
      CrashDiagDir = "/";
    path::append(CrashDiagDir, "Library/Logs/DiagnosticReports");
    int PID =
  #if LLVM_ON_UNIX
        getpid();
  #else
        0;
  #endif
    std::error_code EC;
    fs::file_status FileStatus;
    TimePoint<> LastAccessTime;
    SmallString<128> CrashFilePath;
    // Lookup the .crash files and get the one generated by a subprocess spawned
    // by this driver invocation.
    for (fs::directory_iterator File(CrashDiagDir, EC), FileEnd;
         File != FileEnd && !EC; File.increment(EC)) {
      StringRef FileName = path::filename(File->path());
      if (!FileName.startswith(Name))
        continue;
      if (fs::status(File->path(), FileStatus))
        continue;
      llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> CrashFile =
          llvm::MemoryBuffer::getFile(File->path());
      if (!CrashFile)
        continue;
      // The first line should start with "Process:", otherwise this isn't a real
      // .crash file.
      StringRef Data = CrashFile.get()->getBuffer();
      if (!Data.startswith("Process:"))
        continue;
      // Parse parent process pid line, e.g: "Parent Process: clang-4.0 [79141]"
      size_t ParentProcPos = Data.find("Parent Process:");
      if (ParentProcPos == StringRef::npos)
        continue;
      size_t LineEnd = Data.find_first_of("\n", ParentProcPos);
      if (LineEnd == StringRef::npos)
        continue;
      StringRef ParentProcess = Data.slice(ParentProcPos+15, LineEnd).trim();
      int OpenBracket = -1, CloseBracket = -1;
      for (size_t i = 0, e = ParentProcess.size(); i < e; ++i) {
        if (ParentProcess[i] == '[')
          OpenBracket = i;
        if (ParentProcess[i] == ']')
          CloseBracket = i;
      }
      // Extract the parent process PID from the .crash file and check whether
      // it matches this driver invocation pid.
      int CrashPID;
      if (OpenBracket < 0 || CloseBracket < 0 ||
          ParentProcess.slice(OpenBracket + 1, CloseBracket)
              .getAsInteger(10, CrashPID) || CrashPID != PID) {
        continue;
      }
  
      // Found a .crash file matching the driver pid. To avoid getting an older
      // and misleading crash file, continue looking for the most recent.
      // FIXME: the driver can dispatch multiple cc1 invocations, leading to
      // multiple crashes poiting to the same parent process. Since the driver
      // does not collect pid information for the dispatched invocation there's
      // currently no way to distinguish among them.
      const auto FileAccessTime = FileStatus.getLastModificationTime();
      if (FileAccessTime > LastAccessTime) {
        CrashFilePath.assign(File->path());
        LastAccessTime = FileAccessTime;
      }
    }
  
    // If found, copy it over to the location of other reproducer files.
    if (!CrashFilePath.empty()) {
      EC = fs::copy_file(CrashFilePath, ReproCrashFilename);
      if (EC)
        return false;
      return true;
    }
  
    return false;
  }
  
  // When clang crashes, produce diagnostic information including the fully
  // preprocessed source file(s).  Request that the developer attach the
  // diagnostic information to a bug report.
  void Driver::generateCompilationDiagnostics(
      Compilation &C, const Command &FailingCommand,
      StringRef AdditionalInformation, CompilationDiagnosticReport *Report) {
    if (C.getArgs().hasArg(options::OPT_fno_crash_diagnostics))
      return;
  
    // Don't try to generate diagnostics for link or dsymutil jobs.
    if (FailingCommand.getCreator().isLinkJob() ||
        FailingCommand.getCreator().isDsymutilJob())
      return;
  
    // Print the version of the compiler.
    PrintVersion(C, llvm::errs());
  
    // Suppress driver output and emit preprocessor output to temp file.
    CCGenDiagnostics = true;
  
    // Save the original job command(s).
    Command Cmd = FailingCommand;
  
    // Keep track of whether we produce any errors while trying to produce
    // preprocessed sources.
    DiagnosticErrorTrap Trap(Diags);
  
    // Suppress tool output.
    C.initCompilationForDiagnostics();
  
    // Construct the list of inputs.
    InputList Inputs;
    BuildInputs(C.getDefaultToolChain(), C.getArgs(), Inputs);
  
    for (InputList::iterator it = Inputs.begin(), ie = Inputs.end(); it != ie;) {
      bool IgnoreInput = false;
  
      // Ignore input from stdin or any inputs that cannot be preprocessed.
      // Check type first as not all linker inputs have a value.
      if (types::getPreprocessedType(it->first) == types::TY_INVALID) {
        IgnoreInput = true;
      } else if (!strcmp(it->second->getValue(), "-")) {
        Diag(clang::diag::note_drv_command_failed_diag_msg)
            << "Error generating preprocessed source(s) - "
               "ignoring input from stdin.";
        IgnoreInput = true;
      }
  
      if (IgnoreInput) {
        it = Inputs.erase(it);
        ie = Inputs.end();
      } else {
        ++it;
      }
    }
  
    if (Inputs.empty()) {
      Diag(clang::diag::note_drv_command_failed_diag_msg)
          << "Error generating preprocessed source(s) - "
             "no preprocessable inputs.";
      return;
    }
  
    // Don't attempt to generate preprocessed files if multiple -arch options are
    // used, unless they're all duplicates.
    llvm::StringSet<> ArchNames;
    for (const Arg *A : C.getArgs()) {
      if (A->getOption().matches(options::OPT_arch)) {
        StringRef ArchName = A->getValue();
        ArchNames.insert(ArchName);
      }
    }
    if (ArchNames.size() > 1) {
      Diag(clang::diag::note_drv_command_failed_diag_msg)
          << "Error generating preprocessed source(s) - cannot generate "
             "preprocessed source with multiple -arch options.";
      return;
    }
  
    // Construct the list of abstract actions to perform for this compilation. On
    // Darwin OSes this uses the driver-driver and builds universal actions.
    const ToolChain &TC = C.getDefaultToolChain();
    if (TC.getTriple().isOSBinFormatMachO())
      BuildUniversalActions(C, TC, Inputs);
    else
      BuildActions(C, C.getArgs(), Inputs, C.getActions());
  
    BuildJobs(C);
  
    // If there were errors building the compilation, quit now.
    if (Trap.hasErrorOccurred()) {
      Diag(clang::diag::note_drv_command_failed_diag_msg)
          << "Error generating preprocessed source(s).";
      return;
    }
  
    // Generate preprocessed output.
    SmallVector<std::pair<int, const Command *>, 4> FailingCommands;
    C.ExecuteJobs(C.getJobs(), FailingCommands);
  
    // If any of the preprocessing commands failed, clean up and exit.
    if (!FailingCommands.empty()) {
      Diag(clang::diag::note_drv_command_failed_diag_msg)
          << "Error generating preprocessed source(s).";
      return;
    }
  
    const ArgStringList &TempFiles = C.getTempFiles();
    if (TempFiles.empty()) {
      Diag(clang::diag::note_drv_command_failed_diag_msg)
          << "Error generating preprocessed source(s).";
      return;
    }
  
    Diag(clang::diag::note_drv_command_failed_diag_msg)
        << "\n********************\n\n"
           "PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:\n"
           "Preprocessed source(s) and associated run script(s) are located at:";
  
    SmallString<128> VFS;
    SmallString<128> ReproCrashFilename;
    for (const char *TempFile : TempFiles) {
      Diag(clang::diag::note_drv_command_failed_diag_msg) << TempFile;
      if (Report)
        Report->TemporaryFiles.push_back(TempFile);
      if (ReproCrashFilename.empty()) {
        ReproCrashFilename = TempFile;
        llvm::sys::path::replace_extension(ReproCrashFilename, ".crash");
      }
      if (StringRef(TempFile).endswith(".cache")) {
        // In some cases (modules) we'll dump extra data to help with reproducing
        // the crash into a directory next to the output.
        VFS = llvm::sys::path::filename(TempFile);
        llvm::sys::path::append(VFS, "vfs", "vfs.yaml");
      }
    }
  
    // Assume associated files are based off of the first temporary file.
    CrashReportInfo CrashInfo(TempFiles[0], VFS);
  
    llvm::SmallString<128> Script(CrashInfo.Filename);
    llvm::sys::path::replace_extension(Script, "sh");
    std::error_code EC;
    llvm::raw_fd_ostream ScriptOS(Script, EC, llvm::sys::fs::CD_CreateNew,
                                  llvm::sys::fs::FA_Write,
                                  llvm::sys::fs::OF_Text);
    if (EC) {
      Diag(clang::diag::note_drv_command_failed_diag_msg)
          << "Error generating run script: " << Script << " " << EC.message();
    } else {
      ScriptOS << "# Crash reproducer for " << getClangFullVersion() << "\n"
               << "# Driver args: ";
      printArgList(ScriptOS, C.getInputArgs());
      ScriptOS << "# Original command: ";
      Cmd.Print(ScriptOS, "\n", /*Quote=*/true);
      Cmd.Print(ScriptOS, "\n", /*Quote=*/true, &CrashInfo);
      if (!AdditionalInformation.empty())
        ScriptOS << "\n# Additional information: " << AdditionalInformation
                 << "\n";
      if (Report)
        Report->TemporaryFiles.push_back(std::string(Script.str()));
      Diag(clang::diag::note_drv_command_failed_diag_msg) << Script;
    }
  
    // On darwin, provide information about the .crash diagnostic report.
    if (llvm::Triple(llvm::sys::getProcessTriple()).isOSDarwin()) {
      SmallString<128> CrashDiagDir;
      if (getCrashDiagnosticFile(ReproCrashFilename, CrashDiagDir)) {
        Diag(clang::diag::note_drv_command_failed_diag_msg)
            << ReproCrashFilename.str();
      } else { // Suggest a directory for the user to look for .crash files.
        llvm::sys::path::append(CrashDiagDir, Name);
        CrashDiagDir += "_<YYYY-MM-DD-HHMMSS>_<hostname>.crash";
        Diag(clang::diag::note_drv_command_failed_diag_msg)
            << "Crash backtrace is located in";
        Diag(clang::diag::note_drv_command_failed_diag_msg)
            << CrashDiagDir.str();
        Diag(clang::diag::note_drv_command_failed_diag_msg)
            << "(choose the .crash file that corresponds to your crash)";
      }
    }
  
    for (const auto &A : C.getArgs().filtered(options::OPT_frewrite_map_file_EQ))
      Diag(clang::diag::note_drv_command_failed_diag_msg) << A->getValue();
  
    Diag(clang::diag::note_drv_command_failed_diag_msg)
        << "\n\n********************";
  }
  
  void Driver::setUpResponseFiles(Compilation &C, Command &Cmd) {
    // Since commandLineFitsWithinSystemLimits() may underestimate system's
    // capacity if the tool does not support response files, there is a chance/
    // that things will just work without a response file, so we silently just
    // skip it.
    if (Cmd.getResponseFileSupport().ResponseKind ==
            ResponseFileSupport::RF_None ||
        llvm::sys::commandLineFitsWithinSystemLimits(Cmd.getExecutable(),
                                                     Cmd.getArguments()))
      return;
  
    std::string TmpName = GetTemporaryPath("response", "txt");
    Cmd.setResponseFile(C.addTempFile(C.getArgs().MakeArgString(TmpName)));
  }
  
  int Driver::ExecuteCompilation(
      Compilation &C,
      SmallVectorImpl<std::pair<int, const Command *>> &FailingCommands) {
    // Just print if -### was present.
    if (C.getArgs().hasArg(options::OPT__HASH_HASH_HASH)) {
      C.getJobs().Print(llvm::errs(), "\n", true);
      return 0;
    }
  
    // If there were errors building the compilation, quit now.
    if (Diags.hasErrorOccurred())
      return 1;
  
    // Set up response file names for each command, if necessary.
    for (auto &Job : C.getJobs())
      setUpResponseFiles(C, Job);
  
    C.ExecuteJobs(C.getJobs(), FailingCommands);
  
    // If the command succeeded, we are done.
    if (FailingCommands.empty())
      return 0;
  
    // Otherwise, remove result files and print extra information about abnormal
    // failures.
    int Res = 0;
    for (const auto &CmdPair : FailingCommands) {
      int CommandRes = CmdPair.first;
      const Command *FailingCommand = CmdPair.second;
  
      // Remove result files if we're not saving temps.
      if (!isSaveTempsEnabled()) {
        const JobAction *JA = cast<JobAction>(&FailingCommand->getSource());
        C.CleanupFileMap(C.getResultFiles(), JA, true);
  
        // Failure result files are valid unless we crashed.
        if (CommandRes < 0)
          C.CleanupFileMap(C.getFailureResultFiles(), JA, true);
      }
  
  #if LLVM_ON_UNIX
      // llvm/lib/Support/Unix/Signals.inc will exit with a special return code
      // for SIGPIPE. Do not print diagnostics for this case.
      if (CommandRes == EX_IOERR) {
        Res = CommandRes;
        continue;
      }
  #endif
  
      // Print extra information about abnormal failures, if possible.
      //
      // This is ad-hoc, but we don't want to be excessively noisy. If the result
      // status was 1, assume the command failed normally. In particular, if it
      // was the compiler then assume it gave a reasonable error code. Failures
      // in other tools are less common, and they generally have worse
      // diagnostics, so always print the diagnostic there.
      const Tool &FailingTool = FailingCommand->getCreator();
  
      if (!FailingCommand->getCreator().hasGoodDiagnostics() || CommandRes != 1) {
        // FIXME: See FIXME above regarding result code interpretation.
        if (CommandRes < 0)
          Diag(clang::diag::err_drv_command_signalled)
              << FailingTool.getShortName();
        else
          Diag(clang::diag::err_drv_command_failed)
              << FailingTool.getShortName() << CommandRes;
      }
    }
    return Res;
  }
  
  void Driver::PrintHelp(bool ShowHidden) const {
    unsigned IncludedFlagsBitmask;
    unsigned ExcludedFlagsBitmask;
    std::tie(IncludedFlagsBitmask, ExcludedFlagsBitmask) =
        getIncludeExcludeOptionFlagMasks(IsCLMode());
  
    ExcludedFlagsBitmask |= options::NoDriverOption;
    if (!ShowHidden)
      ExcludedFlagsBitmask |= HelpHidden;
  
    if (IsFlangMode())
      IncludedFlagsBitmask |= options::FlangOption;
    else
      ExcludedFlagsBitmask |= options::FlangOnlyOption;
  
    std::string Usage = llvm::formatv("{0} [options] file...", Name).str();
    getOpts().printHelp(llvm::outs(), Usage.c_str(), DriverTitle.c_str(),
                        IncludedFlagsBitmask, ExcludedFlagsBitmask,
                        /*ShowAllAliases=*/false);
  }
  
  void Driver::PrintVersion(const Compilation &C, raw_ostream &OS) const {
    if (IsFlangMode()) {
      OS << getClangToolFullVersion("flang-new") << '\n';
    } else {
      // FIXME: The following handlers should use a callback mechanism, we don't
      // know what the client would like to do.
      OS << getClangFullVersion() << '\n';
    }
    const ToolChain &TC = C.getDefaultToolChain();
    OS << "Target: " << TC.getTripleString() << '\n';
  
    // Print the threading model.
    if (Arg *A = C.getArgs().getLastArg(options::OPT_mthread_model)) {
      // Don't print if the ToolChain would have barfed on it already
      if (TC.isThreadModelSupported(A->getValue()))
        OS << "Thread model: " << A->getValue();
    } else
      OS << "Thread model: " << TC.getThreadModel();
    OS << '\n';
  
    // Print out the install directory.
    OS << "InstalledDir: " << InstalledDir << '\n';
  
    // If configuration file was used, print its path.
    if (!ConfigFile.empty())
      OS << "Configuration file: " << ConfigFile << '\n';
  }
  
  /// PrintDiagnosticCategories - Implement the --print-diagnostic-categories
  /// option.
  static void PrintDiagnosticCategories(raw_ostream &OS) {
    // Skip the empty category.
    for (unsigned i = 1, max = DiagnosticIDs::getNumberOfCategories(); i != max;
         ++i)
      OS << i << ',' << DiagnosticIDs::getCategoryNameFromID(i) << '\n';
  }
  
  void Driver::HandleAutocompletions(StringRef PassedFlags) const {
    if (PassedFlags == "")
      return;
    // Print out all options that start with a given argument. This is used for
    // shell autocompletion.
    std::vector<std::string> SuggestedCompletions;
    std::vector<std::string> Flags;
  
    unsigned int DisableFlags =
        options::NoDriverOption | options::Unsupported | options::Ignored;
  
    // Make sure that Flang-only options don't pollute the Clang output
    // TODO: Make sure that Clang-only options don't pollute Flang output
    if (!IsFlangMode())
      DisableFlags |= options::FlangOnlyOption;
  
    // Distinguish "--autocomplete=-someflag" and "--autocomplete=-someflag,"
    // because the latter indicates that the user put space before pushing tab
    // which should end up in a file completion.
    const bool HasSpace = PassedFlags.endswith(",");
  
    // Parse PassedFlags by "," as all the command-line flags are passed to this
    // function separated by ","
    StringRef TargetFlags = PassedFlags;
    while (TargetFlags != "") {
      StringRef CurFlag;
      std::tie(CurFlag, TargetFlags) = TargetFlags.split(",");
      Flags.push_back(std::string(CurFlag));
    }
  
    // We want to show cc1-only options only when clang is invoked with -cc1 or
    // -Xclang.
    if (llvm::is_contained(Flags, "-Xclang") || llvm::is_contained(Flags, "-cc1"))
      DisableFlags &= ~options::NoDriverOption;
  
    const llvm::opt::OptTable &Opts = getOpts();
    StringRef Cur;
    Cur = Flags.at(Flags.size() - 1);
    StringRef Prev;
    if (Flags.size() >= 2) {
      Prev = Flags.at(Flags.size() - 2);
      SuggestedCompletions = Opts.suggestValueCompletions(Prev, Cur);
    }
  
    if (SuggestedCompletions.empty())
      SuggestedCompletions = Opts.suggestValueCompletions(Cur, "");
  
    // If Flags were empty, it means the user typed `clang [tab]` where we should
    // list all possible flags. If there was no value completion and the user
    // pressed tab after a space, we should fall back to a file completion.
    // We're printing a newline to be consistent with what we print at the end of
    // this function.
    if (SuggestedCompletions.empty() && HasSpace && !Flags.empty()) {
      llvm::outs() << '\n';
      return;
    }
  
    // When flag ends with '=' and there was no value completion, return empty
    // string and fall back to the file autocompletion.
    if (SuggestedCompletions.empty() && !Cur.endswith("=")) {
      // If the flag is in the form of "--autocomplete=-foo",
      // we were requested to print out all option names that start with "-foo".
      // For example, "--autocomplete=-fsyn" is expanded to "-fsyntax-only".
      SuggestedCompletions = Opts.findByPrefix(Cur, DisableFlags);
  
      // We have to query the -W flags manually as they're not in the OptTable.
      // TODO: Find a good way to add them to OptTable instead and them remove
      // this code.
      for (StringRef S : DiagnosticIDs::getDiagnosticFlags())
        if (S.startswith(Cur))
          SuggestedCompletions.push_back(std::string(S));
    }
  
    // Sort the autocomplete candidates so that shells print them out in a
    // deterministic order. We could sort in any way, but we chose
    // case-insensitive sorting for consistency with the -help option
    // which prints out options in the case-insensitive alphabetical order.
    llvm::sort(SuggestedCompletions, [](StringRef A, StringRef B) {
      if (int X = A.compare_insensitive(B))
        return X < 0;
      return A.compare(B) > 0;
    });
  
    llvm::outs() << llvm::join(SuggestedCompletions, "\n") << '\n';
  }
  
  bool Driver::HandleImmediateArgs(const Compilation &C) {
    // The order these options are handled in gcc is all over the place, but we
    // don't expect inconsistencies w.r.t. that to matter in practice.
  
    if (C.getArgs().hasArg(options::OPT_dumpmachine)) {
      llvm::outs() << C.getDefaultToolChain().getTripleString() << '\n';
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_dumpversion)) {
      // Since -dumpversion is only implemented for pedantic GCC compatibility, we
      // return an answer which matches our definition of __VERSION__.
      llvm::outs() << CLANG_VERSION_STRING << "\n";
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT__print_diagnostic_categories)) {
      PrintDiagnosticCategories(llvm::outs());
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_help) ||
        C.getArgs().hasArg(options::OPT__help_hidden)) {
      PrintHelp(C.getArgs().hasArg(options::OPT__help_hidden));
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT__version)) {
      // Follow gcc behavior and use stdout for --version and stderr for -v.
      PrintVersion(C, llvm::outs());
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_v) ||
        C.getArgs().hasArg(options::OPT__HASH_HASH_HASH) ||
        C.getArgs().hasArg(options::OPT_print_supported_cpus)) {
      PrintVersion(C, llvm::errs());
      SuppressMissingInputWarning = true;
    }
  
    if (C.getArgs().hasArg(options::OPT_v)) {
      if (!SystemConfigDir.empty())
        llvm::errs() << "System configuration file directory: "
                     << SystemConfigDir << "\n";
      if (!UserConfigDir.empty())
        llvm::errs() << "User configuration file directory: "
                     << UserConfigDir << "\n";
    }
  
    const ToolChain &TC = C.getDefaultToolChain();
  
    if (C.getArgs().hasArg(options::OPT_v))
      TC.printVerboseInfo(llvm::errs());
  
    if (C.getArgs().hasArg(options::OPT_print_resource_dir)) {
      llvm::outs() << ResourceDir << '\n';
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_print_search_dirs)) {
      llvm::outs() << "programs: =";
      bool separator = false;
      // Print -B and COMPILER_PATH.
      for (const std::string &Path : PrefixDirs) {
        if (separator)
          llvm::outs() << llvm::sys::EnvPathSeparator;
        llvm::outs() << Path;
        separator = true;
      }
      for (const std::string &Path : TC.getProgramPaths()) {
        if (separator)
          llvm::outs() << llvm::sys::EnvPathSeparator;
        llvm::outs() << Path;
        separator = true;
      }
      llvm::outs() << "\n";
      llvm::outs() << "libraries: =" << ResourceDir;
  
      StringRef sysroot = C.getSysRoot();
  
      for (const std::string &Path : TC.getFilePaths()) {
        // Always print a separator. ResourceDir was the first item shown.
        llvm::outs() << llvm::sys::EnvPathSeparator;
        // Interpretation of leading '=' is needed only for NetBSD.
        if (Path[0] == '=')
          llvm::outs() << sysroot << Path.substr(1);
        else
          llvm::outs() << Path;
      }
      llvm::outs() << "\n";
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_print_runtime_dir)) {
      std::string RuntimePath;
      // Get the first existing path, if any.
      for (auto Path : TC.getRuntimePaths()) {
        if (getVFS().exists(Path)) {
          RuntimePath = Path;
          break;
        }
      }
      if (!RuntimePath.empty())
        llvm::outs() << RuntimePath << '\n';
      else
        llvm::outs() << TC.getCompilerRTPath() << '\n';
      return false;
    }
  
    // FIXME: The following handlers should use a callback mechanism, we don't
    // know what the client would like to do.
    if (Arg *A = C.getArgs().getLastArg(options::OPT_print_file_name_EQ)) {
      llvm::outs() << GetFilePath(A->getValue(), TC) << "\n";
      return false;
    }
  
    if (Arg *A = C.getArgs().getLastArg(options::OPT_print_prog_name_EQ)) {
      StringRef ProgName = A->getValue();
  
      // Null program name cannot have a path.
      if (! ProgName.empty())
        llvm::outs() << GetProgramPath(ProgName, TC);
  
      llvm::outs() << "\n";
      return false;
    }
  
    if (Arg *A = C.getArgs().getLastArg(options::OPT_autocomplete)) {
      StringRef PassedFlags = A->getValue();
      HandleAutocompletions(PassedFlags);
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_print_libgcc_file_name)) {
      ToolChain::RuntimeLibType RLT = TC.GetRuntimeLibType(C.getArgs());
      const llvm::Triple Triple(TC.ComputeEffectiveClangTriple(C.getArgs()));
      RegisterEffectiveTriple TripleRAII(TC, Triple);
      switch (RLT) {
      case ToolChain::RLT_CompilerRT:
        llvm::outs() << TC.getCompilerRT(C.getArgs(), "builtins") << "\n";
        break;
      case ToolChain::RLT_Libgcc:
        llvm::outs() << GetFilePath("libgcc.a", TC) << "\n";
        break;
      }
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_print_multi_lib)) {
      for (const Multilib &Multilib : TC.getMultilibs())
        llvm::outs() << Multilib << "\n";
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_print_multi_directory)) {
      const Multilib &Multilib = TC.getMultilib();
      if (Multilib.gccSuffix().empty())
        llvm::outs() << ".\n";
      else {
        StringRef Suffix(Multilib.gccSuffix());
        assert(Suffix.front() == '/');
        llvm::outs() << Suffix.substr(1) << "\n";
      }
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_print_target_triple)) {
      llvm::outs() << TC.getTripleString() << "\n";
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_print_effective_triple)) {
      const llvm::Triple Triple(TC.ComputeEffectiveClangTriple(C.getArgs()));
      llvm::outs() << Triple.getTriple() << "\n";
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_print_multiarch)) {
      llvm::outs() << TC.getMultiarchTriple(*this, TC.getTriple(), SysRoot)
                   << "\n";
      return false;
    }
  
    if (C.getArgs().hasArg(options::OPT_print_targets)) {
      llvm::TargetRegistry::printRegisteredTargetsForVersion(llvm::outs());
      return false;
    }
  
    return true;
  }
  
  enum {
    TopLevelAction = 0,
    HeadSibAction = 1,
    OtherSibAction = 2,
  };
  
  // Display an action graph human-readably.  Action A is the "sink" node
  // and latest-occuring action. Traversal is in pre-order, visiting the
  // inputs to each action before printing the action itself.
  static unsigned PrintActions1(const Compilation &C, Action *A,
                                std::map<Action *, unsigned> &Ids,
                                Twine Indent = {}, int Kind = TopLevelAction) {
    if (Ids.count(A)) // A was already visited.
      return Ids[A];
  
    std::string str;
    llvm::raw_string_ostream os(str);
  
    auto getSibIndent = [](int K) -> Twine {
      return (K == HeadSibAction) ? "   " : (K == OtherSibAction) ? "|  " : "";
    };
  
    Twine SibIndent = Indent + getSibIndent(Kind);
    int SibKind = HeadSibAction;
    os << Action::getClassName(A->getKind()) << ", ";
    if (InputAction *IA = dyn_cast<InputAction>(A)) {
      os << "\"" << IA->getInputArg().getValue() << "\"";
    } else if (BindArchAction *BIA = dyn_cast<BindArchAction>(A)) {
      os << '"' << BIA->getArchName() << '"' << ", {"
         << PrintActions1(C, *BIA->input_begin(), Ids, SibIndent, SibKind) << "}";
    } else if (OffloadAction *OA = dyn_cast<OffloadAction>(A)) {
      bool IsFirst = true;
      OA->doOnEachDependence(
          [&](Action *A, const ToolChain *TC, const char *BoundArch) {
            assert(TC && "Unknown host toolchain");
            // E.g. for two CUDA device dependences whose bound arch is sm_20 and
            // sm_35 this will generate:
            // "cuda-device" (nvptx64-nvidia-cuda:sm_20) {#ID}, "cuda-device"
            // (nvptx64-nvidia-cuda:sm_35) {#ID}
            if (!IsFirst)
              os << ", ";
            os << '"';
            os << A->getOffloadingKindPrefix();
            os << " (";
            os << TC->getTriple().normalize();
            if (BoundArch)
              os << ":" << BoundArch;
            os << ")";
            os << '"';
            os << " {" << PrintActions1(C, A, Ids, SibIndent, SibKind) << "}";
            IsFirst = false;
            SibKind = OtherSibAction;
          });
    } else {
      const ActionList *AL = &A->getInputs();
  
      if (AL->size()) {
        const char *Prefix = "{";
        for (Action *PreRequisite : *AL) {
          os << Prefix << PrintActions1(C, PreRequisite, Ids, SibIndent, SibKind);
          Prefix = ", ";
          SibKind = OtherSibAction;
        }
        os << "}";
      } else
        os << "{}";
    }
  
    // Append offload info for all options other than the offloading action
    // itself (e.g. (cuda-device, sm_20) or (cuda-host)).
    std::string offload_str;
    llvm::raw_string_ostream offload_os(offload_str);
    if (!isa<OffloadAction>(A)) {
      auto S = A->getOffloadingKindPrefix();
      if (!S.empty()) {
        offload_os << ", (" << S;
        if (A->getOffloadingArch())
          offload_os << ", " << A->getOffloadingArch();
        offload_os << ")";
      }
    }
  
    auto getSelfIndent = [](int K) -> Twine {
      return (K == HeadSibAction) ? "+- " : (K == OtherSibAction) ? "|- " : "";
    };
  
    unsigned Id = Ids.size();
    Ids[A] = Id;
    llvm::errs() << Indent + getSelfIndent(Kind) << Id << ": " << os.str() << ", "
                 << types::getTypeName(A->getType()) << offload_os.str() << "\n";
  
    return Id;
  }
  
  // Print the action graphs in a compilation C.
  // For example "clang -c file1.c file2.c" is composed of two subgraphs.
  void Driver::PrintActions(const Compilation &C) const {
    std::map<Action *, unsigned> Ids;
    for (Action *A : C.getActions())
      PrintActions1(C, A, Ids);
  }
  
  /// Check whether the given input tree contains any compilation or
  /// assembly actions.
  static bool ContainsCompileOrAssembleAction(const Action *A) {
    if (isa<CompileJobAction>(A) || isa<BackendJobAction>(A) ||
        isa<AssembleJobAction>(A))
      return true;
  
    return llvm::any_of(A->inputs(), ContainsCompileOrAssembleAction);
  }
  
  void Driver::BuildUniversalActions(Compilation &C, const ToolChain &TC,
                                     const InputList &BAInputs) const {
    DerivedArgList &Args = C.getArgs();
    ActionList &Actions = C.getActions();
    llvm::PrettyStackTraceString CrashInfo("Building universal build actions");
    // Collect the list of architectures. Duplicates are allowed, but should only
    // be handled once (in the order seen).
    llvm::StringSet<> ArchNames;
    SmallVector<const char *, 4> Archs;
    for (Arg *A : Args) {
      if (A->getOption().matches(options::OPT_arch)) {
        // Validate the option here; we don't save the type here because its
        // particular spelling may participate in other driver choices.
        llvm::Triple::ArchType Arch =
            tools::darwin::getArchTypeForMachOArchName(A->getValue());
        if (Arch == llvm::Triple::UnknownArch) {
          Diag(clang::diag::err_drv_invalid_arch_name) << A->getAsString(Args);
          continue;
        }
  
        A->claim();
        if (ArchNames.insert(A->getValue()).second)
          Archs.push_back(A->getValue());
      }
    }
  
    // When there is no explicit arch for this platform, make sure we still bind
    // the architecture (to the default) so that -Xarch_ is handled correctly.
    if (!Archs.size())
      Archs.push_back(Args.MakeArgString(TC.getDefaultUniversalArchName()));
  
    ActionList SingleActions;
    BuildActions(C, Args, BAInputs, SingleActions);
  
    // Add in arch bindings for every top level action, as well as lipo and
    // dsymutil steps if needed.
    for (Action* Act : SingleActions) {
      // Make sure we can lipo this kind of output. If not (and it is an actual
      // output) then we disallow, since we can't create an output file with the
      // right name without overwriting it. We could remove this oddity by just
      // changing the output names to include the arch, which would also fix
      // -save-temps. Compatibility wins for now.
  
      if (Archs.size() > 1 && !types::canLipoType(Act->getType()))
        Diag(clang::diag::err_drv_invalid_output_with_multiple_archs)
            << types::getTypeName(Act->getType());
  
      ActionList Inputs;
      for (unsigned i = 0, e = Archs.size(); i != e; ++i)
        Inputs.push_back(C.MakeAction<BindArchAction>(Act, Archs[i]));
  
      // Lipo if necessary, we do it this way because we need to set the arch flag
      // so that -Xarch_ gets overwritten.
      if (Inputs.size() == 1 || Act->getType() == types::TY_Nothing)
        Actions.append(Inputs.begin(), Inputs.end());
      else
        Actions.push_back(C.MakeAction<LipoJobAction>(Inputs, Act->getType()));
  
      // Handle debug info queries.
      Arg *A = Args.getLastArg(options::OPT_g_Group);
      bool enablesDebugInfo = A && !A->getOption().matches(options::OPT_g0) &&
                              !A->getOption().matches(options::OPT_gstabs);
      if ((enablesDebugInfo || willEmitRemarks(Args)) &&
          ContainsCompileOrAssembleAction(Actions.back())) {
  
        // Add a 'dsymutil' step if necessary, when debug info is enabled and we
        // have a compile input. We need to run 'dsymutil' ourselves in such cases
        // because the debug info will refer to a temporary object file which
        // will be removed at the end of the compilation process.
        if (Act->getType() == types::TY_Image) {
          ActionList Inputs;
          Inputs.push_back(Actions.back());
          Actions.pop_back();
          Actions.push_back(
              C.MakeAction<DsymutilJobAction>(Inputs, types::TY_dSYM));
        }
  
        // Verify the debug info output.
        if (Args.hasArg(options::OPT_verify_debug_info)) {
          Action* LastAction = Actions.back();
          Actions.pop_back();
          Actions.push_back(C.MakeAction<VerifyDebugInfoJobAction>(
              LastAction, types::TY_Nothing));
        }
      }
    }
  }
  
  bool Driver::DiagnoseInputExistence(const DerivedArgList &Args, StringRef Value,
                                      types::ID Ty, bool TypoCorrect) const {
    if (!getCheckInputsExist())
      return true;
  
    // stdin always exists.
    if (Value == "-")
      return true;
  
    if (getVFS().exists(Value))
      return true;
  
    if (TypoCorrect) {
      // Check if the filename is a typo for an option flag. OptTable thinks
      // that all args that are not known options and that start with / are
      // filenames, but e.g. `/diagnostic:caret` is more likely a typo for
      // the option `/diagnostics:caret` than a reference to a file in the root
      // directory.
      unsigned IncludedFlagsBitmask;
      unsigned ExcludedFlagsBitmask;
      std::tie(IncludedFlagsBitmask, ExcludedFlagsBitmask) =
          getIncludeExcludeOptionFlagMasks(IsCLMode());
      std::string Nearest;
      if (getOpts().findNearest(Value, Nearest, IncludedFlagsBitmask,
                                ExcludedFlagsBitmask) <= 1) {
        Diag(clang::diag::err_drv_no_such_file_with_suggestion)
            << Value << Nearest;
        return false;
      }
    }
  
    // In CL mode, don't error on apparently non-existent linker inputs, because
    // they can be influenced by linker flags the clang driver might not
    // understand.
    // Examples:
    // - `clang-cl main.cc ole32.lib` in a a non-MSVC shell will make the driver
    //   module look for an MSVC installation in the registry. (We could ask
    //   the MSVCToolChain object if it can find `ole32.lib`, but the logic to
    //   look in the registry might move into lld-link in the future so that
    //   lld-link invocations in non-MSVC shells just work too.)
    // - `clang-cl ... /link ...` can pass arbitrary flags to the linker,
    //   including /libpath:, which is used to find .lib and .obj files.
    // So do not diagnose this on the driver level. Rely on the linker diagnosing
    // it. (If we don't end up invoking the linker, this means we'll emit a
    // "'linker' input unused [-Wunused-command-line-argument]" warning instead
    // of an error.)
    //
    // Only do this skip after the typo correction step above. `/Brepo` is treated
    // as TY_Object, but it's clearly a typo for `/Brepro`. It seems fine to emit
    // an error if we have a flag that's within an edit distance of 1 from a
    // flag. (Users can use `-Wl,` or `/linker` to launder the flag past the
    // driver in the unlikely case they run into this.)
    //
    // Don't do this for inputs that start with a '/', else we'd pass options
    // like /libpath: through to the linker silently.
    //
    // Emitting an error for linker inputs can also cause incorrect diagnostics
    // with the gcc driver. The command
    //     clang -fuse-ld=lld -Wl,--chroot,some/dir /file.o
    // will make lld look for some/dir/file.o, while we will diagnose here that
    // `/file.o` does not exist. However, configure scripts check if
    // `clang /GR-` compiles without error to see if the compiler is cl.exe,
    // so we can't downgrade diagnostics for `/GR-` from an error to a warning
    // in cc mode. (We can in cl mode because cl.exe itself only warns on
    // unknown flags.)
    if (IsCLMode() && Ty == types::TY_Object && !Value.startswith("/"))
      return true;
  
    Diag(clang::diag::err_drv_no_such_file) << Value;
    return false;
  }
  
  // Construct a the list of inputs and their types.
  void Driver::BuildInputs(const ToolChain &TC, DerivedArgList &Args,
                           InputList &Inputs) const {
    const llvm::opt::OptTable &Opts = getOpts();
    // Track the current user specified (-x) input. We also explicitly track the
    // argument used to set the type; we only want to claim the type when we
    // actually use it, so we warn about unused -x arguments.
    types::ID InputType = types::TY_Nothing;
    Arg *InputTypeArg = nullptr;
  
    // The last /TC or /TP option sets the input type to C or C++ globally.
    if (Arg *TCTP = Args.getLastArgNoClaim(options::OPT__SLASH_TC,
                                           options::OPT__SLASH_TP)) {
      InputTypeArg = TCTP;
      InputType = TCTP->getOption().matches(options::OPT__SLASH_TC)
                      ? types::TY_C
                      : types::TY_CXX;
  
      Arg *Previous = nullptr;
      bool ShowNote = false;
      for (Arg *A :
           Args.filtered(options::OPT__SLASH_TC, options::OPT__SLASH_TP)) {
        if (Previous) {
          Diag(clang::diag::warn_drv_overriding_flag_option)
            << Previous->getSpelling() << A->getSpelling();
          ShowNote = true;
        }
        Previous = A;
      }
      if (ShowNote)
        Diag(clang::diag::note_drv_t_option_is_global);
  
      // No driver mode exposes -x and /TC or /TP; we don't support mixing them.
      assert(!Args.hasArg(options::OPT_x) && "-x and /TC or /TP is not allowed");
    }
  
    for (Arg *A : Args) {
      if (A->getOption().getKind() == Option::InputClass) {
        const char *Value = A->getValue();
        types::ID Ty = types::TY_INVALID;
  
        // Infer the input type if necessary.
        if (InputType == types::TY_Nothing) {
          // If there was an explicit arg for this, claim it.
          if (InputTypeArg)
            InputTypeArg->claim();
  
          // stdin must be handled specially.
          if (memcmp(Value, "-", 2) == 0) {
            if (IsFlangMode()) {
              Ty = types::TY_Fortran;
            } else {
              // If running with -E, treat as a C input (this changes the
              // builtin macros, for example). This may be overridden by -ObjC
              // below.
              //
              // Otherwise emit an error but still use a valid type to avoid
              // spurious errors (e.g., no inputs).
              assert(!CCGenDiagnostics && "stdin produces no crash reproducer");
              if (!Args.hasArgNoClaim(options::OPT_E) && !CCCIsCPP())
                Diag(IsCLMode() ? clang::diag::err_drv_unknown_stdin_type_clang_cl
                                : clang::diag::err_drv_unknown_stdin_type);
              Ty = types::TY_C;
            }
          } else {
            // Otherwise lookup by extension.
            // Fallback is C if invoked as C preprocessor, C++ if invoked with
            // clang-cl /E, or Object otherwise.
            // We use a host hook here because Darwin at least has its own
            // idea of what .s is.
            if (const char *Ext = strrchr(Value, '.'))
              Ty = TC.LookupTypeForExtension(Ext + 1);
  
            if (Ty == types::TY_INVALID) {
              if (IsCLMode() && (Args.hasArgNoClaim(options::OPT_E) || CCGenDiagnostics))
                Ty = types::TY_CXX;
              else if (CCCIsCPP() || CCGenDiagnostics)
                Ty = types::TY_C;
              else
                Ty = types::TY_Object;
            }
  
            // If the driver is invoked as C++ compiler (like clang++ or c++) it
            // should autodetect some input files as C++ for g++ compatibility.
            if (CCCIsCXX()) {
              types::ID OldTy = Ty;
              Ty = types::lookupCXXTypeForCType(Ty);
  
              if (Ty != OldTy)
                Diag(clang::diag::warn_drv_treating_input_as_cxx)
                    << getTypeName(OldTy) << getTypeName(Ty);
            }
  
            // If running with -fthinlto-index=, extensions that normally identify
            // native object files actually identify LLVM bitcode files.
            if (Args.hasArgNoClaim(options::OPT_fthinlto_index_EQ) &&
                Ty == types::TY_Object)
              Ty = types::TY_LLVM_BC;
          }
  
          // -ObjC and -ObjC++ override the default language, but only for "source
          // files". We just treat everything that isn't a linker input as a
          // source file.
          //
          // FIXME: Clean this up if we move the phase sequence into the type.
          if (Ty != types::TY_Object) {
            if (Args.hasArg(options::OPT_ObjC))
              Ty = types::TY_ObjC;
            else if (Args.hasArg(options::OPT_ObjCXX))
              Ty = types::TY_ObjCXX;
          }
        } else {
          assert(InputTypeArg && "InputType set w/o InputTypeArg");
          if (!InputTypeArg->getOption().matches(options::OPT_x)) {
            // If emulating cl.exe, make sure that /TC and /TP don't affect input
            // object files.
            const char *Ext = strrchr(Value, '.');
            if (Ext && TC.LookupTypeForExtension(Ext + 1) == types::TY_Object)
              Ty = types::TY_Object;
          }
          if (Ty == types::TY_INVALID) {
            Ty = InputType;
            InputTypeArg->claim();
          }
        }
  
        if (DiagnoseInputExistence(Args, Value, Ty, /*TypoCorrect=*/true))
          Inputs.push_back(std::make_pair(Ty, A));
  
      } else if (A->getOption().matches(options::OPT__SLASH_Tc)) {
        StringRef Value = A->getValue();
        if (DiagnoseInputExistence(Args, Value, types::TY_C,
                                   /*TypoCorrect=*/false)) {
          Arg *InputArg = MakeInputArg(Args, Opts, A->getValue());
          Inputs.push_back(std::make_pair(types::TY_C, InputArg));
        }
        A->claim();
      } else if (A->getOption().matches(options::OPT__SLASH_Tp)) {
        StringRef Value = A->getValue();
        if (DiagnoseInputExistence(Args, Value, types::TY_CXX,
                                   /*TypoCorrect=*/false)) {
          Arg *InputArg = MakeInputArg(Args, Opts, A->getValue());
          Inputs.push_back(std::make_pair(types::TY_CXX, InputArg));
        }
        A->claim();
      } else if (A->getOption().hasFlag(options::LinkerInput)) {
        // Just treat as object type, we could make a special type for this if
        // necessary.
        Inputs.push_back(std::make_pair(types::TY_Object, A));
  
      } else if (A->getOption().matches(options::OPT_x)) {
        InputTypeArg = A;
        InputType = types::lookupTypeForTypeSpecifier(A->getValue());
        A->claim();
  
        // Follow gcc behavior and treat as linker input for invalid -x
        // options. Its not clear why we shouldn't just revert to unknown; but
        // this isn't very important, we might as well be bug compatible.
        if (!InputType) {
          Diag(clang::diag::err_drv_unknown_language) << A->getValue();
          InputType = types::TY_Object;
        }
      } else if (A->getOption().getID() == options::OPT_U) {
        assert(A->getNumValues() == 1 && "The /U option has one value.");
        StringRef Val = A->getValue(0);
        if (Val.find_first_of("/\\") != StringRef::npos) {
          // Warn about e.g. "/Users/me/myfile.c".
          Diag(diag::warn_slash_u_filename) << Val;
          Diag(diag::note_use_dashdash);
        }
      }
    }
    if (CCCIsCPP() && Inputs.empty()) {
      // If called as standalone preprocessor, stdin is processed
      // if no other input is present.
      Arg *A = MakeInputArg(Args, Opts, "-");
      Inputs.push_back(std::make_pair(types::TY_C, A));
    }
  }
  
  namespace {
  /// Provides a convenient interface for different programming models to generate
  /// the required device actions.
  class OffloadingActionBuilder final {
    /// Flag used to trace errors in the builder.
    bool IsValid = false;
  
    /// The compilation that is using this builder.
    Compilation &C;
  
    /// Map between an input argument and the offload kinds used to process it.
    std::map<const Arg *, unsigned> InputArgToOffloadKindMap;
  
    /// Builder interface. It doesn't build anything or keep any state.
    class DeviceActionBuilder {
    public:
      typedef const llvm::SmallVectorImpl<phases::ID> PhasesTy;
  
      enum ActionBuilderReturnCode {
        // The builder acted successfully on the current action.
        ABRT_Success,
        // The builder didn't have to act on the current action.
        ABRT_Inactive,
        // The builder was successful and requested the host action to not be
        // generated.
        ABRT_Ignore_Host,
      };
  
    protected:
      /// Compilation associated with this builder.
      Compilation &C;
  
      /// Tool chains associated with this builder. The same programming
      /// model may have associated one or more tool chains.
      SmallVector<const ToolChain *, 2> ToolChains;
  
      /// The derived arguments associated with this builder.
      DerivedArgList &Args;
  
      /// The inputs associated with this builder.
      const Driver::InputList &Inputs;
  
      /// The associated offload kind.
      Action::OffloadKind AssociatedOffloadKind = Action::OFK_None;
  
    public:
      DeviceActionBuilder(Compilation &C, DerivedArgList &Args,
                          const Driver::InputList &Inputs,
                          Action::OffloadKind AssociatedOffloadKind)
          : C(C), Args(Args), Inputs(Inputs),
            AssociatedOffloadKind(AssociatedOffloadKind) {}
      virtual ~DeviceActionBuilder() {}
  
      /// Fill up the array \a DA with all the device dependences that should be
      /// added to the provided host action \a HostAction. By default it is
      /// inactive.
      virtual ActionBuilderReturnCode
      getDeviceDependences(OffloadAction::DeviceDependences &DA,
                           phases::ID CurPhase, phases::ID FinalPhase,
                           PhasesTy &Phases) {
        return ABRT_Inactive;
      }
  
      /// Update the state to include the provided host action \a HostAction as a
      /// dependency of the current device action. By default it is inactive.
      virtual ActionBuilderReturnCode addDeviceDepences(Action *HostAction) {
        return ABRT_Inactive;
      }
  
      /// Append top level actions generated by the builder.
      virtual void appendTopLevelActions(ActionList &AL) {}
  
      /// Append linker device actions generated by the builder.
      virtual void appendLinkDeviceActions(ActionList &AL) {}
  
      /// Append linker host action generated by the builder.
      virtual Action* appendLinkHostActions(ActionList &AL) { return nullptr; }
  
      /// Append linker actions generated by the builder.
      virtual void appendLinkDependences(OffloadAction::DeviceDependences &DA) {}
  
      /// Initialize the builder. Return true if any initialization errors are
      /// found.
      virtual bool initialize() { return false; }
  
      /// Return true if the builder can use bundling/unbundling.
      virtual bool canUseBundlerUnbundler() const { return false; }
  
      /// Return true if this builder is valid. We have a valid builder if we have
      /// associated device tool chains.
      bool isValid() { return !ToolChains.empty(); }
  
      /// Return the associated offload kind.
      Action::OffloadKind getAssociatedOffloadKind() {
        return AssociatedOffloadKind;
      }
    };
  
    /// Base class for CUDA/HIP action builder. It injects device code in
    /// the host backend action.
    class CudaActionBuilderBase : public DeviceActionBuilder {
    protected:
      /// Flags to signal if the user requested host-only or device-only
      /// compilation.
      bool CompileHostOnly = false;
      bool CompileDeviceOnly = false;
      bool EmitLLVM = false;
      bool EmitAsm = false;
  
      /// ID to identify each device compilation. For CUDA it is simply the
      /// GPU arch string. For HIP it is either the GPU arch string or GPU
      /// arch string plus feature strings delimited by a plus sign, e.g.
      /// gfx906+xnack.
      struct TargetID {
        /// Target ID string which is persistent throughout the compilation.
        const char *ID;
        TargetID(CudaArch Arch) { ID = CudaArchToString(Arch); }
        TargetID(const char *ID) : ID(ID) {}
        operator const char *() { return ID; }
        operator StringRef() { return StringRef(ID); }
      };
      /// List of GPU architectures to use in this compilation.
      SmallVector<TargetID, 4> GpuArchList;
  
      /// The CUDA actions for the current input.
      ActionList CudaDeviceActions;
  
      /// The CUDA fat binary if it was generated for the current input.
      Action *CudaFatBinary = nullptr;
  
      /// Flag that is set to true if this builder acted on the current input.
      bool IsActive = false;
  
      /// Flag for -fgpu-rdc.
      bool Relocatable = false;
  
      /// Default GPU architecture if there's no one specified.
      CudaArch DefaultCudaArch = CudaArch::UNKNOWN;
  
      /// Method to generate compilation unit ID specified by option
      /// '-fuse-cuid='.
      enum UseCUIDKind { CUID_Hash, CUID_Random, CUID_None, CUID_Invalid };
      UseCUIDKind UseCUID = CUID_Hash;
  
      /// Compilation unit ID specified by option '-cuid='.
      StringRef FixedCUID;
  
    public:
      CudaActionBuilderBase(Compilation &C, DerivedArgList &Args,
                            const Driver::InputList &Inputs,
                            Action::OffloadKind OFKind)
          : DeviceActionBuilder(C, Args, Inputs, OFKind) {}
  
      ActionBuilderReturnCode addDeviceDepences(Action *HostAction) override {
        // While generating code for CUDA, we only depend on the host input action
        // to trigger the creation of all the CUDA device actions.
  
        // If we are dealing with an input action, replicate it for each GPU
        // architecture. If we are in host-only mode we return 'success' so that
        // the host uses the CUDA offload kind.
        if (auto *IA = dyn_cast<InputAction>(HostAction)) {
          assert(!GpuArchList.empty() &&
                 "We should have at least one GPU architecture.");
  
          // If the host input is not CUDA or HIP, we don't need to bother about
          // this input.
          if (!(IA->getType() == types::TY_CUDA ||
                IA->getType() == types::TY_HIP ||
                IA->getType() == types::TY_PP_HIP)) {
            // The builder will ignore this input.
            IsActive = false;
            return ABRT_Inactive;
          }
  
          // Set the flag to true, so that the builder acts on the current input.
          IsActive = true;
  
          if (CompileHostOnly)
            return ABRT_Success;
  
          // Replicate inputs for each GPU architecture.
          auto Ty = IA->getType() == types::TY_HIP ? types::TY_HIP_DEVICE
                                                   : types::TY_CUDA_DEVICE;
          std::string CUID = FixedCUID.str();
          if (CUID.empty()) {
            if (UseCUID == CUID_Random)
              CUID = llvm::utohexstr(llvm::sys::Process::GetRandomNumber(),
                                     /*LowerCase=*/true);
            else if (UseCUID == CUID_Hash) {
              llvm::MD5 Hasher;
              llvm::MD5::MD5Result Hash;
              SmallString<256> RealPath;
              llvm::sys::fs::real_path(IA->getInputArg().getValue(), RealPath,
                                       /*expand_tilde=*/true);
              Hasher.update(RealPath);
              for (auto *A : Args) {
                if (A->getOption().matches(options::OPT_INPUT))
                  continue;
                Hasher.update(A->getAsString(Args));
              }
              Hasher.final(Hash);
              CUID = llvm::utohexstr(Hash.low(), /*LowerCase=*/true);
            }
          }
          IA->setId(CUID);
  
          for (unsigned I = 0, E = GpuArchList.size(); I != E; ++I) {
            CudaDeviceActions.push_back(
                C.MakeAction<InputAction>(IA->getInputArg(), Ty, IA->getId()));
          }
  
          return ABRT_Success;
        }
  
        // If this is an unbundling action use it as is for each CUDA toolchain.
        if (auto *UA = dyn_cast<OffloadUnbundlingJobAction>(HostAction)) {
  
          // If -fgpu-rdc is disabled, should not unbundle since there is no
          // device code to link.
          if (UA->getType() == types::TY_Object && !Relocatable)
            return ABRT_Inactive;
  
          CudaDeviceActions.clear();
          auto *IA = cast<InputAction>(UA->getInputs().back());
          std::string FileName = IA->getInputArg().getAsString(Args);
          // Check if the type of the file is the same as the action. Do not
          // unbundle it if it is not. Do not unbundle .so files, for example,
          // which are not object files.
          if (IA->getType() == types::TY_Object &&
              (!llvm::sys::path::has_extension(FileName) ||
               types::lookupTypeForExtension(
                   llvm::sys::path::extension(FileName).drop_front()) !=
                   types::TY_Object))
            return ABRT_Inactive;
  
          for (auto Arch : GpuArchList) {
            CudaDeviceActions.push_back(UA);
            UA->registerDependentActionInfo(ToolChains[0], Arch,
                                            AssociatedOffloadKind);
          }
          return ABRT_Success;
        }
  
        return IsActive ? ABRT_Success : ABRT_Inactive;
      }
  
      void appendTopLevelActions(ActionList &AL) override {
        // Utility to append actions to the top level list.
        auto AddTopLevel = [&](Action *A, TargetID TargetID) {
          OffloadAction::DeviceDependences Dep;
          Dep.add(*A, *ToolChains.front(), TargetID, AssociatedOffloadKind);
          AL.push_back(C.MakeAction<OffloadAction>(Dep, A->getType()));
        };
  
        // If we have a fat binary, add it to the list.
        if (CudaFatBinary) {
          AddTopLevel(CudaFatBinary, CudaArch::UNUSED);
          CudaDeviceActions.clear();
          CudaFatBinary = nullptr;
          return;
        }
  
        if (CudaDeviceActions.empty())
          return;
  
        // If we have CUDA actions at this point, that's because we have a have
        // partial compilation, so we should have an action for each GPU
        // architecture.
        assert(CudaDeviceActions.size() == GpuArchList.size() &&
               "Expecting one action per GPU architecture.");
        assert(ToolChains.size() == 1 &&
               "Expecting to have a single CUDA toolchain.");
        for (unsigned I = 0, E = GpuArchList.size(); I != E; ++I)
          AddTopLevel(CudaDeviceActions[I], GpuArchList[I]);
  
        CudaDeviceActions.clear();
      }
  
      /// Get canonicalized offload arch option. \returns empty StringRef if the
      /// option is invalid.
      virtual StringRef getCanonicalOffloadArch(StringRef Arch) = 0;
  
      virtual llvm::Optional<std::pair<llvm::StringRef, llvm::StringRef>>
      getConflictOffloadArchCombination(const std::set<StringRef> &GpuArchs) = 0;
  
      bool initialize() override {
        assert(AssociatedOffloadKind == Action::OFK_Cuda ||
               AssociatedOffloadKind == Action::OFK_HIP);
  
        // We don't need to support CUDA.
        if (AssociatedOffloadKind == Action::OFK_Cuda &&
            !C.hasOffloadToolChain<Action::OFK_Cuda>())
          return false;
  
        // We don't need to support HIP.
        if (AssociatedOffloadKind == Action::OFK_HIP &&
            !C.hasOffloadToolChain<Action::OFK_HIP>())
          return false;
  
        Relocatable = Args.hasFlag(options::OPT_fgpu_rdc,
            options::OPT_fno_gpu_rdc, /*Default=*/false);
  
        const ToolChain *HostTC = C.getSingleOffloadToolChain<Action::OFK_Host>();
        assert(HostTC && "No toolchain for host compilation.");
        if (HostTC->getTriple().isNVPTX() ||
            HostTC->getTriple().getArch() == llvm::Triple::amdgcn) {
          // We do not support targeting NVPTX/AMDGCN for host compilation. Throw
          // an error and abort pipeline construction early so we don't trip
          // asserts that assume device-side compilation.
          C.getDriver().Diag(diag::err_drv_cuda_host_arch)
              << HostTC->getTriple().getArchName();
          return true;
        }
  
        ToolChains.push_back(
            AssociatedOffloadKind == Action::OFK_Cuda
                ? C.getSingleOffloadToolChain<Action::OFK_Cuda>()
                : C.getSingleOffloadToolChain<Action::OFK_HIP>());
  
        Arg *PartialCompilationArg = Args.getLastArg(
            options::OPT_cuda_host_only, options::OPT_cuda_device_only,
            options::OPT_cuda_compile_host_device);
        CompileHostOnly = PartialCompilationArg &&
                          PartialCompilationArg->getOption().matches(
                              options::OPT_cuda_host_only);
        CompileDeviceOnly = PartialCompilationArg &&
                            PartialCompilationArg->getOption().matches(
                                options::OPT_cuda_device_only);
        EmitLLVM = Args.getLastArg(options::OPT_emit_llvm);
        EmitAsm = Args.getLastArg(options::OPT_S);
        FixedCUID = Args.getLastArgValue(options::OPT_cuid_EQ);
        if (Arg *A = Args.getLastArg(options::OPT_fuse_cuid_EQ)) {
          StringRef UseCUIDStr = A->getValue();
          UseCUID = llvm::StringSwitch<UseCUIDKind>(UseCUIDStr)
                        .Case("hash", CUID_Hash)
                        .Case("random", CUID_Random)
                        .Case("none", CUID_None)
                        .Default(CUID_Invalid);
          if (UseCUID == CUID_Invalid) {
            C.getDriver().Diag(diag::err_drv_invalid_value)
                << A->getAsString(Args) << UseCUIDStr;
            C.setContainsError();
            return true;
          }
        }
  
        // --offload and --offload-arch options are mutually exclusive.
        if (Args.hasArgNoClaim(options::OPT_offload_EQ) &&
            Args.hasArgNoClaim(options::OPT_offload_arch_EQ,
                               options::OPT_no_offload_arch_EQ)) {
          C.getDriver().Diag(diag::err_opt_not_valid_with_opt) << "--offload-arch"
                                                               << "--offload";
        }
  
        // Collect all cuda_gpu_arch parameters, removing duplicates.
        std::set<StringRef> GpuArchs;
        bool Error = false;
        for (Arg *A : Args) {
          if (!(A->getOption().matches(options::OPT_offload_arch_EQ) ||
                A->getOption().matches(options::OPT_no_offload_arch_EQ)))
            continue;
          A->claim();
  
          StringRef ArchStr = A->getValue();
          if (A->getOption().matches(options::OPT_no_offload_arch_EQ) &&
              ArchStr == "all") {
            GpuArchs.clear();
            continue;
          }
          ArchStr = getCanonicalOffloadArch(ArchStr);
          if (ArchStr.empty()) {
            Error = true;
          } else if (A->getOption().matches(options::OPT_offload_arch_EQ))
            GpuArchs.insert(ArchStr);
          else if (A->getOption().matches(options::OPT_no_offload_arch_EQ))
            GpuArchs.erase(ArchStr);
          else
            llvm_unreachable("Unexpected option.");
        }
  
        auto &&ConflictingArchs = getConflictOffloadArchCombination(GpuArchs);
        if (ConflictingArchs) {
          C.getDriver().Diag(clang::diag::err_drv_bad_offload_arch_combo)
              << ConflictingArchs.getValue().first
              << ConflictingArchs.getValue().second;
          C.setContainsError();
          return true;
        }
  
        // Collect list of GPUs remaining in the set.
        for (auto Arch : GpuArchs)
          GpuArchList.push_back(Arch.data());
  
        // Default to sm_20 which is the lowest common denominator for
        // supported GPUs.  sm_20 code should work correctly, if
        // suboptimally, on all newer GPUs.
        if (GpuArchList.empty()) {
          if (ToolChains.front()->getTriple().isSPIRV())
            GpuArchList.push_back(CudaArch::Generic);
          else
            GpuArchList.push_back(DefaultCudaArch);
        }
  
        return Error;
      }
    };
  
    /// \brief CUDA action builder. It injects device code in the host backend
    /// action.
    class CudaActionBuilder final : public CudaActionBuilderBase {
    public:
      CudaActionBuilder(Compilation &C, DerivedArgList &Args,
                        const Driver::InputList &Inputs)
          : CudaActionBuilderBase(C, Args, Inputs, Action::OFK_Cuda) {
        DefaultCudaArch = CudaArch::SM_35;
      }
  
      StringRef getCanonicalOffloadArch(StringRef ArchStr) override {
        CudaArch Arch = StringToCudaArch(ArchStr);
        if (Arch == CudaArch::UNKNOWN || !IsNVIDIAGpuArch(Arch)) {
          C.getDriver().Diag(clang::diag::err_drv_cuda_bad_gpu_arch) << ArchStr;
          return StringRef();
        }
        return CudaArchToString(Arch);
      }
  
      llvm::Optional<std::pair<llvm::StringRef, llvm::StringRef>>
      getConflictOffloadArchCombination(
          const std::set<StringRef> &GpuArchs) override {
        return llvm::None;
      }
  
      ActionBuilderReturnCode
      getDeviceDependences(OffloadAction::DeviceDependences &DA,
                           phases::ID CurPhase, phases::ID FinalPhase,
                           PhasesTy &Phases) override {
        if (!IsActive)
          return ABRT_Inactive;
  
        // If we don't have more CUDA actions, we don't have any dependences to
        // create for the host.
        if (CudaDeviceActions.empty())
          return ABRT_Success;
  
        assert(CudaDeviceActions.size() == GpuArchList.size() &&
               "Expecting one action per GPU architecture.");
        assert(!CompileHostOnly &&
               "Not expecting CUDA actions in host-only compilation.");
  
        // If we are generating code for the device or we are in a backend phase,
        // we attempt to generate the fat binary. We compile each arch to ptx and
        // assemble to cubin, then feed the cubin *and* the ptx into a device
        // "link" action, which uses fatbinary to combine these cubins into one
        // fatbin.  The fatbin is then an input to the host action if not in
        // device-only mode.
        if (CompileDeviceOnly || CurPhase == phases::Backend) {
          ActionList DeviceActions;
          for (unsigned I = 0, E = GpuArchList.size(); I != E; ++I) {
            // Produce the device action from the current phase up to the assemble
            // phase.
            for (auto Ph : Phases) {
              // Skip the phases that were already dealt with.
              if (Ph < CurPhase)
                continue;
              // We have to be consistent with the host final phase.
              if (Ph > FinalPhase)
                break;
  
              CudaDeviceActions[I] = C.getDriver().ConstructPhaseAction(
                  C, Args, Ph, CudaDeviceActions[I], Action::OFK_Cuda);
  
              if (Ph == phases::Assemble)
                break;
            }
  
            // If we didn't reach the assemble phase, we can't generate the fat
            // binary. We don't need to generate the fat binary if we are not in
            // device-only mode.
            if (!isa<AssembleJobAction>(CudaDeviceActions[I]) ||
                CompileDeviceOnly)
              continue;
  
            Action *AssembleAction = CudaDeviceActions[I];
            assert(AssembleAction->getType() == types::TY_Object);
            assert(AssembleAction->getInputs().size() == 1);
  
            Action *BackendAction = AssembleAction->getInputs()[0];
            assert(BackendAction->getType() == types::TY_PP_Asm);
  
            for (auto &A : {AssembleAction, BackendAction}) {
              OffloadAction::DeviceDependences DDep;
              DDep.add(*A, *ToolChains.front(), GpuArchList[I], Action::OFK_Cuda);
              DeviceActions.push_back(
                  C.MakeAction<OffloadAction>(DDep, A->getType()));
            }
          }
  
          // We generate the fat binary if we have device input actions.
          if (!DeviceActions.empty()) {
            CudaFatBinary =
                C.MakeAction<LinkJobAction>(DeviceActions, types::TY_CUDA_FATBIN);
  
            if (!CompileDeviceOnly) {
              DA.add(*CudaFatBinary, *ToolChains.front(), /*BoundArch=*/nullptr,
                     Action::OFK_Cuda);
              // Clear the fat binary, it is already a dependence to an host
              // action.
              CudaFatBinary = nullptr;
            }
  
            // Remove the CUDA actions as they are already connected to an host
            // action or fat binary.
            CudaDeviceActions.clear();
          }
  
          // We avoid creating host action in device-only mode.
          return CompileDeviceOnly ? ABRT_Ignore_Host : ABRT_Success;
        } else if (CurPhase > phases::Backend) {
          // If we are past the backend phase and still have a device action, we
          // don't have to do anything as this action is already a device
          // top-level action.
          return ABRT_Success;
        }
  
        assert(CurPhase < phases::Backend && "Generating single CUDA "
                                             "instructions should only occur "
                                             "before the backend phase!");
  
        // By default, we produce an action for each device arch.
        for (Action *&A : CudaDeviceActions)
          A = C.getDriver().ConstructPhaseAction(C, Args, CurPhase, A);
  
        return ABRT_Success;
      }
    };
    /// \brief HIP action builder. It injects device code in the host backend
    /// action.
    class HIPActionBuilder final : public CudaActionBuilderBase {
      /// The linker inputs obtained for each device arch.
      SmallVector<ActionList, 8> DeviceLinkerInputs;
      // The default bundling behavior depends on the type of output, therefore
      // BundleOutput needs to be tri-value: None, true, or false.
      // Bundle code objects except --no-gpu-output is specified for device
      // only compilation. Bundle other type of output files only if
      // --gpu-bundle-output is specified for device only compilation.
      Optional<bool> BundleOutput;
  
    public:
      HIPActionBuilder(Compilation &C, DerivedArgList &Args,
                       const Driver::InputList &Inputs)
          : CudaActionBuilderBase(C, Args, Inputs, Action::OFK_HIP) {
        DefaultCudaArch = CudaArch::GFX803;
        if (Args.hasArg(options::OPT_gpu_bundle_output,
                        options::OPT_no_gpu_bundle_output))
          BundleOutput = Args.hasFlag(options::OPT_gpu_bundle_output,
                                      options::OPT_no_gpu_bundle_output);
      }
  
      bool canUseBundlerUnbundler() const override { return true; }
  
      StringRef getCanonicalOffloadArch(StringRef IdStr) override {
        llvm::StringMap<bool> Features;
        // getHIPOffloadTargetTriple() is known to return valid value as it has
        // been called successfully in the CreateOffloadingDeviceToolChains().
        auto ArchStr = parseTargetID(
            *getHIPOffloadTargetTriple(C.getDriver(), C.getInputArgs()), IdStr,
            &Features);
        if (!ArchStr) {
          C.getDriver().Diag(clang::diag::err_drv_bad_target_id) << IdStr;
          C.setContainsError();
          return StringRef();
        }
        auto CanId = getCanonicalTargetID(ArchStr.getValue(), Features);
        return Args.MakeArgStringRef(CanId);
      };
  
      llvm::Optional<std::pair<llvm::StringRef, llvm::StringRef>>
      getConflictOffloadArchCombination(
          const std::set<StringRef> &GpuArchs) override {
        return getConflictTargetIDCombination(GpuArchs);
      }
  
      ActionBuilderReturnCode
      getDeviceDependences(OffloadAction::DeviceDependences &DA,
                           phases::ID CurPhase, phases::ID FinalPhase,
                           PhasesTy &Phases) override {
        // amdgcn does not support linking of object files, therefore we skip
        // backend and assemble phases to output LLVM IR. Except for generating
        // non-relocatable device coee, where we generate fat binary for device
        // code and pass to host in Backend phase.
        if (CudaDeviceActions.empty())
          return ABRT_Success;
  
        assert(((CurPhase == phases::Link && Relocatable) ||
                CudaDeviceActions.size() == GpuArchList.size()) &&
               "Expecting one action per GPU architecture.");
        assert(!CompileHostOnly &&
               "Not expecting CUDA actions in host-only compilation.");
  
        if (!Relocatable && CurPhase == phases::Backend && !EmitLLVM &&
            !EmitAsm) {
          // If we are in backend phase, we attempt to generate the fat binary.
          // We compile each arch to IR and use a link action to generate code
          // object containing ISA. Then we use a special "link" action to create
          // a fat binary containing all the code objects for different GPU's.
          // The fat binary is then an input to the host action.
          for (unsigned I = 0, E = GpuArchList.size(); I != E; ++I) {
            if (C.getDriver().isUsingLTO(/*IsOffload=*/true)) {
              // When LTO is enabled, skip the backend and assemble phases and
              // use lld to link the bitcode.
              ActionList AL;
              AL.push_back(CudaDeviceActions[I]);
              // Create a link action to link device IR with device library
              // and generate ISA.
              CudaDeviceActions[I] =
                  C.MakeAction<LinkJobAction>(AL, types::TY_Image);
            } else {
              // When LTO is not enabled, we follow the conventional
              // compiler phases, including backend and assemble phases.
              ActionList AL;
              Action *BackendAction = nullptr;
              if (ToolChains.front()->getTriple().isSPIRV()) {
                // Emit LLVM bitcode for SPIR-V targets. SPIR-V device tool chain
                // (HIPSPVToolChain) runs post-link LLVM IR passes.
                types::ID Output = Args.hasArg(options::OPT_S)
                                       ? types::TY_LLVM_IR
                                       : types::TY_LLVM_BC;
                BackendAction =
                    C.MakeAction<BackendJobAction>(CudaDeviceActions[I], Output);
              } else
                BackendAction = C.getDriver().ConstructPhaseAction(
                    C, Args, phases::Backend, CudaDeviceActions[I],
                    AssociatedOffloadKind);
              auto AssembleAction = C.getDriver().ConstructPhaseAction(
                  C, Args, phases::Assemble, BackendAction,
                  AssociatedOffloadKind);
              AL.push_back(AssembleAction);
              // Create a link action to link device IR with device library
              // and generate ISA.
              CudaDeviceActions[I] =
                  C.MakeAction<LinkJobAction>(AL, types::TY_Image);
            }
  
            // OffloadingActionBuilder propagates device arch until an offload
            // action. Since the next action for creating fatbin does
            // not have device arch, whereas the above link action and its input
            // have device arch, an offload action is needed to stop the null
            // device arch of the next action being propagated to the above link
            // action.
            OffloadAction::DeviceDependences DDep;
            DDep.add(*CudaDeviceActions[I], *ToolChains.front(), GpuArchList[I],
                     AssociatedOffloadKind);
            CudaDeviceActions[I] = C.MakeAction<OffloadAction>(
                DDep, CudaDeviceActions[I]->getType());
          }
  
          if (!CompileDeviceOnly || !BundleOutput.hasValue() ||
              BundleOutput.getValue()) {
            // Create HIP fat binary with a special "link" action.
            CudaFatBinary = C.MakeAction<LinkJobAction>(CudaDeviceActions,
                                                        types::TY_HIP_FATBIN);
  
            if (!CompileDeviceOnly) {
              DA.add(*CudaFatBinary, *ToolChains.front(), /*BoundArch=*/nullptr,
                     AssociatedOffloadKind);
              // Clear the fat binary, it is already a dependence to an host
              // action.
              CudaFatBinary = nullptr;
            }
  
            // Remove the CUDA actions as they are already connected to an host
            // action or fat binary.
            CudaDeviceActions.clear();
          }
  
          return CompileDeviceOnly ? ABRT_Ignore_Host : ABRT_Success;
        } else if (CurPhase == phases::Link) {
          // Save CudaDeviceActions to DeviceLinkerInputs for each GPU subarch.
          // This happens to each device action originated from each input file.
          // Later on, device actions in DeviceLinkerInputs are used to create
          // device link actions in appendLinkDependences and the created device
          // link actions are passed to the offload action as device dependence.
          DeviceLinkerInputs.resize(CudaDeviceActions.size());
          auto LI = DeviceLinkerInputs.begin();
          for (auto *A : CudaDeviceActions) {
            LI->push_back(A);
            ++LI;
          }
  
          // We will pass the device action as a host dependence, so we don't
          // need to do anything else with them.
          CudaDeviceActions.clear();
          return CompileDeviceOnly ? ABRT_Ignore_Host : ABRT_Success;
        }
  
        // By default, we produce an action for each device arch.
        for (Action *&A : CudaDeviceActions)
          A = C.getDriver().ConstructPhaseAction(C, Args, CurPhase, A,
                                                 AssociatedOffloadKind);
  
        if (CompileDeviceOnly && CurPhase == FinalPhase &&
            BundleOutput.hasValue() && BundleOutput.getValue()) {
          for (unsigned I = 0, E = GpuArchList.size(); I != E; ++I) {
            OffloadAction::DeviceDependences DDep;
            DDep.add(*CudaDeviceActions[I], *ToolChains.front(), GpuArchList[I],
                     AssociatedOffloadKind);
            CudaDeviceActions[I] = C.MakeAction<OffloadAction>(
                DDep, CudaDeviceActions[I]->getType());
          }
          CudaFatBinary =
              C.MakeAction<OffloadBundlingJobAction>(CudaDeviceActions);
          CudaDeviceActions.clear();
        }
  
        return (CompileDeviceOnly && CurPhase == FinalPhase) ? ABRT_Ignore_Host
                                                             : ABRT_Success;
      }
  
      void appendLinkDeviceActions(ActionList &AL) override {
        if (DeviceLinkerInputs.size() == 0)
          return;
  
        assert(DeviceLinkerInputs.size() == GpuArchList.size() &&
               "Linker inputs and GPU arch list sizes do not match.");
  
        ActionList Actions;
        // Append a new link action for each device.
        unsigned I = 0;
        for (auto &LI : DeviceLinkerInputs) {
          // Each entry in DeviceLinkerInputs corresponds to a GPU arch.
          auto *DeviceLinkAction =
              C.MakeAction<LinkJobAction>(LI, types::TY_Image);
          // Linking all inputs for the current GPU arch.
          // LI contains all the inputs for the linker.
          OffloadAction::DeviceDependences DeviceLinkDeps;
          DeviceLinkDeps.add(*DeviceLinkAction, *ToolChains[0],
              GpuArchList[I], AssociatedOffloadKind);
          Actions.push_back(C.MakeAction<OffloadAction>(
              DeviceLinkDeps, DeviceLinkAction->getType()));
          ++I;
        }
        DeviceLinkerInputs.clear();
  
        // Create a host object from all the device images by embedding them
        // in a fat binary for mixed host-device compilation. For device-only
        // compilation, creates a fat binary.
        OffloadAction::DeviceDependences DDeps;
        if (!CompileDeviceOnly || !BundleOutput.hasValue() ||
            BundleOutput.getValue()) {
          auto *TopDeviceLinkAction = C.MakeAction<LinkJobAction>(
              Actions,
              CompileDeviceOnly ? types::TY_HIP_FATBIN : types::TY_Object);
          DDeps.add(*TopDeviceLinkAction, *ToolChains[0], nullptr,
                    AssociatedOffloadKind);
          // Offload the host object to the host linker.
          AL.push_back(
              C.MakeAction<OffloadAction>(DDeps, TopDeviceLinkAction->getType()));
        } else {
          AL.append(Actions);
        }
      }
  
      Action* appendLinkHostActions(ActionList &AL) override { return AL.back(); }
  
      void appendLinkDependences(OffloadAction::DeviceDependences &DA) override {}
    };
  
    /// OpenMP action builder. The host bitcode is passed to the device frontend
    /// and all the device linked images are passed to the host link phase.
    class OpenMPActionBuilder final : public DeviceActionBuilder {
      /// The OpenMP actions for the current input.
      ActionList OpenMPDeviceActions;
  
      /// The linker inputs obtained for each toolchain.
      SmallVector<ActionList, 8> DeviceLinkerInputs;
  
    public:
      OpenMPActionBuilder(Compilation &C, DerivedArgList &Args,
                          const Driver::InputList &Inputs)
          : DeviceActionBuilder(C, Args, Inputs, Action::OFK_OpenMP) {}
  
      ActionBuilderReturnCode
      getDeviceDependences(OffloadAction::DeviceDependences &DA,
                           phases::ID CurPhase, phases::ID FinalPhase,
                           PhasesTy &Phases) override {
        if (OpenMPDeviceActions.empty())
          return ABRT_Inactive;
  
        // We should always have an action for each input.
        assert(OpenMPDeviceActions.size() == ToolChains.size() &&
               "Number of OpenMP actions and toolchains do not match.");
  
        // The host only depends on device action in the linking phase, when all
        // the device images have to be embedded in the host image.
        if (CurPhase == phases::Link) {
          assert(ToolChains.size() == DeviceLinkerInputs.size() &&
                 "Toolchains and linker inputs sizes do not match.");
          auto LI = DeviceLinkerInputs.begin();
          for (auto *A : OpenMPDeviceActions) {
            LI->push_back(A);
            ++LI;
          }
  
          // We passed the device action as a host dependence, so we don't need to
          // do anything else with them.
          OpenMPDeviceActions.clear();
          return ABRT_Success;
        }
  
        // By default, we produce an action for each device arch.
        for (Action *&A : OpenMPDeviceActions)
          A = C.getDriver().ConstructPhaseAction(C, Args, CurPhase, A);
  
        return ABRT_Success;
      }
  
      ActionBuilderReturnCode addDeviceDepences(Action *HostAction) override {
  
        // If this is an input action replicate it for each OpenMP toolchain.
        if (auto *IA = dyn_cast<InputAction>(HostAction)) {
          OpenMPDeviceActions.clear();
          for (unsigned I = 0; I < ToolChains.size(); ++I)
            OpenMPDeviceActions.push_back(
                C.MakeAction<InputAction>(IA->getInputArg(), IA->getType()));
          return ABRT_Success;
        }
  
        // If this is an unbundling action use it as is for each OpenMP toolchain.
        if (auto *UA = dyn_cast<OffloadUnbundlingJobAction>(HostAction)) {
          OpenMPDeviceActions.clear();
          auto *IA = cast<InputAction>(UA->getInputs().back());
          std::string FileName = IA->getInputArg().getAsString(Args);
          // Check if the type of the file is the same as the action. Do not
          // unbundle it if it is not. Do not unbundle .so files, for example,
          // which are not object files.
          if (IA->getType() == types::TY_Object &&
              (!llvm::sys::path::has_extension(FileName) ||
               types::lookupTypeForExtension(
                   llvm::sys::path::extension(FileName).drop_front()) !=
                   types::TY_Object))
            return ABRT_Inactive;
          for (unsigned I = 0; I < ToolChains.size(); ++I) {
            OpenMPDeviceActions.push_back(UA);
            UA->registerDependentActionInfo(
                ToolChains[I], /*BoundArch=*/StringRef(), Action::OFK_OpenMP);
          }
          return ABRT_Success;
        }
  
        // When generating code for OpenMP we use the host compile phase result as
        // a dependence to the device compile phase so that it can learn what
        // declarations should be emitted. However, this is not the only use for
        // the host action, so we prevent it from being collapsed.
        if (isa<CompileJobAction>(HostAction)) {
          HostAction->setCannotBeCollapsedWithNextDependentAction();
          assert(ToolChains.size() == OpenMPDeviceActions.size() &&
                 "Toolchains and device action sizes do not match.");
          OffloadAction::HostDependence HDep(
              *HostAction, *C.getSingleOffloadToolChain<Action::OFK_Host>(),
              /*BoundArch=*/nullptr, Action::OFK_OpenMP);
          auto TC = ToolChains.begin();
          for (Action *&A : OpenMPDeviceActions) {
            assert(isa<CompileJobAction>(A));
            OffloadAction::DeviceDependences DDep;
            DDep.add(*A, **TC, /*BoundArch=*/nullptr, Action::OFK_OpenMP);
            A = C.MakeAction<OffloadAction>(HDep, DDep);
            ++TC;
          }
        }
        return ABRT_Success;
      }
  
      void appendTopLevelActions(ActionList &AL) override {
        if (OpenMPDeviceActions.empty())
          return;
  
        // We should always have an action for each input.
        assert(OpenMPDeviceActions.size() == ToolChains.size() &&
               "Number of OpenMP actions and toolchains do not match.");
  
        // Append all device actions followed by the proper offload action.
        auto TI = ToolChains.begin();
        for (auto *A : OpenMPDeviceActions) {
          OffloadAction::DeviceDependences Dep;
          Dep.add(*A, **TI, /*BoundArch=*/nullptr, Action::OFK_OpenMP);
          AL.push_back(C.MakeAction<OffloadAction>(Dep, A->getType()));
          ++TI;
        }
        // We no longer need the action stored in this builder.
        OpenMPDeviceActions.clear();
      }
  
      void appendLinkDeviceActions(ActionList &AL) override {
        assert(ToolChains.size() == DeviceLinkerInputs.size() &&
               "Toolchains and linker inputs sizes do not match.");
  
        // Append a new link action for each device.
        auto TC = ToolChains.begin();
        for (auto &LI : DeviceLinkerInputs) {
          auto *DeviceLinkAction =
              C.MakeAction<LinkJobAction>(LI, types::TY_Image);
          OffloadAction::DeviceDependences DeviceLinkDeps;
          DeviceLinkDeps.add(*DeviceLinkAction, **TC, /*BoundArch=*/nullptr,
  		        Action::OFK_OpenMP);
          AL.push_back(C.MakeAction<OffloadAction>(DeviceLinkDeps,
              DeviceLinkAction->getType()));
          ++TC;
        }
        DeviceLinkerInputs.clear();
      }
  
      Action* appendLinkHostActions(ActionList &AL) override {
        // Create wrapper bitcode from the result of device link actions and compile
        // it to an object which will be added to the host link command.
        auto *BC = C.MakeAction<OffloadWrapperJobAction>(AL, types::TY_LLVM_BC);
        auto *ASM = C.MakeAction<BackendJobAction>(BC, types::TY_PP_Asm);
        return C.MakeAction<AssembleJobAction>(ASM, types::TY_Object);
      }
  
      void appendLinkDependences(OffloadAction::DeviceDependences &DA) override {}
  
      bool initialize() override {
        // Get the OpenMP toolchains. If we don't get any, the action builder will
        // know there is nothing to do related to OpenMP offloading.
        auto OpenMPTCRange = C.getOffloadToolChains<Action::OFK_OpenMP>();
        for (auto TI = OpenMPTCRange.first, TE = OpenMPTCRange.second; TI != TE;
             ++TI)
          ToolChains.push_back(TI->second);
  
        DeviceLinkerInputs.resize(ToolChains.size());
        return false;
      }
  
      bool canUseBundlerUnbundler() const override {
        // OpenMP should use bundled files whenever possible.
        return true;
      }
    };
  
    ///
    /// TODO: Add the implementation for other specialized builders here.
    ///
  
    /// Specialized builders being used by this offloading action builder.
    SmallVector<DeviceActionBuilder *, 4> SpecializedBuilders;
  
    /// Flag set to true if all valid builders allow file bundling/unbundling.
    bool CanUseBundler;
  
  public:
    OffloadingActionBuilder(Compilation &C, DerivedArgList &Args,
                            const Driver::InputList &Inputs)
        : C(C) {
      // Create a specialized builder for each device toolchain.
  
      IsValid = true;
  
      // Create a specialized builder for CUDA.
      SpecializedBuilders.push_back(new CudaActionBuilder(C, Args, Inputs));
  
      // Create a specialized builder for HIP.
      SpecializedBuilders.push_back(new HIPActionBuilder(C, Args, Inputs));
  
      // Create a specialized builder for OpenMP.
      SpecializedBuilders.push_back(new OpenMPActionBuilder(C, Args, Inputs));
  
      //
      // TODO: Build other specialized builders here.
      //
  
      // Initialize all the builders, keeping track of errors. If all valid
      // builders agree that we can use bundling, set the flag to true.
      unsigned ValidBuilders = 0u;
      unsigned ValidBuildersSupportingBundling = 0u;
      for (auto *SB : SpecializedBuilders) {
        IsValid = IsValid && !SB->initialize();
  
        // Update the counters if the builder is valid.
        if (SB->isValid()) {
          ++ValidBuilders;
          if (SB->canUseBundlerUnbundler())
            ++ValidBuildersSupportingBundling;
        }
      }
      CanUseBundler =
          ValidBuilders && ValidBuilders == ValidBuildersSupportingBundling;
    }
  
    ~OffloadingActionBuilder() {
      for (auto *SB : SpecializedBuilders)
        delete SB;
    }
  
    /// Generate an action that adds device dependences (if any) to a host action.
    /// If no device dependence actions exist, just return the host action \a
    /// HostAction. If an error is found or if no builder requires the host action
    /// to be generated, return nullptr.
    Action *
    addDeviceDependencesToHostAction(Action *HostAction, const Arg *InputArg,
                                     phases::ID CurPhase, phases::ID FinalPhase,
                                     DeviceActionBuilder::PhasesTy &Phases) {
      if (!IsValid)
        return nullptr;
  
      if (SpecializedBuilders.empty())
        return HostAction;
  
      assert(HostAction && "Invalid host action!");
  
      OffloadAction::DeviceDependences DDeps;
      // Check if all the programming models agree we should not emit the host
      // action. Also, keep track of the offloading kinds employed.
      auto &OffloadKind = InputArgToOffloadKindMap[InputArg];
      unsigned InactiveBuilders = 0u;
      unsigned IgnoringBuilders = 0u;
      for (auto *SB : SpecializedBuilders) {
        if (!SB->isValid()) {
          ++InactiveBuilders;
          continue;
        }
  
        auto RetCode =
            SB->getDeviceDependences(DDeps, CurPhase, FinalPhase, Phases);
  
        // If the builder explicitly says the host action should be ignored,
        // we need to increment the variable that tracks the builders that request
        // the host object to be ignored.
        if (RetCode == DeviceActionBuilder::ABRT_Ignore_Host)
          ++IgnoringBuilders;
  
        // Unless the builder was inactive for this action, we have to record the
        // offload kind because the host will have to use it.
        if (RetCode != DeviceActionBuilder::ABRT_Inactive)
          OffloadKind |= SB->getAssociatedOffloadKind();
      }
  
      // If all builders agree that the host object should be ignored, just return
      // nullptr.
      if (IgnoringBuilders &&
          SpecializedBuilders.size() == (InactiveBuilders + IgnoringBuilders))
        return nullptr;
  
      if (DDeps.getActions().empty())
        return HostAction;
  
      // We have dependences we need to bundle together. We use an offload action
      // for that.
      OffloadAction::HostDependence HDep(
          *HostAction, *C.getSingleOffloadToolChain<Action::OFK_Host>(),
          /*BoundArch=*/nullptr, DDeps);
      return C.MakeAction<OffloadAction>(HDep, DDeps);
    }
  
    /// Generate an action that adds a host dependence to a device action. The
    /// results will be kept in this action builder. Return true if an error was
    /// found.
    bool addHostDependenceToDeviceActions(Action *&HostAction,
                                          const Arg *InputArg) {
      if (!IsValid)
        return true;
  
      // If we are supporting bundling/unbundling and the current action is an
      // input action of non-source file, we replace the host action by the
      // unbundling action. The bundler tool has the logic to detect if an input
      // is a bundle or not and if the input is not a bundle it assumes it is a
      // host file. Therefore it is safe to create an unbundling action even if
      // the input is not a bundle.
      if (CanUseBundler && isa<InputAction>(HostAction) &&
          InputArg->getOption().getKind() == llvm::opt::Option::InputClass &&
          (!types::isSrcFile(HostAction->getType()) ||
           HostAction->getType() == types::TY_PP_HIP)) {
        auto UnbundlingHostAction =
            C.MakeAction<OffloadUnbundlingJobAction>(HostAction);
        UnbundlingHostAction->registerDependentActionInfo(
            C.getSingleOffloadToolChain<Action::OFK_Host>(),
            /*BoundArch=*/StringRef(), Action::OFK_Host);
        HostAction = UnbundlingHostAction;
      }
  
      assert(HostAction && "Invalid host action!");
  
      // Register the offload kinds that are used.
      auto &OffloadKind = InputArgToOffloadKindMap[InputArg];
      for (auto *SB : SpecializedBuilders) {
        if (!SB->isValid())
          continue;
  
        auto RetCode = SB->addDeviceDepences(HostAction);
  
        // Host dependences for device actions are not compatible with that same
        // action being ignored.
        assert(RetCode != DeviceActionBuilder::ABRT_Ignore_Host &&
               "Host dependence not expected to be ignored.!");
  
        // Unless the builder was inactive for this action, we have to record the
        // offload kind because the host will have to use it.
        if (RetCode != DeviceActionBuilder::ABRT_Inactive)
          OffloadKind |= SB->getAssociatedOffloadKind();
      }
  
      // Do not use unbundler if the Host does not depend on device action.
      if (OffloadKind == Action::OFK_None && CanUseBundler)
        if (auto *UA = dyn_cast<OffloadUnbundlingJobAction>(HostAction))
          HostAction = UA->getInputs().back();
  
      return false;
    }
  
    /// Add the offloading top level actions to the provided action list. This
    /// function can replace the host action by a bundling action if the
    /// programming models allow it.
    bool appendTopLevelActions(ActionList &AL, Action *HostAction,
                               const Arg *InputArg) {
      // Get the device actions to be appended.
      ActionList OffloadAL;
      for (auto *SB : SpecializedBuilders) {
        if (!SB->isValid())
          continue;
        SB->appendTopLevelActions(OffloadAL);
      }
  
      // If we can use the bundler, replace the host action by the bundling one in
      // the resulting list. Otherwise, just append the device actions. For
      // device only compilation, HostAction is a null pointer, therefore only do
      // this when HostAction is not a null pointer.
      if (CanUseBundler && HostAction &&
          HostAction->getType() != types::TY_Nothing && !OffloadAL.empty()) {
        // Add the host action to the list in order to create the bundling action.
        OffloadAL.push_back(HostAction);
  
        // We expect that the host action was just appended to the action list
        // before this method was called.
        assert(HostAction == AL.back() && "Host action not in the list??");
        HostAction = C.MakeAction<OffloadBundlingJobAction>(OffloadAL);
        AL.back() = HostAction;
      } else
        AL.append(OffloadAL.begin(), OffloadAL.end());
  
      // Propagate to the current host action (if any) the offload information
      // associated with the current input.
      if (HostAction)
        HostAction->propagateHostOffloadInfo(InputArgToOffloadKindMap[InputArg],
                                             /*BoundArch=*/nullptr);
      return false;
    }
  
    void appendDeviceLinkActions(ActionList &AL) {
      for (DeviceActionBuilder *SB : SpecializedBuilders) {
        if (!SB->isValid())
          continue;
        SB->appendLinkDeviceActions(AL);
      }
    }
  
    Action *makeHostLinkAction() {
      // Build a list of device linking actions.
      ActionList DeviceAL;
      appendDeviceLinkActions(DeviceAL);
      if (DeviceAL.empty())
        return nullptr;
  
      // Let builders add host linking actions.
      Action* HA = nullptr;
      for (DeviceActionBuilder *SB : SpecializedBuilders) {
        if (!SB->isValid())
          continue;
        HA = SB->appendLinkHostActions(DeviceAL);
      }
      return HA;
    }
  
    /// Processes the host linker action. This currently consists of replacing it
    /// with an offload action if there are device link objects and propagate to
    /// the host action all the offload kinds used in the current compilation. The
    /// resulting action is returned.
    Action *processHostLinkAction(Action *HostAction) {
      // Add all the dependences from the device linking actions.
      OffloadAction::DeviceDependences DDeps;
      for (auto *SB : SpecializedBuilders) {
        if (!SB->isValid())
          continue;
  
        SB->appendLinkDependences(DDeps);
      }
  
      // Calculate all the offload kinds used in the current compilation.
      unsigned ActiveOffloadKinds = 0u;
      for (auto &I : InputArgToOffloadKindMap)
        ActiveOffloadKinds |= I.second;
  
      // If we don't have device dependencies, we don't have to create an offload
      // action.
      if (DDeps.getActions().empty()) {
        // Propagate all the active kinds to host action. Given that it is a link
        // action it is assumed to depend on all actions generated so far.
        HostAction->propagateHostOffloadInfo(ActiveOffloadKinds,
                                             /*BoundArch=*/nullptr);
        return HostAction;
      }
  
      // Create the offload action with all dependences. When an offload action
      // is created the kinds are propagated to the host action, so we don't have
      // to do that explicitly here.
      OffloadAction::HostDependence HDep(
          *HostAction, *C.getSingleOffloadToolChain<Action::OFK_Host>(),
          /*BoundArch*/ nullptr, ActiveOffloadKinds);
      return C.MakeAction<OffloadAction>(HDep, DDeps);
    }
  };
  } // anonymous namespace.
  
  void Driver::handleArguments(Compilation &C, DerivedArgList &Args,
                               const InputList &Inputs,
                               ActionList &Actions) const {
  
    // Ignore /Yc/Yu if both /Yc and /Yu passed but with different filenames.
    Arg *YcArg = Args.getLastArg(options::OPT__SLASH_Yc);
    Arg *YuArg = Args.getLastArg(options::OPT__SLASH_Yu);
    if (YcArg && YuArg && strcmp(YcArg->getValue(), YuArg->getValue()) != 0) {
      Diag(clang::diag::warn_drv_ycyu_different_arg_clang_cl);
      Args.eraseArg(options::OPT__SLASH_Yc);
      Args.eraseArg(options::OPT__SLASH_Yu);
      YcArg = YuArg = nullptr;
    }
    if (YcArg && Inputs.size() > 1) {
      Diag(clang::diag::warn_drv_yc_multiple_inputs_clang_cl);
      Args.eraseArg(options::OPT__SLASH_Yc);
      YcArg = nullptr;
    }
  
    Arg *FinalPhaseArg;
    phases::ID FinalPhase = getFinalPhase(Args, &FinalPhaseArg);
  
    if (FinalPhase == phases::Link) {
      if (Args.hasArg(options::OPT_emit_llvm))
        Diag(clang::diag::err_drv_emit_llvm_link);
      if (IsCLMode() && LTOMode != LTOK_None &&
          !Args.getLastArgValue(options::OPT_fuse_ld_EQ)
               .equals_insensitive("lld"))
        Diag(clang::diag::err_drv_lto_without_lld);
    }
  
    if (FinalPhase == phases::Preprocess || Args.hasArg(options::OPT__SLASH_Y_)) {
      // If only preprocessing or /Y- is used, all pch handling is disabled.
      // Rather than check for it everywhere, just remove clang-cl pch-related
      // flags here.
      Args.eraseArg(options::OPT__SLASH_Fp);
      Args.eraseArg(options::OPT__SLASH_Yc);
      Args.eraseArg(options::OPT__SLASH_Yu);
      YcArg = YuArg = nullptr;
    }
  
    unsigned LastPLSize = 0;
    for (auto &I : Inputs) {
      types::ID InputType = I.first;
      const Arg *InputArg = I.second;
  
      auto PL = types::getCompilationPhases(InputType);
      LastPLSize = PL.size();
  
      // If the first step comes after the final phase we are doing as part of
      // this compilation, warn the user about it.
      phases::ID InitialPhase = PL[0];
      if (InitialPhase > FinalPhase) {
        if (InputArg->isClaimed())
          continue;
  
        // Claim here to avoid the more general unused warning.
        InputArg->claim();
  
        // Suppress all unused style warnings with -Qunused-arguments
        if (Args.hasArg(options::OPT_Qunused_arguments))
          continue;
  
        // Special case when final phase determined by binary name, rather than
        // by a command-line argument with a corresponding Arg.
        if (CCCIsCPP())
          Diag(clang::diag::warn_drv_input_file_unused_by_cpp)
              << InputArg->getAsString(Args) << getPhaseName(InitialPhase);
        // Special case '-E' warning on a previously preprocessed file to make
        // more sense.
        else if (InitialPhase == phases::Compile &&
                 (Args.getLastArg(options::OPT__SLASH_EP,
                                  options::OPT__SLASH_P) ||
                  Args.getLastArg(options::OPT_E) ||
                  Args.getLastArg(options::OPT_M, options::OPT_MM)) &&
                 getPreprocessedType(InputType) == types::TY_INVALID)
          Diag(clang::diag::warn_drv_preprocessed_input_file_unused)
              << InputArg->getAsString(Args) << !!FinalPhaseArg
              << (FinalPhaseArg ? FinalPhaseArg->getOption().getName() : "");
        else
          Diag(clang::diag::warn_drv_input_file_unused)
              << InputArg->getAsString(Args) << getPhaseName(InitialPhase)
              << !!FinalPhaseArg
              << (FinalPhaseArg ? FinalPhaseArg->getOption().getName() : "");
        continue;
      }
  
      if (YcArg) {
        // Add a separate precompile phase for the compile phase.
        if (FinalPhase >= phases::Compile) {
          const types::ID HeaderType = lookupHeaderTypeForSourceType(InputType);
          // Build the pipeline for the pch file.
          Action *ClangClPch = C.MakeAction<InputAction>(*InputArg, HeaderType);
          for (phases::ID Phase : types::getCompilationPhases(HeaderType))
            ClangClPch = ConstructPhaseAction(C, Args, Phase, ClangClPch);
          assert(ClangClPch);
          Actions.push_back(ClangClPch);
          // The driver currently exits after the first failed command.  This
          // relies on that behavior, to make sure if the pch generation fails,
          // the main compilation won't run.
          // FIXME: If the main compilation fails, the PCH generation should
          // probably not be considered successful either.
        }
      }
    }
  
    // If we are linking, claim any options which are obviously only used for
    // compilation.
    // FIXME: Understand why the last Phase List length is used here.
    if (FinalPhase == phases::Link && LastPLSize == 1) {
      Args.ClaimAllArgs(options::OPT_CompileOnly_Group);
      Args.ClaimAllArgs(options::OPT_cl_compile_Group);
    }
  }
  
  void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
                            const InputList &Inputs, ActionList &Actions) const {
    llvm::PrettyStackTraceString CrashInfo("Building compilation actions");
  
    if (!SuppressMissingInputWarning && Inputs.empty()) {
      Diag(clang::diag::err_drv_no_input_files);
      return;
    }
  
    // Reject -Z* at the top level, these options should never have been exposed
    // by gcc.
    if (Arg *A = Args.getLastArg(options::OPT_Z_Joined))
      Diag(clang::diag::err_drv_use_of_Z_option) << A->getAsString(Args);
  
    // Diagnose misuse of /Fo.
    if (Arg *A = Args.getLastArg(options::OPT__SLASH_Fo)) {
      StringRef V = A->getValue();
      if (Inputs.size() > 1 && !V.empty() &&
          !llvm::sys::path::is_separator(V.back())) {
        // Check whether /Fo tries to name an output file for multiple inputs.
        Diag(clang::diag::err_drv_out_file_argument_with_multiple_sources)
            << A->getSpelling() << V;
        Args.eraseArg(options::OPT__SLASH_Fo);
      }
    }
  
    // Diagnose misuse of /Fa.
    if (Arg *A = Args.getLastArg(options::OPT__SLASH_Fa)) {
      StringRef V = A->getValue();
      if (Inputs.size() > 1 && !V.empty() &&
          !llvm::sys::path::is_separator(V.back())) {
        // Check whether /Fa tries to name an asm file for multiple inputs.
        Diag(clang::diag::err_drv_out_file_argument_with_multiple_sources)
            << A->getSpelling() << V;
        Args.eraseArg(options::OPT__SLASH_Fa);
      }
    }
  
    // Diagnose misuse of /o.
    if (Arg *A = Args.getLastArg(options::OPT__SLASH_o)) {
      if (A->getValue()[0] == '\0') {
        // It has to have a value.
        Diag(clang::diag::err_drv_missing_argument) << A->getSpelling() << 1;
        Args.eraseArg(options::OPT__SLASH_o);
      }
    }
  
    handleArguments(C, Args, Inputs, Actions);
  
    // Builder to be used to build offloading actions.
    OffloadingActionBuilder OffloadBuilder(C, Args, Inputs);
  
    // Construct the actions to perform.
    HeaderModulePrecompileJobAction *HeaderModuleAction = nullptr;
    ActionList LinkerInputs;
    ActionList MergerInputs;
  
    for (auto &I : Inputs) {
      types::ID InputType = I.first;
      const Arg *InputArg = I.second;
  
      auto PL = types::getCompilationPhases(*this, Args, InputType);
      if (PL.empty())
        continue;
  
      auto FullPL = types::getCompilationPhases(InputType);
  
      // Build the pipeline for this file.
      Action *Current = C.MakeAction<InputAction>(*InputArg, InputType);
  
      // Use the current host action in any of the offloading actions, if
      // required.
      if (OffloadBuilder.addHostDependenceToDeviceActions(Current, InputArg))
        break;
  
      for (phases::ID Phase : PL) {
  
        // Add any offload action the host action depends on.
        Current = OffloadBuilder.addDeviceDependencesToHostAction(
            Current, InputArg, Phase, PL.back(), FullPL);
        if (!Current)
          break;
  
        // Queue linker inputs.
        if (Phase == phases::Link) {
          assert(Phase == PL.back() && "linking must be final compilation step.");
          LinkerInputs.push_back(Current);
          Current = nullptr;
          break;
        }
  
        // TODO: Consider removing this because the merged may not end up being
        // the final Phase in the pipeline. Perhaps the merged could just merge
        // and then pass an artifact of some sort to the Link Phase.
        // Queue merger inputs.
        if (Phase == phases::IfsMerge) {
          assert(Phase == PL.back() && "merging must be final compilation step.");
          MergerInputs.push_back(Current);
          Current = nullptr;
          break;
        }
  
        // Each precompiled header file after a module file action is a module
        // header of that same module file, rather than being compiled to a
        // separate PCH.
        if (Phase == phases::Precompile && HeaderModuleAction &&
            getPrecompiledType(InputType) == types::TY_PCH) {
          HeaderModuleAction->addModuleHeaderInput(Current);
          Current = nullptr;
          break;
        }
  
        // FIXME: Should we include any prior module file outputs as inputs of
        // later actions in the same command line?
  
        // Otherwise construct the appropriate action.
        Action *NewCurrent = ConstructPhaseAction(C, Args, Phase, Current);
  
        // We didn't create a new action, so we will just move to the next phase.
        if (NewCurrent == Current)
          continue;
  
        if (auto *HMA = dyn_cast<HeaderModulePrecompileJobAction>(NewCurrent))
          HeaderModuleAction = HMA;
  
        Current = NewCurrent;
  
        // Use the current host action in any of the offloading actions, if
        // required.
        if (OffloadBuilder.addHostDependenceToDeviceActions(Current, InputArg))
          break;
  
        if (Current->getType() == types::TY_Nothing)
          break;
      }
  
      // If we ended with something, add to the output list.
      if (Current)
        Actions.push_back(Current);
  
      // Add any top level actions generated for offloading.
      OffloadBuilder.appendTopLevelActions(Actions, Current, InputArg);
    }
  
    // Add a link action if necessary.
  
    if (LinkerInputs.empty()) {
      Arg *FinalPhaseArg;
      if (getFinalPhase(Args, &FinalPhaseArg) == phases::Link)
        OffloadBuilder.appendDeviceLinkActions(Actions);
    }
  
    if (!LinkerInputs.empty()) {
      if (Action *Wrapper = OffloadBuilder.makeHostLinkAction())
        LinkerInputs.push_back(Wrapper);
      Action *LA;
      // Check if this Linker Job should emit a static library.
      if (ShouldEmitStaticLibrary(Args)) {
        LA = C.MakeAction<StaticLibJobAction>(LinkerInputs, types::TY_Image);
      } else {
        LA = C.MakeAction<LinkJobAction>(LinkerInputs, types::TY_Image);
      }
      LA = OffloadBuilder.processHostLinkAction(LA);
      Actions.push_back(LA);
    }
  
    // Add an interface stubs merge action if necessary.
    if (!MergerInputs.empty())
      Actions.push_back(
          C.MakeAction<IfsMergeJobAction>(MergerInputs, types::TY_Image));
  
    if (Args.hasArg(options::OPT_emit_interface_stubs)) {
      auto PhaseList = types::getCompilationPhases(
          types::TY_IFS_CPP,
          Args.hasArg(options::OPT_c) ? phases::Compile : phases::IfsMerge);
  
      ActionList MergerInputs;
  
      for (auto &I : Inputs) {
        types::ID InputType = I.first;
        const Arg *InputArg = I.second;
  
        // Currently clang and the llvm assembler do not support generating symbol
        // stubs from assembly, so we skip the input on asm files. For ifs files
        // we rely on the normal pipeline setup in the pipeline setup code above.
        if (InputType == types::TY_IFS || InputType == types::TY_PP_Asm ||
            InputType == types::TY_Asm)
          continue;
  
        Action *Current = C.MakeAction<InputAction>(*InputArg, InputType);
  
        for (auto Phase : PhaseList) {
          switch (Phase) {
          default:
            llvm_unreachable(
                "IFS Pipeline can only consist of Compile followed by IfsMerge.");
          case phases::Compile: {
            // Only IfsMerge (llvm-ifs) can handle .o files by looking for ifs
            // files where the .o file is located. The compile action can not
            // handle this.
            if (InputType == types::TY_Object)
              break;
  
            Current = C.MakeAction<CompileJobAction>(Current, types::TY_IFS_CPP);
            break;
          }
          case phases::IfsMerge: {
            assert(Phase == PhaseList.back() &&
                   "merging must be final compilation step.");
            MergerInputs.push_back(Current);
            Current = nullptr;
            break;
          }
          }
        }
  
        // If we ended with something, add to the output list.
        if (Current)
          Actions.push_back(Current);
      }
  
      // Add an interface stubs merge action if necessary.
      if (!MergerInputs.empty())
        Actions.push_back(
            C.MakeAction<IfsMergeJobAction>(MergerInputs, types::TY_Image));
    }
  
    // If --print-supported-cpus, -mcpu=? or -mtune=? is specified, build a custom
    // Compile phase that prints out supported cpu models and quits.
    if (Arg *A = Args.getLastArg(options::OPT_print_supported_cpus)) {
      // Use the -mcpu=? flag as the dummy input to cc1.
      Actions.clear();
      Action *InputAc = C.MakeAction<InputAction>(*A, types::TY_C);
      Actions.push_back(
          C.MakeAction<PrecompileJobAction>(InputAc, types::TY_Nothing));
      for (auto &I : Inputs)
        I.second->claim();
    }
  
    // Claim ignored clang-cl options.
    Args.ClaimAllArgs(options::OPT_cl_ignored_Group);
  
    // Claim --cuda-host-only and --cuda-compile-host-device, which may be passed
    // to non-CUDA compilations and should not trigger warnings there.
    Args.ClaimAllArgs(options::OPT_cuda_host_only);
    Args.ClaimAllArgs(options::OPT_cuda_compile_host_device);
  }
  
  Action *Driver::ConstructPhaseAction(
      Compilation &C, const ArgList &Args, phases::ID Phase, Action *Input,
      Action::OffloadKind TargetDeviceOffloadKind) const {
    llvm::PrettyStackTraceString CrashInfo("Constructing phase actions");
  
    // Some types skip the assembler phase (e.g., llvm-bc), but we can't
    // encode this in the steps because the intermediate type depends on
    // arguments. Just special case here.
    if (Phase == phases::Assemble && Input->getType() != types::TY_PP_Asm)
      return Input;
  
    // Build the appropriate action.
    switch (Phase) {
    case phases::Link:
      llvm_unreachable("link action invalid here.");
    case phases::IfsMerge:
      llvm_unreachable("ifsmerge action invalid here.");
    case phases::Preprocess: {
      types::ID OutputTy;
      // -M and -MM specify the dependency file name by altering the output type,
      // -if -MD and -MMD are not specified.
      if (Args.hasArg(options::OPT_M, options::OPT_MM) &&
          !Args.hasArg(options::OPT_MD, options::OPT_MMD)) {
        OutputTy = types::TY_Dependencies;
      } else {
        OutputTy = Input->getType();
        if (!Args.hasFlag(options::OPT_frewrite_includes,
                          options::OPT_fno_rewrite_includes, false) &&
            !Args.hasFlag(options::OPT_frewrite_imports,
                          options::OPT_fno_rewrite_imports, false) &&
            !CCGenDiagnostics)
          OutputTy = types::getPreprocessedType(OutputTy);
        assert(OutputTy != types::TY_INVALID &&
               "Cannot preprocess this input type!");
      }
      return C.MakeAction<PreprocessJobAction>(Input, OutputTy);
    }
    case phases::Precompile: {
      types::ID OutputTy = getPrecompiledType(Input->getType());
      assert(OutputTy != types::TY_INVALID &&
             "Cannot precompile this input type!");
  
      // If we're given a module name, precompile header file inputs as a
      // module, not as a precompiled header.
      const char *ModName = nullptr;
      if (OutputTy == types::TY_PCH) {
        if (Arg *A = Args.getLastArg(options::OPT_fmodule_name_EQ))
          ModName = A->getValue();
        if (ModName)
          OutputTy = types::TY_ModuleFile;
      }
  
      if (Args.hasArg(options::OPT_fsyntax_only)) {
        // Syntax checks should not emit a PCH file
        OutputTy = types::TY_Nothing;
      }
  
      if (ModName)
        return C.MakeAction<HeaderModulePrecompileJobAction>(Input, OutputTy,
                                                             ModName);
      return C.MakeAction<PrecompileJobAction>(Input, OutputTy);
    }
    case phases::Compile: {
      if (Args.hasArg(options::OPT_fsyntax_only))
        return C.MakeAction<CompileJobAction>(Input, types::TY_Nothing);
      if (Args.hasArg(options::OPT_rewrite_objc))
        return C.MakeAction<CompileJobAction>(Input, types::TY_RewrittenObjC);
      if (Args.hasArg(options::OPT_rewrite_legacy_objc))
        return C.MakeAction<CompileJobAction>(Input,
                                              types::TY_RewrittenLegacyObjC);
      if (Args.hasArg(options::OPT__analyze))
        return C.MakeAction<AnalyzeJobAction>(Input, types::TY_Plist);
      if (Args.hasArg(options::OPT__migrate))
        return C.MakeAction<MigrateJobAction>(Input, types::TY_Remap);
      if (Args.hasArg(options::OPT_emit_ast))
        return C.MakeAction<CompileJobAction>(Input, types::TY_AST);
      if (Args.hasArg(options::OPT_module_file_info))
        return C.MakeAction<CompileJobAction>(Input, types::TY_ModuleFile);
      if (Args.hasArg(options::OPT_verify_pch))
        return C.MakeAction<VerifyPCHJobAction>(Input, types::TY_Nothing);
      return C.MakeAction<CompileJobAction>(Input, types::TY_LLVM_BC);
    }
    case phases::Backend: {
      if (isUsingLTO() && TargetDeviceOffloadKind == Action::OFK_None) {
        types::ID Output =
            Args.hasArg(options::OPT_S) ? types::TY_LTO_IR : types::TY_LTO_BC;
        return C.MakeAction<BackendJobAction>(Input, Output);
      }
      if (Args.hasArg(options::OPT_emit_llvm) ||
          (TargetDeviceOffloadKind == Action::OFK_HIP &&
           Args.hasFlag(options::OPT_fgpu_rdc, options::OPT_fno_gpu_rdc,
                        false))) {
        types::ID Output =
            Args.hasArg(options::OPT_S) ? types::TY_LLVM_IR : types::TY_LLVM_BC;
        return C.MakeAction<BackendJobAction>(Input, Output);
      }
      return C.MakeAction<BackendJobAction>(Input, types::TY_PP_Asm);
    }
    case phases::Assemble:
      return C.MakeAction<AssembleJobAction>(std::move(Input), types::TY_Object);
    }
  
    llvm_unreachable("invalid phase in ConstructPhaseAction");
  }
  
  void Driver::BuildJobs(Compilation &C) const {
    llvm::PrettyStackTraceString CrashInfo("Building compilation jobs");
  
    Arg *FinalOutput = C.getArgs().getLastArg(options::OPT_o);
  
    // It is an error to provide a -o option if we are making multiple output
    // files. There are exceptions:
    //
    // IfsMergeJob: when generating interface stubs enabled we want to be able to
    // generate the stub file at the same time that we generate the real
    // library/a.out. So when a .o, .so, etc are the output, with clang interface
    // stubs there will also be a .ifs and .ifso at the same location.
    //
    // CompileJob of type TY_IFS_CPP: when generating interface stubs is enabled
    // and -c is passed, we still want to be able to generate a .ifs file while
    // we are also generating .o files. So we allow more than one output file in
    // this case as well.
    //
    if (FinalOutput) {
      unsigned NumOutputs = 0;
      unsigned NumIfsOutputs = 0;
      for (const Action *A : C.getActions())
        if (A->getType() != types::TY_Nothing &&
            !(A->getKind() == Action::IfsMergeJobClass ||
              (A->getType() == clang::driver::types::TY_IFS_CPP &&
               A->getKind() == clang::driver::Action::CompileJobClass &&
               0 == NumIfsOutputs++) ||
              (A->getKind() == Action::BindArchClass && A->getInputs().size() &&
               A->getInputs().front()->getKind() == Action::IfsMergeJobClass)))
          ++NumOutputs;
  
      if (NumOutputs > 1) {
        Diag(clang::diag::err_drv_output_argument_with_multiple_files);
        FinalOutput = nullptr;
      }
    }
  
    const llvm::Triple &RawTriple = C.getDefaultToolChain().getTriple();
    if (RawTriple.isOSAIX()) {
      if (Arg *A = C.getArgs().getLastArg(options::OPT_G))
        Diag(diag::err_drv_unsupported_opt_for_target)
            << A->getSpelling() << RawTriple.str();
      if (LTOMode == LTOK_Thin)
        Diag(diag::err_drv_clang_unsupported) << "thinLTO on AIX";
    }
  
    // Collect the list of architectures.
    llvm::StringSet<> ArchNames;
    if (RawTriple.isOSBinFormatMachO())
      for (const Arg *A : C.getArgs())
        if (A->getOption().matches(options::OPT_arch))
          ArchNames.insert(A->getValue());
  
    // Set of (Action, canonical ToolChain triple) pairs we've built jobs for.
    std::map<std::pair<const Action *, std::string>, InputInfo> CachedResults;
    for (Action *A : C.getActions()) {
      // If we are linking an image for multiple archs then the linker wants
      // -arch_multiple and -final_output <final image name>. Unfortunately, this
      // doesn't fit in cleanly because we have to pass this information down.
      //
      // FIXME: This is a hack; find a cleaner way to integrate this into the
      // process.
      const char *LinkingOutput = nullptr;
      if (isa<LipoJobAction>(A)) {
        if (FinalOutput)
          LinkingOutput = FinalOutput->getValue();
        else
          LinkingOutput = getDefaultImageName();
      }
  
      BuildJobsForAction(C, A, &C.getDefaultToolChain(),
                         /*BoundArch*/ StringRef(),
                         /*AtTopLevel*/ true,
                         /*MultipleArchs*/ ArchNames.size() > 1,
                         /*LinkingOutput*/ LinkingOutput, CachedResults,
                         /*TargetDeviceOffloadKind*/ Action::OFK_None);
    }
  
    // If we have more than one job, then disable integrated-cc1 for now. Do this
    // also when we need to report process execution statistics.
    if (C.getJobs().size() > 1 || CCPrintProcessStats)
      for (auto &J : C.getJobs())
        J.InProcess = false;
  
    if (CCPrintProcessStats) {
      C.setPostCallback([=](const Command &Cmd, int Res) {
        Optional<llvm::sys::ProcessStatistics> ProcStat =
            Cmd.getProcessStatistics();
        if (!ProcStat)
          return;
  
        const char *LinkingOutput = nullptr;
        if (FinalOutput)
          LinkingOutput = FinalOutput->getValue();
        else if (!Cmd.getOutputFilenames().empty())
          LinkingOutput = Cmd.getOutputFilenames().front().c_str();
        else
          LinkingOutput = getDefaultImageName();
  
        if (CCPrintStatReportFilename.empty()) {
          using namespace llvm;
          // Human readable output.
          outs() << sys::path::filename(Cmd.getExecutable()) << ": "
                 << "output=" << LinkingOutput;
          outs() << ", total="
                 << format("%.3f", ProcStat->TotalTime.count() / 1000.) << " ms"
                 << ", user="
                 << format("%.3f", ProcStat->UserTime.count() / 1000.) << " ms"
                 << ", mem=" << ProcStat->PeakMemory << " Kb\n";
        } else {
          // CSV format.
          std::string Buffer;
          llvm::raw_string_ostream Out(Buffer);
          llvm::sys::printArg(Out, llvm::sys::path::filename(Cmd.getExecutable()),
                              /*Quote*/ true);
          Out << ',';
          llvm::sys::printArg(Out, LinkingOutput, true);
          Out << ',' << ProcStat->TotalTime.count() << ','
              << ProcStat->UserTime.count() << ',' << ProcStat->PeakMemory
              << '\n';
          Out.flush();
          std::error_code EC;
          llvm::raw_fd_ostream OS(CCPrintStatReportFilename, EC,
                                  llvm::sys::fs::OF_Append |
                                      llvm::sys::fs::OF_Text);
          if (EC)
            return;
          auto L = OS.lock();
          if (!L) {
            llvm::errs() << "ERROR: Cannot lock file "
                         << CCPrintStatReportFilename << ": "
                         << toString(L.takeError()) << "\n";
            return;
          }
          OS << Buffer;
          OS.flush();
        }
      });
    }
  
    // If the user passed -Qunused-arguments or there were errors, don't warn
    // about any unused arguments.
    if (Diags.hasErrorOccurred() ||
        C.getArgs().hasArg(options::OPT_Qunused_arguments))
      return;
  
    // Claim -### here.
    (void)C.getArgs().hasArg(options::OPT__HASH_HASH_HASH);
  
    // Claim --driver-mode, --rsp-quoting, it was handled earlier.
    (void)C.getArgs().hasArg(options::OPT_driver_mode);
    (void)C.getArgs().hasArg(options::OPT_rsp_quoting);
  
    for (Arg *A : C.getArgs()) {
      // FIXME: It would be nice to be able to send the argument to the
      // DiagnosticsEngine, so that extra values, position, and so on could be
      // printed.
      if (!A->isClaimed()) {
        if (A->getOption().hasFlag(options::NoArgumentUnused))
          continue;
  
        // Suppress the warning automatically if this is just a flag, and it is an
        // instance of an argument we already claimed.
        const Option &Opt = A->getOption();
        if (Opt.getKind() == Option::FlagClass) {
          bool DuplicateClaimed = false;
  
          for (const Arg *AA : C.getArgs().filtered(&Opt)) {
            if (AA->isClaimed()) {
              DuplicateClaimed = true;
              break;
            }
          }
  
          if (DuplicateClaimed)
            continue;
        }
  
        // In clang-cl, don't mention unknown arguments here since they have
        // already been warned about.
        if (!IsCLMode() || !A->getOption().matches(options::OPT_UNKNOWN))
          Diag(clang::diag::warn_drv_unused_argument)
              << A->getAsString(C.getArgs());
      }
    }
  }
  
  namespace {
  /// Utility class to control the collapse of dependent actions and select the
  /// tools accordingly.
  class ToolSelector final {
    /// The tool chain this selector refers to.
    const ToolChain &TC;
  
    /// The compilation this selector refers to.
    const Compilation &C;
  
    /// The base action this selector refers to.
    const JobAction *BaseAction;
  
    /// Set to true if the current toolchain refers to host actions.
    bool IsHostSelector;
  
    /// Set to true if save-temps and embed-bitcode functionalities are active.
    bool SaveTemps;
    bool EmbedBitcode;
  
    /// Get previous dependent action or null if that does not exist. If
    /// \a CanBeCollapsed is false, that action must be legal to collapse or
    /// null will be returned.
    const JobAction *getPrevDependentAction(const ActionList &Inputs,
                                            ActionList &SavedOffloadAction,
                                            bool CanBeCollapsed = true) {
      // An option can be collapsed only if it has a single input.
      if (Inputs.size() != 1)
        return nullptr;
  
      Action *CurAction = *Inputs.begin();
      if (CanBeCollapsed &&
          !CurAction->isCollapsingWithNextDependentActionLegal())
        return nullptr;
  
      // If the input action is an offload action. Look through it and save any
      // offload action that can be dropped in the event of a collapse.
      if (auto *OA = dyn_cast<OffloadAction>(CurAction)) {
        // If the dependent action is a device action, we will attempt to collapse
        // only with other device actions. Otherwise, we would do the same but
        // with host actions only.
        if (!IsHostSelector) {
          if (OA->hasSingleDeviceDependence(/*DoNotConsiderHostActions=*/true)) {
            CurAction =
                OA->getSingleDeviceDependence(/*DoNotConsiderHostActions=*/true);
            if (CanBeCollapsed &&
                !CurAction->isCollapsingWithNextDependentActionLegal())
              return nullptr;
            SavedOffloadAction.push_back(OA);
            return dyn_cast<JobAction>(CurAction);
          }
        } else if (OA->hasHostDependence()) {
          CurAction = OA->getHostDependence();
          if (CanBeCollapsed &&
              !CurAction->isCollapsingWithNextDependentActionLegal())
            return nullptr;
          SavedOffloadAction.push_back(OA);
          return dyn_cast<JobAction>(CurAction);
        }
        return nullptr;
      }
  
      return dyn_cast<JobAction>(CurAction);
    }
  
    /// Return true if an assemble action can be collapsed.
    bool canCollapseAssembleAction() const {
      return TC.useIntegratedAs() && !SaveTemps &&
             !C.getArgs().hasArg(options::OPT_via_file_asm) &&
             !C.getArgs().hasArg(options::OPT__SLASH_FA) &&
             !C.getArgs().hasArg(options::OPT__SLASH_Fa);
    }
  
    /// Return true if a preprocessor action can be collapsed.
    bool canCollapsePreprocessorAction() const {
      return !C.getArgs().hasArg(options::OPT_no_integrated_cpp) &&
             !C.getArgs().hasArg(options::OPT_traditional_cpp) && !SaveTemps &&
             !C.getArgs().hasArg(options::OPT_rewrite_objc);
    }
  
    /// Struct that relates an action with the offload actions that would be
    /// collapsed with it.
    struct JobActionInfo final {
      /// The action this info refers to.
      const JobAction *JA = nullptr;
      /// The offload actions we need to take care off if this action is
      /// collapsed.
      ActionList SavedOffloadAction;
    };
  
    /// Append collapsed offload actions from the give nnumber of elements in the
    /// action info array.
    static void AppendCollapsedOffloadAction(ActionList &CollapsedOffloadAction,
                                             ArrayRef<JobActionInfo> &ActionInfo,
                                             unsigned ElementNum) {
      assert(ElementNum <= ActionInfo.size() && "Invalid number of elements.");
      for (unsigned I = 0; I < ElementNum; ++I)
        CollapsedOffloadAction.append(ActionInfo[I].SavedOffloadAction.begin(),
                                      ActionInfo[I].SavedOffloadAction.end());
    }
  
    /// Functions that attempt to perform the combining. They detect if that is
    /// legal, and if so they update the inputs \a Inputs and the offload action
    /// that were collapsed in \a CollapsedOffloadAction. A tool that deals with
    /// the combined action is returned. If the combining is not legal or if the
    /// tool does not exist, null is returned.
    /// Currently three kinds of collapsing are supported:
    ///  - Assemble + Backend + Compile;
    ///  - Assemble + Backend ;
    ///  - Backend + Compile.
    const Tool *
    combineAssembleBackendCompile(ArrayRef<JobActionInfo> ActionInfo,
                                  ActionList &Inputs,
                                  ActionList &CollapsedOffloadAction) {
      if (ActionInfo.size() < 3 || !canCollapseAssembleAction())
        return nullptr;
      auto *AJ = dyn_cast<AssembleJobAction>(ActionInfo[0].JA);
      auto *BJ = dyn_cast<BackendJobAction>(ActionInfo[1].JA);
      auto *CJ = dyn_cast<CompileJobAction>(ActionInfo[2].JA);
      if (!AJ || !BJ || !CJ)
        return nullptr;
  
      // Get compiler tool.
      const Tool *T = TC.SelectTool(*CJ);
      if (!T)
        return nullptr;
  
      // Can't collapse if we don't have codegen support unless we are
      // emitting LLVM IR.
      bool OutputIsLLVM = types::isLLVMIR(ActionInfo[0].JA->getType());
      if (!T->hasIntegratedBackend() && !(OutputIsLLVM && T->canEmitIR()))
        return nullptr;
  
      // When using -fembed-bitcode, it is required to have the same tool (clang)
      // for both CompilerJA and BackendJA. Otherwise, combine two stages.
      if (EmbedBitcode) {
        const Tool *BT = TC.SelectTool(*BJ);
        if (BT == T)
          return nullptr;
      }
  
      if (!T->hasIntegratedAssembler())
        return nullptr;
  
      Inputs = CJ->getInputs();
      AppendCollapsedOffloadAction(CollapsedOffloadAction, ActionInfo,
                                   /*NumElements=*/3);
      return T;
    }
    const Tool *combineAssembleBackend(ArrayRef<JobActionInfo> ActionInfo,
                                       ActionList &Inputs,
                                       ActionList &CollapsedOffloadAction) {
      if (ActionInfo.size() < 2 || !canCollapseAssembleAction())
        return nullptr;
      auto *AJ = dyn_cast<AssembleJobAction>(ActionInfo[0].JA);
      auto *BJ = dyn_cast<BackendJobAction>(ActionInfo[1].JA);
      if (!AJ || !BJ)
        return nullptr;
  
      // Get backend tool.
      const Tool *T = TC.SelectTool(*BJ);
      if (!T)
        return nullptr;
  
      if (!T->hasIntegratedAssembler())
        return nullptr;
  
      Inputs = BJ->getInputs();
      AppendCollapsedOffloadAction(CollapsedOffloadAction, ActionInfo,
                                   /*NumElements=*/2);
      return T;
    }
    const Tool *combineBackendCompile(ArrayRef<JobActionInfo> ActionInfo,
                                      ActionList &Inputs,
                                      ActionList &CollapsedOffloadAction) {
      if (ActionInfo.size() < 2)
        return nullptr;
      auto *BJ = dyn_cast<BackendJobAction>(ActionInfo[0].JA);
      auto *CJ = dyn_cast<CompileJobAction>(ActionInfo[1].JA);
      if (!BJ || !CJ)
        return nullptr;
  
      // Check if the initial input (to the compile job or its predessor if one
      // exists) is LLVM bitcode. In that case, no preprocessor step is required
      // and we can still collapse the compile and backend jobs when we have
      // -save-temps. I.e. there is no need for a separate compile job just to
      // emit unoptimized bitcode.
      bool InputIsBitcode = true;
      for (size_t i = 1; i < ActionInfo.size(); i++)
        if (ActionInfo[i].JA->getType() != types::TY_LLVM_BC &&
            ActionInfo[i].JA->getType() != types::TY_LTO_BC) {
          InputIsBitcode = false;
          break;
        }
      if (!InputIsBitcode && !canCollapsePreprocessorAction())
        return nullptr;
  
      // Get compiler tool.
      const Tool *T = TC.SelectTool(*CJ);
      if (!T)
        return nullptr;
  
      // Can't collapse if we don't have codegen support unless we are
      // emitting LLVM IR.
      bool OutputIsLLVM = types::isLLVMIR(ActionInfo[0].JA->getType());
      if (!T->hasIntegratedBackend() && !(OutputIsLLVM && T->canEmitIR()))
        return nullptr;
  
      if (T->canEmitIR() && ((SaveTemps && !InputIsBitcode) || EmbedBitcode))
        return nullptr;
  
      Inputs = CJ->getInputs();
      AppendCollapsedOffloadAction(CollapsedOffloadAction, ActionInfo,
                                   /*NumElements=*/2);
      return T;
    }
  
    /// Updates the inputs if the obtained tool supports combining with
    /// preprocessor action, and the current input is indeed a preprocessor
    /// action. If combining results in the collapse of offloading actions, those
    /// are appended to \a CollapsedOffloadAction.
    void combineWithPreprocessor(const Tool *T, ActionList &Inputs,
                                 ActionList &CollapsedOffloadAction) {
      if (!T || !canCollapsePreprocessorAction() || !T->hasIntegratedCPP())
        return;
  
      // Attempt to get a preprocessor action dependence.
      ActionList PreprocessJobOffloadActions;
      ActionList NewInputs;
      for (Action *A : Inputs) {
        auto *PJ = getPrevDependentAction({A}, PreprocessJobOffloadActions);
        if (!PJ || !isa<PreprocessJobAction>(PJ)) {
          NewInputs.push_back(A);
          continue;
        }
  
        // This is legal to combine. Append any offload action we found and add the
        // current input to preprocessor inputs.
        CollapsedOffloadAction.append(PreprocessJobOffloadActions.begin(),
                                      PreprocessJobOffloadActions.end());
        NewInputs.append(PJ->input_begin(), PJ->input_end());
      }
      Inputs = NewInputs;
    }
  
  public:
    ToolSelector(const JobAction *BaseAction, const ToolChain &TC,
                 const Compilation &C, bool SaveTemps, bool EmbedBitcode)
        : TC(TC), C(C), BaseAction(BaseAction), SaveTemps(SaveTemps),
          EmbedBitcode(EmbedBitcode) {
      assert(BaseAction && "Invalid base action.");
      IsHostSelector = BaseAction->getOffloadingDeviceKind() == Action::OFK_None;
    }
  
    /// Check if a chain of actions can be combined and return the tool that can
    /// handle the combination of actions. The pointer to the current inputs \a
    /// Inputs and the list of offload actions \a CollapsedOffloadActions
    /// connected to collapsed actions are updated accordingly. The latter enables
    /// the caller of the selector to process them afterwards instead of just
    /// dropping them. If no suitable tool is found, null will be returned.
    const Tool *getTool(ActionList &Inputs,
                        ActionList &CollapsedOffloadAction) {
      //
      // Get the largest chain of actions that we could combine.
      //
  
      SmallVector<JobActionInfo, 5> ActionChain(1);
      ActionChain.back().JA = BaseAction;
      while (ActionChain.back().JA) {
        const Action *CurAction = ActionChain.back().JA;
  
        // Grow the chain by one element.
        ActionChain.resize(ActionChain.size() + 1);
        JobActionInfo &AI = ActionChain.back();
  
        // Attempt to fill it with the
        AI.JA =
            getPrevDependentAction(CurAction->getInputs(), AI.SavedOffloadAction);
      }
  
      // Pop the last action info as it could not be filled.
      ActionChain.pop_back();
  
      //
      // Attempt to combine actions. If all combining attempts failed, just return
      // the tool of the provided action. At the end we attempt to combine the
      // action with any preprocessor action it may depend on.
      //
  
      const Tool *T = combineAssembleBackendCompile(ActionChain, Inputs,
                                                    CollapsedOffloadAction);
      if (!T)
        T = combineAssembleBackend(ActionChain, Inputs, CollapsedOffloadAction);
      if (!T)
        T = combineBackendCompile(ActionChain, Inputs, CollapsedOffloadAction);
      if (!T) {
        Inputs = BaseAction->getInputs();
        T = TC.SelectTool(*BaseAction);
      }
  
      combineWithPreprocessor(T, Inputs, CollapsedOffloadAction);
      return T;
    }
  };
  }
  
  /// Return a string that uniquely identifies the result of a job. The bound arch
  /// is not necessarily represented in the toolchain's triple -- for example,
  /// armv7 and armv7s both map to the same triple -- so we need both in our map.
  /// Also, we need to add the offloading device kind, as the same tool chain can
  /// be used for host and device for some programming models, e.g. OpenMP.
  static std::string GetTriplePlusArchString(const ToolChain *TC,
                                             StringRef BoundArch,
                                             Action::OffloadKind OffloadKind) {
    std::string TriplePlusArch = TC->getTriple().normalize();
    if (!BoundArch.empty()) {
      TriplePlusArch += "-";
      TriplePlusArch += BoundArch;
    }
    TriplePlusArch += "-";
    TriplePlusArch += Action::GetOffloadKindName(OffloadKind);
    return TriplePlusArch;
  }
  
  InputInfo Driver::BuildJobsForAction(
      Compilation &C, const Action *A, const ToolChain *TC, StringRef BoundArch,
      bool AtTopLevel, bool MultipleArchs, const char *LinkingOutput,
      std::map<std::pair<const Action *, std::string>, InputInfo> &CachedResults,
      Action::OffloadKind TargetDeviceOffloadKind) const {
    std::pair<const Action *, std::string> ActionTC = {
        A, GetTriplePlusArchString(TC, BoundArch, TargetDeviceOffloadKind)};
    auto CachedResult = CachedResults.find(ActionTC);
    if (CachedResult != CachedResults.end()) {
      return CachedResult->second;
    }
    InputInfo Result = BuildJobsForActionNoCache(
        C, A, TC, BoundArch, AtTopLevel, MultipleArchs, LinkingOutput,
        CachedResults, TargetDeviceOffloadKind);
    CachedResults[ActionTC] = Result;
    return Result;
  }
  
  InputInfo Driver::BuildJobsForActionNoCache(
      Compilation &C, const Action *A, const ToolChain *TC, StringRef BoundArch,
      bool AtTopLevel, bool MultipleArchs, const char *LinkingOutput,
      std::map<std::pair<const Action *, std::string>, InputInfo> &CachedResults,
      Action::OffloadKind TargetDeviceOffloadKind) const {
    llvm::PrettyStackTraceString CrashInfo("Building compilation jobs");
  
    InputInfoList OffloadDependencesInputInfo;
    bool BuildingForOffloadDevice = TargetDeviceOffloadKind != Action::OFK_None;
    if (const OffloadAction *OA = dyn_cast<OffloadAction>(A)) {
      // The 'Darwin' toolchain is initialized only when its arguments are
      // computed. Get the default arguments for OFK_None to ensure that
      // initialization is performed before processing the offload action.
      // FIXME: Remove when darwin's toolchain is initialized during construction.
      C.getArgsForToolChain(TC, BoundArch, Action::OFK_None);
  
      // The offload action is expected to be used in four different situations.
      //
      // a) Set a toolchain/architecture/kind for a host action:
      //    Host Action 1 -> OffloadAction -> Host Action 2
      //
      // b) Set a toolchain/architecture/kind for a device action;
      //    Device Action 1 -> OffloadAction -> Device Action 2
      //
      // c) Specify a device dependence to a host action;
      //    Device Action 1  _
      //                      \
      //      Host Action 1  ---> OffloadAction -> Host Action 2
      //
      // d) Specify a host dependence to a device action.
      //      Host Action 1  _
      //                      \
      //    Device Action 1  ---> OffloadAction -> Device Action 2
      //
      // For a) and b), we just return the job generated for the dependence. For
      // c) and d) we override the current action with the host/device dependence
      // if the current toolchain is host/device and set the offload dependences
      // info with the jobs obtained from the device/host dependence(s).
  
      // If there is a single device option, just generate the job for it.
      if (OA->hasSingleDeviceDependence()) {
        InputInfo DevA;
        OA->doOnEachDeviceDependence([&](Action *DepA, const ToolChain *DepTC,
                                         const char *DepBoundArch) {
          DevA =
              BuildJobsForAction(C, DepA, DepTC, DepBoundArch, AtTopLevel,
                                 /*MultipleArchs*/ !!DepBoundArch, LinkingOutput,
                                 CachedResults, DepA->getOffloadingDeviceKind());
        });
        return DevA;
      }
  
      // If 'Action 2' is host, we generate jobs for the device dependences and
      // override the current action with the host dependence. Otherwise, we
      // generate the host dependences and override the action with the device
      // dependence. The dependences can't therefore be a top-level action.
      OA->doOnEachDependence(
          /*IsHostDependence=*/BuildingForOffloadDevice,
          [&](Action *DepA, const ToolChain *DepTC, const char *DepBoundArch) {
            OffloadDependencesInputInfo.push_back(BuildJobsForAction(
                C, DepA, DepTC, DepBoundArch, /*AtTopLevel=*/false,
                /*MultipleArchs*/ !!DepBoundArch, LinkingOutput, CachedResults,
                DepA->getOffloadingDeviceKind()));
          });
  
      A = BuildingForOffloadDevice
              ? OA->getSingleDeviceDependence(/*DoNotConsiderHostActions=*/true)
              : OA->getHostDependence();
    }
  
    if (const InputAction *IA = dyn_cast<InputAction>(A)) {
      // FIXME: It would be nice to not claim this here; maybe the old scheme of
      // just using Args was better?
      const Arg &Input = IA->getInputArg();
      Input.claim();
      if (Input.getOption().matches(options::OPT_INPUT)) {
        const char *Name = Input.getValue();
        return InputInfo(A, Name, /* _BaseInput = */ Name);
      }
      return InputInfo(A, &Input, /* _BaseInput = */ "");
    }
  
    if (const BindArchAction *BAA = dyn_cast<BindArchAction>(A)) {
      const ToolChain *TC;
      StringRef ArchName = BAA->getArchName();
  
      if (!ArchName.empty())
        TC = &getToolChain(C.getArgs(),
                           computeTargetTriple(*this, TargetTriple,
                                               C.getArgs(), ArchName));
      else
        TC = &C.getDefaultToolChain();
  
      return BuildJobsForAction(C, *BAA->input_begin(), TC, ArchName, AtTopLevel,
                                MultipleArchs, LinkingOutput, CachedResults,
                                TargetDeviceOffloadKind);
    }
  
  
    ActionList Inputs = A->getInputs();
  
    const JobAction *JA = cast<JobAction>(A);
    ActionList CollapsedOffloadActions;
  
    ToolSelector TS(JA, *TC, C, isSaveTempsEnabled(),
                    embedBitcodeInObject() && !isUsingLTO());
    const Tool *T = TS.getTool(Inputs, CollapsedOffloadActions);
  
    if (!T)
      return InputInfo();
  
    if (BuildingForOffloadDevice &&
        A->getOffloadingDeviceKind() == Action::OFK_OpenMP) {
      if (TC->getTriple().isAMDGCN()) {
        // AMDGCN treats backend and assemble actions as no-op because
        // linker does not support object files.
        if (const BackendJobAction *BA = dyn_cast<BackendJobAction>(A)) {
          return BuildJobsForAction(C, *BA->input_begin(), TC, BoundArch,
                                    AtTopLevel, MultipleArchs, LinkingOutput,
                                    CachedResults, TargetDeviceOffloadKind);
        }
  
        if (const AssembleJobAction *AA = dyn_cast<AssembleJobAction>(A)) {
          return BuildJobsForAction(C, *AA->input_begin(), TC, BoundArch,
                                    AtTopLevel, MultipleArchs, LinkingOutput,
                                    CachedResults, TargetDeviceOffloadKind);
        }
      }
    }
  
    // If we've collapsed action list that contained OffloadAction we
    // need to build jobs for host/device-side inputs it may have held.
    for (const auto *OA : CollapsedOffloadActions)
      cast<OffloadAction>(OA)->doOnEachDependence(
          /*IsHostDependence=*/BuildingForOffloadDevice,
          [&](Action *DepA, const ToolChain *DepTC, const char *DepBoundArch) {
            OffloadDependencesInputInfo.push_back(BuildJobsForAction(
                C, DepA, DepTC, DepBoundArch, /* AtTopLevel */ false,
                /*MultipleArchs=*/!!DepBoundArch, LinkingOutput, CachedResults,
                DepA->getOffloadingDeviceKind()));
          });
  
    // Only use pipes when there is exactly one input.
    InputInfoList InputInfos;
    for (const Action *Input : Inputs) {
      // Treat dsymutil and verify sub-jobs as being at the top-level too, they
      // shouldn't get temporary output names.
      // FIXME: Clean this up.
      bool SubJobAtTopLevel =
          AtTopLevel && (isa<DsymutilJobAction>(A) || isa<VerifyJobAction>(A));
      InputInfos.push_back(BuildJobsForAction(
          C, Input, TC, BoundArch, SubJobAtTopLevel, MultipleArchs, LinkingOutput,
          CachedResults, A->getOffloadingDeviceKind()));
    }
  
    // Always use the first file input as the base input.
    const char *BaseInput = InputInfos[0].getBaseInput();
    for (auto &Info : InputInfos) {
      if (Info.isFilename()) {
        BaseInput = Info.getBaseInput();
        break;
      }
    }
  
    // ... except dsymutil actions, which use their actual input as the base
    // input.
    if (JA->getType() == types::TY_dSYM)
      BaseInput = InputInfos[0].getFilename();
  
    // ... and in header module compilations, which use the module name.
    if (auto *ModuleJA = dyn_cast<HeaderModulePrecompileJobAction>(JA))
      BaseInput = ModuleJA->getModuleName();
  
    // Append outputs of offload device jobs to the input list
    if (!OffloadDependencesInputInfo.empty())
      InputInfos.append(OffloadDependencesInputInfo.begin(),
                        OffloadDependencesInputInfo.end());
  
    // Set the effective triple of the toolchain for the duration of this job.
    llvm::Triple EffectiveTriple;
    const ToolChain &ToolTC = T->getToolChain();
    const ArgList &Args =
        C.getArgsForToolChain(TC, BoundArch, A->getOffloadingDeviceKind());
    if (InputInfos.size() != 1) {
      EffectiveTriple = llvm::Triple(ToolTC.ComputeEffectiveClangTriple(Args));
    } else {
      // Pass along the input type if it can be unambiguously determined.
      EffectiveTriple = llvm::Triple(
          ToolTC.ComputeEffectiveClangTriple(Args, InputInfos[0].getType()));
    }
    RegisterEffectiveTriple TripleRAII(ToolTC, EffectiveTriple);
  
    // Determine the place to write output to, if any.
    InputInfo Result;
    InputInfoList UnbundlingResults;
    if (auto *UA = dyn_cast<OffloadUnbundlingJobAction>(JA)) {
      // If we have an unbundling job, we need to create results for all the
      // outputs. We also update the results cache so that other actions using
      // this unbundling action can get the right results.
      for (auto &UI : UA->getDependentActionsInfo()) {
        assert(UI.DependentOffloadKind != Action::OFK_None &&
               "Unbundling with no offloading??");
  
        // Unbundling actions are never at the top level. When we generate the
        // offloading prefix, we also do that for the host file because the
        // unbundling action does not change the type of the output which can
        // cause a overwrite.
        std::string OffloadingPrefix = Action::GetOffloadingFileNamePrefix(
            UI.DependentOffloadKind,
            UI.DependentToolChain->getTriple().normalize(),
            /*CreatePrefixForHost=*/true);
        auto CurI = InputInfo(
            UA,
            GetNamedOutputPath(C, *UA, BaseInput, UI.DependentBoundArch,
                               /*AtTopLevel=*/false,
                               MultipleArchs ||
                                   UI.DependentOffloadKind == Action::OFK_HIP,
                               OffloadingPrefix),
            BaseInput);
        // Save the unbundling result.
        UnbundlingResults.push_back(CurI);
  
        // Get the unique string identifier for this dependence and cache the
        // result.
        StringRef Arch;
        if (TargetDeviceOffloadKind == Action::OFK_HIP) {
          if (UI.DependentOffloadKind == Action::OFK_Host)
            Arch = StringRef();
          else
            Arch = UI.DependentBoundArch;
        } else
          Arch = BoundArch;
  
        CachedResults[{A, GetTriplePlusArchString(UI.DependentToolChain, Arch,
                                                  UI.DependentOffloadKind)}] =
            CurI;
      }
  
      // Now that we have all the results generated, select the one that should be
      // returned for the current depending action.
      std::pair<const Action *, std::string> ActionTC = {
          A, GetTriplePlusArchString(TC, BoundArch, TargetDeviceOffloadKind)};
      assert(CachedResults.find(ActionTC) != CachedResults.end() &&
             "Result does not exist??");
      Result = CachedResults[ActionTC];
    } else if (JA->getType() == types::TY_Nothing)
      Result = InputInfo(A, BaseInput);
    else {
      // We only have to generate a prefix for the host if this is not a top-level
      // action.
      std::string OffloadingPrefix = Action::GetOffloadingFileNamePrefix(
          A->getOffloadingDeviceKind(), TC->getTriple().normalize(),
          /*CreatePrefixForHost=*/!!A->getOffloadingHostActiveKinds() &&
              !AtTopLevel);
      if (isa<OffloadWrapperJobAction>(JA)) {
        if (Arg *FinalOutput = C.getArgs().getLastArg(options::OPT_o))
          BaseInput = FinalOutput->getValue();
        else
          BaseInput = getDefaultImageName();
        BaseInput =
            C.getArgs().MakeArgString(std::string(BaseInput) + "-wrapper");
      }
      Result = InputInfo(A, GetNamedOutputPath(C, *JA, BaseInput, BoundArch,
                                               AtTopLevel, MultipleArchs,
                                               OffloadingPrefix),
                         BaseInput);
    }
  
    if (CCCPrintBindings && !CCGenDiagnostics) {
      llvm::errs() << "# \"" << T->getToolChain().getTripleString() << '"'
                   << " - \"" << T->getName() << "\", inputs: [";
      for (unsigned i = 0, e = InputInfos.size(); i != e; ++i) {
        llvm::errs() << InputInfos[i].getAsString();
        if (i + 1 != e)
          llvm::errs() << ", ";
      }
      if (UnbundlingResults.empty())
        llvm::errs() << "], output: " << Result.getAsString() << "\n";
      else {
        llvm::errs() << "], outputs: [";
        for (unsigned i = 0, e = UnbundlingResults.size(); i != e; ++i) {
          llvm::errs() << UnbundlingResults[i].getAsString();
          if (i + 1 != e)
            llvm::errs() << ", ";
        }
        llvm::errs() << "] \n";
      }
    } else {
      if (UnbundlingResults.empty())
        T->ConstructJob(
            C, *JA, Result, InputInfos,
            C.getArgsForToolChain(TC, BoundArch, JA->getOffloadingDeviceKind()),
            LinkingOutput);
      else
        T->ConstructJobMultipleOutputs(
            C, *JA, UnbundlingResults, InputInfos,
            C.getArgsForToolChain(TC, BoundArch, JA->getOffloadingDeviceKind()),
            LinkingOutput);
    }
    return Result;
  }
  
  const char *Driver::getDefaultImageName() const {
    llvm::Triple Target(llvm::Triple::normalize(TargetTriple));
    return Target.isOSWindows() ? "a.exe" : "a.out";
  }
  
  /// Create output filename based on ArgValue, which could either be a
  /// full filename, filename without extension, or a directory. If ArgValue
  /// does not provide a filename, then use BaseName, and use the extension
  /// suitable for FileType.
  static const char *MakeCLOutputFilename(const ArgList &Args, StringRef ArgValue,
                                          StringRef BaseName,
                                          types::ID FileType) {
    SmallString<128> Filename = ArgValue;
  
    if (ArgValue.empty()) {
      // If the argument is empty, output to BaseName in the current dir.
      Filename = BaseName;
    } else if (llvm::sys::path::is_separator(Filename.back())) {
      // If the argument is a directory, output to BaseName in that dir.
      llvm::sys::path::append(Filename, BaseName);
    }
  
    if (!llvm::sys::path::has_extension(ArgValue)) {
      // If the argument didn't provide an extension, then set it.
      const char *Extension = types::getTypeTempSuffix(FileType, true);
  
      if (FileType == types::TY_Image &&
          Args.hasArg(options::OPT__SLASH_LD, options::OPT__SLASH_LDd)) {
        // The output file is a dll.
        Extension = "dll";
      }
  
      llvm::sys::path::replace_extension(Filename, Extension);
    }
  
    return Args.MakeArgString(Filename.c_str());
  }
  
  static bool HasPreprocessOutput(const Action &JA) {
    if (isa<PreprocessJobAction>(JA))
      return true;
    if (isa<OffloadAction>(JA) && isa<PreprocessJobAction>(JA.getInputs()[0]))
      return true;
    if (isa<OffloadBundlingJobAction>(JA) &&
        HasPreprocessOutput(*(JA.getInputs()[0])))
      return true;
    return false;
  }
  
  const char *Driver::GetNamedOutputPath(Compilation &C, const JobAction &JA,
                                         const char *BaseInput,
                                         StringRef OrigBoundArch, bool AtTopLevel,
                                         bool MultipleArchs,
                                         StringRef OffloadingPrefix) const {
    std::string BoundArch = OrigBoundArch.str();
    if (is_style_windows(llvm::sys::path::Style::native)) {
      // BoundArch may contains ':', which is invalid in file names on Windows,
      // therefore replace it with '%'.
      std::replace(BoundArch.begin(), BoundArch.end(), ':', '@');
    }
  
    llvm::PrettyStackTraceString CrashInfo("Computing output path");
    // Output to a user requested destination?
    if (AtTopLevel && !isa<DsymutilJobAction>(JA) && !isa<VerifyJobAction>(JA)) {
      if (Arg *FinalOutput = C.getArgs().getLastArg(options::OPT_o))
        return C.addResultFile(FinalOutput->getValue(), &JA);
    }
  
    // For /P, preprocess to file named after BaseInput.
    if (C.getArgs().hasArg(options::OPT__SLASH_P)) {
      assert(AtTopLevel && isa<PreprocessJobAction>(JA));
      StringRef BaseName = llvm::sys::path::filename(BaseInput);
      StringRef NameArg;
      if (Arg *A = C.getArgs().getLastArg(options::OPT__SLASH_Fi))
        NameArg = A->getValue();
      return C.addResultFile(
          MakeCLOutputFilename(C.getArgs(), NameArg, BaseName, types::TY_PP_C),
          &JA);
    }
  
    // Default to writing to stdout?
    if (AtTopLevel && !CCGenDiagnostics && HasPreprocessOutput(JA)) {
      return "-";
    }
  
    if (JA.getType() == types::TY_ModuleFile &&
        C.getArgs().getLastArg(options::OPT_module_file_info)) {
      return "-";
    }
  
    // Is this the assembly listing for /FA?
    if (JA.getType() == types::TY_PP_Asm &&
        (C.getArgs().hasArg(options::OPT__SLASH_FA) ||
         C.getArgs().hasArg(options::OPT__SLASH_Fa))) {
      // Use /Fa and the input filename to determine the asm file name.
      StringRef BaseName = llvm::sys::path::filename(BaseInput);
      StringRef FaValue = C.getArgs().getLastArgValue(options::OPT__SLASH_Fa);
      return C.addResultFile(
          MakeCLOutputFilename(C.getArgs(), FaValue, BaseName, JA.getType()),
          &JA);
    }
  
    // Output to a temporary file?
    if ((!AtTopLevel && !isSaveTempsEnabled() &&
         !C.getArgs().hasArg(options::OPT__SLASH_Fo)) ||
        CCGenDiagnostics) {
      StringRef Name = llvm::sys::path::filename(BaseInput);
      std::pair<StringRef, StringRef> Split = Name.split('.');
      SmallString<128> TmpName;
      const char *Suffix = types::getTypeTempSuffix(JA.getType(), IsCLMode());
      Arg *A = C.getArgs().getLastArg(options::OPT_fcrash_diagnostics_dir);
      if (CCGenDiagnostics && A) {
        SmallString<128> CrashDirectory(A->getValue());
        if (!getVFS().exists(CrashDirectory))
          llvm::sys::fs::create_directories(CrashDirectory);
        llvm::sys::path::append(CrashDirectory, Split.first);
        const char *Middle = Suffix ? "-%%%%%%." : "-%%%%%%";
        std::error_code EC = llvm::sys::fs::createUniqueFile(
            CrashDirectory + Middle + Suffix, TmpName);
        if (EC) {
          Diag(clang::diag::err_unable_to_make_temp) << EC.message();
          return "";
        }
      } else {
        if (MultipleArchs && !BoundArch.empty()) {
          TmpName = GetTemporaryDirectory(Split.first);
          llvm::sys::path::append(TmpName,
                                  Split.first + "-" + BoundArch + "." + Suffix);
        } else {
          TmpName = GetTemporaryPath(Split.first, Suffix);
        }
      }
      return C.addTempFile(C.getArgs().MakeArgString(TmpName));
    }
  
    SmallString<128> BasePath(BaseInput);
    SmallString<128> ExternalPath("");
    StringRef BaseName;
  
    // Dsymutil actions should use the full path.
    if (isa<DsymutilJobAction>(JA) && C.getArgs().hasArg(options::OPT_dsym_dir)) {
      ExternalPath += C.getArgs().getLastArg(options::OPT_dsym_dir)->getValue();
      // We use posix style here because the tests (specifically
      // darwin-dsymutil.c) demonstrate that posix style paths are acceptable
      // even on Windows and if we don't then the similar test covering this
      // fails.
      llvm::sys::path::append(ExternalPath, llvm::sys::path::Style::posix,
                              llvm::sys::path::filename(BasePath));
      BaseName = ExternalPath;
    } else if (isa<DsymutilJobAction>(JA) || isa<VerifyJobAction>(JA))
      BaseName = BasePath;
    else
      BaseName = llvm::sys::path::filename(BasePath);
  
    // Determine what the derived output name should be.
    const char *NamedOutput;
  
    if ((JA.getType() == types::TY_Object || JA.getType() == types::TY_LTO_BC) &&
        C.getArgs().hasArg(options::OPT__SLASH_Fo, options::OPT__SLASH_o)) {
      // The /Fo or /o flag decides the object filename.
      StringRef Val =
          C.getArgs()
              .getLastArg(options::OPT__SLASH_Fo, options::OPT__SLASH_o)
              ->getValue();
      NamedOutput =
          MakeCLOutputFilename(C.getArgs(), Val, BaseName, types::TY_Object);
    } else if (JA.getType() == types::TY_Image &&
               C.getArgs().hasArg(options::OPT__SLASH_Fe,
                                  options::OPT__SLASH_o)) {
      // The /Fe or /o flag names the linked file.
      StringRef Val =
          C.getArgs()
              .getLastArg(options::OPT__SLASH_Fe, options::OPT__SLASH_o)
              ->getValue();
      NamedOutput =
          MakeCLOutputFilename(C.getArgs(), Val, BaseName, types::TY_Image);
    } else if (JA.getType() == types::TY_Image) {
      if (IsCLMode()) {
        // clang-cl uses BaseName for the executable name.
        NamedOutput =
            MakeCLOutputFilename(C.getArgs(), "", BaseName, types::TY_Image);
      } else {
        SmallString<128> Output(getDefaultImageName());
        // HIP image for device compilation with -fno-gpu-rdc is per compilation
        // unit.
        bool IsHIPNoRDC = JA.getOffloadingDeviceKind() == Action::OFK_HIP &&
                          !C.getArgs().hasFlag(options::OPT_fgpu_rdc,
                                               options::OPT_fno_gpu_rdc, false);
        if (IsHIPNoRDC) {
          Output = BaseName;
          llvm::sys::path::replace_extension(Output, "");
        }
        Output += OffloadingPrefix;
        if (MultipleArchs && !BoundArch.empty()) {
          Output += "-";
          Output.append(BoundArch);
        }
        if (IsHIPNoRDC)
          Output += ".out";
        NamedOutput = C.getArgs().MakeArgString(Output.c_str());
      }
    } else if (JA.getType() == types::TY_PCH && IsCLMode()) {
      NamedOutput = C.getArgs().MakeArgString(GetClPchPath(C, BaseName));
    } else {
      const char *Suffix = types::getTypeTempSuffix(JA.getType(), IsCLMode());
      assert(Suffix && "All types used for output should have a suffix.");
  
      std::string::size_type End = std::string::npos;
      if (!types::appendSuffixForType(JA.getType()))
        End = BaseName.rfind('.');
      SmallString<128> Suffixed(BaseName.substr(0, End));
      Suffixed += OffloadingPrefix;
      if (MultipleArchs && !BoundArch.empty()) {
        Suffixed += "-";
        Suffixed.append(BoundArch);
      }
      // When using both -save-temps and -emit-llvm, use a ".tmp.bc" suffix for
      // the unoptimized bitcode so that it does not get overwritten by the ".bc"
      // optimized bitcode output.
      auto IsHIPRDCInCompilePhase = [](const JobAction &JA,
                                       const llvm::opt::DerivedArgList &Args) {
        // The relocatable compilation in HIP implies -emit-llvm. Similarly, use a
        // ".tmp.bc" suffix for the unoptimized bitcode (generated in the compile
        // phase.)
        return isa<CompileJobAction>(JA) &&
               JA.getOffloadingDeviceKind() == Action::OFK_HIP &&
               Args.hasFlag(options::OPT_fgpu_rdc, options::OPT_fno_gpu_rdc,
                            false);
      };
      if (!AtTopLevel && JA.getType() == types::TY_LLVM_BC &&
          (C.getArgs().hasArg(options::OPT_emit_llvm) ||
           IsHIPRDCInCompilePhase(JA, C.getArgs())))
        Suffixed += ".tmp";
      Suffixed += '.';
      Suffixed += Suffix;
      NamedOutput = C.getArgs().MakeArgString(Suffixed.c_str());
    }
  
    // Prepend object file path if -save-temps=obj
    if (!AtTopLevel && isSaveTempsObj() && C.getArgs().hasArg(options::OPT_o) &&
        JA.getType() != types::TY_PCH) {
      Arg *FinalOutput = C.getArgs().getLastArg(options::OPT_o);
      SmallString<128> TempPath(FinalOutput->getValue());
      llvm::sys::path::remove_filename(TempPath);
      StringRef OutputFileName = llvm::sys::path::filename(NamedOutput);
      llvm::sys::path::append(TempPath, OutputFileName);
      NamedOutput = C.getArgs().MakeArgString(TempPath.c_str());
    }
  
    // If we're saving temps and the temp file conflicts with the input file,
    // then avoid overwriting input file.
    if (!AtTopLevel && isSaveTempsEnabled() && NamedOutput == BaseName) {
      bool SameFile = false;
      SmallString<256> Result;
      llvm::sys::fs::current_path(Result);
      llvm::sys::path::append(Result, BaseName);
      llvm::sys::fs::equivalent(BaseInput, Result.c_str(), SameFile);
      // Must share the same path to conflict.
      if (SameFile) {
        StringRef Name = llvm::sys::path::filename(BaseInput);
        std::pair<StringRef, StringRef> Split = Name.split('.');
        std::string TmpName = GetTemporaryPath(
            Split.first, types::getTypeTempSuffix(JA.getType(), IsCLMode()));
        return C.addTempFile(C.getArgs().MakeArgString(TmpName));
      }
    }
  
    // As an annoying special case, PCH generation doesn't strip the pathname.
    if (JA.getType() == types::TY_PCH && !IsCLMode()) {
      llvm::sys::path::remove_filename(BasePath);
      if (BasePath.empty())
        BasePath = NamedOutput;
      else
        llvm::sys::path::append(BasePath, NamedOutput);
      return C.addResultFile(C.getArgs().MakeArgString(BasePath.c_str()), &JA);
    } else {
      return C.addResultFile(NamedOutput, &JA);
    }
  }
  
  std::string Driver::GetFilePath(StringRef Name, const ToolChain &TC) const {
    // Search for Name in a list of paths.
    auto SearchPaths = [&](const llvm::SmallVectorImpl<std::string> &P)
        -> llvm::Optional<std::string> {
      // Respect a limited subset of the '-Bprefix' functionality in GCC by
      // attempting to use this prefix when looking for file paths.
      for (const auto &Dir : P) {
        if (Dir.empty())
          continue;
        SmallString<128> P(Dir[0] == '=' ? SysRoot + Dir.substr(1) : Dir);
        llvm::sys::path::append(P, Name);
        if (llvm::sys::fs::exists(Twine(P)))
          return std::string(P);
      }
      return None;
    };
  
    if (auto P = SearchPaths(PrefixDirs))
      return *P;
  
    SmallString<128> R(ResourceDir);
    llvm::sys::path::append(R, Name);
    if (llvm::sys::fs::exists(Twine(R)))
      return std::string(R.str());
  
    SmallString<128> P(TC.getCompilerRTPath());
    llvm::sys::path::append(P, Name);
    if (llvm::sys::fs::exists(Twine(P)))
      return std::string(P.str());
  
    SmallString<128> D(Dir);
    llvm::sys::path::append(D, "..", Name);
    if (llvm::sys::fs::exists(Twine(D)))
      return std::string(D.str());
  
    if (auto P = SearchPaths(TC.getLibraryPaths()))
      return *P;
  
    if (auto P = SearchPaths(TC.getFilePaths()))
      return *P;
  
    return std::string(Name);
  }
  
  void Driver::generatePrefixedToolNames(
      StringRef Tool, const ToolChain &TC,
      SmallVectorImpl<std::string> &Names) const {
    // FIXME: Needs a better variable than TargetTriple
    Names.emplace_back((TargetTriple + "-" + Tool).str());
    Names.emplace_back(Tool);
  }
  
  static bool ScanDirForExecutable(SmallString<128> &Dir, StringRef Name) {
    llvm::sys::path::append(Dir, Name);
    if (llvm::sys::fs::can_execute(Twine(Dir)))
      return true;
    llvm::sys::path::remove_filename(Dir);
    return false;
  }
  
  std::string Driver::GetProgramPath(StringRef Name, const ToolChain &TC) const {
    SmallVector<std::string, 2> TargetSpecificExecutables;
    generatePrefixedToolNames(Name, TC, TargetSpecificExecutables);
  
    // Respect a limited subset of the '-Bprefix' functionality in GCC by
    // attempting to use this prefix when looking for program paths.
    for (const auto &PrefixDir : PrefixDirs) {
      if (llvm::sys::fs::is_directory(PrefixDir)) {
        SmallString<128> P(PrefixDir);
        if (ScanDirForExecutable(P, Name))
          return std::string(P.str());
      } else {
        SmallString<128> P((PrefixDir + Name).str());
        if (llvm::sys::fs::can_execute(Twine(P)))
          return std::string(P.str());
      }
    }
  
    const ToolChain::path_list &List = TC.getProgramPaths();
    for (const auto &TargetSpecificExecutable : TargetSpecificExecutables) {
      // For each possible name of the tool look for it in
      // program paths first, then the path.
      // Higher priority names will be first, meaning that
      // a higher priority name in the path will be found
      // instead of a lower priority name in the program path.
      // E.g. <triple>-gcc on the path will be found instead
      // of gcc in the program path
      for (const auto &Path : List) {
        SmallString<128> P(Path);
        if (ScanDirForExecutable(P, TargetSpecificExecutable))
          return std::string(P.str());
      }
  
      // Fall back to the path
      if (llvm::ErrorOr<std::string> P =
              llvm::sys::findProgramByName(TargetSpecificExecutable))
        return *P;
    }
  
    return std::string(Name);
  }
  
  std::string Driver::GetTemporaryPath(StringRef Prefix, StringRef Suffix) const {
    SmallString<128> Path;
    std::error_code EC = llvm::sys::fs::createTemporaryFile(Prefix, Suffix, Path);
    if (EC) {
      Diag(clang::diag::err_unable_to_make_temp) << EC.message();
      return "";
    }
  
    return std::string(Path.str());
  }
  
  std::string Driver::GetTemporaryDirectory(StringRef Prefix) const {
    SmallString<128> Path;
    std::error_code EC = llvm::sys::fs::createUniqueDirectory(Prefix, Path);
    if (EC) {
      Diag(clang::diag::err_unable_to_make_temp) << EC.message();
      return "";
    }
  
    return std::string(Path.str());
  }
  
  std::string Driver::GetClPchPath(Compilation &C, StringRef BaseName) const {
    SmallString<128> Output;
    if (Arg *FpArg = C.getArgs().getLastArg(options::OPT__SLASH_Fp)) {
      // FIXME: If anybody needs it, implement this obscure rule:
      // "If you specify a directory without a file name, the default file name
      // is VCx0.pch., where x is the major version of Visual C++ in use."
      Output = FpArg->getValue();
  
      // "If you do not specify an extension as part of the path name, an
      // extension of .pch is assumed. "
      if (!llvm::sys::path::has_extension(Output))
        Output += ".pch";
    } else {
      if (Arg *YcArg = C.getArgs().getLastArg(options::OPT__SLASH_Yc))
        Output = YcArg->getValue();
      if (Output.empty())
        Output = BaseName;
      llvm::sys::path::replace_extension(Output, ".pch");
    }
    return std::string(Output.str());
  }
  
  const ToolChain &Driver::getToolChain(const ArgList &Args,
                                        const llvm::Triple &Target) const {
  
    auto &TC = ToolChains[Target.str()];
    if (!TC) {
      switch (Target.getOS()) {
      case llvm::Triple::AIX:
        TC = std::make_unique<toolchains::AIX>(*this, Target, Args);
        break;
      case llvm::Triple::Haiku:
        TC = std::make_unique<toolchains::Haiku>(*this, Target, Args);
        break;
      case llvm::Triple::Ananas:
        TC = std::make_unique<toolchains::Ananas>(*this, Target, Args);
        break;
      case llvm::Triple::CloudABI:
        TC = std::make_unique<toolchains::CloudABI>(*this, Target, Args);
        break;
      case llvm::Triple::Darwin:
      case llvm::Triple::MacOSX:
      case llvm::Triple::IOS:
      case llvm::Triple::TvOS:
      case llvm::Triple::WatchOS:
        TC = std::make_unique<toolchains::DarwinClang>(*this, Target, Args);
        break;
      case llvm::Triple::DragonFly:
        TC = std::make_unique<toolchains::DragonFly>(*this, Target, Args);
        break;
      case llvm::Triple::OpenBSD:
        TC = std::make_unique<toolchains::OpenBSD>(*this, Target, Args);
        break;
      case llvm::Triple::NetBSD:
        TC = std::make_unique<toolchains::NetBSD>(*this, Target, Args);
        break;
      case llvm::Triple::FreeBSD:
        if (Target.isPPC())
          TC = std::make_unique<toolchains::PPCFreeBSDToolChain>(*this, Target,
                                                                 Args);
        else
          TC = std::make_unique<toolchains::FreeBSD>(*this, Target, Args);
        break;
      case llvm::Triple::Minix:
        TC = std::make_unique<toolchains::Minix>(*this, Target, Args);
        break;
      case llvm::Triple::Linux:
      case llvm::Triple::ELFIAMCU:
        if (Target.getArch() == llvm::Triple::hexagon)
          TC = std::make_unique<toolchains::HexagonToolChain>(*this, Target,
                                                               Args);
        else if ((Target.getVendor() == llvm::Triple::MipsTechnologies) &&
                 !Target.hasEnvironment())
          TC = std::make_unique<toolchains::MipsLLVMToolChain>(*this, Target,
                                                                Args);
        else if (Target.isPPC())
          TC = std::make_unique<toolchains::PPCLinuxToolChain>(*this, Target,
                                                                Args);
        else if (Target.getArch() == llvm::Triple::ve)
          TC = std::make_unique<toolchains::VEToolChain>(*this, Target, Args);
  
        else
          TC = std::make_unique<toolchains::Linux>(*this, Target, Args);
        break;
      case llvm::Triple::NaCl:
        TC = std::make_unique<toolchains::NaClToolChain>(*this, Target, Args);
        break;
      case llvm::Triple::Fuchsia:
        TC = std::make_unique<toolchains::Fuchsia>(*this, Target, Args);
        break;
      case llvm::Triple::Solaris:
        TC = std::make_unique<toolchains::Solaris>(*this, Target, Args);
        break;
      case llvm::Triple::AMDHSA:
        TC = std::make_unique<toolchains::ROCMToolChain>(*this, Target, Args);
        break;
      case llvm::Triple::AMDPAL:
      case llvm::Triple::Mesa3D:
        TC = std::make_unique<toolchains::AMDGPUToolChain>(*this, Target, Args);
        break;
      case llvm::Triple::Win32:
        switch (Target.getEnvironment()) {
        default:
          if (Target.isOSBinFormatELF())
            TC = std::make_unique<toolchains::Generic_ELF>(*this, Target, Args);
          else if (Target.isOSBinFormatMachO())
            TC = std::make_unique<toolchains::MachO>(*this, Target, Args);
          else
            TC = std::make_unique<toolchains::Generic_GCC>(*this, Target, Args);
          break;
        case llvm::Triple::GNU:
          TC = std::make_unique<toolchains::MinGW>(*this, Target, Args);
          break;
        case llvm::Triple::Itanium:
          TC = std::make_unique<toolchains::CrossWindowsToolChain>(*this, Target,
                                                                    Args);
          break;
        case llvm::Triple::MSVC:
        case llvm::Triple::UnknownEnvironment:
          if (Args.getLastArgValue(options::OPT_fuse_ld_EQ)
                  .startswith_insensitive("bfd"))
            TC = std::make_unique<toolchains::CrossWindowsToolChain>(
                *this, Target, Args);
          else
            TC =
                std::make_unique<toolchains::MSVCToolChain>(*this, Target, Args);
          break;
        }
        break;
      case llvm::Triple::PS4:
        TC = std::make_unique<toolchains::PS4CPU>(*this, Target, Args);
        break;
      case llvm::Triple::Contiki:
        TC = std::make_unique<toolchains::Contiki>(*this, Target, Args);
        break;
      case llvm::Triple::Hurd:
        TC = std::make_unique<toolchains::Hurd>(*this, Target, Args);
        break;
      case llvm::Triple::ZOS:
        TC = std::make_unique<toolchains::ZOS>(*this, Target, Args);
        break;
      default:
        // Of these targets, Hexagon is the only one that might have
        // an OS of Linux, in which case it got handled above already.
        switch (Target.getArch()) {
        case llvm::Triple::tce:
          TC = std::make_unique<toolchains::TCEToolChain>(*this, Target, Args);
          break;
        case llvm::Triple::tcele:
          TC = std::make_unique<toolchains::TCELEToolChain>(*this, Target, Args);
          break;
        case llvm::Triple::hexagon:
          TC = std::make_unique<toolchains::HexagonToolChain>(*this, Target,
                                                               Args);
          break;
        case llvm::Triple::lanai:
          TC = std::make_unique<toolchains::LanaiToolChain>(*this, Target, Args);
          break;
        case llvm::Triple::xcore:
          TC = std::make_unique<toolchains::XCoreToolChain>(*this, Target, Args);
          break;
        case llvm::Triple::wasm32:
        case llvm::Triple::wasm64:
          TC = std::make_unique<toolchains::WebAssembly>(*this, Target, Args);
          break;
        case llvm::Triple::avr:
          TC = std::make_unique<toolchains::AVRToolChain>(*this, Target, Args);
          break;
        case llvm::Triple::msp430:
          TC =
              std::make_unique<toolchains::MSP430ToolChain>(*this, Target, Args);
          break;
        case llvm::Triple::riscv32:
        case llvm::Triple::riscv64:
          if (toolchains::RISCVToolChain::hasGCCToolchain(*this, Args))
            TC =
                std::make_unique<toolchains::RISCVToolChain>(*this, Target, Args);
          else
            TC = std::make_unique<toolchains::BareMetal>(*this, Target, Args);
          break;
        case llvm::Triple::ve:
          TC = std::make_unique<toolchains::VEToolChain>(*this, Target, Args);
          break;
        case llvm::Triple::spirv32:
        case llvm::Triple::spirv64:
          TC = std::make_unique<toolchains::SPIRVToolChain>(*this, Target, Args);
          break;
        default:
          if (Target.getVendor() == llvm::Triple::Myriad)
            TC = std::make_unique<toolchains::MyriadToolChain>(*this, Target,
                                                                Args);
          else if (toolchains::BareMetal::handlesTarget(Target))
            TC = std::make_unique<toolchains::BareMetal>(*this, Target, Args);
          else if (Target.isOSBinFormatELF())
            TC = std::make_unique<toolchains::Generic_ELF>(*this, Target, Args);
          else if (Target.isOSBinFormatMachO())
            TC = std::make_unique<toolchains::MachO>(*this, Target, Args);
          else
            TC = std::make_unique<toolchains::Generic_GCC>(*this, Target, Args);
        }
      }
    }
  
    // Intentionally omitted from the switch above: llvm::Triple::CUDA.  CUDA
    // compiles always need two toolchains, the CUDA toolchain and the host
    // toolchain.  So the only valid way to create a CUDA toolchain is via
    // CreateOffloadingDeviceToolChains.
  
    return *TC;
  }
  
  const ToolChain &Driver::getOffloadingDeviceToolChain(
      const ArgList &Args, const llvm::Triple &Target, const ToolChain &HostTC,
      const Action::OffloadKind &TargetDeviceOffloadKind) const {
    // Use device / host triples as the key into the ToolChains map because the
    // device ToolChain we create depends on both.
    auto &TC = ToolChains[Target.str() + "/" + HostTC.getTriple().str()];
    if (!TC) {
      // Categorized by offload kind > arch rather than OS > arch like
      // the normal getToolChain call, as it seems a reasonable way to categorize
      // things.
      switch (TargetDeviceOffloadKind) {
      case Action::OFK_HIP: {
        if (Target.getArch() == llvm::Triple::amdgcn &&
            Target.getVendor() == llvm::Triple::AMD &&
            Target.getOS() == llvm::Triple::AMDHSA)
          TC = std::make_unique<toolchains::HIPAMDToolChain>(*this, Target,
                                                             HostTC, Args);
        else if (Target.getArch() == llvm::Triple::spirv64 &&
                 Target.getVendor() == llvm::Triple::UnknownVendor &&
                 Target.getOS() == llvm::Triple::UnknownOS)
          TC = std::make_unique<toolchains::HIPSPVToolChain>(*this, Target,
                                                             HostTC, Args);
        break;
      }
      default:
        break;
      }
    }
  
    return *TC;
  }
  
  bool Driver::ShouldUseClangCompiler(const JobAction &JA) const {
    // Say "no" if there is not exactly one input of a type clang understands.
    if (JA.size() != 1 ||
        !types::isAcceptedByClang((*JA.input_begin())->getType()))
      return false;
  
    // And say "no" if this is not a kind of action clang understands.
    if (!isa<PreprocessJobAction>(JA) && !isa<PrecompileJobAction>(JA) &&
        !isa<CompileJobAction>(JA) && !isa<BackendJobAction>(JA))
      return false;
  
    return true;
  }
  
  bool Driver::ShouldUseFlangCompiler(const JobAction &JA) const {
    // Say "no" if there is not exactly one input of a type flang understands.
    if (JA.size() != 1 ||
        !types::isFortran((*JA.input_begin())->getType()))
      return false;
  
    // And say "no" if this is not a kind of action flang understands.
    if (!isa<PreprocessJobAction>(JA) && !isa<CompileJobAction>(JA) && !isa<BackendJobAction>(JA))
      return false;
  
    return true;
  }
  
  bool Driver::ShouldEmitStaticLibrary(const ArgList &Args) const {
    // Only emit static library if the flag is set explicitly.
    if (Args.hasArg(options::OPT_emit_static_lib))
      return true;
    return false;
  }
  
  /// GetReleaseVersion - Parse (([0-9]+)(.([0-9]+)(.([0-9]+)?))?)? and return the
  /// grouped values as integers. Numbers which are not provided are set to 0.
  ///
  /// \return True if the entire string was parsed (9.2), or all groups were
  /// parsed (10.3.5extrastuff).
  bool Driver::GetReleaseVersion(StringRef Str, unsigned &Major, unsigned &Minor,
                                 unsigned &Micro, bool &HadExtra) {
    HadExtra = false;
  
    Major = Minor = Micro = 0;
    if (Str.empty())
      return false;
  
    if (Str.consumeInteger(10, Major))
      return false;
    if (Str.empty())
      return true;
    if (Str[0] != '.')
      return false;
  
    Str = Str.drop_front(1);
  
    if (Str.consumeInteger(10, Minor))
      return false;
    if (Str.empty())
      return true;
    if (Str[0] != '.')
      return false;
    Str = Str.drop_front(1);
  
    if (Str.consumeInteger(10, Micro))
      return false;
    if (!Str.empty())
      HadExtra = true;
    return true;
  }
  
  /// Parse digits from a string \p Str and fulfill \p Digits with
  /// the parsed numbers. This method assumes that the max number of
  /// digits to look for is equal to Digits.size().
  ///
  /// \return True if the entire string was parsed and there are
  /// no extra characters remaining at the end.
  bool Driver::GetReleaseVersion(StringRef Str,
                                 MutableArrayRef<unsigned> Digits) {
    if (Str.empty())
      return false;
  
    unsigned CurDigit = 0;
    while (CurDigit < Digits.size()) {
      unsigned Digit;
      if (Str.consumeInteger(10, Digit))
        return false;
      Digits[CurDigit] = Digit;
      if (Str.empty())
        return true;
      if (Str[0] != '.')
        return false;
      Str = Str.drop_front(1);
      CurDigit++;
    }
  
    // More digits than requested, bail out...
    return false;
  }
  
  std::pair<unsigned, unsigned>
  Driver::getIncludeExcludeOptionFlagMasks(bool IsClCompatMode) const {
    unsigned IncludedFlagsBitmask = 0;
    unsigned ExcludedFlagsBitmask = options::NoDriverOption;
  
    if (IsClCompatMode) {
      // Include CL and Core options.
      IncludedFlagsBitmask |= options::CLOption;
      IncludedFlagsBitmask |= options::CoreOption;
    } else {
      ExcludedFlagsBitmask |= options::CLOption;
    }
  
    return std::make_pair(IncludedFlagsBitmask, ExcludedFlagsBitmask);
  }
  
  bool clang::driver::isOptimizationLevelFast(const ArgList &Args) {
    return Args.hasFlag(options::OPT_Ofast, options::OPT_O_Group, false);
  }
  
  bool clang::driver::willEmitRemarks(const ArgList &Args) {
    // -fsave-optimization-record enables it.
    if (Args.hasFlag(options::OPT_fsave_optimization_record,
                     options::OPT_fno_save_optimization_record, false))
      return true;
  
    // -fsave-optimization-record=<format> enables it as well.
    if (Args.hasFlag(options::OPT_fsave_optimization_record_EQ,
                     options::OPT_fno_save_optimization_record, false))
      return true;
  
    // -foptimization-record-file alone enables it too.
    if (Args.hasFlag(options::OPT_foptimization_record_file_EQ,
                     options::OPT_fno_save_optimization_record, false))
      return true;
  
    // -foptimization-record-passes alone enables it too.
    if (Args.hasFlag(options::OPT_foptimization_record_passes_EQ,
                     options::OPT_fno_save_optimization_record, false))
      return true;
    return false;
  }
  
  llvm::StringRef clang::driver::getDriverMode(StringRef ProgName,
                                               ArrayRef<const char *> Args) {
    static const std::string OptName =
        getDriverOptTable().getOption(options::OPT_driver_mode).getPrefixedName();
    llvm::StringRef Opt;
    for (StringRef Arg : Args) {
      if (!Arg.startswith(OptName))
        continue;
      Opt = Arg;
    }
    if (Opt.empty())
      Opt = ToolChain::getTargetAndModeFromProgramName(ProgName).DriverMode;
    return Opt.consume_front(OptName) ? Opt : "";
  }
  
  bool driver::IsClangCL(StringRef DriverMode) { return DriverMode.equals("cl"); }
  