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      1 //===--- ToolChain.cpp - Collections of tools for one platform ------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 #include "Tools.h"
     11 #include "clang/Basic/ObjCRuntime.h"
     12 #include "clang/Config/config.h"
     13 #include "clang/Driver/Action.h"
     14 #include "clang/Driver/Driver.h"
     15 #include "clang/Driver/DriverDiagnostic.h"
     16 #include "clang/Driver/Options.h"
     17 #include "clang/Driver/SanitizerArgs.h"
     18 #include "clang/Driver/ToolChain.h"
     19 #include "llvm/ADT/SmallString.h"
     20 #include "llvm/ADT/StringSwitch.h"
     21 #include "llvm/Option/Arg.h"
     22 #include "llvm/Option/ArgList.h"
     23 #include "llvm/Option/Option.h"
     24 #include "llvm/Support/ErrorHandling.h"
     25 #include "llvm/Support/FileSystem.h"
     26 #include "llvm/Support/TargetRegistry.h"
     27 #include "llvm/Support/TargetParser.h"
     28 
     29 using namespace clang::driver;
     30 using namespace clang::driver::tools;
     31 using namespace clang;
     32 using namespace llvm;
     33 using namespace llvm::opt;
     34 
     35 static llvm::opt::Arg *GetRTTIArgument(const ArgList &Args) {
     36   return Args.getLastArg(options::OPT_mkernel, options::OPT_fapple_kext,
     37                          options::OPT_fno_rtti, options::OPT_frtti);
     38 }
     39 
     40 static ToolChain::RTTIMode CalculateRTTIMode(const ArgList &Args,
     41                                              const llvm::Triple &Triple,
     42                                              const Arg *CachedRTTIArg) {
     43   // Explicit rtti/no-rtti args
     44   if (CachedRTTIArg) {
     45     if (CachedRTTIArg->getOption().matches(options::OPT_frtti))
     46       return ToolChain::RM_EnabledExplicitly;
     47     else
     48       return ToolChain::RM_DisabledExplicitly;
     49   }
     50 
     51   // -frtti is default, except for the PS4 CPU.
     52   if (!Triple.isPS4CPU())
     53     return ToolChain::RM_EnabledImplicitly;
     54 
     55   // On the PS4, turning on c++ exceptions turns on rtti.
     56   // We're assuming that, if we see -fexceptions, rtti gets turned on.
     57   Arg *Exceptions = Args.getLastArgNoClaim(
     58       options::OPT_fcxx_exceptions, options::OPT_fno_cxx_exceptions,
     59       options::OPT_fexceptions, options::OPT_fno_exceptions);
     60   if (Exceptions &&
     61       (Exceptions->getOption().matches(options::OPT_fexceptions) ||
     62        Exceptions->getOption().matches(options::OPT_fcxx_exceptions)))
     63     return ToolChain::RM_EnabledImplicitly;
     64 
     65   return ToolChain::RM_DisabledImplicitly;
     66 }
     67 
     68 ToolChain::ToolChain(const Driver &D, const llvm::Triple &T,
     69                      const ArgList &Args)
     70     : D(D), Triple(T), Args(Args), CachedRTTIArg(GetRTTIArgument(Args)),
     71       CachedRTTIMode(CalculateRTTIMode(Args, Triple, CachedRTTIArg)) {
     72   if (Arg *A = Args.getLastArg(options::OPT_mthread_model))
     73     if (!isThreadModelSupported(A->getValue()))
     74       D.Diag(diag::err_drv_invalid_thread_model_for_target)
     75           << A->getValue() << A->getAsString(Args);
     76 }
     77 
     78 ToolChain::~ToolChain() {
     79 }
     80 
     81 vfs::FileSystem &ToolChain::getVFS() const { return getDriver().getVFS(); }
     82 
     83 bool ToolChain::useIntegratedAs() const {
     84   return Args.hasFlag(options::OPT_fintegrated_as,
     85                       options::OPT_fno_integrated_as,
     86                       IsIntegratedAssemblerDefault());
     87 }
     88 
     89 const SanitizerArgs& ToolChain::getSanitizerArgs() const {
     90   if (!SanitizerArguments.get())
     91     SanitizerArguments.reset(new SanitizerArgs(*this, Args));
     92   return *SanitizerArguments.get();
     93 }
     94 
     95 namespace {
     96 struct DriverSuffix {
     97   const char *Suffix;
     98   const char *ModeFlag;
     99 };
    100 
    101 const DriverSuffix *FindDriverSuffix(StringRef ProgName) {
    102   // A list of known driver suffixes. Suffixes are compared against the
    103   // program name in order. If there is a match, the frontend type is updated as
    104   // necessary by applying the ModeFlag.
    105   static const DriverSuffix DriverSuffixes[] = {
    106       {"clang", nullptr},
    107       {"clang++", "--driver-mode=g++"},
    108       {"clang-c++", "--driver-mode=g++"},
    109       {"clang-cc", nullptr},
    110       {"clang-cpp", "--driver-mode=cpp"},
    111       {"clang-g++", "--driver-mode=g++"},
    112       {"clang-gcc", nullptr},
    113       {"clang-cl", "--driver-mode=cl"},
    114       {"cc", nullptr},
    115       {"cpp", "--driver-mode=cpp"},
    116       {"cl", "--driver-mode=cl"},
    117       {"++", "--driver-mode=g++"},
    118   };
    119 
    120   for (size_t i = 0; i < llvm::array_lengthof(DriverSuffixes); ++i)
    121     if (ProgName.endswith(DriverSuffixes[i].Suffix))
    122       return &DriverSuffixes[i];
    123   return nullptr;
    124 }
    125 
    126 /// Normalize the program name from argv[0] by stripping the file extension if
    127 /// present and lower-casing the string on Windows.
    128 std::string normalizeProgramName(llvm::StringRef Argv0) {
    129   std::string ProgName = llvm::sys::path::stem(Argv0);
    130 #ifdef LLVM_ON_WIN32
    131   // Transform to lowercase for case insensitive file systems.
    132   std::transform(ProgName.begin(), ProgName.end(), ProgName.begin(), ::tolower);
    133 #endif
    134   return ProgName;
    135 }
    136 
    137 const DriverSuffix *parseDriverSuffix(StringRef ProgName) {
    138   // Try to infer frontend type and default target from the program name by
    139   // comparing it against DriverSuffixes in order.
    140 
    141   // If there is a match, the function tries to identify a target as prefix.
    142   // E.g. "x86_64-linux-clang" as interpreted as suffix "clang" with target
    143   // prefix "x86_64-linux". If such a target prefix is found, it may be
    144   // added via -target as implicit first argument.
    145   const DriverSuffix *DS = FindDriverSuffix(ProgName);
    146 
    147   if (!DS) {
    148     // Try again after stripping any trailing version number:
    149     // clang++3.5 -> clang++
    150     ProgName = ProgName.rtrim("0123456789.");
    151     DS = FindDriverSuffix(ProgName);
    152   }
    153 
    154   if (!DS) {
    155     // Try again after stripping trailing -component.
    156     // clang++-tot -> clang++
    157     ProgName = ProgName.slice(0, ProgName.rfind('-'));
    158     DS = FindDriverSuffix(ProgName);
    159   }
    160   return DS;
    161 }
    162 } // anonymous namespace
    163 
    164 std::pair<std::string, std::string>
    165 ToolChain::getTargetAndModeFromProgramName(StringRef PN) {
    166   std::string ProgName = normalizeProgramName(PN);
    167   const DriverSuffix *DS = parseDriverSuffix(ProgName);
    168   if (!DS)
    169     return std::make_pair("", "");
    170   std::string ModeFlag = DS->ModeFlag == nullptr ? "" : DS->ModeFlag;
    171 
    172   std::string::size_type LastComponent =
    173       ProgName.rfind('-', ProgName.size() - strlen(DS->Suffix));
    174   if (LastComponent == std::string::npos)
    175     return std::make_pair("", ModeFlag);
    176 
    177   // Infer target from the prefix.
    178   StringRef Prefix(ProgName);
    179   Prefix = Prefix.slice(0, LastComponent);
    180   std::string IgnoredError;
    181   std::string Target;
    182   if (llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError)) {
    183     Target = Prefix;
    184   }
    185   return std::make_pair(Target, ModeFlag);
    186 }
    187 
    188 StringRef ToolChain::getDefaultUniversalArchName() const {
    189   // In universal driver terms, the arch name accepted by -arch isn't exactly
    190   // the same as the ones that appear in the triple. Roughly speaking, this is
    191   // an inverse of the darwin::getArchTypeForDarwinArchName() function, but the
    192   // only interesting special case is powerpc.
    193   switch (Triple.getArch()) {
    194   case llvm::Triple::ppc:
    195     return "ppc";
    196   case llvm::Triple::ppc64:
    197     return "ppc64";
    198   case llvm::Triple::ppc64le:
    199     return "ppc64le";
    200   default:
    201     return Triple.getArchName();
    202   }
    203 }
    204 
    205 bool ToolChain::IsUnwindTablesDefault() const {
    206   return false;
    207 }
    208 
    209 Tool *ToolChain::getClang() const {
    210   if (!Clang)
    211     Clang.reset(new tools::Clang(*this));
    212   return Clang.get();
    213 }
    214 
    215 Tool *ToolChain::buildAssembler() const {
    216   return new tools::ClangAs(*this);
    217 }
    218 
    219 Tool *ToolChain::buildLinker() const {
    220   llvm_unreachable("Linking is not supported by this toolchain");
    221 }
    222 
    223 Tool *ToolChain::getAssemble() const {
    224   if (!Assemble)
    225     Assemble.reset(buildAssembler());
    226   return Assemble.get();
    227 }
    228 
    229 Tool *ToolChain::getClangAs() const {
    230   if (!Assemble)
    231     Assemble.reset(new tools::ClangAs(*this));
    232   return Assemble.get();
    233 }
    234 
    235 Tool *ToolChain::getLink() const {
    236   if (!Link)
    237     Link.reset(buildLinker());
    238   return Link.get();
    239 }
    240 
    241 Tool *ToolChain::getTool(Action::ActionClass AC) const {
    242   switch (AC) {
    243   case Action::AssembleJobClass:
    244     return getAssemble();
    245 
    246   case Action::LinkJobClass:
    247     return getLink();
    248 
    249   case Action::InputClass:
    250   case Action::BindArchClass:
    251   case Action::CudaDeviceClass:
    252   case Action::CudaHostClass:
    253   case Action::LipoJobClass:
    254   case Action::DsymutilJobClass:
    255   case Action::VerifyDebugInfoJobClass:
    256     llvm_unreachable("Invalid tool kind.");
    257 
    258   case Action::CompileJobClass:
    259   case Action::PrecompileJobClass:
    260   case Action::PreprocessJobClass:
    261   case Action::AnalyzeJobClass:
    262   case Action::MigrateJobClass:
    263   case Action::VerifyPCHJobClass:
    264   case Action::BackendJobClass:
    265     return getClang();
    266   }
    267 
    268   llvm_unreachable("Invalid tool kind.");
    269 }
    270 
    271 static StringRef getArchNameForCompilerRTLib(const ToolChain &TC,
    272                                              const ArgList &Args) {
    273   const llvm::Triple &Triple = TC.getTriple();
    274   bool IsWindows = Triple.isOSWindows();
    275 
    276   if (Triple.isWindowsMSVCEnvironment() && TC.getArch() == llvm::Triple::x86)
    277     return "i386";
    278 
    279   if (TC.getArch() == llvm::Triple::arm || TC.getArch() == llvm::Triple::armeb)
    280     return (arm::getARMFloatABI(TC, Args) == arm::FloatABI::Hard && !IsWindows)
    281                ? "armhf"
    282                : "arm";
    283 
    284   return TC.getArchName();
    285 }
    286 
    287 std::string ToolChain::getCompilerRT(const ArgList &Args, StringRef Component,
    288                                      bool Shared) const {
    289   const llvm::Triple &TT = getTriple();
    290   const char *Env = TT.isAndroid() ? "-android" : "";
    291   bool IsITANMSVCWindows =
    292       TT.isWindowsMSVCEnvironment() || TT.isWindowsItaniumEnvironment();
    293 
    294   StringRef Arch = getArchNameForCompilerRTLib(*this, Args);
    295   const char *Prefix = IsITANMSVCWindows ? "" : "lib";
    296   const char *Suffix = Shared ? (Triple.isOSWindows() ? ".dll" : ".so")
    297                               : (IsITANMSVCWindows ? ".lib" : ".a");
    298 
    299   SmallString<128> Path(getDriver().ResourceDir);
    300   StringRef OSLibName = Triple.isOSFreeBSD() ? "freebsd" : getOS();
    301   llvm::sys::path::append(Path, "lib", OSLibName);
    302   llvm::sys::path::append(Path, Prefix + Twine("clang_rt.") + Component + "-" +
    303                                     Arch + Env + Suffix);
    304   return Path.str();
    305 }
    306 
    307 const char *ToolChain::getCompilerRTArgString(const llvm::opt::ArgList &Args,
    308                                               StringRef Component,
    309                                               bool Shared) const {
    310   return Args.MakeArgString(getCompilerRT(Args, Component, Shared));
    311 }
    312 
    313 bool ToolChain::needsProfileRT(const ArgList &Args) {
    314   if (Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
    315                    false) ||
    316       Args.hasArg(options::OPT_fprofile_generate) ||
    317       Args.hasArg(options::OPT_fprofile_generate_EQ) ||
    318       Args.hasArg(options::OPT_fprofile_instr_generate) ||
    319       Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
    320       Args.hasArg(options::OPT_fcreate_profile) ||
    321       Args.hasArg(options::OPT_coverage))
    322     return true;
    323 
    324   return false;
    325 }
    326 
    327 Tool *ToolChain::SelectTool(const JobAction &JA) const {
    328   if (getDriver().ShouldUseClangCompiler(JA)) return getClang();
    329   Action::ActionClass AC = JA.getKind();
    330   if (AC == Action::AssembleJobClass && useIntegratedAs())
    331     return getClangAs();
    332   return getTool(AC);
    333 }
    334 
    335 std::string ToolChain::GetFilePath(const char *Name) const {
    336   return D.GetFilePath(Name, *this);
    337 }
    338 
    339 std::string ToolChain::GetProgramPath(const char *Name) const {
    340   return D.GetProgramPath(Name, *this);
    341 }
    342 
    343 std::string ToolChain::GetLinkerPath() const {
    344   if (Arg *A = Args.getLastArg(options::OPT_fuse_ld_EQ)) {
    345     StringRef UseLinker = A->getValue();
    346 
    347     if (llvm::sys::path::is_absolute(UseLinker)) {
    348       // If we're passed -fuse-ld= with what looks like an absolute path,
    349       // don't attempt to second-guess that.
    350       if (llvm::sys::fs::exists(UseLinker))
    351         return UseLinker;
    352     } else {
    353       // If we're passed -fuse-ld= with no argument, or with the argument ld,
    354       // then use whatever the default system linker is.
    355       if (UseLinker.empty() || UseLinker == "ld")
    356         return GetProgramPath("ld");
    357 
    358       llvm::SmallString<8> LinkerName("ld.");
    359       LinkerName.append(UseLinker);
    360 
    361       std::string LinkerPath(GetProgramPath(LinkerName.c_str()));
    362       if (llvm::sys::fs::exists(LinkerPath))
    363         return LinkerPath;
    364     }
    365 
    366     getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
    367     return "";
    368   }
    369 
    370   return GetProgramPath(DefaultLinker);
    371 }
    372 
    373 types::ID ToolChain::LookupTypeForExtension(const char *Ext) const {
    374   return types::lookupTypeForExtension(Ext);
    375 }
    376 
    377 bool ToolChain::HasNativeLLVMSupport() const {
    378   return false;
    379 }
    380 
    381 bool ToolChain::isCrossCompiling() const {
    382   llvm::Triple HostTriple(LLVM_HOST_TRIPLE);
    383   switch (HostTriple.getArch()) {
    384   // The A32/T32/T16 instruction sets are not separate architectures in this
    385   // context.
    386   case llvm::Triple::arm:
    387   case llvm::Triple::armeb:
    388   case llvm::Triple::thumb:
    389   case llvm::Triple::thumbeb:
    390     return getArch() != llvm::Triple::arm && getArch() != llvm::Triple::thumb &&
    391            getArch() != llvm::Triple::armeb && getArch() != llvm::Triple::thumbeb;
    392   default:
    393     return HostTriple.getArch() != getArch();
    394   }
    395 }
    396 
    397 ObjCRuntime ToolChain::getDefaultObjCRuntime(bool isNonFragile) const {
    398   return ObjCRuntime(isNonFragile ? ObjCRuntime::GNUstep : ObjCRuntime::GCC,
    399                      VersionTuple());
    400 }
    401 
    402 bool ToolChain::isThreadModelSupported(const StringRef Model) const {
    403   if (Model == "single") {
    404     // FIXME: 'single' is only supported on ARM and WebAssembly so far.
    405     return Triple.getArch() == llvm::Triple::arm ||
    406            Triple.getArch() == llvm::Triple::armeb ||
    407            Triple.getArch() == llvm::Triple::thumb ||
    408            Triple.getArch() == llvm::Triple::thumbeb ||
    409            Triple.getArch() == llvm::Triple::wasm32 ||
    410            Triple.getArch() == llvm::Triple::wasm64;
    411   } else if (Model == "posix")
    412     return true;
    413 
    414   return false;
    415 }
    416 
    417 std::string ToolChain::ComputeLLVMTriple(const ArgList &Args,
    418                                          types::ID InputType) const {
    419   switch (getTriple().getArch()) {
    420   default:
    421     return getTripleString();
    422 
    423   case llvm::Triple::x86_64: {
    424     llvm::Triple Triple = getTriple();
    425     if (!Triple.isOSBinFormatMachO())
    426       return getTripleString();
    427 
    428     if (Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
    429       // x86_64h goes in the triple. Other -march options just use the
    430       // vanilla triple we already have.
    431       StringRef MArch = A->getValue();
    432       if (MArch == "x86_64h")
    433         Triple.setArchName(MArch);
    434     }
    435     return Triple.getTriple();
    436   }
    437   case llvm::Triple::aarch64: {
    438     llvm::Triple Triple = getTriple();
    439     if (!Triple.isOSBinFormatMachO())
    440       return getTripleString();
    441 
    442     // FIXME: older versions of ld64 expect the "arm64" component in the actual
    443     // triple string and query it to determine whether an LTO file can be
    444     // handled. Remove this when we don't care any more.
    445     Triple.setArchName("arm64");
    446     return Triple.getTriple();
    447   }
    448   case llvm::Triple::arm:
    449   case llvm::Triple::armeb:
    450   case llvm::Triple::thumb:
    451   case llvm::Triple::thumbeb: {
    452     // FIXME: Factor into subclasses.
    453     llvm::Triple Triple = getTriple();
    454     bool IsBigEndian = getTriple().getArch() == llvm::Triple::armeb ||
    455                        getTriple().getArch() == llvm::Triple::thumbeb;
    456 
    457     // Handle pseudo-target flags '-mlittle-endian'/'-EL' and
    458     // '-mbig-endian'/'-EB'.
    459     if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
    460                                  options::OPT_mbig_endian)) {
    461       IsBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
    462     }
    463 
    464     // Thumb2 is the default for V7 on Darwin.
    465     //
    466     // FIXME: Thumb should just be another -target-feaure, not in the triple.
    467     StringRef MCPU, MArch;
    468     if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
    469       MCPU = A->getValue();
    470     if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
    471       MArch = A->getValue();
    472     std::string CPU =
    473         Triple.isOSBinFormatMachO()
    474             ? tools::arm::getARMCPUForMArch(MArch, Triple).str()
    475             : tools::arm::getARMTargetCPU(MCPU, MArch, Triple);
    476     StringRef Suffix =
    477       tools::arm::getLLVMArchSuffixForARM(CPU, MArch, Triple);
    478     bool IsMProfile = ARM::parseArchProfile(Suffix) == ARM::PK_M;
    479     bool ThumbDefault = IsMProfile || (ARM::parseArchVersion(Suffix) == 7 &&
    480                                        getTriple().isOSBinFormatMachO());
    481     // FIXME: this is invalid for WindowsCE
    482     if (getTriple().isOSWindows())
    483       ThumbDefault = true;
    484     std::string ArchName;
    485     if (IsBigEndian)
    486       ArchName = "armeb";
    487     else
    488       ArchName = "arm";
    489 
    490     // Assembly files should start in ARM mode, unless arch is M-profile.
    491     if ((InputType != types::TY_PP_Asm && Args.hasFlag(options::OPT_mthumb,
    492          options::OPT_mno_thumb, ThumbDefault)) || IsMProfile) {
    493       if (IsBigEndian)
    494         ArchName = "thumbeb";
    495       else
    496         ArchName = "thumb";
    497     }
    498     Triple.setArchName(ArchName + Suffix.str());
    499 
    500     return Triple.getTriple();
    501   }
    502   }
    503 }
    504 
    505 std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args,
    506                                                    types::ID InputType) const {
    507   return ComputeLLVMTriple(Args, InputType);
    508 }
    509 
    510 void ToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
    511                                           ArgStringList &CC1Args) const {
    512   // Each toolchain should provide the appropriate include flags.
    513 }
    514 
    515 void ToolChain::addClangTargetOptions(const ArgList &DriverArgs,
    516                                       ArgStringList &CC1Args) const {
    517 }
    518 
    519 void ToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {}
    520 
    521 void ToolChain::addProfileRTLibs(const llvm::opt::ArgList &Args,
    522                                  llvm::opt::ArgStringList &CmdArgs) const {
    523   if (!needsProfileRT(Args)) return;
    524 
    525   CmdArgs.push_back(getCompilerRTArgString(Args, "profile"));
    526 }
    527 
    528 ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
    529     const ArgList &Args) const {
    530   if (Arg *A = Args.getLastArg(options::OPT_rtlib_EQ)) {
    531     StringRef Value = A->getValue();
    532     if (Value == "compiler-rt")
    533       return ToolChain::RLT_CompilerRT;
    534     if (Value == "libgcc")
    535       return ToolChain::RLT_Libgcc;
    536     getDriver().Diag(diag::err_drv_invalid_rtlib_name)
    537       << A->getAsString(Args);
    538   }
    539 
    540   return GetDefaultRuntimeLibType();
    541 }
    542 
    543 static bool ParseCXXStdlibType(const StringRef& Name,
    544                                ToolChain::CXXStdlibType& Type) {
    545   if (Name == "libc++")
    546     Type = ToolChain::CST_Libcxx;
    547   else if (Name == "libstdc++")
    548     Type = ToolChain::CST_Libstdcxx;
    549   else
    550     return false;
    551 
    552   return true;
    553 }
    554 
    555 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
    556   ToolChain::CXXStdlibType Type;
    557   bool HasValidType = false;
    558   bool ForcePlatformDefault = false;
    559 
    560   const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
    561   if (A) {
    562     StringRef Value = A->getValue();
    563     HasValidType = ParseCXXStdlibType(Value, Type);
    564 
    565     // Only use in tests to override CLANG_DEFAULT_CXX_STDLIB!
    566     if (Value == "platform")
    567       ForcePlatformDefault = true;
    568     else if (!HasValidType)
    569       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
    570         << A->getAsString(Args);
    571   }
    572 
    573   if (!HasValidType && (ForcePlatformDefault ||
    574       !ParseCXXStdlibType(CLANG_DEFAULT_CXX_STDLIB, Type)))
    575     Type = GetDefaultCXXStdlibType();
    576 
    577   return Type;
    578 }
    579 
    580 /// \brief Utility function to add a system include directory to CC1 arguments.
    581 /*static*/ void ToolChain::addSystemInclude(const ArgList &DriverArgs,
    582                                             ArgStringList &CC1Args,
    583                                             const Twine &Path) {
    584   CC1Args.push_back("-internal-isystem");
    585   CC1Args.push_back(DriverArgs.MakeArgString(Path));
    586 }
    587 
    588 /// \brief Utility function to add a system include directory with extern "C"
    589 /// semantics to CC1 arguments.
    590 ///
    591 /// Note that this should be used rarely, and only for directories that
    592 /// historically and for legacy reasons are treated as having implicit extern
    593 /// "C" semantics. These semantics are *ignored* by and large today, but its
    594 /// important to preserve the preprocessor changes resulting from the
    595 /// classification.
    596 /*static*/ void ToolChain::addExternCSystemInclude(const ArgList &DriverArgs,
    597                                                    ArgStringList &CC1Args,
    598                                                    const Twine &Path) {
    599   CC1Args.push_back("-internal-externc-isystem");
    600   CC1Args.push_back(DriverArgs.MakeArgString(Path));
    601 }
    602 
    603 void ToolChain::addExternCSystemIncludeIfExists(const ArgList &DriverArgs,
    604                                                 ArgStringList &CC1Args,
    605                                                 const Twine &Path) {
    606   if (llvm::sys::fs::exists(Path))
    607     addExternCSystemInclude(DriverArgs, CC1Args, Path);
    608 }
    609 
    610 /// \brief Utility function to add a list of system include directories to CC1.
    611 /*static*/ void ToolChain::addSystemIncludes(const ArgList &DriverArgs,
    612                                              ArgStringList &CC1Args,
    613                                              ArrayRef<StringRef> Paths) {
    614   for (StringRef Path : Paths) {
    615     CC1Args.push_back("-internal-isystem");
    616     CC1Args.push_back(DriverArgs.MakeArgString(Path));
    617   }
    618 }
    619 
    620 void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
    621                                              ArgStringList &CC1Args) const {
    622   // Header search paths should be handled by each of the subclasses.
    623   // Historically, they have not been, and instead have been handled inside of
    624   // the CC1-layer frontend. As the logic is hoisted out, this generic function
    625   // will slowly stop being called.
    626   //
    627   // While it is being called, replicate a bit of a hack to propagate the
    628   // '-stdlib=' flag down to CC1 so that it can in turn customize the C++
    629   // header search paths with it. Once all systems are overriding this
    630   // function, the CC1 flag and this line can be removed.
    631   DriverArgs.AddAllArgs(CC1Args, options::OPT_stdlib_EQ);
    632 }
    633 
    634 void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
    635                                     ArgStringList &CmdArgs) const {
    636   CXXStdlibType Type = GetCXXStdlibType(Args);
    637 
    638   switch (Type) {
    639   case ToolChain::CST_Libcxx:
    640     CmdArgs.push_back("-lc++");
    641     break;
    642 
    643   case ToolChain::CST_Libstdcxx:
    644     CmdArgs.push_back("-lstdc++");
    645     break;
    646   }
    647 }
    648 
    649 void ToolChain::AddFilePathLibArgs(const ArgList &Args,
    650                                    ArgStringList &CmdArgs) const {
    651   for (const auto &LibPath : getFilePaths())
    652     if(LibPath.length() > 0)
    653       CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
    654 }
    655 
    656 void ToolChain::AddCCKextLibArgs(const ArgList &Args,
    657                                  ArgStringList &CmdArgs) const {
    658   CmdArgs.push_back("-lcc_kext");
    659 }
    660 
    661 bool ToolChain::AddFastMathRuntimeIfAvailable(const ArgList &Args,
    662                                               ArgStringList &CmdArgs) const {
    663   // Do not check for -fno-fast-math or -fno-unsafe-math when -Ofast passed
    664   // (to keep the linker options consistent with gcc and clang itself).
    665   if (!isOptimizationLevelFast(Args)) {
    666     // Check if -ffast-math or -funsafe-math.
    667     Arg *A =
    668         Args.getLastArg(options::OPT_ffast_math, options::OPT_fno_fast_math,
    669                         options::OPT_funsafe_math_optimizations,
    670                         options::OPT_fno_unsafe_math_optimizations);
    671 
    672     if (!A || A->getOption().getID() == options::OPT_fno_fast_math ||
    673         A->getOption().getID() == options::OPT_fno_unsafe_math_optimizations)
    674       return false;
    675   }
    676   // If crtfastmath.o exists add it to the arguments.
    677   std::string Path = GetFilePath("crtfastmath.o");
    678   if (Path == "crtfastmath.o") // Not found.
    679     return false;
    680 
    681   CmdArgs.push_back(Args.MakeArgString(Path));
    682   return true;
    683 }
    684 
    685 SanitizerMask ToolChain::getSupportedSanitizers() const {
    686   // Return sanitizers which don't require runtime support and are not
    687   // platform dependent.
    688   using namespace SanitizerKind;
    689   SanitizerMask Res = (Undefined & ~Vptr & ~Function) | (CFI & ~CFIICall) |
    690                       CFICastStrict | UnsignedIntegerOverflow | LocalBounds;
    691   if (getTriple().getArch() == llvm::Triple::x86 ||
    692       getTriple().getArch() == llvm::Triple::x86_64)
    693     Res |= CFIICall;
    694   return Res;
    695 }
    696 
    697 void ToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
    698                                    ArgStringList &CC1Args) const {}
    699 
    700 void ToolChain::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
    701                                     ArgStringList &CC1Args) const {}
    702