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 "clang/Driver/ToolChain.h"
11 #include "Tools.h"
12 #include "clang/Basic/ObjCRuntime.h"
13 #include "clang/Config/config.h"
14 #include "clang/Driver/Action.h"
15 #include "clang/Driver/Driver.h"
16 #include "clang/Driver/DriverDiagnostic.h"
17 #include "clang/Driver/Options.h"
18 #include "clang/Driver/SanitizerArgs.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/Option/Arg.h"
21 #include "llvm/Option/ArgList.h"
22 #include "llvm/Option/Option.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/FileSystem.h"
25 #include "llvm/Support/Path.h"
26 #include "llvm/Support/TargetParser.h"
27 #include "llvm/Support/TargetRegistry.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       EffectiveTriple() {
73   if (Arg *A = Args.getLastArg(options::OPT_mthread_model))
74     if (!isThreadModelSupported(A->getValue()))
75       D.Diag(diag::err_drv_invalid_thread_model_for_target)
76           << A->getValue() << A->getAsString(Args);
77 }
78 
79 ToolChain::~ToolChain() {
80 }
81 
82 vfs::FileSystem &ToolChain::getVFS() const { return getDriver().getVFS(); }
83 
84 bool ToolChain::useIntegratedAs() const {
85   return Args.hasFlag(options::OPT_fintegrated_as,
86                       options::OPT_fno_integrated_as,
87                       IsIntegratedAssemblerDefault());
88 }
89 
90 const SanitizerArgs& ToolChain::getSanitizerArgs() const {
91   if (!SanitizerArguments.get())
92     SanitizerArguments.reset(new SanitizerArgs(*this, Args));
93   return *SanitizerArguments.get();
94 }
95 
96 namespace {
97 struct DriverSuffix {
98   const char *Suffix;
99   const char *ModeFlag;
100 };
101 
102 const DriverSuffix *FindDriverSuffix(StringRef ProgName) {
103   // A list of known driver suffixes. Suffixes are compared against the
104   // program name in order. If there is a match, the frontend type is updated as
105   // necessary by applying the ModeFlag.
106   static const DriverSuffix DriverSuffixes[] = {
107       {"clang", nullptr},
108       {"clang++", "--driver-mode=g++"},
109       {"clang-c++", "--driver-mode=g++"},
110       {"clang-cc", nullptr},
111       {"clang-cpp", "--driver-mode=cpp"},
112       {"clang-g++", "--driver-mode=g++"},
113       {"clang-gcc", nullptr},
114       {"clang-cl", "--driver-mode=cl"},
115       {"cc", nullptr},
116       {"cpp", "--driver-mode=cpp"},
117       {"cl", "--driver-mode=cl"},
118       {"++", "--driver-mode=g++"},
119   };
120 
121   for (size_t i = 0; i < llvm::array_lengthof(DriverSuffixes); ++i)
122     if (ProgName.endswith(DriverSuffixes[i].Suffix))
123       return &DriverSuffixes[i];
124   return nullptr;
125 }
126 
127 /// Normalize the program name from argv[0] by stripping the file extension if
128 /// present and lower-casing the string on Windows.
129 std::string normalizeProgramName(llvm::StringRef Argv0) {
130   std::string ProgName = llvm::sys::path::stem(Argv0);
131 #ifdef LLVM_ON_WIN32
132   // Transform to lowercase for case insensitive file systems.
133   std::transform(ProgName.begin(), ProgName.end(), ProgName.begin(), ::tolower);
134 #endif
135   return ProgName;
136 }
137 
138 const DriverSuffix *parseDriverSuffix(StringRef ProgName) {
139   // Try to infer frontend type and default target from the program name by
140   // comparing it against DriverSuffixes in order.
141 
142   // If there is a match, the function tries to identify a target as prefix.
143   // E.g. "x86_64-linux-clang" as interpreted as suffix "clang" with target
144   // prefix "x86_64-linux". If such a target prefix is found, it may be
145   // added via -target as implicit first argument.
146   const DriverSuffix *DS = FindDriverSuffix(ProgName);
147 
148   if (!DS) {
149     // Try again after stripping any trailing version number:
150     // clang++3.5 -> clang++
151     ProgName = ProgName.rtrim("0123456789.");
152     DS = FindDriverSuffix(ProgName);
153   }
154 
155   if (!DS) {
156     // Try again after stripping trailing -component.
157     // clang++-tot -> clang++
158     ProgName = ProgName.slice(0, ProgName.rfind('-'));
159     DS = FindDriverSuffix(ProgName);
160   }
161   return DS;
162 }
163 } // anonymous namespace
164 
165 std::pair<std::string, std::string>
166 ToolChain::getTargetAndModeFromProgramName(StringRef PN) {
167   std::string ProgName = normalizeProgramName(PN);
168   const DriverSuffix *DS = parseDriverSuffix(ProgName);
169   if (!DS)
170     return std::make_pair("", "");
171   std::string ModeFlag = DS->ModeFlag == nullptr ? "" : DS->ModeFlag;
172 
173   std::string::size_type LastComponent =
174       ProgName.rfind('-', ProgName.size() - strlen(DS->Suffix));
175   if (LastComponent == std::string::npos)
176     return std::make_pair("", ModeFlag);
177 
178   // Infer target from the prefix.
179   StringRef Prefix(ProgName);
180   Prefix = Prefix.slice(0, LastComponent);
181   std::string IgnoredError;
182   std::string Target;
183   if (llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError)) {
184     Target = Prefix;
185   }
186   return std::make_pair(Target, ModeFlag);
187 }
188 
189 StringRef ToolChain::getDefaultUniversalArchName() const {
190   // In universal driver terms, the arch name accepted by -arch isn't exactly
191   // the same as the ones that appear in the triple. Roughly speaking, this is
192   // an inverse of the darwin::getArchTypeForDarwinArchName() function, but the
193   // only interesting special case is powerpc.
194   switch (Triple.getArch()) {
195   case llvm::Triple::ppc:
196     return "ppc";
197   case llvm::Triple::ppc64:
198     return "ppc64";
199   case llvm::Triple::ppc64le:
200     return "ppc64le";
201   default:
202     return Triple.getArchName();
203   }
204 }
205 
206 bool ToolChain::IsUnwindTablesDefault() const {
207   return false;
208 }
209 
210 Tool *ToolChain::getClang() const {
211   if (!Clang)
212     Clang.reset(new tools::Clang(*this));
213   return Clang.get();
214 }
215 
216 Tool *ToolChain::buildAssembler() const {
217   return new tools::ClangAs(*this);
218 }
219 
220 Tool *ToolChain::buildLinker() const {
221   llvm_unreachable("Linking is not supported by this toolchain");
222 }
223 
224 Tool *ToolChain::getAssemble() const {
225   if (!Assemble)
226     Assemble.reset(buildAssembler());
227   return Assemble.get();
228 }
229 
230 Tool *ToolChain::getClangAs() const {
231   if (!Assemble)
232     Assemble.reset(new tools::ClangAs(*this));
233   return Assemble.get();
234 }
235 
236 Tool *ToolChain::getLink() const {
237   if (!Link)
238     Link.reset(buildLinker());
239   return Link.get();
240 }
241 
242 Tool *ToolChain::getTool(Action::ActionClass AC) const {
243   switch (AC) {
244   case Action::AssembleJobClass:
245     return getAssemble();
246 
247   case Action::LinkJobClass:
248     return getLink();
249 
250   case Action::InputClass:
251   case Action::BindArchClass:
252   case Action::OffloadClass:
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(StringRef 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     // Windows is always thumb.
492     if ((InputType != types::TY_PP_Asm && Args.hasFlag(options::OPT_mthumb,
493          options::OPT_mno_thumb, ThumbDefault)) || IsMProfile ||
494          getTriple().isOSWindows()) {
495       if (IsBigEndian)
496         ArchName = "thumbeb";
497       else
498         ArchName = "thumb";
499     }
500     Triple.setArchName(ArchName + Suffix.str());
501 
502     return Triple.getTriple();
503   }
504   }
505 }
506 
507 std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args,
508                                                    types::ID InputType) const {
509   return ComputeLLVMTriple(Args, InputType);
510 }
511 
512 void ToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
513                                           ArgStringList &CC1Args) const {
514   // Each toolchain should provide the appropriate include flags.
515 }
516 
517 void ToolChain::addClangTargetOptions(const ArgList &DriverArgs,
518                                       ArgStringList &CC1Args) const {
519 }
520 
521 void ToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {}
522 
523 void ToolChain::addProfileRTLibs(const llvm::opt::ArgList &Args,
524                                  llvm::opt::ArgStringList &CmdArgs) const {
525   if (!needsProfileRT(Args)) return;
526 
527   CmdArgs.push_back(getCompilerRTArgString(Args, "profile"));
528 }
529 
530 ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
531     const ArgList &Args) const {
532   const Arg* A = Args.getLastArg(options::OPT_rtlib_EQ);
533   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_RTLIB;
534 
535   // "platform" is only used in tests to override CLANG_DEFAULT_RTLIB
536   if (LibName == "compiler-rt")
537     return ToolChain::RLT_CompilerRT;
538   else if (LibName == "libgcc")
539     return ToolChain::RLT_Libgcc;
540   else if (LibName == "platform")
541     return GetDefaultRuntimeLibType();
542 
543   if (A)
544     getDriver().Diag(diag::err_drv_invalid_rtlib_name) << A->getAsString(Args);
545 
546   return GetDefaultRuntimeLibType();
547 }
548 
549 static bool ParseCXXStdlibType(const StringRef& Name,
550                                ToolChain::CXXStdlibType& Type) {
551   if (Name == "libc++")
552     Type = ToolChain::CST_Libcxx;
553   else if (Name == "libstdc++")
554     Type = ToolChain::CST_Libstdcxx;
555   else
556     return false;
557 
558   return true;
559 }
560 
561 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
562   ToolChain::CXXStdlibType Type;
563   bool HasValidType = false;
564   bool ForcePlatformDefault = false;
565 
566   const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
567   if (A) {
568     StringRef Value = A->getValue();
569     HasValidType = ParseCXXStdlibType(Value, Type);
570 
571     // Only use in tests to override CLANG_DEFAULT_CXX_STDLIB!
572     if (Value == "platform")
573       ForcePlatformDefault = true;
574     else if (!HasValidType)
575       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
576         << A->getAsString(Args);
577   }
578 
579   // If no argument was provided or its value was invalid, look for the
580   // default unless forced or configured to take the platform default.
581   if (!HasValidType && (ForcePlatformDefault ||
582       !ParseCXXStdlibType(CLANG_DEFAULT_CXX_STDLIB, Type)))
583     Type = GetDefaultCXXStdlibType();
584 
585   return Type;
586 }
587 
588 /// \brief Utility function to add a system include directory to CC1 arguments.
589 /*static*/ void ToolChain::addSystemInclude(const ArgList &DriverArgs,
590                                             ArgStringList &CC1Args,
591                                             const Twine &Path) {
592   CC1Args.push_back("-internal-isystem");
593   CC1Args.push_back(DriverArgs.MakeArgString(Path));
594 }
595 
596 /// \brief Utility function to add a system include directory with extern "C"
597 /// semantics to CC1 arguments.
598 ///
599 /// Note that this should be used rarely, and only for directories that
600 /// historically and for legacy reasons are treated as having implicit extern
601 /// "C" semantics. These semantics are *ignored* by and large today, but its
602 /// important to preserve the preprocessor changes resulting from the
603 /// classification.
604 /*static*/ void ToolChain::addExternCSystemInclude(const ArgList &DriverArgs,
605                                                    ArgStringList &CC1Args,
606                                                    const Twine &Path) {
607   CC1Args.push_back("-internal-externc-isystem");
608   CC1Args.push_back(DriverArgs.MakeArgString(Path));
609 }
610 
611 void ToolChain::addExternCSystemIncludeIfExists(const ArgList &DriverArgs,
612                                                 ArgStringList &CC1Args,
613                                                 const Twine &Path) {
614   if (llvm::sys::fs::exists(Path))
615     addExternCSystemInclude(DriverArgs, CC1Args, Path);
616 }
617 
618 /// \brief Utility function to add a list of system include directories to CC1.
619 /*static*/ void ToolChain::addSystemIncludes(const ArgList &DriverArgs,
620                                              ArgStringList &CC1Args,
621                                              ArrayRef<StringRef> Paths) {
622   for (StringRef Path : Paths) {
623     CC1Args.push_back("-internal-isystem");
624     CC1Args.push_back(DriverArgs.MakeArgString(Path));
625   }
626 }
627 
628 void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
629                                              ArgStringList &CC1Args) const {
630   // Header search paths should be handled by each of the subclasses.
631   // Historically, they have not been, and instead have been handled inside of
632   // the CC1-layer frontend. As the logic is hoisted out, this generic function
633   // will slowly stop being called.
634   //
635   // While it is being called, replicate a bit of a hack to propagate the
636   // '-stdlib=' flag down to CC1 so that it can in turn customize the C++
637   // header search paths with it. Once all systems are overriding this
638   // function, the CC1 flag and this line can be removed.
639   DriverArgs.AddAllArgs(CC1Args, options::OPT_stdlib_EQ);
640 }
641 
642 void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
643                                     ArgStringList &CmdArgs) const {
644   CXXStdlibType Type = GetCXXStdlibType(Args);
645 
646   switch (Type) {
647   case ToolChain::CST_Libcxx:
648     CmdArgs.push_back("-lc++");
649     break;
650 
651   case ToolChain::CST_Libstdcxx:
652     CmdArgs.push_back("-lstdc++");
653     break;
654   }
655 }
656 
657 void ToolChain::AddFilePathLibArgs(const ArgList &Args,
658                                    ArgStringList &CmdArgs) const {
659   for (const auto &LibPath : getFilePaths())
660     if(LibPath.length() > 0)
661       CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
662 }
663 
664 void ToolChain::AddCCKextLibArgs(const ArgList &Args,
665                                  ArgStringList &CmdArgs) const {
666   CmdArgs.push_back("-lcc_kext");
667 }
668 
669 bool ToolChain::AddFastMathRuntimeIfAvailable(const ArgList &Args,
670                                               ArgStringList &CmdArgs) const {
671   // Do not check for -fno-fast-math or -fno-unsafe-math when -Ofast passed
672   // (to keep the linker options consistent with gcc and clang itself).
673   if (!isOptimizationLevelFast(Args)) {
674     // Check if -ffast-math or -funsafe-math.
675     Arg *A =
676         Args.getLastArg(options::OPT_ffast_math, options::OPT_fno_fast_math,
677                         options::OPT_funsafe_math_optimizations,
678                         options::OPT_fno_unsafe_math_optimizations);
679 
680     if (!A || A->getOption().getID() == options::OPT_fno_fast_math ||
681         A->getOption().getID() == options::OPT_fno_unsafe_math_optimizations)
682       return false;
683   }
684   // If crtfastmath.o exists add it to the arguments.
685   std::string Path = GetFilePath("crtfastmath.o");
686   if (Path == "crtfastmath.o") // Not found.
687     return false;
688 
689   CmdArgs.push_back(Args.MakeArgString(Path));
690   return true;
691 }
692 
693 SanitizerMask ToolChain::getSupportedSanitizers() const {
694   // Return sanitizers which don't require runtime support and are not
695   // platform dependent.
696   using namespace SanitizerKind;
697   SanitizerMask Res = (Undefined & ~Vptr & ~Function) | (CFI & ~CFIICall) |
698                       CFICastStrict | UnsignedIntegerOverflow | LocalBounds;
699   if (getTriple().getArch() == llvm::Triple::x86 ||
700       getTriple().getArch() == llvm::Triple::x86_64 ||
701       getTriple().getArch() == llvm::Triple::wasm32 ||
702       getTriple().getArch() == llvm::Triple::wasm64)
703     Res |= CFIICall;
704   return Res;
705 }
706 
707 void ToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
708                                    ArgStringList &CC1Args) const {}
709 
710 void ToolChain::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
711                                     ArgStringList &CC1Args) const {}
712