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 "InputInfo.h"
12 #include "ToolChains/Arch/ARM.h"
13 #include "ToolChains/Clang.h"
14 #include "clang/Basic/ObjCRuntime.h"
15 #include "clang/Basic/Sanitizers.h"
16 #include "clang/Config/config.h"
17 #include "clang/Driver/Action.h"
18 #include "clang/Driver/Driver.h"
19 #include "clang/Driver/DriverDiagnostic.h"
20 #include "clang/Driver/Job.h"
21 #include "clang/Driver/Options.h"
22 #include "clang/Driver/SanitizerArgs.h"
23 #include "clang/Driver/XRayArgs.h"
24 #include "llvm/ADT/STLExtras.h"
25 #include "llvm/ADT/SmallString.h"
26 #include "llvm/ADT/StringRef.h"
27 #include "llvm/ADT/Triple.h"
28 #include "llvm/ADT/Twine.h"
29 #include "llvm/Config/llvm-config.h"
30 #include "llvm/MC/MCTargetOptions.h"
31 #include "llvm/Option/Arg.h"
32 #include "llvm/Option/ArgList.h"
33 #include "llvm/Option/OptTable.h"
34 #include "llvm/Option/Option.h"
35 #include "llvm/Support/ErrorHandling.h"
36 #include "llvm/Support/FileSystem.h"
37 #include "llvm/Support/Path.h"
38 #include "llvm/Support/TargetParser.h"
39 #include "llvm/Support/TargetRegistry.h"
40 #include "llvm/Support/VersionTuple.h"
41 #include "llvm/Support/VirtualFileSystem.h"
42 #include <cassert>
43 #include <cstddef>
44 #include <cstring>
45 #include <string>
46 
47 using namespace clang;
48 using namespace driver;
49 using namespace tools;
50 using namespace llvm;
51 using namespace llvm::opt;
52 
53 static llvm::opt::Arg *GetRTTIArgument(const ArgList &Args) {
54   return Args.getLastArg(options::OPT_mkernel, options::OPT_fapple_kext,
55                          options::OPT_fno_rtti, options::OPT_frtti);
56 }
57 
58 static ToolChain::RTTIMode CalculateRTTIMode(const ArgList &Args,
59                                              const llvm::Triple &Triple,
60                                              const Arg *CachedRTTIArg) {
61   // Explicit rtti/no-rtti args
62   if (CachedRTTIArg) {
63     if (CachedRTTIArg->getOption().matches(options::OPT_frtti))
64       return ToolChain::RM_Enabled;
65     else
66       return ToolChain::RM_Disabled;
67   }
68 
69   // -frtti is default, except for the PS4 CPU.
70   return (Triple.isPS4CPU()) ? ToolChain::RM_Disabled : ToolChain::RM_Enabled;
71 }
72 
73 ToolChain::ToolChain(const Driver &D, const llvm::Triple &T,
74                      const ArgList &Args)
75     : D(D), Triple(T), Args(Args), CachedRTTIArg(GetRTTIArgument(Args)),
76       CachedRTTIMode(CalculateRTTIMode(Args, Triple, CachedRTTIArg)) {
77   SmallString<128> P;
78 
79   P.assign(D.ResourceDir);
80   llvm::sys::path::append(P, D.getTargetTriple(), "lib");
81   if (getVFS().exists(P))
82     getLibraryPaths().push_back(P.str());
83 
84   P.assign(D.ResourceDir);
85   llvm::sys::path::append(P, Triple.str(), "lib");
86   if (getVFS().exists(P))
87     getLibraryPaths().push_back(P.str());
88 
89   std::string CandidateLibPath = getArchSpecificLibPath();
90   if (getVFS().exists(CandidateLibPath))
91     getFilePaths().push_back(CandidateLibPath);
92 }
93 
94 void ToolChain::setTripleEnvironment(llvm::Triple::EnvironmentType Env) {
95   Triple.setEnvironment(Env);
96   if (EffectiveTriple != llvm::Triple())
97     EffectiveTriple.setEnvironment(Env);
98 }
99 
100 ToolChain::~ToolChain() = default;
101 
102 llvm::vfs::FileSystem &ToolChain::getVFS() const {
103   return getDriver().getVFS();
104 }
105 
106 bool ToolChain::useIntegratedAs() const {
107   return Args.hasFlag(options::OPT_fintegrated_as,
108                       options::OPT_fno_integrated_as,
109                       IsIntegratedAssemblerDefault());
110 }
111 
112 bool ToolChain::useRelaxRelocations() const {
113   return ENABLE_X86_RELAX_RELOCATIONS;
114 }
115 
116 const SanitizerArgs& ToolChain::getSanitizerArgs() const {
117   if (!SanitizerArguments.get())
118     SanitizerArguments.reset(new SanitizerArgs(*this, Args));
119   return *SanitizerArguments.get();
120 }
121 
122 const XRayArgs& ToolChain::getXRayArgs() const {
123   if (!XRayArguments.get())
124     XRayArguments.reset(new XRayArgs(*this, Args));
125   return *XRayArguments.get();
126 }
127 
128 namespace {
129 
130 struct DriverSuffix {
131   const char *Suffix;
132   const char *ModeFlag;
133 };
134 
135 } // namespace
136 
137 static const DriverSuffix *FindDriverSuffix(StringRef ProgName, size_t &Pos) {
138   // A list of known driver suffixes. Suffixes are compared against the
139   // program name in order. If there is a match, the frontend type is updated as
140   // necessary by applying the ModeFlag.
141   static const DriverSuffix DriverSuffixes[] = {
142       {"clang", nullptr},
143       {"clang++", "--driver-mode=g++"},
144       {"clang-c++", "--driver-mode=g++"},
145       {"clang-cc", nullptr},
146       {"clang-cpp", "--driver-mode=cpp"},
147       {"clang-g++", "--driver-mode=g++"},
148       {"clang-gcc", nullptr},
149       {"clang-cl", "--driver-mode=cl"},
150       {"cc", nullptr},
151       {"cpp", "--driver-mode=cpp"},
152       {"cl", "--driver-mode=cl"},
153       {"++", "--driver-mode=g++"},
154   };
155 
156   for (size_t i = 0; i < llvm::array_lengthof(DriverSuffixes); ++i) {
157     StringRef Suffix(DriverSuffixes[i].Suffix);
158     if (ProgName.endswith(Suffix)) {
159       Pos = ProgName.size() - Suffix.size();
160       return &DriverSuffixes[i];
161     }
162   }
163   return nullptr;
164 }
165 
166 /// Normalize the program name from argv[0] by stripping the file extension if
167 /// present and lower-casing the string on Windows.
168 static std::string normalizeProgramName(llvm::StringRef Argv0) {
169   std::string ProgName = llvm::sys::path::stem(Argv0);
170 #ifdef _WIN32
171   // Transform to lowercase for case insensitive file systems.
172   std::transform(ProgName.begin(), ProgName.end(), ProgName.begin(), ::tolower);
173 #endif
174   return ProgName;
175 }
176 
177 static const DriverSuffix *parseDriverSuffix(StringRef ProgName, size_t &Pos) {
178   // Try to infer frontend type and default target from the program name by
179   // comparing it against DriverSuffixes in order.
180 
181   // If there is a match, the function tries to identify a target as prefix.
182   // E.g. "x86_64-linux-clang" as interpreted as suffix "clang" with target
183   // prefix "x86_64-linux". If such a target prefix is found, it may be
184   // added via -target as implicit first argument.
185   const DriverSuffix *DS = FindDriverSuffix(ProgName, Pos);
186 
187   if (!DS) {
188     // Try again after stripping any trailing version number:
189     // clang++3.5 -> clang++
190     ProgName = ProgName.rtrim("0123456789.");
191     DS = FindDriverSuffix(ProgName, Pos);
192   }
193 
194   if (!DS) {
195     // Try again after stripping trailing -component.
196     // clang++-tot -> clang++
197     ProgName = ProgName.slice(0, ProgName.rfind('-'));
198     DS = FindDriverSuffix(ProgName, Pos);
199   }
200   return DS;
201 }
202 
203 ParsedClangName
204 ToolChain::getTargetAndModeFromProgramName(StringRef PN) {
205   std::string ProgName = normalizeProgramName(PN);
206   size_t SuffixPos;
207   const DriverSuffix *DS = parseDriverSuffix(ProgName, SuffixPos);
208   if (!DS)
209     return {};
210   size_t SuffixEnd = SuffixPos + strlen(DS->Suffix);
211 
212   size_t LastComponent = ProgName.rfind('-', SuffixPos);
213   if (LastComponent == std::string::npos)
214     return ParsedClangName(ProgName.substr(0, SuffixEnd), DS->ModeFlag);
215   std::string ModeSuffix = ProgName.substr(LastComponent + 1,
216                                            SuffixEnd - LastComponent - 1);
217 
218   // Infer target from the prefix.
219   StringRef Prefix(ProgName);
220   Prefix = Prefix.slice(0, LastComponent);
221   std::string IgnoredError;
222   bool IsRegistered = llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError);
223   return ParsedClangName{Prefix, ModeSuffix, DS->ModeFlag, IsRegistered};
224 }
225 
226 StringRef ToolChain::getDefaultUniversalArchName() const {
227   // In universal driver terms, the arch name accepted by -arch isn't exactly
228   // the same as the ones that appear in the triple. Roughly speaking, this is
229   // an inverse of the darwin::getArchTypeForDarwinArchName() function, but the
230   // only interesting special case is powerpc.
231   switch (Triple.getArch()) {
232   case llvm::Triple::ppc:
233     return "ppc";
234   case llvm::Triple::ppc64:
235     return "ppc64";
236   case llvm::Triple::ppc64le:
237     return "ppc64le";
238   default:
239     return Triple.getArchName();
240   }
241 }
242 
243 std::string ToolChain::getInputFilename(const InputInfo &Input) const {
244   return Input.getFilename();
245 }
246 
247 bool ToolChain::IsUnwindTablesDefault(const ArgList &Args) const {
248   return false;
249 }
250 
251 Tool *ToolChain::getClang() const {
252   if (!Clang)
253     Clang.reset(new tools::Clang(*this));
254   return Clang.get();
255 }
256 
257 Tool *ToolChain::buildAssembler() const {
258   return new tools::ClangAs(*this);
259 }
260 
261 Tool *ToolChain::buildLinker() const {
262   llvm_unreachable("Linking is not supported by this toolchain");
263 }
264 
265 Tool *ToolChain::getAssemble() const {
266   if (!Assemble)
267     Assemble.reset(buildAssembler());
268   return Assemble.get();
269 }
270 
271 Tool *ToolChain::getClangAs() const {
272   if (!Assemble)
273     Assemble.reset(new tools::ClangAs(*this));
274   return Assemble.get();
275 }
276 
277 Tool *ToolChain::getLink() const {
278   if (!Link)
279     Link.reset(buildLinker());
280   return Link.get();
281 }
282 
283 Tool *ToolChain::getOffloadBundler() const {
284   if (!OffloadBundler)
285     OffloadBundler.reset(new tools::OffloadBundler(*this));
286   return OffloadBundler.get();
287 }
288 
289 Tool *ToolChain::getTool(Action::ActionClass AC) const {
290   switch (AC) {
291   case Action::AssembleJobClass:
292     return getAssemble();
293 
294   case Action::LinkJobClass:
295     return getLink();
296 
297   case Action::InputClass:
298   case Action::BindArchClass:
299   case Action::OffloadClass:
300   case Action::LipoJobClass:
301   case Action::DsymutilJobClass:
302   case Action::VerifyDebugInfoJobClass:
303     llvm_unreachable("Invalid tool kind.");
304 
305   case Action::CompileJobClass:
306   case Action::PrecompileJobClass:
307   case Action::HeaderModulePrecompileJobClass:
308   case Action::PreprocessJobClass:
309   case Action::AnalyzeJobClass:
310   case Action::MigrateJobClass:
311   case Action::VerifyPCHJobClass:
312   case Action::BackendJobClass:
313     return getClang();
314 
315   case Action::OffloadBundlingJobClass:
316   case Action::OffloadUnbundlingJobClass:
317     return getOffloadBundler();
318   }
319 
320   llvm_unreachable("Invalid tool kind.");
321 }
322 
323 static StringRef getArchNameForCompilerRTLib(const ToolChain &TC,
324                                              const ArgList &Args) {
325   const llvm::Triple &Triple = TC.getTriple();
326   bool IsWindows = Triple.isOSWindows();
327 
328   if (TC.getArch() == llvm::Triple::arm || TC.getArch() == llvm::Triple::armeb)
329     return (arm::getARMFloatABI(TC, Args) == arm::FloatABI::Hard && !IsWindows)
330                ? "armhf"
331                : "arm";
332 
333   // For historic reasons, Android library is using i686 instead of i386.
334   if (TC.getArch() == llvm::Triple::x86 && Triple.isAndroid())
335     return "i686";
336 
337   return llvm::Triple::getArchTypeName(TC.getArch());
338 }
339 
340 StringRef ToolChain::getOSLibName() const {
341   switch (Triple.getOS()) {
342   case llvm::Triple::FreeBSD:
343     return "freebsd";
344   case llvm::Triple::NetBSD:
345     return "netbsd";
346   case llvm::Triple::OpenBSD:
347     return "openbsd";
348   case llvm::Triple::Solaris:
349     return "sunos";
350   default:
351     return getOS();
352   }
353 }
354 
355 std::string ToolChain::getCompilerRTPath() const {
356   SmallString<128> Path(getDriver().ResourceDir);
357   if (Triple.isOSUnknown()) {
358     llvm::sys::path::append(Path, "lib");
359   } else {
360     llvm::sys::path::append(Path, "lib", getOSLibName());
361   }
362   return Path.str();
363 }
364 
365 std::string ToolChain::getCompilerRT(const ArgList &Args, StringRef Component,
366                                      bool Shared) const {
367   const llvm::Triple &TT = getTriple();
368   bool IsITANMSVCWindows =
369       TT.isWindowsMSVCEnvironment() || TT.isWindowsItaniumEnvironment();
370 
371   const char *Prefix = IsITANMSVCWindows ? "" : "lib";
372   const char *Suffix = Shared ? (Triple.isOSWindows() ? ".lib" : ".so")
373                               : (IsITANMSVCWindows ? ".lib" : ".a");
374   if (Shared && Triple.isWindowsGNUEnvironment())
375     Suffix = ".dll.a";
376 
377   for (const auto &LibPath : getLibraryPaths()) {
378     SmallString<128> P(LibPath);
379     llvm::sys::path::append(P, Prefix + Twine("clang_rt.") + Component + Suffix);
380     if (getVFS().exists(P))
381       return P.str();
382   }
383 
384   StringRef Arch = getArchNameForCompilerRTLib(*this, Args);
385   const char *Env = TT.isAndroid() ? "-android" : "";
386   SmallString<128> Path(getCompilerRTPath());
387   llvm::sys::path::append(Path, Prefix + Twine("clang_rt.") + Component + "-" +
388                                     Arch + Env + Suffix);
389   return Path.str();
390 }
391 
392 const char *ToolChain::getCompilerRTArgString(const llvm::opt::ArgList &Args,
393                                               StringRef Component,
394                                               bool Shared) const {
395   return Args.MakeArgString(getCompilerRT(Args, Component, Shared));
396 }
397 
398 std::string ToolChain::getArchSpecificLibPath() const {
399   SmallString<128> Path(getDriver().ResourceDir);
400   llvm::sys::path::append(Path, "lib", getOSLibName(),
401                           llvm::Triple::getArchTypeName(getArch()));
402   return Path.str();
403 }
404 
405 bool ToolChain::needsProfileRT(const ArgList &Args) {
406   if (Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
407                    false) ||
408       Args.hasArg(options::OPT_fprofile_generate) ||
409       Args.hasArg(options::OPT_fprofile_generate_EQ) ||
410       Args.hasArg(options::OPT_fprofile_instr_generate) ||
411       Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
412       Args.hasArg(options::OPT_fcreate_profile) ||
413       Args.hasArg(options::OPT_coverage))
414     return true;
415 
416   return false;
417 }
418 
419 Tool *ToolChain::SelectTool(const JobAction &JA) const {
420   if (getDriver().ShouldUseClangCompiler(JA)) return getClang();
421   Action::ActionClass AC = JA.getKind();
422   if (AC == Action::AssembleJobClass && useIntegratedAs())
423     return getClangAs();
424   return getTool(AC);
425 }
426 
427 std::string ToolChain::GetFilePath(const char *Name) const {
428   return D.GetFilePath(Name, *this);
429 }
430 
431 std::string ToolChain::GetProgramPath(const char *Name) const {
432   return D.GetProgramPath(Name, *this);
433 }
434 
435 std::string ToolChain::GetLinkerPath() const {
436   const Arg* A = Args.getLastArg(options::OPT_fuse_ld_EQ);
437   StringRef UseLinker = A ? A->getValue() : CLANG_DEFAULT_LINKER;
438 
439   if (llvm::sys::path::is_absolute(UseLinker)) {
440     // If we're passed what looks like an absolute path, don't attempt to
441     // second-guess that.
442     if (llvm::sys::fs::can_execute(UseLinker))
443       return UseLinker;
444   } else if (UseLinker.empty() || UseLinker == "ld") {
445     // If we're passed -fuse-ld= with no argument, or with the argument ld,
446     // then use whatever the default system linker is.
447     return GetProgramPath(getDefaultLinker());
448   } else {
449     llvm::SmallString<8> LinkerName;
450     if (Triple.isOSDarwin())
451       LinkerName.append("ld64.");
452     else
453       LinkerName.append("ld.");
454     LinkerName.append(UseLinker);
455 
456     std::string LinkerPath(GetProgramPath(LinkerName.c_str()));
457     if (llvm::sys::fs::can_execute(LinkerPath))
458       return LinkerPath;
459   }
460 
461   if (A)
462     getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
463 
464   return GetProgramPath(getDefaultLinker());
465 }
466 
467 types::ID ToolChain::LookupTypeForExtension(StringRef Ext) const {
468   return types::lookupTypeForExtension(Ext);
469 }
470 
471 bool ToolChain::HasNativeLLVMSupport() const {
472   return false;
473 }
474 
475 bool ToolChain::isCrossCompiling() const {
476   llvm::Triple HostTriple(LLVM_HOST_TRIPLE);
477   switch (HostTriple.getArch()) {
478   // The A32/T32/T16 instruction sets are not separate architectures in this
479   // context.
480   case llvm::Triple::arm:
481   case llvm::Triple::armeb:
482   case llvm::Triple::thumb:
483   case llvm::Triple::thumbeb:
484     return getArch() != llvm::Triple::arm && getArch() != llvm::Triple::thumb &&
485            getArch() != llvm::Triple::armeb && getArch() != llvm::Triple::thumbeb;
486   default:
487     return HostTriple.getArch() != getArch();
488   }
489 }
490 
491 ObjCRuntime ToolChain::getDefaultObjCRuntime(bool isNonFragile) const {
492   return ObjCRuntime(isNonFragile ? ObjCRuntime::GNUstep : ObjCRuntime::GCC,
493                      VersionTuple());
494 }
495 
496 llvm::ExceptionHandling
497 ToolChain::GetExceptionModel(const llvm::opt::ArgList &Args) const {
498   return llvm::ExceptionHandling::None;
499 }
500 
501 bool ToolChain::isThreadModelSupported(const StringRef Model) const {
502   if (Model == "single") {
503     // FIXME: 'single' is only supported on ARM and WebAssembly so far.
504     return Triple.getArch() == llvm::Triple::arm ||
505            Triple.getArch() == llvm::Triple::armeb ||
506            Triple.getArch() == llvm::Triple::thumb ||
507            Triple.getArch() == llvm::Triple::thumbeb ||
508            Triple.getArch() == llvm::Triple::wasm32 ||
509            Triple.getArch() == llvm::Triple::wasm64;
510   } else if (Model == "posix")
511     return true;
512 
513   return false;
514 }
515 
516 std::string ToolChain::ComputeLLVMTriple(const ArgList &Args,
517                                          types::ID InputType) const {
518   switch (getTriple().getArch()) {
519   default:
520     return getTripleString();
521 
522   case llvm::Triple::x86_64: {
523     llvm::Triple Triple = getTriple();
524     if (!Triple.isOSBinFormatMachO())
525       return getTripleString();
526 
527     if (Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
528       // x86_64h goes in the triple. Other -march options just use the
529       // vanilla triple we already have.
530       StringRef MArch = A->getValue();
531       if (MArch == "x86_64h")
532         Triple.setArchName(MArch);
533     }
534     return Triple.getTriple();
535   }
536   case llvm::Triple::aarch64: {
537     llvm::Triple Triple = getTriple();
538     if (!Triple.isOSBinFormatMachO())
539       return getTripleString();
540 
541     // FIXME: older versions of ld64 expect the "arm64" component in the actual
542     // triple string and query it to determine whether an LTO file can be
543     // handled. Remove this when we don't care any more.
544     Triple.setArchName("arm64");
545     return Triple.getTriple();
546   }
547   case llvm::Triple::arm:
548   case llvm::Triple::armeb:
549   case llvm::Triple::thumb:
550   case llvm::Triple::thumbeb: {
551     // FIXME: Factor into subclasses.
552     llvm::Triple Triple = getTriple();
553     bool IsBigEndian = getTriple().getArch() == llvm::Triple::armeb ||
554                        getTriple().getArch() == llvm::Triple::thumbeb;
555 
556     // Handle pseudo-target flags '-mlittle-endian'/'-EL' and
557     // '-mbig-endian'/'-EB'.
558     if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
559                                  options::OPT_mbig_endian)) {
560       IsBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
561     }
562 
563     // Thumb2 is the default for V7 on Darwin.
564     //
565     // FIXME: Thumb should just be another -target-feaure, not in the triple.
566     StringRef MCPU, MArch;
567     if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
568       MCPU = A->getValue();
569     if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
570       MArch = A->getValue();
571     std::string CPU =
572         Triple.isOSBinFormatMachO()
573             ? tools::arm::getARMCPUForMArch(MArch, Triple).str()
574             : tools::arm::getARMTargetCPU(MCPU, MArch, Triple);
575     StringRef Suffix =
576       tools::arm::getLLVMArchSuffixForARM(CPU, MArch, Triple);
577     bool IsMProfile = ARM::parseArchProfile(Suffix) == ARM::ProfileKind::M;
578     bool ThumbDefault = IsMProfile || (ARM::parseArchVersion(Suffix) == 7 &&
579                                        getTriple().isOSBinFormatMachO());
580     // FIXME: this is invalid for WindowsCE
581     if (getTriple().isOSWindows())
582       ThumbDefault = true;
583     std::string ArchName;
584     if (IsBigEndian)
585       ArchName = "armeb";
586     else
587       ArchName = "arm";
588 
589     // Check if ARM ISA was explicitly selected (using -mno-thumb or -marm) for
590     // M-Class CPUs/architecture variants, which is not supported.
591     bool ARMModeRequested = !Args.hasFlag(options::OPT_mthumb,
592                                           options::OPT_mno_thumb, ThumbDefault);
593     if (IsMProfile && ARMModeRequested) {
594       if (!MCPU.empty())
595         getDriver().Diag(diag::err_cpu_unsupported_isa) << CPU << "ARM";
596        else
597         getDriver().Diag(diag::err_arch_unsupported_isa)
598           << tools::arm::getARMArch(MArch, getTriple()) << "ARM";
599     }
600 
601     // Check to see if an explicit choice to use thumb has been made via
602     // -mthumb. For assembler files we must check for -mthumb in the options
603     // passed to the assember via -Wa or -Xassembler.
604     bool IsThumb = false;
605     if (InputType != types::TY_PP_Asm)
606       IsThumb = Args.hasFlag(options::OPT_mthumb, options::OPT_mno_thumb,
607                               ThumbDefault);
608     else {
609       // Ideally we would check for these flags in
610       // CollectArgsForIntegratedAssembler but we can't change the ArchName at
611       // that point. There is no assembler equivalent of -mno-thumb, -marm, or
612       // -mno-arm.
613       for (const auto *A :
614            Args.filtered(options::OPT_Wa_COMMA, options::OPT_Xassembler)) {
615         for (StringRef Value : A->getValues()) {
616           if (Value == "-mthumb")
617             IsThumb = true;
618         }
619       }
620     }
621     // Assembly files should start in ARM mode, unless arch is M-profile, or
622     // -mthumb has been passed explicitly to the assembler. Windows is always
623     // thumb.
624     if (IsThumb || IsMProfile || getTriple().isOSWindows()) {
625       if (IsBigEndian)
626         ArchName = "thumbeb";
627       else
628         ArchName = "thumb";
629     }
630     Triple.setArchName(ArchName + Suffix.str());
631 
632     return Triple.getTriple();
633   }
634   }
635 }
636 
637 std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args,
638                                                    types::ID InputType) const {
639   return ComputeLLVMTriple(Args, InputType);
640 }
641 
642 void ToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
643                                           ArgStringList &CC1Args) const {
644   // Each toolchain should provide the appropriate include flags.
645 }
646 
647 void ToolChain::addClangTargetOptions(
648     const ArgList &DriverArgs, ArgStringList &CC1Args,
649     Action::OffloadKind DeviceOffloadKind) const {}
650 
651 void ToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {}
652 
653 void ToolChain::addProfileRTLibs(const llvm::opt::ArgList &Args,
654                                  llvm::opt::ArgStringList &CmdArgs) const {
655   if (!needsProfileRT(Args)) return;
656 
657   CmdArgs.push_back(getCompilerRTArgString(Args, "profile"));
658 }
659 
660 ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
661     const ArgList &Args) const {
662   const Arg* A = Args.getLastArg(options::OPT_rtlib_EQ);
663   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_RTLIB;
664 
665   // Only use "platform" in tests to override CLANG_DEFAULT_RTLIB!
666   if (LibName == "compiler-rt")
667     return ToolChain::RLT_CompilerRT;
668   else if (LibName == "libgcc")
669     return ToolChain::RLT_Libgcc;
670   else if (LibName == "platform")
671     return GetDefaultRuntimeLibType();
672 
673   if (A)
674     getDriver().Diag(diag::err_drv_invalid_rtlib_name) << A->getAsString(Args);
675 
676   return GetDefaultRuntimeLibType();
677 }
678 
679 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
680   const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
681   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_CXX_STDLIB;
682 
683   // Only use "platform" in tests to override CLANG_DEFAULT_CXX_STDLIB!
684   if (LibName == "libc++")
685     return ToolChain::CST_Libcxx;
686   else if (LibName == "libstdc++")
687     return ToolChain::CST_Libstdcxx;
688   else if (LibName == "platform")
689     return GetDefaultCXXStdlibType();
690 
691   if (A)
692     getDriver().Diag(diag::err_drv_invalid_stdlib_name) << A->getAsString(Args);
693 
694   return GetDefaultCXXStdlibType();
695 }
696 
697 /// Utility function to add a system include directory to CC1 arguments.
698 /*static*/ void ToolChain::addSystemInclude(const ArgList &DriverArgs,
699                                             ArgStringList &CC1Args,
700                                             const Twine &Path) {
701   CC1Args.push_back("-internal-isystem");
702   CC1Args.push_back(DriverArgs.MakeArgString(Path));
703 }
704 
705 /// Utility function to add a system include directory with extern "C"
706 /// semantics to CC1 arguments.
707 ///
708 /// Note that this should be used rarely, and only for directories that
709 /// historically and for legacy reasons are treated as having implicit extern
710 /// "C" semantics. These semantics are *ignored* by and large today, but its
711 /// important to preserve the preprocessor changes resulting from the
712 /// classification.
713 /*static*/ void ToolChain::addExternCSystemInclude(const ArgList &DriverArgs,
714                                                    ArgStringList &CC1Args,
715                                                    const Twine &Path) {
716   CC1Args.push_back("-internal-externc-isystem");
717   CC1Args.push_back(DriverArgs.MakeArgString(Path));
718 }
719 
720 void ToolChain::addExternCSystemIncludeIfExists(const ArgList &DriverArgs,
721                                                 ArgStringList &CC1Args,
722                                                 const Twine &Path) {
723   if (llvm::sys::fs::exists(Path))
724     addExternCSystemInclude(DriverArgs, CC1Args, Path);
725 }
726 
727 /// Utility function to add a list of system include directories to CC1.
728 /*static*/ void ToolChain::addSystemIncludes(const ArgList &DriverArgs,
729                                              ArgStringList &CC1Args,
730                                              ArrayRef<StringRef> Paths) {
731   for (const auto Path : Paths) {
732     CC1Args.push_back("-internal-isystem");
733     CC1Args.push_back(DriverArgs.MakeArgString(Path));
734   }
735 }
736 
737 void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
738                                              ArgStringList &CC1Args) const {
739   // Header search paths should be handled by each of the subclasses.
740   // Historically, they have not been, and instead have been handled inside of
741   // the CC1-layer frontend. As the logic is hoisted out, this generic function
742   // will slowly stop being called.
743   //
744   // While it is being called, replicate a bit of a hack to propagate the
745   // '-stdlib=' flag down to CC1 so that it can in turn customize the C++
746   // header search paths with it. Once all systems are overriding this
747   // function, the CC1 flag and this line can be removed.
748   DriverArgs.AddAllArgs(CC1Args, options::OPT_stdlib_EQ);
749 }
750 
751 bool ToolChain::ShouldLinkCXXStdlib(const llvm::opt::ArgList &Args) const {
752   return getDriver().CCCIsCXX() &&
753          !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
754                       options::OPT_nostdlibxx);
755 }
756 
757 void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
758                                     ArgStringList &CmdArgs) const {
759   assert(!Args.hasArg(options::OPT_nostdlibxx) &&
760          "should not have called this");
761   CXXStdlibType Type = GetCXXStdlibType(Args);
762 
763   switch (Type) {
764   case ToolChain::CST_Libcxx:
765     CmdArgs.push_back("-lc++");
766     break;
767 
768   case ToolChain::CST_Libstdcxx:
769     CmdArgs.push_back("-lstdc++");
770     break;
771   }
772 }
773 
774 void ToolChain::AddFilePathLibArgs(const ArgList &Args,
775                                    ArgStringList &CmdArgs) const {
776   for (const auto &LibPath : getLibraryPaths())
777     if(LibPath.length() > 0)
778       CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
779 
780   for (const auto &LibPath : getFilePaths())
781     if(LibPath.length() > 0)
782       CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
783 }
784 
785 void ToolChain::AddCCKextLibArgs(const ArgList &Args,
786                                  ArgStringList &CmdArgs) const {
787   CmdArgs.push_back("-lcc_kext");
788 }
789 
790 bool ToolChain::AddFastMathRuntimeIfAvailable(const ArgList &Args,
791                                               ArgStringList &CmdArgs) const {
792   // Do not check for -fno-fast-math or -fno-unsafe-math when -Ofast passed
793   // (to keep the linker options consistent with gcc and clang itself).
794   if (!isOptimizationLevelFast(Args)) {
795     // Check if -ffast-math or -funsafe-math.
796     Arg *A =
797         Args.getLastArg(options::OPT_ffast_math, options::OPT_fno_fast_math,
798                         options::OPT_funsafe_math_optimizations,
799                         options::OPT_fno_unsafe_math_optimizations);
800 
801     if (!A || A->getOption().getID() == options::OPT_fno_fast_math ||
802         A->getOption().getID() == options::OPT_fno_unsafe_math_optimizations)
803       return false;
804   }
805   // If crtfastmath.o exists add it to the arguments.
806   std::string Path = GetFilePath("crtfastmath.o");
807   if (Path == "crtfastmath.o") // Not found.
808     return false;
809 
810   CmdArgs.push_back(Args.MakeArgString(Path));
811   return true;
812 }
813 
814 SanitizerMask ToolChain::getSupportedSanitizers() const {
815   // Return sanitizers which don't require runtime support and are not
816   // platform dependent.
817 
818   using namespace SanitizerKind;
819 
820   SanitizerMask Res = (Undefined & ~Vptr & ~Function) | (CFI & ~CFIICall) |
821                       CFICastStrict | UnsignedIntegerOverflow |
822                       ImplicitConversion | Nullability | LocalBounds;
823   if (getTriple().getArch() == llvm::Triple::x86 ||
824       getTriple().getArch() == llvm::Triple::x86_64 ||
825       getTriple().getArch() == llvm::Triple::arm ||
826       getTriple().getArch() == llvm::Triple::aarch64 ||
827       getTriple().getArch() == llvm::Triple::wasm32 ||
828       getTriple().getArch() == llvm::Triple::wasm64)
829     Res |= CFIICall;
830   if (getTriple().getArch() == llvm::Triple::x86_64 ||
831       getTriple().getArch() == llvm::Triple::aarch64)
832     Res |= ShadowCallStack;
833   return Res;
834 }
835 
836 void ToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
837                                    ArgStringList &CC1Args) const {}
838 
839 void ToolChain::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
840                                     ArgStringList &CC1Args) const {}
841 
842 static VersionTuple separateMSVCFullVersion(unsigned Version) {
843   if (Version < 100)
844     return VersionTuple(Version);
845 
846   if (Version < 10000)
847     return VersionTuple(Version / 100, Version % 100);
848 
849   unsigned Build = 0, Factor = 1;
850   for (; Version > 10000; Version = Version / 10, Factor = Factor * 10)
851     Build = Build + (Version % 10) * Factor;
852   return VersionTuple(Version / 100, Version % 100, Build);
853 }
854 
855 VersionTuple
856 ToolChain::computeMSVCVersion(const Driver *D,
857                               const llvm::opt::ArgList &Args) const {
858   const Arg *MSCVersion = Args.getLastArg(options::OPT_fmsc_version);
859   const Arg *MSCompatibilityVersion =
860       Args.getLastArg(options::OPT_fms_compatibility_version);
861 
862   if (MSCVersion && MSCompatibilityVersion) {
863     if (D)
864       D->Diag(diag::err_drv_argument_not_allowed_with)
865           << MSCVersion->getAsString(Args)
866           << MSCompatibilityVersion->getAsString(Args);
867     return VersionTuple();
868   }
869 
870   if (MSCompatibilityVersion) {
871     VersionTuple MSVT;
872     if (MSVT.tryParse(MSCompatibilityVersion->getValue())) {
873       if (D)
874         D->Diag(diag::err_drv_invalid_value)
875             << MSCompatibilityVersion->getAsString(Args)
876             << MSCompatibilityVersion->getValue();
877     } else {
878       return MSVT;
879     }
880   }
881 
882   if (MSCVersion) {
883     unsigned Version = 0;
884     if (StringRef(MSCVersion->getValue()).getAsInteger(10, Version)) {
885       if (D)
886         D->Diag(diag::err_drv_invalid_value)
887             << MSCVersion->getAsString(Args) << MSCVersion->getValue();
888     } else {
889       return separateMSVCFullVersion(Version);
890     }
891   }
892 
893   return VersionTuple();
894 }
895 
896 llvm::opt::DerivedArgList *ToolChain::TranslateOpenMPTargetArgs(
897     const llvm::opt::DerivedArgList &Args, bool SameTripleAsHost,
898     SmallVectorImpl<llvm::opt::Arg *> &AllocatedArgs) const {
899   DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
900   const OptTable &Opts = getDriver().getOpts();
901   bool Modified = false;
902 
903   // Handle -Xopenmp-target flags
904   for (auto *A : Args) {
905     // Exclude flags which may only apply to the host toolchain.
906     // Do not exclude flags when the host triple (AuxTriple)
907     // matches the current toolchain triple. If it is not present
908     // at all, target and host share a toolchain.
909     if (A->getOption().matches(options::OPT_m_Group)) {
910       if (SameTripleAsHost)
911         DAL->append(A);
912       else
913         Modified = true;
914       continue;
915     }
916 
917     unsigned Index;
918     unsigned Prev;
919     bool XOpenMPTargetNoTriple =
920         A->getOption().matches(options::OPT_Xopenmp_target);
921 
922     if (A->getOption().matches(options::OPT_Xopenmp_target_EQ)) {
923       // Passing device args: -Xopenmp-target=<triple> -opt=val.
924       if (A->getValue(0) == getTripleString())
925         Index = Args.getBaseArgs().MakeIndex(A->getValue(1));
926       else
927         continue;
928     } else if (XOpenMPTargetNoTriple) {
929       // Passing device args: -Xopenmp-target -opt=val.
930       Index = Args.getBaseArgs().MakeIndex(A->getValue(0));
931     } else {
932       DAL->append(A);
933       continue;
934     }
935 
936     // Parse the argument to -Xopenmp-target.
937     Prev = Index;
938     std::unique_ptr<Arg> XOpenMPTargetArg(Opts.ParseOneArg(Args, Index));
939     if (!XOpenMPTargetArg || Index > Prev + 1) {
940       getDriver().Diag(diag::err_drv_invalid_Xopenmp_target_with_args)
941           << A->getAsString(Args);
942       continue;
943     }
944     if (XOpenMPTargetNoTriple && XOpenMPTargetArg &&
945         Args.getAllArgValues(options::OPT_fopenmp_targets_EQ).size() != 1) {
946       getDriver().Diag(diag::err_drv_Xopenmp_target_missing_triple);
947       continue;
948     }
949     XOpenMPTargetArg->setBaseArg(A);
950     A = XOpenMPTargetArg.release();
951     AllocatedArgs.push_back(A);
952     DAL->append(A);
953     Modified = true;
954   }
955 
956   if (Modified)
957     return DAL;
958 
959   delete DAL;
960   return nullptr;
961 }
962