1 //===- ToolChain.cpp - Collections of tools for one platform --------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "clang/Driver/ToolChain.h"
10 #include "InputInfo.h"
11 #include "ToolChains/Arch/ARM.h"
12 #include "ToolChains/Clang.h"
13 #include "clang/Basic/ObjCRuntime.h"
14 #include "clang/Basic/Sanitizers.h"
15 #include "clang/Config/config.h"
16 #include "clang/Driver/Action.h"
17 #include "clang/Driver/Driver.h"
18 #include "clang/Driver/DriverDiagnostic.h"
19 #include "clang/Driver/Job.h"
20 #include "clang/Driver/Options.h"
21 #include "clang/Driver/SanitizerArgs.h"
22 #include "clang/Driver/XRayArgs.h"
23 #include "llvm/ADT/STLExtras.h"
24 #include "llvm/ADT/SmallString.h"
25 #include "llvm/ADT/StringRef.h"
26 #include "llvm/ADT/Triple.h"
27 #include "llvm/ADT/Twine.h"
28 #include "llvm/Config/llvm-config.h"
29 #include "llvm/MC/MCTargetOptions.h"
30 #include "llvm/Option/Arg.h"
31 #include "llvm/Option/ArgList.h"
32 #include "llvm/Option/OptTable.h"
33 #include "llvm/Option/Option.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/FileSystem.h"
36 #include "llvm/Support/Path.h"
37 #include "llvm/Support/TargetParser.h"
38 #include "llvm/Support/TargetRegistry.h"
39 #include "llvm/Support/VersionTuple.h"
40 #include "llvm/Support/VirtualFileSystem.h"
41 #include <cassert>
42 #include <cstddef>
43 #include <cstring>
44 #include <string>
45 
46 using namespace clang;
47 using namespace driver;
48 using namespace tools;
49 using namespace llvm;
50 using namespace llvm::opt;
51 
52 static llvm::opt::Arg *GetRTTIArgument(const ArgList &Args) {
53   return Args.getLastArg(options::OPT_mkernel, options::OPT_fapple_kext,
54                          options::OPT_fno_rtti, options::OPT_frtti);
55 }
56 
57 static ToolChain::RTTIMode CalculateRTTIMode(const ArgList &Args,
58                                              const llvm::Triple &Triple,
59                                              const Arg *CachedRTTIArg) {
60   // Explicit rtti/no-rtti args
61   if (CachedRTTIArg) {
62     if (CachedRTTIArg->getOption().matches(options::OPT_frtti))
63       return ToolChain::RM_Enabled;
64     else
65       return ToolChain::RM_Disabled;
66   }
67 
68   // -frtti is default, except for the PS4 CPU.
69   return (Triple.isPS4CPU()) ? ToolChain::RM_Disabled : ToolChain::RM_Enabled;
70 }
71 
72 ToolChain::ToolChain(const Driver &D, const llvm::Triple &T,
73                      const ArgList &Args)
74     : D(D), Triple(T), Args(Args), CachedRTTIArg(GetRTTIArgument(Args)),
75       CachedRTTIMode(CalculateRTTIMode(Args, Triple, CachedRTTIArg)) {
76   if (D.CCCIsCXX()) {
77     if (auto CXXStdlibPath = getCXXStdlibPath())
78       getFilePaths().push_back(*CXXStdlibPath);
79   }
80 
81   if (auto RuntimePath = getRuntimePath())
82     getLibraryPaths().push_back(*RuntimePath);
83 
84   std::string CandidateLibPath = getArchSpecificLibPath();
85   if (getVFS().exists(CandidateLibPath))
86     getFilePaths().push_back(CandidateLibPath);
87 }
88 
89 void ToolChain::setTripleEnvironment(llvm::Triple::EnvironmentType Env) {
90   Triple.setEnvironment(Env);
91   if (EffectiveTriple != llvm::Triple())
92     EffectiveTriple.setEnvironment(Env);
93 }
94 
95 ToolChain::~ToolChain() = default;
96 
97 llvm::vfs::FileSystem &ToolChain::getVFS() const {
98   return getDriver().getVFS();
99 }
100 
101 bool ToolChain::useIntegratedAs() const {
102   return Args.hasFlag(options::OPT_fintegrated_as,
103                       options::OPT_fno_integrated_as,
104                       IsIntegratedAssemblerDefault());
105 }
106 
107 bool ToolChain::useRelaxRelocations() const {
108   return ENABLE_X86_RELAX_RELOCATIONS;
109 }
110 
111 bool ToolChain::isNoExecStackDefault() const {
112     return false;
113 }
114 
115 const SanitizerArgs& ToolChain::getSanitizerArgs() const {
116   if (!SanitizerArguments.get())
117     SanitizerArguments.reset(new SanitizerArgs(*this, Args));
118   return *SanitizerArguments.get();
119 }
120 
121 const XRayArgs& ToolChain::getXRayArgs() const {
122   if (!XRayArguments.get())
123     XRayArguments.reset(new XRayArgs(*this, Args));
124   return *XRayArguments.get();
125 }
126 
127 namespace {
128 
129 struct DriverSuffix {
130   const char *Suffix;
131   const char *ModeFlag;
132 };
133 
134 } // namespace
135 
136 static const DriverSuffix *FindDriverSuffix(StringRef ProgName, size_t &Pos) {
137   // A list of known driver suffixes. Suffixes are compared against the
138   // program name in order. If there is a match, the frontend type is updated as
139   // necessary by applying the ModeFlag.
140   static const DriverSuffix DriverSuffixes[] = {
141       {"clang", nullptr},
142       {"clang++", "--driver-mode=g++"},
143       {"clang-c++", "--driver-mode=g++"},
144       {"clang-cc", nullptr},
145       {"clang-cpp", "--driver-mode=cpp"},
146       {"clang-g++", "--driver-mode=g++"},
147       {"clang-gcc", nullptr},
148       {"clang-cl", "--driver-mode=cl"},
149       {"cc", nullptr},
150       {"cpp", "--driver-mode=cpp"},
151       {"cl", "--driver-mode=cl"},
152       {"++", "--driver-mode=g++"},
153   };
154 
155   for (size_t i = 0; i < llvm::array_lengthof(DriverSuffixes); ++i) {
156     StringRef Suffix(DriverSuffixes[i].Suffix);
157     if (ProgName.endswith(Suffix)) {
158       Pos = ProgName.size() - Suffix.size();
159       return &DriverSuffixes[i];
160     }
161   }
162   return nullptr;
163 }
164 
165 /// Normalize the program name from argv[0] by stripping the file extension if
166 /// present and lower-casing the string on Windows.
167 static std::string normalizeProgramName(llvm::StringRef Argv0) {
168   std::string ProgName = llvm::sys::path::stem(Argv0);
169 #ifdef _WIN32
170   // Transform to lowercase for case insensitive file systems.
171   std::transform(ProgName.begin(), ProgName.end(), ProgName.begin(), ::tolower);
172 #endif
173   return ProgName;
174 }
175 
176 static const DriverSuffix *parseDriverSuffix(StringRef ProgName, size_t &Pos) {
177   // Try to infer frontend type and default target from the program name by
178   // comparing it against DriverSuffixes in order.
179 
180   // If there is a match, the function tries to identify a target as prefix.
181   // E.g. "x86_64-linux-clang" as interpreted as suffix "clang" with target
182   // prefix "x86_64-linux". If such a target prefix is found, it may be
183   // added via -target as implicit first argument.
184   const DriverSuffix *DS = FindDriverSuffix(ProgName, Pos);
185 
186   if (!DS) {
187     // Try again after stripping any trailing version number:
188     // clang++3.5 -> clang++
189     ProgName = ProgName.rtrim("0123456789.");
190     DS = FindDriverSuffix(ProgName, Pos);
191   }
192 
193   if (!DS) {
194     // Try again after stripping trailing -component.
195     // clang++-tot -> clang++
196     ProgName = ProgName.slice(0, ProgName.rfind('-'));
197     DS = FindDriverSuffix(ProgName, Pos);
198   }
199   return DS;
200 }
201 
202 ParsedClangName
203 ToolChain::getTargetAndModeFromProgramName(StringRef PN) {
204   std::string ProgName = normalizeProgramName(PN);
205   size_t SuffixPos;
206   const DriverSuffix *DS = parseDriverSuffix(ProgName, SuffixPos);
207   if (!DS)
208     return {};
209   size_t SuffixEnd = SuffixPos + strlen(DS->Suffix);
210 
211   size_t LastComponent = ProgName.rfind('-', SuffixPos);
212   if (LastComponent == std::string::npos)
213     return ParsedClangName(ProgName.substr(0, SuffixEnd), DS->ModeFlag);
214   std::string ModeSuffix = ProgName.substr(LastComponent + 1,
215                                            SuffixEnd - LastComponent - 1);
216 
217   // Infer target from the prefix.
218   StringRef Prefix(ProgName);
219   Prefix = Prefix.slice(0, LastComponent);
220   std::string IgnoredError;
221   bool IsRegistered = llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError);
222   return ParsedClangName{Prefix, ModeSuffix, DS->ModeFlag, IsRegistered};
223 }
224 
225 StringRef ToolChain::getDefaultUniversalArchName() const {
226   // In universal driver terms, the arch name accepted by -arch isn't exactly
227   // the same as the ones that appear in the triple. Roughly speaking, this is
228   // an inverse of the darwin::getArchTypeForDarwinArchName() function, but the
229   // only interesting special case is powerpc.
230   switch (Triple.getArch()) {
231   case llvm::Triple::ppc:
232     return "ppc";
233   case llvm::Triple::ppc64:
234     return "ppc64";
235   case llvm::Triple::ppc64le:
236     return "ppc64le";
237   default:
238     return Triple.getArchName();
239   }
240 }
241 
242 std::string ToolChain::getInputFilename(const InputInfo &Input) const {
243   return Input.getFilename();
244 }
245 
246 bool ToolChain::IsUnwindTablesDefault(const ArgList &Args) const {
247   return false;
248 }
249 
250 Tool *ToolChain::getClang() const {
251   if (!Clang)
252     Clang.reset(new tools::Clang(*this));
253   return Clang.get();
254 }
255 
256 Tool *ToolChain::buildAssembler() const {
257   return new tools::ClangAs(*this);
258 }
259 
260 Tool *ToolChain::buildLinker() const {
261   llvm_unreachable("Linking is not supported by this toolchain");
262 }
263 
264 Tool *ToolChain::getAssemble() const {
265   if (!Assemble)
266     Assemble.reset(buildAssembler());
267   return Assemble.get();
268 }
269 
270 Tool *ToolChain::getClangAs() const {
271   if (!Assemble)
272     Assemble.reset(new tools::ClangAs(*this));
273   return Assemble.get();
274 }
275 
276 Tool *ToolChain::getLink() const {
277   if (!Link)
278     Link.reset(buildLinker());
279   return Link.get();
280 }
281 
282 Tool *ToolChain::getOffloadBundler() const {
283   if (!OffloadBundler)
284     OffloadBundler.reset(new tools::OffloadBundler(*this));
285   return OffloadBundler.get();
286 }
287 
288 Tool *ToolChain::getTool(Action::ActionClass AC) const {
289   switch (AC) {
290   case Action::AssembleJobClass:
291     return getAssemble();
292 
293   case Action::LinkJobClass:
294     return getLink();
295 
296   case Action::InputClass:
297   case Action::BindArchClass:
298   case Action::OffloadClass:
299   case Action::LipoJobClass:
300   case Action::DsymutilJobClass:
301   case Action::VerifyDebugInfoJobClass:
302     llvm_unreachable("Invalid tool kind.");
303 
304   case Action::CompileJobClass:
305   case Action::PrecompileJobClass:
306   case Action::HeaderModulePrecompileJobClass:
307   case Action::PreprocessJobClass:
308   case Action::AnalyzeJobClass:
309   case Action::MigrateJobClass:
310   case Action::VerifyPCHJobClass:
311   case Action::BackendJobClass:
312     return getClang();
313 
314   case Action::OffloadBundlingJobClass:
315   case Action::OffloadUnbundlingJobClass:
316     return getOffloadBundler();
317   }
318 
319   llvm_unreachable("Invalid tool kind.");
320 }
321 
322 static StringRef getArchNameForCompilerRTLib(const ToolChain &TC,
323                                              const ArgList &Args) {
324   const llvm::Triple &Triple = TC.getTriple();
325   bool IsWindows = Triple.isOSWindows();
326 
327   if (TC.getArch() == llvm::Triple::arm || TC.getArch() == llvm::Triple::armeb)
328     return (arm::getARMFloatABI(TC, Args) == arm::FloatABI::Hard && !IsWindows)
329                ? "armhf"
330                : "arm";
331 
332   // For historic reasons, Android library is using i686 instead of i386.
333   if (TC.getArch() == llvm::Triple::x86 && Triple.isAndroid())
334     return "i686";
335 
336   return llvm::Triple::getArchTypeName(TC.getArch());
337 }
338 
339 StringRef ToolChain::getOSLibName() const {
340   switch (Triple.getOS()) {
341   case llvm::Triple::FreeBSD:
342     return "freebsd";
343   case llvm::Triple::NetBSD:
344     return "netbsd";
345   case llvm::Triple::OpenBSD:
346     return "openbsd";
347   case llvm::Triple::Solaris:
348     return "sunos";
349   default:
350     return getOS();
351   }
352 }
353 
354 std::string ToolChain::getCompilerRTPath() const {
355   SmallString<128> Path(getDriver().ResourceDir);
356   if (Triple.isOSUnknown()) {
357     llvm::sys::path::append(Path, "lib");
358   } else {
359     llvm::sys::path::append(Path, "lib", getOSLibName());
360   }
361   return Path.str();
362 }
363 
364 std::string ToolChain::getCompilerRT(const ArgList &Args, StringRef Component,
365                                      FileType Type) const {
366   const llvm::Triple &TT = getTriple();
367   bool IsITANMSVCWindows =
368       TT.isWindowsMSVCEnvironment() || TT.isWindowsItaniumEnvironment();
369 
370   const char *Prefix =
371       IsITANMSVCWindows || Type == ToolChain::FT_Object ? "" : "lib";
372   const char *Suffix;
373   switch (Type) {
374   case ToolChain::FT_Object:
375     Suffix = IsITANMSVCWindows ? ".obj" : ".o";
376     break;
377   case ToolChain::FT_Static:
378     Suffix = IsITANMSVCWindows ? ".lib" : ".a";
379     break;
380   case ToolChain::FT_Shared:
381     Suffix = Triple.isOSWindows()
382                  ? (Triple.isWindowsGNUEnvironment() ? ".dll.a" : ".lib")
383                  : ".so";
384     break;
385   }
386 
387   for (const auto &LibPath : getLibraryPaths()) {
388     SmallString<128> P(LibPath);
389     llvm::sys::path::append(P, Prefix + Twine("clang_rt.") + Component + Suffix);
390     if (getVFS().exists(P))
391       return P.str();
392   }
393 
394   StringRef Arch = getArchNameForCompilerRTLib(*this, Args);
395   const char *Env = TT.isAndroid() ? "-android" : "";
396   SmallString<128> Path(getCompilerRTPath());
397   llvm::sys::path::append(Path, Prefix + Twine("clang_rt.") + Component + "-" +
398                                     Arch + Env + Suffix);
399   return Path.str();
400 }
401 
402 const char *ToolChain::getCompilerRTArgString(const llvm::opt::ArgList &Args,
403                                               StringRef Component,
404                                               FileType Type) const {
405   return Args.MakeArgString(getCompilerRT(Args, Component, Type));
406 }
407 
408 
409 Optional<std::string> ToolChain::getRuntimePath() const {
410   SmallString<128> P;
411 
412   // First try the triple passed to driver as --target=<triple>.
413   P.assign(D.ResourceDir);
414   llvm::sys::path::append(P, "lib", D.getTargetTriple());
415   if (getVFS().exists(P))
416     return llvm::Optional<std::string>(P.str());
417 
418   // Second try the normalized triple.
419   P.assign(D.ResourceDir);
420   llvm::sys::path::append(P, "lib", Triple.str());
421   if (getVFS().exists(P))
422     return llvm::Optional<std::string>(P.str());
423 
424   return None;
425 }
426 
427 Optional<std::string> ToolChain::getCXXStdlibPath() const {
428   SmallString<128> P;
429 
430   // First try the triple passed to driver as --target=<triple>.
431   P.assign(D.Dir);
432   llvm::sys::path::append(P, "..", "lib", D.getTargetTriple(), "c++");
433   if (getVFS().exists(P))
434     return llvm::Optional<std::string>(P.str());
435 
436   // Second try the normalized triple.
437   P.assign(D.Dir);
438   llvm::sys::path::append(P, "..", "lib", Triple.str(), "c++");
439   if (getVFS().exists(P))
440     return llvm::Optional<std::string>(P.str());
441 
442   return None;
443 }
444 
445 std::string ToolChain::getArchSpecificLibPath() const {
446   SmallString<128> Path(getDriver().ResourceDir);
447   llvm::sys::path::append(Path, "lib", getOSLibName(),
448                           llvm::Triple::getArchTypeName(getArch()));
449   return Path.str();
450 }
451 
452 bool ToolChain::needsProfileRT(const ArgList &Args) {
453   if (needsGCovInstrumentation(Args) ||
454       Args.hasArg(options::OPT_fprofile_generate) ||
455       Args.hasArg(options::OPT_fprofile_generate_EQ) ||
456       Args.hasArg(options::OPT_fcs_profile_generate) ||
457       Args.hasArg(options::OPT_fcs_profile_generate_EQ) ||
458       Args.hasArg(options::OPT_fprofile_instr_generate) ||
459       Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
460       Args.hasArg(options::OPT_fcreate_profile) ||
461       Args.hasArg(options::OPT_forder_file_instrumentation))
462     return true;
463 
464   return false;
465 }
466 
467 bool ToolChain::needsGCovInstrumentation(const llvm::opt::ArgList &Args) {
468   return Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
469                       false) ||
470          Args.hasArg(options::OPT_coverage);
471 }
472 
473 Tool *ToolChain::SelectTool(const JobAction &JA) const {
474   if (getDriver().ShouldUseClangCompiler(JA)) return getClang();
475   Action::ActionClass AC = JA.getKind();
476   if (AC == Action::AssembleJobClass && useIntegratedAs())
477     return getClangAs();
478   return getTool(AC);
479 }
480 
481 std::string ToolChain::GetFilePath(const char *Name) const {
482   return D.GetFilePath(Name, *this);
483 }
484 
485 std::string ToolChain::GetProgramPath(const char *Name) const {
486   return D.GetProgramPath(Name, *this);
487 }
488 
489 std::string ToolChain::GetLinkerPath() const {
490   const Arg* A = Args.getLastArg(options::OPT_fuse_ld_EQ);
491   StringRef UseLinker = A ? A->getValue() : CLANG_DEFAULT_LINKER;
492 
493   if (llvm::sys::path::is_absolute(UseLinker)) {
494     // If we're passed what looks like an absolute path, don't attempt to
495     // second-guess that.
496     if (llvm::sys::fs::can_execute(UseLinker))
497       return UseLinker;
498   } else if (UseLinker.empty() || UseLinker == "ld") {
499     // If we're passed -fuse-ld= with no argument, or with the argument ld,
500     // then use whatever the default system linker is.
501     return GetProgramPath(getDefaultLinker());
502   } else {
503     llvm::SmallString<8> LinkerName;
504     if (Triple.isOSDarwin())
505       LinkerName.append("ld64.");
506     else
507       LinkerName.append("ld.");
508     LinkerName.append(UseLinker);
509 
510     std::string LinkerPath(GetProgramPath(LinkerName.c_str()));
511     if (llvm::sys::fs::can_execute(LinkerPath))
512       return LinkerPath;
513   }
514 
515   if (A)
516     getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
517 
518   return GetProgramPath(getDefaultLinker());
519 }
520 
521 types::ID ToolChain::LookupTypeForExtension(StringRef Ext) const {
522   return types::lookupTypeForExtension(Ext);
523 }
524 
525 bool ToolChain::HasNativeLLVMSupport() const {
526   return false;
527 }
528 
529 bool ToolChain::isCrossCompiling() const {
530   llvm::Triple HostTriple(LLVM_HOST_TRIPLE);
531   switch (HostTriple.getArch()) {
532   // The A32/T32/T16 instruction sets are not separate architectures in this
533   // context.
534   case llvm::Triple::arm:
535   case llvm::Triple::armeb:
536   case llvm::Triple::thumb:
537   case llvm::Triple::thumbeb:
538     return getArch() != llvm::Triple::arm && getArch() != llvm::Triple::thumb &&
539            getArch() != llvm::Triple::armeb && getArch() != llvm::Triple::thumbeb;
540   default:
541     return HostTriple.getArch() != getArch();
542   }
543 }
544 
545 ObjCRuntime ToolChain::getDefaultObjCRuntime(bool isNonFragile) const {
546   return ObjCRuntime(isNonFragile ? ObjCRuntime::GNUstep : ObjCRuntime::GCC,
547                      VersionTuple());
548 }
549 
550 llvm::ExceptionHandling
551 ToolChain::GetExceptionModel(const llvm::opt::ArgList &Args) const {
552   return llvm::ExceptionHandling::None;
553 }
554 
555 bool ToolChain::isThreadModelSupported(const StringRef Model) const {
556   if (Model == "single") {
557     // FIXME: 'single' is only supported on ARM and WebAssembly so far.
558     return Triple.getArch() == llvm::Triple::arm ||
559            Triple.getArch() == llvm::Triple::armeb ||
560            Triple.getArch() == llvm::Triple::thumb ||
561            Triple.getArch() == llvm::Triple::thumbeb ||
562            Triple.getArch() == llvm::Triple::wasm32 ||
563            Triple.getArch() == llvm::Triple::wasm64;
564   } else if (Model == "posix")
565     return true;
566 
567   return false;
568 }
569 
570 std::string ToolChain::ComputeLLVMTriple(const ArgList &Args,
571                                          types::ID InputType) const {
572   switch (getTriple().getArch()) {
573   default:
574     return getTripleString();
575 
576   case llvm::Triple::x86_64: {
577     llvm::Triple Triple = getTriple();
578     if (!Triple.isOSBinFormatMachO())
579       return getTripleString();
580 
581     if (Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
582       // x86_64h goes in the triple. Other -march options just use the
583       // vanilla triple we already have.
584       StringRef MArch = A->getValue();
585       if (MArch == "x86_64h")
586         Triple.setArchName(MArch);
587     }
588     return Triple.getTriple();
589   }
590   case llvm::Triple::aarch64: {
591     llvm::Triple Triple = getTriple();
592     if (!Triple.isOSBinFormatMachO())
593       return getTripleString();
594 
595     // FIXME: older versions of ld64 expect the "arm64" component in the actual
596     // triple string and query it to determine whether an LTO file can be
597     // handled. Remove this when we don't care any more.
598     Triple.setArchName("arm64");
599     return Triple.getTriple();
600   }
601   case llvm::Triple::arm:
602   case llvm::Triple::armeb:
603   case llvm::Triple::thumb:
604   case llvm::Triple::thumbeb: {
605     // FIXME: Factor into subclasses.
606     llvm::Triple Triple = getTriple();
607     bool IsBigEndian = getTriple().getArch() == llvm::Triple::armeb ||
608                        getTriple().getArch() == llvm::Triple::thumbeb;
609 
610     // Handle pseudo-target flags '-mlittle-endian'/'-EL' and
611     // '-mbig-endian'/'-EB'.
612     if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
613                                  options::OPT_mbig_endian)) {
614       IsBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
615     }
616 
617     // Thumb2 is the default for V7 on Darwin.
618     //
619     // FIXME: Thumb should just be another -target-feaure, not in the triple.
620     StringRef MCPU, MArch;
621     if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
622       MCPU = A->getValue();
623     if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
624       MArch = A->getValue();
625     std::string CPU =
626         Triple.isOSBinFormatMachO()
627             ? tools::arm::getARMCPUForMArch(MArch, Triple).str()
628             : tools::arm::getARMTargetCPU(MCPU, MArch, Triple);
629     StringRef Suffix =
630       tools::arm::getLLVMArchSuffixForARM(CPU, MArch, Triple);
631     bool IsMProfile = ARM::parseArchProfile(Suffix) == ARM::ProfileKind::M;
632     bool ThumbDefault = IsMProfile || (ARM::parseArchVersion(Suffix) == 7 &&
633                                        getTriple().isOSBinFormatMachO());
634     // FIXME: this is invalid for WindowsCE
635     if (getTriple().isOSWindows())
636       ThumbDefault = true;
637     std::string ArchName;
638     if (IsBigEndian)
639       ArchName = "armeb";
640     else
641       ArchName = "arm";
642 
643     // Check if ARM ISA was explicitly selected (using -mno-thumb or -marm) for
644     // M-Class CPUs/architecture variants, which is not supported.
645     bool ARMModeRequested = !Args.hasFlag(options::OPT_mthumb,
646                                           options::OPT_mno_thumb, ThumbDefault);
647     if (IsMProfile && ARMModeRequested) {
648       if (!MCPU.empty())
649         getDriver().Diag(diag::err_cpu_unsupported_isa) << CPU << "ARM";
650        else
651         getDriver().Diag(diag::err_arch_unsupported_isa)
652           << tools::arm::getARMArch(MArch, getTriple()) << "ARM";
653     }
654 
655     // Check to see if an explicit choice to use thumb has been made via
656     // -mthumb. For assembler files we must check for -mthumb in the options
657     // passed to the assembler via -Wa or -Xassembler.
658     bool IsThumb = false;
659     if (InputType != types::TY_PP_Asm)
660       IsThumb = Args.hasFlag(options::OPT_mthumb, options::OPT_mno_thumb,
661                               ThumbDefault);
662     else {
663       // Ideally we would check for these flags in
664       // CollectArgsForIntegratedAssembler but we can't change the ArchName at
665       // that point. There is no assembler equivalent of -mno-thumb, -marm, or
666       // -mno-arm.
667       for (const auto *A :
668            Args.filtered(options::OPT_Wa_COMMA, options::OPT_Xassembler)) {
669         for (StringRef Value : A->getValues()) {
670           if (Value == "-mthumb")
671             IsThumb = true;
672         }
673       }
674     }
675     // Assembly files should start in ARM mode, unless arch is M-profile, or
676     // -mthumb has been passed explicitly to the assembler. Windows is always
677     // thumb.
678     if (IsThumb || IsMProfile || getTriple().isOSWindows()) {
679       if (IsBigEndian)
680         ArchName = "thumbeb";
681       else
682         ArchName = "thumb";
683     }
684     Triple.setArchName(ArchName + Suffix.str());
685 
686     return Triple.getTriple();
687   }
688   }
689 }
690 
691 std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args,
692                                                    types::ID InputType) const {
693   return ComputeLLVMTriple(Args, InputType);
694 }
695 
696 void ToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
697                                           ArgStringList &CC1Args) const {
698   // Each toolchain should provide the appropriate include flags.
699 }
700 
701 void ToolChain::addClangTargetOptions(
702     const ArgList &DriverArgs, ArgStringList &CC1Args,
703     Action::OffloadKind DeviceOffloadKind) const {}
704 
705 void ToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {}
706 
707 void ToolChain::addProfileRTLibs(const llvm::opt::ArgList &Args,
708                                  llvm::opt::ArgStringList &CmdArgs) const {
709   if (!needsProfileRT(Args)) return;
710 
711   CmdArgs.push_back(getCompilerRTArgString(Args, "profile"));
712 }
713 
714 ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
715     const ArgList &Args) const {
716   const Arg* A = Args.getLastArg(options::OPT_rtlib_EQ);
717   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_RTLIB;
718 
719   // Only use "platform" in tests to override CLANG_DEFAULT_RTLIB!
720   if (LibName == "compiler-rt")
721     return ToolChain::RLT_CompilerRT;
722   else if (LibName == "libgcc")
723     return ToolChain::RLT_Libgcc;
724   else if (LibName == "platform")
725     return GetDefaultRuntimeLibType();
726 
727   if (A)
728     getDriver().Diag(diag::err_drv_invalid_rtlib_name) << A->getAsString(Args);
729 
730   return GetDefaultRuntimeLibType();
731 }
732 
733 ToolChain::UnwindLibType ToolChain::GetUnwindLibType(
734     const ArgList &Args) const {
735   const Arg *A = Args.getLastArg(options::OPT_unwindlib_EQ);
736   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_UNWINDLIB;
737 
738   if (LibName == "none")
739     return ToolChain::UNW_None;
740   else if (LibName == "platform" || LibName == "") {
741     ToolChain::RuntimeLibType RtLibType = GetRuntimeLibType(Args);
742     if (RtLibType == ToolChain::RLT_CompilerRT)
743       return ToolChain::UNW_None;
744     else if (RtLibType == ToolChain::RLT_Libgcc)
745       return ToolChain::UNW_Libgcc;
746   } else if (LibName == "libunwind") {
747     if (GetRuntimeLibType(Args) == RLT_Libgcc)
748       getDriver().Diag(diag::err_drv_incompatible_unwindlib);
749     return ToolChain::UNW_CompilerRT;
750   } else if (LibName == "libgcc")
751     return ToolChain::UNW_Libgcc;
752 
753   if (A)
754     getDriver().Diag(diag::err_drv_invalid_unwindlib_name)
755         << A->getAsString(Args);
756 
757   return GetDefaultUnwindLibType();
758 }
759 
760 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
761   const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
762   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_CXX_STDLIB;
763 
764   // Only use "platform" in tests to override CLANG_DEFAULT_CXX_STDLIB!
765   if (LibName == "libc++")
766     return ToolChain::CST_Libcxx;
767   else if (LibName == "libstdc++")
768     return ToolChain::CST_Libstdcxx;
769   else if (LibName == "platform")
770     return GetDefaultCXXStdlibType();
771 
772   if (A)
773     getDriver().Diag(diag::err_drv_invalid_stdlib_name) << A->getAsString(Args);
774 
775   return GetDefaultCXXStdlibType();
776 }
777 
778 /// Utility function to add a system include directory to CC1 arguments.
779 /*static*/ void ToolChain::addSystemInclude(const ArgList &DriverArgs,
780                                             ArgStringList &CC1Args,
781                                             const Twine &Path) {
782   CC1Args.push_back("-internal-isystem");
783   CC1Args.push_back(DriverArgs.MakeArgString(Path));
784 }
785 
786 /// Utility function to add a system include directory with extern "C"
787 /// semantics to CC1 arguments.
788 ///
789 /// Note that this should be used rarely, and only for directories that
790 /// historically and for legacy reasons are treated as having implicit extern
791 /// "C" semantics. These semantics are *ignored* by and large today, but its
792 /// important to preserve the preprocessor changes resulting from the
793 /// classification.
794 /*static*/ void ToolChain::addExternCSystemInclude(const ArgList &DriverArgs,
795                                                    ArgStringList &CC1Args,
796                                                    const Twine &Path) {
797   CC1Args.push_back("-internal-externc-isystem");
798   CC1Args.push_back(DriverArgs.MakeArgString(Path));
799 }
800 
801 void ToolChain::addExternCSystemIncludeIfExists(const ArgList &DriverArgs,
802                                                 ArgStringList &CC1Args,
803                                                 const Twine &Path) {
804   if (llvm::sys::fs::exists(Path))
805     addExternCSystemInclude(DriverArgs, CC1Args, Path);
806 }
807 
808 /// Utility function to add a list of system include directories to CC1.
809 /*static*/ void ToolChain::addSystemIncludes(const ArgList &DriverArgs,
810                                              ArgStringList &CC1Args,
811                                              ArrayRef<StringRef> Paths) {
812   for (const auto Path : Paths) {
813     CC1Args.push_back("-internal-isystem");
814     CC1Args.push_back(DriverArgs.MakeArgString(Path));
815   }
816 }
817 
818 void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
819                                              ArgStringList &CC1Args) const {
820   // Header search paths should be handled by each of the subclasses.
821   // Historically, they have not been, and instead have been handled inside of
822   // the CC1-layer frontend. As the logic is hoisted out, this generic function
823   // will slowly stop being called.
824   //
825   // While it is being called, replicate a bit of a hack to propagate the
826   // '-stdlib=' flag down to CC1 so that it can in turn customize the C++
827   // header search paths with it. Once all systems are overriding this
828   // function, the CC1 flag and this line can be removed.
829   DriverArgs.AddAllArgs(CC1Args, options::OPT_stdlib_EQ);
830 }
831 
832 bool ToolChain::ShouldLinkCXXStdlib(const llvm::opt::ArgList &Args) const {
833   return getDriver().CCCIsCXX() &&
834          !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
835                       options::OPT_nostdlibxx);
836 }
837 
838 void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
839                                     ArgStringList &CmdArgs) const {
840   assert(!Args.hasArg(options::OPT_nostdlibxx) &&
841          "should not have called this");
842   CXXStdlibType Type = GetCXXStdlibType(Args);
843 
844   switch (Type) {
845   case ToolChain::CST_Libcxx:
846     CmdArgs.push_back("-lc++");
847     break;
848 
849   case ToolChain::CST_Libstdcxx:
850     CmdArgs.push_back("-lstdc++");
851     break;
852   }
853 }
854 
855 void ToolChain::AddFilePathLibArgs(const ArgList &Args,
856                                    ArgStringList &CmdArgs) const {
857   for (const auto &LibPath : getFilePaths())
858     if(LibPath.length() > 0)
859       CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
860 }
861 
862 void ToolChain::AddCCKextLibArgs(const ArgList &Args,
863                                  ArgStringList &CmdArgs) const {
864   CmdArgs.push_back("-lcc_kext");
865 }
866 
867 bool ToolChain::AddFastMathRuntimeIfAvailable(const ArgList &Args,
868                                               ArgStringList &CmdArgs) const {
869   // Do not check for -fno-fast-math or -fno-unsafe-math when -Ofast passed
870   // (to keep the linker options consistent with gcc and clang itself).
871   if (!isOptimizationLevelFast(Args)) {
872     // Check if -ffast-math or -funsafe-math.
873     Arg *A =
874         Args.getLastArg(options::OPT_ffast_math, options::OPT_fno_fast_math,
875                         options::OPT_funsafe_math_optimizations,
876                         options::OPT_fno_unsafe_math_optimizations);
877 
878     if (!A || A->getOption().getID() == options::OPT_fno_fast_math ||
879         A->getOption().getID() == options::OPT_fno_unsafe_math_optimizations)
880       return false;
881   }
882   // If crtfastmath.o exists add it to the arguments.
883   std::string Path = GetFilePath("crtfastmath.o");
884   if (Path == "crtfastmath.o") // Not found.
885     return false;
886 
887   CmdArgs.push_back(Args.MakeArgString(Path));
888   return true;
889 }
890 
891 SanitizerMask ToolChain::getSupportedSanitizers() const {
892   // Return sanitizers which don't require runtime support and are not
893   // platform dependent.
894 
895   SanitizerMask Res = (SanitizerKind::Undefined & ~SanitizerKind::Vptr &
896                        ~SanitizerKind::Function) |
897                       (SanitizerKind::CFI & ~SanitizerKind::CFIICall) |
898                       SanitizerKind::CFICastStrict |
899                       SanitizerKind::UnsignedIntegerOverflow |
900                       SanitizerKind::ImplicitConversion |
901                       SanitizerKind::Nullability | SanitizerKind::LocalBounds;
902   if (getTriple().getArch() == llvm::Triple::x86 ||
903       getTriple().getArch() == llvm::Triple::x86_64 ||
904       getTriple().getArch() == llvm::Triple::arm ||
905       getTriple().getArch() == llvm::Triple::aarch64 ||
906       getTriple().getArch() == llvm::Triple::wasm32 ||
907       getTriple().getArch() == llvm::Triple::wasm64)
908     Res |= SanitizerKind::CFIICall;
909   if (getTriple().getArch() == llvm::Triple::x86_64 ||
910       getTriple().getArch() == llvm::Triple::aarch64)
911     Res |= SanitizerKind::ShadowCallStack;
912   return Res;
913 }
914 
915 void ToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
916                                    ArgStringList &CC1Args) const {}
917 
918 void ToolChain::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
919                                     ArgStringList &CC1Args) const {}
920 
921 static VersionTuple separateMSVCFullVersion(unsigned Version) {
922   if (Version < 100)
923     return VersionTuple(Version);
924 
925   if (Version < 10000)
926     return VersionTuple(Version / 100, Version % 100);
927 
928   unsigned Build = 0, Factor = 1;
929   for (; Version > 10000; Version = Version / 10, Factor = Factor * 10)
930     Build = Build + (Version % 10) * Factor;
931   return VersionTuple(Version / 100, Version % 100, Build);
932 }
933 
934 VersionTuple
935 ToolChain::computeMSVCVersion(const Driver *D,
936                               const llvm::opt::ArgList &Args) const {
937   const Arg *MSCVersion = Args.getLastArg(options::OPT_fmsc_version);
938   const Arg *MSCompatibilityVersion =
939       Args.getLastArg(options::OPT_fms_compatibility_version);
940 
941   if (MSCVersion && MSCompatibilityVersion) {
942     if (D)
943       D->Diag(diag::err_drv_argument_not_allowed_with)
944           << MSCVersion->getAsString(Args)
945           << MSCompatibilityVersion->getAsString(Args);
946     return VersionTuple();
947   }
948 
949   if (MSCompatibilityVersion) {
950     VersionTuple MSVT;
951     if (MSVT.tryParse(MSCompatibilityVersion->getValue())) {
952       if (D)
953         D->Diag(diag::err_drv_invalid_value)
954             << MSCompatibilityVersion->getAsString(Args)
955             << MSCompatibilityVersion->getValue();
956     } else {
957       return MSVT;
958     }
959   }
960 
961   if (MSCVersion) {
962     unsigned Version = 0;
963     if (StringRef(MSCVersion->getValue()).getAsInteger(10, Version)) {
964       if (D)
965         D->Diag(diag::err_drv_invalid_value)
966             << MSCVersion->getAsString(Args) << MSCVersion->getValue();
967     } else {
968       return separateMSVCFullVersion(Version);
969     }
970   }
971 
972   return VersionTuple();
973 }
974 
975 llvm::opt::DerivedArgList *ToolChain::TranslateOpenMPTargetArgs(
976     const llvm::opt::DerivedArgList &Args, bool SameTripleAsHost,
977     SmallVectorImpl<llvm::opt::Arg *> &AllocatedArgs) const {
978   DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
979   const OptTable &Opts = getDriver().getOpts();
980   bool Modified = false;
981 
982   // Handle -Xopenmp-target flags
983   for (auto *A : Args) {
984     // Exclude flags which may only apply to the host toolchain.
985     // Do not exclude flags when the host triple (AuxTriple)
986     // matches the current toolchain triple. If it is not present
987     // at all, target and host share a toolchain.
988     if (A->getOption().matches(options::OPT_m_Group)) {
989       if (SameTripleAsHost)
990         DAL->append(A);
991       else
992         Modified = true;
993       continue;
994     }
995 
996     unsigned Index;
997     unsigned Prev;
998     bool XOpenMPTargetNoTriple =
999         A->getOption().matches(options::OPT_Xopenmp_target);
1000 
1001     if (A->getOption().matches(options::OPT_Xopenmp_target_EQ)) {
1002       // Passing device args: -Xopenmp-target=<triple> -opt=val.
1003       if (A->getValue(0) == getTripleString())
1004         Index = Args.getBaseArgs().MakeIndex(A->getValue(1));
1005       else
1006         continue;
1007     } else if (XOpenMPTargetNoTriple) {
1008       // Passing device args: -Xopenmp-target -opt=val.
1009       Index = Args.getBaseArgs().MakeIndex(A->getValue(0));
1010     } else {
1011       DAL->append(A);
1012       continue;
1013     }
1014 
1015     // Parse the argument to -Xopenmp-target.
1016     Prev = Index;
1017     std::unique_ptr<Arg> XOpenMPTargetArg(Opts.ParseOneArg(Args, Index));
1018     if (!XOpenMPTargetArg || Index > Prev + 1) {
1019       getDriver().Diag(diag::err_drv_invalid_Xopenmp_target_with_args)
1020           << A->getAsString(Args);
1021       continue;
1022     }
1023     if (XOpenMPTargetNoTriple && XOpenMPTargetArg &&
1024         Args.getAllArgValues(options::OPT_fopenmp_targets_EQ).size() != 1) {
1025       getDriver().Diag(diag::err_drv_Xopenmp_target_missing_triple);
1026       continue;
1027     }
1028     XOpenMPTargetArg->setBaseArg(A);
1029     A = XOpenMPTargetArg.release();
1030     AllocatedArgs.push_back(A);
1031     DAL->append(A);
1032     Modified = true;
1033   }
1034 
1035   if (Modified)
1036     return DAL;
1037 
1038   delete DAL;
1039   return nullptr;
1040 }
1041