xref: /freebsd/contrib/llvm-project/clang/lib/Driver/ToolChain.cpp (revision b64c5a0ace59af62eff52bfe110a521dc73c937b) 
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 "ToolChains/Arch/AArch64.h"
11 #include "ToolChains/Arch/ARM.h"
12 #include "ToolChains/Clang.h"
13 #include "ToolChains/CommonArgs.h"
14 #include "ToolChains/Flang.h"
15 #include "ToolChains/InterfaceStubs.h"
16 #include "clang/Basic/ObjCRuntime.h"
17 #include "clang/Basic/Sanitizers.h"
18 #include "clang/Config/config.h"
19 #include "clang/Driver/Action.h"
20 #include "clang/Driver/Driver.h"
21 #include "clang/Driver/DriverDiagnostic.h"
22 #include "clang/Driver/InputInfo.h"
23 #include "clang/Driver/Job.h"
24 #include "clang/Driver/Options.h"
25 #include "clang/Driver/SanitizerArgs.h"
26 #include "clang/Driver/XRayArgs.h"
27 #include "llvm/ADT/STLExtras.h"
28 #include "llvm/ADT/SmallString.h"
29 #include "llvm/ADT/StringExtras.h"
30 #include "llvm/ADT/StringRef.h"
31 #include "llvm/ADT/Twine.h"
32 #include "llvm/Config/llvm-config.h"
33 #include "llvm/MC/MCTargetOptions.h"
34 #include "llvm/MC/TargetRegistry.h"
35 #include "llvm/Option/Arg.h"
36 #include "llvm/Option/ArgList.h"
37 #include "llvm/Option/OptTable.h"
38 #include "llvm/Option/Option.h"
39 #include "llvm/Support/ErrorHandling.h"
40 #include "llvm/Support/FileSystem.h"
41 #include "llvm/Support/FileUtilities.h"
42 #include "llvm/Support/Path.h"
43 #include "llvm/Support/VersionTuple.h"
44 #include "llvm/Support/VirtualFileSystem.h"
45 #include "llvm/TargetParser/AArch64TargetParser.h"
46 #include "llvm/TargetParser/TargetParser.h"
47 #include "llvm/TargetParser/Triple.h"
48 #include <cassert>
49 #include <cstddef>
50 #include <cstring>
51 #include <string>
52 
53 using namespace clang;
54 using namespace driver;
55 using namespace tools;
56 using namespace llvm;
57 using namespace llvm::opt;
58 
59 static llvm::opt::Arg *GetRTTIArgument(const ArgList &Args) {
60   return Args.getLastArg(options::OPT_mkernel, options::OPT_fapple_kext,
61                          options::OPT_fno_rtti, options::OPT_frtti);
62 }
63 
64 static ToolChain::RTTIMode CalculateRTTIMode(const ArgList &Args,
65                                              const llvm::Triple &Triple,
66                                              const Arg *CachedRTTIArg) {
67   // Explicit rtti/no-rtti args
68   if (CachedRTTIArg) {
69     if (CachedRTTIArg->getOption().matches(options::OPT_frtti))
70       return ToolChain::RM_Enabled;
71     else
72       return ToolChain::RM_Disabled;
73   }
74 
75   // -frtti is default, except for the PS4/PS5 and DriverKit.
76   bool NoRTTI = Triple.isPS() || Triple.isDriverKit();
77   return NoRTTI ? ToolChain::RM_Disabled : ToolChain::RM_Enabled;
78 }
79 
80 static ToolChain::ExceptionsMode CalculateExceptionsMode(const ArgList &Args) {
81   if (Args.hasFlag(options::OPT_fexceptions, options::OPT_fno_exceptions,
82                    true)) {
83     return ToolChain::EM_Enabled;
84   }
85   return ToolChain::EM_Disabled;
86 }
87 
88 ToolChain::ToolChain(const Driver &D, const llvm::Triple &T,
89                      const ArgList &Args)
90     : D(D), Triple(T), Args(Args), CachedRTTIArg(GetRTTIArgument(Args)),
91       CachedRTTIMode(CalculateRTTIMode(Args, Triple, CachedRTTIArg)),
92       CachedExceptionsMode(CalculateExceptionsMode(Args)) {
93   auto addIfExists = [this](path_list &List, const std::string &Path) {
94     if (getVFS().exists(Path))
95       List.push_back(Path);
96   };
97 
98   if (std::optional<std::string> Path = getRuntimePath())
99     getLibraryPaths().push_back(*Path);
100   if (std::optional<std::string> Path = getStdlibPath())
101     getFilePaths().push_back(*Path);
102   for (const auto &Path : getArchSpecificLibPaths())
103     addIfExists(getFilePaths(), Path);
104 }
105 
106 llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
107 ToolChain::executeToolChainProgram(StringRef Executable,
108                                    unsigned SecondsToWait) const {
109   llvm::SmallString<64> OutputFile;
110   llvm::sys::fs::createTemporaryFile("toolchain-program", "txt", OutputFile);
111   llvm::FileRemover OutputRemover(OutputFile.c_str());
112   std::optional<llvm::StringRef> Redirects[] = {
113       {""},
114       OutputFile.str(),
115       {""},
116   };
117 
118   std::string ErrorMessage;
119   if (llvm::sys::ExecuteAndWait(Executable, {}, {}, Redirects, SecondsToWait,
120                                 /*MemoryLimit=*/0, &ErrorMessage))
121     return llvm::createStringError(std::error_code(),
122                                    Executable + ": " + ErrorMessage);
123 
124   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> OutputBuf =
125       llvm::MemoryBuffer::getFile(OutputFile.c_str());
126   if (!OutputBuf)
127     return llvm::createStringError(OutputBuf.getError(),
128                                    "Failed to read stdout of " + Executable +
129                                        ": " + OutputBuf.getError().message());
130   return std::move(*OutputBuf);
131 }
132 
133 void ToolChain::setTripleEnvironment(llvm::Triple::EnvironmentType Env) {
134   Triple.setEnvironment(Env);
135   if (EffectiveTriple != llvm::Triple())
136     EffectiveTriple.setEnvironment(Env);
137 }
138 
139 ToolChain::~ToolChain() = default;
140 
141 llvm::vfs::FileSystem &ToolChain::getVFS() const {
142   return getDriver().getVFS();
143 }
144 
145 bool ToolChain::useIntegratedAs() const {
146   return Args.hasFlag(options::OPT_fintegrated_as,
147                       options::OPT_fno_integrated_as,
148                       IsIntegratedAssemblerDefault());
149 }
150 
151 bool ToolChain::useIntegratedBackend() const {
152   assert(
153       ((IsIntegratedBackendDefault() && IsIntegratedBackendSupported()) ||
154        (!IsIntegratedBackendDefault() || IsNonIntegratedBackendSupported())) &&
155       "(Non-)integrated backend set incorrectly!");
156 
157   bool IBackend = Args.hasFlag(options::OPT_fintegrated_objemitter,
158                                options::OPT_fno_integrated_objemitter,
159                                IsIntegratedBackendDefault());
160 
161   // Diagnose when integrated-objemitter options are not supported by this
162   // toolchain.
163   unsigned DiagID;
164   if ((IBackend && !IsIntegratedBackendSupported()) ||
165       (!IBackend && !IsNonIntegratedBackendSupported()))
166     DiagID = clang::diag::err_drv_unsupported_opt_for_target;
167   else
168     DiagID = clang::diag::warn_drv_unsupported_opt_for_target;
169   Arg *A = Args.getLastArg(options::OPT_fno_integrated_objemitter);
170   if (A && !IsNonIntegratedBackendSupported())
171     D.Diag(DiagID) << A->getAsString(Args) << Triple.getTriple();
172   A = Args.getLastArg(options::OPT_fintegrated_objemitter);
173   if (A && !IsIntegratedBackendSupported())
174     D.Diag(DiagID) << A->getAsString(Args) << Triple.getTriple();
175 
176   return IBackend;
177 }
178 
179 bool ToolChain::useRelaxRelocations() const {
180   return ENABLE_X86_RELAX_RELOCATIONS;
181 }
182 
183 bool ToolChain::defaultToIEEELongDouble() const {
184   return PPC_LINUX_DEFAULT_IEEELONGDOUBLE && getTriple().isOSLinux();
185 }
186 
187 static void getAArch64MultilibFlags(const Driver &D,
188                                           const llvm::Triple &Triple,
189                                           const llvm::opt::ArgList &Args,
190                                           Multilib::flags_list &Result) {
191   std::vector<StringRef> Features;
192   tools::aarch64::getAArch64TargetFeatures(D, Triple, Args, Features, false);
193   const auto UnifiedFeatures = tools::unifyTargetFeatures(Features);
194   llvm::DenseSet<StringRef> FeatureSet(UnifiedFeatures.begin(),
195                                        UnifiedFeatures.end());
196   std::vector<std::string> MArch;
197   for (const auto &Ext : AArch64::Extensions)
198     if (!Ext.UserVisibleName.empty())
199       if (FeatureSet.contains(Ext.PosTargetFeature))
200         MArch.push_back(Ext.UserVisibleName.str());
201   for (const auto &Ext : AArch64::Extensions)
202     if (!Ext.UserVisibleName.empty())
203       if (FeatureSet.contains(Ext.NegTargetFeature))
204         MArch.push_back(("no" + Ext.UserVisibleName).str());
205   StringRef ArchName;
206   for (const auto &ArchInfo : AArch64::ArchInfos)
207     if (FeatureSet.contains(ArchInfo->ArchFeature))
208       ArchName = ArchInfo->Name;
209   assert(!ArchName.empty() && "at least one architecture should be found");
210   MArch.insert(MArch.begin(), ("-march=" + ArchName).str());
211   Result.push_back(llvm::join(MArch, "+"));
212 }
213 
214 static void getARMMultilibFlags(const Driver &D,
215                                       const llvm::Triple &Triple,
216                                       const llvm::opt::ArgList &Args,
217                                       Multilib::flags_list &Result) {
218   std::vector<StringRef> Features;
219   llvm::ARM::FPUKind FPUKind = tools::arm::getARMTargetFeatures(
220       D, Triple, Args, Features, false /*ForAs*/, true /*ForMultilib*/);
221   const auto UnifiedFeatures = tools::unifyTargetFeatures(Features);
222   llvm::DenseSet<StringRef> FeatureSet(UnifiedFeatures.begin(),
223                                        UnifiedFeatures.end());
224   std::vector<std::string> MArch;
225   for (const auto &Ext : ARM::ARCHExtNames)
226     if (!Ext.Name.empty())
227       if (FeatureSet.contains(Ext.Feature))
228         MArch.push_back(Ext.Name.str());
229   for (const auto &Ext : ARM::ARCHExtNames)
230     if (!Ext.Name.empty())
231       if (FeatureSet.contains(Ext.NegFeature))
232         MArch.push_back(("no" + Ext.Name).str());
233   MArch.insert(MArch.begin(), ("-march=" + Triple.getArchName()).str());
234   Result.push_back(llvm::join(MArch, "+"));
235 
236   switch (FPUKind) {
237 #define ARM_FPU(NAME, KIND, VERSION, NEON_SUPPORT, RESTRICTION)                \
238   case llvm::ARM::KIND:                                                        \
239     Result.push_back("-mfpu=" NAME);                                           \
240     break;
241 #include "llvm/TargetParser/ARMTargetParser.def"
242   default:
243     llvm_unreachable("Invalid FPUKind");
244   }
245 
246   switch (arm::getARMFloatABI(D, Triple, Args)) {
247   case arm::FloatABI::Soft:
248     Result.push_back("-mfloat-abi=soft");
249     break;
250   case arm::FloatABI::SoftFP:
251     Result.push_back("-mfloat-abi=softfp");
252     break;
253   case arm::FloatABI::Hard:
254     Result.push_back("-mfloat-abi=hard");
255     break;
256   case arm::FloatABI::Invalid:
257     llvm_unreachable("Invalid float ABI");
258   }
259 }
260 
261 Multilib::flags_list
262 ToolChain::getMultilibFlags(const llvm::opt::ArgList &Args) const {
263   using namespace clang::driver::options;
264 
265   std::vector<std::string> Result;
266   const llvm::Triple Triple(ComputeEffectiveClangTriple(Args));
267   Result.push_back("--target=" + Triple.str());
268 
269   switch (Triple.getArch()) {
270   case llvm::Triple::aarch64:
271   case llvm::Triple::aarch64_32:
272   case llvm::Triple::aarch64_be:
273     getAArch64MultilibFlags(D, Triple, Args, Result);
274     break;
275   case llvm::Triple::arm:
276   case llvm::Triple::armeb:
277   case llvm::Triple::thumb:
278   case llvm::Triple::thumbeb:
279     getARMMultilibFlags(D, Triple, Args, Result);
280     break;
281   default:
282     break;
283   }
284 
285   // Include fno-exceptions and fno-rtti
286   // to improve multilib selection
287   if (getRTTIMode() == ToolChain::RTTIMode::RM_Disabled)
288     Result.push_back("-fno-rtti");
289   else
290     Result.push_back("-frtti");
291 
292   if (getExceptionsMode() == ToolChain::ExceptionsMode::EM_Disabled)
293     Result.push_back("-fno-exceptions");
294   else
295     Result.push_back("-fexceptions");
296 
297   // Sort and remove duplicates.
298   std::sort(Result.begin(), Result.end());
299   Result.erase(std::unique(Result.begin(), Result.end()), Result.end());
300   return Result;
301 }
302 
303 SanitizerArgs
304 ToolChain::getSanitizerArgs(const llvm::opt::ArgList &JobArgs) const {
305   SanitizerArgs SanArgs(*this, JobArgs, !SanitizerArgsChecked);
306   SanitizerArgsChecked = true;
307   return SanArgs;
308 }
309 
310 const XRayArgs& ToolChain::getXRayArgs() const {
311   if (!XRayArguments)
312     XRayArguments.reset(new XRayArgs(*this, Args));
313   return *XRayArguments;
314 }
315 
316 namespace {
317 
318 struct DriverSuffix {
319   const char *Suffix;
320   const char *ModeFlag;
321 };
322 
323 } // namespace
324 
325 static const DriverSuffix *FindDriverSuffix(StringRef ProgName, size_t &Pos) {
326   // A list of known driver suffixes. Suffixes are compared against the
327   // program name in order. If there is a match, the frontend type is updated as
328   // necessary by applying the ModeFlag.
329   static const DriverSuffix DriverSuffixes[] = {
330       {"clang", nullptr},
331       {"clang++", "--driver-mode=g++"},
332       {"clang-c++", "--driver-mode=g++"},
333       {"clang-cc", nullptr},
334       {"clang-cpp", "--driver-mode=cpp"},
335       {"clang-g++", "--driver-mode=g++"},
336       {"clang-gcc", nullptr},
337       {"clang-cl", "--driver-mode=cl"},
338       {"cc", nullptr},
339       {"cpp", "--driver-mode=cpp"},
340       {"cl", "--driver-mode=cl"},
341       {"++", "--driver-mode=g++"},
342       {"flang", "--driver-mode=flang"},
343       {"clang-dxc", "--driver-mode=dxc"},
344   };
345 
346   for (const auto &DS : DriverSuffixes) {
347     StringRef Suffix(DS.Suffix);
348     if (ProgName.ends_with(Suffix)) {
349       Pos = ProgName.size() - Suffix.size();
350       return &DS;
351     }
352   }
353   return nullptr;
354 }
355 
356 /// Normalize the program name from argv[0] by stripping the file extension if
357 /// present and lower-casing the string on Windows.
358 static std::string normalizeProgramName(llvm::StringRef Argv0) {
359   std::string ProgName = std::string(llvm::sys::path::filename(Argv0));
360   if (is_style_windows(llvm::sys::path::Style::native)) {
361     // Transform to lowercase for case insensitive file systems.
362     std::transform(ProgName.begin(), ProgName.end(), ProgName.begin(),
363                    ::tolower);
364   }
365   return ProgName;
366 }
367 
368 static const DriverSuffix *parseDriverSuffix(StringRef ProgName, size_t &Pos) {
369   // Try to infer frontend type and default target from the program name by
370   // comparing it against DriverSuffixes in order.
371 
372   // If there is a match, the function tries to identify a target as prefix.
373   // E.g. "x86_64-linux-clang" as interpreted as suffix "clang" with target
374   // prefix "x86_64-linux". If such a target prefix is found, it may be
375   // added via -target as implicit first argument.
376   const DriverSuffix *DS = FindDriverSuffix(ProgName, Pos);
377 
378   if (!DS && ProgName.ends_with(".exe")) {
379     // Try again after stripping the executable suffix:
380     // clang++.exe -> clang++
381     ProgName = ProgName.drop_back(StringRef(".exe").size());
382     DS = FindDriverSuffix(ProgName, Pos);
383   }
384 
385   if (!DS) {
386     // Try again after stripping any trailing version number:
387     // clang++3.5 -> clang++
388     ProgName = ProgName.rtrim("0123456789.");
389     DS = FindDriverSuffix(ProgName, Pos);
390   }
391 
392   if (!DS) {
393     // Try again after stripping trailing -component.
394     // clang++-tot -> clang++
395     ProgName = ProgName.slice(0, ProgName.rfind('-'));
396     DS = FindDriverSuffix(ProgName, Pos);
397   }
398   return DS;
399 }
400 
401 ParsedClangName
402 ToolChain::getTargetAndModeFromProgramName(StringRef PN) {
403   std::string ProgName = normalizeProgramName(PN);
404   size_t SuffixPos;
405   const DriverSuffix *DS = parseDriverSuffix(ProgName, SuffixPos);
406   if (!DS)
407     return {};
408   size_t SuffixEnd = SuffixPos + strlen(DS->Suffix);
409 
410   size_t LastComponent = ProgName.rfind('-', SuffixPos);
411   if (LastComponent == std::string::npos)
412     return ParsedClangName(ProgName.substr(0, SuffixEnd), DS->ModeFlag);
413   std::string ModeSuffix = ProgName.substr(LastComponent + 1,
414                                            SuffixEnd - LastComponent - 1);
415 
416   // Infer target from the prefix.
417   StringRef Prefix(ProgName);
418   Prefix = Prefix.slice(0, LastComponent);
419   std::string IgnoredError;
420   bool IsRegistered =
421       llvm::TargetRegistry::lookupTarget(std::string(Prefix), IgnoredError);
422   return ParsedClangName{std::string(Prefix), ModeSuffix, DS->ModeFlag,
423                          IsRegistered};
424 }
425 
426 StringRef ToolChain::getDefaultUniversalArchName() const {
427   // In universal driver terms, the arch name accepted by -arch isn't exactly
428   // the same as the ones that appear in the triple. Roughly speaking, this is
429   // an inverse of the darwin::getArchTypeForDarwinArchName() function.
430   switch (Triple.getArch()) {
431   case llvm::Triple::aarch64: {
432     if (getTriple().isArm64e())
433       return "arm64e";
434     return "arm64";
435   }
436   case llvm::Triple::aarch64_32:
437     return "arm64_32";
438   case llvm::Triple::ppc:
439     return "ppc";
440   case llvm::Triple::ppcle:
441     return "ppcle";
442   case llvm::Triple::ppc64:
443     return "ppc64";
444   case llvm::Triple::ppc64le:
445     return "ppc64le";
446   default:
447     return Triple.getArchName();
448   }
449 }
450 
451 std::string ToolChain::getInputFilename(const InputInfo &Input) const {
452   return Input.getFilename();
453 }
454 
455 ToolChain::UnwindTableLevel
456 ToolChain::getDefaultUnwindTableLevel(const ArgList &Args) const {
457   return UnwindTableLevel::None;
458 }
459 
460 Tool *ToolChain::getClang() const {
461   if (!Clang)
462     Clang.reset(new tools::Clang(*this, useIntegratedBackend()));
463   return Clang.get();
464 }
465 
466 Tool *ToolChain::getFlang() const {
467   if (!Flang)
468     Flang.reset(new tools::Flang(*this));
469   return Flang.get();
470 }
471 
472 Tool *ToolChain::buildAssembler() const {
473   return new tools::ClangAs(*this);
474 }
475 
476 Tool *ToolChain::buildLinker() const {
477   llvm_unreachable("Linking is not supported by this toolchain");
478 }
479 
480 Tool *ToolChain::buildStaticLibTool() const {
481   llvm_unreachable("Creating static lib is not supported by this toolchain");
482 }
483 
484 Tool *ToolChain::getAssemble() const {
485   if (!Assemble)
486     Assemble.reset(buildAssembler());
487   return Assemble.get();
488 }
489 
490 Tool *ToolChain::getClangAs() const {
491   if (!Assemble)
492     Assemble.reset(new tools::ClangAs(*this));
493   return Assemble.get();
494 }
495 
496 Tool *ToolChain::getLink() const {
497   if (!Link)
498     Link.reset(buildLinker());
499   return Link.get();
500 }
501 
502 Tool *ToolChain::getStaticLibTool() const {
503   if (!StaticLibTool)
504     StaticLibTool.reset(buildStaticLibTool());
505   return StaticLibTool.get();
506 }
507 
508 Tool *ToolChain::getIfsMerge() const {
509   if (!IfsMerge)
510     IfsMerge.reset(new tools::ifstool::Merger(*this));
511   return IfsMerge.get();
512 }
513 
514 Tool *ToolChain::getOffloadBundler() const {
515   if (!OffloadBundler)
516     OffloadBundler.reset(new tools::OffloadBundler(*this));
517   return OffloadBundler.get();
518 }
519 
520 Tool *ToolChain::getOffloadPackager() const {
521   if (!OffloadPackager)
522     OffloadPackager.reset(new tools::OffloadPackager(*this));
523   return OffloadPackager.get();
524 }
525 
526 Tool *ToolChain::getLinkerWrapper() const {
527   if (!LinkerWrapper)
528     LinkerWrapper.reset(new tools::LinkerWrapper(*this, getLink()));
529   return LinkerWrapper.get();
530 }
531 
532 Tool *ToolChain::getTool(Action::ActionClass AC) const {
533   switch (AC) {
534   case Action::AssembleJobClass:
535     return getAssemble();
536 
537   case Action::IfsMergeJobClass:
538     return getIfsMerge();
539 
540   case Action::LinkJobClass:
541     return getLink();
542 
543   case Action::StaticLibJobClass:
544     return getStaticLibTool();
545 
546   case Action::InputClass:
547   case Action::BindArchClass:
548   case Action::OffloadClass:
549   case Action::LipoJobClass:
550   case Action::DsymutilJobClass:
551   case Action::VerifyDebugInfoJobClass:
552   case Action::BinaryAnalyzeJobClass:
553     llvm_unreachable("Invalid tool kind.");
554 
555   case Action::CompileJobClass:
556   case Action::PrecompileJobClass:
557   case Action::PreprocessJobClass:
558   case Action::ExtractAPIJobClass:
559   case Action::AnalyzeJobClass:
560   case Action::MigrateJobClass:
561   case Action::VerifyPCHJobClass:
562   case Action::BackendJobClass:
563     return getClang();
564 
565   case Action::OffloadBundlingJobClass:
566   case Action::OffloadUnbundlingJobClass:
567     return getOffloadBundler();
568 
569   case Action::OffloadPackagerJobClass:
570     return getOffloadPackager();
571   case Action::LinkerWrapperJobClass:
572     return getLinkerWrapper();
573   }
574 
575   llvm_unreachable("Invalid tool kind.");
576 }
577 
578 static StringRef getArchNameForCompilerRTLib(const ToolChain &TC,
579                                              const ArgList &Args) {
580   const llvm::Triple &Triple = TC.getTriple();
581   bool IsWindows = Triple.isOSWindows();
582 
583   if (TC.isBareMetal())
584     return Triple.getArchName();
585 
586   if (TC.getArch() == llvm::Triple::arm || TC.getArch() == llvm::Triple::armeb)
587     return (arm::getARMFloatABI(TC, Args) == arm::FloatABI::Hard && !IsWindows)
588                ? "armhf"
589                : "arm";
590 
591   // For historic reasons, Android library is using i686 instead of i386.
592   if (TC.getArch() == llvm::Triple::x86 && Triple.isAndroid())
593     return "i686";
594 
595   if (TC.getArch() == llvm::Triple::x86_64 && Triple.isX32())
596     return "x32";
597 
598   return llvm::Triple::getArchTypeName(TC.getArch());
599 }
600 
601 StringRef ToolChain::getOSLibName() const {
602   if (Triple.isOSDarwin())
603     return "darwin";
604 
605   switch (Triple.getOS()) {
606   case llvm::Triple::FreeBSD:
607     return "freebsd";
608   case llvm::Triple::NetBSD:
609     return "netbsd";
610   case llvm::Triple::OpenBSD:
611     return "openbsd";
612   case llvm::Triple::Solaris:
613     return "sunos";
614   case llvm::Triple::AIX:
615     return "aix";
616   default:
617     return getOS();
618   }
619 }
620 
621 std::string ToolChain::getCompilerRTPath() const {
622   SmallString<128> Path(getDriver().ResourceDir);
623   if (isBareMetal()) {
624     llvm::sys::path::append(Path, "lib", getOSLibName());
625     if (!SelectedMultilibs.empty()) {
626       Path += SelectedMultilibs.back().gccSuffix();
627     }
628   } else if (Triple.isOSUnknown()) {
629     llvm::sys::path::append(Path, "lib");
630   } else {
631     llvm::sys::path::append(Path, "lib", getOSLibName());
632   }
633   return std::string(Path);
634 }
635 
636 std::string ToolChain::getCompilerRTBasename(const ArgList &Args,
637                                              StringRef Component,
638                                              FileType Type) const {
639   std::string CRTAbsolutePath = getCompilerRT(Args, Component, Type);
640   return llvm::sys::path::filename(CRTAbsolutePath).str();
641 }
642 
643 std::string ToolChain::buildCompilerRTBasename(const llvm::opt::ArgList &Args,
644                                                StringRef Component,
645                                                FileType Type,
646                                                bool AddArch) const {
647   const llvm::Triple &TT = getTriple();
648   bool IsITANMSVCWindows =
649       TT.isWindowsMSVCEnvironment() || TT.isWindowsItaniumEnvironment();
650 
651   const char *Prefix =
652       IsITANMSVCWindows || Type == ToolChain::FT_Object ? "" : "lib";
653   const char *Suffix;
654   switch (Type) {
655   case ToolChain::FT_Object:
656     Suffix = IsITANMSVCWindows ? ".obj" : ".o";
657     break;
658   case ToolChain::FT_Static:
659     Suffix = IsITANMSVCWindows ? ".lib" : ".a";
660     break;
661   case ToolChain::FT_Shared:
662     Suffix = TT.isOSWindows()
663                  ? (TT.isWindowsGNUEnvironment() ? ".dll.a" : ".lib")
664                  : ".so";
665     break;
666   }
667 
668   std::string ArchAndEnv;
669   if (AddArch) {
670     StringRef Arch = getArchNameForCompilerRTLib(*this, Args);
671     const char *Env = TT.isAndroid() ? "-android" : "";
672     ArchAndEnv = ("-" + Arch + Env).str();
673   }
674   return (Prefix + Twine("clang_rt.") + Component + ArchAndEnv + Suffix).str();
675 }
676 
677 std::string ToolChain::getCompilerRT(const ArgList &Args, StringRef Component,
678                                      FileType Type) const {
679   // Check for runtime files in the new layout without the architecture first.
680   std::string CRTBasename =
681       buildCompilerRTBasename(Args, Component, Type, /*AddArch=*/false);
682   SmallString<128> Path;
683   for (const auto &LibPath : getLibraryPaths()) {
684     SmallString<128> P(LibPath);
685     llvm::sys::path::append(P, CRTBasename);
686     if (getVFS().exists(P))
687       return std::string(P);
688     if (Path.empty())
689       Path = P;
690   }
691   if (getTriple().isOSAIX())
692     Path.clear();
693 
694   // Check the filename for the old layout if the new one does not exist.
695   CRTBasename =
696       buildCompilerRTBasename(Args, Component, Type, /*AddArch=*/true);
697   SmallString<128> OldPath(getCompilerRTPath());
698   llvm::sys::path::append(OldPath, CRTBasename);
699   if (Path.empty() || getVFS().exists(OldPath))
700     return std::string(OldPath);
701 
702   // If none is found, use a file name from the new layout, which may get
703   // printed in an error message, aiding users in knowing what Clang is
704   // looking for.
705   return std::string(Path);
706 }
707 
708 const char *ToolChain::getCompilerRTArgString(const llvm::opt::ArgList &Args,
709                                               StringRef Component,
710                                               FileType Type) const {
711   return Args.MakeArgString(getCompilerRT(Args, Component, Type));
712 }
713 
714 // Android target triples contain a target version. If we don't have libraries
715 // for the exact target version, we should fall back to the next newest version
716 // or a versionless path, if any.
717 std::optional<std::string>
718 ToolChain::getFallbackAndroidTargetPath(StringRef BaseDir) const {
719   llvm::Triple TripleWithoutLevel(getTriple());
720   TripleWithoutLevel.setEnvironmentName("android"); // remove any version number
721   const std::string &TripleWithoutLevelStr = TripleWithoutLevel.str();
722   unsigned TripleVersion = getTriple().getEnvironmentVersion().getMajor();
723   unsigned BestVersion = 0;
724 
725   SmallString<32> TripleDir;
726   bool UsingUnversionedDir = false;
727   std::error_code EC;
728   for (llvm::vfs::directory_iterator LI = getVFS().dir_begin(BaseDir, EC), LE;
729        !EC && LI != LE; LI = LI.increment(EC)) {
730     StringRef DirName = llvm::sys::path::filename(LI->path());
731     StringRef DirNameSuffix = DirName;
732     if (DirNameSuffix.consume_front(TripleWithoutLevelStr)) {
733       if (DirNameSuffix.empty() && TripleDir.empty()) {
734         TripleDir = DirName;
735         UsingUnversionedDir = true;
736       } else {
737         unsigned Version;
738         if (!DirNameSuffix.getAsInteger(10, Version) && Version > BestVersion &&
739             Version < TripleVersion) {
740           BestVersion = Version;
741           TripleDir = DirName;
742           UsingUnversionedDir = false;
743         }
744       }
745     }
746   }
747 
748   if (TripleDir.empty())
749     return {};
750 
751   SmallString<128> P(BaseDir);
752   llvm::sys::path::append(P, TripleDir);
753   if (UsingUnversionedDir)
754     D.Diag(diag::warn_android_unversioned_fallback) << P << getTripleString();
755   return std::string(P);
756 }
757 
758 std::optional<std::string>
759 ToolChain::getTargetSubDirPath(StringRef BaseDir) const {
760   auto getPathForTriple =
761       [&](const llvm::Triple &Triple) -> std::optional<std::string> {
762     SmallString<128> P(BaseDir);
763     llvm::sys::path::append(P, Triple.str());
764     if (getVFS().exists(P))
765       return std::string(P);
766     return {};
767   };
768 
769   if (auto Path = getPathForTriple(getTriple()))
770     return *Path;
771 
772   // When building with per target runtime directories, various ways of naming
773   // the Arm architecture may have been normalised to simply "arm".
774   // For example "armv8l" (Armv8 AArch32 little endian) is replaced with "arm".
775   // Since an armv8l system can use libraries built for earlier architecture
776   // versions assuming endian and float ABI match.
777   //
778   // Original triple: armv8l-unknown-linux-gnueabihf
779   //  Runtime triple: arm-unknown-linux-gnueabihf
780   //
781   // We do not do this for armeb (big endian) because doing so could make us
782   // select little endian libraries. In addition, all known armeb triples only
783   // use the "armeb" architecture name.
784   //
785   // M profile Arm is bare metal and we know they will not be using the per
786   // target runtime directory layout.
787   if (getTriple().getArch() == Triple::arm && !getTriple().isArmMClass()) {
788     llvm::Triple ArmTriple = getTriple();
789     ArmTriple.setArch(Triple::arm);
790     if (auto Path = getPathForTriple(ArmTriple))
791       return *Path;
792   }
793 
794   if (getTriple().isAndroid())
795     return getFallbackAndroidTargetPath(BaseDir);
796 
797   return {};
798 }
799 
800 std::optional<std::string> ToolChain::getRuntimePath() const {
801   SmallString<128> P(D.ResourceDir);
802   llvm::sys::path::append(P, "lib");
803   if (auto Ret = getTargetSubDirPath(P))
804     return Ret;
805   // Darwin does not use per-target runtime directory.
806   if (Triple.isOSDarwin())
807     return {};
808   llvm::sys::path::append(P, Triple.str());
809   return std::string(P);
810 }
811 
812 std::optional<std::string> ToolChain::getStdlibPath() const {
813   SmallString<128> P(D.Dir);
814   llvm::sys::path::append(P, "..", "lib");
815   return getTargetSubDirPath(P);
816 }
817 
818 std::optional<std::string> ToolChain::getStdlibIncludePath() const {
819   SmallString<128> P(D.Dir);
820   llvm::sys::path::append(P, "..", "include");
821   return getTargetSubDirPath(P);
822 }
823 
824 ToolChain::path_list ToolChain::getArchSpecificLibPaths() const {
825   path_list Paths;
826 
827   auto AddPath = [&](const ArrayRef<StringRef> &SS) {
828     SmallString<128> Path(getDriver().ResourceDir);
829     llvm::sys::path::append(Path, "lib");
830     for (auto &S : SS)
831       llvm::sys::path::append(Path, S);
832     Paths.push_back(std::string(Path));
833   };
834 
835   AddPath({getTriple().str()});
836   AddPath({getOSLibName(), llvm::Triple::getArchTypeName(getArch())});
837   return Paths;
838 }
839 
840 bool ToolChain::needsProfileRT(const ArgList &Args) {
841   if (Args.hasArg(options::OPT_noprofilelib))
842     return false;
843 
844   return Args.hasArg(options::OPT_fprofile_generate) ||
845          Args.hasArg(options::OPT_fprofile_generate_EQ) ||
846          Args.hasArg(options::OPT_fcs_profile_generate) ||
847          Args.hasArg(options::OPT_fcs_profile_generate_EQ) ||
848          Args.hasArg(options::OPT_fprofile_instr_generate) ||
849          Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
850          Args.hasArg(options::OPT_fcreate_profile) ||
851          Args.hasArg(options::OPT_forder_file_instrumentation);
852 }
853 
854 bool ToolChain::needsGCovInstrumentation(const llvm::opt::ArgList &Args) {
855   return Args.hasArg(options::OPT_coverage) ||
856          Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
857                       false);
858 }
859 
860 Tool *ToolChain::SelectTool(const JobAction &JA) const {
861   if (D.IsFlangMode() && getDriver().ShouldUseFlangCompiler(JA)) return getFlang();
862   if (getDriver().ShouldUseClangCompiler(JA)) return getClang();
863   Action::ActionClass AC = JA.getKind();
864   if (AC == Action::AssembleJobClass && useIntegratedAs() &&
865       !getTriple().isOSAIX())
866     return getClangAs();
867   return getTool(AC);
868 }
869 
870 std::string ToolChain::GetFilePath(const char *Name) const {
871   return D.GetFilePath(Name, *this);
872 }
873 
874 std::string ToolChain::GetProgramPath(const char *Name) const {
875   return D.GetProgramPath(Name, *this);
876 }
877 
878 std::string ToolChain::GetLinkerPath(bool *LinkerIsLLD) const {
879   if (LinkerIsLLD)
880     *LinkerIsLLD = false;
881 
882   // Get -fuse-ld= first to prevent -Wunused-command-line-argument. -fuse-ld= is
883   // considered as the linker flavor, e.g. "bfd", "gold", or "lld".
884   const Arg* A = Args.getLastArg(options::OPT_fuse_ld_EQ);
885   StringRef UseLinker = A ? A->getValue() : CLANG_DEFAULT_LINKER;
886 
887   // --ld-path= takes precedence over -fuse-ld= and specifies the executable
888   // name. -B, COMPILER_PATH and PATH and consulted if the value does not
889   // contain a path component separator.
890   // -fuse-ld=lld can be used with --ld-path= to inform clang that the binary
891   // that --ld-path= points to is lld.
892   if (const Arg *A = Args.getLastArg(options::OPT_ld_path_EQ)) {
893     std::string Path(A->getValue());
894     if (!Path.empty()) {
895       if (llvm::sys::path::parent_path(Path).empty())
896         Path = GetProgramPath(A->getValue());
897       if (llvm::sys::fs::can_execute(Path)) {
898         if (LinkerIsLLD)
899           *LinkerIsLLD = UseLinker == "lld";
900         return std::string(Path);
901       }
902     }
903     getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
904     return GetProgramPath(getDefaultLinker());
905   }
906   // If we're passed -fuse-ld= with no argument, or with the argument ld,
907   // then use whatever the default system linker is.
908   if (UseLinker.empty() || UseLinker == "ld") {
909     const char *DefaultLinker = getDefaultLinker();
910     if (llvm::sys::path::is_absolute(DefaultLinker))
911       return std::string(DefaultLinker);
912     else
913       return GetProgramPath(DefaultLinker);
914   }
915 
916   // Extending -fuse-ld= to an absolute or relative path is unexpected. Checking
917   // for the linker flavor is brittle. In addition, prepending "ld." or "ld64."
918   // to a relative path is surprising. This is more complex due to priorities
919   // among -B, COMPILER_PATH and PATH. --ld-path= should be used instead.
920   if (UseLinker.contains('/'))
921     getDriver().Diag(diag::warn_drv_fuse_ld_path);
922 
923   if (llvm::sys::path::is_absolute(UseLinker)) {
924     // If we're passed what looks like an absolute path, don't attempt to
925     // second-guess that.
926     if (llvm::sys::fs::can_execute(UseLinker))
927       return std::string(UseLinker);
928   } else {
929     llvm::SmallString<8> LinkerName;
930     if (Triple.isOSDarwin())
931       LinkerName.append("ld64.");
932     else
933       LinkerName.append("ld.");
934     LinkerName.append(UseLinker);
935 
936     std::string LinkerPath(GetProgramPath(LinkerName.c_str()));
937     if (llvm::sys::fs::can_execute(LinkerPath)) {
938       if (LinkerIsLLD)
939         *LinkerIsLLD = UseLinker == "lld";
940       return LinkerPath;
941     }
942   }
943 
944   if (A)
945     getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
946 
947   return GetProgramPath(getDefaultLinker());
948 }
949 
950 std::string ToolChain::GetStaticLibToolPath() const {
951   // TODO: Add support for static lib archiving on Windows
952   if (Triple.isOSDarwin())
953     return GetProgramPath("libtool");
954   return GetProgramPath("llvm-ar");
955 }
956 
957 types::ID ToolChain::LookupTypeForExtension(StringRef Ext) const {
958   types::ID id = types::lookupTypeForExtension(Ext);
959 
960   // Flang always runs the preprocessor and has no notion of "preprocessed
961   // fortran". Here, TY_PP_Fortran is coerced to TY_Fortran to avoid treating
962   // them differently.
963   if (D.IsFlangMode() && id == types::TY_PP_Fortran)
964     id = types::TY_Fortran;
965 
966   return id;
967 }
968 
969 bool ToolChain::HasNativeLLVMSupport() const {
970   return false;
971 }
972 
973 bool ToolChain::isCrossCompiling() const {
974   llvm::Triple HostTriple(LLVM_HOST_TRIPLE);
975   switch (HostTriple.getArch()) {
976   // The A32/T32/T16 instruction sets are not separate architectures in this
977   // context.
978   case llvm::Triple::arm:
979   case llvm::Triple::armeb:
980   case llvm::Triple::thumb:
981   case llvm::Triple::thumbeb:
982     return getArch() != llvm::Triple::arm && getArch() != llvm::Triple::thumb &&
983            getArch() != llvm::Triple::armeb && getArch() != llvm::Triple::thumbeb;
984   default:
985     return HostTriple.getArch() != getArch();
986   }
987 }
988 
989 ObjCRuntime ToolChain::getDefaultObjCRuntime(bool isNonFragile) const {
990   return ObjCRuntime(isNonFragile ? ObjCRuntime::GNUstep : ObjCRuntime::GCC,
991                      VersionTuple());
992 }
993 
994 llvm::ExceptionHandling
995 ToolChain::GetExceptionModel(const llvm::opt::ArgList &Args) const {
996   return llvm::ExceptionHandling::None;
997 }
998 
999 bool ToolChain::isThreadModelSupported(const StringRef Model) const {
1000   if (Model == "single") {
1001     // FIXME: 'single' is only supported on ARM and WebAssembly so far.
1002     return Triple.getArch() == llvm::Triple::arm ||
1003            Triple.getArch() == llvm::Triple::armeb ||
1004            Triple.getArch() == llvm::Triple::thumb ||
1005            Triple.getArch() == llvm::Triple::thumbeb || Triple.isWasm();
1006   } else if (Model == "posix")
1007     return true;
1008 
1009   return false;
1010 }
1011 
1012 std::string ToolChain::ComputeLLVMTriple(const ArgList &Args,
1013                                          types::ID InputType) const {
1014   switch (getTriple().getArch()) {
1015   default:
1016     return getTripleString();
1017 
1018   case llvm::Triple::x86_64: {
1019     llvm::Triple Triple = getTriple();
1020     if (!Triple.isOSBinFormatMachO())
1021       return getTripleString();
1022 
1023     if (Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
1024       // x86_64h goes in the triple. Other -march options just use the
1025       // vanilla triple we already have.
1026       StringRef MArch = A->getValue();
1027       if (MArch == "x86_64h")
1028         Triple.setArchName(MArch);
1029     }
1030     return Triple.getTriple();
1031   }
1032   case llvm::Triple::aarch64: {
1033     llvm::Triple Triple = getTriple();
1034     tools::aarch64::setPAuthABIInTriple(getDriver(), Args, Triple);
1035     if (!Triple.isOSBinFormatMachO())
1036       return Triple.getTriple();
1037 
1038     if (Triple.isArm64e())
1039       return Triple.getTriple();
1040 
1041     // FIXME: older versions of ld64 expect the "arm64" component in the actual
1042     // triple string and query it to determine whether an LTO file can be
1043     // handled. Remove this when we don't care any more.
1044     Triple.setArchName("arm64");
1045     return Triple.getTriple();
1046   }
1047   case llvm::Triple::aarch64_32:
1048     return getTripleString();
1049   case llvm::Triple::arm:
1050   case llvm::Triple::armeb:
1051   case llvm::Triple::thumb:
1052   case llvm::Triple::thumbeb: {
1053     llvm::Triple Triple = getTriple();
1054     tools::arm::setArchNameInTriple(getDriver(), Args, InputType, Triple);
1055     tools::arm::setFloatABIInTriple(getDriver(), Args, Triple);
1056     return Triple.getTriple();
1057   }
1058   }
1059 }
1060 
1061 std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args,
1062                                                    types::ID InputType) const {
1063   return ComputeLLVMTriple(Args, InputType);
1064 }
1065 
1066 std::string ToolChain::computeSysRoot() const {
1067   return D.SysRoot;
1068 }
1069 
1070 void ToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
1071                                           ArgStringList &CC1Args) const {
1072   // Each toolchain should provide the appropriate include flags.
1073 }
1074 
1075 void ToolChain::addClangTargetOptions(
1076     const ArgList &DriverArgs, ArgStringList &CC1Args,
1077     Action::OffloadKind DeviceOffloadKind) const {}
1078 
1079 void ToolChain::addClangCC1ASTargetOptions(const ArgList &Args,
1080                                            ArgStringList &CC1ASArgs) const {}
1081 
1082 void ToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {}
1083 
1084 void ToolChain::addProfileRTLibs(const llvm::opt::ArgList &Args,
1085                                  llvm::opt::ArgStringList &CmdArgs) const {
1086   if (!needsProfileRT(Args) && !needsGCovInstrumentation(Args))
1087     return;
1088 
1089   CmdArgs.push_back(getCompilerRTArgString(Args, "profile"));
1090 }
1091 
1092 ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
1093     const ArgList &Args) const {
1094   if (runtimeLibType)
1095     return *runtimeLibType;
1096 
1097   const Arg* A = Args.getLastArg(options::OPT_rtlib_EQ);
1098   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_RTLIB;
1099 
1100   // Only use "platform" in tests to override CLANG_DEFAULT_RTLIB!
1101   if (LibName == "compiler-rt")
1102     runtimeLibType = ToolChain::RLT_CompilerRT;
1103   else if (LibName == "libgcc")
1104     runtimeLibType = ToolChain::RLT_Libgcc;
1105   else if (LibName == "platform")
1106     runtimeLibType = GetDefaultRuntimeLibType();
1107   else {
1108     if (A)
1109       getDriver().Diag(diag::err_drv_invalid_rtlib_name)
1110           << A->getAsString(Args);
1111 
1112     runtimeLibType = GetDefaultRuntimeLibType();
1113   }
1114 
1115   return *runtimeLibType;
1116 }
1117 
1118 ToolChain::UnwindLibType ToolChain::GetUnwindLibType(
1119     const ArgList &Args) const {
1120   if (unwindLibType)
1121     return *unwindLibType;
1122 
1123   const Arg *A = Args.getLastArg(options::OPT_unwindlib_EQ);
1124   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_UNWINDLIB;
1125 
1126   if (LibName == "none")
1127     unwindLibType = ToolChain::UNW_None;
1128   else if (LibName == "platform" || LibName == "") {
1129     ToolChain::RuntimeLibType RtLibType = GetRuntimeLibType(Args);
1130     if (RtLibType == ToolChain::RLT_CompilerRT) {
1131       if (getTriple().isAndroid() || getTriple().isOSAIX())
1132         unwindLibType = ToolChain::UNW_CompilerRT;
1133       else
1134         unwindLibType = ToolChain::UNW_None;
1135     } else if (RtLibType == ToolChain::RLT_Libgcc)
1136       unwindLibType = ToolChain::UNW_Libgcc;
1137   } else if (LibName == "libunwind") {
1138     if (GetRuntimeLibType(Args) == RLT_Libgcc)
1139       getDriver().Diag(diag::err_drv_incompatible_unwindlib);
1140     unwindLibType = ToolChain::UNW_CompilerRT;
1141   } else if (LibName == "libgcc")
1142     unwindLibType = ToolChain::UNW_Libgcc;
1143   else {
1144     if (A)
1145       getDriver().Diag(diag::err_drv_invalid_unwindlib_name)
1146           << A->getAsString(Args);
1147 
1148     unwindLibType = GetDefaultUnwindLibType();
1149   }
1150 
1151   return *unwindLibType;
1152 }
1153 
1154 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
1155   if (cxxStdlibType)
1156     return *cxxStdlibType;
1157 
1158   const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
1159   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_CXX_STDLIB;
1160 
1161   // Only use "platform" in tests to override CLANG_DEFAULT_CXX_STDLIB!
1162   if (LibName == "libc++")
1163     cxxStdlibType = ToolChain::CST_Libcxx;
1164   else if (LibName == "libstdc++")
1165     cxxStdlibType = ToolChain::CST_Libstdcxx;
1166   else if (LibName == "platform")
1167     cxxStdlibType = GetDefaultCXXStdlibType();
1168   else {
1169     if (A)
1170       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
1171           << A->getAsString(Args);
1172 
1173     cxxStdlibType = GetDefaultCXXStdlibType();
1174   }
1175 
1176   return *cxxStdlibType;
1177 }
1178 
1179 /// Utility function to add a system include directory to CC1 arguments.
1180 /*static*/ void ToolChain::addSystemInclude(const ArgList &DriverArgs,
1181                                             ArgStringList &CC1Args,
1182                                             const Twine &Path) {
1183   CC1Args.push_back("-internal-isystem");
1184   CC1Args.push_back(DriverArgs.MakeArgString(Path));
1185 }
1186 
1187 /// Utility function to add a system include directory with extern "C"
1188 /// semantics to CC1 arguments.
1189 ///
1190 /// Note that this should be used rarely, and only for directories that
1191 /// historically and for legacy reasons are treated as having implicit extern
1192 /// "C" semantics. These semantics are *ignored* by and large today, but its
1193 /// important to preserve the preprocessor changes resulting from the
1194 /// classification.
1195 /*static*/ void ToolChain::addExternCSystemInclude(const ArgList &DriverArgs,
1196                                                    ArgStringList &CC1Args,
1197                                                    const Twine &Path) {
1198   CC1Args.push_back("-internal-externc-isystem");
1199   CC1Args.push_back(DriverArgs.MakeArgString(Path));
1200 }
1201 
1202 void ToolChain::addExternCSystemIncludeIfExists(const ArgList &DriverArgs,
1203                                                 ArgStringList &CC1Args,
1204                                                 const Twine &Path) {
1205   if (llvm::sys::fs::exists(Path))
1206     addExternCSystemInclude(DriverArgs, CC1Args, Path);
1207 }
1208 
1209 /// Utility function to add a list of system include directories to CC1.
1210 /*static*/ void ToolChain::addSystemIncludes(const ArgList &DriverArgs,
1211                                              ArgStringList &CC1Args,
1212                                              ArrayRef<StringRef> Paths) {
1213   for (const auto &Path : Paths) {
1214     CC1Args.push_back("-internal-isystem");
1215     CC1Args.push_back(DriverArgs.MakeArgString(Path));
1216   }
1217 }
1218 
1219 /*static*/ std::string ToolChain::concat(StringRef Path, const Twine &A,
1220                                          const Twine &B, const Twine &C,
1221                                          const Twine &D) {
1222   SmallString<128> Result(Path);
1223   llvm::sys::path::append(Result, llvm::sys::path::Style::posix, A, B, C, D);
1224   return std::string(Result);
1225 }
1226 
1227 std::string ToolChain::detectLibcxxVersion(StringRef IncludePath) const {
1228   std::error_code EC;
1229   int MaxVersion = 0;
1230   std::string MaxVersionString;
1231   SmallString<128> Path(IncludePath);
1232   llvm::sys::path::append(Path, "c++");
1233   for (llvm::vfs::directory_iterator LI = getVFS().dir_begin(Path, EC), LE;
1234        !EC && LI != LE; LI = LI.increment(EC)) {
1235     StringRef VersionText = llvm::sys::path::filename(LI->path());
1236     int Version;
1237     if (VersionText[0] == 'v' &&
1238         !VersionText.slice(1, StringRef::npos).getAsInteger(10, Version)) {
1239       if (Version > MaxVersion) {
1240         MaxVersion = Version;
1241         MaxVersionString = std::string(VersionText);
1242       }
1243     }
1244   }
1245   if (!MaxVersion)
1246     return "";
1247   return MaxVersionString;
1248 }
1249 
1250 void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
1251                                              ArgStringList &CC1Args) const {
1252   // Header search paths should be handled by each of the subclasses.
1253   // Historically, they have not been, and instead have been handled inside of
1254   // the CC1-layer frontend. As the logic is hoisted out, this generic function
1255   // will slowly stop being called.
1256   //
1257   // While it is being called, replicate a bit of a hack to propagate the
1258   // '-stdlib=' flag down to CC1 so that it can in turn customize the C++
1259   // header search paths with it. Once all systems are overriding this
1260   // function, the CC1 flag and this line can be removed.
1261   DriverArgs.AddAllArgs(CC1Args, options::OPT_stdlib_EQ);
1262 }
1263 
1264 void ToolChain::AddClangCXXStdlibIsystemArgs(
1265     const llvm::opt::ArgList &DriverArgs,
1266     llvm::opt::ArgStringList &CC1Args) const {
1267   DriverArgs.ClaimAllArgs(options::OPT_stdlibxx_isystem);
1268   // This intentionally only looks at -nostdinc++, and not -nostdinc or
1269   // -nostdlibinc. The purpose of -stdlib++-isystem is to support toolchain
1270   // setups with non-standard search logic for the C++ headers, while still
1271   // allowing users of the toolchain to bring their own C++ headers. Such a
1272   // toolchain likely also has non-standard search logic for the C headers and
1273   // uses -nostdinc to suppress the default logic, but -stdlib++-isystem should
1274   // still work in that case and only be suppressed by an explicit -nostdinc++
1275   // in a project using the toolchain.
1276   if (!DriverArgs.hasArg(options::OPT_nostdincxx))
1277     for (const auto &P :
1278          DriverArgs.getAllArgValues(options::OPT_stdlibxx_isystem))
1279       addSystemInclude(DriverArgs, CC1Args, P);
1280 }
1281 
1282 bool ToolChain::ShouldLinkCXXStdlib(const llvm::opt::ArgList &Args) const {
1283   return getDriver().CCCIsCXX() &&
1284          !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
1285                       options::OPT_nostdlibxx);
1286 }
1287 
1288 void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
1289                                     ArgStringList &CmdArgs) const {
1290   assert(!Args.hasArg(options::OPT_nostdlibxx) &&
1291          "should not have called this");
1292   CXXStdlibType Type = GetCXXStdlibType(Args);
1293 
1294   switch (Type) {
1295   case ToolChain::CST_Libcxx:
1296     CmdArgs.push_back("-lc++");
1297     if (Args.hasArg(options::OPT_fexperimental_library))
1298       CmdArgs.push_back("-lc++experimental");
1299     break;
1300 
1301   case ToolChain::CST_Libstdcxx:
1302     CmdArgs.push_back("-lstdc++");
1303     break;
1304   }
1305 }
1306 
1307 void ToolChain::AddFilePathLibArgs(const ArgList &Args,
1308                                    ArgStringList &CmdArgs) const {
1309   for (const auto &LibPath : getFilePaths())
1310     if(LibPath.length() > 0)
1311       CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
1312 }
1313 
1314 void ToolChain::AddCCKextLibArgs(const ArgList &Args,
1315                                  ArgStringList &CmdArgs) const {
1316   CmdArgs.push_back("-lcc_kext");
1317 }
1318 
1319 bool ToolChain::isFastMathRuntimeAvailable(const ArgList &Args,
1320                                            std::string &Path) const {
1321   // Don't implicitly link in mode-changing libraries in a shared library, since
1322   // this can have very deleterious effects. See the various links from
1323   // https://github.com/llvm/llvm-project/issues/57589 for more information.
1324   bool Default = !Args.hasArgNoClaim(options::OPT_shared);
1325 
1326   // Do not check for -fno-fast-math or -fno-unsafe-math when -Ofast passed
1327   // (to keep the linker options consistent with gcc and clang itself).
1328   if (Default && !isOptimizationLevelFast(Args)) {
1329     // Check if -ffast-math or -funsafe-math.
1330     Arg *A = Args.getLastArg(
1331         options::OPT_ffast_math, options::OPT_fno_fast_math,
1332         options::OPT_funsafe_math_optimizations,
1333         options::OPT_fno_unsafe_math_optimizations, options::OPT_ffp_model_EQ);
1334 
1335     if (!A || A->getOption().getID() == options::OPT_fno_fast_math ||
1336         A->getOption().getID() == options::OPT_fno_unsafe_math_optimizations)
1337       Default = false;
1338     if (A && A->getOption().getID() == options::OPT_ffp_model_EQ) {
1339       StringRef Model = A->getValue();
1340       if (Model != "fast")
1341         Default = false;
1342     }
1343   }
1344 
1345   // Whatever decision came as a result of the above implicit settings, either
1346   // -mdaz-ftz or -mno-daz-ftz is capable of overriding it.
1347   if (!Args.hasFlag(options::OPT_mdaz_ftz, options::OPT_mno_daz_ftz, Default))
1348     return false;
1349 
1350   // If crtfastmath.o exists add it to the arguments.
1351   Path = GetFilePath("crtfastmath.o");
1352   return (Path != "crtfastmath.o"); // Not found.
1353 }
1354 
1355 bool ToolChain::addFastMathRuntimeIfAvailable(const ArgList &Args,
1356                                               ArgStringList &CmdArgs) const {
1357   std::string Path;
1358   if (isFastMathRuntimeAvailable(Args, Path)) {
1359     CmdArgs.push_back(Args.MakeArgString(Path));
1360     return true;
1361   }
1362 
1363   return false;
1364 }
1365 
1366 Expected<SmallVector<std::string>>
1367 ToolChain::getSystemGPUArchs(const llvm::opt::ArgList &Args) const {
1368   return SmallVector<std::string>();
1369 }
1370 
1371 SanitizerMask ToolChain::getSupportedSanitizers() const {
1372   // Return sanitizers which don't require runtime support and are not
1373   // platform dependent.
1374 
1375   SanitizerMask Res =
1376       (SanitizerKind::Undefined & ~SanitizerKind::Vptr) |
1377       (SanitizerKind::CFI & ~SanitizerKind::CFIICall) |
1378       SanitizerKind::CFICastStrict | SanitizerKind::FloatDivideByZero |
1379       SanitizerKind::KCFI | SanitizerKind::UnsignedIntegerOverflow |
1380       SanitizerKind::UnsignedShiftBase | SanitizerKind::ImplicitConversion |
1381       SanitizerKind::Nullability | SanitizerKind::LocalBounds;
1382   if (getTriple().getArch() == llvm::Triple::x86 ||
1383       getTriple().getArch() == llvm::Triple::x86_64 ||
1384       getTriple().getArch() == llvm::Triple::arm || getTriple().isWasm() ||
1385       getTriple().isAArch64() || getTriple().isRISCV() ||
1386       getTriple().isLoongArch64())
1387     Res |= SanitizerKind::CFIICall;
1388   if (getTriple().getArch() == llvm::Triple::x86_64 ||
1389       getTriple().isAArch64(64) || getTriple().isRISCV())
1390     Res |= SanitizerKind::ShadowCallStack;
1391   if (getTriple().isAArch64(64))
1392     Res |= SanitizerKind::MemTag;
1393   return Res;
1394 }
1395 
1396 void ToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
1397                                    ArgStringList &CC1Args) const {}
1398 
1399 void ToolChain::AddHIPIncludeArgs(const ArgList &DriverArgs,
1400                                   ArgStringList &CC1Args) const {}
1401 
1402 llvm::SmallVector<ToolChain::BitCodeLibraryInfo, 12>
1403 ToolChain::getDeviceLibs(const ArgList &DriverArgs) const {
1404   return {};
1405 }
1406 
1407 void ToolChain::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
1408                                     ArgStringList &CC1Args) const {}
1409 
1410 static VersionTuple separateMSVCFullVersion(unsigned Version) {
1411   if (Version < 100)
1412     return VersionTuple(Version);
1413 
1414   if (Version < 10000)
1415     return VersionTuple(Version / 100, Version % 100);
1416 
1417   unsigned Build = 0, Factor = 1;
1418   for (; Version > 10000; Version = Version / 10, Factor = Factor * 10)
1419     Build = Build + (Version % 10) * Factor;
1420   return VersionTuple(Version / 100, Version % 100, Build);
1421 }
1422 
1423 VersionTuple
1424 ToolChain::computeMSVCVersion(const Driver *D,
1425                               const llvm::opt::ArgList &Args) const {
1426   const Arg *MSCVersion = Args.getLastArg(options::OPT_fmsc_version);
1427   const Arg *MSCompatibilityVersion =
1428       Args.getLastArg(options::OPT_fms_compatibility_version);
1429 
1430   if (MSCVersion && MSCompatibilityVersion) {
1431     if (D)
1432       D->Diag(diag::err_drv_argument_not_allowed_with)
1433           << MSCVersion->getAsString(Args)
1434           << MSCompatibilityVersion->getAsString(Args);
1435     return VersionTuple();
1436   }
1437 
1438   if (MSCompatibilityVersion) {
1439     VersionTuple MSVT;
1440     if (MSVT.tryParse(MSCompatibilityVersion->getValue())) {
1441       if (D)
1442         D->Diag(diag::err_drv_invalid_value)
1443             << MSCompatibilityVersion->getAsString(Args)
1444             << MSCompatibilityVersion->getValue();
1445     } else {
1446       return MSVT;
1447     }
1448   }
1449 
1450   if (MSCVersion) {
1451     unsigned Version = 0;
1452     if (StringRef(MSCVersion->getValue()).getAsInteger(10, Version)) {
1453       if (D)
1454         D->Diag(diag::err_drv_invalid_value)
1455             << MSCVersion->getAsString(Args) << MSCVersion->getValue();
1456     } else {
1457       return separateMSVCFullVersion(Version);
1458     }
1459   }
1460 
1461   return VersionTuple();
1462 }
1463 
1464 llvm::opt::DerivedArgList *ToolChain::TranslateOpenMPTargetArgs(
1465     const llvm::opt::DerivedArgList &Args, bool SameTripleAsHost,
1466     SmallVectorImpl<llvm::opt::Arg *> &AllocatedArgs) const {
1467   DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
1468   const OptTable &Opts = getDriver().getOpts();
1469   bool Modified = false;
1470 
1471   // Handle -Xopenmp-target flags
1472   for (auto *A : Args) {
1473     // Exclude flags which may only apply to the host toolchain.
1474     // Do not exclude flags when the host triple (AuxTriple)
1475     // matches the current toolchain triple. If it is not present
1476     // at all, target and host share a toolchain.
1477     if (A->getOption().matches(options::OPT_m_Group)) {
1478       // Pass code object version to device toolchain
1479       // to correctly set metadata in intermediate files.
1480       if (SameTripleAsHost ||
1481           A->getOption().matches(options::OPT_mcode_object_version_EQ))
1482         DAL->append(A);
1483       else
1484         Modified = true;
1485       continue;
1486     }
1487 
1488     unsigned Index;
1489     unsigned Prev;
1490     bool XOpenMPTargetNoTriple =
1491         A->getOption().matches(options::OPT_Xopenmp_target);
1492 
1493     if (A->getOption().matches(options::OPT_Xopenmp_target_EQ)) {
1494       llvm::Triple TT(getOpenMPTriple(A->getValue(0)));
1495 
1496       // Passing device args: -Xopenmp-target=<triple> -opt=val.
1497       if (TT.getTriple() == getTripleString())
1498         Index = Args.getBaseArgs().MakeIndex(A->getValue(1));
1499       else
1500         continue;
1501     } else if (XOpenMPTargetNoTriple) {
1502       // Passing device args: -Xopenmp-target -opt=val.
1503       Index = Args.getBaseArgs().MakeIndex(A->getValue(0));
1504     } else {
1505       DAL->append(A);
1506       continue;
1507     }
1508 
1509     // Parse the argument to -Xopenmp-target.
1510     Prev = Index;
1511     std::unique_ptr<Arg> XOpenMPTargetArg(Opts.ParseOneArg(Args, Index));
1512     if (!XOpenMPTargetArg || Index > Prev + 1) {
1513       getDriver().Diag(diag::err_drv_invalid_Xopenmp_target_with_args)
1514           << A->getAsString(Args);
1515       continue;
1516     }
1517     if (XOpenMPTargetNoTriple && XOpenMPTargetArg &&
1518         Args.getAllArgValues(options::OPT_fopenmp_targets_EQ).size() != 1) {
1519       getDriver().Diag(diag::err_drv_Xopenmp_target_missing_triple);
1520       continue;
1521     }
1522     XOpenMPTargetArg->setBaseArg(A);
1523     A = XOpenMPTargetArg.release();
1524     AllocatedArgs.push_back(A);
1525     DAL->append(A);
1526     Modified = true;
1527   }
1528 
1529   if (Modified)
1530     return DAL;
1531 
1532   delete DAL;
1533   return nullptr;
1534 }
1535 
1536 // TODO: Currently argument values separated by space e.g.
1537 // -Xclang -mframe-pointer=no cannot be passed by -Xarch_. This should be
1538 // fixed.
1539 void ToolChain::TranslateXarchArgs(
1540     const llvm::opt::DerivedArgList &Args, llvm::opt::Arg *&A,
1541     llvm::opt::DerivedArgList *DAL,
1542     SmallVectorImpl<llvm::opt::Arg *> *AllocatedArgs) const {
1543   const OptTable &Opts = getDriver().getOpts();
1544   unsigned ValuePos = 1;
1545   if (A->getOption().matches(options::OPT_Xarch_device) ||
1546       A->getOption().matches(options::OPT_Xarch_host))
1547     ValuePos = 0;
1548 
1549   unsigned Index = Args.getBaseArgs().MakeIndex(A->getValue(ValuePos));
1550   unsigned Prev = Index;
1551   std::unique_ptr<llvm::opt::Arg> XarchArg(Opts.ParseOneArg(Args, Index));
1552 
1553   // If the argument parsing failed or more than one argument was
1554   // consumed, the -Xarch_ argument's parameter tried to consume
1555   // extra arguments. Emit an error and ignore.
1556   //
1557   // We also want to disallow any options which would alter the
1558   // driver behavior; that isn't going to work in our model. We
1559   // use options::NoXarchOption to control this.
1560   if (!XarchArg || Index > Prev + 1) {
1561     getDriver().Diag(diag::err_drv_invalid_Xarch_argument_with_args)
1562         << A->getAsString(Args);
1563     return;
1564   } else if (XarchArg->getOption().hasFlag(options::NoXarchOption)) {
1565     auto &Diags = getDriver().getDiags();
1566     unsigned DiagID =
1567         Diags.getCustomDiagID(DiagnosticsEngine::Error,
1568                               "invalid Xarch argument: '%0', not all driver "
1569                               "options can be forwared via Xarch argument");
1570     Diags.Report(DiagID) << A->getAsString(Args);
1571     return;
1572   }
1573   XarchArg->setBaseArg(A);
1574   A = XarchArg.release();
1575   if (!AllocatedArgs)
1576     DAL->AddSynthesizedArg(A);
1577   else
1578     AllocatedArgs->push_back(A);
1579 }
1580 
1581 llvm::opt::DerivedArgList *ToolChain::TranslateXarchArgs(
1582     const llvm::opt::DerivedArgList &Args, StringRef BoundArch,
1583     Action::OffloadKind OFK,
1584     SmallVectorImpl<llvm::opt::Arg *> *AllocatedArgs) const {
1585   DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
1586   bool Modified = false;
1587 
1588   bool IsDevice = OFK != Action::OFK_None && OFK != Action::OFK_Host;
1589   for (Arg *A : Args) {
1590     bool NeedTrans = false;
1591     bool Skip = false;
1592     if (A->getOption().matches(options::OPT_Xarch_device)) {
1593       NeedTrans = IsDevice;
1594       Skip = !IsDevice;
1595     } else if (A->getOption().matches(options::OPT_Xarch_host)) {
1596       NeedTrans = !IsDevice;
1597       Skip = IsDevice;
1598     } else if (A->getOption().matches(options::OPT_Xarch__) && IsDevice) {
1599       // Do not translate -Xarch_ options for non CUDA/HIP toolchain since
1600       // they may need special translation.
1601       // Skip this argument unless the architecture matches BoundArch
1602       if (BoundArch.empty() || A->getValue(0) != BoundArch)
1603         Skip = true;
1604       else
1605         NeedTrans = true;
1606     }
1607     if (NeedTrans || Skip)
1608       Modified = true;
1609     if (NeedTrans)
1610       TranslateXarchArgs(Args, A, DAL, AllocatedArgs);
1611     if (!Skip)
1612       DAL->append(A);
1613   }
1614 
1615   if (Modified)
1616     return DAL;
1617 
1618   delete DAL;
1619   return nullptr;
1620 }
1621