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