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