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_fcs_profile_generate) ||
409       Args.hasArg(options::OPT_fcs_profile_generate_EQ) ||
410       Args.hasArg(options::OPT_fprofile_instr_generate) ||
411       Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
412       Args.hasArg(options::OPT_fcreate_profile) ||
413       Args.hasArg(options::OPT_forder_file_instrumentation))
414     return true;
415 
416   return false;
417 }
418 
419 bool ToolChain::needsGCovInstrumentation(const llvm::opt::ArgList &Args) {
420   return Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
421                       false) ||
422          Args.hasArg(options::OPT_coverage);
423 }
424 
425 Tool *ToolChain::SelectTool(const JobAction &JA) const {
426   if (getDriver().ShouldUseClangCompiler(JA)) return getClang();
427   Action::ActionClass AC = JA.getKind();
428   if (AC == Action::AssembleJobClass && useIntegratedAs())
429     return getClangAs();
430   return getTool(AC);
431 }
432 
433 std::string ToolChain::GetFilePath(const char *Name) const {
434   return D.GetFilePath(Name, *this);
435 }
436 
437 std::string ToolChain::GetProgramPath(const char *Name) const {
438   return D.GetProgramPath(Name, *this);
439 }
440 
441 std::string ToolChain::GetLinkerPath() const {
442   const Arg* A = Args.getLastArg(options::OPT_fuse_ld_EQ);
443   StringRef UseLinker = A ? A->getValue() : CLANG_DEFAULT_LINKER;
444 
445   if (llvm::sys::path::is_absolute(UseLinker)) {
446     // If we're passed what looks like an absolute path, don't attempt to
447     // second-guess that.
448     if (llvm::sys::fs::can_execute(UseLinker))
449       return UseLinker;
450   } else if (UseLinker.empty() || UseLinker == "ld") {
451     // If we're passed -fuse-ld= with no argument, or with the argument ld,
452     // then use whatever the default system linker is.
453     return GetProgramPath(getDefaultLinker());
454   } else {
455     llvm::SmallString<8> LinkerName;
456     if (Triple.isOSDarwin())
457       LinkerName.append("ld64.");
458     else
459       LinkerName.append("ld.");
460     LinkerName.append(UseLinker);
461 
462     std::string LinkerPath(GetProgramPath(LinkerName.c_str()));
463     if (llvm::sys::fs::can_execute(LinkerPath))
464       return LinkerPath;
465   }
466 
467   if (A)
468     getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
469 
470   return GetProgramPath(getDefaultLinker());
471 }
472 
473 types::ID ToolChain::LookupTypeForExtension(StringRef Ext) const {
474   return types::lookupTypeForExtension(Ext);
475 }
476 
477 bool ToolChain::HasNativeLLVMSupport() const {
478   return false;
479 }
480 
481 bool ToolChain::isCrossCompiling() const {
482   llvm::Triple HostTriple(LLVM_HOST_TRIPLE);
483   switch (HostTriple.getArch()) {
484   // The A32/T32/T16 instruction sets are not separate architectures in this
485   // context.
486   case llvm::Triple::arm:
487   case llvm::Triple::armeb:
488   case llvm::Triple::thumb:
489   case llvm::Triple::thumbeb:
490     return getArch() != llvm::Triple::arm && getArch() != llvm::Triple::thumb &&
491            getArch() != llvm::Triple::armeb && getArch() != llvm::Triple::thumbeb;
492   default:
493     return HostTriple.getArch() != getArch();
494   }
495 }
496 
497 ObjCRuntime ToolChain::getDefaultObjCRuntime(bool isNonFragile) const {
498   return ObjCRuntime(isNonFragile ? ObjCRuntime::GNUstep : ObjCRuntime::GCC,
499                      VersionTuple());
500 }
501 
502 llvm::ExceptionHandling
503 ToolChain::GetExceptionModel(const llvm::opt::ArgList &Args) const {
504   return llvm::ExceptionHandling::None;
505 }
506 
507 bool ToolChain::isThreadModelSupported(const StringRef Model) const {
508   if (Model == "single") {
509     // FIXME: 'single' is only supported on ARM and WebAssembly so far.
510     return Triple.getArch() == llvm::Triple::arm ||
511            Triple.getArch() == llvm::Triple::armeb ||
512            Triple.getArch() == llvm::Triple::thumb ||
513            Triple.getArch() == llvm::Triple::thumbeb ||
514            Triple.getArch() == llvm::Triple::wasm32 ||
515            Triple.getArch() == llvm::Triple::wasm64;
516   } else if (Model == "posix")
517     return true;
518 
519   return false;
520 }
521 
522 std::string ToolChain::ComputeLLVMTriple(const ArgList &Args,
523                                          types::ID InputType) const {
524   switch (getTriple().getArch()) {
525   default:
526     return getTripleString();
527 
528   case llvm::Triple::x86_64: {
529     llvm::Triple Triple = getTriple();
530     if (!Triple.isOSBinFormatMachO())
531       return getTripleString();
532 
533     if (Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
534       // x86_64h goes in the triple. Other -march options just use the
535       // vanilla triple we already have.
536       StringRef MArch = A->getValue();
537       if (MArch == "x86_64h")
538         Triple.setArchName(MArch);
539     }
540     return Triple.getTriple();
541   }
542   case llvm::Triple::aarch64: {
543     llvm::Triple Triple = getTriple();
544     if (!Triple.isOSBinFormatMachO())
545       return getTripleString();
546 
547     // FIXME: older versions of ld64 expect the "arm64" component in the actual
548     // triple string and query it to determine whether an LTO file can be
549     // handled. Remove this when we don't care any more.
550     Triple.setArchName("arm64");
551     return Triple.getTriple();
552   }
553   case llvm::Triple::arm:
554   case llvm::Triple::armeb:
555   case llvm::Triple::thumb:
556   case llvm::Triple::thumbeb: {
557     // FIXME: Factor into subclasses.
558     llvm::Triple Triple = getTriple();
559     bool IsBigEndian = getTriple().getArch() == llvm::Triple::armeb ||
560                        getTriple().getArch() == llvm::Triple::thumbeb;
561 
562     // Handle pseudo-target flags '-mlittle-endian'/'-EL' and
563     // '-mbig-endian'/'-EB'.
564     if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
565                                  options::OPT_mbig_endian)) {
566       IsBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
567     }
568 
569     // Thumb2 is the default for V7 on Darwin.
570     //
571     // FIXME: Thumb should just be another -target-feaure, not in the triple.
572     StringRef MCPU, MArch;
573     if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
574       MCPU = A->getValue();
575     if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
576       MArch = A->getValue();
577     std::string CPU =
578         Triple.isOSBinFormatMachO()
579             ? tools::arm::getARMCPUForMArch(MArch, Triple).str()
580             : tools::arm::getARMTargetCPU(MCPU, MArch, Triple);
581     StringRef Suffix =
582       tools::arm::getLLVMArchSuffixForARM(CPU, MArch, Triple);
583     bool IsMProfile = ARM::parseArchProfile(Suffix) == ARM::ProfileKind::M;
584     bool ThumbDefault = IsMProfile || (ARM::parseArchVersion(Suffix) == 7 &&
585                                        getTriple().isOSBinFormatMachO());
586     // FIXME: this is invalid for WindowsCE
587     if (getTriple().isOSWindows())
588       ThumbDefault = true;
589     std::string ArchName;
590     if (IsBigEndian)
591       ArchName = "armeb";
592     else
593       ArchName = "arm";
594 
595     // Check if ARM ISA was explicitly selected (using -mno-thumb or -marm) for
596     // M-Class CPUs/architecture variants, which is not supported.
597     bool ARMModeRequested = !Args.hasFlag(options::OPT_mthumb,
598                                           options::OPT_mno_thumb, ThumbDefault);
599     if (IsMProfile && ARMModeRequested) {
600       if (!MCPU.empty())
601         getDriver().Diag(diag::err_cpu_unsupported_isa) << CPU << "ARM";
602        else
603         getDriver().Diag(diag::err_arch_unsupported_isa)
604           << tools::arm::getARMArch(MArch, getTriple()) << "ARM";
605     }
606 
607     // Check to see if an explicit choice to use thumb has been made via
608     // -mthumb. For assembler files we must check for -mthumb in the options
609     // passed to the assembler via -Wa or -Xassembler.
610     bool IsThumb = false;
611     if (InputType != types::TY_PP_Asm)
612       IsThumb = Args.hasFlag(options::OPT_mthumb, options::OPT_mno_thumb,
613                               ThumbDefault);
614     else {
615       // Ideally we would check for these flags in
616       // CollectArgsForIntegratedAssembler but we can't change the ArchName at
617       // that point. There is no assembler equivalent of -mno-thumb, -marm, or
618       // -mno-arm.
619       for (const auto *A :
620            Args.filtered(options::OPT_Wa_COMMA, options::OPT_Xassembler)) {
621         for (StringRef Value : A->getValues()) {
622           if (Value == "-mthumb")
623             IsThumb = true;
624         }
625       }
626     }
627     // Assembly files should start in ARM mode, unless arch is M-profile, or
628     // -mthumb has been passed explicitly to the assembler. Windows is always
629     // thumb.
630     if (IsThumb || IsMProfile || getTriple().isOSWindows()) {
631       if (IsBigEndian)
632         ArchName = "thumbeb";
633       else
634         ArchName = "thumb";
635     }
636     Triple.setArchName(ArchName + Suffix.str());
637 
638     return Triple.getTriple();
639   }
640   }
641 }
642 
643 std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args,
644                                                    types::ID InputType) const {
645   return ComputeLLVMTriple(Args, InputType);
646 }
647 
648 void ToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
649                                           ArgStringList &CC1Args) const {
650   // Each toolchain should provide the appropriate include flags.
651 }
652 
653 void ToolChain::addClangTargetOptions(
654     const ArgList &DriverArgs, ArgStringList &CC1Args,
655     Action::OffloadKind DeviceOffloadKind) const {}
656 
657 void ToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {}
658 
659 void ToolChain::addProfileRTLibs(const llvm::opt::ArgList &Args,
660                                  llvm::opt::ArgStringList &CmdArgs) const {
661   if (!needsProfileRT(Args)) return;
662 
663   CmdArgs.push_back(getCompilerRTArgString(Args, "profile"));
664 }
665 
666 ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
667     const ArgList &Args) const {
668   const Arg* A = Args.getLastArg(options::OPT_rtlib_EQ);
669   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_RTLIB;
670 
671   // Only use "platform" in tests to override CLANG_DEFAULT_RTLIB!
672   if (LibName == "compiler-rt")
673     return ToolChain::RLT_CompilerRT;
674   else if (LibName == "libgcc")
675     return ToolChain::RLT_Libgcc;
676   else if (LibName == "platform")
677     return GetDefaultRuntimeLibType();
678 
679   if (A)
680     getDriver().Diag(diag::err_drv_invalid_rtlib_name) << A->getAsString(Args);
681 
682   return GetDefaultRuntimeLibType();
683 }
684 
685 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
686   const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
687   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_CXX_STDLIB;
688 
689   // Only use "platform" in tests to override CLANG_DEFAULT_CXX_STDLIB!
690   if (LibName == "libc++")
691     return ToolChain::CST_Libcxx;
692   else if (LibName == "libstdc++")
693     return ToolChain::CST_Libstdcxx;
694   else if (LibName == "platform")
695     return GetDefaultCXXStdlibType();
696 
697   if (A)
698     getDriver().Diag(diag::err_drv_invalid_stdlib_name) << A->getAsString(Args);
699 
700   return GetDefaultCXXStdlibType();
701 }
702 
703 /// Utility function to add a system include directory to CC1 arguments.
704 /*static*/ void ToolChain::addSystemInclude(const ArgList &DriverArgs,
705                                             ArgStringList &CC1Args,
706                                             const Twine &Path) {
707   CC1Args.push_back("-internal-isystem");
708   CC1Args.push_back(DriverArgs.MakeArgString(Path));
709 }
710 
711 /// Utility function to add a system include directory with extern "C"
712 /// semantics to CC1 arguments.
713 ///
714 /// Note that this should be used rarely, and only for directories that
715 /// historically and for legacy reasons are treated as having implicit extern
716 /// "C" semantics. These semantics are *ignored* by and large today, but its
717 /// important to preserve the preprocessor changes resulting from the
718 /// classification.
719 /*static*/ void ToolChain::addExternCSystemInclude(const ArgList &DriverArgs,
720                                                    ArgStringList &CC1Args,
721                                                    const Twine &Path) {
722   CC1Args.push_back("-internal-externc-isystem");
723   CC1Args.push_back(DriverArgs.MakeArgString(Path));
724 }
725 
726 void ToolChain::addExternCSystemIncludeIfExists(const ArgList &DriverArgs,
727                                                 ArgStringList &CC1Args,
728                                                 const Twine &Path) {
729   if (llvm::sys::fs::exists(Path))
730     addExternCSystemInclude(DriverArgs, CC1Args, Path);
731 }
732 
733 /// Utility function to add a list of system include directories to CC1.
734 /*static*/ void ToolChain::addSystemIncludes(const ArgList &DriverArgs,
735                                              ArgStringList &CC1Args,
736                                              ArrayRef<StringRef> Paths) {
737   for (const auto Path : Paths) {
738     CC1Args.push_back("-internal-isystem");
739     CC1Args.push_back(DriverArgs.MakeArgString(Path));
740   }
741 }
742 
743 void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
744                                              ArgStringList &CC1Args) const {
745   // Header search paths should be handled by each of the subclasses.
746   // Historically, they have not been, and instead have been handled inside of
747   // the CC1-layer frontend. As the logic is hoisted out, this generic function
748   // will slowly stop being called.
749   //
750   // While it is being called, replicate a bit of a hack to propagate the
751   // '-stdlib=' flag down to CC1 so that it can in turn customize the C++
752   // header search paths with it. Once all systems are overriding this
753   // function, the CC1 flag and this line can be removed.
754   DriverArgs.AddAllArgs(CC1Args, options::OPT_stdlib_EQ);
755 }
756 
757 bool ToolChain::ShouldLinkCXXStdlib(const llvm::opt::ArgList &Args) const {
758   return getDriver().CCCIsCXX() &&
759          !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
760                       options::OPT_nostdlibxx);
761 }
762 
763 void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
764                                     ArgStringList &CmdArgs) const {
765   assert(!Args.hasArg(options::OPT_nostdlibxx) &&
766          "should not have called this");
767   CXXStdlibType Type = GetCXXStdlibType(Args);
768 
769   switch (Type) {
770   case ToolChain::CST_Libcxx:
771     CmdArgs.push_back("-lc++");
772     break;
773 
774   case ToolChain::CST_Libstdcxx:
775     CmdArgs.push_back("-lstdc++");
776     break;
777   }
778 }
779 
780 void ToolChain::AddFilePathLibArgs(const ArgList &Args,
781                                    ArgStringList &CmdArgs) const {
782   for (const auto &LibPath : getLibraryPaths())
783     if(LibPath.length() > 0)
784       CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
785 
786   for (const auto &LibPath : getFilePaths())
787     if(LibPath.length() > 0)
788       CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
789 }
790 
791 void ToolChain::AddCCKextLibArgs(const ArgList &Args,
792                                  ArgStringList &CmdArgs) const {
793   CmdArgs.push_back("-lcc_kext");
794 }
795 
796 bool ToolChain::AddFastMathRuntimeIfAvailable(const ArgList &Args,
797                                               ArgStringList &CmdArgs) const {
798   // Do not check for -fno-fast-math or -fno-unsafe-math when -Ofast passed
799   // (to keep the linker options consistent with gcc and clang itself).
800   if (!isOptimizationLevelFast(Args)) {
801     // Check if -ffast-math or -funsafe-math.
802     Arg *A =
803         Args.getLastArg(options::OPT_ffast_math, options::OPT_fno_fast_math,
804                         options::OPT_funsafe_math_optimizations,
805                         options::OPT_fno_unsafe_math_optimizations);
806 
807     if (!A || A->getOption().getID() == options::OPT_fno_fast_math ||
808         A->getOption().getID() == options::OPT_fno_unsafe_math_optimizations)
809       return false;
810   }
811   // If crtfastmath.o exists add it to the arguments.
812   std::string Path = GetFilePath("crtfastmath.o");
813   if (Path == "crtfastmath.o") // Not found.
814     return false;
815 
816   CmdArgs.push_back(Args.MakeArgString(Path));
817   return true;
818 }
819 
820 SanitizerMask ToolChain::getSupportedSanitizers() const {
821   // Return sanitizers which don't require runtime support and are not
822   // platform dependent.
823 
824   SanitizerMask Res = (SanitizerKind::Undefined & ~SanitizerKind::Vptr &
825                        ~SanitizerKind::Function) |
826                       (SanitizerKind::CFI & ~SanitizerKind::CFIICall) |
827                       SanitizerKind::CFICastStrict |
828                       SanitizerKind::UnsignedIntegerOverflow |
829                       SanitizerKind::ImplicitConversion |
830                       SanitizerKind::Nullability | SanitizerKind::LocalBounds;
831   if (getTriple().getArch() == llvm::Triple::x86 ||
832       getTriple().getArch() == llvm::Triple::x86_64 ||
833       getTriple().getArch() == llvm::Triple::arm ||
834       getTriple().getArch() == llvm::Triple::aarch64 ||
835       getTriple().getArch() == llvm::Triple::wasm32 ||
836       getTriple().getArch() == llvm::Triple::wasm64)
837     Res |= SanitizerKind::CFIICall;
838   if (getTriple().getArch() == llvm::Triple::x86_64 ||
839       getTriple().getArch() == llvm::Triple::aarch64)
840     Res |= SanitizerKind::ShadowCallStack;
841   return Res;
842 }
843 
844 void ToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
845                                    ArgStringList &CC1Args) const {}
846 
847 void ToolChain::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
848                                     ArgStringList &CC1Args) const {}
849 
850 static VersionTuple separateMSVCFullVersion(unsigned Version) {
851   if (Version < 100)
852     return VersionTuple(Version);
853 
854   if (Version < 10000)
855     return VersionTuple(Version / 100, Version % 100);
856 
857   unsigned Build = 0, Factor = 1;
858   for (; Version > 10000; Version = Version / 10, Factor = Factor * 10)
859     Build = Build + (Version % 10) * Factor;
860   return VersionTuple(Version / 100, Version % 100, Build);
861 }
862 
863 VersionTuple
864 ToolChain::computeMSVCVersion(const Driver *D,
865                               const llvm::opt::ArgList &Args) const {
866   const Arg *MSCVersion = Args.getLastArg(options::OPT_fmsc_version);
867   const Arg *MSCompatibilityVersion =
868       Args.getLastArg(options::OPT_fms_compatibility_version);
869 
870   if (MSCVersion && MSCompatibilityVersion) {
871     if (D)
872       D->Diag(diag::err_drv_argument_not_allowed_with)
873           << MSCVersion->getAsString(Args)
874           << MSCompatibilityVersion->getAsString(Args);
875     return VersionTuple();
876   }
877 
878   if (MSCompatibilityVersion) {
879     VersionTuple MSVT;
880     if (MSVT.tryParse(MSCompatibilityVersion->getValue())) {
881       if (D)
882         D->Diag(diag::err_drv_invalid_value)
883             << MSCompatibilityVersion->getAsString(Args)
884             << MSCompatibilityVersion->getValue();
885     } else {
886       return MSVT;
887     }
888   }
889 
890   if (MSCVersion) {
891     unsigned Version = 0;
892     if (StringRef(MSCVersion->getValue()).getAsInteger(10, Version)) {
893       if (D)
894         D->Diag(diag::err_drv_invalid_value)
895             << MSCVersion->getAsString(Args) << MSCVersion->getValue();
896     } else {
897       return separateMSVCFullVersion(Version);
898     }
899   }
900 
901   return VersionTuple();
902 }
903 
904 llvm::opt::DerivedArgList *ToolChain::TranslateOpenMPTargetArgs(
905     const llvm::opt::DerivedArgList &Args, bool SameTripleAsHost,
906     SmallVectorImpl<llvm::opt::Arg *> &AllocatedArgs) const {
907   DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
908   const OptTable &Opts = getDriver().getOpts();
909   bool Modified = false;
910 
911   // Handle -Xopenmp-target flags
912   for (auto *A : Args) {
913     // Exclude flags which may only apply to the host toolchain.
914     // Do not exclude flags when the host triple (AuxTriple)
915     // matches the current toolchain triple. If it is not present
916     // at all, target and host share a toolchain.
917     if (A->getOption().matches(options::OPT_m_Group)) {
918       if (SameTripleAsHost)
919         DAL->append(A);
920       else
921         Modified = true;
922       continue;
923     }
924 
925     unsigned Index;
926     unsigned Prev;
927     bool XOpenMPTargetNoTriple =
928         A->getOption().matches(options::OPT_Xopenmp_target);
929 
930     if (A->getOption().matches(options::OPT_Xopenmp_target_EQ)) {
931       // Passing device args: -Xopenmp-target=<triple> -opt=val.
932       if (A->getValue(0) == getTripleString())
933         Index = Args.getBaseArgs().MakeIndex(A->getValue(1));
934       else
935         continue;
936     } else if (XOpenMPTargetNoTriple) {
937       // Passing device args: -Xopenmp-target -opt=val.
938       Index = Args.getBaseArgs().MakeIndex(A->getValue(0));
939     } else {
940       DAL->append(A);
941       continue;
942     }
943 
944     // Parse the argument to -Xopenmp-target.
945     Prev = Index;
946     std::unique_ptr<Arg> XOpenMPTargetArg(Opts.ParseOneArg(Args, Index));
947     if (!XOpenMPTargetArg || Index > Prev + 1) {
948       getDriver().Diag(diag::err_drv_invalid_Xopenmp_target_with_args)
949           << A->getAsString(Args);
950       continue;
951     }
952     if (XOpenMPTargetNoTriple && XOpenMPTargetArg &&
953         Args.getAllArgValues(options::OPT_fopenmp_targets_EQ).size() != 1) {
954       getDriver().Diag(diag::err_drv_Xopenmp_target_missing_triple);
955       continue;
956     }
957     XOpenMPTargetArg->setBaseArg(A);
958     A = XOpenMPTargetArg.release();
959     AllocatedArgs.push_back(A);
960     DAL->append(A);
961     Modified = true;
962   }
963 
964   if (Modified)
965     return DAL;
966 
967   delete DAL;
968   return nullptr;
969 }
970