1 //===--- ToolChain.cpp - Collections of tools for one platform ------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "clang/Driver/ToolChain.h"
11 #include "ToolChains/CommonArgs.h"
12 #include "ToolChains/Arch/ARM.h"
13 #include "ToolChains/Clang.h"
14 #include "clang/Basic/ObjCRuntime.h"
15 #include "clang/Basic/VirtualFileSystem.h"
16 #include "clang/Config/config.h"
17 #include "clang/Driver/Action.h"
18 #include "clang/Driver/Driver.h"
19 #include "clang/Driver/DriverDiagnostic.h"
20 #include "clang/Driver/Options.h"
21 #include "clang/Driver/SanitizerArgs.h"
22 #include "clang/Driver/XRayArgs.h"
23 #include "llvm/ADT/SmallString.h"
24 #include "llvm/Option/Arg.h"
25 #include "llvm/Option/ArgList.h"
26 #include "llvm/Option/Option.h"
27 #include "llvm/Support/ErrorHandling.h"
28 #include "llvm/Support/FileSystem.h"
29 #include "llvm/Support/Path.h"
30 #include "llvm/Support/TargetParser.h"
31 #include "llvm/Support/TargetRegistry.h"
32 
33 using namespace clang::driver;
34 using namespace clang::driver::tools;
35 using namespace clang;
36 using namespace llvm;
37 using namespace llvm::opt;
38 
39 static llvm::opt::Arg *GetRTTIArgument(const ArgList &Args) {
40   return Args.getLastArg(options::OPT_mkernel, options::OPT_fapple_kext,
41                          options::OPT_fno_rtti, options::OPT_frtti);
42 }
43 
44 static ToolChain::RTTIMode CalculateRTTIMode(const ArgList &Args,
45                                              const llvm::Triple &Triple,
46                                              const Arg *CachedRTTIArg) {
47   // Explicit rtti/no-rtti args
48   if (CachedRTTIArg) {
49     if (CachedRTTIArg->getOption().matches(options::OPT_frtti))
50       return ToolChain::RM_EnabledExplicitly;
51     else
52       return ToolChain::RM_DisabledExplicitly;
53   }
54 
55   // -frtti is default, except for the PS4 CPU.
56   if (!Triple.isPS4CPU())
57     return ToolChain::RM_EnabledImplicitly;
58 
59   // On the PS4, turning on c++ exceptions turns on rtti.
60   // We're assuming that, if we see -fexceptions, rtti gets turned on.
61   Arg *Exceptions = Args.getLastArgNoClaim(
62       options::OPT_fcxx_exceptions, options::OPT_fno_cxx_exceptions,
63       options::OPT_fexceptions, options::OPT_fno_exceptions);
64   if (Exceptions &&
65       (Exceptions->getOption().matches(options::OPT_fexceptions) ||
66        Exceptions->getOption().matches(options::OPT_fcxx_exceptions)))
67     return ToolChain::RM_EnabledImplicitly;
68 
69   return ToolChain::RM_DisabledImplicitly;
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       EffectiveTriple() {
77   if (Arg *A = Args.getLastArg(options::OPT_mthread_model))
78     if (!isThreadModelSupported(A->getValue()))
79       D.Diag(diag::err_drv_invalid_thread_model_for_target)
80           << A->getValue() << A->getAsString(Args);
81 
82   std::string CandidateLibPath = getArchSpecificLibPath();
83   if (getVFS().exists(CandidateLibPath))
84     getFilePaths().push_back(CandidateLibPath);
85 }
86 
87 ToolChain::~ToolChain() {
88 }
89 
90 vfs::FileSystem &ToolChain::getVFS() const { return getDriver().getVFS(); }
91 
92 bool ToolChain::useIntegratedAs() const {
93   return Args.hasFlag(options::OPT_fintegrated_as,
94                       options::OPT_fno_integrated_as,
95                       IsIntegratedAssemblerDefault());
96 }
97 
98 const SanitizerArgs& ToolChain::getSanitizerArgs() const {
99   if (!SanitizerArguments.get())
100     SanitizerArguments.reset(new SanitizerArgs(*this, Args));
101   return *SanitizerArguments.get();
102 }
103 
104 const XRayArgs& ToolChain::getXRayArgs() const {
105   if (!XRayArguments.get())
106     XRayArguments.reset(new XRayArgs(*this, Args));
107   return *XRayArguments.get();
108 }
109 
110 namespace {
111 struct DriverSuffix {
112   const char *Suffix;
113   const char *ModeFlag;
114 };
115 
116 const DriverSuffix *FindDriverSuffix(StringRef ProgName) {
117   // A list of known driver suffixes. Suffixes are compared against the
118   // program name in order. If there is a match, the frontend type is updated as
119   // necessary by applying the ModeFlag.
120   static const DriverSuffix DriverSuffixes[] = {
121       {"clang", nullptr},
122       {"clang++", "--driver-mode=g++"},
123       {"clang-c++", "--driver-mode=g++"},
124       {"clang-cc", nullptr},
125       {"clang-cpp", "--driver-mode=cpp"},
126       {"clang-g++", "--driver-mode=g++"},
127       {"clang-gcc", nullptr},
128       {"clang-cl", "--driver-mode=cl"},
129       {"cc", nullptr},
130       {"cpp", "--driver-mode=cpp"},
131       {"cl", "--driver-mode=cl"},
132       {"++", "--driver-mode=g++"},
133   };
134 
135   for (size_t i = 0; i < llvm::array_lengthof(DriverSuffixes); ++i)
136     if (ProgName.endswith(DriverSuffixes[i].Suffix))
137       return &DriverSuffixes[i];
138   return nullptr;
139 }
140 
141 /// Normalize the program name from argv[0] by stripping the file extension if
142 /// present and lower-casing the string on Windows.
143 std::string normalizeProgramName(llvm::StringRef Argv0) {
144   std::string ProgName = llvm::sys::path::stem(Argv0);
145 #ifdef LLVM_ON_WIN32
146   // Transform to lowercase for case insensitive file systems.
147   std::transform(ProgName.begin(), ProgName.end(), ProgName.begin(), ::tolower);
148 #endif
149   return ProgName;
150 }
151 
152 const DriverSuffix *parseDriverSuffix(StringRef ProgName) {
153   // Try to infer frontend type and default target from the program name by
154   // comparing it against DriverSuffixes in order.
155 
156   // If there is a match, the function tries to identify a target as prefix.
157   // E.g. "x86_64-linux-clang" as interpreted as suffix "clang" with target
158   // prefix "x86_64-linux". If such a target prefix is found, it may be
159   // added via -target as implicit first argument.
160   const DriverSuffix *DS = FindDriverSuffix(ProgName);
161 
162   if (!DS) {
163     // Try again after stripping any trailing version number:
164     // clang++3.5 -> clang++
165     ProgName = ProgName.rtrim("0123456789.");
166     DS = FindDriverSuffix(ProgName);
167   }
168 
169   if (!DS) {
170     // Try again after stripping trailing -component.
171     // clang++-tot -> clang++
172     ProgName = ProgName.slice(0, ProgName.rfind('-'));
173     DS = FindDriverSuffix(ProgName);
174   }
175   return DS;
176 }
177 } // anonymous namespace
178 
179 std::pair<std::string, std::string>
180 ToolChain::getTargetAndModeFromProgramName(StringRef PN) {
181   std::string ProgName = normalizeProgramName(PN);
182   const DriverSuffix *DS = parseDriverSuffix(ProgName);
183   if (!DS)
184     return std::make_pair("", "");
185   std::string ModeFlag = DS->ModeFlag == nullptr ? "" : DS->ModeFlag;
186 
187   std::string::size_type LastComponent =
188       ProgName.rfind('-', ProgName.size() - strlen(DS->Suffix));
189   if (LastComponent == std::string::npos)
190     return std::make_pair("", ModeFlag);
191 
192   // Infer target from the prefix.
193   StringRef Prefix(ProgName);
194   Prefix = Prefix.slice(0, LastComponent);
195   std::string IgnoredError;
196   std::string Target;
197   if (llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError)) {
198     Target = Prefix;
199   }
200   return std::make_pair(Target, ModeFlag);
201 }
202 
203 StringRef ToolChain::getDefaultUniversalArchName() const {
204   // In universal driver terms, the arch name accepted by -arch isn't exactly
205   // the same as the ones that appear in the triple. Roughly speaking, this is
206   // an inverse of the darwin::getArchTypeForDarwinArchName() function, but the
207   // only interesting special case is powerpc.
208   switch (Triple.getArch()) {
209   case llvm::Triple::ppc:
210     return "ppc";
211   case llvm::Triple::ppc64:
212     return "ppc64";
213   case llvm::Triple::ppc64le:
214     return "ppc64le";
215   default:
216     return Triple.getArchName();
217   }
218 }
219 
220 bool ToolChain::IsUnwindTablesDefault(const ArgList &Args) const {
221   return false;
222 }
223 
224 Tool *ToolChain::getClang() const {
225   if (!Clang)
226     Clang.reset(new tools::Clang(*this));
227   return Clang.get();
228 }
229 
230 Tool *ToolChain::buildAssembler() const {
231   return new tools::ClangAs(*this);
232 }
233 
234 Tool *ToolChain::buildLinker() const {
235   llvm_unreachable("Linking is not supported by this toolchain");
236 }
237 
238 Tool *ToolChain::getAssemble() const {
239   if (!Assemble)
240     Assemble.reset(buildAssembler());
241   return Assemble.get();
242 }
243 
244 Tool *ToolChain::getClangAs() const {
245   if (!Assemble)
246     Assemble.reset(new tools::ClangAs(*this));
247   return Assemble.get();
248 }
249 
250 Tool *ToolChain::getLink() const {
251   if (!Link)
252     Link.reset(buildLinker());
253   return Link.get();
254 }
255 
256 Tool *ToolChain::getOffloadBundler() const {
257   if (!OffloadBundler)
258     OffloadBundler.reset(new tools::OffloadBundler(*this));
259   return OffloadBundler.get();
260 }
261 
262 Tool *ToolChain::getTool(Action::ActionClass AC) const {
263   switch (AC) {
264   case Action::AssembleJobClass:
265     return getAssemble();
266 
267   case Action::LinkJobClass:
268     return getLink();
269 
270   case Action::InputClass:
271   case Action::BindArchClass:
272   case Action::OffloadClass:
273   case Action::LipoJobClass:
274   case Action::DsymutilJobClass:
275   case Action::VerifyDebugInfoJobClass:
276     llvm_unreachable("Invalid tool kind.");
277 
278   case Action::CompileJobClass:
279   case Action::PrecompileJobClass:
280   case Action::PreprocessJobClass:
281   case Action::AnalyzeJobClass:
282   case Action::MigrateJobClass:
283   case Action::VerifyPCHJobClass:
284   case Action::BackendJobClass:
285     return getClang();
286 
287   case Action::OffloadBundlingJobClass:
288   case Action::OffloadUnbundlingJobClass:
289     return getOffloadBundler();
290   }
291 
292   llvm_unreachable("Invalid tool kind.");
293 }
294 
295 static StringRef getArchNameForCompilerRTLib(const ToolChain &TC,
296                                              const ArgList &Args) {
297   const llvm::Triple &Triple = TC.getTriple();
298   bool IsWindows = Triple.isOSWindows();
299 
300   if (Triple.isWindowsMSVCEnvironment() && TC.getArch() == llvm::Triple::x86)
301     return "i386";
302 
303   if (TC.getArch() == llvm::Triple::arm || TC.getArch() == llvm::Triple::armeb)
304     return (arm::getARMFloatABI(TC, Args) == arm::FloatABI::Hard && !IsWindows)
305                ? "armhf"
306                : "arm";
307 
308   return TC.getArchName();
309 }
310 
311 std::string ToolChain::getCompilerRTPath() const {
312   SmallString<128> Path(getDriver().ResourceDir);
313   StringRef OSLibName = Triple.isOSFreeBSD() ? "freebsd" : getOS();
314   llvm::sys::path::append(Path, "lib", OSLibName);
315   return Path.str();
316 }
317 
318 std::string ToolChain::getCompilerRT(const ArgList &Args, StringRef Component,
319                                      bool Shared) const {
320   const llvm::Triple &TT = getTriple();
321   const char *Env = TT.isAndroid() ? "-android" : "";
322   bool IsITANMSVCWindows =
323       TT.isWindowsMSVCEnvironment() || TT.isWindowsItaniumEnvironment();
324 
325   StringRef Arch = getArchNameForCompilerRTLib(*this, Args);
326   const char *Prefix = IsITANMSVCWindows ? "" : "lib";
327   const char *Suffix = Shared ? (Triple.isOSWindows() ? ".dll" : ".so")
328                               : (IsITANMSVCWindows ? ".lib" : ".a");
329 
330   SmallString<128> Path(getCompilerRTPath());
331   llvm::sys::path::append(Path, Prefix + Twine("clang_rt.") + Component + "-" +
332                                     Arch + Env + Suffix);
333   return Path.str();
334 }
335 
336 const char *ToolChain::getCompilerRTArgString(const llvm::opt::ArgList &Args,
337                                               StringRef Component,
338                                               bool Shared) const {
339   return Args.MakeArgString(getCompilerRT(Args, Component, Shared));
340 }
341 
342 std::string ToolChain::getArchSpecificLibPath() const {
343   SmallString<128> Path(getDriver().ResourceDir);
344   StringRef OSLibName = getTriple().isOSFreeBSD() ? "freebsd" : getOS();
345   llvm::sys::path::append(Path, "lib", OSLibName,
346                           llvm::Triple::getArchTypeName(getArch()));
347   return Path.str();
348 }
349 
350 bool ToolChain::needsProfileRT(const ArgList &Args) {
351   if (Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
352                    false) ||
353       Args.hasArg(options::OPT_fprofile_generate) ||
354       Args.hasArg(options::OPT_fprofile_generate_EQ) ||
355       Args.hasArg(options::OPT_fprofile_instr_generate) ||
356       Args.hasArg(options::OPT_fprofile_instr_generate_EQ) ||
357       Args.hasArg(options::OPT_fcreate_profile) ||
358       Args.hasArg(options::OPT_coverage))
359     return true;
360 
361   return false;
362 }
363 
364 Tool *ToolChain::SelectTool(const JobAction &JA) const {
365   if (getDriver().ShouldUseClangCompiler(JA)) return getClang();
366   Action::ActionClass AC = JA.getKind();
367   if (AC == Action::AssembleJobClass && useIntegratedAs())
368     return getClangAs();
369   return getTool(AC);
370 }
371 
372 std::string ToolChain::GetFilePath(const char *Name) const {
373   return D.GetFilePath(Name, *this);
374 }
375 
376 std::string ToolChain::GetProgramPath(const char *Name) const {
377   return D.GetProgramPath(Name, *this);
378 }
379 
380 std::string ToolChain::GetLinkerPath() const {
381   const Arg* A = Args.getLastArg(options::OPT_fuse_ld_EQ);
382   StringRef UseLinker = A ? A->getValue() : CLANG_DEFAULT_LINKER;
383 
384   if (llvm::sys::path::is_absolute(UseLinker)) {
385     // If we're passed what looks like an absolute path, don't attempt to
386     // second-guess that.
387     if (llvm::sys::fs::exists(UseLinker))
388       return UseLinker;
389   } else if (UseLinker.empty() || UseLinker == "ld") {
390     // If we're passed -fuse-ld= with no argument, or with the argument ld,
391     // then use whatever the default system linker is.
392     return GetProgramPath(getDefaultLinker());
393   } else {
394     llvm::SmallString<8> LinkerName("ld.");
395     LinkerName.append(UseLinker);
396 
397     std::string LinkerPath(GetProgramPath(LinkerName.c_str()));
398     if (llvm::sys::fs::exists(LinkerPath))
399       return LinkerPath;
400   }
401 
402   if (A)
403     getDriver().Diag(diag::err_drv_invalid_linker_name) << A->getAsString(Args);
404 
405   return GetProgramPath(getDefaultLinker());
406 }
407 
408 types::ID ToolChain::LookupTypeForExtension(StringRef Ext) const {
409   return types::lookupTypeForExtension(Ext);
410 }
411 
412 bool ToolChain::HasNativeLLVMSupport() const {
413   return false;
414 }
415 
416 bool ToolChain::isCrossCompiling() const {
417   llvm::Triple HostTriple(LLVM_HOST_TRIPLE);
418   switch (HostTriple.getArch()) {
419   // The A32/T32/T16 instruction sets are not separate architectures in this
420   // context.
421   case llvm::Triple::arm:
422   case llvm::Triple::armeb:
423   case llvm::Triple::thumb:
424   case llvm::Triple::thumbeb:
425     return getArch() != llvm::Triple::arm && getArch() != llvm::Triple::thumb &&
426            getArch() != llvm::Triple::armeb && getArch() != llvm::Triple::thumbeb;
427   default:
428     return HostTriple.getArch() != getArch();
429   }
430 }
431 
432 ObjCRuntime ToolChain::getDefaultObjCRuntime(bool isNonFragile) const {
433   return ObjCRuntime(isNonFragile ? ObjCRuntime::GNUstep : ObjCRuntime::GCC,
434                      VersionTuple());
435 }
436 
437 bool ToolChain::isThreadModelSupported(const StringRef Model) const {
438   if (Model == "single") {
439     // FIXME: 'single' is only supported on ARM and WebAssembly so far.
440     return Triple.getArch() == llvm::Triple::arm ||
441            Triple.getArch() == llvm::Triple::armeb ||
442            Triple.getArch() == llvm::Triple::thumb ||
443            Triple.getArch() == llvm::Triple::thumbeb ||
444            Triple.getArch() == llvm::Triple::wasm32 ||
445            Triple.getArch() == llvm::Triple::wasm64;
446   } else if (Model == "posix")
447     return true;
448 
449   return false;
450 }
451 
452 std::string ToolChain::ComputeLLVMTriple(const ArgList &Args,
453                                          types::ID InputType) const {
454   switch (getTriple().getArch()) {
455   default:
456     return getTripleString();
457 
458   case llvm::Triple::x86_64: {
459     llvm::Triple Triple = getTriple();
460     if (!Triple.isOSBinFormatMachO())
461       return getTripleString();
462 
463     if (Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
464       // x86_64h goes in the triple. Other -march options just use the
465       // vanilla triple we already have.
466       StringRef MArch = A->getValue();
467       if (MArch == "x86_64h")
468         Triple.setArchName(MArch);
469     }
470     return Triple.getTriple();
471   }
472   case llvm::Triple::aarch64: {
473     llvm::Triple Triple = getTriple();
474     if (!Triple.isOSBinFormatMachO())
475       return getTripleString();
476 
477     // FIXME: older versions of ld64 expect the "arm64" component in the actual
478     // triple string and query it to determine whether an LTO file can be
479     // handled. Remove this when we don't care any more.
480     Triple.setArchName("arm64");
481     return Triple.getTriple();
482   }
483   case llvm::Triple::arm:
484   case llvm::Triple::armeb:
485   case llvm::Triple::thumb:
486   case llvm::Triple::thumbeb: {
487     // FIXME: Factor into subclasses.
488     llvm::Triple Triple = getTriple();
489     bool IsBigEndian = getTriple().getArch() == llvm::Triple::armeb ||
490                        getTriple().getArch() == llvm::Triple::thumbeb;
491 
492     // Handle pseudo-target flags '-mlittle-endian'/'-EL' and
493     // '-mbig-endian'/'-EB'.
494     if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
495                                  options::OPT_mbig_endian)) {
496       IsBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
497     }
498 
499     // Thumb2 is the default for V7 on Darwin.
500     //
501     // FIXME: Thumb should just be another -target-feaure, not in the triple.
502     StringRef MCPU, MArch;
503     if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
504       MCPU = A->getValue();
505     if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
506       MArch = A->getValue();
507     std::string CPU =
508         Triple.isOSBinFormatMachO()
509             ? tools::arm::getARMCPUForMArch(MArch, Triple).str()
510             : tools::arm::getARMTargetCPU(MCPU, MArch, Triple);
511     StringRef Suffix =
512       tools::arm::getLLVMArchSuffixForARM(CPU, MArch, Triple);
513     bool IsMProfile = ARM::parseArchProfile(Suffix) == ARM::ProfileKind::M;
514     bool ThumbDefault = IsMProfile || (ARM::parseArchVersion(Suffix) == 7 &&
515                                        getTriple().isOSBinFormatMachO());
516     // FIXME: this is invalid for WindowsCE
517     if (getTriple().isOSWindows())
518       ThumbDefault = true;
519     std::string ArchName;
520     if (IsBigEndian)
521       ArchName = "armeb";
522     else
523       ArchName = "arm";
524 
525     // Check if ARM ISA was explicitly selected (using -mno-thumb or -marm) for
526     // M-Class CPUs/architecture variants, which is not supported.
527     bool ARMModeRequested = !Args.hasFlag(options::OPT_mthumb,
528                                           options::OPT_mno_thumb, ThumbDefault);
529     if (IsMProfile && ARMModeRequested) {
530       if (!MCPU.empty())
531         getDriver().Diag(diag::err_cpu_unsupported_isa) << CPU << "ARM";
532        else
533         getDriver().Diag(diag::err_arch_unsupported_isa)
534           << tools::arm::getARMArch(MArch, getTriple()) << "ARM";
535     }
536 
537     // Assembly files should start in ARM mode, unless arch is M-profile.
538     // Windows is always thumb.
539     if ((InputType != types::TY_PP_Asm && Args.hasFlag(options::OPT_mthumb,
540          options::OPT_mno_thumb, ThumbDefault)) || IsMProfile ||
541          getTriple().isOSWindows()) {
542       if (IsBigEndian)
543         ArchName = "thumbeb";
544       else
545         ArchName = "thumb";
546     }
547     Triple.setArchName(ArchName + Suffix.str());
548 
549     return Triple.getTriple();
550   }
551   }
552 }
553 
554 std::string ToolChain::ComputeEffectiveClangTriple(const ArgList &Args,
555                                                    types::ID InputType) const {
556   return ComputeLLVMTriple(Args, InputType);
557 }
558 
559 void ToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
560                                           ArgStringList &CC1Args) const {
561   // Each toolchain should provide the appropriate include flags.
562 }
563 
564 void ToolChain::addClangTargetOptions(
565     const ArgList &DriverArgs, ArgStringList &CC1Args,
566     Action::OffloadKind DeviceOffloadKind) const {}
567 
568 void ToolChain::addClangWarningOptions(ArgStringList &CC1Args) const {}
569 
570 void ToolChain::addProfileRTLibs(const llvm::opt::ArgList &Args,
571                                  llvm::opt::ArgStringList &CmdArgs) const {
572   if (!needsProfileRT(Args)) return;
573 
574   CmdArgs.push_back(getCompilerRTArgString(Args, "profile"));
575 }
576 
577 ToolChain::RuntimeLibType ToolChain::GetRuntimeLibType(
578     const ArgList &Args) const {
579   const Arg* A = Args.getLastArg(options::OPT_rtlib_EQ);
580   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_RTLIB;
581 
582   // Only use "platform" in tests to override CLANG_DEFAULT_RTLIB!
583   if (LibName == "compiler-rt")
584     return ToolChain::RLT_CompilerRT;
585   else if (LibName == "libgcc")
586     return ToolChain::RLT_Libgcc;
587   else if (LibName == "platform")
588     return GetDefaultRuntimeLibType();
589 
590   if (A)
591     getDriver().Diag(diag::err_drv_invalid_rtlib_name) << A->getAsString(Args);
592 
593   return GetDefaultRuntimeLibType();
594 }
595 
596 ToolChain::CXXStdlibType ToolChain::GetCXXStdlibType(const ArgList &Args) const{
597   const Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
598   StringRef LibName = A ? A->getValue() : CLANG_DEFAULT_CXX_STDLIB;
599 
600   // Only use "platform" in tests to override CLANG_DEFAULT_CXX_STDLIB!
601   if (LibName == "libc++")
602     return ToolChain::CST_Libcxx;
603   else if (LibName == "libstdc++")
604     return ToolChain::CST_Libstdcxx;
605   else if (LibName == "platform")
606     return GetDefaultCXXStdlibType();
607 
608   if (A)
609     getDriver().Diag(diag::err_drv_invalid_stdlib_name) << A->getAsString(Args);
610 
611   return GetDefaultCXXStdlibType();
612 }
613 
614 /// \brief Utility function to add a system include directory to CC1 arguments.
615 /*static*/ void ToolChain::addSystemInclude(const ArgList &DriverArgs,
616                                             ArgStringList &CC1Args,
617                                             const Twine &Path) {
618   CC1Args.push_back("-internal-isystem");
619   CC1Args.push_back(DriverArgs.MakeArgString(Path));
620 }
621 
622 /// \brief Utility function to add a system include directory with extern "C"
623 /// semantics to CC1 arguments.
624 ///
625 /// Note that this should be used rarely, and only for directories that
626 /// historically and for legacy reasons are treated as having implicit extern
627 /// "C" semantics. These semantics are *ignored* by and large today, but its
628 /// important to preserve the preprocessor changes resulting from the
629 /// classification.
630 /*static*/ void ToolChain::addExternCSystemInclude(const ArgList &DriverArgs,
631                                                    ArgStringList &CC1Args,
632                                                    const Twine &Path) {
633   CC1Args.push_back("-internal-externc-isystem");
634   CC1Args.push_back(DriverArgs.MakeArgString(Path));
635 }
636 
637 void ToolChain::addExternCSystemIncludeIfExists(const ArgList &DriverArgs,
638                                                 ArgStringList &CC1Args,
639                                                 const Twine &Path) {
640   if (llvm::sys::fs::exists(Path))
641     addExternCSystemInclude(DriverArgs, CC1Args, Path);
642 }
643 
644 /// \brief Utility function to add a list of system include directories to CC1.
645 /*static*/ void ToolChain::addSystemIncludes(const ArgList &DriverArgs,
646                                              ArgStringList &CC1Args,
647                                              ArrayRef<StringRef> Paths) {
648   for (StringRef Path : Paths) {
649     CC1Args.push_back("-internal-isystem");
650     CC1Args.push_back(DriverArgs.MakeArgString(Path));
651   }
652 }
653 
654 void ToolChain::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
655                                              ArgStringList &CC1Args) const {
656   // Header search paths should be handled by each of the subclasses.
657   // Historically, they have not been, and instead have been handled inside of
658   // the CC1-layer frontend. As the logic is hoisted out, this generic function
659   // will slowly stop being called.
660   //
661   // While it is being called, replicate a bit of a hack to propagate the
662   // '-stdlib=' flag down to CC1 so that it can in turn customize the C++
663   // header search paths with it. Once all systems are overriding this
664   // function, the CC1 flag and this line can be removed.
665   DriverArgs.AddAllArgs(CC1Args, options::OPT_stdlib_EQ);
666 }
667 
668 bool ToolChain::ShouldLinkCXXStdlib(const llvm::opt::ArgList &Args) const {
669   return getDriver().CCCIsCXX() &&
670          !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
671                       options::OPT_nostdlibxx);
672 }
673 
674 void ToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
675                                     ArgStringList &CmdArgs) const {
676   assert(!Args.hasArg(options::OPT_nostdlibxx) &&
677          "should not have called this");
678   CXXStdlibType Type = GetCXXStdlibType(Args);
679 
680   switch (Type) {
681   case ToolChain::CST_Libcxx:
682     CmdArgs.push_back("-lc++");
683     break;
684 
685   case ToolChain::CST_Libstdcxx:
686     CmdArgs.push_back("-lstdc++");
687     break;
688   }
689 }
690 
691 void ToolChain::AddFilePathLibArgs(const ArgList &Args,
692                                    ArgStringList &CmdArgs) const {
693   for (const auto &LibPath : getFilePaths())
694     if(LibPath.length() > 0)
695       CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
696 }
697 
698 void ToolChain::AddCCKextLibArgs(const ArgList &Args,
699                                  ArgStringList &CmdArgs) const {
700   CmdArgs.push_back("-lcc_kext");
701 }
702 
703 bool ToolChain::AddFastMathRuntimeIfAvailable(const ArgList &Args,
704                                               ArgStringList &CmdArgs) const {
705   // Do not check for -fno-fast-math or -fno-unsafe-math when -Ofast passed
706   // (to keep the linker options consistent with gcc and clang itself).
707   if (!isOptimizationLevelFast(Args)) {
708     // Check if -ffast-math or -funsafe-math.
709     Arg *A =
710         Args.getLastArg(options::OPT_ffast_math, options::OPT_fno_fast_math,
711                         options::OPT_funsafe_math_optimizations,
712                         options::OPT_fno_unsafe_math_optimizations);
713 
714     if (!A || A->getOption().getID() == options::OPT_fno_fast_math ||
715         A->getOption().getID() == options::OPT_fno_unsafe_math_optimizations)
716       return false;
717   }
718   // If crtfastmath.o exists add it to the arguments.
719   std::string Path = GetFilePath("crtfastmath.o");
720   if (Path == "crtfastmath.o") // Not found.
721     return false;
722 
723   CmdArgs.push_back(Args.MakeArgString(Path));
724   return true;
725 }
726 
727 SanitizerMask ToolChain::getSupportedSanitizers() const {
728   // Return sanitizers which don't require runtime support and are not
729   // platform dependent.
730   using namespace SanitizerKind;
731   SanitizerMask Res = (Undefined & ~Vptr & ~Function) | (CFI & ~CFIICall) |
732                       CFICastStrict | UnsignedIntegerOverflow | Nullability |
733                       LocalBounds;
734   if (getTriple().getArch() == llvm::Triple::x86 ||
735       getTriple().getArch() == llvm::Triple::x86_64 ||
736       getTriple().getArch() == llvm::Triple::arm ||
737       getTriple().getArch() == llvm::Triple::aarch64 ||
738       getTriple().getArch() == llvm::Triple::wasm32 ||
739       getTriple().getArch() == llvm::Triple::wasm64)
740     Res |= CFIICall;
741   return Res;
742 }
743 
744 void ToolChain::AddCudaIncludeArgs(const ArgList &DriverArgs,
745                                    ArgStringList &CC1Args) const {}
746 
747 void ToolChain::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
748                                     ArgStringList &CC1Args) const {}
749 
750 static VersionTuple separateMSVCFullVersion(unsigned Version) {
751   if (Version < 100)
752     return VersionTuple(Version);
753 
754   if (Version < 10000)
755     return VersionTuple(Version / 100, Version % 100);
756 
757   unsigned Build = 0, Factor = 1;
758   for (; Version > 10000; Version = Version / 10, Factor = Factor * 10)
759     Build = Build + (Version % 10) * Factor;
760   return VersionTuple(Version / 100, Version % 100, Build);
761 }
762 
763 VersionTuple
764 ToolChain::computeMSVCVersion(const Driver *D,
765                               const llvm::opt::ArgList &Args) const {
766   const Arg *MSCVersion = Args.getLastArg(options::OPT_fmsc_version);
767   const Arg *MSCompatibilityVersion =
768       Args.getLastArg(options::OPT_fms_compatibility_version);
769 
770   if (MSCVersion && MSCompatibilityVersion) {
771     if (D)
772       D->Diag(diag::err_drv_argument_not_allowed_with)
773           << MSCVersion->getAsString(Args)
774           << MSCompatibilityVersion->getAsString(Args);
775     return VersionTuple();
776   }
777 
778   if (MSCompatibilityVersion) {
779     VersionTuple MSVT;
780     if (MSVT.tryParse(MSCompatibilityVersion->getValue())) {
781       if (D)
782         D->Diag(diag::err_drv_invalid_value)
783             << MSCompatibilityVersion->getAsString(Args)
784             << MSCompatibilityVersion->getValue();
785     } else {
786       return MSVT;
787     }
788   }
789 
790   if (MSCVersion) {
791     unsigned Version = 0;
792     if (StringRef(MSCVersion->getValue()).getAsInteger(10, Version)) {
793       if (D)
794         D->Diag(diag::err_drv_invalid_value)
795             << MSCVersion->getAsString(Args) << MSCVersion->getValue();
796     } else {
797       return separateMSVCFullVersion(Version);
798     }
799   }
800 
801   return VersionTuple();
802 }
803 
804 llvm::opt::DerivedArgList *
805 ToolChain::TranslateOpenMPTargetArgs(const llvm::opt::DerivedArgList &Args,
806     Action::OffloadKind DeviceOffloadKind) const {
807   if (DeviceOffloadKind == Action::OFK_OpenMP) {
808     DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
809     const OptTable &Opts = getDriver().getOpts();
810     bool NewArgAdded = false;
811 
812     // Handle -Xopenmp-target flags
813     for (Arg *A : Args) {
814       // Exclude flags which may only apply to the host toolchain.
815       // Do not exclude flags when the host triple (AuxTriple),
816       // matches the current toolchain triple.
817       if (A->getOption().matches(options::OPT_m_Group)) {
818         if (getAuxTriple() && getAuxTriple()->str() == getTriple().str())
819           DAL->append(A);
820         continue;
821       }
822 
823       unsigned Index;
824       unsigned Prev;
825       bool XOpenMPTargetNoTriple = A->getOption().matches(
826           options::OPT_Xopenmp_target);
827 
828       if (A->getOption().matches(options::OPT_Xopenmp_target_EQ)) {
829         // Passing device args: -Xopenmp-target=<triple> -opt=val.
830         if (A->getValue(0) == getTripleString())
831           Index = Args.getBaseArgs().MakeIndex(A->getValue(1));
832         else
833           continue;
834       } else if (XOpenMPTargetNoTriple) {
835         // Passing device args: -Xopenmp-target -opt=val.
836         Index = Args.getBaseArgs().MakeIndex(A->getValue(0));
837       } else {
838         DAL->append(A);
839         continue;
840       }
841 
842       // Parse the argument to -Xopenmp-target.
843       Prev = Index;
844       std::unique_ptr<Arg> XOpenMPTargetArg(Opts.ParseOneArg(Args, Index));
845       if (!XOpenMPTargetArg || Index > Prev + 1) {
846         getDriver().Diag(diag::err_drv_invalid_Xopenmp_target_with_args)
847             << A->getAsString(Args);
848         continue;
849       }
850       if (XOpenMPTargetNoTriple && XOpenMPTargetArg &&
851           Args.getAllArgValues(
852               options::OPT_fopenmp_targets_EQ).size() != 1) {
853         getDriver().Diag(diag::err_drv_Xopenmp_target_missing_triple);
854         continue;
855       }
856       XOpenMPTargetArg->setBaseArg(A);
857       A = XOpenMPTargetArg.release();
858       DAL->append(A);
859       NewArgAdded = true;
860     }
861 
862     if (NewArgAdded) {
863       return DAL;
864     } else {
865       delete DAL;
866     }
867   }
868 
869   return nullptr;
870 }
871