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