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