1 //===--- Gnu.cpp - Gnu Tool and ToolChain Implementations -------*- C++ -*-===//
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 "Gnu.h"
11 #include "Linux.h"
12 #include "Arch/ARM.h"
13 #include "Arch/Mips.h"
14 #include "Arch/PPC.h"
15 #include "Arch/Sparc.h"
16 #include "Arch/SystemZ.h"
17 #include "CommonArgs.h"
18 #include "clang/Basic/VirtualFileSystem.h"
19 #include "clang/Config/config.h" // for GCC_INSTALL_PREFIX
20 #include "clang/Driver/Compilation.h"
21 #include "clang/Driver/Driver.h"
22 #include "clang/Driver/DriverDiagnostic.h"
23 #include "clang/Driver/Options.h"
24 #include "clang/Driver/Tool.h"
25 #include "llvm/Option/ArgList.h"
26 #include "llvm/Support/CodeGen.h"
27 #include "llvm/Support/Path.h"
28 #include "llvm/Support/TargetParser.h"
29 #include <system_error>
30 
31 using namespace clang::driver;
32 using namespace clang::driver::toolchains;
33 using namespace clang;
34 using namespace llvm::opt;
35 
36 void tools::GnuTool::anchor() {}
37 
38 static bool forwardToGCC(const Option &O) {
39   // Don't forward inputs from the original command line.  They are added from
40   // InputInfoList.
41   return O.getKind() != Option::InputClass &&
42          !O.hasFlag(options::DriverOption) && !O.hasFlag(options::LinkerInput);
43 }
44 
45 void tools::gcc::Common::ConstructJob(Compilation &C, const JobAction &JA,
46                                       const InputInfo &Output,
47                                       const InputInfoList &Inputs,
48                                       const ArgList &Args,
49                                       const char *LinkingOutput) const {
50   const Driver &D = getToolChain().getDriver();
51   ArgStringList CmdArgs;
52 
53   for (const auto &A : Args) {
54     if (forwardToGCC(A->getOption())) {
55       // It is unfortunate that we have to claim here, as this means
56       // we will basically never report anything interesting for
57       // platforms using a generic gcc, even if we are just using gcc
58       // to get to the assembler.
59       A->claim();
60 
61       // Don't forward any -g arguments to assembly steps.
62       if (isa<AssembleJobAction>(JA) &&
63           A->getOption().matches(options::OPT_g_Group))
64         continue;
65 
66       // Don't forward any -W arguments to assembly and link steps.
67       if ((isa<AssembleJobAction>(JA) || isa<LinkJobAction>(JA)) &&
68           A->getOption().matches(options::OPT_W_Group))
69         continue;
70 
71       A->render(Args, CmdArgs);
72     }
73   }
74 
75   RenderExtraToolArgs(JA, CmdArgs);
76 
77   // If using a driver driver, force the arch.
78   if (getToolChain().getTriple().isOSDarwin()) {
79     CmdArgs.push_back("-arch");
80     CmdArgs.push_back(
81         Args.MakeArgString(getToolChain().getDefaultUniversalArchName()));
82   }
83 
84   // Try to force gcc to match the tool chain we want, if we recognize
85   // the arch.
86   //
87   // FIXME: The triple class should directly provide the information we want
88   // here.
89   switch (getToolChain().getArch()) {
90   default:
91     break;
92   case llvm::Triple::x86:
93   case llvm::Triple::ppc:
94     CmdArgs.push_back("-m32");
95     break;
96   case llvm::Triple::x86_64:
97   case llvm::Triple::ppc64:
98   case llvm::Triple::ppc64le:
99     CmdArgs.push_back("-m64");
100     break;
101   case llvm::Triple::sparcel:
102     CmdArgs.push_back("-EL");
103     break;
104   }
105 
106   if (Output.isFilename()) {
107     CmdArgs.push_back("-o");
108     CmdArgs.push_back(Output.getFilename());
109   } else {
110     assert(Output.isNothing() && "Unexpected output");
111     CmdArgs.push_back("-fsyntax-only");
112   }
113 
114   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
115 
116   // Only pass -x if gcc will understand it; otherwise hope gcc
117   // understands the suffix correctly. The main use case this would go
118   // wrong in is for linker inputs if they happened to have an odd
119   // suffix; really the only way to get this to happen is a command
120   // like '-x foobar a.c' which will treat a.c like a linker input.
121   //
122   // FIXME: For the linker case specifically, can we safely convert
123   // inputs into '-Wl,' options?
124   for (const auto &II : Inputs) {
125     // Don't try to pass LLVM or AST inputs to a generic gcc.
126     if (types::isLLVMIR(II.getType()))
127       D.Diag(clang::diag::err_drv_no_linker_llvm_support)
128           << getToolChain().getTripleString();
129     else if (II.getType() == types::TY_AST)
130       D.Diag(diag::err_drv_no_ast_support) << getToolChain().getTripleString();
131     else if (II.getType() == types::TY_ModuleFile)
132       D.Diag(diag::err_drv_no_module_support)
133           << getToolChain().getTripleString();
134 
135     if (types::canTypeBeUserSpecified(II.getType())) {
136       CmdArgs.push_back("-x");
137       CmdArgs.push_back(types::getTypeName(II.getType()));
138     }
139 
140     if (II.isFilename())
141       CmdArgs.push_back(II.getFilename());
142     else {
143       const Arg &A = II.getInputArg();
144 
145       // Reverse translate some rewritten options.
146       if (A.getOption().matches(options::OPT_Z_reserved_lib_stdcxx)) {
147         CmdArgs.push_back("-lstdc++");
148         continue;
149       }
150 
151       // Don't render as input, we need gcc to do the translations.
152       A.render(Args, CmdArgs);
153     }
154   }
155 
156   const std::string &customGCCName = D.getCCCGenericGCCName();
157   const char *GCCName;
158   if (!customGCCName.empty())
159     GCCName = customGCCName.c_str();
160   else if (D.CCCIsCXX()) {
161     GCCName = "g++";
162   } else
163     GCCName = "gcc";
164 
165   const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath(GCCName));
166   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
167 }
168 
169 void tools::gcc::Preprocessor::RenderExtraToolArgs(
170     const JobAction &JA, ArgStringList &CmdArgs) const {
171   CmdArgs.push_back("-E");
172 }
173 
174 void tools::gcc::Compiler::RenderExtraToolArgs(const JobAction &JA,
175                                                ArgStringList &CmdArgs) const {
176   const Driver &D = getToolChain().getDriver();
177 
178   switch (JA.getType()) {
179   // If -flto, etc. are present then make sure not to force assembly output.
180   case types::TY_LLVM_IR:
181   case types::TY_LTO_IR:
182   case types::TY_LLVM_BC:
183   case types::TY_LTO_BC:
184     CmdArgs.push_back("-c");
185     break;
186   // We assume we've got an "integrated" assembler in that gcc will produce an
187   // object file itself.
188   case types::TY_Object:
189     CmdArgs.push_back("-c");
190     break;
191   case types::TY_PP_Asm:
192     CmdArgs.push_back("-S");
193     break;
194   case types::TY_Nothing:
195     CmdArgs.push_back("-fsyntax-only");
196     break;
197   default:
198     D.Diag(diag::err_drv_invalid_gcc_output_type) << getTypeName(JA.getType());
199   }
200 }
201 
202 void tools::gcc::Linker::RenderExtraToolArgs(const JobAction &JA,
203                                              ArgStringList &CmdArgs) const {
204   // The types are (hopefully) good enough.
205 }
206 
207 static bool addXRayRuntime(const ToolChain &TC, const ArgList &Args,
208                            ArgStringList &CmdArgs) {
209   if (Args.hasFlag(options::OPT_fxray_instrument,
210                    options::OPT_fnoxray_instrument, false)) {
211     CmdArgs.push_back("-whole-archive");
212     CmdArgs.push_back(TC.getCompilerRTArgString(Args, "xray", false));
213     CmdArgs.push_back("-no-whole-archive");
214     return true;
215   }
216   return false;
217 }
218 
219 static void linkXRayRuntimeDeps(const ToolChain &TC, const ArgList &Args,
220                                 ArgStringList &CmdArgs) {
221   CmdArgs.push_back("--no-as-needed");
222   CmdArgs.push_back("-lpthread");
223   CmdArgs.push_back("-lrt");
224   CmdArgs.push_back("-lm");
225 
226   if (TC.getTriple().getOS() != llvm::Triple::FreeBSD)
227     CmdArgs.push_back("-ldl");
228 }
229 
230 static const char *getLDMOption(const llvm::Triple &T, const ArgList &Args) {
231   switch (T.getArch()) {
232   case llvm::Triple::x86:
233     if (T.isOSIAMCU())
234       return "elf_iamcu";
235     return "elf_i386";
236   case llvm::Triple::aarch64:
237     return "aarch64linux";
238   case llvm::Triple::aarch64_be:
239     return "aarch64_be_linux";
240   case llvm::Triple::arm:
241   case llvm::Triple::thumb:
242     return "armelf_linux_eabi";
243   case llvm::Triple::armeb:
244   case llvm::Triple::thumbeb:
245     return "armelfb_linux_eabi";
246   case llvm::Triple::ppc:
247     return "elf32ppclinux";
248   case llvm::Triple::ppc64:
249     return "elf64ppc";
250   case llvm::Triple::ppc64le:
251     return "elf64lppc";
252   case llvm::Triple::sparc:
253   case llvm::Triple::sparcel:
254     return "elf32_sparc";
255   case llvm::Triple::sparcv9:
256     return "elf64_sparc";
257   case llvm::Triple::mips:
258     return "elf32btsmip";
259   case llvm::Triple::mipsel:
260     return "elf32ltsmip";
261   case llvm::Triple::mips64:
262     if (tools::mips::hasMipsAbiArg(Args, "n32"))
263       return "elf32btsmipn32";
264     return "elf64btsmip";
265   case llvm::Triple::mips64el:
266     if (tools::mips::hasMipsAbiArg(Args, "n32"))
267       return "elf32ltsmipn32";
268     return "elf64ltsmip";
269   case llvm::Triple::systemz:
270     return "elf64_s390";
271   case llvm::Triple::x86_64:
272     if (T.getEnvironment() == llvm::Triple::GNUX32)
273       return "elf32_x86_64";
274     return "elf_x86_64";
275   default:
276     return nullptr;
277   }
278 }
279 
280 void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
281                                            const InputInfo &Output,
282                                            const InputInfoList &Inputs,
283                                            const ArgList &Args,
284                                            const char *LinkingOutput) const {
285   const toolchains::Linux &ToolChain =
286       static_cast<const toolchains::Linux &>(getToolChain());
287   const Driver &D = ToolChain.getDriver();
288 
289   const llvm::Triple &Triple = getToolChain().getEffectiveTriple();
290 
291   const llvm::Triple::ArchType Arch = ToolChain.getArch();
292   const bool isAndroid = ToolChain.getTriple().isAndroid();
293   const bool IsIAMCU = ToolChain.getTriple().isOSIAMCU();
294   const bool IsPIE =
295       !Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_static) &&
296       (Args.hasArg(options::OPT_pie) || ToolChain.isPIEDefault());
297   const bool HasCRTBeginEndFiles =
298       ToolChain.getTriple().hasEnvironment() ||
299       (ToolChain.getTriple().getVendor() != llvm::Triple::MipsTechnologies);
300 
301   ArgStringList CmdArgs;
302 
303   // Silence warning for "clang -g foo.o -o foo"
304   Args.ClaimAllArgs(options::OPT_g_Group);
305   // and "clang -emit-llvm foo.o -o foo"
306   Args.ClaimAllArgs(options::OPT_emit_llvm);
307   // and for "clang -w foo.o -o foo". Other warning options are already
308   // handled somewhere else.
309   Args.ClaimAllArgs(options::OPT_w);
310 
311   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
312   if (llvm::sys::path::stem(Exec) == "lld") {
313     CmdArgs.push_back("-flavor");
314     CmdArgs.push_back("old-gnu");
315     CmdArgs.push_back("-target");
316     CmdArgs.push_back(Args.MakeArgString(getToolChain().getTripleString()));
317   }
318 
319   if (!D.SysRoot.empty())
320     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
321 
322   if (IsPIE)
323     CmdArgs.push_back("-pie");
324 
325   if (Args.hasArg(options::OPT_rdynamic))
326     CmdArgs.push_back("-export-dynamic");
327 
328   if (Args.hasArg(options::OPT_s))
329     CmdArgs.push_back("-s");
330 
331   if (Arch == llvm::Triple::armeb || Arch == llvm::Triple::thumbeb)
332     arm::appendEBLinkFlags(Args, CmdArgs, Triple);
333 
334   // Most Android ARM64 targets should enable the linker fix for erratum
335   // 843419. Only non-Cortex-A53 devices are allowed to skip this flag.
336   if (Arch == llvm::Triple::aarch64 && isAndroid) {
337     std::string CPU = getCPUName(Args, Triple);
338     if (CPU.empty() || CPU == "generic" || CPU == "cortex-a53")
339       CmdArgs.push_back("--fix-cortex-a53-843419");
340   }
341 
342   for (const auto &Opt : ToolChain.ExtraOpts)
343     CmdArgs.push_back(Opt.c_str());
344 
345   if (!Args.hasArg(options::OPT_static)) {
346     CmdArgs.push_back("--eh-frame-hdr");
347   }
348 
349   if (const char *LDMOption = getLDMOption(ToolChain.getTriple(), Args)) {
350     CmdArgs.push_back("-m");
351     CmdArgs.push_back(LDMOption);
352   } else {
353     D.Diag(diag::err_target_unknown_triple) << Triple.str();
354     return;
355   }
356 
357   if (Args.hasArg(options::OPT_static)) {
358     if (Arch == llvm::Triple::arm || Arch == llvm::Triple::armeb ||
359         Arch == llvm::Triple::thumb || Arch == llvm::Triple::thumbeb)
360       CmdArgs.push_back("-Bstatic");
361     else
362       CmdArgs.push_back("-static");
363   } else if (Args.hasArg(options::OPT_shared)) {
364     CmdArgs.push_back("-shared");
365   }
366 
367   if (!Args.hasArg(options::OPT_static)) {
368     if (Args.hasArg(options::OPT_rdynamic))
369       CmdArgs.push_back("-export-dynamic");
370 
371     if (!Args.hasArg(options::OPT_shared)) {
372       const std::string Loader =
373           D.DyldPrefix + ToolChain.getDynamicLinker(Args);
374       CmdArgs.push_back("-dynamic-linker");
375       CmdArgs.push_back(Args.MakeArgString(Loader));
376     }
377   }
378 
379   CmdArgs.push_back("-o");
380   CmdArgs.push_back(Output.getFilename());
381 
382   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
383     if (!isAndroid && !IsIAMCU) {
384       const char *crt1 = nullptr;
385       if (!Args.hasArg(options::OPT_shared)) {
386         if (Args.hasArg(options::OPT_pg))
387           crt1 = "gcrt1.o";
388         else if (IsPIE)
389           crt1 = "Scrt1.o";
390         else
391           crt1 = "crt1.o";
392       }
393       if (crt1)
394         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crt1)));
395 
396       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crti.o")));
397     }
398 
399     if (IsIAMCU)
400       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt0.o")));
401     else {
402       const char *crtbegin;
403       if (Args.hasArg(options::OPT_static))
404         crtbegin = isAndroid ? "crtbegin_static.o" : "crtbeginT.o";
405       else if (Args.hasArg(options::OPT_shared))
406         crtbegin = isAndroid ? "crtbegin_so.o" : "crtbeginS.o";
407       else if (IsPIE)
408         crtbegin = isAndroid ? "crtbegin_dynamic.o" : "crtbeginS.o";
409       else
410         crtbegin = isAndroid ? "crtbegin_dynamic.o" : "crtbegin.o";
411 
412       if (HasCRTBeginEndFiles)
413         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtbegin)));
414     }
415 
416     // Add crtfastmath.o if available and fast math is enabled.
417     ToolChain.AddFastMathRuntimeIfAvailable(Args, CmdArgs);
418   }
419 
420   Args.AddAllArgs(CmdArgs, options::OPT_L);
421   Args.AddAllArgs(CmdArgs, options::OPT_u);
422 
423   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
424 
425   if (D.isUsingLTO())
426     AddGoldPlugin(ToolChain, Args, CmdArgs, D.getLTOMode() == LTOK_Thin, D);
427 
428   if (Args.hasArg(options::OPT_Z_Xlinker__no_demangle))
429     CmdArgs.push_back("--no-demangle");
430 
431   bool NeedsSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
432   bool NeedsXRayDeps = addXRayRuntime(ToolChain, Args, CmdArgs);
433   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
434   // The profile runtime also needs access to system libraries.
435   getToolChain().addProfileRTLibs(Args, CmdArgs);
436 
437   if (D.CCCIsCXX() &&
438       !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
439     if (ToolChain.ShouldLinkCXXStdlib(Args)) {
440       bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
441                                  !Args.hasArg(options::OPT_static);
442       if (OnlyLibstdcxxStatic)
443         CmdArgs.push_back("-Bstatic");
444       ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
445       if (OnlyLibstdcxxStatic)
446         CmdArgs.push_back("-Bdynamic");
447     }
448     CmdArgs.push_back("-lm");
449   }
450   // Silence warnings when linking C code with a C++ '-stdlib' argument.
451   Args.ClaimAllArgs(options::OPT_stdlib_EQ);
452 
453   if (!Args.hasArg(options::OPT_nostdlib)) {
454     if (!Args.hasArg(options::OPT_nodefaultlibs)) {
455       if (Args.hasArg(options::OPT_static))
456         CmdArgs.push_back("--start-group");
457 
458       if (NeedsSanitizerDeps)
459         linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
460 
461       if (NeedsXRayDeps)
462         linkXRayRuntimeDeps(ToolChain, Args, CmdArgs);
463 
464       bool WantPthread = Args.hasArg(options::OPT_pthread) ||
465                          Args.hasArg(options::OPT_pthreads);
466 
467       // FIXME: Only pass GompNeedsRT = true for platforms with libgomp that
468       // require librt. Most modern Linux platforms do, but some may not.
469       if (addOpenMPRuntime(CmdArgs, ToolChain, Args,
470                            JA.isHostOffloading(Action::OFK_OpenMP),
471                            /* GompNeedsRT= */ true))
472         // OpenMP runtimes implies pthreads when using the GNU toolchain.
473         // FIXME: Does this really make sense for all GNU toolchains?
474         WantPthread = true;
475 
476       AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
477 
478       if (WantPthread && !isAndroid)
479         CmdArgs.push_back("-lpthread");
480 
481       if (Args.hasArg(options::OPT_fsplit_stack))
482         CmdArgs.push_back("--wrap=pthread_create");
483 
484       CmdArgs.push_back("-lc");
485 
486       // Add IAMCU specific libs, if needed.
487       if (IsIAMCU)
488         CmdArgs.push_back("-lgloss");
489 
490       if (Args.hasArg(options::OPT_static))
491         CmdArgs.push_back("--end-group");
492       else
493         AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
494 
495       // Add IAMCU specific libs (outside the group), if needed.
496       if (IsIAMCU) {
497         CmdArgs.push_back("--as-needed");
498         CmdArgs.push_back("-lsoftfp");
499         CmdArgs.push_back("--no-as-needed");
500       }
501     }
502 
503     if (!Args.hasArg(options::OPT_nostartfiles) && !IsIAMCU) {
504       const char *crtend;
505       if (Args.hasArg(options::OPT_shared))
506         crtend = isAndroid ? "crtend_so.o" : "crtendS.o";
507       else if (IsPIE)
508         crtend = isAndroid ? "crtend_android.o" : "crtendS.o";
509       else
510         crtend = isAndroid ? "crtend_android.o" : "crtend.o";
511 
512       if (HasCRTBeginEndFiles)
513         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtend)));
514       if (!isAndroid)
515         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtn.o")));
516     }
517   }
518 
519   // Add OpenMP offloading linker script args if required.
520   AddOpenMPLinkerScript(getToolChain(), C, Output, Inputs, Args, CmdArgs, JA);
521 
522   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
523 }
524 
525 void tools::gnutools::Assembler::ConstructJob(Compilation &C,
526                                               const JobAction &JA,
527                                               const InputInfo &Output,
528                                               const InputInfoList &Inputs,
529                                               const ArgList &Args,
530                                               const char *LinkingOutput) const {
531   const auto &D = getToolChain().getDriver();
532 
533   claimNoWarnArgs(Args);
534 
535   ArgStringList CmdArgs;
536 
537   llvm::Reloc::Model RelocationModel;
538   unsigned PICLevel;
539   bool IsPIE;
540   std::tie(RelocationModel, PICLevel, IsPIE) =
541       ParsePICArgs(getToolChain(), Args);
542 
543   if (const Arg *A = Args.getLastArg(options::OPT_gz, options::OPT_gz_EQ)) {
544     if (A->getOption().getID() == options::OPT_gz) {
545       CmdArgs.push_back("-compress-debug-sections");
546     } else {
547       StringRef Value = A->getValue();
548       if (Value == "none") {
549         CmdArgs.push_back("-compress-debug-sections=none");
550       } else if (Value == "zlib" || Value == "zlib-gnu") {
551         CmdArgs.push_back(
552             Args.MakeArgString("-compress-debug-sections=" + Twine(Value)));
553       } else {
554         D.Diag(diag::err_drv_unsupported_option_argument)
555             << A->getOption().getName() << Value;
556       }
557     }
558   }
559 
560   switch (getToolChain().getArch()) {
561   default:
562     break;
563   // Add --32/--64 to make sure we get the format we want.
564   // This is incomplete
565   case llvm::Triple::x86:
566     CmdArgs.push_back("--32");
567     break;
568   case llvm::Triple::x86_64:
569     if (getToolChain().getTriple().getEnvironment() == llvm::Triple::GNUX32)
570       CmdArgs.push_back("--x32");
571     else
572       CmdArgs.push_back("--64");
573     break;
574   case llvm::Triple::ppc: {
575     CmdArgs.push_back("-a32");
576     CmdArgs.push_back("-mppc");
577     CmdArgs.push_back(
578       ppc::getPPCAsmModeForCPU(getCPUName(Args, getToolChain().getTriple())));
579     break;
580   }
581   case llvm::Triple::ppc64: {
582     CmdArgs.push_back("-a64");
583     CmdArgs.push_back("-mppc64");
584     CmdArgs.push_back(
585       ppc::getPPCAsmModeForCPU(getCPUName(Args, getToolChain().getTriple())));
586     break;
587   }
588   case llvm::Triple::ppc64le: {
589     CmdArgs.push_back("-a64");
590     CmdArgs.push_back("-mppc64");
591     CmdArgs.push_back("-mlittle-endian");
592     CmdArgs.push_back(
593       ppc::getPPCAsmModeForCPU(getCPUName(Args, getToolChain().getTriple())));
594     break;
595   }
596   case llvm::Triple::sparc:
597   case llvm::Triple::sparcel: {
598     CmdArgs.push_back("-32");
599     std::string CPU = getCPUName(Args, getToolChain().getTriple());
600     CmdArgs.push_back(sparc::getSparcAsmModeForCPU(CPU, getToolChain().getTriple()));
601     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
602     break;
603   }
604   case llvm::Triple::sparcv9: {
605     CmdArgs.push_back("-64");
606     std::string CPU = getCPUName(Args, getToolChain().getTriple());
607     CmdArgs.push_back(sparc::getSparcAsmModeForCPU(CPU, getToolChain().getTriple()));
608     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
609     break;
610   }
611   case llvm::Triple::arm:
612   case llvm::Triple::armeb:
613   case llvm::Triple::thumb:
614   case llvm::Triple::thumbeb: {
615     const llvm::Triple &Triple2 = getToolChain().getTriple();
616     switch (Triple2.getSubArch()) {
617     case llvm::Triple::ARMSubArch_v7:
618       CmdArgs.push_back("-mfpu=neon");
619       break;
620     case llvm::Triple::ARMSubArch_v8:
621       CmdArgs.push_back("-mfpu=crypto-neon-fp-armv8");
622       break;
623     default:
624       break;
625     }
626 
627     switch (arm::getARMFloatABI(getToolChain(), Args)) {
628     case arm::FloatABI::Invalid: llvm_unreachable("must have an ABI!");
629     case arm::FloatABI::Soft:
630       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=soft"));
631       break;
632     case arm::FloatABI::SoftFP:
633       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=softfp"));
634       break;
635     case arm::FloatABI::Hard:
636       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=hard"));
637       break;
638     }
639 
640     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
641 
642     // FIXME: remove krait check when GNU tools support krait cpu
643     // for now replace it with -mcpu=cortex-a15 to avoid a lower
644     // march from being picked in the absence of a cpu flag.
645     Arg *A;
646     if ((A = Args.getLastArg(options::OPT_mcpu_EQ)) &&
647         StringRef(A->getValue()).equals_lower("krait"))
648       CmdArgs.push_back("-mcpu=cortex-a15");
649     else
650       Args.AddLastArg(CmdArgs, options::OPT_mcpu_EQ);
651     Args.AddLastArg(CmdArgs, options::OPT_mfpu_EQ);
652     break;
653   }
654   case llvm::Triple::aarch64:
655   case llvm::Triple::aarch64_be: {
656     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
657     Args.AddLastArg(CmdArgs, options::OPT_mcpu_EQ);
658     break;
659   }
660   case llvm::Triple::mips:
661   case llvm::Triple::mipsel:
662   case llvm::Triple::mips64:
663   case llvm::Triple::mips64el: {
664     StringRef CPUName;
665     StringRef ABIName;
666     mips::getMipsCPUAndABI(Args, getToolChain().getTriple(), CPUName, ABIName);
667     ABIName = mips::getGnuCompatibleMipsABIName(ABIName);
668 
669     CmdArgs.push_back("-march");
670     CmdArgs.push_back(CPUName.data());
671 
672     CmdArgs.push_back("-mabi");
673     CmdArgs.push_back(ABIName.data());
674 
675     // -mno-shared should be emitted unless -fpic, -fpie, -fPIC, -fPIE,
676     // or -mshared (not implemented) is in effect.
677     if (RelocationModel == llvm::Reloc::Static)
678       CmdArgs.push_back("-mno-shared");
679 
680     // LLVM doesn't support -mplt yet and acts as if it is always given.
681     // However, -mplt has no effect with the N64 ABI.
682     if (ABIName != "64" && !Args.hasArg(options::OPT_mno_abicalls))
683       CmdArgs.push_back("-call_nonpic");
684 
685     if (getToolChain().getArch() == llvm::Triple::mips ||
686         getToolChain().getArch() == llvm::Triple::mips64)
687       CmdArgs.push_back("-EB");
688     else
689       CmdArgs.push_back("-EL");
690 
691     if (Arg *A = Args.getLastArg(options::OPT_mnan_EQ)) {
692       if (StringRef(A->getValue()) == "2008")
693         CmdArgs.push_back(Args.MakeArgString("-mnan=2008"));
694     }
695 
696     // Add the last -mfp32/-mfpxx/-mfp64 or -mfpxx if it is enabled by default.
697     if (Arg *A = Args.getLastArg(options::OPT_mfp32, options::OPT_mfpxx,
698                                  options::OPT_mfp64)) {
699       A->claim();
700       A->render(Args, CmdArgs);
701     } else if (mips::shouldUseFPXX(
702                    Args, getToolChain().getTriple(), CPUName, ABIName,
703                    mips::getMipsFloatABI(getToolChain().getDriver(), Args)))
704       CmdArgs.push_back("-mfpxx");
705 
706     // Pass on -mmips16 or -mno-mips16. However, the assembler equivalent of
707     // -mno-mips16 is actually -no-mips16.
708     if (Arg *A =
709             Args.getLastArg(options::OPT_mips16, options::OPT_mno_mips16)) {
710       if (A->getOption().matches(options::OPT_mips16)) {
711         A->claim();
712         A->render(Args, CmdArgs);
713       } else {
714         A->claim();
715         CmdArgs.push_back("-no-mips16");
716       }
717     }
718 
719     Args.AddLastArg(CmdArgs, options::OPT_mmicromips,
720                     options::OPT_mno_micromips);
721     Args.AddLastArg(CmdArgs, options::OPT_mdsp, options::OPT_mno_dsp);
722     Args.AddLastArg(CmdArgs, options::OPT_mdspr2, options::OPT_mno_dspr2);
723 
724     if (Arg *A = Args.getLastArg(options::OPT_mmsa, options::OPT_mno_msa)) {
725       // Do not use AddLastArg because not all versions of MIPS assembler
726       // support -mmsa / -mno-msa options.
727       if (A->getOption().matches(options::OPT_mmsa))
728         CmdArgs.push_back(Args.MakeArgString("-mmsa"));
729     }
730 
731     Args.AddLastArg(CmdArgs, options::OPT_mhard_float,
732                     options::OPT_msoft_float);
733 
734     Args.AddLastArg(CmdArgs, options::OPT_mdouble_float,
735                     options::OPT_msingle_float);
736 
737     Args.AddLastArg(CmdArgs, options::OPT_modd_spreg,
738                     options::OPT_mno_odd_spreg);
739 
740     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
741     break;
742   }
743   case llvm::Triple::systemz: {
744     // Always pass an -march option, since our default of z10 is later
745     // than the GNU assembler's default.
746     StringRef CPUName = systemz::getSystemZTargetCPU(Args);
747     CmdArgs.push_back(Args.MakeArgString("-march=" + CPUName));
748     break;
749   }
750   }
751 
752   Args.AddAllArgs(CmdArgs, options::OPT_I);
753   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
754 
755   CmdArgs.push_back("-o");
756   CmdArgs.push_back(Output.getFilename());
757 
758   for (const auto &II : Inputs)
759     CmdArgs.push_back(II.getFilename());
760 
761   const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath("as"));
762   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
763 
764   // Handle the debug info splitting at object creation time if we're
765   // creating an object.
766   // TODO: Currently only works on linux with newer objcopy.
767   if (Args.hasArg(options::OPT_gsplit_dwarf) &&
768       getToolChain().getTriple().isOSLinux())
769     SplitDebugInfo(getToolChain(), C, *this, JA, Args, Output,
770                    SplitDebugName(Args, Inputs[0]));
771 }
772 
773 namespace {
774 // Filter to remove Multilibs that don't exist as a suffix to Path
775 class FilterNonExistent {
776   StringRef Base, File;
777   vfs::FileSystem &VFS;
778 
779 public:
780   FilterNonExistent(StringRef Base, StringRef File, vfs::FileSystem &VFS)
781       : Base(Base), File(File), VFS(VFS) {}
782   bool operator()(const Multilib &M) {
783     return !VFS.exists(Base + M.gccSuffix() + File);
784   }
785 };
786 } // end anonymous namespace
787 
788 static bool isSoftFloatABI(const ArgList &Args) {
789   Arg *A = Args.getLastArg(options::OPT_msoft_float, options::OPT_mhard_float,
790                            options::OPT_mfloat_abi_EQ);
791   if (!A)
792     return false;
793 
794   return A->getOption().matches(options::OPT_msoft_float) ||
795          (A->getOption().matches(options::OPT_mfloat_abi_EQ) &&
796           A->getValue() == StringRef("soft"));
797 }
798 
799 /// \p Flag must be a flag accepted by the driver with its leading '-' removed,
800 //     otherwise '-print-multi-lib' will not emit them correctly.
801 static void addMultilibFlag(bool Enabled, const char *const Flag,
802                             std::vector<std::string> &Flags) {
803   if (Enabled)
804     Flags.push_back(std::string("+") + Flag);
805   else
806     Flags.push_back(std::string("-") + Flag);
807 }
808 
809 static bool isArmOrThumbArch(llvm::Triple::ArchType Arch) {
810   return Arch == llvm::Triple::arm || Arch == llvm::Triple::thumb;
811 }
812 
813 static bool isMips32(llvm::Triple::ArchType Arch) {
814   return Arch == llvm::Triple::mips || Arch == llvm::Triple::mipsel;
815 }
816 
817 static bool isMips64(llvm::Triple::ArchType Arch) {
818   return Arch == llvm::Triple::mips64 || Arch == llvm::Triple::mips64el;
819 }
820 
821 static bool isMipsEL(llvm::Triple::ArchType Arch) {
822   return Arch == llvm::Triple::mipsel || Arch == llvm::Triple::mips64el;
823 }
824 
825 static bool isMips16(const ArgList &Args) {
826   Arg *A = Args.getLastArg(options::OPT_mips16, options::OPT_mno_mips16);
827   return A && A->getOption().matches(options::OPT_mips16);
828 }
829 
830 static bool isMicroMips(const ArgList &Args) {
831   Arg *A = Args.getLastArg(options::OPT_mmicromips, options::OPT_mno_micromips);
832   return A && A->getOption().matches(options::OPT_mmicromips);
833 }
834 
835 static Multilib makeMultilib(StringRef commonSuffix) {
836   return Multilib(commonSuffix, commonSuffix, commonSuffix);
837 }
838 
839 static bool findMipsCsMultilibs(const Multilib::flags_list &Flags,
840                                 FilterNonExistent &NonExistent,
841                                 DetectedMultilibs &Result) {
842   // Check for Code Sourcery toolchain multilibs
843   MultilibSet CSMipsMultilibs;
844   {
845     auto MArchMips16 = makeMultilib("/mips16").flag("+m32").flag("+mips16");
846 
847     auto MArchMicroMips =
848         makeMultilib("/micromips").flag("+m32").flag("+mmicromips");
849 
850     auto MArchDefault = makeMultilib("").flag("-mips16").flag("-mmicromips");
851 
852     auto UCLibc = makeMultilib("/uclibc").flag("+muclibc");
853 
854     auto SoftFloat = makeMultilib("/soft-float").flag("+msoft-float");
855 
856     auto Nan2008 = makeMultilib("/nan2008").flag("+mnan=2008");
857 
858     auto DefaultFloat =
859         makeMultilib("").flag("-msoft-float").flag("-mnan=2008");
860 
861     auto BigEndian = makeMultilib("").flag("+EB").flag("-EL");
862 
863     auto LittleEndian = makeMultilib("/el").flag("+EL").flag("-EB");
864 
865     // Note that this one's osSuffix is ""
866     auto MAbi64 = makeMultilib("")
867                       .gccSuffix("/64")
868                       .includeSuffix("/64")
869                       .flag("+mabi=n64")
870                       .flag("-mabi=n32")
871                       .flag("-m32");
872 
873     CSMipsMultilibs =
874         MultilibSet()
875             .Either(MArchMips16, MArchMicroMips, MArchDefault)
876             .Maybe(UCLibc)
877             .Either(SoftFloat, Nan2008, DefaultFloat)
878             .FilterOut("/micromips/nan2008")
879             .FilterOut("/mips16/nan2008")
880             .Either(BigEndian, LittleEndian)
881             .Maybe(MAbi64)
882             .FilterOut("/mips16.*/64")
883             .FilterOut("/micromips.*/64")
884             .FilterOut(NonExistent)
885             .setIncludeDirsCallback([](const Multilib &M) {
886               std::vector<std::string> Dirs({"/include"});
887               if (StringRef(M.includeSuffix()).startswith("/uclibc"))
888                 Dirs.push_back(
889                     "/../../../../mips-linux-gnu/libc/uclibc/usr/include");
890               else
891                 Dirs.push_back("/../../../../mips-linux-gnu/libc/usr/include");
892               return Dirs;
893             });
894   }
895 
896   MultilibSet DebianMipsMultilibs;
897   {
898     Multilib MAbiN32 =
899         Multilib().gccSuffix("/n32").includeSuffix("/n32").flag("+mabi=n32");
900 
901     Multilib M64 = Multilib()
902                        .gccSuffix("/64")
903                        .includeSuffix("/64")
904                        .flag("+m64")
905                        .flag("-m32")
906                        .flag("-mabi=n32");
907 
908     Multilib M32 = Multilib().flag("-m64").flag("+m32").flag("-mabi=n32");
909 
910     DebianMipsMultilibs =
911         MultilibSet().Either(M32, M64, MAbiN32).FilterOut(NonExistent);
912   }
913 
914   // Sort candidates. Toolchain that best meets the directories tree goes first.
915   // Then select the first toolchains matches command line flags.
916   MultilibSet *Candidates[] = {&CSMipsMultilibs, &DebianMipsMultilibs};
917   if (CSMipsMultilibs.size() < DebianMipsMultilibs.size())
918     std::iter_swap(Candidates, Candidates + 1);
919   for (const MultilibSet *Candidate : Candidates) {
920     if (Candidate->select(Flags, Result.SelectedMultilib)) {
921       if (Candidate == &DebianMipsMultilibs)
922         Result.BiarchSibling = Multilib();
923       Result.Multilibs = *Candidate;
924       return true;
925     }
926   }
927   return false;
928 }
929 
930 static bool findMipsAndroidMultilibs(vfs::FileSystem &VFS, StringRef Path,
931                                      const Multilib::flags_list &Flags,
932                                      FilterNonExistent &NonExistent,
933                                      DetectedMultilibs &Result) {
934 
935   MultilibSet AndroidMipsMultilibs =
936       MultilibSet()
937           .Maybe(Multilib("/mips-r2").flag("+march=mips32r2"))
938           .Maybe(Multilib("/mips-r6").flag("+march=mips32r6"))
939           .FilterOut(NonExistent);
940 
941   MultilibSet AndroidMipselMultilibs =
942       MultilibSet()
943           .Either(Multilib().flag("+march=mips32"),
944                   Multilib("/mips-r2", "", "/mips-r2").flag("+march=mips32r2"),
945                   Multilib("/mips-r6", "", "/mips-r6").flag("+march=mips32r6"))
946           .FilterOut(NonExistent);
947 
948   MultilibSet AndroidMips64elMultilibs =
949       MultilibSet()
950           .Either(
951               Multilib().flag("+march=mips64r6"),
952               Multilib("/32/mips-r1", "", "/mips-r1").flag("+march=mips32"),
953               Multilib("/32/mips-r2", "", "/mips-r2").flag("+march=mips32r2"),
954               Multilib("/32/mips-r6", "", "/mips-r6").flag("+march=mips32r6"))
955           .FilterOut(NonExistent);
956 
957   MultilibSet *MS = &AndroidMipsMultilibs;
958   if (VFS.exists(Path + "/mips-r6"))
959     MS = &AndroidMipselMultilibs;
960   else if (VFS.exists(Path + "/32"))
961     MS = &AndroidMips64elMultilibs;
962   if (MS->select(Flags, Result.SelectedMultilib)) {
963     Result.Multilibs = *MS;
964     return true;
965   }
966   return false;
967 }
968 
969 static bool findMipsMuslMultilibs(const Multilib::flags_list &Flags,
970                                   FilterNonExistent &NonExistent,
971                                   DetectedMultilibs &Result) {
972   // Musl toolchain multilibs
973   MultilibSet MuslMipsMultilibs;
974   {
975     auto MArchMipsR2 = makeMultilib("")
976                            .osSuffix("/mips-r2-hard-musl")
977                            .flag("+EB")
978                            .flag("-EL")
979                            .flag("+march=mips32r2");
980 
981     auto MArchMipselR2 = makeMultilib("/mipsel-r2-hard-musl")
982                              .flag("-EB")
983                              .flag("+EL")
984                              .flag("+march=mips32r2");
985 
986     MuslMipsMultilibs = MultilibSet().Either(MArchMipsR2, MArchMipselR2);
987 
988     // Specify the callback that computes the include directories.
989     MuslMipsMultilibs.setIncludeDirsCallback([](const Multilib &M) {
990       return std::vector<std::string>(
991           {"/../sysroot" + M.osSuffix() + "/usr/include"});
992     });
993   }
994   if (MuslMipsMultilibs.select(Flags, Result.SelectedMultilib)) {
995     Result.Multilibs = MuslMipsMultilibs;
996     return true;
997   }
998   return false;
999 }
1000 
1001 static bool findMipsMtiMultilibs(const Multilib::flags_list &Flags,
1002                                  FilterNonExistent &NonExistent,
1003                                  DetectedMultilibs &Result) {
1004   // CodeScape MTI toolchain v1.2 and early.
1005   MultilibSet MtiMipsMultilibsV1;
1006   {
1007     auto MArchMips32 = makeMultilib("/mips32")
1008                            .flag("+m32")
1009                            .flag("-m64")
1010                            .flag("-mmicromips")
1011                            .flag("+march=mips32");
1012 
1013     auto MArchMicroMips = makeMultilib("/micromips")
1014                               .flag("+m32")
1015                               .flag("-m64")
1016                               .flag("+mmicromips");
1017 
1018     auto MArchMips64r2 = makeMultilib("/mips64r2")
1019                              .flag("-m32")
1020                              .flag("+m64")
1021                              .flag("+march=mips64r2");
1022 
1023     auto MArchMips64 = makeMultilib("/mips64").flag("-m32").flag("+m64").flag(
1024         "-march=mips64r2");
1025 
1026     auto MArchDefault = makeMultilib("")
1027                             .flag("+m32")
1028                             .flag("-m64")
1029                             .flag("-mmicromips")
1030                             .flag("+march=mips32r2");
1031 
1032     auto Mips16 = makeMultilib("/mips16").flag("+mips16");
1033 
1034     auto UCLibc = makeMultilib("/uclibc").flag("+muclibc");
1035 
1036     auto MAbi64 =
1037         makeMultilib("/64").flag("+mabi=n64").flag("-mabi=n32").flag("-m32");
1038 
1039     auto BigEndian = makeMultilib("").flag("+EB").flag("-EL");
1040 
1041     auto LittleEndian = makeMultilib("/el").flag("+EL").flag("-EB");
1042 
1043     auto SoftFloat = makeMultilib("/sof").flag("+msoft-float");
1044 
1045     auto Nan2008 = makeMultilib("/nan2008").flag("+mnan=2008");
1046 
1047     MtiMipsMultilibsV1 =
1048         MultilibSet()
1049             .Either(MArchMips32, MArchMicroMips, MArchMips64r2, MArchMips64,
1050                     MArchDefault)
1051             .Maybe(UCLibc)
1052             .Maybe(Mips16)
1053             .FilterOut("/mips64/mips16")
1054             .FilterOut("/mips64r2/mips16")
1055             .FilterOut("/micromips/mips16")
1056             .Maybe(MAbi64)
1057             .FilterOut("/micromips/64")
1058             .FilterOut("/mips32/64")
1059             .FilterOut("^/64")
1060             .FilterOut("/mips16/64")
1061             .Either(BigEndian, LittleEndian)
1062             .Maybe(SoftFloat)
1063             .Maybe(Nan2008)
1064             .FilterOut(".*sof/nan2008")
1065             .FilterOut(NonExistent)
1066             .setIncludeDirsCallback([](const Multilib &M) {
1067               std::vector<std::string> Dirs({"/include"});
1068               if (StringRef(M.includeSuffix()).startswith("/uclibc"))
1069                 Dirs.push_back("/../../../../sysroot/uclibc/usr/include");
1070               else
1071                 Dirs.push_back("/../../../../sysroot/usr/include");
1072               return Dirs;
1073             });
1074   }
1075 
1076   // CodeScape IMG toolchain starting from v1.3.
1077   MultilibSet MtiMipsMultilibsV2;
1078   {
1079     auto BeHard = makeMultilib("/mips-r2-hard")
1080                       .flag("+EB")
1081                       .flag("-msoft-float")
1082                       .flag("-mnan=2008")
1083                       .flag("-muclibc");
1084     auto BeSoft = makeMultilib("/mips-r2-soft")
1085                       .flag("+EB")
1086                       .flag("+msoft-float")
1087                       .flag("-mnan=2008");
1088     auto ElHard = makeMultilib("/mipsel-r2-hard")
1089                       .flag("+EL")
1090                       .flag("-msoft-float")
1091                       .flag("-mnan=2008")
1092                       .flag("-muclibc");
1093     auto ElSoft = makeMultilib("/mipsel-r2-soft")
1094                       .flag("+EL")
1095                       .flag("+msoft-float")
1096                       .flag("-mnan=2008")
1097                       .flag("-mmicromips");
1098     auto BeHardNan = makeMultilib("/mips-r2-hard-nan2008")
1099                          .flag("+EB")
1100                          .flag("-msoft-float")
1101                          .flag("+mnan=2008")
1102                          .flag("-muclibc");
1103     auto ElHardNan = makeMultilib("/mipsel-r2-hard-nan2008")
1104                          .flag("+EL")
1105                          .flag("-msoft-float")
1106                          .flag("+mnan=2008")
1107                          .flag("-muclibc")
1108                          .flag("-mmicromips");
1109     auto BeHardNanUclibc = makeMultilib("/mips-r2-hard-nan2008-uclibc")
1110                                .flag("+EB")
1111                                .flag("-msoft-float")
1112                                .flag("+mnan=2008")
1113                                .flag("+muclibc");
1114     auto ElHardNanUclibc = makeMultilib("/mipsel-r2-hard-nan2008-uclibc")
1115                                .flag("+EL")
1116                                .flag("-msoft-float")
1117                                .flag("+mnan=2008")
1118                                .flag("+muclibc");
1119     auto BeHardUclibc = makeMultilib("/mips-r2-hard-uclibc")
1120                             .flag("+EB")
1121                             .flag("-msoft-float")
1122                             .flag("-mnan=2008")
1123                             .flag("+muclibc");
1124     auto ElHardUclibc = makeMultilib("/mipsel-r2-hard-uclibc")
1125                             .flag("+EL")
1126                             .flag("-msoft-float")
1127                             .flag("-mnan=2008")
1128                             .flag("+muclibc");
1129     auto ElMicroHardNan = makeMultilib("/micromipsel-r2-hard-nan2008")
1130                               .flag("+EL")
1131                               .flag("-msoft-float")
1132                               .flag("+mnan=2008")
1133                               .flag("+mmicromips");
1134     auto ElMicroSoft = makeMultilib("/micromipsel-r2-soft")
1135                            .flag("+EL")
1136                            .flag("+msoft-float")
1137                            .flag("-mnan=2008")
1138                            .flag("+mmicromips");
1139 
1140     auto O32 =
1141         makeMultilib("/lib").osSuffix("").flag("-mabi=n32").flag("-mabi=n64");
1142     auto N32 =
1143         makeMultilib("/lib32").osSuffix("").flag("+mabi=n32").flag("-mabi=n64");
1144     auto N64 =
1145         makeMultilib("/lib64").osSuffix("").flag("-mabi=n32").flag("+mabi=n64");
1146 
1147     MtiMipsMultilibsV2 =
1148         MultilibSet()
1149             .Either({BeHard, BeSoft, ElHard, ElSoft, BeHardNan, ElHardNan,
1150                      BeHardNanUclibc, ElHardNanUclibc, BeHardUclibc,
1151                      ElHardUclibc, ElMicroHardNan, ElMicroSoft})
1152             .Either(O32, N32, N64)
1153             .FilterOut(NonExistent)
1154             .setIncludeDirsCallback([](const Multilib &M) {
1155               return std::vector<std::string>({"/../../../../sysroot" +
1156                                                M.includeSuffix() +
1157                                                "/../usr/include"});
1158             })
1159             .setFilePathsCallback([](const Multilib &M) {
1160               return std::vector<std::string>(
1161                   {"/../../../../mips-mti-linux-gnu/lib" + M.gccSuffix()});
1162             });
1163   }
1164   for (auto Candidate : {&MtiMipsMultilibsV1, &MtiMipsMultilibsV2}) {
1165     if (Candidate->select(Flags, Result.SelectedMultilib)) {
1166       Result.Multilibs = *Candidate;
1167       return true;
1168     }
1169   }
1170   return false;
1171 }
1172 
1173 static bool findMipsImgMultilibs(const Multilib::flags_list &Flags,
1174                                  FilterNonExistent &NonExistent,
1175                                  DetectedMultilibs &Result) {
1176   // CodeScape IMG toolchain v1.2 and early.
1177   MultilibSet ImgMultilibsV1;
1178   {
1179     auto Mips64r6 = makeMultilib("/mips64r6").flag("+m64").flag("-m32");
1180 
1181     auto LittleEndian = makeMultilib("/el").flag("+EL").flag("-EB");
1182 
1183     auto MAbi64 =
1184         makeMultilib("/64").flag("+mabi=n64").flag("-mabi=n32").flag("-m32");
1185 
1186     ImgMultilibsV1 =
1187         MultilibSet()
1188             .Maybe(Mips64r6)
1189             .Maybe(MAbi64)
1190             .Maybe(LittleEndian)
1191             .FilterOut(NonExistent)
1192             .setIncludeDirsCallback([](const Multilib &M) {
1193               return std::vector<std::string>(
1194                   {"/include", "/../../../../sysroot/usr/include"});
1195             });
1196   }
1197 
1198   // CodeScape IMG toolchain starting from v1.3.
1199   MultilibSet ImgMultilibsV2;
1200   {
1201     auto BeHard = makeMultilib("/mips-r6-hard")
1202                       .flag("+EB")
1203                       .flag("-msoft-float")
1204                       .flag("-mmicromips");
1205     auto BeSoft = makeMultilib("/mips-r6-soft")
1206                       .flag("+EB")
1207                       .flag("+msoft-float")
1208                       .flag("-mmicromips");
1209     auto ElHard = makeMultilib("/mipsel-r6-hard")
1210                       .flag("+EL")
1211                       .flag("-msoft-float")
1212                       .flag("-mmicromips");
1213     auto ElSoft = makeMultilib("/mipsel-r6-soft")
1214                       .flag("+EL")
1215                       .flag("+msoft-float")
1216                       .flag("-mmicromips");
1217     auto BeMicroHard = makeMultilib("/micromips-r6-hard")
1218                            .flag("+EB")
1219                            .flag("-msoft-float")
1220                            .flag("+mmicromips");
1221     auto BeMicroSoft = makeMultilib("/micromips-r6-soft")
1222                            .flag("+EB")
1223                            .flag("+msoft-float")
1224                            .flag("+mmicromips");
1225     auto ElMicroHard = makeMultilib("/micromipsel-r6-hard")
1226                            .flag("+EL")
1227                            .flag("-msoft-float")
1228                            .flag("+mmicromips");
1229     auto ElMicroSoft = makeMultilib("/micromipsel-r6-soft")
1230                            .flag("+EL")
1231                            .flag("+msoft-float")
1232                            .flag("+mmicromips");
1233 
1234     auto O32 =
1235         makeMultilib("/lib").osSuffix("").flag("-mabi=n32").flag("-mabi=n64");
1236     auto N32 =
1237         makeMultilib("/lib32").osSuffix("").flag("+mabi=n32").flag("-mabi=n64");
1238     auto N64 =
1239         makeMultilib("/lib64").osSuffix("").flag("-mabi=n32").flag("+mabi=n64");
1240 
1241     ImgMultilibsV2 =
1242         MultilibSet()
1243             .Either({BeHard, BeSoft, ElHard, ElSoft, BeMicroHard, BeMicroSoft,
1244                      ElMicroHard, ElMicroSoft})
1245             .Either(O32, N32, N64)
1246             .FilterOut(NonExistent)
1247             .setIncludeDirsCallback([](const Multilib &M) {
1248               return std::vector<std::string>({"/../../../../sysroot" +
1249                                                M.includeSuffix() +
1250                                                "/../usr/include"});
1251             })
1252             .setFilePathsCallback([](const Multilib &M) {
1253               return std::vector<std::string>(
1254                   {"/../../../../mips-img-linux-gnu/lib" + M.gccSuffix()});
1255             });
1256   }
1257   for (auto Candidate : {&ImgMultilibsV1, &ImgMultilibsV2}) {
1258     if (Candidate->select(Flags, Result.SelectedMultilib)) {
1259       Result.Multilibs = *Candidate;
1260       return true;
1261     }
1262   }
1263   return false;
1264 }
1265 
1266 bool clang::driver::findMIPSMultilibs(const Driver &D,
1267                                       const llvm::Triple &TargetTriple,
1268                                       StringRef Path, const ArgList &Args,
1269                                       DetectedMultilibs &Result) {
1270   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1271 
1272   StringRef CPUName;
1273   StringRef ABIName;
1274   tools::mips::getMipsCPUAndABI(Args, TargetTriple, CPUName, ABIName);
1275 
1276   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
1277 
1278   Multilib::flags_list Flags;
1279   addMultilibFlag(isMips32(TargetArch), "m32", Flags);
1280   addMultilibFlag(isMips64(TargetArch), "m64", Flags);
1281   addMultilibFlag(isMips16(Args), "mips16", Flags);
1282   addMultilibFlag(CPUName == "mips32", "march=mips32", Flags);
1283   addMultilibFlag(CPUName == "mips32r2" || CPUName == "mips32r3" ||
1284                       CPUName == "mips32r5" || CPUName == "p5600",
1285                   "march=mips32r2", Flags);
1286   addMultilibFlag(CPUName == "mips32r6", "march=mips32r6", Flags);
1287   addMultilibFlag(CPUName == "mips64", "march=mips64", Flags);
1288   addMultilibFlag(CPUName == "mips64r2" || CPUName == "mips64r3" ||
1289                       CPUName == "mips64r5" || CPUName == "octeon",
1290                   "march=mips64r2", Flags);
1291   addMultilibFlag(CPUName == "mips64r6", "march=mips64r6", Flags);
1292   addMultilibFlag(isMicroMips(Args), "mmicromips", Flags);
1293   addMultilibFlag(tools::mips::isUCLibc(Args), "muclibc", Flags);
1294   addMultilibFlag(tools::mips::isNaN2008(Args, TargetTriple), "mnan=2008",
1295                   Flags);
1296   addMultilibFlag(ABIName == "n32", "mabi=n32", Flags);
1297   addMultilibFlag(ABIName == "n64", "mabi=n64", Flags);
1298   addMultilibFlag(isSoftFloatABI(Args), "msoft-float", Flags);
1299   addMultilibFlag(!isSoftFloatABI(Args), "mhard-float", Flags);
1300   addMultilibFlag(isMipsEL(TargetArch), "EL", Flags);
1301   addMultilibFlag(!isMipsEL(TargetArch), "EB", Flags);
1302 
1303   if (TargetTriple.isAndroid())
1304     return findMipsAndroidMultilibs(D.getVFS(), Path, Flags, NonExistent,
1305                                     Result);
1306 
1307   if (TargetTriple.getVendor() == llvm::Triple::MipsTechnologies &&
1308       TargetTriple.getOS() == llvm::Triple::Linux &&
1309       TargetTriple.getEnvironment() == llvm::Triple::UnknownEnvironment)
1310     return findMipsMuslMultilibs(Flags, NonExistent, Result);
1311 
1312   if (TargetTriple.getVendor() == llvm::Triple::MipsTechnologies &&
1313       TargetTriple.getOS() == llvm::Triple::Linux &&
1314       TargetTriple.getEnvironment() == llvm::Triple::GNU)
1315     return findMipsMtiMultilibs(Flags, NonExistent, Result);
1316 
1317   if (TargetTriple.getVendor() == llvm::Triple::ImaginationTechnologies &&
1318       TargetTriple.getOS() == llvm::Triple::Linux &&
1319       TargetTriple.getEnvironment() == llvm::Triple::GNU)
1320     return findMipsImgMultilibs(Flags, NonExistent, Result);
1321 
1322   if (findMipsCsMultilibs(Flags, NonExistent, Result))
1323     return true;
1324 
1325   // Fallback to the regular toolchain-tree structure.
1326   Multilib Default;
1327   Result.Multilibs.push_back(Default);
1328   Result.Multilibs.FilterOut(NonExistent);
1329 
1330   if (Result.Multilibs.select(Flags, Result.SelectedMultilib)) {
1331     Result.BiarchSibling = Multilib();
1332     return true;
1333   }
1334 
1335   return false;
1336 }
1337 
1338 static void findAndroidArmMultilibs(const Driver &D,
1339                                     const llvm::Triple &TargetTriple,
1340                                     StringRef Path, const ArgList &Args,
1341                                     DetectedMultilibs &Result) {
1342   // Find multilibs with subdirectories like armv7-a, thumb, armv7-a/thumb.
1343   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1344   Multilib ArmV7Multilib = makeMultilib("/armv7-a")
1345                                .flag("+march=armv7-a")
1346                                .flag("-mthumb");
1347   Multilib ThumbMultilib = makeMultilib("/thumb")
1348                                .flag("-march=armv7-a")
1349                                .flag("+mthumb");
1350   Multilib ArmV7ThumbMultilib = makeMultilib("/armv7-a/thumb")
1351                                .flag("+march=armv7-a")
1352                                .flag("+mthumb");
1353   Multilib DefaultMultilib = makeMultilib("")
1354                                .flag("-march=armv7-a")
1355                                .flag("-mthumb");
1356   MultilibSet AndroidArmMultilibs =
1357       MultilibSet()
1358           .Either(ThumbMultilib, ArmV7Multilib,
1359                   ArmV7ThumbMultilib, DefaultMultilib)
1360           .FilterOut(NonExistent);
1361 
1362   Multilib::flags_list Flags;
1363   llvm::StringRef Arch = Args.getLastArgValue(options::OPT_march_EQ);
1364   bool IsArmArch = TargetTriple.getArch() == llvm::Triple::arm;
1365   bool IsThumbArch = TargetTriple.getArch() == llvm::Triple::thumb;
1366   bool IsV7SubArch = TargetTriple.getSubArch() == llvm::Triple::ARMSubArch_v7;
1367   bool IsThumbMode = IsThumbArch ||
1368       Args.hasFlag(options::OPT_mthumb, options::OPT_mno_thumb, false) ||
1369       (IsArmArch && llvm::ARM::parseArchISA(Arch) == llvm::ARM::ISAKind::THUMB);
1370   bool IsArmV7Mode = (IsArmArch || IsThumbArch) &&
1371       (llvm::ARM::parseArchVersion(Arch) == 7 ||
1372        (IsArmArch && Arch == "" && IsV7SubArch));
1373   addMultilibFlag(IsArmV7Mode, "march=armv7-a", Flags);
1374   addMultilibFlag(IsThumbMode, "mthumb", Flags);
1375 
1376   if (AndroidArmMultilibs.select(Flags, Result.SelectedMultilib))
1377     Result.Multilibs = AndroidArmMultilibs;
1378 }
1379 
1380 static bool findBiarchMultilibs(const Driver &D,
1381                                 const llvm::Triple &TargetTriple,
1382                                 StringRef Path, const ArgList &Args,
1383                                 bool NeedsBiarchSuffix,
1384                                 DetectedMultilibs &Result) {
1385   // Some versions of SUSE and Fedora on ppc64 put 32-bit libs
1386   // in what would normally be GCCInstallPath and put the 64-bit
1387   // libs in a subdirectory named 64. The simple logic we follow is that
1388   // *if* there is a subdirectory of the right name with crtbegin.o in it,
1389   // we use that. If not, and if not a biarch triple alias, we look for
1390   // crtbegin.o without the subdirectory.
1391 
1392   Multilib Default;
1393   Multilib Alt64 = Multilib()
1394                        .gccSuffix("/64")
1395                        .includeSuffix("/64")
1396                        .flag("-m32")
1397                        .flag("+m64")
1398                        .flag("-mx32");
1399   Multilib Alt32 = Multilib()
1400                        .gccSuffix("/32")
1401                        .includeSuffix("/32")
1402                        .flag("+m32")
1403                        .flag("-m64")
1404                        .flag("-mx32");
1405   Multilib Altx32 = Multilib()
1406                         .gccSuffix("/x32")
1407                         .includeSuffix("/x32")
1408                         .flag("-m32")
1409                         .flag("-m64")
1410                         .flag("+mx32");
1411 
1412   // GCC toolchain for IAMCU doesn't have crtbegin.o, so look for libgcc.a.
1413   FilterNonExistent NonExistent(
1414       Path, TargetTriple.isOSIAMCU() ? "/libgcc.a" : "/crtbegin.o", D.getVFS());
1415 
1416   // Determine default multilib from: 32, 64, x32
1417   // Also handle cases such as 64 on 32, 32 on 64, etc.
1418   enum { UNKNOWN, WANT32, WANT64, WANTX32 } Want = UNKNOWN;
1419   const bool IsX32 = TargetTriple.getEnvironment() == llvm::Triple::GNUX32;
1420   if (TargetTriple.isArch32Bit() && !NonExistent(Alt32))
1421     Want = WANT64;
1422   else if (TargetTriple.isArch64Bit() && IsX32 && !NonExistent(Altx32))
1423     Want = WANT64;
1424   else if (TargetTriple.isArch64Bit() && !IsX32 && !NonExistent(Alt64))
1425     Want = WANT32;
1426   else {
1427     if (TargetTriple.isArch32Bit())
1428       Want = NeedsBiarchSuffix ? WANT64 : WANT32;
1429     else if (IsX32)
1430       Want = NeedsBiarchSuffix ? WANT64 : WANTX32;
1431     else
1432       Want = NeedsBiarchSuffix ? WANT32 : WANT64;
1433   }
1434 
1435   if (Want == WANT32)
1436     Default.flag("+m32").flag("-m64").flag("-mx32");
1437   else if (Want == WANT64)
1438     Default.flag("-m32").flag("+m64").flag("-mx32");
1439   else if (Want == WANTX32)
1440     Default.flag("-m32").flag("-m64").flag("+mx32");
1441   else
1442     return false;
1443 
1444   Result.Multilibs.push_back(Default);
1445   Result.Multilibs.push_back(Alt64);
1446   Result.Multilibs.push_back(Alt32);
1447   Result.Multilibs.push_back(Altx32);
1448 
1449   Result.Multilibs.FilterOut(NonExistent);
1450 
1451   Multilib::flags_list Flags;
1452   addMultilibFlag(TargetTriple.isArch64Bit() && !IsX32, "m64", Flags);
1453   addMultilibFlag(TargetTriple.isArch32Bit(), "m32", Flags);
1454   addMultilibFlag(TargetTriple.isArch64Bit() && IsX32, "mx32", Flags);
1455 
1456   if (!Result.Multilibs.select(Flags, Result.SelectedMultilib))
1457     return false;
1458 
1459   if (Result.SelectedMultilib == Alt64 || Result.SelectedMultilib == Alt32 ||
1460       Result.SelectedMultilib == Altx32)
1461     Result.BiarchSibling = Default;
1462 
1463   return true;
1464 }
1465 
1466 /// Generic_GCC - A tool chain using the 'gcc' command to perform
1467 /// all subcommands; this relies on gcc translating the majority of
1468 /// command line options.
1469 
1470 /// \brief Less-than for GCCVersion, implementing a Strict Weak Ordering.
1471 bool Generic_GCC::GCCVersion::isOlderThan(int RHSMajor, int RHSMinor,
1472                                           int RHSPatch,
1473                                           StringRef RHSPatchSuffix) const {
1474   if (Major != RHSMajor)
1475     return Major < RHSMajor;
1476   if (Minor != RHSMinor)
1477     return Minor < RHSMinor;
1478   if (Patch != RHSPatch) {
1479     // Note that versions without a specified patch sort higher than those with
1480     // a patch.
1481     if (RHSPatch == -1)
1482       return true;
1483     if (Patch == -1)
1484       return false;
1485 
1486     // Otherwise just sort on the patch itself.
1487     return Patch < RHSPatch;
1488   }
1489   if (PatchSuffix != RHSPatchSuffix) {
1490     // Sort empty suffixes higher.
1491     if (RHSPatchSuffix.empty())
1492       return true;
1493     if (PatchSuffix.empty())
1494       return false;
1495 
1496     // Provide a lexicographic sort to make this a total ordering.
1497     return PatchSuffix < RHSPatchSuffix;
1498   }
1499 
1500   // The versions are equal.
1501   return false;
1502 }
1503 
1504 /// \brief Parse a GCCVersion object out of a string of text.
1505 ///
1506 /// This is the primary means of forming GCCVersion objects.
1507 /*static*/
1508 Generic_GCC::GCCVersion Generic_GCC::GCCVersion::Parse(StringRef VersionText) {
1509   const GCCVersion BadVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
1510   std::pair<StringRef, StringRef> First = VersionText.split('.');
1511   std::pair<StringRef, StringRef> Second = First.second.split('.');
1512 
1513   GCCVersion GoodVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
1514   if (First.first.getAsInteger(10, GoodVersion.Major) || GoodVersion.Major < 0)
1515     return BadVersion;
1516   GoodVersion.MajorStr = First.first.str();
1517   if (First.second.empty())
1518     return GoodVersion;
1519   if (Second.first.getAsInteger(10, GoodVersion.Minor) || GoodVersion.Minor < 0)
1520     return BadVersion;
1521   GoodVersion.MinorStr = Second.first.str();
1522 
1523   // First look for a number prefix and parse that if present. Otherwise just
1524   // stash the entire patch string in the suffix, and leave the number
1525   // unspecified. This covers versions strings such as:
1526   //   5        (handled above)
1527   //   4.4
1528   //   4.4.0
1529   //   4.4.x
1530   //   4.4.2-rc4
1531   //   4.4.x-patched
1532   // And retains any patch number it finds.
1533   StringRef PatchText = GoodVersion.PatchSuffix = Second.second.str();
1534   if (!PatchText.empty()) {
1535     if (size_t EndNumber = PatchText.find_first_not_of("0123456789")) {
1536       // Try to parse the number and any suffix.
1537       if (PatchText.slice(0, EndNumber).getAsInteger(10, GoodVersion.Patch) ||
1538           GoodVersion.Patch < 0)
1539         return BadVersion;
1540       GoodVersion.PatchSuffix = PatchText.substr(EndNumber);
1541     }
1542   }
1543 
1544   return GoodVersion;
1545 }
1546 
1547 static llvm::StringRef getGCCToolchainDir(const ArgList &Args) {
1548   const Arg *A = Args.getLastArg(clang::driver::options::OPT_gcc_toolchain);
1549   if (A)
1550     return A->getValue();
1551   return GCC_INSTALL_PREFIX;
1552 }
1553 
1554 /// \brief Initialize a GCCInstallationDetector from the driver.
1555 ///
1556 /// This performs all of the autodetection and sets up the various paths.
1557 /// Once constructed, a GCCInstallationDetector is essentially immutable.
1558 ///
1559 /// FIXME: We shouldn't need an explicit TargetTriple parameter here, and
1560 /// should instead pull the target out of the driver. This is currently
1561 /// necessary because the driver doesn't store the final version of the target
1562 /// triple.
1563 void Generic_GCC::GCCInstallationDetector::init(
1564     const llvm::Triple &TargetTriple, const ArgList &Args,
1565     ArrayRef<std::string> ExtraTripleAliases) {
1566   llvm::Triple BiarchVariantTriple = TargetTriple.isArch32Bit()
1567                                          ? TargetTriple.get64BitArchVariant()
1568                                          : TargetTriple.get32BitArchVariant();
1569   // The library directories which may contain GCC installations.
1570   SmallVector<StringRef, 4> CandidateLibDirs, CandidateBiarchLibDirs;
1571   // The compatible GCC triples for this particular architecture.
1572   SmallVector<StringRef, 16> CandidateTripleAliases;
1573   SmallVector<StringRef, 16> CandidateBiarchTripleAliases;
1574   CollectLibDirsAndTriples(TargetTriple, BiarchVariantTriple, CandidateLibDirs,
1575                            CandidateTripleAliases, CandidateBiarchLibDirs,
1576                            CandidateBiarchTripleAliases);
1577 
1578   // Compute the set of prefixes for our search.
1579   SmallVector<std::string, 8> Prefixes(D.PrefixDirs.begin(),
1580                                        D.PrefixDirs.end());
1581 
1582   StringRef GCCToolchainDir = getGCCToolchainDir(Args);
1583   if (GCCToolchainDir != "") {
1584     if (GCCToolchainDir.back() == '/')
1585       GCCToolchainDir = GCCToolchainDir.drop_back(); // remove the /
1586 
1587     Prefixes.push_back(GCCToolchainDir);
1588   } else {
1589     // If we have a SysRoot, try that first.
1590     if (!D.SysRoot.empty()) {
1591       Prefixes.push_back(D.SysRoot);
1592       Prefixes.push_back(D.SysRoot + "/usr");
1593     }
1594 
1595     // Then look for gcc installed alongside clang.
1596     Prefixes.push_back(D.InstalledDir + "/..");
1597 
1598     // Then look for distribution supplied gcc installations.
1599     if (D.SysRoot.empty()) {
1600       // Look for RHEL devtoolsets.
1601       Prefixes.push_back("/opt/rh/devtoolset-6/root/usr");
1602       Prefixes.push_back("/opt/rh/devtoolset-4/root/usr");
1603       Prefixes.push_back("/opt/rh/devtoolset-3/root/usr");
1604       Prefixes.push_back("/opt/rh/devtoolset-2/root/usr");
1605       // And finally in /usr.
1606       Prefixes.push_back("/usr");
1607     }
1608   }
1609 
1610   // Try to respect gcc-config on Gentoo. However, do that only
1611   // if --gcc-toolchain is not provided or equal to the Gentoo install
1612   // in /usr. This avoids accidentally enforcing the system GCC version
1613   // when using a custom toolchain.
1614   if (GCCToolchainDir == "" || GCCToolchainDir == D.SysRoot + "/usr") {
1615     for (StringRef CandidateTriple : ExtraTripleAliases) {
1616       if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple))
1617         return;
1618     }
1619     for (StringRef CandidateTriple : CandidateTripleAliases) {
1620       if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple))
1621         return;
1622     }
1623     for (StringRef CandidateTriple : CandidateBiarchTripleAliases) {
1624       if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple, true))
1625         return;
1626     }
1627   }
1628 
1629   // Loop over the various components which exist and select the best GCC
1630   // installation available. GCC installs are ranked by version number.
1631   Version = GCCVersion::Parse("0.0.0");
1632   for (const std::string &Prefix : Prefixes) {
1633     if (!D.getVFS().exists(Prefix))
1634       continue;
1635     for (StringRef Suffix : CandidateLibDirs) {
1636       const std::string LibDir = Prefix + Suffix.str();
1637       if (!D.getVFS().exists(LibDir))
1638         continue;
1639       for (StringRef Candidate : ExtraTripleAliases) // Try these first.
1640         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate);
1641       for (StringRef Candidate : CandidateTripleAliases)
1642         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate);
1643     }
1644     for (StringRef Suffix : CandidateBiarchLibDirs) {
1645       const std::string LibDir = Prefix + Suffix.str();
1646       if (!D.getVFS().exists(LibDir))
1647         continue;
1648       for (StringRef Candidate : CandidateBiarchTripleAliases)
1649         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate,
1650                                /*NeedsBiarchSuffix=*/ true);
1651     }
1652   }
1653 }
1654 
1655 void Generic_GCC::GCCInstallationDetector::print(raw_ostream &OS) const {
1656   for (const auto &InstallPath : CandidateGCCInstallPaths)
1657     OS << "Found candidate GCC installation: " << InstallPath << "\n";
1658 
1659   if (!GCCInstallPath.empty())
1660     OS << "Selected GCC installation: " << GCCInstallPath << "\n";
1661 
1662   for (const auto &Multilib : Multilibs)
1663     OS << "Candidate multilib: " << Multilib << "\n";
1664 
1665   if (Multilibs.size() != 0 || !SelectedMultilib.isDefault())
1666     OS << "Selected multilib: " << SelectedMultilib << "\n";
1667 }
1668 
1669 bool Generic_GCC::GCCInstallationDetector::getBiarchSibling(Multilib &M) const {
1670   if (BiarchSibling.hasValue()) {
1671     M = BiarchSibling.getValue();
1672     return true;
1673   }
1674   return false;
1675 }
1676 
1677 /*static*/ void Generic_GCC::GCCInstallationDetector::CollectLibDirsAndTriples(
1678     const llvm::Triple &TargetTriple, const llvm::Triple &BiarchTriple,
1679     SmallVectorImpl<StringRef> &LibDirs,
1680     SmallVectorImpl<StringRef> &TripleAliases,
1681     SmallVectorImpl<StringRef> &BiarchLibDirs,
1682     SmallVectorImpl<StringRef> &BiarchTripleAliases) {
1683   // Declare a bunch of static data sets that we'll select between below. These
1684   // are specifically designed to always refer to string literals to avoid any
1685   // lifetime or initialization issues.
1686   static const char *const AArch64LibDirs[] = {"/lib64", "/lib"};
1687   static const char *const AArch64Triples[] = {
1688       "aarch64-none-linux-gnu", "aarch64-linux-gnu", "aarch64-linux-android",
1689       "aarch64-redhat-linux", "aarch64-suse-linux"};
1690   static const char *const AArch64beLibDirs[] = {"/lib"};
1691   static const char *const AArch64beTriples[] = {"aarch64_be-none-linux-gnu",
1692                                                  "aarch64_be-linux-gnu"};
1693 
1694   static const char *const ARMLibDirs[] = {"/lib"};
1695   static const char *const ARMTriples[] = {"arm-linux-gnueabi",
1696                                            "arm-linux-androideabi"};
1697   static const char *const ARMHFTriples[] = {"arm-linux-gnueabihf",
1698                                              "armv7hl-redhat-linux-gnueabi",
1699                                              "armv6hl-suse-linux-gnueabi",
1700                                              "armv7hl-suse-linux-gnueabi"};
1701   static const char *const ARMebLibDirs[] = {"/lib"};
1702   static const char *const ARMebTriples[] = {"armeb-linux-gnueabi",
1703                                              "armeb-linux-androideabi"};
1704   static const char *const ARMebHFTriples[] = {
1705       "armeb-linux-gnueabihf", "armebv7hl-redhat-linux-gnueabi"};
1706 
1707   static const char *const X86_64LibDirs[] = {"/lib64", "/lib"};
1708   static const char *const X86_64Triples[] = {
1709       "x86_64-linux-gnu",       "x86_64-unknown-linux-gnu",
1710       "x86_64-pc-linux-gnu",    "x86_64-redhat-linux6E",
1711       "x86_64-redhat-linux",    "x86_64-suse-linux",
1712       "x86_64-manbo-linux-gnu", "x86_64-linux-gnu",
1713       "x86_64-slackware-linux", "x86_64-linux-android",
1714       "x86_64-unknown-linux"};
1715   static const char *const X32LibDirs[] = {"/libx32"};
1716   static const char *const X86LibDirs[] = {"/lib32", "/lib"};
1717   static const char *const X86Triples[] = {
1718       "i686-linux-gnu",       "i686-pc-linux-gnu",     "i486-linux-gnu",
1719       "i386-linux-gnu",       "i386-redhat-linux6E",   "i686-redhat-linux",
1720       "i586-redhat-linux",    "i386-redhat-linux",     "i586-suse-linux",
1721       "i486-slackware-linux", "i686-montavista-linux", "i686-linux-android",
1722       "i586-linux-gnu"};
1723 
1724   static const char *const MIPSLibDirs[] = {"/lib"};
1725   static const char *const MIPSTriples[] = {"mips-linux-gnu", "mips-mti-linux",
1726                                             "mips-mti-linux-gnu",
1727                                             "mips-img-linux-gnu"};
1728   static const char *const MIPSELLibDirs[] = {"/lib"};
1729   static const char *const MIPSELTriples[] = {"mipsel-linux-gnu",
1730                                               "mips-img-linux-gnu"};
1731 
1732   static const char *const MIPS64LibDirs[] = {"/lib64", "/lib"};
1733   static const char *const MIPS64Triples[] = {
1734       "mips64-linux-gnu", "mips-mti-linux-gnu", "mips-img-linux-gnu",
1735       "mips64-linux-gnuabi64"};
1736   static const char *const MIPS64ELLibDirs[] = {"/lib64", "/lib"};
1737   static const char *const MIPS64ELTriples[] = {
1738       "mips64el-linux-gnu", "mips-mti-linux-gnu", "mips-img-linux-gnu",
1739       "mips64el-linux-gnuabi64"};
1740 
1741   static const char *const MIPSELAndroidLibDirs[] = {"/lib", "/libr2",
1742                                                      "/libr6"};
1743   static const char *const MIPSELAndroidTriples[] = {"mipsel-linux-android"};
1744   static const char *const MIPS64ELAndroidLibDirs[] = {"/lib64", "/lib",
1745                                                        "/libr2", "/libr6"};
1746   static const char *const MIPS64ELAndroidTriples[] = {
1747       "mips64el-linux-android"};
1748 
1749   static const char *const PPCLibDirs[] = {"/lib32", "/lib"};
1750   static const char *const PPCTriples[] = {
1751       "powerpc-linux-gnu", "powerpc-unknown-linux-gnu", "powerpc-linux-gnuspe",
1752       "powerpc-suse-linux", "powerpc-montavista-linuxspe"};
1753   static const char *const PPC64LibDirs[] = {"/lib64", "/lib"};
1754   static const char *const PPC64Triples[] = {
1755       "powerpc64-linux-gnu", "powerpc64-unknown-linux-gnu",
1756       "powerpc64-suse-linux", "ppc64-redhat-linux"};
1757   static const char *const PPC64LELibDirs[] = {"/lib64", "/lib"};
1758   static const char *const PPC64LETriples[] = {
1759       "powerpc64le-linux-gnu", "powerpc64le-unknown-linux-gnu",
1760       "powerpc64le-suse-linux", "ppc64le-redhat-linux"};
1761 
1762   static const char *const SPARCv8LibDirs[] = {"/lib32", "/lib"};
1763   static const char *const SPARCv8Triples[] = {"sparc-linux-gnu",
1764                                                "sparcv8-linux-gnu"};
1765   static const char *const SPARCv9LibDirs[] = {"/lib64", "/lib"};
1766   static const char *const SPARCv9Triples[] = {"sparc64-linux-gnu",
1767                                                "sparcv9-linux-gnu"};
1768 
1769   static const char *const SystemZLibDirs[] = {"/lib64", "/lib"};
1770   static const char *const SystemZTriples[] = {
1771       "s390x-linux-gnu", "s390x-unknown-linux-gnu", "s390x-ibm-linux-gnu",
1772       "s390x-suse-linux", "s390x-redhat-linux"};
1773 
1774   // Solaris.
1775   static const char *const SolarisSPARCLibDirs[] = {"/gcc"};
1776   static const char *const SolarisSPARCTriples[] = {"sparc-sun-solaris2.11",
1777                                                     "i386-pc-solaris2.11"};
1778 
1779   using std::begin;
1780   using std::end;
1781 
1782   if (TargetTriple.getOS() == llvm::Triple::Solaris) {
1783     LibDirs.append(begin(SolarisSPARCLibDirs), end(SolarisSPARCLibDirs));
1784     TripleAliases.append(begin(SolarisSPARCTriples), end(SolarisSPARCTriples));
1785     return;
1786   }
1787 
1788   switch (TargetTriple.getArch()) {
1789   case llvm::Triple::aarch64:
1790     LibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
1791     TripleAliases.append(begin(AArch64Triples), end(AArch64Triples));
1792     BiarchLibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
1793     BiarchTripleAliases.append(begin(AArch64Triples), end(AArch64Triples));
1794     break;
1795   case llvm::Triple::aarch64_be:
1796     LibDirs.append(begin(AArch64beLibDirs), end(AArch64beLibDirs));
1797     TripleAliases.append(begin(AArch64beTriples), end(AArch64beTriples));
1798     BiarchLibDirs.append(begin(AArch64beLibDirs), end(AArch64beLibDirs));
1799     BiarchTripleAliases.append(begin(AArch64beTriples), end(AArch64beTriples));
1800     break;
1801   case llvm::Triple::arm:
1802   case llvm::Triple::thumb:
1803     LibDirs.append(begin(ARMLibDirs), end(ARMLibDirs));
1804     if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
1805       TripleAliases.append(begin(ARMHFTriples), end(ARMHFTriples));
1806     } else {
1807       TripleAliases.append(begin(ARMTriples), end(ARMTriples));
1808     }
1809     break;
1810   case llvm::Triple::armeb:
1811   case llvm::Triple::thumbeb:
1812     LibDirs.append(begin(ARMebLibDirs), end(ARMebLibDirs));
1813     if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
1814       TripleAliases.append(begin(ARMebHFTriples), end(ARMebHFTriples));
1815     } else {
1816       TripleAliases.append(begin(ARMebTriples), end(ARMebTriples));
1817     }
1818     break;
1819   case llvm::Triple::x86_64:
1820     LibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
1821     TripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
1822     // x32 is always available when x86_64 is available, so adding it as
1823     // secondary arch with x86_64 triples
1824     if (TargetTriple.getEnvironment() == llvm::Triple::GNUX32) {
1825       BiarchLibDirs.append(begin(X32LibDirs), end(X32LibDirs));
1826       BiarchTripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
1827     } else {
1828       BiarchLibDirs.append(begin(X86LibDirs), end(X86LibDirs));
1829       BiarchTripleAliases.append(begin(X86Triples), end(X86Triples));
1830     }
1831     break;
1832   case llvm::Triple::x86:
1833     LibDirs.append(begin(X86LibDirs), end(X86LibDirs));
1834     // MCU toolchain is 32 bit only and its triple alias is TargetTriple
1835     // itself, which will be appended below.
1836     if (!TargetTriple.isOSIAMCU()) {
1837       TripleAliases.append(begin(X86Triples), end(X86Triples));
1838       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
1839       BiarchTripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
1840     }
1841     break;
1842   case llvm::Triple::mips:
1843     LibDirs.append(begin(MIPSLibDirs), end(MIPSLibDirs));
1844     TripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
1845     BiarchLibDirs.append(begin(MIPS64LibDirs), end(MIPS64LibDirs));
1846     BiarchTripleAliases.append(begin(MIPS64Triples), end(MIPS64Triples));
1847     break;
1848   case llvm::Triple::mipsel:
1849     if (TargetTriple.isAndroid()) {
1850       LibDirs.append(begin(MIPSELAndroidLibDirs), end(MIPSELAndroidLibDirs));
1851       TripleAliases.append(begin(MIPSELAndroidTriples),
1852                            end(MIPSELAndroidTriples));
1853       BiarchLibDirs.append(begin(MIPS64ELAndroidLibDirs),
1854                            end(MIPS64ELAndroidLibDirs));
1855       BiarchTripleAliases.append(begin(MIPS64ELAndroidTriples),
1856                                  end(MIPS64ELAndroidTriples));
1857 
1858     } else {
1859       LibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
1860       TripleAliases.append(begin(MIPSELTriples), end(MIPSELTriples));
1861       TripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
1862       BiarchLibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
1863       BiarchTripleAliases.append(begin(MIPS64ELTriples), end(MIPS64ELTriples));
1864     }
1865     break;
1866   case llvm::Triple::mips64:
1867     LibDirs.append(begin(MIPS64LibDirs), end(MIPS64LibDirs));
1868     TripleAliases.append(begin(MIPS64Triples), end(MIPS64Triples));
1869     BiarchLibDirs.append(begin(MIPSLibDirs), end(MIPSLibDirs));
1870     BiarchTripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
1871     break;
1872   case llvm::Triple::mips64el:
1873     if (TargetTriple.isAndroid()) {
1874       LibDirs.append(begin(MIPS64ELAndroidLibDirs),
1875                      end(MIPS64ELAndroidLibDirs));
1876       TripleAliases.append(begin(MIPS64ELAndroidTriples),
1877                            end(MIPS64ELAndroidTriples));
1878       BiarchLibDirs.append(begin(MIPSELAndroidLibDirs),
1879                            end(MIPSELAndroidLibDirs));
1880       BiarchTripleAliases.append(begin(MIPSELAndroidTriples),
1881                                  end(MIPSELAndroidTriples));
1882 
1883     } else {
1884       LibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
1885       TripleAliases.append(begin(MIPS64ELTriples), end(MIPS64ELTriples));
1886       BiarchLibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
1887       BiarchTripleAliases.append(begin(MIPSELTriples), end(MIPSELTriples));
1888       BiarchTripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
1889     }
1890     break;
1891   case llvm::Triple::ppc:
1892     LibDirs.append(begin(PPCLibDirs), end(PPCLibDirs));
1893     TripleAliases.append(begin(PPCTriples), end(PPCTriples));
1894     BiarchLibDirs.append(begin(PPC64LibDirs), end(PPC64LibDirs));
1895     BiarchTripleAliases.append(begin(PPC64Triples), end(PPC64Triples));
1896     break;
1897   case llvm::Triple::ppc64:
1898     LibDirs.append(begin(PPC64LibDirs), end(PPC64LibDirs));
1899     TripleAliases.append(begin(PPC64Triples), end(PPC64Triples));
1900     BiarchLibDirs.append(begin(PPCLibDirs), end(PPCLibDirs));
1901     BiarchTripleAliases.append(begin(PPCTriples), end(PPCTriples));
1902     break;
1903   case llvm::Triple::ppc64le:
1904     LibDirs.append(begin(PPC64LELibDirs), end(PPC64LELibDirs));
1905     TripleAliases.append(begin(PPC64LETriples), end(PPC64LETriples));
1906     break;
1907   case llvm::Triple::sparc:
1908   case llvm::Triple::sparcel:
1909     LibDirs.append(begin(SPARCv8LibDirs), end(SPARCv8LibDirs));
1910     TripleAliases.append(begin(SPARCv8Triples), end(SPARCv8Triples));
1911     BiarchLibDirs.append(begin(SPARCv9LibDirs), end(SPARCv9LibDirs));
1912     BiarchTripleAliases.append(begin(SPARCv9Triples), end(SPARCv9Triples));
1913     break;
1914   case llvm::Triple::sparcv9:
1915     LibDirs.append(begin(SPARCv9LibDirs), end(SPARCv9LibDirs));
1916     TripleAliases.append(begin(SPARCv9Triples), end(SPARCv9Triples));
1917     BiarchLibDirs.append(begin(SPARCv8LibDirs), end(SPARCv8LibDirs));
1918     BiarchTripleAliases.append(begin(SPARCv8Triples), end(SPARCv8Triples));
1919     break;
1920   case llvm::Triple::systemz:
1921     LibDirs.append(begin(SystemZLibDirs), end(SystemZLibDirs));
1922     TripleAliases.append(begin(SystemZTriples), end(SystemZTriples));
1923     break;
1924   default:
1925     // By default, just rely on the standard lib directories and the original
1926     // triple.
1927     break;
1928   }
1929 
1930   // Always append the drivers target triple to the end, in case it doesn't
1931   // match any of our aliases.
1932   TripleAliases.push_back(TargetTriple.str());
1933 
1934   // Also include the multiarch variant if it's different.
1935   if (TargetTriple.str() != BiarchTriple.str())
1936     BiarchTripleAliases.push_back(BiarchTriple.str());
1937 }
1938 
1939 void Generic_GCC::GCCInstallationDetector::scanLibDirForGCCTripleSolaris(
1940     const llvm::Triple &TargetArch, const llvm::opt::ArgList &Args,
1941     const std::string &LibDir, StringRef CandidateTriple,
1942     bool NeedsBiarchSuffix) {
1943   // Solaris is a special case. The GCC installation is under
1944   // /usr/gcc/<major>.<minor>/lib/gcc/<triple>/<major>.<minor>.<patch>/, so we
1945   // need to iterate twice.
1946   std::error_code EC;
1947   for (vfs::directory_iterator LI = D.getVFS().dir_begin(LibDir, EC), LE;
1948        !EC && LI != LE; LI = LI.increment(EC)) {
1949     StringRef VersionText = llvm::sys::path::filename(LI->getName());
1950     GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
1951 
1952     if (CandidateVersion.Major != -1) // Filter obviously bad entries.
1953       if (!CandidateGCCInstallPaths.insert(LI->getName()).second)
1954         continue; // Saw this path before; no need to look at it again.
1955     if (CandidateVersion.isOlderThan(4, 1, 1))
1956       continue;
1957     if (CandidateVersion <= Version)
1958       continue;
1959 
1960     GCCInstallPath =
1961         LibDir + "/" + VersionText.str() + "/lib/gcc/" + CandidateTriple.str();
1962     if (!D.getVFS().exists(GCCInstallPath))
1963       continue;
1964 
1965     // If we make it here there has to be at least one GCC version, let's just
1966     // use the latest one.
1967     std::error_code EEC;
1968     for (vfs::directory_iterator
1969              LLI = D.getVFS().dir_begin(GCCInstallPath, EEC),
1970              LLE;
1971          !EEC && LLI != LLE; LLI = LLI.increment(EEC)) {
1972 
1973       StringRef SubVersionText = llvm::sys::path::filename(LLI->getName());
1974       GCCVersion CandidateSubVersion = GCCVersion::Parse(SubVersionText);
1975 
1976       if (CandidateSubVersion > Version)
1977         Version = CandidateSubVersion;
1978     }
1979 
1980     GCCTriple.setTriple(CandidateTriple);
1981 
1982     GCCInstallPath += "/" + Version.Text;
1983     GCCParentLibPath = GCCInstallPath + "/../../../../";
1984 
1985     IsValid = true;
1986   }
1987 }
1988 
1989 bool Generic_GCC::GCCInstallationDetector::ScanGCCForMultilibs(
1990     const llvm::Triple &TargetTriple, const ArgList &Args,
1991     StringRef Path, bool NeedsBiarchSuffix) {
1992   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
1993   DetectedMultilibs Detected;
1994 
1995   // Android standalone toolchain could have multilibs for ARM and Thumb.
1996   // Debian mips multilibs behave more like the rest of the biarch ones,
1997   // so handle them there
1998   if (isArmOrThumbArch(TargetArch) && TargetTriple.isAndroid()) {
1999     // It should also work without multilibs in a simplified toolchain.
2000     findAndroidArmMultilibs(D, TargetTriple, Path, Args, Detected);
2001   } else if (tools::isMipsArch(TargetArch)) {
2002     if (!findMIPSMultilibs(D, TargetTriple, Path, Args, Detected))
2003       return false;
2004   } else if (!findBiarchMultilibs(D, TargetTriple, Path, Args,
2005                                   NeedsBiarchSuffix, Detected)) {
2006     return false;
2007   }
2008 
2009   Multilibs = Detected.Multilibs;
2010   SelectedMultilib = Detected.SelectedMultilib;
2011   BiarchSibling = Detected.BiarchSibling;
2012 
2013   return true;
2014 }
2015 
2016 void Generic_GCC::GCCInstallationDetector::ScanLibDirForGCCTriple(
2017     const llvm::Triple &TargetTriple, const ArgList &Args,
2018     const std::string &LibDir, StringRef CandidateTriple,
2019     bool NeedsBiarchSuffix) {
2020   if (TargetTriple.getOS() == llvm::Triple::Solaris) {
2021     scanLibDirForGCCTripleSolaris(TargetTriple, Args, LibDir, CandidateTriple,
2022                                   NeedsBiarchSuffix);
2023     return;
2024   }
2025 
2026   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
2027   // Locations relative to the system lib directory where GCC's triple-specific
2028   // directories might reside.
2029   struct GCCLibSuffix {
2030     // Path from system lib directory to GCC triple-specific directory.
2031     std::string LibSuffix;
2032     // Path from GCC triple-specific directory back to system lib directory.
2033     // This is one '..' component per component in LibSuffix.
2034     StringRef ReversePath;
2035     // Whether this library suffix is relevant for the triple.
2036     bool Active;
2037   } Suffixes[] = {
2038     // This is the normal place.
2039     {"gcc/" + CandidateTriple.str(), "../..", true},
2040 
2041     // Debian puts cross-compilers in gcc-cross.
2042     {"gcc-cross/" + CandidateTriple.str(), "../..", true},
2043 
2044     // The Freescale PPC SDK has the gcc libraries in
2045     // <sysroot>/usr/lib/<triple>/x.y.z so have a look there as well. Only do
2046     // this on Freescale triples, though, since some systems put a *lot* of
2047     // files in that location, not just GCC installation data.
2048     {CandidateTriple.str(), "..",
2049       TargetTriple.getVendor() == llvm::Triple::Freescale},
2050 
2051     // Natively multiarch systems sometimes put the GCC triple-specific
2052     // directory within their multiarch lib directory, resulting in the
2053     // triple appearing twice.
2054     {CandidateTriple.str() + "/gcc/" + CandidateTriple.str(), "../../..", true},
2055 
2056     // Deal with cases (on Ubuntu) where the system architecture could be i386
2057     // but the GCC target architecture could be (say) i686.
2058     // FIXME: It may be worthwhile to generalize this and look for a second
2059     // triple.
2060     {"i386-linux-gnu/gcc/" + CandidateTriple.str(), "../../..",
2061       TargetArch == llvm::Triple::x86}
2062   };
2063 
2064   for (auto &Suffix : Suffixes) {
2065     if (!Suffix.Active)
2066       continue;
2067 
2068     StringRef LibSuffix = Suffix.LibSuffix;
2069     std::error_code EC;
2070     for (vfs::directory_iterator
2071              LI = D.getVFS().dir_begin(LibDir + "/" + LibSuffix, EC),
2072              LE;
2073          !EC && LI != LE; LI = LI.increment(EC)) {
2074       StringRef VersionText = llvm::sys::path::filename(LI->getName());
2075       GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
2076       if (CandidateVersion.Major != -1) // Filter obviously bad entries.
2077         if (!CandidateGCCInstallPaths.insert(LI->getName()).second)
2078           continue; // Saw this path before; no need to look at it again.
2079       if (CandidateVersion.isOlderThan(4, 1, 1))
2080         continue;
2081       if (CandidateVersion <= Version)
2082         continue;
2083 
2084       if (!ScanGCCForMultilibs(TargetTriple, Args, LI->getName(),
2085                                NeedsBiarchSuffix))
2086         continue;
2087 
2088       Version = CandidateVersion;
2089       GCCTriple.setTriple(CandidateTriple);
2090       // FIXME: We hack together the directory name here instead of
2091       // using LI to ensure stable path separators across Windows and
2092       // Linux.
2093       GCCInstallPath = (LibDir + "/" + LibSuffix + "/" + VersionText).str();
2094       GCCParentLibPath = (GCCInstallPath + "/../" + Suffix.ReversePath).str();
2095       IsValid = true;
2096     }
2097   }
2098 }
2099 
2100 bool Generic_GCC::GCCInstallationDetector::ScanGentooGccConfig(
2101     const llvm::Triple &TargetTriple, const ArgList &Args,
2102     StringRef CandidateTriple, bool NeedsBiarchSuffix) {
2103   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
2104       D.getVFS().getBufferForFile(D.SysRoot + "/etc/env.d/gcc/config-" +
2105                                   CandidateTriple.str());
2106   if (File) {
2107     SmallVector<StringRef, 2> Lines;
2108     File.get()->getBuffer().split(Lines, "\n");
2109     for (StringRef Line : Lines) {
2110       Line = Line.trim();
2111       // CURRENT=triple-version
2112       if (Line.consume_front("CURRENT=")) {
2113         const std::pair<StringRef, StringRef> ActiveVersion =
2114           Line.rsplit('-');
2115         // Note: Strictly speaking, we should be reading
2116         // /etc/env.d/gcc/${CURRENT} now. However, the file doesn't
2117         // contain anything new or especially useful to us.
2118         const std::string GentooPath = D.SysRoot + "/usr/lib/gcc/" +
2119                                        ActiveVersion.first.str() + "/" +
2120                                        ActiveVersion.second.str();
2121         if (D.getVFS().exists(GentooPath + "/crtbegin.o")) {
2122           if (!ScanGCCForMultilibs(TargetTriple, Args, GentooPath,
2123                                    NeedsBiarchSuffix))
2124             return false;
2125 
2126           Version = GCCVersion::Parse(ActiveVersion.second);
2127           GCCInstallPath = GentooPath;
2128           GCCParentLibPath = GentooPath + "/../../..";
2129           GCCTriple.setTriple(ActiveVersion.first);
2130           IsValid = true;
2131           return true;
2132         }
2133       }
2134     }
2135   }
2136 
2137   return false;
2138 }
2139 
2140 Generic_GCC::Generic_GCC(const Driver &D, const llvm::Triple &Triple,
2141                          const ArgList &Args)
2142     : ToolChain(D, Triple, Args), GCCInstallation(D),
2143       CudaInstallation(D, Triple, Args) {
2144   getProgramPaths().push_back(getDriver().getInstalledDir());
2145   if (getDriver().getInstalledDir() != getDriver().Dir)
2146     getProgramPaths().push_back(getDriver().Dir);
2147 }
2148 
2149 Generic_GCC::~Generic_GCC() {}
2150 
2151 Tool *Generic_GCC::getTool(Action::ActionClass AC) const {
2152   switch (AC) {
2153   case Action::PreprocessJobClass:
2154     if (!Preprocess)
2155       Preprocess.reset(new clang::driver::tools::gcc::Preprocessor(*this));
2156     return Preprocess.get();
2157   case Action::CompileJobClass:
2158     if (!Compile)
2159       Compile.reset(new tools::gcc::Compiler(*this));
2160     return Compile.get();
2161   default:
2162     return ToolChain::getTool(AC);
2163   }
2164 }
2165 
2166 Tool *Generic_GCC::buildAssembler() const {
2167   return new tools::gnutools::Assembler(*this);
2168 }
2169 
2170 Tool *Generic_GCC::buildLinker() const { return new tools::gcc::Linker(*this); }
2171 
2172 void Generic_GCC::printVerboseInfo(raw_ostream &OS) const {
2173   // Print the information about how we detected the GCC installation.
2174   GCCInstallation.print(OS);
2175   CudaInstallation.print(OS);
2176 }
2177 
2178 bool Generic_GCC::IsUnwindTablesDefault(const ArgList &Args) const {
2179   return getArch() == llvm::Triple::x86_64;
2180 }
2181 
2182 bool Generic_GCC::isPICDefault() const {
2183   switch (getArch()) {
2184   case llvm::Triple::x86_64:
2185     return getTriple().isOSWindows();
2186   case llvm::Triple::ppc64:
2187   case llvm::Triple::ppc64le:
2188     return !getTriple().isOSBinFormatMachO() && !getTriple().isMacOSX();
2189   case llvm::Triple::mips64:
2190   case llvm::Triple::mips64el:
2191     return true;
2192   default:
2193     return false;
2194   }
2195 }
2196 
2197 bool Generic_GCC::isPIEDefault() const { return false; }
2198 
2199 bool Generic_GCC::isPICDefaultForced() const {
2200   return getArch() == llvm::Triple::x86_64 && getTriple().isOSWindows();
2201 }
2202 
2203 bool Generic_GCC::IsIntegratedAssemblerDefault() const {
2204   switch (getTriple().getArch()) {
2205   case llvm::Triple::x86:
2206   case llvm::Triple::x86_64:
2207   case llvm::Triple::aarch64:
2208   case llvm::Triple::aarch64_be:
2209   case llvm::Triple::arm:
2210   case llvm::Triple::armeb:
2211   case llvm::Triple::avr:
2212   case llvm::Triple::bpfel:
2213   case llvm::Triple::bpfeb:
2214   case llvm::Triple::thumb:
2215   case llvm::Triple::thumbeb:
2216   case llvm::Triple::ppc:
2217   case llvm::Triple::ppc64:
2218   case llvm::Triple::ppc64le:
2219   case llvm::Triple::systemz:
2220   case llvm::Triple::mips:
2221   case llvm::Triple::mipsel:
2222     return true;
2223   case llvm::Triple::mips64:
2224   case llvm::Triple::mips64el:
2225     // Enabled for Debian and Android mips64/mipsel, as they can precisely
2226     // identify the ABI in use (Debian) or only use N64 for MIPS64 (Android).
2227     // Other targets are unable to distinguish N32 from N64.
2228     if (getTriple().getEnvironment() == llvm::Triple::GNUABI64 ||
2229         getTriple().isAndroid())
2230       return true;
2231     return false;
2232   default:
2233     return false;
2234   }
2235 }
2236 
2237 void Generic_GCC::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
2238                                                ArgStringList &CC1Args) const {
2239   if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
2240       DriverArgs.hasArg(options::OPT_nostdincxx))
2241     return;
2242 
2243   switch (GetCXXStdlibType(DriverArgs)) {
2244   case ToolChain::CST_Libcxx: {
2245     std::string Path = findLibCxxIncludePath();
2246     if (!Path.empty())
2247       addSystemInclude(DriverArgs, CC1Args, Path);
2248     break;
2249   }
2250 
2251   case ToolChain::CST_Libstdcxx:
2252     addLibStdCxxIncludePaths(DriverArgs, CC1Args);
2253     break;
2254   }
2255 }
2256 
2257 std::string Generic_GCC::findLibCxxIncludePath() const {
2258   // FIXME: The Linux behavior would probaby be a better approach here.
2259   return getDriver().SysRoot + "/usr/include/c++/v1";
2260 }
2261 
2262 void
2263 Generic_GCC::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
2264                                       llvm::opt::ArgStringList &CC1Args) const {
2265   // By default, we don't assume we know where libstdc++ might be installed.
2266   // FIXME: If we have a valid GCCInstallation, use it.
2267 }
2268 
2269 /// \brief Helper to add the variant paths of a libstdc++ installation.
2270 bool Generic_GCC::addLibStdCXXIncludePaths(
2271     Twine Base, Twine Suffix, StringRef GCCTriple, StringRef GCCMultiarchTriple,
2272     StringRef TargetMultiarchTriple, Twine IncludeSuffix,
2273     const ArgList &DriverArgs, ArgStringList &CC1Args) const {
2274   if (!getVFS().exists(Base + Suffix))
2275     return false;
2276 
2277   addSystemInclude(DriverArgs, CC1Args, Base + Suffix);
2278 
2279   // The vanilla GCC layout of libstdc++ headers uses a triple subdirectory. If
2280   // that path exists or we have neither a GCC nor target multiarch triple, use
2281   // this vanilla search path.
2282   if ((GCCMultiarchTriple.empty() && TargetMultiarchTriple.empty()) ||
2283       getVFS().exists(Base + Suffix + "/" + GCCTriple + IncludeSuffix)) {
2284     addSystemInclude(DriverArgs, CC1Args,
2285                      Base + Suffix + "/" + GCCTriple + IncludeSuffix);
2286   } else {
2287     // Otherwise try to use multiarch naming schemes which have normalized the
2288     // triples and put the triple before the suffix.
2289     //
2290     // GCC surprisingly uses *both* the GCC triple with a multilib suffix and
2291     // the target triple, so we support that here.
2292     addSystemInclude(DriverArgs, CC1Args,
2293                      Base + "/" + GCCMultiarchTriple + Suffix + IncludeSuffix);
2294     addSystemInclude(DriverArgs, CC1Args,
2295                      Base + "/" + TargetMultiarchTriple + Suffix);
2296   }
2297 
2298   addSystemInclude(DriverArgs, CC1Args, Base + Suffix + "/backward");
2299   return true;
2300 }
2301 
2302 llvm::opt::DerivedArgList *
2303 Generic_GCC::TranslateArgs(const llvm::opt::DerivedArgList &Args, StringRef,
2304                            Action::OffloadKind DeviceOffloadKind) const {
2305 
2306   // If this tool chain is used for an OpenMP offloading device we have to make
2307   // sure we always generate a shared library regardless of the commands the
2308   // user passed to the host. This is required because the runtime library
2309   // is required to load the device image dynamically at run time.
2310   if (DeviceOffloadKind == Action::OFK_OpenMP) {
2311     DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
2312     const OptTable &Opts = getDriver().getOpts();
2313 
2314     // Request the shared library. Given that these options are decided
2315     // implicitly, they do not refer to any base argument.
2316     DAL->AddFlagArg(/*BaseArg=*/nullptr, Opts.getOption(options::OPT_shared));
2317     DAL->AddFlagArg(/*BaseArg=*/nullptr, Opts.getOption(options::OPT_fPIC));
2318 
2319     // Filter all the arguments we don't care passing to the offloading
2320     // toolchain as they can mess up with the creation of a shared library.
2321     for (auto *A : Args) {
2322       switch ((options::ID)A->getOption().getID()) {
2323       default:
2324         DAL->append(A);
2325         break;
2326       case options::OPT_shared:
2327       case options::OPT_dynamic:
2328       case options::OPT_static:
2329       case options::OPT_fPIC:
2330       case options::OPT_fno_PIC:
2331       case options::OPT_fpic:
2332       case options::OPT_fno_pic:
2333       case options::OPT_fPIE:
2334       case options::OPT_fno_PIE:
2335       case options::OPT_fpie:
2336       case options::OPT_fno_pie:
2337         break;
2338       }
2339     }
2340     return DAL;
2341   }
2342   return nullptr;
2343 }
2344 
2345 void Generic_ELF::anchor() {}
2346 
2347 void Generic_ELF::addClangTargetOptions(const ArgList &DriverArgs,
2348                                         ArgStringList &CC1Args,
2349                                         Action::OffloadKind) const {
2350   const Generic_GCC::GCCVersion &V = GCCInstallation.getVersion();
2351   bool UseInitArrayDefault =
2352       getTriple().getArch() == llvm::Triple::aarch64 ||
2353       getTriple().getArch() == llvm::Triple::aarch64_be ||
2354       (getTriple().getOS() == llvm::Triple::Linux &&
2355        (!V.isOlderThan(4, 7, 0) || getTriple().isAndroid())) ||
2356       getTriple().getOS() == llvm::Triple::NaCl ||
2357       (getTriple().getVendor() == llvm::Triple::MipsTechnologies &&
2358        !getTriple().hasEnvironment()) ||
2359       getTriple().getOS() == llvm::Triple::Solaris;
2360 
2361   if (DriverArgs.hasFlag(options::OPT_fuse_init_array,
2362                          options::OPT_fno_use_init_array, UseInitArrayDefault))
2363     CC1Args.push_back("-fuse-init-array");
2364 }
2365