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 "Arch/ARM.h"
12 #include "Arch/Mips.h"
13 #include "Arch/PPC.h"
14 #include "Arch/RISCV.h"
15 #include "Arch/Sparc.h"
16 #include "Arch/SystemZ.h"
17 #include "CommonArgs.h"
18 #include "Linux.h"
19 #include "clang/Basic/VirtualFileSystem.h"
20 #include "clang/Config/config.h" // for GCC_INSTALL_PREFIX
21 #include "clang/Driver/Compilation.h"
22 #include "clang/Driver/Driver.h"
23 #include "clang/Driver/DriverDiagnostic.h"
24 #include "clang/Driver/Options.h"
25 #include "clang/Driver/Tool.h"
26 #include "llvm/Option/ArgList.h"
27 #include "llvm/Support/CodeGen.h"
28 #include "llvm/Support/Path.h"
29 #include "llvm/Support/TargetParser.h"
30 #include <system_error>
31 
32 using namespace clang::driver;
33 using namespace clang::driver::toolchains;
34 using namespace clang;
35 using namespace llvm::opt;
36 
37 void tools::GnuTool::anchor() {}
38 
39 static bool forwardToGCC(const Option &O) {
40   // Don't forward inputs from the original command line.  They are added from
41   // InputInfoList.
42   return O.getKind() != Option::InputClass &&
43          !O.hasFlag(options::DriverOption) && !O.hasFlag(options::LinkerInput);
44 }
45 
46 // Switch CPU names not recognized by GNU assembler to a close CPU that it does
47 // recognize, instead of a lower march from being picked in the absence of a cpu
48 // flag.
49 static void normalizeCPUNamesForAssembler(const ArgList &Args,
50                                           ArgStringList &CmdArgs) {
51   if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
52     StringRef CPUArg(A->getValue());
53     if (CPUArg.equals_lower("krait"))
54       CmdArgs.push_back("-mcpu=cortex-a15");
55     else if(CPUArg.equals_lower("kryo"))
56       CmdArgs.push_back("-mcpu=cortex-a57");
57     else
58       Args.AddLastArg(CmdArgs, options::OPT_mcpu_EQ);
59   }
60 }
61 
62 void tools::gcc::Common::ConstructJob(Compilation &C, const JobAction &JA,
63                                       const InputInfo &Output,
64                                       const InputInfoList &Inputs,
65                                       const ArgList &Args,
66                                       const char *LinkingOutput) const {
67   const Driver &D = getToolChain().getDriver();
68   ArgStringList CmdArgs;
69 
70   for (const auto &A : Args) {
71     if (forwardToGCC(A->getOption())) {
72       // It is unfortunate that we have to claim here, as this means
73       // we will basically never report anything interesting for
74       // platforms using a generic gcc, even if we are just using gcc
75       // to get to the assembler.
76       A->claim();
77 
78       // Don't forward any -g arguments to assembly steps.
79       if (isa<AssembleJobAction>(JA) &&
80           A->getOption().matches(options::OPT_g_Group))
81         continue;
82 
83       // Don't forward any -W arguments to assembly and link steps.
84       if ((isa<AssembleJobAction>(JA) || isa<LinkJobAction>(JA)) &&
85           A->getOption().matches(options::OPT_W_Group))
86         continue;
87 
88       // Don't forward -mno-unaligned-access since GCC doesn't understand
89       // it and because it doesn't affect the assembly or link steps.
90       if ((isa<AssembleJobAction>(JA) || isa<LinkJobAction>(JA)) &&
91           (A->getOption().matches(options::OPT_munaligned_access) ||
92            A->getOption().matches(options::OPT_mno_unaligned_access)))
93         continue;
94 
95       A->render(Args, CmdArgs);
96     }
97   }
98 
99   RenderExtraToolArgs(JA, CmdArgs);
100 
101   // If using a driver driver, force the arch.
102   if (getToolChain().getTriple().isOSDarwin()) {
103     CmdArgs.push_back("-arch");
104     CmdArgs.push_back(
105         Args.MakeArgString(getToolChain().getDefaultUniversalArchName()));
106   }
107 
108   // Try to force gcc to match the tool chain we want, if we recognize
109   // the arch.
110   //
111   // FIXME: The triple class should directly provide the information we want
112   // here.
113   switch (getToolChain().getArch()) {
114   default:
115     break;
116   case llvm::Triple::x86:
117   case llvm::Triple::ppc:
118     CmdArgs.push_back("-m32");
119     break;
120   case llvm::Triple::x86_64:
121   case llvm::Triple::ppc64:
122   case llvm::Triple::ppc64le:
123     CmdArgs.push_back("-m64");
124     break;
125   case llvm::Triple::sparcel:
126     CmdArgs.push_back("-EL");
127     break;
128   }
129 
130   if (Output.isFilename()) {
131     CmdArgs.push_back("-o");
132     CmdArgs.push_back(Output.getFilename());
133   } else {
134     assert(Output.isNothing() && "Unexpected output");
135     CmdArgs.push_back("-fsyntax-only");
136   }
137 
138   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
139 
140   // Only pass -x if gcc will understand it; otherwise hope gcc
141   // understands the suffix correctly. The main use case this would go
142   // wrong in is for linker inputs if they happened to have an odd
143   // suffix; really the only way to get this to happen is a command
144   // like '-x foobar a.c' which will treat a.c like a linker input.
145   //
146   // FIXME: For the linker case specifically, can we safely convert
147   // inputs into '-Wl,' options?
148   for (const auto &II : Inputs) {
149     // Don't try to pass LLVM or AST inputs to a generic gcc.
150     if (types::isLLVMIR(II.getType()))
151       D.Diag(clang::diag::err_drv_no_linker_llvm_support)
152           << getToolChain().getTripleString();
153     else if (II.getType() == types::TY_AST)
154       D.Diag(diag::err_drv_no_ast_support) << getToolChain().getTripleString();
155     else if (II.getType() == types::TY_ModuleFile)
156       D.Diag(diag::err_drv_no_module_support)
157           << getToolChain().getTripleString();
158 
159     if (types::canTypeBeUserSpecified(II.getType())) {
160       CmdArgs.push_back("-x");
161       CmdArgs.push_back(types::getTypeName(II.getType()));
162     }
163 
164     if (II.isFilename())
165       CmdArgs.push_back(II.getFilename());
166     else {
167       const Arg &A = II.getInputArg();
168 
169       // Reverse translate some rewritten options.
170       if (A.getOption().matches(options::OPT_Z_reserved_lib_stdcxx)) {
171         CmdArgs.push_back("-lstdc++");
172         continue;
173       }
174 
175       // Don't render as input, we need gcc to do the translations.
176       A.render(Args, CmdArgs);
177     }
178   }
179 
180   const std::string &customGCCName = D.getCCCGenericGCCName();
181   const char *GCCName;
182   if (!customGCCName.empty())
183     GCCName = customGCCName.c_str();
184   else if (D.CCCIsCXX()) {
185     GCCName = "g++";
186   } else
187     GCCName = "gcc";
188 
189   const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath(GCCName));
190   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
191 }
192 
193 void tools::gcc::Preprocessor::RenderExtraToolArgs(
194     const JobAction &JA, ArgStringList &CmdArgs) const {
195   CmdArgs.push_back("-E");
196 }
197 
198 void tools::gcc::Compiler::RenderExtraToolArgs(const JobAction &JA,
199                                                ArgStringList &CmdArgs) const {
200   const Driver &D = getToolChain().getDriver();
201 
202   switch (JA.getType()) {
203   // If -flto, etc. are present then make sure not to force assembly output.
204   case types::TY_LLVM_IR:
205   case types::TY_LTO_IR:
206   case types::TY_LLVM_BC:
207   case types::TY_LTO_BC:
208     CmdArgs.push_back("-c");
209     break;
210   // We assume we've got an "integrated" assembler in that gcc will produce an
211   // object file itself.
212   case types::TY_Object:
213     CmdArgs.push_back("-c");
214     break;
215   case types::TY_PP_Asm:
216     CmdArgs.push_back("-S");
217     break;
218   case types::TY_Nothing:
219     CmdArgs.push_back("-fsyntax-only");
220     break;
221   default:
222     D.Diag(diag::err_drv_invalid_gcc_output_type) << getTypeName(JA.getType());
223   }
224 }
225 
226 void tools::gcc::Linker::RenderExtraToolArgs(const JobAction &JA,
227                                              ArgStringList &CmdArgs) const {
228   // The types are (hopefully) good enough.
229 }
230 
231 static const char *getLDMOption(const llvm::Triple &T, const ArgList &Args) {
232   switch (T.getArch()) {
233   case llvm::Triple::x86:
234     if (T.isOSIAMCU())
235       return "elf_iamcu";
236     return "elf_i386";
237   case llvm::Triple::aarch64:
238     return "aarch64linux";
239   case llvm::Triple::aarch64_be:
240     return "aarch64_be_linux";
241   case llvm::Triple::arm:
242   case llvm::Triple::thumb:
243     return "armelf_linux_eabi";
244   case llvm::Triple::armeb:
245   case llvm::Triple::thumbeb:
246     return "armelfb_linux_eabi";
247   case llvm::Triple::ppc:
248     return "elf32ppclinux";
249   case llvm::Triple::ppc64:
250     return "elf64ppc";
251   case llvm::Triple::ppc64le:
252     return "elf64lppc";
253   case llvm::Triple::riscv32:
254     return "elf32lriscv";
255   case llvm::Triple::riscv64:
256     return "elf64lriscv";
257   case llvm::Triple::sparc:
258   case llvm::Triple::sparcel:
259     return "elf32_sparc";
260   case llvm::Triple::sparcv9:
261     return "elf64_sparc";
262   case llvm::Triple::mips:
263     return "elf32btsmip";
264   case llvm::Triple::mipsel:
265     return "elf32ltsmip";
266   case llvm::Triple::mips64:
267     if (tools::mips::hasMipsAbiArg(Args, "n32"))
268       return "elf32btsmipn32";
269     return "elf64btsmip";
270   case llvm::Triple::mips64el:
271     if (tools::mips::hasMipsAbiArg(Args, "n32"))
272       return "elf32ltsmipn32";
273     return "elf64ltsmip";
274   case llvm::Triple::systemz:
275     return "elf64_s390";
276   case llvm::Triple::x86_64:
277     if (T.getEnvironment() == llvm::Triple::GNUX32)
278       return "elf32_x86_64";
279     return "elf_x86_64";
280   default:
281     return nullptr;
282   }
283 }
284 
285 static bool getPIE(const ArgList &Args, const toolchains::Linux &ToolChain) {
286   if (Args.hasArg(options::OPT_shared) || Args.hasArg(options::OPT_static) ||
287       Args.hasArg(options::OPT_r))
288     return false;
289 
290   Arg *A = Args.getLastArg(options::OPT_pie, options::OPT_no_pie,
291                            options::OPT_nopie);
292   if (!A)
293     return ToolChain.isPIEDefault();
294   return A->getOption().matches(options::OPT_pie);
295 }
296 
297 void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
298                                            const InputInfo &Output,
299                                            const InputInfoList &Inputs,
300                                            const ArgList &Args,
301                                            const char *LinkingOutput) const {
302   const toolchains::Linux &ToolChain =
303       static_cast<const toolchains::Linux &>(getToolChain());
304   const Driver &D = ToolChain.getDriver();
305 
306   const llvm::Triple &Triple = getToolChain().getEffectiveTriple();
307 
308   const llvm::Triple::ArchType Arch = ToolChain.getArch();
309   const bool isAndroid = ToolChain.getTriple().isAndroid();
310   const bool IsIAMCU = ToolChain.getTriple().isOSIAMCU();
311   const bool IsPIE = getPIE(Args, ToolChain);
312   const bool HasCRTBeginEndFiles =
313       ToolChain.getTriple().hasEnvironment() ||
314       (ToolChain.getTriple().getVendor() != llvm::Triple::MipsTechnologies);
315 
316   ArgStringList CmdArgs;
317 
318   // Silence warning for "clang -g foo.o -o foo"
319   Args.ClaimAllArgs(options::OPT_g_Group);
320   // and "clang -emit-llvm foo.o -o foo"
321   Args.ClaimAllArgs(options::OPT_emit_llvm);
322   // and for "clang -w foo.o -o foo". Other warning options are already
323   // handled somewhere else.
324   Args.ClaimAllArgs(options::OPT_w);
325 
326   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
327   if (llvm::sys::path::stem(Exec) == "lld") {
328     CmdArgs.push_back("-flavor");
329     CmdArgs.push_back("old-gnu");
330     CmdArgs.push_back("-target");
331     CmdArgs.push_back(Args.MakeArgString(getToolChain().getTripleString()));
332   }
333 
334   if (!D.SysRoot.empty())
335     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
336 
337   if (IsPIE)
338     CmdArgs.push_back("-pie");
339 
340   if (Args.hasArg(options::OPT_rdynamic))
341     CmdArgs.push_back("-export-dynamic");
342 
343   if (Args.hasArg(options::OPT_s))
344     CmdArgs.push_back("-s");
345 
346   if (Arch == llvm::Triple::armeb || Arch == llvm::Triple::thumbeb)
347     arm::appendEBLinkFlags(Args, CmdArgs, Triple);
348 
349   // Most Android ARM64 targets should enable the linker fix for erratum
350   // 843419. Only non-Cortex-A53 devices are allowed to skip this flag.
351   if (Arch == llvm::Triple::aarch64 && isAndroid) {
352     std::string CPU = getCPUName(Args, Triple);
353     if (CPU.empty() || CPU == "generic" || CPU == "cortex-a53")
354       CmdArgs.push_back("--fix-cortex-a53-843419");
355   }
356 
357   for (const auto &Opt : ToolChain.ExtraOpts)
358     CmdArgs.push_back(Opt.c_str());
359 
360   CmdArgs.push_back("--eh-frame-hdr");
361 
362   if (const char *LDMOption = getLDMOption(ToolChain.getTriple(), Args)) {
363     CmdArgs.push_back("-m");
364     CmdArgs.push_back(LDMOption);
365   } else {
366     D.Diag(diag::err_target_unknown_triple) << Triple.str();
367     return;
368   }
369 
370   if (Args.hasArg(options::OPT_static)) {
371     if (Arch == llvm::Triple::arm || Arch == llvm::Triple::armeb ||
372         Arch == llvm::Triple::thumb || Arch == llvm::Triple::thumbeb)
373       CmdArgs.push_back("-Bstatic");
374     else
375       CmdArgs.push_back("-static");
376   } else if (Args.hasArg(options::OPT_shared)) {
377     CmdArgs.push_back("-shared");
378   }
379 
380   if (!Args.hasArg(options::OPT_static)) {
381     if (Args.hasArg(options::OPT_rdynamic))
382       CmdArgs.push_back("-export-dynamic");
383 
384     if (!Args.hasArg(options::OPT_shared)) {
385       const std::string Loader =
386           D.DyldPrefix + ToolChain.getDynamicLinker(Args);
387       CmdArgs.push_back("-dynamic-linker");
388       CmdArgs.push_back(Args.MakeArgString(Loader));
389     }
390   }
391 
392   CmdArgs.push_back("-o");
393   CmdArgs.push_back(Output.getFilename());
394 
395   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
396     if (!isAndroid && !IsIAMCU) {
397       const char *crt1 = nullptr;
398       if (!Args.hasArg(options::OPT_shared)) {
399         if (Args.hasArg(options::OPT_pg))
400           crt1 = "gcrt1.o";
401         else if (IsPIE)
402           crt1 = "Scrt1.o";
403         else
404           crt1 = "crt1.o";
405       }
406       if (crt1)
407         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crt1)));
408 
409       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crti.o")));
410     }
411 
412     if (IsIAMCU)
413       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt0.o")));
414     else {
415       const char *crtbegin;
416       if (Args.hasArg(options::OPT_static))
417         crtbegin = isAndroid ? "crtbegin_static.o" : "crtbeginT.o";
418       else if (Args.hasArg(options::OPT_shared))
419         crtbegin = isAndroid ? "crtbegin_so.o" : "crtbeginS.o";
420       else if (IsPIE)
421         crtbegin = isAndroid ? "crtbegin_dynamic.o" : "crtbeginS.o";
422       else
423         crtbegin = isAndroid ? "crtbegin_dynamic.o" : "crtbegin.o";
424 
425       if (HasCRTBeginEndFiles)
426         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtbegin)));
427     }
428 
429     // Add crtfastmath.o if available and fast math is enabled.
430     ToolChain.AddFastMathRuntimeIfAvailable(Args, CmdArgs);
431   }
432 
433   Args.AddAllArgs(CmdArgs, options::OPT_L);
434   Args.AddAllArgs(CmdArgs, options::OPT_u);
435 
436   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
437 
438   if (D.isUsingLTO()) {
439     assert(!Inputs.empty() && "Must have at least one input.");
440     AddGoldPlugin(ToolChain, Args, CmdArgs, Output, Inputs[0],
441                   D.getLTOMode() == LTOK_Thin);
442   }
443 
444   if (Args.hasArg(options::OPT_Z_Xlinker__no_demangle))
445     CmdArgs.push_back("--no-demangle");
446 
447   bool NeedsSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
448   bool NeedsXRayDeps = addXRayRuntime(ToolChain, Args, CmdArgs);
449   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
450   // The profile runtime also needs access to system libraries.
451   getToolChain().addProfileRTLibs(Args, CmdArgs);
452 
453   if (D.CCCIsCXX() &&
454       !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
455     if (ToolChain.ShouldLinkCXXStdlib(Args)) {
456       bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
457                                  !Args.hasArg(options::OPT_static);
458       if (OnlyLibstdcxxStatic)
459         CmdArgs.push_back("-Bstatic");
460       ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
461       if (OnlyLibstdcxxStatic)
462         CmdArgs.push_back("-Bdynamic");
463     }
464     CmdArgs.push_back("-lm");
465   }
466   // Silence warnings when linking C code with a C++ '-stdlib' argument.
467   Args.ClaimAllArgs(options::OPT_stdlib_EQ);
468 
469   if (!Args.hasArg(options::OPT_nostdlib)) {
470     if (!Args.hasArg(options::OPT_nodefaultlibs)) {
471       if (Args.hasArg(options::OPT_static))
472         CmdArgs.push_back("--start-group");
473 
474       if (NeedsSanitizerDeps)
475         linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
476 
477       if (NeedsXRayDeps)
478         linkXRayRuntimeDeps(ToolChain, CmdArgs);
479 
480       bool WantPthread = Args.hasArg(options::OPT_pthread) ||
481                          Args.hasArg(options::OPT_pthreads);
482 
483       // FIXME: Only pass GompNeedsRT = true for platforms with libgomp that
484       // require librt. Most modern Linux platforms do, but some may not.
485       if (addOpenMPRuntime(CmdArgs, ToolChain, Args,
486                            JA.isHostOffloading(Action::OFK_OpenMP),
487                            /* GompNeedsRT= */ true))
488         // OpenMP runtimes implies pthreads when using the GNU toolchain.
489         // FIXME: Does this really make sense for all GNU toolchains?
490         WantPthread = true;
491 
492       AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
493 
494       if (WantPthread && !isAndroid)
495         CmdArgs.push_back("-lpthread");
496 
497       if (Args.hasArg(options::OPT_fsplit_stack))
498         CmdArgs.push_back("--wrap=pthread_create");
499 
500       CmdArgs.push_back("-lc");
501 
502       // Add IAMCU specific libs, if needed.
503       if (IsIAMCU)
504         CmdArgs.push_back("-lgloss");
505 
506       if (Args.hasArg(options::OPT_static))
507         CmdArgs.push_back("--end-group");
508       else
509         AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
510 
511       // Add IAMCU specific libs (outside the group), if needed.
512       if (IsIAMCU) {
513         CmdArgs.push_back("--as-needed");
514         CmdArgs.push_back("-lsoftfp");
515         CmdArgs.push_back("--no-as-needed");
516       }
517     }
518 
519     if (!Args.hasArg(options::OPT_nostartfiles) && !IsIAMCU) {
520       const char *crtend;
521       if (Args.hasArg(options::OPT_shared))
522         crtend = isAndroid ? "crtend_so.o" : "crtendS.o";
523       else if (IsPIE)
524         crtend = isAndroid ? "crtend_android.o" : "crtendS.o";
525       else
526         crtend = isAndroid ? "crtend_android.o" : "crtend.o";
527 
528       if (HasCRTBeginEndFiles)
529         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtend)));
530       if (!isAndroid)
531         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtn.o")));
532     }
533   }
534 
535   // Add OpenMP offloading linker script args if required.
536   AddOpenMPLinkerScript(getToolChain(), C, Output, Inputs, Args, CmdArgs, JA);
537 
538   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
539 }
540 
541 void tools::gnutools::Assembler::ConstructJob(Compilation &C,
542                                               const JobAction &JA,
543                                               const InputInfo &Output,
544                                               const InputInfoList &Inputs,
545                                               const ArgList &Args,
546                                               const char *LinkingOutput) const {
547   const auto &D = getToolChain().getDriver();
548 
549   claimNoWarnArgs(Args);
550 
551   ArgStringList CmdArgs;
552 
553   llvm::Reloc::Model RelocationModel;
554   unsigned PICLevel;
555   bool IsPIE;
556   std::tie(RelocationModel, PICLevel, IsPIE) =
557       ParsePICArgs(getToolChain(), Args);
558 
559   if (const Arg *A = Args.getLastArg(options::OPT_gz, options::OPT_gz_EQ)) {
560     if (A->getOption().getID() == options::OPT_gz) {
561       CmdArgs.push_back("-compress-debug-sections");
562     } else {
563       StringRef Value = A->getValue();
564       if (Value == "none") {
565         CmdArgs.push_back("-compress-debug-sections=none");
566       } else if (Value == "zlib" || Value == "zlib-gnu") {
567         CmdArgs.push_back(
568             Args.MakeArgString("-compress-debug-sections=" + Twine(Value)));
569       } else {
570         D.Diag(diag::err_drv_unsupported_option_argument)
571             << A->getOption().getName() << Value;
572       }
573     }
574   }
575 
576   switch (getToolChain().getArch()) {
577   default:
578     break;
579   // Add --32/--64 to make sure we get the format we want.
580   // This is incomplete
581   case llvm::Triple::x86:
582     CmdArgs.push_back("--32");
583     break;
584   case llvm::Triple::x86_64:
585     if (getToolChain().getTriple().getEnvironment() == llvm::Triple::GNUX32)
586       CmdArgs.push_back("--x32");
587     else
588       CmdArgs.push_back("--64");
589     break;
590   case llvm::Triple::ppc: {
591     CmdArgs.push_back("-a32");
592     CmdArgs.push_back("-mppc");
593     CmdArgs.push_back(
594       ppc::getPPCAsmModeForCPU(getCPUName(Args, getToolChain().getTriple())));
595     break;
596   }
597   case llvm::Triple::ppc64: {
598     CmdArgs.push_back("-a64");
599     CmdArgs.push_back("-mppc64");
600     CmdArgs.push_back(
601       ppc::getPPCAsmModeForCPU(getCPUName(Args, getToolChain().getTriple())));
602     break;
603   }
604   case llvm::Triple::ppc64le: {
605     CmdArgs.push_back("-a64");
606     CmdArgs.push_back("-mppc64");
607     CmdArgs.push_back("-mlittle-endian");
608     CmdArgs.push_back(
609       ppc::getPPCAsmModeForCPU(getCPUName(Args, getToolChain().getTriple())));
610     break;
611   }
612   case llvm::Triple::riscv32:
613   case llvm::Triple::riscv64: {
614     StringRef ABIName = riscv::getRISCVABI(Args, getToolChain().getTriple());
615     CmdArgs.push_back("-mabi");
616     CmdArgs.push_back(ABIName.data());
617     if (const Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
618       StringRef MArch = A->getValue();
619       CmdArgs.push_back("-march");
620       CmdArgs.push_back(MArch.data());
621     }
622     break;
623   }
624   case llvm::Triple::sparc:
625   case llvm::Triple::sparcel: {
626     CmdArgs.push_back("-32");
627     std::string CPU = getCPUName(Args, getToolChain().getTriple());
628     CmdArgs.push_back(sparc::getSparcAsmModeForCPU(CPU, getToolChain().getTriple()));
629     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
630     break;
631   }
632   case llvm::Triple::sparcv9: {
633     CmdArgs.push_back("-64");
634     std::string CPU = getCPUName(Args, getToolChain().getTriple());
635     CmdArgs.push_back(sparc::getSparcAsmModeForCPU(CPU, getToolChain().getTriple()));
636     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
637     break;
638   }
639   case llvm::Triple::arm:
640   case llvm::Triple::armeb:
641   case llvm::Triple::thumb:
642   case llvm::Triple::thumbeb: {
643     const llvm::Triple &Triple2 = getToolChain().getTriple();
644     switch (Triple2.getSubArch()) {
645     case llvm::Triple::ARMSubArch_v7:
646       CmdArgs.push_back("-mfpu=neon");
647       break;
648     case llvm::Triple::ARMSubArch_v8:
649       CmdArgs.push_back("-mfpu=crypto-neon-fp-armv8");
650       break;
651     default:
652       break;
653     }
654 
655     switch (arm::getARMFloatABI(getToolChain(), Args)) {
656     case arm::FloatABI::Invalid: llvm_unreachable("must have an ABI!");
657     case arm::FloatABI::Soft:
658       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=soft"));
659       break;
660     case arm::FloatABI::SoftFP:
661       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=softfp"));
662       break;
663     case arm::FloatABI::Hard:
664       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=hard"));
665       break;
666     }
667 
668     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
669     normalizeCPUNamesForAssembler(Args, CmdArgs);
670 
671     Args.AddLastArg(CmdArgs, options::OPT_mfpu_EQ);
672     break;
673   }
674   case llvm::Triple::aarch64:
675   case llvm::Triple::aarch64_be: {
676     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
677     normalizeCPUNamesForAssembler(Args, CmdArgs);
678 
679     break;
680   }
681   case llvm::Triple::mips:
682   case llvm::Triple::mipsel:
683   case llvm::Triple::mips64:
684   case llvm::Triple::mips64el: {
685     StringRef CPUName;
686     StringRef ABIName;
687     mips::getMipsCPUAndABI(Args, getToolChain().getTriple(), CPUName, ABIName);
688     ABIName = mips::getGnuCompatibleMipsABIName(ABIName);
689 
690     CmdArgs.push_back("-march");
691     CmdArgs.push_back(CPUName.data());
692 
693     CmdArgs.push_back("-mabi");
694     CmdArgs.push_back(ABIName.data());
695 
696     // -mno-shared should be emitted unless -fpic, -fpie, -fPIC, -fPIE,
697     // or -mshared (not implemented) is in effect.
698     if (RelocationModel == llvm::Reloc::Static)
699       CmdArgs.push_back("-mno-shared");
700 
701     // LLVM doesn't support -mplt yet and acts as if it is always given.
702     // However, -mplt has no effect with the N64 ABI.
703     if (ABIName != "64" && !Args.hasArg(options::OPT_mno_abicalls))
704       CmdArgs.push_back("-call_nonpic");
705 
706     if (getToolChain().getArch() == llvm::Triple::mips ||
707         getToolChain().getArch() == llvm::Triple::mips64)
708       CmdArgs.push_back("-EB");
709     else
710       CmdArgs.push_back("-EL");
711 
712     if (Arg *A = Args.getLastArg(options::OPT_mnan_EQ)) {
713       if (StringRef(A->getValue()) == "2008")
714         CmdArgs.push_back(Args.MakeArgString("-mnan=2008"));
715     }
716 
717     // Add the last -mfp32/-mfpxx/-mfp64 or -mfpxx if it is enabled by default.
718     if (Arg *A = Args.getLastArg(options::OPT_mfp32, options::OPT_mfpxx,
719                                  options::OPT_mfp64)) {
720       A->claim();
721       A->render(Args, CmdArgs);
722     } else if (mips::shouldUseFPXX(
723                    Args, getToolChain().getTriple(), CPUName, ABIName,
724                    mips::getMipsFloatABI(getToolChain().getDriver(), Args)))
725       CmdArgs.push_back("-mfpxx");
726 
727     // Pass on -mmips16 or -mno-mips16. However, the assembler equivalent of
728     // -mno-mips16 is actually -no-mips16.
729     if (Arg *A =
730             Args.getLastArg(options::OPT_mips16, options::OPT_mno_mips16)) {
731       if (A->getOption().matches(options::OPT_mips16)) {
732         A->claim();
733         A->render(Args, CmdArgs);
734       } else {
735         A->claim();
736         CmdArgs.push_back("-no-mips16");
737       }
738     }
739 
740     Args.AddLastArg(CmdArgs, options::OPT_mmicromips,
741                     options::OPT_mno_micromips);
742     Args.AddLastArg(CmdArgs, options::OPT_mdsp, options::OPT_mno_dsp);
743     Args.AddLastArg(CmdArgs, options::OPT_mdspr2, options::OPT_mno_dspr2);
744 
745     if (Arg *A = Args.getLastArg(options::OPT_mmsa, options::OPT_mno_msa)) {
746       // Do not use AddLastArg because not all versions of MIPS assembler
747       // support -mmsa / -mno-msa options.
748       if (A->getOption().matches(options::OPT_mmsa))
749         CmdArgs.push_back(Args.MakeArgString("-mmsa"));
750     }
751 
752     Args.AddLastArg(CmdArgs, options::OPT_mhard_float,
753                     options::OPT_msoft_float);
754 
755     Args.AddLastArg(CmdArgs, options::OPT_mdouble_float,
756                     options::OPT_msingle_float);
757 
758     Args.AddLastArg(CmdArgs, options::OPT_modd_spreg,
759                     options::OPT_mno_odd_spreg);
760 
761     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
762     break;
763   }
764   case llvm::Triple::systemz: {
765     // Always pass an -march option, since our default of z10 is later
766     // than the GNU assembler's default.
767     StringRef CPUName = systemz::getSystemZTargetCPU(Args);
768     CmdArgs.push_back(Args.MakeArgString("-march=" + CPUName));
769     break;
770   }
771   }
772 
773   Args.AddAllArgs(CmdArgs, options::OPT_I);
774   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
775 
776   CmdArgs.push_back("-o");
777   CmdArgs.push_back(Output.getFilename());
778 
779   for (const auto &II : Inputs)
780     CmdArgs.push_back(II.getFilename());
781 
782   const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath("as"));
783   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
784 
785   // Handle the debug info splitting at object creation time if we're
786   // creating an object.
787   // TODO: Currently only works on linux with newer objcopy.
788   if (Args.hasArg(options::OPT_gsplit_dwarf) &&
789       getToolChain().getTriple().isOSLinux())
790     SplitDebugInfo(getToolChain(), C, *this, JA, Args, Output,
791                    SplitDebugName(Args, Inputs[0]));
792 }
793 
794 namespace {
795 // Filter to remove Multilibs that don't exist as a suffix to Path
796 class FilterNonExistent {
797   StringRef Base, File;
798   vfs::FileSystem &VFS;
799 
800 public:
801   FilterNonExistent(StringRef Base, StringRef File, vfs::FileSystem &VFS)
802       : Base(Base), File(File), VFS(VFS) {}
803   bool operator()(const Multilib &M) {
804     return !VFS.exists(Base + M.gccSuffix() + File);
805   }
806 };
807 } // end anonymous namespace
808 
809 static bool isSoftFloatABI(const ArgList &Args) {
810   Arg *A = Args.getLastArg(options::OPT_msoft_float, options::OPT_mhard_float,
811                            options::OPT_mfloat_abi_EQ);
812   if (!A)
813     return false;
814 
815   return A->getOption().matches(options::OPT_msoft_float) ||
816          (A->getOption().matches(options::OPT_mfloat_abi_EQ) &&
817           A->getValue() == StringRef("soft"));
818 }
819 
820 /// \p Flag must be a flag accepted by the driver with its leading '-' removed,
821 //     otherwise '-print-multi-lib' will not emit them correctly.
822 static void addMultilibFlag(bool Enabled, const char *const Flag,
823                             std::vector<std::string> &Flags) {
824   if (Enabled)
825     Flags.push_back(std::string("+") + Flag);
826   else
827     Flags.push_back(std::string("-") + Flag);
828 }
829 
830 static bool isArmOrThumbArch(llvm::Triple::ArchType Arch) {
831   return Arch == llvm::Triple::arm || Arch == llvm::Triple::thumb;
832 }
833 
834 static bool isMips32(llvm::Triple::ArchType Arch) {
835   return Arch == llvm::Triple::mips || Arch == llvm::Triple::mipsel;
836 }
837 
838 static bool isMips64(llvm::Triple::ArchType Arch) {
839   return Arch == llvm::Triple::mips64 || Arch == llvm::Triple::mips64el;
840 }
841 
842 static bool isMipsEL(llvm::Triple::ArchType Arch) {
843   return Arch == llvm::Triple::mipsel || Arch == llvm::Triple::mips64el;
844 }
845 
846 static bool isMips16(const ArgList &Args) {
847   Arg *A = Args.getLastArg(options::OPT_mips16, options::OPT_mno_mips16);
848   return A && A->getOption().matches(options::OPT_mips16);
849 }
850 
851 static bool isMicroMips(const ArgList &Args) {
852   Arg *A = Args.getLastArg(options::OPT_mmicromips, options::OPT_mno_micromips);
853   return A && A->getOption().matches(options::OPT_mmicromips);
854 }
855 
856 static bool isRISCV(llvm::Triple::ArchType Arch) {
857   return Arch == llvm::Triple::riscv32 || Arch == llvm::Triple::riscv64;
858 }
859 
860 static Multilib makeMultilib(StringRef commonSuffix) {
861   return Multilib(commonSuffix, commonSuffix, commonSuffix);
862 }
863 
864 static bool findMipsCsMultilibs(const Multilib::flags_list &Flags,
865                                 FilterNonExistent &NonExistent,
866                                 DetectedMultilibs &Result) {
867   // Check for Code Sourcery toolchain multilibs
868   MultilibSet CSMipsMultilibs;
869   {
870     auto MArchMips16 = makeMultilib("/mips16").flag("+m32").flag("+mips16");
871 
872     auto MArchMicroMips =
873         makeMultilib("/micromips").flag("+m32").flag("+mmicromips");
874 
875     auto MArchDefault = makeMultilib("").flag("-mips16").flag("-mmicromips");
876 
877     auto UCLibc = makeMultilib("/uclibc").flag("+muclibc");
878 
879     auto SoftFloat = makeMultilib("/soft-float").flag("+msoft-float");
880 
881     auto Nan2008 = makeMultilib("/nan2008").flag("+mnan=2008");
882 
883     auto DefaultFloat =
884         makeMultilib("").flag("-msoft-float").flag("-mnan=2008");
885 
886     auto BigEndian = makeMultilib("").flag("+EB").flag("-EL");
887 
888     auto LittleEndian = makeMultilib("/el").flag("+EL").flag("-EB");
889 
890     // Note that this one's osSuffix is ""
891     auto MAbi64 = makeMultilib("")
892                       .gccSuffix("/64")
893                       .includeSuffix("/64")
894                       .flag("+mabi=n64")
895                       .flag("-mabi=n32")
896                       .flag("-m32");
897 
898     CSMipsMultilibs =
899         MultilibSet()
900             .Either(MArchMips16, MArchMicroMips, MArchDefault)
901             .Maybe(UCLibc)
902             .Either(SoftFloat, Nan2008, DefaultFloat)
903             .FilterOut("/micromips/nan2008")
904             .FilterOut("/mips16/nan2008")
905             .Either(BigEndian, LittleEndian)
906             .Maybe(MAbi64)
907             .FilterOut("/mips16.*/64")
908             .FilterOut("/micromips.*/64")
909             .FilterOut(NonExistent)
910             .setIncludeDirsCallback([](const Multilib &M) {
911               std::vector<std::string> Dirs({"/include"});
912               if (StringRef(M.includeSuffix()).startswith("/uclibc"))
913                 Dirs.push_back(
914                     "/../../../../mips-linux-gnu/libc/uclibc/usr/include");
915               else
916                 Dirs.push_back("/../../../../mips-linux-gnu/libc/usr/include");
917               return Dirs;
918             });
919   }
920 
921   MultilibSet DebianMipsMultilibs;
922   {
923     Multilib MAbiN32 =
924         Multilib().gccSuffix("/n32").includeSuffix("/n32").flag("+mabi=n32");
925 
926     Multilib M64 = Multilib()
927                        .gccSuffix("/64")
928                        .includeSuffix("/64")
929                        .flag("+m64")
930                        .flag("-m32")
931                        .flag("-mabi=n32");
932 
933     Multilib M32 = Multilib().flag("-m64").flag("+m32").flag("-mabi=n32");
934 
935     DebianMipsMultilibs =
936         MultilibSet().Either(M32, M64, MAbiN32).FilterOut(NonExistent);
937   }
938 
939   // Sort candidates. Toolchain that best meets the directories tree goes first.
940   // Then select the first toolchains matches command line flags.
941   MultilibSet *Candidates[] = {&CSMipsMultilibs, &DebianMipsMultilibs};
942   if (CSMipsMultilibs.size() < DebianMipsMultilibs.size())
943     std::iter_swap(Candidates, Candidates + 1);
944   for (const MultilibSet *Candidate : Candidates) {
945     if (Candidate->select(Flags, Result.SelectedMultilib)) {
946       if (Candidate == &DebianMipsMultilibs)
947         Result.BiarchSibling = Multilib();
948       Result.Multilibs = *Candidate;
949       return true;
950     }
951   }
952   return false;
953 }
954 
955 static bool findMipsAndroidMultilibs(vfs::FileSystem &VFS, StringRef Path,
956                                      const Multilib::flags_list &Flags,
957                                      FilterNonExistent &NonExistent,
958                                      DetectedMultilibs &Result) {
959 
960   MultilibSet AndroidMipsMultilibs =
961       MultilibSet()
962           .Maybe(Multilib("/mips-r2").flag("+march=mips32r2"))
963           .Maybe(Multilib("/mips-r6").flag("+march=mips32r6"))
964           .FilterOut(NonExistent);
965 
966   MultilibSet AndroidMipselMultilibs =
967       MultilibSet()
968           .Either(Multilib().flag("+march=mips32"),
969                   Multilib("/mips-r2", "", "/mips-r2").flag("+march=mips32r2"),
970                   Multilib("/mips-r6", "", "/mips-r6").flag("+march=mips32r6"))
971           .FilterOut(NonExistent);
972 
973   MultilibSet AndroidMips64elMultilibs =
974       MultilibSet()
975           .Either(
976               Multilib().flag("+march=mips64r6"),
977               Multilib("/32/mips-r1", "", "/mips-r1").flag("+march=mips32"),
978               Multilib("/32/mips-r2", "", "/mips-r2").flag("+march=mips32r2"),
979               Multilib("/32/mips-r6", "", "/mips-r6").flag("+march=mips32r6"))
980           .FilterOut(NonExistent);
981 
982   MultilibSet *MS = &AndroidMipsMultilibs;
983   if (VFS.exists(Path + "/mips-r6"))
984     MS = &AndroidMipselMultilibs;
985   else if (VFS.exists(Path + "/32"))
986     MS = &AndroidMips64elMultilibs;
987   if (MS->select(Flags, Result.SelectedMultilib)) {
988     Result.Multilibs = *MS;
989     return true;
990   }
991   return false;
992 }
993 
994 static bool findMipsMuslMultilibs(const Multilib::flags_list &Flags,
995                                   FilterNonExistent &NonExistent,
996                                   DetectedMultilibs &Result) {
997   // Musl toolchain multilibs
998   MultilibSet MuslMipsMultilibs;
999   {
1000     auto MArchMipsR2 = makeMultilib("")
1001                            .osSuffix("/mips-r2-hard-musl")
1002                            .flag("+EB")
1003                            .flag("-EL")
1004                            .flag("+march=mips32r2");
1005 
1006     auto MArchMipselR2 = makeMultilib("/mipsel-r2-hard-musl")
1007                              .flag("-EB")
1008                              .flag("+EL")
1009                              .flag("+march=mips32r2");
1010 
1011     MuslMipsMultilibs = MultilibSet().Either(MArchMipsR2, MArchMipselR2);
1012 
1013     // Specify the callback that computes the include directories.
1014     MuslMipsMultilibs.setIncludeDirsCallback([](const Multilib &M) {
1015       return std::vector<std::string>(
1016           {"/../sysroot" + M.osSuffix() + "/usr/include"});
1017     });
1018   }
1019   if (MuslMipsMultilibs.select(Flags, Result.SelectedMultilib)) {
1020     Result.Multilibs = MuslMipsMultilibs;
1021     return true;
1022   }
1023   return false;
1024 }
1025 
1026 static bool findMipsMtiMultilibs(const Multilib::flags_list &Flags,
1027                                  FilterNonExistent &NonExistent,
1028                                  DetectedMultilibs &Result) {
1029   // CodeScape MTI toolchain v1.2 and early.
1030   MultilibSet MtiMipsMultilibsV1;
1031   {
1032     auto MArchMips32 = makeMultilib("/mips32")
1033                            .flag("+m32")
1034                            .flag("-m64")
1035                            .flag("-mmicromips")
1036                            .flag("+march=mips32");
1037 
1038     auto MArchMicroMips = makeMultilib("/micromips")
1039                               .flag("+m32")
1040                               .flag("-m64")
1041                               .flag("+mmicromips");
1042 
1043     auto MArchMips64r2 = makeMultilib("/mips64r2")
1044                              .flag("-m32")
1045                              .flag("+m64")
1046                              .flag("+march=mips64r2");
1047 
1048     auto MArchMips64 = makeMultilib("/mips64").flag("-m32").flag("+m64").flag(
1049         "-march=mips64r2");
1050 
1051     auto MArchDefault = makeMultilib("")
1052                             .flag("+m32")
1053                             .flag("-m64")
1054                             .flag("-mmicromips")
1055                             .flag("+march=mips32r2");
1056 
1057     auto Mips16 = makeMultilib("/mips16").flag("+mips16");
1058 
1059     auto UCLibc = makeMultilib("/uclibc").flag("+muclibc");
1060 
1061     auto MAbi64 =
1062         makeMultilib("/64").flag("+mabi=n64").flag("-mabi=n32").flag("-m32");
1063 
1064     auto BigEndian = makeMultilib("").flag("+EB").flag("-EL");
1065 
1066     auto LittleEndian = makeMultilib("/el").flag("+EL").flag("-EB");
1067 
1068     auto SoftFloat = makeMultilib("/sof").flag("+msoft-float");
1069 
1070     auto Nan2008 = makeMultilib("/nan2008").flag("+mnan=2008");
1071 
1072     MtiMipsMultilibsV1 =
1073         MultilibSet()
1074             .Either(MArchMips32, MArchMicroMips, MArchMips64r2, MArchMips64,
1075                     MArchDefault)
1076             .Maybe(UCLibc)
1077             .Maybe(Mips16)
1078             .FilterOut("/mips64/mips16")
1079             .FilterOut("/mips64r2/mips16")
1080             .FilterOut("/micromips/mips16")
1081             .Maybe(MAbi64)
1082             .FilterOut("/micromips/64")
1083             .FilterOut("/mips32/64")
1084             .FilterOut("^/64")
1085             .FilterOut("/mips16/64")
1086             .Either(BigEndian, LittleEndian)
1087             .Maybe(SoftFloat)
1088             .Maybe(Nan2008)
1089             .FilterOut(".*sof/nan2008")
1090             .FilterOut(NonExistent)
1091             .setIncludeDirsCallback([](const Multilib &M) {
1092               std::vector<std::string> Dirs({"/include"});
1093               if (StringRef(M.includeSuffix()).startswith("/uclibc"))
1094                 Dirs.push_back("/../../../../sysroot/uclibc/usr/include");
1095               else
1096                 Dirs.push_back("/../../../../sysroot/usr/include");
1097               return Dirs;
1098             });
1099   }
1100 
1101   // CodeScape IMG toolchain starting from v1.3.
1102   MultilibSet MtiMipsMultilibsV2;
1103   {
1104     auto BeHard = makeMultilib("/mips-r2-hard")
1105                       .flag("+EB")
1106                       .flag("-msoft-float")
1107                       .flag("-mnan=2008")
1108                       .flag("-muclibc");
1109     auto BeSoft = makeMultilib("/mips-r2-soft")
1110                       .flag("+EB")
1111                       .flag("+msoft-float")
1112                       .flag("-mnan=2008");
1113     auto ElHard = makeMultilib("/mipsel-r2-hard")
1114                       .flag("+EL")
1115                       .flag("-msoft-float")
1116                       .flag("-mnan=2008")
1117                       .flag("-muclibc");
1118     auto ElSoft = makeMultilib("/mipsel-r2-soft")
1119                       .flag("+EL")
1120                       .flag("+msoft-float")
1121                       .flag("-mnan=2008")
1122                       .flag("-mmicromips");
1123     auto BeHardNan = makeMultilib("/mips-r2-hard-nan2008")
1124                          .flag("+EB")
1125                          .flag("-msoft-float")
1126                          .flag("+mnan=2008")
1127                          .flag("-muclibc");
1128     auto ElHardNan = makeMultilib("/mipsel-r2-hard-nan2008")
1129                          .flag("+EL")
1130                          .flag("-msoft-float")
1131                          .flag("+mnan=2008")
1132                          .flag("-muclibc")
1133                          .flag("-mmicromips");
1134     auto BeHardNanUclibc = makeMultilib("/mips-r2-hard-nan2008-uclibc")
1135                                .flag("+EB")
1136                                .flag("-msoft-float")
1137                                .flag("+mnan=2008")
1138                                .flag("+muclibc");
1139     auto ElHardNanUclibc = makeMultilib("/mipsel-r2-hard-nan2008-uclibc")
1140                                .flag("+EL")
1141                                .flag("-msoft-float")
1142                                .flag("+mnan=2008")
1143                                .flag("+muclibc");
1144     auto BeHardUclibc = makeMultilib("/mips-r2-hard-uclibc")
1145                             .flag("+EB")
1146                             .flag("-msoft-float")
1147                             .flag("-mnan=2008")
1148                             .flag("+muclibc");
1149     auto ElHardUclibc = makeMultilib("/mipsel-r2-hard-uclibc")
1150                             .flag("+EL")
1151                             .flag("-msoft-float")
1152                             .flag("-mnan=2008")
1153                             .flag("+muclibc");
1154     auto ElMicroHardNan = makeMultilib("/micromipsel-r2-hard-nan2008")
1155                               .flag("+EL")
1156                               .flag("-msoft-float")
1157                               .flag("+mnan=2008")
1158                               .flag("+mmicromips");
1159     auto ElMicroSoft = makeMultilib("/micromipsel-r2-soft")
1160                            .flag("+EL")
1161                            .flag("+msoft-float")
1162                            .flag("-mnan=2008")
1163                            .flag("+mmicromips");
1164 
1165     auto O32 =
1166         makeMultilib("/lib").osSuffix("").flag("-mabi=n32").flag("-mabi=n64");
1167     auto N32 =
1168         makeMultilib("/lib32").osSuffix("").flag("+mabi=n32").flag("-mabi=n64");
1169     auto N64 =
1170         makeMultilib("/lib64").osSuffix("").flag("-mabi=n32").flag("+mabi=n64");
1171 
1172     MtiMipsMultilibsV2 =
1173         MultilibSet()
1174             .Either({BeHard, BeSoft, ElHard, ElSoft, BeHardNan, ElHardNan,
1175                      BeHardNanUclibc, ElHardNanUclibc, BeHardUclibc,
1176                      ElHardUclibc, ElMicroHardNan, ElMicroSoft})
1177             .Either(O32, N32, N64)
1178             .FilterOut(NonExistent)
1179             .setIncludeDirsCallback([](const Multilib &M) {
1180               return std::vector<std::string>({"/../../../../sysroot" +
1181                                                M.includeSuffix() +
1182                                                "/../usr/include"});
1183             })
1184             .setFilePathsCallback([](const Multilib &M) {
1185               return std::vector<std::string>(
1186                   {"/../../../../mips-mti-linux-gnu/lib" + M.gccSuffix()});
1187             });
1188   }
1189   for (auto Candidate : {&MtiMipsMultilibsV1, &MtiMipsMultilibsV2}) {
1190     if (Candidate->select(Flags, Result.SelectedMultilib)) {
1191       Result.Multilibs = *Candidate;
1192       return true;
1193     }
1194   }
1195   return false;
1196 }
1197 
1198 static bool findMipsImgMultilibs(const Multilib::flags_list &Flags,
1199                                  FilterNonExistent &NonExistent,
1200                                  DetectedMultilibs &Result) {
1201   // CodeScape IMG toolchain v1.2 and early.
1202   MultilibSet ImgMultilibsV1;
1203   {
1204     auto Mips64r6 = makeMultilib("/mips64r6").flag("+m64").flag("-m32");
1205 
1206     auto LittleEndian = makeMultilib("/el").flag("+EL").flag("-EB");
1207 
1208     auto MAbi64 =
1209         makeMultilib("/64").flag("+mabi=n64").flag("-mabi=n32").flag("-m32");
1210 
1211     ImgMultilibsV1 =
1212         MultilibSet()
1213             .Maybe(Mips64r6)
1214             .Maybe(MAbi64)
1215             .Maybe(LittleEndian)
1216             .FilterOut(NonExistent)
1217             .setIncludeDirsCallback([](const Multilib &M) {
1218               return std::vector<std::string>(
1219                   {"/include", "/../../../../sysroot/usr/include"});
1220             });
1221   }
1222 
1223   // CodeScape IMG toolchain starting from v1.3.
1224   MultilibSet ImgMultilibsV2;
1225   {
1226     auto BeHard = makeMultilib("/mips-r6-hard")
1227                       .flag("+EB")
1228                       .flag("-msoft-float")
1229                       .flag("-mmicromips");
1230     auto BeSoft = makeMultilib("/mips-r6-soft")
1231                       .flag("+EB")
1232                       .flag("+msoft-float")
1233                       .flag("-mmicromips");
1234     auto ElHard = makeMultilib("/mipsel-r6-hard")
1235                       .flag("+EL")
1236                       .flag("-msoft-float")
1237                       .flag("-mmicromips");
1238     auto ElSoft = makeMultilib("/mipsel-r6-soft")
1239                       .flag("+EL")
1240                       .flag("+msoft-float")
1241                       .flag("-mmicromips");
1242     auto BeMicroHard = makeMultilib("/micromips-r6-hard")
1243                            .flag("+EB")
1244                            .flag("-msoft-float")
1245                            .flag("+mmicromips");
1246     auto BeMicroSoft = makeMultilib("/micromips-r6-soft")
1247                            .flag("+EB")
1248                            .flag("+msoft-float")
1249                            .flag("+mmicromips");
1250     auto ElMicroHard = makeMultilib("/micromipsel-r6-hard")
1251                            .flag("+EL")
1252                            .flag("-msoft-float")
1253                            .flag("+mmicromips");
1254     auto ElMicroSoft = makeMultilib("/micromipsel-r6-soft")
1255                            .flag("+EL")
1256                            .flag("+msoft-float")
1257                            .flag("+mmicromips");
1258 
1259     auto O32 =
1260         makeMultilib("/lib").osSuffix("").flag("-mabi=n32").flag("-mabi=n64");
1261     auto N32 =
1262         makeMultilib("/lib32").osSuffix("").flag("+mabi=n32").flag("-mabi=n64");
1263     auto N64 =
1264         makeMultilib("/lib64").osSuffix("").flag("-mabi=n32").flag("+mabi=n64");
1265 
1266     ImgMultilibsV2 =
1267         MultilibSet()
1268             .Either({BeHard, BeSoft, ElHard, ElSoft, BeMicroHard, BeMicroSoft,
1269                      ElMicroHard, ElMicroSoft})
1270             .Either(O32, N32, N64)
1271             .FilterOut(NonExistent)
1272             .setIncludeDirsCallback([](const Multilib &M) {
1273               return std::vector<std::string>({"/../../../../sysroot" +
1274                                                M.includeSuffix() +
1275                                                "/../usr/include"});
1276             })
1277             .setFilePathsCallback([](const Multilib &M) {
1278               return std::vector<std::string>(
1279                   {"/../../../../mips-img-linux-gnu/lib" + M.gccSuffix()});
1280             });
1281   }
1282   for (auto Candidate : {&ImgMultilibsV1, &ImgMultilibsV2}) {
1283     if (Candidate->select(Flags, Result.SelectedMultilib)) {
1284       Result.Multilibs = *Candidate;
1285       return true;
1286     }
1287   }
1288   return false;
1289 }
1290 
1291 bool clang::driver::findMIPSMultilibs(const Driver &D,
1292                                       const llvm::Triple &TargetTriple,
1293                                       StringRef Path, const ArgList &Args,
1294                                       DetectedMultilibs &Result) {
1295   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1296 
1297   StringRef CPUName;
1298   StringRef ABIName;
1299   tools::mips::getMipsCPUAndABI(Args, TargetTriple, CPUName, ABIName);
1300 
1301   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
1302 
1303   Multilib::flags_list Flags;
1304   addMultilibFlag(isMips32(TargetArch), "m32", Flags);
1305   addMultilibFlag(isMips64(TargetArch), "m64", Flags);
1306   addMultilibFlag(isMips16(Args), "mips16", Flags);
1307   addMultilibFlag(CPUName == "mips32", "march=mips32", Flags);
1308   addMultilibFlag(CPUName == "mips32r2" || CPUName == "mips32r3" ||
1309                       CPUName == "mips32r5" || CPUName == "p5600",
1310                   "march=mips32r2", Flags);
1311   addMultilibFlag(CPUName == "mips32r6", "march=mips32r6", Flags);
1312   addMultilibFlag(CPUName == "mips64", "march=mips64", Flags);
1313   addMultilibFlag(CPUName == "mips64r2" || CPUName == "mips64r3" ||
1314                       CPUName == "mips64r5" || CPUName == "octeon",
1315                   "march=mips64r2", Flags);
1316   addMultilibFlag(CPUName == "mips64r6", "march=mips64r6", Flags);
1317   addMultilibFlag(isMicroMips(Args), "mmicromips", Flags);
1318   addMultilibFlag(tools::mips::isUCLibc(Args), "muclibc", Flags);
1319   addMultilibFlag(tools::mips::isNaN2008(Args, TargetTriple), "mnan=2008",
1320                   Flags);
1321   addMultilibFlag(ABIName == "n32", "mabi=n32", Flags);
1322   addMultilibFlag(ABIName == "n64", "mabi=n64", Flags);
1323   addMultilibFlag(isSoftFloatABI(Args), "msoft-float", Flags);
1324   addMultilibFlag(!isSoftFloatABI(Args), "mhard-float", Flags);
1325   addMultilibFlag(isMipsEL(TargetArch), "EL", Flags);
1326   addMultilibFlag(!isMipsEL(TargetArch), "EB", Flags);
1327 
1328   if (TargetTriple.isAndroid())
1329     return findMipsAndroidMultilibs(D.getVFS(), Path, Flags, NonExistent,
1330                                     Result);
1331 
1332   if (TargetTriple.getVendor() == llvm::Triple::MipsTechnologies &&
1333       TargetTriple.getOS() == llvm::Triple::Linux &&
1334       TargetTriple.getEnvironment() == llvm::Triple::UnknownEnvironment)
1335     return findMipsMuslMultilibs(Flags, NonExistent, Result);
1336 
1337   if (TargetTriple.getVendor() == llvm::Triple::MipsTechnologies &&
1338       TargetTriple.getOS() == llvm::Triple::Linux &&
1339       TargetTriple.isGNUEnvironment())
1340     return findMipsMtiMultilibs(Flags, NonExistent, Result);
1341 
1342   if (TargetTriple.getVendor() == llvm::Triple::ImaginationTechnologies &&
1343       TargetTriple.getOS() == llvm::Triple::Linux &&
1344       TargetTriple.isGNUEnvironment())
1345     return findMipsImgMultilibs(Flags, NonExistent, Result);
1346 
1347   if (findMipsCsMultilibs(Flags, NonExistent, Result))
1348     return true;
1349 
1350   // Fallback to the regular toolchain-tree structure.
1351   Multilib Default;
1352   Result.Multilibs.push_back(Default);
1353   Result.Multilibs.FilterOut(NonExistent);
1354 
1355   if (Result.Multilibs.select(Flags, Result.SelectedMultilib)) {
1356     Result.BiarchSibling = Multilib();
1357     return true;
1358   }
1359 
1360   return false;
1361 }
1362 
1363 static void findAndroidArmMultilibs(const Driver &D,
1364                                     const llvm::Triple &TargetTriple,
1365                                     StringRef Path, const ArgList &Args,
1366                                     DetectedMultilibs &Result) {
1367   // Find multilibs with subdirectories like armv7-a, thumb, armv7-a/thumb.
1368   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1369   Multilib ArmV7Multilib = makeMultilib("/armv7-a")
1370                                .flag("+march=armv7-a")
1371                                .flag("-mthumb");
1372   Multilib ThumbMultilib = makeMultilib("/thumb")
1373                                .flag("-march=armv7-a")
1374                                .flag("+mthumb");
1375   Multilib ArmV7ThumbMultilib = makeMultilib("/armv7-a/thumb")
1376                                .flag("+march=armv7-a")
1377                                .flag("+mthumb");
1378   Multilib DefaultMultilib = makeMultilib("")
1379                                .flag("-march=armv7-a")
1380                                .flag("-mthumb");
1381   MultilibSet AndroidArmMultilibs =
1382       MultilibSet()
1383           .Either(ThumbMultilib, ArmV7Multilib,
1384                   ArmV7ThumbMultilib, DefaultMultilib)
1385           .FilterOut(NonExistent);
1386 
1387   Multilib::flags_list Flags;
1388   llvm::StringRef Arch = Args.getLastArgValue(options::OPT_march_EQ);
1389   bool IsArmArch = TargetTriple.getArch() == llvm::Triple::arm;
1390   bool IsThumbArch = TargetTriple.getArch() == llvm::Triple::thumb;
1391   bool IsV7SubArch = TargetTriple.getSubArch() == llvm::Triple::ARMSubArch_v7;
1392   bool IsThumbMode = IsThumbArch ||
1393       Args.hasFlag(options::OPT_mthumb, options::OPT_mno_thumb, false) ||
1394       (IsArmArch && llvm::ARM::parseArchISA(Arch) == llvm::ARM::ISAKind::THUMB);
1395   bool IsArmV7Mode = (IsArmArch || IsThumbArch) &&
1396       (llvm::ARM::parseArchVersion(Arch) == 7 ||
1397        (IsArmArch && Arch == "" && IsV7SubArch));
1398   addMultilibFlag(IsArmV7Mode, "march=armv7-a", Flags);
1399   addMultilibFlag(IsThumbMode, "mthumb", Flags);
1400 
1401   if (AndroidArmMultilibs.select(Flags, Result.SelectedMultilib))
1402     Result.Multilibs = AndroidArmMultilibs;
1403 }
1404 
1405 static void findRISCVMultilibs(const Driver &D,
1406                                const llvm::Triple &TargetTriple, StringRef Path,
1407                                const ArgList &Args, DetectedMultilibs &Result) {
1408 
1409   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1410   Multilib Ilp32 = makeMultilib("lib32/ilp32").flag("+m32").flag("+mabi=ilp32");
1411   Multilib Ilp32f =
1412       makeMultilib("lib32/ilp32f").flag("+m32").flag("+mabi=ilp32f");
1413   Multilib Ilp32d =
1414       makeMultilib("lib32/ilp32d").flag("+m32").flag("+mabi=ilp32d");
1415   Multilib Lp64 = makeMultilib("lib64/lp64").flag("+m64").flag("+mabi=lp64");
1416   Multilib Lp64f = makeMultilib("lib64/lp64f").flag("+m64").flag("+mabi=lp64f");
1417   Multilib Lp64d = makeMultilib("lib64/lp64d").flag("+m64").flag("+mabi=lp64d");
1418   MultilibSet RISCVMultilibs =
1419       MultilibSet()
1420           .Either({Ilp32, Ilp32f, Ilp32d, Lp64, Lp64f, Lp64d})
1421           .FilterOut(NonExistent);
1422 
1423   Multilib::flags_list Flags;
1424   bool IsRV64 = TargetTriple.getArch() == llvm::Triple::riscv64;
1425   StringRef ABIName = tools::riscv::getRISCVABI(Args, TargetTriple);
1426 
1427   addMultilibFlag(!IsRV64, "m32", Flags);
1428   addMultilibFlag(IsRV64, "m64", Flags);
1429   addMultilibFlag(ABIName == "ilp32", "mabi=ilp32", Flags);
1430   addMultilibFlag(ABIName == "ilp32f", "mabi=ilp32f", Flags);
1431   addMultilibFlag(ABIName == "ilp32d", "mabi=ilp32d", Flags);
1432   addMultilibFlag(ABIName == "lp64", "mabi=lp64", Flags);
1433   addMultilibFlag(ABIName == "lp64f", "mabi=lp64f", Flags);
1434   addMultilibFlag(ABIName == "lp64d", "mabi=lp64d", Flags);
1435 
1436   if (RISCVMultilibs.select(Flags, Result.SelectedMultilib))
1437     Result.Multilibs = RISCVMultilibs;
1438 }
1439 
1440 static bool findBiarchMultilibs(const Driver &D,
1441                                 const llvm::Triple &TargetTriple,
1442                                 StringRef Path, const ArgList &Args,
1443                                 bool NeedsBiarchSuffix,
1444                                 DetectedMultilibs &Result) {
1445   Multilib Default;
1446 
1447   // Some versions of SUSE and Fedora on ppc64 put 32-bit libs
1448   // in what would normally be GCCInstallPath and put the 64-bit
1449   // libs in a subdirectory named 64. The simple logic we follow is that
1450   // *if* there is a subdirectory of the right name with crtbegin.o in it,
1451   // we use that. If not, and if not a biarch triple alias, we look for
1452   // crtbegin.o without the subdirectory.
1453 
1454   StringRef Suff64 = "/64";
1455   // Solaris uses platform-specific suffixes instead of /64.
1456   if (TargetTriple.getOS() == llvm::Triple::Solaris) {
1457     switch (TargetTriple.getArch()) {
1458     case llvm::Triple::x86:
1459     case llvm::Triple::x86_64:
1460       Suff64 = "/amd64";
1461       break;
1462     case llvm::Triple::sparc:
1463     case llvm::Triple::sparcv9:
1464       Suff64 = "/sparcv9";
1465       break;
1466     default:
1467       break;
1468     }
1469   }
1470 
1471   Multilib Alt64 = Multilib()
1472                        .gccSuffix(Suff64)
1473                        .includeSuffix(Suff64)
1474                        .flag("-m32")
1475                        .flag("+m64")
1476                        .flag("-mx32");
1477   Multilib Alt32 = Multilib()
1478                        .gccSuffix("/32")
1479                        .includeSuffix("/32")
1480                        .flag("+m32")
1481                        .flag("-m64")
1482                        .flag("-mx32");
1483   Multilib Altx32 = Multilib()
1484                         .gccSuffix("/x32")
1485                         .includeSuffix("/x32")
1486                         .flag("-m32")
1487                         .flag("-m64")
1488                         .flag("+mx32");
1489 
1490   // GCC toolchain for IAMCU doesn't have crtbegin.o, so look for libgcc.a.
1491   FilterNonExistent NonExistent(
1492       Path, TargetTriple.isOSIAMCU() ? "/libgcc.a" : "/crtbegin.o", D.getVFS());
1493 
1494   // Determine default multilib from: 32, 64, x32
1495   // Also handle cases such as 64 on 32, 32 on 64, etc.
1496   enum { UNKNOWN, WANT32, WANT64, WANTX32 } Want = UNKNOWN;
1497   const bool IsX32 = TargetTriple.getEnvironment() == llvm::Triple::GNUX32;
1498   if (TargetTriple.isArch32Bit() && !NonExistent(Alt32))
1499     Want = WANT64;
1500   else if (TargetTriple.isArch64Bit() && IsX32 && !NonExistent(Altx32))
1501     Want = WANT64;
1502   else if (TargetTriple.isArch64Bit() && !IsX32 && !NonExistent(Alt64))
1503     Want = WANT32;
1504   else {
1505     if (TargetTriple.isArch32Bit())
1506       Want = NeedsBiarchSuffix ? WANT64 : WANT32;
1507     else if (IsX32)
1508       Want = NeedsBiarchSuffix ? WANT64 : WANTX32;
1509     else
1510       Want = NeedsBiarchSuffix ? WANT32 : WANT64;
1511   }
1512 
1513   if (Want == WANT32)
1514     Default.flag("+m32").flag("-m64").flag("-mx32");
1515   else if (Want == WANT64)
1516     Default.flag("-m32").flag("+m64").flag("-mx32");
1517   else if (Want == WANTX32)
1518     Default.flag("-m32").flag("-m64").flag("+mx32");
1519   else
1520     return false;
1521 
1522   Result.Multilibs.push_back(Default);
1523   Result.Multilibs.push_back(Alt64);
1524   Result.Multilibs.push_back(Alt32);
1525   Result.Multilibs.push_back(Altx32);
1526 
1527   Result.Multilibs.FilterOut(NonExistent);
1528 
1529   Multilib::flags_list Flags;
1530   addMultilibFlag(TargetTriple.isArch64Bit() && !IsX32, "m64", Flags);
1531   addMultilibFlag(TargetTriple.isArch32Bit(), "m32", Flags);
1532   addMultilibFlag(TargetTriple.isArch64Bit() && IsX32, "mx32", Flags);
1533 
1534   if (!Result.Multilibs.select(Flags, Result.SelectedMultilib))
1535     return false;
1536 
1537   if (Result.SelectedMultilib == Alt64 || Result.SelectedMultilib == Alt32 ||
1538       Result.SelectedMultilib == Altx32)
1539     Result.BiarchSibling = Default;
1540 
1541   return true;
1542 }
1543 
1544 /// Generic_GCC - A tool chain using the 'gcc' command to perform
1545 /// all subcommands; this relies on gcc translating the majority of
1546 /// command line options.
1547 
1548 /// \brief Less-than for GCCVersion, implementing a Strict Weak Ordering.
1549 bool Generic_GCC::GCCVersion::isOlderThan(int RHSMajor, int RHSMinor,
1550                                           int RHSPatch,
1551                                           StringRef RHSPatchSuffix) const {
1552   if (Major != RHSMajor)
1553     return Major < RHSMajor;
1554   if (Minor != RHSMinor)
1555     return Minor < RHSMinor;
1556   if (Patch != RHSPatch) {
1557     // Note that versions without a specified patch sort higher than those with
1558     // a patch.
1559     if (RHSPatch == -1)
1560       return true;
1561     if (Patch == -1)
1562       return false;
1563 
1564     // Otherwise just sort on the patch itself.
1565     return Patch < RHSPatch;
1566   }
1567   if (PatchSuffix != RHSPatchSuffix) {
1568     // Sort empty suffixes higher.
1569     if (RHSPatchSuffix.empty())
1570       return true;
1571     if (PatchSuffix.empty())
1572       return false;
1573 
1574     // Provide a lexicographic sort to make this a total ordering.
1575     return PatchSuffix < RHSPatchSuffix;
1576   }
1577 
1578   // The versions are equal.
1579   return false;
1580 }
1581 
1582 /// \brief Parse a GCCVersion object out of a string of text.
1583 ///
1584 /// This is the primary means of forming GCCVersion objects.
1585 /*static*/
1586 Generic_GCC::GCCVersion Generic_GCC::GCCVersion::Parse(StringRef VersionText) {
1587   const GCCVersion BadVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
1588   std::pair<StringRef, StringRef> First = VersionText.split('.');
1589   std::pair<StringRef, StringRef> Second = First.second.split('.');
1590 
1591   GCCVersion GoodVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
1592   if (First.first.getAsInteger(10, GoodVersion.Major) || GoodVersion.Major < 0)
1593     return BadVersion;
1594   GoodVersion.MajorStr = First.first.str();
1595   if (First.second.empty())
1596     return GoodVersion;
1597   StringRef MinorStr = Second.first;
1598   if (Second.second.empty()) {
1599     if (size_t EndNumber = MinorStr.find_first_not_of("0123456789")) {
1600       GoodVersion.PatchSuffix = MinorStr.substr(EndNumber);
1601       MinorStr = MinorStr.slice(0, EndNumber);
1602     }
1603   }
1604   if (MinorStr.getAsInteger(10, GoodVersion.Minor) || GoodVersion.Minor < 0)
1605     return BadVersion;
1606   GoodVersion.MinorStr = MinorStr.str();
1607 
1608   // First look for a number prefix and parse that if present. Otherwise just
1609   // stash the entire patch string in the suffix, and leave the number
1610   // unspecified. This covers versions strings such as:
1611   //   5        (handled above)
1612   //   4.4
1613   //   4.4-patched
1614   //   4.4.0
1615   //   4.4.x
1616   //   4.4.2-rc4
1617   //   4.4.x-patched
1618   // And retains any patch number it finds.
1619   StringRef PatchText = Second.second;
1620   if (!PatchText.empty()) {
1621     if (size_t EndNumber = PatchText.find_first_not_of("0123456789")) {
1622       // Try to parse the number and any suffix.
1623       if (PatchText.slice(0, EndNumber).getAsInteger(10, GoodVersion.Patch) ||
1624           GoodVersion.Patch < 0)
1625         return BadVersion;
1626       GoodVersion.PatchSuffix = PatchText.substr(EndNumber);
1627     }
1628   }
1629 
1630   return GoodVersion;
1631 }
1632 
1633 static llvm::StringRef getGCCToolchainDir(const ArgList &Args) {
1634   const Arg *A = Args.getLastArg(clang::driver::options::OPT_gcc_toolchain);
1635   if (A)
1636     return A->getValue();
1637   return GCC_INSTALL_PREFIX;
1638 }
1639 
1640 /// \brief Initialize a GCCInstallationDetector from the driver.
1641 ///
1642 /// This performs all of the autodetection and sets up the various paths.
1643 /// Once constructed, a GCCInstallationDetector is essentially immutable.
1644 ///
1645 /// FIXME: We shouldn't need an explicit TargetTriple parameter here, and
1646 /// should instead pull the target out of the driver. This is currently
1647 /// necessary because the driver doesn't store the final version of the target
1648 /// triple.
1649 void Generic_GCC::GCCInstallationDetector::init(
1650     const llvm::Triple &TargetTriple, const ArgList &Args,
1651     ArrayRef<std::string> ExtraTripleAliases) {
1652   llvm::Triple BiarchVariantTriple = TargetTriple.isArch32Bit()
1653                                          ? TargetTriple.get64BitArchVariant()
1654                                          : TargetTriple.get32BitArchVariant();
1655   // The library directories which may contain GCC installations.
1656   SmallVector<StringRef, 4> CandidateLibDirs, CandidateBiarchLibDirs;
1657   // The compatible GCC triples for this particular architecture.
1658   SmallVector<StringRef, 16> CandidateTripleAliases;
1659   SmallVector<StringRef, 16> CandidateBiarchTripleAliases;
1660   CollectLibDirsAndTriples(TargetTriple, BiarchVariantTriple, CandidateLibDirs,
1661                            CandidateTripleAliases, CandidateBiarchLibDirs,
1662                            CandidateBiarchTripleAliases);
1663 
1664   // Compute the set of prefixes for our search.
1665   SmallVector<std::string, 8> Prefixes(D.PrefixDirs.begin(),
1666                                        D.PrefixDirs.end());
1667 
1668   StringRef GCCToolchainDir = getGCCToolchainDir(Args);
1669   if (GCCToolchainDir != "") {
1670     if (GCCToolchainDir.back() == '/')
1671       GCCToolchainDir = GCCToolchainDir.drop_back(); // remove the /
1672 
1673     Prefixes.push_back(GCCToolchainDir);
1674   } else {
1675     // If we have a SysRoot, try that first.
1676     if (!D.SysRoot.empty()) {
1677       Prefixes.push_back(D.SysRoot);
1678       AddDefaultGCCPrefixes(TargetTriple, Prefixes, D.SysRoot);
1679     }
1680 
1681     // Then look for gcc installed alongside clang.
1682     Prefixes.push_back(D.InstalledDir + "/..");
1683 
1684     // Next, look for prefix(es) that correspond to distribution-supplied gcc
1685     // installations.
1686     if (D.SysRoot.empty()) {
1687       // Typically /usr.
1688       AddDefaultGCCPrefixes(TargetTriple, Prefixes, D.SysRoot);
1689     }
1690   }
1691 
1692   // Try to respect gcc-config on Gentoo. However, do that only
1693   // if --gcc-toolchain is not provided or equal to the Gentoo install
1694   // in /usr. This avoids accidentally enforcing the system GCC version
1695   // when using a custom toolchain.
1696   if (GCCToolchainDir == "" || GCCToolchainDir == D.SysRoot + "/usr") {
1697     SmallVector<StringRef, 16> GentooTestTriples;
1698     // Try to match an exact triple as target triple first.
1699     // e.g. crossdev -S x86_64-gentoo-linux-gnu will install gcc libs for
1700     // x86_64-gentoo-linux-gnu. But "clang -target x86_64-gentoo-linux-gnu"
1701     // may pick the libraries for x86_64-pc-linux-gnu even when exact matching
1702     // triple x86_64-gentoo-linux-gnu is present.
1703     GentooTestTriples.push_back(TargetTriple.str());
1704     // Check rest of triples.
1705     GentooTestTriples.append(ExtraTripleAliases.begin(),
1706                              ExtraTripleAliases.end());
1707     GentooTestTriples.append(CandidateTripleAliases.begin(),
1708                              CandidateTripleAliases.end());
1709     if (ScanGentooConfigs(TargetTriple, Args, GentooTestTriples,
1710                           CandidateBiarchTripleAliases))
1711       return;
1712   }
1713 
1714   // Loop over the various components which exist and select the best GCC
1715   // installation available. GCC installs are ranked by version number.
1716   Version = GCCVersion::Parse("0.0.0");
1717   for (const std::string &Prefix : Prefixes) {
1718     if (!D.getVFS().exists(Prefix))
1719       continue;
1720     for (StringRef Suffix : CandidateLibDirs) {
1721       const std::string LibDir = Prefix + Suffix.str();
1722       if (!D.getVFS().exists(LibDir))
1723         continue;
1724       // Try to match the exact target triple first.
1725       ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, TargetTriple.str());
1726       // Try rest of possible triples.
1727       for (StringRef Candidate : ExtraTripleAliases) // Try these first.
1728         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate);
1729       for (StringRef Candidate : CandidateTripleAliases)
1730         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate);
1731     }
1732     for (StringRef Suffix : CandidateBiarchLibDirs) {
1733       const std::string LibDir = Prefix + Suffix.str();
1734       if (!D.getVFS().exists(LibDir))
1735         continue;
1736       for (StringRef Candidate : CandidateBiarchTripleAliases)
1737         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate,
1738                                /*NeedsBiarchSuffix=*/ true);
1739     }
1740   }
1741 }
1742 
1743 void Generic_GCC::GCCInstallationDetector::print(raw_ostream &OS) const {
1744   for (const auto &InstallPath : CandidateGCCInstallPaths)
1745     OS << "Found candidate GCC installation: " << InstallPath << "\n";
1746 
1747   if (!GCCInstallPath.empty())
1748     OS << "Selected GCC installation: " << GCCInstallPath << "\n";
1749 
1750   for (const auto &Multilib : Multilibs)
1751     OS << "Candidate multilib: " << Multilib << "\n";
1752 
1753   if (Multilibs.size() != 0 || !SelectedMultilib.isDefault())
1754     OS << "Selected multilib: " << SelectedMultilib << "\n";
1755 }
1756 
1757 bool Generic_GCC::GCCInstallationDetector::getBiarchSibling(Multilib &M) const {
1758   if (BiarchSibling.hasValue()) {
1759     M = BiarchSibling.getValue();
1760     return true;
1761   }
1762   return false;
1763 }
1764 
1765 void Generic_GCC::GCCInstallationDetector::AddDefaultGCCPrefixes(
1766     const llvm::Triple &TargetTriple, SmallVectorImpl<std::string> &Prefixes,
1767     StringRef SysRoot) {
1768   if (TargetTriple.getOS() == llvm::Triple::Solaris) {
1769     // Solaris is a special case.
1770     // The GCC installation is under
1771     //   /usr/gcc/<major>.<minor>/lib/gcc/<triple>/<major>.<minor>.<patch>/
1772     // so we need to find those /usr/gcc/*/lib/gcc libdirs and go with
1773     // /usr/gcc/<version> as a prefix.
1774 
1775     std::string PrefixDir = SysRoot.str() + "/usr/gcc";
1776     std::error_code EC;
1777     for (vfs::directory_iterator LI = D.getVFS().dir_begin(PrefixDir, EC), LE;
1778          !EC && LI != LE; LI = LI.increment(EC)) {
1779       StringRef VersionText = llvm::sys::path::filename(LI->getName());
1780       GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
1781 
1782       // Filter out obviously bad entries.
1783       if (CandidateVersion.Major == -1 || CandidateVersion.isOlderThan(4, 1, 1))
1784         continue;
1785 
1786       std::string CandidatePrefix = PrefixDir + "/" + VersionText.str();
1787       std::string CandidateLibPath = CandidatePrefix + "/lib/gcc";
1788       if (!D.getVFS().exists(CandidateLibPath))
1789         continue;
1790 
1791       Prefixes.push_back(CandidatePrefix);
1792     }
1793     return;
1794   }
1795 
1796   // Non-Solaris is much simpler - most systems just go with "/usr".
1797   if (SysRoot.empty() && TargetTriple.getOS() == llvm::Triple::Linux) {
1798     // Yet, still look for RHEL devtoolsets.
1799     Prefixes.push_back("/opt/rh/devtoolset-7/root/usr");
1800     Prefixes.push_back("/opt/rh/devtoolset-6/root/usr");
1801     Prefixes.push_back("/opt/rh/devtoolset-4/root/usr");
1802     Prefixes.push_back("/opt/rh/devtoolset-3/root/usr");
1803     Prefixes.push_back("/opt/rh/devtoolset-2/root/usr");
1804   }
1805   Prefixes.push_back(SysRoot.str() + "/usr");
1806 }
1807 
1808 /*static*/ void Generic_GCC::GCCInstallationDetector::CollectLibDirsAndTriples(
1809     const llvm::Triple &TargetTriple, const llvm::Triple &BiarchTriple,
1810     SmallVectorImpl<StringRef> &LibDirs,
1811     SmallVectorImpl<StringRef> &TripleAliases,
1812     SmallVectorImpl<StringRef> &BiarchLibDirs,
1813     SmallVectorImpl<StringRef> &BiarchTripleAliases) {
1814   // Declare a bunch of static data sets that we'll select between below. These
1815   // are specifically designed to always refer to string literals to avoid any
1816   // lifetime or initialization issues.
1817   static const char *const AArch64LibDirs[] = {"/lib64", "/lib"};
1818   static const char *const AArch64Triples[] = {
1819       "aarch64-none-linux-gnu", "aarch64-linux-gnu", "aarch64-redhat-linux",
1820       "aarch64-suse-linux"};
1821   static const char *const AArch64beLibDirs[] = {"/lib"};
1822   static const char *const AArch64beTriples[] = {"aarch64_be-none-linux-gnu",
1823                                                  "aarch64_be-linux-gnu"};
1824 
1825   static const char *const ARMLibDirs[] = {"/lib"};
1826   static const char *const ARMTriples[] = {"arm-linux-gnueabi"};
1827   static const char *const ARMHFTriples[] = {"arm-linux-gnueabihf",
1828                                              "armv7hl-redhat-linux-gnueabi",
1829                                              "armv6hl-suse-linux-gnueabi",
1830                                              "armv7hl-suse-linux-gnueabi"};
1831   static const char *const ARMebLibDirs[] = {"/lib"};
1832   static const char *const ARMebTriples[] = {"armeb-linux-gnueabi"};
1833   static const char *const ARMebHFTriples[] = {
1834       "armeb-linux-gnueabihf", "armebv7hl-redhat-linux-gnueabi"};
1835 
1836   static const char *const X86_64LibDirs[] = {"/lib64", "/lib"};
1837   static const char *const X86_64Triples[] = {
1838       "x86_64-linux-gnu",       "x86_64-unknown-linux-gnu",
1839       "x86_64-pc-linux-gnu",    "x86_64-redhat-linux6E",
1840       "x86_64-redhat-linux",    "x86_64-suse-linux",
1841       "x86_64-manbo-linux-gnu", "x86_64-linux-gnu",
1842       "x86_64-slackware-linux", "x86_64-unknown-linux"};
1843   static const char *const X32LibDirs[] = {"/libx32"};
1844   static const char *const X86LibDirs[] = {"/lib32", "/lib"};
1845   static const char *const X86Triples[] = {
1846       "i686-linux-gnu",       "i686-pc-linux-gnu",     "i486-linux-gnu",
1847       "i386-linux-gnu",       "i386-redhat-linux6E",   "i686-redhat-linux",
1848       "i586-redhat-linux",    "i386-redhat-linux",     "i586-suse-linux",
1849       "i486-slackware-linux", "i686-montavista-linux", "i586-linux-gnu"};
1850 
1851   static const char *const MIPSLibDirs[] = {"/lib"};
1852   static const char *const MIPSTriples[] = {"mips-linux-gnu", "mips-mti-linux",
1853                                             "mips-mti-linux-gnu",
1854                                             "mips-img-linux-gnu"};
1855   static const char *const MIPSELLibDirs[] = {"/lib"};
1856   static const char *const MIPSELTriples[] = {"mipsel-linux-gnu",
1857                                               "mips-img-linux-gnu"};
1858 
1859   static const char *const MIPS64LibDirs[] = {"/lib64", "/lib"};
1860   static const char *const MIPS64Triples[] = {
1861       "mips64-linux-gnu", "mips-mti-linux-gnu", "mips-img-linux-gnu",
1862       "mips64-linux-gnuabi64"};
1863   static const char *const MIPS64ELLibDirs[] = {"/lib64", "/lib"};
1864   static const char *const MIPS64ELTriples[] = {
1865       "mips64el-linux-gnu", "mips-mti-linux-gnu", "mips-img-linux-gnu",
1866       "mips64el-linux-gnuabi64"};
1867 
1868 
1869   static const char *const PPCLibDirs[] = {"/lib32", "/lib"};
1870   static const char *const PPCTriples[] = {
1871       "powerpc-linux-gnu", "powerpc-unknown-linux-gnu", "powerpc-linux-gnuspe",
1872       "powerpc-suse-linux", "powerpc-montavista-linuxspe"};
1873   static const char *const PPC64LibDirs[] = {"/lib64", "/lib"};
1874   static const char *const PPC64Triples[] = {
1875       "powerpc64-linux-gnu", "powerpc64-unknown-linux-gnu",
1876       "powerpc64-suse-linux", "ppc64-redhat-linux"};
1877   static const char *const PPC64LELibDirs[] = {"/lib64", "/lib"};
1878   static const char *const PPC64LETriples[] = {
1879       "powerpc64le-linux-gnu", "powerpc64le-unknown-linux-gnu",
1880       "powerpc64le-suse-linux", "ppc64le-redhat-linux"};
1881 
1882   static const char *const RISCV32LibDirs[] = {"/lib", "/lib32"};
1883   static const char *const RISCVTriples[] = {"riscv32-unknown-linux-gnu",
1884                                              "riscv64-unknown-linux-gnu"};
1885 
1886   static const char *const SPARCv8LibDirs[] = {"/lib32", "/lib"};
1887   static const char *const SPARCv8Triples[] = {"sparc-linux-gnu",
1888                                                "sparcv8-linux-gnu"};
1889   static const char *const SPARCv9LibDirs[] = {"/lib64", "/lib"};
1890   static const char *const SPARCv9Triples[] = {"sparc64-linux-gnu",
1891                                                "sparcv9-linux-gnu"};
1892 
1893   static const char *const SystemZLibDirs[] = {"/lib64", "/lib"};
1894   static const char *const SystemZTriples[] = {
1895       "s390x-linux-gnu", "s390x-unknown-linux-gnu", "s390x-ibm-linux-gnu",
1896       "s390x-suse-linux", "s390x-redhat-linux"};
1897 
1898 
1899   using std::begin;
1900   using std::end;
1901 
1902   if (TargetTriple.getOS() == llvm::Triple::Solaris) {
1903     static const char *const SolarisLibDirs[] = {"/lib"};
1904     static const char *const SolarisSparcV8Triples[] = {
1905         "sparc-sun-solaris2.11", "sparc-sun-solaris2.12"};
1906     static const char *const SolarisSparcV9Triples[] = {
1907         "sparcv9-sun-solaris2.11", "sparcv9-sun-solaris2.12"};
1908     static const char *const SolarisX86Triples[] = {"i386-pc-solaris2.11",
1909                                                     "i386-pc-solaris2.12"};
1910     static const char *const SolarisX86_64Triples[] = {"x86_64-pc-solaris2.11",
1911                                                        "x86_64-pc-solaris2.12"};
1912     LibDirs.append(begin(SolarisLibDirs), end(SolarisLibDirs));
1913     BiarchLibDirs.append(begin(SolarisLibDirs), end(SolarisLibDirs));
1914     switch (TargetTriple.getArch()) {
1915     case llvm::Triple::x86:
1916       TripleAliases.append(begin(SolarisX86Triples), end(SolarisX86Triples));
1917       BiarchTripleAliases.append(begin(SolarisX86_64Triples),
1918                                  end(SolarisX86_64Triples));
1919       break;
1920     case llvm::Triple::x86_64:
1921       TripleAliases.append(begin(SolarisX86_64Triples),
1922                            end(SolarisX86_64Triples));
1923       BiarchTripleAliases.append(begin(SolarisX86Triples),
1924                                  end(SolarisX86Triples));
1925       break;
1926     case llvm::Triple::sparc:
1927       TripleAliases.append(begin(SolarisSparcV8Triples),
1928                            end(SolarisSparcV8Triples));
1929       BiarchTripleAliases.append(begin(SolarisSparcV9Triples),
1930                                  end(SolarisSparcV9Triples));
1931       break;
1932     case llvm::Triple::sparcv9:
1933       TripleAliases.append(begin(SolarisSparcV9Triples),
1934                            end(SolarisSparcV9Triples));
1935       BiarchTripleAliases.append(begin(SolarisSparcV8Triples),
1936                                  end(SolarisSparcV8Triples));
1937       break;
1938     default:
1939       break;
1940     }
1941     return;
1942   }
1943 
1944   // Android targets should not use GNU/Linux tools or libraries.
1945   if (TargetTriple.isAndroid()) {
1946     static const char *const AArch64AndroidTriples[] = {
1947         "aarch64-linux-android"};
1948     static const char *const ARMAndroidTriples[] = {"arm-linux-androideabi"};
1949     static const char *const MIPSELAndroidTriples[] = {"mipsel-linux-android"};
1950     static const char *const MIPS64ELAndroidTriples[] = {
1951         "mips64el-linux-android"};
1952     static const char *const X86AndroidTriples[] = {"i686-linux-android"};
1953     static const char *const X86_64AndroidTriples[] = {"x86_64-linux-android"};
1954 
1955     switch (TargetTriple.getArch()) {
1956     case llvm::Triple::aarch64:
1957       LibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
1958       TripleAliases.append(begin(AArch64AndroidTriples),
1959                            end(AArch64AndroidTriples));
1960       break;
1961     case llvm::Triple::arm:
1962     case llvm::Triple::thumb:
1963       LibDirs.append(begin(ARMLibDirs), end(ARMLibDirs));
1964       TripleAliases.append(begin(ARMAndroidTriples), end(ARMAndroidTriples));
1965       break;
1966     case llvm::Triple::mipsel:
1967       LibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
1968       TripleAliases.append(begin(MIPSELAndroidTriples),
1969                            end(MIPSELAndroidTriples));
1970       BiarchLibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
1971       BiarchTripleAliases.append(begin(MIPS64ELAndroidTriples),
1972                                  end(MIPS64ELAndroidTriples));
1973       break;
1974     case llvm::Triple::mips64el:
1975       LibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
1976       TripleAliases.append(begin(MIPS64ELAndroidTriples),
1977                            end(MIPS64ELAndroidTriples));
1978       BiarchLibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
1979       BiarchTripleAliases.append(begin(MIPSELAndroidTriples),
1980                                  end(MIPSELAndroidTriples));
1981       break;
1982     case llvm::Triple::x86_64:
1983       LibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
1984       TripleAliases.append(begin(X86_64AndroidTriples),
1985                            end(X86_64AndroidTriples));
1986       BiarchLibDirs.append(begin(X86LibDirs), end(X86LibDirs));
1987       BiarchTripleAliases.append(begin(X86AndroidTriples),
1988                                  end(X86AndroidTriples));
1989       break;
1990     case llvm::Triple::x86:
1991       LibDirs.append(begin(X86LibDirs), end(X86LibDirs));
1992       TripleAliases.append(begin(X86AndroidTriples), end(X86AndroidTriples));
1993       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
1994       BiarchTripleAliases.append(begin(X86_64AndroidTriples),
1995                                  end(X86_64AndroidTriples));
1996       break;
1997     default:
1998       break;
1999     }
2000 
2001     return;
2002   }
2003 
2004   switch (TargetTriple.getArch()) {
2005   case llvm::Triple::aarch64:
2006     LibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
2007     TripleAliases.append(begin(AArch64Triples), end(AArch64Triples));
2008     BiarchLibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
2009     BiarchTripleAliases.append(begin(AArch64Triples), end(AArch64Triples));
2010     break;
2011   case llvm::Triple::aarch64_be:
2012     LibDirs.append(begin(AArch64beLibDirs), end(AArch64beLibDirs));
2013     TripleAliases.append(begin(AArch64beTriples), end(AArch64beTriples));
2014     BiarchLibDirs.append(begin(AArch64beLibDirs), end(AArch64beLibDirs));
2015     BiarchTripleAliases.append(begin(AArch64beTriples), end(AArch64beTriples));
2016     break;
2017   case llvm::Triple::arm:
2018   case llvm::Triple::thumb:
2019     LibDirs.append(begin(ARMLibDirs), end(ARMLibDirs));
2020     if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
2021       TripleAliases.append(begin(ARMHFTriples), end(ARMHFTriples));
2022     } else {
2023       TripleAliases.append(begin(ARMTriples), end(ARMTriples));
2024     }
2025     break;
2026   case llvm::Triple::armeb:
2027   case llvm::Triple::thumbeb:
2028     LibDirs.append(begin(ARMebLibDirs), end(ARMebLibDirs));
2029     if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
2030       TripleAliases.append(begin(ARMebHFTriples), end(ARMebHFTriples));
2031     } else {
2032       TripleAliases.append(begin(ARMebTriples), end(ARMebTriples));
2033     }
2034     break;
2035   case llvm::Triple::x86_64:
2036     LibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2037     TripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
2038     // x32 is always available when x86_64 is available, so adding it as
2039     // secondary arch with x86_64 triples
2040     if (TargetTriple.getEnvironment() == llvm::Triple::GNUX32) {
2041       BiarchLibDirs.append(begin(X32LibDirs), end(X32LibDirs));
2042       BiarchTripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
2043     } else {
2044       BiarchLibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2045       BiarchTripleAliases.append(begin(X86Triples), end(X86Triples));
2046     }
2047     break;
2048   case llvm::Triple::x86:
2049     LibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2050     // MCU toolchain is 32 bit only and its triple alias is TargetTriple
2051     // itself, which will be appended below.
2052     if (!TargetTriple.isOSIAMCU()) {
2053       TripleAliases.append(begin(X86Triples), end(X86Triples));
2054       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2055       BiarchTripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
2056     }
2057     break;
2058   case llvm::Triple::mips:
2059     LibDirs.append(begin(MIPSLibDirs), end(MIPSLibDirs));
2060     TripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2061     BiarchLibDirs.append(begin(MIPS64LibDirs), end(MIPS64LibDirs));
2062     BiarchTripleAliases.append(begin(MIPS64Triples), end(MIPS64Triples));
2063     break;
2064   case llvm::Triple::mipsel:
2065     LibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
2066     TripleAliases.append(begin(MIPSELTriples), end(MIPSELTriples));
2067     TripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2068     BiarchLibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
2069     BiarchTripleAliases.append(begin(MIPS64ELTriples), end(MIPS64ELTriples));
2070     break;
2071   case llvm::Triple::mips64:
2072     LibDirs.append(begin(MIPS64LibDirs), end(MIPS64LibDirs));
2073     TripleAliases.append(begin(MIPS64Triples), end(MIPS64Triples));
2074     BiarchLibDirs.append(begin(MIPSLibDirs), end(MIPSLibDirs));
2075     BiarchTripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2076     break;
2077   case llvm::Triple::mips64el:
2078     LibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
2079     TripleAliases.append(begin(MIPS64ELTriples), end(MIPS64ELTriples));
2080     BiarchLibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
2081     BiarchTripleAliases.append(begin(MIPSELTriples), end(MIPSELTriples));
2082     BiarchTripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2083     break;
2084   case llvm::Triple::ppc:
2085     LibDirs.append(begin(PPCLibDirs), end(PPCLibDirs));
2086     TripleAliases.append(begin(PPCTriples), end(PPCTriples));
2087     BiarchLibDirs.append(begin(PPC64LibDirs), end(PPC64LibDirs));
2088     BiarchTripleAliases.append(begin(PPC64Triples), end(PPC64Triples));
2089     break;
2090   case llvm::Triple::ppc64:
2091     LibDirs.append(begin(PPC64LibDirs), end(PPC64LibDirs));
2092     TripleAliases.append(begin(PPC64Triples), end(PPC64Triples));
2093     BiarchLibDirs.append(begin(PPCLibDirs), end(PPCLibDirs));
2094     BiarchTripleAliases.append(begin(PPCTriples), end(PPCTriples));
2095     break;
2096   case llvm::Triple::ppc64le:
2097     LibDirs.append(begin(PPC64LELibDirs), end(PPC64LELibDirs));
2098     TripleAliases.append(begin(PPC64LETriples), end(PPC64LETriples));
2099     break;
2100   case llvm::Triple::riscv32:
2101     LibDirs.append(begin(RISCV32LibDirs), end(RISCV32LibDirs));
2102     BiarchLibDirs.append(begin(RISCV32LibDirs), end(RISCV32LibDirs));
2103     TripleAliases.append(begin(RISCVTriples), end(RISCVTriples));
2104     BiarchTripleAliases.append(begin(RISCVTriples), end(RISCVTriples));
2105     break;
2106   case llvm::Triple::sparc:
2107   case llvm::Triple::sparcel:
2108     LibDirs.append(begin(SPARCv8LibDirs), end(SPARCv8LibDirs));
2109     TripleAliases.append(begin(SPARCv8Triples), end(SPARCv8Triples));
2110     BiarchLibDirs.append(begin(SPARCv9LibDirs), end(SPARCv9LibDirs));
2111     BiarchTripleAliases.append(begin(SPARCv9Triples), end(SPARCv9Triples));
2112     break;
2113   case llvm::Triple::sparcv9:
2114     LibDirs.append(begin(SPARCv9LibDirs), end(SPARCv9LibDirs));
2115     TripleAliases.append(begin(SPARCv9Triples), end(SPARCv9Triples));
2116     BiarchLibDirs.append(begin(SPARCv8LibDirs), end(SPARCv8LibDirs));
2117     BiarchTripleAliases.append(begin(SPARCv8Triples), end(SPARCv8Triples));
2118     break;
2119   case llvm::Triple::systemz:
2120     LibDirs.append(begin(SystemZLibDirs), end(SystemZLibDirs));
2121     TripleAliases.append(begin(SystemZTriples), end(SystemZTriples));
2122     break;
2123   default:
2124     // By default, just rely on the standard lib directories and the original
2125     // triple.
2126     break;
2127   }
2128 
2129   // Always append the drivers target triple to the end, in case it doesn't
2130   // match any of our aliases.
2131   TripleAliases.push_back(TargetTriple.str());
2132 
2133   // Also include the multiarch variant if it's different.
2134   if (TargetTriple.str() != BiarchTriple.str())
2135     BiarchTripleAliases.push_back(BiarchTriple.str());
2136 }
2137 
2138 bool Generic_GCC::GCCInstallationDetector::ScanGCCForMultilibs(
2139     const llvm::Triple &TargetTriple, const ArgList &Args,
2140     StringRef Path, bool NeedsBiarchSuffix) {
2141   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
2142   DetectedMultilibs Detected;
2143 
2144   // Android standalone toolchain could have multilibs for ARM and Thumb.
2145   // Debian mips multilibs behave more like the rest of the biarch ones,
2146   // so handle them there
2147   if (isArmOrThumbArch(TargetArch) && TargetTriple.isAndroid()) {
2148     // It should also work without multilibs in a simplified toolchain.
2149     findAndroidArmMultilibs(D, TargetTriple, Path, Args, Detected);
2150   } else if (tools::isMipsArch(TargetArch)) {
2151     if (!findMIPSMultilibs(D, TargetTriple, Path, Args, Detected))
2152       return false;
2153   } else if (isRISCV(TargetArch)) {
2154     findRISCVMultilibs(D, TargetTriple, Path, Args, Detected);
2155   } else if (!findBiarchMultilibs(D, TargetTriple, Path, Args,
2156                                   NeedsBiarchSuffix, Detected)) {
2157     return false;
2158   }
2159 
2160   Multilibs = Detected.Multilibs;
2161   SelectedMultilib = Detected.SelectedMultilib;
2162   BiarchSibling = Detected.BiarchSibling;
2163 
2164   return true;
2165 }
2166 
2167 void Generic_GCC::GCCInstallationDetector::ScanLibDirForGCCTriple(
2168     const llvm::Triple &TargetTriple, const ArgList &Args,
2169     const std::string &LibDir, StringRef CandidateTriple,
2170     bool NeedsBiarchSuffix) {
2171   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
2172   // Locations relative to the system lib directory where GCC's triple-specific
2173   // directories might reside.
2174   struct GCCLibSuffix {
2175     // Path from system lib directory to GCC triple-specific directory.
2176     std::string LibSuffix;
2177     // Path from GCC triple-specific directory back to system lib directory.
2178     // This is one '..' component per component in LibSuffix.
2179     StringRef ReversePath;
2180     // Whether this library suffix is relevant for the triple.
2181     bool Active;
2182   } Suffixes[] = {
2183       // This is the normal place.
2184       {"gcc/" + CandidateTriple.str(), "../..", true},
2185 
2186       // Debian puts cross-compilers in gcc-cross.
2187       {"gcc-cross/" + CandidateTriple.str(), "../..",
2188        TargetTriple.getOS() != llvm::Triple::Solaris},
2189 
2190       // The Freescale PPC SDK has the gcc libraries in
2191       // <sysroot>/usr/lib/<triple>/x.y.z so have a look there as well. Only do
2192       // this on Freescale triples, though, since some systems put a *lot* of
2193       // files in that location, not just GCC installation data.
2194       {CandidateTriple.str(), "..",
2195        TargetTriple.getVendor() == llvm::Triple::Freescale},
2196 
2197       // Natively multiarch systems sometimes put the GCC triple-specific
2198       // directory within their multiarch lib directory, resulting in the
2199       // triple appearing twice.
2200       {CandidateTriple.str() + "/gcc/" + CandidateTriple.str(), "../../..",
2201        TargetTriple.getOS() != llvm::Triple::Solaris},
2202 
2203       // Deal with cases (on Ubuntu) where the system architecture could be i386
2204       // but the GCC target architecture could be (say) i686.
2205       // FIXME: It may be worthwhile to generalize this and look for a second
2206       // triple.
2207       {"i386-linux-gnu/gcc/" + CandidateTriple.str(), "../../..",
2208        (TargetArch == llvm::Triple::x86 &&
2209         TargetTriple.getOS() != llvm::Triple::Solaris)}};
2210 
2211   for (auto &Suffix : Suffixes) {
2212     if (!Suffix.Active)
2213       continue;
2214 
2215     StringRef LibSuffix = Suffix.LibSuffix;
2216     std::error_code EC;
2217     for (vfs::directory_iterator
2218              LI = D.getVFS().dir_begin(LibDir + "/" + LibSuffix, EC),
2219              LE;
2220          !EC && LI != LE; LI = LI.increment(EC)) {
2221       StringRef VersionText = llvm::sys::path::filename(LI->getName());
2222       GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
2223       if (CandidateVersion.Major != -1) // Filter obviously bad entries.
2224         if (!CandidateGCCInstallPaths.insert(LI->getName()).second)
2225           continue; // Saw this path before; no need to look at it again.
2226       if (CandidateVersion.isOlderThan(4, 1, 1))
2227         continue;
2228       if (CandidateVersion <= Version)
2229         continue;
2230 
2231       if (!ScanGCCForMultilibs(TargetTriple, Args, LI->getName(),
2232                                NeedsBiarchSuffix))
2233         continue;
2234 
2235       Version = CandidateVersion;
2236       GCCTriple.setTriple(CandidateTriple);
2237       // FIXME: We hack together the directory name here instead of
2238       // using LI to ensure stable path separators across Windows and
2239       // Linux.
2240       GCCInstallPath = (LibDir + "/" + LibSuffix + "/" + VersionText).str();
2241       GCCParentLibPath = (GCCInstallPath + "/../" + Suffix.ReversePath).str();
2242       IsValid = true;
2243     }
2244   }
2245 }
2246 
2247 bool Generic_GCC::GCCInstallationDetector::ScanGentooConfigs(
2248     const llvm::Triple &TargetTriple, const ArgList &Args,
2249     const SmallVectorImpl<StringRef> &CandidateTriples,
2250     const SmallVectorImpl<StringRef> &CandidateBiarchTriples) {
2251   for (StringRef CandidateTriple : CandidateTriples) {
2252     if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple))
2253       return true;
2254   }
2255 
2256   for (StringRef CandidateTriple : CandidateBiarchTriples) {
2257     if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple, true))
2258       return true;
2259   }
2260   return false;
2261 }
2262 
2263 bool Generic_GCC::GCCInstallationDetector::ScanGentooGccConfig(
2264     const llvm::Triple &TargetTriple, const ArgList &Args,
2265     StringRef CandidateTriple, bool NeedsBiarchSuffix) {
2266   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
2267       D.getVFS().getBufferForFile(D.SysRoot + "/etc/env.d/gcc/config-" +
2268                                   CandidateTriple.str());
2269   if (File) {
2270     SmallVector<StringRef, 2> Lines;
2271     File.get()->getBuffer().split(Lines, "\n");
2272     for (StringRef Line : Lines) {
2273       Line = Line.trim();
2274       // CURRENT=triple-version
2275       if (!Line.consume_front("CURRENT="))
2276         continue;
2277       // Process the config file pointed to by CURRENT.
2278       llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> ConfigFile =
2279           D.getVFS().getBufferForFile(D.SysRoot + "/etc/env.d/gcc/" +
2280                                       Line.str());
2281       std::pair<StringRef, StringRef> ActiveVersion = Line.rsplit('-');
2282       // List of paths to scan for libraries.
2283       SmallVector<StringRef, 4> GentooScanPaths;
2284       // Scan the Config file to find installed GCC libraries path.
2285       // Typical content of the GCC config file:
2286       // LDPATH="/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.x:/usr/lib/gcc/
2287       // (continued from previous line) x86_64-pc-linux-gnu/4.9.x/32"
2288       // MANPATH="/usr/share/gcc-data/x86_64-pc-linux-gnu/4.9.x/man"
2289       // INFOPATH="/usr/share/gcc-data/x86_64-pc-linux-gnu/4.9.x/info"
2290       // STDCXX_INCDIR="/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.x/include/g++-v4"
2291       // We are looking for the paths listed in LDPATH=... .
2292       if (ConfigFile) {
2293         SmallVector<StringRef, 2> ConfigLines;
2294         ConfigFile.get()->getBuffer().split(ConfigLines, "\n");
2295         for (StringRef ConfLine : ConfigLines) {
2296           ConfLine = ConfLine.trim();
2297           if (ConfLine.consume_front("LDPATH=")) {
2298             // Drop '"' from front and back if present.
2299             ConfLine.consume_back("\"");
2300             ConfLine.consume_front("\"");
2301             // Get all paths sperated by ':'
2302             ConfLine.split(GentooScanPaths, ':', -1, /*AllowEmpty*/ false);
2303           }
2304         }
2305       }
2306       // Test the path based on the version in /etc/env.d/gcc/config-{tuple}.
2307       std::string basePath = "/usr/lib/gcc/" + ActiveVersion.first.str() + "/"
2308           + ActiveVersion.second.str();
2309       GentooScanPaths.push_back(StringRef(basePath));
2310 
2311       // Scan all paths for GCC libraries.
2312       for (const auto &GentooScanPath : GentooScanPaths) {
2313         std::string GentooPath = D.SysRoot + std::string(GentooScanPath);
2314         if (D.getVFS().exists(GentooPath + "/crtbegin.o")) {
2315           if (!ScanGCCForMultilibs(TargetTriple, Args, GentooPath,
2316                                    NeedsBiarchSuffix))
2317             continue;
2318 
2319           Version = GCCVersion::Parse(ActiveVersion.second);
2320           GCCInstallPath = GentooPath;
2321           GCCParentLibPath = GentooPath + std::string("/../../..");
2322           GCCTriple.setTriple(ActiveVersion.first);
2323           IsValid = true;
2324           return true;
2325         }
2326       }
2327     }
2328   }
2329 
2330   return false;
2331 }
2332 
2333 Generic_GCC::Generic_GCC(const Driver &D, const llvm::Triple &Triple,
2334                          const ArgList &Args)
2335     : ToolChain(D, Triple, Args), GCCInstallation(D),
2336       CudaInstallation(D, Triple, Args) {
2337   getProgramPaths().push_back(getDriver().getInstalledDir());
2338   if (getDriver().getInstalledDir() != getDriver().Dir)
2339     getProgramPaths().push_back(getDriver().Dir);
2340 }
2341 
2342 Generic_GCC::~Generic_GCC() {}
2343 
2344 Tool *Generic_GCC::getTool(Action::ActionClass AC) const {
2345   switch (AC) {
2346   case Action::PreprocessJobClass:
2347     if (!Preprocess)
2348       Preprocess.reset(new clang::driver::tools::gcc::Preprocessor(*this));
2349     return Preprocess.get();
2350   case Action::CompileJobClass:
2351     if (!Compile)
2352       Compile.reset(new tools::gcc::Compiler(*this));
2353     return Compile.get();
2354   default:
2355     return ToolChain::getTool(AC);
2356   }
2357 }
2358 
2359 Tool *Generic_GCC::buildAssembler() const {
2360   return new tools::gnutools::Assembler(*this);
2361 }
2362 
2363 Tool *Generic_GCC::buildLinker() const { return new tools::gcc::Linker(*this); }
2364 
2365 void Generic_GCC::printVerboseInfo(raw_ostream &OS) const {
2366   // Print the information about how we detected the GCC installation.
2367   GCCInstallation.print(OS);
2368   CudaInstallation.print(OS);
2369 }
2370 
2371 bool Generic_GCC::IsUnwindTablesDefault(const ArgList &Args) const {
2372   return getArch() == llvm::Triple::x86_64;
2373 }
2374 
2375 bool Generic_GCC::isPICDefault() const {
2376   switch (getArch()) {
2377   case llvm::Triple::x86_64:
2378     return getTriple().isOSWindows();
2379   case llvm::Triple::ppc64:
2380   case llvm::Triple::ppc64le:
2381     return !getTriple().isOSBinFormatMachO() && !getTriple().isMacOSX();
2382   case llvm::Triple::mips64:
2383   case llvm::Triple::mips64el:
2384     return true;
2385   default:
2386     return false;
2387   }
2388 }
2389 
2390 bool Generic_GCC::isPIEDefault() const { return false; }
2391 
2392 bool Generic_GCC::isPICDefaultForced() const {
2393   return getArch() == llvm::Triple::x86_64 && getTriple().isOSWindows();
2394 }
2395 
2396 bool Generic_GCC::IsIntegratedAssemblerDefault() const {
2397   switch (getTriple().getArch()) {
2398   case llvm::Triple::x86:
2399   case llvm::Triple::x86_64:
2400   case llvm::Triple::aarch64:
2401   case llvm::Triple::aarch64_be:
2402   case llvm::Triple::arm:
2403   case llvm::Triple::armeb:
2404   case llvm::Triple::avr:
2405   case llvm::Triple::bpfel:
2406   case llvm::Triple::bpfeb:
2407   case llvm::Triple::thumb:
2408   case llvm::Triple::thumbeb:
2409   case llvm::Triple::ppc:
2410   case llvm::Triple::ppc64:
2411   case llvm::Triple::ppc64le:
2412   case llvm::Triple::riscv32:
2413   case llvm::Triple::riscv64:
2414   case llvm::Triple::systemz:
2415   case llvm::Triple::mips:
2416   case llvm::Triple::mipsel:
2417     return true;
2418   case llvm::Triple::mips64:
2419   case llvm::Triple::mips64el:
2420     // Enabled for Debian and Android mips64/mipsel, as they can precisely
2421     // identify the ABI in use (Debian) or only use N64 for MIPS64 (Android).
2422     // Other targets are unable to distinguish N32 from N64.
2423     if (getTriple().getEnvironment() == llvm::Triple::GNUABI64 ||
2424         getTriple().isAndroid())
2425       return true;
2426     return false;
2427   default:
2428     return false;
2429   }
2430 }
2431 
2432 void Generic_GCC::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
2433                                                ArgStringList &CC1Args) const {
2434   if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
2435       DriverArgs.hasArg(options::OPT_nostdincxx))
2436     return;
2437 
2438   switch (GetCXXStdlibType(DriverArgs)) {
2439   case ToolChain::CST_Libcxx:
2440     addLibCxxIncludePaths(DriverArgs, CC1Args);
2441     break;
2442 
2443   case ToolChain::CST_Libstdcxx:
2444     addLibStdCxxIncludePaths(DriverArgs, CC1Args);
2445     break;
2446   }
2447 }
2448 
2449 void
2450 Generic_GCC::addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
2451                                    llvm::opt::ArgStringList &CC1Args) const {
2452   // FIXME: The Linux behavior would probaby be a better approach here.
2453   addSystemInclude(DriverArgs, CC1Args,
2454                    getDriver().SysRoot + "/usr/include/c++/v1");
2455 }
2456 
2457 void
2458 Generic_GCC::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
2459                                       llvm::opt::ArgStringList &CC1Args) const {
2460   // By default, we don't assume we know where libstdc++ might be installed.
2461   // FIXME: If we have a valid GCCInstallation, use it.
2462 }
2463 
2464 /// \brief Helper to add the variant paths of a libstdc++ installation.
2465 bool Generic_GCC::addLibStdCXXIncludePaths(
2466     Twine Base, Twine Suffix, StringRef GCCTriple, StringRef GCCMultiarchTriple,
2467     StringRef TargetMultiarchTriple, Twine IncludeSuffix,
2468     const ArgList &DriverArgs, ArgStringList &CC1Args) const {
2469   if (!getVFS().exists(Base + Suffix))
2470     return false;
2471 
2472   addSystemInclude(DriverArgs, CC1Args, Base + Suffix);
2473 
2474   // The vanilla GCC layout of libstdc++ headers uses a triple subdirectory. If
2475   // that path exists or we have neither a GCC nor target multiarch triple, use
2476   // this vanilla search path.
2477   if ((GCCMultiarchTriple.empty() && TargetMultiarchTriple.empty()) ||
2478       getVFS().exists(Base + Suffix + "/" + GCCTriple + IncludeSuffix)) {
2479     addSystemInclude(DriverArgs, CC1Args,
2480                      Base + Suffix + "/" + GCCTriple + IncludeSuffix);
2481   } else {
2482     // Otherwise try to use multiarch naming schemes which have normalized the
2483     // triples and put the triple before the suffix.
2484     //
2485     // GCC surprisingly uses *both* the GCC triple with a multilib suffix and
2486     // the target triple, so we support that here.
2487     addSystemInclude(DriverArgs, CC1Args,
2488                      Base + "/" + GCCMultiarchTriple + Suffix + IncludeSuffix);
2489     addSystemInclude(DriverArgs, CC1Args,
2490                      Base + "/" + TargetMultiarchTriple + Suffix);
2491   }
2492 
2493   addSystemInclude(DriverArgs, CC1Args, Base + Suffix + "/backward");
2494   return true;
2495 }
2496 
2497 llvm::opt::DerivedArgList *
2498 Generic_GCC::TranslateArgs(const llvm::opt::DerivedArgList &Args, StringRef,
2499                            Action::OffloadKind DeviceOffloadKind) const {
2500 
2501   // If this tool chain is used for an OpenMP offloading device we have to make
2502   // sure we always generate a shared library regardless of the commands the
2503   // user passed to the host. This is required because the runtime library
2504   // is required to load the device image dynamically at run time.
2505   if (DeviceOffloadKind == Action::OFK_OpenMP) {
2506     DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
2507     const OptTable &Opts = getDriver().getOpts();
2508 
2509     // Request the shared library. Given that these options are decided
2510     // implicitly, they do not refer to any base argument.
2511     DAL->AddFlagArg(/*BaseArg=*/nullptr, Opts.getOption(options::OPT_shared));
2512     DAL->AddFlagArg(/*BaseArg=*/nullptr, Opts.getOption(options::OPT_fPIC));
2513 
2514     // Filter all the arguments we don't care passing to the offloading
2515     // toolchain as they can mess up with the creation of a shared library.
2516     for (auto *A : Args) {
2517       switch ((options::ID)A->getOption().getID()) {
2518       default:
2519         DAL->append(A);
2520         break;
2521       case options::OPT_shared:
2522       case options::OPT_dynamic:
2523       case options::OPT_static:
2524       case options::OPT_fPIC:
2525       case options::OPT_fno_PIC:
2526       case options::OPT_fpic:
2527       case options::OPT_fno_pic:
2528       case options::OPT_fPIE:
2529       case options::OPT_fno_PIE:
2530       case options::OPT_fpie:
2531       case options::OPT_fno_pie:
2532         break;
2533       }
2534     }
2535     return DAL;
2536   }
2537   return nullptr;
2538 }
2539 
2540 void Generic_ELF::anchor() {}
2541 
2542 void Generic_ELF::addClangTargetOptions(const ArgList &DriverArgs,
2543                                         ArgStringList &CC1Args,
2544                                         Action::OffloadKind) const {
2545   const Generic_GCC::GCCVersion &V = GCCInstallation.getVersion();
2546   bool UseInitArrayDefault =
2547       getTriple().getArch() == llvm::Triple::aarch64 ||
2548       getTriple().getArch() == llvm::Triple::aarch64_be ||
2549       (getTriple().getOS() == llvm::Triple::Linux &&
2550        ((!GCCInstallation.isValid() || !V.isOlderThan(4, 7, 0)) ||
2551         getTriple().isAndroid())) ||
2552       getTriple().getOS() == llvm::Triple::NaCl ||
2553       (getTriple().getVendor() == llvm::Triple::MipsTechnologies &&
2554        !getTriple().hasEnvironment()) ||
2555       getTriple().getOS() == llvm::Triple::Solaris;
2556 
2557   if (DriverArgs.hasFlag(options::OPT_fuse_init_array,
2558                          options::OPT_fno_use_init_array, UseInitArrayDefault))
2559     CC1Args.push_back("-fuse-init-array");
2560 }
2561