xref: /src/contrib/llvm-project/clang/lib/Driver/ToolChains/Gnu.cpp (revision 81ad626541db97eb356e2c1d4a20eb2a26a766ab)
1 //===--- Gnu.cpp - Gnu Tool and ToolChain Implementations -------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "Gnu.h"
10 #include "Arch/ARM.h"
11 #include "Arch/CSKY.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/Config/config.h" // for GCC_INSTALL_PREFIX
20 #include "clang/Driver/Compilation.h"
21 #include "clang/Driver/Driver.h"
22 #include "clang/Driver/DriverDiagnostic.h"
23 #include "clang/Driver/Options.h"
24 #include "clang/Driver/Tool.h"
25 #include "clang/Driver/ToolChain.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 "llvm/Support/VirtualFileSystem.h"
31 #include <system_error>
32 
33 using namespace clang::driver;
34 using namespace clang::driver::toolchains;
35 using namespace clang;
36 using namespace llvm::opt;
37 
38 using tools::addMultilibFlag;
39 using tools::addPathIfExists;
40 
41 static bool forwardToGCC(const Option &O) {
42   // LinkerInput options have been forwarded. Don't duplicate.
43   if (O.hasFlag(options::LinkerInput))
44     return false;
45   return O.matches(options::OPT_Link_Group) || O.hasFlag(options::LinkOption);
46 }
47 
48 // Switch CPU names not recognized by GNU assembler to a close CPU that it does
49 // recognize, instead of a lower march from being picked in the absence of a cpu
50 // flag.
51 static void normalizeCPUNamesForAssembler(const ArgList &Args,
52                                           ArgStringList &CmdArgs) {
53   if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
54     StringRef CPUArg(A->getValue());
55     if (CPUArg.equals_insensitive("krait"))
56       CmdArgs.push_back("-mcpu=cortex-a15");
57     else if (CPUArg.equals_insensitive("kryo"))
58       CmdArgs.push_back("-mcpu=cortex-a57");
59     else
60       Args.AddLastArg(CmdArgs, options::OPT_mcpu_EQ);
61   }
62 }
63 
64 void tools::gcc::Common::ConstructJob(Compilation &C, const JobAction &JA,
65                                       const InputInfo &Output,
66                                       const InputInfoList &Inputs,
67                                       const ArgList &Args,
68                                       const char *LinkingOutput) const {
69   const Driver &D = getToolChain().getDriver();
70   ArgStringList CmdArgs;
71 
72   for (const auto &A : Args) {
73     if (forwardToGCC(A->getOption())) {
74       // It is unfortunate that we have to claim here, as this means
75       // we will basically never report anything interesting for
76       // platforms using a generic gcc, even if we are just using gcc
77       // to get to the assembler.
78       A->claim();
79 
80       A->render(Args, CmdArgs);
81     }
82   }
83 
84   RenderExtraToolArgs(JA, CmdArgs);
85 
86   // If using a driver driver, force the arch.
87   if (getToolChain().getTriple().isOSDarwin()) {
88     CmdArgs.push_back("-arch");
89     CmdArgs.push_back(
90         Args.MakeArgString(getToolChain().getDefaultUniversalArchName()));
91   }
92 
93   // Try to force gcc to match the tool chain we want, if we recognize
94   // the arch.
95   //
96   // FIXME: The triple class should directly provide the information we want
97   // here.
98   switch (getToolChain().getArch()) {
99   default:
100     break;
101   case llvm::Triple::x86:
102   case llvm::Triple::ppc:
103   case llvm::Triple::ppcle:
104     CmdArgs.push_back("-m32");
105     break;
106   case llvm::Triple::x86_64:
107   case llvm::Triple::ppc64:
108   case llvm::Triple::ppc64le:
109     CmdArgs.push_back("-m64");
110     break;
111   case llvm::Triple::sparcel:
112     CmdArgs.push_back("-EL");
113     break;
114   }
115 
116   if (Output.isFilename()) {
117     CmdArgs.push_back("-o");
118     CmdArgs.push_back(Output.getFilename());
119   } else {
120     assert(Output.isNothing() && "Unexpected output");
121     CmdArgs.push_back("-fsyntax-only");
122   }
123 
124   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
125 
126   // Only pass -x if gcc will understand it; otherwise hope gcc
127   // understands the suffix correctly. The main use case this would go
128   // wrong in is for linker inputs if they happened to have an odd
129   // suffix; really the only way to get this to happen is a command
130   // like '-x foobar a.c' which will treat a.c like a linker input.
131   //
132   // FIXME: For the linker case specifically, can we safely convert
133   // inputs into '-Wl,' options?
134   for (const auto &II : Inputs) {
135     // Don't try to pass LLVM or AST inputs to a generic gcc.
136     if (types::isLLVMIR(II.getType()))
137       D.Diag(clang::diag::err_drv_no_linker_llvm_support)
138           << getToolChain().getTripleString();
139     else if (II.getType() == types::TY_AST)
140       D.Diag(diag::err_drv_no_ast_support) << getToolChain().getTripleString();
141     else if (II.getType() == types::TY_ModuleFile)
142       D.Diag(diag::err_drv_no_module_support)
143           << getToolChain().getTripleString();
144 
145     if (types::canTypeBeUserSpecified(II.getType())) {
146       CmdArgs.push_back("-x");
147       CmdArgs.push_back(types::getTypeName(II.getType()));
148     }
149 
150     if (II.isFilename())
151       CmdArgs.push_back(II.getFilename());
152     else {
153       const Arg &A = II.getInputArg();
154 
155       // Reverse translate some rewritten options.
156       if (A.getOption().matches(options::OPT_Z_reserved_lib_stdcxx)) {
157         CmdArgs.push_back("-lstdc++");
158         continue;
159       }
160 
161       // Don't render as input, we need gcc to do the translations.
162       A.render(Args, CmdArgs);
163     }
164   }
165 
166   const std::string &customGCCName = D.getCCCGenericGCCName();
167   const char *GCCName;
168   if (!customGCCName.empty())
169     GCCName = customGCCName.c_str();
170   else if (D.CCCIsCXX()) {
171     GCCName = "g++";
172   } else
173     GCCName = "gcc";
174 
175   const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath(GCCName));
176   C.addCommand(std::make_unique<Command>(JA, *this,
177                                          ResponseFileSupport::AtFileCurCP(),
178                                          Exec, CmdArgs, Inputs, Output));
179 }
180 
181 void tools::gcc::Preprocessor::RenderExtraToolArgs(
182     const JobAction &JA, ArgStringList &CmdArgs) const {
183   CmdArgs.push_back("-E");
184 }
185 
186 void tools::gcc::Compiler::RenderExtraToolArgs(const JobAction &JA,
187                                                ArgStringList &CmdArgs) const {
188   const Driver &D = getToolChain().getDriver();
189 
190   switch (JA.getType()) {
191   // If -flto, etc. are present then make sure not to force assembly output.
192   case types::TY_LLVM_IR:
193   case types::TY_LTO_IR:
194   case types::TY_LLVM_BC:
195   case types::TY_LTO_BC:
196     CmdArgs.push_back("-c");
197     break;
198   // We assume we've got an "integrated" assembler in that gcc will produce an
199   // object file itself.
200   case types::TY_Object:
201     CmdArgs.push_back("-c");
202     break;
203   case types::TY_PP_Asm:
204     CmdArgs.push_back("-S");
205     break;
206   case types::TY_Nothing:
207     CmdArgs.push_back("-fsyntax-only");
208     break;
209   default:
210     D.Diag(diag::err_drv_invalid_gcc_output_type) << getTypeName(JA.getType());
211   }
212 }
213 
214 void tools::gcc::Linker::RenderExtraToolArgs(const JobAction &JA,
215                                              ArgStringList &CmdArgs) const {
216   // The types are (hopefully) good enough.
217 }
218 
219 // On Arm the endianness of the output file is determined by the target and
220 // can be overridden by the pseudo-target flags '-mlittle-endian'/'-EL' and
221 // '-mbig-endian'/'-EB'. Unlike other targets the flag does not result in a
222 // normalized triple so we must handle the flag here.
223 static bool isArmBigEndian(const llvm::Triple &Triple,
224                            const ArgList &Args) {
225   bool IsBigEndian = false;
226   switch (Triple.getArch()) {
227   case llvm::Triple::armeb:
228   case llvm::Triple::thumbeb:
229     IsBigEndian = true;
230     LLVM_FALLTHROUGH;
231   case llvm::Triple::arm:
232   case llvm::Triple::thumb:
233     if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
234                                options::OPT_mbig_endian))
235       IsBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
236     break;
237   default:
238     break;
239   }
240   return IsBigEndian;
241 }
242 
243 static const char *getLDMOption(const llvm::Triple &T, const ArgList &Args) {
244   switch (T.getArch()) {
245   case llvm::Triple::x86:
246     if (T.isOSIAMCU())
247       return "elf_iamcu";
248     return "elf_i386";
249   case llvm::Triple::aarch64:
250     return "aarch64linux";
251   case llvm::Triple::aarch64_be:
252     return "aarch64linuxb";
253   case llvm::Triple::arm:
254   case llvm::Triple::thumb:
255   case llvm::Triple::armeb:
256   case llvm::Triple::thumbeb:
257     return isArmBigEndian(T, Args) ? "armelfb_linux_eabi" : "armelf_linux_eabi";
258   case llvm::Triple::m68k:
259     return "m68kelf";
260   case llvm::Triple::ppc:
261     if (T.isOSLinux())
262       return "elf32ppclinux";
263     return "elf32ppc";
264   case llvm::Triple::ppcle:
265     if (T.isOSLinux())
266       return "elf32lppclinux";
267     return "elf32lppc";
268   case llvm::Triple::ppc64:
269     return "elf64ppc";
270   case llvm::Triple::ppc64le:
271     return "elf64lppc";
272   case llvm::Triple::riscv32:
273     return "elf32lriscv";
274   case llvm::Triple::riscv64:
275     return "elf64lriscv";
276   case llvm::Triple::sparc:
277   case llvm::Triple::sparcel:
278     return "elf32_sparc";
279   case llvm::Triple::sparcv9:
280     return "elf64_sparc";
281   case llvm::Triple::mips:
282     return "elf32btsmip";
283   case llvm::Triple::mipsel:
284     return "elf32ltsmip";
285   case llvm::Triple::mips64:
286     if (tools::mips::hasMipsAbiArg(Args, "n32") ||
287         T.getEnvironment() == llvm::Triple::GNUABIN32)
288       return "elf32btsmipn32";
289     return "elf64btsmip";
290   case llvm::Triple::mips64el:
291     if (tools::mips::hasMipsAbiArg(Args, "n32") ||
292         T.getEnvironment() == llvm::Triple::GNUABIN32)
293       return "elf32ltsmipn32";
294     return "elf64ltsmip";
295   case llvm::Triple::systemz:
296     return "elf64_s390";
297   case llvm::Triple::x86_64:
298     if (T.isX32())
299       return "elf32_x86_64";
300     return "elf_x86_64";
301   case llvm::Triple::ve:
302     return "elf64ve";
303   case llvm::Triple::csky:
304     return "cskyelf_linux";
305   default:
306     return nullptr;
307   }
308 }
309 
310 static bool getPIE(const ArgList &Args, const ToolChain &TC) {
311   if (Args.hasArg(options::OPT_shared) || Args.hasArg(options::OPT_static) ||
312       Args.hasArg(options::OPT_r) || Args.hasArg(options::OPT_static_pie))
313     return false;
314 
315   Arg *A = Args.getLastArg(options::OPT_pie, options::OPT_no_pie,
316                            options::OPT_nopie);
317   if (!A)
318     return TC.isPIEDefault(Args);
319   return A->getOption().matches(options::OPT_pie);
320 }
321 
322 static bool getStaticPIE(const ArgList &Args, const ToolChain &TC) {
323   bool HasStaticPIE = Args.hasArg(options::OPT_static_pie);
324   // -no-pie is an alias for -nopie. So, handling -nopie takes care of
325   // -no-pie as well.
326   if (HasStaticPIE && Args.hasArg(options::OPT_nopie)) {
327     const Driver &D = TC.getDriver();
328     const llvm::opt::OptTable &Opts = D.getOpts();
329     const char *StaticPIEName = Opts.getOptionName(options::OPT_static_pie);
330     const char *NoPIEName = Opts.getOptionName(options::OPT_nopie);
331     D.Diag(diag::err_drv_cannot_mix_options) << StaticPIEName << NoPIEName;
332   }
333   return HasStaticPIE;
334 }
335 
336 static bool getStatic(const ArgList &Args) {
337   return Args.hasArg(options::OPT_static) &&
338       !Args.hasArg(options::OPT_static_pie);
339 }
340 
341 void tools::gnutools::StaticLibTool::ConstructJob(
342     Compilation &C, const JobAction &JA, const InputInfo &Output,
343     const InputInfoList &Inputs, const ArgList &Args,
344     const char *LinkingOutput) const {
345   const Driver &D = getToolChain().getDriver();
346 
347   // Silence warning for "clang -g foo.o -o foo"
348   Args.ClaimAllArgs(options::OPT_g_Group);
349   // and "clang -emit-llvm foo.o -o foo"
350   Args.ClaimAllArgs(options::OPT_emit_llvm);
351   // and for "clang -w foo.o -o foo". Other warning options are already
352   // handled somewhere else.
353   Args.ClaimAllArgs(options::OPT_w);
354   // Silence warnings when linking C code with a C++ '-stdlib' argument.
355   Args.ClaimAllArgs(options::OPT_stdlib_EQ);
356 
357   // ar tool command "llvm-ar <options> <output_file> <input_files>".
358   ArgStringList CmdArgs;
359   // Create and insert file members with a deterministic index.
360   CmdArgs.push_back("rcsD");
361   CmdArgs.push_back(Output.getFilename());
362 
363   for (const auto &II : Inputs) {
364     if (II.isFilename()) {
365        CmdArgs.push_back(II.getFilename());
366     }
367   }
368 
369   // Delete old output archive file if it already exists before generating a new
370   // archive file.
371   auto OutputFileName = Output.getFilename();
372   if (Output.isFilename() && llvm::sys::fs::exists(OutputFileName)) {
373     if (std::error_code EC = llvm::sys::fs::remove(OutputFileName)) {
374       D.Diag(diag::err_drv_unable_to_remove_file) << EC.message();
375       return;
376     }
377   }
378 
379   const char *Exec = Args.MakeArgString(getToolChain().GetStaticLibToolPath());
380   C.addCommand(std::make_unique<Command>(JA, *this,
381                                          ResponseFileSupport::AtFileCurCP(),
382                                          Exec, CmdArgs, Inputs, Output));
383 }
384 
385 void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
386                                            const InputInfo &Output,
387                                            const InputInfoList &Inputs,
388                                            const ArgList &Args,
389                                            const char *LinkingOutput) const {
390   // FIXME: The Linker class constructor takes a ToolChain and not a
391   // Generic_ELF, so the static_cast might return a reference to a invalid
392   // instance (see PR45061). Ideally, the Linker constructor needs to take a
393   // Generic_ELF instead.
394   const toolchains::Generic_ELF &ToolChain =
395       static_cast<const toolchains::Generic_ELF &>(getToolChain());
396   const Driver &D = ToolChain.getDriver();
397 
398   const llvm::Triple &Triple = getToolChain().getEffectiveTriple();
399 
400   const llvm::Triple::ArchType Arch = ToolChain.getArch();
401   const bool isAndroid = ToolChain.getTriple().isAndroid();
402   const bool IsIAMCU = ToolChain.getTriple().isOSIAMCU();
403   const bool IsVE = ToolChain.getTriple().isVE();
404   const bool IsPIE = getPIE(Args, ToolChain);
405   const bool IsStaticPIE = getStaticPIE(Args, ToolChain);
406   const bool IsStatic = getStatic(Args);
407   const bool HasCRTBeginEndFiles =
408       ToolChain.getTriple().hasEnvironment() ||
409       (ToolChain.getTriple().getVendor() != llvm::Triple::MipsTechnologies);
410 
411   ArgStringList CmdArgs;
412 
413   // Silence warning for "clang -g foo.o -o foo"
414   Args.ClaimAllArgs(options::OPT_g_Group);
415   // and "clang -emit-llvm foo.o -o foo"
416   Args.ClaimAllArgs(options::OPT_emit_llvm);
417   // and for "clang -w foo.o -o foo". Other warning options are already
418   // handled somewhere else.
419   Args.ClaimAllArgs(options::OPT_w);
420 
421   if (!D.SysRoot.empty())
422     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
423 
424   if (IsPIE)
425     CmdArgs.push_back("-pie");
426 
427   if (IsStaticPIE) {
428     CmdArgs.push_back("-static");
429     CmdArgs.push_back("-pie");
430     CmdArgs.push_back("--no-dynamic-linker");
431     CmdArgs.push_back("-z");
432     CmdArgs.push_back("text");
433   }
434 
435   if (Args.hasArg(options::OPT_rdynamic))
436     CmdArgs.push_back("-export-dynamic");
437 
438   if (Args.hasArg(options::OPT_s))
439     CmdArgs.push_back("-s");
440 
441   if (Triple.isARM() || Triple.isThumb() || Triple.isAArch64()) {
442     bool IsBigEndian = isArmBigEndian(Triple, Args);
443     if (IsBigEndian)
444       arm::appendBE8LinkFlag(Args, CmdArgs, Triple);
445     IsBigEndian = IsBigEndian || Arch == llvm::Triple::aarch64_be;
446     CmdArgs.push_back(IsBigEndian ? "-EB" : "-EL");
447   }
448 
449   // Most Android ARM64 targets should enable the linker fix for erratum
450   // 843419. Only non-Cortex-A53 devices are allowed to skip this flag.
451   if (Arch == llvm::Triple::aarch64 && isAndroid) {
452     std::string CPU = getCPUName(D, Args, Triple);
453     if (CPU.empty() || CPU == "generic" || CPU == "cortex-a53")
454       CmdArgs.push_back("--fix-cortex-a53-843419");
455   }
456 
457   ToolChain.addExtraOpts(CmdArgs);
458 
459   CmdArgs.push_back("--eh-frame-hdr");
460 
461   if (const char *LDMOption = getLDMOption(ToolChain.getTriple(), Args)) {
462     CmdArgs.push_back("-m");
463     CmdArgs.push_back(LDMOption);
464   } else {
465     D.Diag(diag::err_target_unknown_triple) << Triple.str();
466     return;
467   }
468   if (Triple.isRISCV())
469     CmdArgs.push_back("-X");
470 
471   if (Args.hasArg(options::OPT_shared))
472     CmdArgs.push_back("-shared");
473 
474   if (IsStatic) {
475     CmdArgs.push_back("-static");
476   } else {
477     if (Args.hasArg(options::OPT_rdynamic))
478       CmdArgs.push_back("-export-dynamic");
479 
480     if (!Args.hasArg(options::OPT_shared) && !IsStaticPIE &&
481         !Args.hasArg(options::OPT_r)) {
482       CmdArgs.push_back("-dynamic-linker");
483       CmdArgs.push_back(Args.MakeArgString(Twine(D.DyldPrefix) +
484                                            ToolChain.getDynamicLinker(Args)));
485     }
486   }
487 
488   CmdArgs.push_back("-o");
489   CmdArgs.push_back(Output.getFilename());
490 
491   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
492                    options::OPT_r)) {
493     if (!isAndroid && !IsIAMCU) {
494       const char *crt1 = nullptr;
495       if (!Args.hasArg(options::OPT_shared)) {
496         if (Args.hasArg(options::OPT_pg))
497           crt1 = "gcrt1.o";
498         else if (IsPIE)
499           crt1 = "Scrt1.o";
500         else if (IsStaticPIE)
501           crt1 = "rcrt1.o";
502         else
503           crt1 = "crt1.o";
504       }
505       if (crt1)
506         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crt1)));
507 
508       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crti.o")));
509     }
510 
511     if (IsVE) {
512       CmdArgs.push_back("-z");
513       CmdArgs.push_back("max-page-size=0x4000000");
514     }
515 
516     if (IsIAMCU)
517       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt0.o")));
518     else if (HasCRTBeginEndFiles) {
519       std::string P;
520       if (ToolChain.GetRuntimeLibType(Args) == ToolChain::RLT_CompilerRT &&
521           !isAndroid) {
522         std::string crtbegin = ToolChain.getCompilerRT(Args, "crtbegin",
523                                                        ToolChain::FT_Object);
524         if (ToolChain.getVFS().exists(crtbegin))
525           P = crtbegin;
526       }
527       if (P.empty()) {
528         const char *crtbegin;
529         if (Args.hasArg(options::OPT_shared))
530           crtbegin = isAndroid ? "crtbegin_so.o" : "crtbeginS.o";
531         else if (IsStatic)
532           crtbegin = isAndroid ? "crtbegin_static.o" : "crtbeginT.o";
533         else if (IsPIE || IsStaticPIE)
534           crtbegin = isAndroid ? "crtbegin_dynamic.o" : "crtbeginS.o";
535         else
536           crtbegin = isAndroid ? "crtbegin_dynamic.o" : "crtbegin.o";
537         P = ToolChain.GetFilePath(crtbegin);
538       }
539       CmdArgs.push_back(Args.MakeArgString(P));
540     }
541 
542     // Add crtfastmath.o if available and fast math is enabled.
543     ToolChain.addFastMathRuntimeIfAvailable(Args, CmdArgs);
544   }
545 
546   Args.AddAllArgs(CmdArgs, options::OPT_L);
547   Args.AddAllArgs(CmdArgs, options::OPT_u);
548 
549   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
550 
551   if (D.isUsingLTO()) {
552     assert(!Inputs.empty() && "Must have at least one input.");
553     addLTOOptions(ToolChain, Args, CmdArgs, Output, Inputs[0],
554                   D.getLTOMode() == LTOK_Thin);
555   }
556 
557   if (Args.hasArg(options::OPT_Z_Xlinker__no_demangle))
558     CmdArgs.push_back("--no-demangle");
559 
560   bool NeedsSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
561   bool NeedsXRayDeps = addXRayRuntime(ToolChain, Args, CmdArgs);
562   addLinkerCompressDebugSectionsOption(ToolChain, Args, CmdArgs);
563   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
564 
565   addHIPRuntimeLibArgs(ToolChain, Args, CmdArgs);
566 
567   // The profile runtime also needs access to system libraries.
568   getToolChain().addProfileRTLibs(Args, CmdArgs);
569 
570   if (D.CCCIsCXX() &&
571       !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
572                    options::OPT_r)) {
573     if (ToolChain.ShouldLinkCXXStdlib(Args)) {
574       bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
575                                  !Args.hasArg(options::OPT_static);
576       if (OnlyLibstdcxxStatic)
577         CmdArgs.push_back("-Bstatic");
578       ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
579       if (OnlyLibstdcxxStatic)
580         CmdArgs.push_back("-Bdynamic");
581     }
582     CmdArgs.push_back("-lm");
583   }
584 
585   // If we are linking for the device all symbols should be bound locally. The
586   // symbols are already protected which makes this redundant. This is only
587   // necessary to work around a problem in bfd.
588   // TODO: Remove this once 'lld' becomes the only linker for offloading.
589   if (JA.isDeviceOffloading(Action::OFK_OpenMP))
590     CmdArgs.push_back("-Bsymbolic");
591 
592   // Silence warnings when linking C code with a C++ '-stdlib' argument.
593   Args.ClaimAllArgs(options::OPT_stdlib_EQ);
594 
595   // Additional linker set-up and flags for Fortran. This is required in order
596   // to generate executables. As Fortran runtime depends on the C runtime,
597   // these dependencies need to be listed before the C runtime below (i.e.
598   // AddRuntTimeLibs).
599   if (D.IsFlangMode()) {
600     addFortranRuntimeLibraryPath(ToolChain, Args, CmdArgs);
601     addFortranRuntimeLibs(ToolChain, CmdArgs);
602     CmdArgs.push_back("-lm");
603   }
604 
605   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_r)) {
606     if (!Args.hasArg(options::OPT_nodefaultlibs)) {
607       if (IsStatic || IsStaticPIE)
608         CmdArgs.push_back("--start-group");
609 
610       if (NeedsSanitizerDeps)
611         linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
612 
613       if (NeedsXRayDeps)
614         linkXRayRuntimeDeps(ToolChain, CmdArgs);
615 
616       bool WantPthread = Args.hasArg(options::OPT_pthread) ||
617                          Args.hasArg(options::OPT_pthreads);
618 
619       // Use the static OpenMP runtime with -static-openmp
620       bool StaticOpenMP = Args.hasArg(options::OPT_static_openmp) &&
621                           !Args.hasArg(options::OPT_static);
622 
623       // FIXME: Only pass GompNeedsRT = true for platforms with libgomp that
624       // require librt. Most modern Linux platforms do, but some may not.
625       if (addOpenMPRuntime(CmdArgs, ToolChain, Args, StaticOpenMP,
626                            JA.isHostOffloading(Action::OFK_OpenMP),
627                            /* GompNeedsRT= */ true))
628         // OpenMP runtimes implies pthreads when using the GNU toolchain.
629         // FIXME: Does this really make sense for all GNU toolchains?
630         WantPthread = true;
631 
632       AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
633 
634       if (WantPthread && !isAndroid)
635         CmdArgs.push_back("-lpthread");
636 
637       if (Args.hasArg(options::OPT_fsplit_stack))
638         CmdArgs.push_back("--wrap=pthread_create");
639 
640       if (!Args.hasArg(options::OPT_nolibc))
641         CmdArgs.push_back("-lc");
642 
643       // Add IAMCU specific libs, if needed.
644       if (IsIAMCU)
645         CmdArgs.push_back("-lgloss");
646 
647       if (IsStatic || IsStaticPIE)
648         CmdArgs.push_back("--end-group");
649       else
650         AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
651 
652       // Add IAMCU specific libs (outside the group), if needed.
653       if (IsIAMCU) {
654         CmdArgs.push_back("--as-needed");
655         CmdArgs.push_back("-lsoftfp");
656         CmdArgs.push_back("--no-as-needed");
657       }
658     }
659 
660     if (!Args.hasArg(options::OPT_nostartfiles) && !IsIAMCU) {
661       if (HasCRTBeginEndFiles) {
662         std::string P;
663         if (ToolChain.GetRuntimeLibType(Args) == ToolChain::RLT_CompilerRT &&
664             !isAndroid) {
665           std::string crtend = ToolChain.getCompilerRT(Args, "crtend",
666                                                        ToolChain::FT_Object);
667           if (ToolChain.getVFS().exists(crtend))
668             P = crtend;
669         }
670         if (P.empty()) {
671           const char *crtend;
672           if (Args.hasArg(options::OPT_shared))
673             crtend = isAndroid ? "crtend_so.o" : "crtendS.o";
674           else if (IsPIE || IsStaticPIE)
675             crtend = isAndroid ? "crtend_android.o" : "crtendS.o";
676           else
677             crtend = isAndroid ? "crtend_android.o" : "crtend.o";
678           P = ToolChain.GetFilePath(crtend);
679         }
680         CmdArgs.push_back(Args.MakeArgString(P));
681       }
682       if (!isAndroid)
683         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtn.o")));
684     }
685   }
686 
687   Args.AddAllArgs(CmdArgs, options::OPT_T);
688 
689   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
690   C.addCommand(std::make_unique<Command>(JA, *this,
691                                          ResponseFileSupport::AtFileCurCP(),
692                                          Exec, CmdArgs, Inputs, Output));
693 }
694 
695 void tools::gnutools::Assembler::ConstructJob(Compilation &C,
696                                               const JobAction &JA,
697                                               const InputInfo &Output,
698                                               const InputInfoList &Inputs,
699                                               const ArgList &Args,
700                                               const char *LinkingOutput) const {
701   const auto &D = getToolChain().getDriver();
702 
703   claimNoWarnArgs(Args);
704 
705   ArgStringList CmdArgs;
706 
707   llvm::Reloc::Model RelocationModel;
708   unsigned PICLevel;
709   bool IsPIE;
710   const char *DefaultAssembler = "as";
711   std::tie(RelocationModel, PICLevel, IsPIE) =
712       ParsePICArgs(getToolChain(), Args);
713 
714   if (const Arg *A = Args.getLastArg(options::OPT_gz, options::OPT_gz_EQ)) {
715     if (A->getOption().getID() == options::OPT_gz) {
716       CmdArgs.push_back("--compress-debug-sections");
717     } else {
718       StringRef Value = A->getValue();
719       if (Value == "none" || Value == "zlib") {
720         CmdArgs.push_back(
721             Args.MakeArgString("--compress-debug-sections=" + Twine(Value)));
722       } else {
723         D.Diag(diag::err_drv_unsupported_option_argument)
724             << A->getOption().getName() << Value;
725       }
726     }
727   }
728 
729   switch (getToolChain().getArch()) {
730   default:
731     break;
732   // Add --32/--64 to make sure we get the format we want.
733   // This is incomplete
734   case llvm::Triple::x86:
735     CmdArgs.push_back("--32");
736     break;
737   case llvm::Triple::x86_64:
738     if (getToolChain().getTriple().isX32())
739       CmdArgs.push_back("--x32");
740     else
741       CmdArgs.push_back("--64");
742     break;
743   case llvm::Triple::ppc: {
744     CmdArgs.push_back("-a32");
745     CmdArgs.push_back("-mppc");
746     CmdArgs.push_back("-mbig-endian");
747     CmdArgs.push_back(ppc::getPPCAsmModeForCPU(
748         getCPUName(D, Args, getToolChain().getTriple())));
749     break;
750   }
751   case llvm::Triple::ppcle: {
752     CmdArgs.push_back("-a32");
753     CmdArgs.push_back("-mppc");
754     CmdArgs.push_back("-mlittle-endian");
755     CmdArgs.push_back(ppc::getPPCAsmModeForCPU(
756         getCPUName(D, Args, getToolChain().getTriple())));
757     break;
758   }
759   case llvm::Triple::ppc64: {
760     CmdArgs.push_back("-a64");
761     CmdArgs.push_back("-mppc64");
762     CmdArgs.push_back("-mbig-endian");
763     CmdArgs.push_back(ppc::getPPCAsmModeForCPU(
764         getCPUName(D, Args, getToolChain().getTriple())));
765     break;
766   }
767   case llvm::Triple::ppc64le: {
768     CmdArgs.push_back("-a64");
769     CmdArgs.push_back("-mppc64");
770     CmdArgs.push_back("-mlittle-endian");
771     CmdArgs.push_back(ppc::getPPCAsmModeForCPU(
772         getCPUName(D, Args, getToolChain().getTriple())));
773     break;
774   }
775   case llvm::Triple::riscv32:
776   case llvm::Triple::riscv64: {
777     StringRef ABIName = riscv::getRISCVABI(Args, getToolChain().getTriple());
778     CmdArgs.push_back("-mabi");
779     CmdArgs.push_back(ABIName.data());
780     StringRef MArchName = riscv::getRISCVArch(Args, getToolChain().getTriple());
781     CmdArgs.push_back("-march");
782     CmdArgs.push_back(MArchName.data());
783     if (!Args.hasFlag(options::OPT_mrelax, options::OPT_mno_relax, true))
784       Args.addOptOutFlag(CmdArgs, options::OPT_mrelax, options::OPT_mno_relax);
785     break;
786   }
787   case llvm::Triple::sparc:
788   case llvm::Triple::sparcel: {
789     CmdArgs.push_back("-32");
790     std::string CPU = getCPUName(D, Args, getToolChain().getTriple());
791     CmdArgs.push_back(
792         sparc::getSparcAsmModeForCPU(CPU, getToolChain().getTriple()));
793     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
794     break;
795   }
796   case llvm::Triple::sparcv9: {
797     CmdArgs.push_back("-64");
798     std::string CPU = getCPUName(D, Args, getToolChain().getTriple());
799     CmdArgs.push_back(
800         sparc::getSparcAsmModeForCPU(CPU, getToolChain().getTriple()));
801     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
802     break;
803   }
804   case llvm::Triple::arm:
805   case llvm::Triple::armeb:
806   case llvm::Triple::thumb:
807   case llvm::Triple::thumbeb: {
808     const llvm::Triple &Triple2 = getToolChain().getTriple();
809     CmdArgs.push_back(isArmBigEndian(Triple2, Args) ? "-EB" : "-EL");
810     switch (Triple2.getSubArch()) {
811     case llvm::Triple::ARMSubArch_v7:
812       CmdArgs.push_back("-mfpu=neon");
813       break;
814     case llvm::Triple::ARMSubArch_v8:
815       CmdArgs.push_back("-mfpu=crypto-neon-fp-armv8");
816       break;
817     default:
818       break;
819     }
820 
821     switch (arm::getARMFloatABI(getToolChain(), Args)) {
822     case arm::FloatABI::Invalid: llvm_unreachable("must have an ABI!");
823     case arm::FloatABI::Soft:
824       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=soft"));
825       break;
826     case arm::FloatABI::SoftFP:
827       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=softfp"));
828       break;
829     case arm::FloatABI::Hard:
830       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=hard"));
831       break;
832     }
833 
834     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
835     normalizeCPUNamesForAssembler(Args, CmdArgs);
836 
837     Args.AddLastArg(CmdArgs, options::OPT_mfpu_EQ);
838     break;
839   }
840   case llvm::Triple::aarch64:
841   case llvm::Triple::aarch64_be: {
842     CmdArgs.push_back(
843         getToolChain().getArch() == llvm::Triple::aarch64_be ? "-EB" : "-EL");
844     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
845     normalizeCPUNamesForAssembler(Args, CmdArgs);
846 
847     break;
848   }
849   case llvm::Triple::mips:
850   case llvm::Triple::mipsel:
851   case llvm::Triple::mips64:
852   case llvm::Triple::mips64el: {
853     StringRef CPUName;
854     StringRef ABIName;
855     mips::getMipsCPUAndABI(Args, getToolChain().getTriple(), CPUName, ABIName);
856     ABIName = mips::getGnuCompatibleMipsABIName(ABIName);
857 
858     CmdArgs.push_back("-march");
859     CmdArgs.push_back(CPUName.data());
860 
861     CmdArgs.push_back("-mabi");
862     CmdArgs.push_back(ABIName.data());
863 
864     // -mno-shared should be emitted unless -fpic, -fpie, -fPIC, -fPIE,
865     // or -mshared (not implemented) is in effect.
866     if (RelocationModel == llvm::Reloc::Static)
867       CmdArgs.push_back("-mno-shared");
868 
869     // LLVM doesn't support -mplt yet and acts as if it is always given.
870     // However, -mplt has no effect with the N64 ABI.
871     if (ABIName != "64" && !Args.hasArg(options::OPT_mno_abicalls))
872       CmdArgs.push_back("-call_nonpic");
873 
874     if (getToolChain().getTriple().isLittleEndian())
875       CmdArgs.push_back("-EL");
876     else
877       CmdArgs.push_back("-EB");
878 
879     if (Arg *A = Args.getLastArg(options::OPT_mnan_EQ)) {
880       if (StringRef(A->getValue()) == "2008")
881         CmdArgs.push_back(Args.MakeArgString("-mnan=2008"));
882     }
883 
884     // Add the last -mfp32/-mfpxx/-mfp64 or -mfpxx if it is enabled by default.
885     if (Arg *A = Args.getLastArg(options::OPT_mfp32, options::OPT_mfpxx,
886                                  options::OPT_mfp64)) {
887       A->claim();
888       A->render(Args, CmdArgs);
889     } else if (mips::shouldUseFPXX(
890                    Args, getToolChain().getTriple(), CPUName, ABIName,
891                    mips::getMipsFloatABI(getToolChain().getDriver(), Args,
892                                          getToolChain().getTriple())))
893       CmdArgs.push_back("-mfpxx");
894 
895     // Pass on -mmips16 or -mno-mips16. However, the assembler equivalent of
896     // -mno-mips16 is actually -no-mips16.
897     if (Arg *A =
898             Args.getLastArg(options::OPT_mips16, options::OPT_mno_mips16)) {
899       if (A->getOption().matches(options::OPT_mips16)) {
900         A->claim();
901         A->render(Args, CmdArgs);
902       } else {
903         A->claim();
904         CmdArgs.push_back("-no-mips16");
905       }
906     }
907 
908     Args.AddLastArg(CmdArgs, options::OPT_mmicromips,
909                     options::OPT_mno_micromips);
910     Args.AddLastArg(CmdArgs, options::OPT_mdsp, options::OPT_mno_dsp);
911     Args.AddLastArg(CmdArgs, options::OPT_mdspr2, options::OPT_mno_dspr2);
912 
913     if (Arg *A = Args.getLastArg(options::OPT_mmsa, options::OPT_mno_msa)) {
914       // Do not use AddLastArg because not all versions of MIPS assembler
915       // support -mmsa / -mno-msa options.
916       if (A->getOption().matches(options::OPT_mmsa))
917         CmdArgs.push_back(Args.MakeArgString("-mmsa"));
918     }
919 
920     Args.AddLastArg(CmdArgs, options::OPT_mhard_float,
921                     options::OPT_msoft_float);
922 
923     Args.AddLastArg(CmdArgs, options::OPT_mdouble_float,
924                     options::OPT_msingle_float);
925 
926     Args.AddLastArg(CmdArgs, options::OPT_modd_spreg,
927                     options::OPT_mno_odd_spreg);
928 
929     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
930     break;
931   }
932   case llvm::Triple::systemz: {
933     // Always pass an -march option, since our default of z10 is later
934     // than the GNU assembler's default.
935     std::string CPUName = systemz::getSystemZTargetCPU(Args);
936     CmdArgs.push_back(Args.MakeArgString("-march=" + CPUName));
937     break;
938   }
939   case llvm::Triple::ve:
940     DefaultAssembler = "nas";
941   }
942 
943   for (const Arg *A : Args.filtered(options::OPT_ffile_prefix_map_EQ,
944                                     options::OPT_fdebug_prefix_map_EQ)) {
945     StringRef Map = A->getValue();
946     if (!Map.contains('='))
947       D.Diag(diag::err_drv_invalid_argument_to_option)
948           << Map << A->getOption().getName();
949     else {
950       CmdArgs.push_back(Args.MakeArgString("--debug-prefix-map"));
951       CmdArgs.push_back(Args.MakeArgString(Map));
952     }
953     A->claim();
954   }
955 
956   Args.AddAllArgs(CmdArgs, options::OPT_I);
957   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
958 
959   CmdArgs.push_back("-o");
960   CmdArgs.push_back(Output.getFilename());
961 
962   for (const auto &II : Inputs)
963     CmdArgs.push_back(II.getFilename());
964 
965   const char *Exec =
966       Args.MakeArgString(getToolChain().GetProgramPath(DefaultAssembler));
967   C.addCommand(std::make_unique<Command>(JA, *this,
968                                          ResponseFileSupport::AtFileCurCP(),
969                                          Exec, CmdArgs, Inputs, Output));
970 
971   // Handle the debug info splitting at object creation time if we're
972   // creating an object.
973   // TODO: Currently only works on linux with newer objcopy.
974   if (Args.hasArg(options::OPT_gsplit_dwarf) &&
975       getToolChain().getTriple().isOSLinux())
976     SplitDebugInfo(getToolChain(), C, *this, JA, Args, Output,
977                    SplitDebugName(JA, Args, Inputs[0], Output));
978 }
979 
980 namespace {
981 // Filter to remove Multilibs that don't exist as a suffix to Path
982 class FilterNonExistent {
983   StringRef Base, File;
984   llvm::vfs::FileSystem &VFS;
985 
986 public:
987   FilterNonExistent(StringRef Base, StringRef File, llvm::vfs::FileSystem &VFS)
988       : Base(Base), File(File), VFS(VFS) {}
989   bool operator()(const Multilib &M) {
990     return !VFS.exists(Base + M.gccSuffix() + File);
991   }
992 };
993 } // end anonymous namespace
994 
995 static bool isSoftFloatABI(const ArgList &Args) {
996   Arg *A = Args.getLastArg(options::OPT_msoft_float, options::OPT_mhard_float,
997                            options::OPT_mfloat_abi_EQ);
998   if (!A)
999     return false;
1000 
1001   return A->getOption().matches(options::OPT_msoft_float) ||
1002          (A->getOption().matches(options::OPT_mfloat_abi_EQ) &&
1003           A->getValue() == StringRef("soft"));
1004 }
1005 
1006 static bool isArmOrThumbArch(llvm::Triple::ArchType Arch) {
1007   return Arch == llvm::Triple::arm || Arch == llvm::Triple::thumb;
1008 }
1009 
1010 static bool isMipsEL(llvm::Triple::ArchType Arch) {
1011   return Arch == llvm::Triple::mipsel || Arch == llvm::Triple::mips64el;
1012 }
1013 
1014 static bool isMips16(const ArgList &Args) {
1015   Arg *A = Args.getLastArg(options::OPT_mips16, options::OPT_mno_mips16);
1016   return A && A->getOption().matches(options::OPT_mips16);
1017 }
1018 
1019 static bool isMicroMips(const ArgList &Args) {
1020   Arg *A = Args.getLastArg(options::OPT_mmicromips, options::OPT_mno_micromips);
1021   return A && A->getOption().matches(options::OPT_mmicromips);
1022 }
1023 
1024 static bool isMSP430(llvm::Triple::ArchType Arch) {
1025   return Arch == llvm::Triple::msp430;
1026 }
1027 
1028 static Multilib makeMultilib(StringRef commonSuffix) {
1029   return Multilib(commonSuffix, commonSuffix, commonSuffix);
1030 }
1031 
1032 static bool findMipsCsMultilibs(const Multilib::flags_list &Flags,
1033                                 FilterNonExistent &NonExistent,
1034                                 DetectedMultilibs &Result) {
1035   // Check for Code Sourcery toolchain multilibs
1036   MultilibSet CSMipsMultilibs;
1037   {
1038     auto MArchMips16 = makeMultilib("/mips16").flag("+m32").flag("+mips16");
1039 
1040     auto MArchMicroMips =
1041         makeMultilib("/micromips").flag("+m32").flag("+mmicromips");
1042 
1043     auto MArchDefault = makeMultilib("").flag("-mips16").flag("-mmicromips");
1044 
1045     auto UCLibc = makeMultilib("/uclibc").flag("+muclibc");
1046 
1047     auto SoftFloat = makeMultilib("/soft-float").flag("+msoft-float");
1048 
1049     auto Nan2008 = makeMultilib("/nan2008").flag("+mnan=2008");
1050 
1051     auto DefaultFloat =
1052         makeMultilib("").flag("-msoft-float").flag("-mnan=2008");
1053 
1054     auto BigEndian = makeMultilib("").flag("+EB").flag("-EL");
1055 
1056     auto LittleEndian = makeMultilib("/el").flag("+EL").flag("-EB");
1057 
1058     // Note that this one's osSuffix is ""
1059     auto MAbi64 = makeMultilib("")
1060                       .gccSuffix("/64")
1061                       .includeSuffix("/64")
1062                       .flag("+mabi=n64")
1063                       .flag("-mabi=n32")
1064                       .flag("-m32");
1065 
1066     CSMipsMultilibs =
1067         MultilibSet()
1068             .Either(MArchMips16, MArchMicroMips, MArchDefault)
1069             .Maybe(UCLibc)
1070             .Either(SoftFloat, Nan2008, DefaultFloat)
1071             .FilterOut("/micromips/nan2008")
1072             .FilterOut("/mips16/nan2008")
1073             .Either(BigEndian, LittleEndian)
1074             .Maybe(MAbi64)
1075             .FilterOut("/mips16.*/64")
1076             .FilterOut("/micromips.*/64")
1077             .FilterOut(NonExistent)
1078             .setIncludeDirsCallback([](const Multilib &M) {
1079               std::vector<std::string> Dirs({"/include"});
1080               if (StringRef(M.includeSuffix()).startswith("/uclibc"))
1081                 Dirs.push_back(
1082                     "/../../../../mips-linux-gnu/libc/uclibc/usr/include");
1083               else
1084                 Dirs.push_back("/../../../../mips-linux-gnu/libc/usr/include");
1085               return Dirs;
1086             });
1087   }
1088 
1089   MultilibSet DebianMipsMultilibs;
1090   {
1091     Multilib MAbiN32 =
1092         Multilib().gccSuffix("/n32").includeSuffix("/n32").flag("+mabi=n32");
1093 
1094     Multilib M64 = Multilib()
1095                        .gccSuffix("/64")
1096                        .includeSuffix("/64")
1097                        .flag("+m64")
1098                        .flag("-m32")
1099                        .flag("-mabi=n32");
1100 
1101     Multilib M32 =
1102         Multilib().gccSuffix("/32").flag("-m64").flag("+m32").flag("-mabi=n32");
1103 
1104     DebianMipsMultilibs =
1105         MultilibSet().Either(M32, M64, MAbiN32).FilterOut(NonExistent);
1106   }
1107 
1108   // Sort candidates. Toolchain that best meets the directories tree goes first.
1109   // Then select the first toolchains matches command line flags.
1110   MultilibSet *Candidates[] = {&CSMipsMultilibs, &DebianMipsMultilibs};
1111   if (CSMipsMultilibs.size() < DebianMipsMultilibs.size())
1112     std::iter_swap(Candidates, Candidates + 1);
1113   for (const MultilibSet *Candidate : Candidates) {
1114     if (Candidate->select(Flags, Result.SelectedMultilib)) {
1115       if (Candidate == &DebianMipsMultilibs)
1116         Result.BiarchSibling = Multilib();
1117       Result.Multilibs = *Candidate;
1118       return true;
1119     }
1120   }
1121   return false;
1122 }
1123 
1124 static bool findMipsAndroidMultilibs(llvm::vfs::FileSystem &VFS, StringRef Path,
1125                                      const Multilib::flags_list &Flags,
1126                                      FilterNonExistent &NonExistent,
1127                                      DetectedMultilibs &Result) {
1128 
1129   MultilibSet AndroidMipsMultilibs =
1130       MultilibSet()
1131           .Maybe(Multilib("/mips-r2").flag("+march=mips32r2"))
1132           .Maybe(Multilib("/mips-r6").flag("+march=mips32r6"))
1133           .FilterOut(NonExistent);
1134 
1135   MultilibSet AndroidMipselMultilibs =
1136       MultilibSet()
1137           .Either(Multilib().flag("+march=mips32"),
1138                   Multilib("/mips-r2", "", "/mips-r2").flag("+march=mips32r2"),
1139                   Multilib("/mips-r6", "", "/mips-r6").flag("+march=mips32r6"))
1140           .FilterOut(NonExistent);
1141 
1142   MultilibSet AndroidMips64elMultilibs =
1143       MultilibSet()
1144           .Either(
1145               Multilib().flag("+march=mips64r6"),
1146               Multilib("/32/mips-r1", "", "/mips-r1").flag("+march=mips32"),
1147               Multilib("/32/mips-r2", "", "/mips-r2").flag("+march=mips32r2"),
1148               Multilib("/32/mips-r6", "", "/mips-r6").flag("+march=mips32r6"))
1149           .FilterOut(NonExistent);
1150 
1151   MultilibSet *MS = &AndroidMipsMultilibs;
1152   if (VFS.exists(Path + "/mips-r6"))
1153     MS = &AndroidMipselMultilibs;
1154   else if (VFS.exists(Path + "/32"))
1155     MS = &AndroidMips64elMultilibs;
1156   if (MS->select(Flags, Result.SelectedMultilib)) {
1157     Result.Multilibs = *MS;
1158     return true;
1159   }
1160   return false;
1161 }
1162 
1163 static bool findMipsMuslMultilibs(const Multilib::flags_list &Flags,
1164                                   FilterNonExistent &NonExistent,
1165                                   DetectedMultilibs &Result) {
1166   // Musl toolchain multilibs
1167   MultilibSet MuslMipsMultilibs;
1168   {
1169     auto MArchMipsR2 = makeMultilib("")
1170                            .osSuffix("/mips-r2-hard-musl")
1171                            .flag("+EB")
1172                            .flag("-EL")
1173                            .flag("+march=mips32r2");
1174 
1175     auto MArchMipselR2 = makeMultilib("/mipsel-r2-hard-musl")
1176                              .flag("-EB")
1177                              .flag("+EL")
1178                              .flag("+march=mips32r2");
1179 
1180     MuslMipsMultilibs = MultilibSet().Either(MArchMipsR2, MArchMipselR2);
1181 
1182     // Specify the callback that computes the include directories.
1183     MuslMipsMultilibs.setIncludeDirsCallback([](const Multilib &M) {
1184       return std::vector<std::string>(
1185           {"/../sysroot" + M.osSuffix() + "/usr/include"});
1186     });
1187   }
1188   if (MuslMipsMultilibs.select(Flags, Result.SelectedMultilib)) {
1189     Result.Multilibs = MuslMipsMultilibs;
1190     return true;
1191   }
1192   return false;
1193 }
1194 
1195 static bool findMipsMtiMultilibs(const Multilib::flags_list &Flags,
1196                                  FilterNonExistent &NonExistent,
1197                                  DetectedMultilibs &Result) {
1198   // CodeScape MTI toolchain v1.2 and early.
1199   MultilibSet MtiMipsMultilibsV1;
1200   {
1201     auto MArchMips32 = makeMultilib("/mips32")
1202                            .flag("+m32")
1203                            .flag("-m64")
1204                            .flag("-mmicromips")
1205                            .flag("+march=mips32");
1206 
1207     auto MArchMicroMips = makeMultilib("/micromips")
1208                               .flag("+m32")
1209                               .flag("-m64")
1210                               .flag("+mmicromips");
1211 
1212     auto MArchMips64r2 = makeMultilib("/mips64r2")
1213                              .flag("-m32")
1214                              .flag("+m64")
1215                              .flag("+march=mips64r2");
1216 
1217     auto MArchMips64 = makeMultilib("/mips64").flag("-m32").flag("+m64").flag(
1218         "-march=mips64r2");
1219 
1220     auto MArchDefault = makeMultilib("")
1221                             .flag("+m32")
1222                             .flag("-m64")
1223                             .flag("-mmicromips")
1224                             .flag("+march=mips32r2");
1225 
1226     auto Mips16 = makeMultilib("/mips16").flag("+mips16");
1227 
1228     auto UCLibc = makeMultilib("/uclibc").flag("+muclibc");
1229 
1230     auto MAbi64 =
1231         makeMultilib("/64").flag("+mabi=n64").flag("-mabi=n32").flag("-m32");
1232 
1233     auto BigEndian = makeMultilib("").flag("+EB").flag("-EL");
1234 
1235     auto LittleEndian = makeMultilib("/el").flag("+EL").flag("-EB");
1236 
1237     auto SoftFloat = makeMultilib("/sof").flag("+msoft-float");
1238 
1239     auto Nan2008 = makeMultilib("/nan2008").flag("+mnan=2008");
1240 
1241     MtiMipsMultilibsV1 =
1242         MultilibSet()
1243             .Either(MArchMips32, MArchMicroMips, MArchMips64r2, MArchMips64,
1244                     MArchDefault)
1245             .Maybe(UCLibc)
1246             .Maybe(Mips16)
1247             .FilterOut("/mips64/mips16")
1248             .FilterOut("/mips64r2/mips16")
1249             .FilterOut("/micromips/mips16")
1250             .Maybe(MAbi64)
1251             .FilterOut("/micromips/64")
1252             .FilterOut("/mips32/64")
1253             .FilterOut("^/64")
1254             .FilterOut("/mips16/64")
1255             .Either(BigEndian, LittleEndian)
1256             .Maybe(SoftFloat)
1257             .Maybe(Nan2008)
1258             .FilterOut(".*sof/nan2008")
1259             .FilterOut(NonExistent)
1260             .setIncludeDirsCallback([](const Multilib &M) {
1261               std::vector<std::string> Dirs({"/include"});
1262               if (StringRef(M.includeSuffix()).startswith("/uclibc"))
1263                 Dirs.push_back("/../../../../sysroot/uclibc/usr/include");
1264               else
1265                 Dirs.push_back("/../../../../sysroot/usr/include");
1266               return Dirs;
1267             });
1268   }
1269 
1270   // CodeScape IMG toolchain starting from v1.3.
1271   MultilibSet MtiMipsMultilibsV2;
1272   {
1273     auto BeHard = makeMultilib("/mips-r2-hard")
1274                       .flag("+EB")
1275                       .flag("-msoft-float")
1276                       .flag("-mnan=2008")
1277                       .flag("-muclibc");
1278     auto BeSoft = makeMultilib("/mips-r2-soft")
1279                       .flag("+EB")
1280                       .flag("+msoft-float")
1281                       .flag("-mnan=2008");
1282     auto ElHard = makeMultilib("/mipsel-r2-hard")
1283                       .flag("+EL")
1284                       .flag("-msoft-float")
1285                       .flag("-mnan=2008")
1286                       .flag("-muclibc");
1287     auto ElSoft = makeMultilib("/mipsel-r2-soft")
1288                       .flag("+EL")
1289                       .flag("+msoft-float")
1290                       .flag("-mnan=2008")
1291                       .flag("-mmicromips");
1292     auto BeHardNan = makeMultilib("/mips-r2-hard-nan2008")
1293                          .flag("+EB")
1294                          .flag("-msoft-float")
1295                          .flag("+mnan=2008")
1296                          .flag("-muclibc");
1297     auto ElHardNan = makeMultilib("/mipsel-r2-hard-nan2008")
1298                          .flag("+EL")
1299                          .flag("-msoft-float")
1300                          .flag("+mnan=2008")
1301                          .flag("-muclibc")
1302                          .flag("-mmicromips");
1303     auto BeHardNanUclibc = makeMultilib("/mips-r2-hard-nan2008-uclibc")
1304                                .flag("+EB")
1305                                .flag("-msoft-float")
1306                                .flag("+mnan=2008")
1307                                .flag("+muclibc");
1308     auto ElHardNanUclibc = makeMultilib("/mipsel-r2-hard-nan2008-uclibc")
1309                                .flag("+EL")
1310                                .flag("-msoft-float")
1311                                .flag("+mnan=2008")
1312                                .flag("+muclibc");
1313     auto BeHardUclibc = makeMultilib("/mips-r2-hard-uclibc")
1314                             .flag("+EB")
1315                             .flag("-msoft-float")
1316                             .flag("-mnan=2008")
1317                             .flag("+muclibc");
1318     auto ElHardUclibc = makeMultilib("/mipsel-r2-hard-uclibc")
1319                             .flag("+EL")
1320                             .flag("-msoft-float")
1321                             .flag("-mnan=2008")
1322                             .flag("+muclibc");
1323     auto ElMicroHardNan = makeMultilib("/micromipsel-r2-hard-nan2008")
1324                               .flag("+EL")
1325                               .flag("-msoft-float")
1326                               .flag("+mnan=2008")
1327                               .flag("+mmicromips");
1328     auto ElMicroSoft = makeMultilib("/micromipsel-r2-soft")
1329                            .flag("+EL")
1330                            .flag("+msoft-float")
1331                            .flag("-mnan=2008")
1332                            .flag("+mmicromips");
1333 
1334     auto O32 =
1335         makeMultilib("/lib").osSuffix("").flag("-mabi=n32").flag("-mabi=n64");
1336     auto N32 =
1337         makeMultilib("/lib32").osSuffix("").flag("+mabi=n32").flag("-mabi=n64");
1338     auto N64 =
1339         makeMultilib("/lib64").osSuffix("").flag("-mabi=n32").flag("+mabi=n64");
1340 
1341     MtiMipsMultilibsV2 =
1342         MultilibSet()
1343             .Either({BeHard, BeSoft, ElHard, ElSoft, BeHardNan, ElHardNan,
1344                      BeHardNanUclibc, ElHardNanUclibc, BeHardUclibc,
1345                      ElHardUclibc, ElMicroHardNan, ElMicroSoft})
1346             .Either(O32, N32, N64)
1347             .FilterOut(NonExistent)
1348             .setIncludeDirsCallback([](const Multilib &M) {
1349               return std::vector<std::string>({"/../../../../sysroot" +
1350                                                M.includeSuffix() +
1351                                                "/../usr/include"});
1352             })
1353             .setFilePathsCallback([](const Multilib &M) {
1354               return std::vector<std::string>(
1355                   {"/../../../../mips-mti-linux-gnu/lib" + M.gccSuffix()});
1356             });
1357   }
1358   for (auto Candidate : {&MtiMipsMultilibsV1, &MtiMipsMultilibsV2}) {
1359     if (Candidate->select(Flags, Result.SelectedMultilib)) {
1360       Result.Multilibs = *Candidate;
1361       return true;
1362     }
1363   }
1364   return false;
1365 }
1366 
1367 static bool findMipsImgMultilibs(const Multilib::flags_list &Flags,
1368                                  FilterNonExistent &NonExistent,
1369                                  DetectedMultilibs &Result) {
1370   // CodeScape IMG toolchain v1.2 and early.
1371   MultilibSet ImgMultilibsV1;
1372   {
1373     auto Mips64r6 = makeMultilib("/mips64r6").flag("+m64").flag("-m32");
1374 
1375     auto LittleEndian = makeMultilib("/el").flag("+EL").flag("-EB");
1376 
1377     auto MAbi64 =
1378         makeMultilib("/64").flag("+mabi=n64").flag("-mabi=n32").flag("-m32");
1379 
1380     ImgMultilibsV1 =
1381         MultilibSet()
1382             .Maybe(Mips64r6)
1383             .Maybe(MAbi64)
1384             .Maybe(LittleEndian)
1385             .FilterOut(NonExistent)
1386             .setIncludeDirsCallback([](const Multilib &M) {
1387               return std::vector<std::string>(
1388                   {"/include", "/../../../../sysroot/usr/include"});
1389             });
1390   }
1391 
1392   // CodeScape IMG toolchain starting from v1.3.
1393   MultilibSet ImgMultilibsV2;
1394   {
1395     auto BeHard = makeMultilib("/mips-r6-hard")
1396                       .flag("+EB")
1397                       .flag("-msoft-float")
1398                       .flag("-mmicromips");
1399     auto BeSoft = makeMultilib("/mips-r6-soft")
1400                       .flag("+EB")
1401                       .flag("+msoft-float")
1402                       .flag("-mmicromips");
1403     auto ElHard = makeMultilib("/mipsel-r6-hard")
1404                       .flag("+EL")
1405                       .flag("-msoft-float")
1406                       .flag("-mmicromips");
1407     auto ElSoft = makeMultilib("/mipsel-r6-soft")
1408                       .flag("+EL")
1409                       .flag("+msoft-float")
1410                       .flag("-mmicromips");
1411     auto BeMicroHard = makeMultilib("/micromips-r6-hard")
1412                            .flag("+EB")
1413                            .flag("-msoft-float")
1414                            .flag("+mmicromips");
1415     auto BeMicroSoft = makeMultilib("/micromips-r6-soft")
1416                            .flag("+EB")
1417                            .flag("+msoft-float")
1418                            .flag("+mmicromips");
1419     auto ElMicroHard = makeMultilib("/micromipsel-r6-hard")
1420                            .flag("+EL")
1421                            .flag("-msoft-float")
1422                            .flag("+mmicromips");
1423     auto ElMicroSoft = makeMultilib("/micromipsel-r6-soft")
1424                            .flag("+EL")
1425                            .flag("+msoft-float")
1426                            .flag("+mmicromips");
1427 
1428     auto O32 =
1429         makeMultilib("/lib").osSuffix("").flag("-mabi=n32").flag("-mabi=n64");
1430     auto N32 =
1431         makeMultilib("/lib32").osSuffix("").flag("+mabi=n32").flag("-mabi=n64");
1432     auto N64 =
1433         makeMultilib("/lib64").osSuffix("").flag("-mabi=n32").flag("+mabi=n64");
1434 
1435     ImgMultilibsV2 =
1436         MultilibSet()
1437             .Either({BeHard, BeSoft, ElHard, ElSoft, BeMicroHard, BeMicroSoft,
1438                      ElMicroHard, ElMicroSoft})
1439             .Either(O32, N32, N64)
1440             .FilterOut(NonExistent)
1441             .setIncludeDirsCallback([](const Multilib &M) {
1442               return std::vector<std::string>({"/../../../../sysroot" +
1443                                                M.includeSuffix() +
1444                                                "/../usr/include"});
1445             })
1446             .setFilePathsCallback([](const Multilib &M) {
1447               return std::vector<std::string>(
1448                   {"/../../../../mips-img-linux-gnu/lib" + M.gccSuffix()});
1449             });
1450   }
1451   for (auto Candidate : {&ImgMultilibsV1, &ImgMultilibsV2}) {
1452     if (Candidate->select(Flags, Result.SelectedMultilib)) {
1453       Result.Multilibs = *Candidate;
1454       return true;
1455     }
1456   }
1457   return false;
1458 }
1459 
1460 bool clang::driver::findMIPSMultilibs(const Driver &D,
1461                                       const llvm::Triple &TargetTriple,
1462                                       StringRef Path, const ArgList &Args,
1463                                       DetectedMultilibs &Result) {
1464   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1465 
1466   StringRef CPUName;
1467   StringRef ABIName;
1468   tools::mips::getMipsCPUAndABI(Args, TargetTriple, CPUName, ABIName);
1469 
1470   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
1471 
1472   Multilib::flags_list Flags;
1473   addMultilibFlag(TargetTriple.isMIPS32(), "m32", Flags);
1474   addMultilibFlag(TargetTriple.isMIPS64(), "m64", Flags);
1475   addMultilibFlag(isMips16(Args), "mips16", Flags);
1476   addMultilibFlag(CPUName == "mips32", "march=mips32", Flags);
1477   addMultilibFlag(CPUName == "mips32r2" || CPUName == "mips32r3" ||
1478                       CPUName == "mips32r5" || CPUName == "p5600",
1479                   "march=mips32r2", Flags);
1480   addMultilibFlag(CPUName == "mips32r6", "march=mips32r6", Flags);
1481   addMultilibFlag(CPUName == "mips64", "march=mips64", Flags);
1482   addMultilibFlag(CPUName == "mips64r2" || CPUName == "mips64r3" ||
1483                       CPUName == "mips64r5" || CPUName == "octeon" ||
1484                       CPUName == "octeon+",
1485                   "march=mips64r2", Flags);
1486   addMultilibFlag(CPUName == "mips64r6", "march=mips64r6", Flags);
1487   addMultilibFlag(isMicroMips(Args), "mmicromips", Flags);
1488   addMultilibFlag(tools::mips::isUCLibc(Args), "muclibc", Flags);
1489   addMultilibFlag(tools::mips::isNaN2008(D, Args, TargetTriple), "mnan=2008",
1490                   Flags);
1491   addMultilibFlag(ABIName == "n32", "mabi=n32", Flags);
1492   addMultilibFlag(ABIName == "n64", "mabi=n64", Flags);
1493   addMultilibFlag(isSoftFloatABI(Args), "msoft-float", Flags);
1494   addMultilibFlag(!isSoftFloatABI(Args), "mhard-float", Flags);
1495   addMultilibFlag(isMipsEL(TargetArch), "EL", Flags);
1496   addMultilibFlag(!isMipsEL(TargetArch), "EB", Flags);
1497 
1498   if (TargetTriple.isAndroid())
1499     return findMipsAndroidMultilibs(D.getVFS(), Path, Flags, NonExistent,
1500                                     Result);
1501 
1502   if (TargetTriple.getVendor() == llvm::Triple::MipsTechnologies &&
1503       TargetTriple.getOS() == llvm::Triple::Linux &&
1504       TargetTriple.getEnvironment() == llvm::Triple::UnknownEnvironment)
1505     return findMipsMuslMultilibs(Flags, NonExistent, Result);
1506 
1507   if (TargetTriple.getVendor() == llvm::Triple::MipsTechnologies &&
1508       TargetTriple.getOS() == llvm::Triple::Linux &&
1509       TargetTriple.isGNUEnvironment())
1510     return findMipsMtiMultilibs(Flags, NonExistent, Result);
1511 
1512   if (TargetTriple.getVendor() == llvm::Triple::ImaginationTechnologies &&
1513       TargetTriple.getOS() == llvm::Triple::Linux &&
1514       TargetTriple.isGNUEnvironment())
1515     return findMipsImgMultilibs(Flags, NonExistent, Result);
1516 
1517   if (findMipsCsMultilibs(Flags, NonExistent, Result))
1518     return true;
1519 
1520   // Fallback to the regular toolchain-tree structure.
1521   Multilib Default;
1522   Result.Multilibs.push_back(Default);
1523   Result.Multilibs.FilterOut(NonExistent);
1524 
1525   if (Result.Multilibs.select(Flags, Result.SelectedMultilib)) {
1526     Result.BiarchSibling = Multilib();
1527     return true;
1528   }
1529 
1530   return false;
1531 }
1532 
1533 static void findAndroidArmMultilibs(const Driver &D,
1534                                     const llvm::Triple &TargetTriple,
1535                                     StringRef Path, const ArgList &Args,
1536                                     DetectedMultilibs &Result) {
1537   // Find multilibs with subdirectories like armv7-a, thumb, armv7-a/thumb.
1538   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1539   Multilib ArmV7Multilib = makeMultilib("/armv7-a")
1540                                .flag("+march=armv7-a")
1541                                .flag("-mthumb");
1542   Multilib ThumbMultilib = makeMultilib("/thumb")
1543                                .flag("-march=armv7-a")
1544                                .flag("+mthumb");
1545   Multilib ArmV7ThumbMultilib = makeMultilib("/armv7-a/thumb")
1546                                .flag("+march=armv7-a")
1547                                .flag("+mthumb");
1548   Multilib DefaultMultilib = makeMultilib("")
1549                                .flag("-march=armv7-a")
1550                                .flag("-mthumb");
1551   MultilibSet AndroidArmMultilibs =
1552       MultilibSet()
1553           .Either(ThumbMultilib, ArmV7Multilib,
1554                   ArmV7ThumbMultilib, DefaultMultilib)
1555           .FilterOut(NonExistent);
1556 
1557   Multilib::flags_list Flags;
1558   llvm::StringRef Arch = Args.getLastArgValue(options::OPT_march_EQ);
1559   bool IsArmArch = TargetTriple.getArch() == llvm::Triple::arm;
1560   bool IsThumbArch = TargetTriple.getArch() == llvm::Triple::thumb;
1561   bool IsV7SubArch = TargetTriple.getSubArch() == llvm::Triple::ARMSubArch_v7;
1562   bool IsThumbMode = IsThumbArch ||
1563       Args.hasFlag(options::OPT_mthumb, options::OPT_mno_thumb, false) ||
1564       (IsArmArch && llvm::ARM::parseArchISA(Arch) == llvm::ARM::ISAKind::THUMB);
1565   bool IsArmV7Mode = (IsArmArch || IsThumbArch) &&
1566       (llvm::ARM::parseArchVersion(Arch) == 7 ||
1567        (IsArmArch && Arch == "" && IsV7SubArch));
1568   addMultilibFlag(IsArmV7Mode, "march=armv7-a", Flags);
1569   addMultilibFlag(IsThumbMode, "mthumb", Flags);
1570 
1571   if (AndroidArmMultilibs.select(Flags, Result.SelectedMultilib))
1572     Result.Multilibs = AndroidArmMultilibs;
1573 }
1574 
1575 static bool findMSP430Multilibs(const Driver &D,
1576                                 const llvm::Triple &TargetTriple,
1577                                 StringRef Path, const ArgList &Args,
1578                                 DetectedMultilibs &Result) {
1579   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1580   Multilib WithoutExceptions = makeMultilib("/430").flag("-exceptions");
1581   Multilib WithExceptions = makeMultilib("/430/exceptions").flag("+exceptions");
1582 
1583   // FIXME: when clang starts to support msp430x ISA additional logic
1584   // to select between multilib must be implemented
1585   // Multilib MSP430xMultilib = makeMultilib("/large");
1586 
1587   Result.Multilibs.push_back(WithoutExceptions);
1588   Result.Multilibs.push_back(WithExceptions);
1589   Result.Multilibs.FilterOut(NonExistent);
1590 
1591   Multilib::flags_list Flags;
1592   addMultilibFlag(Args.hasFlag(options::OPT_fexceptions,
1593                                options::OPT_fno_exceptions, false),
1594                   "exceptions", Flags);
1595   if (Result.Multilibs.select(Flags, Result.SelectedMultilib))
1596     return true;
1597 
1598   return false;
1599 }
1600 
1601 static void findCSKYMultilibs(const Driver &D, const llvm::Triple &TargetTriple,
1602                               StringRef Path, const ArgList &Args,
1603                               DetectedMultilibs &Result) {
1604   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1605 
1606   tools::csky::FloatABI TheFloatABI = tools::csky::getCSKYFloatABI(D, Args);
1607   llvm::Optional<llvm::StringRef> Res = tools::csky::getCSKYArchName(D, Args, TargetTriple);
1608 
1609   if (!Res)
1610     return;
1611   auto ARCHName = *Res;
1612 
1613   Multilib::flags_list Flags;
1614   addMultilibFlag(TheFloatABI == tools::csky::FloatABI::Hard, "hard-fp", Flags);
1615   addMultilibFlag(TheFloatABI == tools::csky::FloatABI::SoftFP, "soft-fp",
1616                   Flags);
1617   addMultilibFlag(TheFloatABI == tools::csky::FloatABI::Soft, "soft", Flags);
1618   addMultilibFlag(ARCHName == "ck801", "march=ck801", Flags);
1619   addMultilibFlag(ARCHName == "ck802", "march=ck802", Flags);
1620   addMultilibFlag(ARCHName == "ck803", "march=ck803", Flags);
1621   addMultilibFlag(ARCHName == "ck804", "march=ck804", Flags);
1622   addMultilibFlag(ARCHName == "ck805", "march=ck805", Flags);
1623   addMultilibFlag(ARCHName == "ck807", "march=ck807", Flags);
1624   addMultilibFlag(ARCHName == "ck810", "march=ck810", Flags);
1625   addMultilibFlag(ARCHName == "ck810v", "march=ck810v", Flags);
1626   addMultilibFlag(ARCHName == "ck860", "march=ck860", Flags);
1627   addMultilibFlag(ARCHName == "ck860v", "march=ck860v", Flags);
1628 
1629   bool isBigEndian = false;
1630   if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
1631                                options::OPT_mbig_endian))
1632     isBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
1633   addMultilibFlag(isBigEndian, "EB", Flags);
1634 
1635   auto HardFloat = makeMultilib("/hard-fp").flag("+hard-fp");
1636   auto SoftFpFloat = makeMultilib("/soft-fp").flag("+soft-fp");
1637   auto SoftFloat = makeMultilib("").flag("+soft");
1638   auto Arch801 = makeMultilib("/ck801").flag("+march=ck801");
1639   auto Arch802 = makeMultilib("/ck802").flag("+march=ck802");
1640   auto Arch803 = makeMultilib("/ck803").flag("+march=ck803");
1641   // CK804 use the same library as CK803
1642   auto Arch804 = makeMultilib("/ck803").flag("+march=ck804");
1643   auto Arch805 = makeMultilib("/ck805").flag("+march=ck805");
1644   auto Arch807 = makeMultilib("/ck807").flag("+march=ck807");
1645   auto Arch810 = makeMultilib("").flag("+march=ck810");
1646   auto Arch810v = makeMultilib("/ck810v").flag("+march=ck810v");
1647   auto Arch860 = makeMultilib("/ck860").flag("+march=ck860");
1648   auto Arch860v = makeMultilib("/ck860v").flag("+march=ck860v");
1649   auto BigEndian = makeMultilib("/big").flag("+EB");
1650 
1651   MultilibSet CSKYMultilibs =
1652       MultilibSet()
1653           .Maybe(BigEndian)
1654           .Either({Arch801, Arch802, Arch803, Arch804, Arch805, Arch807,
1655                    Arch810, Arch810v, Arch860, Arch860v})
1656           .Either(HardFloat, SoftFpFloat, SoftFloat)
1657           .FilterOut(NonExistent);
1658 
1659   if (CSKYMultilibs.select(Flags, Result.SelectedMultilib))
1660     Result.Multilibs = CSKYMultilibs;
1661 }
1662 
1663 static void findRISCVBareMetalMultilibs(const Driver &D,
1664                                         const llvm::Triple &TargetTriple,
1665                                         StringRef Path, const ArgList &Args,
1666                                         DetectedMultilibs &Result) {
1667   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1668   struct RiscvMultilib {
1669     StringRef march;
1670     StringRef mabi;
1671   };
1672   // currently only support the set of multilibs like riscv-gnu-toolchain does.
1673   // TODO: support MULTILIB_REUSE
1674   constexpr RiscvMultilib RISCVMultilibSet[] = {
1675       {"rv32i", "ilp32"},     {"rv32im", "ilp32"},     {"rv32iac", "ilp32"},
1676       {"rv32imac", "ilp32"},  {"rv32imafc", "ilp32f"}, {"rv64imac", "lp64"},
1677       {"rv64imafdc", "lp64d"}};
1678 
1679   std::vector<Multilib> Ms;
1680   for (auto Element : RISCVMultilibSet) {
1681     // multilib path rule is ${march}/${mabi}
1682     Ms.emplace_back(
1683         makeMultilib((Twine(Element.march) + "/" + Twine(Element.mabi)).str())
1684             .flag(Twine("+march=", Element.march).str())
1685             .flag(Twine("+mabi=", Element.mabi).str()));
1686   }
1687   MultilibSet RISCVMultilibs =
1688       MultilibSet()
1689           .Either(ArrayRef<Multilib>(Ms))
1690           .FilterOut(NonExistent)
1691           .setFilePathsCallback([](const Multilib &M) {
1692             return std::vector<std::string>(
1693                 {M.gccSuffix(),
1694                  "/../../../../riscv64-unknown-elf/lib" + M.gccSuffix(),
1695                  "/../../../../riscv32-unknown-elf/lib" + M.gccSuffix()});
1696           });
1697 
1698 
1699   Multilib::flags_list Flags;
1700   llvm::StringSet<> Added_ABIs;
1701   StringRef ABIName = tools::riscv::getRISCVABI(Args, TargetTriple);
1702   StringRef MArch = tools::riscv::getRISCVArch(Args, TargetTriple);
1703   for (auto Element : RISCVMultilibSet) {
1704     addMultilibFlag(MArch == Element.march,
1705                     Twine("march=", Element.march).str().c_str(), Flags);
1706     if (!Added_ABIs.count(Element.mabi)) {
1707       Added_ABIs.insert(Element.mabi);
1708       addMultilibFlag(ABIName == Element.mabi,
1709                       Twine("mabi=", Element.mabi).str().c_str(), Flags);
1710     }
1711   }
1712 
1713   if (RISCVMultilibs.select(Flags, Result.SelectedMultilib))
1714     Result.Multilibs = RISCVMultilibs;
1715 }
1716 
1717 static void findRISCVMultilibs(const Driver &D,
1718                                const llvm::Triple &TargetTriple, StringRef Path,
1719                                const ArgList &Args, DetectedMultilibs &Result) {
1720   if (TargetTriple.getOS() == llvm::Triple::UnknownOS)
1721     return findRISCVBareMetalMultilibs(D, TargetTriple, Path, Args, Result);
1722 
1723   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1724   Multilib Ilp32 = makeMultilib("lib32/ilp32").flag("+m32").flag("+mabi=ilp32");
1725   Multilib Ilp32f =
1726       makeMultilib("lib32/ilp32f").flag("+m32").flag("+mabi=ilp32f");
1727   Multilib Ilp32d =
1728       makeMultilib("lib32/ilp32d").flag("+m32").flag("+mabi=ilp32d");
1729   Multilib Lp64 = makeMultilib("lib64/lp64").flag("+m64").flag("+mabi=lp64");
1730   Multilib Lp64f = makeMultilib("lib64/lp64f").flag("+m64").flag("+mabi=lp64f");
1731   Multilib Lp64d = makeMultilib("lib64/lp64d").flag("+m64").flag("+mabi=lp64d");
1732   MultilibSet RISCVMultilibs =
1733       MultilibSet()
1734           .Either({Ilp32, Ilp32f, Ilp32d, Lp64, Lp64f, Lp64d})
1735           .FilterOut(NonExistent);
1736 
1737   Multilib::flags_list Flags;
1738   bool IsRV64 = TargetTriple.getArch() == llvm::Triple::riscv64;
1739   StringRef ABIName = tools::riscv::getRISCVABI(Args, TargetTriple);
1740 
1741   addMultilibFlag(!IsRV64, "m32", Flags);
1742   addMultilibFlag(IsRV64, "m64", Flags);
1743   addMultilibFlag(ABIName == "ilp32", "mabi=ilp32", Flags);
1744   addMultilibFlag(ABIName == "ilp32f", "mabi=ilp32f", Flags);
1745   addMultilibFlag(ABIName == "ilp32d", "mabi=ilp32d", Flags);
1746   addMultilibFlag(ABIName == "lp64", "mabi=lp64", Flags);
1747   addMultilibFlag(ABIName == "lp64f", "mabi=lp64f", Flags);
1748   addMultilibFlag(ABIName == "lp64d", "mabi=lp64d", Flags);
1749 
1750   if (RISCVMultilibs.select(Flags, Result.SelectedMultilib))
1751     Result.Multilibs = RISCVMultilibs;
1752 }
1753 
1754 static bool findBiarchMultilibs(const Driver &D,
1755                                 const llvm::Triple &TargetTriple,
1756                                 StringRef Path, const ArgList &Args,
1757                                 bool NeedsBiarchSuffix,
1758                                 DetectedMultilibs &Result) {
1759   Multilib Default;
1760 
1761   // Some versions of SUSE and Fedora on ppc64 put 32-bit libs
1762   // in what would normally be GCCInstallPath and put the 64-bit
1763   // libs in a subdirectory named 64. The simple logic we follow is that
1764   // *if* there is a subdirectory of the right name with crtbegin.o in it,
1765   // we use that. If not, and if not a biarch triple alias, we look for
1766   // crtbegin.o without the subdirectory.
1767 
1768   StringRef Suff64 = "/64";
1769   // Solaris uses platform-specific suffixes instead of /64.
1770   if (TargetTriple.getOS() == llvm::Triple::Solaris) {
1771     switch (TargetTriple.getArch()) {
1772     case llvm::Triple::x86:
1773     case llvm::Triple::x86_64:
1774       Suff64 = "/amd64";
1775       break;
1776     case llvm::Triple::sparc:
1777     case llvm::Triple::sparcv9:
1778       Suff64 = "/sparcv9";
1779       break;
1780     default:
1781       break;
1782     }
1783   }
1784 
1785   Multilib Alt64 = Multilib()
1786                        .gccSuffix(Suff64)
1787                        .includeSuffix(Suff64)
1788                        .flag("-m32")
1789                        .flag("+m64")
1790                        .flag("-mx32");
1791   Multilib Alt32 = Multilib()
1792                        .gccSuffix("/32")
1793                        .includeSuffix("/32")
1794                        .flag("+m32")
1795                        .flag("-m64")
1796                        .flag("-mx32");
1797   Multilib Altx32 = Multilib()
1798                         .gccSuffix("/x32")
1799                         .includeSuffix("/x32")
1800                         .flag("-m32")
1801                         .flag("-m64")
1802                         .flag("+mx32");
1803 
1804   // GCC toolchain for IAMCU doesn't have crtbegin.o, so look for libgcc.a.
1805   FilterNonExistent NonExistent(
1806       Path, TargetTriple.isOSIAMCU() ? "/libgcc.a" : "/crtbegin.o", D.getVFS());
1807 
1808   // Determine default multilib from: 32, 64, x32
1809   // Also handle cases such as 64 on 32, 32 on 64, etc.
1810   enum { UNKNOWN, WANT32, WANT64, WANTX32 } Want = UNKNOWN;
1811   const bool IsX32 = TargetTriple.isX32();
1812   if (TargetTriple.isArch32Bit() && !NonExistent(Alt32))
1813     Want = WANT64;
1814   else if (TargetTriple.isArch64Bit() && IsX32 && !NonExistent(Altx32))
1815     Want = WANT64;
1816   else if (TargetTriple.isArch64Bit() && !IsX32 && !NonExistent(Alt64))
1817     Want = WANT32;
1818   else {
1819     if (TargetTriple.isArch32Bit())
1820       Want = NeedsBiarchSuffix ? WANT64 : WANT32;
1821     else if (IsX32)
1822       Want = NeedsBiarchSuffix ? WANT64 : WANTX32;
1823     else
1824       Want = NeedsBiarchSuffix ? WANT32 : WANT64;
1825   }
1826 
1827   if (Want == WANT32)
1828     Default.flag("+m32").flag("-m64").flag("-mx32");
1829   else if (Want == WANT64)
1830     Default.flag("-m32").flag("+m64").flag("-mx32");
1831   else if (Want == WANTX32)
1832     Default.flag("-m32").flag("-m64").flag("+mx32");
1833   else
1834     return false;
1835 
1836   Result.Multilibs.push_back(Default);
1837   Result.Multilibs.push_back(Alt64);
1838   Result.Multilibs.push_back(Alt32);
1839   Result.Multilibs.push_back(Altx32);
1840 
1841   Result.Multilibs.FilterOut(NonExistent);
1842 
1843   Multilib::flags_list Flags;
1844   addMultilibFlag(TargetTriple.isArch64Bit() && !IsX32, "m64", Flags);
1845   addMultilibFlag(TargetTriple.isArch32Bit(), "m32", Flags);
1846   addMultilibFlag(TargetTriple.isArch64Bit() && IsX32, "mx32", Flags);
1847 
1848   if (!Result.Multilibs.select(Flags, Result.SelectedMultilib))
1849     return false;
1850 
1851   if (Result.SelectedMultilib == Alt64 || Result.SelectedMultilib == Alt32 ||
1852       Result.SelectedMultilib == Altx32)
1853     Result.BiarchSibling = Default;
1854 
1855   return true;
1856 }
1857 
1858 /// Generic_GCC - A tool chain using the 'gcc' command to perform
1859 /// all subcommands; this relies on gcc translating the majority of
1860 /// command line options.
1861 
1862 /// Less-than for GCCVersion, implementing a Strict Weak Ordering.
1863 bool Generic_GCC::GCCVersion::isOlderThan(int RHSMajor, int RHSMinor,
1864                                           int RHSPatch,
1865                                           StringRef RHSPatchSuffix) const {
1866   if (Major != RHSMajor)
1867     return Major < RHSMajor;
1868   if (Minor != RHSMinor)
1869     return Minor < RHSMinor;
1870   if (Patch != RHSPatch) {
1871     // Note that versions without a specified patch sort higher than those with
1872     // a patch.
1873     if (RHSPatch == -1)
1874       return true;
1875     if (Patch == -1)
1876       return false;
1877 
1878     // Otherwise just sort on the patch itself.
1879     return Patch < RHSPatch;
1880   }
1881   if (PatchSuffix != RHSPatchSuffix) {
1882     // Sort empty suffixes higher.
1883     if (RHSPatchSuffix.empty())
1884       return true;
1885     if (PatchSuffix.empty())
1886       return false;
1887 
1888     // Provide a lexicographic sort to make this a total ordering.
1889     return PatchSuffix < RHSPatchSuffix;
1890   }
1891 
1892   // The versions are equal.
1893   return false;
1894 }
1895 
1896 /// Parse a GCCVersion object out of a string of text.
1897 ///
1898 /// This is the primary means of forming GCCVersion objects.
1899 /*static*/
1900 Generic_GCC::GCCVersion Generic_GCC::GCCVersion::Parse(StringRef VersionText) {
1901   const GCCVersion BadVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
1902   std::pair<StringRef, StringRef> First = VersionText.split('.');
1903   std::pair<StringRef, StringRef> Second = First.second.split('.');
1904 
1905   GCCVersion GoodVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
1906   if (First.first.getAsInteger(10, GoodVersion.Major) || GoodVersion.Major < 0)
1907     return BadVersion;
1908   GoodVersion.MajorStr = First.first.str();
1909   if (First.second.empty())
1910     return GoodVersion;
1911   StringRef MinorStr = Second.first;
1912   if (Second.second.empty()) {
1913     if (size_t EndNumber = MinorStr.find_first_not_of("0123456789")) {
1914       GoodVersion.PatchSuffix = std::string(MinorStr.substr(EndNumber));
1915       MinorStr = MinorStr.slice(0, EndNumber);
1916     }
1917   }
1918   if (MinorStr.getAsInteger(10, GoodVersion.Minor) || GoodVersion.Minor < 0)
1919     return BadVersion;
1920   GoodVersion.MinorStr = MinorStr.str();
1921 
1922   // First look for a number prefix and parse that if present. Otherwise just
1923   // stash the entire patch string in the suffix, and leave the number
1924   // unspecified. This covers versions strings such as:
1925   //   5        (handled above)
1926   //   4.4
1927   //   4.4-patched
1928   //   4.4.0
1929   //   4.4.x
1930   //   4.4.2-rc4
1931   //   4.4.x-patched
1932   // And retains any patch number it finds.
1933   StringRef PatchText = Second.second;
1934   if (!PatchText.empty()) {
1935     if (size_t EndNumber = PatchText.find_first_not_of("0123456789")) {
1936       // Try to parse the number and any suffix.
1937       if (PatchText.slice(0, EndNumber).getAsInteger(10, GoodVersion.Patch) ||
1938           GoodVersion.Patch < 0)
1939         return BadVersion;
1940       GoodVersion.PatchSuffix = std::string(PatchText.substr(EndNumber));
1941     }
1942   }
1943 
1944   return GoodVersion;
1945 }
1946 
1947 static llvm::StringRef getGCCToolchainDir(const ArgList &Args,
1948                                           llvm::StringRef SysRoot) {
1949   const Arg *A = Args.getLastArg(clang::driver::options::OPT_gcc_toolchain);
1950   if (A)
1951     return A->getValue();
1952 
1953   // If we have a SysRoot, ignore GCC_INSTALL_PREFIX.
1954   // GCC_INSTALL_PREFIX specifies the gcc installation for the default
1955   // sysroot and is likely not valid with a different sysroot.
1956   if (!SysRoot.empty())
1957     return "";
1958 
1959   return GCC_INSTALL_PREFIX;
1960 }
1961 
1962 /// Initialize a GCCInstallationDetector from the driver.
1963 ///
1964 /// This performs all of the autodetection and sets up the various paths.
1965 /// Once constructed, a GCCInstallationDetector is essentially immutable.
1966 ///
1967 /// FIXME: We shouldn't need an explicit TargetTriple parameter here, and
1968 /// should instead pull the target out of the driver. This is currently
1969 /// necessary because the driver doesn't store the final version of the target
1970 /// triple.
1971 void Generic_GCC::GCCInstallationDetector::init(
1972     const llvm::Triple &TargetTriple, const ArgList &Args,
1973     ArrayRef<std::string> ExtraTripleAliases) {
1974   llvm::Triple BiarchVariantTriple = TargetTriple.isArch32Bit()
1975                                          ? TargetTriple.get64BitArchVariant()
1976                                          : TargetTriple.get32BitArchVariant();
1977   // The library directories which may contain GCC installations.
1978   SmallVector<StringRef, 4> CandidateLibDirs, CandidateBiarchLibDirs;
1979   // The compatible GCC triples for this particular architecture.
1980   SmallVector<StringRef, 16> CandidateTripleAliases;
1981   SmallVector<StringRef, 16> CandidateBiarchTripleAliases;
1982   CollectLibDirsAndTriples(TargetTriple, BiarchVariantTriple, CandidateLibDirs,
1983                            CandidateTripleAliases, CandidateBiarchLibDirs,
1984                            CandidateBiarchTripleAliases);
1985 
1986   // Compute the set of prefixes for our search.
1987   SmallVector<std::string, 8> Prefixes;
1988   StringRef GCCToolchainDir = getGCCToolchainDir(Args, D.SysRoot);
1989   if (GCCToolchainDir != "") {
1990     if (GCCToolchainDir.back() == '/')
1991       GCCToolchainDir = GCCToolchainDir.drop_back(); // remove the /
1992 
1993     Prefixes.push_back(std::string(GCCToolchainDir));
1994   } else {
1995     // If we have a SysRoot, try that first.
1996     if (!D.SysRoot.empty()) {
1997       Prefixes.push_back(D.SysRoot);
1998       AddDefaultGCCPrefixes(TargetTriple, Prefixes, D.SysRoot);
1999     }
2000 
2001     // Then look for gcc installed alongside clang.
2002     Prefixes.push_back(D.InstalledDir + "/..");
2003 
2004     // Next, look for prefix(es) that correspond to distribution-supplied gcc
2005     // installations.
2006     if (D.SysRoot.empty()) {
2007       // Typically /usr.
2008       AddDefaultGCCPrefixes(TargetTriple, Prefixes, D.SysRoot);
2009     }
2010 
2011     // Try to respect gcc-config on Gentoo if --gcc-toolchain is not provided.
2012     // This avoids accidentally enforcing the system GCC version when using a
2013     // custom toolchain.
2014     SmallVector<StringRef, 16> GentooTestTriples;
2015     // Try to match an exact triple as target triple first.
2016     // e.g. crossdev -S x86_64-gentoo-linux-gnu will install gcc libs for
2017     // x86_64-gentoo-linux-gnu. But "clang -target x86_64-gentoo-linux-gnu"
2018     // may pick the libraries for x86_64-pc-linux-gnu even when exact matching
2019     // triple x86_64-gentoo-linux-gnu is present.
2020     GentooTestTriples.push_back(TargetTriple.str());
2021     // Check rest of triples.
2022     GentooTestTriples.append(ExtraTripleAliases.begin(),
2023                              ExtraTripleAliases.end());
2024     GentooTestTriples.append(CandidateTripleAliases.begin(),
2025                              CandidateTripleAliases.end());
2026     if (ScanGentooConfigs(TargetTriple, Args, GentooTestTriples,
2027                           CandidateBiarchTripleAliases))
2028       return;
2029   }
2030 
2031   // Loop over the various components which exist and select the best GCC
2032   // installation available. GCC installs are ranked by version number.
2033   const GCCVersion VersionZero = GCCVersion::Parse("0.0.0");
2034   Version = VersionZero;
2035   for (const std::string &Prefix : Prefixes) {
2036     auto &VFS = D.getVFS();
2037     if (!VFS.exists(Prefix))
2038       continue;
2039     for (StringRef Suffix : CandidateLibDirs) {
2040       const std::string LibDir = concat(Prefix, Suffix);
2041       if (!VFS.exists(LibDir))
2042         continue;
2043       // Maybe filter out <libdir>/gcc and <libdir>/gcc-cross.
2044       bool GCCDirExists = VFS.exists(LibDir + "/gcc");
2045       bool GCCCrossDirExists = VFS.exists(LibDir + "/gcc-cross");
2046       // Try to match the exact target triple first.
2047       ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, TargetTriple.str(),
2048                              false, GCCDirExists, GCCCrossDirExists);
2049       // Try rest of possible triples.
2050       for (StringRef Candidate : ExtraTripleAliases) // Try these first.
2051         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate, false,
2052                                GCCDirExists, GCCCrossDirExists);
2053       for (StringRef Candidate : CandidateTripleAliases)
2054         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate, false,
2055                                GCCDirExists, GCCCrossDirExists);
2056     }
2057     for (StringRef Suffix : CandidateBiarchLibDirs) {
2058       const std::string LibDir = Prefix + Suffix.str();
2059       if (!VFS.exists(LibDir))
2060         continue;
2061       bool GCCDirExists = VFS.exists(LibDir + "/gcc");
2062       bool GCCCrossDirExists = VFS.exists(LibDir + "/gcc-cross");
2063       for (StringRef Candidate : CandidateBiarchTripleAliases)
2064         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate, true,
2065                                GCCDirExists, GCCCrossDirExists);
2066     }
2067 
2068     // Skip other prefixes once a GCC installation is found.
2069     if (Version > VersionZero)
2070       break;
2071   }
2072 }
2073 
2074 void Generic_GCC::GCCInstallationDetector::print(raw_ostream &OS) const {
2075   for (const auto &InstallPath : CandidateGCCInstallPaths)
2076     OS << "Found candidate GCC installation: " << InstallPath << "\n";
2077 
2078   if (!GCCInstallPath.empty())
2079     OS << "Selected GCC installation: " << GCCInstallPath << "\n";
2080 
2081   for (const auto &Multilib : Multilibs)
2082     OS << "Candidate multilib: " << Multilib << "\n";
2083 
2084   if (Multilibs.size() != 0 || !SelectedMultilib.isDefault())
2085     OS << "Selected multilib: " << SelectedMultilib << "\n";
2086 }
2087 
2088 bool Generic_GCC::GCCInstallationDetector::getBiarchSibling(Multilib &M) const {
2089   if (BiarchSibling) {
2090     M = BiarchSibling.getValue();
2091     return true;
2092   }
2093   return false;
2094 }
2095 
2096 void Generic_GCC::GCCInstallationDetector::AddDefaultGCCPrefixes(
2097     const llvm::Triple &TargetTriple, SmallVectorImpl<std::string> &Prefixes,
2098     StringRef SysRoot) {
2099   if (TargetTriple.getOS() == llvm::Triple::Solaris) {
2100     // Solaris is a special case.
2101     // The GCC installation is under
2102     //   /usr/gcc/<major>.<minor>/lib/gcc/<triple>/<major>.<minor>.<patch>/
2103     // so we need to find those /usr/gcc/*/lib/gcc libdirs and go with
2104     // /usr/gcc/<version> as a prefix.
2105 
2106     std::string PrefixDir = concat(SysRoot, "/usr/gcc");
2107     std::error_code EC;
2108     for (llvm::vfs::directory_iterator LI = D.getVFS().dir_begin(PrefixDir, EC),
2109                                        LE;
2110          !EC && LI != LE; LI = LI.increment(EC)) {
2111       StringRef VersionText = llvm::sys::path::filename(LI->path());
2112       GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
2113 
2114       // Filter out obviously bad entries.
2115       if (CandidateVersion.Major == -1 || CandidateVersion.isOlderThan(4, 1, 1))
2116         continue;
2117 
2118       std::string CandidatePrefix = PrefixDir + "/" + VersionText.str();
2119       std::string CandidateLibPath = CandidatePrefix + "/lib/gcc";
2120       if (!D.getVFS().exists(CandidateLibPath))
2121         continue;
2122 
2123       Prefixes.push_back(CandidatePrefix);
2124     }
2125     return;
2126   }
2127 
2128   // For Linux, if --sysroot is not specified, look for RHEL/CentOS devtoolsets
2129   // and gcc-toolsets.
2130   if (SysRoot.empty() && TargetTriple.getOS() == llvm::Triple::Linux &&
2131       D.getVFS().exists("/opt/rh")) {
2132     // Find the directory in /opt/rh/ starting with gcc-toolset-* or
2133     // devtoolset-* with the highest version number and add that
2134     // one to our prefixes.
2135     std::string ChosenToolsetDir;
2136     unsigned ChosenToolsetVersion = 0;
2137     std::error_code EC;
2138     for (llvm::vfs::directory_iterator LI = D.getVFS().dir_begin("/opt/rh", EC),
2139                                        LE;
2140          !EC && LI != LE; LI = LI.increment(EC)) {
2141       StringRef ToolsetDir = llvm::sys::path::filename(LI->path());
2142       unsigned ToolsetVersion;
2143       if ((!ToolsetDir.startswith("gcc-toolset-") &&
2144            !ToolsetDir.startswith("devtoolset-")) ||
2145           ToolsetDir.substr(ToolsetDir.rfind('-') + 1)
2146               .getAsInteger(10, ToolsetVersion))
2147         continue;
2148 
2149       if (ToolsetVersion > ChosenToolsetVersion) {
2150         ChosenToolsetVersion = ToolsetVersion;
2151         ChosenToolsetDir = "/opt/rh/" + ToolsetDir.str();
2152       }
2153     }
2154 
2155     if (ChosenToolsetVersion > 0)
2156       Prefixes.push_back(ChosenToolsetDir + "/root/usr");
2157   }
2158 
2159   // Fall back to /usr which is used by most non-Solaris systems.
2160   Prefixes.push_back(concat(SysRoot, "/usr"));
2161 }
2162 
2163 /*static*/ void Generic_GCC::GCCInstallationDetector::CollectLibDirsAndTriples(
2164     const llvm::Triple &TargetTriple, const llvm::Triple &BiarchTriple,
2165     SmallVectorImpl<StringRef> &LibDirs,
2166     SmallVectorImpl<StringRef> &TripleAliases,
2167     SmallVectorImpl<StringRef> &BiarchLibDirs,
2168     SmallVectorImpl<StringRef> &BiarchTripleAliases) {
2169   // Declare a bunch of static data sets that we'll select between below. These
2170   // are specifically designed to always refer to string literals to avoid any
2171   // lifetime or initialization issues.
2172   //
2173   // The *Triples variables hard code some triples so that, for example,
2174   // --target=aarch64 (incomplete triple) can detect lib/aarch64-linux-gnu.
2175   // They are not needed when the user has correct LLVM_DEFAULT_TARGET_TRIPLE
2176   // and always uses the full --target (e.g. --target=aarch64-linux-gnu).  The
2177   // lists should shrink over time. Please don't add more elements to *Triples.
2178   static const char *const AArch64LibDirs[] = {"/lib64", "/lib"};
2179   static const char *const AArch64Triples[] = {
2180       "aarch64-none-linux-gnu", "aarch64-linux-gnu", "aarch64-redhat-linux",
2181       "aarch64-suse-linux"};
2182   static const char *const AArch64beLibDirs[] = {"/lib"};
2183   static const char *const AArch64beTriples[] = {"aarch64_be-none-linux-gnu",
2184                                                  "aarch64_be-linux-gnu"};
2185 
2186   static const char *const ARMLibDirs[] = {"/lib"};
2187   static const char *const ARMTriples[] = {"arm-linux-gnueabi"};
2188   static const char *const ARMHFTriples[] = {"arm-linux-gnueabihf",
2189                                              "armv7hl-redhat-linux-gnueabi",
2190                                              "armv6hl-suse-linux-gnueabi",
2191                                              "armv7hl-suse-linux-gnueabi"};
2192   static const char *const ARMebLibDirs[] = {"/lib"};
2193   static const char *const ARMebTriples[] = {"armeb-linux-gnueabi"};
2194   static const char *const ARMebHFTriples[] = {
2195       "armeb-linux-gnueabihf", "armebv7hl-redhat-linux-gnueabi"};
2196 
2197   static const char *const AVRLibDirs[] = {"/lib"};
2198   static const char *const AVRTriples[] = {"avr"};
2199 
2200   static const char *const CSKYLibDirs[] = {"/lib"};
2201   static const char *const CSKYTriples[] = {
2202       "csky-linux-gnuabiv2", "csky-linux-uclibcabiv2", "csky-elf-noneabiv2"};
2203 
2204   static const char *const X86_64LibDirs[] = {"/lib64", "/lib"};
2205   static const char *const X86_64Triples[] = {
2206       "x86_64-linux-gnu",       "x86_64-unknown-linux-gnu",
2207       "x86_64-pc-linux-gnu",    "x86_64-redhat-linux6E",
2208       "x86_64-redhat-linux",    "x86_64-suse-linux",
2209       "x86_64-manbo-linux-gnu", "x86_64-linux-gnu",
2210       "x86_64-slackware-linux", "x86_64-unknown-linux",
2211       "x86_64-amazon-linux"};
2212   static const char *const X32Triples[] = {"x86_64-linux-gnux32",
2213                                            "x86_64-pc-linux-gnux32"};
2214   static const char *const X32LibDirs[] = {"/libx32", "/lib"};
2215   static const char *const X86LibDirs[] = {"/lib32", "/lib"};
2216   static const char *const X86Triples[] = {
2217       "i586-linux-gnu",      "i686-linux-gnu",        "i686-pc-linux-gnu",
2218       "i386-redhat-linux6E", "i686-redhat-linux",     "i386-redhat-linux",
2219       "i586-suse-linux",     "i686-montavista-linux", "i686-gnu",
2220   };
2221 
2222   static const char *const M68kLibDirs[] = {"/lib"};
2223   static const char *const M68kTriples[] = {
2224       "m68k-linux-gnu", "m68k-unknown-linux-gnu", "m68k-suse-linux"};
2225 
2226   static const char *const MIPSLibDirs[] = {"/libo32", "/lib"};
2227   static const char *const MIPSTriples[] = {
2228       "mips-linux-gnu", "mips-mti-linux", "mips-mti-linux-gnu",
2229       "mips-img-linux-gnu", "mipsisa32r6-linux-gnu"};
2230   static const char *const MIPSELLibDirs[] = {"/libo32", "/lib"};
2231   static const char *const MIPSELTriples[] = {
2232       "mipsel-linux-gnu", "mips-img-linux-gnu", "mipsisa32r6el-linux-gnu"};
2233 
2234   static const char *const MIPS64LibDirs[] = {"/lib64", "/lib"};
2235   static const char *const MIPS64Triples[] = {
2236       "mips64-linux-gnu",      "mips-mti-linux-gnu",
2237       "mips-img-linux-gnu",    "mips64-linux-gnuabi64",
2238       "mipsisa64r6-linux-gnu", "mipsisa64r6-linux-gnuabi64"};
2239   static const char *const MIPS64ELLibDirs[] = {"/lib64", "/lib"};
2240   static const char *const MIPS64ELTriples[] = {
2241       "mips64el-linux-gnu",      "mips-mti-linux-gnu",
2242       "mips-img-linux-gnu",      "mips64el-linux-gnuabi64",
2243       "mipsisa64r6el-linux-gnu", "mipsisa64r6el-linux-gnuabi64"};
2244 
2245   static const char *const MIPSN32LibDirs[] = {"/lib32"};
2246   static const char *const MIPSN32Triples[] = {"mips64-linux-gnuabin32",
2247                                                "mipsisa64r6-linux-gnuabin32"};
2248   static const char *const MIPSN32ELLibDirs[] = {"/lib32"};
2249   static const char *const MIPSN32ELTriples[] = {
2250       "mips64el-linux-gnuabin32", "mipsisa64r6el-linux-gnuabin32"};
2251 
2252   static const char *const MSP430LibDirs[] = {"/lib"};
2253   static const char *const MSP430Triples[] = {"msp430-elf"};
2254 
2255   static const char *const PPCLibDirs[] = {"/lib32", "/lib"};
2256   static const char *const PPCTriples[] = {
2257       "powerpc-linux-gnu", "powerpc-unknown-linux-gnu", "powerpc-linux-gnuspe",
2258       // On 32-bit PowerPC systems running SUSE Linux, gcc is configured as a
2259       // 64-bit compiler which defaults to "-m32", hence "powerpc64-suse-linux".
2260       "powerpc64-suse-linux", "powerpc-montavista-linuxspe"};
2261   static const char *const PPCLELibDirs[] = {"/lib32", "/lib"};
2262   static const char *const PPCLETriples[] = {"powerpcle-linux-gnu",
2263                                              "powerpcle-unknown-linux-gnu",
2264                                              "powerpcle-linux-musl"};
2265 
2266   static const char *const PPC64LibDirs[] = {"/lib64", "/lib"};
2267   static const char *const PPC64Triples[] = {
2268       "powerpc64-linux-gnu", "powerpc64-unknown-linux-gnu",
2269       "powerpc64-suse-linux", "ppc64-redhat-linux"};
2270   static const char *const PPC64LELibDirs[] = {"/lib64", "/lib"};
2271   static const char *const PPC64LETriples[] = {
2272       "powerpc64le-linux-gnu", "powerpc64le-unknown-linux-gnu",
2273       "powerpc64le-none-linux-gnu", "powerpc64le-suse-linux",
2274       "ppc64le-redhat-linux"};
2275 
2276   static const char *const RISCV32LibDirs[] = {"/lib32", "/lib"};
2277   static const char *const RISCV32Triples[] = {"riscv32-unknown-linux-gnu",
2278                                                "riscv32-linux-gnu",
2279                                                "riscv32-unknown-elf"};
2280   static const char *const RISCV64LibDirs[] = {"/lib64", "/lib"};
2281   static const char *const RISCV64Triples[] = {"riscv64-unknown-linux-gnu",
2282                                                "riscv64-linux-gnu",
2283                                                "riscv64-unknown-elf"};
2284 
2285   static const char *const SPARCv8LibDirs[] = {"/lib32", "/lib"};
2286   static const char *const SPARCv8Triples[] = {"sparc-linux-gnu",
2287                                                "sparcv8-linux-gnu"};
2288   static const char *const SPARCv9LibDirs[] = {"/lib64", "/lib"};
2289   static const char *const SPARCv9Triples[] = {"sparc64-linux-gnu",
2290                                                "sparcv9-linux-gnu"};
2291 
2292   static const char *const SystemZLibDirs[] = {"/lib64", "/lib"};
2293   static const char *const SystemZTriples[] = {
2294       "s390x-linux-gnu", "s390x-unknown-linux-gnu", "s390x-ibm-linux-gnu",
2295       "s390x-suse-linux", "s390x-redhat-linux"};
2296 
2297 
2298   using std::begin;
2299   using std::end;
2300 
2301   if (TargetTriple.getOS() == llvm::Triple::Solaris) {
2302     static const char *const SolarisLibDirs[] = {"/lib"};
2303     static const char *const SolarisSparcV8Triples[] = {
2304         "sparc-sun-solaris2.11", "sparc-sun-solaris2.12"};
2305     static const char *const SolarisSparcV9Triples[] = {
2306         "sparcv9-sun-solaris2.11", "sparcv9-sun-solaris2.12"};
2307     static const char *const SolarisX86Triples[] = {"i386-pc-solaris2.11",
2308                                                     "i386-pc-solaris2.12"};
2309     static const char *const SolarisX86_64Triples[] = {"x86_64-pc-solaris2.11",
2310                                                        "x86_64-pc-solaris2.12"};
2311     LibDirs.append(begin(SolarisLibDirs), end(SolarisLibDirs));
2312     BiarchLibDirs.append(begin(SolarisLibDirs), end(SolarisLibDirs));
2313     switch (TargetTriple.getArch()) {
2314     case llvm::Triple::x86:
2315       TripleAliases.append(begin(SolarisX86Triples), end(SolarisX86Triples));
2316       BiarchTripleAliases.append(begin(SolarisX86_64Triples),
2317                                  end(SolarisX86_64Triples));
2318       break;
2319     case llvm::Triple::x86_64:
2320       TripleAliases.append(begin(SolarisX86_64Triples),
2321                            end(SolarisX86_64Triples));
2322       BiarchTripleAliases.append(begin(SolarisX86Triples),
2323                                  end(SolarisX86Triples));
2324       break;
2325     case llvm::Triple::sparc:
2326       TripleAliases.append(begin(SolarisSparcV8Triples),
2327                            end(SolarisSparcV8Triples));
2328       BiarchTripleAliases.append(begin(SolarisSparcV9Triples),
2329                                  end(SolarisSparcV9Triples));
2330       break;
2331     case llvm::Triple::sparcv9:
2332       TripleAliases.append(begin(SolarisSparcV9Triples),
2333                            end(SolarisSparcV9Triples));
2334       BiarchTripleAliases.append(begin(SolarisSparcV8Triples),
2335                                  end(SolarisSparcV8Triples));
2336       break;
2337     default:
2338       break;
2339     }
2340     return;
2341   }
2342 
2343   // Android targets should not use GNU/Linux tools or libraries.
2344   if (TargetTriple.isAndroid()) {
2345     static const char *const AArch64AndroidTriples[] = {
2346         "aarch64-linux-android"};
2347     static const char *const ARMAndroidTriples[] = {"arm-linux-androideabi"};
2348     static const char *const MIPSELAndroidTriples[] = {"mipsel-linux-android"};
2349     static const char *const MIPS64ELAndroidTriples[] = {
2350         "mips64el-linux-android"};
2351     static const char *const X86AndroidTriples[] = {"i686-linux-android"};
2352     static const char *const X86_64AndroidTriples[] = {"x86_64-linux-android"};
2353 
2354     switch (TargetTriple.getArch()) {
2355     case llvm::Triple::aarch64:
2356       LibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
2357       TripleAliases.append(begin(AArch64AndroidTriples),
2358                            end(AArch64AndroidTriples));
2359       break;
2360     case llvm::Triple::arm:
2361     case llvm::Triple::thumb:
2362       LibDirs.append(begin(ARMLibDirs), end(ARMLibDirs));
2363       TripleAliases.append(begin(ARMAndroidTriples), end(ARMAndroidTriples));
2364       break;
2365     case llvm::Triple::mipsel:
2366       LibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
2367       TripleAliases.append(begin(MIPSELAndroidTriples),
2368                            end(MIPSELAndroidTriples));
2369       BiarchLibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
2370       BiarchTripleAliases.append(begin(MIPS64ELAndroidTriples),
2371                                  end(MIPS64ELAndroidTriples));
2372       break;
2373     case llvm::Triple::mips64el:
2374       LibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
2375       TripleAliases.append(begin(MIPS64ELAndroidTriples),
2376                            end(MIPS64ELAndroidTriples));
2377       BiarchLibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
2378       BiarchTripleAliases.append(begin(MIPSELAndroidTriples),
2379                                  end(MIPSELAndroidTriples));
2380       break;
2381     case llvm::Triple::x86_64:
2382       LibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2383       TripleAliases.append(begin(X86_64AndroidTriples),
2384                            end(X86_64AndroidTriples));
2385       BiarchLibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2386       BiarchTripleAliases.append(begin(X86AndroidTriples),
2387                                  end(X86AndroidTriples));
2388       break;
2389     case llvm::Triple::x86:
2390       LibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2391       TripleAliases.append(begin(X86AndroidTriples), end(X86AndroidTriples));
2392       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2393       BiarchTripleAliases.append(begin(X86_64AndroidTriples),
2394                                  end(X86_64AndroidTriples));
2395       break;
2396     default:
2397       break;
2398     }
2399 
2400     return;
2401   }
2402 
2403   switch (TargetTriple.getArch()) {
2404   case llvm::Triple::aarch64:
2405     LibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
2406     TripleAliases.append(begin(AArch64Triples), end(AArch64Triples));
2407     BiarchLibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
2408     BiarchTripleAliases.append(begin(AArch64Triples), end(AArch64Triples));
2409     break;
2410   case llvm::Triple::aarch64_be:
2411     LibDirs.append(begin(AArch64beLibDirs), end(AArch64beLibDirs));
2412     TripleAliases.append(begin(AArch64beTriples), end(AArch64beTriples));
2413     BiarchLibDirs.append(begin(AArch64beLibDirs), end(AArch64beLibDirs));
2414     BiarchTripleAliases.append(begin(AArch64beTriples), end(AArch64beTriples));
2415     break;
2416   case llvm::Triple::arm:
2417   case llvm::Triple::thumb:
2418     LibDirs.append(begin(ARMLibDirs), end(ARMLibDirs));
2419     if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
2420       TripleAliases.append(begin(ARMHFTriples), end(ARMHFTriples));
2421     } else {
2422       TripleAliases.append(begin(ARMTriples), end(ARMTriples));
2423     }
2424     break;
2425   case llvm::Triple::armeb:
2426   case llvm::Triple::thumbeb:
2427     LibDirs.append(begin(ARMebLibDirs), end(ARMebLibDirs));
2428     if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
2429       TripleAliases.append(begin(ARMebHFTriples), end(ARMebHFTriples));
2430     } else {
2431       TripleAliases.append(begin(ARMebTriples), end(ARMebTriples));
2432     }
2433     break;
2434   case llvm::Triple::avr:
2435     LibDirs.append(begin(AVRLibDirs), end(AVRLibDirs));
2436     TripleAliases.append(begin(AVRTriples), end(AVRTriples));
2437     break;
2438   case llvm::Triple::csky:
2439     LibDirs.append(begin(CSKYLibDirs), end(CSKYLibDirs));
2440     TripleAliases.append(begin(CSKYTriples), end(CSKYTriples));
2441     break;
2442   case llvm::Triple::x86_64:
2443     if (TargetTriple.isX32()) {
2444       LibDirs.append(begin(X32LibDirs), end(X32LibDirs));
2445       TripleAliases.append(begin(X32Triples), end(X32Triples));
2446       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2447       BiarchTripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
2448     } else {
2449       LibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2450       TripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
2451       BiarchLibDirs.append(begin(X32LibDirs), end(X32LibDirs));
2452       BiarchTripleAliases.append(begin(X32Triples), end(X32Triples));
2453     }
2454     BiarchLibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2455     BiarchTripleAliases.append(begin(X86Triples), end(X86Triples));
2456     break;
2457   case llvm::Triple::x86:
2458     LibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2459     // MCU toolchain is 32 bit only and its triple alias is TargetTriple
2460     // itself, which will be appended below.
2461     if (!TargetTriple.isOSIAMCU()) {
2462       TripleAliases.append(begin(X86Triples), end(X86Triples));
2463       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2464       BiarchTripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
2465       BiarchLibDirs.append(begin(X32LibDirs), end(X32LibDirs));
2466       BiarchTripleAliases.append(begin(X32Triples), end(X32Triples));
2467     }
2468     break;
2469   case llvm::Triple::m68k:
2470     LibDirs.append(begin(M68kLibDirs), end(M68kLibDirs));
2471     TripleAliases.append(begin(M68kTriples), end(M68kTriples));
2472     break;
2473   case llvm::Triple::mips:
2474     LibDirs.append(begin(MIPSLibDirs), end(MIPSLibDirs));
2475     TripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2476     BiarchLibDirs.append(begin(MIPS64LibDirs), end(MIPS64LibDirs));
2477     BiarchTripleAliases.append(begin(MIPS64Triples), end(MIPS64Triples));
2478     BiarchLibDirs.append(begin(MIPSN32LibDirs), end(MIPSN32LibDirs));
2479     BiarchTripleAliases.append(begin(MIPSN32Triples), end(MIPSN32Triples));
2480     break;
2481   case llvm::Triple::mipsel:
2482     LibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
2483     TripleAliases.append(begin(MIPSELTriples), end(MIPSELTriples));
2484     TripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2485     BiarchLibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
2486     BiarchTripleAliases.append(begin(MIPS64ELTriples), end(MIPS64ELTriples));
2487     BiarchLibDirs.append(begin(MIPSN32ELLibDirs), end(MIPSN32ELLibDirs));
2488     BiarchTripleAliases.append(begin(MIPSN32ELTriples), end(MIPSN32ELTriples));
2489     break;
2490   case llvm::Triple::mips64:
2491     LibDirs.append(begin(MIPS64LibDirs), end(MIPS64LibDirs));
2492     TripleAliases.append(begin(MIPS64Triples), end(MIPS64Triples));
2493     BiarchLibDirs.append(begin(MIPSLibDirs), end(MIPSLibDirs));
2494     BiarchTripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2495     BiarchLibDirs.append(begin(MIPSN32LibDirs), end(MIPSN32LibDirs));
2496     BiarchTripleAliases.append(begin(MIPSN32Triples), end(MIPSN32Triples));
2497     break;
2498   case llvm::Triple::mips64el:
2499     LibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
2500     TripleAliases.append(begin(MIPS64ELTriples), end(MIPS64ELTriples));
2501     BiarchLibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
2502     BiarchTripleAliases.append(begin(MIPSELTriples), end(MIPSELTriples));
2503     BiarchLibDirs.append(begin(MIPSN32ELLibDirs), end(MIPSN32ELLibDirs));
2504     BiarchTripleAliases.append(begin(MIPSN32ELTriples), end(MIPSN32ELTriples));
2505     BiarchTripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2506     break;
2507   case llvm::Triple::msp430:
2508     LibDirs.append(begin(MSP430LibDirs), end(MSP430LibDirs));
2509     TripleAliases.append(begin(MSP430Triples), end(MSP430Triples));
2510     break;
2511   case llvm::Triple::ppc:
2512     LibDirs.append(begin(PPCLibDirs), end(PPCLibDirs));
2513     TripleAliases.append(begin(PPCTriples), end(PPCTriples));
2514     BiarchLibDirs.append(begin(PPC64LibDirs), end(PPC64LibDirs));
2515     BiarchTripleAliases.append(begin(PPC64Triples), end(PPC64Triples));
2516     break;
2517   case llvm::Triple::ppcle:
2518     LibDirs.append(begin(PPCLELibDirs), end(PPCLELibDirs));
2519     TripleAliases.append(begin(PPCLETriples), end(PPCLETriples));
2520     BiarchLibDirs.append(begin(PPC64LELibDirs), end(PPC64LELibDirs));
2521     BiarchTripleAliases.append(begin(PPC64LETriples), end(PPC64LETriples));
2522     break;
2523   case llvm::Triple::ppc64:
2524     LibDirs.append(begin(PPC64LibDirs), end(PPC64LibDirs));
2525     TripleAliases.append(begin(PPC64Triples), end(PPC64Triples));
2526     BiarchLibDirs.append(begin(PPCLibDirs), end(PPCLibDirs));
2527     BiarchTripleAliases.append(begin(PPCTriples), end(PPCTriples));
2528     break;
2529   case llvm::Triple::ppc64le:
2530     LibDirs.append(begin(PPC64LELibDirs), end(PPC64LELibDirs));
2531     TripleAliases.append(begin(PPC64LETriples), end(PPC64LETriples));
2532     BiarchLibDirs.append(begin(PPCLELibDirs), end(PPCLELibDirs));
2533     BiarchTripleAliases.append(begin(PPCLETriples), end(PPCLETriples));
2534     break;
2535   case llvm::Triple::riscv32:
2536     LibDirs.append(begin(RISCV32LibDirs), end(RISCV32LibDirs));
2537     TripleAliases.append(begin(RISCV32Triples), end(RISCV32Triples));
2538     BiarchLibDirs.append(begin(RISCV64LibDirs), end(RISCV64LibDirs));
2539     BiarchTripleAliases.append(begin(RISCV64Triples), end(RISCV64Triples));
2540     break;
2541   case llvm::Triple::riscv64:
2542     LibDirs.append(begin(RISCV64LibDirs), end(RISCV64LibDirs));
2543     TripleAliases.append(begin(RISCV64Triples), end(RISCV64Triples));
2544     BiarchLibDirs.append(begin(RISCV32LibDirs), end(RISCV32LibDirs));
2545     BiarchTripleAliases.append(begin(RISCV32Triples), end(RISCV32Triples));
2546     break;
2547   case llvm::Triple::sparc:
2548   case llvm::Triple::sparcel:
2549     LibDirs.append(begin(SPARCv8LibDirs), end(SPARCv8LibDirs));
2550     TripleAliases.append(begin(SPARCv8Triples), end(SPARCv8Triples));
2551     BiarchLibDirs.append(begin(SPARCv9LibDirs), end(SPARCv9LibDirs));
2552     BiarchTripleAliases.append(begin(SPARCv9Triples), end(SPARCv9Triples));
2553     break;
2554   case llvm::Triple::sparcv9:
2555     LibDirs.append(begin(SPARCv9LibDirs), end(SPARCv9LibDirs));
2556     TripleAliases.append(begin(SPARCv9Triples), end(SPARCv9Triples));
2557     BiarchLibDirs.append(begin(SPARCv8LibDirs), end(SPARCv8LibDirs));
2558     BiarchTripleAliases.append(begin(SPARCv8Triples), end(SPARCv8Triples));
2559     break;
2560   case llvm::Triple::systemz:
2561     LibDirs.append(begin(SystemZLibDirs), end(SystemZLibDirs));
2562     TripleAliases.append(begin(SystemZTriples), end(SystemZTriples));
2563     break;
2564   default:
2565     // By default, just rely on the standard lib directories and the original
2566     // triple.
2567     break;
2568   }
2569 
2570   // Always append the drivers target triple to the end, in case it doesn't
2571   // match any of our aliases.
2572   TripleAliases.push_back(TargetTriple.str());
2573 
2574   // Also include the multiarch variant if it's different.
2575   if (TargetTriple.str() != BiarchTriple.str())
2576     BiarchTripleAliases.push_back(BiarchTriple.str());
2577 }
2578 
2579 bool Generic_GCC::GCCInstallationDetector::ScanGCCForMultilibs(
2580     const llvm::Triple &TargetTriple, const ArgList &Args,
2581     StringRef Path, bool NeedsBiarchSuffix) {
2582   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
2583   DetectedMultilibs Detected;
2584 
2585   // Android standalone toolchain could have multilibs for ARM and Thumb.
2586   // Debian mips multilibs behave more like the rest of the biarch ones,
2587   // so handle them there
2588   if (isArmOrThumbArch(TargetArch) && TargetTriple.isAndroid()) {
2589     // It should also work without multilibs in a simplified toolchain.
2590     findAndroidArmMultilibs(D, TargetTriple, Path, Args, Detected);
2591   } else if (TargetTriple.isCSKY()) {
2592     findCSKYMultilibs(D, TargetTriple, Path, Args, Detected);
2593   } else if (TargetTriple.isMIPS()) {
2594     if (!findMIPSMultilibs(D, TargetTriple, Path, Args, Detected))
2595       return false;
2596   } else if (TargetTriple.isRISCV()) {
2597     findRISCVMultilibs(D, TargetTriple, Path, Args, Detected);
2598   } else if (isMSP430(TargetArch)) {
2599     findMSP430Multilibs(D, TargetTriple, Path, Args, Detected);
2600   } else if (TargetArch == llvm::Triple::avr) {
2601     // AVR has no multilibs.
2602   } else if (!findBiarchMultilibs(D, TargetTriple, Path, Args,
2603                                   NeedsBiarchSuffix, Detected)) {
2604     return false;
2605   }
2606 
2607   Multilibs = Detected.Multilibs;
2608   SelectedMultilib = Detected.SelectedMultilib;
2609   BiarchSibling = Detected.BiarchSibling;
2610 
2611   return true;
2612 }
2613 
2614 void Generic_GCC::GCCInstallationDetector::ScanLibDirForGCCTriple(
2615     const llvm::Triple &TargetTriple, const ArgList &Args,
2616     const std::string &LibDir, StringRef CandidateTriple,
2617     bool NeedsBiarchSuffix, bool GCCDirExists, bool GCCCrossDirExists) {
2618   // Locations relative to the system lib directory where GCC's triple-specific
2619   // directories might reside.
2620   struct GCCLibSuffix {
2621     // Path from system lib directory to GCC triple-specific directory.
2622     std::string LibSuffix;
2623     // Path from GCC triple-specific directory back to system lib directory.
2624     // This is one '..' component per component in LibSuffix.
2625     StringRef ReversePath;
2626     // Whether this library suffix is relevant for the triple.
2627     bool Active;
2628   } Suffixes[] = {
2629       // This is the normal place.
2630       {"gcc/" + CandidateTriple.str(), "../..", GCCDirExists},
2631 
2632       // Debian puts cross-compilers in gcc-cross.
2633       {"gcc-cross/" + CandidateTriple.str(), "../..", GCCCrossDirExists},
2634 
2635       // The Freescale PPC SDK has the gcc libraries in
2636       // <sysroot>/usr/lib/<triple>/x.y.z so have a look there as well. Only do
2637       // this on Freescale triples, though, since some systems put a *lot* of
2638       // files in that location, not just GCC installation data.
2639       {CandidateTriple.str(), "..",
2640        TargetTriple.getVendor() == llvm::Triple::Freescale ||
2641            TargetTriple.getVendor() == llvm::Triple::OpenEmbedded}};
2642 
2643   for (auto &Suffix : Suffixes) {
2644     if (!Suffix.Active)
2645       continue;
2646 
2647     StringRef LibSuffix = Suffix.LibSuffix;
2648     std::error_code EC;
2649     for (llvm::vfs::directory_iterator
2650              LI = D.getVFS().dir_begin(LibDir + "/" + LibSuffix, EC),
2651              LE;
2652          !EC && LI != LE; LI = LI.increment(EC)) {
2653       StringRef VersionText = llvm::sys::path::filename(LI->path());
2654       GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
2655       if (CandidateVersion.Major != -1) // Filter obviously bad entries.
2656         if (!CandidateGCCInstallPaths.insert(std::string(LI->path())).second)
2657           continue; // Saw this path before; no need to look at it again.
2658       if (CandidateVersion.isOlderThan(4, 1, 1))
2659         continue;
2660       if (CandidateVersion <= Version)
2661         continue;
2662 
2663       if (!ScanGCCForMultilibs(TargetTriple, Args, LI->path(),
2664                                NeedsBiarchSuffix))
2665         continue;
2666 
2667       Version = CandidateVersion;
2668       GCCTriple.setTriple(CandidateTriple);
2669       // FIXME: We hack together the directory name here instead of
2670       // using LI to ensure stable path separators across Windows and
2671       // Linux.
2672       GCCInstallPath = (LibDir + "/" + LibSuffix + "/" + VersionText).str();
2673       GCCParentLibPath = (GCCInstallPath + "/../" + Suffix.ReversePath).str();
2674       IsValid = true;
2675     }
2676   }
2677 }
2678 
2679 bool Generic_GCC::GCCInstallationDetector::ScanGentooConfigs(
2680     const llvm::Triple &TargetTriple, const ArgList &Args,
2681     const SmallVectorImpl<StringRef> &CandidateTriples,
2682     const SmallVectorImpl<StringRef> &CandidateBiarchTriples) {
2683   if (!D.getVFS().exists(concat(D.SysRoot, GentooConfigDir)))
2684     return false;
2685 
2686   for (StringRef CandidateTriple : CandidateTriples) {
2687     if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple))
2688       return true;
2689   }
2690 
2691   for (StringRef CandidateTriple : CandidateBiarchTriples) {
2692     if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple, true))
2693       return true;
2694   }
2695   return false;
2696 }
2697 
2698 bool Generic_GCC::GCCInstallationDetector::ScanGentooGccConfig(
2699     const llvm::Triple &TargetTriple, const ArgList &Args,
2700     StringRef CandidateTriple, bool NeedsBiarchSuffix) {
2701   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
2702       D.getVFS().getBufferForFile(concat(D.SysRoot, GentooConfigDir,
2703                                          "/config-" + CandidateTriple.str()));
2704   if (File) {
2705     SmallVector<StringRef, 2> Lines;
2706     File.get()->getBuffer().split(Lines, "\n");
2707     for (StringRef Line : Lines) {
2708       Line = Line.trim();
2709       // CURRENT=triple-version
2710       if (!Line.consume_front("CURRENT="))
2711         continue;
2712       // Process the config file pointed to by CURRENT.
2713       llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> ConfigFile =
2714           D.getVFS().getBufferForFile(
2715               concat(D.SysRoot, GentooConfigDir, "/" + Line));
2716       std::pair<StringRef, StringRef> ActiveVersion = Line.rsplit('-');
2717       // List of paths to scan for libraries.
2718       SmallVector<StringRef, 4> GentooScanPaths;
2719       // Scan the Config file to find installed GCC libraries path.
2720       // Typical content of the GCC config file:
2721       // LDPATH="/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.x:/usr/lib/gcc/
2722       // (continued from previous line) x86_64-pc-linux-gnu/4.9.x/32"
2723       // MANPATH="/usr/share/gcc-data/x86_64-pc-linux-gnu/4.9.x/man"
2724       // INFOPATH="/usr/share/gcc-data/x86_64-pc-linux-gnu/4.9.x/info"
2725       // STDCXX_INCDIR="/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.x/include/g++-v4"
2726       // We are looking for the paths listed in LDPATH=... .
2727       if (ConfigFile) {
2728         SmallVector<StringRef, 2> ConfigLines;
2729         ConfigFile.get()->getBuffer().split(ConfigLines, "\n");
2730         for (StringRef ConfLine : ConfigLines) {
2731           ConfLine = ConfLine.trim();
2732           if (ConfLine.consume_front("LDPATH=")) {
2733             // Drop '"' from front and back if present.
2734             ConfLine.consume_back("\"");
2735             ConfLine.consume_front("\"");
2736             // Get all paths sperated by ':'
2737             ConfLine.split(GentooScanPaths, ':', -1, /*AllowEmpty*/ false);
2738           }
2739         }
2740       }
2741       // Test the path based on the version in /etc/env.d/gcc/config-{tuple}.
2742       std::string basePath = "/usr/lib/gcc/" + ActiveVersion.first.str() + "/"
2743           + ActiveVersion.second.str();
2744       GentooScanPaths.push_back(StringRef(basePath));
2745 
2746       // Scan all paths for GCC libraries.
2747       for (const auto &GentooScanPath : GentooScanPaths) {
2748         std::string GentooPath = concat(D.SysRoot, GentooScanPath);
2749         if (D.getVFS().exists(GentooPath + "/crtbegin.o")) {
2750           if (!ScanGCCForMultilibs(TargetTriple, Args, GentooPath,
2751                                    NeedsBiarchSuffix))
2752             continue;
2753 
2754           Version = GCCVersion::Parse(ActiveVersion.second);
2755           GCCInstallPath = GentooPath;
2756           GCCParentLibPath = GentooPath + std::string("/../../..");
2757           GCCTriple.setTriple(ActiveVersion.first);
2758           IsValid = true;
2759           return true;
2760         }
2761       }
2762     }
2763   }
2764 
2765   return false;
2766 }
2767 
2768 Generic_GCC::Generic_GCC(const Driver &D, const llvm::Triple &Triple,
2769                          const ArgList &Args)
2770     : ToolChain(D, Triple, Args), GCCInstallation(D),
2771       CudaInstallation(D, Triple, Args), RocmInstallation(D, Triple, Args) {
2772   getProgramPaths().push_back(getDriver().getInstalledDir());
2773   if (getDriver().getInstalledDir() != getDriver().Dir)
2774     getProgramPaths().push_back(getDriver().Dir);
2775 }
2776 
2777 Generic_GCC::~Generic_GCC() {}
2778 
2779 Tool *Generic_GCC::getTool(Action::ActionClass AC) const {
2780   switch (AC) {
2781   case Action::PreprocessJobClass:
2782     if (!Preprocess)
2783       Preprocess.reset(new clang::driver::tools::gcc::Preprocessor(*this));
2784     return Preprocess.get();
2785   case Action::CompileJobClass:
2786     if (!Compile)
2787       Compile.reset(new tools::gcc::Compiler(*this));
2788     return Compile.get();
2789   default:
2790     return ToolChain::getTool(AC);
2791   }
2792 }
2793 
2794 Tool *Generic_GCC::buildAssembler() const {
2795   return new tools::gnutools::Assembler(*this);
2796 }
2797 
2798 Tool *Generic_GCC::buildLinker() const { return new tools::gcc::Linker(*this); }
2799 
2800 void Generic_GCC::printVerboseInfo(raw_ostream &OS) const {
2801   // Print the information about how we detected the GCC installation.
2802   GCCInstallation.print(OS);
2803   CudaInstallation.print(OS);
2804   RocmInstallation.print(OS);
2805 }
2806 
2807 bool Generic_GCC::IsUnwindTablesDefault(const ArgList &Args) const {
2808   switch (getArch()) {
2809   case llvm::Triple::aarch64:
2810   case llvm::Triple::ppc:
2811   case llvm::Triple::ppcle:
2812   case llvm::Triple::ppc64:
2813   case llvm::Triple::ppc64le:
2814   case llvm::Triple::x86:
2815   case llvm::Triple::x86_64:
2816     return true;
2817   default:
2818     return false;
2819   }
2820 }
2821 
2822 bool Generic_GCC::isPICDefault() const {
2823   switch (getArch()) {
2824   case llvm::Triple::x86_64:
2825     return getTriple().isOSWindows();
2826   case llvm::Triple::mips64:
2827   case llvm::Triple::mips64el:
2828     return true;
2829   default:
2830     return false;
2831   }
2832 }
2833 
2834 bool Generic_GCC::isPIEDefault(const llvm::opt::ArgList &Args) const {
2835   return false;
2836 }
2837 
2838 bool Generic_GCC::isPICDefaultForced() const {
2839   return getArch() == llvm::Triple::x86_64 && getTriple().isOSWindows();
2840 }
2841 
2842 bool Generic_GCC::IsIntegratedAssemblerDefault() const {
2843   switch (getTriple().getArch()) {
2844   case llvm::Triple::aarch64:
2845   case llvm::Triple::aarch64_be:
2846   case llvm::Triple::arm:
2847   case llvm::Triple::armeb:
2848   case llvm::Triple::avr:
2849   case llvm::Triple::bpfel:
2850   case llvm::Triple::bpfeb:
2851   case llvm::Triple::csky:
2852   case llvm::Triple::hexagon:
2853   case llvm::Triple::lanai:
2854   case llvm::Triple::m68k:
2855   case llvm::Triple::mips:
2856   case llvm::Triple::mipsel:
2857   case llvm::Triple::mips64:
2858   case llvm::Triple::mips64el:
2859   case llvm::Triple::msp430:
2860   case llvm::Triple::ppc:
2861   case llvm::Triple::ppcle:
2862   case llvm::Triple::ppc64:
2863   case llvm::Triple::ppc64le:
2864   case llvm::Triple::riscv32:
2865   case llvm::Triple::riscv64:
2866   case llvm::Triple::sparc:
2867   case llvm::Triple::sparcel:
2868   case llvm::Triple::sparcv9:
2869   case llvm::Triple::systemz:
2870   case llvm::Triple::thumb:
2871   case llvm::Triple::thumbeb:
2872   case llvm::Triple::ve:
2873   case llvm::Triple::x86:
2874   case llvm::Triple::x86_64:
2875     return true;
2876   default:
2877     return false;
2878   }
2879 }
2880 
2881 void Generic_GCC::PushPPaths(ToolChain::path_list &PPaths) {
2882   // Cross-compiling binutils and GCC installations (vanilla and openSUSE at
2883   // least) put various tools in a triple-prefixed directory off of the parent
2884   // of the GCC installation. We use the GCC triple here to ensure that we end
2885   // up with tools that support the same amount of cross compiling as the
2886   // detected GCC installation. For example, if we find a GCC installation
2887   // targeting x86_64, but it is a bi-arch GCC installation, it can also be
2888   // used to target i386.
2889   if (GCCInstallation.isValid()) {
2890     PPaths.push_back(Twine(GCCInstallation.getParentLibPath() + "/../" +
2891                            GCCInstallation.getTriple().str() + "/bin")
2892                          .str());
2893   }
2894 }
2895 
2896 void Generic_GCC::AddMultilibPaths(const Driver &D,
2897                                    const std::string &SysRoot,
2898                                    const std::string &OSLibDir,
2899                                    const std::string &MultiarchTriple,
2900                                    path_list &Paths) {
2901   // Add the multilib suffixed paths where they are available.
2902   if (GCCInstallation.isValid()) {
2903     const llvm::Triple &GCCTriple = GCCInstallation.getTriple();
2904     const std::string &LibPath =
2905         std::string(GCCInstallation.getParentLibPath());
2906 
2907     // Sourcery CodeBench MIPS toolchain holds some libraries under
2908     // a biarch-like suffix of the GCC installation.
2909     if (const auto &PathsCallback = Multilibs.filePathsCallback())
2910       for (const auto &Path : PathsCallback(SelectedMultilib))
2911         addPathIfExists(D, GCCInstallation.getInstallPath() + Path, Paths);
2912 
2913     // Add lib/gcc/$triple/$version, with an optional /multilib suffix.
2914     addPathIfExists(
2915         D, GCCInstallation.getInstallPath() + SelectedMultilib.gccSuffix(),
2916         Paths);
2917 
2918     // Add lib/gcc/$triple/$libdir
2919     // For GCC built with --enable-version-specific-runtime-libs.
2920     addPathIfExists(D, GCCInstallation.getInstallPath() + "/../" + OSLibDir,
2921                     Paths);
2922 
2923     // GCC cross compiling toolchains will install target libraries which ship
2924     // as part of the toolchain under <prefix>/<triple>/<libdir> rather than as
2925     // any part of the GCC installation in
2926     // <prefix>/<libdir>/gcc/<triple>/<version>. This decision is somewhat
2927     // debatable, but is the reality today. We need to search this tree even
2928     // when we have a sysroot somewhere else. It is the responsibility of
2929     // whomever is doing the cross build targeting a sysroot using a GCC
2930     // installation that is *not* within the system root to ensure two things:
2931     //
2932     //  1) Any DSOs that are linked in from this tree or from the install path
2933     //     above must be present on the system root and found via an
2934     //     appropriate rpath.
2935     //  2) There must not be libraries installed into
2936     //     <prefix>/<triple>/<libdir> unless they should be preferred over
2937     //     those within the system root.
2938     //
2939     // Note that this matches the GCC behavior. See the below comment for where
2940     // Clang diverges from GCC's behavior.
2941     addPathIfExists(D,
2942                     LibPath + "/../" + GCCTriple.str() + "/lib/../" + OSLibDir +
2943                         SelectedMultilib.osSuffix(),
2944                     Paths);
2945 
2946     // If the GCC installation we found is inside of the sysroot, we want to
2947     // prefer libraries installed in the parent prefix of the GCC installation.
2948     // It is important to *not* use these paths when the GCC installation is
2949     // outside of the system root as that can pick up unintended libraries.
2950     // This usually happens when there is an external cross compiler on the
2951     // host system, and a more minimal sysroot available that is the target of
2952     // the cross. Note that GCC does include some of these directories in some
2953     // configurations but this seems somewhere between questionable and simply
2954     // a bug.
2955     if (StringRef(LibPath).startswith(SysRoot))
2956       addPathIfExists(D, LibPath + "/../" + OSLibDir, Paths);
2957   }
2958 }
2959 
2960 void Generic_GCC::AddMultiarchPaths(const Driver &D,
2961                                     const std::string &SysRoot,
2962                                     const std::string &OSLibDir,
2963                                     path_list &Paths) {
2964   if (GCCInstallation.isValid()) {
2965     const std::string &LibPath =
2966         std::string(GCCInstallation.getParentLibPath());
2967     const llvm::Triple &GCCTriple = GCCInstallation.getTriple();
2968     const Multilib &Multilib = GCCInstallation.getMultilib();
2969     addPathIfExists(
2970         D, LibPath + "/../" + GCCTriple.str() + "/lib" + Multilib.osSuffix(),
2971                     Paths);
2972   }
2973 }
2974 
2975 void Generic_GCC::AddMultilibIncludeArgs(const ArgList &DriverArgs,
2976                                          ArgStringList &CC1Args) const {
2977   // Add include directories specific to the selected multilib set and multilib.
2978   if (!GCCInstallation.isValid())
2979     return;
2980   // gcc TOOL_INCLUDE_DIR.
2981   const llvm::Triple &GCCTriple = GCCInstallation.getTriple();
2982   std::string LibPath(GCCInstallation.getParentLibPath());
2983   addSystemInclude(DriverArgs, CC1Args,
2984                    Twine(LibPath) + "/../" + GCCTriple.str() + "/include");
2985 
2986   const auto &Callback = Multilibs.includeDirsCallback();
2987   if (Callback) {
2988     for (const auto &Path : Callback(GCCInstallation.getMultilib()))
2989       addExternCSystemIncludeIfExists(DriverArgs, CC1Args,
2990                                       GCCInstallation.getInstallPath() + Path);
2991   }
2992 }
2993 
2994 void Generic_GCC::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
2995                                                ArgStringList &CC1Args) const {
2996   if (DriverArgs.hasArg(options::OPT_nostdinc, options::OPT_nostdincxx,
2997                         options::OPT_nostdlibinc))
2998     return;
2999 
3000   switch (GetCXXStdlibType(DriverArgs)) {
3001   case ToolChain::CST_Libcxx:
3002     addLibCxxIncludePaths(DriverArgs, CC1Args);
3003     break;
3004 
3005   case ToolChain::CST_Libstdcxx:
3006     addLibStdCxxIncludePaths(DriverArgs, CC1Args);
3007     break;
3008   }
3009 }
3010 
3011 void
3012 Generic_GCC::addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
3013                                    llvm::opt::ArgStringList &CC1Args) const {
3014   const Driver &D = getDriver();
3015   std::string SysRoot = computeSysRoot();
3016   std::string Target = getTripleString();
3017 
3018   auto AddIncludePath = [&](std::string Path) {
3019     std::string Version = detectLibcxxVersion(Path);
3020     if (Version.empty())
3021       return false;
3022 
3023     // First add the per-target include path if it exists.
3024     std::string TargetDir = Path + "/" + Target + "/c++/" + Version;
3025     if (D.getVFS().exists(TargetDir))
3026       addSystemInclude(DriverArgs, CC1Args, TargetDir);
3027 
3028     // Second add the generic one.
3029     addSystemInclude(DriverArgs, CC1Args, Path + "/c++/" + Version);
3030     return true;
3031   };
3032 
3033   // Android never uses the libc++ headers installed alongside the toolchain,
3034   // which are generally incompatible with the NDK libraries anyway.
3035   if (!getTriple().isAndroid())
3036     if (AddIncludePath(getDriver().Dir + "/../include"))
3037       return;
3038   // If this is a development, non-installed, clang, libcxx will
3039   // not be found at ../include/c++ but it likely to be found at
3040   // one of the following two locations:
3041   if (AddIncludePath(concat(SysRoot, "/usr/local/include")))
3042     return;
3043   if (AddIncludePath(concat(SysRoot, "/usr/include")))
3044     return;
3045 }
3046 
3047 bool Generic_GCC::addLibStdCXXIncludePaths(Twine IncludeDir, StringRef Triple,
3048                                            Twine IncludeSuffix,
3049                                            const llvm::opt::ArgList &DriverArgs,
3050                                            llvm::opt::ArgStringList &CC1Args,
3051                                            bool DetectDebian) const {
3052   if (!getVFS().exists(IncludeDir))
3053     return false;
3054 
3055   // Debian native gcc uses g++-multiarch-incdir.diff which uses
3056   // include/x86_64-linux-gnu/c++/10$IncludeSuffix instead of
3057   // include/c++/10/x86_64-linux-gnu$IncludeSuffix.
3058   std::string Dir = IncludeDir.str();
3059   StringRef Include =
3060       llvm::sys::path::parent_path(llvm::sys::path::parent_path(Dir));
3061   std::string Path =
3062       (Include + "/" + Triple + Dir.substr(Include.size()) + IncludeSuffix)
3063           .str();
3064   if (DetectDebian && !getVFS().exists(Path))
3065     return false;
3066 
3067   // GPLUSPLUS_INCLUDE_DIR
3068   addSystemInclude(DriverArgs, CC1Args, IncludeDir);
3069   // GPLUSPLUS_TOOL_INCLUDE_DIR. If Triple is not empty, add a target-dependent
3070   // include directory.
3071   if (DetectDebian)
3072     addSystemInclude(DriverArgs, CC1Args, Path);
3073   else if (!Triple.empty())
3074     addSystemInclude(DriverArgs, CC1Args,
3075                      IncludeDir + "/" + Triple + IncludeSuffix);
3076   // GPLUSPLUS_BACKWARD_INCLUDE_DIR
3077   addSystemInclude(DriverArgs, CC1Args, IncludeDir + "/backward");
3078   return true;
3079 }
3080 
3081 bool Generic_GCC::addGCCLibStdCxxIncludePaths(
3082     const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
3083     StringRef DebianMultiarch) const {
3084   assert(GCCInstallation.isValid());
3085 
3086   // By default, look for the C++ headers in an include directory adjacent to
3087   // the lib directory of the GCC installation. Note that this is expect to be
3088   // equivalent to '/usr/include/c++/X.Y' in almost all cases.
3089   StringRef LibDir = GCCInstallation.getParentLibPath();
3090   StringRef InstallDir = GCCInstallation.getInstallPath();
3091   StringRef TripleStr = GCCInstallation.getTriple().str();
3092   const Multilib &Multilib = GCCInstallation.getMultilib();
3093   const GCCVersion &Version = GCCInstallation.getVersion();
3094 
3095   // Try /../$triple/include/c++/$version (gcc --print-multiarch is not empty).
3096   if (addLibStdCXXIncludePaths(
3097           LibDir.str() + "/../" + TripleStr + "/include/c++/" + Version.Text,
3098           TripleStr, Multilib.includeSuffix(), DriverArgs, CC1Args))
3099     return true;
3100 
3101   // Try /gcc/$triple/$version/include/c++/ (gcc --print-multiarch is not
3102   // empty). Like above but for GCC built with
3103   // --enable-version-specific-runtime-libs.
3104   if (addLibStdCXXIncludePaths(LibDir.str() + "/gcc/" + TripleStr + "/" +
3105                                    Version.Text + "/include/c++/",
3106                                TripleStr, Multilib.includeSuffix(), DriverArgs,
3107                                CC1Args))
3108     return true;
3109 
3110   // Detect Debian g++-multiarch-incdir.diff.
3111   if (addLibStdCXXIncludePaths(LibDir.str() + "/../include/c++/" + Version.Text,
3112                                DebianMultiarch, Multilib.includeSuffix(),
3113                                DriverArgs, CC1Args, /*Debian=*/true))
3114     return true;
3115 
3116   // Try /../include/c++/$version (gcc --print-multiarch is empty).
3117   if (addLibStdCXXIncludePaths(LibDir.str() + "/../include/c++/" + Version.Text,
3118                                TripleStr, Multilib.includeSuffix(), DriverArgs,
3119                                CC1Args))
3120     return true;
3121 
3122   // Otherwise, fall back on a bunch of options which don't use multiarch
3123   // layouts for simplicity.
3124   const std::string LibStdCXXIncludePathCandidates[] = {
3125       // Gentoo is weird and places its headers inside the GCC install,
3126       // so if the first attempt to find the headers fails, try these patterns.
3127       InstallDir.str() + "/include/g++-v" + Version.Text,
3128       InstallDir.str() + "/include/g++-v" + Version.MajorStr + "." +
3129           Version.MinorStr,
3130       InstallDir.str() + "/include/g++-v" + Version.MajorStr,
3131   };
3132 
3133   for (const auto &IncludePath : LibStdCXXIncludePathCandidates) {
3134     if (addLibStdCXXIncludePaths(IncludePath, TripleStr,
3135                                  Multilib.includeSuffix(), DriverArgs, CC1Args))
3136       return true;
3137   }
3138   return false;
3139 }
3140 
3141 void
3142 Generic_GCC::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
3143                                       llvm::opt::ArgStringList &CC1Args) const {
3144   if (GCCInstallation.isValid()) {
3145     addGCCLibStdCxxIncludePaths(DriverArgs, CC1Args,
3146                                 GCCInstallation.getTriple().str());
3147   }
3148 }
3149 
3150 llvm::opt::DerivedArgList *
3151 Generic_GCC::TranslateArgs(const llvm::opt::DerivedArgList &Args, StringRef,
3152                            Action::OffloadKind DeviceOffloadKind) const {
3153 
3154   // If this tool chain is used for an OpenMP offloading device we have to make
3155   // sure we always generate a shared library regardless of the commands the
3156   // user passed to the host. This is required because the runtime library
3157   // is required to load the device image dynamically at run time.
3158   if (DeviceOffloadKind == Action::OFK_OpenMP) {
3159     DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
3160     const OptTable &Opts = getDriver().getOpts();
3161 
3162     // Request the shared library. Given that these options are decided
3163     // implicitly, they do not refer to any base argument.
3164     DAL->AddFlagArg(/*BaseArg=*/nullptr, Opts.getOption(options::OPT_shared));
3165     DAL->AddFlagArg(/*BaseArg=*/nullptr, Opts.getOption(options::OPT_fPIC));
3166 
3167     // Filter all the arguments we don't care passing to the offloading
3168     // toolchain as they can mess up with the creation of a shared library.
3169     for (auto *A : Args) {
3170       switch ((options::ID)A->getOption().getID()) {
3171       default:
3172         DAL->append(A);
3173         break;
3174       case options::OPT_shared:
3175       case options::OPT_dynamic:
3176       case options::OPT_static:
3177       case options::OPT_fPIC:
3178       case options::OPT_fno_PIC:
3179       case options::OPT_fpic:
3180       case options::OPT_fno_pic:
3181       case options::OPT_fPIE:
3182       case options::OPT_fno_PIE:
3183       case options::OPT_fpie:
3184       case options::OPT_fno_pie:
3185         break;
3186       }
3187     }
3188     return DAL;
3189   }
3190   return nullptr;
3191 }
3192 
3193 void Generic_ELF::anchor() {}
3194 
3195 void Generic_ELF::addClangTargetOptions(const ArgList &DriverArgs,
3196                                         ArgStringList &CC1Args,
3197                                         Action::OffloadKind) const {
3198   if (!DriverArgs.hasFlag(options::OPT_fuse_init_array,
3199                           options::OPT_fno_use_init_array, true))
3200     CC1Args.push_back("-fno-use-init-array");
3201 }
3202