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/LoongArch.h"
13 #include "Arch/Mips.h"
14 #include "Arch/PPC.h"
15 #include "Arch/RISCV.h"
16 #include "Arch/Sparc.h"
17 #include "Arch/SystemZ.h"
18 #include "CommonArgs.h"
19 #include "Linux.h"
20 #include "clang/Config/config.h" // for GCC_INSTALL_PREFIX
21 #include "clang/Driver/Compilation.h"
22 #include "clang/Driver/Driver.h"
23 #include "clang/Driver/DriverDiagnostic.h"
24 #include "clang/Driver/MultilibBuilder.h"
25 #include "clang/Driver/Options.h"
26 #include "clang/Driver/Tool.h"
27 #include "clang/Driver/ToolChain.h"
28 #include "llvm/ADT/StringSet.h"
29 #include "llvm/ADT/Twine.h"
30 #include "llvm/Option/ArgList.h"
31 #include "llvm/Support/CodeGen.h"
32 #include "llvm/Support/Path.h"
33 #include "llvm/Support/VirtualFileSystem.h"
34 #include "llvm/TargetParser/TargetParser.h"
35 #include <system_error>
36 
37 using namespace clang::driver;
38 using namespace clang::driver::toolchains;
39 using namespace clang;
40 using namespace llvm::opt;
41 
42 using tools::addMultilibFlag;
43 using tools::addPathIfExists;
44 
45 static bool forwardToGCC(const Option &O) {
46   // LinkerInput options have been forwarded. Don't duplicate.
47   if (O.hasFlag(options::LinkerInput))
48     return false;
49   return O.matches(options::OPT_Link_Group) || O.hasFlag(options::LinkOption);
50 }
51 
52 // Switch CPU names not recognized by GNU assembler to a close CPU that it does
53 // recognize, instead of a lower march from being picked in the absence of a cpu
54 // flag.
55 static void normalizeCPUNamesForAssembler(const ArgList &Args,
56                                           ArgStringList &CmdArgs) {
57   if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
58     StringRef CPUArg(A->getValue());
59     if (CPUArg.equals_insensitive("krait"))
60       CmdArgs.push_back("-mcpu=cortex-a15");
61     else if (CPUArg.equals_insensitive("kryo"))
62       CmdArgs.push_back("-mcpu=cortex-a57");
63     else
64       Args.AddLastArg(CmdArgs, options::OPT_mcpu_EQ);
65   }
66 }
67 
68 void tools::gcc::Common::ConstructJob(Compilation &C, const JobAction &JA,
69                                       const InputInfo &Output,
70                                       const InputInfoList &Inputs,
71                                       const ArgList &Args,
72                                       const char *LinkingOutput) const {
73   const Driver &D = getToolChain().getDriver();
74   ArgStringList CmdArgs;
75 
76   for (const auto &A : Args) {
77     if (forwardToGCC(A->getOption())) {
78       // It is unfortunate that we have to claim here, as this means
79       // we will basically never report anything interesting for
80       // platforms using a generic gcc, even if we are just using gcc
81       // to get to the assembler.
82       A->claim();
83 
84       A->render(Args, CmdArgs);
85     }
86   }
87 
88   RenderExtraToolArgs(JA, CmdArgs);
89 
90   // If using a driver, force the arch.
91   if (getToolChain().getTriple().isOSDarwin()) {
92     CmdArgs.push_back("-arch");
93     CmdArgs.push_back(
94         Args.MakeArgString(getToolChain().getDefaultUniversalArchName()));
95   }
96 
97   // Try to force gcc to match the tool chain we want, if we recognize
98   // the arch.
99   //
100   // FIXME: The triple class should directly provide the information we want
101   // here.
102   switch (getToolChain().getArch()) {
103   default:
104     break;
105   case llvm::Triple::x86:
106   case llvm::Triple::ppc:
107   case llvm::Triple::ppcle:
108     CmdArgs.push_back("-m32");
109     break;
110   case llvm::Triple::x86_64:
111   case llvm::Triple::ppc64:
112   case llvm::Triple::ppc64le:
113     CmdArgs.push_back("-m64");
114     break;
115   case llvm::Triple::sparcel:
116     CmdArgs.push_back("-EL");
117     break;
118   }
119 
120   assert((Output.isFilename() || Output.isNothing()) && "Invalid output.");
121   if (Output.isFilename()) {
122     CmdArgs.push_back("-o");
123     CmdArgs.push_back(Output.getFilename());
124   } else {
125     CmdArgs.push_back("-fsyntax-only");
126   }
127 
128   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
129 
130   // Only pass -x if gcc will understand it; otherwise hope gcc
131   // understands the suffix correctly. The main use case this would go
132   // wrong in is for linker inputs if they happened to have an odd
133   // suffix; really the only way to get this to happen is a command
134   // like '-x foobar a.c' which will treat a.c like a linker input.
135   //
136   // FIXME: For the linker case specifically, can we safely convert
137   // inputs into '-Wl,' options?
138   for (const auto &II : Inputs) {
139     // Don't try to pass LLVM or AST inputs to a generic gcc.
140     if (types::isLLVMIR(II.getType()))
141       D.Diag(clang::diag::err_drv_no_linker_llvm_support)
142           << getToolChain().getTripleString();
143     else if (II.getType() == types::TY_AST)
144       D.Diag(diag::err_drv_no_ast_support) << getToolChain().getTripleString();
145     else if (II.getType() == types::TY_ModuleFile)
146       D.Diag(diag::err_drv_no_module_support)
147           << getToolChain().getTripleString();
148 
149     if (types::canTypeBeUserSpecified(II.getType())) {
150       CmdArgs.push_back("-x");
151       CmdArgs.push_back(types::getTypeName(II.getType()));
152     }
153 
154     if (II.isFilename())
155       CmdArgs.push_back(II.getFilename());
156     else {
157       const Arg &A = II.getInputArg();
158 
159       // Reverse translate some rewritten options.
160       if (A.getOption().matches(options::OPT_Z_reserved_lib_stdcxx)) {
161         CmdArgs.push_back("-lstdc++");
162         continue;
163       }
164 
165       // Don't render as input, we need gcc to do the translations.
166       A.render(Args, CmdArgs);
167     }
168   }
169 
170   const std::string &customGCCName = D.getCCCGenericGCCName();
171   const char *GCCName;
172   if (!customGCCName.empty())
173     GCCName = customGCCName.c_str();
174   else if (D.CCCIsCXX()) {
175     GCCName = "g++";
176   } else
177     GCCName = "gcc";
178 
179   const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath(GCCName));
180   C.addCommand(std::make_unique<Command>(JA, *this,
181                                          ResponseFileSupport::AtFileCurCP(),
182                                          Exec, CmdArgs, Inputs, Output));
183 }
184 
185 void tools::gcc::Preprocessor::RenderExtraToolArgs(
186     const JobAction &JA, ArgStringList &CmdArgs) const {
187   CmdArgs.push_back("-E");
188 }
189 
190 void tools::gcc::Compiler::RenderExtraToolArgs(const JobAction &JA,
191                                                ArgStringList &CmdArgs) const {
192   const Driver &D = getToolChain().getDriver();
193 
194   switch (JA.getType()) {
195   // If -flto, etc. are present then make sure not to force assembly output.
196   case types::TY_LLVM_IR:
197   case types::TY_LTO_IR:
198   case types::TY_LLVM_BC:
199   case types::TY_LTO_BC:
200     CmdArgs.push_back("-c");
201     break;
202   // We assume we've got an "integrated" assembler in that gcc will produce an
203   // object file itself.
204   case types::TY_Object:
205     CmdArgs.push_back("-c");
206     break;
207   case types::TY_PP_Asm:
208     CmdArgs.push_back("-S");
209     break;
210   case types::TY_Nothing:
211     CmdArgs.push_back("-fsyntax-only");
212     break;
213   default:
214     D.Diag(diag::err_drv_invalid_gcc_output_type) << getTypeName(JA.getType());
215   }
216 }
217 
218 void tools::gcc::Linker::RenderExtraToolArgs(const JobAction &JA,
219                                              ArgStringList &CmdArgs) const {
220   // The types are (hopefully) good enough.
221 }
222 
223 static const char *getLDMOption(const llvm::Triple &T, const ArgList &Args) {
224   switch (T.getArch()) {
225   case llvm::Triple::x86:
226     if (T.isOSIAMCU())
227       return "elf_iamcu";
228     return "elf_i386";
229   case llvm::Triple::aarch64:
230     return "aarch64linux";
231   case llvm::Triple::aarch64_be:
232     return "aarch64linuxb";
233   case llvm::Triple::arm:
234   case llvm::Triple::thumb:
235   case llvm::Triple::armeb:
236   case llvm::Triple::thumbeb:
237     return tools::arm::isARMBigEndian(T, Args) ? "armelfb_linux_eabi"
238                                                : "armelf_linux_eabi";
239   case llvm::Triple::m68k:
240     return "m68kelf";
241   case llvm::Triple::ppc:
242     if (T.isOSLinux())
243       return "elf32ppclinux";
244     return "elf32ppc";
245   case llvm::Triple::ppcle:
246     if (T.isOSLinux())
247       return "elf32lppclinux";
248     return "elf32lppc";
249   case llvm::Triple::ppc64:
250     return "elf64ppc";
251   case llvm::Triple::ppc64le:
252     return "elf64lppc";
253   case llvm::Triple::riscv32:
254     return "elf32lriscv";
255   case llvm::Triple::riscv64:
256     return "elf64lriscv";
257   case llvm::Triple::sparc:
258   case llvm::Triple::sparcel:
259     return "elf32_sparc";
260   case llvm::Triple::sparcv9:
261     return "elf64_sparc";
262   case llvm::Triple::loongarch32:
263     return "elf32loongarch";
264   case llvm::Triple::loongarch64:
265     return "elf64loongarch";
266   case llvm::Triple::mips:
267     return "elf32btsmip";
268   case llvm::Triple::mipsel:
269     return "elf32ltsmip";
270   case llvm::Triple::mips64:
271     if (tools::mips::hasMipsAbiArg(Args, "n32") ||
272         T.getEnvironment() == llvm::Triple::GNUABIN32)
273       return "elf32btsmipn32";
274     return "elf64btsmip";
275   case llvm::Triple::mips64el:
276     if (tools::mips::hasMipsAbiArg(Args, "n32") ||
277         T.getEnvironment() == llvm::Triple::GNUABIN32)
278       return "elf32ltsmipn32";
279     return "elf64ltsmip";
280   case llvm::Triple::systemz:
281     return "elf64_s390";
282   case llvm::Triple::x86_64:
283     if (T.isX32())
284       return "elf32_x86_64";
285     return "elf_x86_64";
286   case llvm::Triple::ve:
287     return "elf64ve";
288   case llvm::Triple::csky:
289     return "cskyelf_linux";
290   default:
291     return nullptr;
292   }
293 }
294 
295 static bool getStaticPIE(const ArgList &Args, const ToolChain &TC) {
296   bool HasStaticPIE = Args.hasArg(options::OPT_static_pie);
297   if (HasStaticPIE && Args.hasArg(options::OPT_no_pie)) {
298     const Driver &D = TC.getDriver();
299     const llvm::opt::OptTable &Opts = D.getOpts();
300     StringRef StaticPIEName = Opts.getOptionName(options::OPT_static_pie);
301     StringRef NoPIEName = Opts.getOptionName(options::OPT_nopie);
302     D.Diag(diag::err_drv_cannot_mix_options) << StaticPIEName << NoPIEName;
303   }
304   return HasStaticPIE;
305 }
306 
307 static bool getStatic(const ArgList &Args) {
308   return Args.hasArg(options::OPT_static) &&
309       !Args.hasArg(options::OPT_static_pie);
310 }
311 
312 void tools::gnutools::StaticLibTool::ConstructJob(
313     Compilation &C, const JobAction &JA, const InputInfo &Output,
314     const InputInfoList &Inputs, const ArgList &Args,
315     const char *LinkingOutput) const {
316   const Driver &D = getToolChain().getDriver();
317 
318   // Silence warning for "clang -g foo.o -o foo"
319   Args.ClaimAllArgs(options::OPT_g_Group);
320   // and "clang -emit-llvm foo.o -o foo"
321   Args.ClaimAllArgs(options::OPT_emit_llvm);
322   // and for "clang -w foo.o -o foo". Other warning options are already
323   // handled somewhere else.
324   Args.ClaimAllArgs(options::OPT_w);
325   // Silence warnings when linking C code with a C++ '-stdlib' argument.
326   Args.ClaimAllArgs(options::OPT_stdlib_EQ);
327 
328   // ar tool command "llvm-ar <options> <output_file> <input_files>".
329   ArgStringList CmdArgs;
330   // Create and insert file members with a deterministic index.
331   CmdArgs.push_back("rcsD");
332   CmdArgs.push_back(Output.getFilename());
333 
334   for (const auto &II : Inputs) {
335     if (II.isFilename()) {
336        CmdArgs.push_back(II.getFilename());
337     }
338   }
339 
340   // Delete old output archive file if it already exists before generating a new
341   // archive file.
342   auto OutputFileName = Output.getFilename();
343   if (Output.isFilename() && llvm::sys::fs::exists(OutputFileName)) {
344     if (std::error_code EC = llvm::sys::fs::remove(OutputFileName)) {
345       D.Diag(diag::err_drv_unable_to_remove_file) << EC.message();
346       return;
347     }
348   }
349 
350   const char *Exec = Args.MakeArgString(getToolChain().GetStaticLibToolPath());
351   C.addCommand(std::make_unique<Command>(JA, *this,
352                                          ResponseFileSupport::AtFileCurCP(),
353                                          Exec, CmdArgs, Inputs, Output));
354 }
355 
356 void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
357                                            const InputInfo &Output,
358                                            const InputInfoList &Inputs,
359                                            const ArgList &Args,
360                                            const char *LinkingOutput) const {
361   // FIXME: The Linker class constructor takes a ToolChain and not a
362   // Generic_ELF, so the static_cast might return a reference to a invalid
363   // instance (see PR45061). Ideally, the Linker constructor needs to take a
364   // Generic_ELF instead.
365   const auto &ToolChain = static_cast<const Generic_ELF &>(getToolChain());
366   const Driver &D = ToolChain.getDriver();
367 
368   const llvm::Triple &Triple = getToolChain().getEffectiveTriple();
369 
370   const llvm::Triple::ArchType Arch = ToolChain.getArch();
371   const bool isOHOSFamily = ToolChain.getTriple().isOHOSFamily();
372   const bool isAndroid = ToolChain.getTriple().isAndroid();
373   const bool IsIAMCU = ToolChain.getTriple().isOSIAMCU();
374   const bool IsVE = ToolChain.getTriple().isVE();
375   const bool IsStaticPIE = getStaticPIE(Args, ToolChain);
376   const bool IsStatic = getStatic(Args);
377   const bool HasCRTBeginEndFiles =
378       ToolChain.getTriple().hasEnvironment() ||
379       (ToolChain.getTriple().getVendor() != llvm::Triple::MipsTechnologies);
380 
381   ArgStringList CmdArgs;
382 
383   // Silence warning for "clang -g foo.o -o foo"
384   Args.ClaimAllArgs(options::OPT_g_Group);
385   // and "clang -emit-llvm foo.o -o foo"
386   Args.ClaimAllArgs(options::OPT_emit_llvm);
387   // and for "clang -w foo.o -o foo". Other warning options are already
388   // handled somewhere else.
389   Args.ClaimAllArgs(options::OPT_w);
390 
391   if (!D.SysRoot.empty())
392     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
393 
394   if (Args.hasArg(options::OPT_s))
395     CmdArgs.push_back("-s");
396 
397   if (Triple.isARM() || Triple.isThumb()) {
398     bool IsBigEndian = arm::isARMBigEndian(Triple, Args);
399     if (IsBigEndian)
400       arm::appendBE8LinkFlag(Args, CmdArgs, Triple);
401     CmdArgs.push_back(IsBigEndian ? "-EB" : "-EL");
402   } else if (Triple.isAArch64()) {
403     CmdArgs.push_back(Arch == llvm::Triple::aarch64_be ? "-EB" : "-EL");
404   }
405 
406   // Most Android ARM64 targets should enable the linker fix for erratum
407   // 843419. Only non-Cortex-A53 devices are allowed to skip this flag.
408   if (Arch == llvm::Triple::aarch64 && (isAndroid || isOHOSFamily)) {
409     std::string CPU = getCPUName(D, Args, Triple);
410     if (CPU.empty() || CPU == "generic" || CPU == "cortex-a53")
411       CmdArgs.push_back("--fix-cortex-a53-843419");
412   }
413 
414   ToolChain.addExtraOpts(CmdArgs);
415 
416   CmdArgs.push_back("--eh-frame-hdr");
417 
418   if (const char *LDMOption = getLDMOption(ToolChain.getTriple(), Args)) {
419     CmdArgs.push_back("-m");
420     CmdArgs.push_back(LDMOption);
421   } else {
422     D.Diag(diag::err_target_unknown_triple) << Triple.str();
423     return;
424   }
425   if (Triple.isRISCV())
426     CmdArgs.push_back("-X");
427 
428   const bool IsShared = Args.hasArg(options::OPT_shared);
429   if (IsShared)
430     CmdArgs.push_back("-shared");
431   bool IsPIE = false;
432   if (IsStaticPIE) {
433     CmdArgs.push_back("-static");
434     CmdArgs.push_back("-pie");
435     CmdArgs.push_back("--no-dynamic-linker");
436     CmdArgs.push_back("-z");
437     CmdArgs.push_back("text");
438   } else if (IsStatic) {
439     CmdArgs.push_back("-static");
440   } else if (!Args.hasArg(options::OPT_r)) {
441     if (Args.hasArg(options::OPT_rdynamic))
442       CmdArgs.push_back("-export-dynamic");
443     if (!IsShared) {
444       IsPIE = Args.hasFlag(options::OPT_pie, options::OPT_no_pie,
445                            ToolChain.isPIEDefault(Args));
446       if (IsPIE)
447         CmdArgs.push_back("-pie");
448       CmdArgs.push_back("-dynamic-linker");
449       CmdArgs.push_back(Args.MakeArgString(Twine(D.DyldPrefix) +
450                                            ToolChain.getDynamicLinker(Args)));
451     }
452   }
453 
454   CmdArgs.push_back("-o");
455   CmdArgs.push_back(Output.getFilename());
456 
457   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
458                    options::OPT_r)) {
459     if (!isAndroid && !IsIAMCU) {
460       const char *crt1 = nullptr;
461       if (!Args.hasArg(options::OPT_shared)) {
462         if (Args.hasArg(options::OPT_pg))
463           crt1 = "gcrt1.o";
464         else if (IsPIE)
465           crt1 = "Scrt1.o";
466         else if (IsStaticPIE)
467           crt1 = "rcrt1.o";
468         else
469           crt1 = "crt1.o";
470       }
471       if (crt1)
472         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crt1)));
473 
474       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crti.o")));
475     }
476 
477     if (IsVE) {
478       CmdArgs.push_back("-z");
479       CmdArgs.push_back("max-page-size=0x4000000");
480     }
481 
482     if (IsIAMCU)
483       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt0.o")));
484     else if (HasCRTBeginEndFiles) {
485       std::string P;
486       if (ToolChain.GetRuntimeLibType(Args) == ToolChain::RLT_CompilerRT &&
487           !isAndroid) {
488         std::string crtbegin = ToolChain.getCompilerRT(Args, "crtbegin",
489                                                        ToolChain::FT_Object);
490         if (ToolChain.getVFS().exists(crtbegin))
491           P = crtbegin;
492       }
493       if (P.empty()) {
494         const char *crtbegin;
495         if (Args.hasArg(options::OPT_shared))
496           crtbegin = isAndroid ? "crtbegin_so.o" : "crtbeginS.o";
497         else if (IsStatic)
498           crtbegin = isAndroid ? "crtbegin_static.o" : "crtbeginT.o";
499         else if (IsPIE || IsStaticPIE)
500           crtbegin = isAndroid ? "crtbegin_dynamic.o" : "crtbeginS.o";
501         else
502           crtbegin = isAndroid ? "crtbegin_dynamic.o" : "crtbegin.o";
503         P = ToolChain.GetFilePath(crtbegin);
504       }
505       CmdArgs.push_back(Args.MakeArgString(P));
506     }
507 
508     // Add crtfastmath.o if available and fast math is enabled.
509     ToolChain.addFastMathRuntimeIfAvailable(Args, CmdArgs);
510   }
511 
512   Args.addAllArgs(CmdArgs, {options::OPT_L, options::OPT_u});
513 
514   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
515 
516   if (D.isUsingLTO()) {
517     assert(!Inputs.empty() && "Must have at least one input.");
518     // Find the first filename InputInfo object.
519     auto Input = llvm::find_if(
520         Inputs, [](const InputInfo &II) -> bool { return II.isFilename(); });
521     if (Input == Inputs.end())
522       // For a very rare case, all of the inputs to the linker are
523       // InputArg. If that happens, just use the first InputInfo.
524       Input = Inputs.begin();
525 
526     addLTOOptions(ToolChain, Args, CmdArgs, Output, *Input,
527                   D.getLTOMode() == LTOK_Thin);
528   }
529 
530   if (Args.hasArg(options::OPT_Z_Xlinker__no_demangle))
531     CmdArgs.push_back("--no-demangle");
532 
533   bool NeedsSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
534   bool NeedsXRayDeps = addXRayRuntime(ToolChain, Args, CmdArgs);
535   addLinkerCompressDebugSectionsOption(ToolChain, Args, CmdArgs);
536   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
537 
538   addHIPRuntimeLibArgs(ToolChain, C, Args, CmdArgs);
539 
540   // The profile runtime also needs access to system libraries.
541   getToolChain().addProfileRTLibs(Args, CmdArgs);
542 
543   if (D.CCCIsCXX() &&
544       !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
545                    options::OPT_r)) {
546     if (ToolChain.ShouldLinkCXXStdlib(Args)) {
547       bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
548                                  !Args.hasArg(options::OPT_static);
549       if (OnlyLibstdcxxStatic)
550         CmdArgs.push_back("-Bstatic");
551       ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
552       if (OnlyLibstdcxxStatic)
553         CmdArgs.push_back("-Bdynamic");
554     }
555     CmdArgs.push_back("-lm");
556   }
557 
558   // Silence warnings when linking C code with a C++ '-stdlib' argument.
559   Args.ClaimAllArgs(options::OPT_stdlib_EQ);
560 
561   // Additional linker set-up and flags for Fortran. This is required in order
562   // to generate executables. As Fortran runtime depends on the C runtime,
563   // these dependencies need to be listed before the C runtime below (i.e.
564   // AddRunTimeLibs).
565   if (D.IsFlangMode()) {
566     addFortranRuntimeLibraryPath(ToolChain, Args, CmdArgs);
567     addFortranRuntimeLibs(ToolChain, Args, CmdArgs);
568     CmdArgs.push_back("-lm");
569   }
570 
571   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_r)) {
572     if (!Args.hasArg(options::OPT_nodefaultlibs)) {
573       if (IsStatic || IsStaticPIE)
574         CmdArgs.push_back("--start-group");
575 
576       if (NeedsSanitizerDeps)
577         linkSanitizerRuntimeDeps(ToolChain, Args, CmdArgs);
578 
579       if (NeedsXRayDeps)
580         linkXRayRuntimeDeps(ToolChain, Args, CmdArgs);
581 
582       bool WantPthread = Args.hasArg(options::OPT_pthread) ||
583                          Args.hasArg(options::OPT_pthreads);
584 
585       // Use the static OpenMP runtime with -static-openmp
586       bool StaticOpenMP = Args.hasArg(options::OPT_static_openmp) &&
587                           !Args.hasArg(options::OPT_static);
588 
589       // FIXME: Only pass GompNeedsRT = true for platforms with libgomp that
590       // require librt. Most modern Linux platforms do, but some may not.
591       if (addOpenMPRuntime(CmdArgs, ToolChain, Args, StaticOpenMP,
592                            JA.isHostOffloading(Action::OFK_OpenMP),
593                            /* GompNeedsRT= */ true))
594         // OpenMP runtimes implies pthreads when using the GNU toolchain.
595         // FIXME: Does this really make sense for all GNU toolchains?
596         WantPthread = true;
597 
598       AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
599 
600       // LLVM support for atomics on 32-bit SPARC V8+ is incomplete, so
601       // forcibly link with libatomic as a workaround.
602       // TODO: Issue #41880 and D118021.
603       if (getToolChain().getTriple().getArch() == llvm::Triple::sparc) {
604         CmdArgs.push_back("--push-state");
605         CmdArgs.push_back("--as-needed");
606         CmdArgs.push_back("-latomic");
607         CmdArgs.push_back("--pop-state");
608       }
609 
610       // We don't need libpthread neither for bionic (Android) nor for musl,
611       // (used by OHOS as runtime library).
612       if (WantPthread && !isAndroid && !isOHOSFamily)
613         CmdArgs.push_back("-lpthread");
614 
615       if (Args.hasArg(options::OPT_fsplit_stack))
616         CmdArgs.push_back("--wrap=pthread_create");
617 
618       if (!Args.hasArg(options::OPT_nolibc))
619         CmdArgs.push_back("-lc");
620 
621       // Add IAMCU specific libs, if needed.
622       if (IsIAMCU)
623         CmdArgs.push_back("-lgloss");
624 
625       if (IsStatic || IsStaticPIE)
626         CmdArgs.push_back("--end-group");
627       else
628         AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
629 
630       // Add IAMCU specific libs (outside the group), if needed.
631       if (IsIAMCU) {
632         CmdArgs.push_back("--as-needed");
633         CmdArgs.push_back("-lsoftfp");
634         CmdArgs.push_back("--no-as-needed");
635       }
636     }
637 
638     if (!Args.hasArg(options::OPT_nostartfiles) && !IsIAMCU) {
639       if (HasCRTBeginEndFiles) {
640         std::string P;
641         if (ToolChain.GetRuntimeLibType(Args) == ToolChain::RLT_CompilerRT &&
642             !isAndroid) {
643           std::string crtend = ToolChain.getCompilerRT(Args, "crtend",
644                                                        ToolChain::FT_Object);
645           if (ToolChain.getVFS().exists(crtend))
646             P = crtend;
647         }
648         if (P.empty()) {
649           const char *crtend;
650           if (Args.hasArg(options::OPT_shared))
651             crtend = isAndroid ? "crtend_so.o" : "crtendS.o";
652           else if (IsPIE || IsStaticPIE)
653             crtend = isAndroid ? "crtend_android.o" : "crtendS.o";
654           else
655             crtend = isAndroid ? "crtend_android.o" : "crtend.o";
656           P = ToolChain.GetFilePath(crtend);
657         }
658         CmdArgs.push_back(Args.MakeArgString(P));
659       }
660       if (!isAndroid)
661         CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtn.o")));
662     }
663   }
664 
665   Args.AddAllArgs(CmdArgs, options::OPT_T);
666 
667   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
668   C.addCommand(std::make_unique<Command>(JA, *this,
669                                          ResponseFileSupport::AtFileCurCP(),
670                                          Exec, CmdArgs, Inputs, Output));
671 }
672 
673 void tools::gnutools::Assembler::ConstructJob(Compilation &C,
674                                               const JobAction &JA,
675                                               const InputInfo &Output,
676                                               const InputInfoList &Inputs,
677                                               const ArgList &Args,
678                                               const char *LinkingOutput) const {
679   const auto &D = getToolChain().getDriver();
680 
681   claimNoWarnArgs(Args);
682 
683   ArgStringList CmdArgs;
684 
685   llvm::Reloc::Model RelocationModel;
686   unsigned PICLevel;
687   bool IsPIE;
688   const char *DefaultAssembler = "as";
689   // Enforce GNU as on Solaris; the native assembler's input syntax isn't fully
690   // compatible.
691   if (getToolChain().getTriple().isOSSolaris())
692     DefaultAssembler = "gas";
693   std::tie(RelocationModel, PICLevel, IsPIE) =
694       ParsePICArgs(getToolChain(), Args);
695 
696   if (const Arg *A = Args.getLastArg(options::OPT_gz, options::OPT_gz_EQ)) {
697     if (A->getOption().getID() == options::OPT_gz) {
698       CmdArgs.push_back("--compress-debug-sections");
699     } else {
700       StringRef Value = A->getValue();
701       if (Value == "none" || Value == "zlib" || Value == "zstd") {
702         CmdArgs.push_back(
703             Args.MakeArgString("--compress-debug-sections=" + Twine(Value)));
704       } else {
705         D.Diag(diag::err_drv_unsupported_option_argument)
706             << A->getSpelling() << Value;
707       }
708     }
709   }
710 
711   switch (getToolChain().getArch()) {
712   default:
713     break;
714   // Add --32/--64 to make sure we get the format we want.
715   // This is incomplete
716   case llvm::Triple::x86:
717     CmdArgs.push_back("--32");
718     break;
719   case llvm::Triple::x86_64:
720     if (getToolChain().getTriple().isX32())
721       CmdArgs.push_back("--x32");
722     else
723       CmdArgs.push_back("--64");
724     break;
725   case llvm::Triple::ppc: {
726     CmdArgs.push_back("-a32");
727     CmdArgs.push_back("-mppc");
728     CmdArgs.push_back("-mbig-endian");
729     CmdArgs.push_back(ppc::getPPCAsmModeForCPU(
730         getCPUName(D, Args, getToolChain().getTriple())));
731     break;
732   }
733   case llvm::Triple::ppcle: {
734     CmdArgs.push_back("-a32");
735     CmdArgs.push_back("-mppc");
736     CmdArgs.push_back("-mlittle-endian");
737     CmdArgs.push_back(ppc::getPPCAsmModeForCPU(
738         getCPUName(D, Args, getToolChain().getTriple())));
739     break;
740   }
741   case llvm::Triple::ppc64: {
742     CmdArgs.push_back("-a64");
743     CmdArgs.push_back("-mppc64");
744     CmdArgs.push_back("-mbig-endian");
745     CmdArgs.push_back(ppc::getPPCAsmModeForCPU(
746         getCPUName(D, Args, getToolChain().getTriple())));
747     break;
748   }
749   case llvm::Triple::ppc64le: {
750     CmdArgs.push_back("-a64");
751     CmdArgs.push_back("-mppc64");
752     CmdArgs.push_back("-mlittle-endian");
753     CmdArgs.push_back(ppc::getPPCAsmModeForCPU(
754         getCPUName(D, Args, getToolChain().getTriple())));
755     break;
756   }
757   case llvm::Triple::riscv32:
758   case llvm::Triple::riscv64: {
759     StringRef ABIName = riscv::getRISCVABI(Args, getToolChain().getTriple());
760     CmdArgs.push_back("-mabi");
761     CmdArgs.push_back(ABIName.data());
762     StringRef MArchName = riscv::getRISCVArch(Args, getToolChain().getTriple());
763     CmdArgs.push_back("-march");
764     CmdArgs.push_back(MArchName.data());
765     if (!Args.hasFlag(options::OPT_mrelax, options::OPT_mno_relax, true))
766       Args.addOptOutFlag(CmdArgs, options::OPT_mrelax, options::OPT_mno_relax);
767     break;
768   }
769   case llvm::Triple::sparc:
770   case llvm::Triple::sparcel: {
771     CmdArgs.push_back("-32");
772     std::string CPU = getCPUName(D, Args, getToolChain().getTriple());
773     CmdArgs.push_back(
774         sparc::getSparcAsmModeForCPU(CPU, getToolChain().getTriple()));
775     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
776     break;
777   }
778   case llvm::Triple::sparcv9: {
779     CmdArgs.push_back("-64");
780     std::string CPU = getCPUName(D, Args, getToolChain().getTriple());
781     CmdArgs.push_back(
782         sparc::getSparcAsmModeForCPU(CPU, getToolChain().getTriple()));
783     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
784     break;
785   }
786   case llvm::Triple::arm:
787   case llvm::Triple::armeb:
788   case llvm::Triple::thumb:
789   case llvm::Triple::thumbeb: {
790     const llvm::Triple &Triple2 = getToolChain().getTriple();
791     CmdArgs.push_back(arm::isARMBigEndian(Triple2, Args) ? "-EB" : "-EL");
792     switch (Triple2.getSubArch()) {
793     case llvm::Triple::ARMSubArch_v7:
794       CmdArgs.push_back("-mfpu=neon");
795       break;
796     case llvm::Triple::ARMSubArch_v8:
797       CmdArgs.push_back("-mfpu=crypto-neon-fp-armv8");
798       break;
799     default:
800       break;
801     }
802 
803     switch (arm::getARMFloatABI(getToolChain(), Args)) {
804     case arm::FloatABI::Invalid: llvm_unreachable("must have an ABI!");
805     case arm::FloatABI::Soft:
806       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=soft"));
807       break;
808     case arm::FloatABI::SoftFP:
809       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=softfp"));
810       break;
811     case arm::FloatABI::Hard:
812       CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=hard"));
813       break;
814     }
815 
816     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
817     normalizeCPUNamesForAssembler(Args, CmdArgs);
818 
819     Args.AddLastArg(CmdArgs, options::OPT_mfpu_EQ);
820     // The integrated assembler doesn't implement e_flags setting behavior for
821     // -meabi=gnu (gcc -mabi={apcs-gnu,atpcs} passes -meabi=gnu to gas). For
822     // compatibility we accept but warn.
823     if (Arg *A = Args.getLastArgNoClaim(options::OPT_mabi_EQ))
824       A->ignoreTargetSpecific();
825     break;
826   }
827   case llvm::Triple::aarch64:
828   case llvm::Triple::aarch64_be: {
829     CmdArgs.push_back(
830         getToolChain().getArch() == llvm::Triple::aarch64_be ? "-EB" : "-EL");
831     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
832     normalizeCPUNamesForAssembler(Args, CmdArgs);
833 
834     break;
835   }
836   // TODO: handle loongarch32.
837   case llvm::Triple::loongarch64: {
838     StringRef ABIName =
839         loongarch::getLoongArchABI(D, Args, getToolChain().getTriple());
840     CmdArgs.push_back(Args.MakeArgString("-mabi=" + ABIName));
841     break;
842   }
843   case llvm::Triple::mips:
844   case llvm::Triple::mipsel:
845   case llvm::Triple::mips64:
846   case llvm::Triple::mips64el: {
847     StringRef CPUName;
848     StringRef ABIName;
849     mips::getMipsCPUAndABI(Args, getToolChain().getTriple(), CPUName, ABIName);
850     ABIName = mips::getGnuCompatibleMipsABIName(ABIName);
851 
852     CmdArgs.push_back("-march");
853     CmdArgs.push_back(CPUName.data());
854 
855     CmdArgs.push_back("-mabi");
856     CmdArgs.push_back(ABIName.data());
857 
858     // -mno-shared should be emitted unless -fpic, -fpie, -fPIC, -fPIE,
859     // or -mshared (not implemented) is in effect.
860     if (RelocationModel == llvm::Reloc::Static)
861       CmdArgs.push_back("-mno-shared");
862 
863     // LLVM doesn't support -mplt yet and acts as if it is always given.
864     // However, -mplt has no effect with the N64 ABI.
865     if (ABIName != "64" && !Args.hasArg(options::OPT_mno_abicalls))
866       CmdArgs.push_back("-call_nonpic");
867 
868     if (getToolChain().getTriple().isLittleEndian())
869       CmdArgs.push_back("-EL");
870     else
871       CmdArgs.push_back("-EB");
872 
873     if (Arg *A = Args.getLastArg(options::OPT_mnan_EQ)) {
874       if (StringRef(A->getValue()) == "2008")
875         CmdArgs.push_back(Args.MakeArgString("-mnan=2008"));
876     }
877 
878     // Add the last -mfp32/-mfpxx/-mfp64 or -mfpxx if it is enabled by default.
879     if (Arg *A = Args.getLastArg(options::OPT_mfp32, options::OPT_mfpxx,
880                                  options::OPT_mfp64)) {
881       A->claim();
882       A->render(Args, CmdArgs);
883     } else if (mips::shouldUseFPXX(
884                    Args, getToolChain().getTriple(), CPUName, ABIName,
885                    mips::getMipsFloatABI(getToolChain().getDriver(), Args,
886                                          getToolChain().getTriple())))
887       CmdArgs.push_back("-mfpxx");
888 
889     // Pass on -mmips16 or -mno-mips16. However, the assembler equivalent of
890     // -mno-mips16 is actually -no-mips16.
891     if (Arg *A =
892             Args.getLastArg(options::OPT_mips16, options::OPT_mno_mips16)) {
893       if (A->getOption().matches(options::OPT_mips16)) {
894         A->claim();
895         A->render(Args, CmdArgs);
896       } else {
897         A->claim();
898         CmdArgs.push_back("-no-mips16");
899       }
900     }
901 
902     Args.AddLastArg(CmdArgs, options::OPT_mmicromips,
903                     options::OPT_mno_micromips);
904     Args.AddLastArg(CmdArgs, options::OPT_mdsp, options::OPT_mno_dsp);
905     Args.AddLastArg(CmdArgs, options::OPT_mdspr2, options::OPT_mno_dspr2);
906 
907     if (Arg *A = Args.getLastArg(options::OPT_mmsa, options::OPT_mno_msa)) {
908       // Do not use AddLastArg because not all versions of MIPS assembler
909       // support -mmsa / -mno-msa options.
910       if (A->getOption().matches(options::OPT_mmsa))
911         CmdArgs.push_back(Args.MakeArgString("-mmsa"));
912     }
913 
914     Args.AddLastArg(CmdArgs, options::OPT_mhard_float,
915                     options::OPT_msoft_float);
916 
917     Args.AddLastArg(CmdArgs, options::OPT_mdouble_float,
918                     options::OPT_msingle_float);
919 
920     Args.AddLastArg(CmdArgs, options::OPT_modd_spreg,
921                     options::OPT_mno_odd_spreg);
922 
923     AddAssemblerKPIC(getToolChain(), Args, CmdArgs);
924     break;
925   }
926   case llvm::Triple::systemz: {
927     // Always pass an -march option, since our default of z10 is later
928     // than the GNU assembler's default.
929     std::string CPUName = systemz::getSystemZTargetCPU(Args);
930     CmdArgs.push_back(Args.MakeArgString("-march=" + CPUName));
931     break;
932   }
933   case llvm::Triple::ve:
934     DefaultAssembler = "nas";
935   }
936 
937   for (const Arg *A : Args.filtered(options::OPT_ffile_prefix_map_EQ,
938                                     options::OPT_fdebug_prefix_map_EQ)) {
939     StringRef Map = A->getValue();
940     if (!Map.contains('='))
941       D.Diag(diag::err_drv_invalid_argument_to_option)
942           << Map << A->getOption().getName();
943     else {
944       CmdArgs.push_back(Args.MakeArgString("--debug-prefix-map"));
945       CmdArgs.push_back(Args.MakeArgString(Map));
946     }
947     A->claim();
948   }
949 
950   Args.AddAllArgs(CmdArgs, options::OPT_I);
951   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
952 
953   CmdArgs.push_back("-o");
954   CmdArgs.push_back(Output.getFilename());
955 
956   for (const auto &II : Inputs)
957     CmdArgs.push_back(II.getFilename());
958 
959   if (Arg *A = Args.getLastArg(options::OPT_g_Flag, options::OPT_gN_Group,
960                                options::OPT_gdwarf_2, options::OPT_gdwarf_3,
961                                options::OPT_gdwarf_4, options::OPT_gdwarf_5,
962                                options::OPT_gdwarf))
963     if (!A->getOption().matches(options::OPT_g0)) {
964       Args.AddLastArg(CmdArgs, options::OPT_g_Flag);
965 
966       unsigned DwarfVersion = getDwarfVersion(getToolChain(), Args);
967       CmdArgs.push_back(Args.MakeArgString("-gdwarf-" + Twine(DwarfVersion)));
968     }
969 
970   const char *Exec =
971       Args.MakeArgString(getToolChain().GetProgramPath(DefaultAssembler));
972   C.addCommand(std::make_unique<Command>(JA, *this,
973                                          ResponseFileSupport::AtFileCurCP(),
974                                          Exec, CmdArgs, Inputs, Output));
975 
976   // Handle the debug info splitting at object creation time if we're
977   // creating an object.
978   // TODO: Currently only works on linux with newer objcopy.
979   if (Args.hasArg(options::OPT_gsplit_dwarf) &&
980       getToolChain().getTriple().isOSLinux())
981     SplitDebugInfo(getToolChain(), C, *this, JA, Args, Output,
982                    SplitDebugName(JA, Args, Inputs[0], Output));
983 }
984 
985 namespace {
986 // Filter to remove Multilibs that don't exist as a suffix to Path
987 class FilterNonExistent {
988   StringRef Base, File;
989   llvm::vfs::FileSystem &VFS;
990 
991 public:
992   FilterNonExistent(StringRef Base, StringRef File, llvm::vfs::FileSystem &VFS)
993       : Base(Base), File(File), VFS(VFS) {}
994   bool operator()(const Multilib &M) {
995     return !VFS.exists(Base + M.gccSuffix() + File);
996   }
997 };
998 } // end anonymous namespace
999 
1000 static bool isSoftFloatABI(const ArgList &Args) {
1001   Arg *A = Args.getLastArg(options::OPT_msoft_float, options::OPT_mhard_float,
1002                            options::OPT_mfloat_abi_EQ);
1003   if (!A)
1004     return false;
1005 
1006   return A->getOption().matches(options::OPT_msoft_float) ||
1007          (A->getOption().matches(options::OPT_mfloat_abi_EQ) &&
1008           A->getValue() == StringRef("soft"));
1009 }
1010 
1011 static bool isArmOrThumbArch(llvm::Triple::ArchType Arch) {
1012   return Arch == llvm::Triple::arm || Arch == llvm::Triple::thumb;
1013 }
1014 
1015 static bool isMipsEL(llvm::Triple::ArchType Arch) {
1016   return Arch == llvm::Triple::mipsel || Arch == llvm::Triple::mips64el;
1017 }
1018 
1019 static bool isMips16(const ArgList &Args) {
1020   Arg *A = Args.getLastArg(options::OPT_mips16, options::OPT_mno_mips16);
1021   return A && A->getOption().matches(options::OPT_mips16);
1022 }
1023 
1024 static bool isMicroMips(const ArgList &Args) {
1025   Arg *A = Args.getLastArg(options::OPT_mmicromips, options::OPT_mno_micromips);
1026   return A && A->getOption().matches(options::OPT_mmicromips);
1027 }
1028 
1029 static bool isMSP430(llvm::Triple::ArchType Arch) {
1030   return Arch == llvm::Triple::msp430;
1031 }
1032 
1033 static bool findMipsCsMultilibs(const Multilib::flags_list &Flags,
1034                                 FilterNonExistent &NonExistent,
1035                                 DetectedMultilibs &Result) {
1036   // Check for Code Sourcery toolchain multilibs
1037   MultilibSet CSMipsMultilibs;
1038   {
1039     auto MArchMips16 = MultilibBuilder("/mips16").flag("-m32").flag("-mips16");
1040 
1041     auto MArchMicroMips =
1042         MultilibBuilder("/micromips").flag("-m32").flag("-mmicromips");
1043 
1044     auto MArchDefault = MultilibBuilder("")
1045                             .flag("-mips16", /*Disallow=*/true)
1046                             .flag("-mmicromips", /*Disallow=*/true);
1047 
1048     auto UCLibc = MultilibBuilder("/uclibc").flag("-muclibc");
1049 
1050     auto SoftFloat = MultilibBuilder("/soft-float").flag("-msoft-float");
1051 
1052     auto Nan2008 = MultilibBuilder("/nan2008").flag("-mnan=2008");
1053 
1054     auto DefaultFloat = MultilibBuilder("")
1055                             .flag("-msoft-float", /*Disallow=*/true)
1056                             .flag("-mnan=2008", /*Disallow=*/true);
1057 
1058     auto BigEndian =
1059         MultilibBuilder("").flag("-EB").flag("-EL", /*Disallow=*/true);
1060 
1061     auto LittleEndian =
1062         MultilibBuilder("/el").flag("-EL").flag("-EB", /*Disallow=*/true);
1063 
1064     // Note that this one's osSuffix is ""
1065     auto MAbi64 = MultilibBuilder("")
1066                       .gccSuffix("/64")
1067                       .includeSuffix("/64")
1068                       .flag("-mabi=n64")
1069                       .flag("-mabi=n32", /*Disallow=*/true)
1070                       .flag("-m32", /*Disallow=*/true);
1071 
1072     CSMipsMultilibs =
1073         MultilibSetBuilder()
1074             .Either(MArchMips16, MArchMicroMips, MArchDefault)
1075             .Maybe(UCLibc)
1076             .Either(SoftFloat, Nan2008, DefaultFloat)
1077             .FilterOut("/micromips/nan2008")
1078             .FilterOut("/mips16/nan2008")
1079             .Either(BigEndian, LittleEndian)
1080             .Maybe(MAbi64)
1081             .FilterOut("/mips16.*/64")
1082             .FilterOut("/micromips.*/64")
1083             .makeMultilibSet()
1084             .FilterOut(NonExistent)
1085             .setIncludeDirsCallback([](const Multilib &M) {
1086               std::vector<std::string> Dirs({"/include"});
1087               if (StringRef(M.includeSuffix()).starts_with("/uclibc"))
1088                 Dirs.push_back(
1089                     "/../../../../mips-linux-gnu/libc/uclibc/usr/include");
1090               else
1091                 Dirs.push_back("/../../../../mips-linux-gnu/libc/usr/include");
1092               return Dirs;
1093             });
1094   }
1095 
1096   MultilibSet DebianMipsMultilibs;
1097   {
1098     MultilibBuilder MAbiN32 =
1099         MultilibBuilder().gccSuffix("/n32").includeSuffix("/n32").flag(
1100             "-mabi=n32");
1101 
1102     MultilibBuilder M64 = MultilibBuilder()
1103                               .gccSuffix("/64")
1104                               .includeSuffix("/64")
1105                               .flag("-m64")
1106                               .flag("-m32", /*Disallow=*/true)
1107                               .flag("-mabi=n32", /*Disallow=*/true);
1108 
1109     MultilibBuilder M32 = MultilibBuilder()
1110                               .gccSuffix("/32")
1111                               .flag("-m64", /*Disallow=*/true)
1112                               .flag("-m32")
1113                               .flag("-mabi=n32", /*Disallow=*/true);
1114 
1115     DebianMipsMultilibs = MultilibSetBuilder()
1116                               .Either(M32, M64, MAbiN32)
1117                               .makeMultilibSet()
1118                               .FilterOut(NonExistent);
1119   }
1120 
1121   // Sort candidates. Toolchain that best meets the directories tree goes first.
1122   // Then select the first toolchains matches command line flags.
1123   MultilibSet *Candidates[] = {&CSMipsMultilibs, &DebianMipsMultilibs};
1124   if (CSMipsMultilibs.size() < DebianMipsMultilibs.size())
1125     std::iter_swap(Candidates, Candidates + 1);
1126   for (const MultilibSet *Candidate : Candidates) {
1127     if (Candidate->select(Flags, Result.SelectedMultilibs)) {
1128       if (Candidate == &DebianMipsMultilibs)
1129         Result.BiarchSibling = Multilib();
1130       Result.Multilibs = *Candidate;
1131       return true;
1132     }
1133   }
1134   return false;
1135 }
1136 
1137 static bool findMipsAndroidMultilibs(llvm::vfs::FileSystem &VFS, StringRef Path,
1138                                      const Multilib::flags_list &Flags,
1139                                      FilterNonExistent &NonExistent,
1140                                      DetectedMultilibs &Result) {
1141 
1142   MultilibSet AndroidMipsMultilibs =
1143       MultilibSetBuilder()
1144           .Maybe(MultilibBuilder("/mips-r2", {}, {}).flag("-march=mips32r2"))
1145           .Maybe(MultilibBuilder("/mips-r6", {}, {}).flag("-march=mips32r6"))
1146           .makeMultilibSet()
1147           .FilterOut(NonExistent);
1148 
1149   MultilibSet AndroidMipselMultilibs =
1150       MultilibSetBuilder()
1151           .Either(MultilibBuilder().flag("-march=mips32"),
1152                   MultilibBuilder("/mips-r2", "", "/mips-r2")
1153                       .flag("-march=mips32r2"),
1154                   MultilibBuilder("/mips-r6", "", "/mips-r6")
1155                       .flag("-march=mips32r6"))
1156           .makeMultilibSet()
1157           .FilterOut(NonExistent);
1158 
1159   MultilibSet AndroidMips64elMultilibs =
1160       MultilibSetBuilder()
1161           .Either(MultilibBuilder().flag("-march=mips64r6"),
1162                   MultilibBuilder("/32/mips-r1", "", "/mips-r1")
1163                       .flag("-march=mips32"),
1164                   MultilibBuilder("/32/mips-r2", "", "/mips-r2")
1165                       .flag("-march=mips32r2"),
1166                   MultilibBuilder("/32/mips-r6", "", "/mips-r6")
1167                       .flag("-march=mips32r6"))
1168           .makeMultilibSet()
1169           .FilterOut(NonExistent);
1170 
1171   MultilibSet *MS = &AndroidMipsMultilibs;
1172   if (VFS.exists(Path + "/mips-r6"))
1173     MS = &AndroidMipselMultilibs;
1174   else if (VFS.exists(Path + "/32"))
1175     MS = &AndroidMips64elMultilibs;
1176   if (MS->select(Flags, Result.SelectedMultilibs)) {
1177     Result.Multilibs = *MS;
1178     return true;
1179   }
1180   return false;
1181 }
1182 
1183 static bool findMipsMuslMultilibs(const Multilib::flags_list &Flags,
1184                                   FilterNonExistent &NonExistent,
1185                                   DetectedMultilibs &Result) {
1186   // Musl toolchain multilibs
1187   MultilibSet MuslMipsMultilibs;
1188   {
1189     auto MArchMipsR2 = MultilibBuilder("")
1190                            .osSuffix("/mips-r2-hard-musl")
1191                            .flag("-EB")
1192                            .flag("-EL", /*Disallow=*/true)
1193                            .flag("-march=mips32r2");
1194 
1195     auto MArchMipselR2 = MultilibBuilder("/mipsel-r2-hard-musl")
1196                              .flag("-EB", /*Disallow=*/true)
1197                              .flag("-EL")
1198                              .flag("-march=mips32r2");
1199 
1200     MuslMipsMultilibs = MultilibSetBuilder()
1201                             .Either(MArchMipsR2, MArchMipselR2)
1202                             .makeMultilibSet();
1203 
1204     // Specify the callback that computes the include directories.
1205     MuslMipsMultilibs.setIncludeDirsCallback([](const Multilib &M) {
1206       return std::vector<std::string>(
1207           {"/../sysroot" + M.osSuffix() + "/usr/include"});
1208     });
1209   }
1210   if (MuslMipsMultilibs.select(Flags, Result.SelectedMultilibs)) {
1211     Result.Multilibs = MuslMipsMultilibs;
1212     return true;
1213   }
1214   return false;
1215 }
1216 
1217 static bool findMipsMtiMultilibs(const Multilib::flags_list &Flags,
1218                                  FilterNonExistent &NonExistent,
1219                                  DetectedMultilibs &Result) {
1220   // CodeScape MTI toolchain v1.2 and early.
1221   MultilibSet MtiMipsMultilibsV1;
1222   {
1223     auto MArchMips32 = MultilibBuilder("/mips32")
1224                            .flag("-m32")
1225                            .flag("-m64", /*Disallow=*/true)
1226                            .flag("-mmicromips", /*Disallow=*/true)
1227                            .flag("-march=mips32");
1228 
1229     auto MArchMicroMips = MultilibBuilder("/micromips")
1230                               .flag("-m32")
1231                               .flag("-m64", /*Disallow=*/true)
1232                               .flag("-mmicromips");
1233 
1234     auto MArchMips64r2 = MultilibBuilder("/mips64r2")
1235                              .flag("-m32", /*Disallow=*/true)
1236                              .flag("-m64")
1237                              .flag("-march=mips64r2");
1238 
1239     auto MArchMips64 = MultilibBuilder("/mips64")
1240                            .flag("-m32", /*Disallow=*/true)
1241                            .flag("-m64")
1242                            .flag("-march=mips64r2", /*Disallow=*/true);
1243 
1244     auto MArchDefault = MultilibBuilder("")
1245                             .flag("-m32")
1246                             .flag("-m64", /*Disallow=*/true)
1247                             .flag("-mmicromips", /*Disallow=*/true)
1248                             .flag("-march=mips32r2");
1249 
1250     auto Mips16 = MultilibBuilder("/mips16").flag("-mips16");
1251 
1252     auto UCLibc = MultilibBuilder("/uclibc").flag("-muclibc");
1253 
1254     auto MAbi64 = MultilibBuilder("/64")
1255                       .flag("-mabi=n64")
1256                       .flag("-mabi=n32", /*Disallow=*/true)
1257                       .flag("-m32", /*Disallow=*/true);
1258 
1259     auto BigEndian =
1260         MultilibBuilder("").flag("-EB").flag("-EL", /*Disallow=*/true);
1261 
1262     auto LittleEndian =
1263         MultilibBuilder("/el").flag("-EL").flag("-EB", /*Disallow=*/true);
1264 
1265     auto SoftFloat = MultilibBuilder("/sof").flag("-msoft-float");
1266 
1267     auto Nan2008 = MultilibBuilder("/nan2008").flag("-mnan=2008");
1268 
1269     MtiMipsMultilibsV1 =
1270         MultilibSetBuilder()
1271             .Either(MArchMips32, MArchMicroMips, MArchMips64r2, MArchMips64,
1272                     MArchDefault)
1273             .Maybe(UCLibc)
1274             .Maybe(Mips16)
1275             .FilterOut("/mips64/mips16")
1276             .FilterOut("/mips64r2/mips16")
1277             .FilterOut("/micromips/mips16")
1278             .Maybe(MAbi64)
1279             .FilterOut("/micromips/64")
1280             .FilterOut("/mips32/64")
1281             .FilterOut("^/64")
1282             .FilterOut("/mips16/64")
1283             .Either(BigEndian, LittleEndian)
1284             .Maybe(SoftFloat)
1285             .Maybe(Nan2008)
1286             .FilterOut(".*sof/nan2008")
1287             .makeMultilibSet()
1288             .FilterOut(NonExistent)
1289             .setIncludeDirsCallback([](const Multilib &M) {
1290               std::vector<std::string> Dirs({"/include"});
1291               if (StringRef(M.includeSuffix()).starts_with("/uclibc"))
1292                 Dirs.push_back("/../../../../sysroot/uclibc/usr/include");
1293               else
1294                 Dirs.push_back("/../../../../sysroot/usr/include");
1295               return Dirs;
1296             });
1297   }
1298 
1299   // CodeScape IMG toolchain starting from v1.3.
1300   MultilibSet MtiMipsMultilibsV2;
1301   {
1302     auto BeHard = MultilibBuilder("/mips-r2-hard")
1303                       .flag("-EB")
1304                       .flag("-msoft-float", /*Disallow=*/true)
1305                       .flag("-mnan=2008", /*Disallow=*/true)
1306                       .flag("-muclibc", /*Disallow=*/true);
1307     auto BeSoft = MultilibBuilder("/mips-r2-soft")
1308                       .flag("-EB")
1309                       .flag("-msoft-float")
1310                       .flag("-mnan=2008", /*Disallow=*/true);
1311     auto ElHard = MultilibBuilder("/mipsel-r2-hard")
1312                       .flag("-EL")
1313                       .flag("-msoft-float", /*Disallow=*/true)
1314                       .flag("-mnan=2008", /*Disallow=*/true)
1315                       .flag("-muclibc", /*Disallow=*/true);
1316     auto ElSoft = MultilibBuilder("/mipsel-r2-soft")
1317                       .flag("-EL")
1318                       .flag("-msoft-float")
1319                       .flag("-mnan=2008", /*Disallow=*/true)
1320                       .flag("-mmicromips", /*Disallow=*/true);
1321     auto BeHardNan = MultilibBuilder("/mips-r2-hard-nan2008")
1322                          .flag("-EB")
1323                          .flag("-msoft-float", /*Disallow=*/true)
1324                          .flag("-mnan=2008")
1325                          .flag("-muclibc", /*Disallow=*/true);
1326     auto ElHardNan = MultilibBuilder("/mipsel-r2-hard-nan2008")
1327                          .flag("-EL")
1328                          .flag("-msoft-float", /*Disallow=*/true)
1329                          .flag("-mnan=2008")
1330                          .flag("-muclibc", /*Disallow=*/true)
1331                          .flag("-mmicromips", /*Disallow=*/true);
1332     auto BeHardNanUclibc = MultilibBuilder("/mips-r2-hard-nan2008-uclibc")
1333                                .flag("-EB")
1334                                .flag("-msoft-float", /*Disallow=*/true)
1335                                .flag("-mnan=2008")
1336                                .flag("-muclibc");
1337     auto ElHardNanUclibc = MultilibBuilder("/mipsel-r2-hard-nan2008-uclibc")
1338                                .flag("-EL")
1339                                .flag("-msoft-float", /*Disallow=*/true)
1340                                .flag("-mnan=2008")
1341                                .flag("-muclibc");
1342     auto BeHardUclibc = MultilibBuilder("/mips-r2-hard-uclibc")
1343                             .flag("-EB")
1344                             .flag("-msoft-float", /*Disallow=*/true)
1345                             .flag("-mnan=2008", /*Disallow=*/true)
1346                             .flag("-muclibc");
1347     auto ElHardUclibc = MultilibBuilder("/mipsel-r2-hard-uclibc")
1348                             .flag("-EL")
1349                             .flag("-msoft-float", /*Disallow=*/true)
1350                             .flag("-mnan=2008", /*Disallow=*/true)
1351                             .flag("-muclibc");
1352     auto ElMicroHardNan = MultilibBuilder("/micromipsel-r2-hard-nan2008")
1353                               .flag("-EL")
1354                               .flag("-msoft-float", /*Disallow=*/true)
1355                               .flag("-mnan=2008")
1356                               .flag("-mmicromips");
1357     auto ElMicroSoft = MultilibBuilder("/micromipsel-r2-soft")
1358                            .flag("-EL")
1359                            .flag("-msoft-float")
1360                            .flag("-mnan=2008", /*Disallow=*/true)
1361                            .flag("-mmicromips");
1362 
1363     auto O32 = MultilibBuilder("/lib")
1364                    .osSuffix("")
1365                    .flag("-mabi=n32", /*Disallow=*/true)
1366                    .flag("-mabi=n64", /*Disallow=*/true);
1367     auto N32 = MultilibBuilder("/lib32")
1368                    .osSuffix("")
1369                    .flag("-mabi=n32")
1370                    .flag("-mabi=n64", /*Disallow=*/true);
1371     auto N64 = MultilibBuilder("/lib64")
1372                    .osSuffix("")
1373                    .flag("-mabi=n32", /*Disallow=*/true)
1374                    .flag("-mabi=n64");
1375 
1376     MtiMipsMultilibsV2 =
1377         MultilibSetBuilder()
1378             .Either({BeHard, BeSoft, ElHard, ElSoft, BeHardNan, ElHardNan,
1379                      BeHardNanUclibc, ElHardNanUclibc, BeHardUclibc,
1380                      ElHardUclibc, ElMicroHardNan, ElMicroSoft})
1381             .Either(O32, N32, N64)
1382             .makeMultilibSet()
1383             .FilterOut(NonExistent)
1384             .setIncludeDirsCallback([](const Multilib &M) {
1385               return std::vector<std::string>({"/../../../../sysroot" +
1386                                                M.includeSuffix() +
1387                                                "/../usr/include"});
1388             })
1389             .setFilePathsCallback([](const Multilib &M) {
1390               return std::vector<std::string>(
1391                   {"/../../../../mips-mti-linux-gnu/lib" + M.gccSuffix()});
1392             });
1393   }
1394   for (auto *Candidate : {&MtiMipsMultilibsV1, &MtiMipsMultilibsV2}) {
1395     if (Candidate->select(Flags, Result.SelectedMultilibs)) {
1396       Result.Multilibs = *Candidate;
1397       return true;
1398     }
1399   }
1400   return false;
1401 }
1402 
1403 static bool findMipsImgMultilibs(const Multilib::flags_list &Flags,
1404                                  FilterNonExistent &NonExistent,
1405                                  DetectedMultilibs &Result) {
1406   // CodeScape IMG toolchain v1.2 and early.
1407   MultilibSet ImgMultilibsV1;
1408   {
1409     auto Mips64r6 = MultilibBuilder("/mips64r6")
1410                         .flag("-m64")
1411                         .flag("-m32", /*Disallow=*/true);
1412 
1413     auto LittleEndian =
1414         MultilibBuilder("/el").flag("-EL").flag("-EB", /*Disallow=*/true);
1415 
1416     auto MAbi64 = MultilibBuilder("/64")
1417                       .flag("-mabi=n64")
1418                       .flag("-mabi=n32", /*Disallow=*/true)
1419                       .flag("-m32", /*Disallow=*/true);
1420 
1421     ImgMultilibsV1 =
1422         MultilibSetBuilder()
1423             .Maybe(Mips64r6)
1424             .Maybe(MAbi64)
1425             .Maybe(LittleEndian)
1426             .makeMultilibSet()
1427             .FilterOut(NonExistent)
1428             .setIncludeDirsCallback([](const Multilib &M) {
1429               return std::vector<std::string>(
1430                   {"/include", "/../../../../sysroot/usr/include"});
1431             });
1432   }
1433 
1434   // CodeScape IMG toolchain starting from v1.3.
1435   MultilibSet ImgMultilibsV2;
1436   {
1437     auto BeHard = MultilibBuilder("/mips-r6-hard")
1438                       .flag("-EB")
1439                       .flag("-msoft-float", /*Disallow=*/true)
1440                       .flag("-mmicromips", /*Disallow=*/true);
1441     auto BeSoft = MultilibBuilder("/mips-r6-soft")
1442                       .flag("-EB")
1443                       .flag("-msoft-float")
1444                       .flag("-mmicromips", /*Disallow=*/true);
1445     auto ElHard = MultilibBuilder("/mipsel-r6-hard")
1446                       .flag("-EL")
1447                       .flag("-msoft-float", /*Disallow=*/true)
1448                       .flag("-mmicromips", /*Disallow=*/true);
1449     auto ElSoft = MultilibBuilder("/mipsel-r6-soft")
1450                       .flag("-EL")
1451                       .flag("-msoft-float")
1452                       .flag("-mmicromips", /*Disallow=*/true);
1453     auto BeMicroHard = MultilibBuilder("/micromips-r6-hard")
1454                            .flag("-EB")
1455                            .flag("-msoft-float", /*Disallow=*/true)
1456                            .flag("-mmicromips");
1457     auto BeMicroSoft = MultilibBuilder("/micromips-r6-soft")
1458                            .flag("-EB")
1459                            .flag("-msoft-float")
1460                            .flag("-mmicromips");
1461     auto ElMicroHard = MultilibBuilder("/micromipsel-r6-hard")
1462                            .flag("-EL")
1463                            .flag("-msoft-float", /*Disallow=*/true)
1464                            .flag("-mmicromips");
1465     auto ElMicroSoft = MultilibBuilder("/micromipsel-r6-soft")
1466                            .flag("-EL")
1467                            .flag("-msoft-float")
1468                            .flag("-mmicromips");
1469 
1470     auto O32 = MultilibBuilder("/lib")
1471                    .osSuffix("")
1472                    .flag("-mabi=n32", /*Disallow=*/true)
1473                    .flag("-mabi=n64", /*Disallow=*/true);
1474     auto N32 = MultilibBuilder("/lib32")
1475                    .osSuffix("")
1476                    .flag("-mabi=n32")
1477                    .flag("-mabi=n64", /*Disallow=*/true);
1478     auto N64 = MultilibBuilder("/lib64")
1479                    .osSuffix("")
1480                    .flag("-mabi=n32", /*Disallow=*/true)
1481                    .flag("-mabi=n64");
1482 
1483     ImgMultilibsV2 =
1484         MultilibSetBuilder()
1485             .Either({BeHard, BeSoft, ElHard, ElSoft, BeMicroHard, BeMicroSoft,
1486                      ElMicroHard, ElMicroSoft})
1487             .Either(O32, N32, N64)
1488             .makeMultilibSet()
1489             .FilterOut(NonExistent)
1490             .setIncludeDirsCallback([](const Multilib &M) {
1491               return std::vector<std::string>({"/../../../../sysroot" +
1492                                                M.includeSuffix() +
1493                                                "/../usr/include"});
1494             })
1495             .setFilePathsCallback([](const Multilib &M) {
1496               return std::vector<std::string>(
1497                   {"/../../../../mips-img-linux-gnu/lib" + M.gccSuffix()});
1498             });
1499   }
1500   for (auto *Candidate : {&ImgMultilibsV1, &ImgMultilibsV2}) {
1501     if (Candidate->select(Flags, Result.SelectedMultilibs)) {
1502       Result.Multilibs = *Candidate;
1503       return true;
1504     }
1505   }
1506   return false;
1507 }
1508 
1509 bool clang::driver::findMIPSMultilibs(const Driver &D,
1510                                       const llvm::Triple &TargetTriple,
1511                                       StringRef Path, const ArgList &Args,
1512                                       DetectedMultilibs &Result) {
1513   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1514 
1515   StringRef CPUName;
1516   StringRef ABIName;
1517   tools::mips::getMipsCPUAndABI(Args, TargetTriple, CPUName, ABIName);
1518 
1519   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
1520 
1521   Multilib::flags_list Flags;
1522   addMultilibFlag(TargetTriple.isMIPS32(), "-m32", Flags);
1523   addMultilibFlag(TargetTriple.isMIPS64(), "-m64", Flags);
1524   addMultilibFlag(isMips16(Args), "-mips16", Flags);
1525   addMultilibFlag(CPUName == "mips32", "-march=mips32", Flags);
1526   addMultilibFlag(CPUName == "mips32r2" || CPUName == "mips32r3" ||
1527                       CPUName == "mips32r5" || CPUName == "p5600",
1528                   "-march=mips32r2", Flags);
1529   addMultilibFlag(CPUName == "mips32r6", "-march=mips32r6", Flags);
1530   addMultilibFlag(CPUName == "mips64", "-march=mips64", Flags);
1531   addMultilibFlag(CPUName == "mips64r2" || CPUName == "mips64r3" ||
1532                       CPUName == "mips64r5" || CPUName == "octeon" ||
1533                       CPUName == "octeon+",
1534                   "-march=mips64r2", Flags);
1535   addMultilibFlag(CPUName == "mips64r6", "-march=mips64r6", Flags);
1536   addMultilibFlag(isMicroMips(Args), "-mmicromips", Flags);
1537   addMultilibFlag(tools::mips::isUCLibc(Args), "-muclibc", Flags);
1538   addMultilibFlag(tools::mips::isNaN2008(D, Args, TargetTriple), "-mnan=2008",
1539                   Flags);
1540   addMultilibFlag(ABIName == "n32", "-mabi=n32", Flags);
1541   addMultilibFlag(ABIName == "n64", "-mabi=n64", Flags);
1542   addMultilibFlag(isSoftFloatABI(Args), "-msoft-float", Flags);
1543   addMultilibFlag(!isSoftFloatABI(Args), "-mhard-float", Flags);
1544   addMultilibFlag(isMipsEL(TargetArch), "-EL", Flags);
1545   addMultilibFlag(!isMipsEL(TargetArch), "-EB", Flags);
1546 
1547   if (TargetTriple.isAndroid())
1548     return findMipsAndroidMultilibs(D.getVFS(), Path, Flags, NonExistent,
1549                                     Result);
1550 
1551   if (TargetTriple.getVendor() == llvm::Triple::MipsTechnologies &&
1552       TargetTriple.getOS() == llvm::Triple::Linux &&
1553       TargetTriple.getEnvironment() == llvm::Triple::UnknownEnvironment)
1554     return findMipsMuslMultilibs(Flags, NonExistent, Result);
1555 
1556   if (TargetTriple.getVendor() == llvm::Triple::MipsTechnologies &&
1557       TargetTriple.getOS() == llvm::Triple::Linux &&
1558       TargetTriple.isGNUEnvironment())
1559     return findMipsMtiMultilibs(Flags, NonExistent, Result);
1560 
1561   if (TargetTriple.getVendor() == llvm::Triple::ImaginationTechnologies &&
1562       TargetTriple.getOS() == llvm::Triple::Linux &&
1563       TargetTriple.isGNUEnvironment())
1564     return findMipsImgMultilibs(Flags, NonExistent, Result);
1565 
1566   if (findMipsCsMultilibs(Flags, NonExistent, Result))
1567     return true;
1568 
1569   // Fallback to the regular toolchain-tree structure.
1570   Multilib Default;
1571   Result.Multilibs.push_back(Default);
1572   Result.Multilibs.FilterOut(NonExistent);
1573 
1574   if (Result.Multilibs.select(Flags, Result.SelectedMultilibs)) {
1575     Result.BiarchSibling = Multilib();
1576     return true;
1577   }
1578 
1579   return false;
1580 }
1581 
1582 static void findAndroidArmMultilibs(const Driver &D,
1583                                     const llvm::Triple &TargetTriple,
1584                                     StringRef Path, const ArgList &Args,
1585                                     DetectedMultilibs &Result) {
1586   // Find multilibs with subdirectories like armv7-a, thumb, armv7-a/thumb.
1587   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1588   MultilibBuilder ArmV7Multilib = MultilibBuilder("/armv7-a")
1589                                       .flag("-march=armv7-a")
1590                                       .flag("-mthumb", /*Disallow=*/true);
1591   MultilibBuilder ThumbMultilib = MultilibBuilder("/thumb")
1592                                       .flag("-march=armv7-a", /*Disallow=*/true)
1593                                       .flag("-mthumb");
1594   MultilibBuilder ArmV7ThumbMultilib =
1595       MultilibBuilder("/armv7-a/thumb").flag("-march=armv7-a").flag("-mthumb");
1596   MultilibBuilder DefaultMultilib =
1597       MultilibBuilder("")
1598           .flag("-march=armv7-a", /*Disallow=*/true)
1599           .flag("-mthumb", /*Disallow=*/true);
1600   MultilibSet AndroidArmMultilibs =
1601       MultilibSetBuilder()
1602           .Either(ThumbMultilib, ArmV7Multilib, ArmV7ThumbMultilib,
1603                   DefaultMultilib)
1604           .makeMultilibSet()
1605           .FilterOut(NonExistent);
1606 
1607   Multilib::flags_list Flags;
1608   llvm::StringRef Arch = Args.getLastArgValue(options::OPT_march_EQ);
1609   bool IsArmArch = TargetTriple.getArch() == llvm::Triple::arm;
1610   bool IsThumbArch = TargetTriple.getArch() == llvm::Triple::thumb;
1611   bool IsV7SubArch = TargetTriple.getSubArch() == llvm::Triple::ARMSubArch_v7;
1612   bool IsThumbMode = IsThumbArch ||
1613       Args.hasFlag(options::OPT_mthumb, options::OPT_mno_thumb, false) ||
1614       (IsArmArch && llvm::ARM::parseArchISA(Arch) == llvm::ARM::ISAKind::THUMB);
1615   bool IsArmV7Mode = (IsArmArch || IsThumbArch) &&
1616       (llvm::ARM::parseArchVersion(Arch) == 7 ||
1617        (IsArmArch && Arch == "" && IsV7SubArch));
1618   addMultilibFlag(IsArmV7Mode, "-march=armv7-a", Flags);
1619   addMultilibFlag(IsThumbMode, "-mthumb", Flags);
1620 
1621   if (AndroidArmMultilibs.select(Flags, Result.SelectedMultilibs))
1622     Result.Multilibs = AndroidArmMultilibs;
1623 }
1624 
1625 static bool findMSP430Multilibs(const Driver &D,
1626                                 const llvm::Triple &TargetTriple,
1627                                 StringRef Path, const ArgList &Args,
1628                                 DetectedMultilibs &Result) {
1629   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1630   MultilibBuilder WithoutExceptions =
1631       MultilibBuilder("/430").flag("-exceptions", /*Disallow=*/true);
1632   MultilibBuilder WithExceptions =
1633       MultilibBuilder("/430/exceptions").flag("-exceptions");
1634 
1635   // FIXME: when clang starts to support msp430x ISA additional logic
1636   // to select between multilib must be implemented
1637   // MultilibBuilder MSP430xMultilib = MultilibBuilder("/large");
1638 
1639   Result.Multilibs.push_back(WithoutExceptions.makeMultilib());
1640   Result.Multilibs.push_back(WithExceptions.makeMultilib());
1641   Result.Multilibs.FilterOut(NonExistent);
1642 
1643   Multilib::flags_list Flags;
1644   addMultilibFlag(Args.hasFlag(options::OPT_fexceptions,
1645                                options::OPT_fno_exceptions, false),
1646                   "-exceptions", Flags);
1647   if (Result.Multilibs.select(Flags, Result.SelectedMultilibs))
1648     return true;
1649 
1650   return false;
1651 }
1652 
1653 static void findCSKYMultilibs(const Driver &D, const llvm::Triple &TargetTriple,
1654                               StringRef Path, const ArgList &Args,
1655                               DetectedMultilibs &Result) {
1656   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1657 
1658   tools::csky::FloatABI TheFloatABI = tools::csky::getCSKYFloatABI(D, Args);
1659   std::optional<llvm::StringRef> Res =
1660       tools::csky::getCSKYArchName(D, Args, TargetTriple);
1661 
1662   if (!Res)
1663     return;
1664   auto ARCHName = *Res;
1665 
1666   Multilib::flags_list Flags;
1667   addMultilibFlag(TheFloatABI == tools::csky::FloatABI::Hard, "-hard-fp",
1668                   Flags);
1669   addMultilibFlag(TheFloatABI == tools::csky::FloatABI::SoftFP, "-soft-fp",
1670                   Flags);
1671   addMultilibFlag(TheFloatABI == tools::csky::FloatABI::Soft, "-soft", Flags);
1672   addMultilibFlag(ARCHName == "ck801", "-march=ck801", Flags);
1673   addMultilibFlag(ARCHName == "ck802", "-march=ck802", Flags);
1674   addMultilibFlag(ARCHName == "ck803", "-march=ck803", Flags);
1675   addMultilibFlag(ARCHName == "ck804", "-march=ck804", Flags);
1676   addMultilibFlag(ARCHName == "ck805", "-march=ck805", Flags);
1677   addMultilibFlag(ARCHName == "ck807", "-march=ck807", Flags);
1678   addMultilibFlag(ARCHName == "ck810", "-march=ck810", Flags);
1679   addMultilibFlag(ARCHName == "ck810v", "-march=ck810v", Flags);
1680   addMultilibFlag(ARCHName == "ck860", "-march=ck860", Flags);
1681   addMultilibFlag(ARCHName == "ck860v", "-march=ck860v", Flags);
1682 
1683   bool isBigEndian = false;
1684   if (Arg *A = Args.getLastArg(options::OPT_mlittle_endian,
1685                                options::OPT_mbig_endian))
1686     isBigEndian = !A->getOption().matches(options::OPT_mlittle_endian);
1687   addMultilibFlag(isBigEndian, "-EB", Flags);
1688 
1689   auto HardFloat = MultilibBuilder("/hard-fp").flag("-hard-fp");
1690   auto SoftFpFloat = MultilibBuilder("/soft-fp").flag("-soft-fp");
1691   auto SoftFloat = MultilibBuilder("").flag("-soft");
1692   auto Arch801 = MultilibBuilder("/ck801").flag("-march=ck801");
1693   auto Arch802 = MultilibBuilder("/ck802").flag("-march=ck802");
1694   auto Arch803 = MultilibBuilder("/ck803").flag("-march=ck803");
1695   // CK804 use the same library as CK803
1696   auto Arch804 = MultilibBuilder("/ck803").flag("-march=ck804");
1697   auto Arch805 = MultilibBuilder("/ck805").flag("-march=ck805");
1698   auto Arch807 = MultilibBuilder("/ck807").flag("-march=ck807");
1699   auto Arch810 = MultilibBuilder("").flag("-march=ck810");
1700   auto Arch810v = MultilibBuilder("/ck810v").flag("-march=ck810v");
1701   auto Arch860 = MultilibBuilder("/ck860").flag("-march=ck860");
1702   auto Arch860v = MultilibBuilder("/ck860v").flag("-march=ck860v");
1703   auto BigEndian = MultilibBuilder("/big").flag("-EB");
1704 
1705   MultilibSet CSKYMultilibs =
1706       MultilibSetBuilder()
1707           .Maybe(BigEndian)
1708           .Either({Arch801, Arch802, Arch803, Arch804, Arch805, Arch807,
1709                    Arch810, Arch810v, Arch860, Arch860v})
1710           .Either(HardFloat, SoftFpFloat, SoftFloat)
1711           .makeMultilibSet()
1712           .FilterOut(NonExistent);
1713 
1714   if (CSKYMultilibs.select(Flags, Result.SelectedMultilibs))
1715     Result.Multilibs = CSKYMultilibs;
1716 }
1717 
1718 static void findRISCVBareMetalMultilibs(const Driver &D,
1719                                         const llvm::Triple &TargetTriple,
1720                                         StringRef Path, const ArgList &Args,
1721                                         DetectedMultilibs &Result) {
1722   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1723   struct RiscvMultilib {
1724     StringRef march;
1725     StringRef mabi;
1726   };
1727   // currently only support the set of multilibs like riscv-gnu-toolchain does.
1728   // TODO: support MULTILIB_REUSE
1729   constexpr RiscvMultilib RISCVMultilibSet[] = {
1730       {"rv32i", "ilp32"},     {"rv32im", "ilp32"},     {"rv32iac", "ilp32"},
1731       {"rv32imac", "ilp32"},  {"rv32imafc", "ilp32f"}, {"rv64imac", "lp64"},
1732       {"rv64imafdc", "lp64d"}};
1733 
1734   std::vector<MultilibBuilder> Ms;
1735   for (auto Element : RISCVMultilibSet) {
1736     // multilib path rule is ${march}/${mabi}
1737     Ms.emplace_back(
1738         MultilibBuilder(
1739             (Twine(Element.march) + "/" + Twine(Element.mabi)).str())
1740             .flag(Twine("-march=", Element.march).str())
1741             .flag(Twine("-mabi=", Element.mabi).str()));
1742   }
1743   MultilibSet RISCVMultilibs =
1744       MultilibSetBuilder()
1745           .Either(Ms)
1746           .makeMultilibSet()
1747           .FilterOut(NonExistent)
1748           .setFilePathsCallback([](const Multilib &M) {
1749             return std::vector<std::string>(
1750                 {M.gccSuffix(),
1751                  "/../../../../riscv64-unknown-elf/lib" + M.gccSuffix(),
1752                  "/../../../../riscv32-unknown-elf/lib" + M.gccSuffix()});
1753           });
1754 
1755   Multilib::flags_list Flags;
1756   llvm::StringSet<> Added_ABIs;
1757   StringRef ABIName = tools::riscv::getRISCVABI(Args, TargetTriple);
1758   StringRef MArch = tools::riscv::getRISCVArch(Args, TargetTriple);
1759   for (auto Element : RISCVMultilibSet) {
1760     addMultilibFlag(MArch == Element.march,
1761                     Twine("-march=", Element.march).str().c_str(), Flags);
1762     if (!Added_ABIs.count(Element.mabi)) {
1763       Added_ABIs.insert(Element.mabi);
1764       addMultilibFlag(ABIName == Element.mabi,
1765                       Twine("-mabi=", Element.mabi).str().c_str(), Flags);
1766     }
1767   }
1768 
1769   if (RISCVMultilibs.select(Flags, Result.SelectedMultilibs))
1770     Result.Multilibs = RISCVMultilibs;
1771 }
1772 
1773 static void findRISCVMultilibs(const Driver &D,
1774                                const llvm::Triple &TargetTriple, StringRef Path,
1775                                const ArgList &Args, DetectedMultilibs &Result) {
1776   if (TargetTriple.getOS() == llvm::Triple::UnknownOS)
1777     return findRISCVBareMetalMultilibs(D, TargetTriple, Path, Args, Result);
1778 
1779   FilterNonExistent NonExistent(Path, "/crtbegin.o", D.getVFS());
1780   MultilibBuilder Ilp32 =
1781       MultilibBuilder("lib32/ilp32").flag("-m32").flag("-mabi=ilp32");
1782   MultilibBuilder Ilp32f =
1783       MultilibBuilder("lib32/ilp32f").flag("-m32").flag("-mabi=ilp32f");
1784   MultilibBuilder Ilp32d =
1785       MultilibBuilder("lib32/ilp32d").flag("-m32").flag("-mabi=ilp32d");
1786   MultilibBuilder Lp64 =
1787       MultilibBuilder("lib64/lp64").flag("-m64").flag("-mabi=lp64");
1788   MultilibBuilder Lp64f =
1789       MultilibBuilder("lib64/lp64f").flag("-m64").flag("-mabi=lp64f");
1790   MultilibBuilder Lp64d =
1791       MultilibBuilder("lib64/lp64d").flag("-m64").flag("-mabi=lp64d");
1792   MultilibSet RISCVMultilibs =
1793       MultilibSetBuilder()
1794           .Either({Ilp32, Ilp32f, Ilp32d, Lp64, Lp64f, Lp64d})
1795           .makeMultilibSet()
1796           .FilterOut(NonExistent);
1797 
1798   Multilib::flags_list Flags;
1799   bool IsRV64 = TargetTriple.getArch() == llvm::Triple::riscv64;
1800   StringRef ABIName = tools::riscv::getRISCVABI(Args, TargetTriple);
1801 
1802   addMultilibFlag(!IsRV64, "-m32", Flags);
1803   addMultilibFlag(IsRV64, "-m64", Flags);
1804   addMultilibFlag(ABIName == "ilp32", "-mabi=ilp32", Flags);
1805   addMultilibFlag(ABIName == "ilp32f", "-mabi=ilp32f", Flags);
1806   addMultilibFlag(ABIName == "ilp32d", "-mabi=ilp32d", Flags);
1807   addMultilibFlag(ABIName == "lp64", "-mabi=lp64", Flags);
1808   addMultilibFlag(ABIName == "lp64f", "-mabi=lp64f", Flags);
1809   addMultilibFlag(ABIName == "lp64d", "-mabi=lp64d", Flags);
1810 
1811   if (RISCVMultilibs.select(Flags, Result.SelectedMultilibs))
1812     Result.Multilibs = RISCVMultilibs;
1813 }
1814 
1815 static bool findBiarchMultilibs(const Driver &D,
1816                                 const llvm::Triple &TargetTriple,
1817                                 StringRef Path, const ArgList &Args,
1818                                 bool NeedsBiarchSuffix,
1819                                 DetectedMultilibs &Result) {
1820   MultilibBuilder DefaultBuilder;
1821 
1822   // Some versions of SUSE and Fedora on ppc64 put 32-bit libs
1823   // in what would normally be GCCInstallPath and put the 64-bit
1824   // libs in a subdirectory named 64. The simple logic we follow is that
1825   // *if* there is a subdirectory of the right name with crtbegin.o in it,
1826   // we use that. If not, and if not a biarch triple alias, we look for
1827   // crtbegin.o without the subdirectory.
1828 
1829   StringRef Suff64 = "/64";
1830   // Solaris uses platform-specific suffixes instead of /64.
1831   if (TargetTriple.isOSSolaris()) {
1832     switch (TargetTriple.getArch()) {
1833     case llvm::Triple::x86:
1834     case llvm::Triple::x86_64:
1835       Suff64 = "/amd64";
1836       break;
1837     case llvm::Triple::sparc:
1838     case llvm::Triple::sparcv9:
1839       Suff64 = "/sparcv9";
1840       break;
1841     default:
1842       break;
1843     }
1844   }
1845 
1846   Multilib Alt64 = MultilibBuilder()
1847                        .gccSuffix(Suff64)
1848                        .includeSuffix(Suff64)
1849                        .flag("-m32", /*Disallow=*/true)
1850                        .flag("-m64")
1851                        .flag("-mx32", /*Disallow=*/true)
1852                        .makeMultilib();
1853   Multilib Alt32 = MultilibBuilder()
1854                        .gccSuffix("/32")
1855                        .includeSuffix("/32")
1856                        .flag("-m32")
1857                        .flag("-m64", /*Disallow=*/true)
1858                        .flag("-mx32", /*Disallow=*/true)
1859                        .makeMultilib();
1860   Multilib Altx32 = MultilibBuilder()
1861                         .gccSuffix("/x32")
1862                         .includeSuffix("/x32")
1863                         .flag("-m32", /*Disallow=*/true)
1864                         .flag("-m64", /*Disallow=*/true)
1865                         .flag("-mx32")
1866                         .makeMultilib();
1867   Multilib Alt32sparc = MultilibBuilder()
1868                             .gccSuffix("/sparcv8plus")
1869                             .includeSuffix("/sparcv8plus")
1870                             .flag("-m32")
1871                             .flag("-m64", /*Disallow=*/true)
1872                             .makeMultilib();
1873 
1874   // GCC toolchain for IAMCU doesn't have crtbegin.o, so look for libgcc.a.
1875   FilterNonExistent NonExistent(
1876       Path, TargetTriple.isOSIAMCU() ? "/libgcc.a" : "/crtbegin.o", D.getVFS());
1877 
1878   // Determine default multilib from: 32, 64, x32
1879   // Also handle cases such as 64 on 32, 32 on 64, etc.
1880   enum { UNKNOWN, WANT32, WANT64, WANTX32 } Want = UNKNOWN;
1881   const bool IsX32 = TargetTriple.isX32();
1882   if (TargetTriple.isArch32Bit() && !NonExistent(Alt32))
1883     Want = WANT64;
1884   if (TargetTriple.isArch32Bit() && !NonExistent(Alt32sparc))
1885     Want = WANT64;
1886   else if (TargetTriple.isArch64Bit() && IsX32 && !NonExistent(Altx32))
1887     Want = WANT64;
1888   else if (TargetTriple.isArch64Bit() && !IsX32 && !NonExistent(Alt64))
1889     Want = WANT32;
1890   else if (TargetTriple.isArch64Bit() && !NonExistent(Alt32sparc))
1891     Want = WANT64;
1892   else {
1893     if (TargetTriple.isArch32Bit())
1894       Want = NeedsBiarchSuffix ? WANT64 : WANT32;
1895     else if (IsX32)
1896       Want = NeedsBiarchSuffix ? WANT64 : WANTX32;
1897     else
1898       Want = NeedsBiarchSuffix ? WANT32 : WANT64;
1899   }
1900 
1901   if (Want == WANT32)
1902     DefaultBuilder.flag("-m32")
1903         .flag("-m64", /*Disallow=*/true)
1904         .flag("-mx32", /*Disallow=*/true);
1905   else if (Want == WANT64)
1906     DefaultBuilder.flag("-m32", /*Disallow=*/true)
1907         .flag("-m64")
1908         .flag("-mx32", /*Disallow=*/true);
1909   else if (Want == WANTX32)
1910     DefaultBuilder.flag("-m32", /*Disallow=*/true)
1911         .flag("-m64", /*Disallow=*/true)
1912         .flag("-mx32");
1913   else
1914     return false;
1915 
1916   Multilib Default = DefaultBuilder.makeMultilib();
1917 
1918   Result.Multilibs.push_back(Default);
1919   Result.Multilibs.push_back(Alt64);
1920   Result.Multilibs.push_back(Alt32);
1921   Result.Multilibs.push_back(Altx32);
1922   Result.Multilibs.push_back(Alt32sparc);
1923 
1924   Result.Multilibs.FilterOut(NonExistent);
1925 
1926   Multilib::flags_list Flags;
1927   addMultilibFlag(TargetTriple.isArch64Bit() && !IsX32, "-m64", Flags);
1928   addMultilibFlag(TargetTriple.isArch32Bit(), "-m32", Flags);
1929   addMultilibFlag(TargetTriple.isArch64Bit() && IsX32, "-mx32", Flags);
1930 
1931   if (!Result.Multilibs.select(Flags, Result.SelectedMultilibs))
1932     return false;
1933 
1934   if (Result.SelectedMultilibs.back() == Alt64 ||
1935       Result.SelectedMultilibs.back() == Alt32 ||
1936       Result.SelectedMultilibs.back() == Altx32 ||
1937       Result.SelectedMultilibs.back() == Alt32sparc)
1938     Result.BiarchSibling = Default;
1939 
1940   return true;
1941 }
1942 
1943 /// Generic_GCC - A tool chain using the 'gcc' command to perform
1944 /// all subcommands; this relies on gcc translating the majority of
1945 /// command line options.
1946 
1947 /// Less-than for GCCVersion, implementing a Strict Weak Ordering.
1948 bool Generic_GCC::GCCVersion::isOlderThan(int RHSMajor, int RHSMinor,
1949                                           int RHSPatch,
1950                                           StringRef RHSPatchSuffix) const {
1951   if (Major != RHSMajor)
1952     return Major < RHSMajor;
1953   if (Minor != RHSMinor) {
1954     // Note that versions without a specified minor sort higher than those with
1955     // a minor.
1956     if (RHSMinor == -1)
1957       return true;
1958     if (Minor == -1)
1959       return false;
1960     return Minor < RHSMinor;
1961   }
1962   if (Patch != RHSPatch) {
1963     // Note that versions without a specified patch sort higher than those with
1964     // a patch.
1965     if (RHSPatch == -1)
1966       return true;
1967     if (Patch == -1)
1968       return false;
1969 
1970     // Otherwise just sort on the patch itself.
1971     return Patch < RHSPatch;
1972   }
1973   if (PatchSuffix != RHSPatchSuffix) {
1974     // Sort empty suffixes higher.
1975     if (RHSPatchSuffix.empty())
1976       return true;
1977     if (PatchSuffix.empty())
1978       return false;
1979 
1980     // Provide a lexicographic sort to make this a total ordering.
1981     return PatchSuffix < RHSPatchSuffix;
1982   }
1983 
1984   // The versions are equal.
1985   return false;
1986 }
1987 
1988 /// Parse a GCCVersion object out of a string of text.
1989 ///
1990 /// This is the primary means of forming GCCVersion objects.
1991 /*static*/
1992 Generic_GCC::GCCVersion Generic_GCC::GCCVersion::Parse(StringRef VersionText) {
1993   const GCCVersion BadVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
1994   std::pair<StringRef, StringRef> First = VersionText.split('.');
1995   std::pair<StringRef, StringRef> Second = First.second.split('.');
1996 
1997   StringRef MajorStr = First.first;
1998   StringRef MinorStr = Second.first;
1999   StringRef PatchStr = Second.second;
2000 
2001   GCCVersion GoodVersion = {VersionText.str(), -1, -1, -1, "", "", ""};
2002 
2003   // Parse version number strings such as:
2004   //   5
2005   //   4.4
2006   //   4.4-patched
2007   //   4.4.0
2008   //   4.4.x
2009   //   4.4.2-rc4
2010   //   4.4.x-patched
2011   //   10-win32
2012   // Split on '.', handle 1, 2 or 3 such segments. Each segment must contain
2013   // purely a number, except for the last one, where a non-number suffix
2014   // is stored in PatchSuffix. The third segment is allowed to not contain
2015   // a number at all.
2016 
2017   auto TryParseLastNumber = [&](StringRef Segment, int &Number,
2018                                 std::string &OutStr) -> bool {
2019     // Look for a number prefix and parse that, and split out any trailing
2020     // string into GoodVersion.PatchSuffix.
2021 
2022     if (size_t EndNumber = Segment.find_first_not_of("0123456789")) {
2023       StringRef NumberStr = Segment.slice(0, EndNumber);
2024       if (NumberStr.getAsInteger(10, Number) || Number < 0)
2025         return false;
2026       OutStr = NumberStr;
2027       GoodVersion.PatchSuffix = Segment.substr(EndNumber);
2028       return true;
2029     }
2030     return false;
2031   };
2032   auto TryParseNumber = [](StringRef Segment, int &Number) -> bool {
2033     if (Segment.getAsInteger(10, Number) || Number < 0)
2034       return false;
2035     return true;
2036   };
2037 
2038   if (MinorStr.empty()) {
2039     // If no minor string, major is the last segment
2040     if (!TryParseLastNumber(MajorStr, GoodVersion.Major, GoodVersion.MajorStr))
2041       return BadVersion;
2042     return GoodVersion;
2043   }
2044 
2045   if (!TryParseNumber(MajorStr, GoodVersion.Major))
2046     return BadVersion;
2047   GoodVersion.MajorStr = MajorStr;
2048 
2049   if (PatchStr.empty()) {
2050     // If no patch string, minor is the last segment
2051     if (!TryParseLastNumber(MinorStr, GoodVersion.Minor, GoodVersion.MinorStr))
2052       return BadVersion;
2053     return GoodVersion;
2054   }
2055 
2056   if (!TryParseNumber(MinorStr, GoodVersion.Minor))
2057     return BadVersion;
2058   GoodVersion.MinorStr = MinorStr;
2059 
2060   // For the last segment, tolerate a missing number.
2061   std::string DummyStr;
2062   TryParseLastNumber(PatchStr, GoodVersion.Patch, DummyStr);
2063   return GoodVersion;
2064 }
2065 
2066 static llvm::StringRef getGCCToolchainDir(const ArgList &Args,
2067                                           llvm::StringRef SysRoot) {
2068   const Arg *A = Args.getLastArg(clang::driver::options::OPT_gcc_toolchain);
2069   if (A)
2070     return A->getValue();
2071 
2072   // If we have a SysRoot, ignore GCC_INSTALL_PREFIX.
2073   // GCC_INSTALL_PREFIX specifies the gcc installation for the default
2074   // sysroot and is likely not valid with a different sysroot.
2075   if (!SysRoot.empty())
2076     return "";
2077 
2078   return GCC_INSTALL_PREFIX;
2079 }
2080 
2081 /// Initialize a GCCInstallationDetector from the driver.
2082 ///
2083 /// This performs all of the autodetection and sets up the various paths.
2084 /// Once constructed, a GCCInstallationDetector is essentially immutable.
2085 ///
2086 /// FIXME: We shouldn't need an explicit TargetTriple parameter here, and
2087 /// should instead pull the target out of the driver. This is currently
2088 /// necessary because the driver doesn't store the final version of the target
2089 /// triple.
2090 void Generic_GCC::GCCInstallationDetector::init(
2091     const llvm::Triple &TargetTriple, const ArgList &Args) {
2092   llvm::Triple BiarchVariantTriple = TargetTriple.isArch32Bit()
2093                                          ? TargetTriple.get64BitArchVariant()
2094                                          : TargetTriple.get32BitArchVariant();
2095   // The library directories which may contain GCC installations.
2096   SmallVector<StringRef, 4> CandidateLibDirs, CandidateBiarchLibDirs;
2097   // The compatible GCC triples for this particular architecture.
2098   SmallVector<StringRef, 16> CandidateTripleAliases;
2099   SmallVector<StringRef, 16> CandidateBiarchTripleAliases;
2100   // Add some triples that we want to check first.
2101   CandidateTripleAliases.push_back(TargetTriple.str());
2102   std::string TripleNoVendor = TargetTriple.getArchName().str() + "-" +
2103                                TargetTriple.getOSAndEnvironmentName().str();
2104   if (TargetTriple.getVendor() == llvm::Triple::UnknownVendor)
2105     CandidateTripleAliases.push_back(TripleNoVendor);
2106 
2107   CollectLibDirsAndTriples(TargetTriple, BiarchVariantTriple, CandidateLibDirs,
2108                            CandidateTripleAliases, CandidateBiarchLibDirs,
2109                            CandidateBiarchTripleAliases);
2110 
2111   // If --gcc-install-dir= is specified, skip filesystem detection.
2112   if (const Arg *A =
2113           Args.getLastArg(clang::driver::options::OPT_gcc_install_dir_EQ);
2114       A && A->getValue()[0]) {
2115     StringRef InstallDir = A->getValue();
2116     if (!ScanGCCForMultilibs(TargetTriple, Args, InstallDir, false)) {
2117       D.Diag(diag::err_drv_invalid_gcc_install_dir) << InstallDir;
2118     } else {
2119       (void)InstallDir.consume_back("/");
2120       StringRef VersionText = llvm::sys::path::filename(InstallDir);
2121       StringRef TripleText =
2122           llvm::sys::path::filename(llvm::sys::path::parent_path(InstallDir));
2123 
2124       Version = GCCVersion::Parse(VersionText);
2125       GCCTriple.setTriple(TripleText);
2126       GCCInstallPath = std::string(InstallDir);
2127       GCCParentLibPath = GCCInstallPath + "/../../..";
2128       IsValid = true;
2129     }
2130     return;
2131   }
2132 
2133   // Compute the set of prefixes for our search.
2134   SmallVector<std::string, 8> Prefixes;
2135   StringRef GCCToolchainDir = getGCCToolchainDir(Args, D.SysRoot);
2136   if (GCCToolchainDir != "") {
2137     if (GCCToolchainDir.back() == '/')
2138       GCCToolchainDir = GCCToolchainDir.drop_back(); // remove the /
2139 
2140     Prefixes.push_back(std::string(GCCToolchainDir));
2141   } else {
2142     // If we have a SysRoot, try that first.
2143     if (!D.SysRoot.empty()) {
2144       Prefixes.push_back(D.SysRoot);
2145       AddDefaultGCCPrefixes(TargetTriple, Prefixes, D.SysRoot);
2146     }
2147 
2148     // Then look for gcc installed alongside clang.
2149     Prefixes.push_back(D.InstalledDir + "/..");
2150 
2151     // Next, look for prefix(es) that correspond to distribution-supplied gcc
2152     // installations.
2153     if (D.SysRoot.empty()) {
2154       // Typically /usr.
2155       AddDefaultGCCPrefixes(TargetTriple, Prefixes, D.SysRoot);
2156     }
2157 
2158     // Try to respect gcc-config on Gentoo if --gcc-toolchain is not provided.
2159     // This avoids accidentally enforcing the system GCC version when using a
2160     // custom toolchain.
2161     SmallVector<StringRef, 16> GentooTestTriples;
2162     // Try to match an exact triple as target triple first.
2163     // e.g. crossdev -S x86_64-gentoo-linux-gnu will install gcc libs for
2164     // x86_64-gentoo-linux-gnu. But "clang -target x86_64-gentoo-linux-gnu"
2165     // may pick the libraries for x86_64-pc-linux-gnu even when exact matching
2166     // triple x86_64-gentoo-linux-gnu is present.
2167     GentooTestTriples.push_back(TargetTriple.str());
2168     GentooTestTriples.append(CandidateTripleAliases.begin(),
2169                              CandidateTripleAliases.end());
2170     if (ScanGentooConfigs(TargetTriple, Args, GentooTestTriples,
2171                           CandidateBiarchTripleAliases))
2172       return;
2173   }
2174 
2175   // Loop over the various components which exist and select the best GCC
2176   // installation available. GCC installs are ranked by version number.
2177   const GCCVersion VersionZero = GCCVersion::Parse("0.0.0");
2178   Version = VersionZero;
2179   for (const std::string &Prefix : Prefixes) {
2180     auto &VFS = D.getVFS();
2181     if (!VFS.exists(Prefix))
2182       continue;
2183     for (StringRef Suffix : CandidateLibDirs) {
2184       const std::string LibDir = concat(Prefix, Suffix);
2185       if (!VFS.exists(LibDir))
2186         continue;
2187       // Maybe filter out <libdir>/gcc and <libdir>/gcc-cross.
2188       bool GCCDirExists = VFS.exists(LibDir + "/gcc");
2189       bool GCCCrossDirExists = VFS.exists(LibDir + "/gcc-cross");
2190       for (StringRef Candidate : CandidateTripleAliases)
2191         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate, false,
2192                                GCCDirExists, GCCCrossDirExists);
2193     }
2194     for (StringRef Suffix : CandidateBiarchLibDirs) {
2195       const std::string LibDir = Prefix + Suffix.str();
2196       if (!VFS.exists(LibDir))
2197         continue;
2198       bool GCCDirExists = VFS.exists(LibDir + "/gcc");
2199       bool GCCCrossDirExists = VFS.exists(LibDir + "/gcc-cross");
2200       for (StringRef Candidate : CandidateBiarchTripleAliases)
2201         ScanLibDirForGCCTriple(TargetTriple, Args, LibDir, Candidate, true,
2202                                GCCDirExists, GCCCrossDirExists);
2203     }
2204 
2205     // Skip other prefixes once a GCC installation is found.
2206     if (Version > VersionZero)
2207       break;
2208   }
2209 }
2210 
2211 void Generic_GCC::GCCInstallationDetector::print(raw_ostream &OS) const {
2212   for (const auto &InstallPath : CandidateGCCInstallPaths)
2213     OS << "Found candidate GCC installation: " << InstallPath << "\n";
2214 
2215   if (!GCCInstallPath.empty())
2216     OS << "Selected GCC installation: " << GCCInstallPath << "\n";
2217 
2218   for (const auto &Multilib : Multilibs)
2219     OS << "Candidate multilib: " << Multilib << "\n";
2220 
2221   if (Multilibs.size() != 0 || !SelectedMultilib.isDefault())
2222     OS << "Selected multilib: " << SelectedMultilib << "\n";
2223 }
2224 
2225 bool Generic_GCC::GCCInstallationDetector::getBiarchSibling(Multilib &M) const {
2226   if (BiarchSibling) {
2227     M = *BiarchSibling;
2228     return true;
2229   }
2230   return false;
2231 }
2232 
2233 void Generic_GCC::GCCInstallationDetector::AddDefaultGCCPrefixes(
2234     const llvm::Triple &TargetTriple, SmallVectorImpl<std::string> &Prefixes,
2235     StringRef SysRoot) {
2236 
2237   if (TargetTriple.isOSHaiku()) {
2238     Prefixes.push_back(concat(SysRoot, "/boot/system/develop/tools"));
2239     return;
2240   }
2241 
2242   if (TargetTriple.isOSSolaris()) {
2243     // Solaris is a special case.
2244     // The GCC installation is under
2245     //   /usr/gcc/<major>.<minor>/lib/gcc/<triple>/<major>.<minor>.<patch>/
2246     // so we need to find those /usr/gcc/*/lib/gcc libdirs and go with
2247     // /usr/gcc/<version> as a prefix.
2248 
2249     SmallVector<std::pair<GCCVersion, std::string>, 8> SolarisPrefixes;
2250     std::string PrefixDir = concat(SysRoot, "/usr/gcc");
2251     std::error_code EC;
2252     for (llvm::vfs::directory_iterator LI = D.getVFS().dir_begin(PrefixDir, EC),
2253                                        LE;
2254          !EC && LI != LE; LI = LI.increment(EC)) {
2255       StringRef VersionText = llvm::sys::path::filename(LI->path());
2256       GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
2257 
2258       // Filter out obviously bad entries.
2259       if (CandidateVersion.Major == -1 || CandidateVersion.isOlderThan(4, 1, 1))
2260         continue;
2261 
2262       std::string CandidatePrefix = PrefixDir + "/" + VersionText.str();
2263       std::string CandidateLibPath = CandidatePrefix + "/lib/gcc";
2264       if (!D.getVFS().exists(CandidateLibPath))
2265         continue;
2266 
2267       SolarisPrefixes.emplace_back(
2268           std::make_pair(CandidateVersion, CandidatePrefix));
2269     }
2270     // Sort in reverse order so GCCInstallationDetector::init picks the latest.
2271     std::sort(SolarisPrefixes.rbegin(), SolarisPrefixes.rend());
2272     for (auto p : SolarisPrefixes)
2273       Prefixes.emplace_back(p.second);
2274     return;
2275   }
2276 
2277   // For Linux, if --sysroot is not specified, look for RHEL/CentOS devtoolsets
2278   // and gcc-toolsets.
2279   if (SysRoot.empty() && TargetTriple.getOS() == llvm::Triple::Linux &&
2280       D.getVFS().exists("/opt/rh")) {
2281     // TODO: We may want to remove this, since the functionality
2282     //   can be achieved using config files.
2283     Prefixes.push_back("/opt/rh/gcc-toolset-12/root/usr");
2284     Prefixes.push_back("/opt/rh/gcc-toolset-11/root/usr");
2285     Prefixes.push_back("/opt/rh/gcc-toolset-10/root/usr");
2286     Prefixes.push_back("/opt/rh/devtoolset-12/root/usr");
2287     Prefixes.push_back("/opt/rh/devtoolset-11/root/usr");
2288     Prefixes.push_back("/opt/rh/devtoolset-10/root/usr");
2289     Prefixes.push_back("/opt/rh/devtoolset-9/root/usr");
2290     Prefixes.push_back("/opt/rh/devtoolset-8/root/usr");
2291     Prefixes.push_back("/opt/rh/devtoolset-7/root/usr");
2292     Prefixes.push_back("/opt/rh/devtoolset-6/root/usr");
2293     Prefixes.push_back("/opt/rh/devtoolset-4/root/usr");
2294     Prefixes.push_back("/opt/rh/devtoolset-3/root/usr");
2295     Prefixes.push_back("/opt/rh/devtoolset-2/root/usr");
2296   }
2297 
2298   // Fall back to /usr which is used by most non-Solaris systems.
2299   Prefixes.push_back(concat(SysRoot, "/usr"));
2300 }
2301 
2302 /*static*/ void Generic_GCC::GCCInstallationDetector::CollectLibDirsAndTriples(
2303     const llvm::Triple &TargetTriple, const llvm::Triple &BiarchTriple,
2304     SmallVectorImpl<StringRef> &LibDirs,
2305     SmallVectorImpl<StringRef> &TripleAliases,
2306     SmallVectorImpl<StringRef> &BiarchLibDirs,
2307     SmallVectorImpl<StringRef> &BiarchTripleAliases) {
2308   // Declare a bunch of static data sets that we'll select between below. These
2309   // are specifically designed to always refer to string literals to avoid any
2310   // lifetime or initialization issues.
2311   //
2312   // The *Triples variables hard code some triples so that, for example,
2313   // --target=aarch64 (incomplete triple) can detect lib/aarch64-linux-gnu.
2314   // They are not needed when the user has correct LLVM_DEFAULT_TARGET_TRIPLE
2315   // and always uses the full --target (e.g. --target=aarch64-linux-gnu).  The
2316   // lists should shrink over time. Please don't add more elements to *Triples.
2317   static const char *const AArch64LibDirs[] = {"/lib64", "/lib"};
2318   static const char *const AArch64Triples[] = {
2319       "aarch64-none-linux-gnu", "aarch64-linux-gnu", "aarch64-redhat-linux",
2320       "aarch64-suse-linux"};
2321   static const char *const AArch64beLibDirs[] = {"/lib"};
2322   static const char *const AArch64beTriples[] = {"aarch64_be-none-linux-gnu",
2323                                                  "aarch64_be-linux-gnu"};
2324 
2325   static const char *const ARMLibDirs[] = {"/lib"};
2326   static const char *const ARMTriples[] = {"arm-linux-gnueabi"};
2327   static const char *const ARMHFTriples[] = {"arm-linux-gnueabihf",
2328                                              "armv7hl-redhat-linux-gnueabi",
2329                                              "armv6hl-suse-linux-gnueabi",
2330                                              "armv7hl-suse-linux-gnueabi"};
2331   static const char *const ARMebLibDirs[] = {"/lib"};
2332   static const char *const ARMebTriples[] = {"armeb-linux-gnueabi"};
2333   static const char *const ARMebHFTriples[] = {
2334       "armeb-linux-gnueabihf", "armebv7hl-redhat-linux-gnueabi"};
2335 
2336   static const char *const AVRLibDirs[] = {"/lib"};
2337   static const char *const AVRTriples[] = {"avr"};
2338 
2339   static const char *const CSKYLibDirs[] = {"/lib"};
2340   static const char *const CSKYTriples[] = {
2341       "csky-linux-gnuabiv2", "csky-linux-uclibcabiv2", "csky-elf-noneabiv2"};
2342 
2343   static const char *const X86_64LibDirs[] = {"/lib64", "/lib"};
2344   static const char *const X86_64Triples[] = {
2345       "x86_64-linux-gnu",       "x86_64-unknown-linux-gnu",
2346       "x86_64-pc-linux-gnu",    "x86_64-redhat-linux6E",
2347       "x86_64-redhat-linux",    "x86_64-suse-linux",
2348       "x86_64-manbo-linux-gnu", "x86_64-linux-gnu",
2349       "x86_64-slackware-linux", "x86_64-unknown-linux",
2350       "x86_64-amazon-linux"};
2351   static const char *const X32Triples[] = {"x86_64-linux-gnux32",
2352                                            "x86_64-pc-linux-gnux32"};
2353   static const char *const X32LibDirs[] = {"/libx32", "/lib"};
2354   static const char *const X86LibDirs[] = {"/lib32", "/lib"};
2355   static const char *const X86Triples[] = {
2356       "i586-linux-gnu",      "i686-linux-gnu",        "i686-pc-linux-gnu",
2357       "i386-redhat-linux6E", "i686-redhat-linux",     "i386-redhat-linux",
2358       "i586-suse-linux",     "i686-montavista-linux", "i686-gnu",
2359   };
2360 
2361   static const char *const LoongArch64LibDirs[] = {"/lib64", "/lib"};
2362   static const char *const LoongArch64Triples[] = {
2363       "loongarch64-linux-gnu", "loongarch64-unknown-linux-gnu"};
2364 
2365   static const char *const M68kLibDirs[] = {"/lib"};
2366   static const char *const M68kTriples[] = {
2367       "m68k-linux-gnu", "m68k-unknown-linux-gnu", "m68k-suse-linux"};
2368 
2369   static const char *const MIPSLibDirs[] = {"/libo32", "/lib"};
2370   static const char *const MIPSTriples[] = {
2371       "mips-linux-gnu", "mips-mti-linux", "mips-mti-linux-gnu",
2372       "mips-img-linux-gnu", "mipsisa32r6-linux-gnu"};
2373   static const char *const MIPSELLibDirs[] = {"/libo32", "/lib"};
2374   static const char *const MIPSELTriples[] = {
2375       "mipsel-linux-gnu", "mips-img-linux-gnu", "mipsisa32r6el-linux-gnu"};
2376 
2377   static const char *const MIPS64LibDirs[] = {"/lib64", "/lib"};
2378   static const char *const MIPS64Triples[] = {
2379       "mips64-linux-gnu",      "mips-mti-linux-gnu",
2380       "mips-img-linux-gnu",    "mips64-linux-gnuabi64",
2381       "mipsisa64r6-linux-gnu", "mipsisa64r6-linux-gnuabi64"};
2382   static const char *const MIPS64ELLibDirs[] = {"/lib64", "/lib"};
2383   static const char *const MIPS64ELTriples[] = {
2384       "mips64el-linux-gnu",      "mips-mti-linux-gnu",
2385       "mips-img-linux-gnu",      "mips64el-linux-gnuabi64",
2386       "mipsisa64r6el-linux-gnu", "mipsisa64r6el-linux-gnuabi64"};
2387 
2388   static const char *const MIPSN32LibDirs[] = {"/lib32"};
2389   static const char *const MIPSN32Triples[] = {"mips64-linux-gnuabin32",
2390                                                "mipsisa64r6-linux-gnuabin32"};
2391   static const char *const MIPSN32ELLibDirs[] = {"/lib32"};
2392   static const char *const MIPSN32ELTriples[] = {
2393       "mips64el-linux-gnuabin32", "mipsisa64r6el-linux-gnuabin32"};
2394 
2395   static const char *const MSP430LibDirs[] = {"/lib"};
2396   static const char *const MSP430Triples[] = {"msp430-elf"};
2397 
2398   static const char *const PPCLibDirs[] = {"/lib32", "/lib"};
2399   static const char *const PPCTriples[] = {
2400       "powerpc-linux-gnu", "powerpc-unknown-linux-gnu", "powerpc-linux-gnuspe",
2401       // On 32-bit PowerPC systems running SUSE Linux, gcc is configured as a
2402       // 64-bit compiler which defaults to "-m32", hence "powerpc64-suse-linux".
2403       "powerpc64-suse-linux", "powerpc-montavista-linuxspe"};
2404   static const char *const PPCLELibDirs[] = {"/lib32", "/lib"};
2405   static const char *const PPCLETriples[] = {"powerpcle-linux-gnu",
2406                                              "powerpcle-unknown-linux-gnu",
2407                                              "powerpcle-linux-musl"};
2408 
2409   static const char *const PPC64LibDirs[] = {"/lib64", "/lib"};
2410   static const char *const PPC64Triples[] = {
2411       "powerpc64-linux-gnu", "powerpc64-unknown-linux-gnu",
2412       "powerpc64-suse-linux", "ppc64-redhat-linux"};
2413   static const char *const PPC64LELibDirs[] = {"/lib64", "/lib"};
2414   static const char *const PPC64LETriples[] = {
2415       "powerpc64le-linux-gnu", "powerpc64le-unknown-linux-gnu",
2416       "powerpc64le-none-linux-gnu", "powerpc64le-suse-linux",
2417       "ppc64le-redhat-linux"};
2418 
2419   static const char *const RISCV32LibDirs[] = {"/lib32", "/lib"};
2420   static const char *const RISCV32Triples[] = {"riscv32-unknown-linux-gnu",
2421                                                "riscv32-linux-gnu",
2422                                                "riscv32-unknown-elf"};
2423   static const char *const RISCV64LibDirs[] = {"/lib64", "/lib"};
2424   static const char *const RISCV64Triples[] = {"riscv64-unknown-linux-gnu",
2425                                                "riscv64-linux-gnu",
2426                                                "riscv64-unknown-elf"};
2427 
2428   static const char *const SPARCv8LibDirs[] = {"/lib32", "/lib"};
2429   static const char *const SPARCv8Triples[] = {"sparc-linux-gnu",
2430                                                "sparcv8-linux-gnu"};
2431   static const char *const SPARCv9LibDirs[] = {"/lib64", "/lib"};
2432   static const char *const SPARCv9Triples[] = {"sparc64-linux-gnu",
2433                                                "sparcv9-linux-gnu"};
2434 
2435   static const char *const SystemZLibDirs[] = {"/lib64", "/lib"};
2436   static const char *const SystemZTriples[] = {
2437       "s390x-linux-gnu", "s390x-unknown-linux-gnu", "s390x-ibm-linux-gnu",
2438       "s390x-suse-linux", "s390x-redhat-linux"};
2439 
2440 
2441   using std::begin;
2442   using std::end;
2443 
2444   if (TargetTriple.isOSSolaris()) {
2445     static const char *const SolarisLibDirs[] = {"/lib"};
2446     static const char *const SolarisSparcV8Triples[] = {
2447         "sparc-sun-solaris2.11"};
2448     static const char *const SolarisSparcV9Triples[] = {
2449         "sparcv9-sun-solaris2.11"};
2450     static const char *const SolarisX86Triples[] = {"i386-pc-solaris2.11"};
2451     static const char *const SolarisX86_64Triples[] = {"x86_64-pc-solaris2.11"};
2452     LibDirs.append(begin(SolarisLibDirs), end(SolarisLibDirs));
2453     BiarchLibDirs.append(begin(SolarisLibDirs), end(SolarisLibDirs));
2454     switch (TargetTriple.getArch()) {
2455     case llvm::Triple::x86:
2456       TripleAliases.append(begin(SolarisX86Triples), end(SolarisX86Triples));
2457       BiarchTripleAliases.append(begin(SolarisX86_64Triples),
2458                                  end(SolarisX86_64Triples));
2459       break;
2460     case llvm::Triple::x86_64:
2461       TripleAliases.append(begin(SolarisX86_64Triples),
2462                            end(SolarisX86_64Triples));
2463       BiarchTripleAliases.append(begin(SolarisX86Triples),
2464                                  end(SolarisX86Triples));
2465       break;
2466     case llvm::Triple::sparc:
2467       TripleAliases.append(begin(SolarisSparcV8Triples),
2468                            end(SolarisSparcV8Triples));
2469       BiarchTripleAliases.append(begin(SolarisSparcV9Triples),
2470                                  end(SolarisSparcV9Triples));
2471       break;
2472     case llvm::Triple::sparcv9:
2473       TripleAliases.append(begin(SolarisSparcV9Triples),
2474                            end(SolarisSparcV9Triples));
2475       BiarchTripleAliases.append(begin(SolarisSparcV8Triples),
2476                                  end(SolarisSparcV8Triples));
2477       break;
2478     default:
2479       break;
2480     }
2481     return;
2482   }
2483 
2484   // Android targets should not use GNU/Linux tools or libraries.
2485   if (TargetTriple.isAndroid()) {
2486     static const char *const AArch64AndroidTriples[] = {
2487         "aarch64-linux-android"};
2488     static const char *const ARMAndroidTriples[] = {"arm-linux-androideabi"};
2489     static const char *const X86AndroidTriples[] = {"i686-linux-android"};
2490     static const char *const X86_64AndroidTriples[] = {"x86_64-linux-android"};
2491 
2492     switch (TargetTriple.getArch()) {
2493     case llvm::Triple::aarch64:
2494       LibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
2495       TripleAliases.append(begin(AArch64AndroidTriples),
2496                            end(AArch64AndroidTriples));
2497       break;
2498     case llvm::Triple::arm:
2499     case llvm::Triple::thumb:
2500       LibDirs.append(begin(ARMLibDirs), end(ARMLibDirs));
2501       TripleAliases.append(begin(ARMAndroidTriples), end(ARMAndroidTriples));
2502       break;
2503     case llvm::Triple::x86_64:
2504       LibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2505       TripleAliases.append(begin(X86_64AndroidTriples),
2506                            end(X86_64AndroidTriples));
2507       BiarchLibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2508       BiarchTripleAliases.append(begin(X86AndroidTriples),
2509                                  end(X86AndroidTriples));
2510       break;
2511     case llvm::Triple::x86:
2512       LibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2513       TripleAliases.append(begin(X86AndroidTriples), end(X86AndroidTriples));
2514       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2515       BiarchTripleAliases.append(begin(X86_64AndroidTriples),
2516                                  end(X86_64AndroidTriples));
2517       break;
2518     default:
2519       break;
2520     }
2521 
2522     return;
2523   }
2524 
2525   switch (TargetTriple.getArch()) {
2526   case llvm::Triple::aarch64:
2527     LibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
2528     TripleAliases.append(begin(AArch64Triples), end(AArch64Triples));
2529     BiarchLibDirs.append(begin(AArch64LibDirs), end(AArch64LibDirs));
2530     BiarchTripleAliases.append(begin(AArch64Triples), end(AArch64Triples));
2531     break;
2532   case llvm::Triple::aarch64_be:
2533     LibDirs.append(begin(AArch64beLibDirs), end(AArch64beLibDirs));
2534     TripleAliases.append(begin(AArch64beTriples), end(AArch64beTriples));
2535     BiarchLibDirs.append(begin(AArch64beLibDirs), end(AArch64beLibDirs));
2536     BiarchTripleAliases.append(begin(AArch64beTriples), end(AArch64beTriples));
2537     break;
2538   case llvm::Triple::arm:
2539   case llvm::Triple::thumb:
2540     LibDirs.append(begin(ARMLibDirs), end(ARMLibDirs));
2541     if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
2542       TripleAliases.append(begin(ARMHFTriples), end(ARMHFTriples));
2543     } else {
2544       TripleAliases.append(begin(ARMTriples), end(ARMTriples));
2545     }
2546     break;
2547   case llvm::Triple::armeb:
2548   case llvm::Triple::thumbeb:
2549     LibDirs.append(begin(ARMebLibDirs), end(ARMebLibDirs));
2550     if (TargetTriple.getEnvironment() == llvm::Triple::GNUEABIHF) {
2551       TripleAliases.append(begin(ARMebHFTriples), end(ARMebHFTriples));
2552     } else {
2553       TripleAliases.append(begin(ARMebTriples), end(ARMebTriples));
2554     }
2555     break;
2556   case llvm::Triple::avr:
2557     LibDirs.append(begin(AVRLibDirs), end(AVRLibDirs));
2558     TripleAliases.append(begin(AVRTriples), end(AVRTriples));
2559     break;
2560   case llvm::Triple::csky:
2561     LibDirs.append(begin(CSKYLibDirs), end(CSKYLibDirs));
2562     TripleAliases.append(begin(CSKYTriples), end(CSKYTriples));
2563     break;
2564   case llvm::Triple::x86_64:
2565     if (TargetTriple.isX32()) {
2566       LibDirs.append(begin(X32LibDirs), end(X32LibDirs));
2567       TripleAliases.append(begin(X32Triples), end(X32Triples));
2568       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2569       BiarchTripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
2570     } else {
2571       LibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2572       TripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
2573       BiarchLibDirs.append(begin(X32LibDirs), end(X32LibDirs));
2574       BiarchTripleAliases.append(begin(X32Triples), end(X32Triples));
2575     }
2576     BiarchLibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2577     BiarchTripleAliases.append(begin(X86Triples), end(X86Triples));
2578     break;
2579   case llvm::Triple::x86:
2580     LibDirs.append(begin(X86LibDirs), end(X86LibDirs));
2581     // MCU toolchain is 32 bit only and its triple alias is TargetTriple
2582     // itself, which will be appended below.
2583     if (!TargetTriple.isOSIAMCU()) {
2584       TripleAliases.append(begin(X86Triples), end(X86Triples));
2585       BiarchLibDirs.append(begin(X86_64LibDirs), end(X86_64LibDirs));
2586       BiarchTripleAliases.append(begin(X86_64Triples), end(X86_64Triples));
2587       BiarchLibDirs.append(begin(X32LibDirs), end(X32LibDirs));
2588       BiarchTripleAliases.append(begin(X32Triples), end(X32Triples));
2589     }
2590     break;
2591   // TODO: Handle loongarch32.
2592   case llvm::Triple::loongarch64:
2593     LibDirs.append(begin(LoongArch64LibDirs), end(LoongArch64LibDirs));
2594     TripleAliases.append(begin(LoongArch64Triples), end(LoongArch64Triples));
2595     break;
2596   case llvm::Triple::m68k:
2597     LibDirs.append(begin(M68kLibDirs), end(M68kLibDirs));
2598     TripleAliases.append(begin(M68kTriples), end(M68kTriples));
2599     break;
2600   case llvm::Triple::mips:
2601     LibDirs.append(begin(MIPSLibDirs), end(MIPSLibDirs));
2602     TripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2603     BiarchLibDirs.append(begin(MIPS64LibDirs), end(MIPS64LibDirs));
2604     BiarchTripleAliases.append(begin(MIPS64Triples), end(MIPS64Triples));
2605     BiarchLibDirs.append(begin(MIPSN32LibDirs), end(MIPSN32LibDirs));
2606     BiarchTripleAliases.append(begin(MIPSN32Triples), end(MIPSN32Triples));
2607     break;
2608   case llvm::Triple::mipsel:
2609     LibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
2610     TripleAliases.append(begin(MIPSELTriples), end(MIPSELTriples));
2611     TripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2612     BiarchLibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
2613     BiarchTripleAliases.append(begin(MIPS64ELTriples), end(MIPS64ELTriples));
2614     BiarchLibDirs.append(begin(MIPSN32ELLibDirs), end(MIPSN32ELLibDirs));
2615     BiarchTripleAliases.append(begin(MIPSN32ELTriples), end(MIPSN32ELTriples));
2616     break;
2617   case llvm::Triple::mips64:
2618     LibDirs.append(begin(MIPS64LibDirs), end(MIPS64LibDirs));
2619     TripleAliases.append(begin(MIPS64Triples), end(MIPS64Triples));
2620     BiarchLibDirs.append(begin(MIPSLibDirs), end(MIPSLibDirs));
2621     BiarchTripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2622     BiarchLibDirs.append(begin(MIPSN32LibDirs), end(MIPSN32LibDirs));
2623     BiarchTripleAliases.append(begin(MIPSN32Triples), end(MIPSN32Triples));
2624     break;
2625   case llvm::Triple::mips64el:
2626     LibDirs.append(begin(MIPS64ELLibDirs), end(MIPS64ELLibDirs));
2627     TripleAliases.append(begin(MIPS64ELTriples), end(MIPS64ELTriples));
2628     BiarchLibDirs.append(begin(MIPSELLibDirs), end(MIPSELLibDirs));
2629     BiarchTripleAliases.append(begin(MIPSELTriples), end(MIPSELTriples));
2630     BiarchLibDirs.append(begin(MIPSN32ELLibDirs), end(MIPSN32ELLibDirs));
2631     BiarchTripleAliases.append(begin(MIPSN32ELTriples), end(MIPSN32ELTriples));
2632     BiarchTripleAliases.append(begin(MIPSTriples), end(MIPSTriples));
2633     break;
2634   case llvm::Triple::msp430:
2635     LibDirs.append(begin(MSP430LibDirs), end(MSP430LibDirs));
2636     TripleAliases.append(begin(MSP430Triples), end(MSP430Triples));
2637     break;
2638   case llvm::Triple::ppc:
2639     LibDirs.append(begin(PPCLibDirs), end(PPCLibDirs));
2640     TripleAliases.append(begin(PPCTriples), end(PPCTriples));
2641     BiarchLibDirs.append(begin(PPC64LibDirs), end(PPC64LibDirs));
2642     BiarchTripleAliases.append(begin(PPC64Triples), end(PPC64Triples));
2643     break;
2644   case llvm::Triple::ppcle:
2645     LibDirs.append(begin(PPCLELibDirs), end(PPCLELibDirs));
2646     TripleAliases.append(begin(PPCLETriples), end(PPCLETriples));
2647     BiarchLibDirs.append(begin(PPC64LELibDirs), end(PPC64LELibDirs));
2648     BiarchTripleAliases.append(begin(PPC64LETriples), end(PPC64LETriples));
2649     break;
2650   case llvm::Triple::ppc64:
2651     LibDirs.append(begin(PPC64LibDirs), end(PPC64LibDirs));
2652     TripleAliases.append(begin(PPC64Triples), end(PPC64Triples));
2653     BiarchLibDirs.append(begin(PPCLibDirs), end(PPCLibDirs));
2654     BiarchTripleAliases.append(begin(PPCTriples), end(PPCTriples));
2655     break;
2656   case llvm::Triple::ppc64le:
2657     LibDirs.append(begin(PPC64LELibDirs), end(PPC64LELibDirs));
2658     TripleAliases.append(begin(PPC64LETriples), end(PPC64LETriples));
2659     BiarchLibDirs.append(begin(PPCLELibDirs), end(PPCLELibDirs));
2660     BiarchTripleAliases.append(begin(PPCLETriples), end(PPCLETriples));
2661     break;
2662   case llvm::Triple::riscv32:
2663     LibDirs.append(begin(RISCV32LibDirs), end(RISCV32LibDirs));
2664     TripleAliases.append(begin(RISCV32Triples), end(RISCV32Triples));
2665     BiarchLibDirs.append(begin(RISCV64LibDirs), end(RISCV64LibDirs));
2666     BiarchTripleAliases.append(begin(RISCV64Triples), end(RISCV64Triples));
2667     break;
2668   case llvm::Triple::riscv64:
2669     LibDirs.append(begin(RISCV64LibDirs), end(RISCV64LibDirs));
2670     TripleAliases.append(begin(RISCV64Triples), end(RISCV64Triples));
2671     BiarchLibDirs.append(begin(RISCV32LibDirs), end(RISCV32LibDirs));
2672     BiarchTripleAliases.append(begin(RISCV32Triples), end(RISCV32Triples));
2673     break;
2674   case llvm::Triple::sparc:
2675   case llvm::Triple::sparcel:
2676     LibDirs.append(begin(SPARCv8LibDirs), end(SPARCv8LibDirs));
2677     TripleAliases.append(begin(SPARCv8Triples), end(SPARCv8Triples));
2678     BiarchLibDirs.append(begin(SPARCv9LibDirs), end(SPARCv9LibDirs));
2679     BiarchTripleAliases.append(begin(SPARCv9Triples), end(SPARCv9Triples));
2680     break;
2681   case llvm::Triple::sparcv9:
2682     LibDirs.append(begin(SPARCv9LibDirs), end(SPARCv9LibDirs));
2683     TripleAliases.append(begin(SPARCv9Triples), end(SPARCv9Triples));
2684     BiarchLibDirs.append(begin(SPARCv8LibDirs), end(SPARCv8LibDirs));
2685     BiarchTripleAliases.append(begin(SPARCv8Triples), end(SPARCv8Triples));
2686     break;
2687   case llvm::Triple::systemz:
2688     LibDirs.append(begin(SystemZLibDirs), end(SystemZLibDirs));
2689     TripleAliases.append(begin(SystemZTriples), end(SystemZTriples));
2690     break;
2691   default:
2692     // By default, just rely on the standard lib directories and the original
2693     // triple.
2694     break;
2695   }
2696 
2697   // Also include the multiarch variant if it's different.
2698   if (TargetTriple.str() != BiarchTriple.str())
2699     BiarchTripleAliases.push_back(BiarchTriple.str());
2700 }
2701 
2702 bool Generic_GCC::GCCInstallationDetector::ScanGCCForMultilibs(
2703     const llvm::Triple &TargetTriple, const ArgList &Args,
2704     StringRef Path, bool NeedsBiarchSuffix) {
2705   llvm::Triple::ArchType TargetArch = TargetTriple.getArch();
2706   DetectedMultilibs Detected;
2707 
2708   // Android standalone toolchain could have multilibs for ARM and Thumb.
2709   // Debian mips multilibs behave more like the rest of the biarch ones,
2710   // so handle them there
2711   if (isArmOrThumbArch(TargetArch) && TargetTriple.isAndroid()) {
2712     // It should also work without multilibs in a simplified toolchain.
2713     findAndroidArmMultilibs(D, TargetTriple, Path, Args, Detected);
2714   } else if (TargetTriple.isCSKY()) {
2715     findCSKYMultilibs(D, TargetTriple, Path, Args, Detected);
2716   } else if (TargetTriple.isMIPS()) {
2717     if (!findMIPSMultilibs(D, TargetTriple, Path, Args, Detected))
2718       return false;
2719   } else if (TargetTriple.isRISCV()) {
2720     findRISCVMultilibs(D, TargetTriple, Path, Args, Detected);
2721   } else if (isMSP430(TargetArch)) {
2722     findMSP430Multilibs(D, TargetTriple, Path, Args, Detected);
2723   } else if (TargetArch == llvm::Triple::avr) {
2724     // AVR has no multilibs.
2725   } else if (!findBiarchMultilibs(D, TargetTriple, Path, Args,
2726                                   NeedsBiarchSuffix, Detected)) {
2727     return false;
2728   }
2729 
2730   Multilibs = Detected.Multilibs;
2731   SelectedMultilib = Detected.SelectedMultilibs.empty()
2732                          ? Multilib()
2733                          : Detected.SelectedMultilibs.back();
2734   BiarchSibling = Detected.BiarchSibling;
2735 
2736   return true;
2737 }
2738 
2739 void Generic_GCC::GCCInstallationDetector::ScanLibDirForGCCTriple(
2740     const llvm::Triple &TargetTriple, const ArgList &Args,
2741     const std::string &LibDir, StringRef CandidateTriple,
2742     bool NeedsBiarchSuffix, bool GCCDirExists, bool GCCCrossDirExists) {
2743   // Locations relative to the system lib directory where GCC's triple-specific
2744   // directories might reside.
2745   struct GCCLibSuffix {
2746     // Path from system lib directory to GCC triple-specific directory.
2747     std::string LibSuffix;
2748     // Path from GCC triple-specific directory back to system lib directory.
2749     // This is one '..' component per component in LibSuffix.
2750     StringRef ReversePath;
2751     // Whether this library suffix is relevant for the triple.
2752     bool Active;
2753   } Suffixes[] = {
2754       // This is the normal place.
2755       {"gcc/" + CandidateTriple.str(), "../..", GCCDirExists},
2756 
2757       // Debian puts cross-compilers in gcc-cross.
2758       {"gcc-cross/" + CandidateTriple.str(), "../..", GCCCrossDirExists},
2759 
2760       // The Freescale PPC SDK has the gcc libraries in
2761       // <sysroot>/usr/lib/<triple>/x.y.z so have a look there as well. Only do
2762       // this on Freescale triples, though, since some systems put a *lot* of
2763       // files in that location, not just GCC installation data.
2764       {CandidateTriple.str(), "..",
2765        TargetTriple.getVendor() == llvm::Triple::Freescale ||
2766            TargetTriple.getVendor() == llvm::Triple::OpenEmbedded}};
2767 
2768   for (auto &Suffix : Suffixes) {
2769     if (!Suffix.Active)
2770       continue;
2771 
2772     StringRef LibSuffix = Suffix.LibSuffix;
2773     std::error_code EC;
2774     for (llvm::vfs::directory_iterator
2775              LI = D.getVFS().dir_begin(LibDir + "/" + LibSuffix, EC),
2776              LE;
2777          !EC && LI != LE; LI = LI.increment(EC)) {
2778       StringRef VersionText = llvm::sys::path::filename(LI->path());
2779       GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
2780       if (CandidateVersion.Major != -1) // Filter obviously bad entries.
2781         if (!CandidateGCCInstallPaths.insert(std::string(LI->path())).second)
2782           continue; // Saw this path before; no need to look at it again.
2783       if (CandidateVersion.isOlderThan(4, 1, 1))
2784         continue;
2785       if (CandidateVersion <= Version)
2786         continue;
2787 
2788       if (!ScanGCCForMultilibs(TargetTriple, Args, LI->path(),
2789                                NeedsBiarchSuffix))
2790         continue;
2791 
2792       Version = CandidateVersion;
2793       GCCTriple.setTriple(CandidateTriple);
2794       // FIXME: We hack together the directory name here instead of
2795       // using LI to ensure stable path separators across Windows and
2796       // Linux.
2797       GCCInstallPath = (LibDir + "/" + LibSuffix + "/" + VersionText).str();
2798       GCCParentLibPath = (GCCInstallPath + "/../" + Suffix.ReversePath).str();
2799       IsValid = true;
2800     }
2801   }
2802 }
2803 
2804 bool Generic_GCC::GCCInstallationDetector::ScanGentooConfigs(
2805     const llvm::Triple &TargetTriple, const ArgList &Args,
2806     const SmallVectorImpl<StringRef> &CandidateTriples,
2807     const SmallVectorImpl<StringRef> &CandidateBiarchTriples) {
2808   if (!D.getVFS().exists(concat(D.SysRoot, GentooConfigDir)))
2809     return false;
2810 
2811   for (StringRef CandidateTriple : CandidateTriples) {
2812     if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple))
2813       return true;
2814   }
2815 
2816   for (StringRef CandidateTriple : CandidateBiarchTriples) {
2817     if (ScanGentooGccConfig(TargetTriple, Args, CandidateTriple, true))
2818       return true;
2819   }
2820   return false;
2821 }
2822 
2823 bool Generic_GCC::GCCInstallationDetector::ScanGentooGccConfig(
2824     const llvm::Triple &TargetTriple, const ArgList &Args,
2825     StringRef CandidateTriple, bool NeedsBiarchSuffix) {
2826   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> File =
2827       D.getVFS().getBufferForFile(concat(D.SysRoot, GentooConfigDir,
2828                                          "/config-" + CandidateTriple.str()));
2829   if (File) {
2830     SmallVector<StringRef, 2> Lines;
2831     File.get()->getBuffer().split(Lines, "\n");
2832     for (StringRef Line : Lines) {
2833       Line = Line.trim();
2834       // CURRENT=triple-version
2835       if (!Line.consume_front("CURRENT="))
2836         continue;
2837       // Process the config file pointed to by CURRENT.
2838       llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> ConfigFile =
2839           D.getVFS().getBufferForFile(
2840               concat(D.SysRoot, GentooConfigDir, "/" + Line));
2841       std::pair<StringRef, StringRef> ActiveVersion = Line.rsplit('-');
2842       // List of paths to scan for libraries.
2843       SmallVector<StringRef, 4> GentooScanPaths;
2844       // Scan the Config file to find installed GCC libraries path.
2845       // Typical content of the GCC config file:
2846       // LDPATH="/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.x:/usr/lib/gcc/
2847       // (continued from previous line) x86_64-pc-linux-gnu/4.9.x/32"
2848       // MANPATH="/usr/share/gcc-data/x86_64-pc-linux-gnu/4.9.x/man"
2849       // INFOPATH="/usr/share/gcc-data/x86_64-pc-linux-gnu/4.9.x/info"
2850       // STDCXX_INCDIR="/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.x/include/g++-v4"
2851       // We are looking for the paths listed in LDPATH=... .
2852       if (ConfigFile) {
2853         SmallVector<StringRef, 2> ConfigLines;
2854         ConfigFile.get()->getBuffer().split(ConfigLines, "\n");
2855         for (StringRef ConfLine : ConfigLines) {
2856           ConfLine = ConfLine.trim();
2857           if (ConfLine.consume_front("LDPATH=")) {
2858             // Drop '"' from front and back if present.
2859             ConfLine.consume_back("\"");
2860             ConfLine.consume_front("\"");
2861             // Get all paths sperated by ':'
2862             ConfLine.split(GentooScanPaths, ':', -1, /*AllowEmpty*/ false);
2863           }
2864         }
2865       }
2866       // Test the path based on the version in /etc/env.d/gcc/config-{tuple}.
2867       std::string basePath = "/usr/lib/gcc/" + ActiveVersion.first.str() + "/"
2868           + ActiveVersion.second.str();
2869       GentooScanPaths.push_back(StringRef(basePath));
2870 
2871       // Scan all paths for GCC libraries.
2872       for (const auto &GentooScanPath : GentooScanPaths) {
2873         std::string GentooPath = concat(D.SysRoot, GentooScanPath);
2874         if (D.getVFS().exists(GentooPath + "/crtbegin.o")) {
2875           if (!ScanGCCForMultilibs(TargetTriple, Args, GentooPath,
2876                                    NeedsBiarchSuffix))
2877             continue;
2878 
2879           Version = GCCVersion::Parse(ActiveVersion.second);
2880           GCCInstallPath = GentooPath;
2881           GCCParentLibPath = GentooPath + std::string("/../../..");
2882           GCCTriple.setTriple(ActiveVersion.first);
2883           IsValid = true;
2884           return true;
2885         }
2886       }
2887     }
2888   }
2889 
2890   return false;
2891 }
2892 
2893 Generic_GCC::Generic_GCC(const Driver &D, const llvm::Triple &Triple,
2894                          const ArgList &Args)
2895     : ToolChain(D, Triple, Args), GCCInstallation(D),
2896       CudaInstallation(D, Triple, Args), RocmInstallation(D, Triple, Args) {
2897   getProgramPaths().push_back(getDriver().getInstalledDir());
2898   if (getDriver().getInstalledDir() != getDriver().Dir)
2899     getProgramPaths().push_back(getDriver().Dir);
2900 }
2901 
2902 Generic_GCC::~Generic_GCC() {}
2903 
2904 Tool *Generic_GCC::getTool(Action::ActionClass AC) const {
2905   switch (AC) {
2906   case Action::PreprocessJobClass:
2907     if (!Preprocess)
2908       Preprocess.reset(new clang::driver::tools::gcc::Preprocessor(*this));
2909     return Preprocess.get();
2910   case Action::CompileJobClass:
2911     if (!Compile)
2912       Compile.reset(new tools::gcc::Compiler(*this));
2913     return Compile.get();
2914   default:
2915     return ToolChain::getTool(AC);
2916   }
2917 }
2918 
2919 Tool *Generic_GCC::buildAssembler() const {
2920   return new tools::gnutools::Assembler(*this);
2921 }
2922 
2923 Tool *Generic_GCC::buildLinker() const { return new tools::gcc::Linker(*this); }
2924 
2925 void Generic_GCC::printVerboseInfo(raw_ostream &OS) const {
2926   // Print the information about how we detected the GCC installation.
2927   GCCInstallation.print(OS);
2928   CudaInstallation->print(OS);
2929   RocmInstallation->print(OS);
2930 }
2931 
2932 ToolChain::UnwindTableLevel
2933 Generic_GCC::getDefaultUnwindTableLevel(const ArgList &Args) const {
2934   switch (getArch()) {
2935   case llvm::Triple::aarch64:
2936   case llvm::Triple::aarch64_be:
2937   case llvm::Triple::ppc:
2938   case llvm::Triple::ppcle:
2939   case llvm::Triple::ppc64:
2940   case llvm::Triple::ppc64le:
2941   case llvm::Triple::riscv32:
2942   case llvm::Triple::riscv64:
2943   case llvm::Triple::x86:
2944   case llvm::Triple::x86_64:
2945     return UnwindTableLevel::Asynchronous;
2946   default:
2947     return UnwindTableLevel::None;
2948   }
2949 }
2950 
2951 bool Generic_GCC::isPICDefault() const {
2952   switch (getArch()) {
2953   case llvm::Triple::x86_64:
2954     return getTriple().isOSWindows();
2955   case llvm::Triple::mips64:
2956   case llvm::Triple::mips64el:
2957     return true;
2958   default:
2959     return false;
2960   }
2961 }
2962 
2963 bool Generic_GCC::isPIEDefault(const llvm::opt::ArgList &Args) const {
2964   return false;
2965 }
2966 
2967 bool Generic_GCC::isPICDefaultForced() const {
2968   return getArch() == llvm::Triple::x86_64 && getTriple().isOSWindows();
2969 }
2970 
2971 bool Generic_GCC::IsIntegratedAssemblerDefault() const {
2972   switch (getTriple().getArch()) {
2973   case llvm::Triple::nvptx:
2974   case llvm::Triple::nvptx64:
2975   case llvm::Triple::xcore:
2976     return false;
2977   default:
2978     return true;
2979   }
2980 }
2981 
2982 void Generic_GCC::PushPPaths(ToolChain::path_list &PPaths) {
2983   // Cross-compiling binutils and GCC installations (vanilla and openSUSE at
2984   // least) put various tools in a triple-prefixed directory off of the parent
2985   // of the GCC installation. We use the GCC triple here to ensure that we end
2986   // up with tools that support the same amount of cross compiling as the
2987   // detected GCC installation. For example, if we find a GCC installation
2988   // targeting x86_64, but it is a bi-arch GCC installation, it can also be
2989   // used to target i386.
2990   if (GCCInstallation.isValid()) {
2991     PPaths.push_back(Twine(GCCInstallation.getParentLibPath() + "/../" +
2992                            GCCInstallation.getTriple().str() + "/bin")
2993                          .str());
2994   }
2995 }
2996 
2997 void Generic_GCC::AddMultilibPaths(const Driver &D,
2998                                    const std::string &SysRoot,
2999                                    const std::string &OSLibDir,
3000                                    const std::string &MultiarchTriple,
3001                                    path_list &Paths) {
3002   // Add the multilib suffixed paths where they are available.
3003   if (GCCInstallation.isValid()) {
3004     assert(!SelectedMultilibs.empty());
3005     const llvm::Triple &GCCTriple = GCCInstallation.getTriple();
3006     const std::string &LibPath =
3007         std::string(GCCInstallation.getParentLibPath());
3008 
3009     // Sourcery CodeBench MIPS toolchain holds some libraries under
3010     // a biarch-like suffix of the GCC installation.
3011     if (const auto &PathsCallback = Multilibs.filePathsCallback())
3012       for (const auto &Path : PathsCallback(SelectedMultilibs.back()))
3013         addPathIfExists(D, GCCInstallation.getInstallPath() + Path, Paths);
3014 
3015     // Add lib/gcc/$triple/$version, with an optional /multilib suffix.
3016     addPathIfExists(D,
3017                     GCCInstallation.getInstallPath() +
3018                         SelectedMultilibs.back().gccSuffix(),
3019                     Paths);
3020 
3021     // Add lib/gcc/$triple/$libdir
3022     // For GCC built with --enable-version-specific-runtime-libs.
3023     addPathIfExists(D, GCCInstallation.getInstallPath() + "/../" + OSLibDir,
3024                     Paths);
3025 
3026     // GCC cross compiling toolchains will install target libraries which ship
3027     // as part of the toolchain under <prefix>/<triple>/<libdir> rather than as
3028     // any part of the GCC installation in
3029     // <prefix>/<libdir>/gcc/<triple>/<version>. This decision is somewhat
3030     // debatable, but is the reality today. We need to search this tree even
3031     // when we have a sysroot somewhere else. It is the responsibility of
3032     // whomever is doing the cross build targeting a sysroot using a GCC
3033     // installation that is *not* within the system root to ensure two things:
3034     //
3035     //  1) Any DSOs that are linked in from this tree or from the install path
3036     //     above must be present on the system root and found via an
3037     //     appropriate rpath.
3038     //  2) There must not be libraries installed into
3039     //     <prefix>/<triple>/<libdir> unless they should be preferred over
3040     //     those within the system root.
3041     //
3042     // Note that this matches the GCC behavior. See the below comment for where
3043     // Clang diverges from GCC's behavior.
3044     addPathIfExists(D,
3045                     LibPath + "/../" + GCCTriple.str() + "/lib/../" + OSLibDir +
3046                         SelectedMultilibs.back().osSuffix(),
3047                     Paths);
3048 
3049     // If the GCC installation we found is inside of the sysroot, we want to
3050     // prefer libraries installed in the parent prefix of the GCC installation.
3051     // It is important to *not* use these paths when the GCC installation is
3052     // outside of the system root as that can pick up unintended libraries.
3053     // This usually happens when there is an external cross compiler on the
3054     // host system, and a more minimal sysroot available that is the target of
3055     // the cross. Note that GCC does include some of these directories in some
3056     // configurations but this seems somewhere between questionable and simply
3057     // a bug.
3058     if (StringRef(LibPath).starts_with(SysRoot))
3059       addPathIfExists(D, LibPath + "/../" + OSLibDir, Paths);
3060   }
3061 }
3062 
3063 void Generic_GCC::AddMultiarchPaths(const Driver &D,
3064                                     const std::string &SysRoot,
3065                                     const std::string &OSLibDir,
3066                                     path_list &Paths) {
3067   if (GCCInstallation.isValid()) {
3068     const std::string &LibPath =
3069         std::string(GCCInstallation.getParentLibPath());
3070     const llvm::Triple &GCCTriple = GCCInstallation.getTriple();
3071     const Multilib &Multilib = GCCInstallation.getMultilib();
3072     addPathIfExists(
3073         D, LibPath + "/../" + GCCTriple.str() + "/lib" + Multilib.osSuffix(),
3074                     Paths);
3075   }
3076 }
3077 
3078 void Generic_GCC::AddMultilibIncludeArgs(const ArgList &DriverArgs,
3079                                          ArgStringList &CC1Args) const {
3080   // Add include directories specific to the selected multilib set and multilib.
3081   if (!GCCInstallation.isValid())
3082     return;
3083   // gcc TOOL_INCLUDE_DIR.
3084   const llvm::Triple &GCCTriple = GCCInstallation.getTriple();
3085   std::string LibPath(GCCInstallation.getParentLibPath());
3086   addSystemInclude(DriverArgs, CC1Args,
3087                    Twine(LibPath) + "/../" + GCCTriple.str() + "/include");
3088 
3089   const auto &Callback = Multilibs.includeDirsCallback();
3090   if (Callback) {
3091     for (const auto &Path : Callback(GCCInstallation.getMultilib()))
3092       addExternCSystemIncludeIfExists(DriverArgs, CC1Args,
3093                                       GCCInstallation.getInstallPath() + Path);
3094   }
3095 }
3096 
3097 void Generic_GCC::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
3098                                                ArgStringList &CC1Args) const {
3099   if (DriverArgs.hasArg(options::OPT_nostdinc, options::OPT_nostdincxx,
3100                         options::OPT_nostdlibinc))
3101     return;
3102 
3103   switch (GetCXXStdlibType(DriverArgs)) {
3104   case ToolChain::CST_Libcxx:
3105     addLibCxxIncludePaths(DriverArgs, CC1Args);
3106     break;
3107 
3108   case ToolChain::CST_Libstdcxx:
3109     addLibStdCxxIncludePaths(DriverArgs, CC1Args);
3110     break;
3111   }
3112 }
3113 
3114 void
3115 Generic_GCC::addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
3116                                    llvm::opt::ArgStringList &CC1Args) const {
3117   const Driver &D = getDriver();
3118   std::string SysRoot = computeSysRoot();
3119   if (SysRoot.empty())
3120     SysRoot = llvm::sys::path::get_separator();
3121 
3122   auto AddIncludePath = [&](StringRef Path, bool TargetDirRequired = false) {
3123     std::string Version = detectLibcxxVersion(Path);
3124     if (Version.empty())
3125       return false;
3126 
3127     // First add the per-target include path if it exists.
3128     bool TargetDirExists = false;
3129     std::optional<std::string> TargetIncludeDir = getTargetSubDirPath(Path);
3130     if (TargetIncludeDir) {
3131       SmallString<128> TargetDir(*TargetIncludeDir);
3132       llvm::sys::path::append(TargetDir, "c++", Version);
3133       if (D.getVFS().exists(TargetDir)) {
3134         addSystemInclude(DriverArgs, CC1Args, TargetDir);
3135         TargetDirExists = true;
3136       }
3137     }
3138     if (TargetDirRequired && !TargetDirExists)
3139       return false;
3140 
3141     // Second add the generic one.
3142     SmallString<128> GenericDir(Path);
3143     llvm::sys::path::append(GenericDir, "c++", Version);
3144     addSystemInclude(DriverArgs, CC1Args, GenericDir);
3145     return true;
3146   };
3147 
3148   // Android only uses the libc++ headers installed alongside the toolchain if
3149   // they contain an Android-specific target include path, otherwise they're
3150   // incompatible with the NDK libraries.
3151   SmallString<128> DriverIncludeDir(getDriver().Dir);
3152   llvm::sys::path::append(DriverIncludeDir, "..", "include");
3153   if (AddIncludePath(DriverIncludeDir,
3154                      /*TargetDirRequired=*/getTriple().isAndroid()))
3155     return;
3156   // If this is a development, non-installed, clang, libcxx will
3157   // not be found at ../include/c++ but it likely to be found at
3158   // one of the following two locations:
3159   SmallString<128> UsrLocalIncludeDir(SysRoot);
3160   llvm::sys::path::append(UsrLocalIncludeDir, "usr", "local", "include");
3161   if (AddIncludePath(UsrLocalIncludeDir))
3162     return;
3163   SmallString<128> UsrIncludeDir(SysRoot);
3164   llvm::sys::path::append(UsrIncludeDir, "usr", "include");
3165   if (AddIncludePath(UsrIncludeDir))
3166     return;
3167 }
3168 
3169 bool Generic_GCC::addLibStdCXXIncludePaths(Twine IncludeDir, StringRef Triple,
3170                                            Twine IncludeSuffix,
3171                                            const llvm::opt::ArgList &DriverArgs,
3172                                            llvm::opt::ArgStringList &CC1Args,
3173                                            bool DetectDebian) const {
3174   if (!getVFS().exists(IncludeDir))
3175     return false;
3176 
3177   // Debian native gcc uses g++-multiarch-incdir.diff which uses
3178   // include/x86_64-linux-gnu/c++/10$IncludeSuffix instead of
3179   // include/c++/10/x86_64-linux-gnu$IncludeSuffix.
3180   std::string Dir = IncludeDir.str();
3181   StringRef Include =
3182       llvm::sys::path::parent_path(llvm::sys::path::parent_path(Dir));
3183   std::string Path =
3184       (Include + "/" + Triple + Dir.substr(Include.size()) + IncludeSuffix)
3185           .str();
3186   if (DetectDebian && !getVFS().exists(Path))
3187     return false;
3188 
3189   // GPLUSPLUS_INCLUDE_DIR
3190   addSystemInclude(DriverArgs, CC1Args, IncludeDir);
3191   // GPLUSPLUS_TOOL_INCLUDE_DIR. If Triple is not empty, add a target-dependent
3192   // include directory.
3193   if (DetectDebian)
3194     addSystemInclude(DriverArgs, CC1Args, Path);
3195   else if (!Triple.empty())
3196     addSystemInclude(DriverArgs, CC1Args,
3197                      IncludeDir + "/" + Triple + IncludeSuffix);
3198   // GPLUSPLUS_BACKWARD_INCLUDE_DIR
3199   addSystemInclude(DriverArgs, CC1Args, IncludeDir + "/backward");
3200   return true;
3201 }
3202 
3203 bool Generic_GCC::addGCCLibStdCxxIncludePaths(
3204     const llvm::opt::ArgList &DriverArgs, llvm::opt::ArgStringList &CC1Args,
3205     StringRef DebianMultiarch) const {
3206   assert(GCCInstallation.isValid());
3207 
3208   // By default, look for the C++ headers in an include directory adjacent to
3209   // the lib directory of the GCC installation. Note that this is expect to be
3210   // equivalent to '/usr/include/c++/X.Y' in almost all cases.
3211   StringRef LibDir = GCCInstallation.getParentLibPath();
3212   StringRef InstallDir = GCCInstallation.getInstallPath();
3213   StringRef TripleStr = GCCInstallation.getTriple().str();
3214   const Multilib &Multilib = GCCInstallation.getMultilib();
3215   const GCCVersion &Version = GCCInstallation.getVersion();
3216 
3217   // Try /../$triple/include/c++/$version (gcc --print-multiarch is not empty).
3218   if (addLibStdCXXIncludePaths(
3219           LibDir.str() + "/../" + TripleStr + "/include/c++/" + Version.Text,
3220           TripleStr, Multilib.includeSuffix(), DriverArgs, CC1Args))
3221     return true;
3222 
3223   // Try /gcc/$triple/$version/include/c++/ (gcc --print-multiarch is not
3224   // empty). Like above but for GCC built with
3225   // --enable-version-specific-runtime-libs.
3226   if (addLibStdCXXIncludePaths(LibDir.str() + "/gcc/" + TripleStr + "/" +
3227                                    Version.Text + "/include/c++/",
3228                                TripleStr, Multilib.includeSuffix(), DriverArgs,
3229                                CC1Args))
3230     return true;
3231 
3232   // Detect Debian g++-multiarch-incdir.diff.
3233   if (addLibStdCXXIncludePaths(LibDir.str() + "/../include/c++/" + Version.Text,
3234                                DebianMultiarch, Multilib.includeSuffix(),
3235                                DriverArgs, CC1Args, /*Debian=*/true))
3236     return true;
3237 
3238   // Try /../include/c++/$version (gcc --print-multiarch is empty).
3239   if (addLibStdCXXIncludePaths(LibDir.str() + "/../include/c++/" + Version.Text,
3240                                TripleStr, Multilib.includeSuffix(), DriverArgs,
3241                                CC1Args))
3242     return true;
3243 
3244   // Otherwise, fall back on a bunch of options which don't use multiarch
3245   // layouts for simplicity.
3246   const std::string LibStdCXXIncludePathCandidates[] = {
3247       // Gentoo is weird and places its headers inside the GCC install,
3248       // so if the first attempt to find the headers fails, try these patterns.
3249       InstallDir.str() + "/include/g++-v" + Version.Text,
3250       InstallDir.str() + "/include/g++-v" + Version.MajorStr + "." +
3251           Version.MinorStr,
3252       InstallDir.str() + "/include/g++-v" + Version.MajorStr,
3253   };
3254 
3255   for (const auto &IncludePath : LibStdCXXIncludePathCandidates) {
3256     if (addLibStdCXXIncludePaths(IncludePath, TripleStr,
3257                                  Multilib.includeSuffix(), DriverArgs, CC1Args))
3258       return true;
3259   }
3260   return false;
3261 }
3262 
3263 void
3264 Generic_GCC::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
3265                                       llvm::opt::ArgStringList &CC1Args) const {
3266   if (GCCInstallation.isValid()) {
3267     addGCCLibStdCxxIncludePaths(DriverArgs, CC1Args,
3268                                 GCCInstallation.getTriple().str());
3269   }
3270 }
3271 
3272 llvm::opt::DerivedArgList *
3273 Generic_GCC::TranslateArgs(const llvm::opt::DerivedArgList &Args, StringRef,
3274                            Action::OffloadKind DeviceOffloadKind) const {
3275 
3276   // If this tool chain is used for an OpenMP offloading device we have to make
3277   // sure we always generate a shared library regardless of the commands the
3278   // user passed to the host. This is required because the runtime library
3279   // is required to load the device image dynamically at run time.
3280   if (DeviceOffloadKind == Action::OFK_OpenMP) {
3281     DerivedArgList *DAL = new DerivedArgList(Args.getBaseArgs());
3282     const OptTable &Opts = getDriver().getOpts();
3283 
3284     // Request the shared library. Given that these options are decided
3285     // implicitly, they do not refer to any base argument.
3286     DAL->AddFlagArg(/*BaseArg=*/nullptr, Opts.getOption(options::OPT_shared));
3287     DAL->AddFlagArg(/*BaseArg=*/nullptr, Opts.getOption(options::OPT_fPIC));
3288 
3289     // Filter all the arguments we don't care passing to the offloading
3290     // toolchain as they can mess up with the creation of a shared library.
3291     for (auto *A : Args) {
3292       switch ((options::ID)A->getOption().getID()) {
3293       default:
3294         DAL->append(A);
3295         break;
3296       case options::OPT_shared:
3297       case options::OPT_dynamic:
3298       case options::OPT_static:
3299       case options::OPT_fPIC:
3300       case options::OPT_fno_PIC:
3301       case options::OPT_fpic:
3302       case options::OPT_fno_pic:
3303       case options::OPT_fPIE:
3304       case options::OPT_fno_PIE:
3305       case options::OPT_fpie:
3306       case options::OPT_fno_pie:
3307         break;
3308       }
3309     }
3310     return DAL;
3311   }
3312   return nullptr;
3313 }
3314 
3315 void Generic_ELF::anchor() {}
3316 
3317 void Generic_ELF::addClangTargetOptions(const ArgList &DriverArgs,
3318                                         ArgStringList &CC1Args,
3319                                         Action::OffloadKind) const {
3320   if (!DriverArgs.hasFlag(options::OPT_fuse_init_array,
3321                           options::OPT_fno_use_init_array, true))
3322     CC1Args.push_back("-fno-use-init-array");
3323 }
3324