xref: /llvm-project/clang/lib/Driver/ToolChains/Linux.cpp (revision 2a51a0d39a659feeeee57b6d1d768bf08d378c5e)
1 //===--- Linux.h - Linux 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 "Linux.h"
10 #include "Arch/ARM.h"
11 #include "Arch/LoongArch.h"
12 #include "Arch/Mips.h"
13 #include "Arch/PPC.h"
14 #include "Arch/RISCV.h"
15 #include "CommonArgs.h"
16 #include "clang/Config/config.h"
17 #include "clang/Driver/Distro.h"
18 #include "clang/Driver/Driver.h"
19 #include "clang/Driver/Options.h"
20 #include "clang/Driver/SanitizerArgs.h"
21 #include "llvm/Option/ArgList.h"
22 #include "llvm/ProfileData/InstrProf.h"
23 #include "llvm/Support/Path.h"
24 #include "llvm/Support/ScopedPrinter.h"
25 #include "llvm/Support/VirtualFileSystem.h"
26 #include <system_error>
27 
28 using namespace clang::driver;
29 using namespace clang::driver::toolchains;
30 using namespace clang;
31 using namespace llvm::opt;
32 
33 using tools::addPathIfExists;
34 
35 /// Get our best guess at the multiarch triple for a target.
36 ///
37 /// Debian-based systems are starting to use a multiarch setup where they use
38 /// a target-triple directory in the library and header search paths.
39 /// Unfortunately, this triple does not align with the vanilla target triple,
40 /// so we provide a rough mapping here.
41 std::string Linux::getMultiarchTriple(const Driver &D,
42                                       const llvm::Triple &TargetTriple,
43                                       StringRef SysRoot) const {
44   llvm::Triple::EnvironmentType TargetEnvironment =
45       TargetTriple.getEnvironment();
46   bool IsAndroid = TargetTriple.isAndroid();
47   bool IsMipsR6 = TargetTriple.getSubArch() == llvm::Triple::MipsSubArch_r6;
48   bool IsMipsN32Abi = TargetTriple.getEnvironment() == llvm::Triple::GNUABIN32;
49 
50   // For most architectures, just use whatever we have rather than trying to be
51   // clever.
52   switch (TargetTriple.getArch()) {
53   default:
54     break;
55 
56   // We use the existence of '/lib/<triple>' as a directory to detect some
57   // common linux triples that don't quite match the Clang triple for both
58   // 32-bit and 64-bit targets. Multiarch fixes its install triples to these
59   // regardless of what the actual target triple is.
60   case llvm::Triple::arm:
61   case llvm::Triple::thumb:
62     if (IsAndroid)
63       return "arm-linux-androideabi";
64     if (TargetEnvironment == llvm::Triple::GNUEABIHF ||
65         TargetEnvironment == llvm::Triple::MuslEABIHF ||
66         TargetEnvironment == llvm::Triple::EABIHF)
67       return "arm-linux-gnueabihf";
68     return "arm-linux-gnueabi";
69   case llvm::Triple::armeb:
70   case llvm::Triple::thumbeb:
71     if (TargetEnvironment == llvm::Triple::GNUEABIHF ||
72         TargetEnvironment == llvm::Triple::MuslEABIHF ||
73         TargetEnvironment == llvm::Triple::EABIHF)
74       return "armeb-linux-gnueabihf";
75     return "armeb-linux-gnueabi";
76   case llvm::Triple::x86:
77     if (IsAndroid)
78       return "i686-linux-android";
79     return "i386-linux-gnu";
80   case llvm::Triple::x86_64:
81     if (IsAndroid)
82       return "x86_64-linux-android";
83     if (TargetEnvironment == llvm::Triple::GNUX32)
84       return "x86_64-linux-gnux32";
85     return "x86_64-linux-gnu";
86   case llvm::Triple::aarch64:
87     if (IsAndroid)
88       return "aarch64-linux-android";
89     if (hasEffectiveTriple() &&
90         getEffectiveTriple().getEnvironment() == llvm::Triple::PAuthTest)
91       return "aarch64-linux-pauthtest";
92     return "aarch64-linux-gnu";
93   case llvm::Triple::aarch64_be:
94     return "aarch64_be-linux-gnu";
95 
96   case llvm::Triple::loongarch64: {
97     const char *Libc;
98     const char *FPFlavor;
99 
100     if (TargetTriple.isGNUEnvironment()) {
101       Libc = "gnu";
102     } else if (TargetTriple.isMusl()) {
103       Libc = "musl";
104     } else {
105       return TargetTriple.str();
106     }
107 
108     switch (TargetEnvironment) {
109     default:
110       return TargetTriple.str();
111     case llvm::Triple::GNUSF:
112     case llvm::Triple::MuslSF:
113       FPFlavor = "sf";
114       break;
115     case llvm::Triple::GNUF32:
116     case llvm::Triple::MuslF32:
117       FPFlavor = "f32";
118       break;
119     case llvm::Triple::GNU:
120     case llvm::Triple::GNUF64:
121     case llvm::Triple::Musl:
122       // This was going to be "f64" in an earlier Toolchain Conventions
123       // revision, but starting from Feb 2023 the F64 ABI variants are
124       // unmarked in their canonical forms.
125       FPFlavor = "";
126       break;
127     }
128 
129     return (Twine("loongarch64-linux-") + Libc + FPFlavor).str();
130   }
131 
132   case llvm::Triple::m68k:
133     return "m68k-linux-gnu";
134 
135   case llvm::Triple::mips:
136     return IsMipsR6 ? "mipsisa32r6-linux-gnu" : "mips-linux-gnu";
137   case llvm::Triple::mipsel:
138     return IsMipsR6 ? "mipsisa32r6el-linux-gnu" : "mipsel-linux-gnu";
139   case llvm::Triple::mips64: {
140     std::string MT = std::string(IsMipsR6 ? "mipsisa64r6" : "mips64") +
141                      "-linux-" + (IsMipsN32Abi ? "gnuabin32" : "gnuabi64");
142     if (D.getVFS().exists(concat(SysRoot, "/lib", MT)))
143       return MT;
144     if (D.getVFS().exists(concat(SysRoot, "/lib/mips64-linux-gnu")))
145       return "mips64-linux-gnu";
146     break;
147   }
148   case llvm::Triple::mips64el: {
149     std::string MT = std::string(IsMipsR6 ? "mipsisa64r6el" : "mips64el") +
150                      "-linux-" + (IsMipsN32Abi ? "gnuabin32" : "gnuabi64");
151     if (D.getVFS().exists(concat(SysRoot, "/lib", MT)))
152       return MT;
153     if (D.getVFS().exists(concat(SysRoot, "/lib/mips64el-linux-gnu")))
154       return "mips64el-linux-gnu";
155     break;
156   }
157   case llvm::Triple::ppc:
158     if (D.getVFS().exists(concat(SysRoot, "/lib/powerpc-linux-gnuspe")))
159       return "powerpc-linux-gnuspe";
160     return "powerpc-linux-gnu";
161   case llvm::Triple::ppcle:
162     return "powerpcle-linux-gnu";
163   case llvm::Triple::ppc64:
164     return "powerpc64-linux-gnu";
165   case llvm::Triple::ppc64le:
166     return "powerpc64le-linux-gnu";
167   case llvm::Triple::riscv64:
168     if (IsAndroid)
169       return "riscv64-linux-android";
170     return "riscv64-linux-gnu";
171   case llvm::Triple::sparc:
172     return "sparc-linux-gnu";
173   case llvm::Triple::sparcv9:
174     return "sparc64-linux-gnu";
175   case llvm::Triple::systemz:
176     return "s390x-linux-gnu";
177   }
178   return TargetTriple.str();
179 }
180 
181 static StringRef getOSLibDir(const llvm::Triple &Triple, const ArgList &Args) {
182   if (Triple.isMIPS()) {
183     // lib32 directory has a special meaning on MIPS targets.
184     // It contains N32 ABI binaries. Use this folder if produce
185     // code for N32 ABI only.
186     if (tools::mips::hasMipsAbiArg(Args, "n32"))
187       return "lib32";
188     return Triple.isArch32Bit() ? "lib" : "lib64";
189   }
190 
191   // It happens that only x86, PPC and SPARC use the 'lib32' variant of
192   // oslibdir, and using that variant while targeting other architectures causes
193   // problems because the libraries are laid out in shared system roots that
194   // can't cope with a 'lib32' library search path being considered. So we only
195   // enable them when we know we may need it.
196   //
197   // FIXME: This is a bit of a hack. We should really unify this code for
198   // reasoning about oslibdir spellings with the lib dir spellings in the
199   // GCCInstallationDetector, but that is a more significant refactoring.
200   if (Triple.getArch() == llvm::Triple::x86 || Triple.isPPC32() ||
201       Triple.getArch() == llvm::Triple::sparc)
202     return "lib32";
203 
204   if (Triple.getArch() == llvm::Triple::x86_64 && Triple.isX32())
205     return "libx32";
206 
207   if (Triple.getArch() == llvm::Triple::riscv32)
208     return "lib32";
209 
210   return Triple.isArch32Bit() ? "lib" : "lib64";
211 }
212 
213 Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
214     : Generic_ELF(D, Triple, Args) {
215   GCCInstallation.init(Triple, Args);
216   Multilibs = GCCInstallation.getMultilibs();
217   SelectedMultilibs.assign({GCCInstallation.getMultilib()});
218   llvm::Triple::ArchType Arch = Triple.getArch();
219   std::string SysRoot = computeSysRoot();
220   ToolChain::path_list &PPaths = getProgramPaths();
221 
222   Generic_GCC::PushPPaths(PPaths);
223 
224   Distro Distro(D.getVFS(), Triple);
225 
226   if (Distro.IsAlpineLinux() || Triple.isAndroid()) {
227     ExtraOpts.push_back("-z");
228     ExtraOpts.push_back("now");
229   }
230 
231   if (Distro.IsOpenSUSE() || Distro.IsUbuntu() || Distro.IsAlpineLinux() ||
232       Triple.isAndroid()) {
233     ExtraOpts.push_back("-z");
234     ExtraOpts.push_back("relro");
235   }
236 
237   // Note, lld from 11 onwards default max-page-size to 65536 for both ARM and
238   // AArch64.
239   if (Triple.isAndroid()) {
240     if (Triple.isARM()) {
241       // Android ARM uses max-page-size=4096 to reduce VMA usage.
242       ExtraOpts.push_back("-z");
243       ExtraOpts.push_back("max-page-size=4096");
244     } else if (Triple.isAArch64() || Triple.getArch() == llvm::Triple::x86_64) {
245       // Android AArch64 uses max-page-size=16384 to support 4k/16k page sizes.
246       // Android emulates a 16k page size for app testing on x86_64 machines.
247       ExtraOpts.push_back("-z");
248       ExtraOpts.push_back("max-page-size=16384");
249     }
250     if (Triple.isAndroidVersionLT(29)) {
251       // https://github.com/android/ndk/issues/1196
252       // The unwinder used by the crash handler on versions of Android prior to
253       // API 29 did not correctly handle binaries built with rosegment, which is
254       // enabled by default for LLD. Android only supports LLD, so it's not an
255       // issue that this flag is not accepted by other linkers.
256       ExtraOpts.push_back("--no-rosegment");
257     }
258     if (!Triple.isAndroidVersionLT(28)) {
259       // Android supports relr packing starting with API 28 and had its own
260       // flavor (--pack-dyn-relocs=android) starting in API 23.
261       // TODO: It's possible to use both with --pack-dyn-relocs=android+relr,
262       // but we need to gather some data on the impact of that form before we
263       // can know if it's a good default.
264       // On the other hand, relr should always be an improvement.
265       ExtraOpts.push_back("--use-android-relr-tags");
266       ExtraOpts.push_back("--pack-dyn-relocs=relr");
267     }
268   }
269 
270   if (GCCInstallation.getParentLibPath().contains("opt/rh/"))
271     // With devtoolset on RHEL, we want to add a bin directory that is relative
272     // to the detected gcc install, because if we are using devtoolset gcc then
273     // we want to use other tools from devtoolset (e.g. ld) instead of the
274     // standard system tools.
275     PPaths.push_back(Twine(GCCInstallation.getParentLibPath() +
276                      "/../bin").str());
277 
278   if (Arch == llvm::Triple::arm || Arch == llvm::Triple::thumb)
279     ExtraOpts.push_back("-X");
280 
281   const bool IsAndroid = Triple.isAndroid();
282   const bool IsMips = Triple.isMIPS();
283   const bool IsHexagon = Arch == llvm::Triple::hexagon;
284   const bool IsRISCV = Triple.isRISCV();
285   const bool IsCSKY = Triple.isCSKY();
286 
287   if (IsCSKY && !SelectedMultilibs.empty())
288     SysRoot = SysRoot + SelectedMultilibs.back().osSuffix();
289 
290   if ((IsMips || IsCSKY) && !SysRoot.empty())
291     ExtraOpts.push_back("--sysroot=" + SysRoot);
292 
293   // Do not use 'gnu' hash style for Mips targets because .gnu.hash
294   // and the MIPS ABI require .dynsym to be sorted in different ways.
295   // .gnu.hash needs symbols to be grouped by hash code whereas the MIPS
296   // ABI requires a mapping between the GOT and the symbol table.
297   // Android loader does not support .gnu.hash until API 23.
298   // Hexagon linker/loader does not support .gnu.hash
299   if (!IsMips && !IsHexagon) {
300     if (Distro.IsOpenSUSE() || Distro == Distro::UbuntuLucid ||
301         Distro == Distro::UbuntuJaunty || Distro == Distro::UbuntuKarmic ||
302         (IsAndroid && Triple.isAndroidVersionLT(23)))
303       ExtraOpts.push_back("--hash-style=both");
304     else
305       ExtraOpts.push_back("--hash-style=gnu");
306   }
307 
308 #ifdef ENABLE_LINKER_BUILD_ID
309   ExtraOpts.push_back("--build-id");
310 #endif
311 
312   // The selection of paths to try here is designed to match the patterns which
313   // the GCC driver itself uses, as this is part of the GCC-compatible driver.
314   // This was determined by running GCC in a fake filesystem, creating all
315   // possible permutations of these directories, and seeing which ones it added
316   // to the link paths.
317   path_list &Paths = getFilePaths();
318 
319   const std::string OSLibDir = std::string(getOSLibDir(Triple, Args));
320   const std::string MultiarchTriple = getMultiarchTriple(D, Triple, SysRoot);
321 
322   // mips32: Debian multilib, we use /libo32, while in other case, /lib is
323   // used. We need add both libo32 and /lib.
324   if (Arch == llvm::Triple::mips || Arch == llvm::Triple::mipsel) {
325     Generic_GCC::AddMultilibPaths(D, SysRoot, "libo32", MultiarchTriple, Paths);
326     addPathIfExists(D, concat(SysRoot, "/libo32"), Paths);
327     addPathIfExists(D, concat(SysRoot, "/usr/libo32"), Paths);
328   }
329   Generic_GCC::AddMultilibPaths(D, SysRoot, OSLibDir, MultiarchTriple, Paths);
330 
331   addPathIfExists(D, concat(SysRoot, "/lib", MultiarchTriple), Paths);
332   addPathIfExists(D, concat(SysRoot, "/lib/..", OSLibDir), Paths);
333 
334   if (IsAndroid) {
335     // Android sysroots contain a library directory for each supported OS
336     // version as well as some unversioned libraries in the usual multiarch
337     // directory.
338     addPathIfExists(
339         D,
340         concat(SysRoot, "/usr/lib", MultiarchTriple,
341                llvm::to_string(Triple.getEnvironmentVersion().getMajor())),
342         Paths);
343   }
344 
345   addPathIfExists(D, concat(SysRoot, "/usr/lib", MultiarchTriple), Paths);
346   // 64-bit OpenEmbedded sysroots may not have a /usr/lib dir. So they cannot
347   // find /usr/lib64 as it is referenced as /usr/lib/../lib64. So we handle
348   // this here.
349   if (Triple.getVendor() == llvm::Triple::OpenEmbedded &&
350       Triple.isArch64Bit())
351     addPathIfExists(D, concat(SysRoot, "/usr", OSLibDir), Paths);
352   else
353     addPathIfExists(D, concat(SysRoot, "/usr/lib/..", OSLibDir), Paths);
354   if (IsRISCV) {
355     StringRef ABIName = tools::riscv::getRISCVABI(Args, Triple);
356     addPathIfExists(D, concat(SysRoot, "/", OSLibDir, ABIName), Paths);
357     addPathIfExists(D, concat(SysRoot, "/usr", OSLibDir, ABIName), Paths);
358   }
359 
360   Generic_GCC::AddMultiarchPaths(D, SysRoot, OSLibDir, Paths);
361 
362   addPathIfExists(D, concat(SysRoot, "/lib"), Paths);
363   addPathIfExists(D, concat(SysRoot, "/usr/lib"), Paths);
364 }
365 
366 ToolChain::RuntimeLibType Linux::GetDefaultRuntimeLibType() const {
367   if (getTriple().isAndroid())
368     return ToolChain::RLT_CompilerRT;
369   return Generic_ELF::GetDefaultRuntimeLibType();
370 }
371 
372 unsigned Linux::GetDefaultDwarfVersion() const {
373   if (getTriple().isAndroid())
374     return 4;
375   return ToolChain::GetDefaultDwarfVersion();
376 }
377 
378 ToolChain::CXXStdlibType Linux::GetDefaultCXXStdlibType() const {
379   if (getTriple().isAndroid())
380     return ToolChain::CST_Libcxx;
381   return ToolChain::CST_Libstdcxx;
382 }
383 
384 bool Linux::HasNativeLLVMSupport() const { return true; }
385 
386 Tool *Linux::buildLinker() const { return new tools::gnutools::Linker(*this); }
387 
388 Tool *Linux::buildStaticLibTool() const {
389   return new tools::gnutools::StaticLibTool(*this);
390 }
391 
392 Tool *Linux::buildAssembler() const {
393   return new tools::gnutools::Assembler(*this);
394 }
395 
396 std::string Linux::computeSysRoot() const {
397   if (!getDriver().SysRoot.empty())
398     return getDriver().SysRoot;
399 
400   if (getTriple().isAndroid()) {
401     // Android toolchains typically include a sysroot at ../sysroot relative to
402     // the clang binary.
403     const StringRef ClangDir = getDriver().Dir;
404     std::string AndroidSysRootPath = (ClangDir + "/../sysroot").str();
405     if (getVFS().exists(AndroidSysRootPath))
406       return AndroidSysRootPath;
407   }
408 
409   if (getTriple().isCSKY()) {
410     // CSKY toolchains use different names for sysroot folder.
411     if (!GCCInstallation.isValid())
412       return std::string();
413     // GCCInstallation.getInstallPath() =
414     //   $GCCToolchainPath/lib/gcc/csky-linux-gnuabiv2/6.3.0
415     // Path = $GCCToolchainPath/csky-linux-gnuabiv2/libc
416     std::string Path = (GCCInstallation.getInstallPath() + "/../../../../" +
417                         GCCInstallation.getTriple().str() + "/libc")
418                            .str();
419     if (getVFS().exists(Path))
420       return Path;
421     return std::string();
422   }
423 
424   if (!GCCInstallation.isValid() || !getTriple().isMIPS())
425     return std::string();
426 
427   // Standalone MIPS toolchains use different names for sysroot folder
428   // and put it into different places. Here we try to check some known
429   // variants.
430 
431   const StringRef InstallDir = GCCInstallation.getInstallPath();
432   const StringRef TripleStr = GCCInstallation.getTriple().str();
433   const Multilib &Multilib = GCCInstallation.getMultilib();
434 
435   std::string Path =
436       (InstallDir + "/../../../../" + TripleStr + "/libc" + Multilib.osSuffix())
437           .str();
438 
439   if (getVFS().exists(Path))
440     return Path;
441 
442   Path = (InstallDir + "/../../../../sysroot" + Multilib.osSuffix()).str();
443 
444   if (getVFS().exists(Path))
445     return Path;
446 
447   return std::string();
448 }
449 
450 std::string Linux::getDynamicLinker(const ArgList &Args) const {
451   const llvm::Triple::ArchType Arch = getArch();
452   const llvm::Triple &Triple = getTriple();
453 
454   const Distro Distro(getDriver().getVFS(), Triple);
455 
456   if (Triple.isAndroid()) {
457     if (getSanitizerArgs(Args).needsHwasanRt() &&
458         !Triple.isAndroidVersionLT(34) && Triple.isArch64Bit()) {
459       // On Android 14 and newer, there is a special linker_hwasan64 that
460       // allows to run HWASan binaries on non-HWASan system images. This
461       // is also available on HWASan system images, so we can just always
462       // use that instead.
463       return "/system/bin/linker_hwasan64";
464     }
465     return Triple.isArch64Bit() ? "/system/bin/linker64" : "/system/bin/linker";
466   }
467   if (Triple.isMusl()) {
468     std::string ArchName;
469     bool IsArm = false;
470 
471     switch (Arch) {
472     case llvm::Triple::arm:
473     case llvm::Triple::thumb:
474       ArchName = "arm";
475       IsArm = true;
476       break;
477     case llvm::Triple::armeb:
478     case llvm::Triple::thumbeb:
479       ArchName = "armeb";
480       IsArm = true;
481       break;
482     case llvm::Triple::x86:
483       ArchName = "i386";
484       break;
485     case llvm::Triple::x86_64:
486       ArchName = Triple.isX32() ? "x32" : Triple.getArchName().str();
487       break;
488     default:
489       ArchName = Triple.getArchName().str();
490     }
491     if (IsArm &&
492         (Triple.getEnvironment() == llvm::Triple::MuslEABIHF ||
493          tools::arm::getARMFloatABI(*this, Args) == tools::arm::FloatABI::Hard))
494       ArchName += "hf";
495     if (Arch == llvm::Triple::ppc &&
496         Triple.getSubArch() == llvm::Triple::PPCSubArch_spe)
497       ArchName = "powerpc-sf";
498 
499     return "/lib/ld-musl-" + ArchName + ".so.1";
500   }
501 
502   std::string LibDir;
503   std::string Loader;
504 
505   switch (Arch) {
506   default:
507     llvm_unreachable("unsupported architecture");
508 
509   case llvm::Triple::aarch64:
510     LibDir = "lib";
511     Loader = "ld-linux-aarch64.so.1";
512     break;
513   case llvm::Triple::aarch64_be:
514     LibDir = "lib";
515     Loader = "ld-linux-aarch64_be.so.1";
516     break;
517   case llvm::Triple::arm:
518   case llvm::Triple::thumb:
519   case llvm::Triple::armeb:
520   case llvm::Triple::thumbeb: {
521     const bool HF =
522         Triple.getEnvironment() == llvm::Triple::GNUEABIHF ||
523         Triple.getEnvironment() == llvm::Triple::GNUEABIHFT64 ||
524         tools::arm::getARMFloatABI(*this, Args) == tools::arm::FloatABI::Hard;
525 
526     LibDir = "lib";
527     Loader = HF ? "ld-linux-armhf.so.3" : "ld-linux.so.3";
528     break;
529   }
530   case llvm::Triple::loongarch32: {
531     LibDir = "lib32";
532     Loader =
533         ("ld-linux-loongarch-" +
534          tools::loongarch::getLoongArchABI(getDriver(), Args, Triple) + ".so.1")
535             .str();
536     break;
537   }
538   case llvm::Triple::loongarch64: {
539     LibDir = "lib64";
540     Loader =
541         ("ld-linux-loongarch-" +
542          tools::loongarch::getLoongArchABI(getDriver(), Args, Triple) + ".so.1")
543             .str();
544     break;
545   }
546   case llvm::Triple::m68k:
547     LibDir = "lib";
548     Loader = "ld.so.1";
549     break;
550   case llvm::Triple::mips:
551   case llvm::Triple::mipsel:
552   case llvm::Triple::mips64:
553   case llvm::Triple::mips64el: {
554     bool IsNaN2008 = tools::mips::isNaN2008(getDriver(), Args, Triple);
555 
556     LibDir = "lib" + tools::mips::getMipsABILibSuffix(Args, Triple);
557 
558     if (tools::mips::isUCLibc(Args))
559       Loader = IsNaN2008 ? "ld-uClibc-mipsn8.so.0" : "ld-uClibc.so.0";
560     else if (!Triple.hasEnvironment() &&
561              Triple.getVendor() == llvm::Triple::VendorType::MipsTechnologies)
562       Loader =
563           Triple.isLittleEndian() ? "ld-musl-mipsel.so.1" : "ld-musl-mips.so.1";
564     else
565       Loader = IsNaN2008 ? "ld-linux-mipsn8.so.1" : "ld.so.1";
566 
567     break;
568   }
569   case llvm::Triple::ppc:
570     LibDir = "lib";
571     Loader = "ld.so.1";
572     break;
573   case llvm::Triple::ppcle:
574     LibDir = "lib";
575     Loader = "ld.so.1";
576     break;
577   case llvm::Triple::ppc64:
578     LibDir = "lib64";
579     Loader =
580         (tools::ppc::hasPPCAbiArg(Args, "elfv2")) ? "ld64.so.2" : "ld64.so.1";
581     break;
582   case llvm::Triple::ppc64le:
583     LibDir = "lib64";
584     Loader =
585         (tools::ppc::hasPPCAbiArg(Args, "elfv1")) ? "ld64.so.1" : "ld64.so.2";
586     break;
587   case llvm::Triple::riscv32:
588   case llvm::Triple::riscv64: {
589     StringRef ArchName = llvm::Triple::getArchTypeName(Arch);
590     StringRef ABIName = tools::riscv::getRISCVABI(Args, Triple);
591     LibDir = "lib";
592     Loader = ("ld-linux-" + ArchName + "-" + ABIName + ".so.1").str();
593     break;
594   }
595   case llvm::Triple::sparc:
596   case llvm::Triple::sparcel:
597     LibDir = "lib";
598     Loader = "ld-linux.so.2";
599     break;
600   case llvm::Triple::sparcv9:
601     LibDir = "lib64";
602     Loader = "ld-linux.so.2";
603     break;
604   case llvm::Triple::systemz:
605     LibDir = "lib";
606     Loader = "ld64.so.1";
607     break;
608   case llvm::Triple::x86:
609     LibDir = "lib";
610     Loader = "ld-linux.so.2";
611     break;
612   case llvm::Triple::x86_64: {
613     bool X32 = Triple.isX32();
614 
615     LibDir = X32 ? "libx32" : "lib64";
616     Loader = X32 ? "ld-linux-x32.so.2" : "ld-linux-x86-64.so.2";
617     break;
618   }
619   case llvm::Triple::ve:
620     return "/opt/nec/ve/lib/ld-linux-ve.so.1";
621   case llvm::Triple::csky: {
622     LibDir = "lib";
623     Loader = "ld.so.1";
624     break;
625   }
626   }
627 
628   if (Distro == Distro::Exherbo &&
629       (Triple.getVendor() == llvm::Triple::UnknownVendor ||
630        Triple.getVendor() == llvm::Triple::PC))
631     return "/usr/" + Triple.str() + "/lib/" + Loader;
632   return "/" + LibDir + "/" + Loader;
633 }
634 
635 void Linux::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
636                                       ArgStringList &CC1Args) const {
637   const Driver &D = getDriver();
638   std::string SysRoot = computeSysRoot();
639 
640   if (DriverArgs.hasArg(clang::driver::options::OPT_nostdinc))
641     return;
642 
643   // Add 'include' in the resource directory, which is similar to
644   // GCC_INCLUDE_DIR (private headers) in GCC. Note: the include directory
645   // contains some files conflicting with system /usr/include. musl systems
646   // prefer the /usr/include copies which are more relevant.
647   SmallString<128> ResourceDirInclude(D.ResourceDir);
648   llvm::sys::path::append(ResourceDirInclude, "include");
649   if (!DriverArgs.hasArg(options::OPT_nobuiltininc) &&
650       (!getTriple().isMusl() || DriverArgs.hasArg(options::OPT_nostdlibinc)))
651     addSystemInclude(DriverArgs, CC1Args, ResourceDirInclude);
652 
653   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
654     return;
655 
656   // LOCAL_INCLUDE_DIR
657   addSystemInclude(DriverArgs, CC1Args, concat(SysRoot, "/usr/local/include"));
658   // TOOL_INCLUDE_DIR
659   AddMultilibIncludeArgs(DriverArgs, CC1Args);
660 
661   // Check for configure-time C include directories.
662   StringRef CIncludeDirs(C_INCLUDE_DIRS);
663   if (CIncludeDirs != "") {
664     SmallVector<StringRef, 5> dirs;
665     CIncludeDirs.split(dirs, ":");
666     for (StringRef dir : dirs) {
667       StringRef Prefix =
668           llvm::sys::path::is_absolute(dir) ? "" : StringRef(SysRoot);
669       addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
670     }
671     return;
672   }
673 
674   // On systems using multiarch and Android, add /usr/include/$triple before
675   // /usr/include.
676   std::string MultiarchIncludeDir = getMultiarchTriple(D, getTriple(), SysRoot);
677   if (!MultiarchIncludeDir.empty() &&
678       D.getVFS().exists(concat(SysRoot, "/usr/include", MultiarchIncludeDir)))
679     addExternCSystemInclude(
680         DriverArgs, CC1Args,
681         concat(SysRoot, "/usr/include", MultiarchIncludeDir));
682 
683   if (getTriple().getOS() == llvm::Triple::RTEMS)
684     return;
685 
686   // Add an include of '/include' directly. This isn't provided by default by
687   // system GCCs, but is often used with cross-compiling GCCs, and harmless to
688   // add even when Clang is acting as-if it were a system compiler.
689   addExternCSystemInclude(DriverArgs, CC1Args, concat(SysRoot, "/include"));
690 
691   addExternCSystemInclude(DriverArgs, CC1Args, concat(SysRoot, "/usr/include"));
692 
693   if (!DriverArgs.hasArg(options::OPT_nobuiltininc) && getTriple().isMusl())
694     addSystemInclude(DriverArgs, CC1Args, ResourceDirInclude);
695 }
696 
697 void Linux::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
698                                      llvm::opt::ArgStringList &CC1Args) const {
699   // We need a detected GCC installation on Linux to provide libstdc++'s
700   // headers in odd Linuxish places.
701   if (!GCCInstallation.isValid())
702     return;
703 
704   // Detect Debian g++-multiarch-incdir.diff.
705   StringRef TripleStr = GCCInstallation.getTriple().str();
706   StringRef DebianMultiarch =
707       GCCInstallation.getTriple().getArch() == llvm::Triple::x86
708           ? "i386-linux-gnu"
709           : TripleStr;
710 
711   // Try generic GCC detection first.
712   if (Generic_GCC::addGCCLibStdCxxIncludePaths(DriverArgs, CC1Args,
713                                                DebianMultiarch))
714     return;
715 
716   StringRef LibDir = GCCInstallation.getParentLibPath();
717   const Multilib &Multilib = GCCInstallation.getMultilib();
718   const GCCVersion &Version = GCCInstallation.getVersion();
719 
720   const std::string LibStdCXXIncludePathCandidates[] = {
721       // Android standalone toolchain has C++ headers in yet another place.
722       LibDir.str() + "/../" + TripleStr.str() + "/include/c++/" + Version.Text,
723       // Freescale SDK C++ headers are directly in <sysroot>/usr/include/c++,
724       // without a subdirectory corresponding to the gcc version.
725       LibDir.str() + "/../include/c++",
726       // Cray's gcc installation puts headers under "g++" without a
727       // version suffix.
728       LibDir.str() + "/../include/g++",
729   };
730 
731   for (const auto &IncludePath : LibStdCXXIncludePathCandidates) {
732     if (addLibStdCXXIncludePaths(IncludePath, TripleStr,
733                                  Multilib.includeSuffix(), DriverArgs, CC1Args))
734       break;
735   }
736 }
737 
738 void Linux::AddCudaIncludeArgs(const ArgList &DriverArgs,
739                                ArgStringList &CC1Args) const {
740   CudaInstallation->AddCudaIncludeArgs(DriverArgs, CC1Args);
741 }
742 
743 void Linux::AddHIPIncludeArgs(const ArgList &DriverArgs,
744                               ArgStringList &CC1Args) const {
745   RocmInstallation->AddHIPIncludeArgs(DriverArgs, CC1Args);
746 }
747 
748 void Linux::AddHIPRuntimeLibArgs(const ArgList &Args,
749                                  ArgStringList &CmdArgs) const {
750   CmdArgs.push_back(
751       Args.MakeArgString(StringRef("-L") + RocmInstallation->getLibPath()));
752 
753   if (Args.hasFlag(options::OPT_frtlib_add_rpath,
754                    options::OPT_fno_rtlib_add_rpath, false))
755     CmdArgs.append(
756         {"-rpath", Args.MakeArgString(RocmInstallation->getLibPath())});
757 
758   CmdArgs.push_back("-lamdhip64");
759 }
760 
761 void Linux::AddIAMCUIncludeArgs(const ArgList &DriverArgs,
762                                 ArgStringList &CC1Args) const {
763   if (GCCInstallation.isValid()) {
764     CC1Args.push_back("-isystem");
765     CC1Args.push_back(DriverArgs.MakeArgString(
766         GCCInstallation.getParentLibPath() + "/../" +
767         GCCInstallation.getTriple().str() + "/include"));
768   }
769 }
770 
771 void Linux::addSYCLIncludeArgs(const ArgList &DriverArgs,
772                                ArgStringList &CC1Args) const {
773   SYCLInstallation->addSYCLIncludeArgs(DriverArgs, CC1Args);
774 }
775 
776 bool Linux::isPIEDefault(const llvm::opt::ArgList &Args) const {
777   return CLANG_DEFAULT_PIE_ON_LINUX || getTriple().isAndroid() ||
778          getTriple().isMusl() || getSanitizerArgs(Args).requiresPIE();
779 }
780 
781 bool Linux::IsAArch64OutlineAtomicsDefault(const ArgList &Args) const {
782   // Outline atomics for AArch64 are supported by compiler-rt
783   // and libgcc since 9.3.1
784   assert(getTriple().isAArch64() && "expected AArch64 target!");
785   ToolChain::RuntimeLibType RtLib = GetRuntimeLibType(Args);
786   if (RtLib == ToolChain::RLT_CompilerRT)
787     return true;
788   assert(RtLib == ToolChain::RLT_Libgcc && "unexpected runtime library type!");
789   if (GCCInstallation.getVersion().isOlderThan(9, 3, 1))
790     return false;
791   return true;
792 }
793 
794 bool Linux::IsMathErrnoDefault() const {
795   if (getTriple().isAndroid() || getTriple().isMusl())
796     return false;
797   return Generic_ELF::IsMathErrnoDefault();
798 }
799 
800 SanitizerMask Linux::getSupportedSanitizers() const {
801   const bool IsX86 = getTriple().getArch() == llvm::Triple::x86;
802   const bool IsX86_64 = getTriple().getArch() == llvm::Triple::x86_64;
803   const bool IsMIPS = getTriple().isMIPS32();
804   const bool IsMIPS64 = getTriple().isMIPS64();
805   const bool IsPowerPC64 = getTriple().getArch() == llvm::Triple::ppc64 ||
806                            getTriple().getArch() == llvm::Triple::ppc64le;
807   const bool IsAArch64 = getTriple().getArch() == llvm::Triple::aarch64 ||
808                          getTriple().getArch() == llvm::Triple::aarch64_be;
809   const bool IsArmArch = getTriple().getArch() == llvm::Triple::arm ||
810                          getTriple().getArch() == llvm::Triple::thumb ||
811                          getTriple().getArch() == llvm::Triple::armeb ||
812                          getTriple().getArch() == llvm::Triple::thumbeb;
813   const bool IsLoongArch64 = getTriple().getArch() == llvm::Triple::loongarch64;
814   const bool IsRISCV64 = getTriple().getArch() == llvm::Triple::riscv64;
815   const bool IsSystemZ = getTriple().getArch() == llvm::Triple::systemz;
816   const bool IsHexagon = getTriple().getArch() == llvm::Triple::hexagon;
817   const bool IsAndroid = getTriple().isAndroid();
818   SanitizerMask Res = ToolChain::getSupportedSanitizers();
819   Res |= SanitizerKind::Address;
820   Res |= SanitizerKind::PointerCompare;
821   Res |= SanitizerKind::PointerSubtract;
822   Res |= SanitizerKind::Realtime;
823   Res |= SanitizerKind::Fuzzer;
824   Res |= SanitizerKind::FuzzerNoLink;
825   Res |= SanitizerKind::KernelAddress;
826   Res |= SanitizerKind::Vptr;
827   Res |= SanitizerKind::SafeStack;
828   if (IsX86_64 || IsMIPS64 || IsAArch64 || IsLoongArch64)
829     Res |= SanitizerKind::DataFlow;
830   if (IsX86_64 || IsMIPS64 || IsAArch64 || IsX86 || IsArmArch || IsPowerPC64 ||
831       IsRISCV64 || IsSystemZ || IsHexagon || IsLoongArch64)
832     Res |= SanitizerKind::Leak;
833   if (IsX86_64 || IsMIPS64 || IsAArch64 || IsPowerPC64 || IsSystemZ ||
834       IsLoongArch64 || IsRISCV64)
835     Res |= SanitizerKind::Thread;
836   if (IsX86_64 || IsAArch64)
837     Res |= SanitizerKind::Type;
838   if (IsX86_64 || IsSystemZ || IsPowerPC64)
839     Res |= SanitizerKind::KernelMemory;
840   if (IsX86_64 || IsMIPS64 || IsAArch64 || IsX86 || IsMIPS || IsArmArch ||
841       IsPowerPC64 || IsHexagon || IsLoongArch64 || IsRISCV64)
842     Res |= SanitizerKind::Scudo;
843   if (IsX86_64 || IsAArch64 || IsRISCV64) {
844     Res |= SanitizerKind::HWAddress;
845   }
846   if (IsX86_64 || IsAArch64) {
847     Res |= SanitizerKind::KernelHWAddress;
848   }
849   if (IsX86_64)
850     Res |= SanitizerKind::NumericalStability;
851   if (!IsAndroid)
852     Res |= SanitizerKind::Memory;
853 
854   // Work around "Cannot represent a difference across sections".
855   if (getTriple().getArch() == llvm::Triple::ppc64)
856     Res &= ~SanitizerKind::Function;
857   return Res;
858 }
859 
860 void Linux::addProfileRTLibs(const llvm::opt::ArgList &Args,
861                              llvm::opt::ArgStringList &CmdArgs) const {
862   // Add linker option -u__llvm_profile_runtime to cause runtime
863   // initialization module to be linked in.
864   if (needsProfileRT(Args))
865     CmdArgs.push_back(Args.MakeArgString(
866         Twine("-u", llvm::getInstrProfRuntimeHookVarName())));
867   ToolChain::addProfileRTLibs(Args, CmdArgs);
868 }
869 
870 void Linux::addExtraOpts(llvm::opt::ArgStringList &CmdArgs) const {
871   for (const auto &Opt : ExtraOpts)
872     CmdArgs.push_back(Opt.c_str());
873 }
874 
875 const char *Linux::getDefaultLinker() const {
876   if (getTriple().isAndroid())
877     return "ld.lld";
878   return Generic_ELF::getDefaultLinker();
879 }
880