1 //===--- Fuchsia.cpp - Fuchsia 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 "Fuchsia.h"
10 #include "CommonArgs.h"
11 #include "clang/Config/config.h"
12 #include "clang/Driver/Compilation.h"
13 #include "clang/Driver/Driver.h"
14 #include "clang/Driver/DriverDiagnostic.h"
15 #include "clang/Driver/MultilibBuilder.h"
16 #include "clang/Driver/Options.h"
17 #include "clang/Driver/SanitizerArgs.h"
18 #include "llvm/Option/ArgList.h"
19 #include "llvm/ProfileData/InstrProf.h"
20 #include "llvm/Support/FileSystem.h"
21 #include "llvm/Support/Path.h"
22 #include "llvm/Support/VirtualFileSystem.h"
23 
24 using namespace clang::driver;
25 using namespace clang::driver::toolchains;
26 using namespace clang::driver::tools;
27 using namespace clang;
28 using namespace llvm::opt;
29 
30 using tools::addMultilibFlag;
31 
ConstructJob(Compilation & C,const JobAction & JA,const InputInfo & Output,const InputInfoList & Inputs,const ArgList & Args,const char * LinkingOutput) const32 void fuchsia::Linker::ConstructJob(Compilation &C, const JobAction &JA,
33                                    const InputInfo &Output,
34                                    const InputInfoList &Inputs,
35                                    const ArgList &Args,
36                                    const char *LinkingOutput) const {
37   const auto &ToolChain = static_cast<const Fuchsia &>(getToolChain());
38   const Driver &D = ToolChain.getDriver();
39 
40   const llvm::Triple &Triple = ToolChain.getEffectiveTriple();
41 
42   ArgStringList CmdArgs;
43 
44   // Silence warning for "clang -g foo.o -o foo"
45   Args.ClaimAllArgs(options::OPT_g_Group);
46   // and "clang -emit-llvm foo.o -o foo"
47   Args.ClaimAllArgs(options::OPT_emit_llvm);
48   // and for "clang -w foo.o -o foo". Other warning options are already
49   // handled somewhere else.
50   Args.ClaimAllArgs(options::OPT_w);
51 
52   CmdArgs.push_back("-z");
53   CmdArgs.push_back("max-page-size=4096");
54 
55   CmdArgs.push_back("-z");
56   CmdArgs.push_back("now");
57 
58   CmdArgs.push_back("-z");
59   CmdArgs.push_back("start-stop-visibility=hidden");
60 
61   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
62   if (llvm::sys::path::filename(Exec).equals_insensitive("ld.lld") ||
63       llvm::sys::path::stem(Exec).equals_insensitive("ld.lld")) {
64     CmdArgs.push_back("-z");
65     CmdArgs.push_back("rodynamic");
66     CmdArgs.push_back("-z");
67     CmdArgs.push_back("separate-loadable-segments");
68     CmdArgs.push_back("-z");
69     CmdArgs.push_back("rel");
70     CmdArgs.push_back("--pack-dyn-relocs=relr");
71   }
72 
73   if (!D.SysRoot.empty())
74     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
75 
76   if (!Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_r))
77     CmdArgs.push_back("-pie");
78 
79   if (Args.hasArg(options::OPT_rdynamic))
80     CmdArgs.push_back("-export-dynamic");
81 
82   if (Args.hasArg(options::OPT_s))
83     CmdArgs.push_back("-s");
84 
85   if (Args.hasArg(options::OPT_r)) {
86     CmdArgs.push_back("-r");
87   } else {
88     CmdArgs.push_back("--build-id");
89     CmdArgs.push_back("--hash-style=gnu");
90   }
91 
92   if (ToolChain.getArch() == llvm::Triple::aarch64) {
93     CmdArgs.push_back("--execute-only");
94 
95     std::string CPU = getCPUName(D, Args, Triple);
96     if (CPU.empty() || CPU == "generic" || CPU == "cortex-a53")
97       CmdArgs.push_back("--fix-cortex-a53-843419");
98   }
99 
100   CmdArgs.push_back("--eh-frame-hdr");
101 
102   if (Args.hasArg(options::OPT_static))
103     CmdArgs.push_back("-Bstatic");
104   else if (Args.hasArg(options::OPT_shared))
105     CmdArgs.push_back("-shared");
106 
107   const SanitizerArgs &SanArgs = ToolChain.getSanitizerArgs(Args);
108 
109   if (!Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_r)) {
110     std::string Dyld = D.DyldPrefix;
111     if (SanArgs.needsAsanRt() && SanArgs.needsSharedRt())
112       Dyld += "asan/";
113     if (SanArgs.needsHwasanRt() && SanArgs.needsSharedRt())
114       Dyld += "hwasan/";
115     if (SanArgs.needsTsanRt() && SanArgs.needsSharedRt())
116       Dyld += "tsan/";
117     Dyld += "ld.so.1";
118     CmdArgs.push_back("-dynamic-linker");
119     CmdArgs.push_back(Args.MakeArgString(Dyld));
120   }
121 
122   if (ToolChain.getArch() == llvm::Triple::riscv64)
123     CmdArgs.push_back("-X");
124 
125   CmdArgs.push_back("-o");
126   CmdArgs.push_back(Output.getFilename());
127 
128   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
129                    options::OPT_r)) {
130     if (!Args.hasArg(options::OPT_shared)) {
131       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("Scrt1.o")));
132     }
133   }
134 
135   Args.addAllArgs(CmdArgs, {options::OPT_L, options::OPT_u});
136 
137   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
138 
139   if (D.isUsingLTO()) {
140     assert(!Inputs.empty() && "Must have at least one input.");
141     // Find the first filename InputInfo object.
142     auto Input = llvm::find_if(
143         Inputs, [](const InputInfo &II) -> bool { return II.isFilename(); });
144     if (Input == Inputs.end())
145       // For a very rare case, all of the inputs to the linker are
146       // InputArg. If that happens, just use the first InputInfo.
147       Input = Inputs.begin();
148 
149     addLTOOptions(ToolChain, Args, CmdArgs, Output, *Input,
150                   D.getLTOMode() == LTOK_Thin);
151   }
152 
153   addLinkerCompressDebugSectionsOption(ToolChain, Args, CmdArgs);
154   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
155 
156   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
157                    options::OPT_r)) {
158     if (Args.hasArg(options::OPT_static))
159       CmdArgs.push_back("-Bdynamic");
160 
161     if (D.CCCIsCXX()) {
162       if (ToolChain.ShouldLinkCXXStdlib(Args)) {
163         bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
164                                    !Args.hasArg(options::OPT_static);
165         CmdArgs.push_back("--push-state");
166         CmdArgs.push_back("--as-needed");
167         if (OnlyLibstdcxxStatic)
168           CmdArgs.push_back("-Bstatic");
169         ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
170         if (OnlyLibstdcxxStatic)
171           CmdArgs.push_back("-Bdynamic");
172         CmdArgs.push_back("-lm");
173         CmdArgs.push_back("--pop-state");
174       }
175     }
176 
177     // Note that Fuchsia never needs to link in sanitizer runtime deps.  Any
178     // sanitizer runtimes with system dependencies use the `.deplibs` feature
179     // instead.
180     addSanitizerRuntimes(ToolChain, Args, CmdArgs);
181 
182     addXRayRuntime(ToolChain, Args, CmdArgs);
183 
184     ToolChain.addProfileRTLibs(Args, CmdArgs);
185 
186     AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
187 
188     if (Args.hasArg(options::OPT_pthread) ||
189         Args.hasArg(options::OPT_pthreads))
190       CmdArgs.push_back("-lpthread");
191 
192     if (Args.hasArg(options::OPT_fsplit_stack))
193       CmdArgs.push_back("--wrap=pthread_create");
194 
195     if (!Args.hasArg(options::OPT_nolibc))
196       CmdArgs.push_back("-lc");
197   }
198 
199   C.addCommand(std::make_unique<Command>(JA, *this,
200                                          ResponseFileSupport::AtFileCurCP(),
201                                          Exec, CmdArgs, Inputs, Output));
202 }
203 
ConstructJob(Compilation & C,const JobAction & JA,const InputInfo & Output,const InputInfoList & Inputs,const ArgList & Args,const char * LinkingOutput) const204 void fuchsia::StaticLibTool::ConstructJob(Compilation &C, const JobAction &JA,
205                                           const InputInfo &Output,
206                                           const InputInfoList &Inputs,
207                                           const ArgList &Args,
208                                           const char *LinkingOutput) const {
209   const Driver &D = getToolChain().getDriver();
210 
211   // Silence warning for "clang -g foo.o -o foo"
212   Args.ClaimAllArgs(options::OPT_g_Group);
213   // and "clang -emit-llvm foo.o -o foo"
214   Args.ClaimAllArgs(options::OPT_emit_llvm);
215   // and for "clang -w foo.o -o foo". Other warning options are already
216   // handled somewhere else.
217   Args.ClaimAllArgs(options::OPT_w);
218   // Silence warnings when linking C code with a C++ '-stdlib' argument.
219   Args.ClaimAllArgs(options::OPT_stdlib_EQ);
220 
221   // ar tool command "llvm-ar <options> <output_file> <input_files>".
222   ArgStringList CmdArgs;
223   // Create and insert file members with a deterministic index.
224   CmdArgs.push_back("rcsD");
225   CmdArgs.push_back(Output.getFilename());
226 
227   for (const auto &II : Inputs) {
228     if (II.isFilename()) {
229        CmdArgs.push_back(II.getFilename());
230     }
231   }
232 
233   // Delete old output archive file if it already exists before generating a new
234   // archive file.
235   const char *OutputFileName = Output.getFilename();
236   if (Output.isFilename() && llvm::sys::fs::exists(OutputFileName)) {
237     if (std::error_code EC = llvm::sys::fs::remove(OutputFileName)) {
238       D.Diag(diag::err_drv_unable_to_remove_file) << EC.message();
239       return;
240     }
241   }
242 
243   const char *Exec = Args.MakeArgString(getToolChain().GetStaticLibToolPath());
244   C.addCommand(std::make_unique<Command>(JA, *this,
245                                          ResponseFileSupport::AtFileCurCP(),
246                                          Exec, CmdArgs, Inputs, Output));
247 }
248 
249 /// Fuchsia - Fuchsia tool chain which can call as(1) and ld(1) directly.
250 
Fuchsia(const Driver & D,const llvm::Triple & Triple,const ArgList & Args)251 Fuchsia::Fuchsia(const Driver &D, const llvm::Triple &Triple,
252                  const ArgList &Args)
253     : ToolChain(D, Triple, Args) {
254   getProgramPaths().push_back(getDriver().getInstalledDir());
255   if (getDriver().getInstalledDir() != D.Dir)
256     getProgramPaths().push_back(D.Dir);
257 
258   if (!D.SysRoot.empty()) {
259     SmallString<128> P(D.SysRoot);
260     llvm::sys::path::append(P, "lib");
261     getFilePaths().push_back(std::string(P));
262   }
263 
264   auto FilePaths = [&](const Multilib &M) -> std::vector<std::string> {
265     std::vector<std::string> FP;
266     if (std::optional<std::string> Path = getStdlibPath()) {
267       SmallString<128> P(*Path);
268       llvm::sys::path::append(P, M.gccSuffix());
269       FP.push_back(std::string(P));
270     }
271     return FP;
272   };
273 
274   Multilibs.push_back(Multilib());
275   // Use the noexcept variant with -fno-exceptions to avoid the extra overhead.
276   Multilibs.push_back(MultilibBuilder("noexcept", {}, {})
277                           .flag("-fexceptions", /*Disallow=*/true)
278                           .flag("-fno-exceptions")
279                           .makeMultilib());
280   // ASan has higher priority because we always want the instrumentated version.
281   Multilibs.push_back(MultilibBuilder("asan", {}, {})
282                           .flag("-fsanitize=address")
283                           .makeMultilib());
284   // Use the asan+noexcept variant with ASan and -fno-exceptions.
285   Multilibs.push_back(MultilibBuilder("asan+noexcept", {}, {})
286                           .flag("-fsanitize=address")
287                           .flag("-fexceptions", /*Disallow=*/true)
288                           .flag("-fno-exceptions")
289                           .makeMultilib());
290   // HWASan has higher priority because we always want the instrumentated
291   // version.
292   Multilibs.push_back(MultilibBuilder("hwasan", {}, {})
293                           .flag("-fsanitize=hwaddress")
294                           .makeMultilib());
295   // Use the hwasan+noexcept variant with HWASan and -fno-exceptions.
296   Multilibs.push_back(MultilibBuilder("hwasan+noexcept", {}, {})
297                           .flag("-fsanitize=hwaddress")
298                           .flag("-fexceptions", /*Disallow=*/true)
299                           .flag("-fno-exceptions")
300                           .makeMultilib());
301   // Use Itanium C++ ABI for the compat multilib.
302   Multilibs.push_back(MultilibBuilder("compat", {}, {})
303                           .flag("-fc++-abi=itanium")
304                           .makeMultilib());
305 
306   Multilibs.FilterOut([&](const Multilib &M) {
307     std::vector<std::string> RD = FilePaths(M);
308     return llvm::all_of(RD, [&](std::string P) { return !getVFS().exists(P); });
309   });
310 
311   Multilib::flags_list Flags;
312   bool Exceptions =
313       Args.hasFlag(options::OPT_fexceptions, options::OPT_fno_exceptions, true);
314   addMultilibFlag(Exceptions, "-fexceptions", Flags);
315   addMultilibFlag(!Exceptions, "-fno-exceptions", Flags);
316   addMultilibFlag(getSanitizerArgs(Args).needsAsanRt(), "-fsanitize=address",
317                   Flags);
318   addMultilibFlag(getSanitizerArgs(Args).needsHwasanRt(),
319                   "-fsanitize=hwaddress", Flags);
320 
321   addMultilibFlag(Args.getLastArgValue(options::OPT_fcxx_abi_EQ) == "itanium",
322                   "-fc++-abi=itanium", Flags);
323 
324   Multilibs.setFilePathsCallback(FilePaths);
325 
326   if (Multilibs.select(Flags, SelectedMultilibs)) {
327     // Ensure that -print-multi-directory only outputs one multilib directory.
328     Multilib LastSelected = SelectedMultilibs.back();
329     SelectedMultilibs = {LastSelected};
330 
331     if (!SelectedMultilibs.back().isDefault())
332       if (const auto &PathsCallback = Multilibs.filePathsCallback())
333         for (const auto &Path : PathsCallback(SelectedMultilibs.back()))
334           // Prepend the multilib path to ensure it takes the precedence.
335           getFilePaths().insert(getFilePaths().begin(), Path);
336   }
337 }
338 
ComputeEffectiveClangTriple(const ArgList & Args,types::ID InputType) const339 std::string Fuchsia::ComputeEffectiveClangTriple(const ArgList &Args,
340                                                  types::ID InputType) const {
341   llvm::Triple Triple(ComputeLLVMTriple(Args, InputType));
342   return Triple.str();
343 }
344 
buildLinker() const345 Tool *Fuchsia::buildLinker() const {
346   return new tools::fuchsia::Linker(*this);
347 }
348 
buildStaticLibTool() const349 Tool *Fuchsia::buildStaticLibTool() const {
350   return new tools::fuchsia::StaticLibTool(*this);
351 }
352 
GetRuntimeLibType(const ArgList & Args) const353 ToolChain::RuntimeLibType Fuchsia::GetRuntimeLibType(
354     const ArgList &Args) const {
355   if (Arg *A = Args.getLastArg(clang::driver::options::OPT_rtlib_EQ)) {
356     StringRef Value = A->getValue();
357     if (Value != "compiler-rt")
358       getDriver().Diag(clang::diag::err_drv_invalid_rtlib_name)
359           << A->getAsString(Args);
360   }
361 
362   return ToolChain::RLT_CompilerRT;
363 }
364 
365 ToolChain::CXXStdlibType
GetCXXStdlibType(const ArgList & Args) const366 Fuchsia::GetCXXStdlibType(const ArgList &Args) const {
367   if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
368     StringRef Value = A->getValue();
369     if (Value != "libc++")
370       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
371         << A->getAsString(Args);
372   }
373 
374   return ToolChain::CST_Libcxx;
375 }
376 
addClangTargetOptions(const ArgList & DriverArgs,ArgStringList & CC1Args,Action::OffloadKind) const377 void Fuchsia::addClangTargetOptions(const ArgList &DriverArgs,
378                                     ArgStringList &CC1Args,
379                                     Action::OffloadKind) const {
380   if (!DriverArgs.hasFlag(options::OPT_fuse_init_array,
381                           options::OPT_fno_use_init_array, true))
382     CC1Args.push_back("-fno-use-init-array");
383 }
384 
AddClangSystemIncludeArgs(const ArgList & DriverArgs,ArgStringList & CC1Args) const385 void Fuchsia::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
386                                         ArgStringList &CC1Args) const {
387   const Driver &D = getDriver();
388 
389   if (DriverArgs.hasArg(options::OPT_nostdinc))
390     return;
391 
392   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
393     SmallString<128> P(D.ResourceDir);
394     llvm::sys::path::append(P, "include");
395     addSystemInclude(DriverArgs, CC1Args, P);
396   }
397 
398   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
399     return;
400 
401   // Check for configure-time C include directories.
402   StringRef CIncludeDirs(C_INCLUDE_DIRS);
403   if (CIncludeDirs != "") {
404     SmallVector<StringRef, 5> dirs;
405     CIncludeDirs.split(dirs, ":");
406     for (StringRef dir : dirs) {
407       StringRef Prefix =
408           llvm::sys::path::is_absolute(dir) ? "" : StringRef(D.SysRoot);
409       addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
410     }
411     return;
412   }
413 
414   if (!D.SysRoot.empty()) {
415     SmallString<128> P(D.SysRoot);
416     llvm::sys::path::append(P, "include");
417     addExternCSystemInclude(DriverArgs, CC1Args, P.str());
418   }
419 }
420 
AddClangCXXStdlibIncludeArgs(const ArgList & DriverArgs,ArgStringList & CC1Args) const421 void Fuchsia::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
422                                            ArgStringList &CC1Args) const {
423   if (DriverArgs.hasArg(options::OPT_nostdinc, options::OPT_nostdlibinc,
424                         options::OPT_nostdincxx))
425     return;
426 
427   const Driver &D = getDriver();
428   std::string Target = getTripleString();
429 
430   auto AddCXXIncludePath = [&](StringRef Path) {
431     std::string Version = detectLibcxxVersion(Path);
432     if (Version.empty())
433       return;
434 
435     // First add the per-target include path.
436     SmallString<128> TargetDir(Path);
437     llvm::sys::path::append(TargetDir, Target, "c++", Version);
438     if (getVFS().exists(TargetDir))
439       addSystemInclude(DriverArgs, CC1Args, TargetDir);
440 
441     // Second add the generic one.
442     SmallString<128> Dir(Path);
443     llvm::sys::path::append(Dir, "c++", Version);
444     addSystemInclude(DriverArgs, CC1Args, Dir);
445   };
446 
447   switch (GetCXXStdlibType(DriverArgs)) {
448   case ToolChain::CST_Libcxx: {
449     SmallString<128> P(D.Dir);
450     llvm::sys::path::append(P, "..", "include");
451     AddCXXIncludePath(P);
452     break;
453   }
454 
455   default:
456     llvm_unreachable("invalid stdlib name");
457   }
458 }
459 
AddCXXStdlibLibArgs(const ArgList & Args,ArgStringList & CmdArgs) const460 void Fuchsia::AddCXXStdlibLibArgs(const ArgList &Args,
461                                   ArgStringList &CmdArgs) const {
462   switch (GetCXXStdlibType(Args)) {
463   case ToolChain::CST_Libcxx:
464     CmdArgs.push_back("-lc++");
465     if (Args.hasArg(options::OPT_fexperimental_library))
466       CmdArgs.push_back("-lc++experimental");
467     break;
468 
469   case ToolChain::CST_Libstdcxx:
470     llvm_unreachable("invalid stdlib name");
471   }
472 }
473 
getSupportedSanitizers() const474 SanitizerMask Fuchsia::getSupportedSanitizers() const {
475   SanitizerMask Res = ToolChain::getSupportedSanitizers();
476   Res |= SanitizerKind::Address;
477   Res |= SanitizerKind::HWAddress;
478   Res |= SanitizerKind::PointerCompare;
479   Res |= SanitizerKind::PointerSubtract;
480   Res |= SanitizerKind::Fuzzer;
481   Res |= SanitizerKind::FuzzerNoLink;
482   Res |= SanitizerKind::Leak;
483   Res |= SanitizerKind::SafeStack;
484   Res |= SanitizerKind::Scudo;
485   Res |= SanitizerKind::Thread;
486   return Res;
487 }
488 
getDefaultSanitizers() const489 SanitizerMask Fuchsia::getDefaultSanitizers() const {
490   SanitizerMask Res;
491   switch (getTriple().getArch()) {
492   case llvm::Triple::aarch64:
493   case llvm::Triple::riscv64:
494     Res |= SanitizerKind::ShadowCallStack;
495     break;
496   case llvm::Triple::x86_64:
497     Res |= SanitizerKind::SafeStack;
498     break;
499   default:
500     break;
501   }
502   return Res;
503 }
504