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 
32 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 toolchains::Fuchsia &ToolChain =
38       static_cast<const toolchains::Fuchsia &>(getToolChain());
39   const Driver &D = ToolChain.getDriver();
40 
41   const llvm::Triple &Triple = ToolChain.getEffectiveTriple();
42 
43   ArgStringList CmdArgs;
44 
45   // Silence warning for "clang -g foo.o -o foo"
46   Args.ClaimAllArgs(options::OPT_g_Group);
47   // and "clang -emit-llvm foo.o -o foo"
48   Args.ClaimAllArgs(options::OPT_emit_llvm);
49   // and for "clang -w foo.o -o foo". Other warning options are already
50   // handled somewhere else.
51   Args.ClaimAllArgs(options::OPT_w);
52 
53   CmdArgs.push_back("-z");
54   CmdArgs.push_back("max-page-size=4096");
55 
56   CmdArgs.push_back("-z");
57   CmdArgs.push_back("now");
58 
59   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
60   if (llvm::sys::path::filename(Exec).equals_insensitive("ld.lld") ||
61       llvm::sys::path::stem(Exec).equals_insensitive("ld.lld")) {
62     CmdArgs.push_back("-z");
63     CmdArgs.push_back("rodynamic");
64     CmdArgs.push_back("-z");
65     CmdArgs.push_back("separate-loadable-segments");
66     CmdArgs.push_back("-z");
67     CmdArgs.push_back("rel");
68     CmdArgs.push_back("--pack-dyn-relocs=relr");
69   }
70 
71   if (!D.SysRoot.empty())
72     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
73 
74   if (!Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_r))
75     CmdArgs.push_back("-pie");
76 
77   if (Args.hasArg(options::OPT_rdynamic))
78     CmdArgs.push_back("-export-dynamic");
79 
80   if (Args.hasArg(options::OPT_s))
81     CmdArgs.push_back("-s");
82 
83   if (Args.hasArg(options::OPT_r)) {
84     CmdArgs.push_back("-r");
85   } else {
86     CmdArgs.push_back("--build-id");
87     CmdArgs.push_back("--hash-style=gnu");
88   }
89 
90   if (ToolChain.getArch() == llvm::Triple::aarch64) {
91     CmdArgs.push_back("--execute-only");
92 
93     std::string CPU = getCPUName(D, Args, Triple);
94     if (CPU.empty() || CPU == "generic" || CPU == "cortex-a53")
95       CmdArgs.push_back("--fix-cortex-a53-843419");
96   }
97 
98   CmdArgs.push_back("--eh-frame-hdr");
99 
100   if (Args.hasArg(options::OPT_static))
101     CmdArgs.push_back("-Bstatic");
102   else if (Args.hasArg(options::OPT_shared))
103     CmdArgs.push_back("-shared");
104 
105   const SanitizerArgs &SanArgs = ToolChain.getSanitizerArgs(Args);
106 
107   if (!Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_r)) {
108     std::string Dyld = D.DyldPrefix;
109     if (SanArgs.needsAsanRt() && SanArgs.needsSharedRt())
110       Dyld += "asan/";
111     if (SanArgs.needsHwasanRt() && SanArgs.needsSharedRt())
112       Dyld += "hwasan/";
113     if (SanArgs.needsTsanRt() && SanArgs.needsSharedRt())
114       Dyld += "tsan/";
115     Dyld += "ld.so.1";
116     CmdArgs.push_back("-dynamic-linker");
117     CmdArgs.push_back(Args.MakeArgString(Dyld));
118   }
119 
120   if (ToolChain.getArch() == llvm::Triple::riscv64)
121     CmdArgs.push_back("-X");
122 
123   CmdArgs.push_back("-o");
124   CmdArgs.push_back(Output.getFilename());
125 
126   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
127                    options::OPT_r)) {
128     if (!Args.hasArg(options::OPT_shared)) {
129       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("Scrt1.o")));
130     }
131   }
132 
133   Args.AddAllArgs(CmdArgs, options::OPT_L);
134   Args.AddAllArgs(CmdArgs, options::OPT_u);
135 
136   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
137 
138   if (D.isUsingLTO()) {
139     assert(!Inputs.empty() && "Must have at least one input.");
140     addLTOOptions(ToolChain, Args, CmdArgs, Output, Inputs[0],
141                   D.getLTOMode() == LTOK_Thin);
142   }
143 
144   addLinkerCompressDebugSectionsOption(ToolChain, Args, CmdArgs);
145   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
146 
147   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
148                    options::OPT_r)) {
149     if (Args.hasArg(options::OPT_static))
150       CmdArgs.push_back("-Bdynamic");
151 
152     if (D.CCCIsCXX()) {
153       if (ToolChain.ShouldLinkCXXStdlib(Args)) {
154         bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
155                                    !Args.hasArg(options::OPT_static);
156         CmdArgs.push_back("--push-state");
157         CmdArgs.push_back("--as-needed");
158         if (OnlyLibstdcxxStatic)
159           CmdArgs.push_back("-Bstatic");
160         ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
161         if (OnlyLibstdcxxStatic)
162           CmdArgs.push_back("-Bdynamic");
163         CmdArgs.push_back("-lm");
164         CmdArgs.push_back("--pop-state");
165       }
166     }
167 
168     // Note that Fuchsia never needs to link in sanitizer runtime deps.  Any
169     // sanitizer runtimes with system dependencies use the `.deplibs` feature
170     // instead.
171     addSanitizerRuntimes(ToolChain, Args, CmdArgs);
172 
173     addXRayRuntime(ToolChain, Args, CmdArgs);
174 
175     ToolChain.addProfileRTLibs(Args, CmdArgs);
176 
177     AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
178 
179     if (Args.hasArg(options::OPT_pthread) ||
180         Args.hasArg(options::OPT_pthreads))
181       CmdArgs.push_back("-lpthread");
182 
183     if (Args.hasArg(options::OPT_fsplit_stack))
184       CmdArgs.push_back("--wrap=pthread_create");
185 
186     if (!Args.hasArg(options::OPT_nolibc))
187       CmdArgs.push_back("-lc");
188   }
189 
190   C.addCommand(std::make_unique<Command>(JA, *this,
191                                          ResponseFileSupport::AtFileCurCP(),
192                                          Exec, CmdArgs, Inputs, Output));
193 }
194 
195 void fuchsia::StaticLibTool::ConstructJob(Compilation &C, const JobAction &JA,
196                                           const InputInfo &Output,
197                                           const InputInfoList &Inputs,
198                                           const ArgList &Args,
199                                           const char *LinkingOutput) const {
200   const Driver &D = getToolChain().getDriver();
201 
202   // Silence warning for "clang -g foo.o -o foo"
203   Args.ClaimAllArgs(options::OPT_g_Group);
204   // and "clang -emit-llvm foo.o -o foo"
205   Args.ClaimAllArgs(options::OPT_emit_llvm);
206   // and for "clang -w foo.o -o foo". Other warning options are already
207   // handled somewhere else.
208   Args.ClaimAllArgs(options::OPT_w);
209   // Silence warnings when linking C code with a C++ '-stdlib' argument.
210   Args.ClaimAllArgs(options::OPT_stdlib_EQ);
211 
212   // ar tool command "llvm-ar <options> <output_file> <input_files>".
213   ArgStringList CmdArgs;
214   // Create and insert file members with a deterministic index.
215   CmdArgs.push_back("rcsD");
216   CmdArgs.push_back(Output.getFilename());
217 
218   for (const auto &II : Inputs) {
219     if (II.isFilename()) {
220        CmdArgs.push_back(II.getFilename());
221     }
222   }
223 
224   // Delete old output archive file if it already exists before generating a new
225   // archive file.
226   const char *OutputFileName = Output.getFilename();
227   if (Output.isFilename() && llvm::sys::fs::exists(OutputFileName)) {
228     if (std::error_code EC = llvm::sys::fs::remove(OutputFileName)) {
229       D.Diag(diag::err_drv_unable_to_remove_file) << EC.message();
230       return;
231     }
232   }
233 
234   const char *Exec = Args.MakeArgString(getToolChain().GetStaticLibToolPath());
235   C.addCommand(std::make_unique<Command>(JA, *this,
236                                          ResponseFileSupport::AtFileCurCP(),
237                                          Exec, CmdArgs, Inputs, Output));
238 }
239 
240 /// Fuchsia - Fuchsia tool chain which can call as(1) and ld(1) directly.
241 
242 Fuchsia::Fuchsia(const Driver &D, const llvm::Triple &Triple,
243                  const ArgList &Args)
244     : ToolChain(D, Triple, Args) {
245   getProgramPaths().push_back(getDriver().getInstalledDir());
246   if (getDriver().getInstalledDir() != D.Dir)
247     getProgramPaths().push_back(D.Dir);
248 
249   if (!D.SysRoot.empty()) {
250     SmallString<128> P(D.SysRoot);
251     llvm::sys::path::append(P, "lib");
252     getFilePaths().push_back(std::string(P.str()));
253   }
254 
255   auto FilePaths = [&](const Multilib &M) -> std::vector<std::string> {
256     std::vector<std::string> FP;
257     for (const std::string &Path : getStdlibPaths()) {
258       SmallString<128> P(Path);
259       llvm::sys::path::append(P, M.gccSuffix());
260       FP.push_back(std::string(P.str()));
261     }
262     return FP;
263   };
264 
265   Multilibs.push_back(Multilib());
266   // Use the noexcept variant with -fno-exceptions to avoid the extra overhead.
267   Multilibs.push_back(MultilibBuilder("noexcept", {}, {})
268                           .flag("-fexceptions", /*Disallow=*/true)
269                           .flag("-fno-exceptions")
270                           .makeMultilib());
271   // ASan has higher priority because we always want the instrumentated version.
272   Multilibs.push_back(MultilibBuilder("asan", {}, {})
273                           .flag("-fsanitize=address")
274                           .makeMultilib());
275   // Use the asan+noexcept variant with ASan and -fno-exceptions.
276   Multilibs.push_back(MultilibBuilder("asan+noexcept", {}, {})
277                           .flag("-fsanitize=address")
278                           .flag("-fexceptions", /*Disallow=*/true)
279                           .flag("-fno-exceptions")
280                           .makeMultilib());
281   // HWASan has higher priority because we always want the instrumentated
282   // version.
283   Multilibs.push_back(MultilibBuilder("hwasan", {}, {})
284                           .flag("-fsanitize=hwaddress")
285                           .makeMultilib());
286   // Use the hwasan+noexcept variant with HWASan and -fno-exceptions.
287   Multilibs.push_back(MultilibBuilder("hwasan+noexcept", {}, {})
288                           .flag("-fsanitize=hwaddress")
289                           .flag("-fexceptions", /*Disallow=*/true)
290                           .flag("-fno-exceptions")
291                           .makeMultilib());
292   // Use Itanium C++ ABI for the compat multilib.
293   Multilibs.push_back(MultilibBuilder("compat", {}, {})
294                           .flag("-fc++-abi=itanium")
295                           .makeMultilib());
296 
297   Multilibs.FilterOut([&](const Multilib &M) {
298     std::vector<std::string> RD = FilePaths(M);
299     return llvm::all_of(RD, [&](std::string P) { return !getVFS().exists(P); });
300   });
301 
302   Multilib::flags_list Flags;
303   bool Exceptions =
304       Args.hasFlag(options::OPT_fexceptions, options::OPT_fno_exceptions, true);
305   addMultilibFlag(Exceptions, "-fexceptions", Flags);
306   addMultilibFlag(!Exceptions, "-fno-exceptions", Flags);
307   addMultilibFlag(getSanitizerArgs(Args).needsAsanRt(), "-fsanitize=address",
308                   Flags);
309   addMultilibFlag(getSanitizerArgs(Args).needsHwasanRt(),
310                   "-fsanitize=hwaddress", Flags);
311 
312   addMultilibFlag(Args.getLastArgValue(options::OPT_fcxx_abi_EQ) == "itanium",
313                   "-fc++-abi=itanium", Flags);
314 
315   Multilibs.setFilePathsCallback(FilePaths);
316 
317   if (Multilibs.select(Flags, SelectedMultilibs)) {
318     // Ensure that -print-multi-directory only outputs one multilib directory.
319     Multilib LastSelected = SelectedMultilibs.back();
320     SelectedMultilibs = {LastSelected};
321 
322     if (!SelectedMultilibs.back().isDefault())
323       if (const auto &PathsCallback = Multilibs.filePathsCallback())
324         for (const auto &Path : PathsCallback(SelectedMultilibs.back()))
325           // Prepend the multilib path to ensure it takes the precedence.
326           getFilePaths().insert(getFilePaths().begin(), Path);
327   }
328 }
329 
330 std::string Fuchsia::ComputeEffectiveClangTriple(const ArgList &Args,
331                                                  types::ID InputType) const {
332   llvm::Triple Triple(ComputeLLVMTriple(Args, InputType));
333   return Triple.str();
334 }
335 
336 Tool *Fuchsia::buildLinker() const {
337   return new tools::fuchsia::Linker(*this);
338 }
339 
340 Tool *Fuchsia::buildStaticLibTool() const {
341   return new tools::fuchsia::StaticLibTool(*this);
342 }
343 
344 ToolChain::RuntimeLibType Fuchsia::GetRuntimeLibType(
345     const ArgList &Args) const {
346   if (Arg *A = Args.getLastArg(clang::driver::options::OPT_rtlib_EQ)) {
347     StringRef Value = A->getValue();
348     if (Value != "compiler-rt")
349       getDriver().Diag(clang::diag::err_drv_invalid_rtlib_name)
350           << A->getAsString(Args);
351   }
352 
353   return ToolChain::RLT_CompilerRT;
354 }
355 
356 ToolChain::CXXStdlibType
357 Fuchsia::GetCXXStdlibType(const ArgList &Args) const {
358   if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
359     StringRef Value = A->getValue();
360     if (Value != "libc++")
361       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
362         << A->getAsString(Args);
363   }
364 
365   return ToolChain::CST_Libcxx;
366 }
367 
368 void Fuchsia::addClangTargetOptions(const ArgList &DriverArgs,
369                                     ArgStringList &CC1Args,
370                                     Action::OffloadKind) const {
371   if (!DriverArgs.hasFlag(options::OPT_fuse_init_array,
372                           options::OPT_fno_use_init_array, true))
373     CC1Args.push_back("-fno-use-init-array");
374 }
375 
376 void Fuchsia::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
377                                         ArgStringList &CC1Args) const {
378   const Driver &D = getDriver();
379 
380   if (DriverArgs.hasArg(options::OPT_nostdinc))
381     return;
382 
383   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
384     SmallString<128> P(D.ResourceDir);
385     llvm::sys::path::append(P, "include");
386     addSystemInclude(DriverArgs, CC1Args, P);
387   }
388 
389   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
390     return;
391 
392   // Check for configure-time C include directories.
393   StringRef CIncludeDirs(C_INCLUDE_DIRS);
394   if (CIncludeDirs != "") {
395     SmallVector<StringRef, 5> dirs;
396     CIncludeDirs.split(dirs, ":");
397     for (StringRef dir : dirs) {
398       StringRef Prefix =
399           llvm::sys::path::is_absolute(dir) ? "" : StringRef(D.SysRoot);
400       addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
401     }
402     return;
403   }
404 
405   if (!D.SysRoot.empty()) {
406     SmallString<128> P(D.SysRoot);
407     llvm::sys::path::append(P, "include");
408     addExternCSystemInclude(DriverArgs, CC1Args, P.str());
409   }
410 }
411 
412 void Fuchsia::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
413                                            ArgStringList &CC1Args) const {
414   if (DriverArgs.hasArg(options::OPT_nostdinc, options::OPT_nostdlibinc,
415                         options::OPT_nostdincxx))
416     return;
417 
418   const Driver &D = getDriver();
419   std::string Target = getTripleString();
420 
421   auto AddCXXIncludePath = [&](StringRef Path) {
422     std::string Version = detectLibcxxVersion(Path);
423     if (Version.empty())
424       return;
425 
426     // First add the per-target include path.
427     SmallString<128> TargetDir(Path);
428     llvm::sys::path::append(TargetDir, Target, "c++", Version);
429     if (getVFS().exists(TargetDir))
430       addSystemInclude(DriverArgs, CC1Args, TargetDir);
431 
432     // Second add the generic one.
433     SmallString<128> Dir(Path);
434     llvm::sys::path::append(Dir, "c++", Version);
435     addSystemInclude(DriverArgs, CC1Args, Dir);
436   };
437 
438   switch (GetCXXStdlibType(DriverArgs)) {
439   case ToolChain::CST_Libcxx: {
440     SmallString<128> P(D.Dir);
441     llvm::sys::path::append(P, "..", "include");
442     AddCXXIncludePath(P);
443     break;
444   }
445 
446   default:
447     llvm_unreachable("invalid stdlib name");
448   }
449 }
450 
451 void Fuchsia::AddCXXStdlibLibArgs(const ArgList &Args,
452                                   ArgStringList &CmdArgs) const {
453   switch (GetCXXStdlibType(Args)) {
454   case ToolChain::CST_Libcxx:
455     CmdArgs.push_back("-lc++");
456     if (Args.hasArg(options::OPT_fexperimental_library))
457       CmdArgs.push_back("-lc++experimental");
458     break;
459 
460   case ToolChain::CST_Libstdcxx:
461     llvm_unreachable("invalid stdlib name");
462   }
463 }
464 
465 SanitizerMask Fuchsia::getSupportedSanitizers() const {
466   SanitizerMask Res = ToolChain::getSupportedSanitizers();
467   Res |= SanitizerKind::Address;
468   Res |= SanitizerKind::HWAddress;
469   Res |= SanitizerKind::PointerCompare;
470   Res |= SanitizerKind::PointerSubtract;
471   Res |= SanitizerKind::Fuzzer;
472   Res |= SanitizerKind::FuzzerNoLink;
473   Res |= SanitizerKind::Leak;
474   Res |= SanitizerKind::SafeStack;
475   Res |= SanitizerKind::Scudo;
476   Res |= SanitizerKind::Thread;
477   return Res;
478 }
479 
480 SanitizerMask Fuchsia::getDefaultSanitizers() const {
481   SanitizerMask Res;
482   switch (getTriple().getArch()) {
483   case llvm::Triple::aarch64:
484   case llvm::Triple::riscv64:
485     Res |= SanitizerKind::ShadowCallStack;
486     break;
487   case llvm::Triple::x86_64:
488     Res |= SanitizerKind::SafeStack;
489     break;
490   default:
491     break;
492   }
493   return Res;
494 }
495