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/Options.h"
16 #include "clang/Driver/SanitizerArgs.h"
17 #include "llvm/Option/ArgList.h"
18 #include "llvm/ProfileData/InstrProf.h"
19 #include "llvm/Support/FileSystem.h"
20 #include "llvm/Support/Path.h"
21 #include "llvm/Support/VirtualFileSystem.h"
22 
23 using namespace clang::driver;
24 using namespace clang::driver::toolchains;
25 using namespace clang::driver::tools;
26 using namespace clang;
27 using namespace llvm::opt;
28 
29 using tools::addMultilibFlag;
30 
31 void fuchsia::Linker::ConstructJob(Compilation &C, const JobAction &JA,
32                                    const InputInfo &Output,
33                                    const InputInfoList &Inputs,
34                                    const ArgList &Args,
35                                    const char *LinkingOutput) const {
36   const toolchains::Fuchsia &ToolChain =
37       static_cast<const toolchains::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   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
59   if (llvm::sys::path::filename(Exec).equals_insensitive("ld.lld") ||
60       llvm::sys::path::stem(Exec).equals_insensitive("ld.lld")) {
61     CmdArgs.push_back("-z");
62     CmdArgs.push_back("rodynamic");
63     CmdArgs.push_back("-z");
64     CmdArgs.push_back("separate-loadable-segments");
65     CmdArgs.push_back("-z");
66     CmdArgs.push_back("rel");
67     CmdArgs.push_back("--pack-dyn-relocs=relr");
68   }
69 
70   if (!D.SysRoot.empty())
71     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
72 
73   if (!Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_r))
74     CmdArgs.push_back("-pie");
75 
76   if (Args.hasArg(options::OPT_rdynamic))
77     CmdArgs.push_back("-export-dynamic");
78 
79   if (Args.hasArg(options::OPT_s))
80     CmdArgs.push_back("-s");
81 
82   if (Args.hasArg(options::OPT_r)) {
83     CmdArgs.push_back("-r");
84   } else {
85     CmdArgs.push_back("--build-id");
86     CmdArgs.push_back("--hash-style=gnu");
87   }
88 
89   if (ToolChain.getArch() == llvm::Triple::aarch64) {
90     std::string CPU = getCPUName(D, Args, Triple);
91     if (CPU.empty() || CPU == "generic" || CPU == "cortex-a53")
92       CmdArgs.push_back("--fix-cortex-a53-843419");
93   }
94 
95   CmdArgs.push_back("--eh-frame-hdr");
96 
97   if (Args.hasArg(options::OPT_static))
98     CmdArgs.push_back("-Bstatic");
99   else if (Args.hasArg(options::OPT_shared))
100     CmdArgs.push_back("-shared");
101 
102   const SanitizerArgs &SanArgs = ToolChain.getSanitizerArgs(Args);
103 
104   if (!Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_r)) {
105     std::string Dyld = D.DyldPrefix;
106     if (SanArgs.needsAsanRt() && SanArgs.needsSharedRt())
107       Dyld += "asan/";
108     if (SanArgs.needsHwasanRt() && SanArgs.needsSharedRt())
109       Dyld += "hwasan/";
110     if (SanArgs.needsTsanRt() && SanArgs.needsSharedRt())
111       Dyld += "tsan/";
112     Dyld += "ld.so.1";
113     CmdArgs.push_back("-dynamic-linker");
114     CmdArgs.push_back(Args.MakeArgString(Dyld));
115   }
116 
117   if (ToolChain.getArch() == llvm::Triple::riscv64)
118     CmdArgs.push_back("-X");
119 
120   CmdArgs.push_back("-o");
121   CmdArgs.push_back(Output.getFilename());
122 
123   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
124                    options::OPT_r)) {
125     if (!Args.hasArg(options::OPT_shared)) {
126       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("Scrt1.o")));
127     }
128   }
129 
130   Args.AddAllArgs(CmdArgs, options::OPT_L);
131   Args.AddAllArgs(CmdArgs, options::OPT_u);
132 
133   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
134 
135   if (D.isUsingLTO()) {
136     assert(!Inputs.empty() && "Must have at least one input.");
137     addLTOOptions(ToolChain, Args, CmdArgs, Output, Inputs[0],
138                   D.getLTOMode() == LTOK_Thin);
139   }
140 
141   addLinkerCompressDebugSectionsOption(ToolChain, Args, CmdArgs);
142   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
143 
144   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
145                    options::OPT_r)) {
146     if (Args.hasArg(options::OPT_static))
147       CmdArgs.push_back("-Bdynamic");
148 
149     if (D.CCCIsCXX()) {
150       if (ToolChain.ShouldLinkCXXStdlib(Args)) {
151         bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
152                                    !Args.hasArg(options::OPT_static);
153         CmdArgs.push_back("--push-state");
154         CmdArgs.push_back("--as-needed");
155         if (OnlyLibstdcxxStatic)
156           CmdArgs.push_back("-Bstatic");
157         ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
158         if (OnlyLibstdcxxStatic)
159           CmdArgs.push_back("-Bdynamic");
160         CmdArgs.push_back("-lm");
161         CmdArgs.push_back("--pop-state");
162       }
163     }
164 
165     // Note that Fuchsia never needs to link in sanitizer runtime deps.  Any
166     // sanitizer runtimes with system dependencies use the `.deplibs` feature
167     // instead.
168     addSanitizerRuntimes(ToolChain, Args, CmdArgs);
169 
170     addXRayRuntime(ToolChain, Args, CmdArgs);
171 
172     ToolChain.addProfileRTLibs(Args, CmdArgs);
173 
174     AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
175 
176     if (Args.hasArg(options::OPT_pthread) ||
177         Args.hasArg(options::OPT_pthreads))
178       CmdArgs.push_back("-lpthread");
179 
180     if (Args.hasArg(options::OPT_fsplit_stack))
181       CmdArgs.push_back("--wrap=pthread_create");
182 
183     if (!Args.hasArg(options::OPT_nolibc))
184       CmdArgs.push_back("-lc");
185   }
186 
187   C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
188                                          Exec, CmdArgs, Inputs, Output));
189 }
190 
191 /// Fuchsia - Fuchsia tool chain which can call as(1) and ld(1) directly.
192 
193 Fuchsia::Fuchsia(const Driver &D, const llvm::Triple &Triple,
194                  const ArgList &Args)
195     : ToolChain(D, Triple, Args) {
196   getProgramPaths().push_back(getDriver().getInstalledDir());
197   if (getDriver().getInstalledDir() != D.Dir)
198     getProgramPaths().push_back(D.Dir);
199 
200   if (!D.SysRoot.empty()) {
201     SmallString<128> P(D.SysRoot);
202     llvm::sys::path::append(P, "lib");
203     getFilePaths().push_back(std::string(P.str()));
204   }
205 
206   auto FilePaths = [&](const Multilib &M) -> std::vector<std::string> {
207     std::vector<std::string> FP;
208     for (const std::string &Path : getStdlibPaths()) {
209       SmallString<128> P(Path);
210       llvm::sys::path::append(P, M.gccSuffix());
211       FP.push_back(std::string(P.str()));
212     }
213     return FP;
214   };
215 
216   Multilibs.push_back(Multilib());
217   // Use the noexcept variant with -fno-exceptions to avoid the extra overhead.
218   Multilibs.push_back(Multilib("noexcept", {}, {}, 1)
219                           .flag("-fexceptions")
220                           .flag("+fno-exceptions"));
221   // ASan has higher priority because we always want the instrumentated version.
222   Multilibs.push_back(Multilib("asan", {}, {}, 2)
223                           .flag("+fsanitize=address"));
224   // Use the asan+noexcept variant with ASan and -fno-exceptions.
225   Multilibs.push_back(Multilib("asan+noexcept", {}, {}, 3)
226                           .flag("+fsanitize=address")
227                           .flag("-fexceptions")
228                           .flag("+fno-exceptions"));
229   // HWASan has higher priority because we always want the instrumentated
230   // version.
231   Multilibs.push_back(
232       Multilib("hwasan", {}, {}, 4).flag("+fsanitize=hwaddress"));
233   // Use the hwasan+noexcept variant with HWASan and -fno-exceptions.
234   Multilibs.push_back(Multilib("hwasan+noexcept", {}, {}, 5)
235                           .flag("+fsanitize=hwaddress")
236                           .flag("-fexceptions")
237                           .flag("+fno-exceptions"));
238   // Use the relative vtables ABI.
239   // TODO: Remove these multilibs once relative vtables are enabled by default
240   // for Fuchsia.
241   Multilibs.push_back(Multilib("relative-vtables", {}, {}, 6)
242                           .flag("+fexperimental-relative-c++-abi-vtables"));
243   Multilibs.push_back(Multilib("relative-vtables+noexcept", {}, {}, 7)
244                           .flag("+fexperimental-relative-c++-abi-vtables")
245                           .flag("-fexceptions")
246                           .flag("+fno-exceptions"));
247   Multilibs.push_back(Multilib("relative-vtables+asan", {}, {}, 8)
248                           .flag("+fexperimental-relative-c++-abi-vtables")
249                           .flag("+fsanitize=address"));
250   Multilibs.push_back(Multilib("relative-vtables+asan+noexcept", {}, {}, 9)
251                           .flag("+fexperimental-relative-c++-abi-vtables")
252                           .flag("+fsanitize=address")
253                           .flag("-fexceptions")
254                           .flag("+fno-exceptions"));
255   Multilibs.push_back(Multilib("relative-vtables+hwasan", {}, {}, 10)
256                           .flag("+fexperimental-relative-c++-abi-vtables")
257                           .flag("+fsanitize=hwaddress"));
258   Multilibs.push_back(Multilib("relative-vtables+hwasan+noexcept", {}, {}, 11)
259                           .flag("+fexperimental-relative-c++-abi-vtables")
260                           .flag("+fsanitize=hwaddress")
261                           .flag("-fexceptions")
262                           .flag("+fno-exceptions"));
263   // Use Itanium C++ ABI for the compat multilib.
264   Multilibs.push_back(Multilib("compat", {}, {}, 12).flag("+fc++-abi=itanium"));
265 
266   Multilibs.FilterOut([&](const Multilib &M) {
267     std::vector<std::string> RD = FilePaths(M);
268     return llvm::all_of(RD, [&](std::string P) { return !getVFS().exists(P); });
269   });
270 
271   Multilib::flags_list Flags;
272   addMultilibFlag(
273       Args.hasFlag(options::OPT_fexceptions, options::OPT_fno_exceptions, true),
274       "fexceptions", Flags);
275   addMultilibFlag(getSanitizerArgs(Args).needsAsanRt(), "fsanitize=address",
276                   Flags);
277   addMultilibFlag(getSanitizerArgs(Args).needsHwasanRt(), "fsanitize=hwaddress",
278                   Flags);
279 
280   addMultilibFlag(
281       Args.hasFlag(options::OPT_fexperimental_relative_cxx_abi_vtables,
282                    options::OPT_fno_experimental_relative_cxx_abi_vtables,
283                    /*default=*/false),
284       "fexperimental-relative-c++-abi-vtables", Flags);
285   addMultilibFlag(Args.getLastArgValue(options::OPT_fcxx_abi_EQ) == "itanium",
286                   "fc++-abi=itanium", Flags);
287 
288   Multilibs.setFilePathsCallback(FilePaths);
289 
290   if (Multilibs.select(Flags, SelectedMultilib))
291     if (!SelectedMultilib.isDefault())
292       if (const auto &PathsCallback = Multilibs.filePathsCallback())
293         for (const auto &Path : PathsCallback(SelectedMultilib))
294           // Prepend the multilib path to ensure it takes the precedence.
295           getFilePaths().insert(getFilePaths().begin(), Path);
296 }
297 
298 std::string Fuchsia::ComputeEffectiveClangTriple(const ArgList &Args,
299                                                  types::ID InputType) const {
300   llvm::Triple Triple(ComputeLLVMTriple(Args, InputType));
301   return Triple.str();
302 }
303 
304 Tool *Fuchsia::buildLinker() const {
305   return new tools::fuchsia::Linker(*this);
306 }
307 
308 ToolChain::RuntimeLibType Fuchsia::GetRuntimeLibType(
309     const ArgList &Args) const {
310   if (Arg *A = Args.getLastArg(clang::driver::options::OPT_rtlib_EQ)) {
311     StringRef Value = A->getValue();
312     if (Value != "compiler-rt")
313       getDriver().Diag(clang::diag::err_drv_invalid_rtlib_name)
314           << A->getAsString(Args);
315   }
316 
317   return ToolChain::RLT_CompilerRT;
318 }
319 
320 ToolChain::CXXStdlibType
321 Fuchsia::GetCXXStdlibType(const ArgList &Args) const {
322   if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
323     StringRef Value = A->getValue();
324     if (Value != "libc++")
325       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
326         << A->getAsString(Args);
327   }
328 
329   return ToolChain::CST_Libcxx;
330 }
331 
332 void Fuchsia::addClangTargetOptions(const ArgList &DriverArgs,
333                                     ArgStringList &CC1Args,
334                                     Action::OffloadKind) const {
335   if (!DriverArgs.hasFlag(options::OPT_fuse_init_array,
336                           options::OPT_fno_use_init_array, true))
337     CC1Args.push_back("-fno-use-init-array");
338 }
339 
340 void Fuchsia::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
341                                         ArgStringList &CC1Args) const {
342   const Driver &D = getDriver();
343 
344   if (DriverArgs.hasArg(options::OPT_nostdinc))
345     return;
346 
347   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
348     SmallString<128> P(D.ResourceDir);
349     llvm::sys::path::append(P, "include");
350     addSystemInclude(DriverArgs, CC1Args, P);
351   }
352 
353   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
354     return;
355 
356   // Check for configure-time C include directories.
357   StringRef CIncludeDirs(C_INCLUDE_DIRS);
358   if (CIncludeDirs != "") {
359     SmallVector<StringRef, 5> dirs;
360     CIncludeDirs.split(dirs, ":");
361     for (StringRef dir : dirs) {
362       StringRef Prefix =
363           llvm::sys::path::is_absolute(dir) ? "" : StringRef(D.SysRoot);
364       addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
365     }
366     return;
367   }
368 
369   if (!D.SysRoot.empty()) {
370     SmallString<128> P(D.SysRoot);
371     llvm::sys::path::append(P, "include");
372     addExternCSystemInclude(DriverArgs, CC1Args, P.str());
373   }
374 }
375 
376 void Fuchsia::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
377                                            ArgStringList &CC1Args) const {
378   if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
379       DriverArgs.hasArg(options::OPT_nostdincxx))
380     return;
381 
382   const Driver &D = getDriver();
383   std::string Target = getTripleString();
384 
385   auto AddCXXIncludePath = [&](StringRef Path) {
386     std::string Version = detectLibcxxVersion(Path);
387     if (Version.empty())
388       return;
389 
390     // First add the per-target include path.
391     SmallString<128> TargetDir(Path);
392     llvm::sys::path::append(TargetDir, Target, "c++", Version);
393     if (getVFS().exists(TargetDir))
394       addSystemInclude(DriverArgs, CC1Args, TargetDir);
395 
396     // Second add the generic one.
397     SmallString<128> Dir(Path);
398     llvm::sys::path::append(Dir, "c++", Version);
399     addSystemInclude(DriverArgs, CC1Args, Dir);
400   };
401 
402   switch (GetCXXStdlibType(DriverArgs)) {
403   case ToolChain::CST_Libcxx: {
404     SmallString<128> P(D.Dir);
405     llvm::sys::path::append(P, "..", "include");
406     AddCXXIncludePath(P);
407     break;
408   }
409 
410   default:
411     llvm_unreachable("invalid stdlib name");
412   }
413 }
414 
415 void Fuchsia::AddCXXStdlibLibArgs(const ArgList &Args,
416                                   ArgStringList &CmdArgs) const {
417   switch (GetCXXStdlibType(Args)) {
418   case ToolChain::CST_Libcxx:
419     CmdArgs.push_back("-lc++");
420     if (Args.hasArg(options::OPT_fexperimental_library))
421       CmdArgs.push_back("-lc++experimental");
422     break;
423 
424   case ToolChain::CST_Libstdcxx:
425     llvm_unreachable("invalid stdlib name");
426   }
427 }
428 
429 SanitizerMask Fuchsia::getSupportedSanitizers() const {
430   SanitizerMask Res = ToolChain::getSupportedSanitizers();
431   Res |= SanitizerKind::Address;
432   Res |= SanitizerKind::HWAddress;
433   Res |= SanitizerKind::PointerCompare;
434   Res |= SanitizerKind::PointerSubtract;
435   Res |= SanitizerKind::Fuzzer;
436   Res |= SanitizerKind::FuzzerNoLink;
437   Res |= SanitizerKind::Leak;
438   Res |= SanitizerKind::SafeStack;
439   Res |= SanitizerKind::Scudo;
440   Res |= SanitizerKind::Thread;
441   return Res;
442 }
443 
444 SanitizerMask Fuchsia::getDefaultSanitizers() const {
445   SanitizerMask Res;
446   switch (getTriple().getArch()) {
447   case llvm::Triple::aarch64:
448     Res |= SanitizerKind::ShadowCallStack;
449     break;
450   case llvm::Triple::x86_64:
451     Res |= SanitizerKind::SafeStack;
452     break;
453   default:
454     // TODO: Enable SafeStack on RISC-V once tested.
455     break;
456   }
457   return Res;
458 }
459