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