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/Support/FileSystem.h"
19 #include "llvm/Support/Path.h"
20 #include "llvm/Support/VirtualFileSystem.h"
21 
22 using namespace clang::driver;
23 using namespace clang::driver::toolchains;
24 using namespace clang::driver::tools;
25 using namespace clang;
26 using namespace llvm::opt;
27 
28 using tools::addMultilibFlag;
29 
30 void fuchsia::Linker::ConstructJob(Compilation &C, const JobAction &JA,
31                                    const InputInfo &Output,
32                                    const InputInfoList &Inputs,
33                                    const ArgList &Args,
34                                    const char *LinkingOutput) const {
35   const toolchains::Fuchsia &ToolChain =
36       static_cast<const toolchains::Fuchsia &>(getToolChain());
37   const Driver &D = ToolChain.getDriver();
38 
39   ArgStringList CmdArgs;
40 
41   // Silence warning for "clang -g foo.o -o foo"
42   Args.ClaimAllArgs(options::OPT_g_Group);
43   // and "clang -emit-llvm foo.o -o foo"
44   Args.ClaimAllArgs(options::OPT_emit_llvm);
45   // and for "clang -w foo.o -o foo". Other warning options are already
46   // handled somewhere else.
47   Args.ClaimAllArgs(options::OPT_w);
48 
49   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
50   if (llvm::sys::path::filename(Exec).equals_lower("ld.lld") ||
51       llvm::sys::path::stem(Exec).equals_lower("ld.lld")) {
52     CmdArgs.push_back("-z");
53     CmdArgs.push_back("rodynamic");
54   }
55 
56   if (!D.SysRoot.empty())
57     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
58 
59   if (!Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_r))
60     CmdArgs.push_back("-pie");
61 
62   if (Args.hasArg(options::OPT_rdynamic))
63     CmdArgs.push_back("-export-dynamic");
64 
65   if (Args.hasArg(options::OPT_s))
66     CmdArgs.push_back("-s");
67 
68   if (Args.hasArg(options::OPT_r)) {
69     CmdArgs.push_back("-r");
70   } else {
71     CmdArgs.push_back("--build-id");
72     CmdArgs.push_back("--hash-style=gnu");
73   }
74 
75   CmdArgs.push_back("--eh-frame-hdr");
76 
77   if (Args.hasArg(options::OPT_static))
78     CmdArgs.push_back("-Bstatic");
79   else if (Args.hasArg(options::OPT_shared))
80     CmdArgs.push_back("-shared");
81 
82   const SanitizerArgs &SanArgs = ToolChain.getSanitizerArgs();
83 
84   if (!Args.hasArg(options::OPT_shared)) {
85     std::string Dyld = D.DyldPrefix;
86     if (SanArgs.needsAsanRt() && SanArgs.needsSharedRt())
87       Dyld += "asan/";
88     Dyld += "ld.so.1";
89     CmdArgs.push_back("-dynamic-linker");
90     CmdArgs.push_back(Args.MakeArgString(Dyld));
91   }
92 
93   CmdArgs.push_back("-o");
94   CmdArgs.push_back(Output.getFilename());
95 
96   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
97     if (!Args.hasArg(options::OPT_shared)) {
98       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("Scrt1.o")));
99     }
100   }
101 
102   Args.AddAllArgs(CmdArgs, options::OPT_L);
103   Args.AddAllArgs(CmdArgs, options::OPT_u);
104 
105   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
106 
107   if (D.isUsingLTO()) {
108     assert(!Inputs.empty() && "Must have at least one input.");
109     AddGoldPlugin(ToolChain, Args, CmdArgs, Output, Inputs[0],
110                   D.getLTOMode() == LTOK_Thin);
111   }
112 
113   bool NeedsSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
114   bool NeedsXRayDeps = addXRayRuntime(ToolChain, Args, CmdArgs);
115   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
116   ToolChain.addProfileRTLibs(Args, CmdArgs);
117 
118   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
119     if (Args.hasArg(options::OPT_static))
120       CmdArgs.push_back("-Bdynamic");
121 
122     if (D.CCCIsCXX()) {
123       if (ToolChain.ShouldLinkCXXStdlib(Args)) {
124         bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
125                                    !Args.hasArg(options::OPT_static);
126         CmdArgs.push_back("--push-state");
127         CmdArgs.push_back("--as-needed");
128         if (OnlyLibstdcxxStatic)
129           CmdArgs.push_back("-Bstatic");
130         ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
131         if (OnlyLibstdcxxStatic)
132           CmdArgs.push_back("-Bdynamic");
133         CmdArgs.push_back("-lm");
134         CmdArgs.push_back("--pop-state");
135       }
136     }
137 
138     if (NeedsSanitizerDeps)
139       linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
140 
141     if (NeedsXRayDeps)
142       linkXRayRuntimeDeps(ToolChain, CmdArgs);
143 
144     AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
145 
146     if (Args.hasArg(options::OPT_pthread) ||
147         Args.hasArg(options::OPT_pthreads))
148       CmdArgs.push_back("-lpthread");
149 
150     if (Args.hasArg(options::OPT_fsplit_stack))
151       CmdArgs.push_back("--wrap=pthread_create");
152 
153     if (!Args.hasArg(options::OPT_nolibc))
154       CmdArgs.push_back("-lc");
155   }
156 
157   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
158 }
159 
160 /// Fuchsia - Fuchsia tool chain which can call as(1) and ld(1) directly.
161 
162 Fuchsia::Fuchsia(const Driver &D, const llvm::Triple &Triple,
163                  const ArgList &Args)
164     : ToolChain(D, Triple, Args) {
165   getProgramPaths().push_back(getDriver().getInstalledDir());
166   if (getDriver().getInstalledDir() != D.Dir)
167     getProgramPaths().push_back(D.Dir);
168 
169   if (!D.SysRoot.empty()) {
170     SmallString<128> P(D.SysRoot);
171     llvm::sys::path::append(P, "lib");
172     getFilePaths().push_back(P.str());
173   }
174 
175   auto FilePaths = [&](const Multilib &M) -> std::vector<std::string> {
176     std::vector<std::string> FP;
177     if (D.CCCIsCXX()) {
178       if (auto CXXStdlibPath = getCXXStdlibPath()) {
179         SmallString<128> P(*CXXStdlibPath);
180         llvm::sys::path::append(P, M.gccSuffix());
181         FP.push_back(P.str());
182       }
183     }
184     return FP;
185   };
186 
187   Multilibs.push_back(Multilib());
188   // Use the noexcept variant with -fno-exceptions to avoid the extra overhead.
189   Multilibs.push_back(Multilib("noexcept", {}, {}, 1)
190                           .flag("-fexceptions")
191                           .flag("+fno-exceptions"));
192   // ASan has higher priority because we always want the instrumentated version.
193   Multilibs.push_back(Multilib("asan", {}, {}, 2)
194                           .flag("+fsanitize=address"));
195   Multilibs.FilterOut([&](const Multilib &M) {
196     std::vector<std::string> RD = FilePaths(M);
197     return std::all_of(RD.begin(), RD.end(), [&](std::string P) {
198       return !getVFS().exists(P);
199     });
200   });
201 
202   Multilib::flags_list Flags;
203   addMultilibFlag(
204       Args.hasFlag(options::OPT_fexceptions, options::OPT_fno_exceptions, true),
205       "fexceptions", Flags);
206   addMultilibFlag(getSanitizerArgs().needsAsanRt(), "fsanitize=address", Flags);
207   Multilibs.setFilePathsCallback(FilePaths);
208 
209   if (Multilibs.select(Flags, SelectedMultilib))
210     if (!SelectedMultilib.isDefault())
211       if (const auto &PathsCallback = Multilibs.filePathsCallback())
212         for (const auto &Path : PathsCallback(SelectedMultilib))
213           // Prepend the multilib path to ensure it takes the precedence.
214           getFilePaths().insert(getFilePaths().begin(), Path);
215 }
216 
217 std::string Fuchsia::ComputeEffectiveClangTriple(const ArgList &Args,
218                                                  types::ID InputType) const {
219   llvm::Triple Triple(ComputeLLVMTriple(Args, InputType));
220   return (Triple.getArchName() + "-" + Triple.getOSName()).str();
221 }
222 
223 Tool *Fuchsia::buildLinker() const {
224   return new tools::fuchsia::Linker(*this);
225 }
226 
227 ToolChain::RuntimeLibType Fuchsia::GetRuntimeLibType(
228     const ArgList &Args) const {
229   if (Arg *A = Args.getLastArg(clang::driver::options::OPT_rtlib_EQ)) {
230     StringRef Value = A->getValue();
231     if (Value != "compiler-rt")
232       getDriver().Diag(clang::diag::err_drv_invalid_rtlib_name)
233           << A->getAsString(Args);
234   }
235 
236   return ToolChain::RLT_CompilerRT;
237 }
238 
239 ToolChain::CXXStdlibType
240 Fuchsia::GetCXXStdlibType(const ArgList &Args) const {
241   if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
242     StringRef Value = A->getValue();
243     if (Value != "libc++")
244       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
245         << A->getAsString(Args);
246   }
247 
248   return ToolChain::CST_Libcxx;
249 }
250 
251 void Fuchsia::addClangTargetOptions(const ArgList &DriverArgs,
252                                     ArgStringList &CC1Args,
253                                     Action::OffloadKind) const {
254   if (DriverArgs.hasFlag(options::OPT_fuse_init_array,
255                          options::OPT_fno_use_init_array, true))
256     CC1Args.push_back("-fuse-init-array");
257 }
258 
259 void Fuchsia::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
260                                         ArgStringList &CC1Args) const {
261   const Driver &D = getDriver();
262 
263   if (DriverArgs.hasArg(options::OPT_nostdinc))
264     return;
265 
266   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
267     SmallString<128> P(D.ResourceDir);
268     llvm::sys::path::append(P, "include");
269     addSystemInclude(DriverArgs, CC1Args, P);
270   }
271 
272   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
273     return;
274 
275   // Check for configure-time C include directories.
276   StringRef CIncludeDirs(C_INCLUDE_DIRS);
277   if (CIncludeDirs != "") {
278     SmallVector<StringRef, 5> dirs;
279     CIncludeDirs.split(dirs, ":");
280     for (StringRef dir : dirs) {
281       StringRef Prefix =
282           llvm::sys::path::is_absolute(dir) ? StringRef(D.SysRoot) : "";
283       addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
284     }
285     return;
286   }
287 
288   if (!D.SysRoot.empty()) {
289     SmallString<128> P(D.SysRoot);
290     llvm::sys::path::append(P, "include");
291     addExternCSystemInclude(DriverArgs, CC1Args, P.str());
292   }
293 }
294 
295 void Fuchsia::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
296                                            ArgStringList &CC1Args) const {
297   if (DriverArgs.hasArg(options::OPT_nostdlibinc) ||
298       DriverArgs.hasArg(options::OPT_nostdincxx))
299     return;
300 
301   switch (GetCXXStdlibType(DriverArgs)) {
302   case ToolChain::CST_Libcxx: {
303     SmallString<128> P(getDriver().Dir);
304     llvm::sys::path::append(P, "..", "include", "c++", "v1");
305     addSystemInclude(DriverArgs, CC1Args, P.str());
306     break;
307   }
308 
309   default:
310     llvm_unreachable("invalid stdlib name");
311   }
312 }
313 
314 void Fuchsia::AddCXXStdlibLibArgs(const ArgList &Args,
315                                   ArgStringList &CmdArgs) const {
316   switch (GetCXXStdlibType(Args)) {
317   case ToolChain::CST_Libcxx:
318     CmdArgs.push_back("-lc++");
319     break;
320 
321   case ToolChain::CST_Libstdcxx:
322     llvm_unreachable("invalid stdlib name");
323   }
324 }
325 
326 SanitizerMask Fuchsia::getSupportedSanitizers() const {
327   SanitizerMask Res = ToolChain::getSupportedSanitizers();
328   Res |= SanitizerKind::Address;
329   Res |= SanitizerKind::PointerCompare;
330   Res |= SanitizerKind::PointerSubtract;
331   Res |= SanitizerKind::Fuzzer;
332   Res |= SanitizerKind::FuzzerNoLink;
333   Res |= SanitizerKind::SafeStack;
334   Res |= SanitizerKind::Scudo;
335   return Res;
336 }
337 
338 SanitizerMask Fuchsia::getDefaultSanitizers() const {
339   return SanitizerKind::SafeStack;
340 }
341