1 //===--- WebAssembly.cpp - WebAssembly ToolChain Implementation -*- 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 "WebAssembly.h"
10 #include "CommonArgs.h"
11 #include "clang/Basic/Version.h"
12 #include "clang/Config/config.h"
13 #include "clang/Driver/Compilation.h"
14 #include "clang/Driver/Driver.h"
15 #include "clang/Driver/DriverDiagnostic.h"
16 #include "clang/Driver/Options.h"
17 #include "llvm/Support/FileSystem.h"
18 #include "llvm/Support/Path.h"
19 #include "llvm/Option/ArgList.h"
20
21 using namespace clang::driver;
22 using namespace clang::driver::tools;
23 using namespace clang::driver::toolchains;
24 using namespace clang;
25 using namespace llvm::opt;
26
27 /// Following the conventions in https://wiki.debian.org/Multiarch/Tuples,
28 /// we remove the vendor field to form the multiarch triple.
getMultiarchTriple(const Driver & D,const llvm::Triple & TargetTriple,StringRef SysRoot)29 static std::string getMultiarchTriple(const Driver &D,
30 const llvm::Triple &TargetTriple,
31 StringRef SysRoot) {
32 return (TargetTriple.getArchName() + "-" +
33 TargetTriple.getOSAndEnvironmentName()).str();
34 }
35
getLinkerPath(const ArgList & Args) const36 std::string wasm::Linker::getLinkerPath(const ArgList &Args) const {
37 const ToolChain &ToolChain = getToolChain();
38 if (const Arg* A = Args.getLastArg(options::OPT_fuse_ld_EQ)) {
39 StringRef UseLinker = A->getValue();
40 if (!UseLinker.empty()) {
41 if (llvm::sys::path::is_absolute(UseLinker) &&
42 llvm::sys::fs::can_execute(UseLinker))
43 return std::string(UseLinker);
44
45 // Accept 'lld', and 'ld' as aliases for the default linker
46 if (UseLinker != "lld" && UseLinker != "ld")
47 ToolChain.getDriver().Diag(diag::err_drv_invalid_linker_name)
48 << A->getAsString(Args);
49 }
50 }
51
52 return ToolChain.GetProgramPath(ToolChain.getDefaultLinker());
53 }
54
ConstructJob(Compilation & C,const JobAction & JA,const InputInfo & Output,const InputInfoList & Inputs,const ArgList & Args,const char * LinkingOutput) const55 void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
56 const InputInfo &Output,
57 const InputInfoList &Inputs,
58 const ArgList &Args,
59 const char *LinkingOutput) const {
60
61 const ToolChain &ToolChain = getToolChain();
62 const char *Linker = Args.MakeArgString(getLinkerPath(Args));
63 ArgStringList CmdArgs;
64
65 CmdArgs.push_back("-m");
66 if (getToolChain().getTriple().isArch64Bit())
67 CmdArgs.push_back("wasm64");
68 else
69 CmdArgs.push_back("wasm32");
70
71 if (Args.hasArg(options::OPT_s))
72 CmdArgs.push_back("--strip-all");
73
74 Args.AddAllArgs(CmdArgs, options::OPT_L);
75 Args.AddAllArgs(CmdArgs, options::OPT_u);
76 ToolChain.AddFilePathLibArgs(Args, CmdArgs);
77
78 const char *Crt1 = "crt1.o";
79 const char *Entry = NULL;
80 if (const Arg *A = Args.getLastArg(options::OPT_mexec_model_EQ)) {
81 StringRef CM = A->getValue();
82 if (CM == "command") {
83 // Use default values.
84 } else if (CM == "reactor") {
85 Crt1 = "crt1-reactor.o";
86 Entry = "_initialize";
87 } else {
88 ToolChain.getDriver().Diag(diag::err_drv_invalid_argument_to_option)
89 << CM << A->getOption().getName();
90 }
91 }
92 if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles))
93 CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(Crt1)));
94 if (Entry) {
95 CmdArgs.push_back(Args.MakeArgString("--entry"));
96 CmdArgs.push_back(Args.MakeArgString(Entry));
97 }
98
99 AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
100
101 if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
102 if (ToolChain.ShouldLinkCXXStdlib(Args))
103 ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
104
105 if (Args.hasArg(options::OPT_pthread)) {
106 CmdArgs.push_back("-lpthread");
107 CmdArgs.push_back("--shared-memory");
108 }
109
110 CmdArgs.push_back("-lc");
111 AddRunTimeLibs(ToolChain, ToolChain.getDriver(), CmdArgs, Args);
112 }
113
114 CmdArgs.push_back("-o");
115 CmdArgs.push_back(Output.getFilename());
116
117 C.addCommand(std::make_unique<Command>(JA, *this,
118 ResponseFileSupport::AtFileCurCP(),
119 Linker, CmdArgs, Inputs, Output));
120
121 // When optimizing, if wasm-opt is available, run it.
122 if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
123 auto WasmOptPath = getToolChain().GetProgramPath("wasm-opt");
124 if (WasmOptPath != "wasm-opt") {
125 StringRef OOpt = "s";
126 if (A->getOption().matches(options::OPT_O4) ||
127 A->getOption().matches(options::OPT_Ofast))
128 OOpt = "4";
129 else if (A->getOption().matches(options::OPT_O0))
130 OOpt = "0";
131 else if (A->getOption().matches(options::OPT_O))
132 OOpt = A->getValue();
133
134 if (OOpt != "0") {
135 const char *WasmOpt = Args.MakeArgString(WasmOptPath);
136 ArgStringList CmdArgs;
137 CmdArgs.push_back(Output.getFilename());
138 CmdArgs.push_back(Args.MakeArgString(llvm::Twine("-O") + OOpt));
139 CmdArgs.push_back("-o");
140 CmdArgs.push_back(Output.getFilename());
141 C.addCommand(std::make_unique<Command>(
142 JA, *this, ResponseFileSupport::AtFileCurCP(), WasmOpt, CmdArgs,
143 Inputs, Output));
144 }
145 }
146 }
147 }
148
149 /// Given a base library directory, append path components to form the
150 /// LTO directory.
AppendLTOLibDir(const std::string & Dir)151 static std::string AppendLTOLibDir(const std::string &Dir) {
152 // The version allows the path to be keyed to the specific version of
153 // LLVM in used, as the bitcode format is not stable.
154 return Dir + "/llvm-lto/" LLVM_VERSION_STRING;
155 }
156
WebAssembly(const Driver & D,const llvm::Triple & Triple,const llvm::opt::ArgList & Args)157 WebAssembly::WebAssembly(const Driver &D, const llvm::Triple &Triple,
158 const llvm::opt::ArgList &Args)
159 : ToolChain(D, Triple, Args) {
160
161 assert(Triple.isArch32Bit() != Triple.isArch64Bit());
162
163 getProgramPaths().push_back(getDriver().getInstalledDir());
164
165 auto SysRoot = getDriver().SysRoot;
166 if (getTriple().getOS() == llvm::Triple::UnknownOS) {
167 // Theoretically an "unknown" OS should mean no standard libraries, however
168 // it could also mean that a custom set of libraries is in use, so just add
169 // /lib to the search path. Disable multiarch in this case, to discourage
170 // paths containing "unknown" from acquiring meanings.
171 getFilePaths().push_back(SysRoot + "/lib");
172 } else {
173 const std::string MultiarchTriple =
174 getMultiarchTriple(getDriver(), Triple, SysRoot);
175 if (D.isUsingLTO()) {
176 // For LTO, enable use of lto-enabled sysroot libraries too, if available.
177 // Note that the directory is keyed to the LLVM revision, as LLVM's
178 // bitcode format is not stable.
179 auto Dir = AppendLTOLibDir(SysRoot + "/lib/" + MultiarchTriple);
180 getFilePaths().push_back(Dir);
181 }
182 getFilePaths().push_back(SysRoot + "/lib/" + MultiarchTriple);
183 }
184 }
185
IsMathErrnoDefault() const186 bool WebAssembly::IsMathErrnoDefault() const { return false; }
187
IsObjCNonFragileABIDefault() const188 bool WebAssembly::IsObjCNonFragileABIDefault() const { return true; }
189
UseObjCMixedDispatch() const190 bool WebAssembly::UseObjCMixedDispatch() const { return true; }
191
isPICDefault() const192 bool WebAssembly::isPICDefault() const { return false; }
193
isPIEDefault() const194 bool WebAssembly::isPIEDefault() const { return false; }
195
isPICDefaultForced() const196 bool WebAssembly::isPICDefaultForced() const { return false; }
197
IsIntegratedAssemblerDefault() const198 bool WebAssembly::IsIntegratedAssemblerDefault() const { return true; }
199
hasBlocksRuntime() const200 bool WebAssembly::hasBlocksRuntime() const { return false; }
201
202 // TODO: Support profiling.
SupportsProfiling() const203 bool WebAssembly::SupportsProfiling() const { return false; }
204
HasNativeLLVMSupport() const205 bool WebAssembly::HasNativeLLVMSupport() const { return true; }
206
addClangTargetOptions(const ArgList & DriverArgs,ArgStringList & CC1Args,Action::OffloadKind) const207 void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
208 ArgStringList &CC1Args,
209 Action::OffloadKind) const {
210 if (!DriverArgs.hasFlag(clang::driver::options::OPT_fuse_init_array,
211 options::OPT_fno_use_init_array, true))
212 CC1Args.push_back("-fno-use-init-array");
213
214 // '-pthread' implies atomics, bulk-memory, mutable-globals, and sign-ext
215 if (DriverArgs.hasFlag(options::OPT_pthread, options::OPT_no_pthread,
216 false)) {
217 if (DriverArgs.hasFlag(options::OPT_mno_atomics, options::OPT_matomics,
218 false))
219 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
220 << "-pthread"
221 << "-mno-atomics";
222 if (DriverArgs.hasFlag(options::OPT_mno_bulk_memory,
223 options::OPT_mbulk_memory, false))
224 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
225 << "-pthread"
226 << "-mno-bulk-memory";
227 if (DriverArgs.hasFlag(options::OPT_mno_mutable_globals,
228 options::OPT_mmutable_globals, false))
229 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
230 << "-pthread"
231 << "-mno-mutable-globals";
232 if (DriverArgs.hasFlag(options::OPT_mno_sign_ext, options::OPT_msign_ext,
233 false))
234 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
235 << "-pthread"
236 << "-mno-sign-ext";
237 CC1Args.push_back("-target-feature");
238 CC1Args.push_back("+atomics");
239 CC1Args.push_back("-target-feature");
240 CC1Args.push_back("+bulk-memory");
241 CC1Args.push_back("-target-feature");
242 CC1Args.push_back("+mutable-globals");
243 CC1Args.push_back("-target-feature");
244 CC1Args.push_back("+sign-ext");
245 }
246
247 if (!DriverArgs.hasFlag(options::OPT_mmutable_globals,
248 options::OPT_mno_mutable_globals, false)) {
249 // -fPIC implies +mutable-globals because the PIC ABI used by the linker
250 // depends on importing and exporting mutable globals.
251 llvm::Reloc::Model RelocationModel;
252 unsigned PICLevel;
253 bool IsPIE;
254 std::tie(RelocationModel, PICLevel, IsPIE) =
255 ParsePICArgs(*this, DriverArgs);
256 if (RelocationModel == llvm::Reloc::PIC_) {
257 if (DriverArgs.hasFlag(options::OPT_mno_mutable_globals,
258 options::OPT_mmutable_globals, false)) {
259 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
260 << "-fPIC"
261 << "-mno-mutable-globals";
262 }
263 CC1Args.push_back("-target-feature");
264 CC1Args.push_back("+mutable-globals");
265 }
266 }
267
268 if (DriverArgs.getLastArg(options::OPT_fwasm_exceptions)) {
269 // '-fwasm-exceptions' is not compatible with '-mno-exception-handling'
270 if (DriverArgs.hasFlag(options::OPT_mno_exception_handing,
271 options::OPT_mexception_handing, false))
272 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
273 << "-fwasm-exceptions"
274 << "-mno-exception-handling";
275 // '-fwasm-exceptions' is not compatible with '-mno-reference-types'
276 if (DriverArgs.hasFlag(options::OPT_mno_reference_types,
277 options::OPT_mexception_handing, false))
278 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
279 << "-fwasm-exceptions"
280 << "-mno-reference-types";
281 // '-fwasm-exceptions' is not compatible with
282 // '-mllvm -enable-emscripten-cxx-exceptions'
283 for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
284 if (StringRef(A->getValue(0)) == "-enable-emscripten-cxx-exceptions")
285 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
286 << "-fwasm-exceptions"
287 << "-mllvm -enable-emscripten-cxx-exceptions";
288 }
289 // '-fwasm-exceptions' implies exception-handling and reference-types
290 CC1Args.push_back("-target-feature");
291 CC1Args.push_back("+exception-handling");
292 CC1Args.push_back("-target-feature");
293 CC1Args.push_back("+reference-types");
294 }
295 }
296
GetDefaultRuntimeLibType() const297 ToolChain::RuntimeLibType WebAssembly::GetDefaultRuntimeLibType() const {
298 return ToolChain::RLT_CompilerRT;
299 }
300
301 ToolChain::CXXStdlibType
GetCXXStdlibType(const ArgList & Args) const302 WebAssembly::GetCXXStdlibType(const ArgList &Args) const {
303 if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
304 StringRef Value = A->getValue();
305 if (Value != "libc++")
306 getDriver().Diag(diag::err_drv_invalid_stdlib_name)
307 << A->getAsString(Args);
308 }
309 return ToolChain::CST_Libcxx;
310 }
311
AddClangSystemIncludeArgs(const ArgList & DriverArgs,ArgStringList & CC1Args) const312 void WebAssembly::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
313 ArgStringList &CC1Args) const {
314 if (DriverArgs.hasArg(clang::driver::options::OPT_nostdinc))
315 return;
316
317 const Driver &D = getDriver();
318
319 if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
320 SmallString<128> P(D.ResourceDir);
321 llvm::sys::path::append(P, "include");
322 addSystemInclude(DriverArgs, CC1Args, P);
323 }
324
325 if (DriverArgs.hasArg(options::OPT_nostdlibinc))
326 return;
327
328 // Check for configure-time C include directories.
329 StringRef CIncludeDirs(C_INCLUDE_DIRS);
330 if (CIncludeDirs != "") {
331 SmallVector<StringRef, 5> dirs;
332 CIncludeDirs.split(dirs, ":");
333 for (StringRef dir : dirs) {
334 StringRef Prefix =
335 llvm::sys::path::is_absolute(dir) ? "" : StringRef(D.SysRoot);
336 addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
337 }
338 return;
339 }
340
341 if (getTriple().getOS() != llvm::Triple::UnknownOS) {
342 const std::string MultiarchTriple =
343 getMultiarchTriple(D, getTriple(), D.SysRoot);
344 addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include/" + MultiarchTriple);
345 }
346 addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include");
347 }
348
AddClangCXXStdlibIncludeArgs(const ArgList & DriverArgs,ArgStringList & CC1Args) const349 void WebAssembly::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
350 ArgStringList &CC1Args) const {
351 if (!DriverArgs.hasArg(options::OPT_nostdlibinc) &&
352 !DriverArgs.hasArg(options::OPT_nostdincxx)) {
353 if (getTriple().getOS() != llvm::Triple::UnknownOS) {
354 const std::string MultiarchTriple =
355 getMultiarchTriple(getDriver(), getTriple(), getDriver().SysRoot);
356 addSystemInclude(DriverArgs, CC1Args,
357 getDriver().SysRoot + "/include/" + MultiarchTriple +
358 "/c++/v1");
359 }
360 addSystemInclude(DriverArgs, CC1Args,
361 getDriver().SysRoot + "/include/c++/v1");
362 }
363 }
364
AddCXXStdlibLibArgs(const llvm::opt::ArgList & Args,llvm::opt::ArgStringList & CmdArgs) const365 void WebAssembly::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
366 llvm::opt::ArgStringList &CmdArgs) const {
367
368 switch (GetCXXStdlibType(Args)) {
369 case ToolChain::CST_Libcxx:
370 CmdArgs.push_back("-lc++");
371 CmdArgs.push_back("-lc++abi");
372 break;
373 case ToolChain::CST_Libstdcxx:
374 llvm_unreachable("invalid stdlib name");
375 }
376 }
377
getSupportedSanitizers() const378 SanitizerMask WebAssembly::getSupportedSanitizers() const {
379 SanitizerMask Res = ToolChain::getSupportedSanitizers();
380 if (getTriple().isOSEmscripten()) {
381 Res |= SanitizerKind::Vptr | SanitizerKind::Leak | SanitizerKind::Address;
382 }
383 return Res;
384 }
385
buildLinker() const386 Tool *WebAssembly::buildLinker() const {
387 return new tools::wasm::Linker(*this);
388 }
389