1 //===--- WebAssembly.cpp - WebAssembly ToolChain Implementation -*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
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"
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;
27 /// Following the conventions in https://wiki.debian.org/Multiarch/Tuples,
28 /// we remove the vendor field to form the multiarch triple.
29 static std::string getMultiarchTriple(const Driver &D,
30 const llvm::Triple &TargetTriple,
32 return (TargetTriple.getArchName() + "-" +
33 TargetTriple.getOSAndEnvironmentName()).str();
36 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))
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);
52 return ToolChain.GetProgramPath(ToolChain.getDefaultLinker());
55 void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
56 const InputInfo &Output,
57 const InputInfoList &Inputs,
59 const char *LinkingOutput) const {
61 const ToolChain &ToolChain = getToolChain();
62 const char *Linker = Args.MakeArgString(getLinkerPath(Args));
63 ArgStringList CmdArgs;
65 if (Args.hasArg(options::OPT_s))
66 CmdArgs.push_back("--strip-all");
68 Args.AddAllArgs(CmdArgs, options::OPT_L);
69 Args.AddAllArgs(CmdArgs, options::OPT_u);
70 ToolChain.AddFilePathLibArgs(Args, CmdArgs);
72 if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles))
73 CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt1.o")));
75 AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
77 if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
78 if (ToolChain.ShouldLinkCXXStdlib(Args))
79 ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
81 if (Args.hasArg(options::OPT_pthread)) {
82 CmdArgs.push_back("-lpthread");
83 CmdArgs.push_back("--shared-memory");
86 CmdArgs.push_back("-lc");
87 AddRunTimeLibs(ToolChain, ToolChain.getDriver(), CmdArgs, Args);
90 CmdArgs.push_back("-o");
91 CmdArgs.push_back(Output.getFilename());
93 C.addCommand(std::make_unique<Command>(JA, *this, Linker, CmdArgs, Inputs));
95 // When optimizing, if wasm-opt is available, run it.
96 if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
97 auto WasmOptPath = getToolChain().GetProgramPath("wasm-opt");
98 if (WasmOptPath != "wasm-opt") {
100 if (A->getOption().matches(options::OPT_O4) ||
101 A->getOption().matches(options::OPT_Ofast))
103 else if (A->getOption().matches(options::OPT_O0))
105 else if (A->getOption().matches(options::OPT_O))
106 OOpt = A->getValue();
109 const char *WasmOpt = Args.MakeArgString(WasmOptPath);
110 ArgStringList CmdArgs;
111 CmdArgs.push_back(Output.getFilename());
112 CmdArgs.push_back(Args.MakeArgString(llvm::Twine("-O") + OOpt));
113 CmdArgs.push_back("-o");
114 CmdArgs.push_back(Output.getFilename());
115 C.addCommand(std::make_unique<Command>(JA, *this, WasmOpt, CmdArgs, Inputs));
121 /// Given a base library directory, append path components to form the
123 static std::string AppendLTOLibDir(const std::string &Dir) {
124 // The version allows the path to be keyed to the specific version of
125 // LLVM in used, as the bitcode format is not stable.
126 return Dir + "/llvm-lto/" LLVM_VERSION_STRING;
129 WebAssembly::WebAssembly(const Driver &D, const llvm::Triple &Triple,
130 const llvm::opt::ArgList &Args)
131 : ToolChain(D, Triple, Args) {
133 assert(Triple.isArch32Bit() != Triple.isArch64Bit());
135 getProgramPaths().push_back(getDriver().getInstalledDir());
137 auto SysRoot = getDriver().SysRoot;
138 if (getTriple().getOS() == llvm::Triple::UnknownOS) {
139 // Theoretically an "unknown" OS should mean no standard libraries, however
140 // it could also mean that a custom set of libraries is in use, so just add
141 // /lib to the search path. Disable multiarch in this case, to discourage
142 // paths containing "unknown" from acquiring meanings.
143 getFilePaths().push_back(SysRoot + "/lib");
145 const std::string MultiarchTriple =
146 getMultiarchTriple(getDriver(), Triple, SysRoot);
147 if (D.isUsingLTO()) {
148 // For LTO, enable use of lto-enabled sysroot libraries too, if available.
149 // Note that the directory is keyed to the LLVM revision, as LLVM's
150 // bitcode format is not stable.
151 auto Dir = AppendLTOLibDir(SysRoot + "/lib/" + MultiarchTriple);
152 getFilePaths().push_back(Dir);
154 getFilePaths().push_back(SysRoot + "/lib/" + MultiarchTriple);
158 bool WebAssembly::IsMathErrnoDefault() const { return false; }
160 bool WebAssembly::IsObjCNonFragileABIDefault() const { return true; }
162 bool WebAssembly::UseObjCMixedDispatch() const { return true; }
164 bool WebAssembly::isPICDefault() const { return false; }
166 bool WebAssembly::isPIEDefault() const { return false; }
168 bool WebAssembly::isPICDefaultForced() const { return false; }
170 bool WebAssembly::IsIntegratedAssemblerDefault() const { return true; }
172 bool WebAssembly::hasBlocksRuntime() const { return false; }
174 // TODO: Support profiling.
175 bool WebAssembly::SupportsProfiling() const { return false; }
177 bool WebAssembly::HasNativeLLVMSupport() const { return true; }
179 void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
180 ArgStringList &CC1Args,
181 Action::OffloadKind) const {
182 if (!DriverArgs.hasFlag(clang::driver::options::OPT_fuse_init_array,
183 options::OPT_fno_use_init_array, true))
184 CC1Args.push_back("-fno-use-init-array");
186 // '-pthread' implies atomics, bulk-memory, mutable-globals, and sign-ext
187 if (DriverArgs.hasFlag(options::OPT_pthread, options::OPT_no_pthread,
189 if (DriverArgs.hasFlag(options::OPT_mno_atomics, options::OPT_matomics,
191 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
194 if (DriverArgs.hasFlag(options::OPT_mno_bulk_memory,
195 options::OPT_mbulk_memory, false))
196 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
198 << "-mno-bulk-memory";
199 if (DriverArgs.hasFlag(options::OPT_mno_mutable_globals,
200 options::OPT_mmutable_globals, false))
201 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
203 << "-mno-mutable-globals";
204 if (DriverArgs.hasFlag(options::OPT_mno_sign_ext, options::OPT_msign_ext,
206 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
209 CC1Args.push_back("-target-feature");
210 CC1Args.push_back("+atomics");
211 CC1Args.push_back("-target-feature");
212 CC1Args.push_back("+bulk-memory");
213 CC1Args.push_back("-target-feature");
214 CC1Args.push_back("+mutable-globals");
215 CC1Args.push_back("-target-feature");
216 CC1Args.push_back("+sign-ext");
219 if (DriverArgs.getLastArg(options::OPT_fwasm_exceptions)) {
220 // '-fwasm-exceptions' is not compatible with '-mno-exception-handling'
221 if (DriverArgs.hasFlag(options::OPT_mno_exception_handing,
222 options::OPT_mexception_handing, false))
223 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
224 << "-fwasm-exceptions"
225 << "-mno-exception-handling";
226 // '-fwasm-exceptions' is not compatible with '-mno-reference-types'
227 if (DriverArgs.hasFlag(options::OPT_mno_reference_types,
228 options::OPT_mexception_handing, false))
229 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
230 << "-fwasm-exceptions"
231 << "-mno-reference-types";
232 // '-fwasm-exceptions' is not compatible with
233 // '-mllvm -enable-emscripten-cxx-exceptions'
234 for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
235 if (StringRef(A->getValue(0)) == "-enable-emscripten-cxx-exceptions")
236 getDriver().Diag(diag::err_drv_argument_not_allowed_with)
237 << "-fwasm-exceptions"
238 << "-mllvm -enable-emscripten-cxx-exceptions";
240 // '-fwasm-exceptions' implies exception-handling and reference-types
241 CC1Args.push_back("-target-feature");
242 CC1Args.push_back("+exception-handling");
243 CC1Args.push_back("-target-feature");
244 CC1Args.push_back("+reference-types");
248 ToolChain::RuntimeLibType WebAssembly::GetDefaultRuntimeLibType() const {
249 return ToolChain::RLT_CompilerRT;
252 ToolChain::CXXStdlibType
253 WebAssembly::GetCXXStdlibType(const ArgList &Args) const {
254 if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
255 StringRef Value = A->getValue();
256 if (Value != "libc++")
257 getDriver().Diag(diag::err_drv_invalid_stdlib_name)
258 << A->getAsString(Args);
260 return ToolChain::CST_Libcxx;
263 void WebAssembly::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
264 ArgStringList &CC1Args) const {
265 if (DriverArgs.hasArg(clang::driver::options::OPT_nostdinc))
268 const Driver &D = getDriver();
270 if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
271 SmallString<128> P(D.ResourceDir);
272 llvm::sys::path::append(P, "include");
273 addSystemInclude(DriverArgs, CC1Args, P);
276 if (DriverArgs.hasArg(options::OPT_nostdlibinc))
279 // Check for configure-time C include directories.
280 StringRef CIncludeDirs(C_INCLUDE_DIRS);
281 if (CIncludeDirs != "") {
282 SmallVector<StringRef, 5> dirs;
283 CIncludeDirs.split(dirs, ":");
284 for (StringRef dir : dirs) {
286 llvm::sys::path::is_absolute(dir) ? StringRef(D.SysRoot) : "";
287 addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
292 if (getTriple().getOS() != llvm::Triple::UnknownOS) {
293 const std::string MultiarchTriple =
294 getMultiarchTriple(D, getTriple(), D.SysRoot);
295 addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include/" + MultiarchTriple);
297 addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include");
300 void WebAssembly::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
301 ArgStringList &CC1Args) const {
302 if (!DriverArgs.hasArg(options::OPT_nostdlibinc) &&
303 !DriverArgs.hasArg(options::OPT_nostdincxx)) {
304 if (getTriple().getOS() != llvm::Triple::UnknownOS) {
305 const std::string MultiarchTriple =
306 getMultiarchTriple(getDriver(), getTriple(), getDriver().SysRoot);
307 addSystemInclude(DriverArgs, CC1Args,
308 getDriver().SysRoot + "/include/" + MultiarchTriple +
311 addSystemInclude(DriverArgs, CC1Args,
312 getDriver().SysRoot + "/include/c++/v1");
316 void WebAssembly::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
317 llvm::opt::ArgStringList &CmdArgs) const {
319 switch (GetCXXStdlibType(Args)) {
320 case ToolChain::CST_Libcxx:
321 CmdArgs.push_back("-lc++");
322 CmdArgs.push_back("-lc++abi");
324 case ToolChain::CST_Libstdcxx:
325 llvm_unreachable("invalid stdlib name");
329 SanitizerMask WebAssembly::getSupportedSanitizers() const {
330 SanitizerMask Res = ToolChain::getSupportedSanitizers();
331 if (getTriple().isOSEmscripten()) {
332 Res |= SanitizerKind::Vptr | SanitizerKind::Leak | SanitizerKind::Address;
337 Tool *WebAssembly::buildLinker() const {
338 return new tools::wasm::Linker(*this);