contrib/llvm-project/clang/lib/Driver/ToolChains/WebAssembly.cpp

   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.
  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
  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))
  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
  55 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>(
 118       JA, *this, ResponseFileSupport::AtFileCurCP(), Linker, CmdArgs, Inputs));
 119
 120   // When optimizing, if wasm-opt is available, run it.
 121   if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
 122     auto WasmOptPath = getToolChain().GetProgramPath("wasm-opt");
 123     if (WasmOptPath != "wasm-opt") {
 124       StringRef OOpt = "s";
 125       if (A->getOption().matches(options::OPT_O4) ||
 126           A->getOption().matches(options::OPT_Ofast))
 127         OOpt = "4";
 128       else if (A->getOption().matches(options::OPT_O0))
 129         OOpt = "0";
 130       else if (A->getOption().matches(options::OPT_O))
 131         OOpt = A->getValue();
 132
 133       if (OOpt != "0") {
 134         const char *WasmOpt = Args.MakeArgString(WasmOptPath);
 135         ArgStringList CmdArgs;
 136         CmdArgs.push_back(Output.getFilename());
 137         CmdArgs.push_back(Args.MakeArgString(llvm::Twine("-O") + OOpt));
 138         CmdArgs.push_back("-o");
 139         CmdArgs.push_back(Output.getFilename());
 140         C.addCommand(std::make_unique<Command>(
 141             JA, *this, ResponseFileSupport::AtFileCurCP(), WasmOpt, CmdArgs,
 142             Inputs));
 143       }
 144     }
 145   }
 146 }
 147
 148 /// Given a base library directory, append path components to form the
 149 /// LTO directory.
 150 static std::string AppendLTOLibDir(const std::string &Dir) {
 151     // The version allows the path to be keyed to the specific version of
 152     // LLVM in used, as the bitcode format is not stable.
 153     return Dir + "/llvm-lto/" LLVM_VERSION_STRING;
 154 }
 155
 156 WebAssembly::WebAssembly(const Driver &D, const llvm::Triple &Triple,
 157                          const llvm::opt::ArgList &Args)
 158     : ToolChain(D, Triple, Args) {
 159
 160   assert(Triple.isArch32Bit() != Triple.isArch64Bit());
 161
 162   getProgramPaths().push_back(getDriver().getInstalledDir());
 163
 164   auto SysRoot = getDriver().SysRoot;
 165   if (getTriple().getOS() == llvm::Triple::UnknownOS) {
 166     // Theoretically an "unknown" OS should mean no standard libraries, however
 167     // it could also mean that a custom set of libraries is in use, so just add
 168     // /lib to the search path. Disable multiarch in this case, to discourage
 169     // paths containing "unknown" from acquiring meanings.
 170     getFilePaths().push_back(SysRoot + "/lib");
 171   } else {
 172     const std::string MultiarchTriple =
 173         getMultiarchTriple(getDriver(), Triple, SysRoot);
 174     if (D.isUsingLTO()) {
 175       // For LTO, enable use of lto-enabled sysroot libraries too, if available.
 176       // Note that the directory is keyed to the LLVM revision, as LLVM's
 177       // bitcode format is not stable.
 178       auto Dir = AppendLTOLibDir(SysRoot + "/lib/" + MultiarchTriple);
 179       getFilePaths().push_back(Dir);
 180     }
 181     getFilePaths().push_back(SysRoot + "/lib/" + MultiarchTriple);
 182   }
 183 }
 184
 185 bool WebAssembly::IsMathErrnoDefault() const { return false; }
 186
 187 bool WebAssembly::IsObjCNonFragileABIDefault() const { return true; }
 188
 189 bool WebAssembly::UseObjCMixedDispatch() const { return true; }
 190
 191 bool WebAssembly::isPICDefault() const { return false; }
 192
 193 bool WebAssembly::isPIEDefault() const { return false; }
 194
 195 bool WebAssembly::isPICDefaultForced() const { return false; }
 196
 197 bool WebAssembly::IsIntegratedAssemblerDefault() const { return true; }
 198
 199 bool WebAssembly::hasBlocksRuntime() const { return false; }
 200
 201 // TODO: Support profiling.
 202 bool WebAssembly::SupportsProfiling() const { return false; }
 203
 204 bool WebAssembly::HasNativeLLVMSupport() const { return true; }
 205
 206 void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
 207                                         ArgStringList &CC1Args,
 208                                         Action::OffloadKind) const {
 209   if (!DriverArgs.hasFlag(clang::driver::options::OPT_fuse_init_array,
 210                           options::OPT_fno_use_init_array, true))
 211     CC1Args.push_back("-fno-use-init-array");
 212
 213   // '-pthread' implies atomics, bulk-memory, mutable-globals, and sign-ext
 214   if (DriverArgs.hasFlag(options::OPT_pthread, options::OPT_no_pthread,
 215                          false)) {
 216     if (DriverArgs.hasFlag(options::OPT_mno_atomics, options::OPT_matomics,
 217                            false))
 218       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 219           << "-pthread"
 220           << "-mno-atomics";
 221     if (DriverArgs.hasFlag(options::OPT_mno_bulk_memory,
 222                            options::OPT_mbulk_memory, false))
 223       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 224           << "-pthread"
 225           << "-mno-bulk-memory";
 226     if (DriverArgs.hasFlag(options::OPT_mno_mutable_globals,
 227                            options::OPT_mmutable_globals, false))
 228       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 229           << "-pthread"
 230           << "-mno-mutable-globals";
 231     if (DriverArgs.hasFlag(options::OPT_mno_sign_ext, options::OPT_msign_ext,
 232                            false))
 233       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 234           << "-pthread"
 235           << "-mno-sign-ext";
 236     CC1Args.push_back("-target-feature");
 237     CC1Args.push_back("+atomics");
 238     CC1Args.push_back("-target-feature");
 239     CC1Args.push_back("+bulk-memory");
 240     CC1Args.push_back("-target-feature");
 241     CC1Args.push_back("+mutable-globals");
 242     CC1Args.push_back("-target-feature");
 243     CC1Args.push_back("+sign-ext");
 244   }
 245
 246   if (DriverArgs.getLastArg(options::OPT_fwasm_exceptions)) {
 247     // '-fwasm-exceptions' is not compatible with '-mno-exception-handling'
 248     if (DriverArgs.hasFlag(options::OPT_mno_exception_handing,
 249                            options::OPT_mexception_handing, false))
 250       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 251           << "-fwasm-exceptions"
 252           << "-mno-exception-handling";
 253     // '-fwasm-exceptions' is not compatible with '-mno-reference-types'
 254     if (DriverArgs.hasFlag(options::OPT_mno_reference_types,
 255                            options::OPT_mexception_handing, false))
 256       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 257           << "-fwasm-exceptions"
 258           << "-mno-reference-types";
 259     // '-fwasm-exceptions' is not compatible with
 260     // '-mllvm -enable-emscripten-cxx-exceptions'
 261     for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
 262       if (StringRef(A->getValue(0)) == "-enable-emscripten-cxx-exceptions")
 263         getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 264             << "-fwasm-exceptions"
 265             << "-mllvm -enable-emscripten-cxx-exceptions";
 266     }
 267     // '-fwasm-exceptions' implies exception-handling and reference-types
 268     CC1Args.push_back("-target-feature");
 269     CC1Args.push_back("+exception-handling");
 270     CC1Args.push_back("-target-feature");
 271     CC1Args.push_back("+reference-types");
 272   }
 273 }
 274
 275 ToolChain::RuntimeLibType WebAssembly::GetDefaultRuntimeLibType() const {
 276   return ToolChain::RLT_CompilerRT;
 277 }
 278
 279 ToolChain::CXXStdlibType
 280 WebAssembly::GetCXXStdlibType(const ArgList &Args) const {
 281   if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
 282     StringRef Value = A->getValue();
 283     if (Value != "libc++")
 284       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
 285           << A->getAsString(Args);
 286   }
 287   return ToolChain::CST_Libcxx;
 288 }
 289
 290 void WebAssembly::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
 291                                             ArgStringList &CC1Args) const {
 292   if (DriverArgs.hasArg(clang::driver::options::OPT_nostdinc))
 293     return;
 294
 295   const Driver &D = getDriver();
 296
 297   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
 298     SmallString<128> P(D.ResourceDir);
 299     llvm::sys::path::append(P, "include");
 300     addSystemInclude(DriverArgs, CC1Args, P);
 301   }
 302
 303   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
 304     return;
 305
 306   // Check for configure-time C include directories.
 307   StringRef CIncludeDirs(C_INCLUDE_DIRS);
 308   if (CIncludeDirs != "") {
 309     SmallVector<StringRef, 5> dirs;
 310     CIncludeDirs.split(dirs, ":");
 311     for (StringRef dir : dirs) {
 312       StringRef Prefix =
 313           llvm::sys::path::is_absolute(dir) ? "" : StringRef(D.SysRoot);
 314       addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
 315     }
 316     return;
 317   }
 318
 319   if (getTriple().getOS() != llvm::Triple::UnknownOS) {
 320     const std::string MultiarchTriple =
 321         getMultiarchTriple(D, getTriple(), D.SysRoot);
 322     addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include/" + MultiarchTriple);
 323   }
 324   addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include");
 325 }
 326
 327 void WebAssembly::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
 328                                                ArgStringList &CC1Args) const {
 329   if (!DriverArgs.hasArg(options::OPT_nostdlibinc) &&
 330       !DriverArgs.hasArg(options::OPT_nostdincxx)) {
 331     if (getTriple().getOS() != llvm::Triple::UnknownOS) {
 332       const std::string MultiarchTriple =
 333           getMultiarchTriple(getDriver(), getTriple(), getDriver().SysRoot);
 334       addSystemInclude(DriverArgs, CC1Args,
 335                        getDriver().SysRoot + "/include/" + MultiarchTriple +
 336                            "/c++/v1");
 337     }
 338     addSystemInclude(DriverArgs, CC1Args,
 339                      getDriver().SysRoot + "/include/c++/v1");
 340   }
 341 }
 342
 343 void WebAssembly::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
 344                                       llvm::opt::ArgStringList &CmdArgs) const {
 345
 346   switch (GetCXXStdlibType(Args)) {
 347   case ToolChain::CST_Libcxx:
 348     CmdArgs.push_back("-lc++");
 349     CmdArgs.push_back("-lc++abi");
 350     break;
 351   case ToolChain::CST_Libstdcxx:
 352     llvm_unreachable("invalid stdlib name");
 353   }
 354 }
 355
 356 SanitizerMask WebAssembly::getSupportedSanitizers() const {
 357   SanitizerMask Res = ToolChain::getSupportedSanitizers();
 358   if (getTriple().isOSEmscripten()) {
 359     Res |= SanitizerKind::Vptr | SanitizerKind::Leak | SanitizerKind::Address;
 360   }
 361   return Res;
 362 }
 363
 364 Tool *WebAssembly::buildLinker() const {
 365   return new tools::wasm::Linker(*this);
 366 }