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/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 "llvm/Support/FileSystem.h"
  17 #include "llvm/Support/Path.h"
  18 #include "llvm/Option/ArgList.h"
  19
  20 using namespace clang::driver;
  21 using namespace clang::driver::tools;
  22 using namespace clang::driver::toolchains;
  23 using namespace clang;
  24 using namespace llvm::opt;
  25
  26 /// Following the conventions in https://wiki.debian.org/Multiarch/Tuples,
  27 /// we remove the vendor field to form the multiarch triple.
  28 static std::string getMultiarchTriple(const Driver &D,
  29                                       const llvm::Triple &TargetTriple,
  30                                       StringRef SysRoot) {
  31     return (TargetTriple.getArchName() + "-" +
  32             TargetTriple.getOSAndEnvironmentName()).str();
  33 }
  34
  35 std::string wasm::Linker::getLinkerPath(const ArgList &Args) const {
  36   const ToolChain &ToolChain = getToolChain();
  37   if (const Arg* A = Args.getLastArg(options::OPT_fuse_ld_EQ)) {
  38     StringRef UseLinker = A->getValue();
  39     if (!UseLinker.empty()) {
  40       if (llvm::sys::path::is_absolute(UseLinker) &&
  41           llvm::sys::fs::can_execute(UseLinker))
  42         return UseLinker;
  43
  44       // Accept 'lld', and 'ld' as aliases for the default linker
  45       if (UseLinker != "lld" && UseLinker != "ld")
  46         ToolChain.getDriver().Diag(diag::err_drv_invalid_linker_name)
  47             << A->getAsString(Args);
  48     }
  49   }
  50
  51   return ToolChain.GetProgramPath(ToolChain.getDefaultLinker());
  52 }
  53
  54 void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
  55                                 const InputInfo &Output,
  56                                 const InputInfoList &Inputs,
  57                                 const ArgList &Args,
  58                                 const char *LinkingOutput) const {
  59
  60   const ToolChain &ToolChain = getToolChain();
  61   const char *Linker = Args.MakeArgString(getLinkerPath(Args));
  62   ArgStringList CmdArgs;
  63
  64   if (Args.hasArg(options::OPT_s))
  65     CmdArgs.push_back("--strip-all");
  66
  67   Args.AddAllArgs(CmdArgs, options::OPT_L);
  68   Args.AddAllArgs(CmdArgs, options::OPT_u);
  69   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
  70
  71   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles))
  72     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt1.o")));
  73
  74   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
  75
  76   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
  77     if (ToolChain.ShouldLinkCXXStdlib(Args))
  78       ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
  79
  80     if (Args.hasArg(options::OPT_pthread)) {
  81       CmdArgs.push_back("-lpthread");
  82       CmdArgs.push_back("--shared-memory");
  83     }
  84
  85     CmdArgs.push_back("-lc");
  86     AddRunTimeLibs(ToolChain, ToolChain.getDriver(), CmdArgs, Args);
  87   }
  88
  89   CmdArgs.push_back("-o");
  90   CmdArgs.push_back(Output.getFilename());
  91
  92   C.addCommand(std::make_unique<Command>(JA, *this, Linker, CmdArgs, Inputs));
  93 }
  94
  95 WebAssembly::WebAssembly(const Driver &D, const llvm::Triple &Triple,
  96                          const llvm::opt::ArgList &Args)
  97     : ToolChain(D, Triple, Args) {
  98
  99   assert(Triple.isArch32Bit() != Triple.isArch64Bit());
 100
 101   getProgramPaths().push_back(getDriver().getInstalledDir());
 102
 103   if (getTriple().getOS() == llvm::Triple::UnknownOS) {
 104     // Theoretically an "unknown" OS should mean no standard libraries, however
 105     // it could also mean that a custom set of libraries is in use, so just add
 106     // /lib to the search path. Disable multiarch in this case, to discourage
 107     // paths containing "unknown" from acquiring meanings.
 108     getFilePaths().push_back(getDriver().SysRoot + "/lib");
 109   } else {
 110     const std::string MultiarchTriple =
 111         getMultiarchTriple(getDriver(), Triple, getDriver().SysRoot);
 112     getFilePaths().push_back(getDriver().SysRoot + "/lib/" + MultiarchTriple);
 113   }
 114 }
 115
 116 bool WebAssembly::IsMathErrnoDefault() const { return false; }
 117
 118 bool WebAssembly::IsObjCNonFragileABIDefault() const { return true; }
 119
 120 bool WebAssembly::UseObjCMixedDispatch() const { return true; }
 121
 122 bool WebAssembly::isPICDefault() const { return false; }
 123
 124 bool WebAssembly::isPIEDefault() const { return false; }
 125
 126 bool WebAssembly::isPICDefaultForced() const { return false; }
 127
 128 bool WebAssembly::IsIntegratedAssemblerDefault() const { return true; }
 129
 130 bool WebAssembly::hasBlocksRuntime() const { return false; }
 131
 132 // TODO: Support profiling.
 133 bool WebAssembly::SupportsProfiling() const { return false; }
 134
 135 bool WebAssembly::HasNativeLLVMSupport() const { return true; }
 136
 137 void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
 138                                         ArgStringList &CC1Args,
 139                                         Action::OffloadKind) const {
 140   if (DriverArgs.hasFlag(clang::driver::options::OPT_fuse_init_array,
 141                          options::OPT_fno_use_init_array, true))
 142     CC1Args.push_back("-fuse-init-array");
 143
 144   // '-pthread' implies atomics, bulk-memory, mutable-globals, and sign-ext
 145   if (DriverArgs.hasFlag(options::OPT_pthread, options::OPT_no_pthread,
 146                          false)) {
 147     if (DriverArgs.hasFlag(options::OPT_mno_atomics, options::OPT_matomics,
 148                            false))
 149       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 150           << "-pthread"
 151           << "-mno-atomics";
 152     if (DriverArgs.hasFlag(options::OPT_mno_bulk_memory,
 153                            options::OPT_mbulk_memory, false))
 154       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 155           << "-pthread"
 156           << "-mno-bulk-memory";
 157     if (DriverArgs.hasFlag(options::OPT_mno_mutable_globals,
 158                            options::OPT_mmutable_globals, false))
 159       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 160           << "-pthread"
 161           << "-mno-mutable-globals";
 162     if (DriverArgs.hasFlag(options::OPT_mno_sign_ext, options::OPT_msign_ext,
 163                            false))
 164       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 165           << "-pthread"
 166           << "-mno-sign-ext";
 167     CC1Args.push_back("-target-feature");
 168     CC1Args.push_back("+atomics");
 169     CC1Args.push_back("-target-feature");
 170     CC1Args.push_back("+bulk-memory");
 171     CC1Args.push_back("-target-feature");
 172     CC1Args.push_back("+mutable-globals");
 173     CC1Args.push_back("-target-feature");
 174     CC1Args.push_back("+sign-ext");
 175   }
 176
 177   if (DriverArgs.getLastArg(options::OPT_fwasm_exceptions)) {
 178     // '-fwasm-exceptions' is not compatible with '-mno-exception-handling'
 179     if (DriverArgs.hasFlag(options::OPT_mno_exception_handing,
 180                            options::OPT_mexception_handing, false))
 181       getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 182           << "-fwasm-exceptions"
 183           << "-mno-exception-handling";
 184     // '-fwasm-exceptions' is not compatible with
 185     // '-mllvm -enable-emscripten-cxx-exceptions'
 186     for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
 187       if (StringRef(A->getValue(0)) == "-enable-emscripten-cxx-exceptions")
 188         getDriver().Diag(diag::err_drv_argument_not_allowed_with)
 189             << "-fwasm-exceptions"
 190             << "-mllvm -enable-emscripten-cxx-exceptions";
 191     }
 192     // '-fwasm-exceptions' implies exception-handling
 193     CC1Args.push_back("-target-feature");
 194     CC1Args.push_back("+exception-handling");
 195   }
 196 }
 197
 198 ToolChain::RuntimeLibType WebAssembly::GetDefaultRuntimeLibType() const {
 199   return ToolChain::RLT_CompilerRT;
 200 }
 201
 202 ToolChain::CXXStdlibType
 203 WebAssembly::GetCXXStdlibType(const ArgList &Args) const {
 204   if (Arg *A = Args.getLastArg(options::OPT_stdlib_EQ)) {
 205     StringRef Value = A->getValue();
 206     if (Value != "libc++")
 207       getDriver().Diag(diag::err_drv_invalid_stdlib_name)
 208           << A->getAsString(Args);
 209   }
 210   return ToolChain::CST_Libcxx;
 211 }
 212
 213 void WebAssembly::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
 214                                             ArgStringList &CC1Args) const {
 215   if (DriverArgs.hasArg(clang::driver::options::OPT_nostdinc))
 216     return;
 217
 218   const Driver &D = getDriver();
 219
 220   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
 221     SmallString<128> P(D.ResourceDir);
 222     llvm::sys::path::append(P, "include");
 223     addSystemInclude(DriverArgs, CC1Args, P);
 224   }
 225
 226   if (DriverArgs.hasArg(options::OPT_nostdlibinc))
 227     return;
 228
 229   // Check for configure-time C include directories.
 230   StringRef CIncludeDirs(C_INCLUDE_DIRS);
 231   if (CIncludeDirs != "") {
 232     SmallVector<StringRef, 5> dirs;
 233     CIncludeDirs.split(dirs, ":");
 234     for (StringRef dir : dirs) {
 235       StringRef Prefix =
 236           llvm::sys::path::is_absolute(dir) ? StringRef(D.SysRoot) : "";
 237       addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
 238     }
 239     return;
 240   }
 241
 242   if (getTriple().getOS() != llvm::Triple::UnknownOS) {
 243     const std::string MultiarchTriple =
 244         getMultiarchTriple(D, getTriple(), D.SysRoot);
 245     addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include/" + MultiarchTriple);
 246   }
 247   addSystemInclude(DriverArgs, CC1Args, D.SysRoot + "/include");
 248 }
 249
 250 void WebAssembly::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
 251                                                ArgStringList &CC1Args) const {
 252   if (!DriverArgs.hasArg(options::OPT_nostdlibinc) &&
 253       !DriverArgs.hasArg(options::OPT_nostdincxx)) {
 254     if (getTriple().getOS() != llvm::Triple::UnknownOS) {
 255       const std::string MultiarchTriple =
 256           getMultiarchTriple(getDriver(), getTriple(), getDriver().SysRoot);
 257       addSystemInclude(DriverArgs, CC1Args,
 258                        getDriver().SysRoot + "/include/" + MultiarchTriple +
 259                            "/c++/v1");
 260     }
 261     addSystemInclude(DriverArgs, CC1Args,
 262                      getDriver().SysRoot + "/include/c++/v1");
 263   }
 264 }
 265
 266 void WebAssembly::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
 267                                       llvm::opt::ArgStringList &CmdArgs) const {
 268
 269   switch (GetCXXStdlibType(Args)) {
 270   case ToolChain::CST_Libcxx:
 271     CmdArgs.push_back("-lc++");
 272     CmdArgs.push_back("-lc++abi");
 273     break;
 274   case ToolChain::CST_Libstdcxx:
 275     llvm_unreachable("invalid stdlib name");
 276   }
 277 }
 278
 279 SanitizerMask WebAssembly::getSupportedSanitizers() const {
 280   SanitizerMask Res = ToolChain::getSupportedSanitizers();
 281   if (getTriple().isOSEmscripten()) {
 282     Res |= SanitizerKind::Vptr | SanitizerKind::Leak | SanitizerKind::Address;
 283   }
 284   return Res;
 285 }
 286
 287 Tool *WebAssembly::buildLinker() const {
 288   return new tools::wasm::Linker(*this);
 289 }