Exemple #1
0
void tools::AddLinkerInputs(const ToolChain &TC, const InputInfoList &Inputs,
                            const ArgList &Args, ArgStringList &CmdArgs,
                            const JobAction &JA) {
  const Driver &D = TC.getDriver();

  // Add extra linker input arguments which are not treated as inputs
  // (constructed via -Xarch_).
  Args.AddAllArgValues(CmdArgs, options::OPT_Zlinker_input);

  for (const auto &II : Inputs) {
    // If the current tool chain refers to an OpenMP offloading host, we should
    // ignore inputs that refer to OpenMP offloading devices - they will be
    // embedded according to a proper linker script.
    if (auto *IA = II.getAction())
      if (JA.isHostOffloading(Action::OFK_OpenMP) &&
          IA->isDeviceOffloading(Action::OFK_OpenMP))
        continue;

    if (!TC.HasNativeLLVMSupport() && types::isLLVMIR(II.getType()))
      // Don't try to pass LLVM inputs unless we have native support.
      D.Diag(diag::err_drv_no_linker_llvm_support) << TC.getTripleString();

    // Add filenames immediately.
    if (II.isFilename()) {
      CmdArgs.push_back(II.getFilename());
      continue;
    }

    // Otherwise, this is a linker input argument.
    const Arg &A = II.getInputArg();

    // Handle reserved library options.
    if (A.getOption().matches(options::OPT_Z_reserved_lib_stdcxx))
      TC.AddCXXStdlibLibArgs(Args, CmdArgs);
    else if (A.getOption().matches(options::OPT_Z_reserved_lib_cckext))
      TC.AddCCKextLibArgs(Args, CmdArgs);
    else if (A.getOption().matches(options::OPT_z)) {
      // Pass -z prefix for gcc linker compatibility.
      A.claim();
      A.render(Args, CmdArgs);
    } else {
      A.renderAsInput(Args, CmdArgs);
    }
  }

  // LIBRARY_PATH - included following the user specified library paths.
  //                and only supported on native toolchains.
  if (!TC.isCrossCompiling()) {
    addDirectoryList(Args, CmdArgs, "-L", "LIBRARY_PATH");
  }
}
Exemple #2
0
void NVPTX::OpenMPLinker::ConstructJob(Compilation &C, const JobAction &JA,
                                       const InputInfo &Output,
                                       const InputInfoList &Inputs,
                                       const ArgList &Args,
                                       const char *LinkingOutput) const {
  const auto &TC =
      static_cast<const toolchains::CudaToolChain &>(getToolChain());
  assert(TC.getTriple().isNVPTX() && "Wrong platform");

  ArgStringList CmdArgs;

  // OpenMP uses nvlink to link cubin files. The result will be embedded in the
  // host binary by the host linker.
  assert(!JA.isHostOffloading(Action::OFK_OpenMP) &&
         "CUDA toolchain not expected for an OpenMP host device.");

  if (Output.isFilename()) {
    CmdArgs.push_back("-o");
    CmdArgs.push_back(Output.getFilename());
  } else
    assert(Output.isNothing() && "Invalid output.");
  if (Args.hasArg(options::OPT_g_Flag))
    CmdArgs.push_back("-g");

  if (Args.hasArg(options::OPT_v))
    CmdArgs.push_back("-v");

  StringRef GPUArch =
      Args.getLastArgValue(options::OPT_march_EQ);
  assert(!GPUArch.empty() && "At least one GPU Arch required for ptxas.");

  CmdArgs.push_back("-arch");
  CmdArgs.push_back(Args.MakeArgString(GPUArch));

  // Add paths specified in LIBRARY_PATH environment variable as -L options.
  addDirectoryList(Args, CmdArgs, "-L", "LIBRARY_PATH");

  // Add paths for the default clang library path.
  SmallString<256> DefaultLibPath =
      llvm::sys::path::parent_path(TC.getDriver().Dir);
  llvm::sys::path::append(DefaultLibPath, "lib" CLANG_LIBDIR_SUFFIX);
  CmdArgs.push_back(Args.MakeArgString(Twine("-L") + DefaultLibPath));

  // Add linking against library implementing OpenMP calls on NVPTX target.
  CmdArgs.push_back("-lomptarget-nvptx");

  for (const auto &II : Inputs) {
    if (II.getType() == types::TY_LLVM_IR ||
        II.getType() == types::TY_LTO_IR ||
        II.getType() == types::TY_LTO_BC ||
        II.getType() == types::TY_LLVM_BC) {
      C.getDriver().Diag(diag::err_drv_no_linker_llvm_support)
          << getToolChain().getTripleString();
      continue;
    }

    // Currently, we only pass the input files to the linker, we do not pass
    // any libraries that may be valid only for the host.
    if (!II.isFilename())
      continue;

    const char *CubinF = C.addTempFile(
        C.getArgs().MakeArgString(getToolChain().getInputFilename(II)));

    CmdArgs.push_back(CubinF);
  }

  AddOpenMPLinkerScript(getToolChain(), C, Output, Inputs, Args, CmdArgs, JA);

  const char *Exec =
      Args.MakeArgString(getToolChain().GetProgramPath("nvlink"));
  C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
}
Exemple #3
0
/// Add OpenMP linker script arguments at the end of the argument list so that
/// the fat binary is built by embedding each of the device images into the
/// host. The linker script also defines a few symbols required by the code
/// generation so that the images can be easily retrieved at runtime by the
/// offloading library. This should be used only in tool chains that support
/// linker scripts.
void tools::AddOpenMPLinkerScript(const ToolChain &TC, Compilation &C,
                                  const InputInfo &Output,
                                  const InputInfoList &Inputs,
                                  const ArgList &Args, ArgStringList &CmdArgs,
                                  const JobAction &JA) {

  // If this is not an OpenMP host toolchain, we don't need to do anything.
  if (!JA.isHostOffloading(Action::OFK_OpenMP))
    return;

  // Create temporary linker script. Keep it if save-temps is enabled.
  const char *LKS;
  SmallString<256> Name = llvm::sys::path::filename(Output.getFilename());
  if (C.getDriver().isSaveTempsEnabled()) {
    llvm::sys::path::replace_extension(Name, "lk");
    LKS = C.getArgs().MakeArgString(Name.c_str());
  } else {
    llvm::sys::path::replace_extension(Name, "");
    Name = C.getDriver().GetTemporaryPath(Name, "lk");
    LKS = C.addTempFile(C.getArgs().MakeArgString(Name.c_str()));
  }

  // Add linker script option to the command.
  CmdArgs.push_back("-T");
  CmdArgs.push_back(LKS);

  // Create a buffer to write the contents of the linker script.
  std::string LksBuffer;
  llvm::raw_string_ostream LksStream(LksBuffer);

  // Get the OpenMP offload tool chains so that we can extract the triple
  // associated with each device input.
  auto OpenMPToolChains = C.getOffloadToolChains<Action::OFK_OpenMP>();
  assert(OpenMPToolChains.first != OpenMPToolChains.second &&
         "No OpenMP toolchains??");

  // Track the input file name and device triple in order to build the script,
  // inserting binaries in the designated sections.
  SmallVector<std::pair<std::string, const char *>, 8> InputBinaryInfo;

  // Add commands to embed target binaries. We ensure that each section and
  // image is 16-byte aligned. This is not mandatory, but increases the
  // likelihood of data to be aligned with a cache block in several main host
  // machines.
  LksStream << "/*\n";
  LksStream << "       OpenMP Offload Linker Script\n";
  LksStream << " *** Automatically generated by Clang ***\n";
  LksStream << "*/\n";
  LksStream << "TARGET(binary)\n";
  auto DTC = OpenMPToolChains.first;
  for (auto &II : Inputs) {
    const Action *A = II.getAction();
    // Is this a device linking action?
    if (A && isa<LinkJobAction>(A) &&
        A->isDeviceOffloading(Action::OFK_OpenMP)) {
      assert(DTC != OpenMPToolChains.second &&
             "More device inputs than device toolchains??");
      InputBinaryInfo.push_back(std::make_pair(
          DTC->second->getTriple().normalize(), II.getFilename()));
      ++DTC;
      LksStream << "INPUT(" << II.getFilename() << ")\n";
    }
  }

  assert(DTC == OpenMPToolChains.second &&
         "Less device inputs than device toolchains??");

  LksStream << "SECTIONS\n";
  LksStream << "{\n";

  // Put each target binary into a separate section.
  for (const auto &BI : InputBinaryInfo) {
    LksStream << "  .omp_offloading." << BI.first << " :\n";
    LksStream << "  ALIGN(0x10)\n";
    LksStream << "  {\n";
    LksStream << "    PROVIDE_HIDDEN(.omp_offloading.img_start." << BI.first
              << " = .);\n";
    LksStream << "    " << BI.second << "\n";
    LksStream << "    PROVIDE_HIDDEN(.omp_offloading.img_end." << BI.first
              << " = .);\n";
    LksStream << "  }\n";
  }

  // Add commands to define host entries begin and end. We use 1-byte subalign
  // so that the linker does not add any padding and the elements in this
  // section form an array.
  LksStream << "  .omp_offloading.entries :\n";
  LksStream << "  ALIGN(0x10)\n";
  LksStream << "  SUBALIGN(0x01)\n";
  LksStream << "  {\n";
  LksStream << "    PROVIDE_HIDDEN(.omp_offloading.entries_begin = .);\n";
  LksStream << "    *(.omp_offloading.entries)\n";
  LksStream << "    PROVIDE_HIDDEN(.omp_offloading.entries_end = .);\n";
  LksStream << "  }\n";
  LksStream << "}\n";
  LksStream << "INSERT BEFORE .data\n";
  LksStream.flush();

  // Dump the contents of the linker script if the user requested that. We
  // support this option to enable testing of behavior with -###.
  if (C.getArgs().hasArg(options::OPT_fopenmp_dump_offload_linker_script))
    llvm::errs() << LksBuffer;

  // If this is a dry run, do not create the linker script file.
  if (C.getArgs().hasArg(options::OPT__HASH_HASH_HASH))
    return;

  // Open script file and write the contents.
  std::error_code EC;
  llvm::raw_fd_ostream Lksf(LKS, EC, llvm::sys::fs::F_None);

  if (EC) {
    C.getDriver().Diag(clang::diag::err_unable_to_make_temp) << EC.message();
    return;
  }

  Lksf << LksBuffer;
}