Method InitializeLlvm

be/src/codegen/llvm-codegen.cc:154–211

}

Status LlvmCodeGen::InitializeLlvm(const char* procname, bool load_backend) {
  DCHECK(!llvm_initialized_);
  // Treat all functions as having the inline hint
  std::array<const char*, 2> argv = { { procname, "-inline-threshold=325" } };
  CHECK(llvm::cl::ParseCommandLineOptions(argv.size(), argv.data()));
  llvm::remove_fatal_error_handler();
  llvm::install_fatal_error_handler(LlvmCodegenHandleError);
  // These functions can *only* be called once per process and are used to set up
  // LLVM subsystems for code generation targeting the machine we're running on.
  llvm::InitializeNativeTarget();
  llvm::InitializeNativeTargetAsmPrinter();
  llvm::InitializeNativeTargetAsmParser();
  llvm::InitializeNativeTargetDisassembler();
  llvm_initialized_ = true;

  if (load_backend) {
    string path;
    // For test env, we have to load libfesupport.so to provide sym for LLVM.
    PathBuilder::GetFullBuildPath("service/libfesupport.so", &path);
    bool failed = llvm::sys::DynamicLibrary::LoadLibraryPermanently(path.c_str());
    DCHECK_EQ(failed, 0);
  }

  cpu_name_ = llvm::sys::getHostCPUName().str();
  LOG(INFO) << "CPU class for runtime code generation: " << cpu_name_;
  GetHostCPUAttrs(&cpu_attrs_);
  LOG(INFO) << "Detected CPU flags: " << boost::join(cpu_attrs_, ",");
  cpu_attrs_ = ApplyCpuAttrWhitelist(cpu_attrs_);
  target_features_attr_ = boost::join(cpu_attrs_, ",");
  LOG(INFO) << "CPU flags enabled for runtime code generation: " << target_features_attr_;

  // Write an empty map file for perf to find.
  if (FLAGS_perf_map) CodegenSymbolEmitter::WritePerfMap();

  ObjectPool init_pool;
  scoped_ptr<LlvmCodeGen> init_codegen;
  RETURN_IF_ERROR(LlvmCodeGen::CreateFromMemory(
      nullptr, &init_pool, nullptr, "init", &init_codegen));
  // LLVM will construct "use" lists only when the entire module is materialized.
  RETURN_IF_ERROR(init_codegen->MaterializeModule());

  // Validate the module by verifying that functions for all IRFunction::Type
  // can be found.
  for (int i = IRFunction::FN_START; i < IRFunction::FN_END; ++i) {
    DCHECK_EQ(FN_MAPPINGS[i].fn, i);
    const string& fn_name = FN_MAPPINGS[i].fn_name;
    if (init_codegen->module_->getFunction(fn_name) == nullptr) {
      const string& err_msg = Substitute("Failed to find function $0", fn_name);
      LOG(ERROR) << err_msg;
      return Status(err_msg);
    }
  }

  // Initialize the global shared call graph.
  shared_call_graph_.Init(init_codegen->module_);
  init_codegen->Close();
  return Status::OK();
}