process.dlopen sources

DLOpen.cc

// DLOpen is process.dlopen(module, filename).
// Used to load 'module.node' dynamically shared objects.
void DLOpen(const FunctionCallbackInfo<Value>& args) {
  Environment* env = Environment::GetCurrent(args);
  uv_lib_t lib;

  CHECK_EQ(modpending, nullptr);

  if (args.Length() != 2) {
    env->ThrowError("process.dlopen takes exactly 2 arguments.");
    return;
  }

  Local<Object> module = args[0]->ToObject(env->isolate());  // Cast
  node::Utf8Value filename(env->isolate(), args[1]);  // Cast
  const bool is_dlopen_error = uv_dlopen(*filename, &lib);

  // Objects containing v14 or later modules will have registered themselves
  // on the pending list.  Activate all of them now.  At present, only one
  // module per object is supported.
  node_module* const mp = modpending;
  modpending = nullptr;

  if (is_dlopen_error) {
    Local<String> errmsg = OneByteString(env->isolate(), uv_dlerror(&lib));
    uv_dlclose(&lib);
#ifdef _WIN32
    // Windows needs to add the filename into the error message
    errmsg = String::Concat(errmsg, args[1]->ToString(env->isolate()));
#endif  // _WIN32
    env->isolate()->ThrowException(Exception::Error(errmsg));
    return;
  }

  if (mp == nullptr) {
    uv_dlclose(&lib);
    env->ThrowError("Module did not self-register.");
    return;
  }
  if (mp->nm_version != NODE_MODULE_VERSION) {
    char errmsg[1024];
    snprintf(errmsg,
             sizeof(errmsg),
             "The module '%s'"
             "\nwas compiled against a different Node.js version using"
             "\nNODE_MODULE_VERSION %d. This version of Node.js requires"
             "\nNODE_MODULE_VERSION %d. Please try re-compiling or "
             "re-installing\nthe module (for instance, using `npm rebuild` or "
             "`npm install`).",
             *filename, mp->nm_version, NODE_MODULE_VERSION);

    // NOTE: `mp` is allocated inside of the shared library's memory, calling
    // `uv_dlclose` will deallocate it
    uv_dlclose(&lib);
    env->ThrowError(errmsg);
    return;
  }
  if (mp->nm_flags & NM_F_BUILTIN) {
    uv_dlclose(&lib);
    env->ThrowError("Built-in module self-registered.");
    return;
  }

  mp->nm_dso_handle = lib.handle;
  mp->nm_link = modlist_addon;
  modlist_addon = mp;

  Local<String> exports_string = env->exports_string();
  Local<Object> exports = module->Get(exports_string)->ToObject(env->isolate());

  if (mp->nm_context_register_func != nullptr) {
    mp->nm_context_register_func(exports, module, env->context(), mp->nm_priv);
  } else if (mp->nm_register_func != nullptr) {
    mp->nm_register_func(exports, module, mp->nm_priv);
  } else {
    uv_dlclose(&lib);
    env->ThrowError("Module has no declared entry point.");
    return;
  }

  // Tell coverity that 'handle' should not be freed when we return.
  // coverity[leaked_storage]
}