napi-macros.h

#ifndef NAPI_MACROS
#define NAPI_MACROS

#define NAPI_INIT() \
  static void napi_macros_init(napi_env env, napi_value exports); \
  static napi_value napi_macros_init_wrap (napi_env env, napi_value exports) { \
    napi_macros_init(env, exports); \
    return exports; \
  } \
  NAPI_MODULE(NODE_GYP_MODULE_NAME, napi_macros_init_wrap) \
  static void napi_macros_init (napi_env env, napi_value exports)

#define NAPI_TEST_GC(env) \
  { \
    napi_handle_scope scope; \
    napi_open_handle_scope(env, &scope); \
    napi_value s; \
    napi_value r; \
    napi_create_string_utf8(env, "try { global.gc() } catch {}", NAPI_AUTO_LENGTH, &s); \
    napi_run_script(env, s, &r); \
    napi_close_handle_scope(env, scope); \
  }

#define NAPI_UV_ERROR_MAP_ITER(NAME, DESC) { \
  napi_create_array(env, &entry); \
  napi_create_array(env, &val); \
  napi_value name; \
  napi_create_string_utf8(env, #NAME, NAPI_AUTO_LENGTH, &name); \
  napi_set_element(env, val, 0, name); \
  napi_value desc; \
  napi_create_string_utf8(env, DESC, NAPI_AUTO_LENGTH, &desc); \
  napi_set_element(env, val, 1, desc); \
  napi_create_int32(env, UV_ ## NAME, &key); \
  napi_set_element(env, entry, 0, key); \
  napi_set_element(env, entry, 1, val); \
  napi_set_element(env, arr, i++, entry); \
}

#define NAPI_MAKE_CALLBACK(env, nil, ctx, cb, n, argv, res) \
  if (napi_make_callback(env, nil, ctx, cb, n, argv, res) == napi_pending_exception) { \
    napi_value fatal_exception; \
    napi_get_and_clear_last_exception(env, &fatal_exception); \
    napi_fatal_exception(env, fatal_exception); \
  }

#define NAPI_STATUS_THROWS_VOID(call) \
  if ((call) != napi_ok) { \
    napi_throw_error(env, NULL, #call " failed!"); \
    return; \
  }

#define NAPI_STATUS_THROWS(call) \
  if ((call) != napi_ok) { \
    napi_throw_error(env, NULL, #call " failed!"); \
    return NULL; \
  }

#define NAPI_METHOD(name) \
  napi_value name (napi_env env, napi_callback_info info)

#define NAPI_UV_THROWS(err, fn) \
  err = fn; \
  if (err < 0) { \
    napi_throw_error(env, uv_err_name(err), uv_strerror(err)); \
    return NULL; \
  }

#define NAPI_EXPORT_OFFSETOF(type, name) \
  { \
    napi_value name##_offsetof; \
    type tmp; \
    void *ptr = &(tmp.name); \
    void *ptr_base = &tmp; \
    int offset = (char *) ptr - (char *) ptr_base; \
    NAPI_STATUS_THROWS_VOID(napi_create_uint32(env, offset, &name##_offsetof)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, "offsetof_" #type "_" #name, name##_offsetof)) \
  }

#define NAPI_EXPORT_OFFSETOF_STRUCT(type, name) \
  { \
    napi_value name##_offsetof; \
    struct type tmp; \
    void *ptr = &(tmp.name); \
    void *ptr_base = &tmp; \
    int offset = (char *) ptr - (char *) ptr_base; \
    NAPI_STATUS_THROWS_VOID(napi_create_uint32(env, offset, &name##_offsetof)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, "offsetof_struct_" #type "_" #name, name##_offsetof)) \
  }


#define NAPI_EXPORT_ALIGNMENTOF(name) \
  { \
    napi_value name##_alignmentof; \
    struct tmp { \
      char a; \
      name b; \
    }; \
    NAPI_STATUS_THROWS_VOID(napi_create_uint32(env, sizeof(struct tmp) - sizeof(name), &name##_alignmentof)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, "alignmentof_" #name, name##_alignmentof)) \
  }

#define NAPI_EXPORT_ALIGNMENTOF_STRUCT(name) \
  { \
    napi_value name##_alignmentof; \
    struct tmp { \
      char a; \
      struct name b; \
    }; \
    NAPI_STATUS_THROWS_VOID(napi_create_uint32(env, sizeof(struct tmp) - sizeof(struct name), &name##_alignmentof)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, "alignmentof_" #name, name##_alignmentof)) \
  }

#define NAPI_EXPORT_UV_ERROR_MAP() \
  { \
    napi_value arr; \
    napi_value key; \
    napi_value val; \
    napi_value entry; \
    napi_create_array(env, &arr); \
    int i = 0; \
    UV_ERRNO_MAP(NAPI_UV_ERROR_MAP_ITER) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, "uv_error_map", arr)) \
  }

#define NAPI_EXPORT_SIZEOF(name) \
  { \
    napi_value name##_sizeof; \
    NAPI_STATUS_THROWS_VOID(napi_create_uint32(env, sizeof(name), &name##_sizeof)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, "sizeof_" #name, name##_sizeof)) \
  }

#define NAPI_EXPORT_SIZEOF_STRUCT(name) \
  { \
    napi_value name##_sizeof; \
    NAPI_STATUS_THROWS_VOID(napi_create_uint32(env, sizeof(struct name), &name##_sizeof)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, "sizeof_" #name, name##_sizeof)) \
  }

#define NAPI_EXPORT_UINT32(name) \
  { \
    napi_value name##_uint32; \
    NAPI_STATUS_THROWS_VOID(napi_create_uint32(env, name, &name##_uint32)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, #name, name##_uint32)) \
  }

#define NAPI_EXPORT_INT32(name) \
  { \
    napi_value name##_int32; \
    NAPI_STATUS_THROWS_VOID(napi_create_int32(env, name, &name##_int32)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, #name, name##_int32)) \
  }

#define NAPI_EXPORT_FUNCTION(name) \
  { \
    napi_value name##_fn; \
    NAPI_STATUS_THROWS_VOID(napi_create_function(env, NULL, 0, name, NULL, &name##_fn)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, #name, name##_fn)) \
  }

#define NAPI_EXPORT_UTF8(name, len) \
  { \
    napi_value name##_utf8; \
    NAPI_STATUS_THROWS_VOID(napi_create_string_utf8(env, name, len, &name##_utf8)) \
    NAPI_STATUS_THROWS_VOID(napi_set_named_property(env, exports, #name, name##_utf8)) \
  }

#define NAPI_EXPORT_STRING(name) \
  NAPI_EXPORT_UTF8(name, NAPI_AUTO_LENGTH)

#define NAPI_RETURN_INT32(name) \
  napi_value return_int32; \
  NAPI_STATUS_THROWS(napi_create_int32(env, name, &return_int32)) \
  return return_int32;

#define NAPI_RETURN_UINT32(name) \
  napi_value return_uint32; \
  NAPI_STATUS_THROWS(napi_create_uint32(env, name, &return_uint32)) \
  return return_uint32;

#define NAPI_RETURN_UTF8(name, len) \
  napi_value return_utf8; \
  NAPI_STATUS_THROWS(napi_create_string_utf8(env, name, len, &return_utf8)) \
  return return_utf8;

#define NAPI_RETURN_STRING(name) \
  NAPI_RETURN_UTF8(name, NAPI_AUTO_LENGTH)

#define NAPI_UTF8(name, size, val) \
  char name[size]; \
  size_t name##_len; \
  if (napi_get_value_string_utf8(env, val, (char *) &name, size, &name##_len) != napi_ok) { \
    napi_throw_error(env, "EINVAL", "Expected string"); \
    return NULL; \
  }

#define NAPI_UTF8_MALLOC(name, val) \
  size_t name##_size = 0; \
  NAPI_STATUS_THROWS(napi_get_value_string_utf8(env, val, NULL, 0, &name##_size)) \
  char* name = (char*)malloc((name##_size + 1) * sizeof(char)); \
  size_t name##_len; \
  NAPI_STATUS_THROWS(napi_get_value_string_utf8(env, val, name, name##_size + 1, &name##_len)) \
  name[name##_size] = '\0';

#define NAPI_UINT32(name, val) \
  uint32_t name; \
  if (napi_get_value_uint32(env, val, &name) != napi_ok) { \
    napi_throw_error(env, "EINVAL", "Expected unsigned number"); \
    return NULL; \
  }

#define NAPI_INT32(name, val) \
  int32_t name; \
  if (napi_get_value_int32(env, val, &name) != napi_ok) { \
    napi_throw_error(env, "EINVAL", "Expected number"); \
    return NULL; \
  }

#define NAPI_BUFFER_CAST(type, name, val) \
  type name; \
  size_t name##_len; \
  NAPI_STATUS_THROWS(napi_get_buffer_info(env, val, (void **) &name, &name##_len))

#define NAPI_BUFFER(name, val) \
  NAPI_BUFFER_CAST(char *, name, val)

#define NAPI_FOR_EACH(arr, element) \
  uint32_t arr##_len; \
  napi_get_array_length(env, arr, &arr##_len); \
  napi_value element; \
  for (uint32_t i = 0; i < arr##_len && napi_get_element(env, arr, i, &element) == napi_ok; i++)

#define NAPI_ARGV(n) \
  napi_value argv[n]; \
  size_t argc = n; \
  NAPI_STATUS_THROWS(napi_get_cb_info(env, info, &argc, argv, NULL, NULL))

#define NAPI_ARGV_UTF8(name, size, i) \
  NAPI_UTF8(name, size, argv[i])

#define NAPI_ARGV_UTF8_MALLOC(name, i) \
  NAPI_UTF8_MALLOC(name, argv[i])

#define NAPI_ARGV_UINT32(name, i) \
  NAPI_UINT32(name, argv[i])

#define NAPI_ARGV_INT32(name, i) \
  NAPI_INT32(name, argv[i])

#define NAPI_ARGV_BUFFER_CAST(type, name, i) \
  NAPI_BUFFER_CAST(type, name, argv[i])

#define NAPI_ARGV_BUFFER(name, i) \
  NAPI_ARGV_BUFFER_CAST(char *, name, i)

#endif