static VALUE
rg_iface_struct(VALUE self)
{
    GIInterfaceInfo *info;

    info = SELF(self);
    return GI_BASE_INFO2RVAL_WITH_UNREF(g_interface_info_get_iface_struct(info));
}
static void
generic_interface_init (gpointer iface, gpointer data)
{
	GIInterfaceInfo *info = data;
	GIStructInfo *struct_info;
	gint n, i;
	struct_info = g_interface_info_get_iface_struct (info);
	n = g_interface_info_get_n_vfuncs (info);
	for (i = 0; i < n; i++) {
		GIVFuncInfo *vfunc_info;
		const gchar *vfunc_name;
		GIFieldInfo *field_info;
		gint field_offset;
		GITypeInfo *field_type_info;
		gchar *perl_method_name;
		GPerlI11nPerlCallbackInfo *callback_info;

		vfunc_info = g_interface_info_get_vfunc (info, i);
		vfunc_name = g_base_info_get_name (vfunc_info);

		/* FIXME: g_vfunc_info_get_offset does not seem to work here. */
		field_info = get_field_info (struct_info, vfunc_name);
		g_assert (field_info);
		field_offset = g_field_info_get_offset (field_info);
		field_type_info = g_field_info_get_type (field_info);

		perl_method_name = g_ascii_strup (vfunc_name, -1);
		callback_info = create_perl_callback_closure_for_named_sub (
		                  field_type_info, perl_method_name);
		dwarn ("installing vfunc %s as %s at offset %d (vs. %d) inside %p\n",
		       vfunc_name, perl_method_name,
		       field_offset, g_vfunc_info_get_offset (vfunc_info),
		       iface);
		G_STRUCT_MEMBER (gpointer, iface, field_offset) = callback_info->closure;

		g_base_info_unref (field_type_info);
		g_base_info_unref (field_info);
		g_base_info_unref (vfunc_info);
	}
	g_base_info_unref (struct_info);
}
static void
create_native_closure (GType            interface_type,
                       GIInterfaceInfo *iface_info,
                       GIVFuncInfo     *vfunc_info,
                       MethodImpl      *impl)
{
  GIFunctionInfo *invoker_info;
  GIStructInfo *struct_info;
  GIFieldInfo *field_info;
  GITypeInfo *type_info;
  GICallbackInfo *callback_info;
  guint n_fields, i;
  gboolean found_field_info;

  invoker_info = g_vfunc_info_get_invoker (vfunc_info);
  if (invoker_info == NULL)
    {
      g_debug ("No invoker for VFunc '%s.%s'",
               g_base_info_get_name (iface_info),
               g_base_info_get_name (vfunc_info));
      return;
    }

  struct_info = g_interface_info_get_iface_struct (iface_info);
  n_fields = g_struct_info_get_n_fields (struct_info);

  found_field_info = FALSE;
  for (i = 0; i < n_fields; i++)
    {
      field_info = g_struct_info_get_field (struct_info, i);

      if (strcmp (g_base_info_get_name (field_info),
                  g_base_info_get_name (vfunc_info)) == 0)
        {
          found_field_info = TRUE;
          break;
        }

      g_base_info_unref (field_info);
    }

  if (!found_field_info)
    {
      g_debug ("No struct field for VFunc '%s.%s'",
               g_base_info_get_name (iface_info),
               g_base_info_get_name (vfunc_info));
      g_base_info_unref (struct_info);
      g_base_info_unref (invoker_info);
      return;
    }

  type_info = g_field_info_get_type (field_info);
  g_assert (g_type_info_get_tag (type_info) == GI_TYPE_TAG_INTERFACE);

  callback_info = g_type_info_get_interface (type_info);
  g_assert (g_base_info_get_type (callback_info) == GI_INFO_TYPE_CALLBACK);

  impl->interface_type = interface_type;
  impl->invoker_info = invoker_info;
  impl->method_name = g_base_info_get_name (invoker_info);
  impl->closure = g_callable_info_prepare_closure (callback_info, &impl->cif,
                                                   handle_method_impl, impl);
  impl->struct_offset = g_field_info_get_offset (field_info);

  g_base_info_unref (callback_info);
  g_base_info_unref (type_info);
  g_base_info_unref (field_info);
  g_base_info_unref (struct_info);
}