-int copy_override_field(FILE *err, struct bt_event *event,
- struct bt_event *writer_event, struct bt_field *field,
- struct bt_field *copy_field);
+int copy_override_field(FILE *err, const struct bt_event *event,
+ const struct bt_event *writer_event, const struct bt_field *field,
+ const struct bt_field *copy_field);