Macro top_level_options 

macro_rules! top_level_options {
    (
        $(#[$top_level_attr:meta])*
        pub struct Options {
            $(
                $(#[$attr:meta])*
                $opt:ident : $t:ty [
                    $dep_tracking_marker:ident
                    $( $tmod:ident $variant:ident )?
                ],
            )*
        }
    ) => { ... };
}