LALRPOP support conditional compilation of public non-terminal declarations via #[cfg(feature = "FEATURE")] attributes. If run in a build script LALRPOP will automatically pickup the features from cargo and use those. Alternatively an explicit set of features can be set using the Configuration type.

#![allow(unused)]
fn main() {
#[cfg(feature = "FEATURE")]
pub MyRule : () = {
    ...
};
}