No completion in Rocket `routes` macro

Trying out the basic Rocket example, I noticed we don't provide completions in the routes macro, and I'm not sure why.

#[macro_use] extern crate rocket;

#[get("/")]
fn index() -> &'static str {
    "Hello, world!"
}

#[launch]
fn rocket() -> _ {
    rocket::build().mount("/", routes![ind/*cursor here*/])
}

Macro-expanding the routes! call gives:

{
  let ___vec: ::std::vec::Vec< ::rocket::Route>  = (<[_]>::into_vec(box[{
    let ___struct = ind{}
    ;
    let ___item: ::rocket::Route = ___struct.into_route();
    ___item
  }]));
  ___vec
}

so the ind token shows up in the expanded code, and in a position where we would provide completions. And we do provide the generated index struct as a completion outside the macro call. Maybe we lose track of the token identity / spans somehow?

Start by tracing completion handling for the routes! macro expansion at the ind cursor, then compare it with completion for the generated index struct outside the macro call. Done means the index route completion is available at the cursor inside routes! without regressing the existing completion behavior.