Function rustc_mir_build::thir::pattern::check_match::report_arm_reachability

fn report_arm_reachability<'p, 'tcx, F>(
    cx: &MatchCheckCtxt<'p, 'tcx>, 
    report: &UsefulnessReport<'p, 'tcx>, 
    unreachable: F
) where
    F: Fn(usize, Span, HirId, Option<Span>), 

Report unreachable arms, if any.