rust/compiler/rustc_mir/src/transform/mod.rs

use rustc_middle::mir::Body;
use rustc_middle::ty::TyCtxt;
use std::borrow::Cow;

pub mod check_consts;
pub mod promote_consts;
pub mod rustc_peek;
pub mod validate;

/// Generates a default name for the pass based on the name of the
/// type `T`.
pub fn default_name<T: ?Sized>() -> Cow<'static, str> {
    let name = std::any::type_name::<T>();
    if let Some(tail) = name.rfind(':') { Cow::from(&name[tail + 1..]) } else { Cow::from(name) }
}

/// A streamlined trait that you can implement to create a pass; the
/// pass will be named after the type, and it will consist of a main
/// loop that goes over each available MIR and applies `run_pass`.
pub trait MirPass<'tcx> {
    fn name(&self) -> Cow<'_, str> {
        default_name::<Self>()
    }

    fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>);
}