//! This pass removes storage markers if they won't be emitted during codegen.
use crate::MirPass;
use rustc_middle::mir::*;
use rustc_middle::ty::TyCtxt;
pub struct RemoveStorageMarkers;
impl<'tcx> MirPass<'tcx> for RemoveStorageMarkers {
fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
sess.mir_opt_level() > 0
}
fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
if tcx.sess.emit_lifetime_markers() {
return;
}
trace!("Running RemoveStorageMarkers on {:?}", body.source);
for data in body.basic_blocks.as_mut_preserves_cfg() {
data.statements.retain(|statement| match statement.kind {
StatementKind::StorageLive(..)
| StatementKind::StorageDead(..)
| StatementKind::Nop => false,
_ => true,
})
}
}
}