compiler/rustc_mir_transform/src/remove_storage_markers.rs

   1 //! This pass removes storage markers if they won't be emitted during codegen.
   2
   3 use crate::MirPass;
   4 use rustc_middle::mir::*;
   5 use rustc_middle::ty::TyCtxt;
   6
   7 pub struct RemoveStorageMarkers;
   8
   9 impl<'tcx> MirPass<'tcx> for RemoveStorageMarkers {
  10     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
  11         if tcx.sess.emit_lifetime_markers() {
  12             return;
  13         }
  14
  15         trace!("Running RemoveStorageMarkers on {:?}", body.source);
  16         for data in body.basic_blocks_mut() {
  17             data.statements.retain(|statement| match statement.kind {
  18                 StatementKind::StorageLive(..)
  19                 | StatementKind::StorageDead(..)
  20                 | StatementKind::Nop => false,
  21                 _ => true,
  22             })
  23         }
  24     }
  25 }