rustc_mir_transform/remove_place_mention.rs
1//! This pass removes `PlaceMention` statement, which has no effect at codegen.
2
3use rustc_middle::mir::*;
4use rustc_middle::ty::TyCtxt;
5use tracing::trace;
6
7use crate::PassPolicy;
8
9pub(super) struct RemovePlaceMention;
10
11impl<'tcx> crate::MirPass<'tcx> for RemovePlaceMention {
12 fn policy(&self, sess: &rustc_session::Session) -> PassPolicy {
13 PassPolicy::optional_non_optimization(!sess.opts.unstable_opts.mir_preserve_ub)
14 }
15
16 fn run_pass(&self, _: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
17 trace!("Running RemovePlaceMention on {:?}", body.source);
18 for data in body.basic_blocks.as_mut_preserves_cfg() {
19 data.retain_statements(|statement| match statement.kind {
20 StatementKind::PlaceMention(..) | StatementKind::Nop => false,
21 _ => true,
22 })
23 }
24 }
25}