1 use rustc_index::bit_set::BitSet;
2 use rustc_middle::mir::{self, Local};
4 /// The set of locals in a MIR body that do not have `StorageLive`/`StorageDead` annotations.
6 /// These locals have fixed storage for the duration of the body.
8 // FIXME: Currently, we need to traverse the entire MIR to compute this. We should instead store it
9 // as a field in the `LocalDecl` for each `Local`.
10 #[derive(Debug, Clone)]
11 pub struct AlwaysLiveLocals(BitSet<Local>);
13 impl AlwaysLiveLocals {
14 pub fn new(body: &mir::Body<'tcx>) -> Self {
15 let mut locals = BitSet::new_filled(body.local_decls.len());
17 // FIXME: Use a visitor for this when `visit_body` can take a plain `Body`.
18 for block in body.basic_blocks().iter() {
19 for stmt in &block.statements {
20 if let mir::StatementKind::StorageLive(l) | mir::StatementKind::StorageDead(l) =
28 AlwaysLiveLocals(locals)
31 pub fn into_inner(self) -> BitSet<Local> {
36 impl std::ops::Deref for AlwaysLiveLocals {
37 type Target = BitSet<Local>;
39 fn deref(&self) -> &Self::Target {