encapsulate access to liveness values

Author: lqd

compiler/rustc_borrowck/src/dataflow.rs

@@ -286,7 +286,7 @@ impl<'a, 'tcx> PoloniusOutOfScopePrecomputer<'a, 'tcx> {
             .collect();
 
         // Pre-compute the set of live SCCs per point
-        let liveness = &regioncx.liveness_constraints;
+        let liveness = regioncx.liveness_values();
         let mut live_sccs_per_point = SparseBitMatrix::new(num_sccs);
 
         for region in liveness.rows() {
@@ -405,7 +405,7 @@ impl<'tcx> PoloniusOutOfScopePrecomputer<'_, 'tcx> {
                 // `q`. The reachability is location-insensitive, and we could take advantage of
                 // that, by jumping to a further point than the next statement. We can jump to the
                 // furthest point within the block where `r` is live.
-                let point = self.regioncx.liveness_constraints.point_from_location(location);
+                let point = self.regioncx.liveness_values().point_from_location(location);
                 if let Some(live_sccs) = self.live_sccs_per_point.row(point) {
                     for live_scc in live_sccs.iter() {
                         if self.reachability.contains(live_scc) {

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -58,7 +58,7 @@ pub struct RegionInferenceContext<'tcx> {
     /// regions, these start out empty and steadily grow, though for
     /// each universally quantified region R they start out containing
     /// the entire CFG and `end(R)`.
-    pub(crate) liveness_constraints: LivenessValues<RegionVid>,
+    liveness_constraints: LivenessValues<RegionVid>,
 
     /// The outlives constraints computed by the type-check.
     constraints: Frozen<OutlivesConstraintSet<'tcx>>,
@@ -2284,6 +2284,11 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     pub(crate) fn constraint_sccs(&self) -> &Sccs<RegionVid, ConstraintSccIndex> {
         self.constraint_sccs.as_ref()
     }
+
+    /// Access to the liveness values.
+    pub(crate) fn liveness_values(&self) -> &LivenessValues<RegionVid> {
+        &self.liveness_constraints
+    }
 }
 
 impl<'tcx> RegionDefinition<'tcx> {