Some more code cleanup

Author: amandasystems

compiler/rustc_borrowck/src/handle_placeholders.rs

@@ -175,18 +175,6 @@ impl RegionTracker {
     pub(crate) fn max_placeholder_universe_reached(self) -> UniverseIndex {
         self.reachable_placeholders.map(|p| p.max_universe.u).unwrap_or(UniverseIndex::ROOT)
     }
-
-    /// Determine if we can name all the placeholders in `other`.
-    pub(crate) fn can_name_all_placeholders(&self, other: Self) -> bool {
-        self.min_max_nameable_universe.can_name(other.max_placeholder_universe_reached())
-    }
-
-    /// If this SCC reaches at least one placeholder, return
-    /// its region vid. If there's more than one, return the one
-    /// with the smallest vid.
-    pub(crate) fn reached_placeholder(&self) -> Option<RegionVid> {
-        self.reachable_placeholders.map(|p| p.min_placeholder)
-    }
 }
 
 impl scc::Annotation for RegionTracker {
@@ -405,7 +393,7 @@ pub(crate) fn rewrite_placeholder_outlives<'tcx>(
         }
 
         if annotation.min_max_nameable_universe.can_name(max_universe.u) {
-            debug!("All placeholders nameable from {scc:?}!");
+            trace!("All placeholders nameable from {scc:?}!");
             continue;
         }
 

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -499,7 +499,9 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         scc_a: ConstraintSccIndex,
         scc_b: ConstraintSccIndex,
     ) -> bool {
-        self.scc_annotations[scc_a].can_name_all_placeholders(self.scc_annotations[scc_b])
+        self.scc_annotations[scc_a]
+            .max_nameable_universe()
+            .can_name(self.scc_annotations[scc_b].max_placeholder_universe_reached())
     }
 
     /// Once regions have been propagated, this method is used to see
@@ -611,10 +613,8 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         //
         // It doesn't matter *what* universe because the promoted `T` will
         // always be in the root universe.
-        if let Some(min_placeholder) = self.scc_annotations[r_scc].reached_placeholder() {
-            debug!(
-                "encountered placeholder in higher universe: {min_placeholder:?}, requiring 'static"
-            );
+        if !self.scc_annotations[r_scc].max_placeholder_universe_reached().is_root() {
+            debug!("encountered placeholder in higher universe, requiring 'static");
             let static_r = self.universal_regions().fr_static;
             propagated_outlives_requirements.push(ClosureOutlivesRequirement {
                 subject,