Auto merge of #104765 - chenyukang:yukang-fix-104639-lifetime-check, r=oli-obk

[rust.git] / compiler / rustc_borrowck / src / region_infer / mod.rs

diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index b35abbd107b9ce7e148603f91207a64c513e1f84..e9c98bdc514967a63f4f1dc39be0e6be7d1919ed 100644 (file)
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -747,27 +747,14 @@ fn apply_member_constraint(
         // Otherwise, we need to find the minimum remaining choice, if
         // any, and take that.
         debug!("choice_regions remaining are {:#?}", choice_regions);
-        let min = |r1: ty::RegionVid, r2: ty::RegionVid| -> Option<ty::RegionVid> {
-            let r1_outlives_r2 = self.universal_region_relations.outlives(r1, r2);
-            let r2_outlives_r1 = self.universal_region_relations.outlives(r2, r1);
-            match (r1_outlives_r2, r2_outlives_r1) {
-                (true, true) => Some(r1.min(r2)),
-                (true, false) => Some(r2),
-                (false, true) => Some(r1),
-                (false, false) => None,
-            }
+        let Some(&min_choice) = choice_regions.iter().find(|&r1| {
+            choice_regions.iter().all(|&r2| {
+                self.universal_region_relations.outlives(r2, *r1)
+            })
+        }) else {
+            debug!("no choice region outlived by all others");
+            return false;
         };
-        let mut min_choice = choice_regions[0];
-        for &other_option in &choice_regions[1..] {
-            debug!(?min_choice, ?other_option,);
-            match min(min_choice, other_option) {
-                Some(m) => min_choice = m,
-                None => {
-                    debug!(?min_choice, ?other_option, "incomparable; no min choice",);
-                    return false;
-                }
-            }
-        }
 
         let min_choice_scc = self.constraint_sccs.scc(min_choice);
         debug!(?min_choice, ?min_choice_scc);
@@ -1705,6 +1692,7 @@ fn check_bound_universal_region(
         });
     }
 
+    #[instrument(level = "debug", skip(self, infcx, errors_buffer))]
     fn check_member_constraints(
         &self,
         infcx: &InferCtxt<'tcx>,
@@ -1712,22 +1700,21 @@ fn check_member_constraints(
     ) {
         let member_constraints = self.member_constraints.clone();
         for m_c_i in member_constraints.all_indices() {
-            debug!("check_member_constraint(m_c_i={:?})", m_c_i);
+            debug!(?m_c_i);
             let m_c = &member_constraints[m_c_i];
             let member_region_vid = m_c.member_region_vid;
             debug!(
-                "check_member_constraint: member_region_vid={:?} with value {}",
-                member_region_vid,
-                self.region_value_str(member_region_vid),
+                ?member_region_vid,
+                value = ?self.region_value_str(member_region_vid),
             );
             let choice_regions = member_constraints.choice_regions(m_c_i);
-            debug!("check_member_constraint: choice_regions={:?}", choice_regions);
+            debug!(?choice_regions);
 
             // Did the member region wind up equal to any of the option regions?
             if let Some(o) =
                 choice_regions.iter().find(|&&o_r| self.eval_equal(o_r, m_c.member_region_vid))
             {
-                debug!("check_member_constraint: evaluated as equal to {:?}", o);
+                debug!("evaluated as equal to {:?}", o);
                 continue;
             }