simplify tracking and opt for build-pass testing

Author: dingxiangfei2009

compiler/rustc_middle/src/middle/region.rs

@@ -368,7 +368,10 @@ impl ScopeTree {
     }
 
     pub fn record_local_access_scope(&mut self, var: hir::ItemLocalId, proposed_lifetime: Scope) {
-        debug!("record_local_access_scope(sub={:?}, sup={:?})", var, proposed_lifetime);
+        debug!(
+            "record_local_access_scope(var={:?}, proposed_lifetime={:?})",
+            var, proposed_lifetime
+        );
         let mut id = Scope { id: var, data: ScopeData::Node };
 
         while let Some(&(p, _)) = self.parent_map.get(&id) {
@@ -385,6 +388,7 @@ impl ScopeTree {
     }
 
     pub fn record_eager_scope(&mut self, var: hir::ItemLocalId, proposed_lifetime: Scope) {
+        debug!("record_eager_scope(var={:?}, proposed_lifetime={:?})", var, proposed_lifetime);
         if let Some(destruction) = self.temporary_scope(var) {
             if self.is_subscope_of(destruction, proposed_lifetime) {
                 // If the current temporary scope is already a subset of the proposed region,

compiler/rustc_passes/src/region.rs

@@ -219,7 +219,6 @@ fn mark_local_terminating_scopes<'tcx>(expr: &'tcx hir::Expr<'tcx>) -> FxHashSet
                 Ref,
                 Deref,
                 Project,
-                Local,
             }
             // Here we are looking for a chain of access to extract a place reference for
             // a local variable.
@@ -233,7 +232,8 @@ fn mark_local_terminating_scopes<'tcx>(expr: &'tcx hir::Expr<'tcx>) -> FxHashSet
                         _,
                         hir::Path { res: hir::def::Res::Local(_), .. },
                     )) => {
-                        ops.push((nested_expr, OpTy::Local));
+                        // We have reached the end of the access path
+                        // because a local variable access is encountered
                         break;
                     }
                     hir::ExprKind::AddrOf(_, _, subexpr) => {
@@ -261,9 +261,7 @@ fn mark_local_terminating_scopes<'tcx>(expr: &'tcx hir::Expr<'tcx>) -> FxHashSet
                 }
             }
             let mut ref_level = SmallVec::<[_; 4]>::new();
-            let mut ops_iter = ops.into_iter().rev();
-            ops_iter.next().unwrap();
-            for (expr, op) in ops_iter {
+            for (expr, op) in ops.into_iter().rev() {
                 match op {
                     OpTy::Ref => {
                         ref_level.push(expr);
@@ -279,9 +277,6 @@ fn mark_local_terminating_scopes<'tcx>(expr: &'tcx hir::Expr<'tcx>) -> FxHashSet
                         // These temporaries must stay alive even after the field access.
                         ref_level.clear();
                     }
-                    OpTy::Local => {
-                        panic!("unexpected encounter of Local")
-                    }
                 }
             }
             self.locals.insert(expr.hir_id.local_id);

src/test/ui/async-await/issue-69663-lingering-local-borrows.rs

@@ -1,5 +1,5 @@
 // edition:2018
-// run-pass
+// build-pass
 
 use std::ops::Index;
 

src/test/ui/generator/refined-region-for-local-accesses.rs

@@ -1,5 +1,5 @@
 // edition:2018
-// run-pass
+// build-pass
 #![feature(generators, generator_trait, negative_impls)]
 
 fn assert_send<T: Send>(_: T) {}