stop descending to avoid duplicated effort

Author: dingxiangfei2009

compiler/rustc_passes/src/region.rs

@@ -244,15 +244,10 @@ fn mark_local_terminating_scopes<'tcx>(expr: &'tcx hir::Expr<'tcx>) -> FxHashSet
                         ops.push((nested_expr, OpTy::Deref));
                         nested_expr = subexpr;
                     }
-                    hir::ExprKind::Field(subexpr, _) => {
+                    hir::ExprKind::Field(subexpr, _) | hir::ExprKind::Index(subexpr, _) => {
                         ops.push((nested_expr, OpTy::Project));
                         nested_expr = subexpr;
                     }
-                    hir::ExprKind::Index(subexpr, idxexpr) => {
-                        ops.push((nested_expr, OpTy::Project));
-                        nested_expr = subexpr;
-                        intravisit::walk_expr(self, idxexpr);
-                    }
                     _ => {
                         drop(ops);
                         intravisit::walk_expr(self, expr);
@@ -296,7 +291,9 @@ fn mark_local_terminating_scopes<'tcx>(expr: &'tcx hir::Expr<'tcx>) -> FxHashSet
                 | hir::ExprKind::Path(..) => self.probe(expr),
 
                 // We do not probe into other function bodies or blocks.
-                hir::ExprKind::Block(..)
+                hir::ExprKind::If(..)
+                | hir::ExprKind::Match(..)
+                | hir::ExprKind::Block(..)
                 | hir::ExprKind::Closure(..)
                 | hir::ExprKind::ConstBlock(..) => {}
                 _ => intravisit::walk_expr(self, expr),

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

@@ -7,6 +7,10 @@ fn assert_send<T: Send>(_: T) {}
 struct Client;
 
 impl Client {
+    fn zero(&self) -> usize {
+        0
+    }
+
     fn status(&self) -> i16 {
         200
     }
@@ -27,6 +31,10 @@ fn main() {
         match (&*&x).status() {
             _ => yield,
         }
+        let a = [0];
+        match a[Client.zero()] {
+            _ => yield,
+        }
     };
     assert_send(g);
 }