Kill moved locals in borrowed locals analysis

compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs

@@ -91,6 +91,12 @@ where
                 }
             }
 
+            mir::Rvalue::Use(mir::Operand::Move(place)) => {
+                if place.projection.len() == 0 {
+                    self.trans.kill(place.local)
+                }
+            }
+
             mir::Rvalue::Cast(..)
             | mir::Rvalue::ShallowInitBox(..)
             | mir::Rvalue::Use(..)

compiler/rustc_mir_transform/src/generator.rs

@@ -717,6 +717,7 @@ impl GeneratorSavedLocals {
                 out.insert(saved_local);
             }
         }
+
         out
     }
 

tests/ui/async-await/drop-track-field-assign-nonsend.drop_tracking_mir.stderr

@@ -5,14 +5,11 @@ LL |     assert_send(agent.handle());
    |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
    |
    = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
-note: future is not `Send` as this value is used across an await
-  --> $DIR/drop-track-field-assign-nonsend.rs:23:38
+note: captured value is not `Send` because `&mut` references cannot be sent unless their referent is `Send`
+  --> $DIR/drop-track-field-assign-nonsend.rs:19:21
    |
-LL |         let mut info = self.info_result.clone();
-   |             -------- has type `InfoResult` which is not `Send`
-...
-LL |         let _ = send_element(element).await;
-   |                                      ^^^^^^ await occurs here, with `mut info` maybe used later
+LL |     async fn handle(&mut self) {
+   |                     ^^^^^^^^^ has type `&mut Agent` which is not `Send`, because `Agent` is not `Send`
 note: required by a bound in `assert_send`
   --> $DIR/drop-track-field-assign-nonsend.rs:40:19
    |

tests/ui/async-await/field-assign-nonsend.drop_tracking_mir.stderr

@@ -5,14 +5,11 @@ LL |     assert_send(agent.handle());
    |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
    |
    = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
-note: future is not `Send` as this value is used across an await
-  --> $DIR/field-assign-nonsend.rs:23:38
+note: captured value is not `Send` because `&mut` references cannot be sent unless their referent is `Send`
+  --> $DIR/field-assign-nonsend.rs:19:21
    |
-LL |         let mut info = self.info_result.clone();
-   |             -------- has type `InfoResult` which is not `Send`
-...
-LL |         let _ = send_element(element).await;
-   |                                      ^^^^^^ await occurs here, with `mut info` maybe used later
+LL |     async fn handle(&mut self) {
+   |                     ^^^^^^^^^ has type `&mut Agent` which is not `Send`, because `Agent` is not `Send`
 note: required by a bound in `assert_send`
   --> $DIR/field-assign-nonsend.rs:40:19
    |

tests/ui/async-await/issue-96084.rs

@@ -0,0 +1,33 @@
+// run-pass
+// edition:2018
+
+use std::mem;
+
+async fn foo() {
+    let x = [0u8; 100];
+    async {}.await;
+    println!("{}", x.len());
+}
+
+async fn a() {
+    let fut = foo();
+    let fut = fut;
+    fut.await;
+}
+
+async fn b() {
+    let fut = foo();
+    println!("{}", mem::size_of_val(&fut));
+    let fut = fut;
+    fut.await;
+}
+
+fn main() {
+    assert_eq!(mem::size_of_val(&foo()), 102);
+
+    // 1 + sizeof(foo)
+    assert_eq!(mem::size_of_val(&a()), 103);
+
+    // 1 + (sizeof(foo) * 2)
+    assert_eq!(mem::size_of_val(&b()), 103);
+}

tests/ui/generator/size-moved-locals.rs

@@ -73,6 +73,6 @@ fn overlap_x_and_y() -> impl Generator<Yield = (), Return = ()> {
 fn main() {
     assert_eq!(1025, std::mem::size_of_val(&move_before_yield()));
     assert_eq!(1026, std::mem::size_of_val(&move_before_yield_with_noop()));
-    assert_eq!(2051, std::mem::size_of_val(&overlap_move_points()));
+    assert_eq!(1027, std::mem::size_of_val(&overlap_move_points()));
     assert_eq!(1026, std::mem::size_of_val(&overlap_x_and_y()));
 }