Merge branch 'rust-lang:master' into clear-with-drain

tests/ui/redundant_async_block.fixed

@@ -3,6 +3,8 @@
 #![allow(unused)]
 #![warn(clippy::redundant_async_block)]
 
+use std::future::Future;
+
 async fn func1(n: usize) -> usize {
     n + 1
 }
@@ -62,3 +64,48 @@ fn main() {
     let fut = async_await_parameter_in_macro!(func2());
     let fut = async_await_in_macro!(std::convert::identity);
 }
+
+#[allow(clippy::let_and_return)]
+fn capture_local() -> impl Future<Output = i32> {
+    // Lint
+    let fut = async { 17 };
+    fut
+}
+
+fn capture_local_closure(s: &str) -> impl Future<Output = &str> {
+    let f = move || std::future::ready(s);
+    // Do not lint: `f` would not live long enough
+    async move { f().await }
+}
+
+#[allow(clippy::let_and_return)]
+fn capture_arg(s: &str) -> impl Future<Output = &str> {
+    // Lint
+    let fut = async move { s };
+    fut
+}
+
+#[derive(Debug, Clone)]
+struct F {}
+
+impl F {
+    async fn run(&self) {}
+}
+
+pub async fn run() {
+    let f = F {};
+    let c = f.clone();
+    // Do not lint: `c` would not live long enough
+    spawn(async move { c.run().await });
+    let _f = f;
+}
+
+fn spawn<F: Future + 'static>(_: F) {}
+
+async fn work(_: &str) {}
+
+fn capture() {
+    let val = "Hello World".to_owned();
+    // Do not lint: `val` would not live long enough
+    spawn(async { work(&{ val }).await });
+}

tests/ui/redundant_async_block.rs

@@ -3,6 +3,8 @@
 #![allow(unused)]
 #![warn(clippy::redundant_async_block)]
 
+use std::future::Future;
+
 async fn func1(n: usize) -> usize {
     n + 1
 }
@@ -62,3 +64,48 @@ fn main() {
     let fut = async_await_parameter_in_macro!(func2());
     let fut = async_await_in_macro!(std::convert::identity);
 }
+
+#[allow(clippy::let_and_return)]
+fn capture_local() -> impl Future<Output = i32> {
+    // Lint
+    let fut = async { 17 };
+    async move { fut.await }
+}
+
+fn capture_local_closure(s: &str) -> impl Future<Output = &str> {
+    let f = move || std::future::ready(s);
+    // Do not lint: `f` would not live long enough
+    async move { f().await }
+}
+
+#[allow(clippy::let_and_return)]
+fn capture_arg(s: &str) -> impl Future<Output = &str> {
+    // Lint
+    let fut = async move { s };
+    async move { fut.await }
+}
+
+#[derive(Debug, Clone)]
+struct F {}
+
+impl F {
+    async fn run(&self) {}
+}
+
+pub async fn run() {
+    let f = F {};
+    let c = f.clone();
+    // Do not lint: `c` would not live long enough
+    spawn(async move { c.run().await });
+    let _f = f;
+}
+
+fn spawn<F: Future + 'static>(_: F) {}
+
+async fn work(_: &str) {}
+
+fn capture() {
+    let val = "Hello World".to_owned();
+    // Do not lint: `val` would not live long enough
+    spawn(async { work(&{ val }).await });
+}

tests/ui/redundant_async_block.stderr

@@ -1,5 +1,5 @@
 error: this async expression only awaits a single future
-  --> $DIR/redundant_async_block.rs:13:13
+  --> $DIR/redundant_async_block.rs:15:13
    |
 LL |     let x = async { f.await };
    |             ^^^^^^^^^^^^^^^^^ help: you can reduce it to: `f`
@@ -7,22 +7,34 @@ LL |     let x = async { f.await };
    = note: `-D clippy::redundant-async-block` implied by `-D warnings`
 
 error: this async expression only awaits a single future
-  --> $DIR/redundant_async_block.rs:46:16
+  --> $DIR/redundant_async_block.rs:48:16
    |
 LL |     let fut2 = async { fut1.await };
    |                ^^^^^^^^^^^^^^^^^^^^ help: you can reduce it to: `fut1`
 
 error: this async expression only awaits a single future
-  --> $DIR/redundant_async_block.rs:49:16
+  --> $DIR/redundant_async_block.rs:51:16
    |
 LL |     let fut2 = async move { fut1.await };
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^ help: you can reduce it to: `fut1`
 
 error: this async expression only awaits a single future
-  --> $DIR/redundant_async_block.rs:51:15
+  --> $DIR/redundant_async_block.rs:53:15
    |
 LL |     let fut = async { async { 42 }.await };
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: you can reduce it to: `async { 42 }`
 
-error: aborting due to 4 previous errors
+error: this async expression only awaits a single future
+  --> $DIR/redundant_async_block.rs:72:5
+   |
+LL |     async move { fut.await }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ help: you can reduce it to: `fut`
+
+error: this async expression only awaits a single future
+  --> $DIR/redundant_async_block.rs:85:5
+   |
+LL |     async move { fut.await }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ help: you can reduce it to: `fut`
+
+error: aborting due to 6 previous errors