Merging upstream version 1.66.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

57 files changed, 862 insertions, 101 deletions

diff --git a/src/test/ui/async-await/async-fn-nonsend.stderr b/src/test/ui/async-await/async-fn-nonsend.stderr
index 40ad46b48..a7b872fe4 100644
--- a/src/test/ui/async-await/async-fn-nonsend.stderr
+++ b/src/test/ui/async-await/async-fn-nonsend.stderr
@@ -27,7 +27,7 @@ error: future cannot be sent between threads safely
 LL |     assert_send(non_sync_with_method_call());
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call` is not `Send`
    |
-   = help: the trait `Send` is not implemented for `dyn std::fmt::Write`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `dyn std::fmt::Write`
 note: future is not `Send` as this value is used across an await
   --> $DIR/async-fn-nonsend.rs:46:14
    |
diff --git a/src/test/ui/async-await/async-fn-size-moved-locals.rs b/src/test/ui/async-await/async-fn-size-moved-locals.rs
index 155662566..79b7239f3 100644
--- a/src/test/ui/async-await/async-fn-size-moved-locals.rs
+++ b/src/test/ui/async-await/async-fn-size-moved-locals.rs
@@ -7,7 +7,7 @@
 //
 // See issue #59123 for a full explanation.
 
-// ignore-emscripten (sizes don't match)
+// needs-unwind Size of Futures change on panic=abort
 // run-pass
 
 // edition:2018
diff --git a/src/test/ui/async-await/async-fn-size-uninit-locals.rs b/src/test/ui/async-await/async-fn-size-uninit-locals.rs
index 31a086ba9..546172693 100644
--- a/src/test/ui/async-await/async-fn-size-uninit-locals.rs
+++ b/src/test/ui/async-await/async-fn-size-uninit-locals.rs
@@ -5,6 +5,7 @@
 // being reflected in the size.
 
 // ignore-emscripten (sizes don't match)
+// needs-unwind Size of Futures change on panic=abort
 // run-pass
 
 // edition:2018
@@ -67,9 +68,7 @@ async fn joined() {
     let c = Big::new();
 
     fut().await;
-    noop();
     joiner = Joiner { a: Some(a), b: Some(b), c: Some(c) };
-    noop();
 }
 
 async fn joined_with_noop() {
@@ -97,7 +96,7 @@ async fn join_retval() -> Joiner {
 fn main() {
     assert_eq!(2, std::mem::size_of_val(&single()));
     assert_eq!(3, std::mem::size_of_val(&single_with_noop()));
-    assert_eq!(3078, std::mem::size_of_val(&joined()));
+    assert_eq!(3074, std::mem::size_of_val(&joined()));
     assert_eq!(3078, std::mem::size_of_val(&joined_with_noop()));
     assert_eq!(3074, std::mem::size_of_val(&join_retval()));
 }
diff --git a/src/test/ui/async-await/async-trait-fn.rs b/src/test/ui/async-await/async-trait-fn.rs
index 0ea685986..e2062e827 100644
--- a/src/test/ui/async-await/async-trait-fn.rs
+++ b/src/test/ui/async-await/async-trait-fn.rs
@@ -1,11 +1,8 @@
 // edition:2018
 trait T {
     async fn foo() {} //~ ERROR functions in traits cannot be declared `async`
-    //~^ ERROR mismatched types
     async fn bar(&self) {} //~ ERROR functions in traits cannot be declared `async`
-    //~^ ERROR mismatched types
     async fn baz() { //~ ERROR functions in traits cannot be declared `async`
-        //~^ ERROR mismatched types
         // Nested item must not ICE.
         fn a() {}
     }
diff --git a/src/test/ui/async-await/async-trait-fn.stderr b/src/test/ui/async-await/async-trait-fn.stderr
index e5c584e31..afbe25cf7 100644
--- a/src/test/ui/async-await/async-trait-fn.stderr
+++ b/src/test/ui/async-await/async-trait-fn.stderr
@@ -9,10 +9,10 @@ LL |     async fn foo() {}
    = note: `async` trait functions are not currently supported
    = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
    = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
-   = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable
+   = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable
 
 error[E0706]: functions in traits cannot be declared `async`
-  --> $DIR/async-trait-fn.rs:5:5
+  --> $DIR/async-trait-fn.rs:4:5
    |
 LL |     async fn bar(&self) {}
    |     -----^^^^^^^^^^^^^^
@@ -22,10 +22,10 @@ LL |     async fn bar(&self) {}
    = note: `async` trait functions are not currently supported
    = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
    = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
-   = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable
+   = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable
 
 error[E0706]: functions in traits cannot be declared `async`
-  --> $DIR/async-trait-fn.rs:7:5
+  --> $DIR/async-trait-fn.rs:5:5
    |
 LL |     async fn baz() {
    |     -----^^^^^^^^^
@@ -35,56 +35,8 @@ LL |     async fn baz() {
    = note: `async` trait functions are not currently supported
    = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
    = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
-   = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable
-
-error[E0308]: mismatched types
-  --> $DIR/async-trait-fn.rs:3:20
-   |
-LL |     async fn foo() {}
-   |                    ^^ expected associated type, found opaque type
-   |
-  ::: $SRC_DIR/core/src/future/mod.rs:LL:COL
-   |
-LL | pub const fn from_generator<T>(gen: T) -> impl Future<Output = T::Return>
-   |                                           ------------------------------- the found opaque type
-   |
-   = note: expected associated type `impl Future<Output = ()>` (trait associated opaque type at <$DIR/async-trait-fn.rs:3:20>)
-                  found opaque type `impl Future<Output = ()>` (opaque type at <$SRC_DIR/core/src/future/mod.rs:LL:COL>)
-
-error[E0308]: mismatched types
-  --> $DIR/async-trait-fn.rs:5:25
-   |
-LL |     async fn bar(&self) {}
-   |                         ^^ expected associated type, found opaque type
-   |
-  ::: $SRC_DIR/core/src/future/mod.rs:LL:COL
-   |
-LL | pub const fn from_generator<T>(gen: T) -> impl Future<Output = T::Return>
-   |                                           ------------------------------- the found opaque type
-   |
-   = note: expected associated type `impl Future<Output = ()>` (trait associated opaque type at <$DIR/async-trait-fn.rs:5:25>)
-                  found opaque type `impl Future<Output = ()>` (opaque type at <$SRC_DIR/core/src/future/mod.rs:LL:COL>)
-
-error[E0308]: mismatched types
-  --> $DIR/async-trait-fn.rs:7:20
-   |
-LL |       async fn baz() {
-   |  ____________________^
-LL | |
-LL | |         // Nested item must not ICE.
-LL | |         fn a() {}
-LL | |     }
-   | |_____^ expected associated type, found opaque type
-   |
-  ::: $SRC_DIR/core/src/future/mod.rs:LL:COL
-   |
-LL |   pub const fn from_generator<T>(gen: T) -> impl Future<Output = T::Return>
-   |                                             ------------------------------- the found opaque type
-   |
-   = note: expected associated type `impl Future<Output = ()>` (trait associated opaque type at <$DIR/async-trait-fn.rs:7:20>)
-                  found opaque type `impl Future<Output = ()>` (opaque type at <$SRC_DIR/core/src/future/mod.rs:LL:COL>)
+   = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable
 
-error: aborting due to 6 previous errors
+error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0308, E0706.
-For more information about an error, try `rustc --explain E0308`.
+For more information about this error, try `rustc --explain E0706`.
diff --git a/src/test/ui/async-await/await-keyword/2015-edition-error-various-positions.stderr b/src/test/ui/async-await/await-keyword/2015-edition-error-various-positions.stderr
index 50a82c08c..d99967eb2 100644
--- a/src/test/ui/async-await/await-keyword/2015-edition-error-various-positions.stderr
+++ b/src/test/ui/async-await/await-keyword/2015-edition-error-various-positions.stderr
@@ -4,13 +4,13 @@ error: `await` is a keyword in the 2018 edition
 LL |     pub mod await {
    |             ^^^^^ help: you can use a raw identifier to stay compatible: `r#await`
    |
+   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
+   = note: for more information, see issue #49716 <https://github.com/rust-lang/rust/issues/49716>
 note: the lint level is defined here
   --> $DIR/2015-edition-error-various-positions.rs:2:9
    |
 LL | #![deny(keyword_idents)]
    |         ^^^^^^^^^^^^^^
-   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
-   = note: for more information, see issue #49716 <https://github.com/rust-lang/rust/issues/49716>
 
 error: `await` is a keyword in the 2018 edition
   --> $DIR/2015-edition-error-various-positions.rs:7:20
diff --git a/src/test/ui/async-await/await-keyword/2015-edition-warning.stderr b/src/test/ui/async-await/await-keyword/2015-edition-warning.stderr
index 1c4c19ea4..bf5c4d8d6 100644
--- a/src/test/ui/async-await/await-keyword/2015-edition-warning.stderr
+++ b/src/test/ui/async-await/await-keyword/2015-edition-warning.stderr
@@ -4,13 +4,13 @@ error: `await` is a keyword in the 2018 edition
 LL |     pub mod await {
    |             ^^^^^ help: you can use a raw identifier to stay compatible: `r#await`
    |
+   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
+   = note: for more information, see issue #49716 <https://github.com/rust-lang/rust/issues/49716>
 note: the lint level is defined here
   --> $DIR/2015-edition-warning.rs:4:9
    |
 LL | #![deny(keyword_idents)]
    |         ^^^^^^^^^^^^^^
-   = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2018!
-   = note: for more information, see issue #49716 <https://github.com/rust-lang/rust/issues/49716>
 
 error: `await` is a keyword in the 2018 edition
   --> $DIR/2015-edition-warning.rs:10:20
diff --git a/src/test/ui/async-await/await-keyword/2018-edition-error-in-non-macro-position.stderr b/src/test/ui/async-await/await-keyword/2018-edition-error-in-non-macro-position.stderr
index ccbaa1f2a..6bd8f671d 100644
--- a/src/test/ui/async-await/await-keyword/2018-edition-error-in-non-macro-position.stderr
+++ b/src/test/ui/async-await/await-keyword/2018-edition-error-in-non-macro-position.stderr
@@ -46,7 +46,9 @@ error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error-in-non-macro-position.rs:13:14
    |
 LL | struct Foo { await: () }
-   |              ^^^^^ expected identifier, found keyword
+   |        ---   ^^^^^ expected identifier, found keyword
+   |        |
+   |        while parsing this struct
    |
 help: escape `await` to use it as an identifier
    |
diff --git a/src/test/ui/async-await/edition-deny-async-fns-2015.rs b/src/test/ui/async-await/edition-deny-async-fns-2015.rs
index 22a61dcd2..6bd6d879a 100644
--- a/src/test/ui/async-await/edition-deny-async-fns-2015.rs
+++ b/src/test/ui/async-await/edition-deny-async-fns-2015.rs
@@ -17,7 +17,6 @@ impl Foo {
 trait Bar {
     async fn foo() {} //~ ERROR `async fn` is not permitted in Rust 2015
     //~^ ERROR functions in traits cannot be declared `async`
-    //~| ERROR mismatched types
 }
 
 fn main() {
diff --git a/src/test/ui/async-await/edition-deny-async-fns-2015.stderr b/src/test/ui/async-await/edition-deny-async-fns-2015.stderr
index 8c2902d9b..ba918eb28 100644
--- a/src/test/ui/async-await/edition-deny-async-fns-2015.stderr
+++ b/src/test/ui/async-await/edition-deny-async-fns-2015.stderr
@@ -53,7 +53,7 @@ LL |     async fn foo() {}
    = note: for more on editions, read https://doc.rust-lang.org/edition-guide
 
 error[E0670]: `async fn` is not permitted in Rust 2015
-  --> $DIR/edition-deny-async-fns-2015.rs:37:9
+  --> $DIR/edition-deny-async-fns-2015.rs:36:9
    |
 LL |         async fn bar() {}
    |         ^^^^^ to use `async fn`, switch to Rust 2018 or later
@@ -62,7 +62,7 @@ LL |         async fn bar() {}
    = note: for more on editions, read https://doc.rust-lang.org/edition-guide
 
 error[E0670]: `async fn` is not permitted in Rust 2015
-  --> $DIR/edition-deny-async-fns-2015.rs:27:9
+  --> $DIR/edition-deny-async-fns-2015.rs:26:9
    |
 LL |         async fn foo() {}
    |         ^^^^^ to use `async fn`, switch to Rust 2018 or later
@@ -71,7 +71,7 @@ LL |         async fn foo() {}
    = note: for more on editions, read https://doc.rust-lang.org/edition-guide
 
 error[E0670]: `async fn` is not permitted in Rust 2015
-  --> $DIR/edition-deny-async-fns-2015.rs:32:13
+  --> $DIR/edition-deny-async-fns-2015.rs:31:13
    |
 LL |             async fn bar() {}
    |             ^^^^^ to use `async fn`, switch to Rust 2018 or later
@@ -90,23 +90,9 @@ LL |     async fn foo() {}
    = note: `async` trait functions are not currently supported
    = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
    = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
-   = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable
+   = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable
 
-error[E0308]: mismatched types
-  --> $DIR/edition-deny-async-fns-2015.rs:18:20
-   |
-LL |     async fn foo() {}
-   |                    ^^ expected associated type, found opaque type
-   |
-  ::: $SRC_DIR/core/src/future/mod.rs:LL:COL
-   |
-LL | pub const fn from_generator<T>(gen: T) -> impl Future<Output = T::Return>
-   |                                           ------------------------------- the found opaque type
-   |
-   = note: expected associated type `impl Future<Output = ()>` (trait associated opaque type at <$DIR/edition-deny-async-fns-2015.rs:18:20>)
-                  found opaque type `impl Future<Output = ()>` (opaque type at <$SRC_DIR/core/src/future/mod.rs:LL:COL>)
-
-error: aborting due to 11 previous errors
+error: aborting due to 10 previous errors
 
-Some errors have detailed explanations: E0308, E0670, E0706.
-For more information about an error, try `rustc --explain E0308`.
+Some errors have detailed explanations: E0670, E0706.
+For more information about an error, try `rustc --explain E0670`.
diff --git a/src/test/ui/async-await/feature-gate-async_fn_in_trait.rs b/src/test/ui/async-await/feature-gate-async_fn_in_trait.rs
new file mode 100644
index 000000000..792f378cb
--- /dev/null
+++ b/src/test/ui/async-await/feature-gate-async_fn_in_trait.rs
@@ -0,0 +1,25 @@
+// edition:2021
+
+// RPITIT is not enough to allow use of async functions
+#![allow(incomplete_features)]
+#![feature(return_position_impl_trait_in_trait)]
+
+trait T {
+    async fn foo(); //~ ERROR functions in traits cannot be declared `async`
+}
+
+// Both return_position_impl_trait_in_trait and async_fn_in_trait are required for this (see also
+// feature-gate-return_position_impl_trait_in_trait.rs)
+trait T2 {
+    async fn foo() -> impl Sized; //~ ERROR functions in traits cannot be declared `async`
+}
+
+trait T3 {
+    fn foo() -> impl std::future::Future<Output = ()>;
+}
+
+impl T3 for () {
+    async fn foo() {} //~ ERROR functions in traits cannot be declared `async`
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/feature-gate-async_fn_in_trait.stderr b/src/test/ui/async-await/feature-gate-async_fn_in_trait.stderr
new file mode 100644
index 000000000..2a5fbd1ec
--- /dev/null
+++ b/src/test/ui/async-await/feature-gate-async_fn_in_trait.stderr
@@ -0,0 +1,42 @@
+error[E0706]: functions in traits cannot be declared `async`
+  --> $DIR/feature-gate-async_fn_in_trait.rs:8:5
+   |
+LL |     async fn foo();
+   |     -----^^^^^^^^^^
+   |     |
+   |     `async` because of this
+   |
+   = note: `async` trait functions are not currently supported
+   = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
+   = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
+   = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable
+
+error[E0706]: functions in traits cannot be declared `async`
+  --> $DIR/feature-gate-async_fn_in_trait.rs:14:5
+   |
+LL |     async fn foo() -> impl Sized;
+   |     -----^^^^^^^^^^^^^^^^^^^^^^^^
+   |     |
+   |     `async` because of this
+   |
+   = note: `async` trait functions are not currently supported
+   = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
+   = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
+   = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable
+
+error[E0706]: functions in traits cannot be declared `async`
+  --> $DIR/feature-gate-async_fn_in_trait.rs:22:5
+   |
+LL |     async fn foo() {}
+   |     -----^^^^^^^^^
+   |     |
+   |     `async` because of this
+   |
+   = note: `async` trait functions are not currently supported
+   = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
+   = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
+   = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0706`.
diff --git a/src/test/ui/async-await/in-trait/async-associated-types.rs b/src/test/ui/async-await/in-trait/async-associated-types.rs
new file mode 100644
index 000000000..a6f928f3b
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-associated-types.rs
@@ -0,0 +1,24 @@
+// check-fail
+// known-bug: #102682
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+use std::fmt::Debug;
+
+trait MyTrait<'a, 'b, T> where Self: 'a, T: Debug + Sized + 'b {
+    type MyAssoc;
+
+    async fn foo(&'a self, key: &'b T) -> Self::MyAssoc;
+}
+
+impl<'a, 'b, T: Debug + Sized + 'b, U: 'a> MyTrait<'a, 'b, T> for U {
+    type MyAssoc = (&'a U, &'b T);
+
+    async fn foo(&'a self, key: &'b T) -> (&'a U, &'b T) {
+        (self, key)
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-associated-types.stderr b/src/test/ui/async-await/in-trait/async-associated-types.stderr
new file mode 100644
index 000000000..0985150ee
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-associated-types.stderr
@@ -0,0 +1,57 @@
+error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
+  --> $DIR/async-associated-types.rs:19:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a U, &'b T) {
+   |                                           ^^^^^^^^^^^^^^
+   |
+note: first, the lifetime cannot outlive the lifetime `'a` as defined here...
+  --> $DIR/async-associated-types.rs:16:6
+   |
+LL | impl<'a, 'b, T: Debug + Sized + 'b, U: 'a> MyTrait<'a, 'b, T> for U {
+   |      ^^
+note: ...so that the types are compatible
+  --> $DIR/async-associated-types.rs:19:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a U, &'b T) {
+   |                                           ^^^^^^^^^^^^^^
+   = note: expected `(&'a U, &'b T)`
+              found `(&U, &T)`
+   = note: but, the lifetime must be valid for the static lifetime...
+note: ...so that the types are compatible
+  --> $DIR/async-associated-types.rs:19:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a U, &'b T) {
+   |                                           ^^^^^^^^^^^^^^
+   = note: expected `MyTrait<'static, 'static, T>`
+              found `MyTrait<'_, '_, T>`
+
+error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'b` due to conflicting requirements
+  --> $DIR/async-associated-types.rs:19:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a U, &'b T) {
+   |                                           ^^^^^^^^^^^^^^
+   |
+note: first, the lifetime cannot outlive the lifetime `'b` as defined here...
+  --> $DIR/async-associated-types.rs:16:10
+   |
+LL | impl<'a, 'b, T: Debug + Sized + 'b, U: 'a> MyTrait<'a, 'b, T> for U {
+   |          ^^
+note: ...so that the types are compatible
+  --> $DIR/async-associated-types.rs:19:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a U, &'b T) {
+   |                                           ^^^^^^^^^^^^^^
+   = note: expected `(&'a U, &'b T)`
+              found `(&U, &T)`
+   = note: but, the lifetime must be valid for the static lifetime...
+note: ...so that the types are compatible
+  --> $DIR/async-associated-types.rs:19:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a U, &'b T) {
+   |                                           ^^^^^^^^^^^^^^
+   = note: expected `MyTrait<'static, 'static, T>`
+              found `MyTrait<'_, '_, T>`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0495`.
diff --git a/src/test/ui/async-await/in-trait/async-associated-types2.rs b/src/test/ui/async-await/in-trait/async-associated-types2.rs
new file mode 100644
index 000000000..e546a0579
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-associated-types2.rs
@@ -0,0 +1,30 @@
+// check-pass
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+use std::future::Future;
+
+trait MyTrait {
+    type Fut<'a>: Future<Output = i32>
+    where
+        Self: 'a;
+
+    fn foo<'a>(&'a self) -> Self::Fut<'a>;
+}
+
+impl MyTrait for i32 {
+    type Fut<'a> = impl Future<Output = i32> + 'a
+    where
+        Self: 'a;
+
+    fn foo<'a>(&'a self) -> Self::Fut<'a> {
+        async {
+            *self
+        }
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.rs b/src/test/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.rs
new file mode 100644
index 000000000..38ba29718
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.rs
@@ -0,0 +1,21 @@
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+use std::future::Future;
+use std::pin::Pin;
+
+trait MyTrait {
+    fn foo(&self) -> Pin<Box<dyn Future<Output = i32> + '_>>;
+}
+
+impl MyTrait for i32 {
+    async fn foo(&self) -> i32 {
+        //~^ ERROR method `foo` has an incompatible type for trait
+        *self
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.stderr b/src/test/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.stderr
new file mode 100644
index 000000000..22d2928f2
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-example-desugared-boxed-in-trait.stderr
@@ -0,0 +1,17 @@
+error[E0053]: method `foo` has an incompatible type for trait
+  --> $DIR/async-example-desugared-boxed-in-trait.rs:15:28
+   |
+LL |     async fn foo(&self) -> i32 {
+   |                            ^^^ expected struct `Pin`, found opaque type
+   |
+note: type in trait
+  --> $DIR/async-example-desugared-boxed-in-trait.rs:11:22
+   |
+LL |     fn foo(&self) -> Pin<Box<dyn Future<Output = i32> + '_>>;
+   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: expected fn pointer `fn(&i32) -> Pin<Box<dyn Future<Output = i32>>>`
+              found fn pointer `fn(&i32) -> impl Future<Output = i32>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0053`.
diff --git a/src/test/ui/async-await/in-trait/async-example-desugared-boxed.rs b/src/test/ui/async-await/in-trait/async-example-desugared-boxed.rs
new file mode 100644
index 000000000..61d7e2520
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-example-desugared-boxed.rs
@@ -0,0 +1,24 @@
+// check-pass
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+use std::future::Future;
+use std::pin::Pin;
+
+trait MyTrait {
+    async fn foo(&self) -> i32;
+}
+
+impl MyTrait for i32 {
+    // This will break once a PR that implements #102745 is merged
+    fn foo(&self) -> Pin<Box<dyn Future<Output = i32> + '_>> {
+        Box::pin(async {
+            *self
+        })
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-example-desugared-in-trait.rs b/src/test/ui/async-await/in-trait/async-example-desugared-in-trait.rs
new file mode 100644
index 000000000..feeda719e
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-example-desugared-in-trait.rs
@@ -0,0 +1,21 @@
+// check-pass
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+use std::future::Future;
+
+trait MyTrait {
+    fn foo(&self) -> impl Future<Output = i32> + '_;
+}
+
+impl MyTrait for i32 {
+    // This will break once a PR that implements #102745 is merged
+    async fn foo(&self) -> i32 {
+        *self
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-example-desugared.rs b/src/test/ui/async-await/in-trait/async-example-desugared.rs
new file mode 100644
index 000000000..1313c9edd
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-example-desugared.rs
@@ -0,0 +1,23 @@
+// check-pass
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+use std::future::Future;
+
+trait MyTrait {
+    async fn foo(&self) -> i32;
+}
+
+impl MyTrait for i32 {
+    // This will break once a PR that implements #102745 is merged
+    fn foo(&self) -> impl Future<Output = i32> + '_ {
+        async {
+            *self
+        }
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-example.rs b/src/test/ui/async-await/in-trait/async-example.rs
new file mode 100644
index 000000000..abf94ef74
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-example.rs
@@ -0,0 +1,32 @@
+// check-pass
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+trait MyTrait {
+    async fn foo(&self) -> i32;
+    async fn bar(&self) -> i32;
+}
+
+impl MyTrait for i32 {
+    async fn foo(&self) -> i32 {
+        *self
+    }
+
+    async fn bar(&self) -> i32 {
+        self.foo().await
+    }
+}
+
+fn main() {
+    let x = 5;
+    // Calling from non-async context
+    let _ = x.foo();
+    let _ = x.bar();
+    // Calling from async block in non-async context
+    async {
+        let _: i32 = x.foo().await;
+        let _: i32 = x.bar().await;
+    };
+}
diff --git a/src/test/ui/async-await/in-trait/async-generics-and-bounds.rs b/src/test/ui/async-await/in-trait/async-generics-and-bounds.rs
new file mode 100644
index 000000000..a73d55adf
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-generics-and-bounds.rs
@@ -0,0 +1,21 @@
+// check-fail
+// known-bug: #102682
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+use std::fmt::Debug;
+use std::hash::Hash;
+
+trait MyTrait<T, U> {
+    async fn foo(&self) -> &(T, U) where T: Debug + Sized, U: Hash;
+}
+
+impl<T, U> MyTrait<T, U> for (T, U) {
+    async fn foo(&self) -> &(T, U) {
+        self
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-generics-and-bounds.stderr b/src/test/ui/async-await/in-trait/async-generics-and-bounds.stderr
new file mode 100644
index 000000000..5c8d64fc6
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-generics-and-bounds.stderr
@@ -0,0 +1,37 @@
+error[E0311]: the parameter type `U` may not live long enough
+  --> $DIR/async-generics-and-bounds.rs:12:28
+   |
+LL |     async fn foo(&self) -> &(T, U) where T: Debug + Sized, U: Hash;
+   |                            ^^^^^^^
+   |
+note: the parameter type `U` must be valid for the anonymous lifetime as defined here...
+  --> $DIR/async-generics-and-bounds.rs:12:18
+   |
+LL |     async fn foo(&self) -> &(T, U) where T: Debug + Sized, U: Hash;
+   |                  ^
+note: ...so that the reference type `&(T, U)` does not outlive the data it points at
+  --> $DIR/async-generics-and-bounds.rs:12:28
+   |
+LL |     async fn foo(&self) -> &(T, U) where T: Debug + Sized, U: Hash;
+   |                            ^^^^^^^
+
+error[E0311]: the parameter type `T` may not live long enough
+  --> $DIR/async-generics-and-bounds.rs:12:28
+   |
+LL |     async fn foo(&self) -> &(T, U) where T: Debug + Sized, U: Hash;
+   |                            ^^^^^^^
+   |
+note: the parameter type `T` must be valid for the anonymous lifetime as defined here...
+  --> $DIR/async-generics-and-bounds.rs:12:18
+   |
+LL |     async fn foo(&self) -> &(T, U) where T: Debug + Sized, U: Hash;
+   |                  ^
+note: ...so that the reference type `&(T, U)` does not outlive the data it points at
+  --> $DIR/async-generics-and-bounds.rs:12:28
+   |
+LL |     async fn foo(&self) -> &(T, U) where T: Debug + Sized, U: Hash;
+   |                            ^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0311`.
diff --git a/src/test/ui/async-await/in-trait/async-generics.rs b/src/test/ui/async-await/in-trait/async-generics.rs
new file mode 100644
index 000000000..67000e577
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-generics.rs
@@ -0,0 +1,18 @@
+// check-fail
+// known-bug: #102682
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+trait MyTrait<T, U> {
+    async fn foo(&self) -> &(T, U);
+}
+
+impl<T, U> MyTrait<T, U> for (T, U) {
+    async fn foo(&self) -> &(T, U) {
+        self
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-generics.stderr b/src/test/ui/async-await/in-trait/async-generics.stderr
new file mode 100644
index 000000000..6ae73d9e3
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-generics.stderr
@@ -0,0 +1,37 @@
+error[E0311]: the parameter type `U` may not live long enough
+  --> $DIR/async-generics.rs:9:28
+   |
+LL |     async fn foo(&self) -> &(T, U);
+   |                            ^^^^^^^
+   |
+note: the parameter type `U` must be valid for the anonymous lifetime as defined here...
+  --> $DIR/async-generics.rs:9:18
+   |
+LL |     async fn foo(&self) -> &(T, U);
+   |                  ^
+note: ...so that the reference type `&(T, U)` does not outlive the data it points at
+  --> $DIR/async-generics.rs:9:28
+   |
+LL |     async fn foo(&self) -> &(T, U);
+   |                            ^^^^^^^
+
+error[E0311]: the parameter type `T` may not live long enough
+  --> $DIR/async-generics.rs:9:28
+   |
+LL |     async fn foo(&self) -> &(T, U);
+   |                            ^^^^^^^
+   |
+note: the parameter type `T` must be valid for the anonymous lifetime as defined here...
+  --> $DIR/async-generics.rs:9:18
+   |
+LL |     async fn foo(&self) -> &(T, U);
+   |                  ^
+note: ...so that the reference type `&(T, U)` does not outlive the data it points at
+  --> $DIR/async-generics.rs:9:28
+   |
+LL |     async fn foo(&self) -> &(T, U);
+   |                            ^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0311`.
diff --git a/src/test/ui/async-await/in-trait/async-lifetimes-and-bounds.rs b/src/test/ui/async-await/in-trait/async-lifetimes-and-bounds.rs
new file mode 100644
index 000000000..3f7448cec
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-lifetimes-and-bounds.rs
@@ -0,0 +1,20 @@
+// check-fail
+// known-bug: #102682
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+use std::fmt::Debug;
+
+trait MyTrait<'a, 'b, T> {
+    async fn foo(&'a self, key: &'b T) -> (&'a Self, &'b T) where T: Debug + Sized;
+}
+
+impl<'a, 'b, T, U> MyTrait<'a, 'b, T> for U {
+    async fn foo(&'a self, key: &'b T) -> (&'a U, &'b T) {
+        (self, key)
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-lifetimes-and-bounds.stderr b/src/test/ui/async-await/in-trait/async-lifetimes-and-bounds.stderr
new file mode 100644
index 000000000..0f0242027
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-lifetimes-and-bounds.stderr
@@ -0,0 +1,23 @@
+error[E0309]: the parameter type `Self` may not live long enough
+  --> $DIR/async-lifetimes-and-bounds.rs:11:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a Self, &'b T) where T: Debug + Sized;
+   |                                           ^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding an explicit lifetime bound `Self: 'a`...
+   = note: ...so that the reference type `&'a Self` does not outlive the data it points at
+
+error[E0309]: the parameter type `T` may not live long enough
+  --> $DIR/async-lifetimes-and-bounds.rs:11:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a Self, &'b T) where T: Debug + Sized;
+   |                                           ^^^^^^^^^^^^^^^^^ ...so that the reference type `&'b T` does not outlive the data it points at
+   |
+help: consider adding an explicit lifetime bound...
+   |
+LL | trait MyTrait<'a, 'b, T: 'b> {
+   |                        ++++
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0309`.
diff --git a/src/test/ui/async-await/in-trait/async-lifetimes.rs b/src/test/ui/async-await/in-trait/async-lifetimes.rs
new file mode 100644
index 000000000..acbac471c
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-lifetimes.rs
@@ -0,0 +1,18 @@
+// check-fail
+// known-bug: #102682
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+trait MyTrait<'a, 'b, T> {
+    async fn foo(&'a self, key: &'b T) -> (&'a Self, &'b T);
+}
+
+impl<'a, 'b, T, U> MyTrait<'a, 'b, T> for U {
+    async fn foo(&'a self, key: &'b T) -> (&'a U, &'b T) {
+        (self, key)
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-lifetimes.stderr b/src/test/ui/async-await/in-trait/async-lifetimes.stderr
new file mode 100644
index 000000000..9a7d294bb
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-lifetimes.stderr
@@ -0,0 +1,23 @@
+error[E0309]: the parameter type `Self` may not live long enough
+  --> $DIR/async-lifetimes.rs:9:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a Self, &'b T);
+   |                                           ^^^^^^^^^^^^^^^^^
+   |
+   = help: consider adding an explicit lifetime bound `Self: 'a`...
+   = note: ...so that the reference type `&'a Self` does not outlive the data it points at
+
+error[E0309]: the parameter type `T` may not live long enough
+  --> $DIR/async-lifetimes.rs:9:43
+   |
+LL |     async fn foo(&'a self, key: &'b T) -> (&'a Self, &'b T);
+   |                                           ^^^^^^^^^^^^^^^^^ ...so that the reference type `&'b T` does not outlive the data it points at
+   |
+help: consider adding an explicit lifetime bound...
+   |
+LL | trait MyTrait<'a, 'b, T: 'b> {
+   |                        ++++
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0309`.
diff --git a/src/test/ui/async-await/in-trait/async-recursive-generic.rs b/src/test/ui/async-await/in-trait/async-recursive-generic.rs
new file mode 100644
index 000000000..6839abd38
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-recursive-generic.rs
@@ -0,0 +1,21 @@
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+trait MyTrait<T> {
+    async fn foo_recursive(&self, n: usize) -> T;
+}
+
+impl<T> MyTrait<T> for T where T: Copy {
+    async fn foo_recursive(&self, n: usize) -> T {
+        //~^ ERROR recursion in an `async fn` requires boxing
+        if n > 0 {
+            self.foo_recursive(n - 1).await
+        } else {
+            *self
+        }
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-recursive-generic.stderr b/src/test/ui/async-await/in-trait/async-recursive-generic.stderr
new file mode 100644
index 000000000..cab173bdd
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-recursive-generic.stderr
@@ -0,0 +1,12 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/async-recursive-generic.rs:11:48
+   |
+LL |     async fn foo_recursive(&self, n: usize) -> T {
+   |                                                ^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/src/test/ui/async-await/in-trait/async-recursive.rs b/src/test/ui/async-await/in-trait/async-recursive.rs
new file mode 100644
index 000000000..61119f809
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-recursive.rs
@@ -0,0 +1,21 @@
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+trait MyTrait {
+    async fn foo_recursive(&self, n: usize) -> i32;
+}
+
+impl MyTrait for i32 {
+    async fn foo_recursive(&self, n: usize) -> i32 {
+        //~^ ERROR recursion in an `async fn` requires boxing
+        if n > 0 {
+            self.foo_recursive(n - 1).await
+        } else {
+            *self
+        }
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/async-recursive.stderr b/src/test/ui/async-await/in-trait/async-recursive.stderr
new file mode 100644
index 000000000..9feff37b3
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/async-recursive.stderr
@@ -0,0 +1,12 @@
+error[E0733]: recursion in an `async fn` requires boxing
+  --> $DIR/async-recursive.rs:11:48
+   |
+LL |     async fn foo_recursive(&self, n: usize) -> i32 {
+   |                                                ^^^ recursive `async fn`
+   |
+   = note: a recursive `async fn` must be rewritten to return a boxed `dyn Future`
+   = note: consider using the `async_recursion` crate: https://crates.io/crates/async_recursion
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0733`.
diff --git a/src/test/ui/async-await/in-trait/fn-not-async-err.rs b/src/test/ui/async-await/in-trait/fn-not-async-err.rs
new file mode 100644
index 000000000..f94d32145
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/fn-not-async-err.rs
@@ -0,0 +1,17 @@
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+trait MyTrait {
+    async fn foo(&self) -> i32;
+}
+
+impl MyTrait for i32 {
+    fn foo(&self) -> i32 {
+        //~^ ERROR: `i32` is not a future [E0277]
+        *self
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/fn-not-async-err.stderr b/src/test/ui/async-await/in-trait/fn-not-async-err.stderr
new file mode 100644
index 000000000..03321dc5b
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/fn-not-async-err.stderr
@@ -0,0 +1,17 @@
+error[E0277]: `i32` is not a future
+  --> $DIR/fn-not-async-err.rs:11:22
+   |
+LL |     fn foo(&self) -> i32 {
+   |                      ^^^ `i32` is not a future
+   |
+   = help: the trait `Future` is not implemented for `i32`
+   = note: i32 must be a future or must implement `IntoFuture` to be awaited
+note: required by a bound in `MyTrait::foo::{opaque#0}`
+  --> $DIR/fn-not-async-err.rs:7:28
+   |
+LL |     async fn foo(&self) -> i32;
+   |                            ^^^ required by this bound in `MyTrait::foo::{opaque#0}`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/async-await/in-trait/fn-not-async-err2.rs b/src/test/ui/async-await/in-trait/fn-not-async-err2.rs
new file mode 100644
index 000000000..594baa91a
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/fn-not-async-err2.rs
@@ -0,0 +1,21 @@
+// edition: 2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+use std::future::Future;
+
+trait MyTrait {
+    async fn foo(&self) -> i32;
+}
+
+impl MyTrait for i32 {
+    fn foo(&self) -> impl Future<Output = i32> {
+        //~^ ERROR `impl Trait` only allowed in function and inherent method return types, not in `impl` method return [E0562]
+        async {
+            *self
+        }
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/in-trait/fn-not-async-err2.stderr b/src/test/ui/async-await/in-trait/fn-not-async-err2.stderr
new file mode 100644
index 000000000..f591f1847
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/fn-not-async-err2.stderr
@@ -0,0 +1,12 @@
+error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in `impl` method return
+  --> $DIR/fn-not-async-err2.rs:13:22
+   |
+LL |     fn foo(&self) -> impl Future<Output = i32> {
+   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
+   = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.
diff --git a/src/test/ui/async-await/in-trait/issue-102138.rs b/src/test/ui/async-await/in-trait/issue-102138.rs
new file mode 100644
index 000000000..f61b34ed9
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/issue-102138.rs
@@ -0,0 +1,46 @@
+// check-pass
+// edition:2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+use std::future::Future;
+
+async fn yield_now() {}
+
+trait AsyncIterator {
+    type Item;
+    async fn next(&mut self) -> Option<Self::Item>;
+}
+
+struct YieldingRange {
+    counter: u32,
+    stop: u32,
+}
+
+impl AsyncIterator for YieldingRange {
+    type Item = u32;
+
+    async fn next(&mut self) -> Option<Self::Item> {
+        if self.counter == self.stop {
+            None
+        } else {
+            let c = self.counter;
+            self.counter += 1;
+            yield_now().await;
+            Some(c)
+        }
+    }
+}
+
+async fn async_main() {
+    let mut x = YieldingRange { counter: 0, stop: 10 };
+
+    while let Some(v) = x.next().await {
+        println!("Hi: {v}");
+    }
+}
+
+fn main() {
+    let _ = async_main();
+}
diff --git a/src/test/ui/async-await/in-trait/issue-102219.rs b/src/test/ui/async-await/in-trait/issue-102219.rs
new file mode 100644
index 000000000..9a35f6515
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/issue-102219.rs
@@ -0,0 +1,10 @@
+// compile-flags:--crate-type=lib
+// edition:2021
+// check-pass
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+trait T {
+    async fn foo();
+}
diff --git a/src/test/ui/async-await/in-trait/issue-102310.rs b/src/test/ui/async-await/in-trait/issue-102310.rs
new file mode 100644
index 000000000..49c3e9fee
--- /dev/null
+++ b/src/test/ui/async-await/in-trait/issue-102310.rs
@@ -0,0 +1,15 @@
+// check-pass
+// edition:2021
+
+#![feature(async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+pub trait SpiDevice {
+    async fn transaction<F, R>(&mut self);
+}
+
+impl SpiDevice for () {
+    async fn transaction<F, R>(&mut self) {}
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/issue-64130-1-sync.rs b/src/test/ui/async-await/issue-64130-1-sync.rs
index af83f14bb..1714cec52 100644
--- a/src/test/ui/async-await/issue-64130-1-sync.rs
+++ b/src/test/ui/async-await/issue-64130-1-sync.rs
@@ -1,7 +1,7 @@
 #![feature(negative_impls)]
 // edition:2018
 
-// This tests the the specialized async-await-specific error when futures don't implement an
+// This tests the specialized async-await-specific error when futures don't implement an
 // auto trait (which is specifically Sync) due to some type that was captured.
 
 struct Foo;
diff --git a/src/test/ui/async-await/issue-64130-2-send.rs b/src/test/ui/async-await/issue-64130-2-send.rs
index 2362831d8..7a6e5952c 100644
--- a/src/test/ui/async-await/issue-64130-2-send.rs
+++ b/src/test/ui/async-await/issue-64130-2-send.rs
@@ -1,7 +1,7 @@
 #![feature(negative_impls)]
 // edition:2018
 
-// This tests the the specialized async-await-specific error when futures don't implement an
+// This tests the specialized async-await-specific error when futures don't implement an
 // auto trait (which is specifically Send) due to some type that was captured.
 
 struct Foo;
diff --git a/src/test/ui/async-await/issue-64130-3-other.rs b/src/test/ui/async-await/issue-64130-3-other.rs
index 52801c35b..630fb2c41 100644
--- a/src/test/ui/async-await/issue-64130-3-other.rs
+++ b/src/test/ui/async-await/issue-64130-3-other.rs
@@ -2,7 +2,7 @@
 #![feature(negative_impls)]
 // edition:2018
 
-// This tests the the unspecialized async-await-specific error when futures don't implement an
+// This tests the unspecialized async-await-specific error when futures don't implement an
 // auto trait (which is not Send or Sync) due to some type that was captured.
 
 auto trait Qux {}
diff --git a/src/test/ui/async-await/issue-66387-if-without-else.stderr b/src/test/ui/async-await/issue-66387-if-without-else.stderr
index e8e2a4898..8155fcb56 100644
--- a/src/test/ui/async-await/issue-66387-if-without-else.stderr
+++ b/src/test/ui/async-await/issue-66387-if-without-else.stderr
@@ -4,7 +4,7 @@ error[E0317]: `if` may be missing an `else` clause
 LL | /     if true {
 LL | |         return 0;
 LL | |     }
-   | |_____^ expected `()`, found `i32`
+   | |_____^ expected `i32`, found `()`
    |
    = note: `if` expressions without `else` evaluate to `()`
    = help: consider adding an `else` block that evaluates to the expected type
diff --git a/src/test/ui/async-await/issue-70935-complex-spans.drop_tracking.stderr b/src/test/ui/async-await/issue-70935-complex-spans.drop_tracking.stderr
index 198de7bf7..7fb881166 100644
--- a/src/test/ui/async-await/issue-70935-complex-spans.drop_tracking.stderr
+++ b/src/test/ui/async-await/issue-70935-complex-spans.drop_tracking.stderr
@@ -18,7 +18,7 @@ LL |   async fn baz<T>(_c: impl FnMut() -> T) where T: Future<Output=()> {
    |  ___________________________________________________________________^
 LL | | }
    | |_^
-   = note: required because it captures the following types: `ResumeTy`, `impl for<'r, 's, 't0> Future<Output = ()>`, `()`
+   = note: required because it captures the following types: `ResumeTy`, `impl Future<Output = ()>`, `()`
 note: required because it's used within this `async` block
   --> $DIR/issue-70935-complex-spans.rs:16:16
    |
diff --git a/src/test/ui/issues/issue-73541-3.rs b/src/test/ui/async-await/issue-73541-3.rs
index 02ca02da8..02ca02da8 100644
--- a/src/test/ui/issues/issue-73541-3.rs
+++ b/src/test/ui/async-await/issue-73541-3.rs
diff --git a/src/test/ui/issues/issue-73541-3.stderr b/src/test/ui/async-await/issue-73541-3.stderr
index 53487aaca..53487aaca 100644
--- a/src/test/ui/issues/issue-73541-3.stderr
+++ b/src/test/ui/async-await/issue-73541-3.stderr
diff --git a/src/test/ui/issues/issue-73541.rs b/src/test/ui/async-await/issue-73541.rs
index 399a07cd3..399a07cd3 100644
--- a/src/test/ui/issues/issue-73541.rs
+++ b/src/test/ui/async-await/issue-73541.rs
diff --git a/src/test/ui/issues/issue-73541.stderr b/src/test/ui/async-await/issue-73541.stderr
index 4bb466ff1..4bb466ff1 100644
--- a/src/test/ui/issues/issue-73541.stderr
+++ b/src/test/ui/async-await/issue-73541.stderr
diff --git a/src/test/ui/async-await/issue-98634.rs b/src/test/ui/async-await/issue-98634.rs
new file mode 100644
index 000000000..b0d38687f
--- /dev/null
+++ b/src/test/ui/async-await/issue-98634.rs
@@ -0,0 +1,50 @@
+// edition: 2021
+
+use std::{
+    future::Future,
+    pin::Pin,
+    task::{Context, Poll, Waker},
+};
+
+pub struct StructAsync<F: Fn() -> Pin<Box<dyn Future<Output = ()>>>> {
+    pub callback: F,
+}
+
+impl<F> Future for StructAsync<F>
+where
+    F: Fn() -> Pin<Box<dyn Future<Output = ()>>>,
+{
+    type Output = ();
+
+    fn poll(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Self::Output> {
+        Poll::Pending
+    }
+}
+
+async fn callback() {}
+
+struct Runtime;
+
+fn waker() -> &'static Waker {
+    todo!()
+}
+
+impl Runtime {
+    #[track_caller]
+    pub fn block_on<F: Future>(&self, mut future: F) -> F::Output {
+        loop {
+            unsafe {
+                Pin::new_unchecked(&mut future).poll(&mut Context::from_waker(waker()));
+            }
+        }
+    }
+}
+
+fn main() {
+    Runtime.block_on(async {
+        StructAsync { callback }.await;
+        //~^ ERROR expected `fn() -> impl Future<Output = ()> {callback}` to be a fn item that returns `Pin<Box<(dyn Future<Output = ()> + 'static)>>`, but it returns `impl Future<Output = ()>`
+        //~| ERROR expected `fn() -> impl Future<Output = ()> {callback}` to be a fn item that returns `Pin<Box<(dyn Future<Output = ()> + 'static)>>`, but it returns `impl Future<Output = ()>`
+        //~| ERROR expected `fn() -> impl Future<Output = ()> {callback}` to be a fn item that returns `Pin<Box<(dyn Future<Output = ()> + 'static)>>`, but it returns `impl Future<Output = ()>`
+    });
+}
diff --git a/src/test/ui/async-await/issue-98634.stderr b/src/test/ui/async-await/issue-98634.stderr
new file mode 100644
index 000000000..5160e48d8
--- /dev/null
+++ b/src/test/ui/async-await/issue-98634.stderr
@@ -0,0 +1,60 @@
+error[E0271]: expected `fn() -> impl Future<Output = ()> {callback}` to be a fn item that returns `Pin<Box<(dyn Future<Output = ()> + 'static)>>`, but it returns `impl Future<Output = ()>`
+  --> $DIR/issue-98634.rs:45:23
+   |
+LL |         StructAsync { callback }.await;
+   |                       ^^^^^^^^ expected struct `Pin`, found opaque type
+   |
+note: while checking the return type of the `async fn`
+  --> $DIR/issue-98634.rs:24:21
+   |
+LL | async fn callback() {}
+   |                     ^ checked the `Output` of this `async fn`, found opaque type
+   = note:   expected struct `Pin<Box<(dyn Future<Output = ()> + 'static)>>`
+           found opaque type `impl Future<Output = ()>`
+note: required by a bound in `StructAsync`
+  --> $DIR/issue-98634.rs:9:35
+   |
+LL | pub struct StructAsync<F: Fn() -> Pin<Box<dyn Future<Output = ()>>>> {
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `StructAsync`
+
+error[E0271]: expected `fn() -> impl Future<Output = ()> {callback}` to be a fn item that returns `Pin<Box<(dyn Future<Output = ()> + 'static)>>`, but it returns `impl Future<Output = ()>`
+  --> $DIR/issue-98634.rs:45:9
+   |
+LL |         StructAsync { callback }.await;
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^ expected struct `Pin`, found opaque type
+   |
+note: while checking the return type of the `async fn`
+  --> $DIR/issue-98634.rs:24:21
+   |
+LL | async fn callback() {}
+   |                     ^ checked the `Output` of this `async fn`, found opaque type
+   = note:   expected struct `Pin<Box<(dyn Future<Output = ()> + 'static)>>`
+           found opaque type `impl Future<Output = ()>`
+note: required by a bound in `StructAsync`
+  --> $DIR/issue-98634.rs:9:35
+   |
+LL | pub struct StructAsync<F: Fn() -> Pin<Box<dyn Future<Output = ()>>>> {
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `StructAsync`
+
+error[E0271]: expected `fn() -> impl Future<Output = ()> {callback}` to be a fn item that returns `Pin<Box<(dyn Future<Output = ()> + 'static)>>`, but it returns `impl Future<Output = ()>`
+  --> $DIR/issue-98634.rs:45:33
+   |
+LL |         StructAsync { callback }.await;
+   |                                 ^^^^^^ expected struct `Pin`, found opaque type
+   |
+note: while checking the return type of the `async fn`
+  --> $DIR/issue-98634.rs:24:21
+   |
+LL | async fn callback() {}
+   |                     ^ checked the `Output` of this `async fn`, found opaque type
+   = note:   expected struct `Pin<Box<(dyn Future<Output = ()> + 'static)>>`
+           found opaque type `impl Future<Output = ()>`
+note: required by a bound in `StructAsync`
+  --> $DIR/issue-98634.rs:9:35
+   |
+LL | pub struct StructAsync<F: Fn() -> Pin<Box<dyn Future<Output = ()>>>> {
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `StructAsync`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0271`.
diff --git a/src/test/ui/async-await/issues/issue-65419/issue-65419-async-fn-resume-after-panic.rs b/src/test/ui/async-await/issues/issue-65419/issue-65419-async-fn-resume-after-panic.rs
index 5e71229be..b4ea4c9f6 100644
--- a/src/test/ui/async-await/issues/issue-65419/issue-65419-async-fn-resume-after-panic.rs
+++ b/src/test/ui/async-await/issues/issue-65419/issue-65419-async-fn-resume-after-panic.rs
@@ -6,7 +6,6 @@
 // error-pattern: thread 'main' panicked at '`async fn` resumed after panicking'
 // edition:2018
 // ignore-wasm no panic or subprocess support
-// ignore-emscripten no panic or subprocess support
 
 #![feature(generators, generator_trait)]
 
diff --git a/src/test/ui/async-await/issues/issue-95307.stderr b/src/test/ui/async-await/issues/issue-95307.stderr
index 1c12f1e48..a497cebe3 100644
--- a/src/test/ui/async-await/issues/issue-95307.stderr
+++ b/src/test/ui/async-await/issues/issue-95307.stderr
@@ -9,7 +9,7 @@ LL |     async fn new() -> [u8; _];
    = note: `async` trait functions are not currently supported
    = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
    = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
-   = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable
+   = help: add `#![feature(async_fn_in_trait)]` to the crate attributes to enable
 
 error: in expressions, `_` can only be used on the left-hand side of an assignment
   --> $DIR/issue-95307.rs:7:28
diff --git a/src/test/ui/async-await/large_moves.attribute.stderr b/src/test/ui/async-await/large_moves.attribute.stderr
index 8d3f0b77f..da34f44b2 100644
--- a/src/test/ui/async-await/large_moves.attribute.stderr
+++ b/src/test/ui/async-await/large_moves.attribute.stderr
@@ -10,12 +10,12 @@ LL | |         dbg!(y);
 LL | |     };
    | |_____^ value moved from here
    |
+   = note: The current maximum size is 1000, but it can be customized with the move_size_limit attribute: `#![move_size_limit = "..."]`
 note: the lint level is defined here
   --> $DIR/large_moves.rs:1:9
    |
 LL | #![deny(large_assignments)]
    |         ^^^^^^^^^^^^^^^^^
-   = note: The current maximum size is 1000, but it can be customized with the move_size_limit attribute: `#![move_size_limit = "..."]`
 
 error: moving 10024 bytes
   --> $DIR/large_moves.rs:18:14
diff --git a/src/test/ui/async-await/large_moves.option.stderr b/src/test/ui/async-await/large_moves.option.stderr
index 8d3f0b77f..da34f44b2 100644
--- a/src/test/ui/async-await/large_moves.option.stderr
+++ b/src/test/ui/async-await/large_moves.option.stderr
@@ -10,12 +10,12 @@ LL | |         dbg!(y);
 LL | |     };
    | |_____^ value moved from here
    |
+   = note: The current maximum size is 1000, but it can be customized with the move_size_limit attribute: `#![move_size_limit = "..."]`
 note: the lint level is defined here
   --> $DIR/large_moves.rs:1:9
    |
 LL | #![deny(large_assignments)]
    |         ^^^^^^^^^^^^^^^^^
-   = note: The current maximum size is 1000, but it can be customized with the move_size_limit attribute: `#![move_size_limit = "..."]`
 
 error: moving 10024 bytes
   --> $DIR/large_moves.rs:18:14
diff --git a/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.stderr b/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.stderr
index 3128b4df4..ae4d0d585 100644
--- a/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.stderr
+++ b/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-one.stderr
@@ -25,7 +25,7 @@ LL | |     (a, b)
 LL | | }
    | |_^
    |
-help: to declare that the `impl Trait` captures `'b`, you can add an explicit `'b` lifetime bound
+help: to declare that `impl Trait<'a>` captures `'b`, you can add an explicit `'b` lifetime bound
    |
 LL | async fn async_ret_impl_trait1<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a> + 'b {
    |                                                                                ++++
diff --git a/src/test/ui/async-await/no-const-async.stderr b/src/test/ui/async-await/no-const-async.stderr
index e6f6e9e9f..c5bd520aa 100644
--- a/src/test/ui/async-await/no-const-async.stderr
+++ b/src/test/ui/async-await/no-const-async.stderr
@@ -18,7 +18,7 @@ note: ...which requires borrow-checking `x`...
    |
 LL | pub const async fn x() {}
    | ^^^^^^^^^^^^^^^^^^^^^^
-note: ...which requires processing `x`...
+note: ...which requires processing MIR for `x`...
   --> $DIR/no-const-async.rs:4:1
    |
 LL | pub const async fn x() {}