Merging upstream version 1.74.1+dfsg1.

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

46 files changed, 615 insertions, 148 deletions

diff --git a/tests/ui/type-alias-impl-trait/auto-trait-leakage3.rs b/tests/ui/type-alias-impl-trait/auto-trait-leakage3.rs
index fd3f9c614..660950d59 100644
--- a/tests/ui/type-alias-impl-trait/auto-trait-leakage3.rs
+++ b/tests/ui/type-alias-impl-trait/auto-trait-leakage3.rs
@@ -5,8 +5,8 @@
 
 mod m {
     pub type Foo = impl std::fmt::Debug;
-    //~^ ERROR: cycle detected when computing type of `m::Foo::{opaque#0}` [E0391]
-    //~| ERROR: cycle detected when computing type of `m::Foo::{opaque#0}` [E0391]
+    //~^ ERROR: cycle detected when computing type of opaque `m::Foo::{opaque#0}` [E0391]
+    //~| ERROR: cycle detected when computing type of opaque `m::Foo::{opaque#0}` [E0391]
 
     pub fn foo() -> Foo {
         22_u32
diff --git a/tests/ui/type-alias-impl-trait/auto-trait-leakage3.stderr b/tests/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
index 5bd0f76c3..d86988266 100644
--- a/tests/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
+++ b/tests/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
@@ -1,4 +1,4 @@
-error[E0391]: cycle detected when computing type of `m::Foo::{opaque#0}`
+error[E0391]: cycle detected when computing type of opaque `m::Foo::{opaque#0}`
   --> $DIR/auto-trait-leakage3.rs:7:20
    |
 LL |     pub type Foo = impl std::fmt::Debug;
@@ -10,15 +10,15 @@ note: ...which requires type-checking `m::bar`...
 LL |         is_send(foo());
    |         ^^^^^^^
    = note: ...which requires evaluating trait selection obligation `m::Foo: core::marker::Send`...
-   = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in module `m`
-  --> $DIR/auto-trait-leakage3.rs:6:1
+   = note: ...which again requires computing type of opaque `m::Foo::{opaque#0}`, completing the cycle
+note: cycle used when computing type of `m::Foo::{opaque#0}`
+  --> $DIR/auto-trait-leakage3.rs:7:20
    |
-LL | mod m {
-   | ^^^^^
+LL |     pub type Foo = impl std::fmt::Debug;
+   |                    ^^^^^^^^^^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-error[E0391]: cycle detected when computing type of `m::Foo::{opaque#0}`
+error[E0391]: cycle detected when computing type of opaque `m::Foo::{opaque#0}`
   --> $DIR/auto-trait-leakage3.rs:7:20
    |
 LL |     pub type Foo = impl std::fmt::Debug;
@@ -29,12 +29,12 @@ note: ...which requires type-checking `m::bar`...
    |
 LL |     pub fn bar() {
    |     ^^^^^^^^^^^^
-   = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in module `m`
-  --> $DIR/auto-trait-leakage3.rs:6:1
+   = note: ...which again requires computing type of opaque `m::Foo::{opaque#0}`, completing the cycle
+note: cycle used when computing type of `m::Foo::{opaque#0}`
+  --> $DIR/auto-trait-leakage3.rs:7:20
    |
-LL | mod m {
-   | ^^^^^
+LL |     pub type Foo = impl std::fmt::Debug;
+   |                    ^^^^^^^^^^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of `auto_trait_leakage3[211d]::m::Foo::{opaque#0}` satisfies auto traits
diff --git a/tests/ui/type-alias-impl-trait/auxiliary/drop-shim-relates-opaque-aux.rs b/tests/ui/type-alias-impl-trait/auxiliary/drop-shim-relates-opaque-aux.rs
new file mode 100644
index 000000000..54a225100
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/auxiliary/drop-shim-relates-opaque-aux.rs
@@ -0,0 +1,21 @@
+// crate foo
+
+#![feature(type_alias_impl_trait)]
+
+type Tait = impl Sized;
+fn _constrain() -> Tait {}
+
+struct WrapperWithDrop<T>(T);
+impl<T> Drop for WrapperWithDrop<T> {
+    fn drop(&mut self) {}
+}
+
+pub struct Foo(WrapperWithDrop<Tait>);
+
+trait Id {
+    type Id: ?Sized;
+}
+impl<T: ?Sized> Id for T {
+    type Id = T;
+}
+pub struct Bar(WrapperWithDrop<<Tait as Id>::Id>);
diff --git a/tests/ui/type-alias-impl-trait/cross_inference_pattern_bug.rs b/tests/ui/type-alias-impl-trait/cross_inference_pattern_bug.rs
index 9a50c0f98..31fea42fa 100644
--- a/tests/ui/type-alias-impl-trait/cross_inference_pattern_bug.rs
+++ b/tests/ui/type-alias-impl-trait/cross_inference_pattern_bug.rs
@@ -1,5 +1,5 @@
 // compile-flags: --edition=2021
-// check-pass
+// build-pass
 #![feature(type_alias_impl_trait)]
 
 fn main() {
diff --git a/tests/ui/type-alias-impl-trait/destructure_tait-ice-113594.rs b/tests/ui/type-alias-impl-trait/destructure_tait-ice-113594.rs
new file mode 100644
index 000000000..7c2d68cce
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/destructure_tait-ice-113594.rs
@@ -0,0 +1,19 @@
+// build-pass
+// edition: 2021
+
+#![feature(type_alias_impl_trait)]
+
+pub struct Foo {
+    /// This type must have nontrivial drop glue
+    field: String,
+}
+
+pub type Tait = impl Sized;
+
+pub async fn ice_cold(beverage: Tait) {
+    // Must destructure at least one field of `Foo`
+    let Foo { field } = beverage;
+    _ = field;
+}
+
+fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/destructure_tait-layout_of-ice-113594.rs b/tests/ui/type-alias-impl-trait/destructure_tait-layout_of-ice-113594.rs
new file mode 100644
index 000000000..8568b26be
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/destructure_tait-layout_of-ice-113594.rs
@@ -0,0 +1,23 @@
+// build-pass
+// edition: 2021
+
+#![feature(type_alias_impl_trait)]
+
+fn foo<T>(x: T) {
+    type Opaque<T> = impl Sized;
+    let foo: Opaque<T> = (x,);
+    let (a,): (T,) = foo;
+}
+
+const fn bar<T: Copy>(x: T) {
+    type Opaque<T: Copy> = impl Copy;
+    let foo: Opaque<T> = (x, 2u32);
+    let (a, b): (T, u32) = foo;
+}
+
+fn main() {
+    foo::<u32>(1);
+    bar::<u32>(1);
+    const CONST: () = bar::<u32>(42u32);
+    CONST
+}
diff --git a/tests/ui/type-alias-impl-trait/different_lifetimes_defining_uses.rs b/tests/ui/type-alias-impl-trait/different_lifetimes_defining_uses.rs
index 5f75fdc71..4f424b8c6 100644
--- a/tests/ui/type-alias-impl-trait/different_lifetimes_defining_uses.rs
+++ b/tests/ui/type-alias-impl-trait/different_lifetimes_defining_uses.rs
@@ -1,11 +1,7 @@
 #![feature(type_alias_impl_trait)]
 #![allow(dead_code)]
 
-pub trait Captures<'a> {}
-
-impl<'a, T: ?Sized> Captures<'a> for T {}
-
-type OneLifetime<'a, 'b> = impl std::fmt::Debug + Captures<'a> + Captures<'b>;
+type OneLifetime<'a, 'b> = impl std::fmt::Debug;
 
 fn foo<'a, 'b>(a: &'a u32, b: &'b u32) -> OneLifetime<'a, 'b> {
     a
diff --git a/tests/ui/type-alias-impl-trait/different_lifetimes_defining_uses.stderr b/tests/ui/type-alias-impl-trait/different_lifetimes_defining_uses.stderr
index 546598e8a..0c50a84e8 100644
--- a/tests/ui/type-alias-impl-trait/different_lifetimes_defining_uses.stderr
+++ b/tests/ui/type-alias-impl-trait/different_lifetimes_defining_uses.stderr
@@ -1,11 +1,11 @@
 error: concrete type differs from previous defining opaque type use
-  --> $DIR/different_lifetimes_defining_uses.rs:15:5
+  --> $DIR/different_lifetimes_defining_uses.rs:11:5
    |
 LL |     b
    |     ^ expected `&'a u32`, got `&'b u32`
    |
 note: previous use here
-  --> $DIR/different_lifetimes_defining_uses.rs:11:5
+  --> $DIR/different_lifetimes_defining_uses.rs:7:5
    |
 LL |     a
    |     ^
diff --git a/tests/ui/type-alias-impl-trait/drop-shim-relates-opaque-issue-114375.rs b/tests/ui/type-alias-impl-trait/drop-shim-relates-opaque-issue-114375.rs
new file mode 100644
index 000000000..51d287049
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/drop-shim-relates-opaque-issue-114375.rs
@@ -0,0 +1,10 @@
+// aux-build:drop-shim-relates-opaque-aux.rs
+// compile-flags: -Zvalidate-mir --crate-type=lib
+// build-pass
+
+extern crate drop_shim_relates_opaque_aux;
+
+pub fn drop_foo(_: drop_shim_relates_opaque_aux::Foo) {}
+pub fn drop_bar(_: drop_shim_relates_opaque_aux::Bar) {}
+
+fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/escaping-bound-var.rs b/tests/ui/type-alias-impl-trait/escaping-bound-var.rs
new file mode 100644
index 000000000..bf27e76db
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/escaping-bound-var.rs
@@ -0,0 +1,22 @@
+#![feature(type_alias_impl_trait)]
+
+pub trait Trait<'a> {
+    type Assoc;
+}
+
+trait Test<'a> {}
+
+pub type Foo = impl for<'a> Trait<'a, Assoc = impl Test<'a>>;
+//~^ ERROR cannot capture late-bound lifetime in type alias impl trait
+
+impl Trait<'_> for () {
+    type Assoc = ();
+}
+
+impl Test<'_> for () {}
+
+fn constrain() -> Foo {
+    ()
+}
+
+fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/escaping-bound-var.stderr b/tests/ui/type-alias-impl-trait/escaping-bound-var.stderr
new file mode 100644
index 000000000..8205a60cc
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/escaping-bound-var.stderr
@@ -0,0 +1,8 @@
+error: cannot capture late-bound lifetime in type alias impl trait
+  --> $DIR/escaping-bound-var.rs:9:57
+   |
+LL | pub type Foo = impl for<'a> Trait<'a, Assoc = impl Test<'a>>;
+   |                         -- lifetime defined here        ^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_lifetime_param.rs b/tests/ui/type-alias-impl-trait/generic_duplicate_lifetime_param.rs
index 14ced3418..169d4f8d5 100644
--- a/tests/ui/type-alias-impl-trait/generic_duplicate_lifetime_param.rs
+++ b/tests/ui/type-alias-impl-trait/generic_duplicate_lifetime_param.rs
@@ -2,11 +2,7 @@
 
 fn main() {}
 
-pub trait Captures<'a> {}
-
-impl<'a, T: ?Sized> Captures<'a> for T {}
-
-type Two<'a, 'b> = impl std::fmt::Debug + Captures<'a> + Captures<'b>;
+type Two<'a, 'b> = impl std::fmt::Debug;
 
 fn one<'a>(t: &'a ()) -> Two<'a, 'a> {
     //~^ ERROR non-defining opaque type use
diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_lifetime_param.stderr b/tests/ui/type-alias-impl-trait/generic_duplicate_lifetime_param.stderr
index 4da69a705..b03bf2466 100644
--- a/tests/ui/type-alias-impl-trait/generic_duplicate_lifetime_param.stderr
+++ b/tests/ui/type-alias-impl-trait/generic_duplicate_lifetime_param.stderr
@@ -1,25 +1,25 @@
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_duplicate_lifetime_param.rs:11:26
+  --> $DIR/generic_duplicate_lifetime_param.rs:7:26
    |
 LL | fn one<'a>(t: &'a ()) -> Two<'a, 'a> {
    |                          ^^^^^^^^^^^ generic argument `'a` used twice
    |
 note: for this opaque type
-  --> $DIR/generic_duplicate_lifetime_param.rs:9:20
+  --> $DIR/generic_duplicate_lifetime_param.rs:5:20
    |
-LL | type Two<'a, 'b> = impl std::fmt::Debug + Captures<'a> + Captures<'b>;
-   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | type Two<'a, 'b> = impl std::fmt::Debug;
+   |                    ^^^^^^^^^^^^^^^^^^^^
 
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_duplicate_lifetime_param.rs:13:5
+  --> $DIR/generic_duplicate_lifetime_param.rs:9:5
    |
 LL |     t
    |     ^
    |
 note: lifetime used multiple times
-  --> $DIR/generic_duplicate_lifetime_param.rs:9:10
+  --> $DIR/generic_duplicate_lifetime_param.rs:5:10
    |
-LL | type Two<'a, 'b> = impl std::fmt::Debug + Captures<'a> + Captures<'b>;
+LL | type Two<'a, 'b> = impl std::fmt::Debug;
    |          ^^  ^^
 
 error: aborting due to 2 previous errors
diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use.rs b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use.rs
index 1e391b55a..e3c6f4d87 100644
--- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use.rs
+++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use.rs
@@ -14,11 +14,7 @@ fn main() {}
 // test that unused generic parameters are ok
 type TwoTys<T, U> = impl Debug;
 
-pub trait Captures<'a> {}
-
-impl<'a, T: ?Sized> Captures<'a> for T {}
-
-type TwoLifetimes<'a, 'b> = impl Debug + Captures<'a> + Captures<'b>;
+type TwoLifetimes<'a, 'b> = impl Debug;
 
 type TwoConsts<const X: usize, const Y: usize> = impl Debug;
 
diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use.stderr b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use.stderr
index d8330771d..495308a6c 100644
--- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use.stderr
+++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use.stderr
@@ -1,5 +1,5 @@
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_duplicate_param_use.rs:25:30
+  --> $DIR/generic_duplicate_param_use.rs:21:30
    |
 LL | fn one_ty<T: Debug>(t: T) -> TwoTys<T, T> {
    |                              ^^^^^^^^^^^^ generic argument `T` used twice
@@ -11,7 +11,7 @@ LL | type TwoTys<T, U> = impl Debug;
    |                     ^^^^^^^^^^
 
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_duplicate_param_use.rs:27:5
+  --> $DIR/generic_duplicate_param_use.rs:23:5
    |
 LL |     t
    |     ^
@@ -23,49 +23,49 @@ LL | type TwoTys<T, U> = impl Debug;
    |             ^  ^
 
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_duplicate_param_use.rs:31:36
+  --> $DIR/generic_duplicate_param_use.rs:27:36
    |
 LL | fn one_lifetime<'a>(t: &'a u32) -> TwoLifetimes<'a, 'a> {
    |                                    ^^^^^^^^^^^^^^^^^^^^ generic argument `'a` used twice
    |
 note: for this opaque type
-  --> $DIR/generic_duplicate_param_use.rs:21:29
+  --> $DIR/generic_duplicate_param_use.rs:17:29
    |
-LL | type TwoLifetimes<'a, 'b> = impl Debug + Captures<'a> + Captures<'b>;
-   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | type TwoLifetimes<'a, 'b> = impl Debug;
+   |                             ^^^^^^^^^^
 
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_duplicate_param_use.rs:33:5
+  --> $DIR/generic_duplicate_param_use.rs:29:5
    |
 LL |     t
    |     ^
    |
 note: lifetime used multiple times
-  --> $DIR/generic_duplicate_param_use.rs:21:19
+  --> $DIR/generic_duplicate_param_use.rs:17:19
    |
-LL | type TwoLifetimes<'a, 'b> = impl Debug + Captures<'a> + Captures<'b>;
+LL | type TwoLifetimes<'a, 'b> = impl Debug;
    |                   ^^  ^^
 
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_duplicate_param_use.rs:37:50
+  --> $DIR/generic_duplicate_param_use.rs:33:50
    |
 LL | fn one_const<const N: usize>(t: *mut [u8; N]) -> TwoConsts<N, N> {
    |                                                  ^^^^^^^^^^^^^^^ generic argument `N` used twice
    |
 note: for this opaque type
-  --> $DIR/generic_duplicate_param_use.rs:23:50
+  --> $DIR/generic_duplicate_param_use.rs:19:50
    |
 LL | type TwoConsts<const X: usize, const Y: usize> = impl Debug;
    |                                                  ^^^^^^^^^^
 
 error: non-defining opaque type use in defining scope
-  --> $DIR/generic_duplicate_param_use.rs:39:5
+  --> $DIR/generic_duplicate_param_use.rs:35:5
    |
 LL |     t
    |     ^
    |
 note: constant used multiple times
-  --> $DIR/generic_duplicate_param_use.rs:23:16
+  --> $DIR/generic_duplicate_param_use.rs:19:16
    |
 LL | type TwoConsts<const X: usize, const Y: usize> = impl Debug;
    |                ^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^
diff --git a/tests/ui/type-alias-impl-trait/generic_lifetime_param.rs b/tests/ui/type-alias-impl-trait/generic_lifetime_param.rs
index 106efefba..e109c38c9 100644
--- a/tests/ui/type-alias-impl-trait/generic_lifetime_param.rs
+++ b/tests/ui/type-alias-impl-trait/generic_lifetime_param.rs
@@ -1,11 +1,10 @@
-// check-pass
+// build-pass (FIXME(62277): could be check-pass?)
 
 #![feature(type_alias_impl_trait)]
 
 fn main() {}
 
-type Region<'a> = impl std::fmt::Debug + 'a;
-
+type Region<'a> = impl std::fmt::Debug;
 
 fn region<'b>(a: &'b ()) -> Region<'b> {
     a
diff --git a/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check3.rs b/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check3.rs
index 6f9434255..469a493b0 100644
--- a/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check3.rs
+++ b/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check3.rs
@@ -1,7 +1,7 @@
 #![feature(type_alias_impl_trait)]
 
 mod test_lifetime_param {
-    type Ty<'a> = impl Sized + 'a;
+    type Ty<'a> = impl Sized;
     fn defining(a: &str) -> Ty<'_> { a }
     fn assert_static<'a: 'static>() {}
     fn test<'a>() where Ty<'a>: 'static { assert_static::<'a>() }
@@ -9,7 +9,7 @@ mod test_lifetime_param {
 }
 
 mod test_higher_kinded_lifetime_param {
-    type Ty<'a> = impl Sized + 'a;
+    type Ty<'a> = impl Sized;
     fn defining(a: &str) -> Ty<'_> { a }
     fn assert_static<'a: 'static>() {}
     fn test<'a>() where for<'b> Ty<'b>: 'a { assert_static::<'a>() }
diff --git a/tests/ui/type-alias-impl-trait/imply_bounds_from_bounds.rs b/tests/ui/type-alias-impl-trait/imply_bounds_from_bounds.rs
index 4f99236f4..06c119287 100644
--- a/tests/ui/type-alias-impl-trait/imply_bounds_from_bounds.rs
+++ b/tests/ui/type-alias-impl-trait/imply_bounds_from_bounds.rs
@@ -1,16 +1,20 @@
 // check-pass
 
-#![feature(impl_trait_in_assoc_type)]
+#![feature(impl_trait_in_assoc_type, type_alias_impl_trait)]
 
-trait Callable {
-    type Output;
-    fn call() -> Self::Output;
-}
+mod foo {
+    pub trait Callable {
+        type Output;
+        fn call() -> Self::Output;
+    }
 
-impl<'a> Callable for &'a () {
-    type Output = impl Sized;
-    fn call() -> Self::Output {}
+    pub type OutputHelper = impl Sized;
+    impl<'a> Callable for &'a () {
+        type Output = OutputHelper;
+        fn call() -> Self::Output {}
+    }
 }
+use foo::*;
 
 fn test<'a>() -> impl Sized {
     <&'a () as Callable>::call()
diff --git a/tests/ui/type-alias-impl-trait/indirect-recursion-issue-112047.rs b/tests/ui/type-alias-impl-trait/indirect-recursion-issue-112047.rs
new file mode 100644
index 000000000..f6cbbf04d
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/indirect-recursion-issue-112047.rs
@@ -0,0 +1,29 @@
+// edition: 2021
+// build-fail
+//~^^ ERROR cycle detected when computing layout of
+
+#![feature(impl_trait_in_assoc_type)]
+
+use core::future::Future;
+
+trait Recur {
+    type Recur: Future<Output = ()>;
+
+    fn recur(self) -> Self::Recur;
+}
+
+async fn recur(t: impl Recur) {
+    t.recur().await;
+}
+
+impl Recur for () {
+    type Recur = impl Future<Output = ()>;
+
+    fn recur(self) -> Self::Recur {
+        async move { recur(self).await; }
+    }
+}
+
+fn main() {
+    recur(());
+}
diff --git a/tests/ui/type-alias-impl-trait/indirect-recursion-issue-112047.stderr b/tests/ui/type-alias-impl-trait/indirect-recursion-issue-112047.stderr
new file mode 100644
index 000000000..2063becdb
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/indirect-recursion-issue-112047.stderr
@@ -0,0 +1,19 @@
+error[E0391]: cycle detected when computing layout of `{async block@$DIR/indirect-recursion-issue-112047.rs:23:9: 23:42}`
+   |
+   = note: ...which requires computing layout of `core::mem::maybe_uninit::MaybeUninit<{async fn body@$DIR/indirect-recursion-issue-112047.rs:15:31: 17:2}>`...
+   = note: ...which requires computing layout of `core::mem::manually_drop::ManuallyDrop<{async fn body@$DIR/indirect-recursion-issue-112047.rs:15:31: 17:2}>`...
+   = note: ...which requires computing layout of `{async fn body@$DIR/indirect-recursion-issue-112047.rs:15:31: 17:2}`...
+   = note: ...which requires computing layout of `core::mem::maybe_uninit::MaybeUninit<<() as Recur>::Recur>`...
+   = note: ...which requires computing layout of `core::mem::maybe_uninit::MaybeUninit<{async block@$DIR/indirect-recursion-issue-112047.rs:23:9: 23:42}>`...
+   = note: ...which requires computing layout of `core::mem::manually_drop::ManuallyDrop<{async block@$DIR/indirect-recursion-issue-112047.rs:23:9: 23:42}>`...
+   = note: ...which again requires computing layout of `{async block@$DIR/indirect-recursion-issue-112047.rs:23:9: 23:42}`, completing the cycle
+note: cycle used when elaborating drops for `<impl at $DIR/indirect-recursion-issue-112047.rs:19:1: 19:18>::recur`
+  --> $DIR/indirect-recursion-issue-112047.rs:22:5
+   |
+LL |     fn recur(self) -> Self::Recur {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0391`.
diff --git a/tests/ui/type-alias-impl-trait/inference-cycle.stderr b/tests/ui/type-alias-impl-trait/inference-cycle.stderr
index 41530dda9..4ab059d05 100644
--- a/tests/ui/type-alias-impl-trait/inference-cycle.stderr
+++ b/tests/ui/type-alias-impl-trait/inference-cycle.stderr
@@ -1,4 +1,4 @@
-error[E0391]: cycle detected when computing type of `m::Foo::{opaque#0}`
+error[E0391]: cycle detected when computing type of opaque `m::Foo::{opaque#0}`
   --> $DIR/inference-cycle.rs:5:20
    |
 LL |     pub type Foo = impl std::fmt::Debug;
@@ -10,15 +10,15 @@ note: ...which requires type-checking `m::bar`...
 LL |         is_send(foo()); // Today: error
    |         ^^^^^^^
    = note: ...which requires evaluating trait selection obligation `m::Foo: core::marker::Send`...
-   = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in module `m`
-  --> $DIR/inference-cycle.rs:4:1
+   = note: ...which again requires computing type of opaque `m::Foo::{opaque#0}`, completing the cycle
+note: cycle used when computing type of `m::Foo::{opaque#0}`
+  --> $DIR/inference-cycle.rs:5:20
    |
-LL | mod m {
-   | ^^^^^
+LL |     pub type Foo = impl std::fmt::Debug;
+   |                    ^^^^^^^^^^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-error[E0391]: cycle detected when computing type of `m::Foo::{opaque#0}`
+error[E0391]: cycle detected when computing type of opaque `m::Foo::{opaque#0}`
   --> $DIR/inference-cycle.rs:5:20
    |
 LL |     pub type Foo = impl std::fmt::Debug;
@@ -29,12 +29,12 @@ note: ...which requires type-checking `m::bar`...
    |
 LL |     pub fn bar() {
    |     ^^^^^^^^^^^^
-   = note: ...which again requires computing type of `m::Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in module `m`
-  --> $DIR/inference-cycle.rs:4:1
+   = note: ...which again requires computing type of opaque `m::Foo::{opaque#0}`, completing the cycle
+note: cycle used when computing type of `m::Foo::{opaque#0}`
+  --> $DIR/inference-cycle.rs:5:20
    |
-LL | mod m {
-   | ^^^^^
+LL |     pub type Foo = impl std::fmt::Debug;
+   |                    ^^^^^^^^^^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of `inference_cycle[4ecc]::m::Foo::{opaque#0}` satisfies auto traits
diff --git a/tests/ui/type-alias-impl-trait/issue-53092-2.stderr b/tests/ui/type-alias-impl-trait/issue-53092-2.stderr
index 6148131b4..e4054e14a 100644
--- a/tests/ui/type-alias-impl-trait/issue-53092-2.stderr
+++ b/tests/ui/type-alias-impl-trait/issue-53092-2.stderr
@@ -4,6 +4,11 @@ error[E0391]: cycle detected when computing type of `Bug::{opaque#0}`
 LL | type Bug<T, U> = impl Fn(T) -> U + Copy;
    |                  ^^^^^^^^^^^^^^^^^^^^^^
    |
+note: ...which requires computing type of opaque `Bug::{opaque#0}`...
+  --> $DIR/issue-53092-2.rs:4:18
+   |
+LL | type Bug<T, U> = impl Fn(T) -> U + Copy;
+   |                  ^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires type-checking `CONST_BUG`...
   --> $DIR/issue-53092-2.rs:6:1
    |
diff --git a/tests/ui/type-alias-impl-trait/issue-63279.stderr b/tests/ui/type-alias-impl-trait/issue-63279.stderr
index a4f6359b9..a86856247 100644
--- a/tests/ui/type-alias-impl-trait/issue-63279.stderr
+++ b/tests/ui/type-alias-impl-trait/issue-63279.stderr
@@ -23,7 +23,7 @@ LL |     || -> Closure { || () }
    |                     ^^^^^ expected `()`, found closure
    |
    = note: expected unit type `()`
-                found closure `[closure@$DIR/issue-63279.rs:7:21: 7:23]`
+                found closure `{closure@$DIR/issue-63279.rs:7:21: 7:23}`
 help: use parentheses to call this closure
    |
 LL |     || -> Closure { (|| ())() }
@@ -36,7 +36,7 @@ LL |     || -> Closure { || () }
    |     ^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found closure
    |
    = note: expected unit type `()`
-                found closure `[closure@$DIR/issue-63279.rs:7:5: 7:18]`
+                found closure `{closure@$DIR/issue-63279.rs:7:5: 7:18}`
 help: use parentheses to call this closure
    |
 LL |     (|| -> Closure { || () })()
diff --git a/tests/ui/type-alias-impl-trait/issue-89686.rs b/tests/ui/type-alias-impl-trait/issue-89686.rs
index 058417bdb..de070fc9d 100644
--- a/tests/ui/type-alias-impl-trait/issue-89686.rs
+++ b/tests/ui/type-alias-impl-trait/issue-89686.rs
@@ -4,7 +4,7 @@
 
 use std::future::Future;
 
-type G<'a, T> = impl Future<Output = ()> + 'a;
+type G<'a, T> = impl Future<Output = ()>;
 
 trait Trait {
     type F: Future<Output = ()>;
diff --git a/tests/ui/type-alias-impl-trait/issue-89686.stderr b/tests/ui/type-alias-impl-trait/issue-89686.stderr
index 3b95a575a..b636ada8b 100644
--- a/tests/ui/type-alias-impl-trait/issue-89686.stderr
+++ b/tests/ui/type-alias-impl-trait/issue-89686.stderr
@@ -6,7 +6,7 @@ LL |         async move { self.f().await }
    |
 help: consider restricting type parameter `T`
    |
-LL | type G<'a, T: Trait> = impl Future<Output = ()> + 'a;
+LL | type G<'a, T: Trait> = impl Future<Output = ()>;
    |             +++++++
 
 error: aborting due to previous error
diff --git a/tests/ui/type-alias-impl-trait/issue-94429.stderr b/tests/ui/type-alias-impl-trait/issue-94429.stderr
index 8d7f7a07b..26605cdd2 100644
--- a/tests/ui/type-alias-impl-trait/issue-94429.stderr
+++ b/tests/ui/type-alias-impl-trait/issue-94429.stderr
@@ -1,4 +1,4 @@
-error[E0271]: type mismatch resolving `<[generator@$DIR/issue-94429.rs:17:9: 17:16] as Generator>::Yield == ()`
+error[E0271]: type mismatch resolving `<{generator@$DIR/issue-94429.rs:17:9: 17:16} as Generator>::Yield == ()`
   --> $DIR/issue-94429.rs:15:26
    |
 LL |     fn run(&mut self) -> Self::Gen {
diff --git a/tests/ui/type-alias-impl-trait/missing_lifetime_bound.rs b/tests/ui/type-alias-impl-trait/missing_lifetime_bound.rs
index 01d1f5db1..c584a58cb 100644
--- a/tests/ui/type-alias-impl-trait/missing_lifetime_bound.rs
+++ b/tests/ui/type-alias-impl-trait/missing_lifetime_bound.rs
@@ -1,7 +1,8 @@
 #![feature(type_alias_impl_trait)]
 
-type Opaque<'a, T> = impl Sized;
+type Opaque2<T> = impl Sized;
+type Opaque<'a, T> = Opaque2<T>;
 fn defining<'a, T>(x: &'a i32) -> Opaque<T> { x }
-//~^ ERROR: hidden type for `Opaque<'a, T>` captures lifetime that does not appear in bounds
+//~^ ERROR: hidden type for `Opaque2<T>` captures lifetime that does not appear in bounds
 
 fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/missing_lifetime_bound.stderr b/tests/ui/type-alias-impl-trait/missing_lifetime_bound.stderr
index d666e668d..6bcae6e53 100644
--- a/tests/ui/type-alias-impl-trait/missing_lifetime_bound.stderr
+++ b/tests/ui/type-alias-impl-trait/missing_lifetime_bound.stderr
@@ -1,8 +1,9 @@
-error[E0700]: hidden type for `Opaque<'a, T>` captures lifetime that does not appear in bounds
-  --> $DIR/missing_lifetime_bound.rs:4:47
+error[E0700]: hidden type for `Opaque2<T>` captures lifetime that does not appear in bounds
+  --> $DIR/missing_lifetime_bound.rs:5:47
    |
-LL | type Opaque<'a, T> = impl Sized;
-   |                      ---------- opaque type defined here
+LL | type Opaque2<T> = impl Sized;
+   |                   ---------- opaque type defined here
+LL | type Opaque<'a, T> = Opaque2<T>;
 LL | fn defining<'a, T>(x: &'a i32) -> Opaque<T> { x }
    |             --                                ^
    |             |
diff --git a/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-lifetimes.rs b/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-lifetimes.rs
index 65eb2952e..3f122f106 100644
--- a/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-lifetimes.rs
+++ b/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-lifetimes.rs
@@ -1,10 +1,6 @@
 #![feature(type_alias_impl_trait)]
 
-pub trait Captures<'a> {}
-
-impl<'a, T: ?Sized> Captures<'a> for T {}
-
-type Foo<'a, 'b> = impl std::fmt::Debug + Captures<'a> + Captures<'b>;
+type Foo<'a, 'b> = impl std::fmt::Debug;
 
 fn foo<'x, 'y>(i: &'x i32, j: &'y i32) -> (Foo<'x, 'y>, Foo<'y, 'x>) {
     (i, i) //~ ERROR concrete type differs from previous
diff --git a/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-lifetimes.stderr b/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-lifetimes.stderr
index d7676b8e9..81e603e23 100644
--- a/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-lifetimes.stderr
+++ b/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-lifetimes.stderr
@@ -1,5 +1,5 @@
 error: concrete type differs from previous defining opaque type use
-  --> $DIR/multiple-def-uses-in-one-fn-lifetimes.rs:10:5
+  --> $DIR/multiple-def-uses-in-one-fn-lifetimes.rs:6:5
    |
 LL |     (i, i)
    |     ^^^^^^
diff --git a/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-pass.rs b/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-pass.rs
index 21fca047a..83fd9a1da 100644
--- a/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-pass.rs
+++ b/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn-pass.rs
@@ -7,11 +7,7 @@ fn f<A: ToString + Clone, B: ToString + Clone>(a: A, b: B) -> (X<A, B>, X<A, B>)
     (a.clone(), a)
 }
 
-pub trait Captures<'a> {}
-
-impl<'a, T: ?Sized> Captures<'a> for T {}
-
-type Foo<'a, 'b> = impl std::fmt::Debug + Captures<'a> + Captures<'b>;
+type Foo<'a, 'b> = impl std::fmt::Debug;
 
 fn foo<'x, 'y>(i: &'x i32, j: &'y i32) -> (Foo<'x, 'y>, Foo<'y, 'x>) {
     (i, j)
diff --git a/tests/ui/type-alias-impl-trait/mututally-recursive-overflow.rs b/tests/ui/type-alias-impl-trait/mututally-recursive-overflow.rs
new file mode 100644
index 000000000..1ccd1b0cb
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/mututally-recursive-overflow.rs
@@ -0,0 +1,40 @@
+// edition: 2021
+// build-fail
+//~^^ ERROR overflow evaluating the requirement `<() as B>::Assoc == _`
+
+#![feature(rustc_attrs)]
+#![feature(impl_trait_in_assoc_type)]
+
+#[rustc_coinductive]
+trait A {
+    type Assoc;
+
+    fn test() -> Self::Assoc;
+}
+
+#[rustc_coinductive]
+trait B {
+    type Assoc;
+
+    fn test() -> Self::Assoc;
+}
+
+impl<T: A> B for T {
+    type Assoc = impl Sized;
+
+    fn test() -> <Self as B>::Assoc {
+        <T as A>::test()
+    }
+}
+
+fn main() {
+    <() as A>::test();
+}
+
+impl<T: B> A for T {
+    type Assoc = impl Sized;
+
+    fn test() -> <Self as A>::Assoc {
+        <T as B>::test()
+    }
+}
diff --git a/tests/ui/type-alias-impl-trait/mututally-recursive-overflow.stderr b/tests/ui/type-alias-impl-trait/mututally-recursive-overflow.stderr
new file mode 100644
index 000000000..49c59f7eb
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/mututally-recursive-overflow.stderr
@@ -0,0 +1,5 @@
+error[E0275]: overflow evaluating the requirement `<() as B>::Assoc == _`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0275`.
diff --git a/tests/ui/type-alias-impl-trait/nested-impl-trait-in-tait.rs b/tests/ui/type-alias-impl-trait/nested-impl-trait-in-tait.rs
new file mode 100644
index 000000000..fec0fdc46
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/nested-impl-trait-in-tait.rs
@@ -0,0 +1,9 @@
+#![feature(type_alias_impl_trait)]
+
+pub type Tait = impl Iterator<Item = (&'db Key, impl Iterator)>;
+//~^ ERROR use of undeclared lifetime name `'db`
+//~| ERROR cannot find type `Key` in this scope
+//~| ERROR unconstrained opaque type
+//~| ERROR unconstrained opaque type
+
+pub fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/nested-impl-trait-in-tait.stderr b/tests/ui/type-alias-impl-trait/nested-impl-trait-in-tait.stderr
new file mode 100644
index 000000000..d4aeace4a
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/nested-impl-trait-in-tait.stderr
@@ -0,0 +1,47 @@
+error[E0261]: use of undeclared lifetime name `'db`
+  --> $DIR/nested-impl-trait-in-tait.rs:3:40
+   |
+LL | pub type Tait = impl Iterator<Item = (&'db Key, impl Iterator)>;
+   |                                        ^^^ undeclared lifetime
+   |
+   = note: for more information on higher-ranked polymorphism, visit https://doc.rust-lang.org/nomicon/hrtb.html
+help: consider making the bound lifetime-generic with a new `'db` lifetime
+   |
+LL | pub type Tait = impl for<'db> Iterator<Item = (&'db Key, impl Iterator)>;
+   |                      ++++++++
+help: consider introducing lifetime `'db` here
+   |
+LL | pub type Tait<'db> = impl Iterator<Item = (&'db Key, impl Iterator)>;
+   |              +++++
+
+error[E0412]: cannot find type `Key` in this scope
+  --> $DIR/nested-impl-trait-in-tait.rs:3:44
+   |
+LL | pub type Tait = impl Iterator<Item = (&'db Key, impl Iterator)>;
+   |                                            ^^^ not found in this scope
+   |
+help: consider importing this struct
+   |
+LL + use std::thread::local_impl::Key;
+   |
+
+error: unconstrained opaque type
+  --> $DIR/nested-impl-trait-in-tait.rs:3:17
+   |
+LL | pub type Tait = impl Iterator<Item = (&'db Key, impl Iterator)>;
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `Tait` must be used in combination with a concrete type within the same module
+
+error: unconstrained opaque type
+  --> $DIR/nested-impl-trait-in-tait.rs:3:49
+   |
+LL | pub type Tait = impl Iterator<Item = (&'db Key, impl Iterator)>;
+   |                                                 ^^^^^^^^^^^^^
+   |
+   = note: `Tait` must be used in combination with a concrete type within the same module
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0261, E0412.
+For more information about an error, try `rustc --explain E0261`.
diff --git a/tests/ui/type-alias-impl-trait/normalize-alias-type.rs b/tests/ui/type-alias-impl-trait/normalize-alias-type.rs
new file mode 100644
index 000000000..7c62002b9
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/normalize-alias-type.rs
@@ -0,0 +1,32 @@
+// check-pass
+// compile-flags: -Z mir-opt-level=3
+#![feature(type_alias_impl_trait)]
+#![crate_type = "lib"]
+pub trait Tr {
+    fn get(&self) -> u32;
+}
+
+impl Tr for (u32,) {
+    #[inline]
+    fn get(&self) -> u32 { self.0 }
+}
+
+pub fn tr1() -> impl Tr {
+    (32,)
+}
+
+pub fn tr2() -> impl Tr {
+    struct Inner {
+        x: X,
+    }
+    type X = impl Tr;
+    impl Tr for Inner {
+        fn get(&self) -> u32 {
+            self.x.get()
+        }
+    }
+
+    Inner {
+        x: tr1(),
+    }
+}
diff --git a/tests/ui/type-alias-impl-trait/privacy.rs b/tests/ui/type-alias-impl-trait/privacy.rs
index aa092f6f8..3efbfaf09 100644
--- a/tests/ui/type-alias-impl-trait/privacy.rs
+++ b/tests/ui/type-alias-impl-trait/privacy.rs
@@ -1,8 +1,10 @@
+// check-pass
+
 #![feature(type_alias_impl_trait)]
 
 type Foo = (impl Sized, u8);
 pub fn foo() -> Foo {
-    //~^ ERROR private type alias `Foo` in public interface
+    //~^ WARNING type alias `Foo` is more private than the item `foo`
     (42, 42)
 }
 fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/privacy.stderr b/tests/ui/type-alias-impl-trait/privacy.stderr
index e8c6039cd..50870905c 100644
--- a/tests/ui/type-alias-impl-trait/privacy.stderr
+++ b/tests/ui/type-alias-impl-trait/privacy.stderr
@@ -1,11 +1,15 @@
-error[E0446]: private type alias `Foo` in public interface
-  --> $DIR/privacy.rs:4:1
+warning: type alias `Foo` is more private than the item `foo`
+  --> $DIR/privacy.rs:6:1
    |
-LL | type Foo = (impl Sized, u8);
-   | -------- `Foo` declared as private
 LL | pub fn foo() -> Foo {
-   | ^^^^^^^^^^^^^^^^^^^ can't leak private type alias
+   | ^^^^^^^^^^^^^^^^^^^ function `foo` is reachable at visibility `pub`
+   |
+note: but type alias `Foo` is only usable at visibility `pub(crate)`
+  --> $DIR/privacy.rs:5:1
+   |
+LL | type Foo = (impl Sized, u8);
+   | ^^^^^^^^
+   = note: `#[warn(private_interfaces)]` on by default
 
-error: aborting due to previous error
+warning: 1 warning emitted
 
-For more information about this error, try `rustc --explain E0446`.
diff --git a/tests/ui/type-alias-impl-trait/reveal_local.stderr b/tests/ui/type-alias-impl-trait/reveal_local.stderr
index 813185c13..c62fd88f4 100644
--- a/tests/ui/type-alias-impl-trait/reveal_local.stderr
+++ b/tests/ui/type-alias-impl-trait/reveal_local.stderr
@@ -1,4 +1,4 @@
-error[E0391]: cycle detected when computing type of `Foo::{opaque#0}`
+error[E0391]: cycle detected when computing type of opaque `Foo::{opaque#0}`
   --> $DIR/reveal_local.rs:5:12
    |
 LL | type Foo = impl Debug;
@@ -10,21 +10,15 @@ note: ...which requires type-checking `not_good`...
 LL |     is_send::<Foo>();
    |     ^^^^^^^^^^^^^^
    = note: ...which requires evaluating trait selection obligation `Foo: core::marker::Send`...
-   = note: ...which again requires computing type of `Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in top-level module
-  --> $DIR/reveal_local.rs:1:1
-   |
-LL | / #![feature(type_alias_impl_trait)]
-LL | |
-LL | | use std::fmt::Debug;
-LL | |
-...  |
-LL | |
-LL | | fn main() {}
-   | |____________^
+   = note: ...which again requires computing type of opaque `Foo::{opaque#0}`, completing the cycle
+note: cycle used when computing type of `Foo::{opaque#0}`
+  --> $DIR/reveal_local.rs:5:12
+   |
+LL | type Foo = impl Debug;
+   |            ^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-error[E0391]: cycle detected when computing type of `Foo::{opaque#0}`
+error[E0391]: cycle detected when computing type of opaque `Foo::{opaque#0}`
   --> $DIR/reveal_local.rs:5:12
    |
 LL | type Foo = impl Debug;
@@ -35,18 +29,12 @@ note: ...which requires type-checking `not_good`...
    |
 LL | fn not_good() {
    | ^^^^^^^^^^^^^
-   = note: ...which again requires computing type of `Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in top-level module
-  --> $DIR/reveal_local.rs:1:1
-   |
-LL | / #![feature(type_alias_impl_trait)]
-LL | |
-LL | | use std::fmt::Debug;
-LL | |
-...  |
-LL | |
-LL | | fn main() {}
-   | |____________^
+   = note: ...which again requires computing type of opaque `Foo::{opaque#0}`, completing the cycle
+note: cycle used when computing type of `Foo::{opaque#0}`
+  --> $DIR/reveal_local.rs:5:12
+   |
+LL | type Foo = impl Debug;
+   |            ^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of `reveal_local[9507]::Foo::{opaque#0}` satisfies auto traits
@@ -71,7 +59,7 @@ note: required by a bound in `is_send`
 LL | fn is_send<T: Send>() {}
    |               ^^^^ required by this bound in `is_send`
 
-error[E0391]: cycle detected when computing type of `Foo::{opaque#0}`
+error[E0391]: cycle detected when computing type of opaque `Foo::{opaque#0}`
   --> $DIR/reveal_local.rs:5:12
    |
 LL | type Foo = impl Debug;
@@ -82,18 +70,12 @@ note: ...which requires type-checking `not_gooder`...
    |
 LL | fn not_gooder() -> Foo {
    | ^^^^^^^^^^^^^^^^^^^^^^
-   = note: ...which again requires computing type of `Foo::{opaque#0}`, completing the cycle
-note: cycle used when checking item types in top-level module
-  --> $DIR/reveal_local.rs:1:1
-   |
-LL | / #![feature(type_alias_impl_trait)]
-LL | |
-LL | | use std::fmt::Debug;
-LL | |
-...  |
-LL | |
-LL | | fn main() {}
-   | |____________^
+   = note: ...which again requires computing type of opaque `Foo::{opaque#0}`, completing the cycle
+note: cycle used when computing type of `Foo::{opaque#0}`
+  --> $DIR/reveal_local.rs:5:12
+   |
+LL | type Foo = impl Debug;
+   |            ^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of `reveal_local[9507]::Foo::{opaque#0}` satisfies auto traits
diff --git a/tests/ui/type-alias-impl-trait/rpit_tait_equality_in_canonical_query.current.stderr b/tests/ui/type-alias-impl-trait/rpit_tait_equality_in_canonical_query.current.stderr
new file mode 100644
index 000000000..844103d77
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/rpit_tait_equality_in_canonical_query.current.stderr
@@ -0,0 +1,29 @@
+error: internal compiler error: no errors encountered even though `delay_span_bug` issued
+
+error: internal compiler error: {OpaqueTypeKey { def_id: DefId(get_rpit::{opaque#0}), args: [] }: OpaqueTypeDecl { hidden_type: OpaqueHiddenType { span: no-location (#0), ty: Alias(Opaque, AliasTy { args: [], def_id: DefId(Opaque::{opaque#0}) }) } }}
+   |
+   = 
+           
+
+error: internal compiler error: error performing ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: UserFacing }, value: ProvePredicate { predicate: Binder { value: ProjectionPredicate(AliasTy { args: [FnDef(DefId(get_rpit), []), ()], def_id: DefId(ops::function::FnOnce::Output) }, Term::Ty(Alias(Opaque, AliasTy { args: [], def_id: DefId(Opaque::{opaque#0}) }))), bound_vars: [] } } }
+  --> $DIR/rpit_tait_equality_in_canonical_query.rs:28:5
+   |
+LL |     query(get_rpit);
+   |     ^^^^^^^^^^^^^^^
+   |
+
+  --> $DIR/rpit_tait_equality_in_canonical_query.rs:28:5
+   |
+LL |     query(get_rpit);
+   |     ^^^^^^^^^^^^^^^
+
+
+
+
+
+
+
+query stack during panic:
+end of query stack
+error: aborting due to 3 previous errors
+
diff --git a/tests/ui/type-alias-impl-trait/rpit_tait_equality_in_canonical_query.rs b/tests/ui/type-alias-impl-trait/rpit_tait_equality_in_canonical_query.rs
new file mode 100644
index 000000000..0f0002f77
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/rpit_tait_equality_in_canonical_query.rs
@@ -0,0 +1,32 @@
+//! This tries to prove the APIT's bounds in a canonical query,
+//! which doesn't know anything about the defining scope of either
+//! opaque type and thus makes a random choice as to which opaque type
+//! becomes the hidden type of the other. When we leave the canonical
+//! query, we attempt to actually check the defining anchor, but now we
+//! have a situation where the RPIT gets constrained outside its anchor.
+
+// revisions: current next
+//[next] compile-flags: -Ztrait-solver=next
+//[next] check-pass
+
+//[current] known-bug: #108498
+//[current] failure-status: 101
+//[current] normalize-stderr-test: "DefId\(.*?\]::" -> "DefId("
+//[current] normalize-stderr-test: "(?m)note: .*$" -> ""
+//[current] normalize-stderr-test: "(?m)^ *\d+: .*\n" -> ""
+//[current] normalize-stderr-test: "(?m)^ *at .*\n" -> ""
+
+#![feature(type_alias_impl_trait)]
+
+type Opaque = impl Sized;
+
+fn get_rpit() -> impl Clone {}
+
+fn query(_: impl FnOnce() -> Opaque) {}
+
+fn test() -> Opaque {
+    query(get_rpit);
+    get_rpit()
+}
+
+fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/rpit_tait_equality_in_canonical_query_2.rs b/tests/ui/type-alias-impl-trait/rpit_tait_equality_in_canonical_query_2.rs
new file mode 100644
index 000000000..9d7e647dd
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/rpit_tait_equality_in_canonical_query_2.rs
@@ -0,0 +1,18 @@
+// The canonical query `Projection(<get_rpit as FnOnce>::Output = Opaque)`
+// is the *only* site that defines `Opaque` in MIR typeck.
+//
+// check-pass
+
+#![feature(type_alias_impl_trait)]
+
+type Opaque = impl Sized;
+
+fn get_rpit() -> impl Sized {}
+
+fn query(_: impl FnOnce() -> Opaque) {}
+
+fn test(_: Opaque) {
+    query(get_rpit);
+}
+
+fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/self_implication.rs b/tests/ui/type-alias-impl-trait/self_implication.rs
index 4e805ee30..65659a0f3 100644
--- a/tests/ui/type-alias-impl-trait/self_implication.rs
+++ b/tests/ui/type-alias-impl-trait/self_implication.rs
@@ -22,9 +22,9 @@ fn bar() {
     }
 
     // desugared
-    type FooX<'a> = impl Sized;
+    type FooX = impl Sized;
     impl<'a> Foo<'a> {
-        fn foo(&self) -> FooX<'a> {}
+        fn foo(&self) -> FooX {}
     }
 
     // use site
diff --git a/tests/ui/type-alias-impl-trait/tait-normalize.rs b/tests/ui/type-alias-impl-trait/tait-normalize.rs
new file mode 100644
index 000000000..26d94dbb4
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/tait-normalize.rs
@@ -0,0 +1,14 @@
+// check-pass
+
+#![feature(type_alias_impl_trait)]
+
+fn enum_upvar() {
+    type T = impl Copy;
+    let foo: T = Some((1u32, 2u32));
+    let x = move || match foo {
+        None => (),
+        Some((a, b)) => (),
+    };
+}
+
+fn main(){}
diff --git a/tests/ui/type-alias-impl-trait/variance.rs b/tests/ui/type-alias-impl-trait/variance.rs
new file mode 100644
index 000000000..e92cf2513
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/variance.rs
@@ -0,0 +1,44 @@
+#![feature(rustc_attrs, type_alias_impl_trait, impl_trait_in_assoc_type)]
+#![allow(internal_features)]
+#![rustc_variance_of_opaques]
+
+trait Captures<'a> {}
+impl<T> Captures<'_> for T {}
+
+type NotCapturedEarly<'a> = impl Sized; //~ [o]
+
+type CapturedEarly<'a> = impl Sized + Captures<'a>; //~ [o]
+
+// TAIT does *not* capture `'b`
+type NotCapturedLate<'a> = dyn for<'b> Iterator<Item = impl Sized>; //~ [o]
+
+// TAIT does *not* capture `'b`
+type Captured<'a> = dyn for<'b> Iterator<Item = impl Sized + Captures<'a>>; //~ [o]
+
+type Bar<'a, 'b: 'b, T> = impl Sized; //~ ERROR [o, o, o]
+
+trait Foo<'i> {
+    type ImplicitCapture<'a>;
+
+    type ExplicitCaptureFromHeader<'a>;
+
+    type ExplicitCaptureFromGat<'a>;
+}
+
+impl<'i> Foo<'i> for &'i () {
+    type ImplicitCapture<'a> = impl Sized; //~ [o, o]
+
+    type ExplicitCaptureFromHeader<'a> = impl Sized + Captures<'i>; //~ [o, o]
+
+    type ExplicitCaptureFromGat<'a> = impl Sized + Captures<'a>; //~ [o, o]
+}
+
+impl<'i> Foo<'i> for () {
+    type ImplicitCapture<'a> = impl Sized; //~ [o, o]
+
+    type ExplicitCaptureFromHeader<'a> = impl Sized + Captures<'i>; //~ [o, o]
+
+    type ExplicitCaptureFromGat<'a> = impl Sized + Captures<'a>; //~ [o, o]
+}
+
+fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/variance.stderr b/tests/ui/type-alias-impl-trait/variance.stderr
new file mode 100644
index 000000000..1794447c8
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/variance.stderr
@@ -0,0 +1,68 @@
+error: [o]
+  --> $DIR/variance.rs:8:29
+   |
+LL | type NotCapturedEarly<'a> = impl Sized;
+   |                             ^^^^^^^^^^
+
+error: [o]
+  --> $DIR/variance.rs:10:26
+   |
+LL | type CapturedEarly<'a> = impl Sized + Captures<'a>;
+   |                          ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: [o]
+  --> $DIR/variance.rs:13:56
+   |
+LL | type NotCapturedLate<'a> = dyn for<'b> Iterator<Item = impl Sized>;
+   |                                                        ^^^^^^^^^^
+
+error: [o]
+  --> $DIR/variance.rs:16:49
+   |
+LL | type Captured<'a> = dyn for<'b> Iterator<Item = impl Sized + Captures<'a>>;
+   |                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: [o, o, o]
+  --> $DIR/variance.rs:18:27
+   |
+LL | type Bar<'a, 'b: 'b, T> = impl Sized;
+   |                           ^^^^^^^^^^
+
+error: [o, o]
+  --> $DIR/variance.rs:29:32
+   |
+LL |     type ImplicitCapture<'a> = impl Sized;
+   |                                ^^^^^^^^^^
+
+error: [o, o]
+  --> $DIR/variance.rs:31:42
+   |
+LL |     type ExplicitCaptureFromHeader<'a> = impl Sized + Captures<'i>;
+   |                                          ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: [o, o]
+  --> $DIR/variance.rs:33:39
+   |
+LL |     type ExplicitCaptureFromGat<'a> = impl Sized + Captures<'a>;
+   |                                       ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: [o, o]
+  --> $DIR/variance.rs:37:32
+   |
+LL |     type ImplicitCapture<'a> = impl Sized;
+   |                                ^^^^^^^^^^
+
+error: [o, o]
+  --> $DIR/variance.rs:39:42
+   |
+LL |     type ExplicitCaptureFromHeader<'a> = impl Sized + Captures<'i>;
+   |                                          ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: [o, o]
+  --> $DIR/variance.rs:41:39
+   |
+LL |     type ExplicitCaptureFromGat<'a> = impl Sized + Captures<'a>;
+   |                                       ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 11 previous errors
+