Merging upstream version 1.67.1+dfsg1.

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

11 files changed, 296 insertions, 6 deletions

diff --git a/src/test/ui/impl-trait/in-trait/generics-mismatch.rs b/src/test/ui/impl-trait/in-trait/generics-mismatch.rs
new file mode 100644
index 000000000..cc0fc720e
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/generics-mismatch.rs
@@ -0,0 +1,17 @@
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+struct U;
+
+trait Foo {
+    fn bar(&self) -> impl Sized;
+}
+
+impl Foo for U {
+    fn bar<T>(&self) {}
+    //~^ ERROR method `bar` has 1 type parameter but its trait declaration has 0 type parameters
+}
+
+fn main() {
+    U.bar();
+}
diff --git a/src/test/ui/impl-trait/in-trait/generics-mismatch.stderr b/src/test/ui/impl-trait/in-trait/generics-mismatch.stderr
new file mode 100644
index 000000000..cd42683e0
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/generics-mismatch.stderr
@@ -0,0 +1,12 @@
+error[E0049]: method `bar` has 1 type parameter but its trait declaration has 0 type parameters
+  --> $DIR/generics-mismatch.rs:11:12
+   |
+LL |     fn bar(&self) -> impl Sized;
+   |           - expected 0 type parameters
+...
+LL |     fn bar<T>(&self) {}
+   |            ^ found 1 type parameter
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0049`.
diff --git a/src/test/ui/impl-trait/in-trait/method-signature-matches.rs b/src/test/ui/impl-trait/in-trait/method-signature-matches.rs
new file mode 100644
index 000000000..c848ee3f6
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/method-signature-matches.rs
@@ -0,0 +1,51 @@
+// edition: 2021
+
+#![feature(return_position_impl_trait_in_trait, async_fn_in_trait)]
+#![allow(incomplete_features)]
+
+trait Uwu {
+    fn owo(x: ()) -> impl Sized;
+}
+
+impl Uwu for () {
+    fn owo(_: u8) {}
+    //~^ ERROR method `owo` has an incompatible type for trait
+}
+
+trait AsyncUwu {
+    async fn owo(x: ()) {}
+}
+
+impl AsyncUwu for () {
+    async fn owo(_: u8) {}
+    //~^ ERROR method `owo` has an incompatible type for trait
+}
+
+trait TooMuch {
+    fn calm_down_please() -> impl Sized;
+}
+
+impl TooMuch for () {
+    fn calm_down_please(_: (), _: (), _: ()) {}
+    //~^ ERROR method `calm_down_please` has 3 parameters but the declaration in trait `TooMuch::calm_down_please` has 0
+}
+
+trait TooLittle {
+    fn come_on_a_little_more_effort(_: (), _: (), _: ()) -> impl Sized;
+}
+
+impl TooLittle for () {
+    fn come_on_a_little_more_effort() {}
+    //~^ ERROR method `come_on_a_little_more_effort` has 0 parameters but the declaration in trait `TooLittle::come_on_a_little_more_effort` has 3
+}
+
+trait Lifetimes {
+    fn early<'early, T>(x: &'early T) -> impl Sized;
+}
+
+impl Lifetimes for () {
+    fn early<'late, T>(_: &'late ()) {}
+    //~^ ERROR method `early` has an incompatible type for trait
+}
+
+fn main() {}
diff --git a/src/test/ui/impl-trait/in-trait/method-signature-matches.stderr b/src/test/ui/impl-trait/in-trait/method-signature-matches.stderr
new file mode 100644
index 000000000..2b32c52c8
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/method-signature-matches.stderr
@@ -0,0 +1,84 @@
+error[E0053]: method `owo` has an incompatible type for trait
+  --> $DIR/method-signature-matches.rs:11:15
+   |
+LL |     fn owo(_: u8) {}
+   |               ^^
+   |               |
+   |               expected `()`, found `u8`
+   |               help: change the parameter type to match the trait: `()`
+   |
+note: type in trait
+  --> $DIR/method-signature-matches.rs:7:15
+   |
+LL |     fn owo(x: ()) -> impl Sized;
+   |               ^^
+   = note: expected fn pointer `fn(())`
+              found fn pointer `fn(u8)`
+
+error[E0053]: method `owo` has an incompatible type for trait
+  --> $DIR/method-signature-matches.rs:20:21
+   |
+LL |     async fn owo(_: u8) {}
+   |                     ^^
+   |                     |
+   |                     expected `()`, found `u8`
+   |                     help: change the parameter type to match the trait: `()`
+   |
+note: while checking the return type of the `async fn`
+  --> $DIR/method-signature-matches.rs:20:25
+   |
+LL |     async fn owo(_: u8) {}
+   |                         ^ checked the `Output` of this `async fn`, expected opaque type
+note: while checking the return type of the `async fn`
+  --> $DIR/method-signature-matches.rs:20:25
+   |
+LL |     async fn owo(_: u8) {}
+   |                         ^ checked the `Output` of this `async fn`, found opaque type
+note: type in trait
+  --> $DIR/method-signature-matches.rs:16:21
+   |
+LL |     async fn owo(x: ()) {}
+   |                     ^^
+   = note: expected fn pointer `fn(()) -> _`
+              found fn pointer `fn(u8) -> _`
+
+error[E0050]: method `calm_down_please` has 3 parameters but the declaration in trait `TooMuch::calm_down_please` has 0
+  --> $DIR/method-signature-matches.rs:29:28
+   |
+LL |     fn calm_down_please() -> impl Sized;
+   |     ------------------------------------ trait requires 0 parameters
+...
+LL |     fn calm_down_please(_: (), _: (), _: ()) {}
+   |                            ^^^^^^^^^^^^^^^^ expected 0 parameters, found 3
+
+error[E0050]: method `come_on_a_little_more_effort` has 0 parameters but the declaration in trait `TooLittle::come_on_a_little_more_effort` has 3
+  --> $DIR/method-signature-matches.rs:38:5
+   |
+LL |     fn come_on_a_little_more_effort(_: (), _: (), _: ()) -> impl Sized;
+   |                                        ---------------- trait requires 3 parameters
+...
+LL |     fn come_on_a_little_more_effort() {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 3 parameters, found 0
+
+error[E0053]: method `early` has an incompatible type for trait
+  --> $DIR/method-signature-matches.rs:47:27
+   |
+LL |     fn early<'late, T>(_: &'late ()) {}
+   |                     -     ^^^^^^^^^
+   |                     |     |
+   |                     |     expected type parameter `T`, found `()`
+   |                     |     help: change the parameter type to match the trait: `&'early T`
+   |                     this type parameter
+   |
+note: type in trait
+  --> $DIR/method-signature-matches.rs:43:28
+   |
+LL |     fn early<'early, T>(x: &'early T) -> impl Sized;
+   |                            ^^^^^^^^^
+   = note: expected fn pointer `fn(&'early T)`
+              found fn pointer `fn(&())`
+
+error: aborting due to 5 previous errors
+
+Some errors have detailed explanations: E0050, E0053.
+For more information about an error, try `rustc --explain E0050`.
diff --git a/src/test/ui/impl-trait/in-trait/object-safety.stderr b/src/test/ui/impl-trait/in-trait/object-safety.stderr
index 9a1554b5e..ca0e760ff 100644
--- a/src/test/ui/impl-trait/in-trait/object-safety.stderr
+++ b/src/test/ui/impl-trait/in-trait/object-safety.stderr
@@ -5,12 +5,12 @@ LL |     let i = Box::new(42_u32) as Box<dyn Foo>;
    |                                 ^^^^^^^^^^^^ `Foo` cannot be made into an object
    |
 note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
-  --> $DIR/object-safety.rs:7:8
+  --> $DIR/object-safety.rs:7:22
    |
 LL | trait Foo {
    |       --- this trait cannot be made into an object...
 LL |     fn baz(&self) -> impl Debug;
-   |        ^^^ ...because method `baz` references an `impl Trait` type in its return type
+   |                      ^^^^^^^^^^ ...because method `baz` references an `impl Trait` type in its return type
    = help: consider moving `baz` to another trait
 
 error[E0038]: the trait `Foo` cannot be made into an object
@@ -20,12 +20,12 @@ LL |     let s = i.baz();
    |             ^^^^^^^ `Foo` cannot be made into an object
    |
 note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
-  --> $DIR/object-safety.rs:7:8
+  --> $DIR/object-safety.rs:7:22
    |
 LL | trait Foo {
    |       --- this trait cannot be made into an object...
 LL |     fn baz(&self) -> impl Debug;
-   |        ^^^ ...because method `baz` references an `impl Trait` type in its return type
+   |                      ^^^^^^^^^^ ...because method `baz` references an `impl Trait` type in its return type
    = help: consider moving `baz` to another trait
 
 error[E0038]: the trait `Foo` cannot be made into an object
@@ -35,12 +35,12 @@ LL |     let i = Box::new(42_u32) as Box<dyn Foo>;
    |             ^^^^^^^^^^^^^^^^ `Foo` cannot be made into an object
    |
 note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
-  --> $DIR/object-safety.rs:7:8
+  --> $DIR/object-safety.rs:7:22
    |
 LL | trait Foo {
    |       --- this trait cannot be made into an object...
 LL |     fn baz(&self) -> impl Debug;
-   |        ^^^ ...because method `baz` references an `impl Trait` type in its return type
+   |                      ^^^^^^^^^^ ...because method `baz` references an `impl Trait` type in its return type
    = help: consider moving `baz` to another trait
    = note: required for `Box<u32>` to implement `CoerceUnsized<Box<dyn Foo>>`
    = note: required by cast to type `Box<dyn Foo>`
diff --git a/src/test/ui/impl-trait/in-trait/specialization-broken.rs b/src/test/ui/impl-trait/in-trait/specialization-broken.rs
new file mode 100644
index 000000000..9d27d3710
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/specialization-broken.rs
@@ -0,0 +1,26 @@
+// FIXME(compiler-errors): I'm not exactly sure if this is expected to pass or not.
+// But we fixed an ICE anyways.
+
+#![feature(specialization)]
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+trait Foo {
+    fn bar(&self) -> impl Sized;
+}
+
+default impl<U> Foo for U
+where
+    U: Copy,
+{
+    fn bar(&self) -> U {
+        //~^ ERROR method `bar` has an incompatible type for trait
+        *self
+    }
+}
+
+impl Foo for i32 {}
+
+fn main() {
+    1i32.bar();
+}
diff --git a/src/test/ui/impl-trait/in-trait/specialization-broken.stderr b/src/test/ui/impl-trait/in-trait/specialization-broken.stderr
new file mode 100644
index 000000000..a30e6346b
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/specialization-broken.stderr
@@ -0,0 +1,23 @@
+error[E0053]: method `bar` has an incompatible type for trait
+  --> $DIR/specialization-broken.rs:16:22
+   |
+LL | default impl<U> Foo for U
+   |              - this type parameter
+...
+LL |     fn bar(&self) -> U {
+   |                      ^
+   |                      |
+   |                      expected associated type, found type parameter `U`
+   |                      help: change the output type to match the trait: `impl Sized`
+   |
+note: type in trait
+  --> $DIR/specialization-broken.rs:9:22
+   |
+LL |     fn bar(&self) -> impl Sized;
+   |                      ^^^^^^^^^^
+   = note: expected fn pointer `fn(&U) -> impl Sized`
+              found fn pointer `fn(&U) -> U`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0053`.
diff --git a/src/test/ui/impl-trait/in-trait/specialization-substs-remap.rs b/src/test/ui/impl-trait/in-trait/specialization-substs-remap.rs
new file mode 100644
index 000000000..c9ee877db
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/specialization-substs-remap.rs
@@ -0,0 +1,24 @@
+// check-pass
+
+#![feature(specialization)]
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+trait Foo {
+    fn bar(&self) -> impl Sized;
+}
+
+impl<U> Foo for U
+where
+    U: Copy,
+{
+    fn bar(&self) -> U {
+        *self
+    }
+}
+
+impl Foo for i32 {}
+
+fn main() {
+    let _: i32 = 1i32.bar();
+}
diff --git a/src/test/ui/impl-trait/in-trait/trait-more-generics-than-impl.rs b/src/test/ui/impl-trait/in-trait/trait-more-generics-than-impl.rs
new file mode 100644
index 000000000..0bbe50ea6
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/trait-more-generics-than-impl.rs
@@ -0,0 +1,17 @@
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+struct S;
+
+trait Foo {
+    fn bar<T>() -> impl Sized;
+}
+
+impl Foo for S {
+    fn bar() -> impl Sized {}
+    //~^ ERROR method `bar` has 0 type parameters but its trait declaration has 1 type parameter
+}
+
+fn main() {
+    S::bar();
+}
diff --git a/src/test/ui/impl-trait/in-trait/trait-more-generics-than-impl.stderr b/src/test/ui/impl-trait/in-trait/trait-more-generics-than-impl.stderr
new file mode 100644
index 000000000..8ff54cad9
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/trait-more-generics-than-impl.stderr
@@ -0,0 +1,12 @@
+error[E0049]: method `bar` has 0 type parameters but its trait declaration has 1 type parameter
+  --> $DIR/trait-more-generics-than-impl.rs:11:11
+   |
+LL |     fn bar<T>() -> impl Sized;
+   |            - expected 1 type parameter
+...
+LL |     fn bar() -> impl Sized {}
+   |           ^ found 0 type parameters
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0049`.
diff --git a/src/test/ui/impl-trait/in-trait/where-clause.rs b/src/test/ui/impl-trait/in-trait/where-clause.rs
new file mode 100644
index 000000000..87bac519c
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/where-clause.rs
@@ -0,0 +1,24 @@
+// check-pass
+// edition: 2021
+
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+use std::fmt::Debug;
+
+trait Foo<Item> {
+    fn foo<'a>(&'a self) -> impl Debug
+    where
+        Item: 'a;
+}
+
+impl<Item, D: Debug + Clone> Foo<Item> for D {
+    fn foo<'a>(&'a self) -> impl Debug
+    where
+        Item: 'a,
+    {
+        self.clone()
+    }
+}
+
+fn main() {}