handle specialization in the new trait solver

uwu :3

9 files changed, 149 insertions, 6 deletions

diff --git a/tests/ui/specialization/prefer-specializing-impl-over-default.current.stderr b/tests/ui/specialization/prefer-specializing-impl-over-default.current.stderr
new file mode 100644
index 00000000000..7e3df0c83f9
--- /dev/null
+++ b/tests/ui/specialization/prefer-specializing-impl-over-default.current.stderr
@@ -0,0 +1,12 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/prefer-specializing-impl-over-default.rs:5:12
+   |
+LL | #![feature(specialization)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/specialization/prefer-specializing-impl-over-default.next.stderr b/tests/ui/specialization/prefer-specializing-impl-over-default.next.stderr
new file mode 100644
index 00000000000..7e3df0c83f9
--- /dev/null
+++ b/tests/ui/specialization/prefer-specializing-impl-over-default.next.stderr
@@ -0,0 +1,12 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/prefer-specializing-impl-over-default.rs:5:12
+   |
+LL | #![feature(specialization)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/specialization/prefer-specializing-impl-over-default.rs b/tests/ui/specialization/prefer-specializing-impl-over-default.rs
new file mode 100644
index 00000000000..af6837b30ca
--- /dev/null
+++ b/tests/ui/specialization/prefer-specializing-impl-over-default.rs
@@ -0,0 +1,29 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+//@ check-pass
+#![feature(specialization)]
+//~^ WARN the feature `specialization` is incomplete
+
+trait WithAssoc: 'static {
+    type Assoc;
+}
+impl<T: 'static> WithAssoc for (T,) {
+    type Assoc = ();
+}
+
+struct GenericArray<U: WithAssoc>(U::Assoc);
+
+trait AbiExample {
+    fn example();
+}
+impl<U: WithAssoc> AbiExample for GenericArray<U> {
+    fn example() {}
+}
+impl<T> AbiExample for T {
+    default fn example() {}
+}
+
+fn main() {
+    let _ = GenericArray::<((),)>::example();
+}
diff --git a/tests/ui/specialization/specialization-default-projection.stderr b/tests/ui/specialization/specialization-default-projection.current.stderr
index b8b81876d81..038c379c43e 100644
--- a/tests/ui/specialization/specialization-default-projection.stderr
+++ b/tests/ui/specialization/specialization-default-projection.current.stderr
@@ -1,5 +1,5 @@
 warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/specialization-default-projection.rs:1:12
+  --> $DIR/specialization-default-projection.rs:5:12
    |
 LL | #![feature(specialization)]
    |            ^^^^^^^^^^^^^^
@@ -9,7 +9,7 @@ LL | #![feature(specialization)]
    = note: `#[warn(incomplete_features)]` on by default
 
 error[E0308]: mismatched types
-  --> $DIR/specialization-default-projection.rs:21:5
+  --> $DIR/specialization-default-projection.rs:25:5
    |
 LL | fn generic<T>() -> <T as Foo>::Assoc {
    |                    ----------------- expected `<T as Foo>::Assoc` because of return type
@@ -23,7 +23,7 @@ LL |     ()
    = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
 
 error[E0308]: mismatched types
-  --> $DIR/specialization-default-projection.rs:28:5
+  --> $DIR/specialization-default-projection.rs:32:5
    |
 LL | fn monomorphic() -> () {
    |                     -- expected `()` because of return type
diff --git a/tests/ui/specialization/specialization-default-projection.next.stderr b/tests/ui/specialization/specialization-default-projection.next.stderr
new file mode 100644
index 00000000000..9111f173a9c
--- /dev/null
+++ b/tests/ui/specialization/specialization-default-projection.next.stderr
@@ -0,0 +1,43 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/specialization-default-projection.rs:5:12
+   |
+LL | #![feature(specialization)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+   = note: `#[warn(incomplete_features)]` on by default
+
+error[E0308]: mismatched types
+  --> $DIR/specialization-default-projection.rs:25:5
+   |
+LL | fn generic<T>() -> <T as Foo>::Assoc {
+   |                    ----------------- expected `<T as Foo>::Assoc` because of return type
+...
+LL |     ()
+   |     ^^ types differ
+   |
+   = note: expected associated type `<T as Foo>::Assoc`
+                    found unit type `()`
+   = help: consider constraining the associated type `<T as Foo>::Assoc` to `()` or calling a method that returns `<T as Foo>::Assoc`
+   = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
+
+error[E0308]: mismatched types
+  --> $DIR/specialization-default-projection.rs:32:5
+   |
+LL | fn monomorphic() -> () {
+   |                     -- expected `()` because of return type
+...
+LL |     generic::<()>()
+   |     ^^^^^^^^^^^^^^^- help: consider using a semicolon here: `;`
+   |     |
+   |     types differ
+   |
+   = note:    expected unit type `()`
+           found associated type `<() as Foo>::Assoc`
+   = help: consider constraining the associated type `<() as Foo>::Assoc` to `()`
+   = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
+
+error: aborting due to 2 previous errors; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/specialization/specialization-default-projection.rs b/tests/ui/specialization/specialization-default-projection.rs
index 7f3ae951287..4f69ccb5974 100644
--- a/tests/ui/specialization/specialization-default-projection.rs
+++ b/tests/ui/specialization/specialization-default-projection.rs
@@ -1,3 +1,7 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+
 #![feature(specialization)] //~ WARN the feature `specialization` is incomplete
 
 // Make sure we can't project defaulted associated types
diff --git a/tests/ui/specialization/specialization-default-types.stderr b/tests/ui/specialization/specialization-default-types.current.stderr
index 774ac953617..67477f9a6d5 100644
--- a/tests/ui/specialization/specialization-default-types.stderr
+++ b/tests/ui/specialization/specialization-default-types.current.stderr
@@ -1,5 +1,5 @@
 warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
-  --> $DIR/specialization-default-types.rs:5:12
+  --> $DIR/specialization-default-types.rs:9:12
    |
 LL | #![feature(specialization)]
    |            ^^^^^^^^^^^^^^
@@ -9,7 +9,7 @@ LL | #![feature(specialization)]
    = note: `#[warn(incomplete_features)]` on by default
 
 error[E0308]: mismatched types
-  --> $DIR/specialization-default-types.rs:15:9
+  --> $DIR/specialization-default-types.rs:19:9
    |
 LL |     default type Output = Box<T>;
    |     ----------------------------- associated type is `default` and may be overridden
@@ -22,7 +22,7 @@ LL |         Box::new(self)
                        found struct `Box<T>`
 
 error[E0308]: mismatched types
-  --> $DIR/specialization-default-types.rs:25:5
+  --> $DIR/specialization-default-types.rs:29:5
    |
 LL | fn trouble<T>(t: T) -> Box<T> {
    |                        ------ expected `Box<T>` because of return type
diff --git a/tests/ui/specialization/specialization-default-types.next.stderr b/tests/ui/specialization/specialization-default-types.next.stderr
new file mode 100644
index 00000000000..4f7c4765446
--- /dev/null
+++ b/tests/ui/specialization/specialization-default-types.next.stderr
@@ -0,0 +1,39 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/specialization-default-types.rs:9:12
+   |
+LL | #![feature(specialization)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+   = note: `#[warn(incomplete_features)]` on by default
+
+error[E0308]: mismatched types
+  --> $DIR/specialization-default-types.rs:19:9
+   |
+LL |     default type Output = Box<T>;
+   |     ----------------------------- associated type is `default` and may be overridden
+LL |     default fn generate(self) -> Self::Output {
+   |                                  ------------ expected `<T as Example>::Output` because of return type
+LL |         Box::new(self)
+   |         ^^^^^^^^^^^^^^ types differ
+   |
+   = note: expected associated type `<T as Example>::Output`
+                       found struct `Box<T>`
+
+error[E0308]: mismatched types
+  --> $DIR/specialization-default-types.rs:29:5
+   |
+LL | fn trouble<T>(t: T) -> Box<T> {
+   |                        ------ expected `Box<T>` because of return type
+LL |     Example::generate(t)
+   |     ^^^^^^^^^^^^^^^^^^^^ types differ
+   |
+   = note:       expected struct `Box<T>`
+           found associated type `<T as Example>::Output`
+   = help: consider constraining the associated type `<T as Example>::Output` to `Box<T>`
+   = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
+
+error: aborting due to 2 previous errors; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/specialization/specialization-default-types.rs b/tests/ui/specialization/specialization-default-types.rs
index 346471f11e4..77817abea12 100644
--- a/tests/ui/specialization/specialization-default-types.rs
+++ b/tests/ui/specialization/specialization-default-types.rs
@@ -1,3 +1,7 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+
 // It should not be possible to use the concrete value of a defaulted
 // associated type in the impl defining it -- otherwise, what happens
 // if it's overridden?