Auto merge of rust-lang#90724 - JohnTitor:rollup-zg0kbm3, r=JohnTitor

Rollup of 6 pull requests

Successful merges:

 - rust-lang#87530 (Add comments regarding superfluous `!Sync` impls)
 - rust-lang#90591 (treat illumos like solaris in failing ui tests which need it)
 - rust-lang#90678 (Add some GATs-related regression tests)
 - rust-lang#90688 (enable `dotprod` target feature in arm)
 - rust-lang#90708 (Add a note about feature(explicit_generic_args_with_impl_trait) to the relevant error message)
 - rust-lang#90720 (Update cargo)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Cargo.lock

@@ -888,9 +888,9 @@ dependencies = [
 
 [[package]]
 name = "curl"
-version = "0.4.39"
+version = "0.4.40"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aaa3b8db7f3341ddef15786d250106334d4a6c4b0ae4a46cd77082777d9849b9"
+checksum = "877cc2f9b8367e32b6dabb9d581557e651cb3aa693a37f8679091bbf42687d5d"
 dependencies = [
  "curl-sys",
  "libc",
@@ -903,9 +903,9 @@ dependencies = [
 
 [[package]]
 name = "curl-sys"
-version = "0.4.49+curl-7.79.1"
+version = "0.4.50+curl-7.79.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e0f44960aea24a786a46907b8824ebc0e66ca06bf4e4978408c7499620343483"
+checksum = "4856b76919dd599f31236bb18db5f5bd36e2ce131e64f857ca5c259665b76171"
 dependencies = [
  "cc",
  "libc",

compiler/rustc_codegen_ssa/src/target_features.rs

@@ -20,6 +20,7 @@ const ARM_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
     ("aes", Some(sym::arm_target_feature)),
     ("sha2", Some(sym::arm_target_feature)),
     ("i8mm", Some(sym::arm_target_feature)),
+    ("dotprod", Some(sym::arm_target_feature)),
     ("v5te", Some(sym::arm_target_feature)),
     ("v6", Some(sym::arm_target_feature)),
     ("v6k", Some(sym::arm_target_feature)),

compiler/rustc_typeck/src/astconv/generics.rs

@@ -672,6 +672,17 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 err.span_label(span, "explicit generic argument not allowed");
             }
 
+            err.note(
+                "see issue #83701 <https://github.com/rust-lang/rust/issues/83701> \
+                 for more information",
+            );
+            if tcx.sess.is_nightly_build() {
+                err.help(
+                    "add `#![feature(explicit_generic_args_with_impl_trait)]` \
+                     to the crate attributes to enable",
+                );
+            }
+
             err.emit();
         }
 

library/alloc/src/rc.rs

@@ -313,6 +313,12 @@ pub struct Rc<T: ?Sized> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> !marker::Send for Rc<T> {}
+
+// Note that this negative impl isn't strictly necessary for correctness,
+// as `Rc` transitively contains a `Cell`, which is itself `!Sync`.
+// However, given how important `Rc`'s `!Sync`-ness is,
+// having an explicit negative impl is nice for documentation purposes
+// and results in nicer error messages.
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> !marker::Sync for Rc<T> {}
 

library/core/src/cell.rs

@@ -240,6 +240,11 @@ pub struct Cell<T: ?Sized> {
 #[stable(feature = "rust1", since = "1.0.0")]
 unsafe impl<T: ?Sized> Send for Cell<T> where T: Send {}
 
+// Note that this negative impl isn't strictly necessary for correctness,
+// as `Cell` wraps `UnsafeCell`, which is itself `!Sync`.
+// However, given how important `Cell`'s `!Sync`-ness is,
+// having an explicit negative impl is nice for documentation purposes
+// and results in nicer error messages.
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> !Sync for Cell<T> {}
 

src/test/ui/const-generics/impl-trait-with-const-arguments.stderr

@@ -3,6 +3,9 @@ error[E0632]: cannot provide explicit generic arguments when `impl Trait` is use
    |
 LL |     assert_eq!(f::<4usize>(Usizable), 20usize);
    |                    ^^^^^^ explicit generic argument not allowed
+   |
+   = note: see issue #83701 <https://github.com/rust-lang/rust/issues/83701> for more information
+   = help: add `#![feature(explicit_generic_args_with_impl_trait)]` to the crate attributes to enable
 
 error: aborting due to previous error
 

src/test/ui/generic-associated-types/issue-88595.rs

@@ -0,0 +1,24 @@
+#![feature(generic_associated_types)]
+#![feature(type_alias_impl_trait)]
+
+fn main() {}
+
+trait A<'a> {
+    type B<'b>: Clone
+    // FIXME(generic_associated_types): Remove one of the below bounds
+    // https://github.com/rust-lang/rust/pull/90678#discussion_r744976085
+    where
+        'a: 'b, Self: 'a, Self: 'b;
+
+    fn a(&'a self) -> Self::B<'a>;
+}
+
+struct C;
+
+impl<'a> A<'a> for C {
+    type B<'b> = impl Clone;
+    //~^ ERROR: lifetime bound not satisfied
+    //~| ERROR: could not find defining uses
+
+    fn a(&'a self) -> Self::B<'a> {} //~ ERROR: non-defining opaque type use in defining scope
+}

src/test/ui/generic-associated-types/issue-88595.stderr

@@ -0,0 +1,40 @@
+error[E0478]: lifetime bound not satisfied
+  --> $DIR/issue-88595.rs:19:5
+   |
+LL |     type B<'b> = impl Clone;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: lifetime parameter instantiated with the lifetime `'a` as defined here
+  --> $DIR/issue-88595.rs:18:6
+   |
+LL | impl<'a> A<'a> for C {
+   |      ^^
+note: but lifetime parameter must outlive the lifetime `'b` as defined here
+  --> $DIR/issue-88595.rs:19:12
+   |
+LL |     type B<'b> = impl Clone;
+   |            ^^
+
+error: non-defining opaque type use in defining scope
+  --> $DIR/issue-88595.rs:23:23
+   |
+LL |     fn a(&'a self) -> Self::B<'a> {}
+   |                       ^^^^^^^^^^^
+   |
+note: lifetime used multiple times
+  --> $DIR/issue-88595.rs:18:6
+   |
+LL | impl<'a> A<'a> for C {
+   |      ^^
+LL |     type B<'b> = impl Clone;
+   |            ^^
+
+error: could not find defining uses
+  --> $DIR/issue-88595.rs:19:18
+   |
+LL |     type B<'b> = impl Clone;
+   |                  ^^^^^^^^^^
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0478`.

src/test/ui/generic-associated-types/issue-90014.rs

@@ -0,0 +1,22 @@
+// edition:2018
+
+#![feature(generic_associated_types)]
+#![feature(type_alias_impl_trait)]
+
+use std::future::Future;
+
+trait MakeFut {
+    type Fut<'a> where Self: 'a;
+    fn make_fut<'a>(&'a self) -> Self::Fut<'a>;
+}
+
+impl MakeFut for &'_ mut () {
+    type Fut<'a> = impl Future<Output = ()>;
+    //~^ ERROR: the type `&mut ()` does not fulfill the required lifetime
+
+    fn make_fut<'a>(&'a self) -> Self::Fut<'a> {
+        async { () }
+    }
+}
+
+fn main() {}

src/test/ui/generic-associated-types/issue-90014.stderr

@@ -0,0 +1,15 @@
+error[E0477]: the type `&mut ()` does not fulfill the required lifetime
+  --> $DIR/issue-90014.rs:14:5
+   |
+LL |     type Fut<'a> = impl Future<Output = ()>;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: type must outlive the lifetime `'a` as defined here
+  --> $DIR/issue-90014.rs:14:14
+   |
+LL |     type Fut<'a> = impl Future<Output = ()>;
+   |              ^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0477`.