tests: add #![rustc_no_implicit_bounds]

After reviewing all tests with `?Sized`, these tests seem like they
could probably benefit from `#![rustc_no_implicit_bounds]`.

- Skipping most of `tests/ui/unsized` as these seem to want to test
  `?Sized`
- Skipping tests that used `Box<T>` because it's still bound by
  `T: MetaSized`
- Skipping parsing or other tests that cared about `?Sized` syntactically
- Skipping tests for `derive(CoercePointee)` because this appears to
  check that the pointee type is relaxed with `?Sized` explicitly

Author: davidtwco

tests/ui/cast/cast-rfc0401-vtable-kinds.rs

@@ -1,4 +1,8 @@
 //@ run-pass
+
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
+
 // Check that you can cast between different pointers to trait objects
 // whose vtable have the same kind (both lengths, or both trait pointers).
 
@@ -9,11 +13,11 @@ trait Bar { //~ WARN trait `Bar` is never used
 impl Bar for () {}
 
 #[repr(C)]
-struct FooS<T:?Sized>(T);
+struct FooS<T>(T);
 #[repr(C)]
-struct BarS<T:?Sized>(T);
+struct BarS<T>(T);
 
-fn foo_to_bar<T:?Sized>(u: *const FooS<T>) -> *const BarS<T> {
+fn foo_to_bar<T>(u: *const FooS<T>) -> *const BarS<T> {
     u as *const BarS<T>
 }
 

tests/ui/cast/cast-rfc0401-vtable-kinds.stderr

@@ -1,5 +1,5 @@
 warning: trait `Bar` is never used
-  --> $DIR/cast-rfc0401-vtable-kinds.rs:5:7
+  --> $DIR/cast-rfc0401-vtable-kinds.rs:9:7
    |
 LL | trait Bar {
    |       ^^^

tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.current.stderr

@@ -1,5 +1,5 @@
 error: lifetime may not live long enough
-  --> $DIR/ptr-to-trait-obj-different-regions-id-trait.rs:24:27
+  --> $DIR/ptr-to-trait-obj-different-regions-id-trait.rs:26:27
    |
 LL | fn m<'a>() {
    |      -- lifetime `'a` defined here

tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.next.stderr

@@ -1,5 +1,5 @@
 error: lifetime may not live long enough
-  --> $DIR/ptr-to-trait-obj-different-regions-id-trait.rs:24:27
+  --> $DIR/ptr-to-trait-obj-different-regions-id-trait.rs:26:27
    |
 LL | fn m<'a>() {
    |      -- lifetime `'a` defined here

tests/ui/cast/ptr-to-trait-obj-different-regions-id-trait.rs

@@ -2,20 +2,22 @@
 //@ ignore-compare-mode-next-solver (explicit revisions)
 //@[next] compile-flags: -Znext-solver
 //@ check-fail
-//
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
+
 // Make sure we can't trick the compiler by using a projection.
 
 trait Cat<'a> {}
 impl Cat<'_> for () {}
 
 trait Id {
-    type Id: ?Sized;
+    type Id;
 }
-impl<T: ?Sized> Id for T {
+impl<T> Id for T {
     type Id = T;
 }
 
-struct S<T: ?Sized> {
+struct S<T> {
     tail: <T as Id>::Id,
 }
 

tests/ui/coercion/codegen-smart-pointer-with-alias.rs

@@ -8,20 +8,22 @@
 // system, which isn't guaranteed to be normalized after substitution.
 
 #![feature(coerce_unsized)]
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
 
 use std::ops::CoerceUnsized;
 
 trait Mirror {
-    type Assoc: ?Sized;
+    type Assoc;
 }
-impl<T: ?Sized> Mirror for T {
+impl<T> Mirror for T {
     type Assoc = T;
 }
 
 trait Any {}
 impl<T> Any for T {}
 
-struct Signal<'a, T: ?Sized>(<&'a T as Mirror>::Assoc);
+struct Signal<'a, T>(<&'a T as Mirror>::Assoc);
 
 // This `CoerceUnsized` impl isn't special; it's a bit more restricted than we'd see in the wild,
 // but this ICE also reproduces if we were to make it general over `Signal<T> -> Signal<U>`.

tests/ui/coercion/issue-26905-rpass.rs

@@ -1,17 +1,19 @@
 //@ run-pass
 #![feature(unsize, coerce_unsized)]
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
 
 // Verfies that PhantomData is ignored for DST coercions
 
 use std::marker::{Unsize, PhantomData};
 use std::ops::CoerceUnsized;
 
-struct MyRc<T: ?Sized> {
+struct MyRc<T> {
     _ptr: *const T,
     _boo: PhantomData<T>,
 }
 
-impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<MyRc<U>> for MyRc<T>{ }
+impl<T: Unsize<U>, U> CoerceUnsized<MyRc<U>> for MyRc<T>{ }
 
 fn main() {
     let data = [1, 2, 3];

tests/ui/coercion/issue-26905.rs

@@ -1,19 +1,21 @@
 #![feature(unsize, coerce_unsized)]
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
 
 // Verfies that non-PhantomData ZSTs still cause coercions to fail.
 // They might have additional semantics that we don't want to bulldoze.
 
 use std::marker::{Unsize, PhantomData};
 use std::ops::CoerceUnsized;
 
-struct NotPhantomData<T: ?Sized>(PhantomData<T>);
+struct NotPhantomData<T>(PhantomData<T>);
 
-struct MyRc<T: ?Sized> {
+struct MyRc<T> {
     _ptr: *const T,
     _boo: NotPhantomData<T>,
 }
 
-impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<MyRc<U>> for MyRc<T>{ } //~ERROR
+impl<T: Unsize<U>, U> CoerceUnsized<MyRc<U>> for MyRc<T>{ } //~ERROR
 
 fn main() {
     let data = [1, 2, 3];

tests/ui/coercion/issue-26905.stderr

@@ -1,11 +1,11 @@
 error[E0375]: implementing `CoerceUnsized` does not allow multiple fields to be coerced
-  --> $DIR/issue-26905.rs:16:40
+  --> $DIR/issue-26905.rs:18:23
    |
-LL | impl<T: ?Sized + Unsize<U>, U: ?Sized> CoerceUnsized<MyRc<U>> for MyRc<T>{ }
-   |                                        ^^^^^^^^^^^^^^^^^^^^^^
+LL | impl<T: Unsize<U>, U> CoerceUnsized<MyRc<U>> for MyRc<T>{ }
+   |                       ^^^^^^^^^^^^^^^^^^^^^^
    |
 note: the trait `CoerceUnsized` may only be implemented when a single field is being coerced
-  --> $DIR/issue-26905.rs:12:5
+  --> $DIR/issue-26905.rs:14:5
    |
 LL |     _ptr: *const T,
    |     ^^^^^^^^^^^^^^

tests/ui/coercion/sub-principals.rs

@@ -7,10 +7,12 @@
 // a non-higer-ranked instantiation.
 
 #![feature(unsize)]
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
 
 use std::marker::Unsize;
 
-fn test<T: ?Sized, U: ?Sized>()
+fn test<T, U>()
 where
     T: Unsize<U>,
 {

tests/ui/coherence/negative-coherence-placeholder-region-constraints-on-unification.explicit.stderr

@@ -1,10 +1,10 @@
 error: conflicting implementations of trait `FnMarker` for type `fn(&_)`
-  --> $DIR/negative-coherence-placeholder-region-constraints-on-unification.rs:21:1
+  --> $DIR/negative-coherence-placeholder-region-constraints-on-unification.rs:23:1
    |
-LL | impl<T: ?Sized + Marker> FnMarker for fn(T) {}
-   | ------------------------------------------- first implementation here
-LL | impl<T: ?Sized> FnMarker for fn(&T) {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `fn(&_)`
+LL | impl<T: Marker> FnMarker for fn(T) {}
+   | ---------------------------------- first implementation here
+LL | impl<T> FnMarker for fn(&T) {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `fn(&_)`
    |
    = warning: the behavior may change in a future release
    = note: for more information, see issue #56105 <https://github.com/rust-lang/rust/issues/56105>

tests/ui/coherence/negative-coherence-placeholder-region-constraints-on-unification.rs

@@ -3,22 +3,24 @@
 
 #![forbid(coherence_leak_check)]
 #![feature(negative_impls, with_negative_coherence)]
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
 
 pub trait Marker {}
 
 #[cfg(implicit)]
-impl<T: ?Sized> !Marker for &T {}
+impl<T> !Marker for &T {}
 
 #[cfg(explicit)]
-impl<'a, T: ?Sized + 'a> !Marker for &'a T {}
+impl<'a, T: 'a> !Marker for &'a T {}
 
 trait FnMarker {}
 
 // Unifying these two impls below results in a `T: '!0` obligation
 // that we shouldn't need to care about. Ideally, we'd treat that
 // as an assumption when proving `&'!0 T: Marker`...
-impl<T: ?Sized + Marker> FnMarker for fn(T) {}
-impl<T: ?Sized> FnMarker for fn(&T) {}
+impl<T: Marker> FnMarker for fn(T) {}
+impl<T> FnMarker for fn(&T) {}
 //[explicit]~^ ERROR conflicting implementations of trait `FnMarker` for type `fn(&_)`
 //[explicit]~| WARN the behavior may change in a future release
 

tests/ui/const-generics/issues/issue-88119.rs

@@ -2,6 +2,8 @@
 //@ compile-flags: -Znext-solver
 #![allow(incomplete_features)]
 #![feature(const_trait_impl, generic_const_exprs)]
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
 
 #[const_trait]
 trait ConstName {
@@ -12,18 +14,18 @@ impl const ConstName for u8 {
     const NAME_BYTES: &'static [u8] = b"u8";
 }
 
-const fn name_len<T: ?Sized + ConstName>() -> usize {
+const fn name_len<T: ConstName>() -> usize {
     T::NAME_BYTES.len()
 }
 
-impl<T: ?Sized + ConstName> const ConstName for &T
+impl<T: ConstName> const ConstName for &T
 where
     [(); name_len::<T>()]:,
 {
     const NAME_BYTES: &'static [u8] = b"&T";
 }
 
-impl<T: ?Sized + ConstName> const ConstName for &mut T
+impl<T: ConstName> const ConstName for &mut T
 where
     [(); name_len::<T>()]:,
 {

tests/ui/const-generics/issues/issue-88119.stderr

@@ -7,85 +7,85 @@ LL | #![feature(const_trait_impl, generic_const_exprs)]
    = help: remove one of these features
 
 error[E0275]: overflow evaluating the requirement `&T: ~const ConstName`
-  --> $DIR/issue-88119.rs:19:49
+  --> $DIR/issue-88119.rs:21:40
    |
-LL | impl<T: ?Sized + ConstName> const ConstName for &T
-   |                                                 ^^
+LL | impl<T: ConstName> const ConstName for &T
+   |                                        ^^
 
 error[E0275]: overflow evaluating the requirement `&T: ConstName`
-  --> $DIR/issue-88119.rs:19:49
+  --> $DIR/issue-88119.rs:21:40
    |
-LL | impl<T: ?Sized + ConstName> const ConstName for &T
-   |                                                 ^^
+LL | impl<T: ConstName> const ConstName for &T
+   |                                        ^^
 
 error[E0275]: overflow evaluating the requirement `[(); name_len::<T>()] well-formed`
-  --> $DIR/issue-88119.rs:21:5
+  --> $DIR/issue-88119.rs:23:5
    |
 LL |     [(); name_len::<T>()]:,
    |     ^^^^^^^^^^^^^^^^^^^^^
    |
 note: required by a bound in `<&T as ConstName>`
-  --> $DIR/issue-88119.rs:21:5
+  --> $DIR/issue-88119.rs:23:5
    |
 LL |     [(); name_len::<T>()]:,
    |     ^^^^^^^^^^^^^^^^^^^^^ required by this bound in `<&T as ConstName>`
 
 error[E0275]: overflow evaluating the requirement `[(); name_len::<T>()] well-formed`
-  --> $DIR/issue-88119.rs:21:10
+  --> $DIR/issue-88119.rs:23:10
    |
 LL |     [(); name_len::<T>()]:,
    |          ^^^^^^^^^^^^^^^
    |
 note: required by a bound in `<&T as ConstName>`
-  --> $DIR/issue-88119.rs:21:5
+  --> $DIR/issue-88119.rs:23:5
    |
 LL |     [(); name_len::<T>()]:,
    |     ^^^^^^^^^^^^^^^^^^^^^ required by this bound in `<&T as ConstName>`
 
 error[E0275]: overflow evaluating the requirement `&mut T: ~const ConstName`
-  --> $DIR/issue-88119.rs:26:49
+  --> $DIR/issue-88119.rs:28:40
    |
-LL | impl<T: ?Sized + ConstName> const ConstName for &mut T
-   |                                                 ^^^^^^
+LL | impl<T: ConstName> const ConstName for &mut T
+   |                                        ^^^^^^
 
 error[E0275]: overflow evaluating the requirement `&mut T: ConstName`
-  --> $DIR/issue-88119.rs:26:49
+  --> $DIR/issue-88119.rs:28:40
    |
-LL | impl<T: ?Sized + ConstName> const ConstName for &mut T
-   |                                                 ^^^^^^
+LL | impl<T: ConstName> const ConstName for &mut T
+   |                                        ^^^^^^
 
 error[E0275]: overflow evaluating the requirement `[(); name_len::<T>()] well-formed`
-  --> $DIR/issue-88119.rs:28:5
+  --> $DIR/issue-88119.rs:30:5
    |
 LL |     [(); name_len::<T>()]:,
    |     ^^^^^^^^^^^^^^^^^^^^^
    |
 note: required by a bound in `<&mut T as ConstName>`
-  --> $DIR/issue-88119.rs:28:5
+  --> $DIR/issue-88119.rs:30:5
    |
 LL |     [(); name_len::<T>()]:,
    |     ^^^^^^^^^^^^^^^^^^^^^ required by this bound in `<&mut T as ConstName>`
 
 error[E0275]: overflow evaluating the requirement `[(); name_len::<T>()] well-formed`
-  --> $DIR/issue-88119.rs:28:10
+  --> $DIR/issue-88119.rs:30:10
    |
 LL |     [(); name_len::<T>()]:,
    |          ^^^^^^^^^^^^^^^
    |
 note: required by a bound in `<&mut T as ConstName>`
-  --> $DIR/issue-88119.rs:28:5
+  --> $DIR/issue-88119.rs:30:5
    |
 LL |     [(); name_len::<T>()]:,
    |     ^^^^^^^^^^^^^^^^^^^^^ required by this bound in `<&mut T as ConstName>`
 
 error[E0275]: overflow evaluating the requirement `&&mut u8: ConstName`
-  --> $DIR/issue-88119.rs:33:35
+  --> $DIR/issue-88119.rs:35:35
    |
 LL | pub const ICE_1: &'static [u8] = <&&mut u8 as ConstName>::NAME_BYTES;
    |                                   ^^^^^^^^
 
 error[E0275]: overflow evaluating the requirement `&mut &u8: ConstName`
-  --> $DIR/issue-88119.rs:34:35
+  --> $DIR/issue-88119.rs:36:35
    |
 LL | pub const ICE_2: &'static [u8] = <&mut &u8 as ConstName>::NAME_BYTES;
    |                                   ^^^^^^^^

tests/ui/consts/issue-67529.rs

@@ -1,7 +1,10 @@
 //@ compile-flags: -Z mir-opt-level=3
 //@ run-pass
 
-struct Baz<T: ?Sized> {
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
+
+struct Baz<T> {
     a: T
 }
 

tests/ui/dst/dst-bad-coerce1.rs

@@ -1,6 +1,8 @@
 // Attempt to change the type as well as unsizing.
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
 
-struct Fat<T: ?Sized> {
+struct Fat<T> {
     ptr: T
 }