Rollup merge of rust-lang#93953 - jackh726:known_bug, r=Mark-Simulacrum

Add the `known-bug` test directive, use it, and do some cleanup

cc rust-lang/compiler-team#476

Now tests can be annotated with `known-bug`, which should indicate that the test *should* pass (or at least that the current output is a bug). Adding it relaxes the requirement to add error annotations to the test (though it is still allowed). In the future, this could be extended with further relaxations - with the goal to make adding these tests need minimal effort.

I've used this attribute for the GAT tests added in rust-lang#93757.

Finally, I've also cleaned up `header.rs` in compiletest a bit, by extracting out a bit of common logic. I've also split out some of the directives into their own consts. This removes a lot of very similar functions from `Config` and makes `TestProps::load_from` read nicer.

I've split these into separate commits, so I in theory could split these into separate PRs if they're controversial, but I think they're pretty straightforward.

r? `@Mark-Simulacrum`

Author: matthiaskrgr

src/test/ui/generic-associated-types/bugs/issue-80626.rs

@@ -1,4 +1,5 @@
 // check-fail
+// known-bug
 
 // This should pass, but it requires `Sized` to be coinductive.
 
@@ -11,7 +12,6 @@ trait Allocator {
 enum LinkedList<A: Allocator> {
     Head,
     Next(A::Allocated<Self>)
-    //~^ overflow
 }
 
 fn main() {}

src/test/ui/generic-associated-types/bugs/issue-80626.stderr

@@ -1,5 +1,5 @@
 error[E0275]: overflow evaluating the requirement `LinkedList<A>: Sized`
-  --> $DIR/issue-80626.rs:13:10
+  --> $DIR/issue-80626.rs:14:10
    |
 LL |     Next(A::Allocated<Self>)
    |          ^^^^^^^^^^^^^^^^^^

src/test/ui/generic-associated-types/bugs/issue-86218.rs

@@ -1,4 +1,5 @@
 // check-fail
+// known-bug
 
 // This should pass, but seems to run into a TAIT issue.
 
@@ -20,7 +21,6 @@ trait Yay<AdditionalValue> {
 
 impl<'a> Yay<&'a ()> for () {
     type InnerStream<'s> = impl Stream<Item = i32> + 's;
-    //~^ the type
     fn foo<'s>() -> Self::InnerStream<'s> { todo!() }
 }
 

src/test/ui/generic-associated-types/bugs/issue-86218.stderr

@@ -1,11 +1,11 @@
 error[E0477]: the type `impl Stream<Item = i32>` does not fulfill the required lifetime
-  --> $DIR/issue-86218.rs:22:28
+  --> $DIR/issue-86218.rs:23:28
    |
 LL |     type InnerStream<'s> = impl Stream<Item = i32> + 's;
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: type must outlive the lifetime `'s` as defined here as required by this binding
-  --> $DIR/issue-86218.rs:22:22
+  --> $DIR/issue-86218.rs:23:22
    |
 LL |     type InnerStream<'s> = impl Stream<Item = i32> + 's;
    |                      ^^

src/test/ui/generic-associated-types/bugs/issue-87735.rs

@@ -1,4 +1,5 @@
 // check-fail
+// known-bug
 
 // This should pass, but we need an extension of implied bounds (probably).
 
@@ -23,7 +24,7 @@ struct Foo<T>(T);
 #[derive(Debug)]
 struct FooRef<'a, U>(&'a [U]);
 
-impl<'b, T, U> AsRef2 for Foo<T> //~ the type parameter
+impl<'b, T, U> AsRef2 for Foo<T>
 where
     // * `for<'b, 'c> T: AsRef2<Output<'b> = &'c [U]>>` does not work
     //

src/test/ui/generic-associated-types/bugs/issue-87735.stderr

@@ -1,5 +1,5 @@
 error[E0207]: the type parameter `U` is not constrained by the impl trait, self type, or predicates
-  --> $DIR/issue-87735.rs:26:13
+  --> $DIR/issue-87735.rs:27:13
    |
 LL | impl<'b, T, U> AsRef2 for Foo<T>
    |             ^ unconstrained type parameter

src/test/ui/generic-associated-types/bugs/issue-87748.rs

@@ -1,4 +1,5 @@
 // check-fail
+// known-bug
 
 // This should pass, but unnormalized input args aren't treated as implied.
 
@@ -14,7 +15,7 @@ struct Foo;
 impl MyTrait for Foo {
     type Assoc<'a, 'b> where 'b: 'a = u32;
 
-    fn do_sth(_: u32) {} //~ lifetime bound
+    fn do_sth(_: u32) {}
     // fn do_sth(_: Self::Assoc<'static, 'static>) {}
     // fn do_sth(_: Self::Assoc<'_, '_>) {}
 }

src/test/ui/generic-associated-types/bugs/issue-87748.stderr

@@ -1,16 +1,16 @@
 error[E0478]: lifetime bound not satisfied
-  --> $DIR/issue-87748.rs:17:5
+  --> $DIR/issue-87748.rs:18:5
    |
 LL |     fn do_sth(_: u32) {}
    |     ^^^^^^^^^^^^^^^^^
    |
 note: lifetime parameter instantiated with the anonymous lifetime #2 defined here
-  --> $DIR/issue-87748.rs:17:5
+  --> $DIR/issue-87748.rs:18:5
    |
 LL |     fn do_sth(_: u32) {}
    |     ^^^^^^^^^^^^^^^^^
 note: but lifetime parameter must outlive the anonymous lifetime #1 defined here
-  --> $DIR/issue-87748.rs:17:5
+  --> $DIR/issue-87748.rs:18:5
    |
 LL |     fn do_sth(_: u32) {}
    |     ^^^^^^^^^^^^^^^^^

src/test/ui/generic-associated-types/bugs/issue-87755.rs

@@ -1,4 +1,5 @@
 // check-fail
+// known-bug
 
 // This should pass.
 
@@ -15,7 +16,6 @@ struct Bar;
 
 impl Foo for Bar {
     type Ass = Bar;
-    //~^ overflow
 }
 
 fn main() {}

src/test/ui/generic-associated-types/bugs/issue-87755.stderr

@@ -1,5 +1,5 @@
 error[E0275]: overflow evaluating the requirement `<Bar as Foo>::Ass == _`
-  --> $DIR/issue-87755.rs:17:16
+  --> $DIR/issue-87755.rs:18:16
    |
 LL |     type Ass = Bar;
    |                ^^^

src/test/ui/generic-associated-types/bugs/issue-87803.rs

@@ -1,4 +1,5 @@
 // check-fail
+// known-bug
 
 // This should pass, but using a type alias vs a reference directly
 // changes late-bound -> early-bound.
@@ -18,7 +19,7 @@ impl Scanner for IdScanner {
     type Input<'a> = &'a str;
     type Token<'a> = &'a str;
 
-    fn scan<'a>(&mut self, s : &'a str) -> &'a str { //~ lifetime parameters
+    fn scan<'a>(&mut self, s : &'a str) -> &'a str {
         s
     }
 }

src/test/ui/generic-associated-types/bugs/issue-87803.stderr

@@ -1,5 +1,5 @@
 error[E0195]: lifetime parameters or bounds on method `scan` do not match the trait declaration
-  --> $DIR/issue-87803.rs:21:12
+  --> $DIR/issue-87803.rs:22:12
    |
 LL |     fn scan<'a>(&mut self, i : Self::Input<'a>) -> Self::Token<'a>;
    |            ---- lifetimes in impl do not match this method in trait

src/test/ui/generic-associated-types/bugs/issue-88382.rs

@@ -1,4 +1,5 @@
 // check-fail
+// known-bug
 
 // This should pass, but has a missed normalization due to HRTB.
 
@@ -25,7 +26,6 @@ fn do_something<I: Iterable>(i: I, mut f: impl for<'a> Fn(&mut I::Iterator<'a>))
 fn main() {
     do_something(SomeImplementation(), |_| ());
     do_something(SomeImplementation(), test);
-    //~^ type mismatch
 }
 
 fn test<'a, I: Iterable>(_: &mut I::Iterator<'a>) {}

src/test/ui/generic-associated-types/bugs/issue-88382.stderr

@@ -1,5 +1,5 @@
 error[E0631]: type mismatch in function arguments
-  --> $DIR/issue-88382.rs:27:40
+  --> $DIR/issue-88382.rs:28:40
    |
 LL |     do_something(SomeImplementation(), test);
    |     ------------                       ^^^^ expected signature of `for<'a> fn(&mut <SomeImplementation as Iterable>::Iterator<'a>) -> _`
@@ -10,7 +10,7 @@ LL | fn test<'a, I: Iterable>(_: &mut I::Iterator<'a>) {}
    | ------------------------------------------------- found signature of `for<'r> fn(&'r mut std::iter::Empty<usize>) -> _`
    |
 note: required by a bound in `do_something`
-  --> $DIR/issue-88382.rs:21:56
+  --> $DIR/issue-88382.rs:22:56
    |
 LL | fn do_something<I: Iterable>(i: I, mut f: impl for<'a> Fn(&mut I::Iterator<'a>)) {
    |                                                        ^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `do_something`

src/test/ui/generic-associated-types/bugs/issue-88460.rs

@@ -1,4 +1,5 @@
 // check-fail
+// known-bug
 
 // This should pass, but has a missed normalization due to HRTB.
 
@@ -27,5 +28,4 @@ impl Trait for Foo {
 
 fn main() {
     test(Foo);
-    //~^ the trait bound
 }

src/test/ui/generic-associated-types/bugs/issue-88460.stderr

@@ -1,11 +1,11 @@
 error[E0277]: the trait bound `for<'a> <_ as Trait>::Assoc<'a>: Marker` is not satisfied
-  --> $DIR/issue-88460.rs:29:5
+  --> $DIR/issue-88460.rs:30:5
    |
 LL |     test(Foo);
    |     ^^^^ the trait `for<'a> Marker` is not implemented for `<_ as Trait>::Assoc<'a>`
    |
 note: required by a bound in `test`
-  --> $DIR/issue-88460.rs:16:27
+  --> $DIR/issue-88460.rs:17:27
    |
 LL | fn test<T>(value: T)
    |    ---- required by a bound in this

src/test/ui/generic-associated-types/bugs/issue-88526.rs

@@ -1,4 +1,5 @@
 // check-fail
+// known-bug
 
 // This should pass, but requires more logic.
 
@@ -23,7 +24,7 @@ struct TestB<Q, F>
     f: F,
 }
 
-impl<'q, Q, I, F> A for TestB<Q, F> //~ the type parameter
+impl<'q, Q, I, F> A for TestB<Q, F>
 where
     Q: A<I<'q> = &'q I>,
     F: Fn(I),

src/test/ui/generic-associated-types/bugs/issue-88526.stderr

@@ -1,5 +1,5 @@
 error[E0207]: the type parameter `I` is not constrained by the impl trait, self type, or predicates
-  --> $DIR/issue-88526.rs:26:13
+  --> $DIR/issue-88526.rs:27:13
    |
 LL | impl<'q, Q, I, F> A for TestB<Q, F>
    |             ^ unconstrained type parameter

src/test/ui/generic-associated-types/bugs/issue-89008.rs

@@ -1,5 +1,6 @@
 // check-fail
 // edition:2021
+// known-bug
 
 // This should pass, but seems to run into a TAIT bug.
 
@@ -31,11 +32,11 @@ trait X {
 struct Y;
 
 impl X for Y {
-    type LineStream<'a, Repr> = impl Stream<Item = Repr>; //~ could not find
+    type LineStream<'a, Repr> = impl Stream<Item = Repr>;
 
     type LineStreamFut<'a, Repr> = impl Future<Output = Self::LineStream<'a, Repr>> ;
 
-    fn line_stream<'a, Repr>(&'a self) -> Self::LineStreamFut<'a, Repr> { //~ type mismatch
+    fn line_stream<'a, Repr>(&'a self) -> Self::LineStreamFut<'a, Repr> {
         async {empty()}
     }
 }

src/test/ui/generic-associated-types/bugs/issue-89008.stderr

@@ -1,5 +1,5 @@
 error[E0271]: type mismatch resolving `<impl Future<Output = [async output]> as Future>::Output == impl Stream<Item = Repr>`
-  --> $DIR/issue-89008.rs:38:43
+  --> $DIR/issue-89008.rs:39:43
    |
 LL |     type LineStream<'a, Repr> = impl Stream<Item = Repr>;
    |                                 ------------------------ the expected opaque type
@@ -11,7 +11,7 @@ LL |     fn line_stream<'a, Repr>(&'a self) -> Self::LineStreamFut<'a, Repr> {
                    found struct `Empty<_>`
 
 error: could not find defining uses
-  --> $DIR/issue-89008.rs:34:33
+  --> $DIR/issue-89008.rs:35:33
    |
 LL |     type LineStream<'a, Repr> = impl Stream<Item = Repr>;
    |                                 ^^^^^^^^^^^^^^^^^^^^^^^^