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//@ needs-sanitizer-cfi
//@ compile-flags: -Ccodegen-units=1 -Clto -Ctarget-feature=-crt-static -Zsanitizer=cfi
//@ no-prefer-dynamic
//@ only-x86_64-unknown-linux-gnu
//@ build-pass
// See comment below for why this test exists.
trait Tr<U> {
type Projection;
}
impl<F, U> Tr<U> for F
where
F: Fn() -> U
{
type Projection = U;
}
fn test<B: Tr<U>, U>(b: B) -> B::Projection
{
todo!()
}
fn main() {
fn rpit_fn() -> impl Sized {}
// When CFI runs, it tries to compute the signature of the call. This
// ends up giving us a signature of:
// `fn test::<rpit_fn, ()>() -> <rpit_fn as Tr<()>>::Projection`,
// where `rpit_fn` is the ZST FnDef for the function. However, we were
// previously using a Reveal::UserFacing param-env. This means that the
// `<rpit_fn as Tr<()>>::Projection` return type is impossible to normalize,
// since it would require proving `rpit_fn: Fn() -> ()`, but we cannot
// prove that the `impl Sized` opaque is `()` with a user-facing param-env.
// This leads to a normalization error, and then an ICE.
//
// Side-note:
// So why is the second generic of `test` "`()`", and not the
// `impl Sized` since we inferred it from the return type of `rpit_fn`
// during typeck? Well, that's because we're using the generics from the
// terminator of the MIR, which has had the PostAnalysisNormalize pass performed on it.
let _ = test(rpit_fn);
}
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