diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs index 193b6d3e3d97a..d5875a226fe02 100644 --- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs +++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs @@ -192,6 +192,11 @@ impl<'tcx> RegionInferenceContext<'tcx> { .find(|ur_vid| self.eval_equal(vid, **ur_vid)) .and_then(|ur_vid| self.definitions[*ur_vid].external_name) .unwrap_or(infcx.tcx.lifetimes.re_erased), + ty::RePlaceholder(_) => ty::Region::new_error_with_message( + infcx.tcx, + concrete_type.span, + "hidden type contains placeholders, we don't support higher kinded opaques yet", + ), _ => region, }); debug!(?universal_concrete_type); diff --git a/tests/ui/type-alias-impl-trait/hkl_forbidden4.rs b/tests/ui/type-alias-impl-trait/hkl_forbidden4.rs new file mode 100644 index 0000000000000..ef9fe604ea783 --- /dev/null +++ b/tests/ui/type-alias-impl-trait/hkl_forbidden4.rs @@ -0,0 +1,25 @@ +//! This test used to ICE because, while an error was emitted, +//! we still tried to remap generic params used in the hidden type +//! to the ones of the opaque type definition. + +//@ edition: 2021 + +#![feature(type_alias_impl_trait)] +use std::future::Future; + +type FutNothing<'a> = impl 'a + Future; +//~^ ERROR: unconstrained opaque type + +async fn operation(_: &mut ()) -> () { + //~^ ERROR: concrete type differs from previous + call(operation).await +} + +async fn call(_f: F) +where + for<'any> F: FnMut(&'any mut ()) -> FutNothing<'any>, +{ + //~^ ERROR: expected generic lifetime parameter, found `'any` +} + +fn main() {} diff --git a/tests/ui/type-alias-impl-trait/hkl_forbidden4.stderr b/tests/ui/type-alias-impl-trait/hkl_forbidden4.stderr new file mode 100644 index 0000000000000..d7a0452727e83 --- /dev/null +++ b/tests/ui/type-alias-impl-trait/hkl_forbidden4.stderr @@ -0,0 +1,34 @@ +error: unconstrained opaque type + --> $DIR/hkl_forbidden4.rs:10:23 + | +LL | type FutNothing<'a> = impl 'a + Future; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: `FutNothing` must be used in combination with a concrete type within the same module + +error: concrete type differs from previous defining opaque type use + --> $DIR/hkl_forbidden4.rs:13:1 + | +LL | async fn operation(_: &mut ()) -> () { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `FutNothing<'_>`, got `{async fn body@$DIR/hkl_forbidden4.rs:13:38: 16:2}` + | +note: previous use here + --> $DIR/hkl_forbidden4.rs:15:5 + | +LL | call(operation).await + | ^^^^^^^^^^^^^^^ + +error[E0792]: expected generic lifetime parameter, found `'any` + --> $DIR/hkl_forbidden4.rs:21:1 + | +LL | type FutNothing<'a> = impl 'a + Future; + | -- this generic parameter must be used with a generic lifetime parameter +... +LL | / { +LL | | +LL | | } + | |_^ + +error: aborting due to 3 previous errors + +For more information about this error, try `rustc --explain E0792`.