Unnamed repository; edit this file 'description' to name the repository.
| -rw-r--r-- | crates/hir-ty/src/lower.rs | 23 | ||||
| -rw-r--r-- | crates/hir-ty/src/tests/regression.rs | 13 |
2 files changed, 33 insertions, 3 deletions
diff --git a/crates/hir-ty/src/lower.rs b/crates/hir-ty/src/lower.rs index a77dd910ff..223d705b15 100644 --- a/crates/hir-ty/src/lower.rs +++ b/crates/hir-ty/src/lower.rs @@ -1158,11 +1158,28 @@ fn named_associated_type_shorthand_candidates<R>( }; match res { - TypeNs::SelfType(impl_id) => search( + TypeNs::SelfType(impl_id) => { // we're _in_ the impl -- the binders get added back later. Correct, // but it would be nice to make this more explicit - db.impl_trait(impl_id)?.into_value_and_skipped_binders().0, - ), + let trait_ref = db.impl_trait(impl_id)?.into_value_and_skipped_binders().0; + + let impl_id_as_generic_def: GenericDefId = impl_id.into(); + if impl_id_as_generic_def != def { + // `trait_ref` contains `BoundVar`s bound by impl's `Binders`, but here we need + // `BoundVar`s from `def`'s point of view. + // FIXME: A `HirDatabase` query may be handy if this process is needed in more + // places. It'd be almost identical as `impl_trait_query` where `resolver` would be + // of `def` instead of `impl_id`. + let starting_idx = generics(db.upcast(), def).len_self(); + let subst = TyBuilder::subst_for_def(db, impl_id, None) + .fill_with_bound_vars(DebruijnIndex::INNERMOST, starting_idx) + .build(); + let trait_ref = subst.apply(trait_ref, Interner); + search(trait_ref) + } else { + search(trait_ref) + } + } TypeNs::GenericParam(param_id) => { let predicates = db.generic_predicates_for_param(def, param_id.into(), assoc_name); let res = predicates.iter().find_map(|pred| match pred.skip_binders().skip_binders() { diff --git a/crates/hir-ty/src/tests/regression.rs b/crates/hir-ty/src/tests/regression.rs index 16ba3dd6e3..a155adcec6 100644 --- a/crates/hir-ty/src/tests/regression.rs +++ b/crates/hir-ty/src/tests/regression.rs @@ -1694,3 +1694,16 @@ fn foo(a: &dyn DoesNotExist) { "#, ); } + +#[test] +fn self_assoc_with_const_generics_crash() { + check_no_mismatches( + r#" +trait Trait { type Item; } +impl<T, const N: usize> Trait for [T; N] { + type Item = (); + fn f<U>(_: Self::Item) {} +} + "#, + ); +} |