fix: Wrong BoundVar index when lowering impl trait parameter of parent generics

This commit is contained in:
Shoyu Vanilla 2024-08-17 20:56:40 +09:00
parent 07659783fd
commit d7431ecdfa
2 changed files with 50 additions and 18 deletions

View file

@ -377,26 +377,25 @@ impl<'a> TyLoweringContext<'a> {
// Count the number of `impl Trait` things that appear within our bounds.
// Since t hose have been emitted as implicit type args already.
counter.set(idx + count_impl_traits(type_ref) as u16);
let (
_parent_params,
self_param,
type_params,
const_params,
_impl_trait_params,
lifetime_params,
) = self
let kind = self
.generics()
.expect("variable impl trait lowering must be in a generic def")
.provenance_split();
TyKind::BoundVar(BoundVar::new(
self.in_binders,
idx as usize
+ self_param as usize
+ type_params
+ const_params
+ lifetime_params,
))
.intern(Interner)
.iter()
.enumerate()
.filter_map(|(i, (id, data))| match (id, data) {
(
GenericParamId::TypeParamId(_),
GenericParamDataRef::TypeParamData(data),
) if data.provenance == TypeParamProvenance::ArgumentImplTrait => {
Some(i)
}
_ => None,
})
.nth(idx as usize)
.map_or(TyKind::Error, |id| {
TyKind::BoundVar(BoundVar { debruijn: self.in_binders, index: id })
});
kind.intern(Interner)
}
ImplTraitLoweringState::Disallowed => {
// FIXME: report error

View file

@ -2162,3 +2162,36 @@ fn main() {
"#]],
);
}
#[test]
fn issue_17711() {
check_infer(
r#"
//- minicore: deref
use core::ops::Deref;
struct Struct<'a, T>(&'a T);
trait Trait {}
impl<'a, T: Deref<Target = impl Trait>> Struct<'a, T> {
fn foo(&self) -> &Self { self }
fn bar(&self) {
let _ = self.foo();
}
}
"#,
expect![[r#"
137..141 'self': &'? Struct<'a, T>
152..160 '{ self }': &'? Struct<'a, T>
154..158 'self': &'? Struct<'a, T>
174..178 'self': &'? Struct<'a, T>
180..215 '{ ... }': ()
194..195 '_': &'? Struct<'?, T>
198..202 'self': &'? Struct<'a, T>
198..208 'self.foo()': &'? Struct<'?, T>
"#]],
);
}