Skip to content

fix: resolve associated types of bare dyn types #13049

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Aug 18, 2022
Merged

fix: resolve associated types of bare dyn types #13049

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
61 changes: 26 additions & 35 deletions crates/hir-ty/src/lower.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -238,18 +238,7 @@ impl<'a> TyLoweringContext<'a> {
})
.intern(Interner)
}
TypeRef::DynTrait(bounds) => {
let self_ty =
TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)).intern(Interner);
let bounds = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
QuantifiedWhereClauses::from_iter(
Interner,
bounds.iter().flat_map(|b| ctx.lower_type_bound(b, self_ty.clone(), false)),
)
});
let bounds = crate::make_single_type_binders(bounds);
TyKind::Dyn(DynTy { bounds, lifetime: static_lifetime() }).intern(Interner)
}
TypeRef::DynTrait(bounds) => self.lower_dyn_trait(bounds),
TypeRef::ImplTrait(bounds) => {
match self.impl_trait_mode {
ImplTraitLoweringMode::Opaque => {
Expand Down Expand Up @@ -468,29 +457,10 @@ impl<'a> TyLoweringContext<'a> {
}
}
0 => {
let self_ty = Some(
TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0))
.intern(Interner),
);
let trait_ref = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
ctx.lower_trait_ref_from_resolved_path(
trait_,
resolved_segment,
self_ty,
)
});
let dyn_ty = DynTy {
bounds: crate::make_single_type_binders(
QuantifiedWhereClauses::from_iter(
Interner,
Some(crate::wrap_empty_binders(WhereClause::Implemented(
trait_ref,
))),
),
),
lifetime: static_lifetime(),
};
TyKind::Dyn(dyn_ty).intern(Interner)
// Trait object type without dyn; this should be handled in upstream. See
// `lower_path()`.
stdx::never!("unexpected fully resolved trait path");
TyKind::Error.intern(Interner)
}
_ => {
// FIXME report error (ambiguous associated type)
Expand Down Expand Up @@ -555,11 +525,20 @@ impl<'a> TyLoweringContext<'a> {
let (ty, res) = self.lower_ty_ext(type_ref);
return self.lower_ty_relative_path(ty, res, path.segments());
}

let (resolution, remaining_index) =
match self.resolver.resolve_path_in_type_ns(self.db.upcast(), path.mod_path()) {
Some(it) => it,
None => return (TyKind::Error.intern(Interner), None),
};

if matches!(resolution, TypeNs::TraitId(_)) && remaining_index.is_none() {
// trait object type without dyn
let bound = TypeBound::Path(path.clone(), TraitBoundModifier::None);
let ty = self.lower_dyn_trait(&[Interned::new(bound)]);
return (ty, None);
}

let (resolved_segment, remaining_segments) = match remaining_index {
None => (
path.segments().last().expect("resolved path has at least one element"),
Expand Down Expand Up @@ -987,6 +966,18 @@ impl<'a> TyLoweringContext<'a> {
})
}

fn lower_dyn_trait(&self, bounds: &[Interned<TypeBound>]) -> Ty {
let self_ty = TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)).intern(Interner);
let bounds = self.with_shifted_in(DebruijnIndex::ONE, |ctx| {
QuantifiedWhereClauses::from_iter(
Interner,
bounds.iter().flat_map(|b| ctx.lower_type_bound(b, self_ty.clone(), false)),
)
});
let bounds = crate::make_single_type_binders(bounds);
TyKind::Dyn(DynTy { bounds, lifetime: static_lifetime() }).intern(Interner)
}

fn lower_impl_trait(
&self,
bounds: &[Interned<TypeBound>],
Expand Down
28 changes: 28 additions & 0 deletions crates/hir-ty/src/tests/traits.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1476,6 +1476,34 @@ fn test(x: Trait, y: &Trait) -> u64 {
165..172 'z.foo()': u64
"#]],
);

check_infer_with_mismatches(
r#"
//- minicore: fn, coerce_unsized
struct S;
impl S {
fn foo(&self) {}
}
fn f(_: &Fn(S)) {}
fn main() {
f(&|number| number.foo());
}
"#,
expect![[r#"
31..35 'self': &S
37..39 '{}': ()
47..48 '_': &dyn Fn(S)
58..60 '{}': ()
71..105 '{ ...()); }': ()
77..78 'f': fn f(&dyn Fn(S))
77..102 'f(&|nu...foo())': ()
79..101 '&|numb....foo()': &|S| -> ()
80..101 '|numbe....foo()': |S| -> ()
81..87 'number': S
89..95 'number': S
89..101 'number.foo()': ()
"#]],
)
}

#[test]
Expand Down