bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Shift vars for default RPITIT methods correctly

Browse source
This commit is contained in:
Michael Goulet 2023-02-28 21:34:04 +00:00
parent 31f858d9a5
commit b7e0ca993d
3 changed files with 49 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

25
compiler/rustc_ty_utils/src/ty.rs
View file

@ -142,12 +142,14 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> {
&& tcx.associated_item(def_id).container == ty::AssocItemContainer::TraitContainer
{
let sig = tcx.fn_sig(def_id).subst_identity();
sig.visit_with(&mut ImplTraitInTraitFinder {
// We accounted for the binder of the fn sig, so skip the binder.
sig.skip_binder().visit_with(&mut ImplTraitInTraitFinder {
tcx,
fn_def_id: def_id,
bound_vars: sig.bound_vars(),
predicates: &mut predicates,
seen: FxHashSet::default(),
depth: ty::INNERMOST,
});
}
@ -244,15 +246,36 @@ struct ImplTraitInTraitFinder<'a, 'tcx> {
fn_def_id: DefId,
bound_vars: &'tcx ty::List<ty::BoundVariableKind>,
seen: FxHashSet<DefId>,
depth: ty::DebruijnIndex,
}
impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ImplTraitInTraitFinder<'_, 'tcx> {
fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
&mut self,
binder: &ty::Binder<'tcx, T>,
) -> std::ops::ControlFlow<Self::BreakTy> {
self.depth.shift_in(1);
let binder = binder.super_visit_with(self);
self.depth.shift_out(1);
binder
}
fn visit_ty(&mut self, ty: Ty<'tcx>) -> std::ops::ControlFlow<Self::BreakTy> {
if let ty::Alias(ty::Projection, alias_ty) = *ty.kind()
&& self.tcx.def_kind(alias_ty.def_id) == DefKind::ImplTraitPlaceholder
&& self.tcx.impl_trait_in_trait_parent(alias_ty.def_id) == self.fn_def_id
&& self.seen.insert(alias_ty.def_id)
{
// We have entered some binders as we've walked into the
// bounds of the RPITIT. Shift these binders back out when
// constructing the top-level projection predicate.
let alias_ty = self.tcx.fold_regions(alias_ty, |re, _| {
if let ty::ReLateBound(index, bv) = re.kind() {
self.tcx.mk_re_late_bound(index.shifted_out_to_binder(self.depth), bv)
} else {
re
}
});
self.predicates.push(
ty::Binder::bind_with_vars(
ty::ProjectionPredicate {