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Make associated_item_def_ids for traits use an unstable option to also return associated types for RPITITs

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Santiago Pastorino 2023-02-28 13:05:37 -03:00
parent be72beca68
commit 811a1cabda
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2 changed files with 100 additions and 5 deletions
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94
compiler/rustc_ty_utils/src/assoc.rs
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@ -4,7 +4,8 @@ use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::definitions::DefPathData;
use rustc_hir::intravisit::{self, Visitor};
use rustc_middle::ty::{self, DefIdTree, TyCtxt};
use rustc_middle::ty::{self, DefIdTree, ImplTraitInTraitData, InternalSubsts, TyCtxt};
use rustc_span::symbol::kw;
pub fn provide(providers: &mut ty::query::Providers) {
*providers = ty::query::Providers {
@ -21,9 +22,37 @@ pub fn provide(providers: &mut ty::query::Providers) {
fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: DefId) -> &[DefId] {
let item = tcx.hir().expect_item(def_id.expect_local());
match item.kind {
hir::ItemKind::Trait(.., ref trait_item_refs) => tcx.arena.alloc_from_iter(
trait_item_refs.iter().map(|trait_item_ref| trait_item_ref.id.owner_id.to_def_id()),
),
hir::ItemKind::Trait(.., ref trait_item_refs) => {
if tcx.sess.opts.unstable_opts.lower_impl_trait_in_trait_to_assoc_ty {
// We collect RPITITs for each trait method's return type and create a
// corresponding associated item using associated_items_for_impl_trait_in_trait
// query.
tcx.arena.alloc_from_iter(
trait_item_refs
.iter()
.map(|trait_item_ref| trait_item_ref.id.owner_id.to_def_id())
.chain(
trait_item_refs
.iter()
.filter(|trait_item_ref| {
matches!(trait_item_ref.kind, hir::AssocItemKind::Fn { .. })
})
.flat_map(|trait_item_ref| {
let trait_fn_def_id =
trait_item_ref.id.owner_id.def_id.to_def_id();
tcx.associated_items_for_impl_trait_in_trait(trait_fn_def_id)
})
.map(|def_id| *def_id),
),
)
} else {
tcx.arena.alloc_from_iter(
trait_item_refs
.iter()
.map(|trait_item_ref| trait_item_ref.id.owner_id.to_def_id()),
)
}
}
hir::ItemKind::Impl(ref impl_) => tcx.arena.alloc_from_iter(
impl_.items.iter().map(|impl_item_ref| impl_item_ref.id.owner_id.to_def_id()),
),
@ -193,7 +222,62 @@ fn associated_item_for_impl_trait_in_trait(
let span = tcx.def_span(opaque_ty_def_id);
let trait_assoc_ty =
tcx.at(span).create_def(trait_def_id.expect_local(), DefPathData::ImplTraitAssocTy);
trait_assoc_ty.def_id()
let local_def_id = trait_assoc_ty.def_id();
let def_id = local_def_id.to_def_id();
trait_assoc_ty.opt_def_kind(Some(DefKind::AssocTy));
// There's no HIR associated with this new synthesized `def_id`, so feed
// `opt_local_def_id_to_hir_id` with `None`.
trait_assoc_ty.opt_local_def_id_to_hir_id(None);
// Copy span of the opaque.
trait_assoc_ty.def_ident_span(Some(span));
// Add the def_id of the function and opaque that generated this synthesized associated type.
trait_assoc_ty.opt_rpitit_info(Some(ImplTraitInTraitData::Trait {
fn_def_id,
opaque_def_id: opaque_ty_def_id.to_def_id(),
}));
trait_assoc_ty.associated_item(ty::AssocItem {
name: kw::Empty,
kind: ty::AssocKind::Type,
def_id,
trait_item_def_id: None,
container: ty::TraitContainer,
fn_has_self_parameter: false,
});
// Copy visility of the containing function.
trait_assoc_ty.visibility(tcx.visibility(fn_def_id));
// Copy impl_defaultness of the containing function.
trait_assoc_ty.impl_defaultness(tcx.impl_defaultness(fn_def_id));
// Copy type_of of the opaque.
trait_assoc_ty.type_of(ty::EarlyBinder(tcx.mk_opaque(
opaque_ty_def_id.to_def_id(),
InternalSubsts::identity_for_item(tcx, opaque_ty_def_id.to_def_id()),
)));
// Copy generics_of of the opaque.
trait_assoc_ty.generics_of(tcx.generics_of(opaque_ty_def_id).clone());
// There are no predicates for the synthesized associated type.
trait_assoc_ty.explicit_predicates_of(ty::GenericPredicates {
parent: Some(trait_def_id),
predicates: &[],
});
// There are no inferred outlives for the synthesized associated type.
trait_assoc_ty.inferred_outlives_of(&[]);
// FIXME implement this.
trait_assoc_ty.explicit_item_bounds(&[]);
local_def_id
}
/// Given an `trait_assoc_def_id` that corresponds to a previously synthesized impl trait in trait