Skip to content

Commit

Permalink
Make associated_item_def_ids for traits use an unstable option to als…
Browse files Browse the repository at this point in the history 
…o return associated types for RPITITs
  • Loading branch information
@spastorino
spastorino committed Mar 1, 2023
1 parent be72bec commit 811a1ca
Show file tree
Hide file tree
Showing 2 changed files with 100 additions and 5 deletions.
11 changes: 11 additions & 0 deletions compiler/rustc_middle/src/query/mod.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -90,6 +90,7 @@ rustc_queries! {
/// Definitions that were generated with no HIR, would be feeded to return `None`.
query opt_local_def_id_to_hir_id(key: LocalDefId) -> Option<hir::HirId>{
desc { |tcx| "getting HIR ID of `{}`", tcx.def_path_str(key.to_def_id()) }
feedable
}

/// Gives access to the HIR node's parent for the HIR owner `key`.
Expand Down Expand Up @@ -166,6 +167,7 @@ rustc_queries! {
}
cache_on_disk_if { key.is_local() }
separate_provide_extern
feedable
}

query collect_return_position_impl_trait_in_trait_tys(key: DefId)
Expand Down Expand Up @@ -222,6 +224,7 @@ rustc_queries! {
arena_cache
cache_on_disk_if { key.is_local() }
separate_provide_extern
feedable
}

/// Maps from the `DefId` of an item (trait/struct/enum/fn) to the
Expand Down Expand Up @@ -264,6 +267,7 @@ rustc_queries! {
desc { |tcx| "finding item bounds for `{}`", tcx.def_path_str(key) }
cache_on_disk_if { key.is_local() }
separate_provide_extern
feedable
}

/// Elaborated version of the predicates from `explicit_item_bounds`.
Expand Down Expand Up @@ -588,6 +592,7 @@ rustc_queries! {
desc { |tcx| "computing explicit predicates of `{}`", tcx.def_path_str(key) }
cache_on_disk_if { key.is_local() }
separate_provide_extern
feedable
}

/// Returns the inferred outlives predicates (e.g., for `struct
Expand All @@ -596,6 +601,7 @@ rustc_queries! {
desc { |tcx| "computing inferred outlives predicates of `{}`", tcx.def_path_str(key) }
cache_on_disk_if { key.is_local() }
separate_provide_extern
feedable
}

/// Maps from the `DefId` of a trait to the list of
Expand Down Expand Up @@ -728,6 +734,7 @@ rustc_queries! {
desc { |tcx| "computing associated item data for `{}`", tcx.def_path_str(key) }
cache_on_disk_if { key.is_local() }
separate_provide_extern
feedable
}

/// Collects the associated items defined on a trait or impl.
Expand Down Expand Up @@ -1142,6 +1149,7 @@ rustc_queries! {
desc { |tcx| "looking up definition kind of `{}`", tcx.def_path_str(def_id) }
cache_on_disk_if { def_id.is_local() }
separate_provide_extern
feedable
}

/// The `opt_rpitit_info` query returns the pair of the def id of the function where the RPIT
Expand All @@ -1165,6 +1173,7 @@ rustc_queries! {
desc { |tcx| "looking up span for `{}`'s identifier", tcx.def_path_str(def_id) }
cache_on_disk_if { def_id.is_local() }
separate_provide_extern
feedable
}

query lookup_stability(def_id: DefId) -> Option<attr::Stability> {
Expand Down Expand Up @@ -1506,6 +1515,7 @@ rustc_queries! {
desc { |tcx| "looking up whether `{}` is a default impl", tcx.def_path_str(def_id) }
cache_on_disk_if { def_id.is_local() }
separate_provide_extern
feedable
}

query check_well_formed(key: hir::OwnerId) -> () {
Expand Down Expand Up @@ -1703,6 +1713,7 @@ rustc_queries! {
query visibility(def_id: DefId) -> ty::Visibility<DefId> {
desc { |tcx| "computing visibility of `{}`", tcx.def_path_str(def_id) }
separate_provide_extern
feedable
}

query inhabited_predicate_adt(key: DefId) -> ty::inhabitedness::InhabitedPredicate<'tcx> {
Expand Down
94 changes: 89 additions & 5 deletions compiler/rustc_ty_utils/src/assoc.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 {
Expand All @@ -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()),
),
Expand Down Expand Up @@ -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
Expand Down

0 comments on commit 811a1ca

Please sign in to comment.