mirror of
https://github.com/rust-lang/rust
synced 2024-09-15 22:50:55 +00:00
Regular closures now built-in impls for AsyncFn*
This commit is contained in:
Michael Goulet
parent
0dd40786b5
commit
08af64e96b
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@ -394,7 +394,78 @@ pub(in crate::solve) fn extract_tupled_inputs_and_output_from_async_callable<'tc
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))
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}
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ty::FnDef(..) | ty::FnPtr(..) | ty::Closure(..) => Err(NoSolution),
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ty::FnDef(..) | ty::FnPtr(..) => {
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let bound_sig = self_ty.fn_sig(tcx);
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let sig = bound_sig.skip_binder();
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let future_trait_def_id = tcx.require_lang_item(LangItem::Future, None);
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// `FnDef` and `FnPtr` only implement `AsyncFn*` when their
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// return type implements `Future`.
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let nested = vec![
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bound_sig
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.rebind(ty::TraitRef::new(tcx, future_trait_def_id, [sig.output()]))
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.to_predicate(tcx),
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];
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let future_output_def_id = tcx
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.associated_items(future_trait_def_id)
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.filter_by_name_unhygienic(sym::Output)
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.next()
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.unwrap()
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.def_id;
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let future_output_ty = Ty::new_projection(tcx, future_output_def_id, [sig.output()]);
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Ok((
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bound_sig.rebind((Ty::new_tup(tcx, sig.inputs()), sig.output(), future_output_ty)),
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nested,
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))
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}
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ty::Closure(_, args) => {
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let args = args.as_closure();
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let bound_sig = args.sig();
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let sig = bound_sig.skip_binder();
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let future_trait_def_id = tcx.require_lang_item(LangItem::Future, None);
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// `Closure`s only implement `AsyncFn*` when their return type
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// implements `Future`.
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let mut nested = vec![
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bound_sig
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.rebind(ty::TraitRef::new(tcx, future_trait_def_id, [sig.output()]))
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.to_predicate(tcx),
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];
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// Additionally, we need to check that the closure kind
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// is still compatible.
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let kind_ty = args.kind_ty();
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if let Some(closure_kind) = kind_ty.to_opt_closure_kind() {
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if !closure_kind.extends(goal_kind) {
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return Err(NoSolution);
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}
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} else {
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let async_fn_kind_trait_def_id =
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tcx.require_lang_item(LangItem::AsyncFnKindHelper, None);
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// When we don't know the closure kind (and therefore also the closure's upvars,
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// which are computed at the same time), we must delay the computation of the
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// generator's upvars. We do this using the `AsyncFnKindHelper`, which as a trait
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// goal functions similarly to the old `ClosureKind` predicate, and ensures that
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// the goal kind <= the closure kind. As a projection `AsyncFnKindHelper::Upvars`
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// will project to the right upvars for the generator, appending the inputs and
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// coroutine upvars respecting the closure kind.
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nested.push(
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ty::TraitRef::new(
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tcx,
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async_fn_kind_trait_def_id,
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[kind_ty, Ty::from_closure_kind(tcx, goal_kind)],
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)
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.to_predicate(tcx),
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);
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}
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let future_output_def_id = tcx
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.associated_items(future_trait_def_id)
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.filter_by_name_unhygienic(sym::Output)
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.next()
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.unwrap()
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.def_id;
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let future_output_ty = Ty::new_projection(tcx, future_output_def_id, [sig.output()]);
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Ok((bound_sig.rebind((sig.inputs()[0], sig.output(), future_output_ty)), nested))
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}
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ty::Bool
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| ty::Char
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@ -2450,14 +2450,6 @@ fn confirm_async_closure_candidate<'cx, 'tcx>(
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) -> Progress<'tcx> {
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let tcx = selcx.tcx();
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let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty());
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let ty::CoroutineClosure(def_id, args) = *self_ty.kind() else {
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unreachable!(
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"expected coroutine-closure self type for coroutine-closure candidate, found {self_ty}"
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)
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};
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let args = args.as_coroutine_closure();
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let kind_ty = args.kind_ty();
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let sig = args.coroutine_closure_sig().skip_binder();
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let goal_kind =
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tcx.async_fn_trait_kind_from_def_id(obligation.predicate.trait_def_id(tcx)).unwrap();
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@ -2465,84 +2457,163 @@ fn confirm_async_closure_candidate<'cx, 'tcx>(
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ty::ClosureKind::Fn | ty::ClosureKind::FnMut => obligation.predicate.args.region_at(2),
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ty::ClosureKind::FnOnce => tcx.lifetimes.re_static,
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};
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let item_name = tcx.item_name(obligation.predicate.def_id);
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let term = match item_name {
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sym::CallOnceFuture | sym::CallMutFuture | sym::CallFuture => {
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if let Some(closure_kind) = kind_ty.to_opt_closure_kind() {
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if !closure_kind.extends(goal_kind) {
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bug!("we should not be confirming if the closure kind is not met");
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let poly_cache_entry = match *self_ty.kind() {
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ty::CoroutineClosure(def_id, args) => {
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let args = args.as_coroutine_closure();
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let kind_ty = args.kind_ty();
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let sig = args.coroutine_closure_sig().skip_binder();
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let term = match item_name {
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sym::CallOnceFuture | sym::CallMutFuture | sym::CallFuture => {
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if let Some(closure_kind) = kind_ty.to_opt_closure_kind() {
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if !closure_kind.extends(goal_kind) {
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bug!("we should not be confirming if the closure kind is not met");
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}
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sig.to_coroutine_given_kind_and_upvars(
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tcx,
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args.parent_args(),
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tcx.coroutine_for_closure(def_id),
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goal_kind,
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env_region,
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args.tupled_upvars_ty(),
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args.coroutine_captures_by_ref_ty(),
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)
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} else {
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let async_fn_kind_trait_def_id =
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tcx.require_lang_item(LangItem::AsyncFnKindHelper, None);
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let upvars_projection_def_id = tcx
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.associated_items(async_fn_kind_trait_def_id)
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.filter_by_name_unhygienic(sym::Upvars)
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.next()
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.unwrap()
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.def_id;
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// When we don't know the closure kind (and therefore also the closure's upvars,
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// which are computed at the same time), we must delay the computation of the
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// generator's upvars. We do this using the `AsyncFnKindHelper`, which as a trait
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// goal functions similarly to the old `ClosureKind` predicate, and ensures that
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// the goal kind <= the closure kind. As a projection `AsyncFnKindHelper::Upvars`
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// will project to the right upvars for the generator, appending the inputs and
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// coroutine upvars respecting the closure kind.
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// N.B. No need to register a `AsyncFnKindHelper` goal here, it's already in `nested`.
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let tupled_upvars_ty = Ty::new_projection(
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tcx,
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upvars_projection_def_id,
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[
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ty::GenericArg::from(kind_ty),
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Ty::from_closure_kind(tcx, goal_kind).into(),
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env_region.into(),
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sig.tupled_inputs_ty.into(),
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args.tupled_upvars_ty().into(),
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args.coroutine_captures_by_ref_ty().into(),
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],
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);
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sig.to_coroutine(
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tcx,
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args.parent_args(),
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Ty::from_closure_kind(tcx, goal_kind),
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tcx.coroutine_for_closure(def_id),
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tupled_upvars_ty,
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)
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}
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}
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sig.to_coroutine_given_kind_and_upvars(
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sym::Output => sig.return_ty,
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name => bug!("no such associated type: {name}"),
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};
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let projection_ty = match item_name {
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sym::CallOnceFuture | sym::Output => ty::AliasTy::new(
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tcx,
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args.parent_args(),
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tcx.coroutine_for_closure(def_id),
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goal_kind,
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env_region,
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args.tupled_upvars_ty(),
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args.coroutine_captures_by_ref_ty(),
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)
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} else {
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let async_fn_kind_trait_def_id =
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tcx.require_lang_item(LangItem::AsyncFnKindHelper, None);
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let upvars_projection_def_id = tcx
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.associated_items(async_fn_kind_trait_def_id)
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.filter_by_name_unhygienic(sym::Upvars)
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.next()
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.unwrap()
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.def_id;
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// When we don't know the closure kind (and therefore also the closure's upvars,
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// which are computed at the same time), we must delay the computation of the
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// generator's upvars. We do this using the `AsyncFnKindHelper`, which as a trait
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// goal functions similarly to the old `ClosureKind` predicate, and ensures that
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// the goal kind <= the closure kind. As a projection `AsyncFnKindHelper::Upvars`
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// will project to the right upvars for the generator, appending the inputs and
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// coroutine upvars respecting the closure kind.
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// N.B. No need to register a `AsyncFnKindHelper` goal here, it's already in `nested`.
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let tupled_upvars_ty = Ty::new_projection(
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obligation.predicate.def_id,
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[self_ty, sig.tupled_inputs_ty],
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),
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sym::CallMutFuture | sym::CallFuture => ty::AliasTy::new(
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tcx,
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upvars_projection_def_id,
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obligation.predicate.def_id,
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[ty::GenericArg::from(self_ty), sig.tupled_inputs_ty.into(), env_region.into()],
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),
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name => bug!("no such associated type: {name}"),
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};
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args.coroutine_closure_sig()
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.rebind(ty::ProjectionPredicate { projection_ty, term: term.into() })
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}
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ty::FnDef(..) | ty::FnPtr(..) => {
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let bound_sig = self_ty.fn_sig(tcx);
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let sig = bound_sig.skip_binder();
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let term = match item_name {
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sym::CallOnceFuture | sym::CallMutFuture | sym::CallFuture => sig.output(),
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sym::Output => {
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let future_trait_def_id = tcx.require_lang_item(LangItem::Future, None);
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let future_output_def_id = tcx
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.associated_items(future_trait_def_id)
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.filter_by_name_unhygienic(sym::Output)
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.next()
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.unwrap()
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.def_id;
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Ty::new_projection(tcx, future_output_def_id, [sig.output()])
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}
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name => bug!("no such associated type: {name}"),
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};
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let projection_ty = match item_name {
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sym::CallOnceFuture | sym::Output => ty::AliasTy::new(
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tcx,
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obligation.predicate.def_id,
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[self_ty, Ty::new_tup(tcx, sig.inputs())],
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),
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sym::CallMutFuture | sym::CallFuture => ty::AliasTy::new(
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tcx,
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obligation.predicate.def_id,
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[
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ty::GenericArg::from(kind_ty),
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Ty::from_closure_kind(tcx, goal_kind).into(),
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ty::GenericArg::from(self_ty),
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Ty::new_tup(tcx, sig.inputs()).into(),
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env_region.into(),
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sig.tupled_inputs_ty.into(),
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args.tupled_upvars_ty().into(),
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args.coroutine_captures_by_ref_ty().into(),
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],
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);
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sig.to_coroutine(
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),
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name => bug!("no such associated type: {name}"),
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};
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bound_sig.rebind(ty::ProjectionPredicate { projection_ty, term: term.into() })
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}
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ty::Closure(_, args) => {
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let args = args.as_closure();
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let bound_sig = args.sig();
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let sig = bound_sig.skip_binder();
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let term = match item_name {
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sym::CallOnceFuture | sym::CallMutFuture | sym::CallFuture => sig.output(),
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sym::Output => {
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let future_trait_def_id = tcx.require_lang_item(LangItem::Future, None);
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let future_output_def_id = tcx
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.associated_items(future_trait_def_id)
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.filter_by_name_unhygienic(sym::Output)
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.next()
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.unwrap()
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.def_id;
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Ty::new_projection(tcx, future_output_def_id, [sig.output()])
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}
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name => bug!("no such associated type: {name}"),
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};
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let projection_ty = match item_name {
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sym::CallOnceFuture | sym::Output => {
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ty::AliasTy::new(tcx, obligation.predicate.def_id, [self_ty, sig.inputs()[0]])
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}
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sym::CallMutFuture | sym::CallFuture => ty::AliasTy::new(
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tcx,
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args.parent_args(),
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Ty::from_closure_kind(tcx, goal_kind),
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tcx.coroutine_for_closure(def_id),
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tupled_upvars_ty,
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)
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}
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obligation.predicate.def_id,
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[ty::GenericArg::from(self_ty), sig.inputs()[0].into(), env_region.into()],
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),
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name => bug!("no such associated type: {name}"),
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};
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bound_sig.rebind(ty::ProjectionPredicate { projection_ty, term: term.into() })
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}
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sym::Output => sig.return_ty,
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name => bug!("no such associated type: {name}"),
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};
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let projection_ty = match item_name {
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sym::CallOnceFuture | sym::Output => {
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ty::AliasTy::new(tcx, obligation.predicate.def_id, [self_ty, sig.tupled_inputs_ty])
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}
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sym::CallMutFuture | sym::CallFuture => ty::AliasTy::new(
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tcx,
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obligation.predicate.def_id,
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[ty::GenericArg::from(self_ty), sig.tupled_inputs_ty.into(), env_region.into()],
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),
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name => bug!("no such associated type: {name}"),
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_ => bug!("expected callable type for AsyncFn candidate"),
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};
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confirm_param_env_candidate(
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selcx,
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obligation,
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args.coroutine_closure_sig()
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.rebind(ty::ProjectionPredicate { projection_ty, term: term.into() }),
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true,
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)
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.with_addl_obligations(nested)
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confirm_param_env_candidate(selcx, obligation, poly_cache_entry, true)
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.with_addl_obligations(nested)
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}
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fn confirm_async_fn_kind_helper_candidate<'cx, 'tcx>(
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|
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@ -361,8 +361,18 @@ fn assemble_async_closure_candidates(
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}
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candidates.vec.push(AsyncClosureCandidate);
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}
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ty::Infer(ty::TyVar(_)) => {
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candidates.ambiguous = true;
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// Closures and fn pointers implement `AsyncFn*` if their return types
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// implement `Future`, which is checked later.
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ty::Closure(_, args) => {
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if let Some(closure_kind) = args.as_closure().kind_ty().to_opt_closure_kind()
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&& !closure_kind.extends(goal_kind)
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{
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return;
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}
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candidates.vec.push(AsyncClosureCandidate);
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}
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ty::FnDef(..) | ty::FnPtr(..) => {
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candidates.vec.push(AsyncClosureCandidate);
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}
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_ => {}
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}
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|
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@ -883,40 +883,86 @@ fn confirm_async_closure_candidate(
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&mut self,
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obligation: &PolyTraitObligation<'tcx>,
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) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
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// Okay to skip binder because the args on closure types never
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// touch bound regions, they just capture the in-scope
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// type/region parameters.
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let tcx = self.tcx();
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let self_ty = self.infcx.shallow_resolve(obligation.self_ty().skip_binder());
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let ty::CoroutineClosure(closure_def_id, args) = *self_ty.kind() else {
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bug!("async closure candidate for non-coroutine-closure {:?}", obligation);
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let mut nested = vec![];
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let (trait_ref, kind_ty) = match *self_ty.kind() {
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ty::CoroutineClosure(_, args) => {
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let args = args.as_coroutine_closure();
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let trait_ref = args.coroutine_closure_sig().map_bound(|sig| {
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ty::TraitRef::new(
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self.tcx(),
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obligation.predicate.def_id(),
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[self_ty, sig.tupled_inputs_ty],
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)
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});
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(trait_ref, args.kind_ty())
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}
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ty::FnDef(..) | ty::FnPtr(..) => {
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let sig = self_ty.fn_sig(tcx);
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let trait_ref = sig.map_bound(|sig| {
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ty::TraitRef::new(
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self.tcx(),
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obligation.predicate.def_id(),
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[self_ty, Ty::new_tup(tcx, sig.inputs())],
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)
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});
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// We must additionally check that the return type impls `Future`.
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let future_trait_def_id = tcx.require_lang_item(LangItem::Future, None);
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nested.push(obligation.with(
|
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tcx,
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sig.map_bound(|sig| {
|
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ty::TraitRef::new(tcx, future_trait_def_id, [sig.output()])
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}),
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));
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(trait_ref, Ty::from_closure_kind(tcx, ty::ClosureKind::Fn))
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}
|
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ty::Closure(_, args) => {
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let sig = args.as_closure().sig();
|
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let trait_ref = sig.map_bound(|sig| {
|
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ty::TraitRef::new(
|
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self.tcx(),
|
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obligation.predicate.def_id(),
|
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[self_ty, sig.inputs()[0]],
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)
|
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});
|
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// We must additionally check that the return type impls `Future`.
|
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let future_trait_def_id = tcx.require_lang_item(LangItem::Future, None);
|
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nested.push(obligation.with(
|
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tcx,
|
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sig.map_bound(|sig| {
|
||||
ty::TraitRef::new(tcx, future_trait_def_id, [sig.output()])
|
||||
}),
|
||||
));
|
||||
(trait_ref, Ty::from_closure_kind(tcx, ty::ClosureKind::Fn))
|
||||
}
|
||||
_ => bug!("expected callable type for AsyncFn candidate"),
|
||||
};
|
||||
|
||||
let trait_ref = args.as_coroutine_closure().coroutine_closure_sig().map_bound(|sig| {
|
||||
ty::TraitRef::new(
|
||||
self.tcx(),
|
||||
obligation.predicate.def_id(),
|
||||
[self_ty, sig.tupled_inputs_ty],
|
||||
)
|
||||
});
|
||||
|
||||
let mut nested = self.confirm_poly_trait_refs(obligation, trait_ref)?;
|
||||
nested.extend(self.confirm_poly_trait_refs(obligation, trait_ref)?);
|
||||
|
||||
let goal_kind =
|
||||
self.tcx().async_fn_trait_kind_from_def_id(obligation.predicate.def_id()).unwrap();
|
||||
nested.push(obligation.with(
|
||||
self.tcx(),
|
||||
ty::TraitRef::from_lang_item(
|
||||
self.tcx(),
|
||||
LangItem::AsyncFnKindHelper,
|
||||
obligation.cause.span,
|
||||
[
|
||||
args.as_coroutine_closure().kind_ty(),
|
||||
Ty::from_closure_kind(self.tcx(), goal_kind),
|
||||
],
|
||||
),
|
||||
));
|
||||
|
||||
debug!(?closure_def_id, ?trait_ref, ?nested, "confirm closure candidate obligations");
|
||||
// If we have not yet determiend the `ClosureKind` of the closure or coroutine-closure,
|
||||
// then additionally register an `AsyncFnKindHelper` goal which will fail if the kind
|
||||
// is constrained to an insufficient type later on.
|
||||
if let Some(closure_kind) = self.infcx.shallow_resolve(kind_ty).to_opt_closure_kind() {
|
||||
if !closure_kind.extends(goal_kind) {
|
||||
return Err(SelectionError::Unimplemented);
|
||||
}
|
||||
} else {
|
||||
nested.push(obligation.with(
|
||||
self.tcx(),
|
||||
ty::TraitRef::from_lang_item(
|
||||
self.tcx(),
|
||||
LangItem::AsyncFnKindHelper,
|
||||
obligation.cause.span,
|
||||
[kind_ty, Ty::from_closure_kind(self.tcx(), goal_kind)],
|
||||
),
|
||||
));
|
||||
}
|
||||
|
||||
Ok(nested)
|
||||
}
|
||||
|
|
|
|||
|
|
@ -306,6 +306,19 @@ fn resolve_associated_item<'tcx>(
|
|||
Some(Instance::new(coroutine_closure_def_id, args))
|
||||
}
|
||||
}
|
||||
ty::Closure(closure_def_id, args) => {
|
||||
let trait_closure_kind = tcx.fn_trait_kind_from_def_id(trait_id).unwrap();
|
||||
Some(Instance::resolve_closure(
|
||||
tcx,
|
||||
closure_def_id,
|
||||
args,
|
||||
trait_closure_kind,
|
||||
))
|
||||
}
|
||||
ty::FnDef(..) | ty::FnPtr(..) => Some(Instance {
|
||||
def: ty::InstanceDef::FnPtrShim(trait_item_id, rcvr_args.type_at(0)),
|
||||
args: rcvr_args,
|
||||
}),
|
||||
_ => bug!(
|
||||
"no built-in definition for `{trait_ref}::{}` for non-lending-closure type",
|
||||
tcx.item_name(trait_item_id)
|
||||
|
|
|
|||
|
|
@ -1,5 +1,5 @@
|
|||
// edition: 2021
|
||||
// check-pass
|
||||
// build-pass
|
||||
|
||||
#![feature(async_fn_traits)]
|
||||
|
||||
|
|
|
|||
|
|
@ -191,14 +191,7 @@ error[E0223]: ambiguous associated type
|
|||
--> $DIR/bad-assoc-ty.rs:33:10
|
||||
|
|
||||
LL | type H = Fn(u8) -> (u8)::Output;
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^
|
||||
|
|
||||
help: use fully-qualified syntax
|
||||
|
|
||||
LL | type H = <(dyn Fn(u8) -> u8 + 'static) as AsyncFnOnce>::Output;
|
||||
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
LL | type H = <(dyn Fn(u8) -> u8 + 'static) as IntoFuture>::Output;
|
||||
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^ help: use fully-qualified syntax: `<(dyn Fn(u8) -> u8 + 'static) as IntoFuture>::Output`
|
||||
|
||||
error[E0223]: ambiguous associated type
|
||||
--> $DIR/bad-assoc-ty.rs:39:19
|
||||
|
|
|
|||
Loading…
Reference in a new issue