diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/project.rs')
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/project.rs | 327 |
1 files changed, 219 insertions, 108 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index 95f833372fb..054402acb5c 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -2087,7 +2087,9 @@ fn confirm_select_candidate<'cx, 'tcx>( } else if lang_items.async_iterator_trait() == Some(trait_def_id) { confirm_async_iterator_candidate(selcx, obligation, data) } else if selcx.tcx().fn_trait_kind_from_def_id(trait_def_id).is_some() { - if obligation.predicate.self_ty().is_closure() { + if obligation.predicate.self_ty().is_closure() + || obligation.predicate.self_ty().is_coroutine_closure() + { confirm_closure_candidate(selcx, obligation, data) } else { confirm_fn_pointer_candidate(selcx, obligation, data) @@ -2410,11 +2412,75 @@ fn confirm_closure_candidate<'cx, 'tcx>( obligation: &ProjectionTyObligation<'tcx>, nested: Vec<PredicateObligation<'tcx>>, ) -> Progress<'tcx> { + let tcx = selcx.tcx(); let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()); - let ty::Closure(_, args) = self_ty.kind() else { - unreachable!("expected closure self type for closure candidate, found {self_ty}") + let closure_sig = match *self_ty.kind() { + ty::Closure(_, args) => args.as_closure().sig(), + + // Construct a "normal" `FnOnce` signature for coroutine-closure. This is + // basically duplicated with the `AsyncFnOnce::CallOnce` confirmation, but + // I didn't see a good way to unify those. + ty::CoroutineClosure(def_id, args) => { + let args = args.as_coroutine_closure(); + let kind_ty = args.kind_ty(); + args.coroutine_closure_sig().map_bound(|sig| { + // If we know the kind and upvars, use that directly. + // Otherwise, defer to `AsyncFnKindHelper::Upvars` to delay + // the projection, like the `AsyncFn*` traits do. + let output_ty = if let Some(_) = kind_ty.to_opt_closure_kind() { + sig.to_coroutine_given_kind_and_upvars( + tcx, + args.parent_args(), + tcx.coroutine_for_closure(def_id), + ty::ClosureKind::FnOnce, + tcx.lifetimes.re_static, + args.tupled_upvars_ty(), + args.coroutine_captures_by_ref_ty(), + ) + } else { + let async_fn_kind_trait_def_id = + tcx.require_lang_item(LangItem::AsyncFnKindHelper, None); + let upvars_projection_def_id = tcx + .associated_items(async_fn_kind_trait_def_id) + .filter_by_name_unhygienic(sym::Upvars) + .next() + .unwrap() + .def_id; + let tupled_upvars_ty = Ty::new_projection( + tcx, + upvars_projection_def_id, + [ + ty::GenericArg::from(kind_ty), + Ty::from_closure_kind(tcx, ty::ClosureKind::FnOnce).into(), + tcx.lifetimes.re_static.into(), + sig.tupled_inputs_ty.into(), + args.tupled_upvars_ty().into(), + args.coroutine_captures_by_ref_ty().into(), + ], + ); + sig.to_coroutine( + tcx, + args.parent_args(), + Ty::from_closure_kind(tcx, ty::ClosureKind::FnOnce), + tcx.coroutine_for_closure(def_id), + tupled_upvars_ty, + ) + }; + tcx.mk_fn_sig( + [sig.tupled_inputs_ty], + output_ty, + sig.c_variadic, + sig.unsafety, + sig.abi, + ) + }) + } + + _ => { + unreachable!("expected closure self type for closure candidate, found {self_ty}"); + } }; - let closure_sig = args.as_closure().sig(); + let Normalized { value: closure_sig, obligations } = normalize_with_depth( selcx, obligation.param_env, @@ -2470,126 +2536,171 @@ fn confirm_callable_candidate<'cx, 'tcx>( fn confirm_async_closure_candidate<'cx, 'tcx>( selcx: &mut SelectionContext<'cx, 'tcx>, obligation: &ProjectionTyObligation<'tcx>, - mut nested: Vec<PredicateObligation<'tcx>>, + nested: Vec<PredicateObligation<'tcx>>, ) -> Progress<'tcx> { + let tcx = selcx.tcx(); let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()); - let ty::CoroutineClosure(def_id, args) = *self_ty.kind() else { - unreachable!( - "expected coroutine-closure self type for coroutine-closure candidate, found {self_ty}" - ) - }; - let args = args.as_coroutine_closure(); - let kind_ty = args.kind_ty(); - let tcx = selcx.tcx(); let goal_kind = tcx.async_fn_trait_kind_from_def_id(obligation.predicate.trait_def_id(tcx)).unwrap(); - - let async_fn_kind_helper_trait_def_id = - tcx.require_lang_item(LangItem::AsyncFnKindHelper, None); - nested.push(obligation.with( - tcx, - ty::TraitRef::new( - tcx, - async_fn_kind_helper_trait_def_id, - [kind_ty, Ty::from_closure_kind(tcx, goal_kind)], - ), - )); - let env_region = match goal_kind { ty::ClosureKind::Fn | ty::ClosureKind::FnMut => obligation.predicate.args.region_at(2), ty::ClosureKind::FnOnce => tcx.lifetimes.re_static, }; - - let upvars_projection_def_id = tcx - .associated_items(async_fn_kind_helper_trait_def_id) - .filter_by_name_unhygienic(sym::Upvars) - .next() - .unwrap() - .def_id; - - // FIXME(async_closures): Confirmation is kind of a mess here. Ideally, - // we'd short-circuit when we know that the goal_kind >= closure_kind, and not - // register a nested predicate or create a new projection ty here. But I'm too - // lazy to make this more efficient atm, and we can always tweak it later, - // since all this does is make the solver do more work. - // - // The code duplication due to the different length args is kind of weird, too. - // - // See the logic in `structural_traits` in the new solver to understand a bit - // more clearly how this *should* look. - let poly_cache_entry = args.coroutine_closure_sig().map_bound(|sig| { - let (projection_ty, term) = match tcx.item_name(obligation.predicate.def_id) { - sym::CallOnceFuture => { - let tupled_upvars_ty = Ty::new_projection( + let item_name = tcx.item_name(obligation.predicate.def_id); + + let poly_cache_entry = match *self_ty.kind() { + ty::CoroutineClosure(def_id, args) => { + let args = args.as_coroutine_closure(); + let kind_ty = args.kind_ty(); + let sig = args.coroutine_closure_sig().skip_binder(); + + let term = match item_name { + sym::CallOnceFuture | sym::CallMutFuture | sym::CallFuture => { + if let Some(closure_kind) = kind_ty.to_opt_closure_kind() { + if !closure_kind.extends(goal_kind) { + bug!("we should not be confirming if the closure kind is not met"); + } + sig.to_coroutine_given_kind_and_upvars( + tcx, + args.parent_args(), + tcx.coroutine_for_closure(def_id), + goal_kind, + env_region, + args.tupled_upvars_ty(), + args.coroutine_captures_by_ref_ty(), + ) + } else { + let async_fn_kind_trait_def_id = + tcx.require_lang_item(LangItem::AsyncFnKindHelper, None); + let upvars_projection_def_id = tcx + .associated_items(async_fn_kind_trait_def_id) + .filter_by_name_unhygienic(sym::Upvars) + .next() + .unwrap() + .def_id; + // When we don't know the closure kind (and therefore also the closure's upvars, + // which are computed at the same time), we must delay the computation of the + // generator's upvars. We do this using the `AsyncFnKindHelper`, which as a trait + // goal functions similarly to the old `ClosureKind` predicate, and ensures that + // the goal kind <= the closure kind. As a projection `AsyncFnKindHelper::Upvars` + // will project to the right upvars for the generator, appending the inputs and + // coroutine upvars respecting the closure kind. + // N.B. No need to register a `AsyncFnKindHelper` goal here, it's already in `nested`. + let tupled_upvars_ty = Ty::new_projection( + tcx, + upvars_projection_def_id, + [ + ty::GenericArg::from(kind_ty), + Ty::from_closure_kind(tcx, goal_kind).into(), + env_region.into(), + sig.tupled_inputs_ty.into(), + args.tupled_upvars_ty().into(), + args.coroutine_captures_by_ref_ty().into(), + ], + ); + sig.to_coroutine( + tcx, + args.parent_args(), + Ty::from_closure_kind(tcx, goal_kind), + tcx.coroutine_for_closure(def_id), + tupled_upvars_ty, + ) + } + } + sym::Output => sig.return_ty, + name => bug!("no such associated type: {name}"), + }; + let projection_ty = match item_name { + sym::CallOnceFuture | sym::Output => ty::AliasTy::new( tcx, - upvars_projection_def_id, - [ - ty::GenericArg::from(kind_ty), - Ty::from_closure_kind(tcx, goal_kind).into(), - env_region.into(), - sig.tupled_inputs_ty.into(), - args.tupled_upvars_ty().into(), - args.coroutine_captures_by_ref_ty().into(), - ], - ); - let coroutine_ty = sig.to_coroutine( + obligation.predicate.def_id, + [self_ty, sig.tupled_inputs_ty], + ), + sym::CallMutFuture | sym::CallFuture => ty::AliasTy::new( tcx, - args.parent_args(), - Ty::from_closure_kind(tcx, goal_kind), - tcx.coroutine_for_closure(def_id), - tupled_upvars_ty, - ); - ( - ty::AliasTy::new( - tcx, - obligation.predicate.def_id, - [self_ty, sig.tupled_inputs_ty], - ), - coroutine_ty.into(), - ) - } - sym::CallMutFuture | sym::CallFuture => { - let tupled_upvars_ty = Ty::new_projection( + obligation.predicate.def_id, + [ty::GenericArg::from(self_ty), sig.tupled_inputs_ty.into(), env_region.into()], + ), + name => bug!("no such associated type: {name}"), + }; + + args.coroutine_closure_sig() + .rebind(ty::ProjectionPredicate { projection_ty, term: term.into() }) + } + ty::FnDef(..) | ty::FnPtr(..) => { + let bound_sig = self_ty.fn_sig(tcx); + let sig = bound_sig.skip_binder(); + + let term = match item_name { + sym::CallOnceFuture | sym::CallMutFuture | sym::CallFuture => sig.output(), + sym::Output => { + let future_trait_def_id = tcx.require_lang_item(LangItem::Future, None); + let future_output_def_id = tcx + .associated_items(future_trait_def_id) + .filter_by_name_unhygienic(sym::Output) + .next() + .unwrap() + .def_id; + Ty::new_projection(tcx, future_output_def_id, [sig.output()]) + } + name => bug!("no such associated type: {name}"), + }; + let projection_ty = match item_name { + sym::CallOnceFuture | sym::Output => ty::AliasTy::new( + tcx, + obligation.predicate.def_id, + [self_ty, Ty::new_tup(tcx, sig.inputs())], + ), + sym::CallMutFuture | sym::CallFuture => ty::AliasTy::new( tcx, - upvars_projection_def_id, + obligation.predicate.def_id, [ - ty::GenericArg::from(kind_ty), - Ty::from_closure_kind(tcx, goal_kind).into(), + ty::GenericArg::from(self_ty), + Ty::new_tup(tcx, sig.inputs()).into(), env_region.into(), - sig.tupled_inputs_ty.into(), - args.tupled_upvars_ty().into(), - args.coroutine_captures_by_ref_ty().into(), ], - ); - let coroutine_ty = sig.to_coroutine( + ), + name => bug!("no such associated type: {name}"), + }; + + bound_sig.rebind(ty::ProjectionPredicate { projection_ty, term: term.into() }) + } + ty::Closure(_, args) => { + let args = args.as_closure(); + let bound_sig = args.sig(); + let sig = bound_sig.skip_binder(); + + let term = match item_name { + sym::CallOnceFuture | sym::CallMutFuture | sym::CallFuture => sig.output(), + sym::Output => { + let future_trait_def_id = tcx.require_lang_item(LangItem::Future, None); + let future_output_def_id = tcx + .associated_items(future_trait_def_id) + .filter_by_name_unhygienic(sym::Output) + .next() + .unwrap() + .def_id; + Ty::new_projection(tcx, future_output_def_id, [sig.output()]) + } + name => bug!("no such associated type: {name}"), + }; + let projection_ty = match item_name { + sym::CallOnceFuture | sym::Output => { + ty::AliasTy::new(tcx, obligation.predicate.def_id, [self_ty, sig.inputs()[0]]) + } + sym::CallMutFuture | sym::CallFuture => ty::AliasTy::new( tcx, - args.parent_args(), - Ty::from_closure_kind(tcx, goal_kind), - tcx.coroutine_for_closure(def_id), - tupled_upvars_ty, - ); - ( - ty::AliasTy::new( - tcx, - obligation.predicate.def_id, - [ - ty::GenericArg::from(self_ty), - sig.tupled_inputs_ty.into(), - env_region.into(), - ], - ), - coroutine_ty.into(), - ) - } - sym::Output => ( - ty::AliasTy::new(tcx, obligation.predicate.def_id, [self_ty, sig.tupled_inputs_ty]), - sig.return_ty.into(), - ), - name => bug!("no such associated type: {name}"), - }; - ty::ProjectionPredicate { projection_ty, term } - }); + obligation.predicate.def_id, + [ty::GenericArg::from(self_ty), sig.inputs()[0].into(), env_region.into()], + ), + name => bug!("no such associated type: {name}"), + }; + + bound_sig.rebind(ty::ProjectionPredicate { projection_ty, term: term.into() }) + } + _ => bug!("expected callable type for AsyncFn candidate"), + }; confirm_param_env_candidate(selcx, obligation, poly_cache_entry, true) .with_addl_obligations(nested) |