diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/project.rs')
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/project.rs | 281 |
1 files changed, 197 insertions, 84 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index 471d10dbd..a1b0ada0e 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -18,7 +18,7 @@ use rustc_middle::traits::ImplSourceUserDefinedData; use crate::errors::InherentProjectionNormalizationOverflow; use crate::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; -use crate::infer::{InferCtxt, InferOk, LateBoundRegionConversionTime}; +use crate::infer::{BoundRegionConversionTime, InferCtxt, InferOk}; use crate::traits::error_reporting::TypeErrCtxtExt as _; use crate::traits::query::evaluate_obligation::InferCtxtExt as _; use crate::traits::select::ProjectionMatchesProjection; @@ -67,7 +67,7 @@ pub trait NormalizeExt<'tcx> { /// same goals in both a temporary and the shared context which negatively impacts /// performance as these don't share caching. /// - /// FIXME(-Ztrait-solver=next): This has the same behavior as `traits::fully_normalize` + /// FIXME(-Znext-solver): This has the same behavior as `traits::fully_normalize` /// in the new solver, but because of performance reasons, we currently reuse an /// existing fulfillment context in the old solver. Once we also eagerly prove goals with /// the old solver or have removed the old solver, remove `traits::fully_normalize` and @@ -191,7 +191,9 @@ impl<'tcx> ProjectionCandidateSet<'tcx> { match (current, candidate) { (ParamEnv(..), ParamEnv(..)) => convert_to_ambiguous = (), (ParamEnv(..), _) => return false, - (_, ParamEnv(..)) => unreachable!(), + (_, ParamEnv(..)) => bug!( + "should never prefer non-param-env candidates over param-env candidates" + ), (_, _) => convert_to_ambiguous = (), } } @@ -584,7 +586,7 @@ impl<'a, 'b, 'tcx> TypeFolder<TyCtxt<'tcx>> for AssocTypeNormalizer<'a, 'b, 'tcx data, self.cause.clone(), self.depth, - &mut self.obligations, + self.obligations, ) } else { opt_normalize_projection_type( @@ -593,7 +595,7 @@ impl<'a, 'b, 'tcx> TypeFolder<TyCtxt<'tcx>> for AssocTypeNormalizer<'a, 'b, 'tcx data, self.cause.clone(), self.depth, - &mut self.obligations, + self.obligations, ) .ok() .flatten() @@ -632,7 +634,7 @@ impl<'a, 'b, 'tcx> TypeFolder<TyCtxt<'tcx>> for AssocTypeNormalizer<'a, 'b, 'tcx data, self.cause.clone(), self.depth, - &mut self.obligations, + self.obligations, ) .ok() .flatten() @@ -717,7 +719,7 @@ impl<'a, 'b, 'tcx> TypeFolder<TyCtxt<'tcx>> for AssocTypeNormalizer<'a, 'b, 'tcx data, self.cause.clone(), self.depth, - &mut self.obligations, + self.obligations, ) } @@ -732,7 +734,7 @@ impl<'a, 'b, 'tcx> TypeFolder<TyCtxt<'tcx>> for AssocTypeNormalizer<'a, 'b, 'tcx data, self.cause.clone(), self.depth, - &mut self.obligations, + self.obligations, ); PlaceholderReplacer::replace_placeholders( @@ -894,16 +896,16 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for BoundVarReplacer<'_, 'tcx> { fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> { match *r { - ty::ReLateBound(debruijn, _) - if debruijn.as_usize() + 1 - > self.current_index.as_usize() + self.universe_indices.len() => + ty::ReBound(debruijn, _) + if debruijn.as_usize() + >= self.current_index.as_usize() + self.universe_indices.len() => { bug!( "Bound vars {r:#?} outside of `self.universe_indices`: {:#?}", self.universe_indices ); } - ty::ReLateBound(debruijn, br) if debruijn >= self.current_index => { + ty::ReBound(debruijn, br) if debruijn >= self.current_index => { let universe = self.universe_for(debruijn); let p = ty::PlaceholderRegion { universe, bound: br }; self.mapped_regions.insert(p, br); @@ -1001,7 +1003,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for PlaceholderReplacer<'_, 'tcx> { &mut self, t: ty::Binder<'tcx, T>, ) -> ty::Binder<'tcx, T> { - if !t.has_placeholders() && !t.has_infer_regions() { + if !t.has_placeholders() && !t.has_infer() { return t; } self.current_index.shift_in(1); @@ -1034,7 +1036,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for PlaceholderReplacer<'_, 'tcx> { let db = ty::DebruijnIndex::from_usize( self.universe_indices.len() - index + self.current_index.as_usize() - 1, ); - ty::Region::new_late_bound(self.interner(), db, *replace_var) + ty::Region::new_bound(self.interner(), db, *replace_var) } None => r1, } @@ -1048,6 +1050,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for PlaceholderReplacer<'_, 'tcx> { } fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> { + let ty = self.infcx.shallow_resolve(ty); match *ty.kind() { ty::Placeholder(p) => { let replace_var = self.mapped_types.get(&p); @@ -1063,16 +1066,23 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for PlaceholderReplacer<'_, 'tcx> { ); Ty::new_bound(self.infcx.tcx, db, *replace_var) } - None => ty, + None => { + if ty.has_infer() { + ty.super_fold_with(self) + } else { + ty + } + } } } - _ if ty.has_placeholders() || ty.has_infer_regions() => ty.super_fold_with(self), + _ if ty.has_placeholders() || ty.has_infer() => ty.super_fold_with(self), _ => ty, } } fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> { + let ct = self.infcx.shallow_resolve(ct); if let ty::ConstKind::Placeholder(p) = ct.kind() { let replace_var = self.mapped_consts.get(&p); match replace_var { @@ -1087,7 +1097,13 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for PlaceholderReplacer<'_, 'tcx> { ); ty::Const::new_bound(self.infcx.tcx, db, *replace_var, ct.ty()) } - None => ct, + None => { + if ct.has_infer() { + ct.super_fold_with(self) + } else { + ct + } + } } } else { ct.super_fold_with(self) @@ -1440,11 +1456,22 @@ pub fn compute_inherent_assoc_ty_args<'a, 'b, 'tcx>( // Infer the generic parameters of the impl by unifying the // impl type with the self type of the projection. - let self_ty = alias_ty.self_ty(); + let mut self_ty = alias_ty.self_ty(); + if !selcx.infcx.next_trait_solver() { + self_ty = normalize_with_depth_to( + selcx, + param_env, + cause.clone(), + depth + 1, + self_ty, + obligations, + ); + } + match selcx.infcx.at(&cause, param_env).eq(DefineOpaqueTypes::No, impl_ty, self_ty) { Ok(mut ok) => obligations.append(&mut ok.obligations), Err(_) => { - tcx.sess.delay_span_bug( + tcx.sess.span_delayed_bug( cause.span, format!( "{self_ty:?} was a subtype of {impl_ty:?} during selection but now it is not" @@ -1798,11 +1825,18 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()); let lang_items = selcx.tcx().lang_items(); - if [lang_items.coroutine_trait(), lang_items.future_trait(), lang_items.iterator_trait()].contains(&Some(trait_ref.def_id)) - || selcx.tcx().fn_trait_kind_from_def_id(trait_ref.def_id).is_some() + if [ + lang_items.coroutine_trait(), + lang_items.future_trait(), + lang_items.iterator_trait(), + lang_items.async_iterator_trait(), + lang_items.fn_trait(), + lang_items.fn_mut_trait(), + lang_items.fn_once_trait(), + ].contains(&Some(trait_ref.def_id)) { true - } else if lang_items.discriminant_kind_trait() == Some(trait_ref.def_id) { + }else if lang_items.discriminant_kind_trait() == Some(trait_ref.def_id) { match self_ty.kind() { ty::Bool | ty::Char @@ -1949,7 +1983,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( ImplSource::Builtin(BuiltinImplSource::TraitUpcasting { .. }, _) | ImplSource::Builtin(BuiltinImplSource::TupleUnsizing, _) => { // These traits have no associated types. - selcx.tcx().sess.delay_span_bug( + selcx.tcx().sess.span_delayed_bug( obligation.cause.span, format!("Cannot project an associated type from `{impl_source:?}`"), ); @@ -2017,6 +2051,8 @@ fn confirm_select_candidate<'cx, 'tcx>( confirm_future_candidate(selcx, obligation, data) } else if lang_items.iterator_trait() == Some(trait_def_id) { confirm_iterator_candidate(selcx, obligation, data) + } 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() { confirm_closure_candidate(selcx, obligation, data) @@ -2046,12 +2082,13 @@ fn confirm_coroutine_candidate<'cx, 'tcx>( obligation: &ProjectionTyObligation<'tcx>, nested: Vec<PredicateObligation<'tcx>>, ) -> Progress<'tcx> { - let ty::Coroutine(_, args, _) = - selcx.infcx.shallow_resolve(obligation.predicate.self_ty()).kind() - else { - unreachable!() + let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()); + let ty::Coroutine(_, args, _) = self_ty.kind() else { + unreachable!( + "expected coroutine self type for built-in coroutine candidate, found {self_ty}" + ) }; - let coroutine_sig = args.as_coroutine().poly_sig(); + let coroutine_sig = args.as_coroutine().sig(); let Normalized { value: coroutine_sig, obligations } = normalize_with_depth( selcx, obligation.param_env, @@ -2066,29 +2103,31 @@ fn confirm_coroutine_candidate<'cx, 'tcx>( let coroutine_def_id = tcx.require_lang_item(LangItem::Coroutine, None); - let predicate = super::util::coroutine_trait_ref_and_outputs( + let (trait_ref, yield_ty, return_ty) = super::util::coroutine_trait_ref_and_outputs( tcx, coroutine_def_id, obligation.predicate.self_ty(), coroutine_sig, - ) - .map_bound(|(trait_ref, yield_ty, return_ty)| { - let name = tcx.associated_item(obligation.predicate.def_id).name; - let ty = if name == sym::Return { - return_ty - } else if name == sym::Yield { - yield_ty - } else { - bug!() - }; + ); - ty::ProjectionPredicate { - projection_ty: ty::AliasTy::new(tcx, obligation.predicate.def_id, trait_ref.args), - term: ty.into(), - } - }); + let name = tcx.associated_item(obligation.predicate.def_id).name; + let ty = if name == sym::Return { + return_ty + } else if name == sym::Yield { + yield_ty + } else { + span_bug!( + tcx.def_span(obligation.predicate.def_id), + "unexpected associated type: `Coroutine::{name}`" + ); + }; - confirm_param_env_candidate(selcx, obligation, predicate, false) + let predicate = ty::ProjectionPredicate { + projection_ty: ty::AliasTy::new(tcx, obligation.predicate.def_id, trait_ref.args), + term: ty.into(), + }; + + confirm_param_env_candidate(selcx, obligation, ty::Binder::dummy(predicate), false) .with_addl_obligations(nested) .with_addl_obligations(obligations) } @@ -2098,12 +2137,13 @@ fn confirm_future_candidate<'cx, 'tcx>( obligation: &ProjectionTyObligation<'tcx>, nested: Vec<PredicateObligation<'tcx>>, ) -> Progress<'tcx> { - let ty::Coroutine(_, args, _) = - selcx.infcx.shallow_resolve(obligation.predicate.self_ty()).kind() - else { - unreachable!() + let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()); + let ty::Coroutine(_, args, _) = self_ty.kind() else { + unreachable!( + "expected coroutine self type for built-in async future candidate, found {self_ty}" + ) }; - let coroutine_sig = args.as_coroutine().poly_sig(); + let coroutine_sig = args.as_coroutine().sig(); let Normalized { value: coroutine_sig, obligations } = normalize_with_depth( selcx, obligation.param_env, @@ -2117,22 +2157,21 @@ fn confirm_future_candidate<'cx, 'tcx>( let tcx = selcx.tcx(); let fut_def_id = tcx.require_lang_item(LangItem::Future, None); - let predicate = super::util::future_trait_ref_and_outputs( + let (trait_ref, return_ty) = super::util::future_trait_ref_and_outputs( tcx, fut_def_id, obligation.predicate.self_ty(), coroutine_sig, - ) - .map_bound(|(trait_ref, return_ty)| { - debug_assert_eq!(tcx.associated_item(obligation.predicate.def_id).name, sym::Output); + ); - ty::ProjectionPredicate { - projection_ty: ty::AliasTy::new(tcx, obligation.predicate.def_id, trait_ref.args), - term: return_ty.into(), - } - }); + debug_assert_eq!(tcx.associated_item(obligation.predicate.def_id).name, sym::Output); + + let predicate = ty::ProjectionPredicate { + projection_ty: ty::AliasTy::new(tcx, obligation.predicate.def_id, trait_ref.args), + term: return_ty.into(), + }; - confirm_param_env_candidate(selcx, obligation, predicate, false) + confirm_param_env_candidate(selcx, obligation, ty::Binder::dummy(predicate), false) .with_addl_obligations(nested) .with_addl_obligations(obligations) } @@ -2142,12 +2181,54 @@ fn confirm_iterator_candidate<'cx, 'tcx>( obligation: &ProjectionTyObligation<'tcx>, nested: Vec<PredicateObligation<'tcx>>, ) -> Progress<'tcx> { + let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()); + let ty::Coroutine(_, args, _) = self_ty.kind() else { + unreachable!("expected coroutine self type for built-in gen candidate, found {self_ty}") + }; + let gen_sig = args.as_coroutine().sig(); + let Normalized { value: gen_sig, obligations } = normalize_with_depth( + selcx, + obligation.param_env, + obligation.cause.clone(), + obligation.recursion_depth + 1, + gen_sig, + ); + + debug!(?obligation, ?gen_sig, ?obligations, "confirm_iterator_candidate"); + + let tcx = selcx.tcx(); + let iter_def_id = tcx.require_lang_item(LangItem::Iterator, None); + + let (trait_ref, yield_ty) = super::util::iterator_trait_ref_and_outputs( + tcx, + iter_def_id, + obligation.predicate.self_ty(), + gen_sig, + ); + + debug_assert_eq!(tcx.associated_item(obligation.predicate.def_id).name, sym::Item); + + let predicate = ty::ProjectionPredicate { + projection_ty: ty::AliasTy::new(tcx, obligation.predicate.def_id, trait_ref.args), + term: yield_ty.into(), + }; + + confirm_param_env_candidate(selcx, obligation, ty::Binder::dummy(predicate), false) + .with_addl_obligations(nested) + .with_addl_obligations(obligations) +} + +fn confirm_async_iterator_candidate<'cx, 'tcx>( + selcx: &mut SelectionContext<'cx, 'tcx>, + obligation: &ProjectionTyObligation<'tcx>, + nested: Vec<PredicateObligation<'tcx>>, +) -> Progress<'tcx> { let ty::Coroutine(_, args, _) = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()).kind() else { unreachable!() }; - let gen_sig = args.as_coroutine().poly_sig(); + let gen_sig = args.as_coroutine().sig(); let Normalized { value: gen_sig, obligations } = normalize_with_depth( selcx, obligation.param_env, @@ -2156,27 +2237,34 @@ fn confirm_iterator_candidate<'cx, 'tcx>( gen_sig, ); - debug!(?obligation, ?gen_sig, ?obligations, "confirm_iterator_candidate"); + debug!(?obligation, ?gen_sig, ?obligations, "confirm_async_iterator_candidate"); let tcx = selcx.tcx(); - let iter_def_id = tcx.require_lang_item(LangItem::Iterator, None); + let iter_def_id = tcx.require_lang_item(LangItem::AsyncIterator, None); - let predicate = super::util::iterator_trait_ref_and_outputs( + let (trait_ref, yield_ty) = super::util::async_iterator_trait_ref_and_outputs( tcx, iter_def_id, obligation.predicate.self_ty(), gen_sig, - ) - .map_bound(|(trait_ref, yield_ty)| { - debug_assert_eq!(tcx.associated_item(obligation.predicate.def_id).name, sym::Item); + ); - ty::ProjectionPredicate { - projection_ty: ty::AliasTy::new(tcx, obligation.predicate.def_id, trait_ref.args), - term: yield_ty.into(), - } - }); + debug_assert_eq!(tcx.associated_item(obligation.predicate.def_id).name, sym::Item); - confirm_param_env_candidate(selcx, obligation, predicate, false) + let ty::Adt(_poll_adt, args) = *yield_ty.kind() else { + bug!(); + }; + let ty::Adt(_option_adt, args) = *args.type_at(0).kind() else { + bug!(); + }; + let item_ty = args.type_at(0); + + let predicate = ty::ProjectionPredicate { + projection_ty: ty::AliasTy::new(tcx, obligation.predicate.def_id, trait_ref.args), + term: item_ty.into(), + }; + + confirm_param_env_candidate(selcx, obligation, ty::Binder::dummy(predicate), false) .with_addl_obligations(nested) .with_addl_obligations(obligations) } @@ -2239,8 +2327,9 @@ fn confirm_fn_pointer_candidate<'cx, 'tcx>( obligation: &ProjectionTyObligation<'tcx>, nested: Vec<PredicateObligation<'tcx>>, ) -> Progress<'tcx> { + let tcx = selcx.tcx(); let fn_type = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()); - let sig = fn_type.fn_sig(selcx.tcx()); + let sig = fn_type.fn_sig(tcx); let Normalized { value: sig, obligations } = normalize_with_depth( selcx, obligation.param_env, @@ -2249,9 +2338,24 @@ fn confirm_fn_pointer_candidate<'cx, 'tcx>( sig, ); - confirm_callable_candidate(selcx, obligation, sig, util::TupleArgumentsFlag::Yes) - .with_addl_obligations(nested) - .with_addl_obligations(obligations) + let host_effect_param = match *fn_type.kind() { + ty::FnDef(def_id, args) => tcx + .generics_of(def_id) + .host_effect_index + .map_or(tcx.consts.true_, |idx| args.const_at(idx)), + ty::FnPtr(_) => tcx.consts.true_, + _ => unreachable!("only expected FnPtr or FnDef in `confirm_fn_pointer_candidate`"), + }; + + confirm_callable_candidate( + selcx, + obligation, + sig, + util::TupleArgumentsFlag::Yes, + host_effect_param, + ) + .with_addl_obligations(nested) + .with_addl_obligations(obligations) } fn confirm_closure_candidate<'cx, 'tcx>( @@ -2259,9 +2363,9 @@ fn confirm_closure_candidate<'cx, 'tcx>( obligation: &ProjectionTyObligation<'tcx>, nested: Vec<PredicateObligation<'tcx>>, ) -> Progress<'tcx> { - let ty::Closure(_, args) = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()).kind() - else { - unreachable!() + 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 = args.as_closure().sig(); let Normalized { value: closure_sig, obligations } = normalize_with_depth( @@ -2274,9 +2378,16 @@ fn confirm_closure_candidate<'cx, 'tcx>( debug!(?obligation, ?closure_sig, ?obligations, "confirm_closure_candidate"); - confirm_callable_candidate(selcx, obligation, closure_sig, util::TupleArgumentsFlag::No) - .with_addl_obligations(nested) - .with_addl_obligations(obligations) + confirm_callable_candidate( + selcx, + obligation, + closure_sig, + util::TupleArgumentsFlag::No, + // FIXME(effects): This doesn't handle const closures correctly! + selcx.tcx().consts.true_, + ) + .with_addl_obligations(nested) + .with_addl_obligations(obligations) } fn confirm_callable_candidate<'cx, 'tcx>( @@ -2284,6 +2395,7 @@ fn confirm_callable_candidate<'cx, 'tcx>( obligation: &ProjectionTyObligation<'tcx>, fn_sig: ty::PolyFnSig<'tcx>, flag: util::TupleArgumentsFlag, + fn_host_effect: ty::Const<'tcx>, ) -> Progress<'tcx> { let tcx = selcx.tcx(); @@ -2298,6 +2410,7 @@ fn confirm_callable_candidate<'cx, 'tcx>( obligation.predicate.self_ty(), fn_sig, flag, + fn_host_effect, ) .map_bound(|(trait_ref, ret_type)| ty::ProjectionPredicate { projection_ty: ty::AliasTy::new(tcx, fn_once_output_def_id, trait_ref.args), @@ -2319,7 +2432,7 @@ fn confirm_param_env_candidate<'cx, 'tcx>( let cache_entry = infcx.instantiate_binder_with_fresh_vars( cause.span, - LateBoundRegionConversionTime::HigherRankedType, + BoundRegionConversionTime::HigherRankedType, poly_cache_entry, ); |