diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/select/confirmation.rs')
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/select/confirmation.rs | 191 |
1 files changed, 8 insertions, 183 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs index 0ba3b4e6e55..1764777ee69 100644 --- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs +++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs @@ -28,9 +28,9 @@ use super::{BuiltinImplConditions, PredicateObligations, SelectionContext}; use crate::traits::normalize::{normalize_with_depth, normalize_with_depth_to}; use crate::traits::util::{self, closure_trait_ref_and_return_type}; use crate::traits::{ - ImplDerivedCause, ImplSource, ImplSourceUserDefinedData, Normalized, Obligation, - ObligationCause, PolyTraitObligation, PredicateObligation, Selection, SelectionError, - SignatureMismatch, TraitDynIncompatible, TraitObligation, Unimplemented, + ImplSource, ImplSourceUserDefinedData, Normalized, Obligation, ObligationCause, + PolyTraitObligation, PredicateObligation, Selection, SelectionError, SignatureMismatch, + TraitDynIncompatible, TraitObligation, Unimplemented, }; impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { @@ -109,8 +109,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ImplSource::Builtin(BuiltinImplSource::Misc, vtable_iterator) } - FnPointerCandidate { fn_host_effect } => { - let data = self.confirm_fn_pointer_candidate(obligation, fn_host_effect)?; + FnPointerCandidate => { + let data = self.confirm_fn_pointer_candidate(obligation)?; ImplSource::Builtin(BuiltinImplSource::Misc, data) } @@ -131,11 +131,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { TraitUpcastingUnsizeCandidate(idx) => { self.confirm_trait_upcasting_unsize_candidate(obligation, idx)? } - - ConstDestructCandidate(def_id) => { - let data = self.confirm_const_destruct_candidate(obligation, def_id)?; - ImplSource::Builtin(BuiltinImplSource::Misc, data) - } }; // The obligations returned by confirmation are recursively evaluated @@ -708,7 +703,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { fn confirm_fn_pointer_candidate( &mut self, obligation: &PolyTraitObligation<'tcx>, - fn_host_effect: ty::Const<'tcx>, ) -> Result<PredicateObligations<'tcx>, SelectionError<'tcx>> { debug!(?obligation, "confirm_fn_pointer_candidate"); let placeholder_predicate = self.infcx.enter_forall_and_leak_universe(obligation.predicate); @@ -722,7 +716,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { self_ty, sig, util::TupleArgumentsFlag::Yes, - fn_host_effect, ) .map_bound(|(trait_ref, _)| trait_ref); @@ -904,11 +897,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let self_ty: Ty<'_> = self.infcx.shallow_resolve(placeholder_predicate.self_ty()); let trait_ref = match *self_ty.kind() { - ty::Closure(..) => self.closure_trait_ref_unnormalized( - self_ty, - obligation.predicate.def_id(), - self.tcx().consts.true_, - ), + ty::Closure(..) => { + self.closure_trait_ref_unnormalized(self_ty, obligation.predicate.def_id()) + } ty::CoroutineClosure(_, args) => { args.as_coroutine_closure().coroutine_closure_sig().map_bound(|sig| { ty::TraitRef::new(self.tcx(), obligation.predicate.def_id(), [ @@ -1341,170 +1332,4 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { _ => bug!("source: {source}, target: {target}"), }) } - - fn confirm_const_destruct_candidate( - &mut self, - obligation: &PolyTraitObligation<'tcx>, - impl_def_id: Option<DefId>, - ) -> Result<PredicateObligations<'tcx>, SelectionError<'tcx>> { - let Some(host_effect_index) = - self.tcx().generics_of(obligation.predicate.def_id()).host_effect_index - else { - bug!() - }; - let host_effect_param: ty::GenericArg<'tcx> = - obligation.predicate.skip_binder().trait_ref.args.const_at(host_effect_index).into(); - - let drop_trait = self.tcx().require_lang_item(LangItem::Drop, None); - - let tcx = self.tcx(); - let self_ty = obligation.self_ty().map_bound(|ty| self.infcx.shallow_resolve(ty)); - - let mut nested = PredicateObligations::new(); - let cause = obligation.derived_cause(ObligationCauseCode::BuiltinDerived); - - // If we have a custom `impl const Drop`, then - // first check it like a regular impl candidate. - // This is copied from confirm_impl_candidate but remaps the predicate to `~const Drop` beforehand. - if let Some(impl_def_id) = impl_def_id { - let mut new_obligation = obligation.clone(); - new_obligation.predicate = new_obligation.predicate.map_bound(|mut trait_pred| { - trait_pred.trait_ref.def_id = drop_trait; - trait_pred - }); - let args = self.rematch_impl(impl_def_id, &new_obligation); - debug!(?args, "impl args"); - - let cause = obligation.derived_cause(|derived| { - ObligationCauseCode::ImplDerived(Box::new(ImplDerivedCause { - derived, - impl_or_alias_def_id: impl_def_id, - impl_def_predicate_index: None, - span: obligation.cause.span, - })) - }); - let obligations = ensure_sufficient_stack(|| { - self.vtable_impl( - impl_def_id, - args, - &cause, - new_obligation.recursion_depth + 1, - new_obligation.param_env, - obligation.predicate, - ) - }); - nested.extend(obligations.nested); - } - - // We want to confirm the ADT's fields if we have an ADT - let mut stack = match *self_ty.skip_binder().kind() { - ty::Adt(def, args) => def.all_fields().map(|f| f.ty(tcx, args)).collect(), - _ => vec![self_ty.skip_binder()], - }; - - while let Some(nested_ty) = stack.pop() { - match *nested_ty.kind() { - // We know these types are trivially drop - ty::Bool - | ty::Char - | ty::Int(_) - | ty::Uint(_) - | ty::Float(_) - | ty::Infer(ty::IntVar(_)) - | ty::Infer(ty::FloatVar(_)) - | ty::Str - | ty::RawPtr(_, _) - | ty::Ref(..) - | ty::FnDef(..) - | ty::FnPtr(..) - | ty::Never - | ty::Foreign(_) => {} - - // `ManuallyDrop` is trivially drop - ty::Adt(def, _) if def.is_manually_drop() => {} - - // These types are built-in, so we can fast-track by registering - // nested predicates for their constituent type(s) - ty::Array(ty, _) | ty::Slice(ty) | ty::Pat(ty, _) => { - stack.push(ty); - } - ty::Tuple(tys) => { - stack.extend(tys.iter()); - } - ty::Closure(_, args) => { - stack.push(args.as_closure().tupled_upvars_ty()); - } - ty::Coroutine(_, args) => { - let coroutine = args.as_coroutine(); - stack.extend([coroutine.tupled_upvars_ty(), coroutine.witness()]); - } - ty::CoroutineWitness(def_id, args) => { - let tcx = self.tcx(); - stack.extend(tcx.bound_coroutine_hidden_types(def_id).map(|bty| { - self.infcx.enter_forall_and_leak_universe(bty.instantiate(tcx, args)) - })) - } - - // If we have a projection type, make sure to normalize it so we replace it - // with a fresh infer variable - ty::Alias(ty::Projection | ty::Inherent, ..) => { - let predicate = normalize_with_depth_to( - self, - obligation.param_env, - cause.clone(), - obligation.recursion_depth + 1, - self_ty.rebind(ty::TraitPredicate { - trait_ref: ty::TraitRef::new( - self.tcx(), - self.tcx().require_lang_item(LangItem::Destruct, Some(cause.span)), - [nested_ty.into(), host_effect_param], - ), - polarity: ty::PredicatePolarity::Positive, - }), - &mut nested, - ); - - nested.push(Obligation::with_depth( - tcx, - cause.clone(), - obligation.recursion_depth + 1, - obligation.param_env, - predicate, - )); - } - - // If we have any other type (e.g. an ADT), just register a nested obligation - // since it's either not `const Drop` (and we raise an error during selection), - // or it's an ADT (and we need to check for a custom impl during selection) - ty::Error(_) - | ty::Dynamic(..) - | ty::CoroutineClosure(..) - | ty::Param(_) - | ty::Bound(..) - | ty::Adt(..) - | ty::Alias(ty::Opaque | ty::Weak, _) - | ty::Infer(_) - | ty::Placeholder(_) => { - let predicate = self_ty.rebind(ty::TraitPredicate { - trait_ref: ty::TraitRef::new( - self.tcx(), - self.tcx().require_lang_item(LangItem::Destruct, Some(cause.span)), - [nested_ty.into(), host_effect_param], - ), - polarity: ty::PredicatePolarity::Positive, - }); - - nested.push(Obligation::with_depth( - tcx, - cause.clone(), - obligation.recursion_depth + 1, - obligation.param_env, - predicate, - )); - } - } - } - - Ok(nested) - } } |