diff options
Diffstat (limited to 'compiler')
33 files changed, 224 insertions, 97 deletions
diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs index 8a9aac14fb6..703c845eafa 100644 --- a/compiler/rustc_hir_analysis/src/astconv/mod.rs +++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs @@ -1335,7 +1335,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { ty::Clause::RegionOutlives(_) | ty::Clause::ConstArgHasType(..) => bug!(), }, ty::PredicateKind::WellFormed(_) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::ObjectSafe(_) | ty::PredicateKind::ClosureKind(_, _, _) | ty::PredicateKind::Subtype(_) diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs index 91c64eeec1e..7f1e4ccc964 100644 --- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs +++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs @@ -528,7 +528,7 @@ fn trait_predicate_kind<'tcx>( | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(_)) | ty::PredicateKind::Clause(ty::Clause::Projection(_)) | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::WellFormed(_) | ty::PredicateKind::Subtype(_) | ty::PredicateKind::Coerce(_) diff --git a/compiler/rustc_hir_analysis/src/outlives/explicit.rs b/compiler/rustc_hir_analysis/src/outlives/explicit.rs index 9ee6785970c..357deb07b8f 100644 --- a/compiler/rustc_hir_analysis/src/outlives/explicit.rs +++ b/compiler/rustc_hir_analysis/src/outlives/explicit.rs @@ -56,7 +56,7 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> { | ty::PredicateKind::Clause(ty::Clause::Projection(..)) | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) | ty::PredicateKind::WellFormed(..) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs index 8455076de56..3def97bca47 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs @@ -666,7 +666,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..)) | ty::PredicateKind::WellFormed(..) | ty::PredicateKind::ObjectSafe(..) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) // N.B., this predicate is created by breaking down a diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs index b6d39341fe7..0eff5c956ef 100644 --- a/compiler/rustc_hir_typeck/src/method/probe.rs +++ b/compiler/rustc_hir_typeck/src/method/probe.rs @@ -838,7 +838,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> { | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::Ambiguous - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::TypeWellFormedFromEnv(..) => None, } }); diff --git a/compiler/rustc_infer/src/infer/combine.rs b/compiler/rustc_infer/src/infer/combine.rs index 4503af03ca3..88a28e26005 100644 --- a/compiler/rustc_infer/src/infer/combine.rs +++ b/compiler/rustc_infer/src/infer/combine.rs @@ -128,7 +128,7 @@ impl<'tcx> InferCtxt<'tcx> { (_, ty::Alias(AliasKind::Projection, _)) | (ty::Alias(AliasKind::Projection, _), _) if self.tcx.trait_solver_next() => { - relation.register_type_equate_obligation(a, b); + relation.register_type_relate_obligation(a, b); Ok(a) } @@ -842,23 +842,25 @@ pub trait ObligationEmittingRelation<'tcx>: TypeRelation<'tcx> { let (a, b) = if self.a_is_expected() { (a, b) } else { (b, a) }; self.register_predicates([ty::Binder::dummy(if self.tcx().trait_solver_next() { - ty::PredicateKind::AliasEq(a.into(), b.into()) + ty::PredicateKind::AliasRelate(a.into(), b.into(), ty::AliasRelationDirection::Equate) } else { ty::PredicateKind::ConstEquate(a, b) })]); } - /// Register an obligation that both types must be equal to each other. - /// - /// If they aren't equal then the relation doesn't hold. - fn register_type_equate_obligation(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) { - let (a, b) = if self.a_is_expected() { (a, b) } else { (b, a) }; - - self.register_predicates([ty::Binder::dummy(ty::PredicateKind::AliasEq( + /// Register an obligation that both types must be related to each other according to + /// the [`ty::AliasRelationDirection`] given by [`ObligationEmittingRelation::alias_relate_direction`] + fn register_type_relate_obligation(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) { + self.register_predicates([ty::Binder::dummy(ty::PredicateKind::AliasRelate( a.into(), b.into(), + self.alias_relate_direction(), ))]); } + + /// Relation direction emitted for `AliasRelate` predicates, corresponding to the direction + /// of the relation. + fn alias_relate_direction(&self) -> ty::AliasRelationDirection; } fn int_unification_error<'tcx>( diff --git a/compiler/rustc_infer/src/infer/equate.rs b/compiler/rustc_infer/src/infer/equate.rs index c92a74b6241..38002357cde 100644 --- a/compiler/rustc_infer/src/infer/equate.rs +++ b/compiler/rustc_infer/src/infer/equate.rs @@ -210,4 +210,8 @@ impl<'tcx> ObligationEmittingRelation<'tcx> for Equate<'_, '_, 'tcx> { fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { self.fields.register_obligations(obligations); } + + fn alias_relate_direction(&self) -> ty::AliasRelationDirection { + ty::AliasRelationDirection::Equate + } } diff --git a/compiler/rustc_infer/src/infer/glb.rs b/compiler/rustc_infer/src/infer/glb.rs index 5c12351226a..6395c4d4b20 100644 --- a/compiler/rustc_infer/src/infer/glb.rs +++ b/compiler/rustc_infer/src/infer/glb.rs @@ -155,4 +155,9 @@ impl<'tcx> ObligationEmittingRelation<'tcx> for Glb<'_, '_, 'tcx> { fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { self.fields.register_obligations(obligations); } + + fn alias_relate_direction(&self) -> ty::AliasRelationDirection { + // FIXME(deferred_projection_equality): This isn't right, I think? + ty::AliasRelationDirection::Equate + } } diff --git a/compiler/rustc_infer/src/infer/lub.rs b/compiler/rustc_infer/src/infer/lub.rs index dbef42db8f1..98cbd4c561c 100644 --- a/compiler/rustc_infer/src/infer/lub.rs +++ b/compiler/rustc_infer/src/infer/lub.rs @@ -155,4 +155,9 @@ impl<'tcx> ObligationEmittingRelation<'tcx> for Lub<'_, '_, 'tcx> { fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { self.fields.register_obligations(obligations) } + + fn alias_relate_direction(&self) -> ty::AliasRelationDirection { + // FIXME(deferred_projection_equality): This isn't right, I think? + ty::AliasRelationDirection::Equate + } } diff --git a/compiler/rustc_infer/src/infer/nll_relate/mod.rs b/compiler/rustc_infer/src/infer/nll_relate/mod.rs index 2320f6bfb16..f5d20cb7ebf 100644 --- a/compiler/rustc_infer/src/infer/nll_relate/mod.rs +++ b/compiler/rustc_infer/src/infer/nll_relate/mod.rs @@ -711,6 +711,34 @@ where fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { self.delegate.register_obligations(obligations); } + + fn alias_relate_direction(&self) -> ty::AliasRelationDirection { + unreachable!("manually overridden to handle ty::Variance::Contravariant ambient variance") + } + + fn register_type_relate_obligation(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) { + self.register_predicates([ty::Binder::dummy(match self.ambient_variance { + ty::Variance::Covariant => ty::PredicateKind::AliasRelate( + a.into(), + b.into(), + ty::AliasRelationDirection::Subtype, + ), + // a :> b is b <: a + ty::Variance::Contravariant => ty::PredicateKind::AliasRelate( + b.into(), + a.into(), + ty::AliasRelationDirection::Subtype, + ), + ty::Variance::Invariant => ty::PredicateKind::AliasRelate( + a.into(), + b.into(), + ty::AliasRelationDirection::Equate, + ), + // FIXME(deferred_projection_equality): Implement this when we trigger it. + // Probably just need to do nothing here. + ty::Variance::Bivariant => unreachable!(), + })]); + } } /// When we encounter a binder like `for<..> fn(..)`, we actually have diff --git a/compiler/rustc_infer/src/infer/outlives/mod.rs b/compiler/rustc_infer/src/infer/outlives/mod.rs index 83f3d5a74fb..048dad3a48b 100644 --- a/compiler/rustc_infer/src/infer/outlives/mod.rs +++ b/compiler/rustc_infer/src/infer/outlives/mod.rs @@ -22,7 +22,7 @@ pub fn explicit_outlives_bounds<'tcx>( ty::PredicateKind::Clause(ty::Clause::Projection(..)) | ty::PredicateKind::Clause(ty::Clause::Trait(..)) | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::Coerce(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::WellFormed(..) diff --git a/compiler/rustc_infer/src/infer/projection.rs b/compiler/rustc_infer/src/infer/projection.rs index f795047709e..fa6529dfa93 100644 --- a/compiler/rustc_infer/src/infer/projection.rs +++ b/compiler/rustc_infer/src/infer/projection.rs @@ -26,7 +26,7 @@ impl<'tcx> InferCtxt<'tcx> { // completely change the normalization routine with the new solver. // // The new solver correctly handles projection equality so this hack - // is not necessary. if re-enabled it should emit `PredicateKind::AliasEq` + // is not necessary. if re-enabled it should emit `PredicateKind::AliasRelate` // not `PredicateKind::Clause(Clause::Projection(..))` as in the new solver // `Projection` is used as `normalizes-to` which will fail for `<T as Trait>::Assoc eq ?0`. return projection_ty.to_ty(self.tcx); diff --git a/compiler/rustc_infer/src/infer/sub.rs b/compiler/rustc_infer/src/infer/sub.rs index 230cadb1184..fc73ca7606d 100644 --- a/compiler/rustc_infer/src/infer/sub.rs +++ b/compiler/rustc_infer/src/infer/sub.rs @@ -236,4 +236,8 @@ impl<'tcx> ObligationEmittingRelation<'tcx> for Sub<'_, '_, 'tcx> { fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { self.fields.register_obligations(obligations); } + + fn alias_relate_direction(&self) -> ty::AliasRelationDirection { + ty::AliasRelationDirection::Subtype + } } diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index c07ff516579..0d2faeba5fc 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -293,7 +293,7 @@ impl<'tcx> Elaborator<'tcx> { // Nothing to elaborate } ty::PredicateKind::Ambiguous => {} - ty::PredicateKind::AliasEq(..) => { + ty::PredicateKind::AliasRelate(..) => { // No } ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => { diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs index 8af1a663ef5..f8dd8299312 100644 --- a/compiler/rustc_lint/src/builtin.rs +++ b/compiler/rustc_lint/src/builtin.rs @@ -1601,7 +1601,7 @@ impl<'tcx> LateLintPass<'tcx> for TrivialConstraints { // Ignore projections, as they can only be global // if the trait bound is global Clause(Clause::Projection(..)) | - AliasEq(..) | + AliasRelate(..) | // Ignore bounds that a user can't type WellFormed(..) | ObjectSafe(..) | diff --git a/compiler/rustc_middle/src/ty/flags.rs b/compiler/rustc_middle/src/ty/flags.rs index 91241ff404f..5a6ee123811 100644 --- a/compiler/rustc_middle/src/ty/flags.rs +++ b/compiler/rustc_middle/src/ty/flags.rs @@ -288,7 +288,7 @@ impl FlagComputation { self.add_ty(ty); } ty::PredicateKind::Ambiguous => {} - ty::PredicateKind::AliasEq(t1, t2) => { + ty::PredicateKind::AliasRelate(t1, t2, _) => { self.add_term(t1); self.add_term(t2); } diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs index 9b0c6e25d16..b17749c1eba 100644 --- a/compiler/rustc_middle/src/ty/mod.rs +++ b/compiler/rustc_middle/src/ty/mod.rs @@ -543,7 +543,7 @@ impl<'tcx> Predicate<'tcx> { | PredicateKind::Clause(Clause::TypeOutlives(_)) | PredicateKind::Clause(Clause::Projection(_)) | PredicateKind::Clause(Clause::ConstArgHasType(..)) - | PredicateKind::AliasEq(..) + | PredicateKind::AliasRelate(..) | PredicateKind::ObjectSafe(_) | PredicateKind::ClosureKind(_, _, _) | PredicateKind::Subtype(_) @@ -640,7 +640,23 @@ pub enum PredicateKind<'tcx> { /// This predicate requires two terms to be equal to eachother. /// /// Only used for new solver - AliasEq(Term<'tcx>, Term<'tcx>), + AliasRelate(Term<'tcx>, Term<'tcx>, AliasRelationDirection), +} + +#[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] +#[derive(HashStable, Debug)] +pub enum AliasRelationDirection { + Equate, + Subtype, +} + +impl std::fmt::Display for AliasRelationDirection { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match self { + AliasRelationDirection::Equate => write!(f, " == "), + AliasRelationDirection::Subtype => write!(f, " <: "), + } + } } /// The crate outlives map is computed during typeck and contains the @@ -976,11 +992,11 @@ impl<'tcx> Term<'tcx> { } } - /// This function returns `None` for `AliasKind::Opaque`. + /// This function returns the inner `AliasTy` if this term is a projection. /// /// FIXME: rename `AliasTy` to `AliasTerm` and make sure we correctly /// deal with constants. - pub fn to_alias_term_no_opaque(&self, tcx: TyCtxt<'tcx>) -> Option<AliasTy<'tcx>> { + pub fn to_projection_term(&self, tcx: TyCtxt<'tcx>) -> Option<AliasTy<'tcx>> { match self.unpack() { TermKind::Ty(ty) => match ty.kind() { ty::Alias(kind, alias_ty) => match kind { @@ -1206,7 +1222,7 @@ impl<'tcx> Predicate<'tcx> { PredicateKind::Clause(Clause::Trait(t)) => Some(predicate.rebind(t)), PredicateKind::Clause(Clause::Projection(..)) | PredicateKind::Clause(Clause::ConstArgHasType(..)) - | PredicateKind::AliasEq(..) + | PredicateKind::AliasRelate(..) | PredicateKind::Subtype(..) | PredicateKind::Coerce(..) | PredicateKind::Clause(Clause::RegionOutlives(..)) @@ -1227,7 +1243,7 @@ impl<'tcx> Predicate<'tcx> { PredicateKind::Clause(Clause::Projection(t)) => Some(predicate.rebind(t)), PredicateKind::Clause(Clause::Trait(..)) | PredicateKind::Clause(Clause::ConstArgHasType(..)) - | PredicateKind::AliasEq(..) + | PredicateKind::AliasRelate(..) | PredicateKind::Subtype(..) | PredicateKind::Coerce(..) | PredicateKind::Clause(Clause::RegionOutlives(..)) @@ -1249,7 +1265,7 @@ impl<'tcx> Predicate<'tcx> { PredicateKind::Clause(Clause::Trait(..)) | PredicateKind::Clause(Clause::ConstArgHasType(..)) | PredicateKind::Clause(Clause::Projection(..)) - | PredicateKind::AliasEq(..) + | PredicateKind::AliasRelate(..) | PredicateKind::Subtype(..) | PredicateKind::Coerce(..) | PredicateKind::Clause(Clause::RegionOutlives(..)) diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs index fffdbfc9660..e9f8f2e5865 100644 --- a/compiler/rustc_middle/src/ty/print/pretty.rs +++ b/compiler/rustc_middle/src/ty/print/pretty.rs @@ -2847,7 +2847,7 @@ define_print_and_forward_display! { p!("the type `", print(ty), "` is found in the environment") } ty::PredicateKind::Ambiguous => p!("ambiguous"), - ty::PredicateKind::AliasEq(t1, t2) => p!(print(t1), " == ", print(t2)), + ty::PredicateKind::AliasRelate(t1, t2, dir) => p!(print(t1), write(" {} ", dir), print(t2)), } } diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs index ef643531bb2..c6bb8146795 100644 --- a/compiler/rustc_middle/src/ty/structural_impls.rs +++ b/compiler/rustc_middle/src/ty/structural_impls.rs @@ -177,7 +177,9 @@ impl<'tcx> fmt::Debug for ty::PredicateKind<'tcx> { write!(f, "TypeWellFormedFromEnv({:?})", ty) } ty::PredicateKind::Ambiguous => write!(f, "Ambiguous"), - ty::PredicateKind::AliasEq(t1, t2) => write!(f, "AliasEq({t1:?}, {t2:?})"), + ty::PredicateKind::AliasRelate(t1, t2, dir) => { + write!(f, "AliasRelate({t1:?}, {dir:?}, {t2:?})") + } } } } @@ -250,6 +252,7 @@ TrivialTypeTraversalAndLiftImpls! { crate::ty::AssocItem, crate::ty::AssocKind, crate::ty::AliasKind, + crate::ty::AliasRelationDirection, crate::ty::Placeholder<crate::ty::BoundRegionKind>, crate::ty::Placeholder<crate::ty::BoundTyKind>, crate::ty::ClosureKind, diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs index d884ebd9acc..3be0160d561 100644 --- a/compiler/rustc_privacy/src/lib.rs +++ b/compiler/rustc_privacy/src/lib.rs @@ -180,7 +180,7 @@ where | ty::PredicateKind::ConstEquate(_, _) | ty::PredicateKind::TypeWellFormedFromEnv(_) | ty::PredicateKind::Ambiguous - | ty::PredicateKind::AliasEq(_, _) => bug!("unexpected predicate: {:?}", predicate), + | ty::PredicateKind::AliasRelate(..) => bug!("unexpected predicate: {:?}", predicate), } } diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs index 95412922357..75b304cce4e 100644 --- a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs +++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs @@ -223,9 +223,11 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> { ty::PredicateKind::TypeWellFormedFromEnv(..) => { bug!("TypeWellFormedFromEnv is only used for Chalk") } - ty::PredicateKind::AliasEq(lhs, rhs) => { - self.compute_alias_eq_goal(Goal { param_env, predicate: (lhs, rhs) }) - } + ty::PredicateKind::AliasRelate(lhs, rhs, direction) => self + .compute_alias_relate_goal(Goal { + param_env, + predicate: (lhs, rhs, direction), + }), } } else { let kind = self.infcx.instantiate_binder_with_placeholders(kind); @@ -457,6 +459,25 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { }) } + #[instrument(level = "debug", skip(self, param_env), ret)] + pub(super) fn sub<T: ToTrace<'tcx>>( + &mut self, + param_env: ty::ParamEnv<'tcx>, + sub: T, + sup: T, + ) -> Result<(), NoSolution> { + self.infcx + .at(&ObligationCause::dummy(), param_env) + .sub(DefineOpaqueTypes::No, sub, sup) + .map(|InferOk { value: (), obligations }| { + self.add_goals(obligations.into_iter().map(|o| o.into())); + }) + .map_err(|e| { + debug!(?e, "failed to subtype"); + NoSolution + }) + } + /// Equates two values returning the nested goals without adding them /// to the nested goals of the `EvalCtxt`. /// diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs index 38120b9760f..01f171762ab 100644 --- a/compiler/rustc_trait_selection/src/solve/fulfill.rs +++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs @@ -73,7 +73,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> { MismatchedProjectionTypes { err: TypeError::Mismatch }, ) } - ty::PredicateKind::AliasEq(_, _) => { + ty::PredicateKind::AliasRelate(_, _, _) => { FulfillmentErrorCode::CodeProjectionError( MismatchedProjectionTypes { err: TypeError::Mismatch }, ) diff --git a/compiler/rustc_trait_selection/src/solve/mod.rs b/compiler/rustc_trait_selection/src/solve/mod.rs index 606c2eaa510..4c87d36ca0d 100644 --- a/compiler/rustc_trait_selection/src/solve/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/mod.rs @@ -17,7 +17,6 @@ use rustc_hir::def_id::DefId; use rustc_infer::infer::canonical::{Canonical, CanonicalVarValues}; -use rustc_infer::infer::{DefineOpaqueTypes, InferOk}; use rustc_infer::traits::query::NoSolution; use rustc_middle::traits::solve::{ CanonicalGoal, CanonicalResponse, Certainty, ExternalConstraints, ExternalConstraintsData, @@ -101,11 +100,7 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> { // That won't actually reflect in the query response, so it seems moot. self.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS) } else { - let InferOk { value: (), obligations } = self - .infcx - .at(&ObligationCause::dummy(), goal.param_env) - .sub(DefineOpaqueTypes::No, goal.predicate.a, goal.predicate.b)?; - self.add_goals(obligations.into_iter().map(|pred| pred.into())); + self.sub(goal.param_env, goal.predicate.a, goal.predicate.b)?; self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } } @@ -156,55 +151,94 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> { } #[instrument(level = "debug", skip(self), ret)] - fn compute_alias_eq_goal( + fn compute_alias_relate_goal( &mut self, - goal: Goal<'tcx, (ty::Term<'tcx>, ty::Term<'tcx>)>, + goal: Goal<'tcx, (ty::Term<'tcx>, ty::Term<'tcx>, ty::AliasRelationDirection)>, ) -> QueryResult<'tcx> { let tcx = self.tcx(); + // We may need to invert the alias relation direction if dealing an alias on the RHS. + enum Invert { + No, + Yes, + } + let evaluate_normalizes_to = + |ecx: &mut EvalCtxt<'_, 'tcx>, alias, other, direction, invert| { + debug!("evaluate_normalizes_to(alias={:?}, other={:?})", alias, other); + let result = ecx.probe(|ecx| { + let other = match direction { + // This is purely an optimization. + ty::AliasRelationDirection::Equate => other, + + ty::AliasRelationDirection::Subtype => { + let fresh = ecx.next_term_infer_of_kind(other); + let (sub, sup) = match invert { + Invert::No => (fresh, other), + Invert::Yes => (other, fresh), + }; + ecx.sub(goal.param_env, sub, sup)?; + fresh + } + }; + ecx.add_goal(goal.with( + tcx, + ty::Binder::dummy(ty::ProjectionPredicate { + projection_ty: alias, + term: other, + }), + )); + ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) + }); + debug!("evaluate_normalizes_to({alias}, {other}, {direction:?}) -> {result:?}"); + result + }; - let evaluate_normalizes_to = |ecx: &mut EvalCtxt<'_, 'tcx>, alias, other| { - debug!("evaluate_normalizes_to(alias={:?}, other={:?})", alias, other); - let r = ecx.probe(|ecx| { - ecx.add_goal(goal.with( - tcx, - ty::Binder::dummy(ty::ProjectionPredicate { - projection_ty: alias, - term: other, - }), - )); - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - }); - debug!("evaluate_normalizes_to(..) -> {:?}", r); - r - }; + let (lhs, rhs, direction) = goal.predicate; - if goal.predicate.0.is_infer() || goal.predicate.1.is_infer() { + if lhs.is_infer() || rhs.is_infer() { bug!( - "`AliasEq` goal with an infer var on lhs or rhs which should have been instantiated" + "`AliasRelate` goal with an infer var on lhs or rhs which should have been instantiated" ); } - match ( - goal.predicate.0.to_alias_term_no_opaque(tcx), - goal.predicate.1.to_alias_term_no_opaque(tcx), - ) { - (None, None) => bug!("`AliasEq` goal without an alias on either lhs or rhs"), - (Some(alias), None) => evaluate_normalizes_to(self, alias, goal.predicate.1), - (None, Some(alias)) => evaluate_normalizes_to(self, alias, goal.predicate.0), - (Some(alias_lhs), Some(alias_rhs)) => { - debug!("compute_alias_eq_goal: both sides are aliases"); + match (lhs.to_projection_term(tcx), rhs.to_projection_term(tcx)) { + (None, None) => bug!("`AliasRelate` goal without an alias on either lhs or rhs"), - let mut candidates = Vec::with_capacity(3); + // RHS is not a projection, only way this is true is if LHS normalizes-to RHS + (Some(alias_lhs), None) => { + evaluate_normalizes_to(self, alias_lhs, rhs, direction, Invert::No) + } - // Evaluate all 3 potential candidates for the alias' being equal - candidates.push(evaluate_normalizes_to(self, alias_lhs, goal.predicate.1)); - candidates.push(evaluate_normalizes_to(self, alias_rhs, goal.predicate.0)); - candidates.push(self.probe(|ecx| { - debug!("compute_alias_eq_goal: alias defids are equal, equating substs"); - ecx.eq(goal.param_env, alias_lhs, alias_rhs)?; - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - })); + // LHS is not a projection, only way this is true is if RHS normalizes-to LHS + (None, Some(alias_rhs)) => { + evaluate_normalizes_to(self, alias_rhs, lhs, direction, Invert::Yes) + } + (Some(alias_lhs), Some(alias_rhs)) => { + debug!("compute_alias_relate_goal: both sides are aliases"); + + let candidates = vec![ + // LHS normalizes-to RHS + evaluate_normalizes_to(self, alias_lhs, rhs, direction, Invert::No), + // RHS normalizes-to RHS + evaluate_normalizes_to(self, alias_rhs, lhs, direction, Invert::Yes), + // Relate via substs + self.probe(|ecx| { + debug!( + "compute_alias_relate_goal: alias defids are equal, equating substs" + ); + + match direction { + ty::AliasRelationDirection::Equate => { + ecx.eq(goal.param_env, alias_lhs, alias_rhs)?; + } + ty::AliasRelationDirection::Subtype => { + ecx.sub(goal.param_env, alias_lhs, alias_rhs)?; + } + } + + ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) + }), + ]; debug!(?candidates); self.try_merge_responses(candidates.into_iter()) diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs index dbf6775afc2..6b3a59b1ed5 100644 --- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs +++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs @@ -832,7 +832,7 @@ impl<'tcx> AutoTraitFinder<'tcx> { // the `ParamEnv`. ty::PredicateKind::WellFormed(..) | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/method_chain.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/method_chain.rs index 1174efdbfa8..13607b9079a 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/method_chain.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/method_chain.rs @@ -92,6 +92,11 @@ impl<'a, 'tcx> TypeRelation<'tcx> for CollectAllMismatches<'a, 'tcx> { } impl<'tcx> ObligationEmittingRelation<'tcx> for CollectAllMismatches<'_, 'tcx> { + fn alias_relate_direction(&self) -> ty::AliasRelationDirection { + // FIXME(deferred_projection_equality): We really should get rid of this relation. + ty::AliasRelationDirection::Equate + } + fn register_obligations(&mut self, _obligations: PredicateObligations<'tcx>) { // FIXME(deferred_projection_equality) } diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs index 41ffaeeac1c..617d53b609d 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -1276,9 +1276,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { "TypeWellFormedFromEnv predicate should only exist in the environment" ), - ty::PredicateKind::AliasEq(..) => span_bug!( + ty::PredicateKind::AliasRelate(..) => span_bug!( span, - "AliasEq predicate should never be the predicate cause of a SelectionError" + "AliasRelate predicate should never be the predicate cause of a SelectionError" ), ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(ct, ty)) => { diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs index 23754480fcf..07e31e87bfb 100644 --- a/compiler/rustc_trait_selection/src/traits/fulfill.rs +++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs @@ -361,8 +361,8 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> { ty::PredicateKind::TypeWellFormedFromEnv(..) => { bug!("TypeWellFormedFromEnv is only used for Chalk") } - ty::PredicateKind::AliasEq(..) => { - bug!("AliasEq is only used for new solver") + ty::PredicateKind::AliasRelate(..) => { + bug!("AliasRelate is only used for new solver") } }, Some(pred) => match pred { @@ -630,8 +630,8 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> { ty::PredicateKind::TypeWellFormedFromEnv(..) => { bug!("TypeWellFormedFromEnv is only used for Chalk") } - ty::PredicateKind::AliasEq(..) => { - bug!("AliasEq is only used for new solver") + ty::PredicateKind::AliasRelate(..) => { + bug!("AliasRelate is only used for new solver") } ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(ct, ty)) => { match self.selcx.infcx.at(&obligation.cause, obligation.param_env).eq( diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs index 038f8964471..5d2af5ff33c 100644 --- a/compiler/rustc_trait_selection/src/traits/object_safety.rs +++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs @@ -335,7 +335,7 @@ fn predicate_references_self<'tcx>( has_self_ty(&ty.into()).then_some(sp) } - ty::PredicateKind::AliasEq(..) => bug!("`AliasEq` not allowed as assumption"), + ty::PredicateKind::AliasRelate(..) => bug!("`AliasRelate` not allowed as assumption"), ty::PredicateKind::WellFormed(..) | ty::PredicateKind::ObjectSafe(..) @@ -395,7 +395,7 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool { | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..)) | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::Ambiguous | ty::PredicateKind::TypeWellFormedFromEnv(..) => false, } diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index b8758ad9323..bffefdf359a 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -977,8 +977,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ty::PredicateKind::TypeWellFormedFromEnv(..) => { bug!("TypeWellFormedFromEnv is only used for chalk") } - ty::PredicateKind::AliasEq(..) => { - bug!("AliasEq is only used for new solver") + ty::PredicateKind::AliasRelate(..) => { + bug!("AliasRelate is only used for new solver") } ty::PredicateKind::Ambiguous => Ok(EvaluatedToAmbig), ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(ct, ty)) => { diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs index d498af359c5..ec5bd982a3c 100644 --- a/compiler/rustc_trait_selection/src/traits/wf.rs +++ b/compiler/rustc_trait_selection/src/traits/wf.rs @@ -191,8 +191,8 @@ pub fn predicate_obligations<'tcx>( ty::PredicateKind::TypeWellFormedFromEnv(..) => { bug!("TypeWellFormedFromEnv is only used for Chalk") } - ty::PredicateKind::AliasEq(..) => { - bug!("We should only wf check where clauses and `AliasEq` is not a `Clause`") + ty::PredicateKind::AliasRelate(..) => { + bug!("We should only wf check where clauses and `AliasRelate` is not a `Clause`") } } @@ -936,7 +936,7 @@ pub(crate) fn required_region_bounds<'tcx>( | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::Ambiguous - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::TypeWellFormedFromEnv(..) => None, ty::PredicateKind::Clause(ty::Clause::TypeOutlives(ty::OutlivesPredicate( ref t, diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs index 60e22d1001c..0e9bccba8d4 100644 --- a/compiler/rustc_traits/src/chalk/lowering.rs +++ b/compiler/rustc_traits/src/chalk/lowering.rs @@ -119,7 +119,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<' }, ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::Coerce(..) @@ -215,7 +215,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predi // some of these in terms of chalk operations. ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::Coerce(..) | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::Ambiguous @@ -652,7 +652,7 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_ir::QuantifiedWhereClause<RustInterner<' ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => None, ty::PredicateKind::ObjectSafe(..) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::Coerce(..) @@ -787,7 +787,7 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_solve::rust_ir::QuantifiedInlineBound<Ru ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => None, ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..)) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) diff --git a/compiler/rustc_traits/src/implied_outlives_bounds.rs b/compiler/rustc_traits/src/implied_outlives_bounds.rs index ddd4ca1436c..f5bba14d2fb 100644 --- a/compiler/rustc_traits/src/implied_outlives_bounds.rs +++ b/compiler/rustc_traits/src/implied_outlives_bounds.rs @@ -86,7 +86,7 @@ fn compute_implied_outlives_bounds<'tcx>( if obligation.predicate.has_non_region_infer() { match obligation.predicate.kind().skip_binder() { ty::PredicateKind::Clause(ty::Clause::Projection(..)) - | ty::PredicateKind::AliasEq(..) => { + | ty::PredicateKind::AliasRelate(..) => { ocx.register_obligation(obligation.clone()); } _ => {} @@ -110,7 +110,7 @@ fn compute_implied_outlives_bounds<'tcx>( | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::Ambiguous - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::TypeWellFormedFromEnv(..) => {} // We need to search through *all* WellFormed predicates diff --git a/compiler/rustc_traits/src/normalize_erasing_regions.rs b/compiler/rustc_traits/src/normalize_erasing_regions.rs index f0597f19225..126a494f34f 100644 --- a/compiler/rustc_traits/src/normalize_erasing_regions.rs +++ b/compiler/rustc_traits/src/normalize_erasing_regions.rs @@ -61,7 +61,7 @@ fn not_outlives_predicate(p: ty::Predicate<'_>) -> bool { ty::PredicateKind::Clause(ty::Clause::Trait(..)) | ty::PredicateKind::Clause(ty::Clause::Projection(..)) | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) - | ty::PredicateKind::AliasEq(..) + | ty::PredicateKind::AliasRelate(..) | ty::PredicateKind::WellFormed(..) | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ClosureKind(..) |