diff options
46 files changed, 585 insertions, 163 deletions
diff --git a/compiler/rustc_borrowck/src/type_check/relate_tys.rs b/compiler/rustc_borrowck/src/type_check/relate_tys.rs index b2702eafd33..8dd06187877 100644 --- a/compiler/rustc_borrowck/src/type_check/relate_tys.rs +++ b/compiler/rustc_borrowck/src/type_check/relate_tys.rs @@ -1,4 +1,4 @@ -use rustc_infer::infer::nll_relate::{NormalizationStrategy, TypeRelating, TypeRelatingDelegate}; +use rustc_infer::infer::nll_relate::{TypeRelating, TypeRelatingDelegate}; use rustc_infer::infer::NllRegionVariableOrigin; use rustc_infer::traits::PredicateObligations; use rustc_middle::mir::ConstraintCategory; @@ -140,10 +140,6 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx> ); } - fn normalization() -> NormalizationStrategy { - NormalizationStrategy::Eager - } - fn forbid_inference_vars() -> bool { true } diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs index f121979be71..75cc7cbaa60 100644 --- a/compiler/rustc_hir_analysis/src/astconv/mod.rs +++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs @@ -1320,6 +1320,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { ty::Clause::RegionOutlives(_) => bug!(), }, ty::PredicateKind::WellFormed(_) + | ty::PredicateKind::AliasEq(..) | 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 a5dcfab9be8..02f77f9d6af 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 @@ -517,6 +517,7 @@ fn trait_predicate_kind<'tcx>( ty::PredicateKind::Clause(ty::Clause::RegionOutlives(_)) | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(_)) | ty::PredicateKind::Clause(ty::Clause::Projection(_)) + | ty::PredicateKind::AliasEq(..) | 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 663f1c49db7..ecd6849426d 100644 --- a/compiler/rustc_hir_analysis/src/outlives/explicit.rs +++ b/compiler/rustc_hir_analysis/src/outlives/explicit.rs @@ -55,6 +55,7 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> { ty::PredicateKind::Clause(ty::Clause::Trait(..)) | ty::PredicateKind::Clause(ty::Clause::Projection(..)) | ty::PredicateKind::WellFormed(..) + | ty::PredicateKind::AliasEq(..) | 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 e84b3de124c..52c2dabee29 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs @@ -669,6 +669,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..)) | ty::PredicateKind::WellFormed(..) | ty::PredicateKind::ObjectSafe(..) + | ty::PredicateKind::AliasEq(..) | 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 0cf58179ec2..16b0d48002e 100644 --- a/compiler/rustc_hir_typeck/src/method/probe.rs +++ b/compiler/rustc_hir_typeck/src/method/probe.rs @@ -837,6 +837,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> { | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::Ambiguous + | ty::PredicateKind::AliasEq(..) | ty::PredicateKind::TypeWellFormedFromEnv(..) => None, } }); diff --git a/compiler/rustc_infer/src/infer/canonical/query_response.rs b/compiler/rustc_infer/src/infer/canonical/query_response.rs index 7cc9e49b1b6..0c97217bd6a 100644 --- a/compiler/rustc_infer/src/infer/canonical/query_response.rs +++ b/compiler/rustc_infer/src/infer/canonical/query_response.rs @@ -12,7 +12,7 @@ use crate::infer::canonical::{ Canonical, CanonicalQueryResponse, CanonicalVarValues, Certainty, OriginalQueryValues, QueryOutlivesConstraint, QueryRegionConstraints, QueryResponse, }; -use crate::infer::nll_relate::{NormalizationStrategy, TypeRelating, TypeRelatingDelegate}; +use crate::infer::nll_relate::{TypeRelating, TypeRelatingDelegate}; use crate::infer::region_constraints::{Constraint, RegionConstraintData}; use crate::infer::{InferCtxt, InferOk, InferResult, NllRegionVariableOrigin}; use crate::traits::query::{Fallible, NoSolution}; @@ -717,10 +717,6 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for QueryTypeRelatingDelegate<'_, 'tcx> { }); } - fn normalization() -> NormalizationStrategy { - NormalizationStrategy::Eager - } - fn forbid_inference_vars() -> bool { true } diff --git a/compiler/rustc_infer/src/infer/combine.rs b/compiler/rustc_infer/src/infer/combine.rs index 1360044fe75..4da2a674144 100644 --- a/compiler/rustc_infer/src/infer/combine.rs +++ b/compiler/rustc_infer/src/infer/combine.rs @@ -38,8 +38,8 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError}; use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation}; use rustc_middle::ty::subst::SubstsRef; use rustc_middle::ty::{ - self, FallibleTypeFolder, InferConst, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, - TypeVisitable, + self, AliasKind, FallibleTypeFolder, InferConst, ToPredicate, Ty, TyCtxt, TypeFoldable, + TypeSuperFoldable, TypeVisitable, }; use rustc_middle::ty::{IntType, UintType}; use rustc_span::{Span, DUMMY_SP}; @@ -74,7 +74,7 @@ impl<'tcx> InferCtxt<'tcx> { b: Ty<'tcx>, ) -> RelateResult<'tcx, Ty<'tcx>> where - R: TypeRelation<'tcx>, + R: ObligationEmittingRelation<'tcx>, { let a_is_expected = relation.a_is_expected(); @@ -122,6 +122,15 @@ impl<'tcx> InferCtxt<'tcx> { Err(TypeError::Sorts(ty::relate::expected_found(relation, a, b))) } + (ty::Alias(AliasKind::Projection, _), _) if self.tcx.trait_solver_next() => { + relation.register_type_equate_obligation(a.into(), b.into()); + Ok(b) + } + (_, ty::Alias(AliasKind::Projection, _)) if self.tcx.trait_solver_next() => { + relation.register_type_equate_obligation(b.into(), a.into()); + Ok(a) + } + _ => ty::relate::super_relate_tys(relation, a, b), } } @@ -133,7 +142,7 @@ impl<'tcx> InferCtxt<'tcx> { b: ty::Const<'tcx>, ) -> RelateResult<'tcx, ty::Const<'tcx>> where - R: ConstEquateRelation<'tcx>, + R: ObligationEmittingRelation<'tcx>, { debug!("{}.consts({:?}, {:?})", relation.tag(), a, b); if a == b { @@ -169,7 +178,7 @@ impl<'tcx> InferCtxt<'tcx> { // FIXME(#59490): Need to remove the leak check to accommodate // escaping bound variables here. if !a.has_escaping_bound_vars() && !b.has_escaping_bound_vars() { - relation.const_equate_obligation(a, b); + relation.register_const_equate_obligation(a, b); } return Ok(b); } @@ -177,7 +186,7 @@ impl<'tcx> InferCtxt<'tcx> { // FIXME(#59490): Need to remove the leak check to accommodate // escaping bound variables here. if !a.has_escaping_bound_vars() && !b.has_escaping_bound_vars() { - relation.const_equate_obligation(a, b); + relation.register_const_equate_obligation(a, b); } return Ok(a); } @@ -435,32 +444,21 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> { Ok(Generalization { ty, needs_wf }) } - pub fn add_const_equate_obligation( + pub fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { + self.obligations.extend(obligations.into_iter()); + } + + pub fn register_predicates( &mut self, - a_is_expected: bool, - a: ty::Const<'tcx>, - b: ty::Const<'tcx>, + obligations: impl IntoIterator<Item = impl ToPredicate<'tcx>>, ) { - let predicate = if a_is_expected { - ty::PredicateKind::ConstEquate(a, b) - } else { - ty::PredicateKind::ConstEquate(b, a) - }; - self.obligations.push(Obligation::new( - self.tcx(), - self.trace.cause.clone(), - self.param_env, - ty::Binder::dummy(predicate), - )); + self.obligations.extend(obligations.into_iter().map(|to_pred| { + Obligation::new(self.infcx.tcx, self.trace.cause.clone(), self.param_env, to_pred) + })) } pub fn mark_ambiguous(&mut self) { - self.obligations.push(Obligation::new( - self.tcx(), - self.trace.cause.clone(), - self.param_env, - ty::Binder::dummy(ty::PredicateKind::Ambiguous), - )); + self.register_predicates([ty::Binder::dummy(ty::PredicateKind::Ambiguous)]); } } @@ -779,11 +777,42 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> { } } -pub trait ConstEquateRelation<'tcx>: TypeRelation<'tcx> { +pub trait ObligationEmittingRelation<'tcx>: TypeRelation<'tcx> { + /// Register obligations that must hold in order for this relation to hold + fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>); + + /// Register predicates that must hold in order for this relation to hold. Uses + /// a default obligation cause, [`ObligationEmittingRelation::register_obligations`] should + /// be used if control over the obligaton causes is required. + fn register_predicates( + &mut self, + obligations: impl IntoIterator<Item = impl ToPredicate<'tcx>>, + ); + /// Register an obligation that both constants must be equal to each other. /// /// If they aren't equal then the relation doesn't hold. - fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>); + fn register_const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'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()) + } 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( + a.into(), + b.into(), + ))]); + } } fn int_unification_error<'tcx>( diff --git a/compiler/rustc_infer/src/infer/equate.rs b/compiler/rustc_infer/src/infer/equate.rs index 7db4d92a177..742c01efff6 100644 --- a/compiler/rustc_infer/src/infer/equate.rs +++ b/compiler/rustc_infer/src/infer/equate.rs @@ -1,4 +1,6 @@ -use super::combine::{CombineFields, ConstEquateRelation, RelationDir}; +use crate::traits::PredicateObligations; + +use super::combine::{CombineFields, ObligationEmittingRelation, RelationDir}; use super::Subtype; use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation}; @@ -198,8 +200,15 @@ impl<'tcx> TypeRelation<'tcx> for Equate<'_, '_, 'tcx> { } } -impl<'tcx> ConstEquateRelation<'tcx> for Equate<'_, '_, 'tcx> { - fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) { - self.fields.add_const_equate_obligation(self.a_is_expected, a, b); +impl<'tcx> ObligationEmittingRelation<'tcx> for Equate<'_, '_, 'tcx> { + fn register_predicates( + &mut self, + obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>, + ) { + self.fields.register_predicates(obligations); + } + + fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { + self.fields.register_obligations(obligations); } } diff --git a/compiler/rustc_infer/src/infer/glb.rs b/compiler/rustc_infer/src/infer/glb.rs index b92b162a978..74abca7bbea 100644 --- a/compiler/rustc_infer/src/infer/glb.rs +++ b/compiler/rustc_infer/src/infer/glb.rs @@ -1,12 +1,11 @@ //! Greatest lower bound. See [`lattice`]. -use super::combine::CombineFields; +use super::combine::{CombineFields, ObligationEmittingRelation}; use super::lattice::{self, LatticeDir}; use super::InferCtxt; use super::Subtype; -use crate::infer::combine::ConstEquateRelation; -use crate::traits::{ObligationCause, PredicateObligation}; +use crate::traits::{ObligationCause, PredicateObligations}; use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation}; use rustc_middle::ty::{self, Ty, TyCtxt}; @@ -136,10 +135,6 @@ impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Glb<'combine, 'infcx, &self.fields.trace.cause } - fn add_obligations(&mut self, obligations: Vec<PredicateObligation<'tcx>>) { - self.fields.obligations.extend(obligations) - } - fn relate_bound(&mut self, v: Ty<'tcx>, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, ()> { let mut sub = self.fields.sub(self.a_is_expected); sub.relate(v, a)?; @@ -152,8 +147,15 @@ impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Glb<'combine, 'infcx, } } -impl<'tcx> ConstEquateRelation<'tcx> for Glb<'_, '_, 'tcx> { - fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) { - self.fields.add_const_equate_obligation(self.a_is_expected, a, b); +impl<'tcx> ObligationEmittingRelation<'tcx> for Glb<'_, '_, 'tcx> { + fn register_predicates( + &mut self, + obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>, + ) { + self.fields.register_predicates(obligations); + } + + fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { + self.fields.register_obligations(obligations); } } diff --git a/compiler/rustc_infer/src/infer/lattice.rs b/compiler/rustc_infer/src/infer/lattice.rs index 4dbb4b4d7b4..f377ac1d19e 100644 --- a/compiler/rustc_infer/src/infer/lattice.rs +++ b/compiler/rustc_infer/src/infer/lattice.rs @@ -17,11 +17,12 @@ //! //! [lattices]: https://en.wikipedia.org/wiki/Lattice_(order) +use super::combine::ObligationEmittingRelation; use super::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use super::InferCtxt; -use crate::traits::{ObligationCause, PredicateObligation}; -use rustc_middle::ty::relate::{RelateResult, TypeRelation}; +use crate::traits::ObligationCause; +use rustc_middle::ty::relate::RelateResult; use rustc_middle::ty::TyVar; use rustc_middle::ty::{self, Ty}; @@ -30,13 +31,11 @@ use rustc_middle::ty::{self, Ty}; /// /// GLB moves "down" the lattice (to smaller values); LUB moves /// "up" the lattice (to bigger values). -pub trait LatticeDir<'f, 'tcx>: TypeRelation<'tcx> { +pub trait LatticeDir<'f, 'tcx>: ObligationEmittingRelation<'tcx> { fn infcx(&self) -> &'f InferCtxt<'tcx>; fn cause(&self) -> &ObligationCause<'tcx>; - fn add_obligations(&mut self, obligations: Vec<PredicateObligation<'tcx>>); - fn define_opaque_types(&self) -> bool; // Relates the type `v` to `a` and `b` such that `v` represents @@ -113,7 +112,7 @@ where | (_, &ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. })) if this.define_opaque_types() && def_id.is_local() => { - this.add_obligations( + this.register_obligations( infcx .handle_opaque_type(a, b, this.a_is_expected(), this.cause(), this.param_env())? .obligations, diff --git a/compiler/rustc_infer/src/infer/lub.rs b/compiler/rustc_infer/src/infer/lub.rs index f6e0554fd1f..f997171b97f 100644 --- a/compiler/rustc_infer/src/infer/lub.rs +++ b/compiler/rustc_infer/src/infer/lub.rs @@ -1,12 +1,11 @@ //! Least upper bound. See [`lattice`]. -use super::combine::CombineFields; +use super::combine::{CombineFields, ObligationEmittingRelation}; use super::lattice::{self, LatticeDir}; use super::InferCtxt; use super::Subtype; -use crate::infer::combine::ConstEquateRelation; -use crate::traits::{ObligationCause, PredicateObligation}; +use crate::traits::{ObligationCause, PredicateObligations}; use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation}; use rustc_middle::ty::{self, Ty, TyCtxt}; @@ -127,12 +126,6 @@ impl<'tcx> TypeRelation<'tcx> for Lub<'_, '_, 'tcx> { } } -impl<'tcx> ConstEquateRelation<'tcx> for Lub<'_, '_, 'tcx> { - fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) { - self.fields.add_const_equate_obligation(self.a_is_expected, a, b); - } -} - impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Lub<'combine, 'infcx, 'tcx> { fn infcx(&self) -> &'infcx InferCtxt<'tcx> { self.fields.infcx @@ -142,10 +135,6 @@ impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Lub<'combine, 'infcx, &self.fields.trace.cause } - fn add_obligations(&mut self, obligations: Vec<PredicateObligation<'tcx>>) { - self.fields.obligations.extend(obligations) - } - fn relate_bound(&mut self, v: Ty<'tcx>, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, ()> { let mut sub = self.fields.sub(self.a_is_expected); sub.relate(a, v)?; @@ -157,3 +146,16 @@ impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Lub<'combine, 'infcx, self.fields.define_opaque_types } } + +impl<'tcx> ObligationEmittingRelation<'tcx> for Lub<'_, '_, 'tcx> { + fn register_predicates( + &mut self, + obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>, + ) { + self.fields.register_predicates(obligations); + } + + fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { + self.fields.register_obligations(obligations) + } +} diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs index 35918b8bae1..e77924900a0 100644 --- a/compiler/rustc_infer/src/infer/mod.rs +++ b/compiler/rustc_infer/src/infer/mod.rs @@ -4,6 +4,7 @@ pub use self::LateBoundRegionConversionTime::*; pub use self::RegionVariableOrigin::*; pub use self::SubregionOrigin::*; pub use self::ValuePairs::*; +pub use combine::ObligationEmittingRelation; use self::opaque_types::OpaqueTypeStorage; pub(crate) use self::undo_log::{InferCtxtUndoLogs, Snapshot, UndoLog}; diff --git a/compiler/rustc_infer/src/infer/nll_relate/mod.rs b/compiler/rustc_infer/src/infer/nll_relate/mod.rs index a2cfe8d8881..1dd5062acaf 100644 --- a/compiler/rustc_infer/src/infer/nll_relate/mod.rs +++ b/compiler/rustc_infer/src/infer/nll_relate/mod.rs @@ -21,11 +21,10 @@ //! thing we relate in chalk are basically domain goals and their //! constituents) -use crate::infer::combine::ConstEquateRelation; use crate::infer::InferCtxt; use crate::infer::{ConstVarValue, ConstVariableValue}; use crate::infer::{TypeVariableOrigin, TypeVariableOriginKind}; -use crate::traits::{Obligation, PredicateObligation}; +use crate::traits::{Obligation, PredicateObligations}; use rustc_data_structures::fx::FxHashMap; use rustc_middle::traits::ObligationCause; use rustc_middle::ty::error::TypeError; @@ -36,11 +35,7 @@ use rustc_span::Span; use std::fmt::Debug; use std::ops::ControlFlow; -#[derive(PartialEq)] -pub enum NormalizationStrategy { - Lazy, - Eager, -} +use super::combine::ObligationEmittingRelation; pub struct TypeRelating<'me, 'tcx, D> where @@ -92,7 +87,7 @@ pub trait TypeRelatingDelegate<'tcx> { info: ty::VarianceDiagInfo<'tcx>, ); - fn register_obligations(&mut self, obligations: Vec<PredicateObligation<'tcx>>); + fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>); /// Creates a new universe index. Used when instantiating placeholders. fn create_next_universe(&mut self) -> ty::UniverseIndex; @@ -125,9 +120,6 @@ pub trait TypeRelatingDelegate<'tcx> { /// relation stating that `'?0: 'a`). fn generalize_existential(&mut self, universe: ty::UniverseIndex) -> ty::Region<'tcx>; - /// Define the normalization strategy to use, eager or lazy. - fn normalization() -> NormalizationStrategy; - /// Enables some optimizations if we do not expect inference variables /// in the RHS of the relation. fn forbid_inference_vars() -> bool; @@ -265,38 +257,6 @@ where self.delegate.push_outlives(sup, sub, info); } - /// Relate a projection type and some value type lazily. This will always - /// succeed, but we push an additional `ProjectionEq` goal depending - /// on the value type: - /// - if the value type is any type `T` which is not a projection, we push - /// `ProjectionEq(projection = T)`. - /// - if the value type is another projection `other_projection`, we create - /// a new inference variable `?U` and push the two goals - /// `ProjectionEq(projection = ?U)`, `ProjectionEq(other_projection = ?U)`. - fn relate_projection_ty( - &mut self, - projection_ty: ty::AliasTy<'tcx>, - value_ty: Ty<'tcx>, - ) -> Ty<'tcx> { - use rustc_span::DUMMY_SP; - - match *value_ty.kind() { - ty::Alias(ty::Projection, other_projection_ty) => { - let var = self.infcx.next_ty_var(TypeVariableOrigin { - kind: TypeVariableOriginKind::MiscVariable, - span: DUMMY_SP, - }); - // FIXME(lazy-normalization): This will always ICE, because the recursive - // call will end up in the _ arm below. - self.relate_projection_ty(projection_ty, var); - self.relate_projection_ty(other_projection_ty, var); - var - } - - _ => bug!("should never be invoked with eager normalization"), - } - } - /// Relate a type inference variable with a value type. This works /// by creating a "generalization" G of the value where all the /// lifetimes are replaced with fresh inference values. This @@ -335,12 +295,6 @@ where return Ok(value_ty); } - ty::Alias(ty::Projection, projection_ty) - if D::normalization() == NormalizationStrategy::Lazy => - { - return Ok(self.relate_projection_ty(projection_ty, self.infcx.tcx.mk_ty_var(vid))); - } - _ => (), } @@ -627,18 +581,6 @@ where self.relate_opaques(a, b) } - (&ty::Alias(ty::Projection, projection_ty), _) - if D::normalization() == NormalizationStrategy::Lazy => - { - Ok(self.relate_projection_ty(projection_ty, b)) - } - - (_, &ty::Alias(ty::Projection, projection_ty)) - if D::normalization() == NormalizationStrategy::Lazy => - { - Ok(self.relate_projection_ty(projection_ty, a)) - } - _ => { debug!(?a, ?b, ?self.ambient_variance); @@ -813,17 +755,26 @@ where } } -impl<'tcx, D> ConstEquateRelation<'tcx> for TypeRelating<'_, 'tcx, D> +impl<'tcx, D> ObligationEmittingRelation<'tcx> for TypeRelating<'_, 'tcx, D> where D: TypeRelatingDelegate<'tcx>, { - fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) { - self.delegate.register_obligations(vec![Obligation::new( - self.tcx(), - ObligationCause::dummy(), - self.param_env(), - ty::Binder::dummy(ty::PredicateKind::ConstEquate(a, b)), - )]); + fn register_predicates( + &mut self, + obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>, + ) { + self.delegate.register_obligations( + obligations + .into_iter() + .map(|to_pred| { + Obligation::new(self.tcx(), ObligationCause::dummy(), self.param_env(), to_pred) + }) + .collect(), + ); + } + + fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { + self.delegate.register_obligations(obligations); } } diff --git a/compiler/rustc_infer/src/infer/outlives/mod.rs b/compiler/rustc_infer/src/infer/outlives/mod.rs index 4daa257672c..a8e668d81ea 100644 --- a/compiler/rustc_infer/src/infer/outlives/mod.rs +++ b/compiler/rustc_infer/src/infer/outlives/mod.rs @@ -21,6 +21,7 @@ pub fn explicit_outlives_bounds<'tcx>( .filter_map(move |kind| match kind { ty::PredicateKind::Clause(ty::Clause::Projection(..)) | ty::PredicateKind::Clause(ty::Clause::Trait(..)) + | ty::PredicateKind::AliasEq(..) | 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 4667d99ff00..f795047709e 100644 --- a/compiler/rustc_infer/src/infer/projection.rs +++ b/compiler/rustc_infer/src/infer/projection.rs @@ -21,16 +21,28 @@ impl<'tcx> InferCtxt<'tcx> { recursion_depth: usize, obligations: &mut Vec<PredicateObligation<'tcx>>, ) -> Ty<'tcx> { - let def_id = projection_ty.def_id; - let ty_var = self.next_ty_var(TypeVariableOrigin { - kind: TypeVariableOriginKind::NormalizeProjectionType, - span: self.tcx.def_span(def_id), - }); - let projection = - ty::Binder::dummy(ty::ProjectionPredicate { projection_ty, term: ty_var.into() }); - let obligation = - Obligation::with_depth(self.tcx, cause, recursion_depth, param_env, projection); - obligations.push(obligation); - ty_var + if self.tcx.trait_solver_next() { + // FIXME(-Ztrait-solver=next): Instead of branching here, + // 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` + // 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); + } else { + let def_id = projection_ty.def_id; + let ty_var = self.next_ty_var(TypeVariableOrigin { + kind: TypeVariableOriginKind::NormalizeProjectionType, + span: self.tcx.def_span(def_id), + }); + let projection = ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::Projection( + ty::ProjectionPredicate { projection_ty, term: ty_var.into() }, + ))); + let obligation = + Obligation::with_depth(self.tcx, cause, recursion_depth, param_env, projection); + obligations.push(obligation); + ty_var + } } } diff --git a/compiler/rustc_infer/src/infer/sub.rs b/compiler/rustc_infer/src/infer/sub.rs index 532fbd0ffe4..bf1b3441547 100644 --- a/compiler/rustc_infer/src/infer/sub.rs +++ b/compiler/rustc_infer/src/infer/sub.rs @@ -1,8 +1,7 @@ use super::combine::{CombineFields, RelationDir}; -use super::SubregionOrigin; +use super::{ObligationEmittingRelation, SubregionOrigin}; -use crate::infer::combine::ConstEquateRelation; -use crate::traits::Obligation; +use crate::traits::{Obligation, PredicateObligations}; use rustc_middle::ty::relate::{Cause, Relate, RelateResult, TypeRelation}; use rustc_middle::ty::visit::TypeVisitable; use rustc_middle::ty::TyVar; @@ -228,8 +227,15 @@ impl<'tcx> TypeRelation<'tcx> for Sub<'_, '_, 'tcx> { } } -impl<'tcx> ConstEquateRelation<'tcx> for Sub<'_, '_, 'tcx> { - fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>) { - self.fields.add_const_equate_obligation(self.a_is_expected, a, b); +impl<'tcx> ObligationEmittingRelation<'tcx> for Sub<'_, '_, 'tcx> { + fn register_predicates( + &mut self, + obligations: impl IntoIterator<Item = impl ty::ToPredicate<'tcx>>, + ) { + self.fields.register_predicates(obligations); + } + + fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>) { + self.fields.register_obligations(obligations); } } diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index 18a966449aa..e617eb68d47 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -294,6 +294,9 @@ impl<'tcx> Elaborator<'tcx> { // Nothing to elaborate } ty::PredicateKind::Ambiguous => {} + ty::PredicateKind::AliasEq(..) => { + // No + } } } } diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs index 5d85cfe330a..7a50b6aec87 100644 --- a/compiler/rustc_lint/src/builtin.rs +++ b/compiler/rustc_lint/src/builtin.rs @@ -1594,12 +1594,14 @@ impl<'tcx> LateLintPass<'tcx> for TrivialConstraints { // Ignore projections, as they can only be global // if the trait bound is global Clause(Clause::Projection(..)) | + AliasEq(..) | // Ignore bounds that a user can't type WellFormed(..) | ObjectSafe(..) | ClosureKind(..) | Subtype(..) | Coerce(..) | + // FIXME(generic_const_exprs): `ConstEvaluatable` can be written ConstEvaluatable(..) | ConstEquate(..) | Ambiguous | diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index 01f18e8158a..04537ad635a 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -2254,6 +2254,10 @@ impl<'tcx> TyCtxt<'tcx> { }) ) } + + pub fn trait_solver_next(self) -> bool { + self.sess.opts.unstable_opts.trait_solver == rustc_session::config::TraitSolver::Next + } } impl<'tcx> TyCtxtAt<'tcx> { diff --git a/compiler/rustc_middle/src/ty/flags.rs b/compiler/rustc_middle/src/ty/flags.rs index dc6f5851b7d..258bc9c3e41 100644 --- a/compiler/rustc_middle/src/ty/flags.rs +++ b/compiler/rustc_middle/src/ty/flags.rs @@ -264,10 +264,7 @@ impl FlagComputation { term, })) => { self.add_projection_ty(projection_ty); - match term.unpack() { - ty::TermKind::Ty(ty) => self.add_ty(ty), - ty::TermKind::Const(c) => self.add_const(c), - } + self.add_term(term); } ty::PredicateKind::WellFormed(arg) => { self.add_substs(slice::from_ref(&arg)); @@ -287,6 +284,10 @@ impl FlagComputation { self.add_ty(ty); } ty::PredicateKind::Ambiguous => {} + ty::PredicateKind::AliasEq(t1, t2) => { + self.add_term(t1); + self.add_term(t2); + } } } @@ -380,4 +381,11 @@ impl FlagComputation { } } } + + fn add_term(&mut self, term: ty::Term<'_>) { + match term.unpack() { + ty::TermKind::Ty(ty) => self.add_ty(ty), + ty::TermKind::Const(ct) => self.add_const(ct), + } + } } diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs index 09c3d5b736c..0e86b2666b2 100644 --- a/compiler/rustc_middle/src/ty/mod.rs +++ b/compiler/rustc_middle/src/ty/mod.rs @@ -545,6 +545,7 @@ impl<'tcx> Predicate<'tcx> { | PredicateKind::Clause(Clause::RegionOutlives(_)) | PredicateKind::Clause(Clause::TypeOutlives(_)) | PredicateKind::Clause(Clause::Projection(_)) + | PredicateKind::AliasEq(..) | PredicateKind::ObjectSafe(_) | PredicateKind::ClosureKind(_, _, _) | PredicateKind::Subtype(_) @@ -632,6 +633,12 @@ pub enum PredicateKind<'tcx> { /// A marker predicate that is always ambiguous. /// Used for coherence to mark opaque types as possibly equal to each other but ambiguous. Ambiguous, + + /// Separate from `Clause::Projection` which is used for normalization in new solver. + /// This predicate requires two terms to be equal to eachother. + /// + /// Only used for new solver + AliasEq(Term<'tcx>, Term<'tcx>), } /// The crate outlives map is computed during typeck and contains the @@ -963,6 +970,33 @@ impl<'tcx> Term<'tcx> { TermKind::Const(c) => c.into(), } } + + /// This function returns `None` for `AliasKind::Opaque`. + /// + /// 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>> { + match self.unpack() { + TermKind::Ty(ty) => match ty.kind() { + ty::Alias(kind, alias_ty) => match kind { + AliasKind::Projection => Some(*alias_ty), + AliasKind::Opaque => None, + }, + _ => None, + }, + TermKind::Const(ct) => match ct.kind() { + ConstKind::Unevaluated(uv) => Some(tcx.mk_alias_ty(uv.def.did, uv.substs)), + _ => None, + }, + } + } + + pub fn is_infer(&self) -> bool { + match self.unpack() { + TermKind::Ty(ty) => ty.is_ty_or_numeric_infer(), + TermKind::Const(ct) => ct.is_ct_infer(), + } + } } const TAG_MASK: usize = 0b11; @@ -1152,6 +1186,7 @@ impl<'tcx> Predicate<'tcx> { match predicate.skip_binder() { PredicateKind::Clause(Clause::Trait(t)) => Some(predicate.rebind(t)), PredicateKind::Clause(Clause::Projection(..)) + | PredicateKind::AliasEq(..) | PredicateKind::Subtype(..) | PredicateKind::Coerce(..) | PredicateKind::Clause(Clause::RegionOutlives(..)) @@ -1171,6 +1206,7 @@ impl<'tcx> Predicate<'tcx> { match predicate.skip_binder() { PredicateKind::Clause(Clause::Projection(t)) => Some(predicate.rebind(t)), PredicateKind::Clause(Clause::Trait(..)) + | PredicateKind::AliasEq(..) | PredicateKind::Subtype(..) | PredicateKind::Coerce(..) | PredicateKind::Clause(Clause::RegionOutlives(..)) @@ -1191,6 +1227,7 @@ impl<'tcx> Predicate<'tcx> { PredicateKind::Clause(Clause::TypeOutlives(data)) => Some(predicate.rebind(data)), PredicateKind::Clause(Clause::Trait(..)) | PredicateKind::Clause(Clause::Projection(..)) + | PredicateKind::AliasEq(..) | 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 a8b23e64e82..7ba531fba78 100644 --- a/compiler/rustc_middle/src/ty/print/pretty.rs +++ b/compiler/rustc_middle/src/ty/print/pretty.rs @@ -2842,6 +2842,7 @@ 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)), } } diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs index 8df639750c7..1ef66b01ea0 100644 --- a/compiler/rustc_middle/src/ty/structural_impls.rs +++ b/compiler/rustc_middle/src/ty/structural_impls.rs @@ -177,6 +177,7 @@ 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:?})"), } } } diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs index c1936b7dbe4..a55b984fd63 100644 --- a/compiler/rustc_trait_selection/src/solve/fulfill.rs +++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs @@ -73,6 +73,11 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> { MismatchedProjectionTypes { err: TypeError::Mismatch }, ) } + ty::PredicateKind::AliasEq(_, _) => { + FulfillmentErrorCode::CodeProjectionError( + MismatchedProjectionTypes { err: TypeError::Mismatch }, + ) + } ty::PredicateKind::Subtype(pred) => { let (a, b) = infcx.instantiate_binder_with_placeholders( goal.predicate.kind().rebind((pred.a, pred.b)), diff --git a/compiler/rustc_trait_selection/src/solve/mod.rs b/compiler/rustc_trait_selection/src/solve/mod.rs index 9f092b6018f..e56588c58bd 100644 --- a/compiler/rustc_trait_selection/src/solve/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/mod.rs @@ -42,6 +42,8 @@ mod trait_goals; pub use fulfill::FulfillmentCtxt; +use self::infcx_ext::InferCtxtExt; + /// A goal is a statement, i.e. `predicate`, we want to prove /// given some assumptions, i.e. `param_env`. /// @@ -81,6 +83,21 @@ pub struct Response<'tcx> { pub certainty: Certainty, } +trait CanonicalResponseExt { + fn has_no_inference_or_external_constraints(&self) -> bool; +} + +impl<'tcx> CanonicalResponseExt for Canonical<'tcx, Response<'tcx>> { + fn has_no_inference_or_external_constraints(&self) -> bool { + // so that we get a compile error when regions are supported + // so this code can be checked for being correct + let _: () = self.value.external_constraints.regions; + + self.value.var_values.is_identity() + && self.value.external_constraints.opaque_types.is_empty() + } +} + #[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, TypeFoldable, TypeVisitable)] pub enum Certainty { Yes, @@ -302,6 +319,9 @@ 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) }) + } } } else { let kind = self.infcx.instantiate_binder_with_placeholders(kind); @@ -398,6 +418,63 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> { None => self.make_canonical_response(Certainty::AMBIGUOUS), } } + + #[instrument(level = "debug", skip(self), ret)] + fn compute_alias_eq_goal( + &mut self, + goal: Goal<'tcx, (ty::Term<'tcx>, ty::Term<'tcx>)>, + ) -> QueryResult<'tcx> { + let tcx = self.tcx(); + + let evaluate_normalizes_to = |ecx: &mut EvalCtxt<'_, 'tcx>, alias, other| { + debug!("evaluate_normalizes_to(alias={:?}, other={:?})", alias, other); + let r = ecx.infcx.probe(|_| { + let (_, certainty) = ecx.evaluate_goal(goal.with( + tcx, + ty::Binder::dummy(ty::ProjectionPredicate { + projection_ty: alias, + term: other, + }), + ))?; + ecx.make_canonical_response(certainty) + }); + debug!("evaluate_normalizes_to(..) -> {:?}", r); + r + }; + + if goal.predicate.0.is_infer() || goal.predicate.1.is_infer() { + bug!( + "`AliasEq` 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"); + + let mut candidates = Vec::with_capacity(3); + + // 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.infcx.probe(|_| { + debug!("compute_alias_eq_goal: alias defids are equal, equating substs"); + let nested_goals = self.infcx.eq(goal.param_env, alias_lhs, alias_rhs)?; + self.evaluate_all_and_make_canonical_response(nested_goals) + })); + + debug!(?candidates); + + self.try_merge_responses(candidates.into_iter()) + } + } + } } impl<'tcx> EvalCtxt<'_, 'tcx> { @@ -449,6 +526,43 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { ) -> QueryResult<'tcx> { self.evaluate_all(goals).and_then(|certainty| self.make_canonical_response(certainty)) } + + fn try_merge_responses( + &mut self, + responses: impl Iterator<Item = QueryResult<'tcx>>, + ) -> QueryResult<'tcx> { + let candidates = responses.into_iter().flatten().collect::<Box<[_]>>(); + + if candidates.is_empty() { + return Err(NoSolution); + } + + // FIXME(-Ztreat-solver=next): We should instead try to find a `Certainty::Yes` response with + // a subset of the constraints that all the other responses have. + let one = candidates[0]; + if candidates[1..].iter().all(|resp| resp == &one) { + return Ok(one); + } + + if let Some(response) = candidates.iter().find(|response| { + response.value.certainty == Certainty::Yes + && response.has_no_inference_or_external_constraints() + }) { + return Ok(response.clone()); + } + + let certainty = candidates.iter().fold(Certainty::AMBIGUOUS, |certainty, response| { + certainty.unify_and(response.value.certainty) + }); + // FIXME(-Ztrait-solver=next): We should take the intersection of the constraints on all the + // responses and use that for the constraints of this ambiguous response. + let response = self.make_canonical_response(certainty); + if let Ok(response) = &response { + assert!(response.has_no_inference_or_external_constraints()); + } + + response + } } #[instrument(level = "debug", skip(infcx), ret)] diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs index 948632ccc6c..6a840704e86 100644 --- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs +++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs @@ -823,14 +823,17 @@ impl<'tcx> AutoTraitFinder<'tcx> { _ => return false, } } + // There's not really much we can do with these predicates - // we start out with a `ParamEnv` with no inference variables, // and these don't correspond to adding any new bounds to // the `ParamEnv`. ty::PredicateKind::WellFormed(..) + | ty::PredicateKind::AliasEq(..) | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) + // FIXME(generic_const_exprs): you can absolutely add this as a where clauses | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::Coerce(..) | ty::PredicateKind::TypeWellFormedFromEnv(..) => {} 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 ba9ee57d409..9474c70cb53 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 @@ -1,5 +1,7 @@ use crate::infer::InferCtxt; +use rustc_infer::infer::ObligationEmittingRelation; +use rustc_infer::traits::PredicateObligations; use rustc_middle::ty::error::TypeError; use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation}; use rustc_middle::ty::{self, Ty, TyCtxt}; @@ -88,3 +90,16 @@ impl<'a, 'tcx> TypeRelation<'tcx> for CollectAllMismatches<'a, 'tcx> { Ok(a.rebind(self.relate(a.skip_binder(), b.skip_binder())?)) } } + +impl<'tcx> ObligationEmittingRelation<'tcx> for CollectAllMismatches<'_, 'tcx> { + fn register_obligations(&mut self, _obligations: PredicateObligations<'tcx>) { + // FIXME(deferred_projection_equality) + } + + fn register_predicates( + &mut self, + _obligations: impl IntoIterator<Item = impl ty::ToPredicate<'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 cf1e05ada47..4867855c2ae 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -1278,6 +1278,11 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { span, "TypeWellFormedFromEnv predicate should only exist in the environment" ), + + ty::PredicateKind::AliasEq(..) => span_bug!( + span, + "AliasEq predicate should never be the predicate cause of a SelectionError" + ), } } diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs index 3adc1e62e0d..19d47d33f67 100644 --- a/compiler/rustc_trait_selection/src/traits/fulfill.rs +++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs @@ -328,6 +328,9 @@ 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") + } }, Some(pred) => match pred { ty::PredicateKind::Clause(ty::Clause::Trait(data)) => { @@ -594,6 +597,9 @@ 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") + } }, } } diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs index bafa2981a87..977446894e7 100644 --- a/compiler/rustc_trait_selection/src/traits/object_safety.rs +++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs @@ -327,6 +327,8 @@ fn predicate_references_self<'tcx>( // possible alternatives. if data.projection_ty.substs[1..].iter().any(has_self_ty) { Some(sp) } else { None } } + ty::PredicateKind::AliasEq(..) => bug!("`AliasEq` not allowed as assumption"), + ty::PredicateKind::WellFormed(..) | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..)) @@ -334,6 +336,7 @@ fn predicate_references_self<'tcx>( | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::Coerce(..) + // FIXME(generic_const_exprs): this can mention `Self` | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::Ambiguous @@ -368,6 +371,7 @@ 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::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 984d6fde268..45c4811321a 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -991,6 +991,9 @@ 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::Ambiguous => Ok(EvaluatedToAmbig), } }) diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs index 7c5e147a950..1136b70a0b9 100644 --- a/compiler/rustc_trait_selection/src/traits/wf.rs +++ b/compiler/rustc_trait_selection/src/traits/wf.rs @@ -187,6 +187,9 @@ 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`") + } } wf.normalize(infcx) @@ -928,6 +931,7 @@ pub(crate) fn required_region_bounds<'tcx>( | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::Ambiguous + | ty::PredicateKind::AliasEq(..) | 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 65ed3105d10..7c9a014e2ab 100644 --- a/compiler/rustc_traits/src/chalk/lowering.rs +++ b/compiler/rustc_traits/src/chalk/lowering.rs @@ -116,6 +116,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<' )), }, ty::PredicateKind::ObjectSafe(..) + | ty::PredicateKind::AliasEq(..) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::Coerce(..) @@ -210,6 +211,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predi // We can defer this, but ultimately we'll want to express // some of these in terms of chalk operations. ty::PredicateKind::ClosureKind(..) + | ty::PredicateKind::AliasEq(..) | ty::PredicateKind::Coerce(..) | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::Ambiguous @@ -645,6 +647,7 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_ir::QuantifiedWhereClause<RustInterner<' ty::PredicateKind::WellFormed(_ty) => None, ty::PredicateKind::ObjectSafe(..) + | ty::PredicateKind::AliasEq(..) | ty::PredicateKind::ClosureKind(..) | ty::PredicateKind::Subtype(..) | ty::PredicateKind::Coerce(..) @@ -778,6 +781,7 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_solve::rust_ir::QuantifiedInlineBound<Ru ty::PredicateKind::WellFormed(_ty) => None, ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..)) + | ty::PredicateKind::AliasEq(..) | 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 2c6c77072e6..93f9b66e0f8 100644 --- a/compiler/rustc_traits/src/implied_outlives_bounds.rs +++ b/compiler/rustc_traits/src/implied_outlives_bounds.rs @@ -85,7 +85,8 @@ fn compute_implied_outlives_bounds<'tcx>( // learn anything new from those. if obligation.predicate.has_non_region_infer() { match obligation.predicate.kind().skip_binder() { - ty::PredicateKind::Clause(ty::Clause::Projection(..)) => { + ty::PredicateKind::Clause(ty::Clause::Projection(..)) + | ty::PredicateKind::AliasEq(..) => { ocx.register_obligation(obligation.clone()); } _ => {} @@ -106,6 +107,7 @@ fn compute_implied_outlives_bounds<'tcx>( | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::Ambiguous + | ty::PredicateKind::AliasEq(..) | 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 5cad2c2ccb0..07e716cda42 100644 --- a/compiler/rustc_traits/src/normalize_erasing_regions.rs +++ b/compiler/rustc_traits/src/normalize_erasing_regions.rs @@ -60,6 +60,7 @@ fn not_outlives_predicate(p: ty::Predicate<'_>) -> bool { | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..)) => false, ty::PredicateKind::Clause(ty::Clause::Trait(..)) | ty::PredicateKind::Clause(ty::Clause::Projection(..)) + | ty::PredicateKind::AliasEq(..) | ty::PredicateKind::WellFormed(..) | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ClosureKind(..) diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs index 5bda3620dd0..d497f7ea679 100644 --- a/src/librustdoc/clean/mod.rs +++ b/src/librustdoc/clean/mod.rs @@ -311,10 +311,12 @@ pub(crate) fn clean_predicate<'tcx>( ty::PredicateKind::Clause(ty::Clause::Projection(pred)) => { Some(clean_projection_predicate(bound_predicate.rebind(pred), cx)) } + // FIXME(generic_const_exprs): should this do something? ty::PredicateKind::ConstEvaluatable(..) => None, ty::PredicateKind::WellFormed(..) => None, ty::PredicateKind::Subtype(..) + | ty::PredicateKind::AliasEq(..) | ty::PredicateKind::Coerce(..) | ty::PredicateKind::ObjectSafe(..) | ty::PredicateKind::ClosureKind(..) diff --git a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs index 72705878075..26b1d019749 100644 --- a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs +++ b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs @@ -36,6 +36,7 @@ pub fn is_min_const_fn<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>, msrv: &Msrv) | ty::PredicateKind::ConstEvaluatable(..) | ty::PredicateKind::ConstEquate(..) | ty::PredicateKind::TypeWellFormedFromEnv(..) => continue, + ty::PredicateKind::AliasEq(..) => panic!("alias eq predicate on function: {predicate:#?}"), ty::PredicateKind::ObjectSafe(_) => panic!("object safe predicate on function: {predicate:#?}"), ty::PredicateKind::ClosureKind(..) => panic!("closure kind predicate on function: {predicate:#?}"), ty::PredicateKind::Subtype(_) => panic!("subtype predicate on function: {predicate:#?}"), diff --git a/tests/ui/traits/new-solver/alias_eq_cant_be_furthur_normalized.rs b/tests/ui/traits/new-solver/alias_eq_cant_be_furthur_normalized.rs new file mode 100644 index 00000000000..dc726ba51f9 --- /dev/null +++ b/tests/ui/traits/new-solver/alias_eq_cant_be_furthur_normalized.rs @@ -0,0 +1,29 @@ +// check-pass +// compile-flags: -Ztrait-solver=next + +// check that a goal such as `alias-eq(<T as TraitB>::Assoc<bool>, <T as TraitB>::Assoc<?0>)` +// succeeds with a constraint that `?0 = bool` + +// FIXME(deferred_projection_equality): add a test that this is true during coherence + +trait TraitA {} + +trait TraitB { + type Assoc<T: ?Sized>; +} + +impl<T: TraitB> TraitA for (T, T::Assoc<bool>) {} + +impl TraitB for i32 { + type Assoc<T: ?Sized> = u32; +} + +fn needs_a<T: TraitA>() {} + +fn bar<T: TraitB>() { + needs_a::<(T, <T as TraitB>::Assoc<_>)>(); +} + +fn main() { + bar::<i32>(); +} diff --git a/tests/ui/traits/new-solver/alias_eq_dont_use_normalizes_to_if_substs_eq.rs b/tests/ui/traits/new-solver/alias_eq_dont_use_normalizes_to_if_substs_eq.rs new file mode 100644 index 00000000000..fd5d0e3b194 --- /dev/null +++ b/tests/ui/traits/new-solver/alias_eq_dont_use_normalizes_to_if_substs_eq.rs @@ -0,0 +1,45 @@ +// compile-flags: -Ztrait-solver=next + +// check that when computing `alias-eq(<() as Foo<u16, T>>::Assoc, <() as Foo<?0, T>>::Assoc)` +// we do not infer `?0 = u8` via the `for<STOP> (): Foo<u8, STOP>` impl or `?0 = u16` by +// relating substs as either could be a valid solution. + +trait Foo<T, STOP> { + type Assoc; +} + +impl<STOP> Foo<u8, STOP> for () +where + (): Foo<u16, STOP>, +{ + type Assoc = <() as Foo<u16, STOP>>::Assoc; +} + +impl Foo<u16, i8> for () { + type Assoc = u8; +} + +impl Foo<u16, i16> for () { + type Assoc = u16; +} + +fn output<T, U>() -> <() as Foo<T, U>>::Assoc +where + (): Foo<T, U>, +{ + todo!() +} + +fn incomplete<T>() +where + (): Foo<u16, T>, +{ + // `<() as Foo<u16, STOP>>::Assoc == <() as Foo<_, STOP>>::Assoc` + let _: <() as Foo<u16, T>>::Assoc = output::<_, T>(); + //~^ error: type annotations needed + + // let _: <() as Foo<u16, T>>::Assoc = output::<u8, T>(); // OK + // let _: <() as Foo<u16, T>>::Assoc = output::<u16, T>(); // OK +} + +fn main() {} diff --git a/tests/ui/traits/new-solver/alias_eq_dont_use_normalizes_to_if_substs_eq.stderr b/tests/ui/traits/new-solver/alias_eq_dont_use_normalizes_to_if_substs_eq.stderr new file mode 100644 index 00000000000..a6712332c37 --- /dev/null +++ b/tests/ui/traits/new-solver/alias_eq_dont_use_normalizes_to_if_substs_eq.stderr @@ -0,0 +1,9 @@ +error[E0282]: type annotations needed + --> $DIR/alias_eq_dont_use_normalizes_to_if_substs_eq.rs:38:41 + | +LL | let _: <() as Foo<u16, T>>::Assoc = output::<_, T>(); + | ^^^^^^^^^^^^^^ cannot infer type of the type parameter `T` declared on the function `output` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0282`. diff --git a/tests/ui/traits/new-solver/alias_eq_simple.rs b/tests/ui/traits/new-solver/alias_eq_simple.rs new file mode 100644 index 00000000000..6792cf3ce35 --- /dev/null +++ b/tests/ui/traits/new-solver/alias_eq_simple.rs @@ -0,0 +1,22 @@ +// check-pass +// compile-flags: -Ztrait-solver=next + +// test that the new solver can handle `alias-eq(<i32 as TraitB>::Assoc, u32)` + +trait TraitA {} + +trait TraitB { + type Assoc; +} + +impl<T: TraitB> TraitA for (T, T::Assoc) {} + +impl TraitB for i32 { + type Assoc = u32; +} + +fn needs_a<T: TraitA>() {} + +fn main() { + needs_a::<(i32, u32)>(); +} diff --git a/tests/ui/traits/new-solver/alias_eq_substs_eq_not_intercrate.rs b/tests/ui/traits/new-solver/alias_eq_substs_eq_not_intercrate.rs new file mode 100644 index 00000000000..d4cc380fa21 --- /dev/null +++ b/tests/ui/traits/new-solver/alias_eq_substs_eq_not_intercrate.rs @@ -0,0 +1,20 @@ +// compile-flags: -Ztrait-solver=next + +// check that a `alias-eq(<?0 as TraitB>::Assoc, <T as TraitB>::Assoc)` goal fails. + +// FIXME(deferred_projection_equality): add a test that this is true during coherence + +trait TraitB { + type Assoc; +} + +fn needs_a<T: TraitB>() -> T::Assoc { + unimplemented!() +} + +fn bar<T: TraitB>() { + let _: <_ as TraitB>::Assoc = needs_a::<T>(); + //~^ error: type annotations needed +} + +fn main() {} diff --git a/tests/ui/traits/new-solver/alias_eq_substs_eq_not_intercrate.stderr b/tests/ui/traits/new-solver/alias_eq_substs_eq_not_intercrate.stderr new file mode 100644 index 00000000000..d063d8fce11 --- /dev/null +++ b/tests/ui/traits/new-solver/alias_eq_substs_eq_not_intercrate.stderr @@ -0,0 +1,9 @@ +error[E0282]: type annotations needed + --> $DIR/alias_eq_substs_eq_not_intercrate.rs:16:12 + | +LL | let _: <_ as TraitB>::Assoc = needs_a::<T>(); + | ^^^^^^^^^^^^^^^^^^^^ cannot infer type for associated type `<_ as TraitB>::Assoc` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0282`. diff --git a/tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.rs b/tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.rs new file mode 100644 index 00000000000..46343241b45 --- /dev/null +++ b/tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.rs @@ -0,0 +1,40 @@ +// [no_self_infer] check-pass +// compile-flags: -Ztrait-solver=next +// revisions: self_infer no_self_infer + +// checks that the new solver is smart enough to infer `?0 = U` when solving: +// `normalizes-to(<Vec<?0> as Trait>::Assoc, u8)` +// with `normalizes-to(<Vec<U> as Trait>::Assoc, u8)` in the paramenv even when +// there is a separate `Vec<T>: Trait` bound in the paramenv. +// +// FIXME(-Ztrait-solver=next) +// This could also compile for `normalizes-to(<?0 as Trait>::Assoc, u8)` but +// we currently immediately consider a goal ambiguous if the self type is an +// inference variable. + +trait Trait { + type Assoc; +} + +fn foo<T: Trait<Assoc = u8>>(x: T) {} + +#[cfg(self_infer)] +fn unconstrained<T>() -> T { + todo!() +} + +#[cfg(no_self_infer)] +fn unconstrained<T>() -> Vec<T> { + todo!() +} + +fn bar<T, U>() +where + Vec<T>: Trait, + Vec<U>: Trait<Assoc = u8>, +{ + foo(unconstrained()) + //[self_infer]~^ ERROR type annotations needed +} + +fn main() {} diff --git a/tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.self_infer.stderr b/tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.self_infer.stderr new file mode 100644 index 00000000000..06283201261 --- /dev/null +++ b/tests/ui/traits/new-solver/normalizes_to_ignores_unnormalizable_candidate.self_infer.stderr @@ -0,0 +1,14 @@ +error[E0282]: type annotations needed + --> $DIR/normalizes_to_ignores_unnormalizable_candidate.rs:36:5 + | +LL | foo(unconstrained()) + | ^^^ cannot infer type of the type parameter `T` declared on the function `foo` + | +help: consider specifying the generic argument + | +LL | foo::<T>(unconstrained()) + | +++++ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0282`. |