diff options
Diffstat (limited to 'compiler/rustc_infer/src/traits/util.rs')
| -rw-r--r-- | compiler/rustc_infer/src/traits/util.rs | 128 |
1 files changed, 84 insertions, 44 deletions
diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index 74a78f380..074ff7ec9 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -3,7 +3,7 @@ use smallvec::smallvec; use crate::infer::outlives::components::{push_outlives_components, Component}; use crate::traits::{self, Obligation, PredicateObligation}; use rustc_data_structures::fx::{FxHashSet, FxIndexSet}; -use rustc_middle::ty::{self, ToPredicate, TyCtxt}; +use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt}; use rustc_span::symbol::Ident; use rustc_span::Span; @@ -80,14 +80,14 @@ pub struct Elaborator<'tcx, O> { pub trait Elaboratable<'tcx> { fn predicate(&self) -> ty::Predicate<'tcx>; - // Makes a new `Self` but with a different predicate. - fn child(&self, predicate: ty::Predicate<'tcx>) -> Self; + // Makes a new `Self` but with a different clause that comes from elaboration. + fn child(&self, clause: ty::Clause<'tcx>) -> Self; - // Makes a new `Self` but with a different predicate and a different cause - // code (if `Self` has one). + // Makes a new `Self` but with a different clause and a different cause + // code (if `Self` has one, such as [`PredicateObligation`]). fn child_with_derived_cause( &self, - predicate: ty::Predicate<'tcx>, + clause: ty::Clause<'tcx>, span: Span, parent_trait_pred: ty::PolyTraitPredicate<'tcx>, index: usize, @@ -99,18 +99,18 @@ impl<'tcx> Elaboratable<'tcx> for PredicateObligation<'tcx> { self.predicate } - fn child(&self, predicate: ty::Predicate<'tcx>) -> Self { + fn child(&self, clause: ty::Clause<'tcx>) -> Self { Obligation { cause: self.cause.clone(), param_env: self.param_env, recursion_depth: 0, - predicate, + predicate: clause.as_predicate(), } } fn child_with_derived_cause( &self, - predicate: ty::Predicate<'tcx>, + clause: ty::Clause<'tcx>, span: Span, parent_trait_pred: ty::PolyTraitPredicate<'tcx>, index: usize, @@ -123,7 +123,12 @@ impl<'tcx> Elaboratable<'tcx> for PredicateObligation<'tcx> { span, })) }); - Obligation { cause, param_env: self.param_env, recursion_depth: 0, predicate } + Obligation { + cause, + param_env: self.param_env, + recursion_depth: 0, + predicate: clause.as_predicate(), + } } } @@ -132,18 +137,18 @@ impl<'tcx> Elaboratable<'tcx> for ty::Predicate<'tcx> { *self } - fn child(&self, predicate: ty::Predicate<'tcx>) -> Self { - predicate + fn child(&self, clause: ty::Clause<'tcx>) -> Self { + clause.as_predicate() } fn child_with_derived_cause( &self, - predicate: ty::Predicate<'tcx>, + clause: ty::Clause<'tcx>, _span: Span, _parent_trait_pred: ty::PolyTraitPredicate<'tcx>, _index: usize, ) -> Self { - predicate + clause.as_predicate() } } @@ -152,18 +157,58 @@ impl<'tcx> Elaboratable<'tcx> for (ty::Predicate<'tcx>, Span) { self.0 } - fn child(&self, predicate: ty::Predicate<'tcx>) -> Self { - (predicate, self.1) + fn child(&self, clause: ty::Clause<'tcx>) -> Self { + (clause.as_predicate(), self.1) + } + + fn child_with_derived_cause( + &self, + clause: ty::Clause<'tcx>, + _span: Span, + _parent_trait_pred: ty::PolyTraitPredicate<'tcx>, + _index: usize, + ) -> Self { + (clause.as_predicate(), self.1) + } +} + +impl<'tcx> Elaboratable<'tcx> for (ty::Clause<'tcx>, Span) { + fn predicate(&self) -> ty::Predicate<'tcx> { + self.0.as_predicate() + } + + fn child(&self, clause: ty::Clause<'tcx>) -> Self { + (clause, self.1) } fn child_with_derived_cause( &self, - predicate: ty::Predicate<'tcx>, + clause: ty::Clause<'tcx>, _span: Span, _parent_trait_pred: ty::PolyTraitPredicate<'tcx>, _index: usize, ) -> Self { - (predicate, self.1) + (clause, self.1) + } +} + +impl<'tcx> Elaboratable<'tcx> for ty::Clause<'tcx> { + fn predicate(&self) -> ty::Predicate<'tcx> { + self.as_predicate() + } + + fn child(&self, clause: ty::Clause<'tcx>) -> Self { + clause + } + + fn child_with_derived_cause( + &self, + clause: ty::Clause<'tcx>, + _span: Span, + _parent_trait_pred: ty::PolyTraitPredicate<'tcx>, + _index: usize, + ) -> Self { + clause } } @@ -199,7 +244,7 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> { let bound_predicate = elaboratable.predicate().kind(); match bound_predicate.skip_binder() { - ty::PredicateKind::Clause(ty::Clause::Trait(data)) => { + ty::PredicateKind::Clause(ty::ClauseKind::Trait(data)) => { // Negative trait bounds do not imply any supertrait bounds if data.polarity == ty::ImplPolarity::Negative { return; @@ -212,13 +257,13 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> { }; let obligations = - predicates.predicates.iter().enumerate().map(|(index, &(mut pred, span))| { + predicates.predicates.iter().enumerate().map(|(index, &(mut clause, span))| { // when parent predicate is non-const, elaborate it to non-const predicates. if data.constness == ty::BoundConstness::NotConst { - pred = pred.without_const(tcx); + clause = clause.without_const(tcx); } elaboratable.child_with_derived_cause( - pred.subst_supertrait(tcx, &bound_predicate.rebind(data.trait_ref)), + clause.subst_supertrait(tcx, &bound_predicate.rebind(data.trait_ref)), span, bound_predicate.rebind(data), index, @@ -227,7 +272,7 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> { debug!(?data, ?obligations, "super_predicates"); self.extend_deduped(obligations); } - ty::PredicateKind::WellFormed(..) => { + ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(..)) => { // Currently, we do not elaborate WF predicates, // although we easily could. } @@ -243,13 +288,13 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> { // Currently, we do not "elaborate" predicates like `X -> Y`, // though conceivably we might. } - ty::PredicateKind::Clause(ty::Clause::Projection(..)) => { + ty::PredicateKind::Clause(ty::ClauseKind::Projection(..)) => { // Nothing to elaborate in a projection predicate. } ty::PredicateKind::ClosureKind(..) => { // Nothing to elaborate when waiting for a closure's kind to be inferred. } - ty::PredicateKind::ConstEvaluatable(..) => { + ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(..)) => { // Currently, we do not elaborate const-evaluatable // predicates. } @@ -257,10 +302,10 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> { // Currently, we do not elaborate const-equate // predicates. } - ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..)) => { + ty::PredicateKind::Clause(ty::ClauseKind::RegionOutlives(..)) => { // Nothing to elaborate from `'a: 'b`. } - ty::PredicateKind::Clause(ty::Clause::TypeOutlives(ty::OutlivesPredicate( + ty::PredicateKind::Clause(ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate( ty_max, r_min, ))) => { @@ -292,17 +337,15 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> { if r.is_late_bound() { None } else { - Some(ty::PredicateKind::Clause(ty::Clause::RegionOutlives( - ty::OutlivesPredicate(r, r_min), + Some(ty::ClauseKind::RegionOutlives(ty::OutlivesPredicate( + r, r_min, ))) } } Component::Param(p) => { - let ty = tcx.mk_ty_param(p.index, p.name); - Some(ty::PredicateKind::Clause(ty::Clause::TypeOutlives( - ty::OutlivesPredicate(ty, r_min), - ))) + let ty = Ty::new_param(tcx, p.index, p.name); + Some(ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(ty, r_min))) } Component::UnresolvedInferenceVariable(_) => None, @@ -310,8 +353,9 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> { Component::Alias(alias_ty) => { // We might end up here if we have `Foo<<Bar as Baz>::Assoc>: 'a`. // With this, we can deduce that `<Bar as Baz>::Assoc: 'a`. - Some(ty::PredicateKind::Clause(ty::Clause::TypeOutlives( - ty::OutlivesPredicate(alias_ty.to_ty(tcx), r_min), + Some(ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate( + alias_ty.to_ty(tcx), + r_min, ))) } @@ -321,20 +365,16 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> { None } }) - .map(|predicate_kind| { - bound_predicate.rebind(predicate_kind).to_predicate(tcx) - }) - .map(|predicate| elaboratable.child(predicate)), + .map(|clause| { + elaboratable.child(bound_predicate.rebind(clause).to_predicate(tcx)) + }), ); } - ty::PredicateKind::TypeWellFormedFromEnv(..) => { - // Nothing to elaborate - } ty::PredicateKind::Ambiguous => {} ty::PredicateKind::AliasRelate(..) => { // No } - ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => { + ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(..)) => { // Nothing to elaborate } } @@ -400,7 +440,7 @@ pub fn transitive_bounds_that_define_assoc_item<'tcx>( tcx.super_predicates_that_define_assoc_item((trait_ref.def_id(), assoc_name)); for (super_predicate, _) in super_predicates.predicates { let subst_predicate = super_predicate.subst_supertrait(tcx, &trait_ref); - if let Some(binder) = subst_predicate.to_opt_poly_trait_pred() { + if let Some(binder) = subst_predicate.as_trait_clause() { stack.push(binder.map_bound(|t| t.trait_ref)); } } |