Correctly check auto traits on generator interiors

compiler/rustc_middle/src/ty/codec.rs

@@ -381,19 +381,19 @@ impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for ty::List<ty::BoundVaria
     }
 }
 
-impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for ty::List<ty::ProjectionPredicate<'tcx>> {
+impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for ty::List<ty::GeneratorPredicate<'tcx>> {
     fn decode(decoder: &mut D) -> &'tcx Self {
         let len = decoder.read_usize();
-        decoder.tcx().mk_projection_predicates(
-            (0..len).map::<ty::ProjectionPredicate<'tcx>, _>(|_| Decodable::decode(decoder)),
+        decoder.tcx().mk_generator_predicates(
+            (0..len).map::<ty::GeneratorPredicate<'tcx>, _>(|_| Decodable::decode(decoder)),
         )
     }
 }
 
 impl_decodable_via_ref! {
     &'tcx ty::TypeckResults<'tcx>,
     &'tcx ty::List<Ty<'tcx>>,
-    &'tcx ty::List<ty::ProjectionPredicate<'tcx>>,
+    &'tcx ty::List<ty::GeneratorPredicate<'tcx>>,
     &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
     &'tcx Allocation,
     &'tcx mir::Body<'tcx>,
@@ -514,7 +514,7 @@ macro_rules! impl_binder_encode_decode {
 
 impl_binder_encode_decode! {
     &'tcx ty::List<Ty<'tcx>>,
-    &'tcx ty::List<ty::ProjectionPredicate<'tcx>>,
+    &'tcx ty::List<ty::GeneratorPredicate<'tcx>>,
     ty::GeneratorWitnessInner<'tcx>,
     ty::FnSig<'tcx>,
     ty::ExistentialPredicate<'tcx>,

compiler/rustc_middle/src/ty/context.rs

@@ -17,10 +17,10 @@ use crate::ty::TyKind::*;
 use crate::ty::{
     self, AdtDef, AdtKind, Binder, BindingMode, BoundVar, CanonicalPolyFnSig,
     ClosureSizeProfileData, Const, ConstVid, DefIdTree, ExistentialPredicate, FloatTy, FloatVar,
-    FloatVid, GeneratorWitnessInner, GenericParamDefKind, InferConst, InferTy, IntTy, IntVar,
-    IntVid, List, ParamConst, ParamTy, PolyFnSig, Predicate, PredicateInner, PredicateKind,
-    ProjectionPredicate, ProjectionTy, Region, RegionKind, ReprOptions, TraitObjectVisitor, Ty,
-    TyKind, TyS, TyVar, TyVid, TypeAndMut, UintTy,
+    FloatVid, GeneratorPredicate, GeneratorWitnessInner, GenericParamDefKind, InferConst, InferTy,
+    IntTy, IntVar, IntVid, List, ParamConst, ParamTy, PolyFnSig, Predicate, PredicateInner,
+    PredicateKind, ProjectionTy, Region, RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind,
+    TyS, TyVar, TyVid, TypeAndMut, UintTy,
 };
 use rustc_ast as ast;
 use rustc_attr as attr;
@@ -103,7 +103,7 @@ pub struct CtxtInterners<'tcx> {
     substs: InternedSet<'tcx, InternalSubsts<'tcx>>,
     canonical_var_infos: InternedSet<'tcx, List<CanonicalVarInfo<'tcx>>>,
     region: InternedSet<'tcx, RegionKind>,
-    projection_predicates: InternedSet<'tcx, List<ProjectionPredicate<'tcx>>>,
+    generator_predicates: InternedSet<'tcx, List<GeneratorPredicate<'tcx>>>,
     poly_existential_predicates:
         InternedSet<'tcx, List<ty::Binder<'tcx, ExistentialPredicate<'tcx>>>>,
     predicate: InternedSet<'tcx, PredicateInner<'tcx>>,
@@ -131,7 +131,7 @@ impl<'tcx> CtxtInterners<'tcx> {
             type_list: Default::default(),
             substs: Default::default(),
             region: Default::default(),
-            projection_predicates: Default::default(),
+            generator_predicates: Default::default(),
             poly_existential_predicates: Default::default(),
             canonical_var_infos: Default::default(),
             predicate: Default::default(),
@@ -1657,7 +1657,7 @@ nop_lift! {const_allocation; &'a Allocation => &'tcx Allocation}
 nop_lift! {predicate; &'a PredicateInner<'a> => &'tcx PredicateInner<'tcx>}
 
 nop_list_lift! {type_list; Ty<'a> => Ty<'tcx>}
-nop_list_lift! {projection_predicates; ProjectionPredicate<'a> => ProjectionPredicate<'tcx>}
+nop_list_lift! {generator_predicates; GeneratorPredicate<'a> => GeneratorPredicate<'tcx>}
 nop_list_lift! {poly_existential_predicates; ty::Binder<'a, ExistentialPredicate<'a>> => ty::Binder<'tcx, ExistentialPredicate<'tcx>>}
 nop_list_lift! {predicates; Predicate<'a> => Predicate<'tcx>}
 nop_list_lift! {canonical_var_infos; CanonicalVarInfo<'a> => CanonicalVarInfo<'tcx>}
@@ -2119,7 +2119,7 @@ slice_interners!(
     type_list: _intern_type_list(Ty<'tcx>),
     substs: _intern_substs(GenericArg<'tcx>),
     canonical_var_infos: _intern_canonical_var_infos(CanonicalVarInfo<'tcx>),
-    projection_predicates: _intern_projection_predicates(ProjectionPredicate<'tcx>),
+    generator_predicates: _intern_generator_predicates(GeneratorPredicate<'tcx>),
     poly_existential_predicates:
         _intern_poly_existential_predicates(ty::Binder<'tcx, ExistentialPredicate<'tcx>>),
     predicates: _intern_predicates(Predicate<'tcx>),
@@ -2517,14 +2517,14 @@ impl<'tcx> TyCtxt<'tcx> {
         Place { local: place.local, projection: self.intern_place_elems(&projection) }
     }
 
-    pub fn intern_projection_predicates(
+    pub fn intern_generator_predicates(
         self,
-        predicates: &[ProjectionPredicate<'tcx>],
-    ) -> &'tcx List<ProjectionPredicate<'tcx>> {
+        predicates: &[GeneratorPredicate<'tcx>],
+    ) -> &'tcx List<GeneratorPredicate<'tcx>> {
         if predicates.is_empty() {
             List::empty()
         } else {
-            self._intern_projection_predicates(predicates)
+            self._intern_generator_predicates(predicates)
         }
     }
 
@@ -2602,13 +2602,13 @@ impl<'tcx> TyCtxt<'tcx> {
         })
     }
 
-    pub fn mk_projection_predicates<
-        I: InternAs<[ProjectionPredicate<'tcx>], &'tcx List<ProjectionPredicate<'tcx>>>,
+    pub fn mk_generator_predicates<
+        I: InternAs<[GeneratorPredicate<'tcx>], &'tcx List<GeneratorPredicate<'tcx>>>,
     >(
         self,
         iter: I,
     ) -> I::Output {
-        iter.intern_with(|xs| self.intern_projection_predicates(xs))
+        iter.intern_with(|xs| self.intern_generator_predicates(xs))
     }
 
     pub fn mk_poly_existential_predicates<

compiler/rustc_middle/src/ty/flags.rs

@@ -120,8 +120,8 @@ impl FlagComputation {
             &ty::GeneratorWitness(inner) => {
                 self.bound_computation(inner, |computation, inner| {
                     computation.add_tys(&inner.tys);
-                    for predicate in inner.structural_predicates {
-                        computation.add_predicate_atom(ty::PredicateKind::Projection(predicate));
+                    for predicate in inner.predicates {
+                        computation.add_predicate_atom(predicate.to_predicate_atom());
                     }
                 });
             }

compiler/rustc_middle/src/ty/mod.rs

@@ -170,18 +170,8 @@ pub struct ImplHeader<'tcx> {
     pub predicates: Vec<Predicate<'tcx>>,
 }
 
-#[derive(
-    Copy,
-    Clone,
-    PartialEq,
-    Eq,
-    Hash,
-    TyEncodable,
-    TyDecodable,
-    HashStable,
-    Debug,
-    TypeFoldable
-)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[derive(TyEncodable, TyDecodable, HashStable, Debug, TypeFoldable)]
 pub enum ImplPolarity {
     /// `impl Trait for Type`
     Positive,
@@ -225,7 +215,8 @@ pub enum Visibility {
     Invisible,
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable, TyEncodable, TyDecodable)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Hash, HashStable, TyEncodable, TyDecodable)]
 pub enum BoundConstness {
     /// `T: Trait`
     NotConst,
@@ -744,7 +735,7 @@ impl<'tcx> Predicate<'tcx> {
     }
 }
 
-#[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, TyEncodable, TyDecodable)]
 #[derive(HashStable, TypeFoldable)]
 pub struct TraitPredicate<'tcx> {
     pub trait_ref: TraitRef<'tcx>,
@@ -997,6 +988,37 @@ impl<'tcx> Predicate<'tcx> {
     }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Hash, HashStable, TyEncodable, TyDecodable, TypeFoldable)]
+pub enum GeneratorPredicate<'tcx> {
+    Trait(TraitPredicate<'tcx>),
+    RegionOutlives(RegionOutlivesPredicate<'tcx>),
+    TypeOutlives(TypeOutlivesPredicate<'tcx>),
+    Projection(ProjectionPredicate<'tcx>),
+}
+
+impl<'tcx> GeneratorPredicate<'tcx> {
+    pub fn to_predicate_atom(self) -> PredicateKind<'tcx> {
+        match self {
+            GeneratorPredicate::Trait(p) => PredicateKind::Trait(p),
+            GeneratorPredicate::RegionOutlives(p) => PredicateKind::RegionOutlives(p),
+            GeneratorPredicate::TypeOutlives(p) => PredicateKind::TypeOutlives(p),
+            GeneratorPredicate::Projection(p) => PredicateKind::Projection(p),
+        }
+    }
+}
+
+impl<'tcx> ToPredicate<'tcx> for Binder<'tcx, GeneratorPredicate<'tcx>> {
+    fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
+        match self.skip_binder() {
+            GeneratorPredicate::Trait(p) => self.rebind(p).to_predicate(tcx),
+            GeneratorPredicate::RegionOutlives(p) => self.rebind(p).to_predicate(tcx),
+            GeneratorPredicate::TypeOutlives(p) => self.rebind(p).to_predicate(tcx),
+            GeneratorPredicate::Projection(p) => self.rebind(p).to_predicate(tcx),
+        }
+    }
+}
+
 /// Represents the bounds declared on a particular set of type
 /// parameters. Should eventually be generalized into a flag list of
 /// where-clauses. You can obtain an `InstantiatedPredicates` list from a

compiler/rustc_middle/src/ty/relate.rs

@@ -347,16 +347,13 @@ impl<'tcx> Relate<'tcx> for ty::GeneratorWitnessInner<'tcx> {
         b: ty::GeneratorWitnessInner<'tcx>,
     ) -> RelateResult<'tcx, ty::GeneratorWitnessInner<'tcx>> {
         assert_eq!(a.tys.len(), b.tys.len());
-        assert_eq!(a.structural_predicates.len(), b.structural_predicates.len());
+        assert_eq!(a.predicates.len(), b.predicates.len());
         Ok(ty::GeneratorWitnessInner {
             tys: relation
                 .tcx()
                 .mk_type_list(a.tys.iter().zip(b.tys).map(|(a, b)| relation.relate(a, b)))?,
-            structural_predicates: relation.tcx().mk_projection_predicates(
-                a.structural_predicates
-                    .iter()
-                    .zip(b.structural_predicates)
-                    .map(|(a, b)| relation.relate(a, b)),
+            predicates: relation.tcx().mk_generator_predicates(
+                a.predicates.iter().zip(b.predicates).map(|(a, b)| relation.relate(a, b)),
             )?,
         })
     }
@@ -860,6 +857,45 @@ impl<'tcx> Relate<'tcx> for ty::ProjectionPredicate<'tcx> {
     }
 }
 
+impl<'tcx> Relate<'tcx> for ty::GeneratorPredicate<'tcx> {
+    fn relate<R: TypeRelation<'tcx>>(
+        relation: &mut R,
+        a: ty::GeneratorPredicate<'tcx>,
+        b: ty::GeneratorPredicate<'tcx>,
+    ) -> RelateResult<'tcx, ty::GeneratorPredicate<'tcx>> {
+        Ok(match (a, b) {
+            (ty::GeneratorPredicate::Trait(a), ty::GeneratorPredicate::Trait(b)) => {
+                ty::GeneratorPredicate::Trait(relation.relate(a, b)?)
+            }
+            (
+                ty::GeneratorPredicate::RegionOutlives(a),
+                ty::GeneratorPredicate::RegionOutlives(b),
+            ) => ty::GeneratorPredicate::RegionOutlives(relation.relate(a, b)?),
+            (ty::GeneratorPredicate::TypeOutlives(a), ty::GeneratorPredicate::TypeOutlives(b)) => {
+                ty::GeneratorPredicate::TypeOutlives(relation.relate(a, b)?)
+            }
+            (ty::GeneratorPredicate::Projection(a), ty::GeneratorPredicate::Projection(b)) => {
+                ty::GeneratorPredicate::Projection(relation.relate(a, b)?)
+            }
+            _ => bug!("cannot relate {:?} and {:?}", a, b),
+        })
+    }
+}
+
+impl<'tcx, A, B> Relate<'tcx> for ty::OutlivesPredicate<A, B>
+where
+    A: Relate<'tcx>,
+    B: Relate<'tcx>,
+{
+    fn relate<R: TypeRelation<'tcx>>(
+        relation: &mut R,
+        a: ty::OutlivesPredicate<A, B>,
+        b: ty::OutlivesPredicate<A, B>,
+    ) -> RelateResult<'tcx, Self> {
+        Ok(ty::OutlivesPredicate(relation.relate(a.0, b.0)?, relation.relate(a.1, b.1)?))
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////
 // Error handling
 

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -908,12 +908,12 @@ impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<Ty<'tcx>> {
     }
 }
 
-impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<ty::ProjectionPredicate<'tcx>> {
+impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<ty::GeneratorPredicate<'tcx>> {
     fn try_super_fold_with<F: FallibleTypeFolder<'tcx>>(
         self,
         folder: &mut F,
     ) -> Result<Self, F::Error> {
-        ty::util::fold_list(self, folder, |tcx, v| tcx.intern_projection_predicates(v))
+        ty::util::fold_list(self, folder, |tcx, v| tcx.intern_generator_predicates(v))
     }
 
     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {

compiler/rustc_middle/src/ty/sty.rs

@@ -2313,5 +2313,5 @@ impl<'tcx> VarianceDiagInfo<'tcx> {
 #[derive(TyEncodable, TyDecodable, Debug, HashStable, TypeFoldable)]
 pub struct GeneratorWitnessInner<'tcx> {
     pub tys: &'tcx List<Ty<'tcx>>,
-    pub structural_predicates: &'tcx List<ty::ProjectionPredicate<'tcx>>,
+    pub predicates: &'tcx List<ty::GeneratorPredicate<'tcx>>,
 }

compiler/rustc_monomorphize/src/polymorphize.rs

@@ -329,6 +329,7 @@ impl<'a, 'tcx> TypeVisitor<'tcx> for MarkUsedGenericParams<'a, 'tcx> {
                 self.visit_child_body(def_id, substs);
                 ControlFlow::CONTINUE
             }
+            ty::GeneratorWitness(inner) => inner.map_bound(|inner| inner.tys).visit_with(self),
             ty::Param(param) => {
                 debug!(?param);
                 self.unused_parameters.clear(param.index);