progress

7 files changed, 54 insertions, 46 deletions

diff --git a/src/librustc_infer/traits/util.rs b/src/librustc_infer/traits/util.rs
index 02a30195cc8..2a09d9dbee3 100644
--- a/src/librustc_infer/traits/util.rs
+++ b/src/librustc_infer/traits/util.rs
@@ -3,7 +3,7 @@ use smallvec::smallvec;
 use crate::traits::{Obligation, ObligationCause, PredicateObligation};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::ty::outlives::Component;
-use rustc_middle::ty::{self, ToPolyTraitRef, ToPredicate, TyCtxt, WithConstness};
+use rustc_middle::ty::{self, ToPredicate, TyCtxt, WithConstness};
 use rustc_span::Span;
 
 pub fn anonymize_predicate<'tcx>(
@@ -330,8 +330,8 @@ impl<'tcx, I: Iterator<Item = PredicateObligation<'tcx>>> Iterator for FilterToT
 
     fn next(&mut self) -> Option<ty::PolyTraitRef<'tcx>> {
         while let Some(obligation) = self.base_iterator.next() {
-            if let ty::PredicateKind::Trait(data, _) = obligation.predicate.kind() {
-                return Some(data.to_poly_trait_ref());
+            if let Some(data) = obligation.predicate.to_opt_poly_trait_ref() {
+                return Some(data);
             }
         }
         None
diff --git a/src/librustc_lint/builtin.rs b/src/librustc_lint/builtin.rs
index 5c4be715add..a9490c954b5 100644
--- a/src/librustc_lint/builtin.rs
+++ b/src/librustc_lint/builtin.rs
@@ -1202,13 +1202,15 @@ declare_lint_pass!(
 impl<'tcx> LateLintPass<'tcx> for TrivialConstraints {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
         use rustc_middle::ty::fold::TypeFoldable;
-        use rustc_middle::ty::PredicateKind::*;
+        use rustc_middle::ty::PredicateKint::*;
 
         if cx.tcx.features().trivial_bounds {
             let def_id = cx.tcx.hir().local_def_id(item.hir_id);
             let predicates = cx.tcx.predicates_of(def_id);
             for &(predicate, span) in predicates.predicates {
-                let predicate_kind_name = match predicate.kind() {
+                // We don't actually look inside of the predicate,
+                // so it is safe to skip this binder here.
+                let predicate_kind_name = match predicate.kint(cx.tcx).ignore_qualifiers().skip_binder() {
                     Trait(..) => "Trait",
                     TypeOutlives(..) |
                     RegionOutlives(..) => "Lifetime",
@@ -1223,6 +1225,7 @@ impl<'tcx> LateLintPass<'tcx> for TrivialConstraints {
                     Subtype(..) |
                     ConstEvaluatable(..) |
                     ConstEquate(..) => continue,
+                    ForAll(_) => bug!("unexpected predicate: {:?}", predicate)
                 };
                 if predicate.is_global() {
                     cx.struct_span_lint(TRIVIAL_BOUNDS, span, |lint| {
diff --git a/src/librustc_lint/unused.rs b/src/librustc_lint/unused.rs
index 6d6c7b24101..62127f3e12c 100644
--- a/src/librustc_lint/unused.rs
+++ b/src/librustc_lint/unused.rs
@@ -146,11 +146,11 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults {
                 ty::Opaque(def, _) => {
                     let mut has_emitted = false;
                     for (predicate, _) in cx.tcx.predicates_of(def).predicates {
-                        if let ty::PredicateKind::Trait(ref poly_trait_predicate, _) =
-                            predicate.kind()
+                        // We only look at the `DefId`, so it is safe to skip the binder here.
+                        if let ty::PredicateKint::Trait(ref poly_trait_predicate, _) =
+                            predicate.kint(cx.tcx).ignore_qualifiers().skip_binder()
                         {
-                            let trait_ref = poly_trait_predicate.skip_binder().trait_ref;
-                            let def_id = trait_ref.def_id;
+                            let def_id = poly_trait_predicate.trait_ref.def_id;
                             let descr_pre =
                                 &format!("{}implementer{} of ", descr_pre, plural_suffix,);
                             if check_must_use_def(cx, def_id, span, descr_pre, descr_post) {
diff --git a/src/librustc_middle/ty/mod.rs b/src/librustc_middle/ty/mod.rs
index ac1642ec866..b8f95501262 100644
--- a/src/librustc_middle/ty/mod.rs
+++ b/src/librustc_middle/ty/mod.rs
@@ -1217,6 +1217,16 @@ pub enum PredicateKind<'tcx> {
     ConstEquate(&'tcx Const<'tcx>, &'tcx Const<'tcx>),
 }
 
+impl<'tcx> PredicateKint<'tcx> {
+    /// Skips `PredicateKint::ForAll`.
+    pub fn ignore_qualifiers(&'tcx self) -> Binder<&'tcx PredicateKint<'tcx>> {
+        match self {
+            &PredicateKint::ForAll(binder) => binder,
+            pred => Binder::dummy(pred),
+        }
+    }
+}
+
 /// The crate outlives map is computed during typeck and contains the
 /// outlives of every item in the local crate. You should not use it
 /// directly, because to do so will make your pass dependent on the
@@ -1513,34 +1523,37 @@ impl ToPredicate<'tcx> for PredicateKint<'tcx> {
 
 impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<TraitRef<'tcx>> {
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
-        ty::PredicateKind::Trait(
-            ty::Binder::dummy(ty::TraitPredicate { trait_ref: self.value }),
-            self.constness,
-        )
-        .to_predicate(tcx)
-    }
-}
-
-impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<&TraitRef<'tcx>> {
-    fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
-        ty::PredicateKind::Trait(
-            ty::Binder::dummy(ty::TraitPredicate { trait_ref: *self.value }),
-            self.constness,
-        )
-        .to_predicate(tcx)
+        ty::PredicateKint::Trait(ty::TraitPredicate { trait_ref: self.value }, self.constness)
+            .to_predicate(tcx)
     }
 }
 
 impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<PolyTraitRef<'tcx>> {
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
-        ty::PredicateKind::Trait(self.value.to_poly_trait_predicate(), self.constness)
-            .to_predicate(tcx)
+        if let Some(trait_ref) = self.value.no_bound_vars() {
+            ty::PredicateKint::Trait(ty::TraitPredicate { trait_ref }, self.constness)
+        } else {
+            ty::PredicateKint::ForAll(self.value.map_bound(|trait_ref| {
+                tcx.intern_predicate_kint(ty::PredicateKint::Trait(
+                    ty::TraitPredicate { trait_ref },
+                    self.constness,
+                ))
+            }))
+        }
+        .to_predicate(tcx)
     }
 }
 
 impl<'tcx> ToPredicate<'tcx> for PolyRegionOutlivesPredicate<'tcx> {
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
-        PredicateKind::RegionOutlives(self).to_predicate(tcx)
+        if let Some(outlives) = self.no_bound_vars() {
+            PredicateKint::RegionOutlives(outlives)
+        } else {
+            ty::PredicateKint::ForAll(self.map_bound(|outlives| {
+                tcx.intern_predicate_kint(PredicateKint::RegionOutlives(outlives))
+            }))
+        }
+        .to_predicate(tcx)
     }
 }
 
diff --git a/src/librustc_middle/ty/sty.rs b/src/librustc_middle/ty/sty.rs
index 03bf51c95c5..cf9d40a6dc6 100644
--- a/src/librustc_middle/ty/sty.rs
+++ b/src/librustc_middle/ty/sty.rs
@@ -652,8 +652,7 @@ impl<'tcx> Binder<ExistentialPredicate<'tcx>> {
                 Binder(tr).with_self_ty(tcx, self_ty).without_const().to_predicate(tcx)
             }
             ExistentialPredicate::Projection(p) => {
-                ty::PredicateKind::Projection(Binder(p.with_self_ty(tcx, self_ty)))
-                    .to_predicate(tcx)
+                Binder(p.with_self_ty(tcx, self_ty)).to_predicate(tcx)
             }
             ExistentialPredicate::AutoTrait(did) => {
                 let trait_ref =
diff --git a/src/librustc_mir/borrow_check/type_check/mod.rs b/src/librustc_mir/borrow_check/type_check/mod.rs
index 5491c3fb248..9fc5dc0d131 100644
--- a/src/librustc_mir/borrow_check/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/type_check/mod.rs
@@ -28,7 +28,7 @@ use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::{GenericArgKind, Subst, SubstsRef, UserSubsts};
 use rustc_middle::ty::{
     self, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, RegionVid, ToPredicate, Ty,
-    TyCtxt, UserType, UserTypeAnnotationIndex,
+    TyCtxt, UserType, UserTypeAnnotationIndex, WithConstness,
 };
 use rustc_span::{Span, DUMMY_SP};
 use rustc_target::abi::VariantIdx;
@@ -2022,18 +2022,14 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                                         traits::ObligationCauseCode::RepeatVec(should_suggest),
                                     ),
                                     self.param_env,
-                                    ty::PredicateKind::Trait(
-                                        ty::Binder::bind(ty::TraitPredicate {
-                                            trait_ref: ty::TraitRef::new(
-                                                self.tcx().require_lang_item(
-                                                    CopyTraitLangItem,
-                                                    Some(self.last_span),
-                                                ),
-                                                tcx.mk_substs_trait(ty, &[]),
-                                            ),
-                                        }),
-                                        hir::Constness::NotConst,
-                                    )
+                                    ty::Binder::bind(ty::TraitRef::new(
+                                        self.tcx().require_lang_item(
+                                            CopyTraitLangItem,
+                                            Some(self.last_span),
+                                        ),
+                                        tcx.mk_substs_trait(ty, &[]),
+                                    ))
+                                    .without_const()
                                     .to_predicate(self.tcx()),
                                 ),
                                 &traits::SelectionError::Unimplemented,
diff --git a/src/librustc_privacy/lib.rs b/src/librustc_privacy/lib.rs
index 1ecb0320744..0b97695041b 100644
--- a/src/librustc_privacy/lib.rs
+++ b/src/librustc_privacy/lib.rs
@@ -68,10 +68,7 @@ trait DefIdVisitor<'tcx> {
     }
 }
 
-struct DefIdVisitorSkeleton<'v, 'tcx, V>
-where
-    V: DefIdVisitor<'tcx> + ?Sized,
-{
+struct DefIdVisitorSkeleton<'v, 'tcx, V: ?Sized> {
     def_id_visitor: &'v mut V,
     visited_opaque_tys: FxHashSet<DefId>,
     dummy: PhantomData<TyCtxt<'tcx>>,