Add HashStable_NoContext to simplify HashStable implementations in rustc_type_ir

10 files changed, 69 insertions, 291 deletions

diff --git a/compiler/rustc_ast/src/lib.rs b/compiler/rustc_ast/src/lib.rs
index 34303cbbc9a..7e713a49a8c 100644
--- a/compiler/rustc_ast/src/lib.rs
+++ b/compiler/rustc_ast/src/lib.rs
@@ -59,9 +59,7 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 /// Requirements for a `StableHashingContext` to be used in this crate.
 /// This is a hack to allow using the `HashStable_Generic` derive macro
 /// instead of implementing everything in `rustc_middle`.
-pub trait HashStableContext:
-    rustc_type_ir::HashStableContext + rustc_span::HashStableContext
-{
+pub trait HashStableContext: rustc_span::HashStableContext {
     fn hash_attr(&mut self, _: &ast::Attribute, hasher: &mut StableHasher);
 }
 
diff --git a/compiler/rustc_macros/src/hash_stable.rs b/compiler/rustc_macros/src/hash_stable.rs
index 6d23b9ac99d..564e3a1edfa 100644
--- a/compiler/rustc_macros/src/hash_stable.rs
+++ b/compiler/rustc_macros/src/hash_stable.rs
@@ -64,6 +64,50 @@ pub(crate) fn hash_stable_generic_derive(
     )
 }
 
+pub(crate) fn hash_stable_no_context_derive(
+    mut s: synstructure::Structure<'_>,
+) -> proc_macro2::TokenStream {
+    let generic: syn::GenericParam = parse_quote!(__CTX);
+    s.add_bounds(synstructure::AddBounds::Fields);
+    s.add_impl_generic(generic);
+    let body = s.each(|bi| {
+        let attrs = parse_attributes(bi.ast());
+        if attrs.ignore {
+            quote! {}
+        } else if let Some(project) = attrs.project {
+            quote! {
+                (&#bi.#project).hash_stable(__hcx, __hasher);
+            }
+        } else {
+            quote! {
+                #bi.hash_stable(__hcx, __hasher);
+            }
+        }
+    });
+
+    let discriminant = match s.ast().data {
+        syn::Data::Enum(_) => quote! {
+            ::std::mem::discriminant(self).hash_stable(__hcx, __hasher);
+        },
+        syn::Data::Struct(_) => quote! {},
+        syn::Data::Union(_) => panic!("cannot derive on union"),
+    };
+
+    s.bound_impl(
+        quote!(::rustc_data_structures::stable_hasher::HashStable<__CTX>),
+        quote! {
+            #[inline]
+            fn hash_stable(
+                &self,
+                __hcx: &mut __CTX,
+                __hasher: &mut ::rustc_data_structures::stable_hasher::StableHasher) {
+                #discriminant
+                match *self { #body }
+            }
+        },
+    )
+}
+
 pub(crate) fn hash_stable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
     let generic: syn::GenericParam = parse_quote!('__ctx);
     s.add_bounds(synstructure::AddBounds::Generics);
diff --git a/compiler/rustc_macros/src/lib.rs b/compiler/rustc_macros/src/lib.rs
index 2775bd5f629..f558b74be9a 100644
--- a/compiler/rustc_macros/src/lib.rs
+++ b/compiler/rustc_macros/src/lib.rs
@@ -48,6 +48,13 @@ decl_derive!(
     [HashStable_Generic, attributes(stable_hasher)] =>
     hash_stable::hash_stable_generic_derive
 );
+decl_derive!(
+    [HashStable_NoContext] =>
+    /// `HashStable` implementation that has no `HashStableContext` bound and
+    /// which adds `where` bounds for `HashStable` based off of fields and not
+    /// generics. This is suitable for use in crates like `rustc_type_ir`.
+    hash_stable::hash_stable_no_context_derive
+);
 
 decl_derive!([Decodable] => serialize::decodable_derive);
 decl_derive!([Encodable] => serialize::encodable_derive);
diff --git a/compiler/rustc_query_system/src/ich/impls_syntax.rs b/compiler/rustc_query_system/src/ich/impls_syntax.rs
index b2177be0e36..81a7eb604f5 100644
--- a/compiler/rustc_query_system/src/ich/impls_syntax.rs
+++ b/compiler/rustc_query_system/src/ich/impls_syntax.rs
@@ -123,5 +123,3 @@ impl<'tcx> HashStable<StableHashingContext<'tcx>> for rustc_feature::Features {
         });
     }
 }
-
-impl<'ctx> rustc_type_ir::HashStableContext for StableHashingContext<'ctx> {}
diff --git a/compiler/rustc_type_ir/src/canonical.rs b/compiler/rustc_type_ir/src/canonical.rs
index a0e4b4ecbfc..9f170c5b4db 100644
--- a/compiler/rustc_type_ir/src/canonical.rs
+++ b/compiler/rustc_type_ir/src/canonical.rs
@@ -2,9 +2,6 @@ use std::fmt;
 use std::hash::Hash;
 use std::ops::ControlFlow;
 
-#[cfg(feature = "nightly")]
-use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
-
 use crate::fold::{FallibleTypeFolder, TypeFoldable};
 use crate::visit::{TypeVisitable, TypeVisitor};
 use crate::{Interner, UniverseIndex};
@@ -14,7 +11,7 @@ use crate::{Interner, UniverseIndex};
 /// numbered starting from 0 in order of first appearance.
 #[derive(derivative::Derivative)]
 #[derivative(Clone(bound = "V: Clone"), Hash(bound = "V: Hash"))]
-#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable))]
+#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
 pub struct Canonical<I: Interner, V> {
     pub value: V,
     pub max_universe: UniverseIndex,
@@ -61,19 +58,6 @@ impl<I: Interner, V> Canonical<I, V> {
     }
 }
 
-#[cfg(feature = "nightly")]
-impl<CTX: crate::HashStableContext, I: Interner, V: HashStable<CTX>> HashStable<CTX>
-    for Canonical<I, V>
-where
-    I::CanonicalVars: HashStable<CTX>,
-{
-    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
-        self.value.hash_stable(hcx, hasher);
-        self.max_universe.hash_stable(hcx, hasher);
-        self.variables.hash_stable(hcx, hasher);
-    }
-}
-
 impl<I: Interner, V: Eq> Eq for Canonical<I, V> {}
 
 impl<I: Interner, V: PartialEq> PartialEq for Canonical<I, V> {
diff --git a/compiler/rustc_type_ir/src/const_kind.rs b/compiler/rustc_type_ir/src/const_kind.rs
index 1cdd51d68dc..a5f90421de5 100644
--- a/compiler/rustc_type_ir/src/const_kind.rs
+++ b/compiler/rustc_type_ir/src/const_kind.rs
@@ -16,7 +16,7 @@ use self::ConstKind::*;
     Ord = "feature_allow_slow_enum",
     Hash(bound = "")
 )]
-#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable))]
+#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
 pub enum ConstKind<I: Interner> {
     /// A const generic parameter.
     Param(I::ParamConst),
@@ -47,49 +47,6 @@ pub enum ConstKind<I: Interner> {
     Expr(I::ExprConst),
 }
 
-#[cfg(feature = "nightly")]
-const fn const_kind_discriminant<I: Interner>(value: &ConstKind<I>) -> usize {
-    match value {
-        Param(_) => 0,
-        Infer(_) => 1,
-        Bound(_, _) => 2,
-        Placeholder(_) => 3,
-        Unevaluated(_) => 4,
-        Value(_) => 5,
-        Error(_) => 6,
-        Expr(_) => 7,
-    }
-}
-
-#[cfg(feature = "nightly")]
-impl<CTX: crate::HashStableContext, I: Interner> HashStable<CTX> for ConstKind<I>
-where
-    I::ParamConst: HashStable<CTX>,
-    I::BoundConst: HashStable<CTX>,
-    I::PlaceholderConst: HashStable<CTX>,
-    I::AliasConst: HashStable<CTX>,
-    I::ValueConst: HashStable<CTX>,
-    I::ErrorGuaranteed: HashStable<CTX>,
-    I::ExprConst: HashStable<CTX>,
-{
-    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
-        const_kind_discriminant(self).hash_stable(hcx, hasher);
-        match self {
-            Param(p) => p.hash_stable(hcx, hasher),
-            Infer(i) => i.hash_stable(hcx, hasher),
-            Bound(d, b) => {
-                d.hash_stable(hcx, hasher);
-                b.hash_stable(hcx, hasher);
-            }
-            Placeholder(p) => p.hash_stable(hcx, hasher),
-            Unevaluated(u) => u.hash_stable(hcx, hasher),
-            Value(v) => v.hash_stable(hcx, hasher),
-            Error(e) => e.hash_stable(hcx, hasher),
-            Expr(e) => e.hash_stable(hcx, hasher),
-        }
-    }
-}
-
 impl<I: Interner> PartialEq for ConstKind<I> {
     fn eq(&self, other: &Self) -> bool {
         match (self, other) {
diff --git a/compiler/rustc_type_ir/src/lib.rs b/compiler/rustc_type_ir/src/lib.rs
index ba558aa3418..acea7aa46f6 100644
--- a/compiler/rustc_type_ir/src/lib.rs
+++ b/compiler/rustc_type_ir/src/lib.rs
@@ -51,9 +51,6 @@ pub use region_kind::*;
 pub use ty_info::*;
 pub use ty_kind::*;
 
-/// Needed so we can use #[derive(HashStable_Generic)]
-pub trait HashStableContext {}
-
 rustc_index::newtype_index! {
     /// A [De Bruijn index][dbi] is a standard means of representing
     /// regions (and perhaps later types) in a higher-ranked setting. In
@@ -94,7 +91,7 @@ rustc_index::newtype_index! {
     /// is the outer fn.
     ///
     /// [dbi]: https://en.wikipedia.org/wiki/De_Bruijn_index
-    #[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
+    #[cfg_attr(feature = "nightly", derive(HashStable_NoContext))]
     #[debug_format = "DebruijnIndex({})"]
     #[gate_rustc_only]
     pub struct DebruijnIndex {
@@ -179,7 +176,7 @@ pub fn debug_bound_var<T: std::fmt::Write>(
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "nightly", derive(Decodable, Encodable, Hash, HashStable_Generic))]
+#[cfg_attr(feature = "nightly", derive(Decodable, Encodable, Hash, HashStable_NoContext))]
 #[cfg_attr(feature = "nightly", rustc_pass_by_value)]
 pub enum Variance {
     Covariant,     // T<A> <: T<B> iff A <: B -- e.g., function return type
@@ -295,7 +292,7 @@ rustc_index::newtype_index! {
     /// declared, but a type name in a non-zero universe is a placeholder
     /// type -- an idealized representative of "types in general" that we
     /// use for checking generic functions.
-    #[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
+    #[cfg_attr(feature = "nightly", derive(HashStable_NoContext))]
     #[debug_format = "U{}"]
     #[gate_rustc_only]
     pub struct UniverseIndex {}
diff --git a/compiler/rustc_type_ir/src/predicate_kind.rs b/compiler/rustc_type_ir/src/predicate_kind.rs
index c2ba6afc8d0..da041ab1f35 100644
--- a/compiler/rustc_type_ir/src/predicate_kind.rs
+++ b/compiler/rustc_type_ir/src/predicate_kind.rs
@@ -1,5 +1,3 @@
-#[cfg(feature = "nightly")]
-use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use std::fmt;
 use std::ops::ControlFlow;
 
@@ -11,7 +9,7 @@ use crate::Interner;
 /// by implied bounds.
 #[derive(derivative::Derivative)]
 #[derivative(Clone(bound = ""), Hash(bound = ""))]
-#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable))]
+#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
 pub enum ClauseKind<I: Interner> {
     /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be
     /// the `Self` type of the trait reference and `A`, `B`, and `C`
@@ -68,47 +66,6 @@ impl<I: Interner> PartialEq for ClauseKind<I> {
 
 impl<I: Interner> Eq for ClauseKind<I> {}
 
-#[cfg(feature = "nightly")]
-fn clause_kind_discriminant<I: Interner>(value: &ClauseKind<I>) -> usize {
-    match value {
-        ClauseKind::Trait(_) => 0,
-        ClauseKind::RegionOutlives(_) => 1,
-        ClauseKind::TypeOutlives(_) => 2,
-        ClauseKind::Projection(_) => 3,
-        ClauseKind::ConstArgHasType(_, _) => 4,
-        ClauseKind::WellFormed(_) => 5,
-        ClauseKind::ConstEvaluatable(_) => 6,
-    }
-}
-
-#[cfg(feature = "nightly")]
-impl<CTX: crate::HashStableContext, I: Interner> HashStable<CTX> for ClauseKind<I>
-where
-    I::Ty: HashStable<CTX>,
-    I::Const: HashStable<CTX>,
-    I::GenericArg: HashStable<CTX>,
-    I::TraitPredicate: HashStable<CTX>,
-    I::ProjectionPredicate: HashStable<CTX>,
-    I::TypeOutlivesPredicate: HashStable<CTX>,
-    I::RegionOutlivesPredicate: HashStable<CTX>,
-{
-    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
-        clause_kind_discriminant(self).hash_stable(hcx, hasher);
-        match self {
-            ClauseKind::Trait(p) => p.hash_stable(hcx, hasher),
-            ClauseKind::RegionOutlives(p) => p.hash_stable(hcx, hasher),
-            ClauseKind::TypeOutlives(p) => p.hash_stable(hcx, hasher),
-            ClauseKind::Projection(p) => p.hash_stable(hcx, hasher),
-            ClauseKind::ConstArgHasType(c, t) => {
-                c.hash_stable(hcx, hasher);
-                t.hash_stable(hcx, hasher);
-            }
-            ClauseKind::WellFormed(t) => t.hash_stable(hcx, hasher),
-            ClauseKind::ConstEvaluatable(c) => c.hash_stable(hcx, hasher),
-        }
-    }
-}
-
 impl<I: Interner> TypeFoldable<I> for ClauseKind<I>
 where
     I::Ty: TypeFoldable<I>,
@@ -164,7 +121,7 @@ where
 
 #[derive(derivative::Derivative)]
 #[derivative(Clone(bound = ""), Hash(bound = ""))]
-#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable))]
+#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
 pub enum PredicateKind<I: Interner> {
     /// Prove a clause
     Clause(ClauseKind<I>),
@@ -242,58 +199,6 @@ impl<I: Interner> PartialEq for PredicateKind<I> {
 
 impl<I: Interner> Eq for PredicateKind<I> {}
 
-#[cfg(feature = "nightly")]
-fn predicate_kind_discriminant<I: Interner>(value: &PredicateKind<I>) -> usize {
-    match value {
-        PredicateKind::Clause(_) => 0,
-        PredicateKind::ObjectSafe(_) => 1,
-        PredicateKind::ClosureKind(_, _, _) => 2,
-        PredicateKind::Subtype(_) => 3,
-        PredicateKind::Coerce(_) => 4,
-        PredicateKind::ConstEquate(_, _) => 5,
-        PredicateKind::Ambiguous => 6,
-        PredicateKind::AliasRelate(_, _, _) => 7,
-    }
-}
-
-#[cfg(feature = "nightly")]
-impl<CTX: crate::HashStableContext, I: Interner> HashStable<CTX> for PredicateKind<I>
-where
-    I::DefId: HashStable<CTX>,
-    I::Const: HashStable<CTX>,
-    I::GenericArgs: HashStable<CTX>,
-    I::Term: HashStable<CTX>,
-    I::CoercePredicate: HashStable<CTX>,
-    I::SubtypePredicate: HashStable<CTX>,
-    I::ClosureKind: HashStable<CTX>,
-    ClauseKind<I>: HashStable<CTX>,
-{
-    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
-        predicate_kind_discriminant(self).hash_stable(hcx, hasher);
-        match self {
-            PredicateKind::Clause(p) => p.hash_stable(hcx, hasher),
-            PredicateKind::ObjectSafe(d) => d.hash_stable(hcx, hasher),
-            PredicateKind::ClosureKind(d, g, k) => {
-                d.hash_stable(hcx, hasher);
-                g.hash_stable(hcx, hasher);
-                k.hash_stable(hcx, hasher);
-            }
-            PredicateKind::Subtype(p) => p.hash_stable(hcx, hasher),
-            PredicateKind::Coerce(p) => p.hash_stable(hcx, hasher),
-            PredicateKind::ConstEquate(c1, c2) => {
-                c1.hash_stable(hcx, hasher);
-                c2.hash_stable(hcx, hasher);
-            }
-            PredicateKind::Ambiguous => {}
-            PredicateKind::AliasRelate(t1, t2, r) => {
-                t1.hash_stable(hcx, hasher);
-                t2.hash_stable(hcx, hasher);
-                r.hash_stable(hcx, hasher);
-            }
-        }
-    }
-}
-
 impl<I: Interner> TypeFoldable<I> for PredicateKind<I>
 where
     I::DefId: TypeFoldable<I>,
@@ -366,7 +271,7 @@ where
 }
 
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Copy)]
-#[cfg_attr(feature = "nightly", derive(HashStable_Generic, Encodable, Decodable))]
+#[cfg_attr(feature = "nightly", derive(HashStable_NoContext, Encodable, Decodable))]
 pub enum AliasRelationDirection {
     Equate,
     Subtype,
diff --git a/compiler/rustc_type_ir/src/region_kind.rs b/compiler/rustc_type_ir/src/region_kind.rs
index ddd10db1c6c..4157d49287c 100644
--- a/compiler/rustc_type_ir/src/region_kind.rs
+++ b/compiler/rustc_type_ir/src/region_kind.rs
@@ -263,7 +263,7 @@ impl<I: Interner> fmt::Debug for RegionKind<I> {
 
 #[cfg(feature = "nightly")]
 // This is not a derived impl because a derive would require `I: HashStable`
-impl<CTX: crate::HashStableContext, I: Interner> HashStable<CTX> for RegionKind<I>
+impl<CTX, I: Interner> HashStable<CTX> for RegionKind<I>
 where
     I::EarlyParamRegion: HashStable<CTX>,
     I::BoundRegion: HashStable<CTX>,
diff --git a/compiler/rustc_type_ir/src/ty_kind.rs b/compiler/rustc_type_ir/src/ty_kind.rs
index 53446c41f31..494eeaf3dc8 100644
--- a/compiler/rustc_type_ir/src/ty_kind.rs
+++ b/compiler/rustc_type_ir/src/ty_kind.rs
@@ -14,7 +14,7 @@ use self::TyKind::*;
 /// The movability of a coroutine / closure literal:
 /// whether a coroutine contains self-references, causing it to be `!Unpin`.
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Copy)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
 pub enum Movability {
     /// May contain self-references, `!Unpin`.
     Static,
@@ -23,7 +23,7 @@ pub enum Movability {
 }
 
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Copy)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
 pub enum Mutability {
     // N.B. Order is deliberate, so that Not < Mut
     Not,
@@ -75,7 +75,7 @@ impl Mutability {
 
 /// Specifies how a trait object is represented.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
 pub enum DynKind {
     /// An unsized `dyn Trait` object
     Dyn,
@@ -89,7 +89,7 @@ pub enum DynKind {
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
 pub enum AliasKind {
     /// A projection `<Type as Trait>::AssocType`.
     /// Can get normalized away if monomorphic enough.
@@ -119,7 +119,7 @@ pub enum AliasKind {
     Ord = "feature_allow_slow_enum",
     Hash(bound = "")
 )]
-#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable))]
+#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
 pub enum TyKind<I: Interner> {
     /// The primitive boolean type. Written as `bool`.
     Bool,
@@ -472,120 +472,8 @@ impl<I: Interner> fmt::Debug for TyKind<I> {
     }
 }
 
-// This is not a derived impl because a derive would require `I: HashStable`
-#[cfg(feature = "nightly")]
-#[allow(rustc::usage_of_ty_tykind)]
-impl<CTX: crate::HashStableContext, I: Interner> HashStable<CTX> for TyKind<I>
-where
-    I::AdtDef: HashStable<CTX>,
-    I::DefId: HashStable<CTX>,
-    I::GenericArgs: HashStable<CTX>,
-    I::Ty: HashStable<CTX>,
-    I::Const: HashStable<CTX>,
-    I::TypeAndMut: HashStable<CTX>,
-    I::PolyFnSig: HashStable<CTX>,
-    I::BoundExistentialPredicates: HashStable<CTX>,
-    I::Region: HashStable<CTX>,
-    I::Tys: HashStable<CTX>,
-    I::AliasTy: HashStable<CTX>,
-    I::BoundTy: HashStable<CTX>,
-    I::ParamTy: HashStable<CTX>,
-    I::PlaceholderTy: HashStable<CTX>,
-    I::ErrorGuaranteed: HashStable<CTX>,
-{
-    #[inline]
-    fn hash_stable(&self, __hcx: &mut CTX, __hasher: &mut StableHasher) {
-        std::mem::discriminant(self).hash_stable(__hcx, __hasher);
-        match self {
-            Bool => {}
-            Char => {}
-            Int(i) => {
-                i.hash_stable(__hcx, __hasher);
-            }
-            Uint(u) => {
-                u.hash_stable(__hcx, __hasher);
-            }
-            Float(f) => {
-                f.hash_stable(__hcx, __hasher);
-            }
-            Adt(adt, args) => {
-                adt.hash_stable(__hcx, __hasher);
-                args.hash_stable(__hcx, __hasher);
-            }
-            Foreign(def_id) => {
-                def_id.hash_stable(__hcx, __hasher);
-            }
-            Str => {}
-            Array(t, c) => {
-                t.hash_stable(__hcx, __hasher);
-                c.hash_stable(__hcx, __hasher);
-            }
-            Slice(t) => {
-                t.hash_stable(__hcx, __hasher);
-            }
-            RawPtr(tam) => {
-                tam.hash_stable(__hcx, __hasher);
-            }
-            Ref(r, t, m) => {
-                r.hash_stable(__hcx, __hasher);
-                t.hash_stable(__hcx, __hasher);
-                m.hash_stable(__hcx, __hasher);
-            }
-            FnDef(def_id, args) => {
-                def_id.hash_stable(__hcx, __hasher);
-                args.hash_stable(__hcx, __hasher);
-            }
-            FnPtr(polyfnsig) => {
-                polyfnsig.hash_stable(__hcx, __hasher);
-            }
-            Dynamic(l, r, repr) => {
-                l.hash_stable(__hcx, __hasher);
-                r.hash_stable(__hcx, __hasher);
-                repr.hash_stable(__hcx, __hasher);
-            }
-            Closure(def_id, args) => {
-                def_id.hash_stable(__hcx, __hasher);
-                args.hash_stable(__hcx, __hasher);
-            }
-            Coroutine(def_id, args, m) => {
-                def_id.hash_stable(__hcx, __hasher);
-                args.hash_stable(__hcx, __hasher);
-                m.hash_stable(__hcx, __hasher);
-            }
-            CoroutineWitness(def_id, args) => {
-                def_id.hash_stable(__hcx, __hasher);
-                args.hash_stable(__hcx, __hasher);
-            }
-            Never => {}
-            Tuple(args) => {
-                args.hash_stable(__hcx, __hasher);
-            }
-            Alias(k, p) => {
-                k.hash_stable(__hcx, __hasher);
-                p.hash_stable(__hcx, __hasher);
-            }
-            Param(p) => {
-                p.hash_stable(__hcx, __hasher);
-            }
-            Bound(d, b) => {
-                d.hash_stable(__hcx, __hasher);
-                b.hash_stable(__hcx, __hasher);
-            }
-            Placeholder(p) => {
-                p.hash_stable(__hcx, __hasher);
-            }
-            Infer(i) => {
-                i.hash_stable(__hcx, __hasher);
-            }
-            Error(d) => {
-                d.hash_stable(__hcx, __hasher);
-            }
-        }
-    }
-}
-
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
 pub enum IntTy {
     Isize,
     I8,
@@ -643,7 +531,7 @@ impl IntTy {
 }
 
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Copy)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
 pub enum UintTy {
     Usize,
     U8,
@@ -701,7 +589,7 @@ impl UintTy {
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_Generic))]
+#[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
 pub enum FloatTy {
     F32,
     F64,