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Add HashStable_NoContext to simplify HashStable implementations in rustc_type_ir
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10 files changed

+69
-295
lines changed

10 files changed

+69
-295
lines changed

‎compiler/rustc_ast/src/lib.rs

Lines changed: 1 addition & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -59,9 +59,7 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
5959
/// Requirements for a `StableHashingContext` to be used in this crate.
6060
/// This is a hack to allow using the `HashStable_Generic` derive macro
6161
/// instead of implementing everything in `rustc_middle`.
62-
pub trait HashStableContext:
63-
rustc_type_ir::HashStableContext + rustc_span::HashStableContext
64-
{
62+
pub trait HashStableContext: rustc_span::HashStableContext {
6563
fn hash_attr(&mut self, _: &ast::Attribute, hasher: &mut StableHasher);
6664
}
6765

‎compiler/rustc_macros/src/hash_stable.rs

Lines changed: 44 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -64,6 +64,50 @@ pub(crate) fn hash_stable_generic_derive(
6464
)
6565
}
6666

67+
pub(crate) fn hash_stable_no_context_derive(
68+
mut s: synstructure::Structure<'_>,
69+
) -> proc_macro2::TokenStream {
70+
let generic: syn::GenericParam = parse_quote!(__CTX);
71+
s.add_bounds(synstructure::AddBounds::Fields);
72+
s.add_impl_generic(generic);
73+
let body = s.each(|bi| {
74+
let attrs = parse_attributes(bi.ast());
75+
if attrs.ignore {
76+
quote! {}
77+
} else if let Some(project) = attrs.project {
78+
quote! {
79+
(&#bi.#project).hash_stable(__hcx, __hasher);
80+
}
81+
} else {
82+
quote! {
83+
#bi.hash_stable(__hcx, __hasher);
84+
}
85+
}
86+
});
87+
88+
let discriminant = match s.ast().data {
89+
syn::Data::Enum(_) => quote! {
90+
::std::mem::discriminant(self).hash_stable(__hcx, __hasher);
91+
},
92+
syn::Data::Struct(_) => quote! {},
93+
syn::Data::Union(_) => panic!("cannot derive on union"),
94+
};
95+
96+
s.bound_impl(
97+
quote!(::rustc_data_structures::stable_hasher::HashStable<__CTX>),
98+
quote! {
99+
#[inline]
100+
fn hash_stable(
101+
&self,
102+
__hcx: &mut __CTX,
103+
__hasher: &mut ::rustc_data_structures::stable_hasher::StableHasher) {
104+
#discriminant
105+
match *self { #body }
106+
}
107+
},
108+
)
109+
}
110+
67111
pub(crate) fn hash_stable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
68112
let generic: syn::GenericParam = parse_quote!('__ctx);
69113
s.add_bounds(synstructure::AddBounds::Generics);

‎compiler/rustc_macros/src/lib.rs

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -48,6 +48,13 @@ decl_derive!(
4848
[HashStable_Generic, attributes(stable_hasher)] =>
4949
hash_stable::hash_stable_generic_derive
5050
);
51+
decl_derive!(
52+
[HashStable_NoContext] =>
53+
/// `HashStable` implementation that has no `HashStableContext` bound and
54+
/// which adds `where` bounds for `HashStable` based off of fields and not
55+
/// generics. This is suitable for use in crates like `rustc_type_ir`.
56+
hash_stable::hash_stable_no_context_derive
57+
);
5158

5259
decl_derive!([Decodable] => serialize::decodable_derive);
5360
decl_derive!([Encodable] => serialize::encodable_derive);

‎compiler/rustc_query_system/src/ich/impls_syntax.rs

Lines changed: 0 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -123,5 +123,3 @@ impl<'tcx> HashStable<StableHashingContext<'tcx>> for rustc_feature::Features {
123123
});
124124
}
125125
}
126-
127-
impl<'ctx> rustc_type_ir::HashStableContext for StableHashingContext<'ctx> {}

‎compiler/rustc_type_ir/src/canonical.rs

Lines changed: 1 addition & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -2,9 +2,6 @@ use std::fmt;
22
use std::hash::Hash;
33
use std::ops::ControlFlow;
44

5-
#[cfg(feature = "nightly")]
6-
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
7-
85
use crate::fold::{FallibleTypeFolder, TypeFoldable};
96
use crate::visit::{TypeVisitable, TypeVisitor};
107
use crate::{Interner, UniverseIndex};
@@ -14,7 +11,7 @@ use crate::{Interner, UniverseIndex};
1411
/// numbered starting from 0 in order of first appearance.
1512
#[derive(derivative::Derivative)]
1613
#[derivative(Clone(bound = "V: Clone"), Hash(bound = "V: Hash"))]
17-
#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable))]
14+
#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
1815
pub struct Canonical<I: Interner, V> {
1916
pub value: V,
2017
pub max_universe: UniverseIndex,
@@ -61,19 +58,6 @@ impl<I: Interner, V> Canonical<I, V> {
6158
}
6259
}
6360

64-
#[cfg(feature = "nightly")]
65-
impl<CTX: crate::HashStableContext, I: Interner, V: HashStable<CTX>> HashStable<CTX>
66-
for Canonical<I, V>
67-
where
68-
I::CanonicalVars: HashStable<CTX>,
69-
{
70-
fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
71-
self.value.hash_stable(hcx, hasher);
72-
self.max_universe.hash_stable(hcx, hasher);
73-
self.variables.hash_stable(hcx, hasher);
74-
}
75-
}
76-
7761
impl<I: Interner, V: Eq> Eq for Canonical<I, V> {}
7862

7963
impl<I: Interner, V: PartialEq> PartialEq for Canonical<I, V> {

‎compiler/rustc_type_ir/src/const_kind.rs

Lines changed: 1 addition & 47 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,3 @@
1-
#[cfg(feature = "nightly")]
2-
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
31
use std::fmt;
42

53
use crate::{DebruijnIndex, DebugWithInfcx, InferCtxtLike, Interner, WithInfcx};
@@ -16,7 +14,7 @@ use self::ConstKind::*;
1614
Ord = "feature_allow_slow_enum",
1715
Hash(bound = "")
1816
)]
19-
#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable))]
17+
#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
2018
pub enum ConstKind<I: Interner> {
2119
/// A const generic parameter.
2220
Param(I::ParamConst),
@@ -47,50 +45,6 @@ pub enum ConstKind<I: Interner> {
4745
Expr(I::ExprConst),
4846
}
4947

50-
#[cfg(feature = "nightly")]
51-
const fn const_kind_discriminant<I: Interner>(value: &ConstKind<I>) -> usize {
52-
match value {
53-
Param(_) => 0,
54-
Infer(_) => 1,
55-
Bound(_, _) => 2,
56-
Placeholder(_) => 3,
57-
Unevaluated(_) => 4,
58-
Value(_) => 5,
59-
Error(_) => 6,
60-
Expr(_) => 7,
61-
}
62-
}
63-
64-
#[cfg(feature = "nightly")]
65-
impl<CTX: crate::HashStableContext, I: Interner> HashStable<CTX> for ConstKind<I>
66-
where
67-
I::ParamConst: HashStable<CTX>,
68-
I::InferConst: HashStable<CTX>,
69-
I::BoundConst: HashStable<CTX>,
70-
I::PlaceholderConst: HashStable<CTX>,
71-
I::AliasConst: HashStable<CTX>,
72-
I::ValueConst: HashStable<CTX>,
73-
I::ErrorGuaranteed: HashStable<CTX>,
74-
I::ExprConst: HashStable<CTX>,
75-
{
76-
fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
77-
const_kind_discriminant(self).hash_stable(hcx, hasher);
78-
match self {
79-
Param(p) => p.hash_stable(hcx, hasher),
80-
Infer(i) => i.hash_stable(hcx, hasher),
81-
Bound(d, b) => {
82-
d.hash_stable(hcx, hasher);
83-
b.hash_stable(hcx, hasher);
84-
}
85-
Placeholder(p) => p.hash_stable(hcx, hasher),
86-
Unevaluated(u) => u.hash_stable(hcx, hasher),
87-
Value(v) => v.hash_stable(hcx, hasher),
88-
Error(e) => e.hash_stable(hcx, hasher),
89-
Expr(e) => e.hash_stable(hcx, hasher),
90-
}
91-
}
92-
}
93-
9448
impl<I: Interner> PartialEq for ConstKind<I> {
9549
fn eq(&self, other: &Self) -> bool {
9650
match (self, other) {

‎compiler/rustc_type_ir/src/lib.rs

Lines changed: 3 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -51,9 +51,6 @@ pub use region_kind::*;
5151
pub use ty_info::*;
5252
pub use ty_kind::*;
5353

54-
/// Needed so we can use #[derive(HashStable_Generic)]
55-
pub trait HashStableContext {}
56-
5754
rustc_index::newtype_index! {
5855
/// A [De Bruijn index][dbi] is a standard means of representing
5956
/// regions (and perhaps later types) in a higher-ranked setting. In
@@ -94,7 +91,7 @@ rustc_index::newtype_index! {
9491
/// is the outer fn.
9592
///
9693
/// [dbi]: https://en.wikipedia.org/wiki/De_Bruijn_index
97-
#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
94+
#[cfg_attr(feature = "nightly", derive(HashStable_NoContext))]
9895
#[debug_format = "DebruijnIndex({})"]
9996
#[gate_rustc_only]
10097
pub struct DebruijnIndex {
@@ -179,7 +176,7 @@ pub fn debug_bound_var<T: std::fmt::Write>(
179176
}
180177

181178
#[derive(Copy, Clone, PartialEq, Eq)]
182-
#[cfg_attr(feature = "nightly", derive(Decodable, Encodable, Hash, HashStable_Generic))]
179+
#[cfg_attr(feature = "nightly", derive(Decodable, Encodable, Hash, HashStable_NoContext))]
183180
#[cfg_attr(feature = "nightly", rustc_pass_by_value)]
184181
pub enum Variance {
185182
Covariant, // T<A> <: T<B> iff A <: B -- e.g., function return type
@@ -295,7 +292,7 @@ rustc_index::newtype_index! {
295292
/// declared, but a type name in a non-zero universe is a placeholder
296293
/// type -- an idealized representative of "types in general" that we
297294
/// use for checking generic functions.
298-
#[cfg_attr(feature = "nightly", derive(HashStable_Generic))]
295+
#[cfg_attr(feature = "nightly", derive(HashStable_NoContext))]
299296
#[debug_format = "U{}"]
300297
#[gate_rustc_only]
301298
pub struct UniverseIndex {}

‎compiler/rustc_type_ir/src/predicate_kind.rs

Lines changed: 3 additions & 98 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,3 @@
1-
#[cfg(feature = "nightly")]
2-
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
31
use std::fmt;
42
use std::ops::ControlFlow;
53

@@ -11,7 +9,7 @@ use crate::Interner;
119
/// by implied bounds.
1210
#[derive(derivative::Derivative)]
1311
#[derivative(Clone(bound = ""), Hash(bound = ""))]
14-
#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable))]
12+
#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
1513
pub enum ClauseKind<I: Interner> {
1614
/// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be
1715
/// the `Self` type of the trait reference and `A`, `B`, and `C`
@@ -68,47 +66,6 @@ impl<I: Interner> PartialEq for ClauseKind<I> {
6866

6967
impl<I: Interner> Eq for ClauseKind<I> {}
7068

71-
#[cfg(feature = "nightly")]
72-
fn clause_kind_discriminant<I: Interner>(value: &ClauseKind<I>) -> usize {
73-
match value {
74-
ClauseKind::Trait(_) => 0,
75-
ClauseKind::RegionOutlives(_) => 1,
76-
ClauseKind::TypeOutlives(_) => 2,
77-
ClauseKind::Projection(_) => 3,
78-
ClauseKind::ConstArgHasType(_, _) => 4,
79-
ClauseKind::WellFormed(_) => 5,
80-
ClauseKind::ConstEvaluatable(_) => 6,
81-
}
82-
}
83-
84-
#[cfg(feature = "nightly")]
85-
impl<CTX: crate::HashStableContext, I: Interner> HashStable<CTX> for ClauseKind<I>
86-
where
87-
I::Ty: HashStable<CTX>,
88-
I::Const: HashStable<CTX>,
89-
I::GenericArg: HashStable<CTX>,
90-
I::TraitPredicate: HashStable<CTX>,
91-
I::ProjectionPredicate: HashStable<CTX>,
92-
I::TypeOutlivesPredicate: HashStable<CTX>,
93-
I::RegionOutlivesPredicate: HashStable<CTX>,
94-
{
95-
fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
96-
clause_kind_discriminant(self).hash_stable(hcx, hasher);
97-
match self {
98-
ClauseKind::Trait(p) => p.hash_stable(hcx, hasher),
99-
ClauseKind::RegionOutlives(p) => p.hash_stable(hcx, hasher),
100-
ClauseKind::TypeOutlives(p) => p.hash_stable(hcx, hasher),
101-
ClauseKind::Projection(p) => p.hash_stable(hcx, hasher),
102-
ClauseKind::ConstArgHasType(c, t) => {
103-
c.hash_stable(hcx, hasher);
104-
t.hash_stable(hcx, hasher);
105-
}
106-
ClauseKind::WellFormed(t) => t.hash_stable(hcx, hasher),
107-
ClauseKind::ConstEvaluatable(c) => c.hash_stable(hcx, hasher),
108-
}
109-
}
110-
}
111-
11269
impl<I: Interner> TypeFoldable<I> for ClauseKind<I>
11370
where
11471
I::Ty: TypeFoldable<I>,
@@ -164,7 +121,7 @@ where
164121

165122
#[derive(derivative::Derivative)]
166123
#[derivative(Clone(bound = ""), Hash(bound = ""))]
167-
#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable))]
124+
#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
168125
pub enum PredicateKind<I: Interner> {
169126
/// Prove a clause
170127
Clause(ClauseKind<I>),
@@ -242,58 +199,6 @@ impl<I: Interner> PartialEq for PredicateKind<I> {
242199

243200
impl<I: Interner> Eq for PredicateKind<I> {}
244201

245-
#[cfg(feature = "nightly")]
246-
fn predicate_kind_discriminant<I: Interner>(value: &PredicateKind<I>) -> usize {
247-
match value {
248-
PredicateKind::Clause(_) => 0,
249-
PredicateKind::ObjectSafe(_) => 1,
250-
PredicateKind::ClosureKind(_, _, _) => 2,
251-
PredicateKind::Subtype(_) => 3,
252-
PredicateKind::Coerce(_) => 4,
253-
PredicateKind::ConstEquate(_, _) => 5,
254-
PredicateKind::Ambiguous => 6,
255-
PredicateKind::AliasRelate(_, _, _) => 7,
256-
}
257-
}
258-
259-
#[cfg(feature = "nightly")]
260-
impl<CTX: crate::HashStableContext, I: Interner> HashStable<CTX> for PredicateKind<I>
261-
where
262-
I::DefId: HashStable<CTX>,
263-
I::Const: HashStable<CTX>,
264-
I::GenericArgs: HashStable<CTX>,
265-
I::Term: HashStable<CTX>,
266-
I::CoercePredicate: HashStable<CTX>,
267-
I::SubtypePredicate: HashStable<CTX>,
268-
I::ClosureKind: HashStable<CTX>,
269-
ClauseKind<I>: HashStable<CTX>,
270-
{
271-
fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
272-
predicate_kind_discriminant(self).hash_stable(hcx, hasher);
273-
match self {
274-
PredicateKind::Clause(p) => p.hash_stable(hcx, hasher),
275-
PredicateKind::ObjectSafe(d) => d.hash_stable(hcx, hasher),
276-
PredicateKind::ClosureKind(d, g, k) => {
277-
d.hash_stable(hcx, hasher);
278-
g.hash_stable(hcx, hasher);
279-
k.hash_stable(hcx, hasher);
280-
}
281-
PredicateKind::Subtype(p) => p.hash_stable(hcx, hasher),
282-
PredicateKind::Coerce(p) => p.hash_stable(hcx, hasher),
283-
PredicateKind::ConstEquate(c1, c2) => {
284-
c1.hash_stable(hcx, hasher);
285-
c2.hash_stable(hcx, hasher);
286-
}
287-
PredicateKind::Ambiguous => {}
288-
PredicateKind::AliasRelate(t1, t2, r) => {
289-
t1.hash_stable(hcx, hasher);
290-
t2.hash_stable(hcx, hasher);
291-
r.hash_stable(hcx, hasher);
292-
}
293-
}
294-
}
295-
}
296-
297202
impl<I: Interner> TypeFoldable<I> for PredicateKind<I>
298203
where
299204
I::DefId: TypeFoldable<I>,
@@ -366,7 +271,7 @@ where
366271
}
367272

368273
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Copy)]
369-
#[cfg_attr(feature = "nightly", derive(HashStable_Generic, Encodable, Decodable))]
274+
#[cfg_attr(feature = "nightly", derive(HashStable_NoContext, Encodable, Decodable))]
370275
pub enum AliasRelationDirection {
371276
Equate,
372277
Subtype,

‎compiler/rustc_type_ir/src/region_kind.rs

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -263,7 +263,7 @@ impl<I: Interner> fmt::Debug for RegionKind<I> {
263263

264264
#[cfg(feature = "nightly")]
265265
// This is not a derived impl because a derive would require `I: HashStable`
266-
impl<CTX: crate::HashStableContext, I: Interner> HashStable<CTX> for RegionKind<I>
266+
impl<CTX, I: Interner> HashStable<CTX> for RegionKind<I>
267267
where
268268
I::EarlyParamRegion: HashStable<CTX>,
269269
I::BoundRegion: HashStable<CTX>,

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