Move stable hash from TyS into a datastructure that can be shared with other interned types.

This commit is contained in:
Oli Scherer 2022-03-01 14:51:08 +00:00
parent df20355fa9
commit 00c24dd8ce
8 changed files with 140 additions and 64 deletions

View File

@ -4,6 +4,8 @@ use std::hash::{Hash, Hasher};
use std::ops::Deref;
use std::ptr;
use crate::fingerprint::Fingerprint;
mod private {
#[derive(Clone, Copy, Debug)]
pub struct PrivateZst;
@ -108,5 +110,76 @@ where
}
}
/// A helper trait so that `Interned` things can cache stable hashes reproducibly.
pub trait InternedHashingContext {
fn with_def_path_and_no_spans(&mut self, f: impl FnOnce(&mut Self));
}
#[derive(Copy, Clone)]
pub struct InTy<T> {
pub internee: T,
pub stable_hash: Fingerprint,
}
impl<T: PartialEq> PartialEq for InTy<T> {
#[inline]
fn eq(&self, other: &Self) -> bool {
self.internee.eq(&other.internee)
}
}
impl<T: Eq> Eq for InTy<T> {}
impl<T: Ord> PartialOrd for InTy<T> {
fn partial_cmp(&self, other: &InTy<T>) -> Option<Ordering> {
Some(self.internee.cmp(&other.internee))
}
}
impl<T: Ord> Ord for InTy<T> {
fn cmp(&self, other: &InTy<T>) -> Ordering {
self.internee.cmp(&other.internee)
}
}
impl<T> Deref for InTy<T> {
type Target = T;
#[inline]
fn deref(&self) -> &T {
&self.internee
}
}
impl<T: Hash> Hash for InTy<T> {
#[inline]
fn hash<H: Hasher>(&self, s: &mut H) {
self.internee.hash(s)
}
}
impl<T: HashStable<CTX>, CTX: InternedHashingContext> HashStable<CTX> for InTy<T> {
fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
let stable_hash = self.stable_hash;
if stable_hash == Fingerprint::ZERO {
// No cached hash available. This can only mean that incremental is disabled.
// We don't cache stable hashes in non-incremental mode, because they are used
// so rarely that the performance actually suffers.
// We need to build the hash as if we cached it and then hash that hash, as
// otherwise the hashes will differ between cached and non-cached mode.
let stable_hash: Fingerprint = {
let mut hasher = StableHasher::new();
hcx.with_def_path_and_no_spans(|hcx| self.internee.hash_stable(hcx, &mut hasher));
hasher.finish()
};
stable_hash.hash_stable(hcx, hasher);
} else {
stable_hash.hash_stable(hcx, hasher);
}
}
}
#[cfg(test)]
mod tests;

View File

@ -87,7 +87,7 @@ macro_rules! arena_types {
[] hir_id_set: rustc_hir::HirIdSet,
// Interned types
[] tys: rustc_middle::ty::TyS<'tcx>,
[] tys: rustc_data_structures::intern::InTy<rustc_middle::ty::TyS<'tcx>>,
[] predicates: rustc_middle::ty::PredicateS<'tcx>,
[] consts: rustc_middle::ty::ConstS<'tcx>,

View File

@ -26,7 +26,7 @@ use crate::ty::{
use rustc_ast as ast;
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::intern::Interned;
use rustc_data_structures::intern::{InTy, Interned};
use rustc_data_structures::memmap::Mmap;
use rustc_data_structures::profiling::SelfProfilerRef;
use rustc_data_structures::sharded::{IntoPointer, ShardedHashMap};
@ -105,7 +105,7 @@ pub struct CtxtInterners<'tcx> {
// Specifically use a speedy hash algorithm for these hash sets, since
// they're accessed quite often.
type_: InternedSet<'tcx, TyS<'tcx>>,
type_: InternedSet<'tcx, InTy<TyS<'tcx>>>,
substs: InternedSet<'tcx, InternalSubsts<'tcx>>,
canonical_var_infos: InternedSet<'tcx, List<CanonicalVarInfo<'tcx>>>,
region: InternedSet<'tcx, RegionKind>,
@ -178,10 +178,9 @@ impl<'tcx> CtxtInterners<'tcx> {
kind,
flags: flags.flags,
outer_exclusive_binder: flags.outer_exclusive_binder,
stable_hash,
};
InternedInSet(self.arena.alloc(ty_struct))
InternedInSet(self.arena.alloc(InTy { internee: ty_struct, stable_hash }))
})
.0,
))
@ -2048,23 +2047,23 @@ impl<'tcx, T: 'tcx + ?Sized> IntoPointer for InternedInSet<'tcx, T> {
}
#[allow(rustc::usage_of_ty_tykind)]
impl<'tcx> Borrow<TyKind<'tcx>> for InternedInSet<'tcx, TyS<'tcx>> {
impl<'tcx> Borrow<TyKind<'tcx>> for InternedInSet<'tcx, InTy<TyS<'tcx>>> {
fn borrow<'a>(&'a self) -> &'a TyKind<'tcx> {
&self.0.kind
}
}
impl<'tcx> PartialEq for InternedInSet<'tcx, TyS<'tcx>> {
fn eq(&self, other: &InternedInSet<'tcx, TyS<'tcx>>) -> bool {
impl<'tcx> PartialEq for InternedInSet<'tcx, InTy<TyS<'tcx>>> {
fn eq(&self, other: &InternedInSet<'tcx, InTy<TyS<'tcx>>>) -> bool {
// The `Borrow` trait requires that `x.borrow() == y.borrow()` equals
// `x == y`.
self.0.kind == other.0.kind
}
}
impl<'tcx> Eq for InternedInSet<'tcx, TyS<'tcx>> {}
impl<'tcx> Eq for InternedInSet<'tcx, InTy<TyS<'tcx>>> {}
impl<'tcx> Hash for InternedInSet<'tcx, TyS<'tcx>> {
impl<'tcx> Hash for InternedInSet<'tcx, InTy<TyS<'tcx>>> {
fn hash<H: Hasher>(&self, s: &mut H) {
// The `Borrow` trait requires that `x.borrow().hash(s) == x.hash(s)`.
self.0.kind.hash(s)

View File

@ -31,8 +31,8 @@ use crate::ty::util::Discr;
use rustc_ast as ast;
use rustc_attr as attr;
use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
use rustc_data_structures::intern::Interned;
use rustc_data_structures::stable_hasher::{HashStable, NodeIdHashingMode, StableHasher};
use rustc_data_structures::intern::{InTy, Interned};
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_data_structures::tagged_ptr::CopyTaggedPtr;
use rustc_hir as hir;
use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
@ -433,32 +433,28 @@ crate struct TyS<'tcx> {
/// De Bruijn indices within the type are contained within `0..D`
/// (exclusive).
outer_exclusive_binder: ty::DebruijnIndex,
/// The stable hash of the type. This way hashing of types will not have to work
/// on the address of the type anymore, but can instead just read this field
stable_hash: Fingerprint,
}
// `TyS` is used a lot. Make sure it doesn't unintentionally get bigger.
#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
static_assert_size!(TyS<'_>, 56);
static_assert_size!(TyS<'_>, 40);
/// Use this rather than `TyS`, whenever possible.
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, HashStable)]
#[rustc_diagnostic_item = "Ty"]
#[rustc_pass_by_value]
pub struct Ty<'tcx>(Interned<'tcx, TyS<'tcx>>);
pub struct Ty<'tcx>(Interned<'tcx, InTy<TyS<'tcx>>>);
// Statics only used for internal testing.
pub static BOOL_TY: Ty<'static> = Ty(Interned::new_unchecked(&BOOL_TYS));
static BOOL_TYS: TyS<'static> = TyS {
pub static BOOL_TY: Ty<'static> =
Ty(Interned::new_unchecked(&InTy { internee: BOOL_TYS, stable_hash: Fingerprint::ZERO }));
const BOOL_TYS: TyS<'static> = TyS {
kind: ty::Bool,
flags: TypeFlags::empty(),
outer_exclusive_binder: DebruijnIndex::from_usize(0),
stable_hash: Fingerprint::ZERO,
};
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Ty<'tcx> {
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for TyS<'tcx> {
fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
let TyS {
kind,
@ -468,28 +464,9 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Ty<'tcx> {
flags: _,
outer_exclusive_binder: _,
} = self;
stable_hash,
} = self.0.0;
if *stable_hash == Fingerprint::ZERO {
// No cached hash available. This can only mean that incremental is disabled.
// We don't cache stable hashes in non-incremental mode, because they are used
// so rarely that the performance actually suffers.
let stable_hash: Fingerprint = {
let mut hasher = StableHasher::new();
hcx.while_hashing_spans(false, |hcx| {
hcx.with_node_id_hashing_mode(NodeIdHashingMode::HashDefPath, |hcx| {
kind.hash_stable(hcx, &mut hasher)
})
});
hasher.finish()
};
stable_hash.hash_stable(hcx, hasher);
} else {
stable_hash.hash_stable(hcx, hasher);
}
kind.hash_stable(hcx, hasher)
}
}

View File

@ -3,7 +3,7 @@ use crate::ty::subst::{GenericArg, GenericArgKind, Subst};
use crate::ty::{self, ConstInt, DefIdTree, ParamConst, ScalarInt, Term, Ty, TyCtxt, TypeFoldable};
use rustc_apfloat::ieee::{Double, Single};
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::intern::Interned;
use rustc_data_structures::intern::{InTy, Interned};
use rustc_data_structures::sso::SsoHashSet;
use rustc_hir as hir;
use rustc_hir::def::{self, CtorKind, DefKind, Namespace};
@ -1266,18 +1266,29 @@ pub trait PrettyPrinter<'tcx>:
ty::Ref(
_,
Ty(Interned(
ty::TyS {
kind:
ty::Array(
Ty(Interned(ty::TyS { kind: ty::Uint(ty::UintTy::U8), .. }, _)),
ty::Const(Interned(
ty::ConstS {
val: ty::ConstKind::Value(ConstValue::Scalar(int)),
..
},
_,
)),
),
InTy {
internee:
ty::TyS {
kind:
ty::Array(
Ty(Interned(
InTy {
internee:
ty::TyS { kind: ty::Uint(ty::UintTy::U8), .. },
..
},
_,
)),
ty::Const(Interned(
ty::ConstS {
val: ty::ConstKind::Value(ConstValue::Scalar(int)),
..
},
_,
)),
),
..
},
..
},
_,
@ -1439,7 +1450,11 @@ pub trait PrettyPrinter<'tcx>:
// Byte/string slices, printed as (byte) string literals.
(
ConstValue::Slice { data, start, end },
ty::Ref(_, Ty(Interned(ty::TyS { kind: ty::Slice(t), .. }, _)), _),
ty::Ref(
_,
Ty(Interned(InTy { internee: ty::TyS { kind: ty::Slice(t), .. }, .. }, _)),
_,
),
) if *t == u8_type => {
// The `inspect` here is okay since we checked the bounds, and there are
// no relocations (we have an active slice reference here). We don't use
@ -1450,7 +1465,11 @@ pub trait PrettyPrinter<'tcx>:
}
(
ConstValue::Slice { data, start, end },
ty::Ref(_, Ty(Interned(ty::TyS { kind: ty::Str, .. }, _)), _),
ty::Ref(
_,
Ty(Interned(InTy { internee: ty::TyS { kind: ty::Str, .. }, .. }, _)),
_,
),
) => {
// The `inspect` here is okay since we checked the bounds, and there are no
// relocations (we have an active `str` reference here). We don't use this

View File

@ -6,7 +6,7 @@ use crate::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeFolder, TypeVisitor}
use crate::ty::sty::{ClosureSubsts, GeneratorSubsts, InlineConstSubsts};
use crate::ty::{self, Lift, List, ParamConst, Ty, TyCtxt};
use rustc_data_structures::intern::Interned;
use rustc_data_structures::intern::{InTy, Interned};
use rustc_hir::def_id::DefId;
use rustc_macros::HashStable;
use rustc_serialize::{self, Decodable, Encodable};
@ -85,7 +85,7 @@ impl<'tcx> GenericArgKind<'tcx> {
GenericArgKind::Type(ty) => {
// Ensure we can use the tag bits.
assert_eq!(mem::align_of_val(ty.0.0) & TAG_MASK, 0);
(TYPE_TAG, ty.0.0 as *const ty::TyS<'tcx> as usize)
(TYPE_TAG, ty.0.0 as *const InTy<ty::TyS<'tcx>> as usize)
}
GenericArgKind::Const(ct) => {
// Ensure we can use the tag bits.
@ -154,7 +154,7 @@ impl<'tcx> GenericArg<'tcx> {
&*((ptr & !TAG_MASK) as *const ty::RegionKind),
))),
TYPE_TAG => GenericArgKind::Type(Ty(Interned::new_unchecked(
&*((ptr & !TAG_MASK) as *const ty::TyS<'tcx>),
&*((ptr & !TAG_MASK) as *const InTy<ty::TyS<'tcx>>),
))),
CONST_TAG => GenericArgKind::Const(ty::Const(Interned::new_unchecked(
&*((ptr & !TAG_MASK) as *const ty::ConstS<'tcx>),

View File

@ -13,7 +13,7 @@ use rustc_apfloat::Float as _;
use rustc_ast as ast;
use rustc_attr::{self as attr, SignedInt, UnsignedInt};
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_data_structures::intern::Interned;
use rustc_data_structures::intern::{InTy, Interned};
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_errors::ErrorGuaranteed;
use rustc_hir as hir;
@ -427,7 +427,7 @@ impl<'tcx> TyCtxt<'tcx> {
!impl_generics.region_param(ebr, self).pure_wrt_drop
}
GenericArgKind::Type(Ty(Interned(
ty::TyS { kind: ty::Param(ref pt), .. },
InTy { internee: ty::TyS { kind: ty::Param(ref pt), .. }, .. },
_,
))) => !impl_generics.type_param(pt, self).pure_wrt_drop,
GenericArgKind::Const(Const(Interned(

View File

@ -231,4 +231,12 @@ impl<'a> rustc_span::HashStableContext for StableHashingContext<'a> {
}
}
impl<'a> rustc_data_structures::intern::InternedHashingContext for StableHashingContext<'a> {
fn with_def_path_and_no_spans(&mut self, f: impl FnOnce(&mut Self)) {
self.while_hashing_spans(false, |hcx| {
hcx.with_node_id_hashing_mode(NodeIdHashingMode::HashDefPath, |hcx| f(hcx))
});
}
}
impl<'a> rustc_session::HashStableContext for StableHashingContext<'a> {}