1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
//! This module contains `HashStable` implementations for various data types
//! from `rustc_middle::ty` in no particular order.
use crate::middle::region;
use crate::mir;
use crate::ty;
use crate::ty::fast_reject::SimplifiedType;
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::stable_hasher::HashingControls;
use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
use rustc_query_system::ich::StableHashingContext;
use std::cell::RefCell;
impl<'a, 'tcx, T> HashStable<StableHashingContext<'a>> for &'tcx ty::List<T>
where
T: HashStable<StableHashingContext<'a>>,
{
fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
thread_local! {
static CACHE: RefCell<FxHashMap<(usize, usize, HashingControls), Fingerprint>> =
RefCell::new(Default::default());
}
let hash = CACHE.with(|cache| {
let key = (self.as_ptr() as usize, self.len(), hcx.hashing_controls());
if let Some(&hash) = cache.borrow().get(&key) {
return hash;
}
let mut hasher = StableHasher::new();
(&self[..]).hash_stable(hcx, &mut hasher);
let hash: Fingerprint = hasher.finish();
cache.borrow_mut().insert(key, hash);
hash
});
hash.hash_stable(hcx, hasher);
}
}
impl<'a, 'tcx, T> ToStableHashKey<StableHashingContext<'a>> for &'tcx ty::List<T>
where
T: HashStable<StableHashingContext<'a>>,
{
type KeyType = Fingerprint;
#[inline]
fn to_stable_hash_key(&self, hcx: &StableHashingContext<'a>) -> Fingerprint {
let mut hasher = StableHasher::new();
let mut hcx: StableHashingContext<'a> = hcx.clone();
self.hash_stable(&mut hcx, &mut hasher);
hasher.finish()
}
}
impl<'a> ToStableHashKey<StableHashingContext<'a>> for SimplifiedType {
type KeyType = Fingerprint;
#[inline]
fn to_stable_hash_key(&self, hcx: &StableHashingContext<'a>) -> Fingerprint {
let mut hasher = StableHasher::new();
let mut hcx: StableHashingContext<'a> = hcx.clone();
self.hash_stable(&mut hcx, &mut hasher);
hasher.finish()
}
}
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for ty::subst::GenericArg<'tcx> {
fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
self.unpack().hash_stable(hcx, hasher);
}
}
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for ty::subst::GenericArgKind<'tcx> {
fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
match self {
// WARNING: We dedup cache the `HashStable` results for `List`
// while ignoring types and freely transmute
// between `List<Ty<'tcx>>` and `List<GenericArg<'tcx>>`.
// See `fn intern_type_list` for more details.
//
// We therefore hash types without adding a hash for their discriminant.
//
// In order to make it very unlikely for the sequence of bytes being hashed for
// a `GenericArgKind::Type` to be the same as the sequence of bytes being
// hashed for one of the other variants, we hash some very high number instead
// of their actual discriminant since `TyKind` should never start with anything
// that high.
ty::subst::GenericArgKind::Type(ty) => ty.hash_stable(hcx, hasher),
ty::subst::GenericArgKind::Const(ct) => {
0xF3u8.hash_stable(hcx, hasher);
ct.hash_stable(hcx, hasher);
}
ty::subst::GenericArgKind::Lifetime(lt) => {
0xF5u8.hash_stable(hcx, hasher);
lt.hash_stable(hcx, hasher);
}
}
}
}
// AllocIds get resolved to whatever they point to (to be stable)
impl<'a> HashStable<StableHashingContext<'a>> for mir::interpret::AllocId {
fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
ty::tls::with_opt(|tcx| {
trace!("hashing {:?}", *self);
let tcx = tcx.expect("can't hash AllocIds during hir lowering");
tcx.try_get_global_alloc(*self).hash_stable(hcx, hasher);
});
}
}
// `Relocations` with default type parameters is a sorted map.
impl<'a, Prov> HashStable<StableHashingContext<'a>> for mir::interpret::Relocations<Prov>
where
Prov: HashStable<StableHashingContext<'a>>,
{
fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
self.len().hash_stable(hcx, hasher);
for reloc in self.iter() {
reloc.hash_stable(hcx, hasher);
}
}
}
impl<'a> ToStableHashKey<StableHashingContext<'a>> for region::Scope {
type KeyType = region::Scope;
#[inline]
fn to_stable_hash_key(&self, _: &StableHashingContext<'a>) -> region::Scope {
*self
}
}
|
