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Commit | Line | Data |
---|---|---|
9fa01778 | 1 | use crate::sip128::SipHasher128; |
e74abb32 | 2 | use rustc_index::bit_set; |
dfeec247 XL |
3 | use rustc_index::vec; |
4 | use smallvec::SmallVec; | |
5 | use std::hash::{BuildHasher, Hash, Hasher}; | |
064997fb | 6 | use std::marker::PhantomData; |
dfeec247 | 7 | use std::mem; |
476ff2be | 8 | |
1b1a35ee XL |
9 | #[cfg(test)] |
10 | mod tests; | |
11 | ||
abe05a73 XL |
12 | /// When hashing something that ends up affecting properties like symbol names, |
13 | /// we want these symbol names to be calculated independently of other factors | |
14 | /// like what architecture you're compiling *from*. | |
476ff2be | 15 | /// |
abe05a73 XL |
16 | /// To that end we always convert integers to little-endian format before |
17 | /// hashing and the architecture dependent `isize` and `usize` types are | |
18 | /// extended to 64 bits if needed. | |
e74abb32 | 19 | pub struct StableHasher { |
abe05a73 | 20 | state: SipHasher128, |
476ff2be SL |
21 | } |
22 | ||
e74abb32 | 23 | impl ::std::fmt::Debug for StableHasher { |
29967ef6 | 24 | fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { |
cc61c64b XL |
25 | write!(f, "{:?}", self.state) |
26 | } | |
27 | } | |
28 | ||
476ff2be | 29 | pub trait StableHasherResult: Sized { |
e74abb32 | 30 | fn finish(hasher: StableHasher) -> Self; |
476ff2be SL |
31 | } |
32 | ||
e74abb32 | 33 | impl StableHasher { |
74b04a01 | 34 | #[inline] |
476ff2be | 35 | pub fn new() -> Self { |
dfeec247 | 36 | StableHasher { state: SipHasher128::new_with_keys(0, 0) } |
476ff2be SL |
37 | } |
38 | ||
6a06907d | 39 | #[inline] |
e74abb32 | 40 | pub fn finish<W: StableHasherResult>(self) -> W { |
476ff2be SL |
41 | W::finish(self) |
42 | } | |
43 | } | |
44 | ||
041b39d2 | 45 | impl StableHasherResult for u128 { |
a2a8927a | 46 | #[inline] |
e74abb32 | 47 | fn finish(hasher: StableHasher) -> Self { |
abe05a73 | 48 | let (_0, _1) = hasher.finalize(); |
dc9dc135 | 49 | u128::from(_0) | (u128::from(_1) << 64) |
041b39d2 XL |
50 | } |
51 | } | |
52 | ||
476ff2be | 53 | impl StableHasherResult for u64 { |
a2a8927a | 54 | #[inline] |
e74abb32 | 55 | fn finish(hasher: StableHasher) -> Self { |
abe05a73 | 56 | hasher.finalize().0 |
476ff2be SL |
57 | } |
58 | } | |
59 | ||
e74abb32 | 60 | impl StableHasher { |
476ff2be | 61 | #[inline] |
abe05a73 XL |
62 | pub fn finalize(self) -> (u64, u64) { |
63 | self.state.finish128() | |
476ff2be | 64 | } |
476ff2be SL |
65 | } |
66 | ||
e74abb32 | 67 | impl Hasher for StableHasher { |
476ff2be | 68 | fn finish(&self) -> u64 { |
abe05a73 | 69 | panic!("use StableHasher::finalize instead"); |
476ff2be SL |
70 | } |
71 | ||
72 | #[inline] | |
73 | fn write(&mut self, bytes: &[u8]) { | |
74 | self.state.write(bytes); | |
476ff2be SL |
75 | } |
76 | ||
04454e1e FG |
77 | #[inline] |
78 | fn write_str(&mut self, s: &str) { | |
79 | self.state.write_str(s); | |
80 | } | |
81 | ||
82 | #[inline] | |
83 | fn write_length_prefix(&mut self, len: usize) { | |
84 | // Our impl for `usize` will extend it if needed. | |
85 | self.write_usize(len); | |
86 | } | |
87 | ||
476ff2be SL |
88 | #[inline] |
89 | fn write_u8(&mut self, i: u8) { | |
90 | self.state.write_u8(i); | |
476ff2be SL |
91 | } |
92 | ||
93 | #[inline] | |
94 | fn write_u16(&mut self, i: u16) { | |
5099ac24 | 95 | self.state.short_write(i.to_le_bytes()); |
476ff2be SL |
96 | } |
97 | ||
98 | #[inline] | |
99 | fn write_u32(&mut self, i: u32) { | |
5099ac24 | 100 | self.state.short_write(i.to_le_bytes()); |
476ff2be SL |
101 | } |
102 | ||
103 | #[inline] | |
104 | fn write_u64(&mut self, i: u64) { | |
5099ac24 | 105 | self.state.short_write(i.to_le_bytes()); |
abe05a73 XL |
106 | } |
107 | ||
108 | #[inline] | |
109 | fn write_u128(&mut self, i: u128) { | |
5099ac24 | 110 | self.state.write(&i.to_le_bytes()); |
476ff2be SL |
111 | } |
112 | ||
113 | #[inline] | |
114 | fn write_usize(&mut self, i: usize) { | |
abe05a73 XL |
115 | // Always treat usize as u64 so we get the same results on 32 and 64 bit |
116 | // platforms. This is important for symbol hashes when cross compiling, | |
117 | // for example. | |
5099ac24 | 118 | self.state.short_write((i as u64).to_le_bytes()); |
476ff2be SL |
119 | } |
120 | ||
121 | #[inline] | |
122 | fn write_i8(&mut self, i: i8) { | |
123 | self.state.write_i8(i); | |
476ff2be SL |
124 | } |
125 | ||
126 | #[inline] | |
127 | fn write_i16(&mut self, i: i16) { | |
5099ac24 | 128 | self.state.short_write((i as u16).to_le_bytes()); |
476ff2be SL |
129 | } |
130 | ||
131 | #[inline] | |
132 | fn write_i32(&mut self, i: i32) { | |
5099ac24 | 133 | self.state.short_write((i as u32).to_le_bytes()); |
476ff2be SL |
134 | } |
135 | ||
136 | #[inline] | |
137 | fn write_i64(&mut self, i: i64) { | |
5099ac24 | 138 | self.state.short_write((i as u64).to_le_bytes()); |
abe05a73 XL |
139 | } |
140 | ||
141 | #[inline] | |
142 | fn write_i128(&mut self, i: i128) { | |
5099ac24 | 143 | self.state.write(&(i as u128).to_le_bytes()); |
476ff2be SL |
144 | } |
145 | ||
146 | #[inline] | |
147 | fn write_isize(&mut self, i: isize) { | |
5099ac24 | 148 | // Always treat isize as a 64-bit number so we get the same results on 32 and 64 bit |
abe05a73 | 149 | // platforms. This is important for symbol hashes when cross compiling, |
1b1a35ee XL |
150 | // for example. Sign extending here is preferable as it means that the |
151 | // same negative number hashes the same on both 32 and 64 bit platforms. | |
5099ac24 FG |
152 | let value = i as u64; |
153 | ||
154 | // Cold path | |
155 | #[cold] | |
156 | #[inline(never)] | |
157 | fn hash_value(state: &mut SipHasher128, value: u64) { | |
158 | state.write_u8(0xFF); | |
159 | state.short_write(value.to_le_bytes()); | |
160 | } | |
161 | ||
162 | // `isize` values often seem to have a small (positive) numeric value in practice. | |
163 | // To exploit this, if the value is small, we will hash a smaller amount of bytes. | |
164 | // However, we cannot just skip the leading zero bytes, as that would produce the same hash | |
165 | // e.g. if you hash two values that have the same bit pattern when they are swapped. | |
166 | // See https://github.com/rust-lang/rust/pull/93014 for context. | |
167 | // | |
168 | // Therefore, we employ the following strategy: | |
169 | // 1) When we encounter a value that fits within a single byte (the most common case), we | |
170 | // hash just that byte. This is the most common case that is being optimized. However, we do | |
171 | // not do this for the value 0xFF, as that is a reserved prefix (a bit like in UTF-8). | |
172 | // 2) When we encounter a larger value, we hash a "marker" 0xFF and then the corresponding | |
173 | // 8 bytes. Since this prefix cannot occur when we hash a single byte, when we hash two | |
174 | // `isize`s that fit within a different amount of bytes, they should always produce a different | |
175 | // byte stream for the hasher. | |
176 | if value < 0xFF { | |
177 | self.state.write_u8(value as u8); | |
178 | } else { | |
179 | hash_value(&mut self.state, value); | |
180 | } | |
476ff2be SL |
181 | } |
182 | } | |
cc61c64b | 183 | |
cc61c64b | 184 | /// Something that implements `HashStable<CTX>` can be hashed in a way that is |
3b2f2976 | 185 | /// stable across multiple compilation sessions. |
48663c56 XL |
186 | /// |
187 | /// Note that `HashStable` imposes rather more strict requirements than usual | |
188 | /// hash functions: | |
189 | /// | |
190 | /// - Stable hashes are sometimes used as identifiers. Therefore they must | |
191 | /// conform to the corresponding `PartialEq` implementations: | |
192 | /// | |
193 | /// - `x == y` implies `hash_stable(x) == hash_stable(y)`, and | |
194 | /// - `x != y` implies `hash_stable(x) != hash_stable(y)`. | |
195 | /// | |
196 | /// That second condition is usually not required for hash functions | |
197 | /// (e.g. `Hash`). In practice this means that `hash_stable` must feed any | |
60c5eb7d | 198 | /// information into the hasher that a `PartialEq` comparison takes into |
48663c56 XL |
199 | /// account. See [#49300](https://github.com/rust-lang/rust/issues/49300) |
200 | /// for an example where violating this invariant has caused trouble in the | |
201 | /// past. | |
202 | /// | |
203 | /// - `hash_stable()` must be independent of the current | |
204 | /// compilation session. E.g. they must not hash memory addresses or other | |
205 | /// things that are "randomly" assigned per compilation session. | |
206 | /// | |
207 | /// - `hash_stable()` must be independent of the host architecture. The | |
208 | /// `StableHasher` takes care of endianness and `isize`/`usize` platform | |
209 | /// differences. | |
cc61c64b | 210 | pub trait HashStable<CTX> { |
e74abb32 | 211 | fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher); |
cc61c64b XL |
212 | } |
213 | ||
ea8adc8c XL |
214 | /// Implement this for types that can be turned into stable keys like, for |
215 | /// example, for DefId that can be converted to a DefPathHash. This is used for | |
216 | /// bringing maps into a predictable order before hashing them. | |
217 | pub trait ToStableHashKey<HCX> { | |
e74abb32 | 218 | type KeyType: Ord + Sized + HashStable<HCX>; |
ea8adc8c XL |
219 | fn to_stable_hash_key(&self, hcx: &HCX) -> Self::KeyType; |
220 | } | |
221 | ||
04454e1e FG |
222 | /// Implement HashStable by just calling `Hash::hash()`. |
223 | /// | |
224 | /// **WARNING** This is only valid for types that *really* don't need any context for fingerprinting. | |
225 | /// But it is easy to misuse this macro (see [#96013](https://github.com/rust-lang/rust/issues/96013) | |
226 | /// for examples). Therefore this macro is not exported and should only be used in the limited cases | |
227 | /// here in this module. | |
228 | /// | |
229 | /// Use `#[derive(HashStable_Generic)]` instead. | |
cc61c64b | 230 | macro_rules! impl_stable_hash_via_hash { |
dfeec247 | 231 | ($t:ty) => { |
b7449926 | 232 | impl<CTX> $crate::stable_hasher::HashStable<CTX> for $t { |
cc61c64b | 233 | #[inline] |
dfeec247 | 234 | fn hash_stable(&self, _: &mut CTX, hasher: &mut $crate::stable_hasher::StableHasher) { |
cc61c64b XL |
235 | ::std::hash::Hash::hash(self, hasher); |
236 | } | |
237 | } | |
dfeec247 | 238 | }; |
cc61c64b XL |
239 | } |
240 | ||
241 | impl_stable_hash_via_hash!(i8); | |
242 | impl_stable_hash_via_hash!(i16); | |
243 | impl_stable_hash_via_hash!(i32); | |
244 | impl_stable_hash_via_hash!(i64); | |
245 | impl_stable_hash_via_hash!(isize); | |
246 | ||
247 | impl_stable_hash_via_hash!(u8); | |
248 | impl_stable_hash_via_hash!(u16); | |
249 | impl_stable_hash_via_hash!(u32); | |
250 | impl_stable_hash_via_hash!(u64); | |
251 | impl_stable_hash_via_hash!(usize); | |
252 | ||
253 | impl_stable_hash_via_hash!(u128); | |
254 | impl_stable_hash_via_hash!(i128); | |
255 | ||
256 | impl_stable_hash_via_hash!(char); | |
257 | impl_stable_hash_via_hash!(()); | |
258 | ||
c295e0f8 XL |
259 | impl<CTX> HashStable<CTX> for ! { |
260 | fn hash_stable(&self, _ctx: &mut CTX, _hasher: &mut StableHasher) { | |
261 | unreachable!() | |
262 | } | |
263 | } | |
264 | ||
064997fb FG |
265 | impl<CTX, T> HashStable<CTX> for PhantomData<T> { |
266 | fn hash_stable(&self, _ctx: &mut CTX, _hasher: &mut StableHasher) {} | |
267 | } | |
268 | ||
b7449926 | 269 | impl<CTX> HashStable<CTX> for ::std::num::NonZeroU32 { |
04454e1e | 270 | #[inline] |
e74abb32 | 271 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
b7449926 XL |
272 | self.get().hash_stable(ctx, hasher) |
273 | } | |
274 | } | |
275 | ||
ba9703b0 | 276 | impl<CTX> HashStable<CTX> for ::std::num::NonZeroUsize { |
04454e1e | 277 | #[inline] |
ba9703b0 XL |
278 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
279 | self.get().hash_stable(ctx, hasher) | |
280 | } | |
281 | } | |
282 | ||
cc61c64b | 283 | impl<CTX> HashStable<CTX> for f32 { |
e74abb32 | 284 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
3c0e092e | 285 | let val: u32 = unsafe { ::std::mem::transmute(*self) }; |
cc61c64b XL |
286 | val.hash_stable(ctx, hasher); |
287 | } | |
288 | } | |
289 | ||
290 | impl<CTX> HashStable<CTX> for f64 { | |
e74abb32 | 291 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
3c0e092e | 292 | let val: u64 = unsafe { ::std::mem::transmute(*self) }; |
cc61c64b XL |
293 | val.hash_stable(ctx, hasher); |
294 | } | |
295 | } | |
296 | ||
0531ce1d | 297 | impl<CTX> HashStable<CTX> for ::std::cmp::Ordering { |
04454e1e | 298 | #[inline] |
e74abb32 | 299 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
0531ce1d XL |
300 | (*self as i8).hash_stable(ctx, hasher); |
301 | } | |
302 | } | |
303 | ||
041b39d2 | 304 | impl<T1: HashStable<CTX>, CTX> HashStable<CTX> for (T1,) { |
04454e1e | 305 | #[inline] |
e74abb32 | 306 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
ea8adc8c XL |
307 | let (ref _0,) = *self; |
308 | _0.hash_stable(ctx, hasher); | |
041b39d2 XL |
309 | } |
310 | } | |
311 | ||
cc61c64b | 312 | impl<T1: HashStable<CTX>, T2: HashStable<CTX>, CTX> HashStable<CTX> for (T1, T2) { |
e74abb32 | 313 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
ea8adc8c XL |
314 | let (ref _0, ref _1) = *self; |
315 | _0.hash_stable(ctx, hasher); | |
316 | _1.hash_stable(ctx, hasher); | |
317 | } | |
318 | } | |
319 | ||
320 | impl<T1, T2, T3, CTX> HashStable<CTX> for (T1, T2, T3) | |
dfeec247 XL |
321 | where |
322 | T1: HashStable<CTX>, | |
323 | T2: HashStable<CTX>, | |
324 | T3: HashStable<CTX>, | |
ea8adc8c | 325 | { |
e74abb32 | 326 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
ea8adc8c XL |
327 | let (ref _0, ref _1, ref _2) = *self; |
328 | _0.hash_stable(ctx, hasher); | |
329 | _1.hash_stable(ctx, hasher); | |
330 | _2.hash_stable(ctx, hasher); | |
cc61c64b XL |
331 | } |
332 | } | |
333 | ||
b7449926 | 334 | impl<T1, T2, T3, T4, CTX> HashStable<CTX> for (T1, T2, T3, T4) |
dfeec247 XL |
335 | where |
336 | T1: HashStable<CTX>, | |
337 | T2: HashStable<CTX>, | |
338 | T3: HashStable<CTX>, | |
339 | T4: HashStable<CTX>, | |
b7449926 | 340 | { |
e74abb32 | 341 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
b7449926 XL |
342 | let (ref _0, ref _1, ref _2, ref _3) = *self; |
343 | _0.hash_stable(ctx, hasher); | |
344 | _1.hash_stable(ctx, hasher); | |
345 | _2.hash_stable(ctx, hasher); | |
346 | _3.hash_stable(ctx, hasher); | |
347 | } | |
348 | } | |
349 | ||
cc61c64b | 350 | impl<T: HashStable<CTX>, CTX> HashStable<CTX> for [T] { |
e74abb32 | 351 | default fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
cc61c64b XL |
352 | self.len().hash_stable(ctx, hasher); |
353 | for item in self { | |
354 | item.hash_stable(ctx, hasher); | |
355 | } | |
356 | } | |
357 | } | |
358 | ||
3c0e092e XL |
359 | impl<CTX> HashStable<CTX> for [u8] { |
360 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { | |
361 | self.len().hash_stable(ctx, hasher); | |
362 | hasher.write(self); | |
363 | } | |
364 | } | |
365 | ||
cc61c64b XL |
366 | impl<T: HashStable<CTX>, CTX> HashStable<CTX> for Vec<T> { |
367 | #[inline] | |
e74abb32 | 368 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
cc61c64b XL |
369 | (&self[..]).hash_stable(ctx, hasher); |
370 | } | |
371 | } | |
372 | ||
dc9dc135 | 373 | impl<K, V, R, CTX> HashStable<CTX> for indexmap::IndexMap<K, V, R> |
dfeec247 XL |
374 | where |
375 | K: HashStable<CTX> + Eq + Hash, | |
376 | V: HashStable<CTX>, | |
377 | R: BuildHasher, | |
dc9dc135 XL |
378 | { |
379 | #[inline] | |
e74abb32 | 380 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
dc9dc135 XL |
381 | self.len().hash_stable(ctx, hasher); |
382 | for kv in self { | |
383 | kv.hash_stable(ctx, hasher); | |
384 | } | |
385 | } | |
386 | } | |
387 | ||
388 | impl<K, R, CTX> HashStable<CTX> for indexmap::IndexSet<K, R> | |
dfeec247 XL |
389 | where |
390 | K: HashStable<CTX> + Eq + Hash, | |
391 | R: BuildHasher, | |
dc9dc135 XL |
392 | { |
393 | #[inline] | |
e74abb32 | 394 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
dc9dc135 XL |
395 | self.len().hash_stable(ctx, hasher); |
396 | for key in self { | |
397 | key.hash_stable(ctx, hasher); | |
398 | } | |
399 | } | |
400 | } | |
401 | ||
dfeec247 XL |
402 | impl<A, CTX> HashStable<CTX> for SmallVec<[A; 1]> |
403 | where | |
404 | A: HashStable<CTX>, | |
405 | { | |
48663c56 | 406 | #[inline] |
e74abb32 | 407 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
48663c56 XL |
408 | (&self[..]).hash_stable(ctx, hasher); |
409 | } | |
410 | } | |
411 | ||
ea8adc8c | 412 | impl<T: ?Sized + HashStable<CTX>, CTX> HashStable<CTX> for Box<T> { |
041b39d2 | 413 | #[inline] |
e74abb32 | 414 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
041b39d2 XL |
415 | (**self).hash_stable(ctx, hasher); |
416 | } | |
417 | } | |
418 | ||
ea8adc8c XL |
419 | impl<T: ?Sized + HashStable<CTX>, CTX> HashStable<CTX> for ::std::rc::Rc<T> { |
420 | #[inline] | |
e74abb32 | 421 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
ea8adc8c XL |
422 | (**self).hash_stable(ctx, hasher); |
423 | } | |
424 | } | |
425 | ||
426 | impl<T: ?Sized + HashStable<CTX>, CTX> HashStable<CTX> for ::std::sync::Arc<T> { | |
041b39d2 | 427 | #[inline] |
e74abb32 | 428 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
041b39d2 XL |
429 | (**self).hash_stable(ctx, hasher); |
430 | } | |
431 | } | |
432 | ||
cc61c64b XL |
433 | impl<CTX> HashStable<CTX> for str { |
434 | #[inline] | |
a2a8927a XL |
435 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
436 | self.as_bytes().hash_stable(ctx, hasher); | |
cc61c64b XL |
437 | } |
438 | } | |
439 | ||
7cac9316 XL |
440 | impl<CTX> HashStable<CTX> for String { |
441 | #[inline] | |
e74abb32 | 442 | fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) { |
7cac9316 XL |
443 | (&self[..]).hash_stable(hcx, hasher); |
444 | } | |
445 | } | |
446 | ||
ea8adc8c XL |
447 | impl<HCX> ToStableHashKey<HCX> for String { |
448 | type KeyType = String; | |
449 | #[inline] | |
450 | fn to_stable_hash_key(&self, _: &HCX) -> Self::KeyType { | |
451 | self.clone() | |
452 | } | |
453 | } | |
454 | ||
cc61c64b XL |
455 | impl<CTX> HashStable<CTX> for bool { |
456 | #[inline] | |
e74abb32 | 457 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
cc61c64b XL |
458 | (if *self { 1u8 } else { 0u8 }).hash_stable(ctx, hasher); |
459 | } | |
460 | } | |
461 | ||
cc61c64b | 462 | impl<T, CTX> HashStable<CTX> for Option<T> |
dfeec247 XL |
463 | where |
464 | T: HashStable<CTX>, | |
cc61c64b XL |
465 | { |
466 | #[inline] | |
e74abb32 | 467 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
cc61c64b XL |
468 | if let Some(ref value) = *self { |
469 | 1u8.hash_stable(ctx, hasher); | |
470 | value.hash_stable(ctx, hasher); | |
471 | } else { | |
472 | 0u8.hash_stable(ctx, hasher); | |
473 | } | |
474 | } | |
475 | } | |
476 | ||
ea8adc8c | 477 | impl<T1, T2, CTX> HashStable<CTX> for Result<T1, T2> |
dfeec247 XL |
478 | where |
479 | T1: HashStable<CTX>, | |
480 | T2: HashStable<CTX>, | |
ea8adc8c XL |
481 | { |
482 | #[inline] | |
e74abb32 | 483 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
ea8adc8c XL |
484 | mem::discriminant(self).hash_stable(ctx, hasher); |
485 | match *self { | |
486 | Ok(ref x) => x.hash_stable(ctx, hasher), | |
487 | Err(ref x) => x.hash_stable(ctx, hasher), | |
488 | } | |
489 | } | |
490 | } | |
491 | ||
cc61c64b | 492 | impl<'a, T, CTX> HashStable<CTX> for &'a T |
dfeec247 XL |
493 | where |
494 | T: HashStable<CTX> + ?Sized, | |
cc61c64b XL |
495 | { |
496 | #[inline] | |
e74abb32 | 497 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
cc61c64b XL |
498 | (**self).hash_stable(ctx, hasher); |
499 | } | |
500 | } | |
501 | ||
502 | impl<T, CTX> HashStable<CTX> for ::std::mem::Discriminant<T> { | |
503 | #[inline] | |
e74abb32 | 504 | fn hash_stable(&self, _: &mut CTX, hasher: &mut StableHasher) { |
cc61c64b XL |
505 | ::std::hash::Hash::hash(self, hasher); |
506 | } | |
507 | } | |
508 | ||
60c5eb7d | 509 | impl<T, CTX> HashStable<CTX> for ::std::ops::RangeInclusive<T> |
dfeec247 XL |
510 | where |
511 | T: HashStable<CTX>, | |
60c5eb7d XL |
512 | { |
513 | #[inline] | |
514 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { | |
515 | self.start().hash_stable(ctx, hasher); | |
516 | self.end().hash_stable(ctx, hasher); | |
517 | } | |
518 | } | |
519 | ||
e74abb32 | 520 | impl<I: vec::Idx, T, CTX> HashStable<CTX> for vec::IndexVec<I, T> |
dfeec247 XL |
521 | where |
522 | T: HashStable<CTX>, | |
cc61c64b | 523 | { |
e74abb32 | 524 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { |
cc61c64b | 525 | self.len().hash_stable(ctx, hasher); |
ea8adc8c | 526 | for v in &self.raw { |
cc61c64b XL |
527 | v.hash_stable(ctx, hasher); |
528 | } | |
529 | } | |
530 | } | |
531 | ||
dfeec247 | 532 | impl<I: vec::Idx, CTX> HashStable<CTX> for bit_set::BitSet<I> { |
a2a8927a XL |
533 | fn hash_stable(&self, _ctx: &mut CTX, hasher: &mut StableHasher) { |
534 | ::std::hash::Hash::hash(self, hasher); | |
cc61c64b XL |
535 | } |
536 | } | |
537 | ||
dfeec247 | 538 | impl<R: vec::Idx, C: vec::Idx, CTX> HashStable<CTX> for bit_set::BitMatrix<R, C> { |
a2a8927a XL |
539 | fn hash_stable(&self, _ctx: &mut CTX, hasher: &mut StableHasher) { |
540 | ::std::hash::Hash::hash(self, hasher); | |
dc9dc135 XL |
541 | } |
542 | } | |
543 | ||
3dfed10e XL |
544 | impl<T, CTX> HashStable<CTX> for bit_set::FiniteBitSet<T> |
545 | where | |
546 | T: HashStable<CTX> + bit_set::FiniteBitSetTy, | |
547 | { | |
548 | fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) { | |
549 | self.0.hash_stable(hcx, hasher); | |
550 | } | |
551 | } | |
552 | ||
ea8adc8c XL |
553 | impl_stable_hash_via_hash!(::std::path::Path); |
554 | impl_stable_hash_via_hash!(::std::path::PathBuf); | |
555 | ||
556 | impl<K, V, R, HCX> HashStable<HCX> for ::std::collections::HashMap<K, V, R> | |
dfeec247 XL |
557 | where |
558 | K: ToStableHashKey<HCX> + Eq, | |
559 | V: HashStable<HCX>, | |
560 | R: BuildHasher, | |
cc61c64b | 561 | { |
ea8adc8c | 562 | #[inline] |
e74abb32 | 563 | fn hash_stable(&self, hcx: &mut HCX, hasher: &mut StableHasher) { |
a2a8927a XL |
564 | stable_hash_reduce(hcx, hasher, self.iter(), self.len(), |hasher, hcx, (key, value)| { |
565 | let key = key.to_stable_hash_key(hcx); | |
566 | key.hash_stable(hcx, hasher); | |
567 | value.hash_stable(hcx, hasher); | |
568 | }); | |
ea8adc8c XL |
569 | } |
570 | } | |
571 | ||
572 | impl<K, R, HCX> HashStable<HCX> for ::std::collections::HashSet<K, R> | |
dfeec247 XL |
573 | where |
574 | K: ToStableHashKey<HCX> + Eq, | |
575 | R: BuildHasher, | |
ea8adc8c | 576 | { |
e74abb32 | 577 | fn hash_stable(&self, hcx: &mut HCX, hasher: &mut StableHasher) { |
a2a8927a XL |
578 | stable_hash_reduce(hcx, hasher, self.iter(), self.len(), |hasher, hcx, key| { |
579 | let key = key.to_stable_hash_key(hcx); | |
580 | key.hash_stable(hcx, hasher); | |
581 | }); | |
ea8adc8c XL |
582 | } |
583 | } | |
584 | ||
585 | impl<K, V, HCX> HashStable<HCX> for ::std::collections::BTreeMap<K, V> | |
dfeec247 XL |
586 | where |
587 | K: ToStableHashKey<HCX>, | |
588 | V: HashStable<HCX>, | |
ea8adc8c | 589 | { |
e74abb32 | 590 | fn hash_stable(&self, hcx: &mut HCX, hasher: &mut StableHasher) { |
a2a8927a XL |
591 | stable_hash_reduce(hcx, hasher, self.iter(), self.len(), |hasher, hcx, (key, value)| { |
592 | let key = key.to_stable_hash_key(hcx); | |
593 | key.hash_stable(hcx, hasher); | |
594 | value.hash_stable(hcx, hasher); | |
595 | }); | |
ea8adc8c XL |
596 | } |
597 | } | |
598 | ||
599 | impl<K, HCX> HashStable<HCX> for ::std::collections::BTreeSet<K> | |
dfeec247 XL |
600 | where |
601 | K: ToStableHashKey<HCX>, | |
ea8adc8c | 602 | { |
e74abb32 | 603 | fn hash_stable(&self, hcx: &mut HCX, hasher: &mut StableHasher) { |
a2a8927a XL |
604 | stable_hash_reduce(hcx, hasher, self.iter(), self.len(), |hasher, hcx, key| { |
605 | let key = key.to_stable_hash_key(hcx); | |
606 | key.hash_stable(hcx, hasher); | |
607 | }); | |
ea8adc8c XL |
608 | } |
609 | } | |
610 | ||
a2a8927a | 611 | fn stable_hash_reduce<HCX, I, C, F>( |
ea8adc8c | 612 | hcx: &mut HCX, |
e74abb32 | 613 | hasher: &mut StableHasher, |
a2a8927a XL |
614 | mut collection: C, |
615 | length: usize, | |
616 | hash_function: F, | |
dfeec247 | 617 | ) where |
a2a8927a XL |
618 | C: Iterator<Item = I>, |
619 | F: Fn(&mut StableHasher, &mut HCX, I), | |
ea8adc8c | 620 | { |
a2a8927a XL |
621 | length.hash_stable(hcx, hasher); |
622 | ||
623 | match length { | |
624 | 1 => { | |
625 | hash_function(hasher, hcx, collection.next().unwrap()); | |
626 | } | |
627 | _ => { | |
628 | let hash = collection | |
629 | .map(|value| { | |
630 | let mut hasher = StableHasher::new(); | |
631 | hash_function(&mut hasher, hcx, value); | |
632 | hasher.finish::<u128>() | |
633 | }) | |
634 | .reduce(|accum, value| accum.wrapping_add(value)); | |
635 | hash.hash_stable(hcx, hasher); | |
636 | } | |
637 | } | |
ea8adc8c | 638 | } |
5099ac24 | 639 | |
923072b8 | 640 | /// Controls what data we do or do not hash. |
5099ac24 FG |
641 | /// Whenever a `HashStable` implementation caches its |
642 | /// result, it needs to include `HashingControls` as part | |
923072b8 | 643 | /// of the key, to ensure that it does not produce an incorrect |
5099ac24 | 644 | /// result (for example, using a `Fingerprint` produced while |
5e7ed085 | 645 | /// hashing `Span`s when a `Fingerprint` without `Span`s is |
5099ac24 FG |
646 | /// being requested) |
647 | #[derive(Clone, Hash, Eq, PartialEq, Debug)] | |
648 | pub struct HashingControls { | |
649 | pub hash_spans: bool, | |
5099ac24 | 650 | } |