| //! 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::GenericArg<'tcx> { |
| fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { |
| self.unpack().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); |
| }); |
| } |
| } |
| |
| impl<'a> ToStableHashKey<StableHashingContext<'a>> for region::Scope { |
| type KeyType = region::Scope; |
| |
| #[inline] |
| fn to_stable_hash_key(&self, _: &StableHashingContext<'a>) -> region::Scope { |
| *self |
| } |
| } |