rustc_hir/
stable_hash_impls.rs

1use rustc_data_structures::stable_hash::{StableHash, StableHashCtxt, StableHasher};
2
3use crate::HashIgnoredAttrId;
4use crate::hir::{AttributeMap, OwnerInfo, OwnerNodes};
5
6// The following implementations of StableHash for `ItemId`, `TraitItemId`, and
7// `ImplItemId` deserve special attention. Normally we do not hash `NodeId`s within
8// the HIR, since they just signify a HIR nodes own path. But `ItemId` et al
9// are used when another item in the HIR is *referenced* and we certainly
10// want to pick up on a reference changing its target, so we hash the NodeIds
11// in "DefPath Mode".
12
13impl<'tcx> StableHash for OwnerNodes<'tcx> {
14    fn stable_hash<Hcx: StableHashCtxt>(&self, hcx: &mut Hcx, hasher: &mut StableHasher) {
15        // We ignore the other fields since these refer to information included in
16        // `opt_hash` which is hashed in the collector and used for the crate hash.
17        let OwnerNodes { opt_hash, .. } = *self;
18        opt_hash.unwrap().stable_hash(hcx, hasher);
19    }
20}
21
22impl<'tcx> StableHash for AttributeMap<'tcx> {
23    fn stable_hash<Hcx: StableHashCtxt>(&self, hcx: &mut Hcx, hasher: &mut StableHasher) {
24        // We ignore the `map` since it refers to information included in `opt_hash` which is
25        // hashed in the collector and used for the crate hash.
26        let AttributeMap { opt_hash, define_opaque: _, map: _ } = *self;
27        opt_hash.unwrap().stable_hash(hcx, hasher);
28    }
29}
30
31impl<'tcx> StableHash for OwnerInfo<'tcx> {
32    fn stable_hash<Hcx: StableHashCtxt>(&self, hcx: &mut Hcx, hasher: &mut StableHasher) {
33        // We ignore the other fields since these refer to information included in
34        // `opt_hash` which is hashed in the collector and used for the crate hash.
35        let OwnerInfo { opt_hash, .. } = *self;
36        opt_hash.unwrap().stable_hash(hcx, hasher);
37    }
38}
39
40impl StableHash for HashIgnoredAttrId {
41    fn stable_hash<Hcx: StableHashCtxt>(&self, _hcx: &mut Hcx, _hasher: &mut StableHasher) {
42        /* we don't hash HashIgnoredAttrId, we ignore them */
43    }
44}
rustc_hir/stable_hash_impls.rs

rustc_hir/
stable_hash_impls.rs
