1 use crate::definitions::{DefKey, DefPathData, DisambiguatedDefPathData};
2 use rustc_data_structures::fingerprint::Fingerprint;
3 use rustc_span::crate_disambiguator::CrateDisambiguator;
4 use rustc_span::def_id::{DefPathHash, StableCrateId};
7 fn def_path_hash_depends_on_crate_id() {
8 // This test makes sure that *both* halves of a DefPathHash depend on
9 // the crate-id of the defining crate. This is a desirable property
10 // because the crate-id can be more easily changed than the DefPath
11 // of an item, so, in the case of a crate-local DefPathHash collision,
12 // the user can simply "role the dice again" for all DefPathHashes in
13 // the crate by changing the crate disambiguator (e.g. via bumping the
14 // crate's version number).
16 let d0 = CrateDisambiguator::from(Fingerprint::new(12, 34));
17 let d1 = CrateDisambiguator::from(Fingerprint::new(56, 78));
19 let h0 = mk_test_hash("foo", d0);
20 let h1 = mk_test_hash("foo", d1);
22 assert_ne!(h0.stable_crate_id(), h1.stable_crate_id());
23 assert_ne!(h0.local_hash(), h1.local_hash());
25 fn mk_test_hash(crate_name: &str, crate_disambiguator: CrateDisambiguator) -> DefPathHash {
26 let stable_crate_id = StableCrateId::new(crate_name, crate_disambiguator);
27 let parent_hash = DefPathHash::new(stable_crate_id, 0);
31 disambiguated_data: DisambiguatedDefPathData {
32 data: DefPathData::CrateRoot,
37 key.compute_stable_hash(parent_hash)