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use crate::definitions::{DefKey, DefPathData, DisambiguatedDefPathData};
use rustc_data_structures::stable_hasher::Hash64;
use rustc_span::def_id::{DefPathHash, StableCrateId};
use rustc_span::edition::Edition;
use rustc_span::{create_session_if_not_set_then, Symbol};
#[test]
fn def_path_hash_depends_on_crate_id() {
// This test makes sure that *both* halves of a DefPathHash depend on
// the crate-id of the defining crate. This is a desirable property
// because the crate-id can be more easily changed than the DefPath
// of an item, so, in the case of a crate-local DefPathHash collision,
// the user can simply "roll the dice again" for all DefPathHashes in
// the crate by changing the crate disambiguator (e.g. via bumping the
// crate's version number).
create_session_if_not_set_then(Edition::Edition2024, |_| {
let id0 = StableCrateId::new(Symbol::intern("foo"), false, vec!["1".to_string()], "");
let id1 = StableCrateId::new(Symbol::intern("foo"), false, vec!["2".to_string()], "");
let h0 = mk_test_hash(id0);
let h1 = mk_test_hash(id1);
assert_ne!(h0.stable_crate_id(), h1.stable_crate_id());
assert_ne!(h0.local_hash(), h1.local_hash());
fn mk_test_hash(stable_crate_id: StableCrateId) -> DefPathHash {
let parent_hash = DefPathHash::new(stable_crate_id, Hash64::ZERO);
let key = DefKey {
parent: None,
disambiguated_data: DisambiguatedDefPathData {
data: DefPathData::CrateRoot,
disambiguator: 0,
},
};
key.compute_stable_hash(parent_hash)
}
})
}
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