bjoernager/rust
bjoernager/rust
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Let a portion of DefPathHash uniquely identify the DefPath's crate.

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This allows to directly map from a DefPathHash to the crate it
originates from, without constructing side tables to do that mapping.

It also allows to reliably and cheaply check for DefPathHash collisions.
This commit is contained in:
Michael Woerister 2021-01-27 14:28:07 +01:00 • committed by Michael Woerister
parent a3ed564c13
commit 22d489be76
12 changed files with 181 additions and 27 deletions
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35
compiler/rustc_ast/src/crate_disambiguator.rs
View file

@ -1,35 +0,0 @@
// This is here because `rustc_session` wants to refer to it,
// and so does `rustc_hir`, but `rustc_hir` shouldn't refer to `rustc_session`.
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::{base_n, impl_stable_hash_via_hash};
use std::fmt;
/// Hash value constructed out of all the `-C metadata` arguments passed to the
/// compiler. Together with the crate-name forms a unique global identifier for
/// the crate.
#[derive(Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Clone, Copy, Encodable, Decodable)]
pub struct CrateDisambiguator(Fingerprint);
impl CrateDisambiguator {
pub fn to_fingerprint(self) -> Fingerprint {
self.0
}
}
impl fmt::Display for CrateDisambiguator {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
let (a, b) = self.0.as_value();
let as_u128 = a as u128 | ((b as u128) << 64);
f.write_str(&base_n::encode(as_u128, base_n::CASE_INSENSITIVE))
}
}
impl From<Fingerprint> for CrateDisambiguator {
fn from(fingerprint: Fingerprint) -> CrateDisambiguator {
CrateDisambiguator(fingerprint)
}
}
impl_stable_hash_via_hash!(CrateDisambiguator);

1
compiler/rustc_ast/src/lib.rs
View file

@ -41,7 +41,6 @@ pub mod util {
pub mod ast;
pub mod attr;
pub mod crate_disambiguator;
pub mod entry;
pub mod expand;
pub mod mut_visit;