diff options
Diffstat (limited to 'compiler/rustc_data_structures/src/intern.rs')
-rw-r--r-- | compiler/rustc_data_structures/src/intern.rs | 88 |
1 files changed, 2 insertions, 86 deletions
diff --git a/compiler/rustc_data_structures/src/intern.rs b/compiler/rustc_data_structures/src/intern.rs index 009b5d534..ba94f3776 100644 --- a/compiler/rustc_data_structures/src/intern.rs +++ b/compiler/rustc_data_structures/src/intern.rs @@ -4,8 +4,6 @@ use std::hash::{Hash, Hasher}; use std::ops::Deref; use std::ptr; -use crate::fingerprint::Fingerprint; - mod private { #[derive(Clone, Copy, Debug)] pub struct PrivateZst; @@ -72,7 +70,7 @@ impl<'a, T: PartialOrd> PartialOrd for Interned<'a, T> { if ptr::eq(self.0, other.0) { Some(Ordering::Equal) } else { - let res = self.0.partial_cmp(&other.0); + let res = self.0.partial_cmp(other.0); debug_assert_ne!(res, Some(Ordering::Equal)); res } @@ -86,7 +84,7 @@ impl<'a, T: Ord> Ord for Interned<'a, T> { if ptr::eq(self.0, other.0) { Ordering::Equal } else { - let res = self.0.cmp(&other.0); + let res = self.0.cmp(other.0); debug_assert_ne!(res, Ordering::Equal); res } @@ -110,87 +108,5 @@ where } } -/// A helper trait so that `Interned` things can cache stable hashes reproducibly. -pub trait InternedHashingContext { - fn with_def_path_and_no_spans(&mut self, f: impl FnOnce(&mut Self)); -} - -/// A helper type that you can wrap round your own type in order to automatically -/// cache the stable hash on creation and not recompute it whenever the stable hash -/// of the type is computed. -/// This is only done in incremental mode. You can also opt out of caching by using -/// StableHash::ZERO for the hash, in which case the hash gets computed each time. -/// This is useful if you have values that you intern but never (can?) use for stable -/// hashing. -#[derive(Copy, Clone)] -pub struct WithStableHash<T> { - pub internee: T, - pub stable_hash: Fingerprint, -} - -impl<T: PartialEq> PartialEq for WithStableHash<T> { - #[inline] - fn eq(&self, other: &Self) -> bool { - self.internee.eq(&other.internee) - } -} - -impl<T: Eq> Eq for WithStableHash<T> {} - -impl<T: Ord> PartialOrd for WithStableHash<T> { - fn partial_cmp(&self, other: &WithStableHash<T>) -> Option<Ordering> { - Some(self.internee.cmp(&other.internee)) - } -} - -impl<T: Ord> Ord for WithStableHash<T> { - fn cmp(&self, other: &WithStableHash<T>) -> Ordering { - self.internee.cmp(&other.internee) - } -} - -impl<T> Deref for WithStableHash<T> { - type Target = T; - - #[inline] - fn deref(&self) -> &T { - &self.internee - } -} - -impl<T: Hash> Hash for WithStableHash<T> { - #[inline] - fn hash<H: Hasher>(&self, s: &mut H) { - self.internee.hash(s) - } -} - -impl<T: HashStable<CTX>, CTX: InternedHashingContext> HashStable<CTX> for WithStableHash<T> { - fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) { - if self.stable_hash == Fingerprint::ZERO || cfg!(debug_assertions) { - // No cached hash available. This can only mean that incremental is disabled. - // We don't cache stable hashes in non-incremental mode, because they are used - // so rarely that the performance actually suffers. - - // We need to build the hash as if we cached it and then hash that hash, as - // otherwise the hashes will differ between cached and non-cached mode. - let stable_hash: Fingerprint = { - let mut hasher = StableHasher::new(); - hcx.with_def_path_and_no_spans(|hcx| self.internee.hash_stable(hcx, &mut hasher)); - hasher.finish() - }; - if cfg!(debug_assertions) && self.stable_hash != Fingerprint::ZERO { - assert_eq!( - stable_hash, self.stable_hash, - "cached stable hash does not match freshly computed stable hash" - ); - } - stable_hash.hash_stable(hcx, hasher); - } else { - self.stable_hash.hash_stable(hcx, hasher); - } - } -} - #[cfg(test)] mod tests; |