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-rw-r--r--compiler/rustc_data_structures/src/intern.rs88
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;