bjoernager/rust
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Auto merge of #75134 - Aaron1011:feature/expn-data-parent-hash, r=petrochenkov

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Hash parent ExpnData

cc https://github.com/rust-lang/rust/pull/72121#discussion_r460528326
This commit is contained in:
bors 2020-08-09 14:29:42 +00:00
commit 543f03d241
2 changed files with 39 additions and 33 deletions
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8
src/librustc_span/hygiene.rs
View file

@ -80,8 +80,6 @@ pub enum Transparency {
Opaque, Opaque,
} }
pub(crate) const NUM_TRANSPARENCIES: usize = 3;
impl ExpnId { impl ExpnId {
pub fn fresh(expn_data: Option<ExpnData>) -> Self { pub fn fresh(expn_data: Option<ExpnData>) -> Self {
HygieneData::with(|data| data.fresh_expn(expn_data)) HygieneData::with(|data| data.fresh_expn(expn_data))
@ -618,6 +616,11 @@ impl SyntaxContext {
HygieneData::with(|data| data.expn_data(data.outer_expn(self)).clone()) HygieneData::with(|data| data.expn_data(data.outer_expn(self)).clone())
} }
#[inline]
pub fn outer_mark(self) -> (ExpnId, Transparency) {
HygieneData::with(|data| data.outer_mark(self))
}
#[inline] #[inline]
pub fn outer_mark_with_data(self) -> (ExpnId, Transparency, ExpnData) { pub fn outer_mark_with_data(self) -> (ExpnId, Transparency, ExpnData) {
HygieneData::with(|data| { HygieneData::with(|data| {
@ -667,7 +670,6 @@ pub struct ExpnData {
/// The kind of this expansion - macro or compiler desugaring. /// The kind of this expansion - macro or compiler desugaring.
pub kind: ExpnKind, pub kind: ExpnKind,
/// The expansion that produced this expansion. /// The expansion that produced this expansion.
#[stable_hasher(ignore)]
pub parent: ExpnId, pub parent: ExpnId,
/// The location of the actual macro invocation or syntax sugar , e.g. /// The location of the actual macro invocation or syntax sugar , e.g.
/// `let x = foo!();` or `if let Some(y) = x {}` /// `let x = foo!();` or `if let Some(y) = x {}`

52
src/librustc_span/lib.rs
View file

@ -32,8 +32,8 @@ pub mod edition;
use edition::Edition; use edition::Edition;
pub mod hygiene; pub mod hygiene;
pub use hygiene::SyntaxContext; pub use hygiene::SyntaxContext;
use hygiene::Transparency;
pub use hygiene::{DesugaringKind, ExpnData, ExpnId, ExpnKind, ForLoopLoc, MacroKind}; pub use hygiene::{DesugaringKind, ExpnData, ExpnId, ExpnKind, ForLoopLoc, MacroKind};
use hygiene::{Transparency, NUM_TRANSPARENCIES};
pub mod def_id; pub mod def_id;
use def_id::{CrateNum, DefId, LOCAL_CRATE}; use def_id::{CrateNum, DefId, LOCAL_CRATE};
mod span_encoding; mod span_encoding;
@ -1823,47 +1823,51 @@ impl<CTX: HashStableContext> HashStable<CTX> for SyntaxContext {
TAG_NO_EXPANSION.hash_stable(ctx, hasher); TAG_NO_EXPANSION.hash_stable(ctx, hasher);
} else { } else {
TAG_EXPANSION.hash_stable(ctx, hasher); TAG_EXPANSION.hash_stable(ctx, hasher);
let (expn_id, transparency) = self.outer_mark();
expn_id.hash_stable(ctx, hasher);
transparency.hash_stable(ctx, hasher);
}
}
}
impl<CTX: HashStableContext> HashStable<CTX> for ExpnId {
fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
// Since the same expansion context is usually referenced many // Since the same expansion context is usually referenced many
// times, we cache a stable hash of it and hash that instead of // times, we cache a stable hash of it and hash that instead of
// recursing every time. // recursing every time.
thread_local! { thread_local! {
static CACHE: RefCell<Vec<Option<[Option<u64>; NUM_TRANSPARENCIES]>>> = Default::default(); static CACHE: RefCell<Vec<Option<Fingerprint>>> = Default::default();
} }
let sub_hash: u64 = CACHE.with(|cache| { const TAG_ROOT: u8 = 0;
let (expn_id, transparency, _) = self.outer_mark_with_data(); const TAG_NOT_ROOT: u8 = 1;
let index = expn_id.as_u32() as usize;
if let Some(sub_hash_cache) = cache.borrow().get(index).copied().flatten() { if *self == ExpnId::root() {
if let Some(sub_hash) = sub_hash_cache[transparency as usize] { TAG_ROOT.hash_stable(ctx, hasher);
return sub_hash; return;
}
} }
TAG_NOT_ROOT.hash_stable(ctx, hasher);
let index = self.as_u32() as usize;
let res = CACHE.with(|cache| cache.borrow().get(index).copied().flatten());
if let Some(res) = res {
res.hash_stable(ctx, hasher);
} else {
let new_len = index + 1; let new_len = index + 1;
let mut hasher = StableHasher::new(); let mut sub_hasher = StableHasher::new();
expn_id.expn_data().hash_stable(ctx, &mut hasher); self.expn_data().hash_stable(ctx, &mut sub_hasher);
transparency.hash_stable(ctx, &mut hasher); let sub_hash: Fingerprint = sub_hasher.finish();
let sub_hash: Fingerprint = hasher.finish();
let sub_hash = sub_hash.to_smaller_hash();
CACHE.with(|cache| {
let mut cache = cache.borrow_mut(); let mut cache = cache.borrow_mut();
if cache.len() < new_len { if cache.len() < new_len {
cache.resize(new_len, None); cache.resize(new_len, None);
} }
if let Some(mut sub_hash_cache) = cache[index] { cache[index].replace(sub_hash).expect_none("Cache slot was filled");
sub_hash_cache[transparency as usize] = Some(sub_hash);
} else {
let mut sub_hash_cache = [None; NUM_TRANSPARENCIES];
sub_hash_cache[transparency as usize] = Some(sub_hash);
cache[index] = Some(sub_hash_cache);
}
sub_hash
}); });
sub_hash.hash_stable(ctx, hasher); sub_hash.hash_stable(ctx, hasher);
} }
} }