diff --git a/Cargo.lock b/Cargo.lock
index 6c17edd302081..93f8eda66bb85 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1378,6 +1378,15 @@ dependencies = [
"zeroize",
]
+[[package]]
+name = "elsa"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f74077c3c3aedb99a2683919698285596662518ea13e5eedcf8bdd43b0d0453b"
+dependencies = [
+ "stable_deref_trait",
+]
+
[[package]]
name = "ena"
version = "0.14.0"
@@ -3882,6 +3891,7 @@ dependencies = [
"arrayvec 0.7.0",
"bitflags",
"cfg-if",
+ "elsa",
"ena",
"indexmap",
"jobserver",
diff --git a/compiler/rustc_data_structures/Cargo.toml b/compiler/rustc_data_structures/Cargo.toml
index 0366fb0a148c7..a6601fbf43bde 100644
--- a/compiler/rustc_data_structures/Cargo.toml
+++ b/compiler/rustc_data_structures/Cargo.toml
@@ -31,6 +31,7 @@ stacker = "0.1.15"
tempfile = "3.2"
thin-vec = "0.2.9"
tracing = "0.1"
+elsa = "1.8"
[dependencies.parking_lot]
version = "0.11"
diff --git a/compiler/rustc_data_structures/src/sync.rs b/compiler/rustc_data_structures/src/sync.rs
index ad71dcdf9d953..31323c21df009 100644
--- a/compiler/rustc_data_structures/src/sync.rs
+++ b/compiler/rustc_data_structures/src/sync.rs
@@ -26,6 +26,10 @@ use std::panic::{catch_unwind, resume_unwind, AssertUnwindSafe};
pub use std::sync::atomic::Ordering;
pub use std::sync::atomic::Ordering::SeqCst;
+pub use vec::AppendOnlyVec;
+
+mod vec;
+
cfg_if! {
if #[cfg(not(parallel_compiler))] {
pub auto trait Send {}
diff --git a/compiler/rustc_data_structures/src/sync/vec.rs b/compiler/rustc_data_structures/src/sync/vec.rs
new file mode 100644
index 0000000000000..cbea4f0599922
--- /dev/null
+++ b/compiler/rustc_data_structures/src/sync/vec.rs
@@ -0,0 +1,41 @@
+use std::marker::PhantomData;
+
+use rustc_index::vec::Idx;
+
+pub struct AppendOnlyVec<I: Idx, T: Copy> {
+ #[cfg(not(parallel_compiler))]
+ vec: elsa::vec::FrozenVec<T>,
+ #[cfg(parallel_compiler)]
+ vec: elsa::sync::LockFreeFrozenVec<T>,
+ _marker: PhantomData<fn(&I)>,
+}
+
+impl<I: Idx, T: Copy> AppendOnlyVec<I, T> {
+ pub fn new() -> Self {
+ Self {
+ #[cfg(not(parallel_compiler))]
+ vec: elsa::vec::FrozenVec::new(),
+ #[cfg(parallel_compiler)]
+ vec: elsa::sync::LockFreeFrozenVec::new(),
+ _marker: PhantomData,
+ }
+ }
+
+ pub fn push(&self, val: T) -> I {
+ #[cfg(not(parallel_compiler))]
+ let i = self.vec.len();
+ #[cfg(not(parallel_compiler))]
+ self.vec.push(val);
+ #[cfg(parallel_compiler)]
+ let i = self.vec.push(val);
+ I::new(i)
+ }
+
+ pub fn get(&self, i: I) -> Option<T> {
+ let i = i.index();
+ #[cfg(not(parallel_compiler))]
+ return self.vec.get_copy(i);
+ #[cfg(parallel_compiler)]
+ return self.vec.get(i);
+ }
+}
diff --git a/compiler/rustc_interface/src/queries.rs b/compiler/rustc_interface/src/queries.rs
index c957578b59e1d..a96cc95a38446 100644
--- a/compiler/rustc_interface/src/queries.rs
+++ b/compiler/rustc_interface/src/queries.rs
@@ -7,11 +7,10 @@ use rustc_codegen_ssa::traits::CodegenBackend;
use rustc_codegen_ssa::CodegenResults;
use rustc_data_structures::steal::Steal;
use rustc_data_structures::svh::Svh;
-use rustc_data_structures::sync::{Lrc, OnceCell, RwLock, WorkerLocal};
+use rustc_data_structures::sync::{AppendOnlyVec, Lrc, OnceCell, RwLock, WorkerLocal};
use rustc_hir::def_id::{CRATE_DEF_ID, LOCAL_CRATE};
use rustc_hir::definitions::Definitions;
use rustc_incremental::DepGraphFuture;
-use rustc_index::vec::IndexVec;
use rustc_lint::LintStore;
use rustc_metadata::creader::CStore;
use rustc_middle::arena::Arena;
@@ -195,10 +194,9 @@ impl<'tcx> Queries<'tcx> {
let cstore = RwLock::new(Box::new(CStore::new(sess)) as _);
let definitions = RwLock::new(Definitions::new(sess.local_stable_crate_id()));
- let mut source_span = IndexVec::default();
+ let source_span = AppendOnlyVec::new();
let _id = source_span.push(krate.spans.inner_span);
debug_assert_eq!(_id, CRATE_DEF_ID);
- let source_span = RwLock::new(source_span);
let untracked = Untracked { cstore, source_span, definitions };
let qcx = passes::create_global_ctxt(
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index cf4836ded474b..d95e4b56de074 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1030,7 +1030,7 @@ impl<'tcx> TyCtxt<'tcx> {
/// system if the result is otherwise tracked through queries
#[inline]
pub fn source_span_untracked(self, def_id: LocalDefId) -> Span {
- self.untracked.source_span.read().get(def_id).copied().unwrap_or(DUMMY_SP)
+ self.untracked.source_span.get(def_id).unwrap_or(DUMMY_SP)
}
#[inline(always)]
@@ -2521,6 +2521,5 @@ pub fn provide(providers: &mut ty::query::Providers) {
// We want to check if the panic handler was defined in this crate
tcx.lang_items().panic_impl().map_or(false, |did| did.is_local())
};
- providers.source_span =
- |tcx, def_id| tcx.untracked.source_span.read().get(def_id).copied().unwrap_or(DUMMY_SP);
+ providers.source_span = |tcx, def_id| tcx.untracked.source_span.get(def_id).unwrap_or(DUMMY_SP);
}
diff --git a/compiler/rustc_query_system/src/ich/hcx.rs b/compiler/rustc_query_system/src/ich/hcx.rs
index 8db8ee9428bc7..5593a15412fb7 100644
--- a/compiler/rustc_query_system/src/ich/hcx.rs
+++ b/compiler/rustc_query_system/src/ich/hcx.rs
@@ -146,7 +146,7 @@ impl<'a> rustc_span::HashStableContext for StableHashingContext<'a> {
#[inline]
fn def_span(&self, def_id: LocalDefId) -> Span {
- *self.untracked.source_span.read().get(def_id).unwrap_or(&DUMMY_SP)
+ self.untracked.source_span.get(def_id).unwrap_or(DUMMY_SP)
}
#[inline]
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 9aec25fff0b4f..80bc0a2653d9f 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -12,11 +12,10 @@ use rustc_errors::{struct_span_err, SuggestionStyle};
use rustc_feature::BUILTIN_ATTRIBUTES;
use rustc_hir::def::Namespace::{self, *};
use rustc_hir::def::{self, CtorKind, CtorOf, DefKind, NonMacroAttrKind, PerNS};
-use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID, LOCAL_CRATE};
+use rustc_hir::def_id::{DefId, CRATE_DEF_ID, LOCAL_CRATE};
use rustc_hir::PrimTy;
-use rustc_index::vec::IndexVec;
use rustc_middle::bug;
-use rustc_middle::ty::DefIdTree;
+use rustc_middle::ty::{DefIdTree, TyCtxt};
use rustc_session::lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE;
use rustc_session::lint::builtin::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS;
use rustc_session::lint::BuiltinLintDiagnostics;
@@ -154,8 +153,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
if !candidates.is_empty() {
show_candidates(
- &self.tcx.sess,
- &self.tcx.untracked().source_span.read(),
+ self.tcx,
&mut err,
span,
&candidates,
@@ -687,8 +685,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
err.span_help(span, &help_msg);
}
show_candidates(
- &self.tcx.sess,
- &self.tcx.untracked().source_span.read(),
+ self.tcx,
&mut err,
Some(span),
&import_suggestions,
@@ -1352,8 +1349,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
let import_suggestions =
self.lookup_import_candidates(ident, Namespace::MacroNS, parent_scope, is_expected);
show_candidates(
- &self.tcx.sess,
- &self.tcx.untracked().source_span.read(),
+ self.tcx,
err,
None,
&import_suggestions,
@@ -2358,8 +2354,7 @@ pub(crate) enum DiagnosticMode {
}
pub(crate) fn import_candidates(
- session: &Session,
- source_span: &IndexVec<LocalDefId, Span>,
+ tcx: TyCtxt<'_>,
err: &mut Diagnostic,
// This is `None` if all placement locations are inside expansions
use_placement_span: Option<Span>,
@@ -2368,8 +2363,7 @@ pub(crate) fn import_candidates(
append: &str,
) {
show_candidates(
- session,
- source_span,
+ tcx,
err,
use_placement_span,
candidates,
@@ -2385,8 +2379,7 @@ pub(crate) fn import_candidates(
/// entities with that name in all crates. This method allows outputting the
/// results of this search in a programmer-friendly way
fn show_candidates(
- session: &Session,
- source_span: &IndexVec<LocalDefId, Span>,
+ tcx: TyCtxt<'_>,
err: &mut Diagnostic,
// This is `None` if all placement locations are inside expansions
use_placement_span: Option<Span>,
@@ -2511,8 +2504,8 @@ fn show_candidates(
);
if let Some(local_def_id) = def_id.and_then(|did| did.as_local()) {
- let span = source_span[local_def_id];
- let span = session.source_map().guess_head_span(span);
+ let span = tcx.source_span(local_def_id);
+ let span = tcx.sess.source_map().guess_head_span(span);
let mut multi_span = MultiSpan::from_span(span);
multi_span.push_span_label(span, "not accessible");
err.span_note(multi_span, &msg);
@@ -2542,8 +2535,8 @@ fn show_candidates(
let mut spans = Vec::new();
for (name, _, def_id, _) in &inaccessible_path_strings {
if let Some(local_def_id) = def_id.and_then(|did| did.as_local()) {
- let span = source_span[local_def_id];
- let span = session.source_map().guess_head_span(span);
+ let span = tcx.source_span(local_def_id);
+ let span = tcx.sess.source_map().guess_head_span(span);
spans.push((name, span));
} else {
if !has_colon {
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index 449d8094bd60a..e8e31cb498136 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -548,8 +548,7 @@ impl<'a, 'b, 'tcx> ImportResolver<'a, 'b, 'tcx> {
if let Some(candidates) = &err.candidates {
match &import.kind {
ImportKind::Single { nested: false, source, target, .. } => import_candidates(
- self.r.tcx.sess,
- &self.r.tcx.untracked().source_span.read(),
+ self.r.tcx,
&mut diag,
Some(err.span),
&candidates,
@@ -561,8 +560,7 @@ impl<'a, 'b, 'tcx> ImportResolver<'a, 'b, 'tcx> {
),
ImportKind::Single { nested: true, source, target, .. } => {
import_candidates(
- self.r.tcx.sess,
- &self.r.tcx.untracked().source_span.read(),
+ self.r.tcx,
&mut diag,
None,
&candidates,
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 66034baaa0b6b..9fd7edeb5a189 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -1156,7 +1156,7 @@ impl<'tcx> Resolver<'_, 'tcx> {
// A relative span's parent must be an absolute span.
debug_assert_eq!(span.data_untracked().parent, None);
- let _id = self.tcx.untracked().source_span.write().push(span);
+ let _id = self.tcx.untracked().source_span.push(span);
debug_assert_eq!(_id, def_id);
// Some things for which we allocate `LocalDefId`s don't correspond to
diff --git a/compiler/rustc_session/src/cstore.rs b/compiler/rustc_session/src/cstore.rs
index 97aa930b5ec8e..868ffdf0f1da0 100644
--- a/compiler/rustc_session/src/cstore.rs
+++ b/compiler/rustc_session/src/cstore.rs
@@ -6,10 +6,9 @@ use crate::search_paths::PathKind;
use crate::utils::NativeLibKind;
use crate::Session;
use rustc_ast as ast;
-use rustc_data_structures::sync::{self, MetadataRef, RwLock};
+use rustc_data_structures::sync::{self, AppendOnlyVec, MetadataRef, RwLock};
use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, StableCrateId, LOCAL_CRATE};
use rustc_hir::definitions::{DefKey, DefPath, DefPathHash, Definitions};
-use rustc_index::vec::IndexVec;
use rustc_span::hygiene::{ExpnHash, ExpnId};
use rustc_span::symbol::Symbol;
use rustc_span::Span;
@@ -252,10 +251,9 @@ pub trait CrateStore: std::fmt::Debug {
pub type CrateStoreDyn = dyn CrateStore + sync::Sync + sync::Send;
-#[derive(Debug)]
pub struct Untracked {
pub cstore: RwLock<Box<CrateStoreDyn>>,
/// Reference span for definitions.
- pub source_span: RwLock<IndexVec<LocalDefId, Span>>,
+ pub source_span: AppendOnlyVec<LocalDefId, Span>,
pub definitions: RwLock<Definitions>,
}
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index 4c93f8a16b670..bddfdcfaf1941 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -120,6 +120,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
"dissimilar",
"dlmalloc",
"either",
+ "elsa",
"ena",
"expect-test",
"fallible-iterator", // dependency of `thorin`