Auto merge of #109117 - oli-obk:locks, r=michaelwoerister

Avoid a few locks

We can use atomics or datastructures tuned for specific access patterns instead of locks. This may be an improvement for parallel rustc, but it's mostly a cleanup making various datastructures only usable in the way they are used right now (append data, never mutate), instead of having a general purpose lock.

2 files changed, 6 insertions, 3 deletions

diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index 9dbddee5a56..4a7da11a097 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -175,7 +175,7 @@ impl<'a> StringReader<'a> {
                     if !sym.can_be_raw() {
                         self.sess.emit_err(errors::CannotBeRawIdent { span, ident: sym });
                     }
-                    self.sess.raw_identifier_spans.borrow_mut().push(span);
+                    self.sess.raw_identifier_spans.push(span);
                     token::Ident(sym, true)
                 }
                 rustc_lexer::TokenKind::UnknownPrefix => {
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index 53c25a80c4b..aa57b804779 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -29,6 +29,7 @@ use rustc_ast::{Async, AttrArgs, AttrArgsEq, Expr, ExprKind, MacDelimiter, Mutab
 use rustc_ast::{HasAttrs, HasTokens, Unsafe, Visibility, VisibilityKind};
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::sync::Ordering;
 use rustc_errors::PResult;
 use rustc_errors::{
     Applicability, DiagnosticBuilder, ErrorGuaranteed, FatalError, IntoDiagnostic, MultiSpan,
@@ -1540,8 +1541,10 @@ pub(crate) fn make_unclosed_delims_error(
 }
 
 pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedDelim>, sess: &ParseSess) {
-    *sess.reached_eof.borrow_mut() |=
-        unclosed_delims.iter().any(|unmatched_delim| unmatched_delim.found_delim.is_none());
+    let _ = sess.reached_eof.fetch_or(
+        unclosed_delims.iter().any(|unmatched_delim| unmatched_delim.found_delim.is_none()),
+        Ordering::Relaxed,
+    );
     for unmatched in unclosed_delims.drain(..) {
         if let Some(mut e) = make_unclosed_delims_error(unmatched, sess) {
             e.emit();