Auto merge of #64272 - Mark-Simulacrum:parallel-handler, r=estebank

Refactor librustc_errors::Handler API

This should be reviewed by-commit.

The last commit moves all fields into an inner struct behind a single lock; this is done to prevent possible deadlocks in a multi-threaded compiler, as well as inconsistent state observation.

3 files changed, 3 insertions, 3 deletions

diff --git a/src/libsyntax/parse/parser/expr.rs b/src/libsyntax/parse/parser/expr.rs
index 41c3747b950..d0c865a7b8e 100644
--- a/src/libsyntax/parse/parser/expr.rs
+++ b/src/libsyntax/parse/parser/expr.rs
@@ -777,7 +777,7 @@ impl<'a> Parser<'a> {
                         ex = ExprKind::Lit(literal);
                     }
                     Err(mut err) => {
-                        self.cancel(&mut err);
+                        err.cancel();
                         return Err(self.expected_expression_found());
                     }
                 }
diff --git a/src/libsyntax/parse/parser/pat.rs b/src/libsyntax/parse/parser/pat.rs
index 08ee3a6bd86..3c624959ead 100644
--- a/src/libsyntax/parse/parser/pat.rs
+++ b/src/libsyntax/parse/parser/pat.rs
@@ -537,7 +537,7 @@ impl<'a> Parser<'a> {
         mut err: DiagnosticBuilder<'a>,
         expected: Expected,
     ) -> PResult<'a, P<Pat>> {
-        self.cancel(&mut err);
+        err.cancel();
 
         let expected = expected.unwrap_or("pattern");
         let msg = format!("expected {}, found {}", expected, self.this_token_descr());
diff --git a/src/libsyntax/parse/parser/stmt.rs b/src/libsyntax/parse/parser/stmt.rs
index 04bd61a4cfb..02da56f6e35 100644
--- a/src/libsyntax/parse/parser/stmt.rs
+++ b/src/libsyntax/parse/parser/stmt.rs
@@ -361,7 +361,7 @@ impl<'a> Parser<'a> {
                 }
                 Err(mut e) => {
                     self.recover_stmt_(SemiColonMode::Break, BlockMode::Ignore);
-                    self.cancel(&mut e);
+                    e.cancel();
                 }
                 _ => ()
             }