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.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libsyntax/parse/attr.rs b/src/libsyntax/parse/attr.rs
index bba70973631..cf6151d17b1 100644
--- a/src/libsyntax/parse/attr.rs
+++ b/src/libsyntax/parse/attr.rs
@@ -302,14 +302,14 @@ impl<'a> Parser<'a> {
             Ok(lit) => {
                 return Ok(ast::NestedMetaItem::Literal(lit))
             }
-            Err(ref mut err) => self.diagnostic().cancel(err)
+            Err(ref mut err) => err.cancel(),
         }
 
         match self.parse_meta_item() {
             Ok(mi) => {
                 return Ok(ast::NestedMetaItem::MetaItem(mi))
             }
-            Err(ref mut err) => self.diagnostic().cancel(err)
+            Err(ref mut err) => err.cancel(),
         }
 
         let found = self.this_token_to_string();