Re-add 71a7f8f1884b2c83eeb4a545eef16df1f2ea6476 post-revert.

diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index 29e20f2747f1bdf43b63a14beb5106c89ab027b0..c5b961f12b2abad4bfa7163e8864d5d1ae756e39 100644 (file)
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -1469,7 +1469,10 @@ fn parse_field_ident(&mut self, adt_ty: &str, lo: Span) -> PResult<'a, Ident> {
         let (ident, is_raw) = self.ident_or_err()?;
         if !is_raw && ident.is_reserved() {
             let err = if self.check_fn_front_matter(false) {
-                let _ = self.parse_fn(&mut Vec::new(), |_| true, lo);
+                // We use `parse_fn` to get a span for the function
+                if let Err(mut db) = self.parse_fn(&mut Vec::new(), |_| true, lo) {
+                    db.delay_as_bug();
+                }
                 let mut err = self.struct_span_err(
                     lo.to(self.prev_token.span),
                     &format!("functions are not allowed in {} definitions", adt_ty),