Auto merge of #81337 - petrochenkov:kvcollect, r=Aaron1011

parser: Collect tokens for values in key-value attributes

Fixes #81208 which happens when we parse the attribute value for the second time with an overridden span to synthesize tokens.

It also may be faster to collect tokens instead of re-synthesizing them.

1 files changed, 2 insertions, 6 deletions

diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index f11c6591de9..c575c821964 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -980,12 +980,8 @@ impl<'a> Parser<'a> {
                         }
                     }
 
-                    // The value here is never passed to macros as tokens by itself (not as a part
-                    // of the whole attribute), so we don't collect tokens here. If this changes,
-                    // then token will need to be collected. One catch here is that we are using
-                    // a nonterminal for keeping the expression, but this nonterminal should not
-                    // be wrapped into a group when converting to token stream.
-                    let expr = self.parse_expr()?;
+                    // Collect tokens because they are used during lowering to HIR.
+                    let expr = self.collect_tokens(|this| this.parse_expr())?;
                     let span = expr.span;
 
                     match &expr.kind {