attributes: Improve output for #[instrument(ret)]

This ensures that events generated by this instrumentation have a useful name for consumption in common OpenTelemetry tracing tools.
tokio-rs · Sep 20, 2022 · 6c90c68 · 6c90c68
1 parent 3b58df3
commit 6c90c68
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/tracing-attributes/src/expand.rs b/tracing-attributes/src/expand.rs
@@ -243,13 +243,13 @@ fn gen_block<B: ToTokens>(
 
     let ret_event = match args.ret_mode {
         Some(FormatMode::Display) => Some(quote!(
-            tracing::event!(target: #target, #level, return = %x)
+            tracing::event!(target: #target, #level, { return = %x }, "{}", x)
         )),
         Some(FormatMode::Default) | Some(FormatMode::Debug) => Some(quote!(
-            tracing::event!(target: #target, #level, return = ?x)
+            tracing::event!(target: #target, #level, { return = ?x }, "{}", x)
         )),
         Some(FormatMode::Raw) => Some(quote!(
-            tracing::event!(target: #target, #level, return = x)
+            tracing::event!(target: #target, #level, { return = x }, "{}", x)
         )),
         _ => None,
     };