macros: Allow field path segments to be keywords

tracing-attributes/tests/fields.rs

@@ -34,6 +34,9 @@ fn fn_string(s: String) {
     let _ = s;
 }
 
+#[instrument(fields(keywords.impl.type.fn = _arg), skip(_arg))]
+fn fn_keyword_ident_in_field(_arg: &str) {}
+
 #[derive(Debug)]
 struct HasField {
     my_field: &'static str,
@@ -146,6 +149,16 @@ fn string_field() {
     });
 }
 
+#[test]
+fn keyword_ident_in_field_name() {
+    let span = expect::span().with_field(
+        expect::field("keywords.impl.type.fn")
+            .with_value(&"test")
+            .only(),
+    );
+    run_test(span, || fn_keyword_ident_in_field("test"));
+}
+
 fn run_test<F: FnOnce() -> T, T>(span: NewSpan, fun: F) {
     let (collector, handle) = collector::mock()
         .new_span(span)

tracing/src/macros.rs

@@ -3069,8 +3069,8 @@ macro_rules! level_to_log {
 #[doc(hidden)]
 #[macro_export]
 macro_rules! __tracing_stringify {
-    ($s:expr) => {
-        stringify!($s)
+    ($($t:tt)*) => {
+        stringify!($($t)*)
     };
 }