Use is_diagnostic_item to detect format_args/format_args_nl

Author: moatom

compiler/rustc_span/src/symbol.rs

@@ -1056,6 +1056,7 @@ symbols! {
         format_args_capture,
         format_args_macro,
         format_args_nl,
+        format_args_nl_macro,
         format_argument,
         format_arguments,
         format_count,

compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs

@@ -188,13 +188,14 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
 
             match e.obligation.predicate.kind().skip_binder() {
                 ty::PredicateKind::Subtype(_)
-                    if matches! (
-                        outer_expn_data.kind,
-                        ExpnKind::Macro(_, name) if matches!(
-                            name.as_str().rsplit("::").next(),
-                            Some("format_args" | "format_args_nl")
-                        )
-                    ) =>
+                    if let Some(def_id) = outer_expn_data.macro_def_id
+                        && (self
+                            .tcx
+                            .is_diagnostic_item(rustc_span::sym::format_args_nl_macro, def_id)
+                            || self.tcx.is_diagnostic_item(
+                                rustc_span::sym::format_args_macro,
+                                def_id,
+                            )) =>
                 {
                     let sm = self.tcx.sess.source_map();
                     let lc = sm.span_to_location_info(span);

library/core/src/macros/mod.rs

@@ -1012,6 +1012,7 @@ pub(crate) mod builtin {
     ///
     /// This macro will be removed once `format_args` is allowed in const contexts.
     #[unstable(feature = "const_format_args", issue = "none")]
+    #[rustc_diagnostic_item = "format_args_nl_macro"]
     #[allow_internal_unstable(fmt_internals, const_fmt_arguments_new)]
     #[rustc_builtin_macro]
     #[macro_export]