c++: Find annotations in DECL_ATTRIBUTES (TYPE_NAME (r)) for type aliases

On Wed, Feb 25, 2026 at 08:50:40PM +0100, Jakub Jelinek wrote:
> > Sounds like the maybe_strip_typedefs is wrong, since reflection in general
> > tries to preserve aliases.
>
> Actually the maybe_strip_typedefs call is correct, that is for the type
> argument (so when it is std::meta::annotations_with_type) and the standard
> says that dealias should be used
> - https://eel.is/c++draft/meta.reflection#annotation-6.2
> But we probably shouldn't use TYPE_ATTRIBUTES but DECL_ATTRIBUTES (TYPE_NAME (r))
> if r is a type alias.
> I'll test a patch for that separately.

Here it is.

2026-03-04  Jakub Jelinek  <jakub@redhat.com>

	PR c++/123866
	* reflect.cc (eval_annotations_of): For type aliases look for
	annotations in DECL_ATTRIBUTES (TYPE_NAME (r)).

	* g++.dg/reflect/annotations11.C: New test.