Re: [PATCH v1] perf test type profiling: Remote typedef on struct

[Dmitry Dolgov]

> On Mon, Mar 30, 2026 at 11:42:25PM -0700, Namhyung Kim wrote:
>
> We have this:
> 
>   Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
>   {
>       do {
>           vr_die = __die_get_real_type(vr_die, die_mem);
>       } while (vr_die && dwarf_tag(vr_die) == DW_TAG_typedef);
>  
>       return vr_die;
>   }

Indeed, I didn't finish the analysis, fooled that the diff was solving
the issue. Adding DW_TAG_typedef into __die_get_real_type still fixes
the problem, but due to different reasons:

* check_variable calls __die_get_real_type directly at the beginning and
  stores the result in type_die, which is the result of the function.

* if it doesn't resolve DW_TAG_typedef, the flow goes into the
  die_get_real_type, which stores the result in the local variable
  sized_type. But it never copied into the type_die, and never returned
  as a result of the check_variable.

Hence we either need to add DW_TAG_typedef into __die_get_real_type, or
copy sized_type into type_die. After some testing both seems to be
achieving the goal.