[Bug c/116016] enhancement: add __builtin_set_counted_by(P->FAM, COUNT) or equivalent

[qing.zhao at oracle dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116016

--- Comment #27 from Qing Zhao <qing.zhao at oracle dot com> ---
--- Comment #26 from Siddhesh Poyarekar <siddhesh at gcc dot gnu.org> ---
> (In reply to Qing Zhao from comment #25)
>> If (__builtin_get_counted_by (P->FAM))
>>  __builtin_get_counted_by (P->FAM) = COUNT;
> 
> Do we have language constructs where the existence of an identifier/expression
> (and not its value) is evaluated in a condition like this?
Good point (I am not sure here). Any suggestion on what’s the prototype of this
new __builtin_get_counted_by, and how to 
use it in the source code to resolve the original problem?