Re: Deallocating an object twice

[Simon Wright <simon@pushface.org>]

Victor Porton <porton@narod.ru> writes:

> If I understand correctly, it is an undefined behavior (or is it called 
> unbounded error?) if a pool access is deallocated twice with 
> Unchecked_Deallocation.
>
> I think it should be a Program_Error (if checks are on).
>
> Why was not this done even in Ada2012 (not speaking about older Ada)?
>
> It's bad.
>
> Or is it done and I just miss it?

If done at all, this check would be at a low level. AdaCore offer a
Debug Pool facility[1]. Of course, this wouldn't detect a C program
using free() on data allocated in Ada; you'd have to go lower, perhaps
using a tool like valgrind[2].

[1]
https://gcc.gnu.org/onlinedocs/gnat_ugn_unw/The-GNAT-Debug-Pool-Facility.html
[2] http://valgrind.org