Re: [PATCH] New class allocate_on_obstack

[Yao Qi <qiyaoltc@gmail.com>]

On Wed, Feb 7, 2018 at 3:29 PM, Tom Tromey <tom@tromey.com> wrote:
>>>>>> "Yao" == Yao Qi <qiyaoltc@gmail.com> writes:
>
> Yao> This patch adds a new class allocate_on_obstack, and let dwarf2_per_objfile
> Yao> inherit it, so that dwarf2_per_objfile is automatically allocated on
> Yao> obstack, and "delete dwarf2_per_objfile" doesn't de-allocate any space.
>
> I still think it should be restricted to types with a trivial
> destructor.  Otherwise, someday, the lack of actual destruction is going
> to cause a bug.
>

Can you give me some clues on how to do the restriction?  I think I need to
use std::enable_if and std::is_trivially_destructible, but don't know how to put
them into the code.

Lack of destruction causes a bug in any case.  If object is allocated on heap,
and don't do "delete p", the dtor isn't called and memory is leaked.  I
expect use "delete p" no matter where the object is allocated (on heap or
on obstack).

-- 
Yao (齐尧)