[asterisk-dev] backport RAII_VAR to 1.8?

[Tilghman Lesher]

On Mon, May 20, 2013 at 9:22 AM, Jason Parker <jparker at digium.com> wrote:
> On 05/17/2013 04:19 PM, Tilghman Lesher wrote:
>>
>> On Fri, May 17, 2013 at 3:44 PM, Paul Belanger
>> <paul.belanger at polybeacon.com> wrote:
>>>
>>> On 13-05-17 01:54 PM, Russell Bryant wrote:
>>>>
>>>> The size of this backport is tiny.  It's a small macro.  It's just
>>>> incredibly useful and actually helps write code less likely to contain
>>>> errors.
>>>>
>>>> If it's a problem, it shouldn't be *too* hard to pull it back out.  The
>>>> difficultly comes with however many places you have started using it.
>>>> In
>>>> my case, it's in the SLA code, so it's a pretty small fraction of the
>>>> code
>>>> base.  If it gets backported, explodes through the 1.8 code, and then a
>>>> problem is found 6 months later, that would be much more painful.  I
>>>> wouldn't expect it to spread too fast in 1.8, since the changes are
>>>> intentionally minimal.  It just might make fixing some bugs easier.
>>>>
>>>> Compiler version impact is worth considering.  I don't know what the
>>>> specific impact is in terms of distro support, though.  How about we
>>>> assume
>>>> it's ok, and if there's an uproar, I agree to do the work to revert the
>>>> usage I added.
>>>>
>>> For me it comes down to impact, I admit I know nothing about RAII_VAR, so
>>> if
>>> only SLA I agree it should be fine.
>>
>> Since clang is the default on Mac OS X, you're essentially suggesting
>> the end of simple support for Asterisk on the Mac.  I don't know if
>> that's desireable, especially in the middle of a release cycle.
>>
> I was thinking about this a little bit over the weekend, and I may have a
> way to make RAII_VAR not need a nested function.  I'm going to try to find
> some time to play with it for a few minutes, and see if I can't get it
> working.

There's a blog post that describes how to do a similar thing in Clang:
http://www.mikeash.com/pyblog/friday-qa-2012-08-24-things-you-never-wanted-to-know-about-c.html

This is more of a placeholder for me than a "you should go look at
this", though if you get to it before I do, that works, too.

-Tilghman