Re: [Qemu-devel] pty/tty functions for BSD too

[Anthony Liguori <anthony@codemonkey.ws>]

Warner Losh wrote:
> From: Samuel Thibault <samuel.thibault@ens-lyon.org>
> Subject: Re: [Qemu-devel] pty/tty functions for BSD too
> Date: Mon, 18 Aug 2008 15:23:33 +0100
>
>   
>> Anthony Liguori, le Mon 18 Aug 2008 09:06:41 -0500, a écrit :
>>     
>>> Samuel Thibault wrote:
>>>       
>>>> In Xen, pty/tty functions are enabled for BSD too, shouldn't we enable
>>>> them in upstream qemu too, as patched below?
>>>>  
>>>>         
>>> And you're sure that these functions compile/work on NetBSD/OpenBSD?
>>>       
>> The defines are explicit in Xen, so I guess somebody tested it.  I
>> haven't myself.  I wonder why there is no FreeBSD however.
>>     
>
> The TTY/PTY code is 4.2BSD, so everybdoy has it...  Not sure about why
> no FreeBSD.  I haven't looked at the code, but I thought there was a
> different fork it took..
>
> I've noticed many times in the past that the #ifdef sun and/or #ifdef
> linux code works great on FreeBSD.
>   

I hate to admit it, but autoconf really has it right here.

Instead of doing:

#if defined(__linux__) || defined(__FreeBSD__) || ...
fd = openpty();
#endif

we should have:

#ifdef HAVE_openpty
fd = openpty();
#endif

and do a configure check to see if there is a usable openpty.  It makes 
the code easier to maintain and you don't have to deal with all of this 
black magic wrt what individual OSes support.

Regards,

Anthony Liguori

> Warner
>
>
>