[syslinux] [PATCH] define _DEFAULT_SOURCE for glibc-2.20

[Gene Cumm]

On Thu, Sep 25, 2014 at 3:51 AM, Chanho Park <chanho61.park at samsung.com> wrote:
> Hi,
>
>> -----Original Message-----
>> From: Ferenc Wagner [mailto:wferi at niif.hu]
>> Sent: Thursday, September 25, 2014 4:42 PM
>> To: Chanho Park
>> Cc: syslinux at zytor.com
>> Subject: Re: [syslinux] [PATCH] define _DEFAULT_SOURCE for glibc-2.20
>>
>> Chanho Park <chanho61.park at samsung.com> writes:
>>
>> > _BSD_SOURCE was deprecated in favour of _DEFAULT_SOURCE since glibc
>> > 2.20[1]. To avoid build warning on glibc2.20, _DEFAULT_SOURCE should
>> > also be defined.
>>
>> Why exactly is _BSD_SOURCE (or _DEFAULT_SOURCE) needed in the Syslinux
>> sources?  Maybe it would be worth pointing out in a comment.
>
> Actually, I tried to remove _BSD_SOURCE because I think it's unnecessary
> flags.
> However, I'm not sure whether the removing is correct or not.
> Please look this mail thread[1].
>
> [1]: http://www.syslinux.org/archives/2014-September/022643.html

I mostly questioned it as a matter of "Why was it used in the first
place?".  Commit 1769d57c94d7a965168b72b6fd8d48251710b452 at tag
syslinux-2.00-pre8 (which I'd guess is actually from CVS import)
states "Make the syslinux installer be setuid safe (we hope...)".

In lieu of HPA voicing up with a more definitive answer and in light
of the manpage FEATURE_TEST_MACROS(7):

"To allow code that requires _BSD_SOURCE in glibc 2.19 and earlier and
_DEFAULT_SOURCE in glibc 2.20 and later to compile without warnings,
define both _BSD_SOURCE and _DEFAULT_SOURCE."[1]

I'd vote for this additional definition for now.


[1]: http://man7.org/linux/man-pages/man7/feature_test_macros.7.html

-- 
-Gene