Re: ALSA 1.1.8 Release - POLLRDNORM undefined

[Takashi Sakamoto <o-takashi@sakamocchi.jp>]

On Thu, Jan 10, 2019 at 08:44:34AM -0800, Jay Foster wrote:
> On 1/10/2019 12:31 AM, Jaroslav Kysela wrote:
> > Dne 10.1.2019 v 05:24 Takashi Sakamoto napsal(a):
> > > Hi,
> > > 
> > > I'm an author of axfer.
> > > 
> > > On Tue, 08 Jan 2019 18:00:18 +0100, Jay Foster wrote:
> > > > I am attempting to build the 1.1.8 release of alsa-utils and getting
> > > > an error about POLLRDNORM (and others) undefined.  This error comes
> > > > from axfer/waiter-select.c.  axfer/waiter-select.c includes
> > > > "waiter.h", which includes "poll.h".  This build is for a linux
> > > > target.
> > > > On Wed, 09 Jan 2019 17:22:36 +0100, Jay Foster wrote:
> > > > > On 1/9/2019 3:10 AM, Takashi Iwai wrote:
> > > > > > Which libc are you using?  The POSIX man page (man poll.h) mentions
> > > > > > POLLRDNORM defined there, at least, on my system with glibc 2.27.
> > > > > This is a legacy ARM product using glibc 2.9.
> > > I'm sorry for the FTBFS but it's out of my notice to build with too-old glibc.
> > > 
> > > Here, a history of glibc for related events:
> > > * glibc-2.9: 2008/11/13
> > >    * your version
> > > * glibc-2.10: 2009/5/9
> > >    * support XPG7/POSIX-2008
> > >    * add '__USE_XOPEN2k8' for the avove
> > > * glibc-2.19: 2014/2/7
> > >    * add '_DEFAULT_SOURCE' macro
> > >    * XPG7/POSIX-2008 is a default behaviour
> > > * glibc-2.20: 2014/9/7
> > >    * obsolete '_BSD_SOURCE' and '_SYSV_SOURCE' macros
> > > * glibc-2.28: 2018/8/1
> > >    * used my environment (Ubuntu 18.10)
> > > 
> > > The macros, POLLRDNORM and the others, seems to be defined officially in
> > > POSIX-2008 and nowadays glibc supports POSIX-2008 as a default. This is
> > > the reason that I've never faced your issue in my development period.
> > > I guess it's the reason that nothing noted in man of poll(2) and
> > > select(2).
> > > 
> > > I need a bit time to judge whether it's woth to support such old-glibc.
> > > Just removal of the newly-introduced macros is a simple solution.
> > We may add those definitions to CFLAGS (-D) through configure for the
> > old libs. Or just used #ifdef in the waiter-select.c - it's only one
> > place which uses this at this moment, but it's only quick workaround.
> > 
> I can resolve the issue by adding -D_GNU_SOURCE to my CFLAGS when building
> alsa-utils.  It would also be acceptable (to me) if you did nothing about
> this.
> 
> If you wish to check the version of glibc for support of POLLRDNORM through
> configure and add -D_GNU_SOURCE for older versions, that may work too.  I
> can report that-D_GNU_SOURCE is not needed with glibc 2.22.  I am not sure
> precisely which version the POLLRDNORM (and friends) were enabled by
> default.  I can imagine a configure test that compiled a test app which
> tries to use POLLRDNORM, and if it compiles successfully, then nothing else
> is needed.  If not, try again with -D_GNU_SOURCE, and if that works, add
> -D_GNU_SOURCE to the CFLAGS.  Such a test might also be conditional on
> selecting waiter-select (the only place this is used).

I filed this issue:
https://github.com/alsa-project/alsa-utils/issues/9


Regards

Takashi Sakamoto