Re: [PATCH] configure.ac: Fix FIONREAD check to work with gcc-14 on Solaris

[Eli Zaretskii]

> From: Stefan Kangas <stefankangas@gmail.com>
> Date: Sat, 12 Oct 2024 08:20:52 -0500
> Cc: Ali Bahrami <Ali.Bahrami@oracle.com>, Eli Zaretskii <eliz@gnu.org>
> 
> Alan Coopersmith <alan.coopersmith@oracle.com> writes:
> 
> > Before this fix, it would fail to build with gcc-14 with the error:
> > conftest.c: In function 'main':
> > conftest.c:265:11: error: implicit declaration of function 'ioctl'
> >  [-Wimplicit-function-declaration]
> >   265 | int foo = ioctl (0, FIONREAD, &foo);
> >       |           ^~~~~
> >
> > Solaris documents ioctl() as being defined in <unistd.h>
> > ---
> >  configure.ac | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/configure.ac b/configure.ac
> > index 8a5ba7db3d1..947c2827b8e 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -7117,6 +7117,9 @@ AC_DEFUN
> >                         #ifdef USG5_4
> >                         # include <sys/filio.h>
> >                         #endif
> > +                       #ifdef HAVE_UNISTD_H
> > +                       # include <unistd.h> /* defines ioctl() on Solaris 
> > */
> > +                       #endif
> >                       ]],
> >                       [[int foo = ioctl (0, FIONREAD, &foo);]])],
> >      [emacs_cv_usable_FIONREAD=yes],
> > --
> > 2.45.2
> 
> I guess this should be installed on emacs-30.  Eli, WDYT?

I'd prefer on master.  Who knows what addition of unistd.h could cause
to this test?