Re: Fwd: Automagic dependency on selinux

[Jim Meyering]

Bruno Haible wrote:
> Hi Jim,
>
> Johan Hattne wrote:
>> ... trouble if e.g. findutils are compiled on a host
>> where selinux is present, but run on a system without.
>
> For every somewhat complicated or possibly troublesome connection to an
> external package, it makes sense to have a --without-... option.
>
> Paul Eggert wrote:
>> The general idea seems sound, but it sounds like it should be a --with 
>> option,
>
> James Youngman wrote in <https://savannah.gnu.org/bugs/?30608>
>> I sympathise
>
> So here is a proposed patch. Can someone with access to an SELinux machine
> please test it? On such a system, run
>   $ ./gnulib-tool --create-testdir --dir=/tmp/testdir selinux-h
>   $ cd /tmp/testdir
>   $ ./configure --without-selinux
>   $ make
> the observe whether
>   1) gllib/selinux/context.h has been created,
>   2) HAVE_SELINUX_SELINUX_H is not defined in config.h.

Hi Bruno,
Thanks for writing that.
I tested as you suggested and confirm that
gllib/selinux/context.h is indeed created.

However, HAVE_SELINUX_SELINUX_H *is* defined in config.h.

That is due to the use of
gl_CHECK_NEXT_HEADERS([selinux/selinux.h]) in selinux-selinux.m4,
which ends up invoking AC_CHECK_HEADERS_ONCE([selinux/selinux.h]), which
performs the check long before this conditional in selinux-selinux.m4:

  if test "$with_selinux" != no; then