[PATCH] configure.ac: Use libsystemd in REQUIRED_LIBS check

[Emil Velikov]

Hi Jussi,

I'm not as experienced as other devs here so take all of the following
with a pinch of salt.

On 16 November 2015 at 14:46, Jussi Kukkonen <jussi.kukkonen at intel.com> wrote:
> REQUIRED_LIBS needs to be set to the correct systemd library,
> otherwise the later check will either fail or use the wrong
> pc file.
>
> Signed-off-by: Jussi Kukkonen <jussi.kukkonen at intel.com>
> ---
>  configure.ac | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/configure.ac b/configure.ac
> index 96c0242..f63eca1 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -837,9 +837,16 @@ AC_ARG_WITH([systemd-daemon],
>                 [support systemd socket activation (default: auto)]),
>         [WITH_SYSTEMD_DAEMON=$withval], [WITH_SYSTEMD_DAEMON=auto])
>  PKG_CHECK_MODULES([SYSTEMD_DAEMON], [libsystemd-daemon],
> -                  [HAVE_SYSTEMD_DAEMON=yes],
> +                  [REQUIRED_SYSTEMD_DAEMON=libsystemd-daemon],
>                    [PKG_CHECK_MODULES([SYSTEMD_DAEMON], [libsystemd],
> -                                     [HAVE_SYSTEMD_DAEMON=yes], [HAVE_SYSTEMD_DAEMON=no])])
> +                                     [REQUIRED_SYSTEMD_DAEMON=libsystemd],
> +                                     [REQUIRED_SYSTEMD_DAEMON=])])
> +if test "x$REQUIRED_SYSTEMD_DAEMON" = x; then
> +        HAVE_SYSTEMD_DAEMON=no
> +else
> +        HAVE_SYSTEMD_DAEMON=yes
> +fi
> +
>  if test "x$WITH_SYSTEMD_DAEMON" = xauto; then
>         WITH_SYSTEMD_DAEMON="$HAVE_SYSTEMD_DAEMON"
>  fi
> @@ -848,7 +855,7 @@ if test "x$WITH_SYSTEMD_DAEMON" = xyes; then
>                 AC_MSG_ERROR([systemd support requested but no library has been found])
>         fi
>         AC_DEFINE(HAVE_SYSTEMD_DAEMON, 1, [Define to 1 if libsystemd-daemon is available])
> -       REQUIRED_LIBS="$REQUIRED_LIBS libsystemd-daemon"
> +       REQUIRED_LIBS="$REQUIRED_LIBS $REQUIRED_SYSTEMD_DAEMON"
Rather than flipping things into a different (and somewhat obscure)
way, why don't you just use SYSTEMD_DAEMON_LIBS instead of the
hardcoded libsystemd-daemon ?

Shorter diff, consistent checks and it should work (although I haven't
checked it).
-Emil

P.S. We should also be using SYSTEMD_DAEMON_CFLAGS although I haven't
checked where exactly that's required.