[PATCH weston] configure.ac: fixup systemd/systemd-login detection

[Michael Tretter]

On Wed, 14 Mar 2018 14:06:59 +0000, Emil Velikov wrote:
> From: Emil Velikov <emil.velikov at collabora.com>
> 
> Current systemd/systemd-login integration requires dbus. Although that
> is far from clear the way current checks are handled.
> 
> Be explicit and clear, effectively fixing cases where the systemd
> auto detection will trip when dbus is explicitly disabled.
> 
> Using git show -w will make things easier to read ;-)
> 
> Cc: Michael Tretter <m.tretter at pengutronix.de>
> Reported-by: Michael Tretter <m.tretter at pengutronix.de>
> Signed-off-by: Emil Velikov <emil.velikov at collabora.com>
> ---
> Michael, can you give this a try instead?
> ---
>  configure.ac | 29 +++++++++++++++++------------
>  1 file changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index dd344d6a..89b89d3c 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -524,7 +524,11 @@ AC_ARG_ENABLE(systemd-login,
>                AS_HELP_STRING([--enable-systemd-login],
>                               [Enable logind support]),,
>                enable_systemd_login=auto)
> -if test x$enable_systemd_login != xno -a x$have_dbus != xno; then
> +if test x$enable_systemd_login != xno; then
> +  if test x$enable_systemd_login = xyes -a x$enable_dbus = xno; then
> +    AC_MSG_ERROR([systemd-login support explicitly requested, but dbus not available])
> +  fi

These checks allow to configure systemd login support without dbus by
setting enable_systemd_login=auto and enable_dbus=no. In this case,
systemd login support should be disabled without error.

Having a separate message for dbus is good, but not sure if the
conditions are actually clearer.

> +
>    PKG_CHECK_MODULES(SYSTEMD_LOGIN,
>                      [libsystemd >= 209],
>                      [have_systemd_login_209=yes;have_systemd_login=yes],
> @@ -537,20 +541,21 @@ if test x$enable_systemd_login != xno -a x$have_dbus != xno; then
>                            [have_systemd_login=yes],
>                            [have_systemd_login=no])
>          ])
> -else
> -  have_systemd_login=no
> -fi
>  
> -if test "x$have_systemd_login" = "xno" -a "x$enable_systemd_login" = "xyes"; then
> -  AC_MSG_ERROR([systemd-login support explicitly enabled, but can't find libsystemd>=209, libsystemd-login or dbus])
> -fi
> +  if test "x$have_systemd_login" = "xno" -a "x$enable_systemd_login" = "xyes"; then
> +    AC_MSG_ERROR([systemd-login support explicitly requested, but can't find libsystemd>=209 or libsystemd-login])
> +  fi
>  
> -AS_IF([test "x$have_systemd_login" = "xyes"],
> -      [AC_DEFINE([HAVE_SYSTEMD_LOGIN], [1], [Have systemd-login])])
> -AM_CONDITIONAL(HAVE_SYSTEMD_LOGIN, test "x$have_systemd_login" = "xyes")
> +  if test "x$have_systemd_login" = "xyes"; then
> +    AC_DEFINE([HAVE_SYSTEMD_LOGIN], [1], [Have systemd-login])]
> +  else
> +    have_systemd_login=no
> +  fi

The else branch is not needed, because it is only taken if
have_systemd_login already is no.

Michael

>  
> -AS_IF([test "x$have_systemd_login_209" = "xyes"],
> -      [AC_DEFINE([HAVE_SYSTEMD_LOGIN_209], [1], [Have systemd-login >= 209])])
> +  AS_IF([test "x$have_systemd_login_209" = "xyes"],
> +        [AC_DEFINE([HAVE_SYSTEMD_LOGIN_209], [1], [Have systemd-login >= 209])])
> +fi
> +AM_CONDITIONAL(HAVE_SYSTEMD_LOGIN, test "x$have_systemd_login" = "xyes")
>  
>  
>  # Note that other features might want libxml2, or this feature might use