Make utmpx.h optional

configure.ac

@@ -221,7 +221,7 @@ AM_CONDITIONAL([IS_BIONIC], [test "x$is_bionic" = "xyes"])
 AC_CHECK_DECLS([PR_CAPBSET_DROP], [], [], [#include <sys/prctl.h>])
 
 # Check for some headers
-AC_CHECK_HEADERS([sys/signalfd.h pty.h sys/capability.h sys/personality.h])
+AC_CHECK_HEADERS([sys/signalfd.h pty.h sys/capability.h sys/personality.h utmpx.h])
 
 # Check for some syscalls functions
 AC_CHECK_FUNCS([setns pivot_root sethostname unshare])

src/lxc/utmp.c

@@ -21,6 +21,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
+#include "config.h"
+
+#ifdef HAVE_UTMPX_H
+
 #include <stdio.h>
 #include <unistd.h>
 #include <errno.h>
@@ -37,7 +41,10 @@
 #include "mainloop.h"
 #include "lxc.h"
 #include "log.h"
+
+#ifndef __USE_GNU
 #define __USE_GNU
+#endif
 #include <utmpx.h>
 #undef __USE_GNU
 
@@ -410,3 +417,5 @@ int lxc_utmp_del_timer(struct lxc_epoll_descr *descr,
 	else
 		return 0;
 }
+
+#endif

src/lxc/utmp.h

@@ -21,8 +21,17 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
+#include "config.h"
+
 struct lxc_handler;
 struct lxc_epoll_descr;
 
+#ifdef HAVE_UTMPX_H
 int lxc_utmp_mainloop_add(struct lxc_epoll_descr *descr,
 			  struct lxc_handler *handler);
+#else
+static inline int lxc_utmp_mainloop_add(struct lxc_epoll_descr *descr,
+			  struct lxc_handler *handler) {
+		return -1;
+}
+#endif