Admittedly, this could probably be better, but it builds.
https://bugzilla.gnome.org/show_bug.cgi?id=687385
#include <glib.h>
#if TEST_EMULATED_FUTEX
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-prototypes"
+
/* this is defined for the 1bit-mutex-emufutex test.
*
* we want to test the emulated futex even if futex(2) is available.
#define G_BIT_LOCK_FORCE_FUTEX_EMULATION
#include <glib/gbitlock.c>
+
+#pragma GCC diagnostic pop
#endif
volatile GThread *owners[LOCKS];