-# sys_ioctl_h.m4 serial 4
+# sys_ioctl_h.m4 serial 5
dnl Copyright (C) 2008-2010 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
AC_SUBST([HAVE_SYS_IOCTL_H])
dnl <sys/ioctl.h> is always overridden, because of GNULIB_POSIXCHECK.
gl_CHECK_NEXT_HEADERS([sys/ioctl.h])
+
+ dnl Check for declarations of anything we want to poison if the
+ dnl corresponding gnulib module is not in use.
+ gl_WARN_ON_USE_PREPARE([[#include <sys/ioctl.h>
+/* Some platforms declare ioctl in the wrong header. */
+#ifndef __GLIBC__
+# include <unistd.h>
+#endif
+ ]], [ioctl])
])
dnl Unconditionally enables the replacement of <sys/ioctl.h>.