use warnings;
use strict;

use Inline C => <<'EOC';

void ro_on(SV * x) {
     SvREADONLY_on(x);
}

EOC

my ($DBG_ANY, $DBG_INFO, $DBG_KEYS, $DBG_RAND)
    = (-1, 0x0004, 0x0008, 0x0080);

ro_on($_) for($DBG_ANY, $DBG_INFO, $DBG_KEYS, $DBG_RAND);

my $_debug_ops = $DBG_RAND | $DBG_KEYS | $DBG_INFO;

ro_on($_debug_ops);

printf "debugops = 0x%04x\n",$_debug_ops;