#include <mach/mach_types.h> extern void extern_func(); int my_global = 3; extern int extern_global; extern int extern_unused_global; extern int my_used_external_global; kern_return_t mykext_start (kmod_info_t * ki, void * d) { ++my_global; ++extern_global; ++my_used_external_global; extern_func(); return KERN_SUCCESS; } kern_return_t mykext_stop (kmod_info_t * ki, void * d) { --my_global; --extern_global; return KERN_SUCCESS; } void my_dead_code() { ++extern_unused_global; }