default_global_vbl= 1
static_global_vbl = 2
extern_global_vbl = 3

default_global_vbl= 4
static_global_vbl = 5
extern_global_vbl = 6

I am in static_fn
default_global_vbl= 4
static_global_vbl = 5
extern_global_vbl = 6

I am in extern_fn
default_global_vbl= 4
extern_global_vbl = 6

I am in default_fn
default_global_vbl= 4
extern_global_vbl = 6