CALLBACK
rv = CALLBACK(&pn, &en);
rv = CALLBACK(&pn, &en);
rv = CALLBACK(&pn, &en);
rv = CALLBACK(&pn, &en);
rv = CALLBACK(pnp, &en);
rv = CALLBACK(&pn, &en);
rv = CALLBACK(&pn, &en);
rv = CALLBACK(&pn, &en);
static int CALLBACK
#ifdef CALLBACK
#ifdef CALLBACK
#define prom_tree_access(CALLBACK, ARG, GENP) (CALLBACK)((ARG), 0)