makefn
int (*makefn)(struct vnode *, struct vnode **, struct componentname *,
if (makefn) {
rv = makefn(dvp, &vp, cn, va_x);
char *makefn(char *, char *);
outputfile = makefn (sourcefile, "out");
listfile = makefn (sourcefile, "lis");
errorfile = makefn (sourcefile, "err");