ctf_diff_init
if (ctf_diff_init(ifp, ofp, &cdp) != 0) {
if ((ret = ctf_diff_init(ifp, ifp, &cdp)) != 0)
if ((ret = ctf_diff_init(out, source, &cdp)) != 0)
if ((ret = ctf_diff_init(parent, src, &cdp)) != 0) {
extern int ctf_diff_init(ctf_file_t *, ctf_file_t *, ctf_diff_t **);