preprocess
if (0 != cmd_opt.preprocess) {
cmd_line = cmd_opt.preprocess;
cmd_opt.preprocess = cmd_opt.preprocess_default;
cmd_opt.preprocess = cmd_opt.preprocess_specified;
if (NULL == cmd_opt.preprocess) {
(void) execv(cmd_opt.preprocess, cmd_opt.cpp_opt);
cmd_opt.preprocess ? cmd_opt.preprocess : "(no)");
char *preprocess;
token = preprocess(token);
extern struct token *preprocess(struct token *);