32#  define BACKTRACE_SIZE  (4U) 
void backtrace_print(void)
Print up to the last BACKTRACE_SIZE return addresses from call of this function.
void backtrace_print_symbols(void)
Print up to the last BACKTRACE_SIZE symbol_names from call of this function.
int backtrace_len(void)
get the number of stack frames that are printed by print or print_symbols