warning: deprecated conversion from string constant to ‘char*’

Question

I have the warnings from the gcc compiler showing the const char issue.

How to get rid of the warnings?

Thanks, Michael

char * str_convert(int op) {
  /*returns the string corresponding to an operation opcode. Used for screen output.*/
  if(op == PLUS) {
    return "plus";
  }
  else if (op == MULT) {
    return "mult";
  }
  else if (op == SUBS) {
    return "subs";
  }
  else if (op == MOD) {
    return "mod";
  }
  else if (op == ABS) {
    return "abs";
  }
  else if (op == MAX) {
    return "max";
  }
  else if (op == MIN) {
    return "min";
  }
  else {
    return NULL;
  }
}

Answer 1

I think the fix is adding const to the return type (to prevent modification of the contents). I'd also change the if cascade to switch / case, but that's unrelated to the problem.

const char * str_convert(int op) {
  /*returns the string corresponding to an operation opcode. Used for screen output.*/
  switch (op) {
    case ABS:  return "abs";
    case MAX:  return "max";
    case MIN:  return "min";
    case MOD:  return "mod";
    case MULT: return "mult";
    case PLUS: return "plus";
    case SUBS: return "subs";
    default: return NULL;
  }
}