rem: GERB_COMPILE_ERROR("Strange M code [%c%c]\n", (char)op[0], (char)op[1]);
add: GERB_COMPILE_ERROR("Strange M code [%d]\n", op_int);
context: parse_M_code(gerb_file_t *fd){    int op[2];        op[0] = gerb_fgetc(fd);    op[1] = gerb_fgetc(fd);        if ((op[0] == EOF) || (op[1] == EOF))	GERB_COMPILE_ERROR("Unexpected EOF found.\n");        if (op[0] != (int)'0')	GERB_COMPILE_ERROR("Strange M code [%c%c]\n", (char)op[0], (char)op[1]);    switch (op[1]) {    case '0':  /* Program stop */	return 1;    case '1':  /* Optional stop */	return 2;    case '2':  /* End of program */	return 3;    default:	GERB_COMPILE_ERROR("Strange M code [%c%c]\n", (char)op[0], (char)op[1]);    }    return 0;} /* parse_M_code */