[Sheepdog] [PATCH 5/5] logger: fix the vprintf() bug

[Liu Yuan]

On 10/13/2011 03:25 PM, AndyChen wrote:
> 2011/10/13 Liu Yuan<namei.unix at gmail.com>:
>> On 10/13/2011 12:12 PM, AndyChen wrote:
>>>>> -       vprintf(SDOG_INFO "we create a new vdi, %d %s (%zd) %" PRIu64 ",
>>>>> vid: %"
>>>>> +       vprintf(SDOG_INFO, "we create a new vdi, %d %s (%zd) %" PRIu64
>>>>> ", vid: %"
>>>>>                 PRIx32 ", base %" PRIx32 ", cur %" PRIx32 " \n",
>>>>>                 is_snapshot, name, strlen(name), size, *new_vid,
>>>>> base_vid, cur_vid);
>>>>>
>>>>>         if (!copies) {
>>>>> -               vprintf(SDOG_WARNING "qemu doesn't specify the copies...
>>>>> %d\n",
>>>>> +               vprintf(SDOG_WARNING, "qemu doesn't specify the
>>>>> copies... %d\n",
>>>>>                         sys->nr_sobjs);
>>>>>                 copies = sys->nr_sobjs;
>>>>>         }
>>>> Why we need extra ',' in vprintf?
>>> it is not extra, now  vprintf() use log_write() which defined in
>>> sheepdog/include/logger.h,
>>> log_write() has log level parameter 'prio', but vrpintf() does not
>>> parse the log level, use LOG_INFO default.
>>> you mean use vprintf() such as use printk()?
>>>
>> I didn't get you meant. but the definition vprintf(fmt, args...) shows that
>> 'fmt' is the constant char *,  so I don't think we need to place ',' between
>> two format strings. I look at the printk implementation in linux kernel,
>> there is no such ',' between format strings either.
> here the vprintf defined by the sheep logger, not the standard library
> function: vprintf(fmt, args...)

#define vprintf(fmt, args...)                                           \
do {                                                                    \
         log_write(LOG_INFO, __func__, __LINE__, fmt, ##args);           \
} while (0)

extern void log_write(int prio, const char *func, int line, const char 
*fmt, ...)
         __attribute__ ((format (printf, 4, 5)));

So I think, it is safe to say that the type of 'fmt' in vprintf() is, 
const char *.

Thanks,
Yuan