[patch] staging: comedi: cleanup comedi_recognize()

[Ian Abbott]

On 2012-05-24 12:16, Dan Carpenter wrote:
> On Thu, May 24, 2012 at 11:57:44AM +0100, Ian Abbott wrote:
>> On 2012-05-24 11:28, Dan Carpenter wrote:
>>> This function is more complicated than it needs to be because of the
>>> consts.  It's not worth saving them because we drop the consts anyway
>>> when we return (void *)name_ptr.
>>>
>>> Signed-off-by: Dan Carpenter<dan.carpenter at oracle.com>
>>>
>>> diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
>>> index 1c3d638..a8f576d 100644
>>> --- a/drivers/staging/comedi/drivers.c
>>> +++ b/drivers/staging/comedi/drivers.c
>>> @@ -304,14 +304,13 @@ static int postconfig(struct comedi_device *dev)
>>>    * that register their supported board names */
>>>   static void *comedi_recognize(struct comedi_driver *driv, const char *name)
>>>   {
>>> -	unsigned i;
>>> -	const char *const *name_ptr = driv->board_name;
>>> +	char **name_ptr = (char **)driv->board_name;
>>> +	int i;
>>> +
>>>   	for (i = 0; i<   driv->num_names; i++) {
>>>   		if (strcmp(*name_ptr, name) == 0)
>>> -			return (void *)name_ptr;
>>> -		name_ptr =
>>> -		    (const char *const *)((const char *)name_ptr +
>>> -					  driv->offset);
>>> +			return name_ptr;
>>> +		name_ptr = (char **)((void *)name_ptr + driv->offset);
>>>   	}
>>>
>>>   	return NULL;
>>
>> You could simplify it further by keeping one of the consts:
>>
>> static void *comedi_recognize(struct comedi_driver *driv, const char *name)
>> {
>> 	unsigned i;
>> 	const char **name_ptr = driv->board_name;
>> 	for (i = 0; i<  driv->num_names; i++) {
>> 		if (strcmp(*name_ptr, name) == 0)
>> 			return name_ptr;
>> 		name_ptr = (void *)name_ptr + driv->offset;
>> 	}
>> 	return NULL;
>> }
>
> Sure.  I'll resend.

Actually, my version gives a warning about a dropped qualifier, so the 
initializer of name_ptr would need a cast after all.  You could keep 
your version but remove the casts from (void *) when converting to the 
other pointer types.

static void *comedi_recognize(struct comedi_driver *driv, const char *name)
{
	unsigned i;
	char **name_ptr = (char **)driv->board_name;
	for (i = 0; i < driv->num_names; i++) {
		if (strcmp(*name_ptr, name) == 0)
			return name_ptr;
		name_ptr = (void *)name_ptr + driv->offset;
	}

	return NULL;
}

-- 
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbotti at mev.co.uk>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-