From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jerry Van Baren <gvb.uboot@gmail.com>
Date: Sun, 18 May 2008 22:38:33 -0400
Subject: [U-Boot-Users] [PATCH 02/17] examples/eepro100_eeprom:
 Fix	memcpy to return destination pointer
In-Reply-To: <20080519012211.GD19480@game.jcrosoft.org>
References: <20080518222019.GC19480@game.jcrosoft.org>	<20080518230336.5DA772476E@gemini.denx.de>
	<20080519012211.GD19480@game.jcrosoft.org>
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To: u-boot@lists.denx.de

Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 01:03 Mon 19 May     , Wolfgang Denk wrote:
>> In message <20080518222019.GC19480@game.jcrosoft.org> you wrote:
>>>>>  static inline void *memcpy(void *dst, const void *src, unsigned int len)
>>>>>  {
>>>>>  	char *ret = dst;
>>>>> +
>>>>>  	while (len-- > 0) {
>>>>>  		*ret++ = *((char *)src);
>>>>>  		src++;
>>>>>  	}
>>>>> -	return (void *)ret;
>>>>> +
>>>>> +	return (void *)dst;
>>>> While technically correct, this is bogus. We have a variable ret, but
>>>> we don't return it. And we have a variable dst, but we don't use it as
>>>> destination pointer.
>>>>
>>>> Please change the
>>>> 	*ret++ = *((char *)src);
>>>> into
>>>> 	*dst++ = *((char *)src);
>>>> and leave all the rest.
>>> You can not do this because dst is a void
>> Why not? src is void, too.
> gcc will claim about the cast.
> 
> we can do this
>        void *ret = dst;
>        char *d = dst;
>        const char *s = src;
> 
>        while (len-- > 0)
>                *d++ = *s++;
> 
>         return ret;
> 
> Best Regards,
> J.

YES! YES! YES!  This gets my vote.  I marked the start of this thread 
meaning to suggest using temp variables of the right type and get rid of 
the complex casting crap, exactly what you did here.

Thanks,
gvb