Re: Some cleanup patches for: '...lvalues is deprecated'

[Joel Soete]

Thanks first for your attention ;)

Vojtech Pavlik wrote:
> On Sat, Jul 03, 2004 at 12:53:21PM +0000, Joel Soete wrote:
>
> > Hi Marcelo,
> >
> > Please appolgies first for wrong presentation of previous post (that was 
> > the first and certainly the last time that I used the 'forwarding' option 
> > of this webmail interface :( ).
> >
> > Here are some backport to clean up some warning of type: use of cast 
> > experssion
> > as lvalues is deprecated.
> > --- linux-2.4.27-rc2-pa4mm/kernel/sysctl.c.Orig	2004-06-29 
> > 09:03:42.000000000 +0200
> > +++ linux-2.4.27-rc2-pa4mm/kernel/sysctl.c	2004-06-29 
> > 10:10:31.588030256 +0200
> > @@ -890,7 +890,7 @@
> > 				if (!isspace(c))
> > 					break;
> > 				left--;
> > -				((char *) buffer)++;
> > +				buffer += sizeof(char);
>
>
> This (although correct in the end) is a wrong thing to do.
>
> It seems to look like the intention is to move the pointer by a char's
> size, however your change is equivalent to:
>
> 	buffer += 1;
>
> And if buffer wasn't void*, which it fortunately is, it would, unlike
> the older construction, move the pointer by a different size.
Very interesting but well I am not enough fluent in C to understand this fine detail :(
Can you explain me by an example (let say a long*) what would did "((char *) buffer)++;" versus "buffer += sizeof(char);"
(Don't worry, if don't have time, I will perfectly understand and will experiment by myself)

> So just use
>
> 	buffer++;
>
> here, and the intent is then clear.
Yes ;)
> > --- linux-2.4.27-rc2-pa4mm/drivers/video/fbcon.c.Orig	2004-06-29 
> > 10:47:31.901491304 +0200
> > +++ linux-2.4.27-rc2-pa4mm/drivers/video/fbcon.c	2004-06-29 
> > 11:13:31.846343640 +0200
> > @@ -1877,7 +1877,10 @@
> >        font length must be multiple of 256, at least. And 256 is multiple
> >        of 4 */
> >     k = 0;
> > -    while (p > new_data) k += *--(u32 *)p;
> > +    while (p > new_data) {
> > +        p = (u8 *)((u32 *)p - 1);
> > +        k += *(u32 *)p;
> > +    }
>
>
>
> How about
>
> 	p -= 4;
> 	k += *(u32 *)p;
:)

Thanks again,
	Joel
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