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

[Joel Soete <soete.joel@tiscali.be>]

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