[PATCH 08/68] 0 -> NULL, for arch/m68k

[PATCH 08/68] 0 -> NULL, for arch/m68k

[Yoann Padioleau]

When comparing a pointer, it's clearer to compare it to NULL than to 0.

Here is an excerpt of the semantic patch: 

@@
expression *E;
@@

  E ==
- 0
+ NULL

@@
expression *E;
@@

  E !=
- 0
+ NULL

Signed-off-by: Yoann Padioleau <padator@wanadoo.fr>
Cc: geert@linux-m68k.org
Cc: zippel@linux-m68k.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: akpm@linux-foundation.org
---

 stram.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/m68k/atari/stram.c b/arch/m68k/atari/stram.c
index bf4588c..a37b985 100644
--- a/arch/m68k/atari/stram.c
+++ b/arch/m68k/atari/stram.c
@@ -130,7 +130,7 @@ void __init atari_stram_init(void)
 	/* determine whether kernel code resides in ST-RAM (then ST-RAM is the
 	 * first memory block at virtual 0x0) */
 	stram_start = phys_to_virt(0);
-	kernel_in_stram = (stram_start == 0);
+	kernel_in_stram = (stram_start == NULL);
 
 	for( i = 0; i < m68k_num_memory; ++i ) {
 		if (m68k_memory[i].addr == 0) {

Re: [PATCH 08/68] 0 -> NULL, for arch/m68k

[Petr Stehlik]

Yoann Padioleau wrote:
> When comparing a pointer, it's clearer to compare it to NULL than to 0.

>  	stram_start = phys_to_virt(0);
> -	kernel_in_stram = (stram_start == 0);
> +	kernel_in_stram = (stram_start == NULL);

stram_start is more like an offset than pointer, IMHO. And 0 is a valid 
offset. The "==NULL" does not make much sense in this particular case. 
NULL is usually used when checking for an uninitialized pointer, right?

Petr

Re: [PATCH 08/68] 0 -> NULL, for arch/m68k

[Al Viro]

On Fri, Jul 27, 2007 at 12:56:38PM +0200, Petr Stehlik wrote:

> NULL is usually used when checking for an uninitialized pointer, right?

No, we use different LARTs when you do that.