[PATCH 3/5] drivers/isdn: Move a dereference below a NULL test

From: Julia Lawall
Date: Sat Jul 11 2009 - 03:51:57 EST


From: Julia Lawall <julia@xxxxxxx>

If the NULL test is necessary, then the dereference should be moved below
the NULL test.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
type T;
expression E;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
... when != E
when != i
if (E == NULL) S
+ i = E->fld;
// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
drivers/isdn/hysdn/hysdn_net.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff -u -p a/drivers/isdn/hysdn/hysdn_net.c b/drivers/isdn/hysdn/hysdn_net.c
--- a/drivers/isdn/hysdn/hysdn_net.c
+++ b/drivers/isdn/hysdn/hysdn_net.c
@@ -187,11 +187,12 @@ void
hysdn_rx_netpkt(hysdn_card * card, unsigned char *buf, unsigned short len)
{
struct net_local *lp = card->netif;
- struct net_device *dev = lp->dev;
+ struct net_device *dev;
struct sk_buff *skb;

if (!lp)
return; /* non existing device */
+ dev = lp->dev;

dev->stats.rx_bytes += len;

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