[PATCH 1/3] drivers/gpu/drm: Move a dereference below a NULL test

From: Julia Lawall
Date: Fri Dec 19 2008 - 12:10:38 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/). The result has been modified to
move the initialization of driver down closer to where it is used.

// <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/gpu/drm/drm_drv.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 0b9f316..4bdfc98 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -297,7 +297,7 @@ EXPORT_SYMBOL(drm_init);
*/
static void drm_cleanup(struct drm_device * dev)
{
- struct drm_driver *driver = dev->driver;
+ struct drm_driver *driver;

DRM_DEBUG("\n");

@@ -324,8 +324,9 @@ static void drm_cleanup(struct drm_device * dev)
dev->agp = NULL;
}

- if (dev->driver->unload)
- dev->driver->unload(dev);
+ driver = dev->driver;
+ if (driver->unload)
+ driver->unload(dev);

drm_ht_remove(&dev->map_hash);
drm_ctxbitmap_cleanup(dev);
--
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