drivers/misc: elide a non-zero test on a result that is never 0
authorJulia Lawall <julia@diku.dk>
Tue, 29 Apr 2008 07:59:30 +0000 (00:59 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 29 Apr 2008 15:06:04 +0000 (08:06 -0700)
commit3a8ca95e9d62980fd3b41165ec05032c63ce21da
tree885545c795b9bc2c8a542dd78455c178357c7a6c
parent95d8c365b2df2adb904963333a93b15414403ed1
drivers/misc: elide a non-zero test on a result that is never 0

The function thermal_cooling_device_register always returns either a valid
pointer or a value made with ERR_PTR, so a test for non-zero on the result
will always succeed.

The problem was found using the following semantic match.
(http://www.emn.fr/x-info/coccinelle/)

//<smpl>
@a@
expression E, E1;
statement S,S1;
position p;
@@

E = thermal_cooling_device_register(...)
... when != E = E1
if@p (E) S else S1

@n@
position a.p;
expression E,E1;
statement S,S1;
@@

E = NULL
... when != E = E1
if@p (E) S else S1

@depends on !n@
expression E;
statement S,S1;
position a.p;
@@

* if@p (E)
  S else S1
//</smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Thomas Sujith <sujith.thomas@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/misc/intel_menlow.c