tree 877e5ac536ba87cdfe441c95c49e04f7bc8c63a4
parent 86d9fc1293aa9456677eab94e9fd2d3a10920548
author Julia Lawall <julia@diku.dk> 1206596902 -0400
committer Len Brown <len.brown@intel.com> 1206596902 -0400

ACPI: drivers/acpi: 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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>