0 is incorrectly considered a power of 2 in function IsPowerOf2
add src/build to gitignore

Signed-off-by: liuhuahang <liuhuahang@xiaomi.com>
Make a copy of a filename passed to DirectoryContaining()

According to IEEE Std 1003.1, dirname() MAY modify the received value.
http://pubs.opengroup.org/onlinepubs/009604599/functions/dirname.html
Merge pull request #18 from steelman/for-mmp

Make a copy of a filename passed to DirectoryContaining()
Merge pull request #15 from huahang/master

add src/build to gitignore
Merge pull request #12 from GraphicsMe/master

0 is incorrectly considered a power of 2 in function IsPowerOf2