Re: [PATCH] checkpatch: debugfs_remove() can take NULL

[Joe Perches <joe@perches.com>]

On Sat, 2012-11-17 at 14:33 +0200, Constantine Shulyupin wrote:
> From: Constantine Shulyupin <const@MakeLinux.com>
> 
> debugfs_remove() can take a NULL, so let's check and warn about that.
> 
> Signed-off-by: Constantine Shulyupin <const@MakeLinux.com>
> ---
>  scripts/checkpatch.pl |    8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index f18750e..c062476 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -3221,6 +3221,14 @@ sub process {
>  				     "kfree(NULL) is safe this check is probably not required\n" . $hereprev);
>  			}
>  		}
> +# check for needless debugfs_remove() checks
> +		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
> +			my $expr = $1;
> +			if ($line =~ /\bdebugfs_remove\(\Q$expr\E\);/) {
> +				WARN("NEEDLESS_DEBUGFS_REMOVE",
> +				     "debugfs_remove(NULL) is safe this check is probably not required\n" . $hereprev);
> +			}
> +		}
>  # check for needless usb_free_urb() checks
>  		if ($prevline =~ /\bif\s*\(([^\)]*)\)/) {
>  			my $expr = $1;

Perhaps debugfs_remove_recursive should be added too.

Please create a consolidated block of tests for these
checks of:

	if (foo)
		something_with(foo)

and add kfree, usb_free_urb and your debugfs_remove (and
debugfs_remove_recursive?) to that block so that the
"if ($prevline..." test is done only once per patch line.