Re: Checkpatch false positive?

Jan Kara
2009-01-27T16:34:28Z

On Tue 27-01-09 18:06:01, Adrian Bunk wrote:
> On Tue, Jan 27, 2009 at 04:49:05PM +0100, Jan Kara wrote:
> > Hi,
> >
> > I've used checkpatch.pl to verify one of my patches. It complains:
> >
> > ERROR: trailing statements should be on next line
> > #167: FILE: fs/quota/quota_tree.c:249:
> > + for (i = 0, ddquot = buf + sizeof(struct qt_disk_dqdbheader);
> > [...]
> > i++, ddquot += info->dqi_entry_size);
> >
> > But the code looks like:
> > for (i = 0, ddquot = buf + sizeof(struct qt_disk_dqdbheader);
> > i < qtree_dqstr_in_blk(info) && !qtree_entry_unused(info, ddquot);
> > i++, ddquot += info->dqi_entry_size);
> >
> > Which is IMHO correct. Maybe it's because the for has actually empty body
> > and the ; is at the end of the line with for. But I didn't find anything in
> > CodingStyle that would forbid
> > for (...);
> > and
> > for (...)
> > ;
> > Looks a bit strange.
>
> for (...); is a common C programming error, usually it's some kind of:
>
> for(........);
> do_something();
>
> This code does something different than intended.
> And yes, we had such bugs in the kernel.
>
>
> for(........)
> ;
>
> is correct. The "looks a bit strange" is what actually tells readers
> what the code is doing (and that the author did it intentionally).
OK, makes some sence. Thanks for explanation.

Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR