On Fri, Sep 21, 2018 at 01:31:37PM -0700, Nick Desaulniers wrote:
> On Fri, Sep 21, 2018 at 1:03 PM Nathan Chancellor
> <natechancellor@xxxxxxxxx> wrote:
> >
> > Clang warns that the address of a pointer will always evaluated as true
> > in a boolean context.
> >
> > drivers/media/pci/cx18/cx18-driver.c:1255:23: warning: address of
> > 'cx->streams[i].video_dev' will always evaluate to 'true'
> > [-Wpointer-bool-conversion]
> > if (&cx->streams[i].video_dev)
> > ~~ ~~~~~~~~~~~~~~~^~~~~~~~~
> > 1 warning generated.
> >
> > Presumably, the contents of video_dev should have been checked, not the
> > address. This check has been present since 2009, introduced by commit
> > 21a278b85d3c ("V4L/DVB (11619): cx18: Simplify the work handler for
> > outgoing mailbox commands")
> >
> > Reported-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> > ---
> >
> > Alternatively, this if statement could just be removed since it has
> > evaluated to true since 2009 and I assume some issue with this would
> > have been discovered by now.
> >
> > drivers/media/pci/cx18/cx18-driver.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/pci/cx18/cx18-driver.c b/drivers/media/pci/cx18/cx18-driver.c
> > index 56763c4ea1a7..753a37c7100a 100644
> > --- a/drivers/media/pci/cx18/cx18-driver.c
> > +++ b/drivers/media/pci/cx18/cx18-driver.c
> > @@ -1252,7 +1252,7 @@ static void cx18_cancel_out_work_orders(struct cx18 *cx)
> > {
> > int i;
> > for (i = 0; i < CX18_MAX_STREAMS; i++)
> > - if (&cx->streams[i].video_dev)
> > + if (cx->streams[i].video_dev)
>
> cx->streams[i].video_dev has the type `struct video_device video_dev`.
> So wouldn't this change always be true as well, since the struct is
> embedded?
>
Guess I forgot to compile this with Clang before sending because I now
get a build error (sigh...)
drivers/media/pci/cx18/cx18-driver.c:1255:3: error: statement requires
expression of scalar type ('struct video_device' invalid)
if (cx->streams[i].video_dev)
^ ~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
I guess the whole if statement should go unless I'm missing something
else.
Thanks for the review!
Nathan
> > cancel_work_sync(&cx->streams[i].out_work_order);
> > }
> >
> > --
> > 2.19.0
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers
