[libvirt] [PATCH v1 25/40] util: usb: use VIR_AUTOPTR for aggregate types

[Sukrit Bhatnagar]

On Wed, 25 Jul 2018 at 15:03, Erik Skultety <eskultet at redhat.com> wrote:
>
> On Sat, Jul 21, 2018 at 05:36:57PM +0530, Sukrit Bhatnagar wrote:
> > By making use of GNU C's cleanup attribute handled by the
> > VIR_AUTOPTR macro for declaring aggregate pointer variables,
> > majority of the calls to *Free functions can be dropped, which
> > in turn leads to getting rid of most of our cleanup sections.
> >
> > Signed-off-by: Sukrit Bhatnagar <skrtbhtngr at gmail.com>
> > ---
> >  src/util/virusb.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/src/util/virusb.c b/src/util/virusb.c
> > index c14683f..cfeac51 100644
> > --- a/src/util/virusb.c
> > +++ b/src/util/virusb.c
> > @@ -508,8 +508,7 @@ void
> >  virUSBDeviceListDel(virUSBDeviceListPtr list,
> >                      virUSBDevicePtr dev)
> >  {
> > -    virUSBDevicePtr ret = virUSBDeviceListSteal(list, dev);
> > -    virUSBDeviceFree(ret);
> > +    VIR_AUTOPTR(virUSBDevice) ret = virUSBDeviceListSteal(list, dev);
> >  }
> >
>
> Technically, there's also a virUSBDevicePtr instance in virUSBDeviceSearch that
> could be converted to VIR_AUTOPTR, but virUSBDeviceListAdd would have to take a
> double pointer to @dev instead of a single pointer. A bit more background
> info - the current issue is that virUSBDeviceListAdd calls our
> VIR_APPEND_ELEMENT helper which does clear the original pointer which we could
> utilize here, but not while passing a single pointer.
> Not a deal breaker, though, it's just a nice to have, since you're already
> working in this area, because I don't suppose we'd make such a change any time
> soon after your assignment is over.
>
> (regardless)
> Reviewed-by: Erik Skultety <eskultet at redhat.com>

There are many such functions:
virMediatedDeviceListAdd
virSCSIDeviceListAdd
virPCIDeviceListAdd

Making those changes would take a while and it is not directly related
to our cleanup. So, I'll do the necessary after the two cleanup macros
are used in all files. Is that ok?