[libvirt] [PATCH v1 13/32] util: netdevip: use VIR_AUTOPTR for aggregate types

[Erik Skultety]

On Fri, Aug 03, 2018 at 06:38:30PM +0530, Sukrit Bhatnagar wrote:
> On Fri, 3 Aug 2018 at 18:32, Erik Skultety <eskultet at redhat.com> wrote:
> >
> > On Sat, Jul 28, 2018 at 11:31:28PM +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/virnetdevip.c | 55 +++++++++++++++++++++-----------------------------
> > >  1 file changed, 23 insertions(+), 32 deletions(-)
> > >
> > > diff --git a/src/util/virnetdevip.c b/src/util/virnetdevip.c
> > > index 8f1081b..ca206e2 100644
> > > --- a/src/util/virnetdevip.c
> > > +++ b/src/util/virnetdevip.c
> > > @@ -634,19 +634,22 @@ virNetDevIPCheckIPv6Forwarding(void)
> > >      }
> > >
> > >      if (!valid) {
> > > -        virBuffer buf = VIR_BUFFER_INITIALIZER;
> > > +        VIR_AUTOPTR(virBuffer) buf = NULL;
> > > +
> > > +        if (VIR_ALLOC(buf) < 0)
> > > +            goto cleanup;
> >
> > Hmm, this will actually leak memory because @buf is never going to be freed,
> > worse, we'll assign NULL to it.
>
> But since @buf is declared as AUTOPTR, virBufferFreeAndReset will be called
> when it exits the scope, right?
> If I were using virBufferContentAndReset, then it might be the case.

How does virBufferFreeAndReset free @buf? It frees buf->content, but keeps
@buf.

Erik