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

On Fri, Aug 03, 2018 at 06:46:28PM +0530, Sukrit Bhatnagar wrote: > On Fri, 3 Aug 2018 at 18:41, Erik Skultety <eskultet(a)redhat.com&gt; wrote: > > > > On Fri, Aug 03, 2018 at 06:38:30PM +0530, Sukrit Bhatnagar wrote: > > > On Fri, 3 Aug 2018 at 18:32, Erik Skultety <eskultet(a)redhat.com&gt; 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(a)gmail.com&gt; > > > > > --- > > > > > 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. > > Got it. I actually made a lot of such changes, have to revert them all. Luckily I don't see any of that merged yet, so at least we don't have to hunt it down in the release.