[libvirt] [PATCH] Fix building with -Og

[Peter Krempa]

On Fri, Jun 03, 2016 at 13:32:02 +0200, Martin Kletzander wrote:
> When building using -Og, gcc sees that some variables can be used
> uninitialized  It can be debatable whether it is possible with our
> codeflow, but functions should be self-contained and initializations are
> always good.  The return instead of goto is due to actualType being used
> in the cleanup.
> 
> Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
> ---
>  src/lxc/lxc_driver.c                      | 2 +-
>  src/nwfilter/nwfilter_ebiptables_driver.c | 2 +-
>  src/util/virbitmap.c                      | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
> index 67f14fe766a5..f0948eae774e 100644
> --- a/src/lxc/lxc_driver.c
> +++ b/src/lxc/lxc_driver.c
> @@ -4275,7 +4275,7 @@ lxcDomainAttachDeviceNetLive(virConnectPtr conn,
>      if (!priv->initpid) {
>          virReportError(VIR_ERR_OPERATION_INVALID, "%s",
>                         _("Cannot attach disk until init PID is known"));
> -        goto cleanup;
> +        return -1;
>      }

False positive. actualType is never evaluated uninitialized since ret is
set to -1 and veth is NULL.

It makes sense to change it since a lot of stuff below is returning -1
directly.

> 
>      if (virLXCProcessValidateInterface(net) < 0)
> diff --git a/src/nwfilter/nwfilter_ebiptables_driver.c b/src/nwfilter/nwfilter_ebiptables_driver.c
> index 423d069e1b26..b7be2917e29e 100644
> --- a/src/nwfilter/nwfilter_ebiptables_driver.c
> +++ b/src/nwfilter/nwfilter_ebiptables_driver.c
> @@ -1570,7 +1570,7 @@ iptablesCreateRuleInstanceStateCtrl(virFirewallPtr fw,
>                                      const char *ifname,
>                                      virNWFilterVarCombIterPtr vars)
>  {
> -    int rc;
> +    int rc = 0;
>      bool directionIn = false;
>      char chainPrefix[2];
>      bool maySkipICMP, inout = false;

Bah. This function makes my brain hurt. I didn't bother checking.

> diff --git a/src/util/virbitmap.c b/src/util/virbitmap.c
> index 9283aef1735b..4ca59f9d6227 100644
> --- a/src/util/virbitmap.c
> +++ b/src/util/virbitmap.c
> @@ -817,7 +817,7 @@ virBitmapLastSetBit(virBitmapPtr bitmap)
>      ssize_t i;
>      int unusedBits;
>      ssize_t sz;
> -    unsigned long bits;
> +    unsigned long bits = 0;

okay, so there are possible input values ableit being invalid and
impossible that would actually allow to evaluate bits when uninitialized.

ACK, I hope that people get tired of experimenting with bleeding edge
compilers soon.

Peter