[libvirt] [PATCH] libvirt-domain: Drop virDomainMigrateCheckNotLocal attribute

[Laine Stump]

On 10/12/2015 10:41 AM, Michal Privoznik wrote:
> Our apibuild.py script does not cope with ATTRIBUTE_NONNULL:
>
> Parse Error: parsing function type, ')' expected
> Got token  ('name', 'char')
> Last token:  ('name', 'char')
> Token queue:  [('op', '*'), ('name', 'dconnuri'), ('sep', ')')]
> Line 3297 end:
> Makefile:2441: recipe for target '../../docs/apibuild.py.stamp' failed
>
> Let's drop it. Moreover, up until e17ae3ccc2dbc1400 where it was
> introduced we did not really care about NULL-ity of dconnuri. And
> moreover the ATTRIBUTE_NONNULL merely checks for static calls
> over NULL, it won't catch the dynamic ones, where a NULL is
> passed by a variable at runtime.

ACK.

(I have a fairly low opinion of ATTRIBUTE_NONNULL - at first glance it 
*appears* that it should be doing something to guarantee that passed 
args are non-null, but instead it is really just a hint to the 
compiler's optimizer (and to static checkers like coverity) that the 
programmer *thinks* there are no instances of NULL being passed in this 
argument. This can result in useful checks (at runtime and during a 
coverity run) being skipped. I don't remember the details, but have a 
vague memory of a bug I was having trouble tracking down, and it ended 
up being due to an ATTRIBUTE_NONNULL placed on an arg that *wasn't* 
always non-NULL.)

>
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
>   src/libvirt-domain.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
> index e6c8604..6e1aacd 100644
> --- a/src/libvirt-domain.c
> +++ b/src/libvirt-domain.c
> @@ -3293,7 +3293,7 @@ virDomainMigrateVersion3Params(virDomainPtr domain,
>   }
>   
>   
> -static int ATTRIBUTE_NONNULL(1)
> +static int
>   virDomainMigrateCheckNotLocal(const char *dconnuri)
>   {
>       virURIPtr tempuri = NULL;