[libvirt] [PATCH 1/7] qemu: Use switch in qemuMigrationCompleted

[Jiri Denemark]

On Fri, Oct 20, 2017 at 11:28:37 +0200, Marc Hartmayer wrote:
> On Thu, Oct 19, 2017 at 03:56 PM +0200, Jiri Denemark <jdenemar at redhat.com> wrote:
> > When adding a new job state it's useful to let the compiler complain
> > about places where we need to think about what to do with the new
> > state.
> >
> > Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
> > ---
> >  src/qemu/qemu_migration.c | 23 ++++++++++++++++++-----
> >  1 file changed, 18 insertions(+), 5 deletions(-)
> >
> > diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> > index 72edbb667..c3f9c38b2 100644
> > --- a/src/qemu/qemu_migration.c
> > +++ b/src/qemu/qemu_migration.c
> > @@ -1531,18 +1531,31 @@ qemuMigrationCompleted(virQEMUDriverPtr driver,
> >          return 0;
> >
> >   error:
> > -    /* state can not be active or completed at this point */
> > -    if (jobInfo->status == QEMU_DOMAIN_JOB_STATUS_MIGRATING ||
> > -        jobInfo->status == QEMU_DOMAIN_JOB_STATUS_POSTCOPY) {
> > +    switch (jobInfo->status) {
> > +    case QEMU_DOMAIN_JOB_STATUS_MIGRATING:
> > +    case QEMU_DOMAIN_JOB_STATUS_POSTCOPY:
> >          /* The migration was aborted by us rather than QEMU itself. */
> >          jobInfo->status = QEMU_DOMAIN_JOB_STATUS_FAILED;
> >          return -2;
> > -    } else if (jobInfo->status == QEMU_DOMAIN_JOB_STATUS_QEMU_COMPLETED) {
> > +
> > +    case QEMU_DOMAIN_JOB_STATUS_QEMU_COMPLETED:
> > +        /* Something failed after QEMU already finished the migration. */
> >          jobInfo->status = QEMU_DOMAIN_JOB_STATUS_FAILED;
> >          return -1;
> > -    } else {
> > +
> > +    case QEMU_DOMAIN_JOB_STATUS_FAILED:
> > +    case QEMU_DOMAIN_JOB_STATUS_CANCELED:
> > +        /* QEMU aborted the migration. */
> >          return -1;
> > +
> > +    case QEMU_DOMAIN_JOB_STATUS_ACTIVE:
> > +    case QEMU_DOMAIN_JOB_STATUS_COMPLETED:
> > +    case QEMU_DOMAIN_JOB_STATUS_NONE:
> > +        /* Impossible. */
> > +        break;
> >      }
> > +
> > +    return -1;
> >  }
> 
> I think you have to add ATTRIBUTE_FALLTHROUGH for the intended
> fallthroughs (e.g. for gcc 7).

This should only be needed if there was any code between the cases.

Jirka