On 11/06/2013 12:33 PM, Wenchao Xia wrote: > It is possible to reach default case, when an union have a enum > discriminator, so don't abort() but report the error message. > > Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com> > --- > scripts/qapi-visit.py | 14 ++++++++++++-- > 1 files changed, 12 insertions(+), 2 deletions(-)
I still think this is not ideal. You are proposing a runtime error:
> + # Tell caller the value is invalid, since the discriminator value maybe
> an
> + # unmapped enum value.
> ret += mcgen('''
> default:
> - abort();
> + error_setg(&err,
> + "Invalid discriminator value %(pi)s for %(name)s",
> + (*obj)->kind);
> + break;
> }
whereas I'm requesting a compile-time error - it is much easier for
maintenance reasons to have the generator require up-front that all enum
values are covered, and loudly complain if an enum type is extended
without also extending the use of that enum type in a union, than it is
to silently generate a runtime error and wait for the bug reports
several weeks down the road.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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