Re: [libvirt] [PATCH 5/6] libvirt: Ensure modern APIs are implemented

On Mon, Jul 08, 2019 at 22:37:02 -0500, Eric Blake wrote: > As shown in recent patches, several drivers provided only an older > counterpart of an API, making it harder to uniformly use the newer > preferred API form. We can prevent future instances of this by failing > the driver at initialization time if a modern API is forgotten when an > older API is present. For now, the list includes any interface with a > Flags counterpart, except virDomainBlockStatsFlags which is a bit more > complex than virDomainBlockStats. > > Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; > --- > src/libvirt.c | 42 ++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 38 insertions(+), 4 deletions(-) > > diff --git a/src/libvirt.c b/src/libvirt.c > index 7e665b6cba..a12a72a31b 100644 > --- a/src/libvirt.c > +++ b/src/libvirt.c > @@ -567,19 +567,53 @@ int > virRegisterConnectDriver(virConnectDriverPtr driver, > bool setSharedDrivers) > { > - VIR_DEBUG("driver=%p name=%s", driver, > - driver ? NULLSTR(driver->hypervisorDriver->name) : "(null)"); > + const char *driver_name; > + > + driver_name = driver ? NULLSTR(driver->hypervisorDriver->name) : "(null)"; > + VIR_DEBUG("driver=%p name=%s", driver, driver_name); > > virCheckNonNullArgReturn(driver, -1); > if (virConnectDriverTabCount >= MAX_DRIVERS) { > virReportError(VIR_ERR_INTERNAL_ERROR, > _("Too many drivers, cannot register %s"), > - driver->hypervisorDriver->name); > + driver_name); > return -1; > } > > + /* Check for drivers failing to provide a modern counterpart to an > + * older API */ > +#define REQUIRE_API(old, new) \ > + do { \ > + if (driver->hypervisorDriver->old && \ > + !driver->hypervisorDriver->new) { \ > + fprintf(stderr, " ***FIXME!: driver %s is broken on %s\n", \ > + driver ? NULLSTR(driver->hypervisorDriver->name) : "(null)", #new); \ fprintf in a library function is really wrong. Also I don't think this really requires a runtime check as the APIs aren't really going to just disappear.