Re: [libvirt] [PATCH] vbox: add support for v4.2.20+ and v4.3.4+

On Monday 30 December 2013 11:26:08 Ryota Ozaki wrote: > On Mon, Dec 30, 2013 at 5:55 PM, Jean-Baptiste Rouault > > <jean-baptiste.rouault(a)diateam.net&gt; wrote: > > On Sunday 29 December 2013 14:44:10 Ryota Ozaki wrote: > >> On Wed, Dec 25, 2013 at 12:47 AM, Jean-Baptiste Rouault > >> > >> <jean-baptiste.rouault(a)diateam.net&gt; wrote: > >> > While working on adding virDomain*Stats support to the vbox driver, we > >> > found bugs in the VirtualBox API C bindings. These bugs have been > >> > fixed in versions 4.2.20 and 4.3.4. > >> > However, the changes in the C bindings are incompatible with the > >> > vbox_CAPI_v4_2.h and vbox_CAPI_v4_3.h files which are bundled in > >> > libvirt source code. This is why the following patch adds > >> > vbox_CAPI_v4_2_20.h and vbox_CAPI_v4_3_4.h. > >> > > >> > We tried to keep compatibility with older VirtualBox 4.2.x and 4.3.x > >> > releases so we added a "SPECIAL_VERSION" identifier to conditionnaly > >> > include the right header. I'm not really pleased with this > >> > "SPECIAL_VERSION" identifier, maybe we could instead increase the > >> > precision of "VBOX_API_VERSION", for example 4002 would become > >> > 4002000. This would permit us to select the right header based on the > >> > VBOX_API_VERSION only, what do you think ? > >> > >> Can we use VBOX_XPCOMC_VERSION instead of adding a new flag? > >> The version has been bumped up when the incompatibility is introduced. > >> > >> ozaki-r > > > > The problem is that VBOX_XPCOMC_VERSION is defined in the vbox_CAPI_v*.h > > headers and we need a flag to choose which header we have to include. > > Oops. You're right. > > Well, one other idea is to include each vbox_CAPI_X_Y.h in > the corresponding vbox_VX_Y.c. That's rather straightforward > for me than including vbox_CAPI_*.h in vbox_tmpl.c according to > VBOX_API_VERSION. > > ozaki-r This would indeed solve the problem for header inclusion. But what about future code using the new API ? Will it have to check both VBOX_API_VERSION and VBOX_XPCOMC_VERSION ? Wouldn't it be simpler if VBOX_API_VERSION was more precise ? e.g 4003004