Hi all. On Thu, 13 Apr 2023 at 15:37, Mark Wielaard <mark@xxxxxxxxx> wrote: > > Hi, > > On Wed, 2023-04-12 at 09:37 -0700, John Moon via Libabigail wrote: > > On 4/11/2023 11:14 PM, Greg Kroah-Hartman wrote: > > > > Would you find the tool more useful if it simply filtered out all instances > > > > where the size of the type did not change? This would filter out the > > > > following which the tool currently flags: > > > > > > > > - enum expansions > > > > - reserved field expansions > > > > - expansions of a struct with a flex array at the end > > > > - type changes > > > > - re-ordering of existing members > > > > - ...others? > > > > > > Obviously not, as some of those are real breakages, and some are not at > > > all. > > > > > > Please understand what is an abi breakage. Adding new enums is not. > > > Using a reserved field is not. Reording existing members IS. > > > > > > > Yes, understood that method would miss certain classes of breakages. I > > was suggesting it as a way to improve the signal-to-noise ratio of the > > tool since we don't currently have an algorithm for determining > > breakages with 100% accuracy. > > Note that you can check the exit code of libabigail's abidiff to see > whether something is an incompatible abi change or not, see: > https://sourceware.org/libabigail/manual/abidiff.html#return-values > > You can also of course use suppressions to instruct abidiff to avoid > reporting changes involving certain ABI artifacts: > https://sourceware.org/libabigail/manual/libabigail-concepts.html#suppr-spec-label libabigail's abidiff already hides certain differences by default. You can turn this behaviour off with --harmless. Note that abidiff without --harmless treats certain ABI differences asymmetrically, hiding them one way around but not the other. The ABI diff tool I designed for Android always treats differences symmetrically and will only suppress certain kinds of diff if specially requested (which we don't do any more in production). [Technically, we also ignore qualifier changes on function parameter and return types, but we achieve that by stripping them out unconditionally.] Once we get around to UAPI monitoring, we'll do the same there. We can always review the SNR later. Regards, Giuliano. > Cheers, > > Mark > > -- > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@xxxxxxxxxxx. >
