On Tue, Jun 11, 2024 at 10:55 AM David E. Wheeler <da...@justatheory.com> wrote: > Right, it’s just that extension authors could use some notification that such > a change is coming so they can update their code, if necessary.
In general our strategy around ABI breaks is to avoid them whenever possible. We also make the most conservative assumptions about what a true ABI break is -- strictly speaking we can never be fully sure about the impact of a theoretical/mechanical ABI break (we can only make well educated guesses). My sense is that we're approaching having the fewest possible real ABI breaks already -- we're already doing the best we can. That doesn't seem like a useful area to focus on. As an example, my bugfix commit 714780dc was apparently discussed by Yurii Rashkovskii during his pgConf.dev talk. I was (and still am) approaching 100% certainty that that wasn't a true ABI break. Documenting this somewhere seems rather unappealing. Strictly speaking I'm not 100% certain that this is a non-issue, but who benefits from hearing my hand-wavy characterisation of why I believe it's a non-issue? You might as well just look at an ABI change report yourself. Approximately 0% of all extensions actually use the struct in question, and so obviously aren't affected. If anybody is using the struct then it's merely very very likely that they aren't affected. But why trust me here? After all, I can't even imagine why anybody would want to use the struct in question. My hand-wavy speculation about what it would look like if I was wrong about that is inherently suspect, and probably just useless. Is it not? That having been said, it would be useful if there was a community web resource for this -- something akin to coverage.postgresql.org, but with differential ABI breakage reports. You can see an example report here: https://postgr.es/m/CAH2-Wzm-W6hSn71sUkz0Rem=qdeu7tnfmc7_jg2djrlfef_...@mail.gmail.com Theoretically anybody can do this themselves. In practice they don't. So something as simple as providing automated reports about ABI changes might well move the needle here. -- Peter Geoghegan
