On Fri, Apr 12, 2019 at 5:05 PM Steve Dower <steve.do...@python.org> wrote: > > On 12Apr.2019 1643, Nathaniel Smith wrote: > > On Thu, Apr 11, 2019 at 8:26 AM Steve Dower <steve.do...@python.org> wrote: > >> > >> On 10Apr2019 1917, Nathaniel Smith wrote: > > I don't know how many people use Py_TRACE_REFS, but if we can't find > > anyone on python-dev who uses it then it must be pretty rare. If > > dropping Py_TRACE_REFS would let us converge the ABIs and get rid of > > all the stuff above, then that seems like a pretty good trade! But > > maybe the Windows C runtime issue will foil this... > > The very first question I asked was whether this would let us converge > the ABIs, and the answer was "no". > > Otherwise I'd have said go for it, despite the C runtime issues.
I don't see that in the thread... just Victor saying he isn't sure whether there might be other ABI incompatibilities lurking that he hasn't found yet. Did I miss something? I'm mostly interested in this because of the possibility of converging the ABIs. If you think that the C runtime thing isn't a blocker for that, then that's useful information. Though obviously we still need to figure out whether there are any other blockers :-). > >>>> The reason we ship debug Python binaries is because debug builds use a > >>>> different C Runtime, so if you do a debug build of an extension module > >>>> you're working on it won't actually work with a non-debug build of > >>>> CPython. > >>> > >>> ...But this is an important point. I'd forgotten that MSVC has a habit > >>> of changing the entire C runtime when you turn on the compiler's > >>> debugging mode. > >> > >> Technically they are separate options, but most project files are > >> configured such that *their* Debug/Release switch affects both the > >> compiler options (optimization) and the linker options (C runtime linkage). > > > > So how do other projects handle this? I guess historically the main > > target audience for Visual Studio was folks building monolithic apps, > > where you can just rebuild everything with whatever options you want, > > and compared to that Python extensions are messier. But Python isn't > > the only project in this boat. Do ruby, nodejs, R, etc., all provide > > separate debug builds with incompatible ABIs on Windows, and propagate > > that information throughout their module/package ecosystem? > > Mostly I hear complaints about those languages *not* providing any help > here. Python is renowned for having significantly better Windows support > than any of them, so they're the wrong comparison to make in my opinion. > Arguing that we should regress because other languages haven't caught up > to us yet makes no sense. > > The tools that are better than Python typically don't ship debug builds > either, unless you specifically request them. But they also don't leak > their implementation details all over the place. If we had a better C > API, we wouldn't have users who needed to match ABIs. Do you happen to have a list of places where the C API leaks details of the underlying CRT? (I'm mostly curious because whenever I've looked my conclusion was essentially: "Well....... I don't see any places that are *definitely* broken, so maybe mixing CRTs is fine? but I have zero confidence that I caught everything, so probably better to play it safe?". At least on py3 – I know the py2 C API was definitely broken if you mixed CRTs, because of the exposed FILE*.) > For the most part, disabling optimizations in your own extension but > using the non-debug ABI is sufficient, and if you're having to deal with > other people's packages then maybe you don't have any choice (though I > do know of people who have built debug versions of numpy before - turns > out Windows developers are often just as capable as non-Windows > developers when it comes to building things ;) I'm not sure why you think I was implying otherwise? I'm sorry if you thought I was attacking your users or something. I did say that I thought most users downloading the debug builds were probably confused about what they were actually getting, but I didn't mean because they were stupid Windows users, I meant because the debug builds are so confusing that even folks on the Python core team are confused about what they're actually getting. -n -- Nathaniel J. Smith -- https://vorpus.org _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
