On 13/05/2024 10:34, Jonathan Wakely wrote: > > > On Mon, 13 May 2024, 07:30 Iain Sandoe, wrote: > > > > > On 13 May 2024, at 06:06, François Dumont > wrote: > > > > > > On 07/05/2024 18:15, Iain Sandoe wrote: > >> Hi François > >> > >>> On 4 May 2024, at 22:11, François Dumont > wrote: > >>> > >>> Here is the list of patches to restore gnu versioned namespace > mode. > >>> > >>> 1/3: Bump gnu version namespace > >>> > >>> This is important to be done first so that once build of gnu > versioned namespace is fixed there is no chance to have another > build of '__8' version with a different abi than last successful > '__8' build. > > > > The versioned namespace build is not expected to be ABI compatible > though, so nobody should be expecting compatibility with previous > builds. Especially not on the gcc-15 trunk, a week or two after > entering stage 1! Ok, I really thought that we needed to preserve ABI for a given version, '__8' at the moment. > >>> > >>> 2/3: Fix build using cxx11 abi for versioned namespace > >>> > >>> 3/3: Proposal to default to "new" abi when dual abi is > disabled and accept any default-libstdcxx-abi either dual abi is > enabled or not. > >>> > >>> All testsuite run for following configs: > >>> > >>> - dual abi > >>> > >>> - gcc4-compatible only abi > >>> > >>> - new only abi > >>> > >>> - versioned namespace abi > >> At the risk of delaying this (a bit) - I think we should also > consider items like once_call that have broken impls. > > Do you have any pointer to this once_call problem, sorry I'm not > aware about it (apart from your messages). > > (although this mentions one specific target, it applies more widely). > > > I've removed the "on ppc64le" part from the summary. > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66146 > Thanks for the ref, I'll have a look but I fear that I won't be of any help here. > > Also, AFAICT, any nested once_call is a problem (not just exceptions). > > > Could you update the bug with that info please? > > > >>  in the current library - and at least get proposed > replacements available behind the versioned namespace; rather than > using up a namespace version with the current broken code. > > > > I'm not proposing to fix all library bugs on all platforms with > this patch, just fix the versioned namespace mode. > > Sorry, I was not intending to suggest that (although perhaps my > comments read that way). > > I was trying to suggest that, in the case where we have proposed > fixes that are blocked because they are ABI breaks, that those > could be put behind the versioned namspace (it was not an > intention to suggest that such additions should be part of this > patch series). > > > As to do so I also need to adopt cxx11 abi in versioned mode it > already justify a bump of version. > > I see - it’s just a bit strange that we are bumping a version for > a mode that does not currently work; however, i guess someone > might have deployed it even so. > > > It does work though, doesn't it? > It's known to fail on powerpc64 due to conflicts with the ieee128 > stuff, but it should work elsewhere. > It doesn't work with --with-default-libstdcxx-abi=cxx11 but that's > just a "this doesn't work and isn't supported" limitation. > > The point of the patch series is to change it so the versioned > namespace always uses the cxx11 ABI, which does seem worth bumping the > version (even though the versioned namespace is explicitly not a > stable ABI and not backwards compatible). So I just need to wait for proper review, right ? This is what I plan to do on this subject for the moment.