add __cxa_init_primary_exception

[itrofimow]

Aims to resolve #22

Somewhat related libc++ patch: https://reviews.llvm.org/D158620

[davidchisnall]

That looks plausible. Can you add a few tests? I’d like to see, at least, that this exception can be thrown and caught and that the destructor runs in the right place.

[itrofimow]

basically what gcc does: https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-v3/libsupc%2B%2B/exception_ptr.h#L253, with std::decay omitted for brevity

[itrofimow]

@davidchisnall added a std::exception_ptr-alike test.
Could you please have a look?

edit: a guidance on where define LIBCXXRT_HAS_INIT_PRIMARY_EXCEPTION should be put would be appreciated

[davidchisnall]

Looks great, thank you.

@emaste , do you think we could sneak this into FreeBSD 14.0? We can do the libc++ updates a bit later, but it would be nice to have the new APIs in so that external things can depend on them, even if the base system libc++ doesn’t yet.

[davidchisnall]

I’m not sure of the best place to define LIBCXXRT_HAS_INIT_PRIMARY_EXCEPTION. Unfortunately, because the public API is standardised, a lot of consumers provide their own prototypes and don’t actually include any of our headers. It’s probably better for them to use a does-it-link test than rely on our headers.

[emaste]

@emaste , do you think we could sneak this into FreeBSD 14.0?

I think there's still time, we can sync this repo into FreeBSD main and MFC from there.

[davidchisnall]

[ Rebased to pick up the fix to make FreeBSD CI work ]

[itrofimow]

Hi! Is there anything holding this PR back from being merged?

I would like to try to make use of these changes in llvm/llvm-project#65534, and it would be a bit more convenient to do so with master branch of libcxxrt rather than with a fork

[emaste]

@davidchisnall do you want to merge this into this libcxxrt repo? I can do a vendor import into FreeBSD from there

[davidchisnall]

Sorry, I thought I set it to merge when the CI finished.