Re: [PATCH v3 7/7] block: check availablity for preadv/pwritev on mac

[Joelle van Dyne]

No it doesn't return ENOSYS. Dyld calls abort() when a weak link is
not resolved at the time of call.

-j

On Thu, Oct 29, 2020 at 12:54 AM Stefan Hajnoczi <stefanha@gmail.com> wrote:
>
> On Wed, Oct 28, 2020 at 06:07:16PM -0700, Joelle van Dyne wrote:
> > If built with Xcode 12 without the checks, a runtime error will occur.
>
> If that runtime error is ENOSYS then it's handled by existing code:
>
>   if (preadv_present) {
>       nbytes = handle_aiocb_rw_vector(aiocb);
>       if (nbytes == aiocb->aio_nbytes ||
>           (nbytes < 0 && nbytes != -ENOSYS)) {
>           goto out;
>       }
>       preadv_present = false;
>   }
>
> Why is additional code needed for iOS?
>
> Stefan