On Tue, Mar 09, 2021 at 01:21:29PM -0800, Joelle van Dyne wrote: > On Tue, Mar 9, 2021 at 10:24 AM Joelle van Dyne <j...@getutm.app> wrote: > > > > On Tue, Mar 9, 2021 at 7:38 AM Stefan Hajnoczi <stefa...@redhat.com> wrote: > > > > > > On Mon, Mar 08, 2021 at 07:26:36PM -0800, Joelle van Dyne wrote: > > > > iOS does not support ucontext natively for aarch64 and the sigaltstack > > > > is > > > > also unsupported (even worse, it fails silently, see: > > > > https://openradar.appspot.com/13002712 ) > > > > > > > > As a workaround we include a library implementation of ucontext and add > > > > it > > > > as a build option. > > > > > > > > Signed-off-by: Joelle van Dyne <j...@getutm.app> > > > > --- > > > > configure | 21 ++++++++++++++++++--- > > > > meson.build | 12 +++++++++++- > > > > util/coroutine-ucontext.c | 9 +++++++++ > > > > .gitmodules | 3 +++ > > > > MAINTAINERS | 6 ++++++ > > > > meson_options.txt | 2 ++ > > > > subprojects/libucontext | 1 + > > > > 7 files changed, 50 insertions(+), 4 deletions(-) > > > > create mode 160000 subprojects/libucontext > > > > > > > > diff --git a/configure b/configure > > > > index 34fccaa2ba..5f225894a9 100755 > > > > --- a/configure > > > > +++ b/configure > > > > @@ -1773,7 +1773,7 @@ Advanced options (experts only): > > > > --oss-lib path to OSS library > > > > --cpu=CPU Build for host CPU [$cpu] > > > > --with-coroutine=BACKEND coroutine backend. Supported options: > > > > - ucontext, sigaltstack, windows > > > > + ucontext, libucontext, sigaltstack, windows > > > > > > This approach mixes the concept of the coroutine backend (ucontext, > > > sigaltstack, etc) with the optional libucontext library dependency. > > > > > > libucontext is not a coroutine backend. The patch had to introduce > > > $coroutine_impl in addition to $coroutine in order to work around this. > > > Let's avoid combining these two independent concepts into > > > --with-coroutine=. > > > > > > I suggest treating libucontext as an optional library dependency in > > > ./configure with explicit --enable-libucontext/--disable-libucontext > > > options. Most of the time neither option will be provided by the user > > > and ./configure should automatically decide whether libucontext is > > > needed or not. > > > > > > > +case $coroutine in > > > > +libucontext) > > > > + git_submodules="${git_submodules} subprojects/libucontext" > > > > + mkdir -p libucontext > > > > > > Why is this mkdir necessary? > > > > That is a typo, will fix. > > > > Thanks to all the feedback in this thread. I will shelve this patchset > > for now and see if it's possible to fix ucontext on Darwin. Or if we > > go with gcoroutine that would work as well. Either way it seems like > > this isn't ready yet. > > > > -j > > The following is enough to get ucontext working on macOS 11 (Apple > seems to have fixed it when they added ARM64 support for M1 Macs). > However, ucontext still does not work (no symbols) on iOS so there's > not much point in switching from sigaltstack. > > -j > > diff --git a/configure b/configure > index a2736ecf16..042f4e87a5 100755 > --- a/configure > +++ b/configure > @@ -774,7 +774,8 @@ Darwin) > audio_possible_drivers="coreaudio sdl" > # Disable attempts to use ObjectiveC features in os/object.h since they > # won't work when we're compiling with gcc as a C compiler. > - QEMU_CFLAGS="-DOS_OBJECT_USE_OBJC=0 $QEMU_CFLAGS" > + # _XOPEN_SOURCE and _DARWIN_C_SOURCE needed for ucontext > + QEMU_CFLAGS="-D_XOPEN_SOURCE=500 -D_DARWIN_C_SOURCE > -DOS_OBJECT_USE_OBJC=0 $QEMU_CFLAGS" > ;; > SunOS) > solaris="yes" > @@ -4486,17 +4487,15 @@ fi > # specific one. > > ucontext_works=no > -if test "$darwin" != "yes"; then > - cat > $TMPC << EOF > +cat > $TMPC << EOF > #include <ucontext.h> > #ifdef __stub_makecontext > #error Ignoring glibc stub makecontext which will always fail > #endif > int main(void) { makecontext(0, 0, 0); return 0; } > EOF > - if compile_prog "" "" ; then > - ucontext_works=yes > - fi > +if compile_prog "" "" ; then > + ucontext_works=yes > fi > > if test "$coroutine" = ""; then
I have tried doing this before, and while it was enough for the compile to succeed, I found that tests failed / hung when running the macOS CI jobs. Did you actually try running tests with this change directly, and/or under Cirrus CI ? Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
