Re: [Libguestfs] Patchable build problems on OS X 10.10

On Mon, Feb 09, 2015 at 10:56:54AM +0100, Pino Toscano wrote: > On Friday 06 February 2015 10:03:37 Richard W.M. Jones wrote: > > On Thu, Feb 05, 2015 at 10:53:06PM +0000, Margaret Lewicka wrote: > > > +/* Fixes for Mac OS X */ > > > +#if defined __APPLE__ && defined __MACH__ > > > +#include <sys/un.h> > > > +#endif > > > +#ifndef SOCK_CLOEXEC > > > +# define SOCK_CLOEXEC O_CLOEXEC > > > +#endif > > > +#ifndef SOCK_NONBLOCK > > > +# define SOCK_NONBLOCK O_NONBLOCK > > > +#endif > > > +/* End of fixes for Mac OS X */ > > > + > > > /* Check minimum required version of libvirt. The libvirt backend > > > * is new and not the default, so we can get away with forcing > > > * people who want to try it to have a reasonably new version of > > This IMHO is clearly wrong: the O_* constants are for open() & friends, > not for socket & socket4. I checked this out before committing it, and I accepted it because on Linux/glibc, SOCK_CLOEXEC == O_CLOEXEC and SOCK_NONBLOCK == O_NONBLOCK (see the definitions in bits/socket.h and bits/socket_type.h on a Linux system). Of course this is not a law of nature and there could be systems where this is not true. The macros as defined only affect systems that don't define SOCK_* at all. > Theoretically, we could switch the socket() usages in launch-libvirt.c > to socket4(), which can be replaced by gnulib if missing (we already > use the "accept4" gnulib module). On the other hand, it seems that > such gnulib emulation does not provide SOCK_NONBLOCK, so either > a) fix that in gnulib > b) use the "nonblocking" gnulib module, using set_nonblocking_flag() > instead of SOCK_NONBLOCK (b) would not be atomic. I'm not certain if there's a case where that matters for O_NONBLOCK. (Of course it definitely matters for O_CLOEXEC and we've have bugs caused by that in the past)