Adding Olaf, I forgot that Reported-by doesn't turn into a Cc. On Thu, 2016-02-04 at 10:15 +0000, Ian Campbell wrote: > This file stradles the xenevtchn and libxc evtchn_compat worlds, and > hence ends up with two evtchn_port_or_error_t typedefs which older > gcc's (and the C standard) do not like. > > Avoid this by gating the compat definition on a gate provided by the > compat implementation. > > Note that this would still be broken by an application which does: > #define XC_WANT_COMPAT_EVTCHN_API > #include <xenevtchn.h> > #include <xenctrl.h> > > Which effectively means that an application must be ported over to > xenevtchn in one go rather than incrementally (e.g. if it uses > evtchn's for multiple purposes). Since the port is actually fairly > mechanical I hope this is acceptable. > > Reported-by: Olaf Hering <o...@aepfle.de> > Signed-off-by: Ian Campbell <ian.campb...@citrix.com> > Cc: Andrew Cooper <andrew.coop...@citrix.com> > --- > I'm not super happy about this approach, due to the caveat in the > second half of the commit message. > > Other approaches: > > rename the libxenevtchn type, e.g. xenevtchn_port_or_error_t?
Thinking about this some more this might be the best approach. The type is not used by qemu-xen, it is used by qemu-xen-traditional but we can fix that in lockstep. All of the in tree users are easy, of course. Thoughts? > > Some sort of skank based on the header guard #defines, but that's > awful (and fragile). > --- > tools/libxc/include/xenctrl_compat.h | 2 ++ > tools/libxc/xc_evtchn_compat.c | 1 + > 2 files changed, 3 insertions(+) > > diff --git a/tools/libxc/include/xenctrl_compat.h > b/tools/libxc/include/xenctrl_compat.h > index 93ccadb..afc3d88 100644 > --- a/tools/libxc/include/xenctrl_compat.h > +++ b/tools/libxc/include/xenctrl_compat.h > @@ -51,7 +51,9 @@ void *xc_map_foreign_bulk(xc_interface *xch, uint32_t > dom, int prot, > #ifdef XC_WANT_COMPAT_EVTCHN_API > > typedef struct xenevtchn_handle xc_evtchn; > +#ifndef XC_BUILDING_COMPAT_EVTCHN_API > typedef xc_evtchn_port_or_error_t evtchn_port_or_error_t; > +#endif > > xc_evtchn *xc_evtchn_open(xentoollog_logger *logger, > unsigned open_flags); > diff --git a/tools/libxc/xc_evtchn_compat.c > b/tools/libxc/xc_evtchn_compat.c > index 5d3e4ba..99da476 100644 > --- a/tools/libxc/xc_evtchn_compat.c > +++ b/tools/libxc/xc_evtchn_compat.c > @@ -6,6 +6,7 @@ > #include <xenevtchn.h> > > #define XC_WANT_COMPAT_EVTCHN_API > +#define XC_BUILDING_COMPAT_EVTCHN_API > #include "xenctrl.h" > > xc_evtchn *xc_evtchn_open(xentoollog_logger *logger, _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
