Re: [Qemu-devel] [PATCH] Create libqemutrace.a for all trace.o

["Daniel P. Berrange" <berrange@redhat.com>]

On Tue, Mar 28, 2017 at 07:00:34PM +0000, Xu, Anthony wrote:
> > >>> ./trace.o, ./qapi/trace.o and ./util/trace.o are added into
> > >>> libqemuutil.a  to avoid recursive dependencies between
> > >>> libqemuutil.a and libqemutrace.a.
> > >> Why would libqemutrace.a depend on libqemuutil.a?
> > > Each trace.c calls trace_event_register_group to register events,
> > > trace_event_register_group is defined in trace/control.c , which
> > > is linked into libqemuutil.a.
> > 
> > Ah:
> > 
> > util-obj-$(CONFIG_TRACE_SIMPLE) += simple.o
> > util-obj-$(CONFIG_TRACE_FTRACE) += ftrace.o
> > util-obj-y += control.o
> > util-obj-y += qmp.o
> > 
> > With the introduction of libqemutrace.a, I believe these should be moved
> > into libqemutrace.a.
> 
> Agreed,
> But it doesn't solve infinite recursion issue. register_module_init is 
> needed by libqemutrace.a, which is defined util/module.c.
> 
> it is hard to remove libqemutrace.a dependency on libqemuutil.a.
> 
> Removing libqemuutil.a dependency on libqemutrace.a is feasible.
> Just like what I did in this patch, include all util related trace.o 
> to libqemuutila.
> 
> The other simple way is to include all trace.o into libqemuutil.a

Yeah, I'd suggest doing that - i don't see any benefit in having
them in a separate libqemutrace.a


Regards,
Daniel
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