Re: [Qemu-devel] [PATCH] ohci: Fix compile errors without --enable-trace-backend

[Stefan Hajnoczi]

On Thu, Sep 25, 2014 at 10:19:32AM +1000, Alexey Kardashevskiy wrote:
> On 09/24/2014 07:47 PM, Stefan Hajnoczi wrote:
> > On Tue, Sep 23, 2014 at 08:19:41PM +1000, Alexey Kardashevskiy wrote:
> >> This adds a stub for ohci_td_pkt() function (which traces packets)
> >> when configured without --enable-trace-backend
> >>
> >> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> >> ---
> >>
> >> It should probably be squashed to
> >> [PATCH] ohci: Convert fprint/DPRINTF/print to traces
> >>
> >> Sorry about that...
> >>
> >> ---
> >>  hw/usb/hcd-ohci.c | 6 ++++++
> >>  1 file changed, 6 insertions(+)
> >>
> >> diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
> >> index 4a4dd02..7ea871d 100644
> >> --- a/hw/usb/hcd-ohci.c
> >> +++ b/hw/usb/hcd-ohci.c
> >> @@ -920,6 +920,7 @@ static int ohci_service_iso_td(OHCIState *ohci, struct 
> >> ohci_ed *ed,
> >>      return 1;
> >>  }
> >>  
> >> +#ifdef trace_event_get_state
> >>  static void ohci_td_pkt(const char *msg, const uint8_t *buf, size_t len)
> >>  {
> >>      bool print16 = !!trace_event_get_state(TRACE_USB_OHCI_TD_PKT_SHORT);
> > 
> > The preferred define for this is CONFIG_TRACE_NOP.
> > 
> > Checking for trace_event_get_state could break if trace/control.h
> > changes in the future.
> 
> I am not familiar with "dtrace" - are traces configurable with it? With
> --enable-trace-backend=dtrace, trace_event_get_state is not defined.

dtrace has its own tools for enabling/disabling trace events.  QEMU's
command cannot be used with dtrace.

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