RE: [patch v4 20/24] btrace, gdbserver: read branch trace incrementally

["Metzger, Markus T" <markus.t.metzger@intel.com>]

> -----Original Message-----
> From: gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] On Behalf Of Jan Kratochvil


> > > > I need to distinguish different types of errors, e.g. overflow and not
> > > supported.
> > >
> > > Then use enum.  There is for example:
> > > enum return_reason
> > >   {
> > >     /* User interrupt.  */
> > >     RETURN_QUIT = -2,
> > >     /* Any other error.  */
> > >     RETURN_ERROR
> > >   };
> > >
> > > One could even throw and catch specific exceptions (enum errors) but I
> find
> > > that needlessly overcomplicated when we just return to the immediate
> > > caller.
> >
> > In addition to errors I defined myself, I might get errors from the system
> call,
> > e.g. ENOMEM, EOPNOTSUPP, ENOSYS.
> 
> I do not see such system call.  linux_read_btrace can ever return only 0,
> -EOVERFLOW or -ENOSYS and nothing else.  It never returns for example
> variable value like "-errno".

The system call is in linux_enable_btrace where I use a similar scheme.


> > Do you want me to translate those into an enum?
> 
> As it can return only 0, -EOVERFLOW and -ENOSYS yes, I find enum as the
> best
> one.

OK.  I'll wait for more feedback on the other patches in v6 before sending
the v7 version with those changes.

Regards,
Markus.
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