Re: [PATCH v11 8/8] xen: introduce ERRP_AUTO_PROPAGATE

[Vladimir Sementsov-Ogievskiy <vsementsov@xxxxxxxxxxxxx>]

04.07.2020 19:36, Philippe Mathieu-Daudé wrote:
> On 7/3/20 11:08 AM, Vladimir Sementsov-Ogievskiy wrote:
> > If we want to add some info to errp (by error_prepend() or
> > error_append_hint()), we must use the ERRP_AUTO_PROPAGATE macro.
> > Otherwise, this info will not be added when errp == &error_fatal
> > (the program will exit prior to the error_append_hint() or
> > error_prepend() call).  Fix such cases.
> >
> > If we want to check error after errp-function call, we need to
> > introduce local_err and then propagate it to errp. Instead, use
> > ERRP_AUTO_PROPAGATE macro, benefits are:
> > 1. No need of explicit error_propagate call
> > 2. No need of explicit local_err variable: use errp directly
> > 3. ERRP_AUTO_PROPAGATE leaves errp as is if it's not NULL or
> >     &error_fatal, this means that we don't break error_abort
> >     (we'll abort on error_set, not on error_propagate)
> >
> > This commit is generated by command
> >
> >      sed -n '/^X86 Xen CPUs$/,/^$/{s/^F: //p}' MAINTAINERS | \
> >      xargs git ls-files | grep '\.[hc]$' | \
> >      xargs spatch \
> >          --sp-file scripts/coccinelle/auto-propagated-errp.cocci \
> >          --macro-file scripts/cocci-macro-file.h \
> >          --in-place --no-show-diff --max-width 80
> >
> > Reported-by: Kevin Wolf <kwolf@xxxxxxxxxx>
> > Reported-by: Greg Kurz <groug@xxxxxxxx>
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@xxxxxxxxxxxxx>
> > ---
> >   hw/block/dataplane/xen-block.c |  17 +++---
> >   hw/block/xen-block.c           | 102 ++++++++++++++-------------------
> >   hw/pci-host/xen_igd_pt.c       |   7 +--
> >   hw/xen/xen-backend.c           |   7 +--
> >   hw/xen/xen-bus.c               |  92 +++++++++++++----------------
> >   hw/xen/xen-host-pci-device.c   |  27 +++++----
> >   hw/xen/xen_pt.c                |  25 ++++----
> >   hw/xen/xen_pt_config_init.c    |  17 +++---
> >   8 files changed, 128 insertions(+), 166 deletions(-)
> Without the description, this patch has 800 lines of diff...
> It killed me, I don't have the energy to review patch #7 of this
> series after that, sorry.
Sorry for that! I really understand you, take a look at Markus's
"[PATCH v2 00/44] Less clumsy error checking", which I'm trying to review
currently..

Still, the patch exists in such form since
"[RFC v5 000/126] error: auto propagated local_err", where it was reviewed
by Anthony, and I suggested to split it, but it was not needed.
Unfortunately, I've dropped r-bs due to changes..

> Consider splitting such mechanical patches next time. Here it
> could have been hw/block, hw/pci-host, hw/xen.
>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
Thanks a lot!

--
Best regards,
Vladimir