[GEDI] [PATCH v4 04/31] error: auto propagated local_err

[Markus Armbruster]

Vladimir Sementsov-Ogievskiy <vsementsov at virtuozzo.com> writes:

> Here is introduced ERRP_AUTO_PROPAGATE macro, to be used at start of
> functions with errp OUT parameter.
>
> It has three goals:
>
> 1. Fix issue with error_fatal & error_prepend/error_append_hint: user
> can't see this additional information, because exit() happens in
> error_setg earlier than information is added. [Reported by Greg Kurz]

Done in PATCH 07-31.

> 2. Fix issue with error_abort & error_propagate: when we wrap
> error_abort by local_err+error_propagate, resulting coredump will
> refer to error_propagate and not to the place where error happened.
> (the macro itself doesn't fix the issue, but it allows to [3.] drop all
> local_err+error_propagate pattern, which will definitely fix the issue)
> [Reported by Kevin Wolf]
>
> 3. Drop local_err+error_propagate pattern, which is used to workaround
> void functions with errp parameter, when caller wants to know resulting
> status. (Note: actually these functions could be merely updated to
> return int error code).

Not done.  Can you prototype this part?  A few manually done examples
would give us an idea how the complete solution would look like.  A
(semi-)automated complete conversion of a subsystem would additionally
give us an idea how to actually do the conversion.

We can discuss applying ERRP_AUTO_PROPAGATE() as a bug fix for 1., and
leave 2. and 3. for later.  Feels like a half-done job to me.  We've got
too many of those in the tree already.  Dunno.