Re: [Qemu-devel] [RFC PATCH v1 0/5] Add error_abort and associated cleanups

[Paolo Bonzini <pbonzini@redhat.com>]

Il 03/12/2013 21:33, Igor Mammedov ha scritto:
> I'm sorry for hijacking thread, but that actually an issue that started an
> original discussion.
> Where void returning QOM API functions are used with NULL, without any chance
> to detect that error happened. So abusing NULL errp in this functions
> might lead to hard to find runtime errors.
> I think Eric's suggestion was to enforce passing non NULL errp and let caller
> to deal with error gracefully so that above mentioned misuse was impossible.
> Why is ignoring errors from "void foo(...)" like API considered acceptable?

See http://permalink.gmane.org/gmane.comp.emulators.qemu/243779

> * Peter's alternative
>   + self-documenting
>   + consistent
>   + predictable

I'll add another small advantage which is fewer SLOC.

> * make Error* mandatory for all void functions
>   + consistent
>   + almost predictable (because in C you can ignore return values)
>   - not necessarily does the right thing (e.g. cleanup functions)
>   - requires manual effort to abide to the policy

Better wording of the last: a missing &error_abort is easier to spot
than a missing assert_no_error(errp).

Paolo