Re: [PATCH v2 2/3] hw/usb/hcd-xhci-pci: Abort if setting link property failed

[Markus Armbruster <armbru@redhat.com>]

Peter Maydell <peter.maydell@linaro.org> writes:

> On Tue, 24 Aug 2021 at 15:27, Markus Armbruster <armbru@redhat.com> wrote:
>>
>> Peter Maydell <peter.maydell@linaro.org> writes:
>>
>> > On Tue, 24 Aug 2021 at 13:05, Markus Armbruster <armbru@redhat.com> wrote:
>> >> When you know that all callers handle errors like &error_fatal does, use
>> >> of &error_fatal doesn't produce wrong behavior.  It's still kind of
>> >> wrong, because relying on such a non-local argument without a genuine
>> >> need is.
>> >
>> > Not using error_fatal results in quite a bit of extra boilerplate
>> > for all those extra explicit "check for failure, print the error
>> > message and exit" points. If the MachineState init function took
>> > an Error** that might be a mild encouragement to "pass an Error
>> > upward rather than exiting"; but it doesn't.
>> >
>> > Right now we have nearly a thousand instances of error_fatal
>> > in the codebase, incidentally.
>>
>> Use of &error_fatal is clearly superior to accomplishing the same
>> behavior the way you describe.
>>
>> My point was this behavior is usually wrong in functions with an Error
>> **errp parameter.
>
> Right, but as Eduardo has noted, only about 8% of our use of
> error_fatal is like that. The vast bulk is other cases, so
> if you want to call it "kind of wrong" we ought to have a view
> of how it could be done otherwise.

True, except when I called it "kind of wrong", I was still talking about
functions with an Error **errp parameter.

Many (most?) existing uses of &error_fatal are just fine.  Which pleases
me, having created it in commit a29a37b994c.