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 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.

When a function is only ever used in contexts where errors are handled
the way &error_fatal does, then you can keep things a bit more readable
with &error_fatal and without an Error **errp parameter.  Nothing wrong
with that.