Re: [PATCH v3 04/25] error: auto propagated local_err

[Vladimir Sementsov-Ogievskiy]

30.09.2019 19:00, Kevin Wolf wrote:
> Am 30.09.2019 um 17:19 hat Vladimir Sementsov-Ogievskiy geschrieben:
>> 30.09.2019 18:12, Kevin Wolf wrote:
>>> Am 24.09.2019 um 22:08 hat Vladimir Sementsov-Ogievskiy geschrieben:
>>>> Here is introduced ERRP_FUNCTION_BEGIN macro, to be used at start of
>>>> functions with errp parameter.
>>>
>>> A bit of bike shedding, but FOO_BEGIN suggests to me that a FOO_END will
>>> follow. Can we find a different name, especially now that we won't use
>>> this macro in every function that uses an errp, so even the "errp
>>> function" part isn't really correct any more?
>>>
>>> How about ERRP_AUTO_PROPAGATE?
>>
>> I have an idea that with this macro we can (optionally) get the whole call 
>> stack
>> of the error and print it to log, so it's good to give it more generic name, 
>> not
>> limited to propagation..
> 
> Hm, what's the context for this feature?
> 
> The obvious one where you want to have a stack trace is &error_abort,
> but that one crashes, so you get it automatically. If it's just a normal
> error (like a QAPI option contains an invalid value and some function
> down the call chain checks it), why would anyone want to know what the
> call chain in the QEMU code was?
> 

When I have bug from testers, call stack would be a lot more descriptive, than 
just
an error message.

We may add trace point which will print this information, so with disabled 
trace point
- no extra output.



-- 
Best regards,
Vladimir