Hi Jan,
While I've committed this patch (hoping that I got the necessary
context
adjustment right for the
automation/eclair_analysis/ECLAIR/deviations.ecl
change), I'd like to come back to this before going further with
users
of
the new macro: I still think we ought to try to get to the single
evaluation wherever possible. The macro would then be used only in
cases
where the alternative construct (perhaps an isolate_lsb() macro,
living
perhaps in xen/bitops.h) cannot be used. ISOLATE_LSB() would then
want
to
gain a comment directing people to the "better" sibling. Thoughts?
Having the users in place would help me estimate the remaining work
that
needs to be done on this rule and see if my local counts match up
with
the counts in staging.
By "having the users in place", you mean you want other patches in
this
and the dependent series to be committed as-is (except for the name
change)? That's what I'd like to avoid, as it would mean touching all
those use sites again where the proposed isolate_lsb() could be used
instead. I'd rather see all use sites be put into their final shape
right away.
This request is coming a bit late and also after all the patches have
been reviewed already. I for one am not looking forward to review them
again.
That said, if you could be more specified maybe it could become
actionable:
- do you have a pseudo code implementation of the "better" macro you
would like to propose?
May I remind you that I made this request (including a draft
implementation)
before already, and Nicola then merely found that the evaluate-once
form
simply cannot be used everywhere? Anybody could have thought of the
option
of "splitting" the macro. After all I hope that there is no
disagreement on
macro arguments better being evaluated just once, whenever possible.
- do you have an list of call sites you would like to be changed to
use
the "better" macro?
No, I don't have a list. But the pattern is pretty clear: The "better"
form
ought to be used wherever it actually can be used.
Also, you might remember past discussions about time spent making
changes yourself vs. others doing the same. This is one of those cases
that it would be faster for you to make the change and send a patch
than
explaining someone else how to do it, then review the result (and
review it again as it probably won't be exactly as you asked the first
time.)
If you don't want the call sites to be changes twice, may I suggest
you
provide a patch on top of Nicola's series, I review and ack your
patch,
and Nicola or I rebase & resend the series so that the call sites are
only changes once as you would like? I think that's going to be way
faster.
I'll see if I can find time to do so. I don't normally work on top of
other people's uncommitted patches, though ... So I may also choose to
go
a slightly different route. (You realize though that all still pending
patches using the new macro need touching again anyway, don't you?)
Jan
Then perhaps it's best if I give it a try at doing the single evaluation
macro, so that I can make a series modifying the call sites only once on
top of that and send everything in one go. Before doing that, though,
I'll make a thread where various aspects that are not so clear yet can
be discussed, so that we can devise a robust solution (also to dig this
out of this deep thread).
--
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)
