llvm dev - Feb 2020 - amount of camelCase refactoring causing some downstream overhead

Hi Mehdi!

I think the value to upstream (of doing mass reformatting in fewer commits) has
to do with the intrusion of nonfunctional commits into `git blame` kinds of
research.  Every line that someone touches for a formatting reason necessarily
obscures the history of functional changes in that block of code.  The fewer of
those that people have to work around, the better.  I admit this is a small
concern, but it wasn’t so long ago that I was looking back at some history and
had to wade through way more formatting commits than functional commits to get
to the log message that told me what I needed to know.

Some formatting changes just come with the territory, but if I have to deal with
1 or 2 instead of 5 or 8, it does improve my day.

HTH,
--paulr

From: Mehdi AMINI <joker.eph at gmail.com>
Sent: Thursday, February 20, 2020 1:16 PM
To: Robinson, Paul <paul.robinson at sony.com>
Cc: Philip Reames <listmail at philipreames.com>; Eric Christopher
<echristo at gmail.com>; llvm-dev at lists.llvm.org; Valentin Churavy
<v.churavy at gmail.com>
Subject: Re: [llvm-dev] amount of camelCase refactoring causing some downstream
overhead



On Wed, Feb 19, 2020 at 12:10 PM Robinson, Paul via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
Hi Philip,

I think you might be reading more into the suggestion/discussion than is
actually there.


  *   I do not want upstream developers "trying to be polite" if that
delays otherwise worthwhile work.
Nobody suggested that.  It’s perfectly possible to “be polite” and still not
delay worthwhile work.


  *   The current policy is "downstream is on their own".
Nobody disputes that.


  *   There was nothing even remotely unreasonable done in the patch series
which triggered this discussion and I don't want any upstream contributor
coming to believe there was.
I disagree with you about “nothing even remotely unreasonable” in that I think
it was done slightly unreasonably, and I think it’s worthwhile to have other
upstream contributors acknowledge that feeling.


What I’m aware of is a series of 5 separate patches, each of which
re-capitalized a select subset of APIs in the same area.  This fixing-up is
*long overdue* and I’m very happy to see it done.  But I will dispute the
“reasonableness” of doing it in 5 separate stages (plus a few other related
cleanups that were not simply re-capitalizing existing names).
The notion of “reviewable size” is not relevant, because these patches were not
reviewed (in accordance with current policy, that this kind of mechanical fixup
is “obvious” and does not require pre-commit review).
The patches were not really very distinct, with a HUGE overlap in the set of
affected files.

We do like to minimize churn; this kind of fixup clearly qualifies as churn, but
I respectfully submit that the way it was done does not *minimize* the churn.

And minimizing the churn is good for both the project and those of us who live
downstream of it.

If you ignore downstream users, and focus on upstream: what makes it the least
risky and most convenient for the *upstream contributor* in this case? It seems
they believed it was to split their patch up, which I would have done as well:
if you can split it, then in most case you should.
If the patches can land separately, to me their are distinct (they are not
unrelated, but that's not a reason for merging them in a single commit).
Just like David mentioned separately, I may have done this over a much longer
series of individual commits.

If you are arguing that the reason to not split these in separate patch is about
downstream users, then I am with Philip: you start to creep up some expectations
that are going against the current status quo in which (in my opinion)
downstream shouldn't impact upstream development.

Best,

--
Mehdi




--paulr

From: llvm-dev <llvm-dev-bounces at lists.llvm.org<mailto:llvm-dev-bounces
at lists.llvm.org>> On Behalf Of Philip Reames via llvm-dev
Sent: Wednesday, February 19, 2020 2:07 PM
To: Eric Christopher <echristo at gmail.com<mailto:echristo at
gmail.com>>
Cc: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>; Valentin Churavy <v.churavy at
gmail.com<mailto:v.churavy at gmail.com>>
Subject: Re: [llvm-dev] amount of camelCase refactoring causing some downstream
overhead


Eric,

I disagree.  Strongly.   I see the very fact we're engaging in the
discussion of "just being polite" here as normalizing a proposed
change in policy which has potentially profound negative consequences for the
project long term.  I do not want upstream developers "trying to be
polite" if that delays otherwise worthwhile work.  The current policy is
"downstream is on their own".  There was nothing even remotely
unreasonable done in the patch series which triggered this discussion and I
don't want any upstream contributor coming to believe there was.

Again, I'm open to carefully weighted proposals to change current policy.  I
also have a downstream repo which is kept up to date and I understand the pain
point being raised.  I just want to be very careful to distinguish between
existing status, and any proposed changes.  I want the proposed changes to be
carefully weighed before being put into effect.

Philip
On 2/18/20 4:39 PM, Eric Christopher wrote:
Hi Philip,

While it's true we don't I think Valentin is reasonable in saying
"hey, when people do this let's try to combine them if it makes
sense". It's just being polite to everyone, especially if it
doesn't risk the patches or upstream stability. I don't think
there's a policy change being proposed, just a "hey, let's see what
we can do in the future".

-eric

On Tue, Feb 18, 2020 at 4:05 PM Philip Reames via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:

Valentin,

You are proposing to change existing policy.  Current policy is that we
don't consider downstream *at all*.  Your proposal may seem reasonable - it
may even *be* reasonable - but it is definitely a change from historical
practice and must be considered as such.

Philip
On 2/18/20 3:03 PM, Valentin Churavy wrote:
I don't think anyone is arguing to change longstanding policy. From a
downstream perspective many small renaming changes do increase overhead for us.

One thing that happens to downstream projects is that they support more than one
LLVM version, we (JuliaLang) currently try to support latest stable + master.

So for me the question is more, are renaming changes worth downstream projects
not being able to test and provide feedback to upstream?  One way of mitigating
that is to consciously schedule them just before a release and do them all in
short succession.

-V


On Tue, Feb 18, 2020, 17:00 Philip Reames via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
As others have said, our long standing policy has been that downstream
projects must fend for themselves.  We're certainly not going to reverse
that policy without careful discussion of the tradeoffs.

I'm personally of the opinion that there could be a middle ground which
allows upstream to move quickly while reducing headache for downstream
projects.  Given I wear both hats, I know I'd certainly appreciate such
a state.  However, it's important to state that such decisions would
need to be carefully considered and would require some very careful
drafting of proposal to balance the competing interests at hand.

If anyone is curious, I'm happy to share some ideas offline on what
starting points might be, but I have neither the time nor the interest
to drive such a conversion on list.

Philip

On 2/18/20 1:37 AM, Ties Stuij via llvm-dev wrote:
> During that variable renaming debate, there was a discussion about
discussion about doing things all at once, piecemeal or not at all. An issue
that wasn't really resolved I think. I had the impression that the efforts
fizzled out a bit, and I thought this renaming was maybe related to that, but
I'm neutral on if we should do variable renaming.
>
> All I'm asking as a kindness if we could be kind on poor downstream
maintainers not on the issue of variable renaming at large, but on the micro
level of not pushing 5/6 patches of this kind covering closely related
functionality in two days but collating them in 1. I don't think that would
slow down development, and I wanted to highlight the issue, as people might not
be aware that they could save some pain in a simple way. Especially if indeed
there is going to be a big renaming push and this would be a continuous thing.
>
> Cheers,
> /Ties
>
> ________________________________________
> From: Michael Kruse <llvmdev at meinersbur.de<mailto:llvmdev at
meinersbur.de>>
> Sent: 17 February 2020 21:16
> To: Ties Stuij
> Cc: llvm-dev
> Subject: Re: [llvm-dev] amount of camelCase refactoring causing some
downstream overhead
>
> My understanding is that LLVM's general policy is to not let
> downstream slow down upstream development. The C++ API explicitly
> unstable.
>
> Note that we are even considering renaming variables globally:
> https://lists.llvm.org/pipermail/llvm-dev/2019-September/134921.html
>
> Michael
>
> Am Mo., 17. Feb. 2020 um 06:04 Uhr schrieb Ties Stuij via llvm-dev
> <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>:
>> Hi there,
>>
>> At the end of last week we saw a number of commits go in that were
camelCasing batches of MCStreamer::Emit* and AsmPrinter::Emit* functions.
>>
>> For example:
>> - https://reviews.llvm.org/rG549b436beb4129854e729a3e1398f03429149691
>> - https://reviews.llvm.org/rGa55daa146166353236aa528546397226bee9363b
>> - https://reviews.llvm.org/rG0bc77a0f0d1606520c7ad0ea72c434661786a956
>>
>> Unfortunately all these individual commits trigger the same merge
conflicts over and over again with our downstream repo, which takes us some
manual intervention every time.
>>
>> I understand uniformity is a nice to have, but:
>> 1 - is it worth it to do this work right now? I can remember the casing
debate a few months back, which seems unrelated to this work which seems manual,
but I'm unsure of the outcome.
>> 2 - If this work should be done, it would be nice if all of the work is
done in one batch, to save us some of the downstream overhead.
>>
>> Thanks
>> /Ties
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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Hi Paul,

while I absolutely agree with you that a lower number of formatting changes is
certainly also desirable for upstream I wanted to add a little side note: Since
version 2.23 git blame is able to ignore certain patches. See also
https://github.com/llvm/llvm-project/blob/master/.git-blame-ignore-revs
<https://github.com/llvm/llvm-project/blob/master/.git-blame-ignore-revs>.
However, this might be an even stronger argument to keep formatting changes
together since this would allow to add them as one ref to the list.

Thanks,
David
> On 20. Feb 2020, at 19:33, Robinson, Paul via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> Hi Mehdi!
>  
> I think the value to upstream (of doing mass reformatting in fewer commits)
has to do with the intrusion of nonfunctional commits into `git blame` kinds of
research.  Every line that someone touches for a formatting reason necessarily
obscures the history of functional changes in that block of code.  The fewer of
those that people have to work around, the better.  I admit this is a small
concern, but it wasn’t so long ago that I was looking back at some history and
had to wade through way more formatting commits than functional commits to get
to the log message that told me what I needed to know.
>  
> Some formatting changes just come with the territory, but if I have to deal
with 1 or 2 instead of 5 or 8, it does improve my day.
>  
> HTH,
> --paulr
>  
> From: Mehdi AMINI <joker.eph at gmail.com> 
> Sent: Thursday, February 20, 2020 1:16 PM
> To: Robinson, Paul <paul.robinson at sony.com>
> Cc: Philip Reames <listmail at philipreames.com>; Eric Christopher
<echristo at gmail.com>; llvm-dev at lists.llvm.org; Valentin Churavy
<v.churavy at gmail.com>
> Subject: Re: [llvm-dev] amount of camelCase refactoring causing some
downstream overhead
>  
>  
>  
> On Wed, Feb 19, 2020 at 12:10 PM Robinson, Paul via llvm-dev <llvm-dev
at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
> Hi Philip,
>  
> I think you might be reading more into the suggestion/discussion than is
actually there.
>  
> I do not want upstream developers "trying to be polite" if that
delays otherwise worthwhile work.
> Nobody suggested that.  It’s perfectly possible to “be polite” and still
not delay worthwhile work.
>  
> The current policy is "downstream is on their own".
> Nobody disputes that.
>  
> There was nothing even remotely unreasonable done in the patch series which
triggered this discussion and I don't want any upstream contributor coming
to believe there was.
> I disagree with you about “nothing even remotely unreasonable” in that I
think it was done slightly unreasonably, and I think it’s worthwhile to have
other upstream contributors acknowledge that feeling.
>  
>  
> What I’m aware of is a series of 5 separate patches, each of which
re-capitalized a select subset of APIs in the same area.  This fixing-up is
*long overdue* and I’m very happy to see it done.  But I will dispute the
“reasonableness” of doing it in 5 separate stages (plus a few other related
cleanups that were not simply re-capitalizing existing names).
> The notion of “reviewable size” is not relevant, because these patches were
not reviewed (in accordance with current policy, that this kind of mechanical
fixup is “obvious” and does not require pre-commit review).
> The patches were not really very distinct, with a HUGE overlap in the set
of affected files.
>  
> We do like to minimize churn; this kind of fixup clearly qualifies as
churn, but I respectfully submit that the way it was done does not *minimize*
the churn.
>  
> And minimizing the churn is good for both the project and those of us who
live downstream of it.
>  
> If you ignore downstream users, and focus on upstream: what makes it the
least risky and most convenient for the *upstream contributor* in this case? It
seems they believed it was to split their patch up, which I would have done as
well: if you can split it, then in most case you should.
> If the patches can land separately, to me their are distinct (they are not
unrelated, but that's not a reason for merging them in a single commit).
Just like David mentioned separately, I may have done this over a much longer
series of individual commits.
>  
> If you are arguing that the reason to not split these in separate patch is
about downstream users, then I am with Philip: you start to creep up some
expectations that are going against the current status quo in which (in my
opinion) downstream shouldn't impact upstream development.
>  
> Best,
>  
> -- 
> Mehdi
>  
>  
>  
>  
> --paulr
>  
> From: llvm-dev <llvm-dev-bounces at lists.llvm.org
<mailto:llvm-dev-bounces at lists.llvm.org>> On Behalf Of Philip Reames
via llvm-dev
> Sent: Wednesday, February 19, 2020 2:07 PM
> To: Eric Christopher <echristo at gmail.com <mailto:echristo at
gmail.com>>
> Cc: llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at
lists.llvm.org>>; Valentin Churavy <v.churavy at gmail.com
<mailto:v.churavy at gmail.com>>
> Subject: Re: [llvm-dev] amount of camelCase refactoring causing some
downstream overhead
>  
> Eric,
> 
> I disagree.  Strongly.   I see the very fact we're engaging in the
discussion of "just being polite" here as normalizing a proposed
change in policy which has potentially profound negative consequences for the
project long term.  I do not want upstream developers "trying to be
polite" if that delays otherwise worthwhile work.  The current policy is
"downstream is on their own".  There was nothing even remotely
unreasonable done in the patch series which triggered this discussion and I
don't want any upstream contributor coming to believe there was.
> 
> Again, I'm open to carefully weighted proposals to change current
policy.  I also have a downstream repo which is kept up to date and I understand
the pain point being raised.  I just want to be very careful to distinguish
between existing status, and any proposed changes.  I want the proposed changes
to be carefully weighed before being put into effect.
> 
> Philip
> 
> On 2/18/20 4:39 PM, Eric Christopher wrote:
> Hi Philip,
>  
> While it's true we don't I think Valentin is reasonable in saying
"hey, when people do this let's try to combine them if it makes
sense". It's just being polite to everyone, especially if it
doesn't risk the patches or upstream stability. I don't think
there's a policy change being proposed, just a "hey, let's see what
we can do in the future".
>  
> -eric
>  
> On Tue, Feb 18, 2020 at 4:05 PM Philip Reames via llvm-dev <llvm-dev at
lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
> Valentin,
> 
> You are proposing to change existing policy.  Current policy is that we
don't consider downstream *at all*.  Your proposal may seem reasonable - it
may even *be* reasonable - but it is definitely a change from historical
practice and must be considered as such.
> 
> Philip
> 
> On 2/18/20 3:03 PM, Valentin Churavy wrote:
> I don't think anyone is arguing to change longstanding policy. From a
downstream perspective many small renaming changes do increase overhead for us.
>  
> One thing that happens to downstream projects is that they support more
than one LLVM version, we (JuliaLang) currently try to support latest stable +
master.
>  
> So for me the question is more, are renaming changes worth downstream
projects not being able to test and provide feedback to upstream?  One way of
mitigating that is to consciously schedule them just before a release and do
them all in short succession.
>  
> -V
>  
>  
> On Tue, Feb 18, 2020, 17:00 Philip Reames via llvm-dev <llvm-dev at
lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
> As others have said, our long standing policy has been that downstream 
> projects must fend for themselves.  We're certainly not going to
reverse
> that policy without careful discussion of the tradeoffs.
> 
> I'm personally of the opinion that there could be a middle ground which
> allows upstream to move quickly while reducing headache for downstream 
> projects.  Given I wear both hats, I know I'd certainly appreciate such
> a state.  However, it's important to state that such decisions would 
> need to be carefully considered and would require some very careful 
> drafting of proposal to balance the competing interests at hand.
> 
> If anyone is curious, I'm happy to share some ideas offline on what 
> starting points might be, but I have neither the time nor the interest 
> to drive such a conversion on list.
> 
> Philip
> 
> On 2/18/20 1:37 AM, Ties Stuij via llvm-dev wrote:
> > During that variable renaming debate, there was a discussion about
discussion about doing things all at once, piecemeal or not at all. An issue
that wasn't really resolved I think. I had the impression that the efforts
fizzled out a bit, and I thought this renaming was maybe related to that, but
I'm neutral on if we should do variable renaming.
> >
> > All I'm asking as a kindness if we could be kind on poor
downstream maintainers not on the issue of variable renaming at large, but on
the micro level of not pushing 5/6 patches of this kind covering closely related
functionality in two days but collating them in 1. I don't think that would
slow down development, and I wanted to highlight the issue, as people might not
be aware that they could save some pain in a simple way. Especially if indeed
there is going to be a big renaming push and this would be a continuous thing.
> >
> > Cheers,
> > /Ties
> >
> > ________________________________________
> > From: Michael Kruse <llvmdev at meinersbur.de <mailto:llvmdev at
meinersbur.de>>
> > Sent: 17 February 2020 21:16
> > To: Ties Stuij
> > Cc: llvm-dev
> > Subject: Re: [llvm-dev] amount of camelCase refactoring causing some
downstream overhead
> >
> > My understanding is that LLVM's general policy is to not let
> > downstream slow down upstream development. The C++ API explicitly
> > unstable.
> >
> > Note that we are even considering renaming variables globally:
> > https://lists.llvm.org/pipermail/llvm-dev/2019-September/134921.html
<https://lists.llvm.org/pipermail/llvm-dev/2019-September/134921.html>
> >
> > Michael
> >
> > Am Mo., 17. Feb. 2020 um 06:04 Uhr schrieb Ties Stuij via llvm-dev
> > <llvm-dev at lists.llvm.org <mailto:llvm-dev at
lists.llvm.org>>:
> >> Hi there,
> >>
> >> At the end of last week we saw a number of commits go in that were
camelCasing batches of MCStreamer::Emit* and AsmPrinter::Emit* functions.
> >>
> >> For example:
> >> -
https://reviews.llvm.org/rG549b436beb4129854e729a3e1398f03429149691
<https://reviews.llvm.org/rG549b436beb4129854e729a3e1398f03429149691>
> >> -
https://reviews.llvm.org/rGa55daa146166353236aa528546397226bee9363b
<https://reviews.llvm.org/rGa55daa146166353236aa528546397226bee9363b>
> >> -
https://reviews.llvm.org/rG0bc77a0f0d1606520c7ad0ea72c434661786a956
<https://reviews.llvm.org/rG0bc77a0f0d1606520c7ad0ea72c434661786a956>
> >>
> >> Unfortunately all these individual commits trigger the same merge
conflicts over and over again with our downstream repo, which takes us some
manual intervention every time.
> >>
> >> I understand uniformity is a nice to have, but:
> >> 1 - is it worth it to do this work right now? I can remember the
casing debate a few months back, which seems unrelated to this work which seems
manual, but I'm unsure of the outcome.
> >> 2 - If this work should be done, it would be nice if all of the
work is done in one batch, to save us some of the downstream overhead.
> >>
> >> Thanks
> >> /Ties
> >> _______________________________________________
> >> LLVM Developers mailing list
> >> llvm-dev at lists.llvm.org <mailto:llvm-dev at
lists.llvm.org>
> >> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
> > _______________________________________________
> > LLVM Developers mailing list
> > llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
> > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>_______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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Hi,

Thanks for positioning some arguments with respect to upstream development,
appreciate it!

If `git blame` is what you're after, then it seems like we'd bundle
refactoring per "region of code" (function?) rather than multiple
files
together: changes across files shouldn't create a long sequence of `git
blame` tracking right?

-- 
Mehdi


On Thu, Feb 20, 2020 at 10:33 AM Robinson, Paul <paul.robinson at
sony.com>
wrote:
> Hi Mehdi!
>
>
>
> I think the value to upstream (of doing mass reformatting in fewer
> commits) has to do with the intrusion of nonfunctional commits into `git
> blame` kinds of research.  Every line that someone touches for a formatting
> reason necessarily obscures the history of functional changes in that block
> of code.  The fewer of those that people have to work around, the better.
> I admit this is a small concern, but it wasn’t so long ago that I was
> looking back at some history and had to wade through way more formatting
> commits than functional commits to get to the log message that told me what
> I needed to know.
>
>
>
> Some formatting changes just come with the territory, but if I have to
> deal with 1 or 2 instead of 5 or 8, it does improve my day.
>
>
>
> HTH,
>
> --paulr
>
>
>
> *From:* Mehdi AMINI <joker.eph at gmail.com>
> *Sent:* Thursday, February 20, 2020 1:16 PM
> *To:* Robinson, Paul <paul.robinson at sony.com>
> *Cc:* Philip Reames <listmail at philipreames.com>; Eric Christopher
<
> echristo at gmail.com>; llvm-dev at lists.llvm.org; Valentin Churavy
<
> v.churavy at gmail.com>
> *Subject:* Re: [llvm-dev] amount of camelCase refactoring causing some
> downstream overhead
>
>
>
>
>
>
>
> On Wed, Feb 19, 2020 at 12:10 PM Robinson, Paul via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
> Hi Philip,
>
>
>
> I think you might be reading more into the suggestion/discussion than is
> actually there.
>
>
>
>    - I do not want upstream developers "trying to be polite" if
that
>    delays otherwise worthwhile work.
>
> Nobody suggested that.  It’s perfectly possible to “be polite” and still
> not delay worthwhile work.
>
>
>
>    - The current policy is "downstream is on their own".
>
> Nobody disputes that.
>
>
>
>    - There was nothing even remotely unreasonable done in the patch
>    series which triggered this discussion and I don't want any upstream
>    contributor coming to believe there was.
>
> I disagree with you about “nothing even remotely unreasonable” in that I
> think it was done slightly unreasonably, and I think it’s worthwhile to
> have other upstream contributors acknowledge that feeling.
>
>
>
>
>
> What I’m aware of is a series of 5 separate patches, each of which
> re-capitalized a select subset of APIs in the same area.  This fixing-up is
> **long overdue** and I’m very happy to see it done.  But I will dispute
> the “reasonableness” of doing it in 5 separate stages (plus a few other
> related cleanups that were not simply re-capitalizing existing names).
>
> The notion of “reviewable size” is not relevant, because these patches
> were not reviewed (in accordance with current policy, that this kind of
> mechanical fixup is “obvious” and does not require pre-commit review).
>
> The patches were not really very distinct, with a HUGE overlap in the set
> of affected files.
>
>
>
> We do like to minimize churn; this kind of fixup clearly qualifies as
> churn, but I respectfully submit that the way it was done does not *
> *minimize** the churn.
>
>
>
> And minimizing the churn is good for both the project and those of us who
> live downstream of it.
>
>
>
> If you ignore downstream users, and focus on upstream: what makes it the
> least risky and most convenient for the *upstream contributor* in this
> case? It seems they believed it was to split their patch up, which I would
> have done as well: if you can split it, then in most case you should.
>
> If the patches can land separately, to me their are distinct (they are not
> unrelated, but that's not a reason for merging them in a single
commit).
> Just like David mentioned separately, I may have done this over a much
> longer series of individual commits.
>
>
>
> If you are arguing that the reason to not split these in separate patch is
> about downstream users, then I am with Philip: you start to creep up some
> expectations that are going against the current status quo in which (in my
> opinion) downstream shouldn't impact upstream development.
>
>
>
> Best,
>
>
>
> --
>
> Mehdi
>
>
>
>
>
>
>
>
>
> --paulr
>
>
>
> *From:* llvm-dev <llvm-dev-bounces at lists.llvm.org> *On Behalf Of
*Philip
> Reames via llvm-dev
> *Sent:* Wednesday, February 19, 2020 2:07 PM
> *To:* Eric Christopher <echristo at gmail.com>
> *Cc:* llvm-dev <llvm-dev at lists.llvm.org>; Valentin Churavy <
> v.churavy at gmail.com>
> *Subject:* Re: [llvm-dev] amount of camelCase refactoring causing some
> downstream overhead
>
>
>
> Eric,
>
> I disagree.  Strongly.   I see the very fact we're engaging in the
> discussion of "just being polite" here as normalizing a proposed
change in
> policy which has potentially profound negative consequences for the project
> long term.  I do not want upstream developers "trying to be
polite" if that
> delays otherwise worthwhile work.  The current policy is "downstream
is on
> their own".  There was nothing even remotely unreasonable done in the
patch
> series which triggered this discussion and I don't want any upstream
> contributor coming to believe there was.
>
> Again, I'm open to carefully weighted proposals to change current
policy.
> I also have a downstream repo which is kept up to date and I understand the
> pain point being raised.  I just want to be very careful to distinguish
> between existing status, and any proposed changes.  I want the proposed
> changes to be carefully weighed before being put into effect.
>
> Philip
>
> On 2/18/20 4:39 PM, Eric Christopher wrote:
>
> Hi Philip,
>
>
>
> While it's true we don't I think Valentin is reasonable in saying
"hey,
> when people do this let's try to combine them if it makes sense".
It's just
> being polite to everyone, especially if it doesn't risk the patches or
> upstream stability. I don't think there's a policy change being
proposed,
> just a "hey, let's see what we can do in the future".
>
>
>
> -eric
>
>
>
> On Tue, Feb 18, 2020 at 4:05 PM Philip Reames via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
> Valentin,
>
> You are proposing to change existing policy.  Current policy is that we
> don't consider downstream *at all*.  Your proposal may seem reasonable
- it
> may even *be* reasonable - but it is definitely a change from historical
> practice and must be considered as such.
>
> Philip
>
> On 2/18/20 3:03 PM, Valentin Churavy wrote:
>
> I don't think anyone is arguing to change longstanding policy. From a
> downstream perspective many small renaming changes do increase overhead for
> us.
>
>
>
> One thing that happens to downstream projects is that they support more
> than one LLVM version, we (JuliaLang) currently try to support latest
> stable + master.
>
>
>
> So for me the question is more, are renaming changes worth downstream
> projects not being able to test and provide feedback to upstream?  One way
> of mitigating that is to consciously schedule them just before a release
> and do them all in short succession.
>
>
>
> -V
>
>
>
>
>
> On Tue, Feb 18, 2020, 17:00 Philip Reames via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
> As others have said, our long standing policy has been that downstream
> projects must fend for themselves.  We're certainly not going to
reverse
> that policy without careful discussion of the tradeoffs.
>
> I'm personally of the opinion that there could be a middle ground which
> allows upstream to move quickly while reducing headache for downstream
> projects.  Given I wear both hats, I know I'd certainly appreciate such
> a state.  However, it's important to state that such decisions would
> need to be carefully considered and would require some very careful
> drafting of proposal to balance the competing interests at hand.
>
> If anyone is curious, I'm happy to share some ideas offline on what
> starting points might be, but I have neither the time nor the interest
> to drive such a conversion on list.
>
> Philip
>
> On 2/18/20 1:37 AM, Ties Stuij via llvm-dev wrote:
> > During that variable renaming debate, there was a discussion about
> discussion about doing things all at once, piecemeal or not at all. An
> issue that wasn't really resolved I think. I had the impression that
the
> efforts fizzled out a bit, and I thought this renaming was maybe related to
> that, but I'm neutral on if we should do variable renaming.
> >
> > All I'm asking as a kindness if we could be kind on poor
downstream
> maintainers not on the issue of variable renaming at large, but on the
> micro level of not pushing 5/6 patches of this kind covering closely
> related functionality in two days but collating them in 1. I don't
think
> that would slow down development, and I wanted to highlight the issue, as
> people might not be aware that they could save some pain in a simple way.
> Especially if indeed there is going to be a big renaming push and this
> would be a continuous thing.
> >
> > Cheers,
> > /Ties
> >
> > ________________________________________
> > From: Michael Kruse <llvmdev at meinersbur.de>
> > Sent: 17 February 2020 21:16
> > To: Ties Stuij
> > Cc: llvm-dev
> > Subject: Re: [llvm-dev] amount of camelCase refactoring causing some
> downstream overhead
> >
> > My understanding is that LLVM's general policy is to not let
> > downstream slow down upstream development. The C++ API explicitly
> > unstable.
> >
> > Note that we are even considering renaming variables globally:
> > https://lists.llvm.org/pipermail/llvm-dev/2019-September/134921.html
> >
> > Michael
> >
> > Am Mo., 17. Feb. 2020 um 06:04 Uhr schrieb Ties Stuij via llvm-dev
> > <llvm-dev at lists.llvm.org>:
> >> Hi there,
> >>
> >> At the end of last week we saw a number of commits go in that were
> camelCasing batches of MCStreamer::Emit* and AsmPrinter::Emit* functions.
> >>
> >> For example:
> >> -
https://reviews.llvm.org/rG549b436beb4129854e729a3e1398f03429149691
> >> -
https://reviews.llvm.org/rGa55daa146166353236aa528546397226bee9363b
> >> -
https://reviews.llvm.org/rG0bc77a0f0d1606520c7ad0ea72c434661786a956
> >>
> >> Unfortunately all these individual commits trigger the same merge
> conflicts over and over again with our downstream repo, which takes us some
> manual intervention every time.
> >>
> >> I understand uniformity is a nice to have, but:
> >> 1 - is it worth it to do this work right now? I can remember the
casing
> debate a few months back, which seems unrelated to this work which seems
> manual, but I'm unsure of the outcome.
> >> 2 - If this work should be done, it would be nice if all of the
work is
> done in one batch, to save us some of the downstream overhead.
> >>
> >> Thanks
> >> /Ties
> >> _______________________________________________
> >> LLVM Developers mailing list
> >> llvm-dev at lists.llvm.org
> >> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> > _______________________________________________
> > LLVM Developers mailing list
> > llvm-dev at lists.llvm.org
> > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
>
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Hi Mehdi,

When the refactor is an API change (which renaming counts as an API change) and
you’re modifying all calls to popular APIs, those popular APIs get used in lots
of places, and so it’s quite likely (and I saw this in some of our conflicts)
that doing them in multiple patches will end up touching the same “region of
code” multiple times.  Not every patch touched all the same places, of course,
but there was a lot of shall we say repeat business.

So a mass API change to a given class’s public methods should preferably be done
all at once instead of piecemeal, to avoid multiple hits on the same regions of
API users, which messes with git blame.
--paulr

P.S. This discussion has probably already gone on longer than it merits.

From: Mehdi AMINI <joker.eph at gmail.com>
Sent: Thursday, February 20, 2020 2:05 PM
To: Robinson, Paul <paul.robinson at sony.com>
Cc: Philip Reames <listmail at philipreames.com>; Eric Christopher
<echristo at gmail.com>; llvm-dev at lists.llvm.org; Valentin Churavy
<v.churavy at gmail.com>
Subject: Re: [llvm-dev] amount of camelCase refactoring causing some downstream
overhead

Hi,

Thanks for positioning some arguments with respect to upstream development,
appreciate it!

If `git blame` is what you're after, then it seems like we'd bundle
refactoring per "region of code" (function?) rather than multiple
files together: changes across files shouldn't create a long sequence of
`git blame` tracking right?

--
Mehdi


On Thu, Feb 20, 2020 at 10:33 AM Robinson, Paul <paul.robinson at
sony.com<mailto:paul.robinson at sony.com>> wrote:
Hi Mehdi!

I think the value to upstream (of doing mass reformatting in fewer commits) has
to do with the intrusion of nonfunctional commits into `git blame` kinds of
research.  Every line that someone touches for a formatting reason necessarily
obscures the history of functional changes in that block of code.  The fewer of
those that people have to work around, the better.  I admit this is a small
concern, but it wasn’t so long ago that I was looking back at some history and
had to wade through way more formatting commits than functional commits to get
to the log message that told me what I needed to know.

Some formatting changes just come with the territory, but if I have to deal with
1 or 2 instead of 5 or 8, it does improve my day.

HTH,
--paulr

From: Mehdi AMINI <joker.eph at gmail.com<mailto:joker.eph at
gmail.com>>
Sent: Thursday, February 20, 2020 1:16 PM
To: Robinson, Paul <paul.robinson at sony.com<mailto:paul.robinson at
sony.com>>
Cc: Philip Reames <listmail at philipreames.com<mailto:listmail at
philipreames.com>>; Eric Christopher <echristo at
gmail.com<mailto:echristo at gmail.com>>; llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>; Valentin Churavy
<v.churavy at gmail.com<mailto:v.churavy at gmail.com>>
Subject: Re: [llvm-dev] amount of camelCase refactoring causing some downstream
overhead



On Wed, Feb 19, 2020 at 12:10 PM Robinson, Paul via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
Hi Philip,

I think you might be reading more into the suggestion/discussion than is
actually there.


  *   I do not want upstream developers "trying to be polite" if that
delays otherwise worthwhile work.
Nobody suggested that.  It’s perfectly possible to “be polite” and still not
delay worthwhile work.


  *   The current policy is "downstream is on their own".
Nobody disputes that.


  *   There was nothing even remotely unreasonable done in the patch series
which triggered this discussion and I don't want any upstream contributor
coming to believe there was.
I disagree with you about “nothing even remotely unreasonable” in that I think
it was done slightly unreasonably, and I think it’s worthwhile to have other
upstream contributors acknowledge that feeling.


What I’m aware of is a series of 5 separate patches, each of which
re-capitalized a select subset of APIs in the same area.  This fixing-up is
*long overdue* and I’m very happy to see it done.  But I will dispute the
“reasonableness” of doing it in 5 separate stages (plus a few other related
cleanups that were not simply re-capitalizing existing names).
The notion of “reviewable size” is not relevant, because these patches were not
reviewed (in accordance with current policy, that this kind of mechanical fixup
is “obvious” and does not require pre-commit review).
The patches were not really very distinct, with a HUGE overlap in the set of
affected files.

We do like to minimize churn; this kind of fixup clearly qualifies as churn, but
I respectfully submit that the way it was done does not *minimize* the churn.

And minimizing the churn is good for both the project and those of us who live
downstream of it.

If you ignore downstream users, and focus on upstream: what makes it the least
risky and most convenient for the *upstream contributor* in this case? It seems
they believed it was to split their patch up, which I would have done as well:
if you can split it, then in most case you should.
If the patches can land separately, to me their are distinct (they are not
unrelated, but that's not a reason for merging them in a single commit).
Just like David mentioned separately, I may have done this over a much longer
series of individual commits.

If you are arguing that the reason to not split these in separate patch is about
downstream users, then I am with Philip: you start to creep up some expectations
that are going against the current status quo in which (in my opinion)
downstream shouldn't impact upstream development.

Best,

--
Mehdi




--paulr

From: llvm-dev <llvm-dev-bounces at lists.llvm.org<mailto:llvm-dev-bounces
at lists.llvm.org>> On Behalf Of Philip Reames via llvm-dev
Sent: Wednesday, February 19, 2020 2:07 PM
To: Eric Christopher <echristo at gmail.com<mailto:echristo at
gmail.com>>
Cc: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>; Valentin Churavy <v.churavy at
gmail.com<mailto:v.churavy at gmail.com>>
Subject: Re: [llvm-dev] amount of camelCase refactoring causing some downstream
overhead


Eric,

I disagree.  Strongly.   I see the very fact we're engaging in the
discussion of "just being polite" here as normalizing a proposed
change in policy which has potentially profound negative consequences for the
project long term.  I do not want upstream developers "trying to be
polite" if that delays otherwise worthwhile work.  The current policy is
"downstream is on their own".  There was nothing even remotely
unreasonable done in the patch series which triggered this discussion and I
don't want any upstream contributor coming to believe there was.

Again, I'm open to carefully weighted proposals to change current policy.  I
also have a downstream repo which is kept up to date and I understand the pain
point being raised.  I just want to be very careful to distinguish between
existing status, and any proposed changes.  I want the proposed changes to be
carefully weighed before being put into effect.

Philip
On 2/18/20 4:39 PM, Eric Christopher wrote:
Hi Philip,

While it's true we don't I think Valentin is reasonable in saying
"hey, when people do this let's try to combine them if it makes
sense". It's just being polite to everyone, especially if it
doesn't risk the patches or upstream stability. I don't think
there's a policy change being proposed, just a "hey, let's see what
we can do in the future".

-eric

On Tue, Feb 18, 2020 at 4:05 PM Philip Reames via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:

Valentin,

You are proposing to change existing policy.  Current policy is that we
don't consider downstream *at all*.  Your proposal may seem reasonable - it
may even *be* reasonable - but it is definitely a change from historical
practice and must be considered as such.

Philip
On 2/18/20 3:03 PM, Valentin Churavy wrote:
I don't think anyone is arguing to change longstanding policy. From a
downstream perspective many small renaming changes do increase overhead for us.

One thing that happens to downstream projects is that they support more than one
LLVM version, we (JuliaLang) currently try to support latest stable + master.

So for me the question is more, are renaming changes worth downstream projects
not being able to test and provide feedback to upstream?  One way of mitigating
that is to consciously schedule them just before a release and do them all in
short succession.

-V


On Tue, Feb 18, 2020, 17:00 Philip Reames via llvm-dev <llvm-dev at
lists.llvm.org<mailto:llvm-dev at lists.llvm.org>> wrote:
As others have said, our long standing policy has been that downstream
projects must fend for themselves.  We're certainly not going to reverse
that policy without careful discussion of the tradeoffs.

I'm personally of the opinion that there could be a middle ground which
allows upstream to move quickly while reducing headache for downstream
projects.  Given I wear both hats, I know I'd certainly appreciate such
a state.  However, it's important to state that such decisions would
need to be carefully considered and would require some very careful
drafting of proposal to balance the competing interests at hand.

If anyone is curious, I'm happy to share some ideas offline on what
starting points might be, but I have neither the time nor the interest
to drive such a conversion on list.

Philip

On 2/18/20 1:37 AM, Ties Stuij via llvm-dev wrote:
> During that variable renaming debate, there was a discussion about
discussion about doing things all at once, piecemeal or not at all. An issue
that wasn't really resolved I think. I had the impression that the efforts
fizzled out a bit, and I thought this renaming was maybe related to that, but
I'm neutral on if we should do variable renaming.
>
> All I'm asking as a kindness if we could be kind on poor downstream
maintainers not on the issue of variable renaming at large, but on the micro
level of not pushing 5/6 patches of this kind covering closely related
functionality in two days but collating them in 1. I don't think that would
slow down development, and I wanted to highlight the issue, as people might not
be aware that they could save some pain in a simple way. Especially if indeed
there is going to be a big renaming push and this would be a continuous thing.
>
> Cheers,
> /Ties
>
> ________________________________________
> From: Michael Kruse <llvmdev at meinersbur.de<mailto:llvmdev at
meinersbur.de>>
> Sent: 17 February 2020 21:16
> To: Ties Stuij
> Cc: llvm-dev
> Subject: Re: [llvm-dev] amount of camelCase refactoring causing some
downstream overhead
>
> My understanding is that LLVM's general policy is to not let
> downstream slow down upstream development. The C++ API explicitly
> unstable.
>
> Note that we are even considering renaming variables globally:
> https://lists.llvm.org/pipermail/llvm-dev/2019-September/134921.html
>
> Michael
>
> Am Mo., 17. Feb. 2020 um 06:04 Uhr schrieb Ties Stuij via llvm-dev
> <llvm-dev at lists.llvm.org<mailto:llvm-dev at
lists.llvm.org>>:
>> Hi there,
>>
>> At the end of last week we saw a number of commits go in that were
camelCasing batches of MCStreamer::Emit* and AsmPrinter::Emit* functions.
>>
>> For example:
>> - https://reviews.llvm.org/rG549b436beb4129854e729a3e1398f03429149691
>> - https://reviews.llvm.org/rGa55daa146166353236aa528546397226bee9363b
>> - https://reviews.llvm.org/rG0bc77a0f0d1606520c7ad0ea72c434661786a956
>>
>> Unfortunately all these individual commits trigger the same merge
conflicts over and over again with our downstream repo, which takes us some
manual intervention every time.
>>
>> I understand uniformity is a nice to have, but:
>> 1 - is it worth it to do this work right now? I can remember the casing
debate a few months back, which seems unrelated to this work which seems manual,
but I'm unsure of the outcome.
>> 2 - If this work should be done, it would be nice if all of the work is
done in one batch, to save us some of the downstream overhead.
>>
>> Thanks
>> /Ties
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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