<div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Dec 2, 2019 at 12:52 PM Philip Reames <<a href="mailto:listmail@philipreames.com">listmail@philipreames.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<p>Mehdi, David,</p>
<p>I think you're both pointing out exceptions rather than the
general rule. I tried to indicate their might be reasonable
exceptions (see the second sentence past Mehdi's quote), but in
general, particularly for new contributors, I think it is
important we indicate something to this effect. I've seen
multiple new groups have issues around this. In some cases,
patches were reverted in post review. In others, a bunch of time
was sunk in a direction which turned turned out not to have wide
agreement. Cautioning folks to avoid that is important.</p>
<p>Do you have any suggestions on wording which keep the broad
message, but make it more clear that it isn't a hard and fast
rule?</p></div></blockquote><div><br>My take on it is that even the broad message isn't how I think of LLVM code review practices - if the code owner/domain expert is at your company, so be it. If not, that's fine too - I see lots of reviews by people at the same company that generally look pretty good & I don't think their the exception. I'd personally leave this part out - maybe some caveat about not doing internal review & then summarily approving externally? But that I think is more the exception than the rule & perhaps not worth including in the general practices document. But if you've seen several instances of this sort of issue that seem worth addressing through this mechanism - yeah, I'd be OK with an encouragement to avoid insular project areas where possible (especially where there's strong overlap) - seek external/long-term contributor input especially on design documents and early/foundational patches, and in general err on the side of seeking more input from code owners than not. If you ask too often for trivial things, that's fine - they should hopefully get to the point where they encourage you to contribute directly/stop asking for their review/approval. But especially when asking code owners/frequent reviewers/contributors for review, be extra sure to make the patches small and clear, to have design discussion ahead of time to avoid designing in a large unwieldy code review, etc. <br><br>- Dave<br> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>
<p>Philip<br>
</p>
<div>On 12/2/19 7:55 AM, David Blaikie
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Yeah, +1 that people from the same organization are
sometimes the only ones working on a certain feature/area.
(certainly I'd expect some discussion about the feature in
general to be discussed outside that group if it's in any way
contentious - but some stuff's clear enough (I think I
implemented debug_types years ago, likely with only Eric's
approval, both of us being at Google (probably many DWARF
features were added/done this way, to be honest - maybe some
could've done witha bit of broader discussion, but I don't
think either of us were "rubber stamping" the other's work (if
anything I'm harder on my "friends" to be honest... :/ )))</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Wed, Nov 27, 2019 at 10:27
PM Mehdi AMINI via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div dir="ltr">
<div><br>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Sat, Nov 16, 2019
at 5:56 PM Mehdi AMINI <<a href="mailto:joker.eph@gmail.com" target="_blank">joker.eph@gmail.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">+1 in general, and Philip has good
suggestions as well!<br>
<div><br>
</div>
<div>-- </div>
<div>Mehdi</div>
<div><br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Sat, Nov 16,
2019 at 8:37 AM Philip Reames via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">+ 1 in general,
a couple of suggestions<br>
<br>
On 11/14/19 7:46 PM, Finkel, Hal J. via llvm-dev
wrote:<br>
> Hi, everyone,<br>
><br>
> I've been fielding an increasing number of
questions about how our <br>
> code-review process in LLVM works from people
who are new to our <br>
> community, and it's been pointed out to me
that our documentation on <br>
> code reviews is both out of date and not as
helpful as it could be to <br>
> new developers.<br>
><br>
> <a href="http://llvm.org/docs/DeveloperPolicy.html#code-reviews" rel="noreferrer" target="_blank">http://llvm.org/docs/DeveloperPolicy.html#code-reviews</a><br>
><br>
> I would like to compose a patch to update
this, but before I do that, I <br>
> want to highlight some of my thoughts to get
feedback. My intent is to <br>
> capture our community best practices in
writing so that people new to <br>
> our community understand our processes and
expectations. Here are some <br>
> things that I would like to capture:<br>
><br>
> 1. You do not need to be an expert in some
area of the compiler to <br>
> review patches; it's fine to ask questions
about what some piece of code <br>
> is doing. If it's not clear to you what is
going on, you're unlikely to <br>
> be the only one. Extra comments and/or test
cases can often help (and <br>
> asking for comments in the test cases is fine
as well).<br>
Authors are encouraged to interpret questions as
reasons to reexamine<br>
the readability of the code in question.
Structural changes, or further<br>
comments may be appropriate.<br>
><br>
> 2. If you review a patch, but don't intend
for the review process to <br>
> block on your approval, please state that
explicitly. Out of courtesy, <br>
> we generally wait on committing a patch until
all reviewers are <br>
> satisfied, and if you don't intend to look at
the patch again in a <br>
> timely fashion, please communicate that fact
in the review.<br>
><br>
> 3. All comments by reviewers should be
addressed by the patch author. <br>
> It is generally expected that suggested
changes will be incorporated <br>
> into the next revision of the patch unless
the author and/or other <br>
> reviewers can articulate a good reason to do
otherwise (and then the <br>
> reviewers must agree). If you suggest changes
in a code review, but <br>
> don't wish the suggestion to be interpreted
this strongly, please state <br>
> so explicitly.<br>
><br>
> 4. Reviewers may request certain aspects of
a patch to be broken out <br>
> into separate patches for independent review,
and also, reviewers may <br>
> accept a patch conditioned on the author
providing a follow-up patch <br>
> addressing some particular issue or concern
(although no committed patch <br>
> should leave the project in a broken state).
Reviewers can also accept a <br>
> patch conditioned on the author applying some
set of minor updates prior <br>
> to committing, and when applicable, it is
polite for reviewers to do so.<br>
><br>
> 5. Aim to limit the number of iterations in
the review process. For <br>
> example, when suggesting a change, if you
want the author to make a <br>
> similar set of changes at other places in the
code, please explain the <br>
> requested set of changes so that the author
can make all of the changes <br>
> at once. If a patch will require multiple
steps prior to approval (e.g., <br>
> splitting, refactoring, posting data from
specific performance tests), <br>
> please explain as many of these up front as
possible. This allows the <br>
> patch author to make the most-efficient use
of his or her time.<br>
If the path forward is not clear - because the
patch is too large to<br>
meaningful review, or direction needs to be
settled - it is fine to<br>
suggest a clear next step (e.g. landing a
refactoring) followed by a<br>
re-review. Please state explicitly if the path
forward is unclear to<br>
prevent confusions on the part of the author. <br>
><br>
> 6. Some changes are too large for just a
code review. Changes that <br>
> should change the Language Reference (e.g.,
adding new <br>
> target-independent intrinsics), adding
language extensions in Clang, and <br>
> so on, require an RFC on *-dev first. For
changes that promise <br>
> significant impact on users and/or downstream
code bases, reviewers can <br>
> request an RFC (Request for Comment)
achieving consensus before <br>
> proceeding with code review. That having been
said, posting initial <br>
> patches can help with discussions on an RFC.<br>
><br>
> Lastly, the current text reads, "Code reviews
are conducted by email on <br>
> the relevant project’s commit mailing list,
or alternatively on the <br>
> project’s development list or bug tracker.",
and then only later <br>
> mentions Phabricator. I'd like to move
Phabricator to be mentioned on <br>
> this line before the other methods.<br>
><br>
> Please let me know what you think.<br>
><br>
> Thanks again,<br>
><br>
> Hal<br>
<br>
A couple of additional things:<br>
<br>
Only a single LGTM is required. Reviewers are
expected to only LGTM<br>
patches they're confident in their knowledge of.
Reviewers may review<br>
and provide suggestions, but explicitly defer LGTM
to someone else. <br>
This is encouraged and a good way for new
contributors to learn the code. <br>
<br>
There is a cultural expectation that at least one
reviewer is from a<br>
different organization than the author of the
patch. </blockquote>
</div>
</blockquote>
<div><br>
</div>
<div>Actually, while I'm OK with the other suggestions,
I didn't pay attention to this one originally.</div>
<div>I'm very concerned about this: this looks like an
assumption of bad faith or malice in the review
process, and I find this unhealthy if it were part of
the "cultural expectation". Moreover there are many
areas of the compiler where there aren't many people
available to review changes.</div>
<div><br>
</div>
<div>I personally never really paid attention to who is
the author/reviewer of a patch from an organizational
point of view, I haven't perceived this culture of
looking into affiliation so far. I never got the
impression that reviewer were more difficult with me
than they would be with others.</div>
<div>There have been many patches that I reviewed that
originated from other people from the same company as
mine (back when I was at Apple mostly). The notion of
"organization" is blurry: frequently this involved
people from different teams inside the same company,
are they part of "the same organization"? Some of
these people I have never even ever met or never heard
of them before reviewing a patch (sometimes I don't
even realize since there is a Phabricator pseudo and
not everyone is using their business email here).</div>
<div><br>
</div>
<div>-- </div>
<div>Mehdi</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> If that's not<br>
possible, care should be taken to ensure overall
direction has been<br>
widely accepted. <br>
<br>
Post commit review is encouraged via either
phabricator or email. There<br>
is a strong expectation that authors respond
promptly to post commit<br>
feedback and address it. Failure to do so is
cause for the patch to be<br>
reverted. If substantial problems are identified,
it is expected that<br>
the patch is reverted, fixed offline, and then
recommitted (possibly<br>
after further review.)<br>
<br>
<br>
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</blockquote>
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