Stream: t-compiler/wg-nll

Topic: weekly meeting July 3


nikomatsakis (Jul 03 2018 at 19:37, on Zulip):

@everyone hello all! meeting? Sorry I'm running a few minutes late.

nikomatsakis (Jul 03 2018 at 19:37, on Zulip):

let's all update the triage document

nikomatsakis (Jul 03 2018 at 19:44, on Zulip):

@lqd is it still true that html5ever runs out of memory? we should file an issue on that

lqd (Jul 03 2018 at 19:44, on Zulip):

yes it is, I don't think anyone worked on this yet

lqd (Jul 03 2018 at 19:46, on Zulip):

maybe @simulacrum has already opened an issue ?

simulacrum (Jul 03 2018 at 19:47, on Zulip):

There was something, let me look

simulacrum (Jul 03 2018 at 19:47, on Zulip):

there's https://github.com/rust-lang/rust/issues/51372 but that's unrelated

simulacrum (Jul 03 2018 at 19:47, on Zulip):

(also might be outdated)

lqd (Jul 03 2018 at 19:48, on Zulip):

true yeah, and I think @Matthew Jasper was looking at that

simulacrum (Jul 03 2018 at 19:48, on Zulip):

nothing else to my knowledge

simulacrum (Jul 03 2018 at 19:48, on Zulip):

(that I've filed)

nikomatsakis (Jul 03 2018 at 19:49, on Zulip):

ok, can someone file one?

nikomatsakis (Jul 03 2018 at 19:49, on Zulip):

anyway, you can see in the document, but first off: we did great last week

nikomatsakis (Jul 03 2018 at 19:50, on Zulip):

steady progress on performance

nikomatsakis (Jul 03 2018 at 19:50, on Zulip):

looking over the issues it seemed like it was time to focus some on diagnostics + ICEs

nikomatsakis (Jul 03 2018 at 19:50, on Zulip):

I triaged all the remaining issues: I put the "minor suggestions" into the Release Candidate box for now

simulacrum (Jul 03 2018 at 19:50, on Zulip):

I'll file something after checking

nikomatsakis (Jul 03 2018 at 19:50, on Zulip):

and focused on major areas of diagnostic fail

nikomatsakis (Jul 03 2018 at 19:51, on Zulip):

there are two: region error reporting and "unused mut", I think -- but @Matthew Jasper already has a PR around the "unused mut" lint errors :tada:

nikomatsakis (Jul 03 2018 at 19:51, on Zulip):

I opened a PR about the region ones that tries to move us closer to the objective, and I hope to (later today) filer various follow-up issues related to that

nikomatsakis (Jul 03 2018 at 19:51, on Zulip):

I think that we will soon have the results from @simulacrum's crater run

nikomatsakis (Jul 03 2018 at 19:52, on Zulip):

which will probably give us new stuff to triage and ICEs galore

nikomatsakis (Jul 03 2018 at 19:52, on Zulip):

so I expect we will have our hands full

nikomatsakis (Jul 03 2018 at 19:52, on Zulip):

oh yeah and some number of years ago in 1776 the US of A threw off the yoke of monarchic oppression

simulacrum (Jul 03 2018 at 19:52, on Zulip):

Crater claims 11 hours :)

nikomatsakis (Jul 03 2018 at 19:52, on Zulip):

but I plan to be working tomorrow anyway

nikomatsakis (Jul 03 2018 at 19:52, on Zulip):

;)

nikomatsakis (Jul 03 2018 at 19:53, on Zulip):

that said, next week I am going to be on my way to Greece

nikomatsakis (Jul 03 2018 at 19:53, on Zulip):

so I probably wont' be around on Tuesday

nikomatsakis (Jul 03 2018 at 19:53, on Zulip):

I'll be there (in Greece) until August, but I will be working from there 4 days a week, so you probably won't notice the difference ;)

nikomatsakis (Jul 03 2018 at 19:53, on Zulip):

hopefully @pnkfelix will be back around next week though

lqd (Jul 03 2018 at 19:54, on Zulip):

(zulip is seriously lacking in the flags and feta cheese emoji department)

nikomatsakis (Jul 03 2018 at 19:54, on Zulip):

I blame the Unicode committee

nikomatsakis (Jul 03 2018 at 19:54, on Zulip):

or something

davidtwco (Jul 03 2018 at 19:54, on Zulip):

What timezone is that?

nikomatsakis (Jul 03 2018 at 19:54, on Zulip):

PS I love these sorts of headlines: http://www.latimes.com/business/technology/la-fi-tn-emoji-q-and-a-20160125-htmlstory.html

lqd (Jul 03 2018 at 19:54, on Zulip):

gmt+2 I think

nikomatsakis (Jul 03 2018 at 19:54, on Zulip):

"Meet the shadowy overlords who approve emojis "

nikomatsakis (Jul 03 2018 at 19:54, on Zulip):

yes, it is GMT+2

davidtwco (Jul 03 2018 at 19:55, on Zulip):

Unfortunately, our website is currently unavailable in most European countries. We are engaged on the issue and committed to looking at options that support our full range of digital offerings to the EU market. We continue to identify technical compliance solutions that will provide all readers with our award-winning journalism.

nikomatsakis (Jul 03 2018 at 19:55, on Zulip):

so you may notice that difference =)

nikomatsakis (Jul 03 2018 at 19:55, on Zulip):

that said, I tend to work relatively late hours

nikomatsakis (Jul 03 2018 at 19:55, on Zulip):

when I'm in Greece

nikomatsakis (Jul 03 2018 at 19:55, on Zulip):

so as to overlap better with US, and to permit a trip to the beach in the AM

nikomatsakis (Jul 03 2018 at 19:56, on Zulip):

anyway, enough about that. I've been slow but I'll prepare a more detailed schedule in any case (just for my own sanity)

nikomatsakis (Jul 03 2018 at 19:56, on Zulip):

re: the ICEs and things...

nikomatsakis (Jul 03 2018 at 19:56, on Zulip):

I tried to put at least some mentoring instructions on most of the things I nominated, I think?

simulacrum (Jul 03 2018 at 19:57, on Zulip):

https://github.com/rust-lang/rust/issues/52028 for html5ever filed

nikomatsakis (Jul 03 2018 at 19:57, on Zulip):

with varying degrees of comprehensibility

nikomatsakis (Jul 03 2018 at 19:58, on Zulip):

I plan to write an internals post and tweet out the link, encouraging people to sign up if they have time -- but please if you want to grab an issue don't hold back :)

nikomatsakis (Jul 03 2018 at 19:58, on Zulip):

I would particularly like to see somebody start in on https://github.com/rust-lang/rust/issues/46908

Santiago Pastorino (Jul 03 2018 at 19:58, on Zulip):

@nikomatsakis what can I work on?

nikomatsakis (Jul 03 2018 at 19:59, on Zulip):

ah, perfect timing ;)

Santiago Pastorino (Jul 03 2018 at 19:59, on Zulip):

should I tackle this https://github.com/rust-lang/rust/issues/46908 ?

nikomatsakis (Jul 03 2018 at 19:59, on Zulip):

one of the issues — https://github.com/rust-lang/rust/issues/50467 — is mostly about reducing to a standalone test case. I thought @Jake Goulding you might enjoy that ;)

lqd (Jul 03 2018 at 19:59, on Zulip):

(I'm building a fix for 52027 locally)

nikomatsakis (Jul 03 2018 at 19:59, on Zulip):

@Santiago Pastorino please do

Santiago Pastorino (Jul 03 2018 at 19:59, on Zulip):

:+1:

nikomatsakis (Jul 03 2018 at 19:59, on Zulip):

take a look at the instructions and see if they make sense (at least the high-level idea)

davidtwco (Jul 03 2018 at 20:00, on Zulip):

Is there more work you'd like me doing related to the region errors - you mentioned your PR today would open up a handful of opportunities; or would you prefer I just take on whatever?

nikomatsakis (Jul 03 2018 at 20:01, on Zulip):

there is definitely more work but I haven't opened up the issues yet

nikomatsakis (Jul 03 2018 at 20:01, on Zulip):

probably makes sense to do something else to start

nikomatsakis (Jul 03 2018 at 20:01, on Zulip):

as I guess it'd be easiset if that PR were to land first

nikomatsakis (Jul 03 2018 at 20:01, on Zulip):

but we can discuss in the meantime the follow-up plans?

nikomatsakis (Jul 03 2018 at 20:02, on Zulip):

also don't feel you have to focus on the E-mentor ones ;) if something else catches your fancy

nikomatsakis (Jul 03 2018 at 20:02, on Zulip):

@David Wood I forget, did you work on the 2-phase activations stuff? Oh, that was @Reed Koser I think

nikomatsakis (Jul 03 2018 at 20:03, on Zulip):

anyway this might be a small-ish but fun refactoring in that area

nikomatsakis (Jul 03 2018 at 20:03, on Zulip):

https://github.com/rust-lang/rust/issues/51345

davidtwco (Jul 03 2018 at 20:03, on Zulip):

I don't think I did.

nikomatsakis (Jul 03 2018 at 20:03, on Zulip):

https://github.com/rust-lang/rust/issues/51351 is a bit hairier but at least tangentially related to regions

nikomatsakis (Jul 03 2018 at 20:03, on Zulip):

my mentoring instructions there were maybe a bit "notes to myself" ;)

davidtwco (Jul 03 2018 at 20:04, on Zulip):

I'll have a look at them and see what I come up with.

nikomatsakis (Jul 03 2018 at 20:04, on Zulip):

sounds good, well, that's all I got to say :)

nikomatsakis (Jul 03 2018 at 20:05, on Zulip):

not sure if anybody else has any notes or questions

lqd (Jul 03 2018 at 20:05, on Zulip):

is there more work related to liveness maybe ? (maybe the 40-50% left to grab on tuple-stress). I guess we'll also have the crater triage to handle soon

nikomatsakis (Jul 03 2018 at 20:05, on Zulip):

ah good point

nikomatsakis (Jul 03 2018 at 20:05, on Zulip):

so, I think there will be follow-up work on tuple-stress

nikomatsakis (Jul 03 2018 at 20:06, on Zulip):

one thing I was thinking about filing as an issue was experimenting with using sparse bitsets

lqd (Jul 03 2018 at 20:06, on Zulip):

or html5ever, which is basically a simili-ICE

nikomatsakis (Jul 03 2018 at 20:06, on Zulip):

instead of the dense bitsets we are using now

nikomatsakis (Jul 03 2018 at 20:06, on Zulip):

this would be a fairly minor tweak to the code

nikomatsakis (Jul 03 2018 at 20:06, on Zulip):

though it would invalidate @Santiago Pastorino's https://github.com/rust-lang/rust/pull/52007 PR (but if it pays off for tuple-stress, that seems ok)

nikomatsakis (Jul 03 2018 at 20:06, on Zulip):

the advantage would be that iteration is O(number of live things)

nikomatsakis (Jul 03 2018 at 20:07, on Zulip):

well plus if there are way more locals than live locals

nikomatsakis (Jul 03 2018 at 20:07, on Zulip):

then of course it's a win

nikomatsakis (Jul 03 2018 at 20:07, on Zulip):

a more radical thing would be to try and use :frog: somehow :)

nikomatsakis (Jul 03 2018 at 20:07, on Zulip):

I'd prob try the sparse bitsets first

nikomatsakis (Jul 03 2018 at 20:08, on Zulip):

just because it's easy and not disruptive :)

lqd (Jul 03 2018 at 20:10, on Zulip):

we mentioned before doing liveness in Polonius issues I think (at least, parts of it)

lqd (Jul 03 2018 at 20:11, on Zulip):

it was mostly brainstorming of course :)

nikomatsakis (Jul 03 2018 at 20:13, on Zulip):

yeah I mean eventually I'd prob like to move more and more of the dataflow-like analyses into polonius

lqd (Jul 03 2018 at 20:14, on Zulip):

it could also be an interesting issue (sparse bitsets) for other contributors eg in internals thread, twitter etc

lqd (Jul 03 2018 at 20:17, on Zulip):

(this is what I remembered from the Polonius issues linked to liveness, "emit def/use facts from rustc" + :frog: https://github.com/rust-lang-nursery/polonius/pull/45#discussion_r190516457)

lqd (Jul 03 2018 at 20:20, on Zulip):

if it's the end of the meeting, good evening / afternoon everybody :wave:

Last update: Nov 21 2019 at 13:05UTC