GHC Weekly News - 2015/04/14
thoughtpolice - 2015-04-14
Hi *,
It’s been a few weeks since the last news bulletin - your editor
apologizes about that. It’s actually been a relatively slow few weeks
here too, and busy-ness outside of GHC has attracted some of my
attention. Despite that, GHC 7.10.1 was released, a new HP alpha is
out, and things are moving along smoothly. Now that the release is
done, things are quitely moving along in HEAD
- with people
committing code with reckless abandon, of course.
This week, GHC HQ met up, but it’s been very light since the 7.10.1 release. Currently there isn’t anything pushing us to do a 7.10.2 release at least for a few more weeks it looks like - but see below.
We puzzled a bit about the release status of 7.10.2, and thought: it’s only holding up people who are depending on it. So, who’s depending on it, and what do they need fixed? See below for more.
We also talked a bit about performance - it seems the compiler has been getting much slower over time since the 7.8.x release series, and it’s time to reign it in. Austin will be spending his week investigating a bit of this, and the causes.
7.10.2 Status
So, you may be wondering when the 7.10.2 release is. The trick is it happens when you tell us it should happen!
So far, taking a look at milestone:7.10.2, we’ve fixed about half the bugs we currently have marked down to fix. But we’re probably going to punt some of those - and we’re not sure all the ones that are there should be.
So this is a call: If you need something to be fixed during 7.10.2, please file a ticket, set the milestone, and alert us. The sooner the better, because it’ll inform us as to when we should release. Emailing ghc-devs@haskell.org
is also a sure-fire way to get our attention.
And remember: you can always find out the latest about the next release at the Status page (in this case, for 7.10.2) - https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-7.10.2
Call for help: DocBook to AsciiDoc
The GHC team needs some help. A few months ago, we put out a poll to convert our DocBook-based manual to AsciiDoc.
The poll had a mostly lukewarm reception, with the idea that it will A) make life easier for people who frequently modify the users guide, and B) make life easier for people who add things irregularly, as a lower barrier to entry.
It looks like we still want to do this - but alas, many of us don’t have time!
So, we’re asking the public: Is anyone willing to step up and help here? For example, it may be possible to get a long ways with just pandoc
, but we need someone to finish it - and in return, we’ll help along the way!
List chatter
Austin Seipp announced GHC 7.10.1. https://mail.haskell.org/pipermail/ghc-devs/2015-March/008700.html
Mark Lentczner announced an alpha Haskell Platform release. https://mail.haskell.org/pipermail/ghc-devs/2015-March/008724.html
David Macek announced MSYS2 packages for GHC on Windows, and also asked for some help with continuous windows building - Windows hackers should help out! https://mail.haskell.org/pipermail/ghc-devs/2015-March/008735.html
Jan Stolarek reports about increased memory usage with GHC 7.10.1. https://mail.haskell.org/pipermail/ghc-devs/2015-April/008751.html
Thomas Miedema chimed into a thread started by Karel Gardas about better parallelizing the GHC build - and hopefully we can get something good out of it. https://mail.haskell.org/pipermail/ghc-devs/2015-April/008749.html
Austin Seipp made a call for help on working on and improving the GHC homepage, and luckily Sergey Bushnyak answered the call and has helped out! https://mail.haskell.org/pipermail/ghc-devs/2015-April/008762.html
Ozgun Ataman kicked off a thread about slower compilation times, with some nasty numbers. It’s becoming more clear compiler performance should be a priority for 7.12, and we’ve let some things slip away from us: https://mail.haskell.org/pipermail/ghc-devs/2015-April/008766.html
A GHC user, Dave, asked the list about some questions with Cross Compilation, as he’s attempting to get GHC to work natively inside the Open Embedded build environment. Unfortunately, things haven’t been going well so far, and any input from enterprising hackers is appreciated: https://mail.haskell.org/pipermail/ghc-devs/2015-April/008774.html
Dan Aloni has started a discussion about improving GHC’s error messages, spurred by a popular blog post he wrote and posted on Reddit about some Happy/GHC improvements he’s made. This is a difficult area (error messages in general are hard) to work on, so thanks to Dan for helping! https://mail.haskell.org/pipermail/ghc-devs/2015-April/008778.html
Simon Peyton Jones started a discussion about
GeneralizedNewtypeDeriving
and Safe Haskell, in particular, whatever the current status, our documentation doesn’t accurately reflect it! Perhaps someone could help out writing the documentation based on the current status quo? https://mail.haskell.org/pipermail/ghc-devs/2015-April/008783.htmlTamar Christina started a thread about replacing
ghc-split
, an old Perl script inside GHC, but he wanted to know: what do we do about a regex replacement? Mikhail Glushenkov spoke up about a similar decision the LLVM developers used: to use the OpenBSD regex implementation. https://mail.haskell.org/pipermail/ghc-devs/2015-April/008785.htmlAlan Zimmerman has posted several questions and threads about the parser and the status of API annotations, which he’s been furiously working on now that GHC 7.10 is being used on Hackage. Interested onlookers could learn a thing or two! https://mail.haskell.org/pipermail/ghc-devs/2015-April/008782.html & https://mail.haskell.org/pipermail/ghc-devs/2015-April/008787.html & https://mail.haskell.org/pipermail/ghc-devs/2015-April/008794.html
Gabor Greif has a question about some seemingly strange behavior regarding the interaction between poly-kinded
data
types and overlapping instances. Richard sez: this behavior is expected. https://mail.haskell.org/pipermail/ghc-devs/2015-April/008804.html
Noteworthy commits
Commit de1160be047790afde4ec76de0a81ba3be0c73fa - refactor the story around switch cases (with a code-size improvement)
Commit 995e8c1c8692b60c907c7d2ccea179d52ca8e69e - drop old
integer-gmp-0.5
source code.Commit 59f7a7b6091e9c0564f3f370d09398d8c9cd8ad5 - Restore unwind information generation (fixes DWARF generation)
Commit 9f0f99fd41ff82cc223d3b682703e508efb564d2 - Fix an old bug in the demand analyzer (with some nice compiler performance boosts).
Commit a7524eaed33324e2155c47d4a705bef1d70a2b5b - Support for multiple signature files in scope (Backpack).
Closed tickets
#10222, #10219, #8057, #10226, #10220, #9723, #10230, #10208, #10236, #10213, #10231, #10240, #10243, #10237, #10224, #8811, #10197, #10252, #9958, #10253, #8248, #10207, #10214, #9964, #10194, #10251, #10188, #10257, #10247, #10247, #9160, #10259, #9965, #10265, #10264, #10286, #10282, #10290, #10291, #10300, #9929, #8276, #10218, #10148, #10232, #10274, #10275, #10195, and #10233.