November 2014 - ghc-devs

optllvm broken on master?
by Dr. ERDI Gergo 21 Nov '14

21 Nov '14

Hi, Tests fail on master when run the optllvm way, e.g.: /usr/bin/opt: /tmp/ghc16190_0/ghc16190_2.ll:611:25: error: expected 'global' or 'constant' @newCAF$alias = private alias i8* @newCAF I think it's the change in d87fa34: index 7307725..cdc407c 100644 --- a/compiler/llvmGen/Llvm/PpLlvm.hs +++ b/compiler/llvmGen/Llvm/PpLlvm.hs @@ -80,7 +80,7 @@ ppLlvmGlobal (LMGlobal var@(LMGlobalVar _ _ link x a c) dat) = const_link = case c of Global -> ppr link <+> text "global" Constant -> ppr link <+> text "constant" - Alias -> text "alias" <+> ppr link + Alias -> ppr link <+> text "alias" in ppAssignment var $ const_link <+> rhs <> sect <> align $+$ newLine -- .--= ULLA! =-----------------. \ http://gergo.erdi.hu \ `---= gergo(a)erdi.hu =-------' If it ain't broke, I can fix it.

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HEADS UP: Interface file format change
by Jan Stolarek 20 Nov '14

20 Nov '14

I just pushed a large commit that changes format of interface files. This means doing a full rebuild once you pull it. Janek

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Phab + submodules
by Jan Stolarek 20 Nov '14

20 Nov '14

I made changes to a submodule but `arc diff` did not pick these up. This means that: a) Harbormaster build fails b) revision cannot be landed using `arc land` Is there a way around these? Janek

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Daily documentation build?
by Joachim Breitner 20 Nov '14

20 Nov '14

Hi, a while ago someone said that we have daily builds of the documentation. But... * it is slightly tricky to find it. Starting from https://ghc.haskell.org/trac/ghc/wiki/ I had to follow the “Guilde is also availble” link about daily builds, and then the link from the summary. Ok if one knows where to look, but hard to discover by itself. * it seems that they are not built any more. http://haskell.inf.elte.hu/docs/ lists Aug-18 as the latest. Having that would have made it easier for me to review the state of the docs on flags that Jan is writing about. Greetings, Joachim -- Joachim “nomeata” Breitner mail(a)joachim-breitner.de • http://www.joachim-breitner.de/ Jabber: nomeata(a)joachim-breitner.de • GPG-Key: 0xF0FBF51F Debian Developer: nomeata(a)debian.org

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GHC Weekly News - 2014/11/18
by Mikolaj Konarski 19 Nov '14

19 Nov '14

Austin got caught in a rescue operation (which seems to have succeeded, given that haskell.org is up again), so I'm posting his writeup for the GHC Weekly News, straight from the blog post: https://ghc.haskell.org/trac/ghc/blog/weekly20141118 ----------- Hello *, Once more we have the GHC Weekly news! This one is a bit late due to Austin being in limbo unexpectedly for a few days last week. (The next one will of course come again on Friday to keep things straight.) With that out of the way, let's see what exactly is going on: The STABLE freeze is happening at the end of this week! That means if you have something you want to get in, try to get people aware of it! Austin (yours truly) has a backed up review queue it would seem, but hopes to clear a bunch of it out before then. Simon and Gergo started a whole bunch of discussion about type signatures for pattern synonyms. There is a surprising amount of content to talk about here for something that might seem simple: https://www.haskell.org/pipermail/ghc-devs/2014-November/007066.html Herbert Valerio Riedel has finally landed integer-gmp2, AKA Phab:D86, which implements a complete overhaul of the integer-gmp library. This library will be switched on by default in GHC 7.10.1, which means the integer-gmp library version will have a super-major bump (version 1.0.0.0). This is the beginning of a longer-term vision for more flexible Integer support in GHC, as described by Herbert on the design page: https://ghc.haskell.org/trac/ghc/wiki/Design/IntegerGmp2 This implementation also fixes a long standing pain point where GHC would hook GMP allocations to exist on the GHC heap. Now GMP is just called to like any FFI library. Jan Stolarek made a heads up to help out GHC newcomers: if you see a ticket that should be easy, please tag it with the newcomer keyword! This will let us have a live search of bugs that new developers can take over. (Incidentally, Joachim mentions this is the same thing Debian is doing in their bug tracker): https://www.haskell.org/pipermail/ghc-devs/2014-November/007313.html Merijn Verstraaten has put forward a proposal for more flexible literate style Haskell file extensions. There doesn't seem to be any major opposition, just some questions about the actual specification and some other ramifications: https://www.haskell.org/pipermail/ghc-devs/2014-November/007319.html Facundo Domínguez posed a question about CAFs in the GC, which Jost Berthold was fairly quick to reply to: https://www.haskell.org/pipermail/ghc-devs/2014-November/007353.html Adam Gundry, Eric Seidel, and Iavor Diatchki have grouped together to get a new, unexpected feature into 7.10: type checking plugins. Now, GHC will be able to load a regular Haskell package as a plugin during the compilation process. Iavor has a work-in-progress plugin that solves constraints for type-level natural numbers using a SMT solver. The code review from everyone was published in Phab:D489. Austin opened up a discussion about the future of the Haskell98 and Haskell2010 packages, and the unfortunate conclusion is it looks like we're going to drop them for 7.10. Austin has some rationale, and there was some followup in the mailing list thread too: https://www.haskell.org/pipermail/ghc-devs/2014-November/007357.html Closed tickets this week include: #9785, #9053, #9513, #9073, #9077, #9683, #9662, #9646, #9787, #8672, #9791, #9781, #9621, #9594, #9066, #9527, #8100, #9064, #9204, #9788, #9794, #9608, #9442, #9428, #9763, #9664, #8750, #9796, #9341, #9330, #9323, #9322, #9749, #7381, #8701, #9286, #9802, #9800, #9302, #9174, #9171, #9141, #9100, #9134, #8798, #8756, #8716, #8688, #8680, #8664, #8647, #9804, #8620, #9801, #8559, #8559, #8545, #8528, #8544, #8558 -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/

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Pattern synonym type signatures
by Dr. ERDI Gergo 19 Nov '14

19 Nov '14

Hi, I have finished the implementation of type signature support for pattern synonyms. In the end, I went with the following syntax: pattern P :: (Prov b) => (Req a) => a -> b -> Int -> T a which declares a pattern synonym called `P`, with argument types `a`, `b`, and `Int`, and result type `T a`, with provided context `(Prov b)` and required context `(Req a)`. This has the advantage that it doesn't require new syntax at all (no funky `;` business in the contexts), and avoids the 'pattern type' monstrosity that Edward Kmett rightfully hated. I plan to finish up the branch tomorrow (by updating the documentation), and then merging it into master. That is still within the feature freeze window, right? Also, if anything comes up tomorrow and I cannot finish it after all, it'd be a real bummer not to get this into GHC 7.10. So the reason I'm sending this email now is to just make sure that it will make its way into 7.10. Thanks, Gergo

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RE: [commit: ghc] wip/T8584: Add support for pattern synonym type signatures. Syntax is of the form (34acc90)
by Simon Peyton Jones 19 Nov '14

19 Nov '14

Gergo I've lost track. Is this ready to commit? Simon | -----Original Message----- | From: ghc-commits [mailto:ghc-commits-bounces@haskell.org] On Behalf Of | git(a)git.haskell.org | Sent: 19 November 2014 11:17 | To: ghc-commits(a)haskell.org | Subject: [commit: ghc] wip/T8584: Add support for pattern synonym type | signatures. Syntax is of the form (34acc90) | | Repository : ssh://git@git.haskell.org/ghc | | On branch : wip/T8584 | Link : | http://ghc.haskell.org/trac/ghc/changeset/34acc90ccef765ca6a55b69437a7218 | 28a7fba6c/ghc | | >--------------------------------------------------------------- | | commit 34acc90ccef765ca6a55b69437a721828a7fba6c | Author: Dr. ERDI Gergo <gergo(a)erdi.hu> | Date: Fri Nov 7 19:29:06 2014 +0800 | | Add support for pattern synonym type signatures. | Syntax is of the form | | pattern P :: (Prov b) => (Req a) => a -> b -> Int -> T a | | which declares a pattern synonym called `P`, with argument types `a`, | `b`, | and `Int`, and result type `T a`, with provided context `(Prov b)` | and required | context `(Req a)`. | | | >--------------------------------------------------------------- | | 34acc90ccef765ca6a55b69437a721828a7fba6c | compiler/hsSyn/HsBinds.lhs | 51 +++--- | compiler/hsSyn/HsTypes.lhs | 16 +- | compiler/iface/IfaceSyn.lhs | 25 ++- | compiler/iface/IfaceType.lhs | 15 +- | compiler/parser/Parser.y | 51 ++++-- | compiler/parser/RdrHsSyn.hs | 27 +--- | compiler/rename/RnBinds.lhs | 42 ++--- | compiler/typecheck/TcBinds.lhs | 50 +++++- | compiler/typecheck/TcClassDcl.lhs | 4 +- | compiler/typecheck/TcPat.lhs | 23 ++- | compiler/typecheck/TcPatSyn.lhs | 195 | +++++++++++++++++------ | compiler/typecheck/TcPatSyn.lhs-boot | 9 +- | testsuite/tests/ghci/scripts/T8776.stdout | 2 +- | testsuite/tests/patsyn/should_compile/T8584-1.hs | 8 + | testsuite/tests/patsyn/should_compile/T8968-1.hs | 8 + | testsuite/tests/patsyn/should_compile/all.T | 2 + | 16 files changed, 351 insertions(+), 177 deletions(-) | | Diff suppressed because of size. To see it, use: | | git diff-tree --root --patch-with-stat --no-color --find-copies- | harder --ignore-space-at-eol --cc | 34acc90ccef765ca6a55b69437a721828a7fba6c | _______________________________________________ | ghc-commits mailing list | ghc-commits(a)haskell.org | http://www.haskell.org/mailman/listinfo/ghc-commits

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NOTE: the primary webserver is going down for immediate maintenance.
by Austin Seipp 19 Nov '14

19 Nov '14

Hello *, The primary haskell.org domain, www.haskell.org, is hosted on a system which seems to have lost one of its RAID disks completely. We were planning on moving this machine in the next few weeks to new infrastructure, but we are now expediting this plan and will be doing it ASAP. As we move this server, both the webserver and the mailing system will be going down. Please don't be alarmed if your emails aren't delivered or things go quiet. Many services will continue to work, but we do realize this will be upsetting for many. You can follow the progress on #haskell-infrastructure on Freenode, and see updates on https://status.haskell.org If you need to download something like a GHC binary or Haskell Platform package, you can use https://downloads.haskell.org in the mean time, which is a new service we were hoping to announce more officially soon, but is already working today. Unfortunately we cannot give an expected time of completion for the move, but we'll try to keep people well informed through IRC or something like Reddit. Thanks -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/

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RE: The future of the Haskell98 and Haskell2010 packages
by Austin Seipp 18 Nov '14

18 Nov '14

Hello all, A few weeks ago, I opened up a discussion about a particular GHC bug, #9590. This bug is concerned with the future of the Haskell98 and Haskell2010 packages, which try to embody their two respective Haskell standards. They do this by shipping the 'exact library specification' that the standards have. In our discussion this past week between me, SimonM, SPJ, Herbert and Mikolaj, we came to this discussion again since the 7.10 STABLE freeze is almost here, and it seems to have puttered out. In this discussion, we came to the conclusion we think these packages should be removed from GHC for the 7.10 release. To be clear, this was not a 100% unanimous decision or formal vote; SimonM and I supported removal, while everyone else seemed to be rather undecided or ambivalent. Most of the proposed alternative solutions seemed somewhat one-off. Furthermore, we didn't find a solution that wouldn't either A) require some amount of GHC modifications (possibly indefinitely into the future) to support these packages, or B) changing the definitions in these packages to deviate from the standard. Instead, we proposed that we instead overhaul part of the GHC users manual, and clearly outline our deviations from the Haskell 2010 standard library. To be clear: GHC can still typecheck, compile, and efficiently execute Haskell 2010 code. It is merely the distribution of compatible packages that has put us in something of a bind. Furthermore, we aren't aware of any other compilers/platforms like ours that try to maintain such stringent separation of these packages, and furthermore, both of the haskell{98,2010} packages have a fairly small number of reverse dependencies. I'd like to hear what people think about this. It seems likely I will move forward on this by the end of the week unless we face very strong opposition to this idea, or someone is willing to fix #9590 somehow for us. -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/

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Windows breakage agein
by Simon Peyton Jones 18 Nov '14

18 Nov '14

On Windows (sigh). Seems to be due to Simon Marlow's 2a6f193b rts\Schedule.c: In function 'suspendThread': rts\Schedule.c:2239:3: error: expected ';' before 'EnterCriticalSection' rts/ghc.mk:236: recipe for target 'rts/dist/build/Schedule.thr_o' failed

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