November 2014 - ghc-devs

how to write a ghc primop that acts on an unevaluated argument?
by Carter Schonwald 23 Nov '14

23 Nov '14

Hey All, as part of trying to get some fixups for how prefetch works into 7.10, i'm adding a "prefetchValue" primop that prefetchs the memory location of a lifted heap value namely several operations of the following form primop PrefetchValueOp1 "prefetchValue1#" GenPrimOp a -> State# s -> State# s with strictness = { \ _arity -> mkClosedStrictSig [botDmd, topDmd] topRes } I'd like some feedback on the strictness information design by someone who's familiar with how that piece of GHC. the idea being that prefetchValue is lazy in its polymorphic argument (it doesn't force it, it just does a prefetch on the heap location, which may or may not be evaluated). https://phabricator.haskell.org/D350 is the code in question. And i *believe* i'm testing for being lazy in that argument correctly. thoughts? many thanks! -Carter

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OS X breakage: make -j and 4 unexpected failures
by Merijn Verstraaten 23 Nov '14

23 Nov '14

Carter was having difficulty compiling on OS X 10.9 with Xcode 6.0, so I tried building head and ran into some issues. 1) I used to build using make -j, but this fails with cryptic errors now. ./validate (which uses -j) and "make" seem to work. The specific error (appearing somewhere during stage 2 build) is: Couldn't figure out C compiler information! Warning: Make sure you're using GNU gcc, or clang Furthermore, when trying to run ./validate --fast I run into 4 unexpected failures. If anyone can tell me how I can get the test suite to report the exact difference in output I will send those along. Unexpected results from: TEST="cabal01 T5435_dyn_asm subsections_via_symbols cabal06 T4801" OVERALL SUMMARY for test run started at Sat Nov 22 21:35:31 2014 PST 0:07:30 spent to go through 4230 total tests, which gave rise to 13843 test cases, of which 9956 were skipped 53 had missing libraries 3763 expected passes 66 expected failures 0 caused framework failures 0 unexpected passes 4 unexpected failures 1 unexpected stat failures Unexpected failures: cabal/cabal01 cabal01 [bad exit code] (normal) cabal/cabal06 cabal06 [bad stdout] (normal) llvm/should_run/subsections_via_symbols subsections_via_symbols [bad exit code] (normal) rts T5435_dyn_asm [bad stdout] (normal) Unexpected stat failures: perf/compiler T4801 [stat too good] (normal) Cheers, Merijn

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GHC Weekly News - 2014/11/21
by Austin Seipp 22 Nov '14

22 Nov '14

Hi *, To get things back on track, we have a short post following up the earlier one this week. It's been busy today so I'll keep it short: - The STABLE freeze Austin announced two weeks ago is happening now, although at this point a few things we wanted to ship are just 98% ready. So it may wait until Monday. - HEAD has been very busy the past two days as many things are now trying to merge as closely to the window as possible. Some notes follow. - Gergo Erdi merged the implementation of pattern synonym type signatures: https://www.haskell.org/pipermail/ghc-devs/2014-November/007369.html - HEAD now has support for using the 'deriving' clause for arbitrary classes (see #5462). - HEAD now has a new flag `-fwarn-missing-exported-sigs`, which fixes #2526. See https://phabricator.haskell.org/D482 - HEAD now has 64bit iOS and SMP support for ARM64, thanks to Luke Iannini. See #7942. - HEAD no longer ships `haskell98`, `haskell2010`, `old-locale` or `old-time`, per our decision to drop support for `haskell98` and `haskell2010`. GHC 7.10 compatible releases of `old-locale` and `old-time` have been released on hackage. See https://www.haskell.org/pipermail/ghc-devs/2014-November/007357.html and https://www.haskell.org/pipermail/ghc-devs/2014-November/007383.html - `base` now exports a new module for Natural numbers called `Numeric.Natural` following Herbert Valerio Riedel's recent proposal. - HEAD should finally be compatible with LLVM 3.5, AKA #9142. The patch from Ben Gamari is at https://phabricator.haskell.org/D155 - Your author has been busy and delayed due to some bad travel experiences the past week, so the 7.8.4 RC1 hasn't landed this past week. Hopefully it will be out by the end of this week still. Since the last update was only a few days ago, you'd think we haven't closed a lot of tickets, but we have! Thomas Miedema has been very very persistent about closing tickets and cleaning them up, which is greatly appreciated: #9810, #8324, #8310, #9396, #9626, #9776, #9807, #9698, #7942, #9703, #8584, #8968, #8174, #9812, #9209, #9220, #9151, #9201, #9318, #9109, #9126, #8406, #8102, #8093, #8085, #8068, #8094, #9590, #9368, #2526, #9569, #8149, #9815, #5462, #9647, #8568, #9293, #7484, #1476, #9824, #9628, #7942 -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/

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RE: [commit: ghc] master: Add T7220a.stderr (6265f1c)
by Simon Peyton Jones 21 Nov '14

21 Nov '14

Thanks Joachim. Simon | -----Original Message----- | From: ghc-commits [mailto:ghc-commits-bounces@haskell.org] On Behalf Of | git(a)git.haskell.org | Sent: 21 November 2014 20:56 | To: ghc-commits(a)haskell.org | Subject: [commit: ghc] master: Add T7220a.stderr (6265f1c) | | Repository : ssh://git@git.haskell.org/ghc | | On branch : master | Link : | http://ghc.haskell.org/trac/ghc/changeset/6265f1c3162a192220ec03d888e1c1e | f686b2732/ghc | | >--------------------------------------------------------------- | | commit 6265f1c3162a192220ec03d888e1c1ef686b2732 | Author: Joachim Breitner <mail(a)joachim-breitner.de> | Date: Fri Nov 21 21:55:37 2014 +0100 | | Add T7220a.stderr | | which presumably was just forgotten when creating the testcase in | commit 7b1a856. | | | >--------------------------------------------------------------- | | 6265f1c3162a192220ec03d888e1c1ef686b2732 | testsuite/tests/typecheck/should_compile/T7220a.stderr | 14 | ++++++++++++++ | 1 file changed, 14 insertions(+) | | diff --git a/testsuite/tests/typecheck/should_compile/T7220a.stderr | b/testsuite/tests/typecheck/should_compile/T7220a.stderr | new file mode 100644 | index 0000000..4be503d | --- /dev/null | +++ b/testsuite/tests/typecheck/should_compile/T7220a.stderr | @@ -0,0 +1,14 @@ | + | +T7220a.hs:17:6: | + Could not deduce (C a b) | + from the context (C a0 b, TF b ~ Y) | + bound by the type signature for f :: (C a0 b, TF b ~ Y) => b | + at T7220a.hs:17:6-44 | + Possible fix: | + add (C a b) to the context of | + the type signature for f :: (C a0 b, TF b ~ Y) => b | + In the ambiguity check for the type signature for ‘f’: | + f :: forall a. (forall b. (C a b, TF b ~ Y) => b) -> X | + To defer the ambiguity check to use sites, enable | AllowAmbiguousTypes | + In the type signature for ‘f’: | + f :: (forall b. (C a b, TF b ~ Y) => b) -> X | | _______________________________________________ | ghc-commits mailing list | ghc-commits(a)haskell.org | http://www.haskell.org/mailman/listinfo/ghc-commits

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Re: [commit: ghc] master: Be consistent with placement of Safe Haskell mode at top of file (2a523eb)
by Herbert Valerio Riedel 21 Nov '14

21 Nov '14

Hello David, On 2014-11-21 at 22:03:23 +0100, git-4Dsf34iY/NkouOHNgZ69ag(a)public.gmane.org wrote: [...] > commit 2a523ebf091478aea39deef28073320bed628434 > Author: David Terei <code-A0igW9AEfH2M2ScGVVA7yQ(a)public.gmane.org> > Date: Wed Nov 19 18:29:51 2014 -0800 > > Be consistent with placement of Safe Haskell mode at top of file Why is that necessary? Fwiw, I'm afraid that's gonna be hard to retain; it's more obvious/easier to keep all LANGUAGE pragmas in alphabetic order (I've probably done that a couple of times in `base` deliberately myself) than to introduce such an artificial ordering on the language pragmas. The reason is, you can instruct an editor to select the first paragraph which comprises the block of one-per-line language-pragmas is, and have it sorted it alphabetically. That's just a few keystrokes. But it's rather difficult to teach the editor to use an ordering relation other than the usual alphabetic/lexicographic ordering. Cheers, hvr

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RE: Windows breakage
by Simon Peyton Jones 21 Nov '14

21 Nov '14

Hmm. When I got this libraries\hpc\Trace\Hpc\Mix.hs:3:14: Warning: 'Trace.Hpc.Mix' is marked as Trustworthy but has been inferred as safe! I changed "Trustworthy" to "Safe". But then I got libraries\hpc\Trace\Hpc\Mix.hs:24:1: Data.Time: Can't be safely imported! The module itself isn't safe. This seems unhelpful. After all it's been "inferred as safe". What should I do? Thanks. Simon From: Simon Peyton Jones Sent: 14 November 2014 16:51 To: ghc-devs(a)haskell.org Subject: Windows breakage This breakage didn't use to happen. Might someone fix it? Thanks. For now I'm going through changing a dozen "Trustworthy" to "Safe". Is that right? Simon librariesWin32SystemWin32Console.hsc:2:14: Warning: 'System.Win32.Console' is marked as Trustworthy but has been inferred as safe! <no location info>: Failing due to -Werror. libraries/Win32/ghc.mk:4: recipe for target 'libraries/Win32/dist-install/build/System/Win32/Console.o' failed

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GHC filepath sync
by Neil Mitchell 21 Nov '14

21 Nov '14

Hi, As part of the forthcoming GHC release, I assume the filepath library will be sync'd to the latest version in the GitHub repo? When will that sync happen? Who will do the sync? When is the last time I can make changes that go into GHC 7.10? What should I be doing to help? As this is my first time, any details would be most appreciated. When the library is next sync'd, the filepath library will need to be removed from the GHC test suite. The reason is mostly pragmatic - I have good coverage of a library which is entirely pure list manipulations, and the GHC test infrastructure slowed down improving the tests, while gaining nothing. In particular, GHC has been testing the library for years, but the tests got turned off about 4 years ago, so there were (non-critical) test failures that went unspotted for years. Thanks, Neil

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HEADS UP: haskell{98,2010} and old-{time,locale} deleted
by Austin Seipp 21 Nov '14

21 Nov '14

Hi all, When you update your trees, I'll have pushed D510 and D511, which remove the aforementioned libraries. After updating, you can just delete the repositories since git status will alert you about them now: $ rm -rf libraries/old-time libraries/old-locale libraries/haskell98 libraries/haskell2010 I'll be updating the users manual soon as I mentioned earlier this week. -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/

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T7220a failing
by Joachim Breitner 21 Nov '14

21 Nov '14

Hi, I observe --- /dev/null 2014-11-21 13:30:25.126538446 +0000 +++ ./typecheck/should_compile/T7220a.comp.stderr 2014-11-21 13:58:27.078240760 +0000 @@ -0,0 +1,14 @@ + +T7220a.hs:17:6: + Could not deduce (C a b) + from the context (C a0 b, TF b ~ Y) + bound by the type signature for f :: (C a0 b, TF b ~ Y) => b + at T7220a.hs:17:6-44 + Possible fix: + add (C a b) to the context of + the type signature for f :: (C a0 b, TF b ~ Y) => b + In the ambiguity check for the type signature for â€˜fâ€™: + f :: forall a. (forall b. (C a b, TF b ~ Y) => b) -> X + To defer the ambiguity check to use sites, enable AllowAmbiguousTypes + In the type signature for â€˜fâ€™: + f :: (forall b. (C a b, TF b ~ Y) => b) -> X *** unexpected failure for T7220a(normal) https://s3.amazonaws.com/archive.travis-ci.org/jobs/41712832/log.txt probably caused by one of the commits pushed by SPJ in the range b0dd34756613...c5a39389ea06 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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RE: [commit: ghc] master: Rejig builders for pattern synonyms, especially unlifted ones (e876208)
by Simon Peyton Jones 21 Nov '14

21 Nov '14

Heads up: this commit means you need to blow away all your .hi files. Simon | -----Original Message----- | From: ghc-commits [mailto:ghc-commits-bounces@haskell.org] On Behalf | Of git(a)git.haskell.org | Sent: 21 November 2014 13:03 | To: ghc-commits(a)haskell.org | Subject: [commit: ghc] master: Rejig builders for pattern synonyms, | especially unlifted ones (e876208) | | Repository : ssh://git@git.haskell.org/ghc | | On branch : master | Link : | http://ghc.haskell.org/trac/ghc/changeset/e876208117a34fb58f7f1e470de2 | f954b3ca303d/ghc | | >--------------------------------------------------------------- | | commit e876208117a34fb58f7f1e470de2f954b3ca303d | Author: Simon Peyton Jones <simonpj(a)microsoft.com> | Date: Fri Nov 21 10:04:09 2014 +0000 | | Rejig builders for pattern synonyms, especially unlifted ones | | When a pattern synonym is for an unlifted pattern, its "builder" | would | naturally be a top-level unlifted binding, which isn't allowed. | So we | give it an extra Void# argument. | | Our Plan A involved then making *two* Ids for these builders, with | some consequential fuss in the desugarer. This was more pain than | I | liked, so I've re-jigged it. | | * There is just one builder for a pattern synonym. | | * It may have an extra Void# arg, but this decision is signalled | by the Bool in the psBuilder field. | | I did the same for the psMatcher field. | | Both Bools are serialised into interface files, so there is | absolutely no doubt whether that extra Void# argument is | required. | | * I renamed "wrapper" to "builder". We have too may "wrappers" | | * In order to deal with typecchecking occurrences of P in | expressions, | I refactored the tcInferId code in TcExpr. | | All of this allowed me to revert 5fe872 | "Apply compulsory unfoldings during desugaring, except for | `seq` which is special." | which turned out to be a rather messy hack in DsBinds | | | >--------------------------------------------------------------- | | e876208117a34fb58f7f1e470de2f954b3ca303d | compiler/basicTypes/PatSyn.lhs | 207 +++++++++++++++----------- | ---- | compiler/deSugar/DsExpr.lhs | 22 +--- | compiler/deSugar/DsUtils.lhs | 10 +- | compiler/iface/BuildTyCl.lhs | 8 +- | compiler/iface/IfaceSyn.lhs | 12 +- | compiler/iface/MkIface.lhs | 9 +- | compiler/iface/TcIface.lhs | 65 ++-------- | compiler/typecheck/TcBinds.lhs | 14 +-- | compiler/typecheck/TcExpr.lhs | 162 ++++++++---------------- | compiler/typecheck/TcPatSyn.lhs | 237 +++++++++++++++++++++----- | --------- | compiler/typecheck/TcPatSyn.lhs-boot | 4 +- | compiler/typecheck/TcRnMonad.lhs | 5 + | 12 files changed, 338 insertions(+), 417 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 | e876208117a34fb58f7f1e470de2f954b3ca303d | _______________________________________________ | ghc-commits mailing list | ghc-commits(a)haskell.org | http://www.haskell.org/mailman/listinfo/ghc-commits

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