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Error: selected processor does not support ARM mode `ldrd r0,r1,[r7,#64]'
by Joachim Breitner 03 Nov '15

03 Nov '15

Hi, I cannot build ghc-7.10.3 on Debian armel: "inplace/bin/ghc-stage1" -static -H32m -O -lffi -optl-pthread -optl-B/usr/bin/ld.gold -Iincludes -Iincludes/dist -Iincludes/dist-derivedconstants/header -Iincludes/dist-ghcconstants/header -Irts -Irts/dist/build -DCOMPILING_RTS -this-package-key rts -dcmm-lint -i -irts -irts/dist/build -irts/dist/build/autogen -Irts/dist/build -Irts/dist/build/autogen -O2 -c rts/StgStartup.cmm -o rts/dist/build/StgStartup.o /tmp/ghcd0b9_0/ghc_7.s: Assembler messages: /tmp/ghcd0b9_0/ghc_7.s:96:0: Error: selected processor does not support ARM mode `ldrd r0,r1,[r3,#64]' /tmp/ghcd0b9_0/ghc_7.s:99:0: Error: selected processor does not support ARM mode `strd r0,r1,[r3,#64]' /tmp/ghcd0b9_0/ghc_7.s:210:0: Error: selected processor does not support ARM mode `ldrd r0,r1,[r7,#64]' /tmp/ghcd0b9_0/ghc_7.s:214:0: Error: selected processor does not support ARM mode `strd r0,r1,[r7,#64]' rts/ghc.mk:236: recipe for target 'rts/dist/build/StgStartup.o' failed make[3]: *** [rts/dist/build/StgStartup.o] Error 1 Makefile:71: recipe for target 'all' failed make[2]: *** [all] Error 2 Erik, can you comment on that? 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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A big patch
by Simon Peyton Jones 03 Nov '15

03 Nov '15

Ben, Austin I wonder if one of you could put up a big patch on Phab for me? I started about two months ago on a modest refactoring of HsType and friends, to clarify and tidy up exactly where quantification takes place in types. Although initially driven by making the implementation of wildcards more tidy (and fixing a number of bugs), I gradually got drawn into a pretty big process, which I've been doing on and off for quite a long time. It's time to finish! I could just commit, but it's good practice to put it on Phab first. Could you do that for me? · It's in branch wip/spj-wildcard-refactor · It's up to date with HEAD from a day or two back · The principal driving change is described in Note [HsType binders] in HsType. Worth reading! Those data type changes drive almost everything else. · There are some uninteresting knock-on changes in Haddock, which are in wip/spj-wildcard-refactor in utils/haddock. I've done the submodule commit thing so the ghc-repo branch should refer correctly to the Haddock branch. · The commit log on the branch is of no interest; just dump it entirely. I will write a proper commit message in due course. · A handful of tests are failing. I'm working on that, but I want to get this onto Phab now awyway. You could include this email as the Phab description. Thanks! Simon

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process library broken on Windows
by Simon Peyton Jones 02 Nov '15

02 Nov '15

I'm getting this on HEAD in te ' libraries\process\System\Process\Internals.hs:106:16: warning: Defined but not used: data constructor 'CGid' Indeed it looks as if CGId(..) should be exported, else createProcess is unusuable. This looks like the right change. Would someone like to check and make the change Simon diff --git a/System/Process/Internals.hs b/System/Process/Internals.hs index 5575ac4..3e23ad5 100644 --- a/System/Process/Internals.hs +++ b/System/Process/Internals.hs @@ -37,6 +37,8 @@ module System.Process.Internals ( #if !defined(mingw32_HOST_OS) && !defined(__MINGW32__) pPrPr_disableITimers, c_execvpe, ignoreSignal, defaultSignal, +#else + CGid(..), GroupID, UserID, #endif withFilePathException, withCEnvironment, translate,

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Better calling conventions for strict functions (bang patterns)?
by Ryan Newton 02 Nov '15

02 Nov '15

Hi all, With module-level Strict and StrictData pragmas coming soon, one obvious question is what kind of the code quality GHC can achieve for strict programs. When it came up in discussion in our research group we realized we didn't actually know whether the bang patterns, `f !x`, on function arguments were enforced by caller or callee. Here's a Gist that shows the compilation of a trivial function: foo :: Maybe Int -> Intfoo !x = case x of Just y -> y https://gist.github.com/rrnewton/1ac722189c65f26fe9ac If that function is compiled to *assume* its input is in WHNF, it should be just as efficient as the isomorphic MLton/OCaml code, right? It only needs to branch on the tag, do a field dereference, and return. But as you can see from the STG and CMM generated, foo *does indeed* enter the thunk, adding an extra indirect jump. Here's the body: c3aY: if ((Sp + -8) < SpLim) goto c3aZ; else goto c3b0; c3aZ: // nop R1 = PicBaseReg + foo_closure; call (I64[BaseReg - 8])(R2, R1) args: 8, res: 0, upd: 8; c3b0: I64[Sp - 8] = PicBaseReg + block_c3aO_info; R1 = R2; Sp = Sp - 8; if (R1 & 7 != 0) goto c3aO; else goto c3aP; c3aP: call (I64[R1])(R1) returns to c3aO, args: 8, res: 8, upd: 8; c3aO: if (R1 & 7 >= 2) goto c3aW; else goto c3aX; c3aW: R1 = P64[R1 + 6] & (-8); Sp = Sp + 8; call (I64[R1])(R1) args: 8, res: 0, upd: 8; c3aX: R1 = PicBaseReg + lvl_r39S_closure; Sp = Sp + 8; call (I64[R1])(R1) args: 8, res: 0, upd: 8; The call inside c3aP is entering "x" as a thunk, which also incurs all of the stack limit check code. I believe that IF the input could be assumed to be in WHNF, everything above the label "c3aO" could be omitted. So... if GHC is going to be a fabulous pure *and* imperative language, and a fabulous lazy *and* strict compiler/runtime.. is there some work we can do here to improve this situation? Would the following make sense: - Put together a benchmark suite of all-strict programs with Strict/StrictData (compare a few benchmark's generated code to MLton, if time allows) - Modify GHC to change calling conventions for bang patterns -- caller enforces WHNF rather than callee. Existing strictness/demand/cardinality analysis would stay the same. Unless there's something I'm really missing here, the result should be that you can have a whole chain of strict function calls, each of which knows its arguments and the arguments it passes to its callees are all in WHNF, without ever generating thunk-entry sequences. Thanks for your time, -Ryan

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Proposal: accept pull requests on GitHub
by Thomas Miedema 02 Nov '15

02 Nov '15

Hello all, my arguments against Phabricator are here: https://ghc.haskell.org/trac/ghc/wiki/WhyNotPhabricator. Some quotes from #ghc to pique your curiosity (there are some 50 more): * "is arc broken today?" * "arc is a frickin' mystery." * "i have a theory that i've managed to create a revision that phab can't handle." * "Diffs just seem to be too expensive to create ... I can't blame contributors for not wanting to do this for every atomic change" * "but seriously, we can't require this for contributing to GHC... the entry barrier is already high enough" GitHub has side-by-side diffs <https://github.com/blog/1884-introducing-split-diffs> nowadays, and Travis-CI can run `./validate --fast` comfortably <https://travis-ci.org/ghc/ghc/builds>. *Proposal: accept pull requests from contributors on https://github.com/ghc/ghc <https://github.com/ghc/ghc>.* Details: * use Travis-CI to validate pull requests. * keep using the Trac issue tracker (contributors are encouraged to put a link to their pull-request in the 'Differential Revisions' field). * keep using the Trac wiki. * in discussions on GitHub, use https://ghc.haskell.org/ticket/1234 to refer to Trac ticket 1234. The shortcut #1234 only works on Trac itself. * keep pushing to git.haskell.org, where the existing Git receive hooks can do their job keeping tabs, trailing whitespace and dangling submodule references out, notify Trac and send emails. Committers close pull-requests manually, just like they do Trac tickets. * keep running Phabricator for as long as necessary. * mention that pull requests are accepted on https://ghc.haskell.org/trac/ghc/wiki/WorkingConventions/FixingBugs. My expectation is that the majority of patches will start coming in via pull requests, the number of contributions will go up, commits will be smaller, and there will be more of them per pull request (contributors will be able to put style changes and refactorings into separate commits, without jumping through a bunch of hoops). Reviewers will get many more emails. Other arguments against GitHub are here: https://ghc.haskell.org/trac/ghc/wiki/WhyNotGitHub. I probably missed a few things, so fire away. Thanks, Thomas

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Re: [commit: ghc] master: Kill redundant import (da58d15)
by Herbert Valerio Riedel 30 Oct '15

30 Oct '15

originally, http://git.haskell.org/ghc.git/commitdiff/7eb5e29b4a7b6fef55512bc7bf3308e71… the import looked like this: import qualified HsSyn -- hack as we want to reexport the whole module import HsSyn hiding ((<.>)) so it wasn't redundant back then at least. > commit da58d1517ce9c57514f7b2bd7d444c9e3051a717 > Author: Simon Peyton Jones <simonpj(a)microsoft.com> > Date: Fri Oct 30 09:45:16 2015 +0000 > > Kill redundant import > > I don't really understand this. GHC.hs had: > > module GHC( ..., module HsSyn, ... ) where > import HsSyn > import qualified HsSyn -- hack as we want to reexport the whole module > > GHC now reports the 'import qualified' line as redundant; and it certainly > is, because 'import HsSyn' brings everything into scope qualified *and* > unqualified. I have no idea why the "hack" was necessary before, but > following my refactoring of tcg_used_gres (previous commit), it's reported > as redundant, so I've deleted it. > > I'm making it a separate commit because it seems a bit mysterious and I > wanted to draw attention to it.

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Documenting record pattern synonyms
by Simon Peyton Jones 30 Oct '15

30 Oct '15

Matthew: Could you please write the user-manual sections that you have promised? That is, the *specification* this feature. Currently, so far as I can see, there is literally NO user manual documentation. No changes to docs/users_guide whatsoever. We have discussed this on several occasions, and you agreed to do it. I sat with you in person and showed you what I have in mind. There is a sketch on the wiki page. I did not intend this patch to land until the user documentation was done. Now I feel as if I've lost my leverage :-). But it really really really really needs doing. Please. I'm begging you. Compared to what you have already done, it's easy. Simon | -----Original Message----- | From: ghc-commits [mailto:ghc-commits-bounces@haskell.org] On Behalf Of | git(a)git.haskell.org | Sent: 29 October 2015 11:25 | To: ghc-commits(a)haskell.org | Subject: [commit: ghc] master: Record pattern synonyms (2a74a64) | | Repository : ssh://git@git.haskell.org/ghc | | On branch : master | Link : | https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fghc.haskell. | org%2ftrac%2fghc%2fchangeset%2f2a74a64e8329ab9e0c74bec47198cb492d25affb%2fgh | c&data=01%7c01%7csimonpj%40064d.mgd.microsoft.com%7c0deecf24e85641ff3abb08d2 | e05387f2%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=nEAgwVmvFQNgN%2bANGD4H | z1flN%2fucKSRFoZMdhRqQKSM%3d | | >--------------------------------------------------------------- | | commit 2a74a64e8329ab9e0c74bec47198cb492d25affb | Author: Matthew Pickering <matthewtpickering(a)gmail.com> | Date: Mon Oct 19 21:17:29 2015 +0100 | | Record pattern synonyms | | This patch implements an extension to pattern synonyms which allows user | to specify pattern synonyms using record syntax. Doing so generates | appropriate selectors and update functions. | | === Interaction with Duplicate Record Fields === | | The implementation given here isn't quite as general as it could be with | respect to the recently-introduced `DuplicateRecordFields` extension. | | Consider the following module: | | {-# LANGUAGE DuplicateRecordFields #-} | {-# LANGUAGE PatternSynonyms #-} | | module Main where | | pattern S{a, b} = (a, b) | pattern T{a} = Just a | | main = do | print S{ a = "fst", b = "snd" } | print T{ a = "a" } | | In principle, this ought to work, because there is no ambiguity. But at | the moment it leads to a "multiple declarations of a" error. The problem | is that pattern synonym record selectors don't do the same name mangling | as normal datatypes when DuplicateRecordFields is enabled. They could, | but this would require some work to track the field label and selector | name separately. | | In particular, we currently represent datatype selectors in the third | component of AvailTC, but pattern synonym selectors are just represented | as Avails (because they don't have a corresponding type constructor). | Moreover, the GlobalRdrElt for a selector currently requires it to have | a parent tycon. | | (example due to Adam Gundry) | | === Updating Explicitly Bidirectional Pattern Synonyms === | | Consider the following | | ``` | pattern Silly{a} <- [a] where | Silly a = [a, a] | | f1 = a [5] -- 5 | | f2 = [5] {a = 6} -- currently [6,6] | ``` | | === Fixing Polymorphic Updates === | | They were fixed by adding these two lines in `dsExpr`. This might break | record updates but will be easy to fix. | | ``` | + ; let req_wrap = mkWpTyApps (mkTyVarTys univ_tvs) | | - , pat_wrap = idHsWrapper } | +, pat_wrap = req_wrap } | ``` | | === Mixed selectors error === | | Note [Mixed Record Field Updates] | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | | Consider the following pattern synonym. | | data MyRec = MyRec { foo :: Int, qux :: String } | | pattern HisRec{f1, f2} = MyRec{foo = f1, qux=f2} | | This allows updates such as the following | | updater :: MyRec -> MyRec | updater a = a {f1 = 1 } | | It would also make sense to allow the following update (which we | reject). | | updater a = a {f1 = 1, qux = "two" } ==? MyRec 1 "two" | | This leads to confusing behaviour when the selectors in fact refer the | same field. | | updater a = a {f1 = 1, foo = 2} ==? ??? | | For this reason, we reject a mixture of pattern synonym and normal | record selectors in the same update block. Although of course we still | allow the following. | | updater a = (a {f1 = 1}) {foo = 2} | | > updater (MyRec 0 "str") | MyRec 2 "str" | | | >--------------------------------------------------------------- | | 2a74a64e8329ab9e0c74bec47198cb492d25affb | compiler/basicTypes/ConLike.hs | 86 +++++++- | compiler/basicTypes/ConLike.hs-boot | 18 ++ | compiler/basicTypes/Id.hs | 31 ++- | compiler/basicTypes/IdInfo.hs | 21 +- | compiler/basicTypes/PatSyn.hs | 51 +++-- | compiler/deSugar/Coverage.hs | 11 +- | compiler/deSugar/DsExpr.hs | 79 ++++--- | compiler/deSugar/DsMeta.hs | 2 +- | compiler/hsSyn/Convert.hs | 10 +- | compiler/hsSyn/HsBinds.hs | 67 +++++- | compiler/hsSyn/HsExpr.hs | 35 +++- | compiler/hsSyn/HsUtils.hs | 21 +- | compiler/hsSyn/PlaceHolder.hs | 6 +- | compiler/iface/BuildTyCl.hs | 7 +- | compiler/iface/IfaceSyn.hs | 17 +- | compiler/iface/MkIface.hs | 11 +- | compiler/iface/TcIface.hs | 12 +- | compiler/main/HscTypes.hs | 15 +- | compiler/parser/Parser.y | 28 ++- | compiler/parser/RdrHsSyn.hs | 2 +- | compiler/prelude/TysWiredIn.hs | 2 +- | compiler/rename/RnBinds.hs | 18 +- | compiler/rename/RnExpr.hs | 8 +- | compiler/rename/RnNames.hs | 30 +-- | compiler/rename/RnSource.hs | 52 ++++- | compiler/typecheck/TcBinds.hs | 6 +- | compiler/typecheck/TcExpr.hs | 231 +++++++++++++++--- | --- | compiler/typecheck/TcHsSyn.hs | 10 +- | compiler/typecheck/TcPat.hs | 6 +- | compiler/typecheck/TcPatSyn.hs | 124 ++++++++--- | compiler/typecheck/TcPatSyn.hs-boot | 8 +- | compiler/typecheck/TcRnDriver.hs | 3 +- | compiler/typecheck/TcTyClsDecls.hs | 39 ++-- | compiler/types/TyCon.hs | 7 +- | compiler/types/TypeRep.hs | 2 +- | compiler/types/TypeRep.hs-boot | 1 + | testsuite/tests/patsyn/should_compile/all.T | 7 +- | .../tests/patsyn/should_compile/records-compile.hs | 11 + | .../tests/patsyn/should_compile/records-poly.hs | 16 ++ | .../patsyn/should_compile/records-prov-req.hs | 26 +++ | .../patsyn/should_compile/records-req-only.hs | 16 ++ | .../tests/patsyn/should_compile/records-req.hs | 14 ++ | testsuite/tests/patsyn/should_fail/all.T | 7 + | .../should_fail/mixed-pat-syn-record-sels.hs | 9 + | .../should_fail/mixed-pat-syn-record-sels.stderr | 5 + | .../tests/patsyn/should_fail/records-check-sels.hs | 10 + | .../patsyn/should_fail/records-check-sels.stderr | 3 + | .../tests/patsyn/should_fail/records-exquant.hs | 10 + | .../patsyn/should_fail/records-exquant.stderr | 11 + | .../patsyn/should_fail/records-mixing-fields.hs | 12 ++ | .../should_fail/records-mixing-fields.stderr | 17 ++ | .../patsyn/should_fail/records-no-uni-update.hs | 7 + | .../should_fail/records-no-uni-update.stderr | 5 + | .../patsyn/should_fail/records-no-uni-update2.hs | 11 + | .../should_fail/records-no-uni-update2.stderr | 5 + | .../patsyn/should_fail/records-poly-update.hs | 13 ++ | .../patsyn/should_fail/records-poly-update.stderr | 5 + | testsuite/tests/patsyn/should_run/all.T | 1 + | testsuite/tests/patsyn/should_run/records-run.hs | 14 ++ | .../tests/patsyn/should_run/records-run.stdout | 5 + | 60 files changed, 1055 insertions(+), 262 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 2a74a64e8329ab9e0c74bec47198cb492d25affb | _______________________________________________ | ghc-commits mailing list | ghc-commits(a)haskell.org | https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fmail.haskell | .org%2fcgi-bin%2fmailman%2flistinfo%2fghc- | commits&data=01%7c01%7csimonpj%40064d.mgd.microsoft.com%7c0deecf24e85641ff3a | bb08d2e05387f2%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=ymzeKEsSAnOhr4QL | ngFKt0e8B84voue20%2bCyMPwWf%2fQ%3d

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Re: Type-level error messages
by Richard Eisenberg 29 Oct '15

29 Oct '15

On Oct 28, 2015, at 10:02 AM, "Augustsson, Lennart" <Lennart.Augustsson(a)sc.com> wrote: > I've put in my answers to your questions. And I've responded.

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RE: Compiling without -O
by Simon Peyton Jones 29 Oct '15

29 Oct '15

I suspect you are trying to run 'make 1' after a validate failure, and those settings don't get applied. I have put https://phabricator.haskell.org/D1383 up for review to bring 'mk/are-validating.mk<https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fare-validat…>' back, which should fix that. Correct! I can’t wait ☺ Simon From: Thomas Miedema [mailto:thomasmiedema@gmail.com] Sent: 29 October 2015 11:43 To: Simon Peyton Jones Subject: Re: Compiling without -O validate uses options from mk/validate.mk<https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fvalidate.mk…> as always. Nothing should have changed there. You say it doesn't work anymore. How do you know? I suspect you are trying to run 'make 1' after a validate failure, and those settings don't get applied. I have put https://phabricator.haskell.org/D1383 up for review to bring 'mk/are-validating.mk<https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fare-validat…>' back, which should fix that. On Thu, Oct 29, 2015 at 12:10 PM, Simon Peyton Jones <simonpj(a)microsoft.com<mailto:simonpj@microsoft.com>> wrote: I want to validate, but to compile my stage-1 compiler with –O0. How do I do that? I used to add GhcStage1HcOpts += -DDEBUG -O0 to mk/validate.mk<https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fvalidate.mk…>, but that doesn’t seem to work any more. What now? Simon _______________________________________________ ghc-devs mailing list ghc-devs(a)haskell.org<mailto:ghc-devs@haskell.org> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs<https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fmail.haskel…>

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Compiling without -O
by Simon Peyton Jones 29 Oct '15

29 Oct '15

I want to validate, but to compile my stage-1 compiler with -O0. How do I do that? I used to add GhcStage1HcOpts += -DDEBUG -O0 to mk/validate.mk, but that doesn't seem to work any more. What now? Simon

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