May 2014 - ghc-devs - Haskell.org

Adding atomic primops
by Johan Tibell 09 Jun '14

09 Jun '14

Hi, I found myself needing atomic operations on basic, mutable numeric values. I wrote a short design doc that I'd like feedback on: https://ghc.haskell.org/trac/ghc/wiki/AtomicPrimops I will try to implement these for 7.10. -- Johan

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Re: Offering GHC builder build slaves
by Páli Gábor János 07 Jun '14

07 Jun '14

2014-04-09 0:25 GMT+02:00 Lyndon Nerenberg <lyndon(a)orthanc.ca>: > Is there any way to verify that builder-client can actually do a successful build, > without having access to the build system server? 'builder-client --do-build' > wants to connect and authenticate first; it would be helpful if there was a way > to bypass that so that I can first verify the local build environment is sane. This is because the builder client gets the commands to be executed from the server. A naive solution would be to put the commands in the script and run it. You can find the current set of installed commands at one of the active builders page, e.g. [1]. Note that you may have to change some of them, such as the flags passed to configure script and name of the make(1) command. [1] http://haskell.inf.elte.hu/builders/solaris-x86-head/23.html

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Expose Other Parsers for GHC API
by Andrew Gibiansky 04 Jun '14

04 Jun '14

Hello, I would like to be able to use the GHC API for parsing. Right now this is in the Parser and Lexer modules: Parser: http://www.haskell.org/ghc/docs/7.8.2/html/libraries/ghc-7.8.2/Parser.html Lexer: http://www.haskell.org/ghc/docs/7.8.2/html/libraries/ghc-7.8.2/Lexer.html GHC currently exposes only a few parsers here. I'd like to make a few modifications: 1. Expose a few more parsers than currently are exposed in the Parser module. In particular, I'd like import statements, type signatures, declarations, and expressions, at least, in addition to what's already there. 2. Re-export some things from Lexer from Parser, since they're reused. This would include unP, PState, and the 2-3 other core things you *have* to use in order to use the GHC Parser. 3. Add some Haddock documentation to the top of the Parser module describing how to use it, since the types themselves are pretty opaque here. I think (1) and (3) are definitely a good idea, not so sure about (2) though IMHO it would be convenient for using the Parser. Would this make for an acceptable patch? Thoughts? -- Andrew Gibiansky

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Validate failures
by Joachim Breitner 03 Jun '14

03 Jun '14

Hi, I’m seeing these failures on travis. Anyone feeling responsible? master: Actual stderr output differs from expected: --- /dev/null 2014-05-03 18:30:46.325826237 +0000 +++ ./ffi/should_compile/cc004.comp.stderr 2014-05-03 19:08:47.864969234 +0000 @@ -0,0 +1,73 @@ + +cc004.hs:16:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "static p" m_stdcall + :: StablePtr a -> IO (StablePtr b) + +cc004.hs:21:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "static my_sin" my_sin + :: Double -> IO Double + +cc004.hs:22:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "static my_cos" my_cos + :: Double -> IO Double + +cc004.hs:24:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "static m1" m8 :: IO Int8 + +cc004.hs:25:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "static m2" m16 :: IO Int16 + +cc004.hs:26:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "static m3" m32 :: IO Int32 + +cc004.hs:27:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "static m4" m64 :: IO Int64 + +cc004.hs:29:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "dynamic" d8 + :: FunPtr (IO Int8) -> IO Int8 + +cc004.hs:30:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "dynamic" d16 + :: FunPtr (IO Int16) -> IO Int16 + +cc004.hs:31:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "dynamic" d32 + :: FunPtr (IO Int32) -> IO Int32 + +cc004.hs:32:1: Warning: + the 'stdcall' calling convention is unsupported on this platform, + treating as ccall + When checking declaration: + foreign import stdcall safe "dynamic" d64 + :: FunPtr (IO Int64) -> IO Int64 *** unexpected failure for cc004(normal) and Wrong exit code (expected 0 , actual 1 ) Stdout: Stderr: cgrun051: OK *** unexpected failure for cgrun051(normal) (https://s3.amazonaws.com/archive.travis-ci.org/jobs/24347514/log.txt) ghc-7.8: Unexpected failures: annotations/should_compile/th annth_compunits [bad exit code] (normal) annotations/should_compile/th annth_make [bad stdout] (normal) Please merge 0fe726829d468badf830dd82bc296832d709733b into ghc-7.8 (this annotates the tests to require have_dynamic()) 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: [GHC] #8736: GHCi doesn't load .dyn_o files appropriately
by George Colpitts 31 May '14

31 May '14

Please ignore my previous message, I was compiling with -DYNAMIC instead of -dynamic On Sat, May 31, 2014 at 12:39 PM, GHC <ghc-devs(a)haskell.org> wrote: > #8736: GHCi doesn't load .dyn_o files appropriately > -------------------------------------+------------------------------------ > Reporter: thoughtpolice | Owner: thoughtpolice > Type: bug | Status: new > Priority: high | Milestone: 7.8.3 > Component: Compiler | Version: 7.8.1-rc2 > Resolution: | Keywords: > Operating System: Unknown/Multiple | Architecture: Unknown/Multiple > Type of failure: None/Unknown | Difficulty: Unknown > Test Case: | Blocked By: > Blocking: | Related Tickets: > -------------------------------------+------------------------------------ > > Comment (by George): > > Replying to [comment:4 simonpj]: > > Summarising the behaviour. If you say `:load Foo` in GHCi > > * `Foo` was compiled with `-dynamic`: loads `Foo.o` > > * `Foo` was compiled without any dynamic flag: does not find object > files, so interprets. > > * `Foo` was compiled with `-dynamic-too`: fails as above. > > > > Not a release blocker. > > > > The first case > > > * `Foo` was compiled with `-dynamic`: loads `Foo.o` > > does not seem to be the case in 7.8.2, at least on the Mac where the .o > file does not get loaded > > {{{ > ghc --make -O2 -DYNAMIC pfp1.hs > [1 of 1] Compiling Main ( pfp1.hs, pfp1.o ) > Linking pfp1 ... > bash-3.2$ ghci -ignore-dot-ghci > GHCi, version 7.8.2: http://www.haskell.org/ghc/ :? for help > Loading package ghc-prim ... linking ... done. > Loading package integer-gmp ... linking ... done. > Loading package base ... linking ... done. > Prelude> :load pfp1 > [1 of 1] Compiling Main ( pfp1.hs, interpreted ) > Ok, modules loaded: Main. > }}} > > Should I file a bug? > > -- > Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8736#comment:9> > GHC <http://www.haskell.org/ghc/> > The Glasgow Haskell Compiler >

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segfault in RTS - can anyone help me tracking this bug down?
by Ömer Sinan Ağacan 30 May '14

30 May '14

Hi all, I'm suffering from a RTS bug(probably GC related) that makes making progress in my GSoC project impossible. I have very limited knowledge of GHC internals and I currently have no idea how to produce a minimal program that demonstrates the bug. I wrote how to reproduce it and gdb backtrace when segfault happens in a short blog post: http://osa1.net/posts/2014-05-27-worst-bug.html . As also written in the blog post, changing generation count of generational GC will makes the bug disappear in some cases, but it's not a solution. I also pasted backtrace output below for those who don't want to click links. GHC version used is 7.8.2. If anyone give me some pointers to understand what's going wrong or how can I produce a simple program that demonstrates the bug, I'd like to work on that. I'm basically stuck and I can't make any progress with this bug. Thanks, Ömer [ 5 of 202] Compiling GHC.Unicode[boot] ( GHC/Unicode.hs-boot, dist/build/GHC/Unicode.js_p_o-boot ) Detaching after fork from child process 3382. [ 6 of 202] Compiling GHC.IO[boot] ( GHC/IO.hs-boot, dist/build/GHC/IO.js_p_o-boot ) Detaching after fork from child process 3383. [ 7 of 202] Compiling GHC.Exception[boot] ( GHC/Exception.lhs-boot, dist/build/GHC/Exception.js_p_o-boot ) Detaching after fork from child process 3384. [ 51 of 202] Compiling GHC.Fingerprint[boot] ( GHC/Fingerprint.hs-boot, dist/build/GHC/Fingerprint.js_p_o-boot ) Detaching after fork from child process 3385. [ 55 of 202] Compiling GHC.IO.Exception[boot] ( GHC/IO/Exception.hs-boot, dist/build/GHC/IO/Exception.js_p_o-boot ) Detaching after fork from child process 3386. [ 75 of 202] Compiling Foreign.C.Types ( Foreign/C/Types.hs, dist/build/Foreign/C/Types.js_p_o ) Program received signal SIGSEGV, Segmentation fault. 0x000000000425d5c4 in LOOKS_LIKE_CLOSURE_PTR (p=0x0) at includes/rts/storage/ClosureMacros.h:258 258 includes/rts/storage/ClosureMacros.h: No such file or directory. (gdb) bt #0 0x000000000425d5c4 in LOOKS_LIKE_CLOSURE_PTR (p=0x0) at includes/rts/storage/ClosureMacros.h:258 #1 0x000000000425f776 in scavenge_mutable_list1 (bd=0x7fffe5c02a00, gen=0x4d1fd48) at rts/sm/Scav.c:1400 #2 0x000000000425fa13 in scavenge_capability_mut_Lists1 (cap=0x4cfe5c0 <MainCapability>) at rts/sm/Scav.c:1493 #3 0x0000000004256b66 in GarbageCollect (collect_gen=0, do_heap_census=rtsFalse, gc_type=2, cap=0x4cfe5c0 <MainCapability>) at rts/sm/GC.c:342 #4 0x00000000042454a3 in scheduleDoGC (pcap=0x7fffffffc198, task=0x4d32b60, force_major=rtsFalse) at rts/Schedule.c:1650 #5 0x0000000004243de4 in schedule (initialCapability=0x4cfe5c0 <MainCapability>, task=0x4d32b60) at rts/Schedule.c:553 #6 0x0000000004246436 in scheduleWaitThread (tso=0x7ffff6708d60, ret=0x0, pcap=0x7fffffffc2c0) at rts/Schedule.c:2346 #7 0x000000000423e9b4 in rts_evalLazyIO (cap=0x7fffffffc2c0, p=0x477f850, ret=0x0) at rts/RtsAPI.c:500 #8 0x0000000004241666 in real_main () at rts/RtsMain.c:63 #9 0x0000000004241759 in hs_main (argc=237, argv=0x7fffffffc448, main_closure=0x477f850, rts_config=...) at rts/RtsMain.c:114 #10 0x0000000000408ea7 in main ()

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RE: [GHC] #9153: TcCoercible test is failing with context reduction stack overflow
by Simon Peyton Jones 30 May '14

30 May '14

Thanks for this. I've improved Note [Order of Coercible Instances] in TcInteract Generally, it's much better to give an actual, concrete example in the Note, and refer to the ticket for additional background. It took me a few minutes to re-read the long #9117 to reconstruct the example that precisely illustrates the Note. Simon | -----Original Message----- | From: ghc-tickets [mailto:ghc-tickets-bounces@haskell.org] On Behalf Of | GHC | Sent: 30 May 2014 01:35 | Cc: ghc-tickets(a)haskell.org | Subject: [GHC] #9153: TcCoercible test is failing with context reduction | stack overflow | | #9153: TcCoercible test is failing with context reduction stack overflow | ------------------------------------+----------------------------------- | ------------------------------------+-- | Reporter: ezyang | Owner: | Type: bug | Status: new | Priority: low | Milestone: | Component: Test Suite | Version: 7.9 | Keywords: | Operating System: | Unknown/Multiple | Architecture: Unknown/Multiple | Type of failure: None/Unknown | Difficulty: Unknown | Test Case: | Blocked By: | Blocking: | Related Tickets: | | ------------------------------------+----------------------------------- | ------------------------------------+-- | Here is the error: | | {{{ | TcCoercible.hs:62:12: | Context reduction stack overflow; size = 21 | Use -fcontext-stack=N to increase stack size to N | Coercible Int Int | In the expression: coerce | In the first argument of ‘print’, namely | ‘(coerce $ (FixEither (Left age) :: FixEither Age) :: | Either Int (FixEither Int))’ | In a stmt of a 'do' block: | print | (coerce $ (FixEither (Left age) :: FixEither Age) :: | Either Int (FixEither Int)) | }}} | | I do not know enough to know if bumping the stack size is correct. | | Additionally, when run as GHCi I get: | | {{{ | =====> TcCoercible(ghci) 2784 of 3970 [0, 7, 0] cd | ./typecheck/should_run && '/home/hs01/ezyang/ghc-validate/inplace/bin | /ghc-stage2' -fforce-re | comp -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db - | rtsopts -fno-ghci-history Tc Coercible.hs --interactive -v0 -ignore- | dot-ghci +RTS -I0.1 -RTS <TcCoercible.genscript 1>TcCo | ercible.interp.stdout 2>TcCoercible.interp.stderr Actual stderr output | differs from expected: | --- /dev/null 2014-02-15 17:35:19.578872448 -0800 | +++ ./typecheck/should_run/TcCoercible.run.stderr 2014-05-29 | 16:27:30.476701835 -0700 | @@ -0,0 +1,2 @@ | + | +TcCoercible:7:30: Not in scope: ‘Main.main’ | }}} | | -- | Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9153> | GHC <http://www.haskell.org/ghc/> | The Glasgow Haskell Compiler | _______________________________________________ | ghc-tickets mailing list | ghc-tickets(a)haskell.org | http://www.haskell.org/mailman/listinfo/ghc-tickets

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NondecreasingIndentation (& de-tabbing several .hs files)
by Herbert Valerio Riedel 29 May '14

29 May '14

Hello GHC devs, While I refactored the ghc code base to declare LANGUAGE pragmas locally, rather than via -X-flags on the GHC commandline, I've noticed there were a couple of places where NondecreasingIndentation grammar was used. What's the current consensus on the use of NondecreasingIndentation? Is its use still encouraged? ---- Moreover, I touched several files (over 300) while refactoring, would that qualify as "working on this module" in the sense of | While working on this module you are encouraged to remove it and detab | the module (please do the detabbing in a separate patch). or would that overreach wrt the original intent of the guideline quoted above? Cheers, hvr

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Parallelizing the Weak Pointer Lock
by Edward Kmett 29 May '14

29 May '14

How hard *would* it be to replace the global weak pointer lock with something that scales better? I'm looking at switching some of my older BDD code into Haskell. To do so I'd love to be able to use an "intuitive" weak-pointer based cache management scheme, but I have to confess the notion of a global lock getting in the way basically damns whatever solution I come up with to be a single-threaded toy. =/ If I'm trying to sell Haskell's parallelism to others, it seems my only winning moves right now are: 1.) play less satisfying games with typed regions, which scale less well than the tried and tested solutions of GCing hash-consed BDD structures. 2.) just tackle the problem that allocating a weak pointer grabs a global lock. 3.) not to play the game -Edward

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Ghc 7.8 branch broken
by Simon Peyton Jones 27 May '14

27 May '14

Austin, the ghc-7.8 branch does not build. See below. Simon inplace/bin/mkUserGuidePart docs/users_guide/users_guide.xml inplace/bin/mkUserGuidePart docs/users_guide/what_glasgow_exts_does.gen.xml "rm" -rf docs/users_guide/users_guide/ "/usr/bin/xsltproc" --stringparam base.dir docs/users_guide/users_guide/ --stringparam use.id.as.filename 1 --stringparam html.stylesheet fptools.css --nonet --stringparam toc.section.depth 3 --stringparam section.autolabel 1 --stringparam section.label.includes.component.label 1 http://docbook.sourceforge.net/release/xsl/current/html/chunk.xsl docs/users_guide/users_guide.xml docs/users_guide/intro.xml:312: parser error : Entity 'relnotes3' not defined &relnotes3; ^ docs/users_guide/intro.xml:321: parser error : chunk is not well balanced ^ docs/users_guide/ug-book.xml:11: parser error : Failure to process entity intro &intro; ^ docs/users_guide/ug-book.xml:11: parser error : Entity 'intro' not defined &intro; ^ docs/users_guide/users_guide.xml:10: parser error : Failure to process entity ug-book &ug-book; ^ docs/users_guide/users_guide.xml:10: parser error : Entity 'ug-book' not defined &ug-book; ^ unable to parse docs/users_guide/users_guide.xml "cp" -p ghc/stage2/build/tmp/ghc-stage2 inplace/lib/bin/ghc-stage2 make[1]: *** [docs/users_guide/users_guide/index.html] Error 6 make[1]: *** Waiting for unfinished jobs.... make: *** [all] Error 2 simonpj@cam-05-unx:~/5builds/ghc-7.8-branch$

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