- Glasgow-haskell-users

ghc-7.6.2 breaks haddock interface...
by Joachim Breitner 12 Dec '12

12 Dec '12

Hi, I built GHC 7.6.2-rc1 for Debian. Unfortunately, we have this: Control files of package ghc-haddock: lines which differ (wdiff format) ----------------------------------------------------------------------- Depends: ghc (= [-7.6.1-3),-] {+7.6.1.20121207-1),+} libc6 (>= 2.11), libffi5 (>= 3.0.4), libgmp10 Installed-Size: [-32917-] {+33044+} Provides: haddock, [-haddock-interface-21-] {+haddock-interface-22+} Version: [-7.6.1-3-] {+7.6.1.20121207-1+} i.e. upstream has bumped the haddock interface number. I really was not expecting this from a minor release. @GHC devs: Is that intentional? I.e., is there really a change to the on-disk format of the .haddock files? Can we expect this to be stable until 7.6.2 final? In general, please only bump the interface number if really required, makes live much easier for us (and probably also for some of your other users). @Debian: If the answer is yes, what should we do? I think I have automated rebuilding everything (at least everything in Darcs) enough to make that not as painful as it used to be, but it would still take some time. On the other hand, it would break Haskell in experimental for some time (maybe a week, optimistically). But then, it is already partly broken. Thanks, Joachim -- Joachim "nomeata" Breitner Debian Developer nomeata(a)debian.org | ICQ# 74513189 | GPG-Keyid: 4743206C JID: nomeata(a)joachim-breitner.de | http://people.debian.org/~nomeata

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Re: [Haskell-cafe] GHCi + FFI + global C variables
by Brandon Allbery 11 Dec '12

11 Dec '12

On Tue, Dec 11, 2012 at 5:57 AM, Francisco Vieira de Souza < vieira.ufpi(a)gmail.com> wrote: > Hi Simon! Is it not necessary to show the type of igraph_bool_t > igraphhaskell_initialized like > > "int igraph_bool_t igraphhaskell_initialized = 0"? > "igraph_bool_t" uses the _t suffix convention for typedefs in C; in other words, it *is* the type. (And if it weren't, that would be a compile time error, not link time.) -- brandon s allbery kf8nh sine nomine associates allbery.b(a)gmail.com ballbery(a)sinenomine.net unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net

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GHCi + FFI + global C variables
by Nils 11 Dec '12

11 Dec '12

I'm currently working with a C library that needs to use/modify global C variables, for example: igraph_bool_t igraphhaskell_initialized = 0; int igraphhaskell_initialize() { if (igraphhaskell_initialized != 0) { printf("C: Not initializing. igraphhaskell_initialized = %i\n", igraphhaskell_initialized); return 1; } // initialization } If I compile an example programm using this library everything works fine, but if I try to run the same program in GHCi it dies with the message C: Not initializing. igraphhaskell_initialized = -907777 The value (and apparently the adress of the global variable) is completly off, and I have no idea what is causing this or how to solve this issue and make the library GHCi-friendly. Is it possible to run this code in GHCi at all? Also, since it's a foreign library I obviously cannot just change the C code to simply not use any global variables at all. - Nils

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How to use C-land variable from Cmm-land?
by Yuras Shumovich 11 Dec '12

11 Dec '12

Hi, I'm working on that issue as an exercise/playground while studding the GHC internals: http://hackage.haskell.org/trac/ghc/ticket/693 First I tried just to replace "ccall lockClosure(mvar "ptr")" with GET_INFO(mvar) in stg_takeMVarzh and stg_putMVarzh and got 60% speedup (see the test case at the end.) Then I changed lockClosure to read header info directly when enabled_capabilities == 1. The speedup was significantly lower, <20% I tried to hack stg_putMVarzh directly: if (enabled_capabilities == 1) { info = GET_INFO(mvar); } else { ("ptr" info) = ccall lockClosure(mvar "ptr"); } But got no speedup at all. The generated asm (amd64): movl $enabled_capabilities,%eax cmpq $1,%rax je .Lcgq .Lcgp: movq %rbx,%rdi subq $8,%rsp movl $0,%eax call lockClosure addq $8,%rsp .Lcgr: cmpq $stg_MVAR_CLEAN_info,%rax jne .Lcgu {...} .Lcgq: movq (%rbx),%rax jmp .Lcgr It moves enabled_capabilities into %eax and then compares 1 with %rax. It looks wrong for me: the highest part of %rax remains uninitialized. (And actually it ignores the highest 32 bits of enabled_capabilities. That is ok here, but generally wrong.) The compiler knows that enabled_capabilities is 64bit (it complains when trying to assign it to bits32 register.) What do I miss? Any help? Thanks, Yuras -- The test case import Control.Concurrent import Control.Monad main :: IO () main = do var <- newMVar () replicateM_ 100000000 $ do takeMVar var putMVar var ()

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cabal-install use multiple config files?
by Stephen Paul Weber 10 Dec '12

10 Dec '12

I don't see a command-line switch to ask cabal-install to use a different config file. Is there an environment variable for it or something? I want to use the same cabal-install binary with three different installs of ghc and ghc-pkg to allow me to maintain my cross-compiler packages as well. -- Stephen Paul Weber, @singpolyma See <http://singpolyma.net> for how I prefer to be contacted edition right joseph

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building GHC for "antique" OSX
by wren ng thornton 10 Dec '12

10 Dec '12

Hello all, I'm one of those curmudgeons still working on OSX 10.5.8. Recently I finally got around to building the latest GHC and, FWIW, everything seems to have worked out fine. I did get a few failed tests in the testsuite though, and I'm curious what they mean or if they're actually cause for concern? OVERALL SUMMARY for test run started at Fri Dec 7 10:49:39 EST 2012 3402 total tests, which gave rise to 14436 test cases, of which 0 caused framework failures 11364 were skipped 2985 expected passes 47 had missing libraries 34 expected failures 0 unexpected passes 6 unexpected failures Unexpected failures: ../../libraries/directory/tests T4113 [bad stdout] (normal) concurrent/should_run conc070 [bad stdout or stderr] (ghci) ghci/should_run 3171 [bad stdout] (normal) perf/haddock haddock.Cabal [stat too good] (normal) perf/haddock haddock.base [stat too good] (normal) perf/haddock haddock.compiler [stat too good] (normal) -- Live well, ~wren

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Which of the following PrimTyCons have a pointer-sized representations
by Johan Tibell 07 Dec '12

07 Dec '12

Hi, As part of some work I'm doing I need to classify all PrimTyCons by the size of their representation as fields*. I need to classify them into two classes: pointer-sized (or smaller) and larger-than-pointer-sized. I've managed to figure out a bunch of them myself: Pointer-sized: addrPrimTyCon arrayPrimTyCon byteArrayPrimTyCon -- Represented as a pointer to heap object arrayArrayPrimTyCon -- Represented as a pointer to heap object charPrimTyCon doublePrimTyCon -- Only on 64-bit floatPrimTyCon intPrimTyCon int32PrimTyCon int64PrimTyCon -- Only on 64-bit mutableArrayPrimTyCon -- Represented as a pointer to heap object mutableByteArrayPrimTyCon -- Represented as a pointer to heap object mutableArrayArrayPrimTyCon -- Represented as a pointer to heap object wordPrimTyCon word32PrimTyCon word64PrimTyCon -- Only on 64-bit These ones I need help with: bcoPrimTyCon weakPrimTyCon mVarPrimTyCon tVarPrimTyCon mutVarPrimTyCon realWorldTyCon stablePtrPrimTyCon stableNamePrimTyCon statePrimTyCon threadIdPrimTyCon anyTyCon eqPrimTyCon liftedTypeKindTyCon unliftedTypeKindTyCon openTypeKindTyCon constraintKindTyCon superKindTyCon anyKindTyCon I would appreciate any help classifying the bottom half. I will use this to implement -funbox-strict-primitive-fields * For example: while the StgArrWords heap object is a multi-byte object its representation as a field e.g. in data T = C ByteArray# is one pointer (to the StgArrWords heap object). -- Johan

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proposal: separate lists for ghc-cvs commits and ghc-dev chatter
by Carter Schonwald 07 Dec '12

07 Dec '12

hey all, It seems to me (and i've certainly heard other people echo this sentiment) that: ghc dev chatting gets buried in the huge volume of commit + build report emails, and that creates (perhaps) another barrier to involvement in ghc dev at the hobbyist (rather than part time/full time ) scale? So my question for the community (and of course current ghc devs ) 1) do others agree that theres value in separating the two? 2) would this just be another use of the ghc-users list or would it be worth having a ghc-dev list? 3) most importantly, would the folks actively involved in ghc dev be willing/able to do so? That said, it does seem like the majority of the interesting ghc-dev chatter is on Trac issues, which is a good thing, though theres lots of interesting wee nuggets buried on the ghc-cvs list intermittently I hope this question makes sense for y'all! -Carter

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GHCI segfault on Double math
by Ron Alford 07 Dec '12

07 Dec '12

I'm trying to see if this is reproducible, or it's just my machine. I'm on a MacBook Pro (15-inch, Mid 2012), OS X 10.8.2, Haskell Platform 2012.4.0.0 (32 bit): $ ghci GHCi, version 7.4.2: 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> properFraction (-1.1 :: Float) (-1,-0.100000024) Prelude> properFraction (1.1 :: Double) (1,0.10000000000000009) Prelude> properFraction (-1.1 :: Double) (-1,Segmentation fault: 11 'ceiling' and other code that uses properFraction segfaults on negative doubles, too. Compiled code doesn't have this defect. I'm going to try the 64 bit version to see if it resolves this problem. -Ron Alford

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Emitting constants to the .data section from the NatM monad
by Johan Tibell 07 Dec '12

07 Dec '12

Hi! I'm trying to implement word2Double# and I've looked at how e.g. LLVM does it. LLVM outputs quite clever branchless code that uses two predefined constants in the .data section. Is it possible to add contents to the current .data section from a function in the NatM monad e.g. coerceWord2FP :: Width -> Width -> CmmExpr -> NatM Register ? Cheers, Johan P.S. Given this C code double f(unsigned long long u) { return u; } LLVM generates this rather clever code: .section __TEXT,__text,regular,pure_instructions .section __TEXT,__literal8,8byte_literals .align 3 LCPI1_0: .long 1602224128 // constant we'd like to ouput .long 0 // constant we'd like to ouput .section __TEXT,__text,regular,pure_instructions .globl _f .align 4, 0x90 _f: pushl %ebp movl %esp, %ebp subl $16, %esp movl 8(%ebp), %eax movl 12(%ebp), %ecx movl %ecx, -4(%ebp) movl %eax, -8(%ebp) testl %ecx, %ecx // check sign sets %al // check sign xorb $1, %al // check sign movzbl %al, %eax // 0 if signed fildll -8(%ebp) // load integer fadds LCPI1_0(,%eax,4) // add one of two constants fstpl -16(%ebp) // store and pop fldl -16(%ebp) addl $16, %esp popl %ebp ret

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