- Glasgow-haskell-users

Cross-Compiling with GHC?
by Rich Fought 19 Oct '05

19 Oct '05

Hi there - GHC noob here, trying to compile a small app for a Linux/PPC target from a Linux/x86 host. I take it this must be doable, since it is possible to build GHC for new platforms and GHC itself is written in Haskell. I'm just trying to find out if anyone has formulated a guide to this already, before I jump in (and I did try Google without much luck). I'm afraid building GHC for the target is not an option. My first thought to try is to build an unregisterised GHC on x86 from scratch and use it to compile my app to C code, which I can then cross-compile to PPC. Something tells me however that this C code still may have some x86 specific stuff in it. Regards, Rich

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RE: GHC-6.4.1 on FreeBSD-amd64 port progress
by Simon Marlow 18 Oct '05

18 Oct '05

On 17 October 2005 19:19, Wilhelm B. Kloke wrote: > Simon Marlow <simonmar(a)microsoft.com> schrieb: >> On 15 October 2005 23:10, Wilhelm B. Kloke wrote: >> >>> Don't forget to delete Linker.c (for ghci). The stage on teh host >>> system where the process fails jsut now is >>>> $MAKE -C libraries boot all >>> because >>>> Fake happy is not happy! >> >> You mean on the target system? Can you give more details? > > Yes. Sorry for any confusion. The happy error messages was an easy > one, > because I have a working 32bit happy on the system. > >>> But ghc-inplace seems to work pretty good now on amd64. > > I reached the end of hc-build successfully. Now there is a new > problem. > I tried (as root) make install at this point. This fails with error > messages > related to missing stage2 subdirectories. So I tried At this point you can either do 'make install stage=1', or you can just use the compiler you built to build a clean GHC in another tree, i.e. with ./configure --with-ghc=/path/to/bootstrap/ghc/compiler/ghc-inplace. > gmake stage=2 boot > > This fails with messages > ... > cmm/CmmLex.hs:28: unterminated #if > cmm/CmmLex.hs:20: unterminated #if > <<ghc: 55123864 bytes, 6 GCs, 160600/160600 avg/max bytes residency > (1 samples), 16M in use, 0.00 INIT (0.00 elapsed), 0.12 MUT (0.41 > elapsed), 0.01 GC (0.05 elapsed) :ghc>> gmake: *** [depend] Fehler 1 > > This error is due to indented preprocessor lines > #else > #endif I've never seen this one before - very odd. You must have Alex in order to process CmmLex.x into CmmLex.hs, or did you copy this from the host tree? I just checked and a copy of CmmLex.hs from my build tree doesn't have any indented preprocessor directives. Cheers, Simon

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GHC 6.4.1 barfs building haskell-src-exts on MingW/WinXP
by Bayley, Alistair 17 Oct '05

17 Oct '05

Hello all, I'm trying to build haskell-src-exts-0.2 with GHC 6.4.1 under MingW on WinXP. It segfaults on the "runhaskell Setup.hs build" command (in the src/haskell-src-exts subdir). Does anyone else get this, or is it just me? sh-2.04$ runhaskell Setup.hs build -v5 Preprocessing library haskell-src-exts-0.2... c:\happy\happy-1.13\bin\happy.exe -agc -oLanguage\Haskell\Hsx\Parser.hs Language\Haskell\Hsx\Parser.ly shift/reduce conflicts: 5 Building haskell-src-exts-0.2... [segfault: instruction at 0 ref'd memory at 0] sh-2.04$ How do I modify the Cabal setup to get GHC -v output (so I can see which module it fails on)? Alistair.

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RE: GHC-6.4.1 on FreeBSD-amd64 still not ported
by Simon Marlow 17 Oct '05

17 Oct '05

On 15 October 2005 23:10, Wilhelm B. Kloke wrote: > ghc/includes > touch > ghc/includes/{ghcautoconf.h,DerivedConstants.h,GHCConstants.h,mkDerivedC onstants.c} > touch > ghc/includes/{mkDerivedConstantsHdr,mkDerivedConstants.o,mkGHCConstants, mkGHCConstants.o} > touch ghc/includes/{ghcautoconf.h,DerivedConstants.h,GHCConstants.h} > chflags uchg > ghc/includes/{ghcautoconf.h,DerivedConstants.h,GHCConstants.h} (cd > glafp-utils && gmake boot && gmake) (cd ghc && gmake boot && gmake) > (cd libraries && gmake boot && gmake) > (cd ghc/compiler && gmake boot stage=2 && gmake stage=2) > (cd ghc/lib/compat && gmake clean; rm .depend; gmake boot > UseStage1=YES EXTRA_HC_OPTS='-O -fvia-C -keep-hc-files'; gmake -k > UseStage1=YES EXTRA_HC_OPTS='-O -fvia-C -keep-hc-files') (cd ghc/rts > && gmake -k UseStage1=YES EXTRA_HC_OPTS='-O -fvia-C -keep-hc-files') > (cd ghc/utils && gmake clean; gmake -k UseStage1=YES > EXTRA_HC_OPTS='-O -fvia-C -keep-hc-files') > gmake hc-file-bundle Project=Ghc Thanks very much for this, I'll update the docs. > Don't forget to delete Linker.c (for ghci). The stage on teh host > system > where the process fails jsut now is >> $MAKE -C libraries boot all > because >> Fake happy is not happy! You mean on the target system? Can you give more details? > But ghc-inplace seems to work pretty good now on amd64. Great! Cheers, Simon

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RE: Profiling and Data.HashTable
by Simon Marlow 17 Oct '05

17 Oct '05

On 17 October 2005 08:07, Ketil Malde wrote: > BTW, could one cheat by introducing a write barrier manually in some > way? Perhaps by (unsafe?) thaw'ing and freeze'ing the arrays when > they are modified? Might be worthwhile: freezing is very quick (basically a single write), thawing is slightly slower (an out-of-line call, but a short one). The effect of freezing will only be felt after a couple of GCs, when everything the array points to is pulled into the old generation and the GC can take it off the mutable list. Cheers, Simon

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RE: Profiling and Data.HashTable
by Simon Marlow 17 Oct '05

17 Oct '05

On 14 October 2005 20:31, Jan-Willem Maessen wrote: > That "5K" number made me immediately suspicious, so I took a look at > the source code to Data.HashTable. Sure enough, it's allocating a > number of large IOArrays, which are filled with pointers. The > practical upshot is that, for a hash table with (say) 24 entries, the > GC must scan an additional 1000 pointers and discover that each one > is []. > > I've seen other implementations of this two-level technique which use > a smallish sEGMENT_SIZE in order to avoid excessive GC overhead for > less-than-gigantic hash tables. This might be worth doing in the > Data.HashTable implementation. > > [Curious: what (if anything) is being used to test Data.HashTable? > I'd be willing to undertake very small amounts of fiddling if I could > be sure I wasn't slowing down something which mattered.] The few benchmarks I've tried seem to indicate that Data.HashTable performance isn't overwhelming, and can often be bettered by Data.Map. I've never investigated too deeply. GC overhead seems a very plausible cause, though. Please by all means tweak the implementation and try some benchmarks, I'll incorporate any performance fixes that arise. Cheers, Simon

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Dynamic Map
by Lajos Nagy 17 Oct '05

17 Oct '05

Hi, Would it be possible to implement a Map in Haskell that, when asked for a key it doesn't have, would return a 'fresh' (meaning: not in the Map already) value, and afterwards it would consistently return the same value for the given key. In other words, it would behave like a dynamic map which silently extends itself when someone asks for a non-existent key. If the user of this map only depends on the returned value being different from the rest, then it's easy to see that this dynamic map cannot break equational reasoning so one would expect to be able to assign it a non-monadic type: lookup :: k -> DMap a -> a insert :: k -> a -> DMap a -> DMap a Of course, DMap cannot support certain operations because that would break equational reasoning. For example: size :: DMap a -> Int would depend on the order of lookups. However, if we restrict the operations to insert and lookup then ER is restored. (And those two operations is all I need.) I tried several ways of implementing it but those monadic types just kept cropping up in the map interface. I'd appreciate any ideas or pointers. Regards, Lajos Nagy

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RE: GHC-6.4.1 on FreeBSD-amd64 still not ported
by Simon Marlow 17 Oct '05

17 Oct '05

On 12 October 2005 17:34, Wilhelm B. Kloke wrote: > Simon Marlow <simonmar(a)microsoft.com> schrieb: > >> Just doing 'make -k' in ghc/rts should leave all the .hc files >> behind, because you already have the -keep-hc-files flag in your >> command line, so GHC won't delete the intermediate .hc files even >> when the subsequent compilation stage fails. > > This doesn't work. The commands don't leve a .hc file behind, even > with make -k. My apologies: the failure was happening before generation of the .hc file. The error is generated by this in Cmm.h: #if SIZEOF_mp_limb_t != SIZEOF_VOID_P #error mp_limb_t != StgWord: assumptions in PrimOps.cmm are now false #endif SIZEOF_mp_limb_t comes from DerivedConstants.h, and SIZEOF_VOID_P comes from ghcautoconf.h (both in ghc/includes). Both of these files should be from the target system for a cross-compile; I strongly suspect that one of them has been overwritten by the host version in your tree. Sorry that this process is somewhat flaky; we've never got around to making the build system really do cross-compilation properly, and the fact that it usually only needs to be done once for any given platform means there isn't a lot of motivation to do the work. Cheers, Simon

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GHC build failure
by Krasimir Angelov 17 Oct '05

17 Oct '05

When I am trying to build GHC from CVS it fails with: deSugar/DsMeta.hs:288:13: Constructor `ConDecl' should have 6 arguments, but has been given 4 When checking the pattern: ConDecl con [] (L _ []) details When checking the pattern: L loc (ConDecl con [] (L _ []) details) In the definition of `repC': repC (L loc (ConDecl con [] (L _ []) details)) = do con1 <- lookupLOcc con repConstr con1 details HsDecls.ConDecl has been changed in revision 1.112 but DsMeta isn't updated.

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Network Exception
by Arias 15 Oct '05

15 Oct '05

Hi, I've a problem, I'm using this code on GHC compiler version 6.4.1: --- BEGIN --- module Main where import System.IO import Network main = withSocketsDo $ do handle <- connectTo "localhost" ( PortNumber 8080 ) hSetBuffering handle LineBuffering hClose handle --- END --- The problems is that it throws an exception at connectTo, the exception is: getServiceEntry: does not exist (no such service entry) The server and the port is correct, I have apache listening on port 8080 and if I put http://localhost:8080/ on browser it loads a web page. Do somebody knows what it happens and how to fix it? thanks.

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