- Glasgow-haskell-users

How to find out the C type signature corresponding to a Haskell function type in FFI?
by Brian Hulley 09 Mar '06

09 Mar '06

Hi - I've got a Haskell module with the following ffi import: foreign import ccall duma_init :: Int -> IO Int However my problem is that I've got no idea what the type signature for the corresponding C function should be, and when I compile the above module with ghc -fglasgow-exts -fffi --make it doesn't create any stubs either. I've tried looking at the wiki but that only seems to give specific examples. I'm trying to find what the mapping is between Haskell function signatures and C signatures is in general. Any ideas? Also, I really wanted to be able to use () -> IO () but () doesn't seem to be allowed in FFI... A third point is, how would I pass an arbitrary monad instead of just using IO? Thanks, Brian.

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Using GHC with SMP and FFI?
by Li, Peng 09 Mar '06

09 Mar '06

[1] Extending the Haskell Foreign Function Interface with Concurrency [2] Haskell on a Shared-Memory Multiprocessor I read the above two papers [1,2] and I have been trying to write an application that uses both FFI and SMP. The first paper [1] shows how FFI is implemented on uniprocessor concurrent Haskell; the second paper [2] shows how SMP Concurrent Haskell is implemented. However, I found little documentation on using FFI with the latest SMP extension. In addition to [1], what has been changed and what should a programmer know if he wants to use FFI in a multithreaded program running on SMP machines? Best, Peng

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--make keep going?
by John Meacham 09 Mar '06

09 Mar '06

is there an option to get ghc to keep going if it encounters an error building a file with --make? as in, I'd like it to continue compiling as much as it can only skipping what actually depends on the file that failed rather than completly aborting everything. John -- John Meacham - ⑆repetae.net⑆john⑈

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Getting GHC to print "Done" when it's finished linking?
by Brian Hulley 07 Mar '06

07 Mar '06

Hi - I've set up my Visual Studio environment so that ghc is an external tool, where the output from ghc appears on the VS output pane. However when I use this to compile and link a Haskell program (I'm just using the plain text editor that comes with VC++ not the Haskell plugin because of its unfortunate MS-restricted-use licence...) the last thing ghc prints is: Linking ... but when it's finished nothing else is printed out, with the net result that I sit and wait forever! :-) Is there any flag to get ghc or the ghc linker to print "Done" or something when it's finished? Thanks, Brian.

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Re: ghc on on macbook pro (fwd)
by Wolfgang Thaller 05 Mar '06

05 Mar '06

On 4-Mar-06, at 3:33 PM, Geoffrey Alan Washburn wrote: > I don't have MacOS X Intel handy to verify, but I was under the > impression that Rosetta was only automagically invoked by the > operating system on application bundles. However, there is a > dearth of information regarding this point on the web, so I could > be wrong. Fortunately, you are :-). It's automagically invoked by the kernel's executable loader whenever any Mach-O binary is loaded that only has ppc code. You're right about the lack of (easily available) information though. A friend of mine was at the conference when they announced the switch, so I just asked him to try it out; I have found no place on the web that spells it out. Cheers, Wolfgang

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ghc on on macbook pro (fwd)
by S. Alexander Jacobson 05 Mar '06

05 Mar '06

Does ghc work on the (intel) macbooks or does it need to be rebuilt? Will code compiled for the old macs work on the macbooks or does it need to be recompiled? -Alex- ______________________________________________________________ S. Alexander Jacobson tel:917-770-6565 http://alexjacobson.com

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Need help to call ord in Data.Char
by Omar Alvi 04 Mar '06

04 Mar '06

Hello, I am new to Haskell(GHC). When i try to call the function ord which is in Data.Char from Prelude prompt. I get the following error. Not in scope ord. Hope to hear from someone soon. Thanks, Omar

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Re: GHC 6.4.1 and Win32 DLLs: Bug in shutdownHaskell?
by Cyril Schmidt 03 Mar '06

03 Mar '06

Did you try to link the DLL statically (i.e. via import library) and remove the call to shutdownHaskell() ? It worked for me (I am using Visual Studio 7, though). Cheers, Cyril ___ > >I wrapped up some Haskell modules in a Win32 DLL. >Loading the DLL dynamically (with LoadLibrary) works fine. However, >whether I actually use the library or not, the program (an application >with MFC GUI) crashes upon termination. >To find the reason for the crash, I added a new function for unloading >the DLL using FreeLibrary. FreeLibrary works fine, however the program >crashes when it returns to the main event loop. Interestingly, when I >reload the library (FreeLibrary followed by LoadLibrary) the program >continues working. However, every reload cycle causes the virtual size >of the process to increase by about 300K and the fourth reload fails >with the error message "getMBlock: VirtualAlloc failed with: 8" (appears >in a message window) accompanied by many repetitions of the message >"Timer proc: wait failed -- error code: 6" (appears on stderr) and >followed by the message "getMBlocks: misaligned block returned" (again >in a message window). Then the programm crashes. > >Development takes place on Windows XP Professional using MS Visual >Studio 6.0 SP 5 and ghc 6.4.1. There are no references from the C++ side >to the Haskell heap. I build the DLL using the command > >ghc --mk-dll -optdll--def -optdllFoo.def -o Foo.dll Foo.o Foo_stub.o >dllMain.c > >dllMain.c looks as follows: > >#include <windows.h> >#include <Rts.h> > >extern void __stginit_EUzu3820zu85(void); > >static char* args[] = { "ghcDll", NULL }; > /* N.B. argv arrays must end with NULL */ >BOOL >STDCALL >DllMain(HANDLE hModule, DWORD reason, void* reserved) { > if (reason == DLL_PROCESS_ATTACH) { > /* By now, the RTS DLL should have been hoisted in, but we need >to start it up. */ > startupHaskell(1, args, __stginit_Foo); > return TRUE; > } else if (reason == DLL_PROCESS_DETACH) { > shutdownHaskell(); > } > return TRUE; >} > >I played around with hs_exit instead of shutdownHaskell, I moved >initialization and clean-up from DllMain to my library loader, nothing >helps. Even doing no clean-up whatsoever does not change the behaviour. > >Any ideas? >Michael > > > >------------------------------ > >Message: 2 >Date: Wed, 01 Mar 2006 12:06:27 -0800 >From: Ashley Yakeley <ashley(a)semantic.org> >Subject: Re: Missing Folder in ghc? >To: glasgow-haskell-users(a)haskell.org >Message-ID: <du4us3%24cfs%241(a)sea.gmane.org> >Content-Type: text/plain; charset=ISO-8859-1; format=flowed > >Simon Marlow wrote: > >>The configure script has mis-detected your GHC version somehow. Could >>you look through the output of configure, and see what it says about >>GHC? >> > >Nothing special: > >checking build system type... i686-pc-linux-gnu >checking host system type... i686-pc-linux-gnu >checking target system type... i686-pc-linux-gnu >Canonicalised to: i386-unknown-linux >checking for path to top of build tree... >/home/ashley/Projects/Collected/Haskell/ghc >checking for ghc... /usr/bin/ghc >checking version of ghc... 6.4 >checking for nhc... no >checking for nhc98... no >checking for hbc... no > >>Also look in mk/config.mk, at the value of GhcCanonVersion. >> > >GHC = /usr/bin/ghc >GhcDir = $(dir $(GHC)) >GhcVersion = 6.4 >GhcMajVersion = 6 >GhcMinVersion = 4 >GhcPatchLevel = 0 > ># Canonicalised ghc version number, used for easy (integer) version ># comparisons. We must expand $(GhcMinVersion) to two digits by ># adding a leading zero if necessary: >ifneq "$(findstring $(GhcMinVersion), 0 1 2 3 4 5 6 7 8 9)" "" >GhcCanonVersion = $(GhcMajVersion)0$(GhcMinVersion) >else >GhcCanonVersion = $(GhcMajVersion)$(GhcMinVersion) >endif > >>Maybe you switched GHC versions but didn't reconfigure? >> > >I think the problem is that I called autoconf etc. before I called >darcs-all get, but not after. Calling autoreconf fixed the problem. >

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Now -split-objs work with --make
by Bulat Ziganshin 03 Mar '06

03 Mar '06

This means that ghc 6.6 starting from current build can optimize EXE sizes by throwing away all unused functions This is a forwarded message ===8<==============Original message text=============== Date: Thu, 2 Mar 2006 09:07:34 -0800 From: Simon Marlow <simonmar(a)microsoft.com> Subject: patch applied (ghc): Make -split-objs work with --make To: cvs-ghc(a)haskell.org Message-ID: <20060302170734.GA2619(a)cvs.haskell.org> Thu Mar 2 09:05:05 PST 2006 Simon Marlow <simonmar(a)microsoft.com> * Make -split-objs work with --make This turned out to be a lot easier than I thought. Just moving a few bits of -split-objs support from the build system into the compiler was enough. The only thing that Cabal needs to do in order to support -split-objs now is to pass the names of the split objects rather than the monolithic ones to 'ar'. M ./ghc/compiler/Makefile +2 M ./ghc/compiler/main/DriverPhases.hs +1 M ./ghc/compiler/main/DriverPipeline.hs -19 +50 M ./mk/target.mk -28 ===8<===========End of original message text=========== -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com

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building ghc-6.4.1 with gcc-4.1.0 on x86_64
by Jens Petersen 03 Mar '06

03 Mar '06

Hi, I'm having problems building ghc-6.4.1 with gcc-4.1.0 on x86_64 (amd64). It builds fine with gcc-4.1 on 32bit ix86. gcc-4.1.0 is the default compiler in Fedora Core 5, which will be released soon. Below is part of the buildlog where it is failing during stage2 linking. Jens ../../ghc/compiler/stage1/ghc-inplace -o stage2/ghc-6.4.1 -H16m -O -istage2/utils -istage2/basicTypes -istage2/types -istage2/hsSyn -istage2/prelude -istage2/rename -istage2/typecheck -istage2/deSugar -istage2/coreSyn -istage2/specialise -istage2/simplCore -istage2/stranal -istage2/stgSyn -istage2/simplStg -istage2/codeGen -istage2/main -istage2/profiling -istage2/parser -istage2/cprAnalysis -istage2/compMan -istage2/ndpFlatten -istage2/iface -istage2/cmm -istage2/nativeGen -istage2/ghci -Istage2 -DGHCI -package template-haskell -package readline -DUSE_READLINE -cpp -fglasgow-exts -fno-generics -Rghc-timing -I. -IcodeGen -InativeGen -Iparser -package unix -package Cabal -ignore-package lang -recomp -Rghc-timing -H16M '-#include "hschooks.h"' -no-link-chk stage2/basicTypes/BasicTypes.o stage2/basicTypes/DataCon.o stage2/basicTypes/Demand.o stage2/basicTypes/FieldLabel.o stage2/basicTypes/Id.o stage2/basicTypes/IdInfo.o stage2/basicTypes/Literal.o stage2/basicTypes/MkId.o stage2/basicTypes/Module.o stage2/basicTypes/Name.o stage2/basicTypes/NameEnv.o stage2/basicTypes/NameSet.o stage2/basicTypes/NewDemand.o stage2/basicTypes/OccName.o stage2/basicTypes/RdrName.o stage2/basicTypes/SrcLoc.o stage2/basicTypes/UniqSupply.o stage2/basicTypes/Unique.o stage2/basicTypes/Var.o stage2/basicTypes/VarEnv.o stage2/basicTypes/VarSet.o stage2/cmm/CLabel.o stage2/cmm/Cmm.o stage2/cmm/CmmLex.o stage2/cmm/CmmLint.o stage2/cmm/CmmParse.o stage2/cmm/CmmUtils.o stage2/cmm/MachOp.o stage2/cmm/PprC.o stage2/cmm/PprCmm.o stage2/codeGen/Bitmap.o stage2/codeGen/CgBindery.o stage2/codeGen/CgCallConv.o stage2/codeGen/CgCase.o stage2/codeGen/CgClosure.o stage2/codeGen/CgCon.o stage2/codeGen/CgExpr.o stage2/codeGen/CgForeignCall.o stage2/codeGen/CgHeapery.o stage2/codeGen/CgInfoTbls.o stage2/codeGen/CgLetNoEscape.o stage2/codeGen/CgMonad.o stage2/codeGen/CgParallel.o stage2/codeGen/CgPrimOp.o stage2/codeGen/CgProf.o stage2/codeGen/CgStackery.o stage2/codeGen/CgTailCall.o stage2/codeGen/CgTicky.o stage2/codeGen/CgUtils.o stage2/codeGen/ClosureInfo.o stage2/codeGen/CodeGen.o stage2/codeGen/SMRep.o stage2/compMan/CompManager.o stage2/coreSyn/CoreFVs.o stage2/coreSyn/CoreLint.o stage2/coreSyn/CorePrep.o stage2/coreSyn/CoreSubst.o stage2/coreSyn/CoreSyn.o stage2/coreSyn/CoreTidy.o stage2/coreSyn/CoreUnfold.o stage2/coreSyn/CoreUtils.o stage2/coreSyn/ExternalCore.o stage2/coreSyn/MkExternalCore.o stage2/coreSyn/PprCore.o stage2/coreSyn/PprExternalCore.o stage2/cprAnalysis/CprAnalyse.o stage2/deSugar/Check.o stage2/deSugar/Desugar.o stage2/deSugar/DsArrows.o stage2/deSugar/DsBinds.o stage2/deSugar/DsCCall.o stage2/deSugar/DsExpr.o stage2/deSugar/DsForeign.o stage2/deSugar/DsGRHSs.o stage2/deSugar/DsListComp.o stage2/deSugar/DsMeta.o stage2/deSugar/DsMonad.o stage2/deSugar/DsUtils.o stage2/deSugar/Match.o stage2/deSugar/MatchCon.o stage2/deSugar/MatchLit.o stage2/ghci/ByteCodeAsm.o stage2/ghci/ByteCodeFFI.o stage2/ghci/ByteCodeGen.o stage2/ghci/ByteCodeInstr.o stage2/ghci/ByteCodeItbls.o stage2/ghci/ByteCodeLink.o stage2/ghci/InteractiveUI.o stage2/ghci/Linker.o stage2/ghci/ObjLink.o stage2/hsSyn/Convert.o stage2/hsSyn/HsBinds.o stage2/hsSyn/HsDecls.o stage2/hsSyn/HsExpr.o stage2/hsSyn/HsImpExp.o stage2/hsSyn/HsLit.o stage2/hsSyn/HsPat.o stage2/hsSyn/HsSyn.o stage2/hsSyn/HsTypes.o stage2/hsSyn/HsUtils.o stage2/iface/BinIface.o stage2/iface/BuildTyCl.o stage2/iface/IfaceEnv.o stage2/iface/IfaceSyn.o stage2/iface/IfaceType.o stage2/iface/LoadIface.o stage2/iface/MkIface.o stage2/iface/TcIface.o stage2/main/CmdLineOpts.o stage2/main/CodeOutput.o stage2/main/Config.o stage2/main/Constants.o stage2/main/DriverFlags.o stage2/main/DriverMkDepend.o stage2/main/DriverPhases.o stage2/main/DriverPipeline.o stage2/main/DriverState.o stage2/main/DriverUtil.o stage2/main/ErrUtils.o stage2/main/Finder.o stage2/main/GetImports.o stage2/main/HscMain.o stage2/main/HscStats.o stage2/main/HscTypes.o stage2/main/Main.o stage2/main/PackageConfig.o stage2/main/Packages.o stage2/main/ParsePkgConf.o stage2/main/SysTools.o stage2/main/TidyPgm.o stage2/nativeGen/AsmCodeGen.o stage2/nativeGen/MachCodeGen.o stage2/nativeGen/MachInstrs.o stage2/nativeGen/MachRegs.o stage2/nativeGen/NCGMonad.o stage2/nativeGen/PositionIndependentCode.o stage2/nativeGen/PprMach.o stage2/nativeGen/RegAllocInfo.o stage2/nativeGen/RegisterAlloc.o stage2/ndpFlatten/FlattenInfo.o stage2/ndpFlatten/FlattenMonad.o stage2/ndpFlatten/Flattening.o stage2/ndpFlatten/NDPCoreUtils.o stage2/ndpFlatten/PArrAnal.o stage2/parser/Ctype.o stage2/parser/LexCore.o stage2/parser/Lexer.o stage2/parser/Parser.o stage2/parser/ParserCore.o stage2/parser/ParserCoreUtils.o stage2/parser/RdrHsSyn.o stage2/prelude/ForeignCall.o stage2/prelude/PrelInfo.o stage2/prelude/PrelNames.o stage2/prelude/PrelRules.o stage2/prelude/PrimOp.o stage2/prelude/TysPrim.o stage2/prelude/TysWiredIn.o stage2/profiling/CostCentre.o stage2/profiling/SCCfinal.o stage2/rename/RnBinds.o stage2/rename/RnEnv.o stage2/rename/RnExpr.o stage2/rename/RnHsSyn.o stage2/rename/RnNames.o stage2/rename/RnSource.o stage2/rename/RnTypes.o stage2/simplCore/CSE.o stage2/simplCore/FloatIn.o stage2/simplCore/FloatOut.o stage2/simplCore/LiberateCase.o stage2/simplCore/OccurAnal.o stage2/simplCore/SAT.o stage2/simplCore/SATMonad.o stage2/simplCore/SetLevels.o stage2/simplCore/SimplCore.o stage2/simplCore/SimplEnv.o stage2/simplCore/SimplMonad.o stage2/simplCore/SimplUtils.o stage2/simplCore/Simplify.o stage2/simplStg/SRT.o stage2/simplStg/SimplStg.o stage2/simplStg/StgStats.o stage2/specialise/Rules.o stage2/specialise/SpecConstr.o stage2/specialise/Specialise.o stage2/stgSyn/CoreToStg.o stage2/stgSyn/StgLint.o stage2/stgSyn/StgSyn.o stage2/stranal/DmdAnal.o stage2/stranal/SaAbsInt.o stage2/stranal/SaLib.o stage2/stranal/StrictAnal.o stage2/stranal/WorkWrap.o stage2/stranal/WwLib.o stage2/typecheck/Inst.o stage2/typecheck/TcArrows.o stage2/typecheck/TcBinds.o stage2/typecheck/TcClassDcl.o stage2/typecheck/TcDefaults.o stage2/typecheck/TcDeriv.o stage2/typecheck/TcEnv.o stage2/typecheck/TcExpr.o stage2/typecheck/TcForeign.o stage2/typecheck/TcGenDeriv.o stage2/typecheck/TcHsSyn.o stage2/typecheck/TcHsType.o stage2/typecheck/TcInstDcls.o stage2/typecheck/TcMType.o stage2/typecheck/TcMatches.o stage2/typecheck/TcPat.o stage2/typecheck/TcRnDriver.o stage2/typecheck/TcRnMonad.o stage2/typecheck/TcRnTypes.o stage2/typecheck/TcRules.o stage2/typecheck/TcSimplify.o stage2/typecheck/TcSplice.o stage2/typecheck/TcTyClsDecls.o stage2/typecheck/TcTyDecls.o stage2/typecheck/TcType.o stage2/typecheck/TcUnify.o stage2/types/Class.o stage2/types/FunDeps.o stage2/types/Generics.o stage2/types/InstEnv.o stage2/types/Kind.o stage2/types/TyCon.o stage2/types/Type.o stage2/types/TypeRep.o stage2/types/Unify.o stage2/utils/Bag.o stage2/utils/Binary.o stage2/utils/BitSet.o stage2/utils/Digraph.o stage2/utils/FastMutInt.o stage2/utils/FastString.o stage2/utils/FastTypes.o stage2/utils/FiniteMap.o stage2/utils/IOEnv.o stage2/utils/ListSetOps.o stage2/utils/Maybes.o stage2/utils/OrdList.o stage2/utils/Outputable.o stage2/utils/Panic.o stage2/utils/Pretty.o stage2/utils/PrimPacked.o stage2/utils/StringBuffer.o stage2/utils/UnicodeUtil.o stage2/utils/UniqFM.o stage2/utils/UniqSet.o stage2/utils/Util.o stage2/parser/hschooks.o /builddir/build/BUILD/ghc-6.4.1/ghc/rts/libHSrts.a(Linker.o):(.data+0x48): undefined reference to `StgReturn' /builddir/build/BUILD/ghc-6.4.1/ghc/rts/libHSrts.a(RtsStartup.o): In function `hs_add_root':RtsStartup.c:(.text+0x1a9): undefined reference to `StgRun' /builddir/build/BUILD/ghc-6.4.1/ghc/rts/libHSrts.a(Schedule.o): In function `scheduleWaitThread':Schedule.c:(.text+0x1203): undefined reference to `StgRun' /builddir/build/BUILD/ghc-6.4.1/ghc/rts/libHSrts.a(Exception.o): In function `raisezh_fast':ghc11869.hc:(.text+0x2fd): undefined reference to `StgReturn' /builddir/build/BUILD/ghc-6.4.1/ghc/rts/libHSrts.a(Exception.o): In function `killThreadzh_fast':ghc11869.hc:(.text+0x480): undefined reference to `StgReturn' /builddir/build/BUILD/ghc-6.4.1/ghc/rts/libHSrts.a(HeapStackCheck.o): In function `stg_block_putmvar':ghc11877.hc:(.text+0x4a): undefined reference to `StgReturn' /builddir/build/BUILD/ghc-6.4.1/ghc/rts/libHSrts.a(HeapStackCheck.o): In function `stg_block_takemvar':ghc11877.hc:(.text+0xba): undefined reference to `StgReturn' /builddir/build/BUILD/ghc-6.4.1/ghc/rts/libHSrts.a(HeapStackCheck.o): In function `stg_block_1':ghc11877.hc:(.text+0x122): undefined reference to `StgReturn' /builddir/build/BUILD/ghc-6.4.1/ghc/rts/libHSrts.a(HeapStackCheck.o):ghc11877.hc:(.text+0x157): more undefined references to `StgReturn' follow collect2: ld returned 1 exit status <<ghc: 28053064 bytes, 4 GCs, 156296/156296 avg/max bytes residency (1 samples), 15M in use, 0.00 INIT (0.00 elapsed), 0.05 MUT (7.22 elapsed), 0.01 GC (0.05 elapsed) :ghc>> make[2]: *** [stage2/ghc-6.4.1] Error 1

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