Well I tried this statement ghc --mk-dll -fglasgow-exts -fffi -I. --make ExternLib.hs It only compiled the object file, creating ExternLib.o, but it did not create the stub file or attempt to link in the dependent packages. I then went back to this, ghc --mk-dll -fglasgow-exts -fffi -o netsim.dll ExternLib.o ExternLib_stub.o dllNet.o src1.o src1_stub.o src2.o -package parsec -optl-lmatrixstack -optl-L"." This removed the undefined references to the parsec package, however I still can't get it to link to the matrixstack.lib and matrixstack.dll. matrixstack.lib was created using dlltool and does link just fine if linking the sources into a stand alone executable instead of a .dll. I did try to include matrixstack.lib on the command line directly as well but that ended up with the same problem. Is it possible to just compile everything into C? I'd need to link to the haskell runtime libraries somehow. Esa Ilari Vuokko wrote:

Hi

On 9/27/06, Matthew Bromberg wrote:

...

though I have a binary build of ghc 6.5

If you have new ghc 6.5, you can use --mk-dll with --make, in case that helps.

...

ghc --mk-dll -o netsim.dll ExternLib.o ExternLib_stub.o dllNet.o src1.o src1_stub.o src2.o -optl-lmatrixstack -optl-L"."

My external C library is in matrixstack.dll and it has a corresponding static link stub library matrixstack.lib in the same directory as all the sources. It has references in one of the sources (say src1.hs).

If I recall correctly, to link Ms-style import libs, you must specify them as object files (ie no -optl-lfoo, but just foo.lib) or make mingw-style import libs via .def files. But as you've not run into this yet, maybe it works for you like that.

...

Unfortunately I get a host of undefined references to basically all the functions in matrixstack.dll and also some undefined references of the form Parsefile.o:ghc2996_0.hc:(.text+0x130): undefined reference to `TextziParserCombinatorsziParsecziError_show_closure' Parsefile.o:ghc2996_0.hc:(.text+0x220): undefined reference to `TextziParserCombinatorsziParsecziChar_spaces_closure' Parsefile.o:ghc2996_0.hc:(.text+0x24a): undefined reference to `TextziParserCombinatorsziParsecziChar_spaces_closure' Parsefile.o:ghc2996_0.hc:(.text+0x29c): undefined reference to `TextziParserCombinatorsziParsecziChar_spaces_closure'

Add -package parsec to you ghc commandline. And similary for any other packages you used while compiling.

HTH, Esa _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

-- View this message in context: http://www.nabble.com/Creating-DLLs-with-GHC-tf2342692.html#a6529535 Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.

Jason Dagit wrote:

On 9/26/06, Matthew Bromberg wrote:

...

I am having some difficulty with creating a dynamic link library using GHC on windows XP.

I am attempting to follow the example in http://www.haskell.org/ghc/docs/6.4/html/users_guide/win32-dlls.html

though I have a binary build of ghc 6.5

My problem (I think) is that some of my Haskell source files link to an external C library also contained in a DLL.

I generate my Haskell object files when I compile my Haskell executable. I then attempt to use the object files in a ghc compiler statement like this,

ghc --mk-dll -o netsim.dll ExternLib.o ExternLib_stub.o dllNet.o src1.o src1_stub.o src2.o -optl-lmatrixstack -optl-L"."

My external C library is in matrixstack.dll and it has a corresponding static link stub library matrixstack.lib in the same directory as all the sources. It has references in one of the sources (say src1.hs).

Unfortunately I get a host of undefined references to basically all the functions in matrixstack.dll and also some undefined references of the form Parsefile.o:ghc2996_0.hc:(.text+0x130): undefined reference to `TextziParserCombinatorsziParsecziError_show_closure' Parsefile.o:ghc2996_0.hc:(.text+0x220): undefined reference to `TextziParserCombinatorsziParsecziChar_spaces_closure' Parsefile.o:ghc2996_0.hc:(.text+0x24a): undefined reference to `TextziParserCombinatorsziParsecziChar_spaces_closure' Parsefile.o:ghc2996_0.hc:(.text+0x29c): undefined reference to `TextziParserCombinatorsziParsecziChar_spaces_closure' ...

If you use cabal I think can follow an example I put on the wiki to get these undefined references to go away: http://www.haskell.org/haskellwiki/Cabal

Jason _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Does cabal really work on windows? Although it's installed I notice that when I try to build my library using it, it dies on the first foreign import statement in the first .hs source it tries to compile. It is reminiscent of trying to import a foreign C module directly ghci. ghc.exe, on the other hand has no problem with it. Does this scheme address the problem of being unable to link external C libraries (a DLL) into the Haskell DLL? Are there any other workarounds here? Is it possible to create static link libraries compatible with MS VC++? Ultimately I'm trying to link my C code with Matlab. The C code stub will then call a bunch of Haskell routines. -- View this message in context: http://www.nabble.com/Creating-DLLs-with-GHC-tf2342692.html#a6534625 Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.

SevenThunders wrote:

SevenThunders wrote:

...

I am having some difficulty with creating a dynamic link library using GHC on windows XP.

I need to report some additional strange DLL behavior with ghc.exe unfortunately.

Although I solved my linking problems and was able to create a .dll and a MS VC .lib file using a .def file. I get a nasty run time error when my program exits.

Here is a snippet of the Haskell code: module ExternLib where

... import Foreign.C.String import Foreign.Ptr import Foreign.C.Types (CInt, CDouble ) import Foreign.Marshal.Array import Foreign.Storable

foreign export stdcall initNetChan :: CString -> Ptr CInt -> IO ()

-- | initialize network parameters and return an integer array containing -- indices to the uplink channel, downlink channel initNetChan :: CString -> Ptr CInt -> IO() initNetChan simstring cptr = do

-- some processing ...

let hup = mkCInt $ hupchan netop let hdn = mkCInt $ hdnchan netop print $ "hup = " ++ (show hup) print $ "hdn = " ++ (show hdn) -- write results to the output array pokeElemOff cptr 0 hup pokeElemOff cptr 1 hdn peekElemOff cptr 0 >>= print

Here is the C code that calls it, (test.c)

#include

extern void initNetChan(char *str, int *iout) ;

int zout[64] ;

int main(int argc, char *argv[]) { printf("Starting initNetChan\n") ; initNetChan("SimPrams.in", zout) ; printf("Done initNetChan. out: %p\n", zout) ; printf("out[0] = %d out[1] = %d\n", zout[0], zout[1]) ; printf("Done") ; return(1) ; }

The dll itself uses this template taken from the GHC manual on DLLs #include #include

extern void __stginit_ExternLib(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_ExternLib); return TRUE; } return TRUE; }

I link test.c to my dll via a call cl.exe test.c netsim.lib

Running test.exe yields Starting initNetChan "hup = 26" "hdn = 30" 26 Done initNetChan. out: 00408960 out[0] = 26 out[1] = 30 Done D:\Projects\BRPhoenix\NetworkSim\FastSim>test.exe Starting initNetChan "hup = 26" "hdn = 30" 26 Done initNetChan. out: 00408960 out[0] = 26 out[1] = 30 Done

which is correct, but then the code crashes with a run time error. It is an unhandled exception: access violation. Is it possible that the Haskell code needs to do some kind of finalization process before terminating? I haven't seen the documentation for it yet. Hopefully it's just something stupid I've done, but again I am baffled.

Well I'm batting 1000 today. It was my dumb fault again. In case this helps someone else, I forgot to use the --stdcall prefix to the function declaration. Thus my stack was trashed. I needed to use a declaration something like __declspec(dllimport) void __stdcall initNetChan(HsPtr a1, HsPtr a2); -- View this message in context: http://www.nabble.com/Creating-DLLs-with-GHC-tf2342692.html#a6539496 Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.