Better still, could you add a section to that page about DLLs and Excel? That'd be useful for others. Simon From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users-bounces@haskell.org] On Behalf Of Olivier Boudry Sent: 30 November 2007 18:09 To: glasgow-haskell-users@haskell.org Subject: Re: GHC generated dll makes Excel crash on exit. Sorry if I'm talking to myself, but I found a solution and thought it could be interesting for other people who need to call GHC created DLLs from Excel. The solution is based on the information found in : http://haskell.org/haskellwiki/GHC/Using_the_FFI#Debugging_Haskell_DLLs. As suggested, I added two extra functions in my dllMain.c file (adder_Begin, adder_End) and removed the startupHaskell call from the dllMain function. adder_Begin contains the startupHaskell call and adder_End the shutdownHaskell. dllMain just returns true. I also adapted the Excel VBA code to call adder_Begin on a WorkBook_Open event and adder_End on a WorkBook_BeforeClose event. The VBA looks like this: Public functions in a new "Module1" module (cannot declare Public functions in the ThisWorkbook module): Public Declare Function adder Lib " adder.dll" Alias "adder@8" (ByVal x As Long, ByVal y As Long) As Long Public Declare Function adder_Begin Lib "adder.dll" () As Boolean Public Declare Sub adder_End Lib "adder.dll" () Private functions the the "ThisWorkbook" module: Private Sub Workbook_BeforeClose(Cancel As Boolean) adder_End End Sub Private Sub Workbook_Open() adder_Begin End Sub The GHC dllMain.c looks like this: #include #include #define __ADDER_DLL_EXPORT #define ADDER_API _declspec(dllexport) extern void __stginit_Adder(void); static char* args[] = { "ghcDll", NULL }; /* N.B. argv arrays must end with NULL */ BOOL STDCALL DllMain( HANDLE hModule, DWORD ul_reason_for_call, LPVOID lpReserved ){ return TRUE; } ADDER_API BOOL adder_Begin(){ startupHaskell(1, args, __stginit_Adder); return HS_BOOL_TRUE; } ADDER_API void adder_End(){ shutdownHaskell(); } If somebody wants the code and Excel file, just ask, I'll be happy to provide it. Thanks, Olivier.

It's not part of the Haskell documentation! The FFI page http://haskell.org/haskellwiki/GHC/Using_the_FFI is part of the "contributed documentation", linked from here: http://haskell.org/haskellwiki/GHC So it absolutely is a Wiki, and should be editable by you (assuming you log into the wiki). If not, let's see why not. It'd be better to put your new material in with the other FFI stuff; it'll be easier to find that way. THanks SImon From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users-bounces@haskell.org] On Behalf Of Olivier Boudry Sent: 03 December 2007 14:28 To: Simon Peyton-Jones Cc: glasgow-haskell-users@haskell.org Subject: Re: GHC generated dll makes Excel crash on exit. On 12/3/07, Simon Peyton-Jones mailto:simonpj@microsoft.com> wrote: Better still, could you add a section to that page about DLLs and Excel? That'd be useful for others. Simon Simon, As the page is part of the GHC documentation I cannot edit it. I put my notes in a new wiki page : http://haskell.org/haskellwiki/How_to_use_a_Haskell_Dll_from_Excel I hope this is appropriate. Best regards, Olivier.

I moved my stuff to: http://haskell.org/haskellwiki/GHC/Using_the_FFI#Beware_of_dllMain.28.29_-_E... Cheers, Olivier.

Simon, While we're at it, I found a typo in the http://www.haskell.org/ghc/docs/latest/html/users_guide/win32-dlls.htmldocum... page. In ghc-6.6 the flag to build DLLs was --mk-dll (two leading minus signs), the new one is -shared (one leading minus sign) but in the doc it's written "--shared" ghc ––shared -o foo.dll bar.o baz.o wibble.a -lfooble should be ghc –shared -o foo.dll bar.o baz.o wibble.a -lfooble There are 6 occurences of what smells like a copy/paste bug ;-) Cheers, Olivier. On Dec 4, 2007 5:42 AM, Simon Marlow wrote:

Olivier Boudry wrote:

...

On Dec 3, 2007 10:07 AM, Simon Peyton-Jones mailto:simonpj@microsoft.com> wrote:

It's not part of the Haskell documentation! The FFI page

http://haskell.org/haskellwiki/GHC/Using_the_FFI

is part of the "contributed documentation", linked from here:

http://haskell.org/haskellwiki/GHC

So it absolutely is a Wiki, and should be editable by you (assuming you log into the wiki).

If not, let's see why not. It'd be better to put your new material in with the other FFI stuff; it'll be easier to find that way.

THanks

SImon

Simon,

I was talking about this page: http://www.haskell.org/ghc/dist/current/docs/users_guide/win32-dlls.html which is more Win32/Excel specific and is part of the GHC documentation.

But I agree it's easier to keep everything in one place so I will move my stuff to the link you mentioned.

Yes, I moved some of the wiki documentation into the user's guide before 6.8.1, but didn't delete the wiki at the time because 6.8.1 wasn't released yet. Now we have duplication, and I guess I (or someone at least) should sort it out...

Cheers, Simon