Success Story: Cabal and Dlls

[Krasimir Angelov]

Probably this is a bug in GHC or maybe not. In any case it will help
if you can find where is the problem. Alternatively you can try to
make as small as possible example and submit this as a bug.

Cheers,
  Krasimir

On 7/27/06, Jason Dagit <dagit at codersbase.com> wrote:
> Perhaps I spoke too soon.
>
> I loaded my dll into a C++ application (where it will be used) and as
> soon as I hit FreeLibrary() my program crashes.  I tried adding
> shutdownHaskell() to the dll and it gets a little better.  It goes
> from crashing all the time to crashing some of the time.  I wrote a
> small test program in C++ where I added a 100 iteration loop that just
> loads and unloads the Dll.  It seems to crash my program usually
> before getting to the double digits.  I noticed the memory usage seems
> to climb quite a bit too.
>
> I found this thread:
> http://www.haskell.org//pipermail/glasgow-haskell-users/2006-March/009771.html
>
> I don't see a solution listed there.  This is a show stopper for me.
> If I can't get Dlls working reliably then I won't be using haskell :(
> So I'm looking for just about any reasonable solution.
>
> Thanks,
> Jason
>
> On 7/26/06, Jason Dagit <dagit at codersbase.com> wrote:
> > Ah, when I was looking for information on doing this I didn't think to
> > check the Visual Haskell source.  Perhaps I didn't think of it because
> > I have yet to get it building (but I think I've found a few things
> > that are probably easy to improve, for example, when the .cabal file
> > has a syntax error Visual Haskell doesn't report the error correctly).
> >
> > If you get a chance I would appreciate it if you could look over the
> > code I posted on the wiki and try to improve it with your knowledge.
> >
> > Thanks,
> > Jason
> >
> > On 7/26/06, Krasimir Angelov <kr.angelov at gmail.com> wrote:
> > > Hi Jason,
> > >
> > > I am using the same technique to build VSHaskell itself.
> > >
> > > Cheers,
> > >    Krasimir
> > >
> > > On 7/27/06, Jason Dagit <dagit at codersbase.com> wrote:
> > > > Hello,
> > > >
> > > > I would like to report that I was able to use Cabal with Visual
> > > > Haskell to build Dlls in windows.  I have posted the details about
> > > > this on the Haskell wiki (and started an extremely minimal Cabal
> > > > page).  If my content is in the wrong place, please feel free to move
> > > > it (or edit it or whatever).
> > > >
> > > > http://www.haskell.org/haskellwiki/Cabal
> > > >
> > > > The trick was to take the final HSfoo-0.1.o file generated by the
> > > > normal build process (and linked with the DllMain.c code) and tell ghc
> > > > to build a dll.  I use -package with each of the dependencies in the
> > > > cabal file to link with the needed libraries.  The resulting dll seems
> > > > to be working.
> > > >
> > > > This approach is a bit hackish and while I've tried to implement as
> > > > much of it as I can in a general way it requires you to hack your
> > > > Setup.lhs file if you want to 1) build static 2) specify your exports
> > > > 3) specify the name of the resulting dll.  Also, it's only been tested
> > > > on my setup which uses Visual Haskell so it may not be fit for general
> > > > consumption.  Finally, I just started really looking at Cabal
> > > > yestarday so I may not have considered things which an experienced
> > > > Cabal user would think about.
> > > >
> > > > Is it possible to get this functionality built directly into Cabal so
> > > > that I tell it I want a DLL built from a library and it knows how to
> > > > make it happen?
> > > >
> > > > Thanks,
> > > > Jason
> > > > _______________________________________________
> > > > Libraries mailing list
> > > > Libraries at haskell.org
> > > > http://www.haskell.org/mailman/listinfo/libraries
> > > >
> > >
> > >
> >
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