[Haskell-cafe] FFI, C/C++ and undefined references

[Daniel Fischer]

Am Donnerstag 14 Januar 2010 20:42:42 schrieb DNM:
> Which is weird, because 'srilm.o'/'srilm.h' are the files that define
> the mysterious "undefined references".  I'll keep plugging away and
> report back when (or whether) I make some progress.  In the meanwhile,
> if anyone has a clue, I'm all ears.
>
> Best,
> D.N.

Just an idea. Are you on windows?
If so, then your foreign calls would probably have to be

foreign import stdcall "srilm.h whatever" ...

instead of 

foreign import ccall "..."

>
> Malcolm Wallace wrote:
> > However, if you are unsure of which Haskell packages are needed, it is
> > wise to let ghc work out the dependencies for you, e.g. with
> >      ghc --make Main.hs slirm.o
> >
> > It cannot work out the C/C++ dependencies though, so every time you
> > get "undefined reference" linking errors, you must discover which C
> > code provides those symbols, and add its object file to the
> > commandline by hand.