On Mon, 2006-05-29 at 20:06 -0400, ihope wrote:

So I decided to pop into the FFI Report thing. I came up with this C file (which may or not actually be valid C; I'm not a C guy), called ffitest.h:

...

int add(Int x, Int y) { return x+y; }

And ffitest.hs:

...

import Foreign.C.Types

foreign import ccall "ffitest.h add" add :: CInt -> CInt -> CInt

Ye error message:

...

During interactive linking, GHCi couldn't find the following symbol: add This may be due to you not asking GHCi to load extra object files, archives or DLLs needed by your current session. (blah blah blah)

Obviously I'm doing something wrong here, but what is it?

You need to load the .o file too: note that it's not a good idea to have the .c and the .hs file with the same name since they'll want to make the same .o file. So let's assume you've got ffifest.hs and cbits.c gcc -c cbits.c -o sbits.o ghc -c ffifest.hs ghci ffifest.hs sbits.o That should link ok. Or to make a program: gcc -c cbits.c -o sbits.o ghc -c ffifest.hs ghc ffifest.o sbits.o -o ffitest Duncan