Re: Linking to Haskell code from an external program

Colin Paul Adams wrote:

Embarassing - I simply forgot to include Fib.o in the link. So it links now (program crashes, but I can try to sort that out).

I'm still intereted in knowing how to automatically get the list of required libraries.

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"Colin" == Colin Paul Adams writes:

Colin> I am trying to call a Haskell function from an Eiffel Colin> program, using C as an intermediary.

Colin> For starters, I compiled and ran a variation of the program Colin> shown in Colin> http://haskell.org/haskellwiki/Calling_Haskell_from_C, to Colin> make sure I had the C-code right.

Colin> I then attempted to move it into Eiffel. I can compile the Colin> C code OK, but I'm running into problems with linking.

Colin> I solved most of the problems by adding the -v flag to the Colin> call to ghc which I used to link the original (haskell + c Colin> only) program, and cut-and-paste the linker options from Colin> their into the Eiffel configuration file. This isn't really Colin> satisfactory - I would like some automatic way to determine Colin> what the flags should be.

The only other way I can think of is to construct the arguments yourself by querying the package database, e.g. "ghc-pkg field ld-options rts", but you'll have to combine the information from several different fields of the packages you use, and basically reproduce what GHC does to construct the ld command line. Cheers, Simon