Hi Jason,
Following your advice, I was able to get a working main, linking the .o's (no attempt at an SO this time) with GHC.
I haven't tried it, but how about this: 1. Use ghc to link a standard Haskell executable that requires your libraries. Run the link step with -v so you can see the linker flags GHC uses. 2. Use those link flags to link a .so instead. Importantly, this .so will have already been linked against the Haskell RTS, so you will be able to link it into a C program with no further dependencies. Now, there will be at least one additional complication. Before C can call into Haskell functions you will need to arrange for hs_init and hs_add_root to be executed. In order to do this you will probably have to write an additional C file, bootstrap.c. This should contain an initialization procedure that calls hs_init and hs_add_root in an function decorated with the __attribute__((constructor)) GCC extension. Bootstrap.o should then be statically linked in with the .so in order to initialise the Haskell RTS when C dynamically links in that .so.
Is there a tutorial I should be following? Well-Typed's blog post on this in the early days of shared object support seemed to be doing what I was doing.
Last time I checked Well-Typed's blog posts were one of the best sources of information on this rather arcane topic. There is no easy way to make this work at the moment, AFAIK :-( Cheers, Max