Mixed assembly (C/Haskell)

lib.hs

{-# LANGUAGE ForeignFunctionInterface #-}
module Test where
import Foreign.C.Types

hsfun :: CInt -> IO CInt
hsfun x = do
  putStrLn "Hello from haskell"
  return (42 * x)

hsfoo :: CInt -> IO CInt
hsfoo x = do
  putStrLn "Hello foo"
  return (1024 * x)

foreign export ccall hsfun :: CInt -> IO CInt
foreign export ccall hsfoo :: CInt -> IO CInt

linker

# Creates a shared library called libMixed.so

ghc -O2 -dynamic -shared -fPIC -o libMixed.so lib.hs module_init.c -lHSrts-ghc7.10.3

module_init.c

#include <HsFFI.h>
extern void __stginit_Test(void);

static void library_init(void) __attribute__((constructor));
static void library_init(void)
{
    static char *argv[] = { "libMixed.so", 0 }, **argv_ = argv;
    static int argc = 1;

    hs_init(&argc, &argv_);
    hs_add_root(__stginit_Test);
}

static void library_exit(void) __attribute__((destructor));
static void library_exit(void)
{
    hs_exit();
}

int add(int a, int b) {
  return a + b;
}