callFromC.c

#include <stdio.h>
#include "cuwrap.h"

/* C driver to test invocation of wrapped cuInit */

int main(int argc, char **argv)
{
  int r;

  printf("Running main.\n");
  r = cuwrap(0);
  printf("Main completed, result %d\n", r);
}

callFromHs.hs

{-# LANGUAGE ScopedTypeVariables, ForeignFunctionInterface #-}

module Main where

import Foreign.C.Types

-- FFI interface for cuwrap interface function.
foreign import ccall unsafe "cuwrap.h cuwrap" cuwrap :: CInt -> IO CInt

main :: IO ()
main = do
  putStrLn "Running Main"
  i :: Int <- return . fromEnum =<< cuwrap 0
  putStrLn $ "Main completed, result " ++ show i

cuwrap.c

#include <stdio.h>
#include <cuda.h>

/* Invoke cuInit, reporting arg and result. */

int cuwrap(int arg)
{
  CUresult res = cuInit(arg);
  printf("cuInit called: arg %d, result %d\n", arg, res);

  return res;
}

cuwrap.h

/* Interface to cuInit allowing inspection of arg and result between C & Haskell */
int cuwrap(int arg);