Foreign exported function returns wrong type

I call foo, foreign export ccall foo :: Int -> IO CInt, from C code like this: printf("%d\n", (int)foo((HsInt32)2500)); but when I remove the (int) cast, gcc complains (warnings, not errors) because it thinks that the thing that foo returns is a HsInt32, and not a C int. The type for foo clearly specifies it is a CInt.

The bug is that GHC is probably not generating a CInt, but a HsInt32.

{-# LANGUAGE ForeignFunctionInterface #-}
-- name this file ExportHaskellToCStruct.hs
module ExportHaskellToCStruct(foo) where
import Foreign.C
import Data.List
foreign export ccall foo :: Int -> IO CInt

foo = return . genericLength .  f

f :: Int -> [Int]
f 0 = []
f n = n:(f (n-1))

#include <stdio.h>                                                                                                                                           
#include "/correctpathto/include/HsFFI.h"         /*    FIX PATH for your installation */                                                                                                          
#define __GLASGOW_HASKELL__                                                                                                                                  

#ifdef __GLASGOW_HASKELL__
#include "ExportHaskellToCStruct_stub.h"
#endif

#ifdef __GLASGOW_HASKELL__
extern void __stginit_ExportHaskellToCStruct(void);
#endif

int main(int argc, char *argv[])
{
  int i;

  hs_init(&argc, &argv);
#ifdef __GLASGOW_HASKELL__
  hs_add_root(__stginit_ExportHaskellToCStruct);
#endif

  for (i = 0; i < 5; i++) {
    printf("%d\n", (int)foo((HsInt32)2500)); 
  }

  hs_exit();
  return 0;
}

gcc --version
gcc (Ubuntu 4.3.2-1ubuntu11) 4.3.2

Trac metadata

Trac field	Value
Version	6.10.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler (FFI)
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture