[Haskell-cafe] Bulding a library for C users on OS X

[Chris Eidhof]

On 2 nov 2009, at 03:30, Manuel M T Chakravarty wrote:

> Chris Eidhof:
>> I'm trying to call a Haskell function from C, on OS X. There's an  
>> excellent post [1] by Tomáš Janoušek that explains how to do this  
>> on Linux. However, on OS X, it's different. First of all, it looks  
>> like the -no-hs-main flag is ignored, because I get the following  
>> error:
>>
>> > ghc -O2 --make       -no-hs-main -optl '-shared' -optc '- 
>> DMODULE=Test'       -o Test.so Test.hs module_init.c
>> > [1 of 1] Compiling Main             ( Test.hs, Test.o )
>> >
>> > Test.hs:1:0: The function `main' is not defined in module `Main'''
>
> The flag -no-hs-main is a link-time flag that allows you to link  
> without a main function, but you are getting a compile time error.   
> It's as if you try to export main, but don't define it.
>
> Have you had a look at http://www.haskell.org/ghc/docs/latest/html/users_guide/ffi-ghc.html#foreign-export-ghc 
>  ?


Interesting! I didn't see that section before, thanks a lot.

-chris