ghc 7.6.3不生成_stub.c和_stub.o

Question

I'm learning how to make C++ call haskell code from a library, I was following instructions from FFI complete examples http://www.haskell.org/haskellwiki/FFI_complete_examples

however, after

ghc -v Foo.hs

only Foo_stub.h and Foo.o are created, there's no Foo_stub.c or Foo_stub.o . According to Calling Haskell from C , ghc > 7.2 doesn't generate _stub.o anymore.

In this case do I still need a stub.o to link an executable using g++ ?

At the moment after

g++ -o test Foo.o test.o `cat link_options`

I get lots of undefined symbols errors for hs_init and the like. Is it because _stub.o is not present or something else missing?

I can link them correctly using ghc:

ghc -no-hs-main -o test test.o Foo.o -lstdc++

(after reading this question: Building a dynamic library with haskell and using it from C++ )

but I wonder is it still possible to link using g++?

Answer 1

You're looking at an out-of-date example (it's using ghc 6.12.3). This example works for 7.6.3:

http://www.haskell.org/haskellwiki/GHC/Using_the_FFI