大致关注 this tutorial ，我设法让这个玩具项目工作。它从 C++ 程序调用 Haskell 函数。

{-# LANGUAGE ForeignFunctionInterface #-}

module Foo where

foreign export ccall foo :: Int -> Int -> IO Int

foo :: Int -> Int -> IO Int
foo n m = return . sum $ f n ++ f m

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

#include "HsFFI.h"
#include FOO       // Haskell module (path defined in build script)

#include <iostream>

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

  std::cout << foo(37, 19) << "\n";

  hs_exit();
  return 0;
}

name:                call-haskell-from-cxx
version:             0.1.0.0
build-type:          Simple
cabal-version:       >=1.10

executable foo.so
  main-is:          Foo.hs   
  build-depends:       base >=4.10 && <4.11
  ghc-options:         -shared -fPIC -dynamic
  extra-libraries:     HSrts-ghc8.2.1
  default-language:    Haskell2010

#!/bin/bash

hs_lib="foo.so"
hs_obj="dist/build/$hs_lib/$hs_lib"

ghc_version="8.2.1"                          # May need to be tweaked,
ghc_libdir="/usr/local/lib/ghc-$ghc_version" # depending on system setup.

set -x

cabal build

g++ -I "$ghc_libdir/include" -D"FOO=\"${hs_obj}-tmp/Foo_stub.h\"" -c bar.c++ -o test.o
g++ test.o "$hs_obj" \
   -L "$ghc_libdir/rts" "-lHSrts-ghc$ghc_version" \
   -o test

env LD_LIBRARY_PATH="dist/build/$hs_lib:$ghc_libdir/rts:$LD_LIBRARY_PATH" \
  ./test

/usr/local/lib/ghc-8.2.1/rts/libHSrts-ghc8.2.1.so: undefined reference to `base_GHCziTopHandler_flushStdHandles_closure'
/usr/local/lib/ghc-8.2.1/rts/libHSrts-ghc8.2.1.so: undefined reference to `base_GHCziStable_StablePtr_con_info'
/usr/local/lib/ghc-8.2.1/rts/libHSrts-ghc8.2.1.so: undefined reference to `base_GHCziPtr_FunPtr_con_info'
/usr/local/lib/ghc-8.2.1/rts/libHSrts-ghc8.2.1.so: undefined reference to `base_GHCziWord_W8zh_con_info'
/usr/local/lib/ghc-8.2.1/rts/libHSrts-ghc8.2.1.so: undefined reference to `base_GHCziIOziException_cannotCompactPinned_closure'
...

++ cabal build
Preprocessing executable 'foo.so' for call-haskell-from-C-0.1.0.0..
Building executable 'foo.so' for call-haskell-from-C-0.1.0.0..
Linking a.out ...
Linking dist/build/foo.so/foo.so ...
++ g++ -I /usr/local/lib/ghc-8.2.1/include '-DFOO="dist/build/foo.so/foo.so-tmp/Foo_stub.h"' -c bar.c++ -o test.o
++ g++ test.o dist/build/foo.so/foo.so -L /usr/local/lib/ghc-8.2.1/rts -lHSrts-ghc8.2.1 -o test
++ env LD_LIBRARY_PATH=dist/build/foo.so:/usr/local/lib/ghc-8.2.1/rts: sh -c 'ldd ./test; ./test'
    linux-vdso.so.1 =>  (0x00007fff23105000)
    foo.so => dist/build/foo.so/foo.so (0x00007fdfc5360000)
    libHSrts-ghc8.2.1.so => /usr/local/lib/ghc-8.2.1/rts/libHSrts-ghc8.2.1.so (0x00007fdfc52f8000)
    libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fdfc4dbe000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fdfc49f4000)
    libHSbase-4.10.0.0-ghc8.2.1.so => /usr/local/lib/ghc-8.2.1/base-4.10.0.0/libHSbase-4.10.0.0-ghc8.2.1.so (0x00007fdfc4020000)
    libHSinteger-gmp-1.0.1.0-ghc8.2.1.so => /usr/local/lib/ghc-8.2.1/integer-gmp-1.0.1.0/libHSinteger-gmp-1.0.1.0-ghc8.2.1.so (0x00007fdfc528b000)
    libHSghc-prim-0.5.1.0-ghc8.2.1.so => /usr/local/lib/ghc-8.2.1/ghc-prim-0.5.1.0/libHSghc-prim-0.5.1.0-ghc8.2.1.so (0x00007fdfc3b80000)
    libgmp.so.10 => /usr/lib/x86_64-linux-gnu/libgmp.so.10 (0x00007fdfc3900000)
    libffi.so.6 => /usr/local/lib/ghc-8.2.1/rts/libffi.so.6 (0x00007fdfc36f3000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fdfc33ea000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fdfc31e2000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fdfc2fde000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fdfc2dc1000)
    /lib64/ld-linux-x86-64.so.2 (0x00007fdfc5140000)
    libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fdfc2bab000)

最佳答案

这个答案解释了链接过程中发生了什么，为什么使用 -Wl,--no-as-needed 的解决方案工作以及应该做些什么来获得更强大的方法。

简而言之:-lHSrts-ghcXXX.so取决于 libHSbaseXXX.so , libHSinteger-gmpXXX.so和 libHSghc-primXXX.so必须在链接期间提供给链接器。

这里提出的解决方案依赖于大量的手动工作，并且可扩展性不强。但是我对 cabal 的了解还不够。告诉你如何自动化这个，但我希望你能迈出最后一步。

或者也许你会很好地使用 -Wl,--no-as-needed -解决方案，因为您知道幕后发生的事情。

让我们从不调用 foo 的情况下逐步完成版本的链接过程开始。 ，以某种简化的方式(here 是 Eli Bendersky 的一篇很棒的文章，即使它是关于静态链接的):

>>> readelf -d dist/build/foo.so/foo.so | grep NEEDED
 0x0000000000000001 (NEEDED)             Shared library: [libHSrts-ghc7.10.3.so]
 0x0000000000000001 (NEEDED)             Shared library: [libHSbase-4.8.2.0-HQfYBxpPvuw8OunzQu6JGM-ghc7.10.3.so]
 0x0000000000000001 (NEEDED)             Shared library: [libHSinteger-gmp-1.0.0.0-2aU3IZNMF9a7mQ0OzsZ0dS-ghc7.10.3.so]
 0x0000000000000001 (NEEDED)             Shared library: [libHSghc-prim-0.4.0.0-8TmvWUcS1U1IKHT0levwg3-ghc7.10.3.so]
 0x0000000000000001 (NEEDED)             Shared library: [libgmp.so.10]
 0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]

>>> readelf -d dist/build/foo.so/foo.so | grep RPATH
 0x000000000000000f (RPATH)              Library rpath: [
          /usr/lib/ghc/base_HQfYBxpPvuw8OunzQu6JGM:
          /usr/lib/ghc/rts:
          /usr/lib/ghc/ghcpr_8TmvWUcS1U1IKHT0levwg3:
          /usr/lib/ghc/integ_2aU3IZNMF9a7mQ0OzsZ0dS]

g++ ...
    -Wl,--trace-symbol=base_GHCziTopHandler_flushStdHandles_closure \
    -Wl,--verbose \
    -o test

g++ ...
   -L/usr/lib/ghc/base_HQfYBxpPvuw8OunzQu6JGM  -lHSbase-4.8.2.0-HQfYBxpPvuw8OunzQu6JGM-ghc7.10.3 \
   -L/usr/lib/ghc/integ_2aU3IZNMF9a7mQ0OzsZ0dS -lHSinteger-gmp-1.0.0.0-2aU3IZNMF9a7mQ0OzsZ0dS-ghc7.10.3 \
   -L/usr/lib/ghc/ghcpr_8TmvWUcS1U1IKHT0levwg3 -lHSghc-prim-0.4.0.0-8TmvWUcS1U1IKHT0levwg3-ghc7.10.3 \
   ...
   -o test

g++ ...
   -L...  -lHSbase-...  -Wl,-rpath,/usr/lib/ghc/base_HQfYBxpPvuw8OunzQu6JGM  \
   -L... -lHSinteger-gmp-... -Wl,-rpath,/usr/lib/ghc/integ_2aU3IZNMF9a7mQ0OzsZ0dS \
   -L... -lHSghc-prim-...  -Wl,-rpath,/usr/lib/ghc/ghcpr_8TmvWUcS1U1IKHT0levwg3 \
   ...
   -o test

关于c++ - 如何正确链接用 Haskell 编写的目标文件？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50569661/