Packages (again)

[Koen Claessen]

Hi all,

Now, I am almost done with trying to install this package I
am working on. But, somehow, I can't get it to work for both
ghc and ghci.

I have the following simplified situation:

  * a Haskell module, Foo.hs

  * a C file, foo.c

  * a C library that foo.c needs, /path/to/libs/libbar.so

(I only have a .so version of the library.)

I configured the package file as follows:

>>>
Package {
      name            = "foo",
      import_dirs     = ["FooPath"],
      source_dirs     = ["FooPath"],
      library_dirs    = ["FooPath"],
      hs_libraries    = ["HSFoo"],
      extra_libraries = [],
      include_dirs    = [],
      c_includes      = [],
      package_deps    = [],
      extra_ghc_opts  = ["-L/path/to/libs", "-lbar"],
      extra_cc_opts   = [],
      extra_ld_opts   = []
   }
<<<

(adding the linker flags to ld_opts does not make a
difference for the rest of the story)

To make everything work with ghc, I do the following:

  * gcc -c foo.c -o foo.o

  * ghc -c Foo.hs -o Foo.o

  * ar -rsv libHSFoo.a foo.o Foo.o

Now, I can compile programs with "ghc -package foo". Great!

However, when I try ghci, it does not work. So, first, I
make a .o version of libHSFoo.a:

  * gld -r --whole-archive -o HSFoo.o libHSFoo.a

But, when I start "ghci -package foo", it does not find the
library libbar! It does not even find it when I say "ghci
-L/path/to/libs -lbar -package foo"!

No worries, we can make ghci read a .so file instead:

  * rm HSFoo.o

  * gcc -shared Foo.o foo.o -L/path/to/libs -lbar -o libHSFoo.so

Starting ghci now loads libHSFoo.so, and everything works
wonderfully.

Sadly, when I try to compile something with ghc now, it
tries to load the .so version too (instead of the .a
version) and gets mad at me.

What should I do?

/Koen.