nixpkgs/pkgs/development/compilers/ghcs/default.nix

{ ghcPkgUtil, gnum4, perl, ghcboot, stdenv, fetchurl, recurseIntoAttrs, gmp, readline, lib } : rec {
  
  /* What's in here?
     Goal:  really pure GHC. This means put every library into its each package.conf
     and add all together using GHC_PACKAGE_PATH

     First I've tried separating the build of ghc from it's lib. It hase been to painful. I've failed.
     Now there is nix_ghc_pkg_tool.hs which just takes the installed package.conf
     and creates a new package db file for each contained package.

     The final attribute set looks similar to this:
     ghc, core_libs and extra_libraries will then be used to build all the ohter packages availible on hackege..
     (There is much left to be done)

     ghcAndLibraries =  {
      ghc68 = {
        ghc = {
          src = "The compiler source"
          extra_src =  "source of extra libraries"
          version = "GHC version as string"
        }

        core_libs = [ libs distributed the ghc core (see libraries/core-packages ];
        extra_libraries = [ libraries contained extra_src ];
     };

     ghc66 = {
       roughly the same
     };
    }

  */

  # creates a nix package out of the single package.conf files created when after installing ghc (see nix_ghc_pkg_tool.hs)
  packageByPackageDB = ghc : # ghc
      name : 
      packageconfpath : 
      propagatedBuildInputs : 
    stdenv.mkDerivation {
    inherit name;
    phases = "buildPhase fixupPhase";
    buildInputs = [ ghcPkgUtil ];
    propagatedBuildInputs = [ ghc ] ++ propagatedBuildInputs;
    buildPhase = "setupHookRegisteringPackageDatabase \"${ghc}/${packageconfpath}\"";
  };

  # used to automatically get dependencies ( used for core_libs ) 
  # TODO use kind of state and evaluate deps of a dep only once
  resolveDeps = ghc : libs : 
    let attrs = builtins.listToAttrs libs; in
      rec {
        # using undocumented feature that attribute can contain hyphens when using listToAttrs
        # You should be able to get the attribute values using __getAttr
        result = builtins.listToAttrs (map ( l : lib.nv l.name (
                               packageByPackageDB ghc l.name 
                                      ("lib/ghc-${ghc.version}/${l.name}.conf")
                                      (map (n: builtins.getAttr n result) l.deps)
                ) ) libs );
      }.result;


  
  #this only works for ghc-6.8 right now
  ghcAndLibraries = { version, src /* , core_libraries, extra_libraries  */
                    , extra_src
                    , alias_names }:
                   recurseIntoAttrs ( rec {
    inherit src extra_src version;

    ghc = stdenv.mkDerivation {
      name = "ghc-"+version;
      inherit src ghcboot gmp version;

      buildInputs = [readline perl gnum4 gmp];

      preConfigure = "
        chmod u+x rts/gmp/configure
        # still requires a hack for ncurses
        sed -i \"s|^\(library-dirs.*$\)|\1 \\\"$ncurses/lib\\\"|\" libraries/readline/package.conf.in
      ";

      # TODO add unique (filter duplicates?) shouldn't be there? 
      nix_ghc_pkg_tool = ./nix_ghc_pkg_tool.hs;

      configurePhase = "./configure"
       +" --prefix=\$out "
       +" --with-ghc=\$ghcboot/bin/ghc"
       +" --with-gmp-libraries=$gmp/lib"
       +" --with-gmp-includes=${gmp}/include"
       +" --with-readline-libraries=\"$readline/lib\"";

      # now read the main package.conf and create a single package db file for each of them
      # Also create setup hook.

      #  note : I don't know yet wether it's a good idea to have RUNGHC.. It's faster
      # but you can't pass packages, can you?
      postInstall = "
        cp \$nix_ghc_pkg_tool nix_ghc_pkg_tool.hs
        \$out/bin/ghc-\$version --make -o nix_ghc_pkg_tool  nix_ghc_pkg_tool.hs;
        ./nix_ghc_pkg_tool split \$out/lib/ghc-\$version/package.conf \$out/lib/ghc-\$version
        cp nix_ghc_pkg_tool \$out/bin

        if test -x \$out/bin/runghc; then
          RUNHGHC=\$out/bin/runghc # > ghc-6.7/8 ?
        else
          RUNHGHC=\$out/bin/runhaskell # ghc-6.6 and prior 
        fi

        ensureDir \$out/nix-support
        sh=\$out/nix-support/setup-hook
        echo \"RUNHGHC=\$RUNHGHC\" >> \$sh
        
      ";
    };

    # Why this effort? If you want to use pretty-0.9 you can do this now without cabal choosing the 1.0 version hassle 
    core_libs = resolveDeps ghc
      [ { name = "Cabal-1.2.3.0"; deps = ["base-3.0.1.0" "pretty-1.0.0.0" "old-locale-1.0.0.0" "old-time-1.0.0.0" "directory-1.0.0.0" "unix-2.3.0.0" "process-1.0.0.0" "array-0.1.0.0" "containers-0.1.0.1" "rts-1.0" "filepath-1.1.0.0"];} #
        { name = "array-0.1.0.0"; deps = ["base-3.0.1.0"];}
        { name = "base-3.0.1.0"; deps = ["rts-1.0"];} #
        { name = "bytestring-0.9.0.1"; deps = [ "base-3.0.1.0" "array-0.1.0.0" ];}
        { name = "containers-0.1.0.1"; deps = [ "base-3.0.1.0" "array-0.1.0.0" ];}
        { name = "directory-1.0.0.0"; deps = [ "base-3.0.1.0" "old-locale-1.0.0.0" "old-time-1.0.0.0" "filepath-1.1.0.0"];}
        { name = "filepath-1.1.0.0"; deps = [ "base-3.0.1.0" ];} #
        { name = "ghc-${version}"; deps = [ "base-3.0.1.0" "old-locale-1.0.0.0" "old-time-1.0.0.0" "filepath-1.1.0.0" "directory-1.0.0.0" "array-0.1.0.0" "containers-0.1.0.1" "hpc-0.5.0.0" "bytestring-0.9.0.1" "pretty-1.0.0.0" "packedstring-0.1.0.0" "template-haskell-2.2.0.0" "unix-2.3.0.0" "process-1.0.0.0" "readline-1.0.1.0" "Cabal-1.2.3.0" "random-1.0.0.0" "haskell98-1.0.1.0"];}
        { name = "haskell98-1.0.1.0"; deps = [ "base-3.0.1.0" "old-locale-1.0.0.0" "old-time-1.0.0.0" "filepath-1.1.0.0" "directory-1.0.0.0" "random-1.0.0.0" "unix-2.3.0.0" "process-1.0.0.0" "array-0.1.0.0"];}
        { name = "hpc-0.5.0.0"; deps = [ "base-3.0.1.0" "old-locale-1.0.0.0" "old-time-1.0.0.0" "filepath-1.1.0.0" "directory-1.0.0.0" "array-0.1.0.0" "containers-0.1.0.1"]; }
        { name = "old-locale-1.0.0.0"; deps = [ "base-3.0.1.0"];}
        { name = "old-time-1.0.0.0"; deps = [ "base-3.0.1.0" "old-locale-1.0.0.0" ];}
        { name = "packedstring-0.1.0.0"; deps = [ "base-3.0.1.0" "array-0.1.0.0" ];}
        { name = "pretty-1.0.0.0"; deps = [ "base-3.0.1.0" ];}
        { name = "process-1.0.0.0"; deps = [ "base-3.0.1.0" "old-locale-1.0.0.0" "old-time-1.0.0.0" "filepath-1.1.0.0" "directory-1.0.0.0" "unix-2.3.0.0"];}
        { name = "random-1.0.0.0"; deps = [ "base-3.0.1.0" "old-locale-1.0.0.0" "old-time-1.0.0.0"];}
        { name = "readline-1.0.1.0"; deps = [ "base-3.0.1.0" "old-locale-1.0.0.0" "old-time-1.0.0.0" "filepath-1.1.0.0" "directory-1.0.0.0" "unix-2.3.0.0" "process-1.0.0.0" ];}
        { name = "rts-1.0"; deps = [];} #
        { name = "template-haskell-2.2.0.0"; deps = [ "base-3.0.1.0" "pretty-1.0.0.0" "array-0.1.0.0" "packedstring-0.1.0.0" "containers-0.1.0.1" ];}

        { name = "unix-2.3.0.0"; deps = [ "base-3.0.1.0" "old-locale-1.0.0.0" "old-time-1.0.0.0" "filepath-1.1.0.0" "directory-1.0.0.0" ];}
      ];


    extra_libs = {}; # TODO ? at the moment outside of this package 

    # contains core_libs { "base-3.0.1.0" = <derivation> ...
    # and alias names      base = base-3.0.1.0
    # (without version)  }
    # to get a specific version  don't use set.xy-7 but (__getAttr "xy-7" set)
    all_libs = let all = core_libs // extra_libs;
        in all // ( builtins.listToAttrs ( lib.mapRecordFlatten (attr : v : lib.nv attr (__getAttr v all ) ) alias_names ) );
  } );

  ghc68 = ghcAndLibraries rec {
    version = "6.8.2";
    src = fetchurl {
      #url = http://www.haskell.org/ghc/dist/stable/dist/ghc-6.8.0.20071004-src.tar.bz2;
      #sha256 = "1yyl7sxykmvkiwfxkfzpqa6cmgw19phkyjcdv99ml22j16wli63l";
      url = "http://www.haskell.org/ghc/dist/stable/dist/ghc-${version}-src.tar.bz2";
      md5 = "745c6b7d4370610244419cbfec4b2f84";
      #url = http://www.haskell.org/ghc/dist/stable/dist/ghc-6.8.20070912-src.tar.bz2;
      #sha256 = "1b1gvi7hc7sc0fkh29qvzzd5lgnlvdv3ayiak4mkfnzkahvmq85s";
    };

    extra_src = fetchurl {
      url = "http://www.haskell.org/ghc/dist/stable/dist/ghc-${version}-src-extralibs.tar.bz2";
      sha256 = "044mpbzpkbxcnqhjnrnmjs00mr85057d123rrlz2vch795lxbkcn";
      #url = http://www.haskell.org/ghc/dist/stable/dist/ghc-6.8.20070912-src-extralibs.tar.bz2;
      #sha256 = "0py7d9nh3lkhjxr3yb3n9345d0hmzq79bi40al5rcr3sb84rnp9r";
    };

    # to be able to use just array instead of array-0.1.0.0 (versions are likely to change, dependencies not that often)
    alias_names = {
      cabal = "Cabal-1.2.3.0";
      array = "array-0.1.0.0";
      base = "base-3.0.1.0";
      bytestring = "bytestring-0.9.0.1";
      containers = "containers-0.1.0.1";
      directory = "directory-1.0.0.0";
      filepath = "filepath-1.1.0.0";
      haskell98 = "haskell98-1.0.1.0";
      hpc = "hpc-0.5.0.0";
      packedstring = "packedstring-0.1.0.0";
      pretty = "pretty-1.0.0.0";
      process = "process-1.0.0.0";
      random = "random-1.0.0.0";
      readline = "readline-1.0.1.0";
      rts = "rts-1.0";
      template = "template-haskell-2.2.0.0";
      unix = "unix-2.3.0.0";
      template_haskell = "template-haskell-2.2.0.0";
      old_time = "old-time-1.0.0.0";
      old_locale = "old-locale-1.0.0.0";
    };

    # this will change because of dependency hell :) 
    #core_libraries = [ "Cabal" /* "Win32" */ "array" "base" "bytestring" "containers" 
                       #"directory" "doc" "filepath" "haskell98" "hpc" "old-locale" "old-time"
                       #"packedstring" "pretty" "process" "random" "readline" "stamp" 
                       #"template-haskell" "unix" ];

    #extra_libraries = [ "ALUT" "GLUT" "HGL" "HUnit" "ObjectIO" "OpenAL" "OpenGL" "QuickCheck" "X11" 
                        #"arrows" "cgi" "fgl" "haskell-src" "html" "mtl" "network" "parallel" "parsec" 
                        #"regex-base" "regex-compat" "regex-posix" "stm" "time" "xhtm" ];

  };
}