{ lib, stdenv, version, buildPackages, targetPackages, texinfo, which, gettext
, pkg-config ? null, gnused, patchelf, gmp, mpfr, libmpc, libucontext ? null
, libxcrypt ? null, cloog ? null, isl ? null, zlib ? null, gnat-bootstrap ? null
, flex ? null, boehmgc ? null, zip ? null, unzip ? null, gtk2 ? null
, libart_lgpl ? null, perl ? null, xlibs ? null, langJava ? false
, javaAwtGtk ? false, langAda ? false, langGo ? false, withoutTargetLibc ? null
, threadsCross ? null }:

let
  inherit (lib) optionals;
  inherit (stdenv) buildPlatform hostPlatform targetPlatform;

in {
  # same for all gcc's
  depsBuildBuild = [ buildPackages.stdenv.cc ];

  nativeBuildInputs = [ texinfo which gettext ]
    ++ optionals (perl != null) [ perl ] ++ optionals javaAwtGtk [ pkg-config ]
    ++ optionals (with stdenv.targetPlatform; isVc4 || isRedox && flex != null)
    [ flex ] ++ optionals langAda [
      gnat-bootstrap
    ]
    # The builder relies on GNU sed (for instance, Darwin's `sed' fails with
    # "-i may not be used with stdin"), and `stdenvNative' doesn't provide it.
    ++ optionals buildPlatform.isDarwin [ gnused ];

  # For building runtime libs
  # same for all gcc's
  depsBuildTarget = (if hostPlatform == buildPlatform then
    [
      targetPackages.stdenv.cc.bintools # newly-built gcc will be used
    ]
  else
    assert targetPlatform == hostPlatform;
    [
      # build != host == target
      stdenv.cc
    ]) ++ optionals targetPlatform.isLinux [ patchelf ];

  buildInputs = [ gmp mpfr libmpc ]
    ++ optionals (lib.versionAtLeast version "10") [ libxcrypt ] ++ [
      targetPackages.stdenv.cc.bintools # For linking code at run-time
    ] ++ optionals (lib.versionOlder version "5" && cloog != null) [ cloog ]
    ++ optionals (isl != null) [ isl ] ++ optionals (zlib != null) [ zlib ]
    ++ optionals langJava [ boehmgc zip unzip ]
    ++ optionals javaAwtGtk ([ gtk2 libart_lgpl ] ++ xlibs)
    ++ optionals (langGo && stdenv.hostPlatform.isMusl) [ libucontext ];

  # threadsCross.package after gcc6 so i assume its okay for 4.8 and 4.9 too
  depsTargetTarget = optionals
    (!withoutTargetLibc && threadsCross != { } && threadsCross.package != null)
    [ threadsCross.package ];
}