{ lib, stdenv, fetchurl, libcxx, coreutils, gnused }:

let rev = "199626"; in

stdenv.mkDerivation {
  name = "libc++abi-${rev}";

  src = fetchurl {
    url = "http://tarballs.nixos.org/libcxxabi-${rev}.tar.bz2";
    sha256 = "09wr6qwgmdzbmgfkdzfhph9giy0zd6fp3s017fcfy4g0prjn5s4c";
  };

  patches = [ ./no-stdc++.patch ./darwin.patch ];

  buildInputs = [ coreutils ];

  postUnpack = ''
    unpackFile ${libcxx.src}
  '' + lib.optionalString stdenv.isDarwin ''
    export TRIPLE=x86_64-apple-darwin
    # Hack: NIX_CFLAGS_COMPILE doesn't work here because clang++ isn't
    # wrapped at this point.
    export CXX="clang++ -D_LIBCXX_DYNAMIC_FALLBACK=1"
    unset SDKROOT
  '';

  installPhase = if stdenv.isDarwin
    then ''
      install -d -m 755 $out/include $out/lib
      install -m 644 lib/libc++abi.dylib $out/lib
      install -m 644 include/cxxabi.h $out/include
    ''
    else ''
      install -d -m 755 $out/include $out/lib
      install -m 644 lib/libc++abi.so.1.0 $out/lib
      install -m 644 include/cxxabi.h $out/include
      ln -s libc++abi.so.1.0 $out/lib/libc++abi.so
      ln -s libc++abi.so.1.0 $out/lib/libc++abi.so.1
    '';

  buildPhase = "(cd lib; ./buildit)";

  meta = {
    homepage = http://libcxxabi.llvm.org/;
    description = "A new implementation of low level support for a standard C++ library";
    license = "BSD";
    maintainers = [ stdenv.lib.maintainers.shlevy ];
    platforms = stdenv.lib.platforms.unix;
  };
}