{ stdenv
, clang-unwrapped
, binutils-unwrapped
, runCommand

, wrapBintoolsWith
, wrapCCWith
, buildIosSdk, targetIosSdkPkgs
, xcode
, lib
}:

let

minSdkVersion = stdenv.targetPlatform.minSdkVersion or "9.0";

in

rec {
  sdk = rec {
    name = "ios-sdk";
    type = "derivation";
    outPath = xcode + "/Contents/Developer/Platforms/${platform}.platform/Developer/SDKs/${platform}${version}.sdk";

    platform = stdenv.targetPlatform.xcodePlatform;
    version = stdenv.targetPlatform.sdkVer;
  };

  binutils = wrapBintoolsWith {
    libc = targetIosSdkPkgs.libraries;
    bintools = binutils-unwrapped;
  };

  clang = (wrapCCWith {
    cc = clang-unwrapped;
    bintools = binutils;
    libc = targetIosSdkPkgs.libraries;
    extraPackages = [ "${sdk}/System" ];
    extraBuildCommands = ''
      tr '\n' ' ' < $out/nix-support/cc-cflags > cc-cflags.tmp
      mv cc-cflags.tmp $out/nix-support/cc-cflags
      echo "-target ${stdenv.targetPlatform.config}" >> $out/nix-support/cc-cflags
      echo "-isystem ${sdk}/usr/include${lib.optionalString (lib.versionAtLeast "10" sdk.version) " -isystem ${sdk}/usr/include/c++/4.2.1/ -stdlib=libstdc++"}" >> $out/nix-support/cc-cflags
      ${lib.optionalString (lib.versionAtLeast sdk.version "14") "echo -isystem ${xcode}/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1 >> $out/nix-support/cc-cflags"}
    '';
  }) // {
    inherit sdk;
  };

  libraries = let sdk = buildIosSdk; in runCommand "libSystem-prebuilt" {
    passthru = {
      inherit sdk;
    };
  } ''
    if ! [ -d ${sdk} ]; then
        echo "You must have version ${sdk.version} of the ${sdk.platform} sdk installed at ${sdk}" >&2
        exit 1
    fi
    ln -s ${sdk}/usr $out
  '';
}