{ lib
, stdenv
, fetchFromGitHub
, bison
# boost derivation to use for the src and version.
# This is used by the boost derivation to build
# a b2 matching their version (by overriding this
# argument). Infinite recursion is not an issue
# since we only look at src and version of boost.
, useBoost ? {}
}:

let
  defaultVersion = "4.4.1";
in

stdenv.mkDerivation {
  pname = "boost-build";
  version =
    if useBoost ? version
    then "boost-${useBoost.version}"
    else defaultVersion;

  src = useBoost.src or (fetchFromGitHub {
    owner = "boostorg";
    repo = "build";
    rev = defaultVersion;
    sha256 = "1r4rwlq87ydmsdqrik4ly5iai796qalvw7603mridg2nwcbbnf54";
  });

  # b2 is in a subdirectory of boost source tarballs
  postUnpack = lib.optionalString (useBoost ? src) ''
    sourceRoot="$sourceRoot/tools/build"
  '';

  patches = [
    # Upstream defaults to gcc on darwin, but we use clang.
    ./darwin-default-toolset.patch
  ];

  nativeBuildInputs = [
    bison
  ];

  buildPhase = ''
    runHook preBuild
    ./bootstrap.sh
    runHook postBuild
  '';

  installPhase = ''
    runHook preInstall

    ./b2 install --prefix="$out"

    # older versions of b2 created this symlink,
    # which we want to support building via useBoost.
    test -e "$out/bin/bjam" || ln -s b2 "$out/bin/bjam"

    runHook postInstall
  '';

  meta = with lib; {
    homepage = "https://www.boost.org/build/";
    license = lib.licenses.boost;
    platforms = platforms.unix;
    maintainers = with maintainers; [ ivan-tkatchev ];
  };
}