depot/third_party/nixpkgs/pkgs/development/python-modules/cffi/default.nix

{
  lib,
  stdenv,
  buildPythonPackage,
  isPyPy,
  fetchPypi,
  setuptools,
  pytestCheckHook,
  libffi,
  pkg-config,
  pycparser,
  pythonAtLeast,
}:

if isPyPy then
  null
else
  buildPythonPackage rec {
    pname = "cffi";
    version = "1.16.0";
    pyproject = true;

    src = fetchPypi {
      inherit pname version;
      hash = "sha256-vLPvQ+WGZbvaL7GYaY/K5ndkg+DEpjGqVkeAbCXgLMA=";
    };

    patches =
      [
        #
        # Trusts the libffi library inside of nixpkgs on Apple devices.
        #
        # Based on some analysis I did:
        #
        #   https://groups.google.com/g/python-cffi/c/xU0Usa8dvhk
        #
        # I believe that libffi already contains the code from Apple's fork that is
        # deemed safe to trust in cffi.
        #
        ./darwin-use-libffi-closures.diff
      ]
      ++ lib.optionals (stdenv.cc.isClang && lib.versionAtLeast (lib.getVersion stdenv.cc) "13") [
        # -Wnull-pointer-subtraction is enabled with -Wextra. Suppress it to allow the following tests
        # to run and pass when cffi is built with newer versions of clang:
        # - testing/cffi1/test_verify1.py::test_enum_usage
        # - testing/cffi1/test_verify1.py::test_named_pointer_as_argument
        ./clang-pointer-substraction-warning.diff
      ];

    postPatch = lib.optionalString stdenv.isDarwin ''
      # Remove setup.py impurities
      substituteInPlace setup.py \
        --replace "'-iwithsysroot/usr/include/ffi'" "" \
        --replace "'/usr/include/ffi'," "" \
        --replace '/usr/include/libffi' '${lib.getDev libffi}/include'
    '';

    nativeBuildInputs = [
      pkg-config
      setuptools
    ];

    buildInputs = [ libffi ];

    propagatedBuildInputs = [ pycparser ];

    # The tests use -Werror but with python3.6 clang detects some unreachable code.
    env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-unused-command-line-argument -Wno-unreachable-code -Wno-c++11-narrowing";

    doCheck = !stdenv.hostPlatform.isMusl;

    nativeCheckInputs = [ pytestCheckHook ];

    meta = with lib; {
      changelog = "https://github.com/python-cffi/cffi/releases/tag/v${version}";
      description = "Foreign Function Interface for Python calling C code";
      downloadPage = "https://github.com/python-cffi/cffi";
      homepage = "https://cffi.readthedocs.org/";
      license = licenses.mit;
      maintainers = teams.python.members;
    };
  }