boost-python3.rb

class BoostPython3 < Formula
  desc "C++ library for C++/Python3 interoperability"
  homepage "https://www.boost.org/"
  url "https://github.com/boostorg/boost/releases/download/boost-1.89.0/boost-1.89.0-b2-nodocs.tar.xz"
  sha256 "875cc413afa6b86922b6df3b2ad23dec4511c8a741753e57c1129e7fa753d700"
  license "BSL-1.0"
  head "https://github.com/boostorg/boost.git", branch: "master"

  livecheck do
    formula "boost"
  end

  no_autobump! because: :requires_manual_review

  bottle do
    sha256 cellar: :any,                 arm64_sequoia: "c14fd4a92ecf59b0cd310d2b40ac374861acda10acc91bf22a60f561eef32327"
    sha256 cellar: :any,                 arm64_sonoma:  "2a65824b7aa95da392fa6a720bd08ccf7290979f8c93c82de2788e063c9fdb7c"
    sha256                               arm64_ventura: "9a543bda37bf34385df7652f441f37d617473c673b176395e59bfacd26961139"
    sha256 cellar: :any,                 sonoma:        "69721dd8b8966e727b9d3472aea41dea558d918c608e1707f5263a1389199000"
    sha256 cellar: :any,                 ventura:       "98156d65dfdaa46babec13139575e95a6746287ceff3888a70b7479c728c7da7"
    sha256 cellar: :any_skip_relocation, arm64_linux:   "eed54059107d80bdef3c5c82293b088c36cba0a4e47c8f4149c565cf78778158"
    sha256 cellar: :any_skip_relocation, x86_64_linux:  "c0f69d09d2cd72ccaeb2a1cf21280759993ca31090736f55e4b79d07678445b7"
  end

  depends_on "numpy" => :build
  depends_on "boost"
  depends_on "python@3.13"

  def python3
    "python3.13"
  end

  def install
    # "layout" should be synchronized with boost
    args = %W[
      -d2
      -j#{ENV.make_jobs}
      --layout=system
      --user-config=user-config.jam
      install
      threading=multi
      link=shared,static
    ]

    # Boost is using "clang++ -x c" to select C compiler which breaks C++14
    # handling using ENV.cxx14. Using "cxxflags" and "linkflags" still works.
    args << "cxxflags=-std=c++14"
    args << "cxxflags=-stdlib=libc++" << "linkflags=-stdlib=libc++" if ENV.compiler == :clang

    # Avoid linkage to boost container and graph modules
    # Issue ref: https://github.com/boostorg/boost/issues/985
    args << "linkflags=-Wl,-dead_strip_dylibs" if OS.mac?

    # disable python detection in bootstrap.sh; it guesses the wrong include
    # directory for Python 3 headers, so we configure python manually in
    # user-config.jam below.
    inreplace "bootstrap.sh", "using python", "#using python"

    pyver = Language::Python.major_minor_version python3
    py_prefix = if OS.mac?
      Formula["python@#{pyver}"].opt_frameworks/"Python.framework/Versions"/pyver
    else
      Formula["python@#{pyver}"].opt_prefix
    end

    # Force boost to compile with the desired compiler
    (buildpath/"user-config.jam").write <<~EOS
      using #{OS.mac? ? "darwin" : "gcc"} : : #{ENV.cxx} ;
      using python : #{pyver}
                   : #{python3}
                   : #{py_prefix}/include/python#{pyver}
                   : #{py_prefix}/lib ;
    EOS

    system "./bootstrap.sh", "--prefix=#{prefix}",
                             "--libdir=#{lib}",
                             "--with-libraries=python",
                             "--with-python=#{python3}",
                             "--with-python-root=#{py_prefix}"

    system "./b2", "--build-dir=build-python3",
                   "--stagedir=stage-python3",
                   "--libdir=install-python3/lib",
                   "--prefix=install-python3",
                   "python=#{pyver}",
                   *args

    lib.install buildpath.glob("install-python3/lib/*{python,numpy}*")
    (lib/"cmake").install buildpath.glob("install-python3/lib/cmake/*{python,numpy}*")

    # Fix the path to headers installed in `boost` formula
    cmake_configs = lib.glob("cmake/boost_{python,numpy}*/boost_{python,numpy}-config.cmake")
    inreplace cmake_configs, '(_BOOST_INCLUDEDIR "${_BOOST_CMAKEDIR}/../../include/" ABSOLUTE)',
                             "(_BOOST_INCLUDEDIR \"#{Formula["boost"].opt_include}/\" ABSOLUTE)"
  end

  test do
    (testpath/"hello.cpp").write <<~CPP
      #include <boost/python.hpp>
      char const* greet() {
        return "Hello, world!";
      }
      BOOST_PYTHON_MODULE(hello)
      {
        boost::python::def("greet", greet);
      }
    CPP

    pyincludes = shell_output("#{python3}-config --includes").chomp.split
    pylib = shell_output("#{python3}-config --ldflags --embed").chomp.split
    pyver = Language::Python.major_minor_version(python3).to_s.delete(".")

    system ENV.cxx, "-shared", "-fPIC", "-std=c++14", "hello.cpp", "-L#{lib}", "-lboost_python#{pyver}",
                    "-o", "hello.so", *pyincludes, *pylib

    output = <<~PYTHON
      import hello
      print(hello.greet())
    PYTHON
    assert_match "Hello, world!", pipe_output(python3, output, 0)
  end
end