setup.py

import os
import re
import sys
import platform
import subprocess

from setuptools import setup, Extension
from setuptools.command.build_ext import build_ext
from distutils.version import LooseVersion


class CMakeExtension(Extension):
    def __init__(self, name, sourcedir=""):
        Extension.__init__(self, name, sources=[])
        self.sourcedir = os.path.abspath(sourcedir)


class CMakeBuild(build_ext):
    def run(self):
        try:
            out = subprocess.check_output(["cmake", "--version"])
        except OSError:
            raise RuntimeError(
                "CMake must be installed to build the following extensions: "
                + ", ".join(e.name for e in self.extensions)
            )

        if platform.system() == "Windows":
            cmake_version = LooseVersion(
                re.search(r"version\s*([\d.]+)", out.decode()).group(1)
            )
            if cmake_version < "3.1.0":
                raise RuntimeError("CMake >= 3.1.0 is required on Windows")

        for ext in self.extensions:
            self.build_extension(ext)

    def build_extension(self, ext):
        extdir = os.path.abspath(os.path.dirname(self.get_ext_fullpath(ext.name)))
        cmake_args = [
            "-DPython_EXECUTABLE=" + sys.executable,
            "-DPOSELIB_PYTHONPATH=" + os.pathsep.join(sys.path),
            "-DPYTHON_PACKAGE=ON",
            "-DBUILD_SHARED_LIBS=OFF",
        ]
        if os.environ.get("CMAKE_INSTALL_PREFIX") is not None:
            cmake_args += [
                f"-DCMAKE_INSTALL_PREFIX={os.environ.get('CMAKE_INSTALL_PREFIX')}"
            ]
        else:
            # Set the install prefix to the extension directory so install() commands work
            cmake_args += [f"-DCMAKE_INSTALL_PREFIX={extdir}"]

        cfg = "Debug" if self.debug else "Release"
        build_args = ["--config", cfg]

        if platform.system() == "Windows":
            if os.environ.get("CMAKE_TOOLCHAIN_FILE") is not None:
                cmake_toolchain_file = os.environ.get("CMAKE_TOOLCHAIN_FILE")
                cmake_args += [f"-DCMAKE_TOOLCHAIN_FILE={cmake_toolchain_file}"]
            cmake_args += [
                "-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_{}={}".format(cfg.upper(), extdir)
            ]
            if sys.maxsize > 2**32:
                if os.environ.get("CMAKE_TOOLCHAIN_FILE") is not None:
                    cmake_args += ["-DVCPKG_TARGET_TRIPLET=x64-windows"]
                cmake_args += ["-A", "x64"]
            build_args += ["--", "/m"]
        else:
            cmake_args += ["-DCMAKE_BUILD_TYPE=" + cfg]
            build_args += ["--", "-j2"]

        env = os.environ.copy()

        env["CXXFLAGS"] = '{} -DVERSION_INFO=\\"{}\\"'.format(
            env.get("CXXFLAGS", ""), self.distribution.get_version()
        )
        if not os.path.exists(self.build_temp):
            os.makedirs(self.build_temp)
        subprocess.check_call(
            ["cmake", ext.sourcedir] + cmake_args, cwd=self.build_temp, env=env
        )
        subprocess.check_call(
            ["cmake", "--build", "."] + build_args, cwd=self.build_temp
        )

        # Run cmake --install but only install the python component to avoid library headers/libs
        install_args = ["--config", cfg] if platform.system() == "Windows" else []
        install_args += ["--component", "python"]
        subprocess.check_call(
            ["cmake", "--install", "."] + install_args, cwd=self.build_temp
        )


# The information here can also be placed in setup.cfg - better separation of
# logic and declaration, and simpler if you include description/version in a file.
setup(
    name="poselib",
    version=open("VERSION.txt").read().strip(),
    author="Viktor Larsson and contributors",
    author_email="viktor.larsson@math.lth.se",
    description="",
    long_description="",
    ext_modules=[CMakeExtension("poselib._core")],
    packages=["poselib"],
    package_dir={"poselib": "pyposelib"},
    cmdclass={"build_ext": CMakeBuild},
    zip_safe=False,
)