setup.py

"""Build hooks for the CMake-backed C++ extension.

All packaging metadata lives in pyproject.toml; only the pieces that cannot be
expressed declaratively (ext_modules and cmdclass) remain here.
"""

import os
import platform
import subprocess
import sys

from setuptools import Extension, setup
from setuptools.command.build_ext import build_ext


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:
            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)
            )

        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)))
        hexl = "OFF"
        cmake_args = [
            "-DSEAL_USE_INTEL_HEXL=" + hexl,
            "-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=" + extdir,
            "-DPYTHON_EXECUTABLE=" + sys.executable,
        ]

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

        env = os.environ.copy()

        if platform.system() == "Windows":
            cmake_args += [f"-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_{cfg.upper()}={extdir}"]
            if sys.maxsize > 2**32:
                cmake_args += ["-A", "x64"]
            build_args += ["--", "/m", "/p:TrackFileAccess=false"]
        else:
            cmake_args += ["-DCMAKE_BUILD_TYPE=" + cfg]
            if "MAKEFLAGS" not in env:
                build_args += ["--", "-j"]

        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)


setup(
    ext_modules=[CMakeExtension("_tenseal_cpp")],
    cmdclass={"build_ext": CMakeBuild},
    zip_safe=False,
)