setup.py

import os
import re
import subprocess
import sys
from shutil import which

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

# Convert distutils Windows platform specifiers to CMake -A arguments
PLAT_TO_CMAKE = {
    "win32": "Win32",
    "win-amd64": "x64",
    "win-arm32": "ARM",
    "win-arm64": "ARM64",
}


# A CMakeExtension needs a sourcedir instead of a file list.
# The name must be the _single_ output extension from the CMake build.
# If you need multiple extensions, see scikit-build.
class CMakeExtension(Extension):
    def __init__(self, name, sourcedir=""):
        Extension.__init__(self, name, sources=[])
        self.sourcedir = os.path.abspath(sourcedir)


class CMakeBuild(build_ext):
    def build_extension(self, ext):
        extdir = os.path.abspath(os.path.dirname(self.get_ext_fullpath(ext.name)))

        # required for auto-detection & inclusion of auxiliary "native" libs
        if not extdir.endswith(os.path.sep):
            extdir += os.path.sep

        debug = int(os.environ.get("DEBUG", 0)) if self.debug is None else self.debug
        cfg = "Debug" if debug else "Release"

        # CMake lets you override the generator - we need to check this.
        # Can be set with Conda-Build, for example.
        cmake_generator = os.environ.get("CMAKE_GENERATOR", "")

        # Set Python_EXECUTABLE instead if you use PYBIND11_FINDPYTHON
        # EXAMPLE_VERSION_INFO shows you how to pass a value into the C++ code
        # from Python.
        cmake_args = [
            f"-DCMAKE_LIBRARY_OUTPUT_DIRECTORY={extdir}",
            f"-DPYTHON_EXECUTABLE={sys.executable}",
            f"-DCMAKE_BUILD_TYPE={cfg}",  # not used on MSVC, but no harm
        ]
        build_args = []
        # Adding CMake arguments set as environment variable
        # (needed e.g. to build for ARM OSx on conda-forge)
        if "CMAKE_ARGS" in os.environ:
            cmake_args += [item for item in os.environ["CMAKE_ARGS"].split(" ") if item]

        # # In this example, we pass in the version to C++. You might not need to.
        # cmake_args += [f"-DPYMATCHING_VERSION_INFO={self.distribution.get_version()}"]

        if self.compiler.compiler_type != "msvc":
            # Using Ninja-build since it a) is available as a wheel and b)
            # multithreads automatically. MSVC would require all variables be
            # exported for Ninja to pick it up, which is a little tricky to do.
            # Users can override the generator with CMAKE_GENERATOR in CMake
            # 3.15+.
            if not cmake_generator or cmake_generator == "Ninja":
                try:
                    import ninja  # noqa: F401

                    ninja_executable_path = os.path.join(ninja.BIN_DIR, "ninja")
                    cmake_args += [
                        "-GNinja",
                        f"-DCMAKE_MAKE_PROGRAM:FILEPATH={ninja_executable_path}",
                    ]
                except ImportError:
                    pass

        else:

            # Single config generators are handled "normally"
            single_config = any(x in cmake_generator for x in {"NMake", "Ninja"})

            # CMake allows an arch-in-generator style for backward compatibility
            contains_arch = any(x in cmake_generator for x in {"ARM", "Win64"})

            # Specify the arch if using MSVC generator, but only if it doesn't
            # contain a backward-compatibility arch spec already in the
            # generator name.
            if not single_config and not contains_arch:
                cmake_args += ["-A", PLAT_TO_CMAKE[self.plat_name]]

            # Multi-config generators have a different way to specify configs
            if not single_config:
                cmake_args += [
                    f"-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_{cfg.upper()}={extdir}"
                ]
                build_args += ["--config", cfg]

        if sys.platform.startswith("darwin"):
            # Cross-compile support for macOS - respect ARCHFLAGS if set
            archs = re.findall(r"-arch (\S+)", os.environ.get("ARCHFLAGS", ""))
            if archs:
                cmake_args += ["-DCMAKE_OSX_ARCHITECTURES={}".format(";".join(archs))]
            else:
                # If archflag not set, use platform.machine() to detect architecture
                import platform
                arch = platform.machine()
                if arch:
                    cmake_args += [f"-DCMAKE_OSX_ARCHITECTURES={platform.machine()}"]

        if sys.platform.startswith('linux') and which("gcc-10") is not None and which("g++-10") is not None:
            os.environ["CC"] = "gcc-10"
            os.environ["CXX"] = "g++-10"

        # Set CMAKE_BUILD_PARALLEL_LEVEL to control the parallel build level
        # across all generators.
        if "CMAKE_BUILD_PARALLEL_LEVEL" not in os.environ:
            # self.parallel is a Python 3 only way to set parallel jobs by hand
            # using -j in the build_ext call, not supported by pip or PyPA-build.
            if hasattr(self, "parallel") and self.parallel:
                # CMake 3.12+ only.
                build_args += [f"-j{self.parallel}"]

        build_temp = os.path.join(self.build_temp, ext.name)
        if not os.path.exists(build_temp):
            os.makedirs(build_temp)
        subprocess.check_call(["cmake", ext.sourcedir] + cmake_args, cwd=build_temp)
        subprocess.check_call(["cmake", "--build", ".", "--target", "_cpp_pymatching"] + build_args, cwd=build_temp)


version = {}
with open("src/pymatching/_version.py") as fp:
    exec(fp.read(), version)

with open("README.md", "r", encoding="utf-8") as fh:
    long_description = fh.read()

setup(
    name="PyMatching",
    version=version['__version__'],
    author="Oscar Higgott and Craig Gidney",
    url="https://github.com/oscarhiggott/PyMatching",
    description="A package for decoding quantum error correcting codes using minimum-weight perfect matching.",
    long_description=long_description,
    long_description_content_type='text/markdown',
    ext_modules=[CMakeExtension("pymatching._cpp_pymatching")],
    packages=find_packages("src"),
    package_dir={'': 'src'},
    cmdclass={"build_ext": CMakeBuild},
    zip_safe=False,
    extras_require={"test": ["pytest>=6.0"]},
    entry_points={
        'console_scripts': ['pymatching=pymatching._cli_argv:cli_argv'],
    },
    python_requires=">=3.7",
    install_requires=['scipy', 'numpy==1.*', 'networkx', 'matplotlib'],
    # Needed on Windows to avoid the default `build` colliding with Bazel's `BUILD`.
    options={'build': {'build_base': 'python_build_stim'}},
)