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Setuptools extension extension for using CMake in setup.py?

I am writing a Python extension that links the C ++ library, and I use cmake to help with the build process. This means that right now, the only way I know how to link it, I must compile them with cmake first before I can run setup.py bdist_wheel. There must be a better way.

I was wondering if it is possible (or someone tried) to invoke CMake as part of the setup.py ext_modules build process? I suppose there is a way to subclass something, but I'm not sure where to look.

I use CMake because it gives me much more options for creating c and C ++ library extensions with complex assembly lines, just like me. In addition, I can easily create Python extensions directly from cmake using the PYTHON_ADD_MODULE () command in findPythonLibs.cmake. I just want it to be just one step away.

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build_ext build_ext build_ext setup.py . build_ext cmake , . , , distutils (. Distutils); . , build_ext.

, C foo python spam.eggs:

so-42585210/
├── spam
│   ├── __init__.py  # empty
│   ├── eggs.py
│   ├── foo.c
│   └── foo.h
├── CMakeLists.txt
└── setup.py

, .

spam/eggs.py ( ):

from ctypes import cdll
import pathlib


def wrap_bar():
    foo = cdll.LoadLibrary(str(pathlib.Path(__file__).with_name('libfoo.dylib')))
    return foo.bar()

spam/foo.c:

#include "foo.h"

int bar() {
    return 42;
}

spam/foo.h:

#ifndef __FOO_H__
#define __FOO_H__

int bar();

#endif

CMakeLists.txt:

cmake_minimum_required(VERSION 3.10.1)
project(spam)
set(src "spam")
set(foo_src "spam/foo.c")
add_library(foo SHARED ${foo_src})

. , - CMakeExtension ( . Building C C++ Extensions), CMake setup.cfg initialize_options finalize_options ..

import os
import pathlib

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


class CMakeExtension(Extension):

    def __init__(self, name):
        # don't invoke the original build_ext for this special extension
        super().__init__(name, sources=[])


class build_ext(build_ext_orig):

    def run(self):
        for ext in self.extensions:
            self.build_cmake(ext)
        super().run()

    def build_cmake(self, ext):
        cwd = pathlib.Path().absolute()

        # these dirs will be created in build_py, so if you don't have
        # any python sources to bundle, the dirs will be missing
        build_temp = pathlib.Path(self.build_temp)
        build_temp.mkdir(parents=True, exist_ok=True)
        extdir = pathlib.Path(self.get_ext_fullpath(ext.name))
        extdir.mkdir(parents=True, exist_ok=True)

        # example of cmake args
        config = 'Debug' if self.debug else 'Release'
        cmake_args = [
            '-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=' + str(extdir.parent.absolute()),
            '-DCMAKE_BUILD_TYPE=' + config
        ]

        # example of build args
        build_args = [
            '--config', config,
            '--', '-j4'
        ]

        os.chdir(str(build_temp))
        self.spawn(['cmake', str(cwd)] + cmake_args)
        if not self.dry_run:
            self.spawn(['cmake', '--build', '.'] + build_args)
        os.chdir(str(cwd))


setup(
    name='spam',
    version='0.1',
    packages=['spam'],
    ext_modules=[CMakeExtension('spam/foo')],
    cmdclass={
        'build_ext': build_ext,
    }
)

, . :

$ pip show -f spam
Name: spam
Version: 0.1
Summary: UNKNOWN
Home-page: UNKNOWN
Author: UNKNOWN
Author-email: UNKNOWN
License: UNKNOWN
Location: /Users/hoefling/.virtualenvs/stackoverflow/lib/python3.6/site-packages
Requires: 
Files:
  spam-0.1.dist-info/DESCRIPTION.rst
  spam-0.1.dist-info/INSTALLER
  spam-0.1.dist-info/METADATA
  spam-0.1.dist-info/RECORD
  spam-0.1.dist-info/WHEEL
  spam-0.1.dist-info/metadata.json
  spam-0.1.dist-info/top_level.txt
  spam/__init__.py
  spam/__pycache__/__init__.cpython-36.pyc
  spam/__pycache__/eggs.cpython-36.pyc
  spam/eggs.py
  spam/libfoo.dylib

spam.eggs:

$ python -c "from spam import eggs; print(eggs.wrap_bar())"
42
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, , .

, , .

"" . OP C/C++ Python; , C/C++ cmake, .dll/.so *.pyd/so . .py .

cmake... fun. setup.py .

setup.py , / .dll .dll, , , setuptools, , , cmake -b build_ext . , , setuptools , .

, setup.py, bpy, .pyd/.so blender python, :

https://wiki.blender.org/wiki//User:Ideasman42/BlenderAsPyModule ( , ) http://www.gizmoplex.com/wordpress/compile-blender-as-python-m odule/ (, , , , )

github :

https://github.com/TylerGubala/blenderpy

, , , , - , , cmake , , . , .

, , ?

  1. setuptools.Extension , sources libs

  2. setuptools.commands.build_ext.build_ext , , (git, svn, cmake, cmake - -b uild)

  3. distutils.command.install_data.install_data (yuck, distutils... , , setuputils) , setuptools ( files.txt) ,

    • pip uninstall package_name

    • py setup.py bdist_wheel .

  4. setuptools.command.install_lib.install_lib , , setuptools ( Windows .dll bin/Release, , setuptools)

  5. setuptools.command.install_scripts.install_scripts , (Blender , 2.79 )

  6. , setuptools site-packages . setuptools distutils instal-files.txt !

, , ( )

from distutils.command.install_data import install_data
from setuptools import find_packages, setup, Extension
from setuptools.command.build_ext import build_ext
from setuptools.command.install_lib import install_lib
from setuptools.command.install_scripts import install_scripts
import struct

BITS = struct.calcsize("P") * 8
PACKAGE_NAME = "example"

class CMakeExtension(Extension):
    """
    An extension to run the cmake build

    This simply overrides the base extension class so that setuptools
    doesn't try to build your sources for you
    """

    def __init__(self, name, sources=[]):

        super().__init__(name = name, sources = sources)

class InstallCMakeLibsData(install_data):
    """
    Just a wrapper to get the install data into the egg-info

    Listing the installed files in the egg-info guarantees that
    all of the package files will be uninstalled when the user
    uninstalls your package through pip
    """

    def run(self):
        """
        Outfiles are the libraries that were built using cmake
        """

        # There seems to be no other way to do this; I tried listing the
        # libraries during the execution of the InstallCMakeLibs.run() but
        # setuptools never tracked them, seems like setuptools wants to
        # track the libraries through package data more than anything...
        # help would be appriciated

        self.outfiles = self.distribution.data_files

class InstallCMakeLibs(install_lib):
    """
    Get the libraries from the parent distribution, use those as the outfiles

    Skip building anything; everything is already built, forward libraries to
    the installation step
    """

    def run(self):
        """
        Copy libraries from the bin directory and place them as appropriate
        """

        self.announce("Moving library files", level=3)

        # We have already built the libraries in the previous build_ext step

        self.skip_build = True

        bin_dir = self.distribution.bin_dir

        # Depending on the files that are generated from your cmake
        # build chain, you may need to change the below code, such that
        # your files are moved to the appropriate location when the installation
        # is run

        libs = [os.path.join(bin_dir, _lib) for _lib in 
                os.listdir(bin_dir) if 
                os.path.isfile(os.path.join(bin_dir, _lib)) and 
                os.path.splitext(_lib)[1] in [".dll", ".so"]
                and not (_lib.startswith("python") or _lib.startswith(PACKAGE_NAME))]

        for lib in libs:

            shutil.move(lib, os.path.join(self.build_dir,
                                          os.path.basename(lib)))

        # Mark the libs for installation, adding them to 
        # distribution.data_files seems to ensure that setuptools' record 
        # writer appends them to installed-files.txt in the package egg-info
        #
        # Also tried adding the libraries to the distribution.libraries list, 
        # but that never seemed to add them to the installed-files.txt in the 
        # egg-info, and the online recommendation seems to be adding libraries 
        # into eager_resources in the call to setup(), which I think puts them 
        # in data_files anyways. 
        # 
        # What is the best way?

        # These are the additional installation files that should be
        # included in the package, but are resultant of the cmake build
        # step; depending on the files that are generated from your cmake
        # build chain, you may need to modify the below code

        self.distribution.data_files = [os.path.join(self.install_dir, 
                                                     os.path.basename(lib))
                                        for lib in libs]

        # Must be forced to run after adding the libs to data_files

        self.distribution.run_command("install_data")

        super().run()

class InstallCMakeScripts(install_scripts):
    """
    Install the scripts in the build dir
    """

    def run(self):
        """
        Copy the required directory to the build directory and super().run()
        """

        self.announce("Moving scripts files", level=3)

        # Scripts were already built in a previous step

        self.skip_build = True

        bin_dir = self.distribution.bin_dir

        scripts_dirs = [os.path.join(bin_dir, _dir) for _dir in
                        os.listdir(bin_dir) if
                        os.path.isdir(os.path.join(bin_dir, _dir))]

        for scripts_dir in scripts_dirs:

            shutil.move(scripts_dir,
                        os.path.join(self.build_dir,
                                     os.path.basename(scripts_dir)))

        # Mark the scripts for installation, adding them to 
        # distribution.scripts seems to ensure that the setuptools' record 
        # writer appends them to installed-files.txt in the package egg-info

        self.distribution.scripts = scripts_dirs

        super().run()

class BuildCMakeExt(build_ext):
    """
    Builds using cmake instead of the python setuptools implicit build
    """

    def run(self):
        """
        Perform build_cmake before doing the 'normal' stuff
        """

        for extension in self.extensions:

            if extension.name == 'example_extension':

                self.build_cmake(extension)

        super().run()

    def build_cmake(self, extension: Extension):
        """
        The steps required to build the extension
        """

        self.announce("Preparing the build environment", level=3)

        build_dir = pathlib.Path(self.build_temp)

        extension_path = pathlib.Path(self.get_ext_fullpath(extension.name))

        os.makedirs(build_dir, exist_ok=True)
        os.makedirs(extension_path.parent.absolute(), exist_ok=True)

        # Now that the necessary directories are created, build

        self.announce("Configuring cmake project", level=3)

        # Change your cmake arguments below as necessary
        # Below is just an example set of arguments for building Blender as a Python module

        self.spawn(['cmake', '-H'+SOURCE_DIR, '-B'+self.build_temp,
                    '-DWITH_PLAYER=OFF', '-DWITH_PYTHON_INSTALL=OFF',
                    '-DWITH_PYTHON_MODULE=ON',
                    f"-DCMAKE_GENERATOR_PLATFORM=x"
                    f"{'86' if BITS == 32 else '64'}"])

        self.announce("Building binaries", level=3)

        self.spawn(["cmake", "--build", self.build_temp, "--target", "INSTALL",
                    "--config", "Release"])

        # Build finished, now copy the files into the copy directory
        # The copy directory is the parent directory of the extension (.pyd)

        self.announce("Moving built python module", level=3)

        bin_dir = os.path.join(build_dir, 'bin', 'Release')
        self.distribution.bin_dir = bin_dir

        pyd_path = [os.path.join(bin_dir, _pyd) for _pyd in
                    os.listdir(bin_dir) if
                    os.path.isfile(os.path.join(bin_dir, _pyd)) and
                    os.path.splitext(_pyd)[0].startswith(PACKAGE_NAME) and
                    os.path.splitext(_pyd)[1] in [".pyd", ".so"]][0]

        shutil.move(pyd_path, extension_path)

        # After build_ext is run, the following commands will run:
        # 
        # install_lib
        # install_scripts
        # 
        # These commands are subclassed above to avoid pitfalls that
        # setuptools tries to impose when installing these, as it usually
        # wants to build those libs and scripts as well or move them to a
        # different place. See comments above for additional information

setup(name='my_package',
      version='1.0.0a0',
      packages=find_packages(),
      ext_modules=[CMakeExtension(name="example_extension")],
      description='An example cmake extension module',
      long_description=open("./README.md", 'r').read(),
      long_description_content_type="text/markdown",
      keywords="test, cmake, extension",
      classifiers=["Intended Audience :: Developers",
                   "License :: OSI Approved :: "
                   "GNU Lesser General Public License v3 (LGPLv3)",
                   "Natural Language :: English",
                   "Programming Language :: C",
                   "Programming Language :: C++",
                   "Programming Language :: Python",
                   "Programming Language :: Python :: 3.6",
                   "Programming Language :: Python :: Implementation :: CPython"],
      license='GPL-3.0',
      cmdclass={
          'build_ext': BuildCMakeExt,
          'install_data': InstallCMakeLibsData,
          'install_lib': InstallCMakeLibs,
          'install_scripts': InstallCMakeScripts
          }
    )

setup.py , python , py setup.py, .

, . wheel (py -m pip install wheel) , py setup.py bdist_wheel, , twine .

+5

Source: https://habr.com/ru/post/1671390/

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