A cmake buildsystem for compiling Python
CMake C
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jcfr Merge pull request #223 from ihnorton/fix_sqlite3
Fix sqlite3 import by matching upstream build option for load_extension
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README.rst

CPython CMake Buildsystem

Overview

A replacement buildsystem for CPython.

This CMake buildsystem has the following advantages:

  • No compiled program for the target architecture is used in the build itself. This makes cross-compiling easier, less error prone, and reduces manual steps.
  • Same build information for all platforms - there's no need to maintain the autotools configuration separately from four different MSVC project files.
  • Support for other build systems and IDE's like Ninja, Sublime Text, and many others.
  • Easily build C-extensions against other C/C++ libraries built with CMake.
  • It's much faster to compile: 7 seconds instead of 58 seconds in my unscientific test.

Usage

How to use this buildsystem:

  1. Checkout the buildsystem
cd ~/scratch
git clone git://github.com/python-cmake-buildsystem/python-cmake-buildsystem
  1. Build
cd ~/scratch
mkdir -p python-build && mkdir -p python-install
cd python-build
cmake -DCMAKE_INSTALL_PREFIX:PATH=${HOME}/scratch/python-install ../python-cmake-buildsystem
make -j10
make install

Note

By default, the build system will download the python 3.6.4 source from http://www.python.org/ftp/python/

CMake Options

You can pass options to CMake to control the way Python is built. You only need to give each option once - they get saved in CMakeCache.txt. Pass options on the commandline with -DOPTION=VALUE, or use the "ccmake" gui.

PYTHON_VERSION=major.minor.patch (defaults to 3.6.4)
  The version of Python to build.

PYTHON_APPLY_PATCHES=ON|OFF (defaults to ON)
  Apply patches required to build CPython based on the system and compiler
  found when configuring the project. Note that when cross-compiling, patches
  coresponding to the target system are applied.
  Patches can be found in "patches" directory.

CMAKE_BUILD_TYPE=Debug|Release
  Build with debugging symbols or with optimisations.

CMAKE_INSTALL_PREFIX=<path>   (defaults to /usr/local)
  Path in which to install Python.

DOWNLOAD_SOURCES=ON|OFF      (defaults to ON)
  Download, check MD5 sum and extract python sources in the parent directory.
  Source archive is downloaded from http://www.python.org/ftp/python

BUILD_LIBPYTHON_SHARED=ON|OFF (defaults to OFF)
  Build libpython as a shared library (.so or .dll) or a static library
  (.a).

  Note that Python extensions are always built as shared libraries.  On
  Windows it is not possible to build shared .dll extensions against a
  static libpython, so you must build any extensions you want into libpython
  itself (see the BUILTIN flags below).

BUILD_EXTENSIONS_AS_BUILTIN=ON|OFF (defaults to OFF)
  If enabled, all extensions are statically compiled into the built python
  libraries (static and/or shared).

  Note that all previously set BUILTIN_<extension> options are ignored and
  reset to their original value.

WITH_STATIC_DEPENDENCIES=ON|OFF    (defaults to OFF, available only on UNIX)
  If this is set to ON then cmake will compile statically libpython and all
  extensions. External dependencies (ncurses, sqlite, ...) will be builtin
  only if they are available as static libraries.

BUILD_WININST=ON|OFF (only for windows, defaults to ON if not crosscompiling)
  If enabled, build the 'Windows Installer' program for distutils if not
  already provided in the source tree.

BUILD_WININST_ALWAYS=ON|OFF (only for windows, defaults to OFF)
  If enabled, always build 'Windows Installer' program for distutils even
  if it is already provided in the source tree.

INSTALL_DEVELOPMENT=ON|OFF (defaults to ON)
  If enabled, install files required to develop C extensions.

INSTALL_MANUAL=ON|OFF (defaults to ON)
  If enabled, install manuals.

INSTALL_TEST=ON|OFF (defaults to ON)
  If enabled, install test files.

ENABLE_<extension>=ON|OFF     (defaults to ON)
BUILTIN_<extension>=ON|OFF    (defaults to OFF except for POSIX, PWD and
                               NT extensions which are builtin by default)
  These two options control how individual python extensions are built.
  <extension> is the name of the extension in upper case, and without any
  leading underscore (_).  Known extensions for 2.7.12 include:

    ARRAY AUDIOOP BINASCII BISECT BSDDB BZ2 CMATH CODECS_CN CODECS_HK
    CODECS_ISO2022 CODECS_JP CODECS_KR CODECS_TW COLLECTIONS CPICKLE CRYPT
    CSTRINGIO CSV CTYPES CTYPES_TEST CURSES CURSES_PANEL DATETIME DBM
    ELEMENTTREE FCNTL FUNCTOOLS FUTURE_BUILTINS GDBM GRP HASHLIB HEAPQ
    HOTSHOT IO ITERTOOLS JSON LINUXAUDIODEV LOCALE LSPROF MATH MMAP
    MULTIBYTECODEC MULTIPROCESSING NIS NT OPERATOR OSSAUDIODEV PARSER POSIX
    PWD PYEXPAT RANDOM READLINE RESOURCE SELECT SOCKET SPWD SQLITE3 SSL
    STROP STRUCT SYSLOG TERMIOS TESTCAPI TIME TKINTER UNICODEDATA ZLIB

  All extensions are enabled by default, but some might depend on system
  libraries and will get disabled if they're not available (a list of
  extensions that didn't have all their prerequisites available will be
  printed when you run cmake).

  By default extensions are compiled as separate shared libraries (.so or
  .dll files) and installed in lib/python2.7/lib-dynload.  If you set
  BUILTIN_<extension> to ON then the extension is compiled into libpython
  instead.

USE_LIB64=ON|OFF              (defaults to OFF)
  If this is set to ON then cmake will look for dependencies in lib64 as
  well as lib directories.  Compiled python extensions will also be
  installed into lib64/python2.7/lib-dynload instead of
  lib/python2.7/lib-dynload.

Py_USING_UNICODE             (only for python2, defaults to ON)
  Enable unicode support. By default, ucs2 is used. It can be
  forced to ucs4 setting Py_UNICODE_SIZE to 4.

EXTRA_PYTHONPATH=dir1:dir2    (defaults to "")
  Colon (:) separated list of extra directories to add to the compiled-in
  PYTHONPATH.

USE_SYSTEM_LIBRARIES=ON|OFF   (defaults to ON)
  If set to OFF, no attempt to detect system libraries will be done.
  Options documented below allow to enable/disable detection of particular
  libraries.

USE_SYSTEM_Curses=ON|OFF      (defaults to ON)
  If set to OFF, no attempt to detect Curses libraries will be done.
  Associated python extensions are: CURSES, CURSES_PANEL, READLINE
  Following CMake variables can manually be set: CURSES_LIBRARIES, PANEL_LIBRARIES

USE_SYSTEM_EXPAT=ON|OFF       (defaults to ON)
  If set to OFF, no attempt to detect Expat libraries will be done.
  Associated python extensions are: ELEMENTTREE, PYEXPAT
  Following CMake variables can manually be set: EXPAT_LIBRARIES, EXPAT_INCLUDE_DIRS

USE_SYSTEM_OpenSSL=ON|OFF     (defaults to ON)
  If set to OFF, no attempt to detect OpenSSL libraries will be done.
  Associated python extensions are: HASHLIB, SSL, MD5, SHA, SHA256, SHA512
  Following CMake variables can manually be set: OPENSSL_INCLUDE_DIR, OPENSSL_LIBRARIES
  If [OPENSSL_INCLUDE_DIR, OPENSSL_LIBRARIES] are found, extensions [HASHLIB, SSL] will be built
  If [OPENSSL_INCLUDE_DIR, OPENSSL_LIBRARIES] are NOT found, extensions [SHA, SHA256, SHA512] will be built

USE_SYSTEM_TCL=ON|OFF         (defaults to ON)
  If set to OFF, no attempt to detect Tcl libraries will be done.
  Associated python extensions are: TKINTER
  Following CMake variables can manually be set: TCL_LIBRARY, TK_LIBRARY, TCL_INCLUDE_PATH, TK_INCLUDE_PATH

USE_SYSTEM_ZLIB=ON|OFF        (defaults to ON)
  If set to OFF, no attempt to detect ZLIB libraries will be done.
  Associated python extensions are: BINASCII, ZLIB
  Following CMake variables can manually be set: ZLIB_LIBRARY, ZLIB_INCLUDE_DIR, ZLIB_ROOT
  ZLIB_ROOT should be set only if USE_SYSTEM_ZLIB is ON
  If [ZLIB_LIBRARY, ZLIB_INCLUDE_DIR] are found, extensions [BINASCII] will be built with ZLIB_CRC32

USE_SYSTEM_DB=ON|OFF          (defaults to ON)
  If set to OFF, no attempt to detect DB libraries will be done.
  Associated python extensions are: BSDDB
  Following CMake variables can manually be set: DB_INCLUDE_PATH, DB_LIBRARIES

USE_SYSTEM_GDBM=ON|OFF        (defaults to ON)
  If set to OFF, no attempt to detect GDBM libraries will be done.
  Associated python extensions are: DBM, GDBM
  Following CMake variables can manually be set: GDBM_INCLUDE_PATH, GDBM_LIBRARY, GDBM_COMPAT_LIBRARY

USE_SYSTEM_READLINE=ON|OFF    (defaults to ON)
  If set to OFF, no attempt to detect Readline libraries will be done.
  Associated python extensions are: READLINE
  Following CMake variables can manually be set: READLINE_INCLUDE_PATH, READLINE_LIBRARY

USE_SYSTEM_SQLITE3=ON|OFF     (defaults to ON)
  If set to OFF, no attempt to detect SQLITE3 libraries will be done.
  Associated python extensions are: SQLITE3
  Following CMake variables can manually be set: SQLITE3_INCLUDE_PATH, SQLITE3_LIBRARY

CMAKE_OSX_SDK                (MacOSX, default is autodetected, e.g 'macosx10.06')
  By default, the variable is automatically set running `xcrun` and/or `xcodebuild`. Note that its
  value can also be explicitly set when doing a clean configuration either by adding a cache entry in
  `cmake-gui` or by passing the argument `-DCMAKE_OSX_SDK:STRING=macosx10.6` when running `cmake`.
  Then, this variable is used to initialize `CMAKE_OSX_SYSROOT`, `CMAKE_OSX_DEPLOYMENT_TARGET`
  and `MACOSX_DEPLOYMENT_TARGET` variables.

Cross-compiling

Cross-compiling for Windows from Linux

There are some patches in the cmake/patches-win32 directory that make it possible to compile Python using the mingw32 compiler. You have to apply these before running make:

patch -p0 < cmake/patches-win32/01-dynload_win.patch
patch -p0 < cmake/patches-win32/02-signalmodule.patch
patch -p0 < cmake/patches-win32/03-mingw32.patch

Remarks

Note: Currently, multiple versions of Python 2.7 and 3.5 are supported. This repository is maintained separately from Python itself it needs to be manually updated whenever there is a new release of Python.

Licenses

Materials in this repository are distributed under the following licenses:

All software is licensed under the Apache 2.0 License. See LICENSE_Apache_20 file for details.

FAQ

Why Apache 2.0 License?

From the python.org wiki, the answer to the question What if I want to contribute my code to the PSF mentions that if code is going to end up in Python or the standard library, the PSF will require you to license code under "Academic Free License" or "Apache License 2.0".