################################################################################
  #
  # python3
  #
  ################################################################################
  
  PYTHON3_VERSION_MAJOR = 3.5
  PYTHON3_VERSION = $(PYTHON3_VERSION_MAJOR).2
  PYTHON3_SOURCE = Python-$(PYTHON3_VERSION).tar.xz
  PYTHON3_SITE = http://python.org/ftp/python/$(PYTHON3_VERSION)
  PYTHON3_LICENSE = Python software foundation license v2, others
  PYTHON3_LICENSE_FILES = LICENSE
  
  # Python itself doesn't use libtool, but it includes the source code
  # of libffi, which uses libtool. Unfortunately, it uses a beta version
  # of libtool for which we don't have a matching patch. However, this
  # is not a problem, because we don't use the libffi copy included in
  # the Python sources, but instead use an external libffi library.
  PYTHON3_LIBTOOL_PATCH = NO
  
  # Python needs itself and a "pgen" program to build itself, both being
  # provided in the Python sources. So in order to cross-compile Python,
  # we need to build a host Python first. This host Python is also
  # installed in $(HOST_DIR), as it is needed when cross-compiling
  # third-party Python modules.
  
  HOST_PYTHON3_CONF_OPTS += 	\
  	--without-ensurepip	\
  	--without-cxx-main 	\
  	--disable-sqlite3	\
  	--disable-tk		\
  	--with-expat=system	\
  	--disable-curses	\
  	--disable-codecs-cjk	\
  	--disable-nis		\
  	--enable-unicodedata	\
  	--disable-test-modules	\
  	--disable-idle3		\
  	--disable-ossaudiodev
  
  # Make sure that LD_LIBRARY_PATH overrides -rpath.
  # This is needed because libpython may be installed at the same time that
  # python is called.
  HOST_PYTHON3_CONF_ENV += \
  	LDFLAGS="$(HOST_LDFLAGS) -Wl,--enable-new-dtags"
  
  PYTHON3_DEPENDENCIES = host-python3 libffi
  
  HOST_PYTHON3_DEPENDENCIES = host-expat host-zlib
  
  PYTHON3_INSTALL_STAGING = YES
  
  ifeq ($(BR2_PACKAGE_PYTHON3_READLINE),y)
  PYTHON3_DEPENDENCIES += readline
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_CURSES),y)
  PYTHON3_DEPENDENCIES += ncurses
  else
  PYTHON3_CONF_OPTS += --disable-curses
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_DECIMAL),y)
  PYTHON3_DEPENDENCIES += mpdecimal
  PYTHON3_CONF_OPTS += --with-libmpdec=system
  else
  PYTHON3_CONF_OPTS += --with-libmpdec=none
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_PYEXPAT),y)
  PYTHON3_DEPENDENCIES += expat
  PYTHON3_CONF_OPTS += --with-expat=system
  else
  PYTHON3_CONF_OPTS += --with-expat=none
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_PYC_ONLY),y)
  PYTHON3_CONF_OPTS += --enable-old-stdlib-cache
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_SQLITE),y)
  PYTHON3_DEPENDENCIES += sqlite
  else
  PYTHON3_CONF_OPTS += --disable-sqlite3
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_SSL),y)
  PYTHON3_DEPENDENCIES += openssl
  endif
  
  ifneq ($(BR2_PACKAGE_PYTHON3_CODECSCJK),y)
  PYTHON3_CONF_OPTS += --disable-codecs-cjk
  endif
  
  ifneq ($(BR2_PACKAGE_PYTHON3_UNICODEDATA),y)
  PYTHON3_CONF_OPTS += --disable-unicodedata
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_BZIP2),y)
  PYTHON3_DEPENDENCIES += bzip2
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_ZLIB),y)
  PYTHON3_DEPENDENCIES += zlib
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_OSSAUDIODEV),y)
  PYTHON3_CONF_OPTS += --enable-ossaudiodev
  else
  PYTHON3_CONF_OPTS += --disable-ossaudiodev
  endif
  
  PYTHON3_CONF_ENV += \
  	ac_cv_have_long_long_format=yes \
  	ac_cv_file__dev_ptmx=yes \
  	ac_cv_file__dev_ptc=yes \
  	ac_cv_working_tzset=yes
  
  # uClibc is known to have a broken wcsftime() implementation, so tell
  # Python 3 to fall back to strftime() instead.
  ifeq ($(BR2_TOOLCHAIN_USES_UCLIBC),y)
  PYTHON3_CONF_ENV += ac_cv_func_wcsftime=no
  endif
  
  PYTHON3_CONF_OPTS += \
  	--without-ensurepip	\
  	--without-cxx-main 	\
  	--with-system-ffi	\
  	--disable-pydoc		\
  	--disable-test-modules	\
  	--disable-lib2to3	\
  	--disable-tk		\
  	--disable-nis		\
  	--disable-idle3		\
  	--disable-pyc-build
  
  # Python builds two tools to generate code: 'pgen' and
  # '_freeze_importlib'. Unfortunately, for the target Python, they are
  # built for the target, while we need to run them at build time. So
  # when installing host-python, we copy them to
  # $(HOST_DIR)/usr/bin. And then, when building the target python
  # package, we tell the configure script where they are located.
  define HOST_PYTHON3_INSTALL_TOOLS
  	cp $(@D)/Parser/pgen $(HOST_DIR)/usr/bin/python-pgen
  	cp $(@D)/Programs/_freeze_importlib $(HOST_DIR)/usr/bin/python-freeze-importlib
  endef
  HOST_PYTHON3_POST_INSTALL_HOOKS += HOST_PYTHON3_INSTALL_TOOLS
  
  PYTHON3_CONF_ENV += \
  	PGEN_FOR_BUILD=$(HOST_DIR)/usr/bin/python-pgen \
  	FREEZE_IMPORTLIB_FOR_BUILD=$(HOST_DIR)/usr/bin/python-freeze-importlib
  
  #
  # Remove useless files. In the config/ directory, only the Makefile
  # and the pyconfig.h files are needed at runtime.
  #
  define PYTHON3_REMOVE_USELESS_FILES
  	rm -f $(TARGET_DIR)/usr/bin/python$(PYTHON3_VERSION_MAJOR)-config
  	rm -f $(TARGET_DIR)/usr/bin/python$(PYTHON3_VERSION_MAJOR)m-config
  	rm -f $(TARGET_DIR)/usr/bin/python3-config
  	rm -f $(TARGET_DIR)/usr/bin/smtpd.py.3
  	for i in `find $(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/config-$(PYTHON3_VERSION_MAJOR)m/ \
  		-type f -not -name pyconfig.h -a -not -name Makefile` ; do \
  		rm -f $$i ; \
  	done
  	rm -rf $(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/__pycache__/
  	rm -rf $(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/lib-dynload/sysconfigdata/__pycache__
  	rm -rf $(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/collections/__pycache__
  	rm -rf $(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/importlib/__pycache__
  endef
  
  PYTHON3_POST_INSTALL_TARGET_HOOKS += PYTHON3_REMOVE_USELESS_FILES
  
  #
  # Make sure libpython gets stripped out on target
  #
  define PYTHON3_ENSURE_LIBPYTHON_STRIPPED
  	chmod u+w $(TARGET_DIR)/usr/lib/libpython$(PYTHON3_VERSION_MAJOR)*.so
  endef
  
  PYTHON3_POST_INSTALL_TARGET_HOOKS += PYTHON3_ENSURE_LIBPYTHON_STRIPPED
  
  PYTHON3_AUTORECONF = YES
  
  define PYTHON3_INSTALL_SYMLINK
  	ln -fs python3 $(TARGET_DIR)/usr/bin/python
  endef
  
  ifneq ($(BR2_PACKAGE_PYTHON),y)
  PYTHON3_POST_INSTALL_TARGET_HOOKS += PYTHON3_INSTALL_SYMLINK
  endif
  
  # Some packages may have build scripts requiring python3, whatever is the
  # python version chosen for the target.
  # Only install the python symlink in the host tree if python3 is enabled
  # for the target.
  ifeq ($(BR2_PACKAGE_PYTHON3),y)
  define HOST_PYTHON3_INSTALL_SYMLINK
  	ln -fs python3 $(HOST_DIR)/usr/bin/python
  	ln -fs python3-config $(HOST_DIR)/usr/bin/python-config
  endef
  
  HOST_PYTHON3_POST_INSTALL_HOOKS += HOST_PYTHON3_INSTALL_SYMLINK
  endif
  
  # Provided to other packages
  PYTHON3_PATH = $(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/sysconfigdata/:$(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages/
  
  $(eval $(autotools-package))
  $(eval $(host-autotools-package))
  
  define PYTHON3_CREATE_PYC_FILES
  	PYTHONPATH="$(PYTHON3_PATH)" \
  	$(HOST_DIR)/usr/bin/python$(PYTHON3_VERSION_MAJOR) \
  		support/scripts/pycompile.py \
  		$(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)
  endef
  
  ifeq ($(BR2_PACKAGE_PYTHON3_PYC_ONLY)$(BR2_PACKAGE_PYTHON3_PY_PYC),y)
  PYTHON3_TARGET_FINALIZE_HOOKS += PYTHON3_CREATE_PYC_FILES
  endif
  
  ifeq ($(BR2_PACKAGE_PYTHON3_PYC_ONLY),y)
  define PYTHON3_REMOVE_PY_FILES
  	find $(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR) -name '*.py' -print0 | \
  		xargs -0 --no-run-if-empty rm -f
  endef
  PYTHON3_TARGET_FINALIZE_HOOKS += PYTHON3_REMOVE_PY_FILES
  endif
  
  # Normally, *.pyc files should not have been compiled, but just in
  # case, we make sure we remove all of them.
  ifeq ($(BR2_PACKAGE_PYTHON3_PY_ONLY),y)
  define PYTHON3_REMOVE_PYC_FILES
  	find $(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR) -name '*.pyc' -print0 | \
  		xargs -0 --no-run-if-empty rm -f
  endef
  PYTHON3_TARGET_FINALIZE_HOOKS += PYTHON3_REMOVE_PYC_FILES
  endif
  
  # In all cases, we don't want to keep the optimized .opt-1.pyc and
  # .opt-2.pyc files, since they can't work without their non-optimized
  # variant.
  define PYTHON3_REMOVE_OPTIMIZED_PYC_FILES
  	find $(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR) -name '*.opt-1.pyc' -print0 -o -name '*.opt-2.pyc' -print0 | \
  		xargs -0 --no-run-if-empty rm -f
  endef
  PYTHON3_TARGET_FINALIZE_HOOKS += PYTHON3_REMOVE_OPTIMIZED_PYC_FILES