build-python.sh - toolchain/python - Git at Google

 #!/bin/sh
 #
 # Copyright (C) 2012 The Android Open Source Project
 # Copyright (C) 2012 Ray Donnelly <mingw.android at gmail.com>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #      http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
 # Rebuild the host Python binaries from sources.
 # Also copies any gnu libstdc++ pretty-printers
 # found in $TOOLCHAIN_SRC_DIR/gcc/gcc-*
 # and Joachim Reichel's stlport pretty printers
 # found in sources/host-tools/gdb-pretty-printers/stlport
 #

 # include common function and variable definitions
 . "$NDK_BUILDTOOLS_PATH/prebuilt-common.sh"
 . "$NDK_BUILDTOOLS_PATH/common-build-host-funcs.sh"

 PROGRAM_PARAMETERS=""
 PROGRAM_DESCRIPTION="\
 This program is used to rebuild one or more Python client programs from
 sources.

 By default, the script rebuilds Python for you host system [$HOST_TAG],
 but you can use --systems=<tag1>,<tag2>,.. to ask binaries that can run on
 several distinct systems. Each <tag> value in the list can be one of the
 following:

    linux-x86
    linux-x86_64
    windows
    windows-x86  (equivalent to 'windows')
    windows-x86_64
    darwin-x86
    darwin-x86_64

 For example, here's how to rebuild Python 2.7.5 on Linux
 for six different systems:

   $PROGNAME --build-dir=/path/to/toolchain/src \n \
     --python-version=2.7.5 \n \
     --systems=linux-x86,linux-x86_64,windows,windows-x86_64,darwin-x86,darwin-x86_64"

 TOOLCHAIN_SRC_DIR=
 register_var_option "--toolchain-src-dir=<path>" TOOLCHAIN_SRC_DIR "Select toolchain source directory"

 PYTHON_VERSION=$DEFAULT_PYTHON_VERSION
 register_var_option "--python-version=<version>" PYTHON_VERSION "Select Python version."

 NDK_DIR=$ANDROID_NDK_ROOT
 register_var_option "--ndk-dir=<path>" NDK_DIR "Select NDK install directory."

 PACKAGE_DIR=
 register_var_option "--package-dir=<path>" PACKAGE_DIR "Package prebuilt tarballs into directory."

 BUILD_DIR=
 register_var_option "--build-dir=<path>" BUILD_DIR "Build Python into directory"

 bh_register_options
 register_try64_option
 register_canadian_option
 register_jobs_option

 extract_parameters "$@"

 if [ -n "$PARAMETERS" ]; then
     panic "This script doesn't take parameters, only options. See --help"
 fi

 if [ -z "$TOOLCHAIN_SRC_DIR" ]; then
     panic "Please use --toolchain-src-dir=<path> to select toolchain source directory."
 fi
 check_toolchain_src_dir "$TOOLCHAIN_SRC_DIR"
 TOOLCHAIN_SRC_DIR=`cd $TOOLCHAIN_SRC_DIR; pwd`

 BH_HOST_SYSTEMS=$(commas_to_spaces $BH_HOST_SYSTEMS)
 AUTO_BUILD="no"

 if [ "$MINGW" = "yes" ]; then
     BH_HOST_SYSTEMS="windows"
     log "Auto-config: --systems=windows"
 fi

 if [ "$DARWIN" = "yes" ]; then
     BH_HOST_SYSTEMS="darwin-x86"
     log "Auto-config: --systems=darwin-x86"
 fi

 determine_systems ()
 {
     local IN_SYSTEMS="$1"
     local OUT_SYSTEMS

     for SYSTEM in $IN_SYSTEMS; do
         if [ "$TRY64" = "yes" ]; then
             case $SYSTEM in
                 darwin-x86|linux-x86|windows-x86)
                     SYSTEM=${SYSTEM%%x86}x86_64
                     ;;
                 windows)
                     SYSTEM=windows-x86_64
                     ;;
             esac
         else
             # 'windows-x86' causes substitution
             # failure at the packing stage.
             case $SYSTEM in
                 windows-x86)
                     SYSTEM=windows
                     ;;
             esac
         fi
         OUT_SYSTEMS="$OUT_SYSTEMS $SYSTEM"
     done
     echo $OUT_SYSTEMS
 }

 BH_HOST_SYSTEMS=$(determine_systems "$BH_HOST_SYSTEMS")

 # Build python for build machine automatically
 if [ "$(bh_list_contains $BH_BUILD_TAG $BH_HOST_SYSTEMS)" = "no" ]; then
     BH_HOST_SYSTEMS="$BH_BUILD_TAG $BH_HOST_SYSTEMS"
     AUTO_BUILD="yes"
 fi

 # Python needs to execute itself during its build process, so must build the build
 # Python first. It should also be an error if not asked to build for build machine.
 BH_HOST_SYSTEMS=$(bh_sort_systems_build_first "$BH_HOST_SYSTEMS")

 download_package ()
 {
     # Assume the packages are already downloaded under $ARCHIVE_DIR
     local PKG_URL=$1
     local PKG_NAME=$(basename $PKG_URL)

     case $PKG_NAME in
         *.tar.bz2)
             PKG_BASENAME=${PKG_NAME%%.tar.bz2}
             ;;
         *.tar.gz)
             PKG_BASENAME=${PKG_NAME%%.tar.gz}
             ;;
         *)
             panic "Unknown archive type: $PKG_NAME"
     esac

     if [ ! -f "$ARCHIVE_DIR/$PKG_NAME" ]; then
         log "Downloading $PKG_URL..."
         (cd $ARCHIVE_DIR && run curl -L -o "$PKG_NAME" "$PKG_URL")
         fail_panic "Can't download '$PKG_URL'"
     fi

     if [ ! -d "$SRC_DIR/$PKG_BASENAME" ]; then
         log "Uncompressing $PKG_URL into $SRC_DIR"
         case $PKG_NAME in
             *.tar.bz2)
                 run tar xjf $ARCHIVE_DIR/$PKG_NAME -C $SRC_DIR
                 ;;
             *.tar.gz)
                 run tar xzf $ARCHIVE_DIR/$PKG_NAME -C $SRC_DIR
                 ;;
             *)
                 panic "Unknown archive type: $PKG_NAME"
                 ;;
         esac
         fail_panic "Can't uncompress $ARCHIVE_DIR/$PKG_NAME"
     fi
 }

 if [ -z "$BUILD_DIR" ] ; then
     panic "--build-out is required"
 fi

 bh_setup_build_dir $BUILD_DIR

 if [ "$BH_BUILD_MODE" = "debug" ] ; then
    PYDEBUG="-with-pydebug"
 fi

 # Sanity check that we have the right compilers for all hosts
 for SYSTEM in $BH_HOST_SYSTEMS; do
     bh_setup_build_for_host $SYSTEM
 done

 TEMP_DIR=$BUILD_DIR/tmp
 # Download and unpack source packages from official sites
 ARCHIVE_DIR=$TEMP_DIR/archive
 STAMP_DIR=$TEMP_DIR/timestamps
 BUILD_DIR=$TEMP_DIR/build-$HOST_TAG

 mkdir -p $BUILD_DIR

 PROGDIR=`dirname $0`
 PROGDIR=$(cd $PROGDIR && pwd)

 # Sanity check for all Python versions.
 for VERSION in $(commas_to_spaces $PYTHON_VERSION); do
     PYTHON_SRCDIR=$TOOLCHAIN_SRC_DIR/python/Python-$VERSION
     if [ ! -d "$PYTHON_SRCDIR" ]; then
         panic "Missing source directory: $PYTHON_SRCDIR"
     fi
 done

 arch_to_qemu_arch ()
 {
     case $1 in
         x86)
             echo i386
             ;;
         *)
             echo $1
             ;;
     esac
 }

 # $1: host system tag
 # $2: python version
 build_host_python ()
 {
     local SRCDIR=$TOOLCHAIN_SRC_DIR/python/Python-$2
     local BUILDDIR=$BH_BUILD_DIR/build-python-$1-$2
     local INSTALLDIR=$(python_build_install_dir $1 $2)
     local ARGS TEXT

     if [ ! -f "$SRCDIR/configure" ]; then
         panic "Missing configure script in $SRCDIR"
     fi

     # Currently, 2.7.5 and 3.3.0 builds generate $SRCDIR/Lib/_sysconfigdata.py, unless it
     # already exists (in which case it ends up wrong anyway!)... this should really be in
     # the build directory instead.
     if [ ! -f "$SRCDIR/Lib/_sysconfigdata.py" ]; then
         log "Removing old $SRCDIR/Lib/_sysconfigdata.py"
         rm -f $SRCDIR/Lib/_sysconfigdata.py
     fi

     ARGS=" --prefix=$INSTALLDIR"

     ARGS=$ARGS" --build=$BH_BUILD_CONFIG"
     ARGS=$ARGS" --host=$BH_HOST_CONFIG"
     ARGS=$ARGS" --with-build-sysroot"
     ARGS=$ARGS" $PYDEBUG"
     ARGS=$ARGS" --disable-ipv6"

     mkdir -p "$BUILDDIR" && rm -rf "$BUILDDIR"/*
     cd "$BUILDDIR" &&
     bh_setup_host_env

     CFG_SITE=
     # Need to add -L$HOST_STATIC_LIBDIR to LDSHARED if need
     # any static host libs.
     export LDSHARED="$CC -shared "
     if [ ! $BH_HOST_TAG = $BH_BUILD_TAG ]; then

         # Cross compiling.
         CFG_SITE=$BUILDDIR/config.site

         # Ideally would remove all of these configury hacks by
         # patching the issues.

         if [ $1 = darwin-x86 -o $1 = darwin-x86_64 ]; then
             echo "ac_cv_file__dev_ptmx=no"              > $CFG_SITE
             echo "ac_cv_file__dev_ptc=no"              >> $CFG_SITE
             echo "ac_cv_have_long_long_format=yes"     >> $CFG_SITE
             if [ $1 = darwin-x86 ] ; then
                 echo "ac_osx_32bit=yes"                >> $CFG_SITE
             elif [ $1 = darwin-x86_64 ] ; then
                 echo "ac_osx_32bit=no"                 >> $CFG_SITE
             fi
             echo "ac_cv_have_sendfile=no"              >> $CFG_SITE
             # I could change AC_MSG_CHECKING(LDSHARED) in configure.ac
             # to check $host instead of $ac_sys_system/$ac_sys_release
             # but it handles loads of platforms
             # and I can only test on three, so instead...
             export LDSHARED="$CC -bundle -undefined dynamic_lookup"
         elif [ $1 = windows-x86 -o $1 = windows-x86_64 ]; then
             echo "ac_cv_file__dev_ptmx=no"              > $CFG_SITE
             echo "ac_cv_file__dev_ptc=no"              >> $CFG_SITE
             export CFLAGS=$CFLAGS" -D__USE_MINGW_ANSI_STDIO=1 -static-libgcc"
             export CXXFLAGS=$CXXFLAGS" -D__USE_MINGW_ANSI_STDIO=1 -static-libgcc"
             export LDFLAGS="$LDFLAGS -static-libgcc"
         elif [ $1 = linux-x86 -o $1 = linux-x86_64 ]; then
             echo "ac_cv_file__dev_ptmx=yes"             > $CFG_SITE
             echo "ac_cv_file__dev_ptc=no"              >> $CFG_SITE
             echo "ac_cv_have_long_long_format=yes"     >> $CFG_SITE
             echo "ac_cv_pthread_system_supported=yes"  >> $CFG_SITE
             echo "ac_cv_working_tzset=yes"             >> $CFG_SITE
             echo "ac_cv_little_endian_double=yes"      >> $CFG_SITE
         fi

         if [ "$BH_HOST_OS" = "$BH_BUILD_OS" ]; then
             # Only cross compiling from arch perspective.
             # qemu causes failures as cross-compilation is not detected
             # if a test executable can be run successfully, so we test
             # for qemu-${BH_HOST_ARCH} and qemu-${BH_HOST_ARCH}-static
             # and panic if either are found.
             QEMU_HOST_ARCH=$(arch_to_qemu_arch $BH_HOST_ARCH)
             if [ ! -z "$(which qemu-$QEMU_HOST_ARCH 2>/dev/null)" -o \
                  ! -z "$(which qemu-$QEMU_HOST_ARCH-static 2>/dev/null)" ] ; then
                dump "Installed qemu(s) ($(which qemu-$QEMU_HOST_ARCH 2>/dev/null) $(which qemu-$QEMU_HOST_ARCH-static 2>/dev/null))" \
                       "will prevent this build from working."
             fi
         fi
     else
         if [ $1 = darwin-x86 -o $1 = darwin-x86_64 ]; then
             export LDSHARED="$CC -bundle -undefined dynamic_lookup"
         fi
     fi

     TEXT="$(bh_host_text) python-$BH_HOST_CONFIG-$2:"

     touch $SRCDIR/Include/graminit.h
     touch $SRCDIR/Python/graminit.c
     echo "" > $SRCDIR/Parser/pgen.stamp
     touch $SRCDIR/Parser/Python.asdl
     touch $SRCDIR/Parser/asdl.py
     touch $SRCDIR/Parser/asdl_c.py
     touch $SRCDIR/Include/Python-ast.h
     touch $SRCDIR/Python/Python-ast.c

     # By default, the Python build will force the following compiler flags
     # after our own CFLAGS:
     #   -g -fwrap -O3 -Wall -Wstrict-prototypes
     #
     # The '-g' is unfortunate because it makes the generated binaries
     # much larger than necessary, and stripping them after the fact is
     # a bit delicate when cross-compiling. To avoid this, define a
     # custom OPT variable here (see Python-2.7.5/configure.ac) when
     # generating non stripped builds.
     if [ "$BH_BUILD_MODE" = "release" ]; then
       OPT="-fwrapv -O3 -Wall -Wstrict-prototypes"
       export OPT
     fi

     dump "$TEXT Building"
     export CONFIG_SITE=$CFG_SITE &&
     run "$SRCDIR"/configure $ARGS
     fail_panic "Could not configure Python!"

     #
     # Note 1:
     # sharedmods is a phony target, but it's a dependency of both "make all" and also
     # "make install", this causes it to fail on Windows as it tries to rename pydoc3
     # to pydoc3.3 twice, and the second time aroud the file exists. So instead, we
     # just do make install.
     #
     # Note 2:
     # Can't run make install with -j as from the Makefile:
     # install:	 altinstall bininstall maninstall
     #  meaning altinstall and bininstall are kicked off at the same time
     #  but actually, bininstall depends on altinstall being run first
     #  due to libainstall: doing
     #  $(INSTALL_SCRIPT) python-config $(DESTDIR)$(BINDIR)/python$(VERSION)-config
     #  and bininstall: doing
     #  (cd $(DESTDIR)$(BINDIR); $(LN) -s python$(VERSION)-config python2-config)
     #  Though the real fix is to make bininstall depend on libainstall.
     run make -j$NUM_JOBS
     fail_panic "Could not build Python!"

     run make install
     fail_panic "Could not install Python!"
 }

 need_build_host_python ()
 {
     bh_do build_host_python $1 $2
 }

 # Install host Python binaries and support files to the NDK install dir.
 # $1: host tag
 # $2: python version
 install_host_python ()
 {
     local SRCDIR="$(python_build_install_dir $1 $2)"
     local DSTDIR="$NDK_DIR/$(python_ndk_install_dir $1 $2)"

     need_build_host_python $1 $2

     if [ $AUTO_BUILD != "yes" -o $1 != $BH_BUILD_TAG ]; then
         dump "$(bh_host_text) python-$BH_HOST_ARCH-$2: Installing"
         run copy_directory "$SRCDIR/bin"     "$DSTDIR/bin"
         run copy_directory "$SRCDIR/lib"     "$DSTDIR/lib"
         run copy_directory "$SRCDIR/share"   "$DSTDIR/share"
         run copy_directory "$SRCDIR/include" "$DSTDIR/include"
         # remove unneeded files
         run rm -rf "$DSTDIR/share/man"
         run rm -rf "$DSTDIR/share/pretty-printers/libstdcxx/gcc-4.9.*"
         run rm -rf "$DSTDIR/share/pretty-printers/libstdcxx/gcc-4.9-*"
         run rm -rf "$DSTDIR/share/pretty-printers/libstdcxx/gcc-[lm]*"
     fi
 }

 # $1: host tag
 # $2: python version
 need_install_host_python ()
 {
     local SRCDIR="$(python_build_install_dir $1 $2)"

     bh_do install_host_python $1 $2

     # make sharedmods (setup.py) needs to use the build machine's Python
     # for the other hosts to build correctly.
     if [ $BH_BUILD_TAG = $BH_HOST_TAG ]; then
         export PATH=$SRCDIR/bin:$PATH
     fi
 }

 # Package host Python binaries into a tarball
 # $1: host tag
 # $2: python version
 package_host_python ()
 {
     local BLDDIR="$(python_build_install_dir $1 $2)"
     local SRCDIR="$(python_ndk_install_dir $1 $2)"
     # This is similar to BLDDIR=${BLDDIR%%$SRCDIR} (and requires we use windows and not windows-x86)
     BLDDIR=$(echo "$BLDDIR" | sed "s/$(echo "$SRCDIR" | sed -e 's/\\/\\\\/g' -e 's/\//\\\//g' -e 's/&/\\\&/g')//g")
     local PACKAGENAME=ndk-python-$1.tar.bz2
     local PACKAGE="$PACKAGE_DIR/$PACKAGENAME"

     # Remove python tests
     find $BLDDIR/host-tools/lib/python* \( -name test -o -name tests \) -exec rm -rf {} \;

     # Remove precompiled files
     find $BLDDIR/host-tools/lib/python* \( -name "*.pyc" -o -name "*.pyo" \) -delete

     dump "$(bh_host_text) $PACKAGENAME: Packaging"
     run pack_archive "$PACKAGE" "$BLDDIR" "$SRCDIR"
 }

 need_package_host_python ()
 {
     bh_do package_host_python $1 $2
 }

 PYTHON_VERSION=$(commas_to_spaces $PYTHON_VERSION)
 ARCHS=$(commas_to_spaces $ARCHS)

 # Let's build this
 for SYSTEM in $BH_HOST_SYSTEMS; do
     bh_setup_build_for_host $SYSTEM
     for VERSION in $PYTHON_VERSION; do
         need_install_host_python $SYSTEM $VERSION
     done
 done

 if [ "$PACKAGE_DIR" ]; then
     for SYSTEM in $BH_HOST_SYSTEMS; do
         bh_setup_build_for_host $SYSTEM
         if [ $AUTO_BUILD != "yes" -o $SYSTEM != $BH_BUILD_TAG ]; then
             for VERSION in $PYTHON_VERSION; do
                 need_package_host_python $SYSTEM $VERSION
             done
         fi
     done
 fi
	#!/bin/sh
	#
	# Copyright (C) 2012 The Android Open Source Project
	# Copyright (C) 2012 Ray Donnelly <mingw.android at gmail.com>
	#
	# Licensed under the Apache License, Version 2.0 (the "License");
	# you may not use this file except in compliance with the License.
	# You may obtain a copy of the License at
	#
	# http://www.apache.org/licenses/LICENSE-2.0
	#
	# Unless required by applicable law or agreed to in writing, software
	# distributed under the License is distributed on an "AS IS" BASIS,
	# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	# See the License for the specific language governing permissions and
	# limitations under the License.
	#
	# Rebuild the host Python binaries from sources.
	# Also copies any gnu libstdc++ pretty-printers
	# found in $TOOLCHAIN_SRC_DIR/gcc/gcc-*
	# and Joachim Reichel's stlport pretty printers
	# found in sources/host-tools/gdb-pretty-printers/stlport
	#

	# include common function and variable definitions
	. "$NDK_BUILDTOOLS_PATH/prebuilt-common.sh"
	. "$NDK_BUILDTOOLS_PATH/common-build-host-funcs.sh"

	PROGRAM_PARAMETERS=""
	PROGRAM_DESCRIPTION="\
	This program is used to rebuild one or more Python client programs from
	sources.

	By default, the script rebuilds Python for you host system [$HOST_TAG],
	but you can use --systems=<tag1>,<tag2>,.. to ask binaries that can run on
	several distinct systems. Each <tag> value in the list can be one of the
	following:

	linux-x86
	linux-x86_64
	windows
	windows-x86 (equivalent to 'windows')
	windows-x86_64
	darwin-x86
	darwin-x86_64

	For example, here's how to rebuild Python 2.7.5 on Linux
	for six different systems:

	$PROGNAME --build-dir=/path/to/toolchain/src \n \
	--python-version=2.7.5 \n \
	--systems=linux-x86,linux-x86_64,windows,windows-x86_64,darwin-x86,darwin-x86_64"

	TOOLCHAIN_SRC_DIR=
	register_var_option "--toolchain-src-dir=<path>" TOOLCHAIN_SRC_DIR "Select toolchain source directory"

	PYTHON_VERSION=$DEFAULT_PYTHON_VERSION
	register_var_option "--python-version=<version>" PYTHON_VERSION "Select Python version."

	NDK_DIR=$ANDROID_NDK_ROOT
	register_var_option "--ndk-dir=<path>" NDK_DIR "Select NDK install directory."

	PACKAGE_DIR=
	register_var_option "--package-dir=<path>" PACKAGE_DIR "Package prebuilt tarballs into directory."

	BUILD_DIR=
	register_var_option "--build-dir=<path>" BUILD_DIR "Build Python into directory"

	bh_register_options
	register_try64_option
	register_canadian_option
	register_jobs_option

	extract_parameters "$@"

	if [ -n "$PARAMETERS" ]; then
	panic "This script doesn't take parameters, only options. See --help"
	fi

	if [ -z "$TOOLCHAIN_SRC_DIR" ]; then
	panic "Please use --toolchain-src-dir=<path> to select toolchain source directory."
	fi
	check_toolchain_src_dir "$TOOLCHAIN_SRC_DIR"
	TOOLCHAIN_SRC_DIR=`cd $TOOLCHAIN_SRC_DIR; pwd`

	BH_HOST_SYSTEMS=$(commas_to_spaces $BH_HOST_SYSTEMS)
	AUTO_BUILD="no"

	if [ "$MINGW" = "yes" ]; then
	BH_HOST_SYSTEMS="windows"
	log "Auto-config: --systems=windows"
	fi

	if [ "$DARWIN" = "yes" ]; then
	BH_HOST_SYSTEMS="darwin-x86"
	log "Auto-config: --systems=darwin-x86"
	fi

	determine_systems ()
	{
	local IN_SYSTEMS="$1"
	local OUT_SYSTEMS

	for SYSTEM in $IN_SYSTEMS; do
	if [ "$TRY64" = "yes" ]; then
	case $SYSTEM in
	darwin-x86\|linux-x86\|windows-x86)
	SYSTEM=${SYSTEM%%x86}x86_64
	;;
	windows)
	SYSTEM=windows-x86_64
	;;
	esac
	else
	# 'windows-x86' causes substitution
	# failure at the packing stage.
	case $SYSTEM in
	windows-x86)
	SYSTEM=windows
	;;
	esac
	fi
	OUT_SYSTEMS="$OUT_SYSTEMS $SYSTEM"
	done
	echo $OUT_SYSTEMS
	}

	BH_HOST_SYSTEMS=$(determine_systems "$BH_HOST_SYSTEMS")

	# Build python for build machine automatically
	if [ "$(bh_list_contains $BH_BUILD_TAG $BH_HOST_SYSTEMS)" = "no" ]; then
	BH_HOST_SYSTEMS="$BH_BUILD_TAG $BH_HOST_SYSTEMS"
	AUTO_BUILD="yes"
	fi

	# Python needs to execute itself during its build process, so must build the build
	# Python first. It should also be an error if not asked to build for build machine.
	BH_HOST_SYSTEMS=$(bh_sort_systems_build_first "$BH_HOST_SYSTEMS")

	download_package ()
	{
	# Assume the packages are already downloaded under $ARCHIVE_DIR
	local PKG_URL=$1
	local PKG_NAME=$(basename $PKG_URL)

	case $PKG_NAME in
	*.tar.bz2)
	PKG_BASENAME=${PKG_NAME%%.tar.bz2}
	;;
	*.tar.gz)
	PKG_BASENAME=${PKG_NAME%%.tar.gz}
	;;
	*)
	panic "Unknown archive type: $PKG_NAME"
	esac

	if [ ! -f "$ARCHIVE_DIR/$PKG_NAME" ]; then
	log "Downloading $PKG_URL..."
	(cd $ARCHIVE_DIR && run curl -L -o "$PKG_NAME" "$PKG_URL")
	fail_panic "Can't download '$PKG_URL'"
	fi

	if [ ! -d "$SRC_DIR/$PKG_BASENAME" ]; then
	log "Uncompressing $PKG_URL into $SRC_DIR"
	case $PKG_NAME in
	*.tar.bz2)
	run tar xjf $ARCHIVE_DIR/$PKG_NAME -C $SRC_DIR
	;;
	*.tar.gz)
	run tar xzf $ARCHIVE_DIR/$PKG_NAME -C $SRC_DIR
	;;
	*)
	panic "Unknown archive type: $PKG_NAME"
	;;
	esac
	fail_panic "Can't uncompress $ARCHIVE_DIR/$PKG_NAME"
	fi
	}

	if [ -z "$BUILD_DIR" ] ; then
	panic "--build-out is required"
	fi

	bh_setup_build_dir $BUILD_DIR

	if [ "$BH_BUILD_MODE" = "debug" ] ; then
	PYDEBUG="-with-pydebug"
	fi

	# Sanity check that we have the right compilers for all hosts
	for SYSTEM in $BH_HOST_SYSTEMS; do
	bh_setup_build_for_host $SYSTEM
	done

	TEMP_DIR=$BUILD_DIR/tmp
	# Download and unpack source packages from official sites
	ARCHIVE_DIR=$TEMP_DIR/archive
	STAMP_DIR=$TEMP_DIR/timestamps
	BUILD_DIR=$TEMP_DIR/build-$HOST_TAG

	mkdir -p $BUILD_DIR

	PROGDIR=`dirname $0`
	PROGDIR=$(cd $PROGDIR && pwd)

	# Sanity check for all Python versions.
	for VERSION in $(commas_to_spaces $PYTHON_VERSION); do
	PYTHON_SRCDIR=$TOOLCHAIN_SRC_DIR/python/Python-$VERSION
	if [ ! -d "$PYTHON_SRCDIR" ]; then
	panic "Missing source directory: $PYTHON_SRCDIR"
	fi
	done

	arch_to_qemu_arch ()
	{
	case $1 in
	x86)
	echo i386
	;;
	*)
	echo $1
	;;
	esac
	}

	# $1: host system tag
	# $2: python version
	build_host_python ()
	{
	local SRCDIR=$TOOLCHAIN_SRC_DIR/python/Python-$2
	local BUILDDIR=$BH_BUILD_DIR/build-python-$1-$2
	local INSTALLDIR=$(python_build_install_dir $1 $2)
	local ARGS TEXT

	if [ ! -f "$SRCDIR/configure" ]; then
	panic "Missing configure script in $SRCDIR"
	fi

	# Currently, 2.7.5 and 3.3.0 builds generate $SRCDIR/Lib/_sysconfigdata.py, unless it
	# already exists (in which case it ends up wrong anyway!)... this should really be in
	# the build directory instead.
	if [ ! -f "$SRCDIR/Lib/_sysconfigdata.py" ]; then
	log "Removing old $SRCDIR/Lib/_sysconfigdata.py"
	rm -f $SRCDIR/Lib/_sysconfigdata.py
	fi

	ARGS=" --prefix=$INSTALLDIR"

	ARGS=$ARGS" --build=$BH_BUILD_CONFIG"
	ARGS=$ARGS" --host=$BH_HOST_CONFIG"
	ARGS=$ARGS" --with-build-sysroot"
	ARGS=$ARGS" $PYDEBUG"
	ARGS=$ARGS" --disable-ipv6"

	mkdir -p "$BUILDDIR" && rm -rf "$BUILDDIR"/*
	cd "$BUILDDIR" &&
	bh_setup_host_env

	CFG_SITE=
	# Need to add -L$HOST_STATIC_LIBDIR to LDSHARED if need
	# any static host libs.
	export LDSHARED="$CC -shared "
	if [ ! $BH_HOST_TAG = $BH_BUILD_TAG ]; then

	# Cross compiling.
	CFG_SITE=$BUILDDIR/config.site

	# Ideally would remove all of these configury hacks by
	# patching the issues.

	if [ $1 = darwin-x86 -o $1 = darwin-x86_64 ]; then
	echo "ac_cv_file__dev_ptmx=no" > $CFG_SITE
	echo "ac_cv_file__dev_ptc=no" >> $CFG_SITE
	echo "ac_cv_have_long_long_format=yes" >> $CFG_SITE
	if [ $1 = darwin-x86 ] ; then
	echo "ac_osx_32bit=yes" >> $CFG_SITE
	elif [ $1 = darwin-x86_64 ] ; then
	echo "ac_osx_32bit=no" >> $CFG_SITE
	fi
	echo "ac_cv_have_sendfile=no" >> $CFG_SITE
	# I could change AC_MSG_CHECKING(LDSHARED) in configure.ac
	# to check $host instead of $ac_sys_system/$ac_sys_release
	# but it handles loads of platforms
	# and I can only test on three, so instead...
	export LDSHARED="$CC -bundle -undefined dynamic_lookup"
	elif [ $1 = windows-x86 -o $1 = windows-x86_64 ]; then
	echo "ac_cv_file__dev_ptmx=no" > $CFG_SITE
	echo "ac_cv_file__dev_ptc=no" >> $CFG_SITE
	export CFLAGS=$CFLAGS" -D__USE_MINGW_ANSI_STDIO=1 -static-libgcc"
	export CXXFLAGS=$CXXFLAGS" -D__USE_MINGW_ANSI_STDIO=1 -static-libgcc"
	export LDFLAGS="$LDFLAGS -static-libgcc"
	elif [ $1 = linux-x86 -o $1 = linux-x86_64 ]; then
	echo "ac_cv_file__dev_ptmx=yes" > $CFG_SITE
	echo "ac_cv_file__dev_ptc=no" >> $CFG_SITE
	echo "ac_cv_have_long_long_format=yes" >> $CFG_SITE
	echo "ac_cv_pthread_system_supported=yes" >> $CFG_SITE
	echo "ac_cv_working_tzset=yes" >> $CFG_SITE
	echo "ac_cv_little_endian_double=yes" >> $CFG_SITE
	fi

	if [ "$BH_HOST_OS" = "$BH_BUILD_OS" ]; then
	# Only cross compiling from arch perspective.
	# qemu causes failures as cross-compilation is not detected
	# if a test executable can be run successfully, so we test
	# for qemu-${BH_HOST_ARCH} and qemu-${BH_HOST_ARCH}-static
	# and panic if either are found.
	QEMU_HOST_ARCH=$(arch_to_qemu_arch $BH_HOST_ARCH)
	if [ ! -z "$(which qemu-$QEMU_HOST_ARCH 2>/dev/null)" -o \
	! -z "$(which qemu-$QEMU_HOST_ARCH-static 2>/dev/null)" ] ; then
	dump "Installed qemu(s) ($(which qemu-$QEMU_HOST_ARCH 2>/dev/null) $(which qemu-$QEMU_HOST_ARCH-static 2>/dev/null))" \
	"will prevent this build from working."
	fi
	fi
	else
	if [ $1 = darwin-x86 -o $1 = darwin-x86_64 ]; then
	export LDSHARED="$CC -bundle -undefined dynamic_lookup"
	fi
	fi

	TEXT="$(bh_host_text) python-$BH_HOST_CONFIG-$2:"

	touch $SRCDIR/Include/graminit.h
	touch $SRCDIR/Python/graminit.c
	echo "" > $SRCDIR/Parser/pgen.stamp
	touch $SRCDIR/Parser/Python.asdl
	touch $SRCDIR/Parser/asdl.py
	touch $SRCDIR/Parser/asdl_c.py
	touch $SRCDIR/Include/Python-ast.h
	touch $SRCDIR/Python/Python-ast.c

	# By default, the Python build will force the following compiler flags
	# after our own CFLAGS:
	# -g -fwrap -O3 -Wall -Wstrict-prototypes
	#
	# The '-g' is unfortunate because it makes the generated binaries
	# much larger than necessary, and stripping them after the fact is
	# a bit delicate when cross-compiling. To avoid this, define a
	# custom OPT variable here (see Python-2.7.5/configure.ac) when
	# generating non stripped builds.
	if [ "$BH_BUILD_MODE" = "release" ]; then
	OPT="-fwrapv -O3 -Wall -Wstrict-prototypes"
	export OPT
	fi

	dump "$TEXT Building"
	export CONFIG_SITE=$CFG_SITE &&
	run "$SRCDIR"/configure $ARGS
	fail_panic "Could not configure Python!"

	#
	# Note 1:
	# sharedmods is a phony target, but it's a dependency of both "make all" and also
	# "make install", this causes it to fail on Windows as it tries to rename pydoc3
	# to pydoc3.3 twice, and the second time aroud the file exists. So instead, we
	# just do make install.
	#
	# Note 2:
	# Can't run make install with -j as from the Makefile:
	# install: altinstall bininstall maninstall
	# meaning altinstall and bininstall are kicked off at the same time
	# but actually, bininstall depends on altinstall being run first
	# due to libainstall: doing
	# $(INSTALL_SCRIPT) python-config $(DESTDIR)$(BINDIR)/python$(VERSION)-config
	# and bininstall: doing
	# (cd $(DESTDIR)$(BINDIR); $(LN) -s python$(VERSION)-config python2-config)
	# Though the real fix is to make bininstall depend on libainstall.
	run make -j$NUM_JOBS
	fail_panic "Could not build Python!"

	run make install
	fail_panic "Could not install Python!"
	}

	need_build_host_python ()
	{
	bh_do build_host_python $1 $2
	}

	# Install host Python binaries and support files to the NDK install dir.
	# $1: host tag
	# $2: python version
	install_host_python ()
	{
	local SRCDIR="$(python_build_install_dir $1 $2)"
	local DSTDIR="$NDK_DIR/$(python_ndk_install_dir $1 $2)"

	need_build_host_python $1 $2

	if [ $AUTO_BUILD != "yes" -o $1 != $BH_BUILD_TAG ]; then
	dump "$(bh_host_text) python-$BH_HOST_ARCH-$2: Installing"
	run copy_directory "$SRCDIR/bin" "$DSTDIR/bin"
	run copy_directory "$SRCDIR/lib" "$DSTDIR/lib"
	run copy_directory "$SRCDIR/share" "$DSTDIR/share"
	run copy_directory "$SRCDIR/include" "$DSTDIR/include"
	# remove unneeded files
	run rm -rf "$DSTDIR/share/man"
	run rm -rf "$DSTDIR/share/pretty-printers/libstdcxx/gcc-4.9.*"
	run rm -rf "$DSTDIR/share/pretty-printers/libstdcxx/gcc-4.9-*"
	run rm -rf "$DSTDIR/share/pretty-printers/libstdcxx/gcc-[lm]*"
	fi
	}

	# $1: host tag
	# $2: python version
	need_install_host_python ()
	{
	local SRCDIR="$(python_build_install_dir $1 $2)"

	bh_do install_host_python $1 $2

	# make sharedmods (setup.py) needs to use the build machine's Python
	# for the other hosts to build correctly.
	if [ $BH_BUILD_TAG = $BH_HOST_TAG ]; then
	export PATH=$SRCDIR/bin:$PATH
	fi
	}

	# Package host Python binaries into a tarball
	# $1: host tag
	# $2: python version
	package_host_python ()
	{
	local BLDDIR="$(python_build_install_dir $1 $2)"
	local SRCDIR="$(python_ndk_install_dir $1 $2)"
	# This is similar to BLDDIR=${BLDDIR%%$SRCDIR} (and requires we use windows and not windows-x86)
	BLDDIR=$(echo "$BLDDIR" \| sed "s/$(echo "$SRCDIR" \| sed -e 's/\\/\\\\/g' -e 's/\//\\\//g' -e 's/&/\\\&/g')//g")
	local PACKAGENAME=ndk-python-$1.tar.bz2
	local PACKAGE="$PACKAGE_DIR/$PACKAGENAME"

	# Remove python tests
	find $BLDDIR/host-tools/lib/python* \( -name test -o -name tests \) -exec rm -rf {} \;

	# Remove precompiled files
	find $BLDDIR/host-tools/lib/python* \( -name ".pyc" -o -name ".pyo" \) -delete

	dump "$(bh_host_text) $PACKAGENAME: Packaging"
	run pack_archive "$PACKAGE" "$BLDDIR" "$SRCDIR"
	}

	need_package_host_python ()
	{
	bh_do package_host_python $1 $2
	}

	PYTHON_VERSION=$(commas_to_spaces $PYTHON_VERSION)
	ARCHS=$(commas_to_spaces $ARCHS)

	# Let's build this
	for SYSTEM in $BH_HOST_SYSTEMS; do
	bh_setup_build_for_host $SYSTEM
	for VERSION in $PYTHON_VERSION; do
	need_install_host_python $SYSTEM $VERSION
	done
	done

	if [ "$PACKAGE_DIR" ]; then
	for SYSTEM in $BH_HOST_SYSTEMS; do
	bh_setup_build_for_host $SYSTEM
	if [ $AUTO_BUILD != "yes" -o $SYSTEM != $BH_BUILD_TAG ]; then
	for VERSION in $PYTHON_VERSION; do
	need_package_host_python $SYSTEM $VERSION
	done
	fi
	done
	fi