#!/bin/sh
#
# This script builds & bundles Python for Android
# You'll end up with a tar.bz2 file that contains a Python distribution
#
# Requires all prerequisites to build Android on the host, and the NDK
# installed.
#
# This script creates a file python4android.tbz2. Unpack it on your device
# (into a non-noexec partition!) and enjoy.
#
set -e

# Set the correct NDK path here!
NDK=~/android/android-ndk-r10d

# This shouldn't need to be updated often.. but it might need updating, so check this:
NDK_TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin
NDK_SYSROOT=$NDK/platforms/android-21/arch-arm

## The remainder shouldn't need any changes, unless you want a newer Python version:

# 1) Download Python
wget https://www.python.org/ftp/python/2.7.9/Python-2.7.9.tar.xz
tar xaf Python-2.7.9.tar.xz
cd Python-2.7.9

# 2) Compile host pgen/python
(
	./configure
	make python Parser/pgen
	mv python pythonh
	mv Parser/pgen Parser/pgenh
) 2>&1 | tee host-build.log

# 3) Patch the Makefile to use the host versions
sed -i -re 's#^(\s+)\$\(PGEN\)#\1$(PGEN)h#m' Makefile.pre.in
sed -i -re 's#./\$\(BUILDPYTHON\)#./$(BUILDPYTHON)h#m' Makefile.pre.in

make distclean

# 4) Patch some usually misdetected functions, setup modules to compile and fix some other problems
sed -i -re 's# ftime # #' configure
sed -i -re 's#p->pw_gecos#""#' Modules/pwdmodule.c
sed -i -re "s#exit_status = .+#exit_status = 0#" Lib/compileall.py

for MOD in _socket array cmath math _struct time operator _random _collections _heapq itertools strop _functools _elementtree datetime _bisect unicodedata _locale fcntl "select" mmap _md5 _sha256 _sha512 _sha binascii cPickle cStringIO _io; do
	grep "#$MOD" Modules/Setup.dist | grep "\.c" | sed -re 's%^#%%' >> Modules/Setup.local
done

# 5) Configure
export PATH=${PATH}:$NDK_TOOLCHAIN
export SYSROOT=$NDK_SYSROOT
export CFLAGS="-fPIC -fPIE --sysroot $SYSROOT -Dandroid -mandroid"
export LDFLAGS="--sysroot $SYSROOT"
export ac_cv_file__dev_ptmx=no
export ac_cv_file__dev_ptc=no
./configure --disable-ipv6 --host=arm-linux-androideabi --build=x86_64-linux-gnu ac_cv_file__dev_ptmx=no ac_cv_file__dev_ptc=no 2>&1 | tee dev-build.log

# 6) Fix some mistakes configure made
sed -i -re "s%^#define HAVE_GETHOSTBYNAME_.+%%" pyconfig.h
echo "#define HAVE_GETHOSTBYNAME 1" >> pyconfig.h

# 7) Compile python
make 2>&1 | tee -a dev-build.log

# 8) Recompile the python executable as a position independent executable
rm -f python
sed -i -re 's#^LDFLAGS=#LDFLAGS= -pie #' Makefile
make 2>&1 | tee deb-build-pie.log

# 9) Install into our prefix and prepare an archive
make install DESTDIR=`pwd`/../prefix 2>&1 | tee install.log
cd ../prefix/usr/local/lib
rm -f *.a
cd python*
rm -rf test
find -iname "*.pyc" -exec rm \{\} \;
cd ../../bin
arm-linux-androideabi-strip python2.7
cd ..
rm -f python.tbz2
tar cjf python.tbz2 *
mv python.tbz2 ../../../python4android.tbz2

# Done. You may remove the temporary directories now.