build-python-for-iOS

#!/bin/bash

#
# BRIEF:
# This script is used to retrieve and build a static library of python interpreter for iOS.
# 
# DESCRIPTION:
# This script retrieves the python source files and cross compile patch from internet, and
# build a universal (for iphone-os and iphone-simulator) static library, libpythonX.Y.a.
# The static library contains only the interpreter. In order to the the scripts run, you
# still need to
#       * Copy all the headers at ./install/include/ to your project.
#       * Copy all the necessary modules at $BUILD_FOLDER/Lib to some place your app can
#         access at run time, and notify the interpreter about the path with Py_SetPythonHome
#         before calling Py_Initialize.
#         If your Python Home is at <py-home>, the modules should be put at
#               <py-home>/lib/pythonX.Y
#         None of the C modules is compiled.
#
# AUTHOR (GitHub homepage):
# http://github.com/wewei
# 
# CREDIT TO:
# http://randomsplat.com/id5-cross-compiling-python-for-embedded-linux.html
# http://latenitesoft.blogspot.com/2008/10/iphone-programming-tips-building-unix.html
# https://github.com/cobbal/python-for-iphone
#


# Version information

SOURCE_VERSION=2.7.3
MIN_IOS_VERSION="5.0"


# Library information

LIBRARY_VERSION=${SOURCE_VERSION%.*}
LIBRARY_NAME="libpython$LIBRARY_VERSION.a"
LIBRARY_NAME_FOR_IPHONEOS="libpython$LIBRARY_VERSION.ios.a"
LIBRARY_NAME_FOR_SIMULATOR="libpython$LIBRARY_VERSION.sim.a"


# Resource information

PATCH_NAME="Python-$SOURCE_VERSION-xcompile.patch"
PATCH_URL="https://raw.github.com/wewei/Build-Python-for-iOS/master/$PATCH_NAME"

SOURCE_PACK_NAME="Python-$SOURCE_VERSION.tar.bz2"
SOURCE_PACK_URL="http://python.org/ftp/python/$SOURCE_VERSION/$SOURCE_PACK_NAME"


# Build information

BUILD_FOLDER="Python-$SOURCE_VERSION"

HOST_PYTHON="hostpython"
HOST_PGEN="Parser/hostpgen"


# To prepare the resource files

function retrieve_file_if_not_exists ()
{
    local fileName=$(basename "$1")
    if [ ! -e $fileName ]; then
        curl -O $1
    fi
}

function unpack_source_files()
{
    tar jxf $SOURCE_PACK_NAME
}

function prepare_source_files()
{
    retrieve_file_if_not_exists $PATCH_URL
    retrieve_file_if_not_exists $SOURCE_PACK_URL
    unpack_source_files
}


# To build the host utilites (host python, host pgen)

function build_host_utilities()
{
    ./configure
    make python.exe Parser/pgen
}

function rename_host_utilities()
{
    mv python.exe $HOST_PYTHON
    mv Parser/pgen $HOST_PGEN
}

function generate_host_utilities()
{
    pushd $BUILD_FOLDER
    if [[ ! -x $HOST_PYTHON || ! -x $HOST_PGEN ]]; then
        build_host_utilities
        rename_host_utilities
        make distclean
    fi
    popd
}


# To apply the patch

function apply_cross_compile_patch()
{
    pushd $BUILD_FOLDER
    patch -p1 < ../$PATCH_NAME
    popd
}


# To build the libraries

function fix_libgcc_cannot_find_error()
{
    local sdkroot=$1
    mkdir -p "extralibs"
    ln -fs "$sdkroot/usr/lib/libgcc_s.1.dylib" extralibs/libgcc_s.10.4.dylib
}

function cross_compile_library()
{
    local sdkroot=$(xcodebuild -version -sdk "$sdk" Path)

    local cc=$(xcrun -find -sdk "$sdk" llvm-gcc)
    local cpp=$(xcrun -find -sdk "$sdk" cpp)
    local cflags="-arch $arch -isysroot $sdkroot -miphoneos-version-min=$MIN_IOS_VERSION"
    local ldflags="-arch $arch -isysroot $sdkroot -static-libgcc -miphoneos-version-min=$MIN_IOS_VERSION"

    fix_libgcc_cannot_find_error $sdkroot
    ldflags="$ldflags -Lextralibs/"

    CC="$cc" \
    CPP="$cpp" \
    CFLAGS="$cflags" \
    LDFLAGS="$ldflags" \
        ./configure --disable-toolbox-glue --host=$arch-apple-darwin

    HOSTPYTHON=./$HOST_PYTHON \
    HOSTPGEN=./$HOST_PGEN \
    CROSS_COMPILE_TARGET=yes \
        make $LIBRARY_NAME
}

function generate_library_for_iphoneos()
{
    if [[ ! -e $LIBRARY_NAME_FOR_IPHONEOS ]]; then
        pushd $BUILD_FOLDER

        arch="armv7" \
        sdk="iphoneos" \
            cross_compile_library

        cp $LIBRARY_NAME ../$LIBRARY_NAME_FOR_IPHONEOS

		make inclinstall prefix="$PWD/../install"

        #make distclean

        popd
    fi
}

function generate_library_for_simulator()
{
    if [[ ! -e $LIBRARY_NAME_FOR_SIMULATOR ]]; then
        pushd $BUILD_FOLDER

        arch="i386" \
        sdk="iphonesimulator" \
            cross_compile_library

        cp $LIBRARY_NAME ../$LIBRARY_NAME_FOR_SIMULATOR
        make distclean

        popd
    fi
}


# To generate the universal library

function generate_universal_library()
{
    lipo -create \
        $LIBRARY_NAME_FOR_IPHONEOS  \
        $LIBRARY_NAME_FOR_SIMULATOR \
        -output $LIBRARY_NAME
}


# The main entry

function build_python_for_iOS()
{
    prepare_source_files
    generate_host_utilities
    apply_cross_compile_patch
    generate_library_for_simulator
    generate_library_for_iphoneos
    generate_universal_library
}

build_python_for_iOS