Swift Android toolchain build scripts

Automated scripts to build Swift Android cross compilation toolchain for macOS

Based on:

• https://github.com/SwiftJava/swifty-robot-environment
• https://github.com/zayass/swift-android-vagrant

Installation

Prebuilt toolchain can be located here

Prepare environment

1. Install JDK 8 if needed. Call javac from terminal and macOS will guide you.
2. [IMPORTANT] Install Swift 5.0.3 toolchain for Xcode https://swift.org/builds/swift-5.0.3-release/xcode/swift-5.0.3-RELEASE/swift-5.0.3-RELEASE-osx.pkg
3. Install Android Studio 3.5 or higher (optional)
4. Install brew if needed
5. Install tools, NDK and Swift Android Toolchain

# install system tools
brew install coreutils cmake wget
 
cd ~
mkdir android
cd android
 
# install ndk
NDK=17c
wget https://dl.google.com/android/repository/android-ndk-r$NDK-darwin-x86_64.zip
unzip android-ndk-r$NDK-darwin-x86_64.zip
rm -rf android-ndk-r$NDK-darwin-x86_64.zip
unset NDK
 
# instal swift android toolchain
SWIFT_ANDROID=$(curl -fsSL https://api.bintray.com/packages/readdle/swift-android-toolchain/swift-android-toolchain/versions/_latest | python -c 'import json,sys;print(json.load(sys.stdin))["name"]')
wget https://dl.bintray.com/readdle/swift-android-toolchain/swift-android-$SWIFT_ANDROID.zip
unzip swift-android-$SWIFT_ANDROID.zip
rm -rf swift-android-$SWIFT_ANDROID.zip

swift-android-$SWIFT_ANDROID/bin/swift-android tools --update
ln -sfn swift-android-$SWIFT_ANDROID swift-android-current
unset SWIFT_ANDROID

6. Setup environment variables by putting this to .profile

export JAVA_HOME=$(/usr/libexec/java_home --version 1.8)
export TOOLCHAINS=org.swift.50320190830a

NDK=17c
export ANDROID_NDK_HOME=$HOME/android/android-ndk-r$NDK
# Stranger things
export NDK_ROOT=$ANDROID_NDK_HOME
export ANDROID_NDK=$ANDROID_NDK_HOME
export ANDROID_NDK_ROOT=$ANDROID_NDK_HOME

# Uncomment if you install Android Studio
# export ANDROID_HOME=$HOME/Library/Android/sdk

export SWIFT_ANDROID_HOME=$HOME/android/swift-android-current
 
export PATH=$ANDROID_NDK_HOME:$PATH
export PATH=$SWIFT_ANDROID_HOME/bin:$SWIFT_ANDROID_HOME/build-tools/current:$PATH
 
unset NDK
unset SWIFT_ANDROID

7. Include .profile to your .bashrc or .zshrc if needed by adding this line

source $HOME/.profile

Build and Test swift modules

Our current swift build system is tiny wrapper over Swift PM. See Swift PM docs for more info.

Command	Description
swift package clean	Clean build folder
swift package update	Update dependencies
swift-build	Build all products
swift-build --build-tests	Build all products and tests

swift-build wrapper scripts works as swift build from swift package manager but configuresd for android. So you can add any extra params like -Xswiftc -DDEBUG , -Xswiftc -suppress-warnings or --configuration release

Example of compilation flags:

Debug

swift-build --configuration debug \
    -Xswiftc -DDEBUG \
    -Xswiftc -Xfrontend -Xswiftc -experimental-disable-objc-attr

Release

swift-build --configuration release \
    -Xswiftc -Xfrontend -Xswiftc -experimental-disable-objc-attr \
    -Xswiftc -Xllvm -Xswiftc -sil-disable-pass=array-specialize

Build swift modules with Android Studio

This plugin integrates Swift Android Toolchain to Gradle

---

Build Toolchain

System Requirements

Building stdlib require Linux and building macOS compiler requires macOS So building scripts uses vagrant to automate eentire process on macOS host

Vagrant

Install virtualbox
Install vagrant
Install vagrant plugins

vagrant plugin install vagrant-disksize
vagrant plugin install vagrant-scp

macOS build tools

Install cmake and ninja

brew install cmake ninja pkg-config

Android NDK

Install Android NDK 17c from android-ndk-r17c-darwin-x86_64.zip and define ANDROID_NDK_HOME env variable

cd $somewhere
wget https://dl.google.com/android/repository/android-ndk-r17c-darwin-x86_64.zip
unzip android-ndk-r17c-darwin-x86_64.zip
rm android-ndk-r17c-darwin-x86_64.zip
export ANDROID_NDK_HOME=$PWD/android-ndk-r17c

Building

Run build/build.sh from project root. Resulting toolchain will be generated in out/swift-android-$VERSION.zip

To clean building directory run build/clean.sh in project root

It usually take around 2 hours on top MacBook Pro