swift-toolchain-for-android-on-macos

Swift toolchain for android on macos

Prerequisites

• You are on arm64 mac
• Recent xcode vetsion installed on mac
• Install NDK and CMake. Instructions

Use toolchain

Here are steps to compile package

• $ export PATH="<toolchain_path>/usr/bin:$PATH"
• $ export SWIFT_EXEC_MANIFEST=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swiftc
• export SWIFT_EXEC=<toolchain_path>/usr/bin/swiftc-android and swiftc-android should be executable
• cd <package_path>

swift build --triple aarch64-unknown-linux-android \
   --emit-swift-module-separately \
   --sdk <toolchain_path> \
   --toolchain <toolchain_path>/usr/bin \
   -Xswiftc -emit-library \
   -Xswiftc -emit-module \
   -Xcc -I/Users/$USER/Library/Android/sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/include \
   -Xcc -I/Users/$USER/Library/Android/sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/darwin-x86_64/sysroot/usr/include/aarch64-linux-android \
   -v

Build toolchain

$ swift run SwiftBuilder \
  --working-folder <WORKING_FOLDER> \
  --android-sdk <PATH_TO_ANDROID_SDK> \
  --source-root "$PWD"

For example, values might be:

• WORKING_FOLDER - ~/ws/SwiftAndroid, this should be empty folder, which will be used by app for checkout and build
• PATH_TO_ANDROID_SDK - ~/Library/Android/sdk/, inside we expect ndk fodler with NDK v25

To modify some constants:

• NDK version in HostConfig/NDK.swift
• Android API level in AndroidConfig/AndroidAPILevel.swift
• To change macOS target, like arch or min deployment target - check HostConfig/MacOS.swift

While building, we will save progress with completed steps in current-progress.json. This helps us avoid re-running long build operations, if we encountered any problem. If you want start from scratch - just delete file from working folder. Alternatively, you can manually remove steps, which you want to repeat.

How to update code for a new release

1. Find new release tag in github repo
2. Follow steps here to update default checkout hashes
3. Consider changing CMAKE_OSX_DEPLOYMENT_TARGET
4. Execute and fix issue by issue...