libsignal/swift

Overview

This is a binding to the Signal client code in rust/, implemented on top of the C FFI in rust/bridge/ffi/. It's set up as a CocoaPod for integration into the Signal iOS client and as a Swift Package for local development.

Use as CocoaPod

1. Make sure you are using use_frameworks! in your Podfile. SignalClient is a Swift pod and as such cannot be compiled as a plain library.

2. Add 'SignalClient' as a dependency in your Podfile:

    pod 'SignalClient', git: 'https://github.com/signalapp/libsignal-client.git'
   

3. Build as usual. The Rust library will be built as a script phase and linked into the built SignalClient.framework.

Development as a CocoaPod

Instead of a git-based dependency, use a path-based dependency to treat SignalClient as a development pod. If validating SignalClient locally, use the following invocation:

XCODE_XCCONFIG_FILE=swift/PodLibLint.xcconfig pod lib lint \
  --platforms=ios \
  --include-podspecs=../SignalCoreKit/SignalCoreKit.podspec \
  --skip-import-validation \
  --verbose

You will also need to have SignalCoreKit checked out; the above command assumes you have checked it out as a sibling directory to libsignal-client.

Development as a Swift Package

1. Build the Rust library using swift/build_ffi.sh -d. (The Package.swift is configured to use the debug build of the Rust libraries, since they are likely being developed in tandom.)

2. Use swift build and swift test as usual from within the swift/ directory.

Use as a Swift Package

...is not supported. In theory we could make this work through the use of a custom pkg-config file and requiring clients to set PKG_CONFIG_PATH (or install the Rust build products), but since Signal itself does not use this configuration it's considered extra maintenance burden. Development as a package is supported as a lightweight convenience (as well as a cross-platform one), but the CocoaPods build is considered the canonical one.