With the new swift-driver project, Apple is developing a new implementation of the Swift compiler driver. Written in Swift, the new Swift compiler driver is intended to replace the existing driver, which is written in C++, with a more extensible and maintainable code base.
The new Swift compiler driver is still a work in progress, with Apple pursuing a goal to provide a drop-in replacement for the existing driver. This means there is a fixed initial feature set to implement prior to deprecating and removing the existing driver. The development plan covers the feature set and describes tasks to improve the Swift driver including code clean-ups, improving testing, adding missing features, and integrating with existing systems.
The Swift compiler driver is a program to coordinate the compilation of Swift source code into compiled results including executables, libraries, object files, and modules. This program is used to invoke builds of Swift code such as swift or swiftc from the command line, and also is invoked by tools such as the Swift Package Manager and Xcode.
Other goals of swift-driver include:
- Offering a library-based architecture for better integration with build tools.
- Providing a platform for experimenting with more efficient build models for Swift.
- Leveraging existing Swift build technologies such as SwiftPM and llbuild.
Accessing swift-driver
Apple has posted instructions on getting started with swift-driver in GitHub, including using swift-driver in place of the current Swift driver. Contributions to the project are welcome.