What changed in the XCode compilers this year?

This year, several significant changes were introduced to the Xcode compilers:

1. Dynamic Linking Architecture for Previews:

   • Xcode Previews now use the same build artifacts for both previews and when you build and run your project. This avoids the need to rebuild your project when switching between the two, resulting in a smoother and more productive workflow. (Platforms State of the Union)

2. Explicit Modules:

   • Xcode 16 introduces explicit modules, which provide improved parallelism, better diagnostics, and faster debugging without changing a single line of code. For C and Objective-C, explicit modules are enabled by default, while for Swift, developers need to opt-in. (What’s new in Xcode 16)

3. Swift 6 Language Mode:

   • Swift 6 brings a new language mode that provides concurrency safety guarantees, turning data races into compile-time issues. This improves the correctness and safety of your code. (What’s new in Xcode 16)

4. Generative Models for Code Completion:

   • Xcode 16 features a new code completion engine powered by generative models. This engine predicts the code you need, using your project symbols to customize suggestions. It runs locally on your Mac, ensuring privacy and fast results, even when offline. (Platforms State of the Union)

5. Swift Package Integration Improvements:

   • Enhancements to Swift package integration allow for queuing up builds without waiting, streamlining the build process. (What’s new in Xcode 16)

6. Swift 6 Data Isolation Enforcement:

   • Enabling Swift 6 mode brings full data isolation enforcement, with compiler diagnostics guiding developers towards potential bugs, acting like a pair programmer. (Migrate your app to Swift 6)

These updates collectively enhance the development experience by improving build performance, code safety, and developer productivity.