Swift Achieved Dynamic Linking Where Rust Couldn't
3 days ago
- #Swift
- #Dynamic Linking
- #ABI Stability
- Swift achieved ABI stability in Swift 5, enabling dynamic linking and system-wide sharing of the Swift Standard Library.
- Dynamic linking allows system APIs to be updated without rebuilding applications, reducing memory footprint by sharing library implementations.
- Swift's ABI stability is defined by the platform, similar to C, but with more dynamism and resilience to changes.
- Resilient type layouts in Swift allow types to evolve without breaking ABI, using value witness tables for dynamic type information.
- Swift uses polymorphic generics, unlike Rust and C++ which use monomorphization, reducing code size and enabling dynamic linking of generic code.
- Reabstraction thunks in Swift allow functions to adapt to different calling conventions, optimizing performance and code size.
- Materialization in Swift enables taking references to computed fields, with temporary storage for inout parameters.
- Swift's ownership model uses reference counting (+0/+1) to optimize performance, similar to Rust's ownership but with implicit cloning.
- Swift provides attributes to opt out of resilience for performance-critical code, allowing more static optimizations.
- Swift's design emphasizes dynamic linking and resilience, making it more suitable for system APIs compared to Rust's static approach.