A summary of the rustc compiler team design sprint held in Paris (February 2017), covering major architectural discussions: replacing pass-based compilation with on-demand query-based processing, next-generation incremental compilation inspired by Adapton, integrating alternate backends (Cretonne, WASM, miri), MIR optimization strategies, unsafe code guidelines, Macros 2.0 hygiene, diagnostic improvements, miri as a constant evaluator, variable-length arrays/allocas, and a new non-lexical lifetimes design. The post outlines the team's roadmap and design decisions for the coming year.
