Is rust-analyzer implemented as a compiler driver with rustc_driver and/or rustc_interface?

[benwu25]

Just curious whether this is how it works.

[ChayimFriedman2]

No. rust-analyzer is a complete reimplementation of a frontend for Rust.

It does share some parts with rustc (e.g. pattern analysis and hopefully soon the trait solver), but the majority is home-made.

The reason is that traditional compilers are just badly suited to handle IDE scenario. In fact, before rust-analyzer, there was RLS which was implemented on top of rustc, but it was really slow.

[lnicola]

See also https://rust-analyzer.github.io/book/contributing/architecture.html and the linked YouTube series.