src/librustc_driver/README.md

   1 The `driver` crate is effectively the "main" function for the rust
   2 compiler.  It orchestrates the compilation process and "knits together"
   3 the code from the other crates within rustc. This crate itself does
   4 not contain any of the "main logic" of the compiler (though it does
   5 have some code related to pretty printing or other minor compiler
   6 options).
   7
   8 For more information about how the driver works, see the [rustc dev guide].
   9
  10 [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/rustc-driver.html