| # Bootstrapping the compiler | |
| [*Bootstrapping*] is the process of using a compiler to compile itself. | |
| More accurately, it means using an older compiler to compile a newer version of the same compiler. | |
| This raises a chicken-and-egg paradox: where did the first compiler come from? | |
| It must have been written in a different language. | |
| In Rust's case, it was [written in OCaml][ocaml-compiler]. | |
| However, it was abandoned long ago, and the | |
| only way to build a modern version of `rustc` is with a slightly less modern version. | |
| This is exactly how Rust's bootstrap build system works: it downloads the current beta release of | |
| `rustc`, then uses it to compile the new compiler. | |
| In this section, we give a high-level overview of | |
| [what Bootstrap does](./what-bootstrapping-does.md), followed by a high-level | |
| introduction to [how Bootstrap does it](./how-bootstrap-does-it.md). | |
| Additionally, see [debugging bootstrap](./debugging-bootstrap.md) to learn about debugging methods. | |
| [*Bootstrapping*]: https://en.wikipedia.org/wiki/Bootstrapping_(compilers) | |
| [ocaml-compiler]: https://github.com/rust-lang/rust/tree/ef75860a0a72f79f97216f8aaa5b388d98da6480/src/boot |