This project sounds kind of masochistic but the idea is to bootstrap Rust from tinycc, and have traceability down to the lowest level assembly code. There is a step missing though? Tinycc is written in C after all.

I think it would make more sense to bootstrap from a small Lisp written in assembly language, if the traceability goal is worthwhile at all. There is nothing special about C.

There is nothing special about C.

I wish that were true, but isn’t it somewhat wishful thinking? Even an assembly-language Lisp would require an operating system in order to build a functioning compiler, wouldn’t it? And operating system APIs are in C.

In principle you could start from hand assembly. Look up “sectorlisp” as a lowest level option. Or you could start from Forth, which is traditionally implemented using very simple methods. The blog post really doesn’t make clear what problem the author is trying to solve. It gives some general description but leaves a lot to be guessed at.

Then there is the question of where the CPU is supposed to come from. Any modern one was designed using lots of mysterious CAD tools. Maybe scrounge a vintage Z80 out of an old Timex-Sinclair or something?

The author doesn’t explain exactly what their interest in bootstrapping is, but the goal is pretty explicit:

So, for me, it would be really nice if there was a Rust compiler that could be bootstrapped from C. Specifically, a Rust compiler that can be bootstrapped from TinyCC, while assuming that there are no tools on the system yet that could be potentially useful.

It seems it would be a lot easier to work on the GCC compiler, and work with others to bootstrap GCC (if it hasn’t already been done). Getting the GCC Rust compiler able to compile some version of rustc probably wouldn’t be that hard, and then you can just use that version to compile up the chain to modern Rust.

That’s the mrustc project the author mentions. He wants Rust to be bootstrapped earlier in the process.