rustc

A hard fork of mrustc with a different goal.

Upstream mrustc is a bootstrapping seed: a C++ program that compiles Rust just well enough to build the real rustc once, so the official compiler can take over. We are not bootstrapping. We are turning mrustc into a real, standalone Rust compiler — one that stays and is used to build actual projects. (The compiler binary is therefore called rustc, not mrustc.)

how we get there

Not by chasing a spec, but by making real programs compile and pass their tests.

Every real-world crate we throw at the compiler exposes bugs — in type inference, in const evaluation, in the C codegen, in an intrinsic. We fix each one in the compiler and lock it in with a small regression test, then add the whole project as a standing test. The suite grows in two directions at once:

• breadth — more real binaries that build from source and pass their own tests (resvg is the first; more follow);
• depth — a one-file regression under tst/unit/ for every compiler bug we fix along the way.

The compiler gets more correct exactly as fast as the set of programs it can build gets…