Re: [DISCUSS] Introducing Rust into the Git project
From: Trevor Gross <tmgross@umich.edu>
Date: 2024-01-11 23:23:25
On Thu, Jan 11, 2024 at 4:28 PM [off-list ref] wrote:
The usable compilers and interpreters on NonStop are c89, c99 (what we use for git), c11, perl, and python3 (for the x86 only). The perl and python do not have sufficient modules to do what would be needed by git. The compilers are invoked using a CLI and are not callable using a library. gcc is, for all intents and purposes, not possible - so anything requiring gcc (for example, Rust), cannot be built. There is no back-end pluggable component for any of the compilers.
Ah, no pluggable backend is unfortunate. Rust only uses GCC to build the LLVM backend, it isn't actually needed for the language. It does link libgcc_s for unwinding and I believe some math symbols, but unwinding can be disabled and other symbols can come from anywhere. If you can build mrustc (C++ program) [1] then you can use it to transpile Rust to C. This is how rustc is bootstrapped, and would be how you bring it up with a different backend on a new platform. Still, this probably wouldn't be a solution for git. [1]: https://github.com/thepowersgang/mrustc