Written by Michael Larabel in GNU on 27 June 2022 at 02:10 PM EDT. 50 Comments

The Rust-GCC front-end that allows Rust code to be compiled with the GNU Compiler Collection (GCC) could possibly be upstreamed for next year's GCC 13 compiler release but not necessarily complete at that stage. In any case, it's good seeing progress on Rust-GCC as an alternative to Rust's official LLVM-based compiler.

GCC-Rust front-end developer Philip Herron of Embecosm has started a new mailing list discussion with GCC upstream developers. Herron is seeking upstream GCC developer feedback about the review process for merging such a large feature into the compiler, the necessary quality before it can be upstreamed, GCC release management if this code could land sooner rather than later, and associated factors.

As for the current state of the GCC-Rust front-end, Herron commented, "my current project plan brings us to November 2022 where we (unexpected events permitting) should be able to support valid Rust code targeting Rustc version ~1.40 and reuse libcore, liballoc and libstd. This date does not account for the borrow checker feature and the proc macro crate, which we have a plan to implement, but this will be a further six-month project."

If their November plans come to pass, that could still align the GCC-Rust front-end for being upstreamed in time for GCC 13. GCC 13.1 as the first stable release should be out next April albeit the feature cut-off closes prior to that point. But if waiting for more of that functionality to be completed before upstreaming GCC-Rust, that would punt it off until GCC 14 for release in 2024 with GCC's point releases not normally back-porting big ticket features.

GCC-RustSee this mailing list thread where the questions were volleyed for upstream GCC maintainers. The current GCC-Rust code for those interested can be found on GitHub. Monthly GCC-Rust status reports continue to be published on Philip Herron's blog.

If initial Rust support is upstreamed for next year's GCC 13 compiler release that is good news going along with Rust code going mainline in the Linux kernel soon as well - potentially for the 5.20 cycle to cap off the summer.