gccrs learns to build the Linux kernel: results of the first half of 2026

The gccrs project, which is building a frontend for the Rust language within the GCC compiler, spent the first half of 2026 focused on compiling the Linux kernel. According to the team's weekly and monthly reports, this work became a kind of proving ground: by testing the compiler against the kernel's crates, the developers also moved closer to generating correct code for other Rust programs along the way.

Testing against the kernel's real codebase turned out to be a productive way to expose weak spots. The February report describes problems with handling attributes, while the May report takes a detailed look at difficulties with name resolution and resource management. All of these defects were found and fixed precisely thanks to the attempts to compile the kernel.

For now the results remain modest: at this point gccrs is only able to handle simple standalone programs. Still, as noted, the situation could change fairly quickly over the coming months.

The arrival of a second working Rust compiler matters for the kernel: it reduces the dependence on a single LLVM-based implementation and opens up support for those hardware architectures that have a GCC backend but no corresponding target in the main Rust compiler.

Source: LWN.net