crustc: rustc Compiler Translated into 46M Lines of C
Original: crustc: entirety of `rustc`, translated to C
Why This Matters
Enables rustc bootstrapping via C toolchains, broadening Rust compiler portability across platforms.
Developer FractalFir has released crustc, a project that translates the entire rustc Rust compiler (version 1.98.0-nightly) into approximately 46 million lines of C code, buildable using GCC and make.
Developer FractalFir published crustc on GitHub, a project that automatically translates the entirety of the Rust compiler (rustc 1.98.0-nightly, dated 2026-06-16) into C source code. The resulting codebase spans approximately 46 million lines of C. According to the repository, the translated compiler is fully functional: when compiled with GCC using the provided Makefile, it produces a working rustc binary that reports the correct version and is capable of compiling Rust code. The build requires a path to LLVM (specifically libLLVM.so.22.1-rust-1.98.0-nightly), which rustc depends on for code generation. FractalFir notes that pre-built LLVM binaries are intentionally not included in the repository to avoid embedding random binaries. The project currently has 232 stars on GitHub. This work demonstrates a novel approach to compiler bootstrapping and portability, enabling rustc to be built on systems where only a C compiler and make toolchain are available, without requiring an existing Rust toolchain.