A few months ago, I challenged myself to write a C compiler in just 500 lines of Python. The task turned out to be quite difficult but interesting, and the resulting compiler is surprisingly functional and easy to understand. Most compilers use a two-pass approach, where the code is first parsed into a syntax tree, which is then transformed into machine code. However, due to the limited number of lines, I had to go with a single-pass approach where code generation happens during parsing. I also decided to make the compiler target WebAssembly, which added some complexity. Despite its limitations, the compiler can successfully compile and run C programs, passing a significant number of test cases.
https://vgel.me/posts/c500/