DEV Community

Rino Di Paola
Rino Di Paola

Posted on

How I Built a Mini C Compiler to Understand How Compilers Work

I’ve always been fascinated by how programming languages are transformed into executable code.

As a software engineer, I use compilers every day — but I realized I had never really understood what happens behind the scenes.

To change that, I decided to build a Mini C Compiler from scratch, focusing on learning rather than performance or completeness.

The goal was simple: understand how each stage of a compiler works — from lexical analysis to parsing and interpreting — and document everything clearly.

The project supports a basic subset of the C language and runs through an interpreter to execute the code.

While it’s far from a production-grade compiler, it gave me a much clearer picture of how real compilers like GCC or Clang are structured internally.

I tried to make the documentation as clear as possible so that anyone else interested in learning these concepts can follow the same path I did.

🧩 Repository and documentation:

https://github.com/ironrinox/mini-c-compiler

If you’re a beginner or a curious developer looking to understand compilers in a more practical way, I hope this project can be a useful reference.

Top comments (2)

Collapse
 
onlineproxy profile image
OnlineProxy

The hardest part of building my compiler was definitely semantic analysis - dealing with scopes, type checking, and symbol resolution is where sneaky little bugs love to hide. For parsing, I went with a hybrid error-handling setup: I’d let it fail fast early on, then later added some chill recovery stuff to keep user feedback nice and friendly. My compiler still follows the classic Lexer - Parser - AST - IR flow, but it’s way simpler than big dogs like Clang or GCC. If I ever mess with optimizations, I’d start small - maybe a basic three-address code IR to handle things like constant folding and dead code cleanup before jumping into the fancy stuff.

Collapse
 
shemith_mohanan_6361bb8a2 profile image
shemith mohanan

Love this project! I’ve always found compilers a bit mysterious, and your documentation makes it way more approachable. Thanks for open-sourcing it — definitely checking out the repo 🙌