UwU-C

UwU-C is a small programming language and compiler I'm building as a learning project.

The goal is to explore how compilers actually work—from parsing and IR to handwritten assembly—while experimenting with safer memory ideas and a cute syntax.

Warning

This is not a production language. It's a playground for learning low-level internals.

Join the Community

Got questions, want to follow the progress, or just want to hang out? Join the Discord:

Join the UwU-C Discord

Why UwU-C?

I wanted to stop treating compilers like a black box. UwU-C exists to help me learn:

• Compiler internals — The journey from source to binary.
• Stack layout & calling conventions — Managing memory at the metal.
• x86_64 & ARM64 assembly — Writing instructions by hand.
• ABI rules — And the fun of seeing why breaking them causes crashes.

Instead of using LLVM, UwU-C generates assembly directly. This makes the behavior much easier to understand, debug, and trace.

Features

• Custom IR — My own intermediate representation.
• Handwritten codegen — Raw assembly output for full control.
• Experimental memory safety — Testing out some safer memory ideas.
• Cute syntax — Making low-level dev a bit more fun and cute.
• Work in progress — Always evolving.

Project Status

Early and experimental.
Things will break. That’s part of the point.

Supported Platforms

Architecture	OS
x86_64	Linux
ARM64	Linux, macOS

Building

UwU-C supports two build systems: Make (simple and straightforward) or Bazel (fast with great caching).

Using Make

# Build release version
make

# Build debug version (with AddressSanitizer)
make debug

# Build and run tests
make test

# Build examples
make examples

# Clean build artifacts
make clean

Using Bazel

# Build the compiler
bazel build //:uwucc

# Build in debug mode
bazel build --config=debug //:uwucc

# Run the compiler
bazel run //:uwucc -- input.uwu -o output

# Compile an example (e.g., example/ez.uwu)
bazel build //:example_ez
bazel run //:example_ez

# Clean
bazel clean

For more details on Bazel usage, see toasty-software-guide-to-bazel.md.

Requirements

• C compiler (clang recommended, gcc works too)
• Make or Bazel/Bazelisk
• Platform: Linux or macOS
• Architecture: x86_64 or ARM64

Repo Layout

• src/ — compiler source
• include/ — headers
• stdlib/ — experimental standard library
• example/ — example programs
• docs/ — notes and explanations
• kernel/ — operating system

License

WTFPL — do whatever you want.