Immix GC for LLVM-based Languages

Welcome to the Immix GC project! This project aims to provide a highly efficient and easily integrable immix garbage collector (GC) for all languages that use LLVM as their backend. Originally a part of the Pivot Lang project, this GC leverages LLVM's stackmap functionality to assist in stack scanning and supports both conservative and precise garbage collection.

Features

• High Performance: Designed for high efficiency to minimize the overhead of garbage collection.
• Easy Integration: Simple to integrate with any LLVM-based language.
• Support for Conservative and Precise Collection: Flexible enough to work with both conservative and precise memory management paradigms.
• LLVM Stackmap Integration: Utilizes LLVM's stackmap feature for effective stack scanning.
• LLVM Passes and GC Strategy Plugins: Comes with built-in LLVM passes and corresponding GC strategy plugins to facilitate integration.
• Evacuation: Supports object evacuation to reduce fragmentation and improve memory locality.

Supported Platforms

• Linux amd64
• windows amd64
• macOS aaarch64

The above 3 platforms are tested and supported, other platforms may work but are not officially supported.

Theoretically this GC should work on all amd64 and aarch64 platforms.

Build

To build the Immix GC, you will need to have the following dependencies installed:

• LLVM 18.x
• CMake 3.10 or higher
• Rust 1.55 or higher

Once you have the dependencies installed, you can build the Immix GC by following these steps:

1. Clone the repository:

2. Build project with Cargo:

   cargo build

   don't forget to add the --release flag if you want to build the release version.

Usage

Using Immix GC on C Programs

We have some built-in LLVM passes and GC strategy plugins that you can use to integrate the Immix GC with existing C programs.

example.c is a simple C program that playing with a binary tree, it's originally using the system malloc/free to manage memory. You can compile it with clang example.c and run it with ./a.out.

To use the Immix GC, you can recomplie the program running

./compile_example.sh

Then you can run the program with ./a.out. The program will run with the Immix GC, and produce exactly the same result as before.

Using on your own LLVM-based language

TODO

Language using Immix GC

• Pivot Lang

Contributing

We welcome contributions from the community! Here are some ways you can contribute:

• Submit bug reports and feature requests.
• Write documentation and tutorials.
• Improve the performance and capabilities of the GC.
• Integrate Immix GC with more languages and provide examples.

License

This project is licensed under the MIT License. See the LICENSE file for more details.

Acknowledgements

This project is inspired by the need for a performant garbage collection system in the Pivot Lang project and has evolved to become a stand-alone solution for all LLVM-based languages. Special thanks to all contributors and the LLVM community for their support.

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Happy Coding!