# RJIT: Ruby JIT¶ ↑

This document has some tips that might be useful when you work on RJIT.

## Project purpose¶ ↑

This project is for experimental purposes. For production deployment, consider using YJIT instead.

## Supported platforms¶ ↑

The following platforms are assumed to work. `linux-x86_64` is tested on CI.

- OS: Linux, macOS, BSD

- Arch: x86_64

## configure¶ ↑

### –enable-rjit¶ ↑

On supported platforms, `--enable-rjit` is set by default. You usually don’t need to specify this. You may still manually pass `--enable-rjit` to try RJIT on unsupported platforms.

### –enable-rjit=dev¶ ↑

It enables `--rjit-dump-disasm` if libcapstone is available.

## make¶ ↑

### rjit-bindgen¶ ↑

If you see an “RJIT bindgen” GitHub Actions failure, please commit the `git diff` shown on the failed job.

For doing the same thing locally, run `make rjit-bindgen` after installing libclang. macOS seems to have libclang by default. On Ubuntu, you can install it with `apt install libclang1`.

## ruby¶ ↑

### –rjit-stats¶ ↑

This prints RJIT stats at exit.

### –rjit-dump-disasm¶ ↑

This dumps all JIT code. You need to install libcapstone before configure and use `--enable-rjit=dev` on configure.

- Ubuntu: `sudo apt-get install -y libcapstone-dev`

- macOS: `brew install capstone`