# Hacking the LRocket Compiler

`lrc` supports different ways to be extended.

This page gives an overview over the different ways of extending the compiler functionality and references pages that go into detail on each type of extension.

## Overview

As of `lrc v1.2` there are four standartized types of extensions for the compiler:

### otype

An `otype` describes how a concrete thing is built (e.g. a PC executable, a shared library or an Android application). If you want to define your own `otype`, see [Writing an `otype`](writing-an-otype).

### Toolchain

A toolchain tells `lrc` how to configure the underlying C compiler for a specific target platform. This could be an excentric CPU architecture or an operating system/execution environemnt which requires extra processing (such as e.g. WebAssembly).

For details on this type of compiler extension, see [Writing a Toolchain](writing-a-toolchain).

### Target Rule

Target rules are triggers that are activated when the user builds for a specific operating system, architecture or ABI.

They are useful to select the correct [toolchain](#toolchain) automatically, when it is implicitly needed (e.g. the `android`-toolchain when the target OS is `android-`).

To see how to write your own target rule, see [Target Rules](writing-a-toolchain.md#target-rules).

### Language Extension

`lrc` can even be extended to support new languages (yes, that is other than Lua)!

An example for a language extension is `lrc`s integrated [Teal support](https://codeberg.org/lrocket/lrc/src/branch/main/lrocket/lang/teal.lua).

If you want to extend `lrc` with support for a new language, see [Writing a Language Extension](writing-a-language-extension).