<cat>Dev.Modules</cat> <title>Creating Binary Modules: Rust</title> Unlike C++, Rust doesn't require an hour of CMake/other tweaking to build a project, you just need to have [Cargo](https://github.com/rust-lang/cargo). To create binary modules in Rust, there are now two main crates (libraries) - [gmod-rs](https://github.com/WilliamVenner/gmod-rs) and [rglua](https://github.com/Vurv78/rglua) (the library defines functionality and structure). They both have different but similar approaches to writing code, as well as different functionality and threshold of entry. In this article we will look at the ``gmod-rs`` crate (library) from WilliamVenner. # Dependencies Install [rust from official site](https://rust-lang.org), in one installer you will have Cargo (package manager), and the Rust compiler itself at once. ## Rust analyzer (LSP) If you want, you can install [rust-analyzer](https://github.com/rust-lang/rust-analyzer) (it's a set of utilities for easy code writing, including Language Server and other goodies) for your IDE. To install it on vscode, all you need to do is install [the official extension from marketplace](https://marketplace.visualstudio.com/items?itemName=rust-lang.rust-analyzer) # Setup a new project To create a new project on Rust you just need to write one command - ``cargo new <project name>``. To create a new project on Rust you just need to write one command - ``cargo new <project name> --lib``. ``` cargo new my_gmod_dll --lib ``` Congratulations! You have initialized your Rust project. ## Configuring the project Now let's customize our project for gmod: 1. Install ``gmod-rs`` as a dependency: ``` cargo add gmod ``` 2. Add these lines to the ``Cargo.toml`` file: ``` [lib] crate-type = ["cdylib"] ``` It should be something like this: ``` [package] name = "my_gmod_dll" version = "0.1.0" edition = "2021" [lib] crate-type = ["cdylib"] [dependencies] gmod = "17.0.0" ``` 3. Set the ``nightly`` toolchain: ``` rustup override set nightly ``` ## Modifying the code Our project is almost ready, all that is left is to modify the source code of the ``lib.rs`` file - in this case it is ``main.cpp`` in C++. Open the ``lib.rs`` file and trash everything from there. Our project is almost ready, we only need to change the source code of the ``lib.rs`` file - in this case it is a entrypoint file, and it is the analog of ``main.cpp`` in C++. Open the ``lib.rs`` file and remove everything from there. Put this code in it: ``` use gmod::{gmod13_close, gmod13_open, lua::State}; #[gmod13_open] fn gmod13_open(lua: State) -> i32 { println!("Hello from Rust!"); 0 } #[gmod13_close] fn exit(_: State) -> i32 { 0 } ``` Done! Your project only needs to be assembled, and then you can start studying the ``gmod-rs`` device and working with its stack! As you can see, the ``gmod13_open`` and ``gmod13_close`` functions are fluffed with the ``State`` argument. This is an object that is the interface between Lua and your module. Through it we can control the Lua stack. Done! Your project only needs to be builded, and then you can start explore the ``gmod-rs`` crate (library) and working with Lua stack! As you can see, the ``gmod13_open`` and ``gmod13_close`` functions are fluffed with the ``State`` argument. This is an object that is the interface between Lua and your binary module. Through it we can control the Lua stack. # Building WilliamVenner provides ready-made commands in the ``gmod-rs`` [repository for building the project](https://github.com/WilliamVenner/gmod-rs/tree/master/examples/my-first-binary-module), but I'll duplicate them: WilliamVenner provides ready-made CLI commands in the ``gmod-rs`` [repository for building the project](https://github.com/WilliamVenner/gmod-rs/tree/master/examples/my-first-binary-module), but I'll duplicate them: | Platform | Command | Description | |:---:|:---:|:---:| | `win32` | `cargo build --target i686-pc-windows-msvc` | Windows 32-bit<br/>Use this if your server is running Windows and is on the `main` branch of Garry's Mod (this is the default branch.) | | `win64` | `cargo build --target x86_64-pc-windows-msvc` | Windows 64-bit<br/>Use this if your server is running Windows and is on the `x86-64` branch of Garry's Mod. | | `linux` | `cargo build --target i686-unknown-linux-gnu` | Linux 32-bit<br/>Use this if your server is running Linux and is on the `main` branch of Garry's Mod (this is the default branch.) | | `linux64` | `cargo build --target x86_64-unknown-linux-gnu` |Linux 64-bit<br/>Use this if your server is running Linux and is on the `x86-64` branch of Garry's Mod. | After the project has been successfully built, find the built .dll (.so on unix-like systems), and rename it according to the desired result [as written here](https://wiki.facepunch.com/gmod/Creating_Binary_Modules:_CMake#naminglocation). You can find the compiled binary in `target/<TARGET>/debug/my_gmod_dll.dll` on Windows or `target/<TARGET>/debug/libmy_gmod_dll.so` on Linux. If you want to build the project in ``release`` fashion, then add the ``--release`` flag to the build command. If you want to build the project in ``release`` mode, then add the ``--release`` flag to the build command. # Conclusion I don't want you to think that everything is easy in Rust, since we have such handy tools. Yes, unlike C++, our tools are very handy, but the language itself takes a long time to get used to. So if you are thinking about learning it, think a couple of times whether it is worth it.