flyfire/hot-reload-c

Hot Reload C

A simple SDL2 program to demonstrate how to hot reload C.

demo.mp4

Build

This program can be built on MacOS and Linux.

First you need to install SDL2:

• MacOS: brew install sdl2
• Linux: Check your package manager, e.g. on Manjaro, pacman -S sdl2

Then clone the code and build

$ git clone ... && cd ...
$ make run
# while the program is running, modify render.c and rebuild
$ make build
# and then the program will be hot reloaded 🚀

Idea

The main idea behind this is Shared Library a.k.a Dynamic Loaded Library.

We compile the render logic into a separate shared library and load it in main program dynamically via these apis:

• dlopen
• dlclose
• dlsym

So while the main program is running, we can rebuild our render library to hot load the main program.

Google dynamic linking for more details.