Contributing to ANTLR 4

1. Fork the antlr/antlr4 repo, which will give you both key branches, master and dev
2. Make sure to git checkout dev in your fork so that you are working from the latest development branch
3. Create and work from a branch derived from dev such as git checkout -b your-branch-name
4. Install and configure EditorConfig so your text editor or IDE uses the ANTLR 4 coding style
5. Build ANTLR 4
6. Run the ANTLR project unit tests
7. Create a pull request with your changes and make sure you're comparing your dev-derived branch in your fork to the dev branch from the antlr/antlr4 repo:

Note: Each commit requires a "signature", which is simple as using -s (not -S) to the git commit command:

git commit -s -m 'This is my commit message'

Github's pull request process enforces the sig and gives instructions on how to fix any commits that lack the sig. See Github DCO app for more info.