How to programmatically create/update a TAGS file with emacs?

Question

Is there any plugin for emacs to automatically update the TAGS file in my C project (for example on buffer save or access) or create a new one if there is no TAGS file present?

Answer 1

I use combination of semantic + gnu global for my day-to-day work. GNU Global's databases are updated once per day, while semantic use them for basic navigation, and re-parse changed files on the fly.

You can find more about these packages in my article about Cedet