Question: After generating a tags file with `exuberant-ctags` I can jump from a function call to its declaration with `<C-]>` which is pretty convenient.

My question is how to do it in the other way? When my cursor is on the definition of a function, how can I go to the lines where the function is called?

When I look to the file generated by ctags I only see informations related to the location of the definition and not of the calls, does it means that I can't do that, that Vim as a clever workaround or that I need to use something else than `exuberant-ctags`?

Answer: 
You can't do that with ctags.

Try a beefier alternative like [cscope](http://cscope.sourceforge.net/) (which even has its own help section: `:help cscope`) or [global](http://www.gnu.org/software/global/).
One option is to add your own search patterns on the command line or in the config:

```
--regex-c++='/(\.|->)([[:alnum:]_]+)[[:space:]]*\(/\2(/i,function instance or call/'

```

This creates a new tag "kind" with the code 'i' (for Instance or Invocation) to distinguish it from other tags. It also creates the tags with a trailing '(', because when you are looking for the definition, having 100 invocation results can muddy the waters. So searching for 'my\_func(' limits the results in either case. If you don't like that, you can just remove the `(` after the `\2`.

You can use this options multiple times for the same kind. So, instead of trying to come up with a single regex that will match all calls, you can have several, simpler ones that capture different kinds of calls.

This isn't foolproof, and with the patterns I've built up, I still get non-call results, but it's definitely better than nothing! :)