hacking get_links()

I’m working on modding how my links are displayed and need some guidance. Currently , they’re being displayed in li tags, followed by the description. What I want is for the description to be set as the title attribute of the li tag, so it will appear when you mouse-over the link.

What I’m planning is to make a derivative function of the get_links() function. The problem is that I can’t seem to rundown where the get_links() function is defined. I looked at this page https://codex.www.ads-software.com/Template_Tags/get_links which talks about the function, but doesn’t (from what I can see) tell me in which file the function lives.

Can someone point me in the right direction? Alternately, is there a better way to go about this? I’m a PHP hacker, so my inclination is to fire up vim and go to work, but if there’s another way, I’d like to learn.