building an index of references?

I'm happily using source-highlight to generate linked HTML API documentation.

I'd like to produce an index of all symbols in my library (something like
this: https://developer.gnome.org/glib/2.42/api-index-full.html)

It seems like source-highlight handles all the bits that would be required
for this, but I didn't spot any options to produce it.  Did I miss them or
do I need to roll my own?

Thanks,
Britton