This tool automates the task of applying a set of semantic patches using coccinelle (http://coccinelle.lip6.fr/). This is really just a collection of semantic patches and a wrapper to invoke coccinelle. Needless to say, you should always check the results. At this point in time, only local git repositories are supported and there is only a small set of semantic patches to help porting Gtk+ 2 applications to Gtk+ 3.