Juri Linkov <juri@linkov.net> writes:

> PS: Regarding the change in diff.elisp.xfuncname, can we also have
> an appropriate regexp for diff.c.xfuncname as well, to find
> DEFUN in C code?

I'm not sure we need to define a new pattern for C files distinct from
the built-in cpp pattern, but here's a patch extending the cpp and elisp
patterns: