This comment gets font-lock-comment-face in C++ mode, but not in C mode:
/** * \file test.cpp * */
If I add another
/***, it's working in C-mode, too...
I'm not aware of any customisations, but I could be wrong.
Using CC Mode version 5.32.5 GNU Emacs 24.5.1 (x86_64-unknown-cygwin) of 2015-06-23 on desktop-new