c-before-font-lock-functions is a variable defined in `cc-engine.el'.
Its value is

  • Automatically becomes buffer-local when set.
  • This variable may be risky if used as a file-local variable.

If non-nil, a list of functions called just before font locking.
Typically they will extend the region about to be fontified (see
below) and will set `syntax-table' text properties on the region.

These functions will be run in the order given. Each of them
takes 3 parameters, the BEG, END, and OLD-LEN supplied to every
after-change function; point is undefined on both entry and exit;
on entry, the buffer will have been widened and match-data will
have been saved; the return value is ignored.

The functions may extend the region to be fontified by setting the
buffer local variables c-new-BEG and c-new-END.

The functions are called even when font locking is disabled.

When the mode is initialized, these functions are called with
parameters (point-min), (point-max) and .