Re: narrow-to-defun and mark-defun now work properly for CC Mode.

[Chong Yidong <cyd@stupidchicken.com>]

Alan Mackenzie <acm@muc.de> writes:

> I've patched .../lisp/progmodes/cc-{defs,langs,cmds,awk}.el in savannah
> (but not yet at SourceForge) so that these two commands work properly -
> up till now, they've enclosed the region between the braces; now they
> enclose the entire function, including the function header.
>
> The basic idea is to set \(beginning\|end\)-of-defun-function to the
> corresponding CC Mode functions.  However, C-M-[ae] remain bound
> directly to these CC Mode functions to allow optimisation for large
> argument (factor ~10 in speed).

The trouble is that font-lock uses {beginning/end}-of-defun-function.
Because c-{beginning/end}-of-defun-function is slow (which is
apparently unavoidable due to syntactic complications), it makes
font-lock unacceptably slow (> 20 seconds for M-> in xdisp.c).

Having narrow-to-defun including the function header would be nice,
but if no solution to the slowness problem arises quickly, I think
this change should be postphoned to post-22.