From: Alan Mackenzie <acm@muc.de>
To: Dan Nicolaescu <dann@ics.uci.edu>
Cc: emacs-devel@gnu.org
Subject: Re: Unbearably slow editing in .h files
Date: Thu, 3 Apr 2008 17:58:42 +0000 [thread overview]
Message-ID: <20080403175842.GA1146@muc.de> (raw)
In-Reply-To: <200804031522.m33FMAEI002427@sallyv1.ics.uci.edu>
Hi, again!
On Thu, Apr 03, 2008 at 08:22:10AM -0700, Dan Nicolaescu wrote:
> Alan Mackenzie <acm@muc.de> writes:
> > On Thu, Apr 03, 2008 at 06:10:40AM -0700, Dan Nicolaescu wrote:
> > > Alan Mackenzie <acm@muc.de> writes:
> > > > On Wed, Apr 02, 2008 at 04:47:52PM -0700, Dan Nicolaescu wrote:
> > > Note that `diff-add-change-log-entries-other-window' is C-x 4 A not
> > > C-x 4 a, it is the equivalent of:
> > > FOR each hunk in a diff DO
> > > C-x 4 a
> > Wow! I've just tried this. It's amazing! There are one or two
> > things in it which aren't quite right, though.
> Yep, it should not generate duplicate entries. One possible
> improvement is that it should iterate at a lower granularity than a
> hunk, some hunks have changes ! + and - changes. (but that's still not
> enough, a + hunk could be adding 5 functions...)
I tried it (with a window configuration I can't remember exactly) and
ChangeLog ended up in both the upper and lower windows. But that's for
another thread. ;-)
> > > When used on a diff buffer with thousands of lines, it is a bit
> > > slow.
> > Hmmm. I've only tried it on diffs with elisp files. That was a
> > little slow. Do you mean it's _very_ slow with C file diffs? Can
> > you give some numbers here? Processor speed, size of diff file,
> > time it takes.
> Unfortunately I don't have any massive patches handy, so I can't test
> now how much things have improved for exactly the things that had
> problems before. But some quick tests with the diff for lisp.h
> revision 1.606 (i.e. something that had a long ChangeLog entry, 625
> lines unidiff) showed that things have improved quite a lot today vs a
> > 1 month old emacs (a few seconds vs > 2 minutes). Which is great.
> Thanks!
:-)
> Trying C-x 4 A on a 4-5000 lines patch would be more interesting...
Yes.
> > But then again, people are only going to be using it once or twice
> > per patch (and then having to fill out the result by hand), so it
> > is surely not that critical. But if it were taking 20 minutes
> > rather than 45 seconds, that would be too slow, I agree.
> Ideally in the future C-x 4 A should be done automatically when doing a
> checkin, that why it is important to be as fast as possible.
I'm not sure I agree, here. That might make it far too easy for people
to forget (or even to "forget") to write commit comments.
> > > > To the extent that it's still slower than it might be, yes
> > > > it's the K&R stuff making it slow. The function which takes
> > > > time is c-in-knr-argdecl (cc-engine.el, ~L6317). Actually,
> > > > this function gets called twice. It would take a lot of
> > > > refactoring to make it get called only once.
> > > What if it's not called at all? After all, the vast majority of
> > > the users never edit K&R. Just a thought...
> > Well, one set of users who still use K&R is the Emacs development
> > team. ;-)
> Yeah, and many people wish that would change at some point. But that a
> separate discussion that we should get into now.
I'm not sure why we don't just change all the K&R declarations to ANSI
ones. It could probably be done simply enough with a script (awk, perl,
python, Emacs Lisp, or anything else).
> > It would be possible, and very easy, to make K&R a user option.
> > But I don't think that's the right thing to do.
> > The overhead that K&R imposes on C-M-a and C-x 4 a is not _that_
> > high, and it will diminish as processors continue to get faster. I
> > recently put in a hard-coded limit to the number of parameter
> > declarations in a K&R section. That limit is currently 20.
> Just exploring options here...
> Would simply ignoring K&R for the purpose of running C-x 4 a work?
No. You're at the opening brace of a C function/typedef/struct; you've
got, somehow, to get from there to the function name. That involves
jumping backwards over the K&R region, should it be present. Or, point
starts out _outside_ a brace block. You've got to decide whether it's
inside a function/typedef/struct header, and this might be the K&R
region.
> Yes, it might generate the wrong name in the ChangeLog entry in some
> very limited cases (is that true?), .....
I doubt it. I think it would foul up with _every_ K&R function
declaration. To try it out, set the major mode to C++ mode, then try
C-M-a or C-x 4 a. In fact, in xdisp.c, I've just done this, gone to EOB
and typed C-M-a 25 times. It got BOD OK 8 times, failed 17 times.
> ...., but that's not very critical.
I think it would be. It would only need to happen to a hacker once, and
he would lose all confidence in it. He would then feel obliged to check
every entry by hand - and the complaints would find their way to
bug-cc-mode@gnu.org. ;-(
--
Alan Mackenzie (Nuremberg, Germany).
next prev parent reply other threads:[~2008-04-03 17:58 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-04 21:18 patch: add-log.el: changelog find file under poin Jan Nieuwenhuizen
2007-11-06 23:45 ` Juri Linkov
2007-11-07 13:38 ` Jan Nieuwenhuizen
2007-11-09 8:40 ` Dan Nicolaescu
2007-11-09 9:40 ` Juri Linkov
2008-01-20 6:14 ` Richard Stallman
2008-01-21 3:02 ` Glenn Morris
2008-01-21 20:30 ` Richard Stallman
2008-01-21 20:35 ` Glenn Morris
2008-01-22 22:29 ` Richard Stallman
2008-01-22 22:38 ` Glenn Morris
2008-01-22 23:09 ` Dan Nicolaescu
2008-01-23 1:32 ` Juri Linkov
2008-01-23 2:25 ` Dan Nicolaescu
2008-01-23 9:28 ` Juri Linkov
2008-01-23 16:20 ` Richard Stallman
2008-01-27 19:54 ` Dan Nicolaescu
2008-01-28 10:20 ` martin rudalics
2008-01-30 2:58 ` Dan Nicolaescu
2008-02-18 19:46 ` patch: add-log.el: changelog find file under point martin rudalics
2008-02-18 20:09 ` Unbearably slow editing in .h files (was: patch: add-log.el: changelog find file under point) Stefan Monnier
2008-02-23 22:49 ` Alan Mackenzie
2008-02-23 22:51 ` Unbearably slow editing in .h files martin rudalics
2008-02-23 23:25 ` Alan Mackenzie
2008-02-24 8:55 ` martin rudalics
2008-04-02 22:07 ` Alan Mackenzie
2008-04-02 23:47 ` Dan Nicolaescu
2008-04-03 9:14 ` Alan Mackenzie
2008-04-03 13:10 ` Dan Nicolaescu
2008-04-03 14:17 ` Alan Mackenzie
2008-04-03 15:22 ` Dan Nicolaescu
2008-04-03 17:58 ` Alan Mackenzie [this message]
2008-02-24 0:37 ` Stefan Monnier
2008-02-24 8:39 ` Alan Mackenzie
2008-02-24 14:46 ` Jason Rumney
2008-02-24 19:48 ` Eli Zaretskii
2008-02-24 19:49 ` Eli Zaretskii
2008-02-24 10:28 ` Andreas Schwab
2008-02-24 13:49 ` Stefan Monnier
2008-02-24 14:41 ` Alan Mackenzie
2008-02-24 15:42 ` Stefan Monnier
2008-02-24 20:12 ` Alan Mackenzie
2008-02-24 22:29 ` Richard Stallman
2008-02-25 2:14 ` Stefan Monnier
2008-02-18 23:31 ` patch: add-log.el: changelog find file under point Juri Linkov
2008-02-19 6:34 ` martin rudalics
2008-02-20 21:29 ` Juri Linkov
2008-02-21 7:26 ` martin rudalics
2008-02-21 22:29 ` Richard Stallman
2008-02-22 19:26 ` martin rudalics
2008-02-23 19:28 ` Richard Stallman
2008-02-23 22:32 ` martin rudalics
2008-02-24 15:23 ` Richard Stallman
2008-02-24 15:23 ` Richard Stallman
2008-02-24 22:34 ` martin rudalics
2008-02-25 10:57 ` Richard Stallman
2008-02-25 14:05 ` martin rudalics
2008-01-22 0:08 ` patch: add-log.el: changelog find file under poin Juri Linkov
2008-01-22 1:17 ` Drew Adams
2008-01-22 9:54 ` Juri Linkov
2008-01-22 14:34 ` Drew Adams
2008-01-22 22:29 ` Richard Stallman
2008-01-23 1:29 ` Juri Linkov
2008-01-23 16:20 ` Richard Stallman
2008-01-28 8:55 ` Jan Nieuwenhuizen
2008-01-28 9:29 ` Johan Bockgård
2008-01-22 8:21 ` Dan Nicolaescu
2008-01-22 9:56 ` Juri Linkov
2008-01-22 23:13 ` Dan Nicolaescu
2008-01-22 22:29 ` Richard Stallman
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