The Cliffs of Inanity

idutils

I love hearing the odd details of how other people work. Usually I’m hoping to learn something that will help me be more productive, and, if not, to hear about something delightfully awful, convoluted, and obscure.

Talking to Roland at JavaOne yielded a nice mix of both. One interesting thing is that he uses full-text search on his source and basically (AIUI) doesn’t run grep from inside Emacs. I, on the other hand, was a long-time igrep user, switching to rgrep (new in Emacs 22) recently.

I decided to give Roland’s approach a try.

First I took a look at namazu, since I knew it had some sort of Emacs integration, and because it is packaged in Fedora. Unfortunately it doesn’t seem to understand how to index source code.

So then I tried GNU idutils. I had heard of this years ago, and even tried it once or twice, but somehow it didn’t end up in my repertoire. Anyway, it turns out that this is a pretty nice tool. It isn’t packaged for Fedora, but building it only took a couple minutes. The Emacs support code needed some tweaks (email me if you want this), but works ok enough out of the box.

The result is pretty nice. For small projects it may not matter much, but searches over the code I’m indexing (GCC) are much, much faster. This is especially nice since the work I’m doing on GCC at the moment requires repeated searches for all the users of various global variables.

Idutils could use a little love — right now there’s no way to incrementally update the index, which is a pain. If it affects me enough I suppose I’ll set up a cron job or something using inotify. This is just gloss, though. The important thing is that it has removed a pointless wait from my process.

Front End Stuff

I’ve been digging through GCC’s C front end the last couple of weeks, trying to understand how it works and how feasible some parts of my project are.

The parser itself is nice. It is a hand-written recursive descent parser, which means that it is “just plain code” and thus simple to debug. It is written in a typical object-oriented style, where every function in the parser takes a “c_parser” object pointer as its first parameter.

Unfortunately the rest of the C front end is not so nice. There are many (around 200) global variables, and even though the parser itself is quite clean, it implicitly relies on these via functions elsewhere in the front end. This means that making the front end reentrant is going to be a fair amount of work. While much of this will be mechanical, there are some ugly things, like places where lang hooks (a sort of virtual function in the compiler) are designed in a way that implicitly requires a global variable.

I haven’t looked deeply into the C++ front end yet, but a quick look with nm shows that there are about 100 globals there as well.

Making the parser re-entrant is sort of a side plot for me: it will help with part of my project, but it isn’t on the critical path. Still, I’d like to see the C and C++ front ends eventually be written in “gcjx style”: thread-aware reusable libraries, written in an OO style, separated from the back ends.

So why work on this at all right now? I didn’t know the C front end at all, and I thought this would be a way to learn about it without getting bored just reading code. This plan is working pretty well. I’ve also spent a bit of time simply stepping through various parts of the compiler with gdb — another useful technique for learning a foreign code base.

Meanwhile I’ve been working on the design of the more crucial parts of the plan — namely, re-using parsed headers and providing incremental recompilation. My current hope is to have something ready for critique before the GCC Summit.

Ocean’s 13

My brother called this “Ocean’s 11.5”.

I was disappointed by 12 — having the plot be a pointless, artificial contest was, in my opinion, a big cop-out by the writers. Also it was a bit incoherent at points, with a bit too much dialog left implied.

13 takes a stab at avoiding these problems. The plot is about revenge, old-fashioned but still fun. The dialog and situations aren’t quite as hard to follow (though I did spend much of the movie wondering what a “kooker” was, only to find out, via a review, that it was “cougar”, which luckily the review explained).

In the end 13 was a bit formulaic, but I could watch the cast of the movie all day long, and it was enjoyable enough to recommend. I own 11 and 12 and this one is comfortable enough that I’ll probably buy it someday and watch it when I want an easy distraction.

Word Swirl

Here’s Word Swirl, a dictionary-based game you can play in your web browser. You get points for every word you can find, and if you find a word that uses all the letters you will be able to go to the next round. You can use the space bar to rearrange your letters.

My sister says this doesn’t work in IE — sorry about that. I don’t have Windows here and so I don’t know a way to debug it. If you know what is wrong, let me know. I suppose real web developers must run Windows, or they must have 2-3 machines on their desktop at any given time.

It may take a little while to download, since it downloads its entire dictionary at once. Word Swirl is GPL.

Knocked Up

Steve said he thought this movie was hilarious and he laughed all the way through it. I don’t really understand how that is possible. It was funny in parts, occasionally too crude for my taste, but then also occasionally touching.

EMMS

This weekend I installed EMMS, the Emacs multimedia system. I also packaged it for ELPA, but I haven’t uploaded it yet — expect it soon.

EMMS is fairly primitive, but that doesn’t matter to me. I barely use any features of existing music players, I typically just play a lot of songs in a row and ignore the UI. So why move this into Emacs? Just so I can start and stop music without moving my hands to the mouse. At this point I’m almost completely living in Emacs, to the extent that I’ve started trying to migrate all my shell use there as well (changing a 15 year habit of having a couple terminals open — not easy).

I did hook EMMS to my hacked zenity (aka Emacs notification area) code. This, I suppose, goes against the “mouse-free” approach. But first, these notification area hacks are fun (and now more than half of the notification icons on my desktop are Emacs-related — haha), and second sometimes my hand is already on the mouse, and it is sometimes nice to be able to pause that way as well.

Emacs 22 is officially released, in case you didn’t hear. It has an absurd number of new features and new packages — a couple IRC clients, a new gdb UI, Tramp (a way to access files via ssh or — very useful — sudo), Calc (by the legendary Dave Gillespie), and a bunch more.

I haven’t published my “project.el” (per-project settings done in an easy way) yet, but that will come soon. I also started hacking on a keyring for Emacs, to save all those pesky Tramp and ange-ftp passwords. The base code works but I need to wire it in to all the places that ask for a password — I suppose this should really go into the Emacs core. ELPA-wise, work continues and I upload a couple packages a week. I started looking at uploading DVC — I think I want to start getting larger, more useful packages into the repository.

Shrek 3

I remember the earlier Shrek installments as being funnier, but it is hard to say with certainty. This one was reasonably enjoyable, and the gingerbread man’s sequence was downright hilarious.

Web 2.0.3

Every time I read about a new Web 2.0 application, or Y Combinator boot camp, or anything ending in “oogle”, I lose a little piece of my mind. Over time this adds up and I start thinking strange, crazy thoughts, like “maybe I should rewrite Automake as a set of GNU Make include files”.

Occasionally in these moods I brainstorm web site ideas.

For instance, how about vbeer.com, for all your virtual beer-owing needs? Instead of saying “I owe you a beer”, say it via our new social networking site, dedicated to beer redistribution. It has an irc bot so you can /msg your thanks as well. vbeer connects to the free software calendar of events, and will show you a printable chart of how many rounds you have to buy, for whom, at the events you’ll be attending. Version 2 will include some code for (optional) transitive beer forwarding

More seriously, I keep wishing there were a site for “sensitive programmers” (titled perhaps after Elaine Aron’s book, which btw is pretty good) — say a sort of support group with ideas on how to avoid excessive emotional bruising in a field that, in my view, over-tolerates assholes

Finally, I know this is crazy, but what about a web site dedicated to making it easy to download and install random bits of Emacs Lisp code? Oh, wait, I did that. (And if you’re into this at all, there’s an amusing and somewhat strange discussion of package.el on the Emacs devel list.)