lxr + emacs

Introduction

I use lxr at work all the time to cross-reference both Pika code and the Warp specific version of the kernel. I have mainly used the web interface, but have written this package to allow emacs direct access to the lxr database. Really, emacs does a better (and faster!) job.

How it Works

Basically, you need to setup two variables that link the lxr url to the local code base. lxr-url should point at the lxr repository and lxr-base should point at the local code base. Both of these variables are buffer local, since you (well let's face it I) want different repositories for different directories.

Let's assume you only use lxr for the Linux kernel. One way to setup lxr would be to add it to your c-mode-common-hook. It would be overkill, but wouldn't hurt anything since you wouldn't use it outside the kernel.

	(defun lxr-setup ()
	  (setq lxr-url "http://lxr.linux.no/"
	        lxr-version "2.6.26"
                lxr-base (file-truename "/usr/src/linux")))
	(add-hook 'c-mode-common-hook 'lxr-setup)
      

The lxr-version is used by repositories that have multiple versions. It will default to the most current version if left nil.

Requirements

• http.el to grab the lxr file from the url.
• ht2.el to convert the html to text.
• For GNU Emacs you need extent.el
• And of course, lxr.el!

How to Use It

There are currently two main interfaces: web output and definition files. The web output, lxr, gives you a text based version of the lxr web output with clickable links to local files. When you click on a link, a tag is pushed so you can use pop-tag-mark to get back. lxr-at-point is similar except it grabs the word at the point.

Definition files are more like the use in IDEs. With lxr-defined you are prompted for an identifier and then taken to the first file that matches (if any). lxr-defined-at-point is similar except it uses the word under the point.

In both cases, lxr-next-defined can be used to go to the next file in the list (if any). Again tags are marked so you can pop back through the list of files.

Back to http://xemacs.seanm.ca/ or http://emacs.seanm.ca/.