Source code browsing using GNU ID and Emacs

$ dpkg -l | grep id-utils
ii  id-utils  4.5-3  Fast, high-capacity, identifier database tool

$ sudo apt-get install id-utils

The idutils source distribution comes with idutils.el, an Emacs interface to gid, the utility that comes with idutils and that let’s you query the ID database from the command line. At the time of writing, 4.6 is the latest version of the idutils package. However, it probably is safer to use the idutils.el from the same release as the idutils package installed on your system (in my case that is 4.5).

$ cd ~/temp
$ wget http://ftp.gnu.org/gnu/idutils/idutils-4.5.tar.xz
$ xz -d idutils-4.5.tar.xz
$ tar xvf idutils-4.5.tar
$ cp idutils-4.5/lisp/idutils.el "somewhere where emacs can find it"

Add the following to your dotemacs file:

;; Emacs GNU ID utils interface
;; M-x gid to run the command
;; more info at http://www.gnu.org/software/idutils/manual/idutils.html
(autoload 'gid "idutils" nil t)

The next step is to run mkid to build the identifier database. The following commands will produce an ID file in you project’s root directory. This will index your system headers as well as your project’s source code. E.g.:

$ cd "your favorite project"
$ mkid -s /usr/include/ .

Open up any source file from your project, point your cursor at some identifier and run M-x gid. Emacs will ask you something like this:

Run gid (with args): thread_mutex_create

Just hit enter and Emacs will bring up a *compilation* buffer with the results:

-*- mode: gid; default-directory: "/home/juanrubio/3rdparty/icecast/src/" -*-
Gid started at Wed Apr 10 12:57:01

gid thread_mutex_create
thread/thread.h:104:#define thread_spin_create(x)  thread_mutex_create(x)
thread/thread.h:111:#define thread_mutex_create(x) thread_mutex_create_c(x,__LINE__,__FILE__)
thread/thread.h:136:# define thread_mutex_create_c _mangle(thread_mutex_create)
auth.c:683:        thread_mutex_create (&auth->lock);
cfgfile.c:94:    thread_mutex_create(&_locks.relay_lock);
connection.c:147:    thread_mutex_create(&move_clients_mutex);
format_mp3.c:122:    thread_mutex_create (&state->url_lock);
global.c:45:    thread_mutex_create(&_global_mutex);
slave.c:139:    thread_mutex_create (&_slave_mutex);
source.c:106:        thread_mutex_create(&src->lock);
stats.c:134:    thread_mutex_create(&_stats_mutex);
stats.c:138:    thread_mutex_create(&_global_event_mutex);
stats.c:864:    thread_mutex_create (&(listener.mutex));
util.c:719:         thread_mutex_create (&localtime_lock);
xslt.c:101:    thread_mutex_create(&xsltlock);
yp.c:282:    thread_mutex_create (&yp_pending_lock);
net/resolver.c:41:#define thread_mutex_create(x) do{}while(0)
net/resolver.c:206:        thread_mutex_create (&_resolver_mutex);
thread/thread.c:164:    thread_mutex_create(&_threadtree_mutex);
thread/thread.c:165:    thread_mutex_create(&_library_mutex);    

Gid finished at Wed Apr 10 12:57:01

The results can be navigated with the usual Emacs commands M-x next-error and M-x previous-error, (usually assigned to M-g n and M-g p)

There are a number of other source browsing/navigation tools that are specific for Emacs or that also integrate well with Emacs, some of them are:

• Tags tables
• cscope/xcsope
• ebwrose
• CEDET and ECB

• http://www.gnu.org/software/idutils/manual/idutils.html
• http://emacswiki.org/emacs/IdUtils
• http://directory.fsf.org/wiki/Idutils