SoC 09 - Extending XDebug code coverage instrumentation

Hi I'm Allister, a student in Mathematics and Linguistics at the
University of the West Indies, St. Augustine. I'm participating in SoC
2009 with PHP on a project to add decision and path coverage to the
Xdebug debugger. I'll be mentored by Derick Rathans. I'm really
psyched about this project - it's going to be a lot of fun and I'm
going to learn a lot and it will be very beneficial to the PHP
community

My initial idea is to build an AST from the underlying PHP code and
then run analysis on the tree to determine how many branches there
are, then add custom opcode handlers which will fire when a particular
branch is taken
There are a couple of projects that have code can build an AST for PHP

http://code.google.com/p/php-oracle/
http://www.phpcompiler.org

are two I've looked at. If you have any comments or suggestions on the
project I'd love to hear them

Allister