Description: ------------ Running phpcs on a large code base in the context of continuous integration can be very time consuming. Just because a couple of files have changed (for which phpcs would run for a couple of seconds or minutes) should not mean that phpcs needs to be run for all files again (which can take an hour). It would be beneficial if phpcs could be pointed to a previously generated Checkstyle XML logfile and be given a list of changed files. It would then scan the changed files and update the relevant sections of the Checkstyle XML logfile. I am not entirely sure whether this functionality belongs into phpcs itself or if it should be implemented in phpUnderControl, for instance.

Finally closing this as the 3.0 branch has caching support so only modified files are checked. More details here: https://github.com/squizlabs/PHP_CodeSniffer/issues/530