scrooloose/syntastic — pull request #155 by AD7six (2012-01-25 11:34:58+00:00)
Title: only run phpcs if the file has no syntax errors.

running phpcs on a file which contains a parse error generates a huge
number of warnings from the phpcs library.

You can see an example of what phpcs outputs in such cases here: https://gist.github.com/6c6535c3fc22c754ca6b

Therefore - don't run phpcs on files which have parse errors; don't freeze vim for minutes at a time when syntastic is already aware that the file is fundamentally borked