As shown in last comments here https://code.google.com/p/smartypdt/wiki/InstallSmartyPDT smartypdt plugin seems not working in eclipse luna. I used eclipse indigo before. I am wondering if there is a way to export something in indigo version where smartypdt works and import it to luna.
SmartyPDT is not compatible with PDT >= 3.2 due changed feature name. Looks like this project is no longer maintained.
https://code.google.com/p/smartypdt/issues/detail?id=73
Edit:
PDT Extension Group provide now own SmartyPDT compilation, see p2-dev.pdt-extensions.org
This version is compatible with latest PDT (3.2 and 3.3)