I've just updated the Android SDK to version 22.0 (well, more like a fresh install) and started a new project in Eclipse. I went through the project wizard and everything went fine but then I realised that it didn't generate the build files (neither BuildConfig.java nor R.java).
I searched a bit and found others with similar problems and someone pointed out that after updating a new package should be available called Android Build Tools. I had installed them as well and BuildConfig.java generated afterwards but I still don't have the R.java.
Some suggested cleaning up the project, editing manifest files and manually adding an R.java file so it would revert back to a generated one but none of these worked, though it showed a warning message in the IDE console when I edited the file but it didn't actually do anything