  The C preprocessor (CPP) is a standard tool for introducing variability into
source programs and is often applied either implicitly or explicitly for
implementing a Software Product Line (SPL). Despite its practical relevance,
CPP has many drawbacks. Because of that it is very difficult to understand the
variability implemented using CPP. To facilitate this task we provide an
innovative analytics tool which bridges the gap between feature models as more
abstract representations of variability and its concrete implementation with
the means of CPP. It allows to interactively explore the entities of a source
program with respect to the variability realized by conditional compilation.
Thus, it simplifies tracing and understanding the effect of enabling or
disabling feature flags.
