We implemented a translator from a subset of C to Java that guarantees
safety.  For such translation, we need to emulate C's pointer
arithmetics in Java.  We thus defined Java classes to represent C's
pointers and memory blocks.  Next, we defined translation rules which
use these classes, and implemented a translator following the rules.
We also need to translate integers as pointers, because they can be
cast to each other in C.  However, representing all integers as
pointers incurs too much overhead.  We therefore implemented
optimizations, including a data flow analysis for translating C's
integer variables (to which no pointers are assigned) to Java's
integer variables.  We conducted experiments with 9 benchmark
programs.  Without optimizations, the translated programs were 3.3-585
times slower than the original C programs.  After the optimizations,
those numbers improved to 1.3-5.9.