Another step towards a smart compilation manager for Java

In a recent work we have proposed a compilation strategy (that is, a way to decide which unchanged sources have to be recompiled) for a substantial subset of Java which has been shown to be sound and minimal. That is, an unchanged source is recompiled if and only if its recompilation produces a different binary or an error. However, that model does not handle two features of Java, namely, compile-time constant fields (static final fields initialized by a compile-time constant of a primitive type or String) and unreachable code, which turn out to be troublesome for having a sound and minimal compilation strategy. To our best knowledge these two features, probably because of their low-level nature, have been omitted in all models of Java separate compilation written so far. Yet, a compilation strategy for full Java has to deal with them. Thus, in this paper we analyze the implications of handling compile-time constant fields and unreachable code, and extend our previous model in order to handle these two features as well.