Magic-sets for localised analysis of Java bytecode

Static analyses based on denotational semantics can naturally model functional behaviours of the code in a compositional and completely context and flow sensitive way. But they only model the functional i.e., input/output behaviour of a program P , not enough if one needs P ’s internal behaviours i.e., from the input to some internal program points. This is, however, a frequent requirement for a useful static analysis. In this paper, we overcome this limitation, for the case of mono-threaded Java bytecode, with a technique used up to now for logic programs only. Namely, we define a program transformation that adds new magic blocks of code to the program P , whose functional behaviours are the internal behaviours of P . We prove the transformation correct w.r.t. an operational semantics and define an equivalent denotational semantics, devised for abstract interpretation, whose denotations for the magic blocks are hence the internal behaviours of P . We implement our transformation and instantiate it with abstract domains modelling sharing of two variables, non-cyclicity of variables, nullness of variables, class initialisation information and size of the values bound to program variables. We get a static analyser for full mono-threaded Java bytecode that is faster and scales better than another operational pair-sharing analyser. It has the same speed but is more precise than a constraint-based nullness analyser. It makes a polyhedral size analysis of Java bytecode scale up to 1300 methods in a couple of minutes and a zone-based size analysis scale to still larger applications.