Deriving Escape Analysis by Abstract Interpretation

Escape analysis of object-oriented languages approximates the set of objects which do not escape from a given context. If we take a method as context, the non-escaping objects can be allocated on its activation stack; if we take a thread, Java synchronisation locks on such objects are not needed. In this paper, we formalise a basic escape domain E as an abstract interpretation of concrete states, which we then refine into an abstract domain ER which is more concrete than E and, hence, leads to a more precise escape analysis than E. We provide optimality results for both E and ER, in the form of Galois insertions from the concrete to the abstract domains and of optimal abstract operations. The Galois insertion property is obtained by restricting the abstract domains to those elements which do not contain garbage, by using an abstract garbage collector. Our implementation of ER is hence an implementation of a formally correct escape analyser, able to detect the stack allocatable creation points of Java (bytecode) applications

Logic Programs as Compact Denotations

This paper shows how logic programs can be used to implement the transition functions of denotational abstract interpretation. The logic variables express regularity in the abstract behaviour of commands. The technique is applied here to sign, class and escape analysis for object-oriented programs. We show that the time and space costs using logic programs are smaller than those of a ground relational representation. Moreover, we show that, in the case of sign analysis, our technique requires less memory and has an efficiency comparable to that of an implementation based on binary decision diagrams

Logic Programs as Compact Denotations

This paper shows how logic programs can be used to implement the transition functions of denotational abstract interpretation. The logic variables express regularity in the abstract behaviour of commands. The technique has been applied to sign, class and escape analysis for object-oriented programs. We show that the time and space costs using logic programs for these analyses are smaller than those using a ground relational representation