Optimality in Goal-Dependent Analysis of Sharing
In the context of abstract interpretation based static analysis, wecope with the problem of correctness and optimality for logic
program analysis. We propose a new framework equipped with a
denotational, goal-dependent semantics which refines many
goal-driven frameworks appeared in the literature. The key point is
the introduction of two specialized concrete operators for forward
and backward unification. We prove that our goal-dependent
semantics is correct w.r.t. computed answers and we provide the
best correct approximations of all the operators involved in the
semantics for set-sharing analysis. We show that the precision of
the overall analysis is strictly improved and that, in some cases,
we gain precision w.r.t. more complex domains involving linearity
and freeness information.