Dependence condition graph for semantics-based abstract program slicing

Abstract

Many slicing techniques have been proposed based on the traditional Program Dependence Graph (PDG) representation. In traditional PDGs, the notion of dependency between statements is based on syntactic presence of a variable in the definition of another variable or on a conditional expression. Mastroeni and Zanardini introduced a semantics-based dependency both at concrete and abstract domain. This semantic dependency is computed at expression level over all possible (abstract) states appearing at program points. In this paper we strictly improve this approach by (i) considering the semantic relevancy of the statements (not only the expressions), and (ii) adopting conditional dependency. This allows us to transform the semantics-based abstract PDG into an semantics-based abstract Dependence Condition Graph (DCG) that enables to identify the conditions for dependence between program points. The resulting program slicing algorithm is stricly more accurate than the Mastroeni and Zanardini's one.

Tukra: An Abstract Program Slicing Tool

“…Mastroeni and Nicolić (Mastroeni and Nikolic, 2010) recently extended the theoretical framework of slicing proposed by Binkley (Binkley et al, 2006) to an abstract domain in order to define abstract slicing, and to represent and compare different forms of slicing in the abstract domain. Other remarkable works on abstract program slicing include (Cortesi and Halder, 2010;Mastroeni and Zanardini, 2008;Zanardini, 2008;Bhattacharya, 2011).…”

“…In (Cortesi and Halder, 2010), the authors applied the notion of semantic relevancy of statements, and proposed a slicing refinement for imperative programs by combining with statement relevancy the notions of semantic data dependences (Mastroeni and Zanardini, 2008) and conditional dependences (Sukumaran et al, 2010). The combination of these three notions allows us to refine traditional syntax-based dependence graphs into more precise semantics-based dependence graphs, leading to an abstract program slicing algorithm that produces more accurate abstract slices.…”

“…In this paper, we introduce Tukra 1 ., a tool based on the theoretical proposal in (Cortesi and Halder, 2010) that allows the practical evaluation of abstract program slicing algorithms. The tool performs static intraprocedural slicing of a program in an abstract domain of interest.…”

“…The algorithm behind our slicing tool is proposed in (Cortesi and Halder, 2010) that combines the notions of statement relevancy, semantic data dependences and conditional dependences. Let us discuss these three notions and the slicing algorithm in brief.…”

“…Cortesi and Halder (Cortesi and Halder, 2010) applied the notion of semantic relevancy of statements. It determines whether an imperative statement is relevant w.r.t.…”