Dataflow analysis of software fragments

The goal of dataflow analysis is to determine properties of the run-time behavior of software systems by analyzing the software source code. Such analysis has a wide range of uses in software engineering tasks and their supporting tools. Traditionally, interprocedural dataflow analyses are designed as whole-program analyses: they take as input and process complete programs. This analysis model has been used extensively in the previous work on dataflow analysis. The paradigm of whole-program analysis has several limitations. Such analysis cannot be applied to incomplete programs (e.g., library modules), to programs containing unanalyzable modules (e.g., programs built with precompiled components), and to large programs. These restrictions limit the usefulness of whole-program analysis in the context of real-world software development. To address this problem, in this thesis we propose the paradigm of fragment dataflow analysis. Fragment dataflow analysis is an interprocedural dataflow analysis that is designed to analyze software fragments rather than complete programs. This analysis model is more flexible and can be used in situations in which whole-program analysis is not applicable. The first contribution of our work is a theoretical framework for constructing fragment dataflow analyses. This framework provides analysis designers with a sound basis for constructing fragment analyses and for reasoning about their properties. Our second contribution is an approach for performing points-to analysis and side effect analysis for C programs that are built with precompiled libraries modules. We define and evaluate fragment analyses that can be applied to library modules, as well as to the corresponding client modules. Our work enables the use of two fundamental dataflow analyses—points-to analysis and side-effect analysis—for C programs that cannot be handled by the previous work on whole-program analysis. The third contribution of this work is an approach for performing class analysis for the purposes of testing of polymorphism in Java. Our work defines a method for constructing fragment class analyses in order to compute test coverage requirements. We present empirical results showing the precision and practicality of the analyses. This work is the first one to show how to construct high-quality coverage tools for testing of polymorphism in Java software.Technical report DCS-TR-50