Cross-language program analysis for dynamic web applications

Web applications have become one of the most important and prevalent types of software. In modern web applications, the display of any web page is usually an interplay of multiple languages and involves code execution at different locations (the server side, the database side, and the client side). These characteristics make it hard to write and maintain web applications. Much of the existing research and tool support often deals with one single language and therefore is still limited in addressing those challenges. To fill in this gap, this dissertation is aimed at developing an infrastructure for cross-language program analysis for dynamic web applications to support creating reliable and robust web applications with higher quality and lower costs. To reach that goal, we have developed the following research components. First, to understand the client-side code that is embedded in the server-side code, we develop an output-oriented symbolic execution engine that approximates all possible outputs of a server-side program. Second, we use variability-aware parsing, a technique recently developed for parsing conditional code in software product lines, to parse those outputs into a compact tree representation (called VarDOM) that represents all possible DOM variants of a web application. Third, we leverage the VarDOM to extract semantic information from the server-side code. Specifically, we develop novel concepts, techniques, and tools (1) to build call graphs for embedded client code in different languages, (2) to compute cross-language program slices, and (3) to compute a novel test coverage criterion called output coverage that aids testers in creating effective test suites for detecting output-related bugs. The results have been demonstrated in a wide range of applications for web programs such as IDE services, fault localization, bug detection, and testing

Construction of the System Dependence Graph for Web Application Slicing

The computation of program slices on Web applications may be useful during debugging, when the amount of code to be inspected can be reduced, and during understanding, since the search for a given functionality can be better focused. The system dependence graph is an appropriate data structure for slice computation, in that it explicitly represents all dependences that have to be taken into account inslice determination. In this paper, the main problem related to the construction of the system dependence graph are considered. With no loss of generality, solutions are presented with reference to the server side programming language PHP and to the client side language Javascript. Most of the difficulties concern event and hyperlink handling, dynamic generation of HTML code, and direct access to HTML elements by client code. An example of Web application is analyzed, supporting the feasibility of the approac

Construction of the System Dependence Graph for Web Application Slicing

none2The computation of program slices on Web applications may be useful during debugging, when the amount of code to be inspected can be reduced, and during understanding, since the search for a given functionality can be better focused. The system dependence graph is an appropriate data structure for slice computation, in that it explicitly represents all dependences that have to be taken into account in slice determination. In this paper the main problems related to the construction of the system dependence graph are considered. With no loss of generality, solutions are presented with reference to the server side programming language PHP and to the client side language Javascript. Most of the difficulties concern event and hyperlink handling, dynamic generation of HTML code, and direct access to HTML elements by client code. An example of Web application is analyzed, supporting the feasibility of the approachF. Ricca; P. TonellaRicca, Filippo; P., Tonell