A Sound Abstract Interpreter for Dynamic Code

Dynamic languages, such as JavaScript, employ string-to-code primitives to turn dynamically generated text into executable code at run-time. These features make standard static analysis extremely hard if not impossible because its essential data structures, i.e., the control-flow graph and the system of recursive equations associated with the program to analyze, are themselves dynamically mutating objects. Hence, the need to handle string-to-code statements approximating what they can execute, and therefore allowing the analysis to continue (even in presence of string-to-code statements) with an acceptable degree of precision. In order to reach this goal, we propose a static analysis allowing us to collect string values and allowing us to soundly over-approximate and analyze the code potentially executed by a string-to-code statement.