AspectD: Enhancing a Standard Debugger with Aspects

Aspect-oriented techniques have gained some favor in program tracing, profiling, and debugging. Yet, taking advantage of AOP typically requires giving up the traditional benefits of using a debugger, such as interactive exploratory introspection and remote execution. However, the APIs debuggers present to their scripting languages are not designed for aspect weaving, creating technical challenges. This paper discusses the programming primitives debuggers must support for weaving aspects into programs. The implementation choices in a debugger can lead to substantial differences in expressiveness and performance of the aspectoriented language that can be built on top of the debugger. As an initial exploration of the design tradeoffs and implementation possibilities, we present AspectD, a tool that uses the Java Debug Interface (JDI) to weave simple aspects into Java programs. We analyze the performance and complexity of different types of advice in real-world program analysis and identify shortcoming of the current JDI API and propose improvements to enable the use of JDI for weaving aspects. The resulting lessons provide a design space for adding aspect orientation to a wide class of debuggers.