Transparent Debugging of Dynamically Optimized Code

Debugging programs at the source level is essential in the software development cycle. With the growing importance of dynamic optimization, there is a clear need for debugging support in the presence of runtime code transformation. This paper presents a framework, called DeDoc, and lightweight techniques that allow debugging at the source level for programs that have been transformed by a trace-based binary dynamic optimizer. Our techniques provide full transparency and hide from the user the effect of dynamic optimizations on code statements and data values. We describe and evaluate an implementation of DeDoc and its techniques that interface a dynamic optimizer with a native debugger. Our experimental results indicate that DeDoc is able to report over 96% of values, that are otherwise not reportable due to code transformations, and incurs less than 1% performance overhead.