Execution Synthesis: A Technique for Automated Software Debugging

Debugging real systems is hard, requires deep knowledge of the code, and is time-consuming. Bug reports rarely provide sufficient information, thus forcing developers to turn into detectives searching for an explanation of how the program could have arrived at the reported failure point. Execution synthesis is a technique for automating this de-tective work: given a program and a bug report, it automat-ically produces an execution of the program that leads to the reported bug symptoms. Using a combination of static analysis and symbolic execution, it “synthesizes ” a thread schedule and various required program inputs that cause the bug to manifest. The synthesized execution can be played back deterministically in a regular debugger, like gdb. This is particularly useful in debugging concurrency bugs. Our technique requires no runtime tracing or program modifications, thus incurring no runtime overhead and being practical for use in production systems. We evaluate ESD— a debugger based on execution synthesis—on popular soft-ware (e.g., the SQLite database