Proceedings of the ACM Symposium on Applied Computing

© 2016 ACM.C is the dominant programming language for developing embedded software, operating systems, and device drivers. Unlike programs written in managed languages like Java, C programs rely on explicit memory management and are prone to memory leaks. Existing (static or dynamic) detectors only report leaks, but fixing them often requires considerable manual effort by inspecting a list of reported true and false alarms. How to develop on-demand lightweight techniques for automated leak fixing without introducing new memory errors remains challenging. In this paper, we introduce AUTOFIX, a fully automated leak-fixing approach for C programs by combining static and dynamic program analysis. Given a leaky allocation site reported by a static memory leak detector, AUTOFIX performs a graph reachability analysis to identify leaky paths on the value-flow slices of the program, and then conducts a liveness analysis to locate the program points for inserting fixes (i.e., the missing free calls) on the identified leaky paths. We have implemented AUTOFIX in LLVM-3.5.0 and evaluated it using five SPEC2000 benchmarks and three open-source applications. Experimental results show that AUTOFIX can safely fix all the memory leaks reported by a state-of-theart static memory leak detector with small instrumentation overhead