Static Bound Analysis of Dynamically Allocated Resources for C Programs

It is widely desired to precisely predict bounds of resource usages statically in a program, particularly when the program runs in resource-limited contexts. The resource bound problem becomes more challenging for C programs due to the allowed flexible manipulations on dynamically allocated resources in C. In this paper, we present a static analysis approach to deriving the bounds of dynamically allocated resources for C programs. The key idea is to combine numerical value analysis with pointer analysis under the unified framework of abstract interpretation. First, to track resource usage, we intro-duce auxiliary numerical variables to model the resource usage due to resource-manipulating functions such as allocation and deallocation. Second, to handle resource-manipulating functions involving pointers as parameters or return values, we propose a pointer analysis approach designed specifically for resource bound analysis, and combine it with numerical value analysis, to handle pointer arithmetics, dynamic allocation and deallocation, etc. Then, we infer the value bound of auxiliary resource-usage modeling variables to predict resource bounds at each program location. We have implemented our approach in a tool called DARB and conducted experiments on a set of benchmarks extracted from real-world programs. The results show that DARB can deal with C programs with complex resource manipulations.