CSR: Small: Automated Software Failure Causal Path Computation

自动化调试一直是一个长期存在的巨大挑战。自动化调试的核心是识别故障因果路径的能力，这些路径是从根本原因到故障的路径，每个步骤都是因果相连的。这是理解和修复软件故障的关键。该项目开发了一种新颖的可扩展调试技术。给定一个失败和期望的输出，该技术产生失败的因果路径。设计了以下启用技术。给定一个故障和期望的输出，第一种技术是搜索故障的动态补丁，以便补丁执行生成期望的输出。示例补丁包括撤销谓词执行的分支结果。第二种技术是对齐失败的执行和修补的执行，以方便以后的比较。它包括控制流对齐和内存对齐。两个运行在控制流中可能不同，因此需要建立执行点之间的对应关系。一个数据结构可能被分配到不同的内存位置，这样内存也需要对齐。第三种技术是有效地比较两次运行在对齐位置的程序状态，以生成因果路径。其结果包括减少调试的资源消耗和提高软件的生产力和可靠性。

Automating debugging has been a long standing grand challenge.Central to automated debugging is the capability of identifying failure causal paths, which are paths leading from the root cause to the failure with each step causally connected. It is key to understanding and fixing a software fault. The project develops a novel scalable debugging technique. Given a failure and the desired output, the technique produces the failure causal path.The following enabling techniques are devised. Given a failure and the desired output, the first technique is to search for a dynamic patch to the failure such that the patched execution generates the desired output. Sample patches include negating the branch outcome of a predicate execution. The second technique is to align the failing and the patched executions to facilitate later comparison. It consists of control flow alignment and memory alignment. Two runs may differ in control flow so that correspondence between execution points need to be established. A data structure may be allocated to different memory locations so that memories also need to be aligned. The third technique is to efficiently compare the program states of the two runs at the aligned places to generate the causal path. The ramifications include reducing resource consumption of debugging and improving software productivity and dependability.