VarExecution:PHP 的变量感知执行

变量执行 实施以下研究项目： + Varex, "Exploring Variability-Aware Execution for Testing Plugin-Based Web Applications", ICSE 2014 源代码结构 - src folder contains the modified Quercus source code plus Varex source code (edu.iastate.* packages). + The most important class is edu.iastate.hungnv.shadow.Env_ where Varex is instrumented into Quercus. + Results are output through edu.iast