In functional programming language compilation, closure conversion and defunctionalization are two widely used higher-order code eliminating methods. To improve the operational efficiency of functional programming languages, focusing on the higher-order code eliminating phase, a compiler frame to compare the performance of code generated by closure conversion and defunctionalization was proposed. Both closure conversion and defunctionalization were used in parallel in the comparing frame with a diamond structure. A functional programming language named FUN and a compiling system for FUN based on the comparing frame was proposed. Comparison experiments of closure conversion and defunctionalization were conducted on the proposed system by using typical use cases, and the experimental results were compared in code quantity and operation efficiency. The result suggests that compared with closure conversion, defunctionalization can produce shorter and faster target code; the amount of code can be decreased by up to 33.76% and performance can be improved by up to 69.51%.

To address the challenge of Android kernel hook detection, a new approach was proposed to detect Android kernel hooks by combining static technique based on characteristic pattern and dynamic technique based on behavioural analysis. The attacks including modifying system call tables and inline hook could be detected by the proposed approach. Software prototypes and test experiments were given. The experimental results show that the proposed method is effective and efficient in detecting Android kernel hooks, for most of the test cases, the runtime overhead is below 7%; and it is suitable to detect Android kernel hooks.