Abstract Syntax Tree (AST) and Control Flow Graph (CFG) Construction of Notasi Algoritmik

Abstract Syntax Tree (AST) and Control Flow Graph (CFG) are program code representations widely used for static analysis. One of the uses of static analysis is for automated grading programming exercises. Notasi Algoritmik is a notation used in our institution for learning programming, including those related to the evaluation of programming exercises. However, the current condition in our institution is that the grading process of programming exercises using Notasi Algoritmik is still done manually, which has an error-prone risk. Before our work, there was no research about how AST and CFG are constructed from Notasi Algoritmik, even though it is possible to develop an automated grader to solve manual assessment in the evaluation of programming learning. Therefore, in this paper, research was conducted to construct the AST and CFG from Notasi Algoritmik, to make developing an automated grader for programming assignments that uses Notasi Algoritmik possible in the future. The first thing that we need to do is to define the grammar of Notasi Algoritmik. After the grammar is defined, we need to do lexical and syntax analysis to construct the AST. AST itself will be used to represent the Notasi Algoritmik in abstract form to construct the CFG. An algorithm created by Tim Teitelbaum (2008) alongside some modifications can be used as a reference to construct the CFG. The research shows that AST is well constructed after two-phase lexical analysis and syntax analysis. Meanwhile, CFG can be constructed using the recursive technique that traverses nodes in the AST. With the result of this research, the development of an automated grader for Notasi Algoritmik can be tried in the future.