Abstract:

In the view of the code clone and software piracy, we analyzes three kinds of traditional similarity detection method based on program structure, then put forward a similarity detection method based on syntax tree of program. In the method, the source code is parsed and a syntax tree is produced for it. Then the similarity of source codes is calculated by analyzing the structures of their syntax trees. The senior copy means are eliminated from the angle of syntax structure. By using a set of plagiarized scripts as testing programs, the experimental results show that the similarity detection method based on syntax tree is effective to detect 10 kinds of plagiarism means code plagiarism, such as adding redundant statements and replacing control structures with equivalent structures.

Key words: code clone, program structure, similarity detection