Abstract: Abstract syntax tree(AST) is tree representation of program source code,which plays a significant role in code analysis and feature extraction process.GCC can help to export the AST file in the source program of C language,which however contains a large amount of redundant information and irrelevant information that will exert a negative influence on the accomplishment of relevant tasks.To address this problem,a simplified GCC AST algorithm was presented to remove the nodes irrelevant to source program and rebuild AST file by means of linear time complexity based on a complete basic structure of AST for the sake of simplification.

Key words: GCC,Syntax tree,Simplification,Algorithm,C language