Abstract: This paper shows how to implement a compiler’s front end through an actual visual compiler. It’s a visual program contenting C subset and easy to operate. This compiler contents lexical analyzer, syntax analyzer, semantic analyzer, intermediate code generator, and a simple error recovery. Through this project, this paper intuitively shows lexical and syntax's construct processing, and describes lexical and syntax’s function and construct processing.

Key words: top-down, bottom-up, c-minus, lexical, syntax, compiler