Introduction to Compiler Construction in a Java World

Chapter 5

JVM Code Generation

5.1 Introduction

Once the AST has been fully analyzed, all variables and expressions have been typed and

any necessary tree rewriting has been done. Also a certain amount of setup needed for code

generation has been accomplished. The compiler is now ready to traverse the AST one more

time to generate the Java Virtual Machine (JVM) code, that is, build the class file for the

program.

For example, consider the following very simple program:

public class Square {

public int square ( int x) {

return x * x ;

}

}

Compiling this with our j-- compiler,

> $j / j - -/ bin/j - - Square . java

produces a class file, Square.class. If we run