int.java

一个JAVA编写的简单编译器

package ast.declaration;

 // int object in the project

  public class Int extends ast.declaration.JSubObject {
  private int value;

  public Int (String name) {
    super (name, ast.declaration.JSubObject.TINT);
    value = new Integer (name).intValue();
  }
  
  public void dump (String prefix) {
    System.out.print (prefix + "constant ");
    super.dump ("");
  }
  
  public String getLoadString () {
    if (0 <= value && value <= 5)
      return "iconst_" + value;//push the int value 0 to 5 on the stack
    if (-(2 << 7) <= value && value <= (2 << 7) - 1)
      return "bipush " + value;// value is an integer >= -128 and <= 127 that is pushed onto the stack.(byte)
    if (-(2 << 15) <= value && value <= (2 << 15) - 1)
      return "sipush " + value;//value is a signed integer in the range -32768 to 32767.(short)
    return "ldc " + value;  //value is an int, a float, or a quoted (i.e. literal) string.
  public String getStoreString () {
    util.Error.e3 ("no value allocate to constant");
    return "";
  }
  public boolean isParameter () {
    return false;
  }
  public String getXMLType () {
    return "int";
  }
  public void genXML (java.io.PrintStream p, String prefix) {
    p.println (prefix + "<Int value = \"" + value +"\"/>");
  }  
  
}