001package io.ebean.enhance.entity;
002
003import io.ebean.enhance.asm.ClassVisitor;
004import io.ebean.enhance.asm.Label;
005import io.ebean.enhance.asm.MethodVisitor;
006import io.ebean.enhance.asm.Opcodes;
007import io.ebean.enhance.common.ClassMeta;
008
009/**
010 * Adds a default constructor for the cases when there is not one already defined.
011 */
012public class DefaultConstructor {
013
014    /**
015     * Adds a default constructor.
016     */
017    public static void add(ClassVisitor cw, ClassMeta classMeta) {
018        
019        if (classMeta.isLog(3)) {
020            classMeta.log("... adding default constructor, super class: "+classMeta.getSuperClassName());
021        }
022        
023        MethodVisitor underlyingMV = cw.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null, null);
024        
025        ConstructorAdapter mv = new ConstructorAdapter(underlyingMV, classMeta, "()V");
026        
027        mv.visitCode();
028        Label l0 = new Label();
029        mv.visitLabel(l0);
030        mv.visitLineNumber(1, l0);
031        mv.visitVarInsn(Opcodes.ALOAD, 0);
032        mv.visitMethodInsn(Opcodes.INVOKESPECIAL, classMeta.getSuperClassName(), "<init>", "()V", false);
033        Label l1 = new Label();
034        mv.visitLabel(l1);
035        mv.visitLineNumber(2, l1);
036        mv.visitInsn(Opcodes.RETURN);
037        
038        Label l2 = new Label();
039        mv.visitLabel(l2);
040        mv.visitLocalVariable("this", "L"+classMeta.getClassName()+";", null, l0, l2, 0);
041        mv.visitMaxs(1, 1);
042        mv.visitEnd();
043    }
044}