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StackMapFrame.javaAPI DocGlassfish v2 API5801Thu Mar 02 11:51:14 GMT 2006oracle.toplink.libraries.asm.attrs

StackMapFrame

public class StackMapFrame extends Object
StackMapFrame is used by {@link StackMapAttribute} to hold state of the stack and local variables for a single execution branch. Note that Long and Double types are represented by two entries in locals and stack. Second entry sohould be always of type Top.
see
JSR 139 : Connected Limited Device Configuration 1.1
author
Eugene Kuleshov

Fields Summary
public Label
label
public List
locals
public List
stack
Constructors Summary
Methods Summary
public voidgetLabels(java.util.Set labels)

    labels.add(label);
    getTypeInfoLabels(labels, locals);
    getTypeInfoLabels(labels, stack);
private voidgetTypeInfoLabels(java.util.Set labels, java.util.List info)

    for (Iterator it = info.iterator(); it.hasNext();) {
      StackMapType typeInfo = (StackMapType)it.next();
      if (typeInfo.getType() == StackMapType.ITEM_Uninitialized) {
        labels.add(typeInfo.getLabel());
      }
    }
public intread(oracle.toplink.libraries.asm.ClassReader cr, int off, char[] buf, int codeOff, oracle.toplink.libraries.asm.Label[] labels)


      
                           
    int n = cr.readUnsignedShort(off);
    off += 2;
    if (labels[n] == null) {
      labels[n] = new Label();
    }
    label = labels[n];
    off = readTypeInfo(cr, off, locals, labels, buf,
                       cr.readUnsignedShort(codeOff + 2));  //  maxLocals
    off = readTypeInfo(cr, off, stack, labels, buf,
                       cr.readUnsignedShort(codeOff));  // maxStack
    return off;
private intreadTypeInfo(oracle.toplink.libraries.asm.ClassReader cr, int off, java.util.List info, oracle.toplink.libraries.asm.Label[] labels, char[] buf, int max)

    int n = 0;
    if (max > StackMapAttribute.MAX_SIZE) {
      n = cr.readInt(off);
      off += 4;
    } else {
      n = cr.readUnsignedShort(off);
      off += 2;
    }
    for (int j = 0; j < n; j++) {
      int itemType = cr.readByte(off++);
      StackMapType typeInfo = StackMapType.getTypeInfo(itemType);
      info.add(typeInfo);
      switch (itemType) {
        // case StackMapType.ITEM_Long:  //
        // case StackMapType.ITEM_Double:  //
          // info.add(StackMapType.getTypeInfo(StackMapType.ITEM_Top));
        //   break;

        case StackMapType.ITEM_Object:  //
          typeInfo.setObject(cr.readClass(off, buf));
          off += 2;
          break;

        case StackMapType.ITEM_Uninitialized:  //
          int o = cr.readUnsignedShort(off);
          off += 2;
          if (labels[o] == null) {
            labels[o] = new Label();
          }
          typeInfo.setLabel(labels[o]);
          break;
      }
    }
    return off;
public java.lang.StringtoString()

    StringBuffer sb = new StringBuffer("Frame:L");
    sb.append(System.identityHashCode(label));
    sb.append(" locals").append(locals);
    sb.append(" stack").append(stack);
    return sb.toString();
public voidwrite(oracle.toplink.libraries.asm.ClassWriter cw, int maxStack, int maxLocals, oracle.toplink.libraries.asm.ByteVector bv)

    bv.putShort(label.getOffset());
    writeTypeInfo(bv, cw, locals, maxLocals);
    writeTypeInfo(bv, cw, stack, maxStack);
private voidwriteTypeInfo(oracle.toplink.libraries.asm.ByteVector bv, oracle.toplink.libraries.asm.ClassWriter cw, java.util.List info, int max)

    if (max > StackMapAttribute.MAX_SIZE) {
      bv.putInt(info.size());
    } else {
      bv.putShort(info.size());
    }
    for (int j = 0; j < info.size(); j++) {
      StackMapType typeInfo = (StackMapType)info.get(j);
      bv.putByte(typeInfo.getType());
      switch (typeInfo.getType()) {
        case StackMapType.ITEM_Object:  //
          bv.putShort(cw.newClass(typeInfo.getObject()));
          break;

        case StackMapType.ITEM_Uninitialized:  //
          bv.putShort(typeInfo.getLabel().getOffset());
          break;
          
      }
    }