org.apache.bcel.classfile.ConstantClass Java Examples

/**
 * Determine the outer class of obj.
 *
 * @param obj
 * @return JavaClass for outer class, or null if obj is not an outer class
 * @throws ClassNotFoundException
 */

@CheckForNull
public static JavaClass getOuterClass(JavaClass obj) throws ClassNotFoundException {
    for (Attribute a : obj.getAttributes()) {
        if (a instanceof InnerClasses) {
            for (InnerClass ic : ((InnerClasses) a).getInnerClasses()) {
                if (obj.getClassNameIndex() == ic.getInnerClassIndex()) {
                    // System.out.println("Outer class is " +
                    // ic.getOuterClassIndex());
                    ConstantClass oc = (ConstantClass) obj.getConstantPool().getConstant(ic.getOuterClassIndex());
                    String ocName = oc.getBytes(obj.getConstantPool());
                    return Repository.lookupClass(ocName);
                }
            }
        }
    }
    return null;
}
 

/**
 * Override this method to create you own classes on the fly. The
 * name contains the special token $$BCEL$$. Everything before that
 * token is considered to be a package name. You can encode your own
 * arguments into the subsequent string. You must ensure however not
 * to use any "illegal" characters, i.e., characters that may not
 * appear in a Java class name too
 * <p>
 * The default implementation interprets the string as a encoded compressed
 * Java class, unpacks and decodes it with the Utility.decode() method, and
 * parses the resulting byte array and returns the resulting JavaClass object.
 * </p>
 *
 * @param class_name compressed byte code with "$$BCEL$$" in it
 */
protected JavaClass createClass( final String class_name ) {
    final int index = class_name.indexOf(BCEL_TOKEN);
    final String real_name = class_name.substring(index + BCEL_TOKEN.length());
    JavaClass clazz = null;
    try {
        final byte[] bytes = Utility.decode(real_name, true);
        final ClassParser parser = new ClassParser(new ByteArrayInputStream(bytes), "foo");
        clazz = parser.parse();
    } catch (final IOException e) {
        e.printStackTrace();
        return null;
    }
    // Adapt the class name to the passed value
    final ConstantPool cp = clazz.getConstantPool();
    final ConstantClass cl = (ConstantClass) cp.getConstant(clazz.getClassNameIndex(),
            Const.CONSTANT_Class);
    final ConstantUtf8 name = (ConstantUtf8) cp.getConstant(cl.getNameIndex(),
            Const.CONSTANT_Utf8);
    name.setBytes(class_name.replace('.', '/'));
    return clazz;
}
 

/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
// LDC and LDC_W (LDC_W is a subclass of LDC in BCEL's model)
@Override
public void visitLDC(final LDC ldc) {
    indexValid(ldc, ldc.getIndex());
    final Constant c = constantPoolGen.getConstant(ldc.getIndex());
    if (c instanceof ConstantClass) {
      addMessage("Operand of LDC or LDC_W is CONSTANT_Class '"+c+"' - this is only supported in JDK 1.5 and higher.");
    }
    else{
      if (! ( (c instanceof ConstantInteger)    ||
              (c instanceof ConstantFloat)         ||
        (c instanceof ConstantString) ) ) {
    constraintViolated(ldc,
        "Operand of LDC or LDC_W must be one of CONSTANT_Integer, CONSTANT_Float or CONSTANT_String, but is '"+c+"'.");
      }
    }
}
 

public static String[] getClassDependencies(final ConstantPool pool) {
    final String[] tempArray = new String[pool.getLength()];
    int size = 0;
    final StringBuilder buf = new StringBuilder();

    for (int idx = 0; idx < pool.getLength(); idx++) {
        final Constant c = pool.getConstant(idx);
        if (c != null && c.getTag() == Constants.CONSTANT_Class) {
            final ConstantUtf8 c1 = (ConstantUtf8) pool.getConstant(((ConstantClass) c).getNameIndex());
            buf.setLength(0);
            buf.append(c1.getBytes());
            for (int n = 0; n < buf.length(); n++) {
                if (buf.charAt(n) == '/') {
                    buf.setCharAt(n, '.');
                }
            }

            tempArray[size++] = buf.toString();
        }
    }

    final String[] dependencies = new String[size];
    System.arraycopy(tempArray, 0, dependencies, 0, size);
    return dependencies;
}
 

/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
@Override
public void visitNEW(final NEW o) {
    indexValid(o, o.getIndex());
    final Constant c = constantPoolGen.getConstant(o.getIndex());
    if (!    (c instanceof ConstantClass)) {
        constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
    }
    else{
        final ConstantUtf8 cutf8 = (ConstantUtf8) (constantPoolGen.getConstant( ((ConstantClass) c).getNameIndex() ));
        final Type t = Type.getType("L"+cutf8.getBytes()+";");
        if (t instanceof ArrayType) {
            constraintViolated(o, "NEW must not be used to create an array.");
        }
    }

}
 

/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
@Override
public void visitMULTIANEWARRAY(final MULTIANEWARRAY o) {
    indexValid(o, o.getIndex());
    final Constant c = constantPoolGen.getConstant(o.getIndex());
    if (!    (c instanceof ConstantClass)) {
        constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
    }
    final int dimensions2create = o.getDimensions();
    if (dimensions2create < 1) {
        constraintViolated(o, "Number of dimensions to create must be greater than zero.");
    }
    final Type t = o.getType(constantPoolGen);
    if (t instanceof ArrayType) {
        final int dimensions = ((ArrayType) t).getDimensions();
        if (dimensions < dimensions2create) {
            constraintViolated(o,
                "Not allowed to create array with more dimensions ('"+dimensions2create+
                "') than the one referenced by the CONSTANT_Class '"+t+"'.");
        }
    }
    else{
        constraintViolated(o, "Expecting a CONSTANT_Class referencing an array type."+
            " [Constraint not found in The Java Virtual Machine Specification, Second Edition, 4.8.1]");
    }
}
 

/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
@Override
public void visitANEWARRAY(final ANEWARRAY o) {
    indexValid(o, o.getIndex());
    final Constant c = constantPoolGen.getConstant(o.getIndex());
    if (!    (c instanceof ConstantClass)) {
        constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
    }
    final Type t = o.getType(constantPoolGen);
    if (t instanceof ArrayType) {
        final int dimensions = ((ArrayType) t).getDimensions();
        if (dimensions > Const.MAX_ARRAY_DIMENSIONS) {
            constraintViolated(o,
                "Not allowed to create an array with more than "+ Const.MAX_ARRAY_DIMENSIONS + " dimensions;"+
                " actual: " + dimensions);
        }
    }
}
 

/**
 * Called to indicate that a field load or store was encountered.
 *
 * @param cpIndex
 *            the constant pool index of the fieldref
 * @param isStatic
 *            true if it is a static field access
 * @param isLoad
 *            true if the access is a load
 */
private void setField(int cpIndex, boolean isStatic, boolean isLoad) {
    // We only allow one field access for an accessor method.
    accessCount++;
    if (accessCount != 1) {
        access = null;
        return;
    }

    ConstantPool cp = javaClass.getConstantPool();
    ConstantFieldref fieldref = (ConstantFieldref) cp.getConstant(cpIndex);

    ConstantClass cls = (ConstantClass) cp.getConstant(fieldref.getClassIndex());
    String className = cls.getBytes(cp).replace('/', '.');

    ConstantNameAndType nameAndType = (ConstantNameAndType) cp.getConstant(fieldref.getNameAndTypeIndex());
    String fieldName = nameAndType.getName(cp);
    String fieldSig = nameAndType.getSignature(cp);


    XField xfield = Hierarchy.findXField(className, fieldName, fieldSig, isStatic);
    if (xfield != null && xfield.isStatic() == isStatic && isValidAccessMethod(methodSig, xfield, isLoad)) {
        access = new InnerClassAccess(methodName, methodSig, xfield, isLoad);
    }

}
 

private void pushByConstant(DismantleBytecode dbc, Constant c) {

        if (c instanceof ConstantClass) {
            push(new Item("Ljava/lang/Class;", ((ConstantClass) c).getConstantValue(dbc.getConstantPool())));
        } else if (c instanceof ConstantInteger) {
            push(new Item("I", Integer.valueOf(((ConstantInteger) c).getBytes())));
        } else if (c instanceof ConstantString) {
            int s = ((ConstantString) c).getStringIndex();
            push(new Item("Ljava/lang/String;", getStringFromIndex(dbc, s)));
        } else if (c instanceof ConstantFloat) {
            push(new Item("F", Float.valueOf(((ConstantFloat) c).getBytes())));
        } else if (c instanceof ConstantDouble) {
            push(new Item("D", Double.valueOf(((ConstantDouble) c).getBytes())));
        } else if (c instanceof ConstantLong) {
            push(new Item("J", Long.valueOf(((ConstantLong) c).getBytes())));
        } else {
            throw new UnsupportedOperationException("StaticConstant type not expected");
        }
    }
 

private CPESSC_Visitor(final JavaClass _jc) {
    jc = _jc;
    cp = _jc.getConstantPool();
    cplen = cp.getLength();

    CONST_Class = ConstantClass.class;
    /*
    CONST_Fieldref = ConstantFieldref.class;
    CONST_Methodref = ConstantMethodref.class;
    CONST_InterfaceMethodref = ConstantInterfaceMethodref.class;
    */
    CONST_String = ConstantString.class;
    CONST_Integer = ConstantInteger.class;
    CONST_Float = ConstantFloat.class;
    CONST_Long = ConstantLong.class;
    CONST_Double = ConstantDouble.class;
    CONST_NameAndType = ConstantNameAndType.class;
    CONST_Utf8 = ConstantUtf8.class;

    carrier = new DescendingVisitor(_jc, this);
    carrier.visit();
}
 

@Override
public void visit(ConstantPool pool) {
    for (Constant constant : pool.getConstantPool()) {
        if (constant instanceof ConstantClass) {
            ConstantClass cc = (ConstantClass) constant;
            @SlashedClassName
            String className = cc.getBytes(pool);
            if ("java/util/Calendar".equals(className) || "java/text/DateFormat".equals(className)) {
                sawDateClass = true;
                break;
            }
            if (className.charAt(0) != '[') {
                try {
                    ClassDescriptor cDesc = DescriptorFactory.createClassDescriptor(className);

                    if (subtypes2.isSubtype(cDesc, calendarType) || subtypes2.isSubtype(cDesc, dateFormatType)) {
                        sawDateClass = true;
                        break;
                    }
                } catch (ClassNotFoundException e) {
                    reporter.reportMissingClass(e);
                }
            }
        }
    }
}
 

/** Symbolically executes the corresponding Java Virtual Machine instruction. */
@Override
public void visitLDC(final LDC o) {
    final Constant c = cpg.getConstant(o.getIndex());
    if (c instanceof ConstantInteger) {
        stack().push(Type.INT);
    }
    if (c instanceof ConstantFloat) {
        stack().push(Type.FLOAT);
    }
    if (c instanceof ConstantString) {
        stack().push(Type.STRING);
    }
    if (c instanceof ConstantClass) {
        stack().push(Type.CLASS);
    }
}
 

/**
 * Ensures the specific preconditions of the said instruction.
 */
@Override
public void visitCHECKCAST(final CHECKCAST o) {
    // The objectref must be of type reference.
    final Type objectref = stack().peek(0);
    if (!(objectref instanceof ReferenceType)) {
        constraintViolated(o, "The 'objectref' is not of a ReferenceType but of type "+objectref+".");
    }
    //else{
    //    referenceTypeIsInitialized(o, (ReferenceType) objectref);
    //}
    // The unsigned indexbyte1 and indexbyte2 are used to construct an index into the runtime constant pool of the
    // current class (�3.6), where the value of the index is (indexbyte1 << 8) | indexbyte2. The runtime constant
    // pool item at the index must be a symbolic reference to a class, array, or interface type.
    final Constant c = cpg.getConstant(o.getIndex());
    if (! (c instanceof ConstantClass)) {
        constraintViolated(o, "The Constant at 'index' is not a ConstantClass, but '"+c+"'.");
    }
}
 

/** Symbolically executes the corresponding Java Virtual Machine instruction. */
public void visitLDC_W(final LDC_W o) {
    final Constant c = cpg.getConstant(o.getIndex());
    if (c instanceof ConstantInteger) {
        stack().push(Type.INT);
    }
    if (c instanceof ConstantFloat) {
        stack().push(Type.FLOAT);
    }
    if (c instanceof ConstantString) {
        stack().push(Type.STRING);
    }
    if (c instanceof ConstantClass) {
        stack().push(Type.CLASS);
    }
}
 

/**
 * Returns the indices of all class symbol references to {@code targetClassName} in the constant
 * pool of {@code sourceJavaClass}.
 */
ImmutableSet<Integer> constantPoolIndexForClass(
    JavaClass sourceJavaClass, String targetClassName) {
  ImmutableSet.Builder<Integer> constantPoolIndicesForTarget = ImmutableSet.builder();

  ConstantPool sourceConstantPool = sourceJavaClass.getConstantPool();
  Constant[] constantPool = sourceConstantPool.getConstantPool();
  // constantPool indexes start from 1. 0th entry is null.
  for (int poolIndex = 1; poolIndex < constantPool.length; poolIndex++) {
    Constant constant = constantPool[poolIndex];
    if (constant != null) {
      byte constantTag = constant.getTag();
      if (constantTag == Const.CONSTANT_Class) {
        ConstantClass constantClass = (ConstantClass) constant;
        ClassSymbol classSymbol = makeSymbol(constantClass, sourceConstantPool, sourceJavaClass);
        if (targetClassName.equals(classSymbol.getClassBinaryName())) {
          constantPoolIndicesForTarget.add(poolIndex);
        }
      }
    }
  }

  return constantPoolIndicesForTarget.build();
}
 

/**
 * Ensures the specific preconditions of the said instruction.
 */
public void visitCHECKCAST(CHECKCAST o){
	// The objectref must be of type reference.
	Type objectref = stack().peek(0);
	if (!(objectref instanceof ReferenceType)){
		constraintViolated(o, "The 'objectref' is not of a ReferenceType but of type "+objectref+".");
	}
	else{
		referenceTypeIsInitialized(o, (ReferenceType) objectref);
	}
	// The unsigned indexbyte1 and indexbyte2 are used to construct an index into the runtime constant pool of the
	// current class (�3.6), where the value of the index is (indexbyte1 << 8) | indexbyte2. The runtime constant
	// pool item at the index must be a symbolic reference to a class, array, or interface type.
	Constant c = cpg.getConstant(o.getIndex());
	if (! (c instanceof ConstantClass)){
		constraintViolated(o, "The Constant at 'index' is not a ConstantClass, but '"+c+"'.");
	}
}
 

/**
 * Ensures the specific preconditions of the said instruction.
 */
@Override
public void visitINSTANCEOF(final INSTANCEOF o) {
    // The objectref must be of type reference.
    final Type objectref = stack().peek(0);
    if (!(objectref instanceof ReferenceType)) {
        constraintViolated(o, "The 'objectref' is not of a ReferenceType but of type "+objectref+".");
    }
    //else{
    //    referenceTypeIsInitialized(o, (ReferenceType) objectref);
    //}
    // The unsigned indexbyte1 and indexbyte2 are used to construct an index into the runtime constant pool of the
    // current class (�3.6), where the value of the index is (indexbyte1 << 8) | indexbyte2. The runtime constant
    // pool item at the index must be a symbolic reference to a class, array, or interface type.
    final Constant c = cpg.getConstant(o.getIndex());
    if (! (c instanceof ConstantClass)) {
        constraintViolated(o, "The Constant at 'index' is not a ConstantClass, but '"+c+"'.");
    }
}
 

/**
 * Ensures the specific preconditions of the said instruction.
 */
public void visitINSTANCEOF(INSTANCEOF o){
	// The objectref must be of type reference.
	Type objectref = stack().peek(0);
	if (!(objectref instanceof ReferenceType)){
		constraintViolated(o, "The 'objectref' is not of a ReferenceType but of type "+objectref+".");
	}
	else{
		referenceTypeIsInitialized(o, (ReferenceType) objectref);
	}
	// The unsigned indexbyte1 and indexbyte2 are used to construct an index into the runtime constant pool of the
	// current class (�3.6), where the value of the index is (indexbyte1 << 8) | indexbyte2. The runtime constant
	// pool item at the index must be a symbolic reference to a class, array, or interface type.
	Constant c = cpg.getConstant(o.getIndex());
	if (! (c instanceof ConstantClass)){
		constraintViolated(o, "The Constant at 'index' is not a ConstantClass, but '"+c+"'.");
	}
}
 

public void setupVisitorForClass(JavaClass obj) {
    constantPool = obj.getConstantPool();
    thisClass = obj;
    ConstantClass c = (ConstantClass) constantPool.getConstant(obj.getClassNameIndex());
    className = getStringFromIndex(c.getNameIndex());
    dottedClassName = className.replace('/', '.');
    packageName = obj.getPackageName();
    sourceFile = obj.getSourceFileName();
    dottedSuperclassName = obj.getSuperclassName();
    superclassName = dottedSuperclassName.replace('.', '/');

    ClassDescriptor cDesc = DescriptorFactory.createClassDescriptor(className);
    if (!FindBugs.isNoAnalysis()) {
        try {
            thisClassInfo = (ClassInfo) Global.getAnalysisCache().getClassAnalysis(XClass.class, cDesc);
        } catch (CheckedAnalysisException e) {
            throw new AssertionError("Can't find ClassInfo for " + cDesc);
        }
    }

    super.visitJavaClass(obj);
}
 

private static ClassSymbol makeSymbol(
    ConstantClass constantClass, ConstantPool constantPool, JavaClass sourceClass) {
  int nameIndex = constantClass.getNameIndex();
  Constant classNameConstant = constantPool.getConstant(nameIndex);
  if (!(classNameConstant instanceof ConstantUtf8)) {
    // This constant_pool entry must be a CONSTANT_Utf8_info
    // as specified https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.4.1
    throw new ClassFormatException(
        "Failed to lookup ConstantUtf8 constant indexed at "
            + nameIndex
            + ". However, the content is not ConstantUtf8. It is "
            + classNameConstant);
  }
  ConstantUtf8 classNameConstantUtf8 = (ConstantUtf8) classNameConstant;
  // classNameConstantUtf8 has internal form of class names that uses '.' to separate identifiers
  String targetClassNameInternalForm = classNameConstantUtf8.getBytes();
  // Adjust the internal form to comply with binary names defined in JLS 13.1
  String targetClassName = targetClassNameInternalForm.replace('/', '.');
  String superClassName = sourceClass.getSuperclassName();

  // Relationships between superclass and subclass need special validation for 'final' keyword
  boolean referenceIsForInheritance = superClassName.equals(targetClassName);
  if (referenceIsForInheritance) {
    return new SuperClassSymbol(targetClassName);
  }
  return new ClassSymbol(targetClassName);
}
 

/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
@Override
public void visitINSTANCEOF(final INSTANCEOF o) {
    indexValid(o, o.getIndex());
    final Constant c = constantPoolGen.getConstant(o.getIndex());
    if (!    (c instanceof ConstantClass)) {
        constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
    }
}
 

/** Checks if the constraints of operands of the said instruction(s) are satisfied. */
@Override
public void visitCHECKCAST(final CHECKCAST o) {
    indexValid(o, o.getIndex());
    final Constant c = constantPoolGen.getConstant(o.getIndex());
    if (!    (c instanceof ConstantClass)) {
        constraintViolated(o, "Expecting a CONSTANT_Class operand, but found a '"+c+"'.");
    }
}
 

/**
 * Ensures the specific preconditions of the said instruction.
 */
public void visitLDC_W(final LDC_W o) {
    // visitCPInstruction is called first.

    final Constant c = cpg.getConstant(o.getIndex());
    if     (!    (    ( c instanceof ConstantInteger) ||
                ( c instanceof ConstantFloat    )    ||
                ( c instanceof ConstantString    )    ||
                ( c instanceof ConstantClass    ) )    ) {
        constraintViolated(o,
            "Referenced constant should be a CONSTANT_Integer, a CONSTANT_Float, a CONSTANT_String or a CONSTANT_Class, but is '"+
             c + "'.");
    }
}
 

/**
 * Ensures the specific preconditions of the said instruction.
 */
@Override
public void visitLDC(final LDC o) {
    // visitCPInstruction is called first.

    final Constant c = cpg.getConstant(o.getIndex());
    if     (!    (    ( c instanceof ConstantInteger) ||
                ( c instanceof ConstantFloat    )    ||
                ( c instanceof ConstantString    )    ||
                ( c instanceof ConstantClass    ) )    ) {
        constraintViolated(o,
            "Referenced constant should be a CONSTANT_Integer, a CONSTANT_Float, a CONSTANT_String or a CONSTANT_Class, but is '"+
             c + "'.");
    }
}
 

@Override
public void visitConstantClass(final ConstantClass obj) {
    if (obj.getTag() != Const.CONSTANT_Class) {
        throw new ClassConstraintException("Wrong constant tag in '"+tostring(obj)+"'.");
    }
    checkIndex(obj, obj.getNameIndex(), CONST_Utf8);

}
 

@Override
public void visitConstantFieldref(final ConstantFieldref obj) {
    if (obj.getTag() != Const.CONSTANT_Fieldref) {
        throw new ClassConstraintException("ConstantFieldref '"+tostring(obj)+"' has wrong tag!");
    }
    final int name_and_type_index = obj.getNameAndTypeIndex();
    final ConstantNameAndType cnat = (ConstantNameAndType) (cp.getConstant(name_and_type_index));
    final String name = ((ConstantUtf8) (cp.getConstant(cnat.getNameIndex()))).getBytes(); // Field or Method name
    if (!validFieldName(name)) {
        throw new ClassConstraintException("Invalid field name '"+name+"' referenced by '"+tostring(obj)+"'.");
    }

    final int class_index = obj.getClassIndex();
    final ConstantClass cc = (ConstantClass) (cp.getConstant(class_index));
    final String className = ((ConstantUtf8) (cp.getConstant(cc.getNameIndex()))).getBytes(); // Class Name in internal form
    if (! validClassName(className)) {
        throw new ClassConstraintException("Illegal class name '"+className+"' used by '"+tostring(obj)+"'.");
    }

    final String sig  = ((ConstantUtf8) (cp.getConstant(cnat.getSignatureIndex()))).getBytes(); // Field or Method sig.(=descriptor)

    try{
        Type.getType(sig); /* Don't need the return value */
    }
    catch (final ClassFormatException cfe) {
        throw new ClassConstraintException("Illegal descriptor (==signature) '"+sig+"' used by '"+tostring(obj)+"'.", cfe);
    }
}
 

@Override
public void visitConstantMethodref(final ConstantMethodref obj) {
    if (obj.getTag() != Const.CONSTANT_Methodref) {
        throw new ClassConstraintException("ConstantMethodref '"+tostring(obj)+"' has wrong tag!");
    }
    final int name_and_type_index = obj.getNameAndTypeIndex();
    final ConstantNameAndType cnat = (ConstantNameAndType) (cp.getConstant(name_and_type_index));
    final String name = ((ConstantUtf8) (cp.getConstant(cnat.getNameIndex()))).getBytes(); // Field or Method name
    if (!validClassMethodName(name)) {
        throw new ClassConstraintException(
            "Invalid (non-interface) method name '"+name+"' referenced by '"+tostring(obj)+"'.");
    }

    final int class_index = obj.getClassIndex();
    final ConstantClass cc = (ConstantClass) (cp.getConstant(class_index));
    final String className = ((ConstantUtf8) (cp.getConstant(cc.getNameIndex()))).getBytes(); // Class Name in internal form
    if (! validClassName(className)) {
        throw new ClassConstraintException("Illegal class name '"+className+"' used by '"+tostring(obj)+"'.");
    }

    final String sig  = ((ConstantUtf8) (cp.getConstant(cnat.getSignatureIndex()))).getBytes(); // Field or Method sig.(=descriptor)

    try{
        final Type   t  = Type.getReturnType(sig);
        if ( name.equals(Const.CONSTRUCTOR_NAME) && (t != Type.VOID) ) {
            throw new ClassConstraintException("Instance initialization method must have VOID return type.");
        }
    }
    catch (final ClassFormatException cfe) {
        throw new ClassConstraintException("Illegal descriptor (==signature) '"+sig+"' used by '"+tostring(obj)+"'.", cfe);
    }
}
 

@Override
public void visitConstantInterfaceMethodref(final ConstantInterfaceMethodref obj) {
    if (obj.getTag() != Const.CONSTANT_InterfaceMethodref) {
        throw new ClassConstraintException("ConstantInterfaceMethodref '"+tostring(obj)+"' has wrong tag!");
    }
    final int name_and_type_index = obj.getNameAndTypeIndex();
    final ConstantNameAndType cnat = (ConstantNameAndType) (cp.getConstant(name_and_type_index));
    final String name = ((ConstantUtf8) (cp.getConstant(cnat.getNameIndex()))).getBytes(); // Field or Method name
    if (!validInterfaceMethodName(name)) {
        throw new ClassConstraintException("Invalid (interface) method name '"+name+"' referenced by '"+tostring(obj)+"'.");
    }

    final int class_index = obj.getClassIndex();
    final ConstantClass cc = (ConstantClass) (cp.getConstant(class_index));
    final String className = ((ConstantUtf8) (cp.getConstant(cc.getNameIndex()))).getBytes(); // Class Name in internal form
    if (! validClassName(className)) {
        throw new ClassConstraintException("Illegal class name '"+className+"' used by '"+tostring(obj)+"'.");
    }

    final String sig  = ((ConstantUtf8) (cp.getConstant(cnat.getSignatureIndex()))).getBytes(); // Field or Method sig.(=descriptor)

    try{
        final Type   t  = Type.getReturnType(sig);
        if ( name.equals(Const.STATIC_INITIALIZER_NAME) && (t != Type.VOID) ) {
            addMessage("Class or interface initialization method '"+Const.STATIC_INITIALIZER_NAME+
                "' usually has VOID return type instead of '"+t+
                "'. Note this is really not a requirement of The Java Virtual Machine Specification, Second Edition.");
        }
    }
    catch (final ClassFormatException cfe) {
        throw new ClassConstraintException("Illegal descriptor (==signature) '"+sig+"' used by '"+tostring(obj)+"'.", cfe);
    }

}
 

/** This method casually visits ConstantClass references. */
@Override
public void visitConstantClass(final ConstantClass obj) {
    final Constant c = cp.getConstant(obj.getNameIndex());
    if (c instanceof ConstantUtf8) { //Ignore the case where it's not a ConstantUtf8 here, we'll find out later.
        final String classname = ((ConstantUtf8) c).getBytes();
        if (classname.startsWith(jc.getClassName().replace('.','/')+"$")) {
            hasInnerClass = true;
        }
    }
}
 

private int addClass_( final String clazz ) {
    int ret;
    if ((ret = lookupClass(clazz)) != -1) {
        return ret; // Already in CP
    }
    adjustSize();
    final ConstantClass c = new ConstantClass(addUtf8(clazz));
    ret = index;
    constants[index++] = c;
    if (!classTable.containsKey(clazz)) {
        classTable.put(clazz, new Index(ret));
    }
    return ret;
}