org.apache.bcel.classfile.Constant Java Examples

@Override
public void visit(ConstantValue s) {
    if (!visitingField()) {
        return;
    }
    int i = s.getConstantValueIndex();
    Constant c = getConstantPool().getConstant(i);
    if (c instanceof ConstantString) {
        String value = ((ConstantString) c).getBytes(getConstantPool());
        if (value.length() < SIZE_OF_HUGE_CONSTANT) {
            return;
        }
        String key = getStringKey(value);
        definition.put(key, XFactory.createXField(this));
        stringSize.put(key, value.length());
    }

}
 

/**
 * Ensures the general preconditions of a FieldInstruction instance.
 */
 @Override
public void visitFieldInstruction(final FieldInstruction o) {
     // visitLoadClass(o) has been called before: Every FieldOrMethod
     // implements LoadClass.
     // visitCPInstruction(o) has been called before.
    // A FieldInstruction may be: GETFIELD, GETSTATIC, PUTFIELD, PUTSTATIC
        final Constant c = cpg.getConstant(o.getIndex());
        if (!(c instanceof ConstantFieldref)) {
            constraintViolated(o,
                "Index '"+o.getIndex()+"' should refer to a CONSTANT_Fieldref_info structure, but refers to '"+c+"'.");
        }
        // the o.getClassType(cpg) type has passed pass 2; see visitLoadClass(o).
        final Type t = o.getType(cpg);
        if (t instanceof ObjectType) {
            final String name = ((ObjectType)t).getClassName();
            final Verifier v = VerifierFactory.getVerifier( name );
            final VerificationResult vr = v.doPass2();
            if (vr.getStatus() != VerificationResult.VERIFIED_OK) {
                constraintViolated(o, "Class '"+name+"' is referenced, but cannot be loaded and resolved: '"+vr+"'.");
            }
        }
 }
 

/**
 * 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+"'.");
    }
}
 

/**
 * 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+"'.");
    }
}
 

/**
 * 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();
}
 

/** 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);
    }
}
 

/**
* Ensures the general preconditions of a FieldInstruction instance.
*/
public void visitFieldInstruction(FieldInstruction o){
	// visitLoadClass(o) has been called before: Every FieldOrMethod
	// implements LoadClass.
	// visitCPInstruction(o) has been called before.
// A FieldInstruction may be: GETFIELD, GETSTATIC, PUTFIELD, PUTSTATIC 
	Constant c = cpg.getConstant(o.getIndex());
	if (!(c instanceof ConstantFieldref)){
		constraintViolated(o, "Index '"+o.getIndex()+"' should refer to a CONSTANT_Fieldref_info structure, but refers to '"+c+"'.");
	}
	// the o.getClassType(cpg) type has passed pass 2; see visitLoadClass(o).
	Type t = o.getType(cpg);
	if (t instanceof ObjectType){
		String name = ((ObjectType)t).getClassName();
		Verifier v = VerifierFactory.getVerifier( name );
		VerificationResult vr = v.doPass2();
		if (vr.getStatus() != VerificationResult.VERIFIED_OK){
			constraintViolated((Instruction) o, "Class '"+name+"' is referenced, but cannot be loaded and resolved: '"+vr+"'.");
		}
	}
}
 

/**
 * 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.
 */
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+"'.");
	}
}
 

/** 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);
    }
}
 

/**
 * Main class, to find strings in class files.
 * @param args Arguments to program.
 */
public static void main(String[] args) {
    try {
        JavaClass clazz = Repository.lookupClass(args[0]);
        ConstantPool cp = clazz.getConstantPool();
        Constant[] consts = cp.getConstantPool();


        for (int i = 0; i < consts.length; i++) {

            if (consts[i] instanceof ConstantString) {
                System.out.println("Found String: " +
                        ((ConstantString)consts[i]).getBytes(cp));
            }
        }
    }
    catch (Exception e) {
        e.printStackTrace();
    }
}
 

/** 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);
        }
    }
}
 

/** 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. */
// LDC2_W
@Override
public void visitLDC2_W(final LDC2_W o) {
    indexValid(o, o.getIndex());
    final Constant c = constantPoolGen.getConstant(o.getIndex());
    if (! ( (c instanceof ConstantLong)    ||
                    (c instanceof ConstantDouble) ) ) {
        constraintViolated(o, "Operand of LDC2_W must be CONSTANT_Long or CONSTANT_Double, but is '"+c+"'.");
    }
    try{
        indexValid(o, o.getIndex()+1);
    }
    catch(final StaticCodeInstructionOperandConstraintException e) {
        throw new AssertionViolatedException("Does not BCEL handle that? LDC2_W operand has a problem.", e);
    }
}
 

/** 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+"'.");
      }
    }
}
 

/**
 * @return mnemonic for instruction with symbolic references resolved
 */
@Override
public String toString( final ConstantPool cp ) {
    final Constant c = cp.getConstant(super.getIndex());
    final StringTokenizer tok = new StringTokenizer(cp.constantToString(c));

    final String opcodeName = Const.getOpcodeName(super.getOpcode());

    final StringBuilder sb = new StringBuilder(opcodeName);
    if (tok.hasMoreTokens()) {
        sb.append(" ");
        sb.append(tok.nextToken().replace('.', '/'));
        if (tok.hasMoreTokens()) {
            sb.append(tok.nextToken());
        }
    }

    return sb.toString();
}
 

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;
}
 

/**
 * Returns true if given constant pool probably has a reference to any of supplied methods
 * Useful to exclude from analysis uninteresting classes
 * @param cp constant pool
 * @param methods methods collection
 * @return true if method is found
 */
public static boolean hasInterestingMethod(ConstantPool cp, Collection<MethodDescriptor> methods) {
    for (Constant c : cp.getConstantPool()) {
        if (c instanceof ConstantMethodref || c instanceof ConstantInterfaceMethodref) {
            ConstantCP desc = (ConstantCP) c;
            ConstantNameAndType nameAndType = (ConstantNameAndType) cp.getConstant(desc.getNameAndTypeIndex());
            String className = cp.getConstantString(desc.getClassIndex(), Const.CONSTANT_Class);
            String name = ((ConstantUtf8) cp.getConstant(nameAndType.getNameIndex())).getBytes();
            String signature = ((ConstantUtf8) cp.getConstant(nameAndType.getSignatureIndex())).getBytes();
            // We don't know whether method is static thus cannot use equals
            int hash = FieldOrMethodDescriptor.getNameSigHashCode(name, signature);
            for (MethodDescriptor method : methods) {
                if (method.getNameSigHashCode() == hash
                        && (method.getSlashedClassName().isEmpty() || method.getSlashedClassName().equals(className))
                        && method.getName().equals(name) && method.getSignature().equals(signature)) {
                    return true;
                }
            }
        }
    }
    return false;
}
 

@Override
public void sawOpcode(int seen) {
    if (seen == Const.LDC || seen == Const.LDC_W || seen == Const.LDC2_W) {
        Constant c = getConstantRefOperand();
        if (c instanceof ConstantFloat) {
            checkConst(((ConstantFloat) c).getBytes());
        } else if (c instanceof ConstantDouble) {
            checkConst(((ConstantDouble) c).getBytes());
        }
        return;
    }
    // Lower priority if the constant is put into array immediately or after the boxing:
    // this is likely to be just similar number in some predefined dataset (like lookup table)
    if (seen == Const.INVOKESTATIC && lastBug != null) {
        if (getNextOpcode() == Const.AASTORE
                && getNameConstantOperand().equals("valueOf")
                && (getClassConstantOperand().equals("java/lang/Double") || getClassConstantOperand().equals(
                        "java/lang/Float"))) {
            lastBug = ((BugInstance) lastBug.clone());
            lastBug.setPriority(lastPriority + 1);
            bugAccumulator.forgetLastBug();
            bugAccumulator.accumulateBug(lastBug, this);
        }
    }
    lastBug = null;
}
 

@Override
public void visit(Field field) {
    ConstantValue value = field.getConstantValue();
    if (value == null) {
        return;
    }
    Constant c = getConstantPool().getConstant(value.getConstantValueIndex());

    if (testingEnabled && c instanceof ConstantLong && ((ConstantLong) c).getBytes() == MICROS_PER_DAY_OVERFLOWED_AS_INT) {
        bugReporter.reportBug(new BugInstance(this, "TESTING", HIGH_PRIORITY).addClass(this).addField(this)
                .addString("Did you mean MICROS_PER_DAY")
                .addInt(MICROS_PER_DAY_OVERFLOWED_AS_INT)
                .describe(IntAnnotation.INT_VALUE));

    }
}
 

/**
 * Main class, to find strings in class files.
 * @param args Arguments to program.
 */
public static void main(String[] args) {
    try {
        JavaClass clazz = Repository.lookupClass(args[0]);
        ConstantPool cp = clazz.getConstantPool();
        Constant[] consts = cp.getConstantPool();


        for (int i = 0; i < consts.length; i++) {

            if (consts[i] instanceof ConstantString) {
                System.out.println("Found String: " +
                        ((ConstantString)consts[i]).getBytes(cp));
            }
        }
    }
    catch (Exception e) {
        e.printStackTrace();
    }
}
 

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");
        }
    }
 

@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);
                }
            }
        }
    }
}
 

/**
 * Ensures the specific preconditions of the said instruction.
 */
@Override
public void visitLDC2_W(final LDC2_W o) {
    // visitCPInstruction is called first.

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

public static String getExceptionSig(DismantleBytecode dbc, CodeException e) {
    if (e.getCatchType() == 0) {
        return "Ljava/lang/Throwable;";
    }
    Constant c = dbc.getConstantPool().getConstant(e.getCatchType());
    if (c instanceof ConstantClass) {
        return "L" + ((ConstantClass) c).getBytes(dbc.getConstantPool()) + ";";
    }
    return "Ljava/lang/Throwable;";
}
 

@Override
public void sawOpcode(int seen) {
    if (state == SEEN_NOTHING) {
        if ((seen == Const.DCONST_0) || (seen == Const.DCONST_1)) {
            constValue = seen - Const.DCONST_0;
            state = SEEN_DCONST;
        } else if ((seen == Const.LDC2_W) || (seen == Const.LDC_W)) {
            state = SEEN_DCONST;
            Constant c = this.getConstantRefOperand();
            if (c instanceof ConstantDouble) {
                constValue = ((ConstantDouble) c).getBytes();
            } else if (c instanceof ConstantFloat) {
                constValue = ((ConstantFloat) c).getBytes();
            } else if (c instanceof ConstantLong) {
                constValue = ((ConstantLong) c).getBytes();
            } else {
                state = SEEN_NOTHING;
            }
        }
    } else if (state == SEEN_DCONST) {
        if (seen == Const.INVOKESTATIC) {
            state = SEEN_NOTHING;
            if ("java.lang.Math".equals(getDottedClassConstantOperand())) {
                String methodName = getNameConstantOperand();

                if (((constValue == 0.0) && zeroMethods.contains(methodName))
                        || ((constValue == 1.0) && oneMethods.contains(methodName)) || (anyMethods.contains(methodName))) {
                    bugReporter.reportBug(new BugInstance(this, "UM_UNNECESSARY_MATH", LOW_PRIORITY).addClassAndMethod(this)
                            .addSourceLine(this));
                }
            }
        }
        state = SEEN_NOTHING;
    }
}
 

/**
 * 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 + "'.");
    }
}
 

/**
 * 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 + "'.");
    }
}
 

/** Symbolically executes the corresponding Java Virtual Machine instruction. */
@Override
public void visitLDC2_W(final LDC2_W o) {
    final Constant c = cpg.getConstant(o.getIndex());
    if (c instanceof ConstantLong) {
        stack().push(Type.LONG);
    }
    if (c instanceof ConstantDouble) {
        stack().push(Type.DOUBLE);
    }
}