Java Code Examples for org.apache.bcel.generic.Type#VOID

private void createMethod_1() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC | Const.ACC_STATIC, Type.VOID, new Type[] { Type.OBJECT },
          new String[] { "arg0" }, "test", TEST_PACKAGE+".TestArrayAccess03", il, _cp);

  final InstructionHandle ih_0 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createNewArray(new ObjectType(TEST_PACKAGE+".TestArrayAccess03"), (short) 1));
  il.append(InstructionFactory.createStore(Type.OBJECT, 1));
  final InstructionHandle ih_5 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_5); // TODO why is this not used
  il.append(new PUSH(_cp, 0));
  il.append(_factory.createNew(TEST_PACKAGE+".TestArrayAccess03"));
  il.append(InstructionConst.DUP);
  il.append(_factory.createInvoke(TEST_PACKAGE+".TestArrayAccess03", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  il.append(InstructionConst.AASTORE);
  final InstructionHandle ih_15 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_15); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_1() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC | Const.ACC_STATIC, Type.VOID, new Type[] { Type.OBJECT },
          new String[] { "arg0" }, "test", TEST_PACKAGE+".TestArrayAccess04", il, _cp);

  final InstructionHandle ih_0 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createNewArray(Type.OBJECT, (short) 1));
  il.append(InstructionFactory.createStore(Type.OBJECT, 1));
  final InstructionHandle ih_5 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_5); // TODO why is this not used
  il.append(InstructionFactory.createStore(Type.INT, 2));
  final InstructionHandle ih_7 = il.append(InstructionFactory.createLoad(Type.OBJECT, 1));
  Assert.assertNotNull(ih_7); // TODO why is this not used
  il.append(new PUSH(_cp, 0));
  il.append(InstructionFactory.createLoad(Type.INT, 2));
  il.append(InstructionConst.AASTORE);
  final InstructionHandle ih_11 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_11); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_1() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC | Const.ACC_STATIC, Type.VOID, Type.NO_ARGS,
          new String[] {  }, "foo", TEST_PACKAGE+".TestReturn01", il, _cp);

  final InstructionHandle ih_0 = il.append(_factory.createNew("java.lang.Object"));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(InstructionConst.DUP);
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  il.append(InstructionConst.NOP);
  final InstructionHandle ih_8 = il.append(InstructionFactory.createReturn(Type.OBJECT));
  Assert.assertNotNull(ih_8); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

boolean propagateToReturnValue(Set<ValueInfo> vals, ValueNumber vn, GenLocation location, MethodDescriptor m)
        throws DataflowAnalysisException {
    for (ValueInfo vi : vals) {
        if (vi.type.getSignature().startsWith("[") && vi.hasObjectOnlyCall && vi.var == null && vn.getNumber() == vi.origValue) {
            // Ignore initialized arrays passed to methods
            vi.escaped = true;
            count--;
        }
    }
    if (Type.getReturnType(m.getSignature()) == Type.VOID || location instanceof ExceptionLocation) {
        return false;
    }
    InstructionHandle nextHandle = location.getHandle().getNext();
    if (nextHandle == null || (nextHandle.getInstruction() instanceof POP || nextHandle.getInstruction() instanceof POP2)) {
        return false;
    }
    return propagateValues(vals, null, location.frameAfter().getTopValue());
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  },
          "<init>", TEST_PACKAGE+".TestReturn01", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  }, "<init>",
          TEST_PACKAGE+".TestArrayAccess03", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_1() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC | Const.ACC_STATIC, Type.VOID, Type.NO_ARGS, new String[] {  },
          "test", TEST_PACKAGE+".TestArrayAccess02", il, _cp);

  final InstructionHandle ih_0 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createNewArray(new ObjectType(TEST_PACKAGE+".TestArrayAccess02"), (short) 1));
  il.append(InstructionFactory.createStore(Type.OBJECT, 0));
  final InstructionHandle ih_5 = il.append(new PUSH(_cp, 1));
  Assert.assertNotNull(ih_5); // TODO why is this not used
  il.append(_factory.createNewArray(Type.STRING, (short) 1));
  il.append(InstructionFactory.createStore(Type.OBJECT, 1));
  final InstructionHandle ih_10 = il.append(InstructionFactory.createLoad(Type.OBJECT, 1));
  Assert.assertNotNull(ih_10); // TODO why is this not used
  il.append(new PUSH(_cp, 0));
  il.append(_factory.createNew(TEST_PACKAGE+".TestArrayAccess02"));
  il.append(InstructionConst.DUP);
  il.append(_factory.createInvoke(TEST_PACKAGE+".TestArrayAccess02", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  il.append(InstructionConst.AASTORE);
  final InstructionHandle ih_20 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_20); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  }, "<init>",
          TEST_PACKAGE+".TestArrayAccess02", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  },
          "<init>", TEST_PACKAGE+".TestReturn03", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  final InstructionList il = new InstructionList();
  final MethodGen method = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  }, "<init>",
          TEST_PACKAGE+".TestArrayAccess04", il, _cp);

  final InstructionHandle ih_0 = il.append(InstructionFactory.createLoad(Type.OBJECT, 0));
  Assert.assertNotNull(ih_0); // TODO why is this not used
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Const.INVOKESPECIAL));
  final InstructionHandle ih_4 = il.append(InstructionFactory.createReturn(Type.VOID));
  Assert.assertNotNull(ih_4); // TODO why is this not used
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

@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);
    }

}
 

@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);
    }
}
 

private void createMethod_0() {
  InstructionList il = new InstructionList();
  MethodGen method = new MethodGen(ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  }, "<init>", objectType, il, _cp);

  InstructionHandle ih_0 = il.append(_factory.createLoad(Type.OBJECT, 0));
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
  InstructionHandle ih_4 = il.append(_factory.createReturn(Type.VOID));
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  InstructionList il = new InstructionList();
  MethodGen method = new MethodGen(ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  }, "<init>", objectType, il, _cp);

  InstructionHandle ih_0 = il.append(_factory.createLoad(Type.OBJECT, 0));
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
  InstructionHandle ih_4 = il.append(_factory.createReturn(Type.VOID));
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

private void createMethod_0() {
  InstructionList il = new InstructionList();
  MethodGen method = new MethodGen(ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[] {  }, "<init>", objectType, il, _cp);

  InstructionHandle ih_0 = il.append(_factory.createLoad(Type.OBJECT, 0));
  il.append(_factory.createInvoke("java.lang.Object", "<init>", Type.VOID, Type.NO_ARGS, Constants.INVOKESPECIAL));
  InstructionHandle ih_4 = il.append(_factory.createReturn(Type.VOID));
  method.setMaxStack();
  method.setMaxLocals();
  _cg.addMethod(method.getMethod());
  il.dispose();
}
 

/**
 * @param methodDescriptor
 */
private void sawNoSideEffectCall(MethodDescriptor methodDescriptor) {
    if (uselessVoidCandidate && Type.getReturnType(methodDescriptor.getSignature()) == Type.VOID
            && !methodDescriptor.getName().equals(Const.CONSTRUCTOR_NAME)) {
        /* To reduce false-positives we do not mark method as useless void if it calls
         * another useless void method. If that another method also in the scope of our project
         * then we will report it instead. If there's a cycle of no-side-effect calls, then
         * it's probably some delegation pattern and methods can be extended in future/derived
         * projects to do something useful.
         */
        uselessVoidCandidate = false;
    }
}
 

/**
 * Create JavaClass object for a simple proxy for an java.awt.event.ActionListener
 * that just prints the passed arguments, load and use it via the class loader
 * mechanism.
 */
public static void main(final String[] argv) throws Exception {
    final ClassLoader loader = ProxyCreator.class.getClassLoader();

    // instanceof won't work here ...
    // TODO this is broken; cannot ever be true now that ClassLoader has been dropped
    if (loader.getClass().toString().equals("class org.apache.bcel.util.ClassLoader")) {
        // Real class name will be set by the class loader
        final ClassGen cg = new ClassGen("foo", "java.lang.Object", "", Constants.ACC_PUBLIC,
                new String[]{"java.awt.event.ActionListener"});

        // That's important, otherwise newInstance() won't work
        cg.addEmptyConstructor(Constants.ACC_PUBLIC);

        final InstructionList il = new InstructionList();
        final ConstantPoolGen cp = cg.getConstantPool();
        final InstructionFactory factory = new InstructionFactory(cg);

        final int out = cp.addFieldref("java.lang.System", "out",
                "Ljava/io/PrintStream;");
        final int println = cp.addMethodref("java.io.PrintStream", "println",
                "(Ljava/lang/Object;)V");
        final MethodGen mg = new MethodGen(Constants.ACC_PUBLIC, Type.VOID,
                new Type[]{
                        new ObjectType("java.awt.event.ActionEvent")
                }, null, "actionPerformed", "foo", il, cp);

        // System.out.println("actionPerformed:" + event);
        il.append(new GETSTATIC(out));
        il.append(factory.createNew("java.lang.StringBuffer"));
        il.append(InstructionConstants.DUP);
        il.append(new PUSH(cp, "actionPerformed:"));
        il.append(factory.createInvoke("java.lang.StringBuffer", "<init>", Type.VOID,
                new Type[]{Type.STRING}, Constants.INVOKESPECIAL));

        il.append(new ALOAD(1));
        il.append(factory.createAppend(Type.OBJECT));
        il.append(new INVOKEVIRTUAL(println));
        il.append(InstructionConstants.RETURN);

        mg.stripAttributes(true);
        mg.setMaxStack();
        mg.setMaxLocals();
        cg.addMethod(mg.getMethod());

        final byte[] bytes = cg.getJavaClass().getBytes();

        System.out.println("Uncompressed class: " + bytes.length);

        final String s = Utility.encode(bytes, true);
        System.out.println("Encoded class: " + s.length());

        System.out.print("Creating proxy ... ");
        final ActionListener a = (ActionListener) createProxy("foo.bar.", s);
        System.out.println("Done. Now calling actionPerformed()");

        a.actionPerformed(new ActionEvent(a, ActionEvent.ACTION_PERFORMED, "hello"));
    } else {
        System.err.println("Call me with java org.apache.bcel.util.JavaWrapper ProxyCreator");
    }
}
 

@Override
public void visit(Code obj) {
    uselessVoidCandidate = !classInit && !constructor && !getXMethod().isSynthetic() && Type.getReturnType(getMethodSig()) == Type.VOID;
    byte[] code = obj.getCode();
    if (code.length == 4 && (code[0] & 0xFF) == Const.GETSTATIC && (code[3] & 0xFF) == Const.ARETURN) {
        getStaticMethods.add(getMethodDescriptor());
        handleStatus();
        return;
    }

    if (code.length <= 2 && !getXMethod().isStatic() && (getXMethod().isPublic() || getXMethod().isProtected())
            && !getXMethod().isFinal() && (getXClass().isPublic() || getXClass().isProtected())) {
        for (byte[] stubMethod : STUB_METHODS) {
            if (Arrays.equals(stubMethod, code)
                    && (getClassName().endsWith("Visitor") || getClassName().endsWith("Listener") || !hasOtherImplementations(getXMethod()))) {
                // stub method which can be extended: assume it can be extended with possible side-effect
                status = SideEffectStatus.SIDE_EFFECT;
                handleStatus();
                return;
            }
        }
    }
    if (statusMap.containsKey(getMethodDescriptor())) {
        return;
    }
    finallyTargets = new HashSet<>();
    for (CodeException ex : getCode().getExceptionTable()) {
        if (ex.getCatchType() == 0) {
            finallyTargets.add(ex.getHandlerPC());
        }
    }
    finallyExceptionRegisters = new HashSet<>();
    try {
        super.visit(obj);
    } catch (EarlyExitException e) {
        // Ignore
    }
    if (uselessVoidCandidate && code.length > 1
            && (status == SideEffectStatus.UNSURE || status == SideEffectStatus.NO_SIDE_EFFECT)) {
        uselessVoidCandidates.add(getMethodDescriptor());
    }
    handleStatus();
}