/**
* add a bogus constructor call to a bytecode sequence so a constructor can pass bytecode
* validation
*
* @param bytecode
*/
public static boolean addBogusConstructorCall(ClassFile file, Bytecode code) {
MethodInfo constructorToCall = null;
for (Object meth : file.getMethods()) {
MethodInfo m = (MethodInfo) meth;
if (m.getName().equals("<init>")) {
constructorToCall = m;
break;
}
}
if (constructorToCall == null) {
return false;
}
// push this onto the stack
code.add(Bytecode.ALOAD_0);
String[] params =
DescriptorUtils.descriptorStringToParameterArray(constructorToCall.getDescriptor());
for (String p : params) {
// int char short boolean byte
if (p.equals("I") || p.equals("C") || p.equals("S") || p.equals("Z") || p.equals("B")) {
// push integer 0
code.add(Opcode.ICONST_0);
}
// long
else if (p.equals("J")) {
code.add(Opcode.LCONST_0);
}
// double
else if (p.equals("D")) {
code.add(Opcode.DCONST_0);
}
// float
else if (p.equals("F")) {
code.add(Opcode.FCONST_0);
}
// arrays and reference types
else {
code.add(Opcode.ACONST_NULL);
}
}
// all our args should be pushed onto the stack, call the constructor
code.addInvokespecial(file.getName(), "<init>", constructorToCall.getDescriptor());
code.add(Opcode.RETURN);
return true;
}
public static void pushParametersIntoArray(Bytecode bc, String methodDescriptor) {
String[] params = DescriptorUtils.descriptorStringToParameterArray(methodDescriptor);
// now we need an array:
bc.addIconst(params.length);
bc.addAnewarray("java.lang.Object");
// now we have our array sitting on top of the stack
// we need to stick our parameters into it. We do this is reverse
// as we can't pull them from the bottom of the stack
for (int i = params.length - 1; i >= 0; --i) {
if (DescriptorUtils.isWide(params[i])) {
// dup the array below the wide
bc.add(Opcode.DUP_X2);
// now do it again so we have two copies
bc.add(Opcode.DUP_X2);
// now pop it, the is the equivalent of a wide swap
bc.add(Opcode.POP);
} else {
// duplicate the array to place 3
bc.add(Opcode.DUP_X1);
// now swap
bc.add(Opcode.SWAP);
}
// now the parameter is above the array
// box it if nessesary
if (DescriptorUtils.isPrimitive(params[i])) {
Boxing.box(bc, params[i].charAt(0));
}
// add the array index
bc.addIconst(i);
bc.add(Opcode.SWAP);
bc.add(Opcode.AASTORE);
// we still have the array on the top of the stack becuase we
// duplicated it earlier
}
}
@Override
public boolean transform(
ClassLoader loader,
String className,
Class<?> classBeingRedefined,
ProtectionDomain protectionDomain,
ClassFile file)
throws IllegalClassFormatException, BadBytecode {
/**
* Hack up the proxy factory so it stores the proxy ClassFile. We need this to regenerate
* proxies.
*/
if (file.getName().equals("org.jboss.weld.bean.proxy.ProxyFactory")) {
for (final MethodInfo method : (List<MethodInfo>) file.getMethods()) {
if (method.getName().equals("createProxyClass")) {
final MethodInvokationManipulator methodInvokationManipulator =
new MethodInvokationManipulator();
methodInvokationManipulator.replaceVirtualMethodInvokationWithStatic(
ClassLoader.class.getName(),
WeldProxyClassLoadingDelegate.class.getName(),
"loadClass",
"(Ljava/lang/String;)Ljava/lang/Class;",
"(Ljava/lang/ClassLoader;Ljava/lang/String;)Ljava/lang/Class;",
loader);
methodInvokationManipulator.replaceVirtualMethodInvokationWithStatic(
"org.jboss.weld.util.bytecode.ClassFileUtils",
WeldProxyClassLoadingDelegate.class.getName(),
"toClass",
"(Ljavassist/bytecode/ClassFile;Ljava/lang/ClassLoader;Ljava/security/ProtectionDomain;)Ljava/lang/Class;",
"(Ljavassist/bytecode/ClassFile;Ljava/lang/ClassLoader;Ljava/security/ProtectionDomain;)Ljava/lang/Class;",
loader);
HashSet<MethodInfo> modifiedMethods = new HashSet<MethodInfo>();
methodInvokationManipulator.transformClass(file, loader, true, modifiedMethods);
for (MethodInfo m : modifiedMethods) {
m.rebuildStackMap(ClassPool.getDefault());
}
return true;
} else if (method.getName().equals("<init>")) {
Integer beanArgument = null;
int count = 0;
for (final String paramType :
DescriptorUtils.descriptorStringToParameterArray(method.getDescriptor())) {
if (paramType.equals("javax/enterprise/inject/spi/Bean")) {
beanArgument = count;
break;
} else if (paramType.equals("D") || paramType.equals("J")) {
count += 2;
} else {
count++;
}
}
if (beanArgument == null) {
log.error(
"Constructor org.jboss.weld.bean.proxy.ProxyFactory.<init>"
+ method.getDescriptor()
+ " does not have a bean parameter, proxies produced by this factory will not be reloadable");
continue;
}
// similar to other tracked instances
// but we need a strong ref
Bytecode code = new Bytecode(file.getConstPool());
code.addAload(0);
code.addAload(beanArgument);
code.addInvokestatic(
WeldClassChangeAware.class.getName(),
"addProxyFactory",
"(Lorg/jboss/weld/bean/proxy/ProxyFactory;)V");
CodeIterator it = method.getCodeAttribute().iterator();
it.skipConstructor();
it.insert(code.get());
}
}
}
return false;
}
/** Add a method to a class that simply delegates to the parent implementation of the method */
public static void addDelegatingMethod(ClassFile file, MethodData mData)
throws BadBytecode, DuplicateMemberException {
MethodInfo m =
new MethodInfo(file.getConstPool(), mData.getMethodName(), mData.getDescriptor());
m.setAccessFlags(mData.getAccessFlags());
Bytecode code = new Bytecode(file.getConstPool());
String[] params = DescriptorUtils.descriptorStringToParameterArray(mData.getDescriptor());
code.add(Opcode.ALOAD_0); // push this
int count = 1; // zero is the this pointer
int maxLocals = 1;
for (String p : params) {
// int char short boolean byte
if (p.equals("I") || p.equals("C") || p.equals("S") || p.equals("Z") || p.equals("B")) {
// push integer 0
code.addIload(count);
maxLocals++;
}
// long
else if (p.equals("J")) {
code.addLload(count);
maxLocals += 2;
count++;
}
// double
else if (p.equals("D")) {
code.addDload(count);
maxLocals += 2;
count++;
}
// float
else if (p.equals("F")) {
code.addFload(count);
maxLocals++;
}
// arrays and reference types
else {
code.addAload(count);
maxLocals++;
}
count++;
}
code.addInvokespecial(file.getSuperclass(), mData.getMethodName(), mData.getDescriptor());
String p = DescriptorUtils.getReturnTypeInJvmFormat(mData.getDescriptor());
// int char short boolean byte
if (p.equals("I") || p.equals("C") || p.equals("S") || p.equals("Z") || p.equals("B")) {
code.add(Opcode.IRETURN);
}
// long
else if (p.equals("J")) {
code.add(Opcode.LRETURN);
}
// double
else if (p.equals("D")) {
code.add(Opcode.DRETURN);
}
// float
else if (p.equals("F")) {
code.add(Opcode.FRETURN);
}
// void
else if (p.equals("V")) {
code.add(Opcode.RETURN);
}
// arrays and reference types
else {
code.add(Opcode.ARETURN);
}
CodeAttribute ca = code.toCodeAttribute();
ca.computeMaxStack();
ca.setMaxLocals(maxLocals);
m.setCodeAttribute(ca);
file.addMethod(m);
}