/** 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);
}
