Method convertArgument

src/com/sun/jna/Function.java:504–635

(Object[] args, int index,
                                   Method invokingMethod, TypeMapper mapper,
                                   boolean allowObjects, Class<?> expectedType)

    }

    private Object convertArgument(Object[] args, int index,
                                   Method invokingMethod, TypeMapper mapper,
                                   boolean allowObjects, Class<?> expectedType) {
        Object arg = args[index];
        if (arg != null) {
            Class<?> type = arg.getClass();
            ToNativeConverter converter = null;
            if (NativeMapped.class.isAssignableFrom(type)) {
                converter = NativeMappedConverter.getInstance(type);
            } else if (mapper != null) {
                converter = mapper.getToNativeConverter(type);
            }
            if (converter != null) {
                ToNativeContext context;
                if (invokingMethod != null) {
                    context = new MethodParameterContext(this, args, index, invokingMethod) ;
                }
                else {
                    context = new FunctionParameterContext(this, args, index);
                }
                arg = converter.toNative(arg, context);
            }
        }
        if (arg == null || isPrimitiveArray(arg.getClass())) {
            return arg;
        }

        Class<?> argClass = arg.getClass();
        // Convert Structures to native pointers
        if (arg instanceof Structure) {
            Structure struct = (Structure)arg;
            struct.autoWrite();
            if (struct instanceof Structure.ByValue) {
                // Double-check against the method signature, if available
                Class<?> ptype = struct.getClass();
                if (invokingMethod != null) {
                    Class<?>[] ptypes = invokingMethod.getParameterTypes();
                    if (IS_VARARGS.isVarArgs(invokingMethod)) {
                        if (index < ptypes.length-1) {
                            ptype = ptypes[index];
                        } else {
                            Class<?> etype = ptypes[ptypes.length-1].getComponentType();
                            if (etype != Object.class) {
                                ptype = etype;
                            }
                        }
                    } else {
                        ptype = ptypes[index];
                    }
                }
                if (Structure.ByValue.class.isAssignableFrom(ptype)) {
                    return struct;
                }
            }
            return struct.getPointer();
        } else if (arg instanceof Callback) {
            // Convert Callback to Pointer
            return CallbackReference.getFunctionPointer((Callback)arg);