在PHP中，可以判断parent是否显式调用了一个方法::

Is it possible to tell if a method in the parent class is called explicitly by parent:: as opposed to being called automatically because the sub class doesn't contain the method being called?

well, I'm not sure you can get it easily. anyway, I think you could follow one of this way, if you need a work-around:

example 1:

class Par

{
    function printit($which = false)
    {
        // when you call this method, based on variable it tells how it was called
        if ($which) {
            echo "called with parent 
";
        } else {
            echo "called with this 
";
        }
    }
}

class Chi extends Par

{
    function callParent()
    {
        parent::printit(TRUE);
    }

    function callFunction()
    {
        $this->printit(FALSE);
    }
}

$chi = new Chi();
$chi->callParent();
$chi->callFunction();

example 2:

class Par

{
    function printit()
    {
        // get all functions in child class
        $child_methods = array_diff(get_class_methods("Chi") , get_class_methods("Par"));
        // if the function there is in child class, probably it was called from there
        if (in_array(__FUNCTION__, $child_methods)) {
            echo "called with child 
";
        } else {
            echo "called with parent 
";
        }
    }
}

class Chi extends Par

{
    function callParent()
    {
        parent::printit();
    }

    function callFunction()
    {
        $this->printit();
    }
}

$chi = new Chi();
$chi->callParent();
$chi->callFunction();