simple_backtrace.php

<?php

function simple_backtrace()
{
    $map = function($row) {
        $filter = function($k) {
            return in_array($k, ['function', 'class', 'file', 'line', 'type']);
        };
        return array_filter($row, $filter, ARRAY_FILTER_USE_KEY);
    };

    $backtrace = debug_backtrace();
    array_shift($backtrace);

    return array_map($map, $backtrace);
}