[php] How to get name of calling function/method in PHP?

As of php 5.4 you can use

        $dbt=debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS,2);
        $caller = isset($dbt[1]['function']) ? $dbt[1]['function'] : null;

This will not waste memory as it ignores arguments and returns only the last 2 backtrace stack entries, and will not generate notices as other answers here.