How does it work if an exception gets thrown through a C stack frame that has outstanding resources (for instance, pointers that are freed later in the frame)?

How does it work if an exception gets thrown through a C stack frame that has outstanding resources (for instance, pointers that are freed later in the frame)? Are you referring to manual SJLJ? In any case, it seems like C manual destruction has exactly the same problems as with RAII, because fundamentally the issue is passing exceptions through something that doesn't understand it, rather than with RAII.