:unwind the stack: vi. 1. [techspeak] During the execution of a
procedural language, one is said to `unwind the stack' from a
called procedure up to a caller when one discards the stack frame
and any number of frames above it, popping back up to the level of
the given caller. In C this is done with
`longjmp'/`setjmp', in LISP with `throw/catch'.
See also {smash the stack}. 2. People can unwind the stack as
well, by quickly dealing with a bunch of problems: "Oh heck, let's
do lunch. Just a second while I unwind my stack."
-- The AI Hackers Dictionary