1. Rudra Dutta CSC 230 - Spring 2007, Section 001
Longjumps
Rudra Dutta
CSC Spring 2007, Section 001

2. “Long” jumps Violates function call-return discipline
“Jump” is on stack, not source code
Provided by the standard library
Include <setjmp.h>
Mark a place in the executing code where to come back (irrespective of current function call nesting) under certain circumstances
Sometimes used for recovering from serious errors
Copyright Rudra Dutta, NCSU, Spring, 2007

3. Longjump on the Stack Mark a place in the execution where to jump to
Use setjmp to mark
Pointer to current top of stack is saved
At a future time, from inside a nested function call, can jump straight to this place in the stack
Use longjmp
Nested functions do not return (retroactively converted to “were not called”)
MUST be nested (original function must still be on stack)
Copyright Rudra Dutta, NCSU, Spring, 2007