-/* The cleanup list records things that have to be undone
- if an error happens (descriptors to be closed, memory to be freed, etc.)
- Each link in the chain records a function to call and an
- argument to give it.
-
- Use make_cleanup to add an element to the cleanup chain.
- Use do_cleanups to do all cleanup actions back to a given
- point in the chain. Use discard_cleanups to remove cleanups
- from the chain back to a given point, not doing them.
-
- If the argument is pointer to allocated memory, then you need
- to additionally set the 'free_arg' member to a function that will
- free that memory. This function will be called both when the cleanup
- is executed and when it's discarded. */
-
-struct cleanup
- {
- struct cleanup *next;
- void (*function) (void *);
- void (*free_arg) (void *);
- void *arg;
- };