talloc: added talloc_stackframe_exists()

This can be used to tell if a talloc stackframe is currently
available. Callers can use this to decide if they will use
talloc_tos() or instead use an alternative strategy. This gives us a
way to safely have calls to talloc_tos() in common code that may end
up in external libraries, as long as all talloc_tos() calls in these
pieces of common code check first that a stackframe is available.

0 files changed, 0 insertions, 0 deletions