libstage: support caller-supplied stage memory

When !stage_conf_t.replace and stage_conf_t.stage is non-NULL,
stage_conf_t.stage will be used for the stage memory in stage_new()
instead of allocating some.

It's up to the caller to free this memory as needed, which may safely
be done from stage_ops_t.free_func() if needed.

Note that at this time there's no way for external callers to actually
know the stage_t size, as it's entirely opaque.  A future commit will
expose a padded variant of the struct, exposing its size appropriately
without making it completely public.

0 files changed, 0 insertions, 0 deletions