Finding depended-upon systems

[Ahmon Dancy]

Robert Goldman <rpgoldman at sift.net> wrote:

>> There was some discussion about this in connection with finding what
>> needed to be recompiled.  Is the latter even a query that ASDF can
>> answer?  In old ASDF we computed the plan first, and only after that did
>> we decide whether the operations needed performing.

I was the one who asked about that and this is what I ended up with:

(defun out-of-date-components (system &key (other-systems t))
  "Returns a list of the components of SYSTEM (or its dependent systems,
   if OTHER-SYSTEMS is true (which is the default)) which are out-of-date."
  (let ((op (make-instance 'asdf/lisp-action:compile-op))
	res)
    (dolist (c (asdf:required-components system 
					 :force nil :force-not nil :keep-component 'asdf:cl-source-file :keep-operation 'asdf:compile-op
					 :other-systems other-systems))
      (when (eq (asdf/action:compute-action-stamp nil op c) t)
	;; Operation timestamp is in the future.  This indicates that the operation
	;; needs to be performed.
	(push c res)))
    res))

I would have been nice if I hadn't had to write this myself.