nadvice.el: Use OClosures

* lisp/emacs-lisp/nadvice.el (advice): New OClosure type.
(advice--how-alist): Make it hold prototype OClosures rather
than bytecode strings.
(advice--bytecodes): Delete var.
(advice--where): Make it an obsolete alias of new `advice--how`.
(oclosure-interactive-form, cl-print-object) <advice>: New methods.
(advice--make-1): Delete function.
(advice--make): Use `advice-copy` and `advice-cons`.
(advice--tweak): Use `advice-cons`.
(add-function, advice-add): Rename `where` arg to `how`.

* lisp/emacs-lisp/cl-print.el (cl-print-object) <:extra "nadvice">:
Remove now-redundant ad-hoc method.

* test/lisp/emacs-lisp/nadvice-tests.el (advice-test-print): New test.

1 files changed, 9 insertions, 0 deletions

diff --git a/test/lisp/emacs-lisp/nadvice-tests.el b/test/lisp/emacs-lisp/nadvice-tests.el
index 1185bee447b..a675986b90b 100644
--- a/test/lisp/emacs-lisp/nadvice-tests.el
+++ b/test/lisp/emacs-lisp/nadvice-tests.el
@@ -204,6 +204,15 @@ function being an around advice."
     (remove-function (var sm-test10) sm-advice)
     (should (equal (funcall sm-test10 5) 15))))
 
+(ert-deftest advice-test-print ()
+  (let ((x (list 'cdr)))
+    (add-function :after (car x) 'car)
+    (should (equal (cl-prin1-to-string (car x))
+                   "#f(advice car :after cdr)"))
+    (add-function :before (car x) 'first)
+    (should (equal (cl-prin1-to-string (car x))
+                   "#f(advice first :before #f(advice car :after cdr))"))))
+
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