Re: describe-function and advised C functions

[Tassilo Horn <tsdh@gnu.org>]

Hi again,

my previous patch had an unreachable code path & one always-nil test I
forgot to delete.  Here's a better patch.  The C-h f output is the same
as in my last mail.

BTW, why are the advice annotations in the *Help* buffer fontified for
`load', `append', and `concat-seqs', but not for `scheme-mode' and
`quack-mode'.

Bye,
Tassilo

--8<---------------cut here---------------start------------->8---
=== modified file 'lisp/help-fns.el'
--- lisp/help-fns.el	2013-06-15 01:12:05 +0000
+++ lisp/help-fns.el	2013-12-04 13:59:39 +0000
@@ -382,8 +382,6 @@
 			    (match-string 1 str))))
 	(and src-file (file-readable-p src-file) src-file))))))
 
-(declare-function ad-get-advice-info "advice" (function))
-
 (defun help-fns--key-bindings (function)
   (when (commandp function)
     (let ((pt2 (with-current-buffer standard-output (point)))
@@ -531,27 +529,39 @@
 
 ;;;###autoload
 (defun describe-function-1 (function)
-  (let* ((advised (and (symbolp function) (featurep 'advice)
-		       (ad-get-advice-info function)))
+  (let* ((advised (and (symbolp function)
+		       (featurep 'nadvice)
+		       (advice--p (advice--symbol-function function))))
 	 ;; If the function is advised, use the symbol that has the
 	 ;; real definition, if that symbol is already set up.
 	 (real-function
 	  (or (and advised
-		   (let ((origname (cdr (assq 'origname advised))))
-		     (and (fboundp origname) origname)))
+		   (let* ((f function)
+			  (advised-fn (advice--cdr (advice--symbol-function f))))
+		     (while (advice--p advised-fn)
+		       (setq f advised-fn)
+		       (setq advised-fn (advice--cdr (if (symbolp f)
+							 (advice--symbol-function f)
+						       f))))
+		     advised-fn))
 	      function))
 	 ;; Get the real definition.
 	 (def (if (symbolp real-function)
 		  (symbol-function real-function)
-		function))
-	 (aliased (symbolp def))
-	 (real-def (if aliased
-		       (let ((f def))
-			 (while (and (fboundp f)
-				     (symbolp (symbol-function f)))
-			   (setq f (symbol-function f)))
-			 f)
-		     def))
+		real-function))
+	 (aliased (or (symbolp def)
+		      ;; advised & aliased
+		      (and (symbolp function)
+			   (symbolp real-function)
+			   (not (eq function real-function)))))
+	 (real-def (cond
+		    (aliased (let ((f real-function))
+			       (while (and (fboundp f)
+					   (symbolp (symbol-function f)))
+				 (setq f (symbol-function f)))
+			       f))
+		    ((subrp def) (intern (subr-name def)))
+		    (t def)))
 	 (file-name (find-lisp-object-file-name function def))
          (pt1 (with-current-buffer (help-buffer) (point)))
 	 (beg (if (and (or (byte-code-function-p def)
@@ -567,14 +577,14 @@
     ;; Print what kind of function-like object FUNCTION is.
     (princ (cond ((or (stringp def) (vectorp def))
 		  "a keyboard macro")
+		 (aliased
+		  (format "an alias for `%s'" real-def))
 		 ((subrp def)
 		  (if (eq 'unevalled (cdr (subr-arity def)))
 		      (concat beg "special form")
 		    (concat beg "built-in function")))
 		 ((byte-code-function-p def)
 		  (concat beg "compiled Lisp function"))
-		 (aliased
-		  (format "an alias for `%s'" real-def))
 		 ((eq (car-safe def) 'lambda)
 		  (concat beg "Lisp function"))
 		 ((eq (car-safe def) 'macro)
--8<---------------cut here---------------end--------------->8---

Bye,
Tassilo