master 693484d36b: * lisp/emacs-lisp/cl-generic.el (cl-defgeneric): Warn suspicious args

[Stefan Monnier]

branch: master
commit 693484d36b1326aebd895314570167ca8da87d69
Author: Stefan Monnier <monnier@iro.umontreal.ca>
Commit: Stefan Monnier <monnier@iro.umontreal.ca>

    * lisp/emacs-lisp/cl-generic.el (cl-defgeneric): Warn suspicious args
---
 lisp/emacs-lisp/cl-generic.el | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/lisp/emacs-lisp/cl-generic.el b/lisp/emacs-lisp/cl-generic.el
index b44dda6f9d..7b11c0c815 100644
--- a/lisp/emacs-lisp/cl-generic.el
+++ b/lisp/emacs-lisp/cl-generic.el
@@ -262,6 +262,16 @@ DEFAULT-BODY, if present, is used as the body of a default 
method.
          (declarations nil)
          (methods ())
          (options ())
+         (warnings
+          (let ((nonsymargs
+                 (delq nil (mapcar (lambda (arg) (unless (symbolp arg) arg))
+                                   args))))
+            (when nonsymargs
+              (list
+               (macroexp-warn-and-return
+                (format "Non-symbol arguments to cl-defgeneric: %s"
+                        (mapconcat #'prin1-to-string nonsymargs ""))
+                nil nil nil nonsymargs)))))
          next-head)
     (while (progn (setq next-head (car-safe (car options-and-methods)))
                   (or (keywordp next-head)
@@ -284,6 +294,7 @@ DEFAULT-BODY, if present, is used as the body of a default 
method.
       (setq name (gv-setter (cadr name))))
     `(prog1
          (progn
+           ,@warnings
            (defalias ',name
              (cl-generic-define ',name ',args ',(nreverse options))
              ,(if (consp doc)           ;An expression rather than a constant.