Synch to Gnus 200312260545.

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index be20d47..a69d4c8 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2003-12-26  Katsumi Yamaoka  <yamaoka@jpl.org>
+
+       * dgnushack.el: Add an advice to byte-optimize-form-code-walker to
+       avoid the warning ``...called for effect'' for the pop form when
+       running Emacs 21.3.
+
 2003-12-26  Jesper Harder  <harder@ifa.au.dk>
 
        * mm-bodies.el (mm-body-encoding): Don't use 7bit if the body

diff --git a/lisp/dgnushack.el b/lisp/dgnushack.el
index acbe183..97670f4 100644 (file)
--- a/lisp/dgnushack.el
+++ b/lisp/dgnushack.el
@@ -99,6 +99,43 @@
 ;  (cons 'progn (cdr form)))
 ;(defalias 'byte-compile-file-form-defsubst 'byte-compile-file-form-defun)
 
+(when (and (not (featurep 'xemacs))
+          (= emacs-major-version 21)
+          (= emacs-minor-version 3)
+          (condition-case code
+              (let ((byte-compile-error-on-warn t))
+                (byte-optimize-form (quote (pop x)) t)
+                nil)
+            (error (string-match "called for effect"
+                                 (error-message-string code)))))
+  (defadvice byte-optimize-form-code-walker (around silence-warn-for-pop
+                                                   (form for-effect)
+                                                   activate)
+    "Silence the warning \"...called for effect\" for the `pop' form.
+It is effective only when the `pop' macro is defined by cl.el rather
+than subr.el."
+    (let (tmp)
+      (if (and (eq (car-safe form) 'car)
+              for-effect
+              (setq tmp (get 'car 'side-effect-free))
+              (not byte-compile-delete-errors)
+              (not (eq tmp 'error-free))
+              (eq (car-safe (cadr form)) 'prog1)
+              (let ((var (cadr (cadr form)))
+                    (last (nth 2 (cadr form))))
+                (and (symbolp var)
+                     (null (nthcdr 3 (cadr form)))
+                     (eq (car-safe last) 'setq)
+                     (eq (cadr last) var)
+                     (eq (car-safe (nth 2 last)) 'cdr)
+                     (eq (cadr (nth 2 last)) var))))
+         (progn
+           (put 'car 'side-effect-free 'error-free)
+           (unwind-protect
+               ad-do-it
+             (put 'car 'side-effect-free tmp)))
+       ad-do-it))))
+
 (when (boundp 'MULE)
   (let (current-load-list)
     ;; Make the function to be silent at compile-time.