Provide byte-compiler warnings when set-default a read-only var.

[gnu-emacs] / lisp / emacs-lisp / bytecomp.el

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index bf7c2c113f0a96c44e2458e55d025843b191c4a9..0c3a7b69798c4e7945544d110be538e052b49c87 100644 (file)
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -1,7 +1,7 @@
 ;;; bytecomp.el --- compilation of Lisp code into byte code
 
 ;; Copyright (C) 1985, 1986, 1987, 1992, 1994, 1998, 2000, 2001, 2002,
-;;   2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+;;   2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
 
 ;; Author: Jamie Zawinski <jwz@lucid.com>
 ;;     Hallvard Furuseth <hbf@ulrik.uio.no>
@@ -1894,7 +1894,8 @@ Call from the source buffer."
           (concat (user-login-name) "@" (system-name)))
        " on " (current-time-string) "\n"
        ";;; from file " filename "\n"
-       ";;; in Emacs version " emacs-version ", with"
+       ";;; in Emacs version " emacs-version "\n"
+       ";;; with"
        (cond
        ((eq optimize 'source) " source-level optimization only")
        ((eq optimize 'byte) " byte-level optimization only")
@@ -3332,21 +3333,31 @@ If it is nil, then the handler is \"byte-compile-SYMBOL.\""
     (setq for-effect nil)))
 
 (defun byte-compile-setq-default (form)
-  (let ((bytecomp-args (cdr form))
-       setters)
-    (while bytecomp-args
-      (let ((var (car bytecomp-args)))
-       (and (or (not (symbolp var))
-                (byte-compile-const-symbol-p var t))
-            (byte-compile-warning-enabled-p 'constants)
-            (byte-compile-warn
-             "variable assignment to %s `%s'"
-             (if (symbolp var) "constant" "nonvariable")
-             (prin1-to-string var)))
-       (push (list 'set-default (list 'quote var) (car (cdr bytecomp-args)))
-             setters))
-      (setq bytecomp-args (cdr (cdr bytecomp-args))))
-    (byte-compile-form (cons 'progn (nreverse setters)))))
+  (setq form (cdr form))
+  (if (> (length form) 2)
+      (let ((setters ()))
+        (while (consp form)
+          (push `(setq-default ,(pop form) ,(pop form)) setters))
+        (byte-compile-form (cons 'progn (nreverse setters))))
+    (let ((var (car form)))
+      (and (or (not (symbolp var))
+               (byte-compile-const-symbol-p var t))
+           (byte-compile-warning-enabled-p 'constants)
+           (byte-compile-warn
+            "variable assignment to %s `%s'"
+            (if (symbolp var) "constant" "nonvariable")
+            (prin1-to-string var)))
+      (byte-compile-normal-call `(set-default ',var ,@(cdr form))))))
+
+(byte-defop-compiler-1 set-default)
+(defun byte-compile-set-default (form)
+  (let ((varexp (car-safe (cdr-safe form))))
+    (if (eq (car-safe varexp) 'quote)
+        ;; If the varexp is constant, compile it as a setq-default
+        ;; so we get more warnings.
+        (byte-compile-setq-default `(setq-default ,(car-safe (cdr varexp))
+                                                  ,@(cddr form)))
+      (byte-compile-normal-call form))))
 
 (defun byte-compile-quote (form)
   (byte-compile-constant (car (cdr form))))
@@ -3714,7 +3725,7 @@ that suppresses all warnings during execution of BODY."
 (defun byte-compile-save-excursion (form)
   (if (and (eq 'set-buffer (car-safe (car-safe (cdr form))))
            (byte-compile-warning-enabled-p 'suspicious))
-      (byte-compile-warn "`save-excursion' defeated by `set-buffer'."))
+      (byte-compile-warn "`save-excursion' defeated by `set-buffer'"))
   (byte-compile-out 'byte-save-excursion 0)
   (byte-compile-body-do-effect (cdr form))
   (byte-compile-out 'byte-unbind 1))