* lisp/emacs-lisp/bytecomp.el (byte-compile-warning-types): New type

`lexical' for warnings related to lexical scoping.
(byte-compile-file-form-defvar, byte-compile-defvar): Warn about
global vars which don't have a prefix and could hence affect lexical
scoping in unrelated files.

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 28d197d92beee02d9ecafac3cae09b483898eec9..789d41ad1da17ead69b0b3099127a45e647c4e02 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,11 @@
+2010-09-15  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+       * emacs-lisp/bytecomp.el (byte-compile-warning-types): New type
+       `lexical' for warnings related to lexical scoping.
+       (byte-compile-file-form-defvar, byte-compile-defvar): Warn about
+       global vars which don't have a prefix and could hence affect lexical
+       scoping in unrelated files.
+
 2010-09-14  Lars Magne Ingebrigtsen  <larsi@gnus.org>
 
        * net/imap.el: Revert back to version
@@ -106,8 +114,8 @@
        * Makefile.in (TRAMP_SRC): Remove tramp-fish.el.  Add tramp-sh.el.
 
        * net/tramp.el (top): Don't show loading message.  Require just
-       'tramp-compat, everything else is required there.  Use
-       `ignore-errors' where appropriate.
+       'tramp-compat, everything else is required there.
+       Use `ignore-errors' where appropriate.
        (tramp-inline-compress-start-size, tramp-copy-size-limit)
        (tramp-terminal-type, tramp-end-of-output)
        (tramp-initial-end-of-output, tramp-completion-function-alist-rsh)

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 8b47e0421e08c570968d569b4d4eafa58064626b..cf12847d093e9a0f80cf656c3c0da90c072e9fa6 100644 (file)
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -265,7 +265,7 @@ If it is 'byte, then only byte-level optimizations will be logged."
 (defconst byte-compile-warning-types
   '(redefine callargs free-vars unresolved
             obsolete noruntime cl-functions interactive-only
-            make-local mapcar constants suspicious)
+            make-local mapcar constants suspicious lexical)
   "The list of warning types used when `byte-compile-warnings' is t.")
 (defcustom byte-compile-warnings t
   "List of warnings that the byte-compiler should issue (t for all).
@@ -2153,6 +2153,11 @@ list that represents a doc string reference.
       ;; Since there is no doc string, we can compile this as a normal form,
       ;; and not do a file-boundary.
       (byte-compile-keep-pending form)
+    (when (and (symbolp (nth 1 form))
+               (not (string-match "[-*:$]" (symbol-name (nth 1 form))))
+               (byte-compile-warning-enabled-p 'lexical))
+      (byte-compile-warn "Global/dynamic var `%s' lacks a prefix"
+                         (nth 1 form)))
     (push (nth 1 form) byte-compile-bound-variables)
     (if (eq (car form) 'defconst)
        (push (nth 1 form) byte-compile-const-variables))
@@ -3804,6 +3809,11 @@ that suppresses all warnings during execution of BODY."
 
 (defun byte-compile-defvar (form)
   ;; This is not used for file-level defvar/consts with doc strings.
+  (when (and (symbolp (nth 1 form))
+             (not (string-match "[-*:$]" (symbol-name (nth 1 form))))
+             (byte-compile-warning-enabled-p 'lexical))
+    (byte-compile-warn "Global/dynamic var `%s' lacks a prefix"
+                       (nth 1 form)))
   (let ((fun (nth 0 form))
        (var (nth 1 form))
        (value (nth 2 form))