Re: (require ...) and file dependencies.

[Oleksandr Gavenko <gavenkoa@gmail.com>]

On 2014-12-28, Stefan Monnier wrote:

>> They may fixed by:
>>
>>   (eval-when-compile
>>     (defvar ...))
>
> No, it's fixed with
>
>     (defvar <foo>)
>
> Siuch (defvar <foo>) declarations (i.e. without an initial value) are
> annotations for the *compiler*, so you don't want to pas them to the
> `eval'uator (hence you don't want to wrap them in `eval-when-compile').
> The fact that they also work when wrapped in `eval-when-compile' is an
> accident which might get fixed at any point.

Thanks for tips. I found:

>>   (eval-when-compile
>>     (defvar ...))

by grepping some sources. I usually try to check how things done by another
before inventing own style.

Currently Emacs sources have some occurrences of such code (so I send replay
also in private to rise attention). I run:

  ack -C 4 eval-when-compile  # with 4 line context 

and look to `defvar`. Before showing complete list I put weird code, which
seems need to be fixed:

  lisp/progmodes/sql.el
  1391:(eval-when-compile
  1392-  (defvar sql-mode-ansi-font-lock-keywords)
  1393-  (setq sql-mode-ansi-font-lock-keywords nil))

Here strange comment and strange conditional defvar:

  lisp/progmodes/verilog-mode.el
  8407:(eval-when-compile
  8408-  ;; Prevent compile warnings; these are let's, not globals
  8409:  ;; Do not remove the eval-when-compile
  8410-  ;; - we want an error when we are debugging this code if they are refed.
  8411-  (defvar sigs-in)
  8412-  (defvar sigs-inout)
  8413-  (defvar sigs-intf)
    (defvar sigs-out)
    (defvar sigs-out-d)
    (defvar sigs-out-i)
    (defvar sigs-out-unk)
    (defvar sigs-temp)
    ;; These are known to be from other packages and may not be defined
    (defvar diff-command nil)
    (defvar vector-skip-list)
    ;; There are known to be from newer versions of Emacs
    (defvar create-lockfiles))
  10065:(eval-when-compile
  10066-  (if (not (boundp 'indent-pt))
  10067-      (defvar indent-pt nil "Local used by insert-indent")))

I don't understand Gnus magic for XEmacs:

  lisp/gnus/gnus-ml.el
  87:(eval-when-compile
  88-  (when (featurep 'xemacs)
  89-    (defvar gnus-mailing-list-mode-hook)
  90-    (defvar gnus-mailing-list-mode-on-hook)
  91-    (defvar gnus-mailing-list-mode-off-hook)))

  lisp/gnus/gnus-salt.el
  103:(eval-when-compile
  104-  (when (featurep 'xemacs)
  105-    (defvar gnus-pick-mode-on-hook)
  106-    (defvar gnus-pick-mode-off-hook)))
  342:(eval-when-compile
  343-  (when (featurep 'xemacs)
  344-    (defvar gnus-binary-mode-on-hook)
  345-    (defvar gnus-binary-mode-off-hook)))

  lisp/gnus/gnus-dired.el
  89:(eval-when-compile
  90-  (when (featurep 'xemacs)
  91-    (defvar gnus-dired-mode-hook)
  92-    (defvar gnus-dired-mode-on-hook)
  93-    (defvar gnus-dired-mode-off-hook)))

Seems that this can be fixed by anyone with commit right away:

  lisp/org/org.el
  8477:(eval-when-compile
  8478-  (defvar org-property-drawer-re))

  lisp/org/org-colview.el
  752:(eval-when-compile (defvar org-columns-time))

  lisp/printing.el
  1099:(eval-when-compile
  1100-  ;; User Interface --- declared here to avoid compiler warnings
  1101-  (defvar pr-path-style)
  1102-  (defvar pr-auto-region)
  1103-  (defvar pr-menu-char-height)

-- 
Best regards!