all messages for Emacs-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
* bug#39385: Erroneous interaction of eval-when-compile and condition-case
@ 2020-02-01 21:47 Alan Mackenzie
  2020-02-02  1:04 ` Noam Postavsky
  0 siblings, 1 reply; 4+ messages in thread
From: Alan Mackenzie @ 2020-02-01 21:47 UTC (permalink / raw)
  To: 39385

Hello, Emacs.

On master, with emacs -Q.

Create the following file, bad-eval-when-compile.el:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defmacro c-safe (&rest body)
  ;; safely execute BODY, return nil if an error occurred
  `(condition-case nil
       (progn ,@body)
     (error nil)))

(defmacro foo ()
  (error "This message should not be seen"))

(eval-when-compile
  (c-safe (foo)))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

Now do M-x byte-compile-file <CR> bad-eval-when-compile.el <CR>.  This
erroneously throws the error:

    This message should not be seen

.  This should have been caught by the condition-case generated by
(c-safe ...).

As a matter of interest, if eval-when-compile is replaced by
cc-eval-when-compile:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defmacro cc-eval-when-compile (&rest body)
  `(eval-when-compile
    (eval '(progn ,@body))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

, then the compilation succeeds.  So it would appear that there is a bug
in the byte compiler's handling of eval-when-compile.

-- 
Alan Mackenzie (Nuremberg, Germany).





^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2020-02-02 15:37 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2020-02-01 21:47 bug#39385: Erroneous interaction of eval-when-compile and condition-case Alan Mackenzie
2020-02-02  1:04 ` Noam Postavsky
2020-02-02 13:20   ` Alan Mackenzie
2020-02-02 15:37   ` Alan Mackenzie

Code repositories for project(s) associated with this external index

	https://git.savannah.gnu.org/cgit/emacs.git
	https://git.savannah.gnu.org/cgit/emacs/org-mode.git

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.