* 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
* bug#39385: Erroneous interaction of eval-when-compile and condition-case
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
0 siblings, 2 replies; 4+ messages in thread
From: Noam Postavsky @ 2020-02-02 1:04 UTC (permalink / raw)
To: Alan Mackenzie; +Cc: 39385
Alan Mackenzie <acm@muc.de> writes:
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> (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
The same happens without eval-when-compile.
> . This should have been caught by the condition-case generated by
> (c-safe ...).
I don't think so, because the condition-case is in the code generated by
c-safe (because the condition-case is quoted), whereas the error is
signaled while generating the code (because the error call is not
quoted).
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#39385: Erroneous interaction of eval-when-compile and condition-case
2020-02-02 1:04 ` Noam Postavsky
@ 2020-02-02 13:20 ` Alan Mackenzie
2020-02-02 15:37 ` Alan Mackenzie
1 sibling, 0 replies; 4+ messages in thread
From: Alan Mackenzie @ 2020-02-02 13:20 UTC (permalink / raw)
To: Noam Postavsky; +Cc: 39385
Hello, Noam.
On Sat, Feb 01, 2020 at 20:04:11 -0500, Noam Postavsky wrote:
> Alan Mackenzie <acm@muc.de> writes:
> > ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> > (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
> The same happens without eval-when-compile.
> > . This should have been caught by the condition-case generated by
> > (c-safe ...).
> I don't think so, because the condition-case is in the code generated by
> c-safe (because the condition-case is quoted), whereas the error is
> signaled while generating the code (because the error call is not
> quoted).
Ah, I think I've got it. The macro is being expanded before the
condition-case is active, and this is when it throws the error.
Thanks for the help.
I'll close this as notabug.
--
Alan Mackenzie (Nuremberg, Germany).
^ permalink raw reply [flat|nested] 4+ messages in thread
* bug#39385: Erroneous interaction of eval-when-compile and condition-case
2020-02-02 1:04 ` Noam Postavsky
2020-02-02 13:20 ` Alan Mackenzie
@ 2020-02-02 15:37 ` Alan Mackenzie
1 sibling, 0 replies; 4+ messages in thread
From: Alan Mackenzie @ 2020-02-02 15:37 UTC (permalink / raw)
To: control; +Cc: 39385
tags 39385 notabug
close 39385
quit
--
Alan Mackenzie (Nuremberg, Germany).
^ permalink raw reply [flat|nested] 4+ messages in thread
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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
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