From: Stefan Monnier <monnier@iro.umontreal.ca>
To: Dmitry Antipov <dmantipov@yandex.ru>
Cc: Paul Eggert <eggert@cs.ucla.edu>, 18410@debbugs.gnu.org
Subject: bug#18410: Use SAFE_ALLOCA etc. to avoid unbounded stack allocation.
Date: Fri, 05 Sep 2014 11:44:25 -0400 [thread overview]
Message-ID: <jwviol2cbwn.fsf-monnier+emacsbugs@gnu.org> (raw)
In-Reply-To: <54097827.1020508@yandex.ru> (Dmitry Antipov's message of "Fri, 05 Sep 2014 12:45:27 +0400")
> USE_SAFE_ALLOCA; |-
> ptrdiff_t count = SPECPDL_INDEX (); |- |
> ... | inner bind | outer bind
> Lisp_Object result = unbind_to (count, Fsome_func ()); |- |
> SAFE_FREE (); |-
> return result;
>
> looks suboptimal because it calls unbind_to twice.
Only if the object is "too large" and requires heap allocation.
BTW, AFAIK
Lisp_Object result = unbind_to (count, Fsome_func ());
can always be written
Lisp_Object result = Fsome_func ();
unbind_to (count, Qnil);
which I find more readable (if it were me, unbind_to would take
a single arg and return void).
Stefan
next prev parent reply other threads:[~2014-09-05 15:44 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-05 6:08 bug#18410: Use SAFE_ALLOCA etc. to avoid unbounded stack allocation Paul Eggert
2014-09-05 8:45 ` Dmitry Antipov
2014-09-05 15:01 ` Paul Eggert
2014-09-05 15:44 ` Stefan Monnier [this message]
2014-09-05 16:04 ` Andreas Schwab
2014-09-05 17:22 ` Stefan Monnier
2014-09-05 8:59 ` Dmitry Antipov
2014-09-05 15:03 ` Paul Eggert
2014-09-07 7:20 ` Paul Eggert
2014-09-07 17:09 ` Eli Zaretskii
2014-09-07 20:33 ` Paul Eggert
2014-09-08 2:22 ` Stefan Monnier
2014-09-08 2:35 ` Eli Zaretskii
2014-09-08 2:43 ` Stefan Monnier
2014-09-08 2:38 ` Paul Eggert
2014-09-08 3:17 ` Demetrios Obenour
2014-09-08 3:19 ` Daniel Colascione
2014-09-08 3:20 ` Demetrios Obenour
2014-09-08 7:26 ` Dmitry Antipov
2014-09-08 2:36 ` Eli Zaretskii
2014-09-08 12:48 ` Stefan Monnier
2014-09-09 13:17 ` Eli Zaretskii
2014-09-09 13:49 ` Stefan Monnier
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