From: "Óscar Fuentes" <ofv@wanadoo.es>
To: emacs-devel@gnu.org
Subject: Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c
Date: Mon, 26 Aug 2019 20:20:23 +0200 [thread overview]
Message-ID: <87ftln4wm0.fsf@telefonica.net> (raw)
In-Reply-To: 83imqjgb1g.fsf@gnu.org
Eli Zaretskii <eliz@gnu.org> writes:
>> > What debugging tools can make a significant difference here, and how
>> > easy/practical is it to use them? I very much doubt they will catch
>> > every use-before-set bug anyway.
>>
>> Valgrind tracks each byte at the machine instruction level.
>>
>> Given the complexity of the Emacs C code, IMAO it is very useful to test
>> for this type of nasty errors. I dislike hacks that pollute the source
>> code, but on this case it is warranted.
>
> Does valgrind know about UNINIT? I'd be surprised, since UNINIT is a
> source-level feature.
Valgrind knows nothing about UNINIT as it works with machine code, not
with source code. But AFAIK that macro is conditionally defined to "=0"
(for silencing bogus gcc warnings) or to nothing (for leaving the
variable uninitalized at the declaration point). The later allows
Valgrind to do a proper check.
Simply changing
int x;
to
int x = 0;
just for silencing the gcc warning can hide a bug that Valgrind would
detect otherwise.
next prev parent reply other threads:[~2019-08-26 18:20 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-24 6:14 [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c Eli Zaretskii
2019-08-25 0:52 ` Paul Eggert
2019-08-25 7:13 ` Eli Zaretskii
2019-08-26 6:34 ` Paul Eggert
2019-08-26 7:54 ` Eli Zaretskii
2019-08-26 8:15 ` Paul Eggert
2019-08-26 9:47 ` Eli Zaretskii
2019-08-26 15:21 ` Óscar Fuentes
2019-08-26 16:13 ` Eli Zaretskii
2019-08-26 18:20 ` Óscar Fuentes [this message]
2019-08-26 18:39 ` Eli Zaretskii
2019-08-26 19:09 ` Paul Eggert
2019-08-26 19:15 ` Óscar Fuentes
2019-08-26 19:33 ` Eli Zaretskii
2019-08-26 19:49 ` Óscar Fuentes
2019-08-26 22:33 ` Paul Eggert
2019-08-27 6:12 ` Eli Zaretskii
2019-08-27 7:28 ` Paul Eggert
2019-08-27 8:02 ` Eli Zaretskii
2019-08-27 9:28 ` Paul Eggert
2019-08-27 10:15 ` Eli Zaretskii
2019-08-27 12:05 ` Paul Eggert
2019-08-27 12:43 ` Eli Zaretskii
2019-08-26 18:50 ` Paul Eggert
2019-08-26 18:56 ` Eli Zaretskii
2019-08-26 23:17 ` Richard Stallman
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