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Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c
From: |
Eli Zaretskii |
Subject: |
Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c |
Date: |
Mon, 26 Aug 2019 21:39:17 +0300 |
> From: Óscar Fuentes <address@hidden>
> Date: Mon, 26 Aug 2019 20:20:23 +0200
>
> 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.
This is backwards: it would mean we should use UNINIT all over the
place just to be sure we will be able to spot some imaginary bugs by
flipping a compiler switch.
The initialization in this case was added because GCC flagged a
potential use-before-define. After that, there's no more bug for
Valgrind to find, so I see no reason to leave UNINIT around.
I could understand using UNINIT (or something similar) when the
developer has no idea what not initializing could cause. But this is
not that case.
- [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Eli Zaretskii, 2019/08/24
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Paul Eggert, 2019/08/24
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Eli Zaretskii, 2019/08/25
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Paul Eggert, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Eli Zaretskii, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Paul Eggert, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Eli Zaretskii, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Óscar Fuentes, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Eli Zaretskii, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Óscar Fuentes, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c,
Eli Zaretskii <=
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Paul Eggert, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Óscar Fuentes, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Eli Zaretskii, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Óscar Fuentes, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Paul Eggert, 2019/08/26
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Eli Zaretskii, 2019/08/27
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Paul Eggert, 2019/08/27
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Eli Zaretskii, 2019/08/27
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Paul Eggert, 2019/08/27
- Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c, Eli Zaretskii, 2019/08/27