From: "SZEDER Gábor" <szeder.dev@gmail.com>
To: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: "SZEDER Gábor" <szeder.dev@gmail.com>,
"Olga Telezhnaya" <olyatelezhnaya@gmail.com>,
git@vger.kernel.org
Subject: Re: [PATCH 3/4] ref-filter: merge get_obj and get_object
Date: Tue, 10 Jul 2018 12:29:37 +0200 [thread overview]
Message-ID: <20180710102937.12499-1-szeder.dev@gmail.com> (raw)
In-Reply-To: <nycvar.QRO.7.76.6.1807101115570.75@tvgsbejvaqbjf.bet>
> This causes GCC to complain thusly:
>
>
> ```
> 2018-07-10T04:59:38.6368270Z ref-filter.c:1477:6: error: variable 'eaten' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
> 2018-07-10T04:59:38.6468620Z if (oi->info.contentp) {
> 2018-07-10T04:59:38.6568710Z ^~~~~~~~~~~~~~~~~
> 2018-07-10T04:59:38.6669970Z ref-filter.c:1489:7: note: uninitialized use occurs here
> 2018-07-10T04:59:38.6774240Z if (!eaten)
> 2018-07-10T04:59:38.6874860Z ^~~~~
> 2018-07-10T04:59:38.6976740Z ref-filter.c:1477:2: note: remove the 'if' if its condition is always true
> 2018-07-10T04:59:38.7072330Z if (oi->info.contentp) {
> 2018-07-10T04:59:38.7172760Z ^~~~~~~~~~~~~~~~~~~~~~~
> 2018-07-10T04:59:38.7274040Z ref-filter.c:1466:11: note: initialize the variable 'eaten' to silence this warning
> 2018-07-10T04:59:38.7374670Z int eaten;
> 2018-07-10T04:59:38.7474870Z ^
> 2018-07-10T04:59:38.7575690Z = 0
> ```
>
> (See
> https://mseng.visualstudio.com/VSOnline/_build/results?buildId=6640204&view=logs
> for details)
>
> I think that GCC is correct, and at the same time, it isn't. Because it
> does not matter whether `eaten` is uninitialized here:
It's undefined behaviour; 'eaten' is int, and an int may have padding
bits and trap representations.
> if it is, then
> `buf` is NULL, and the `free(buf);` call does nothing in particular.
next prev parent reply other threads:[~2018-07-10 10:29 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-09 8:12 [PATCH 1/4] ref-filter: add info_source to valid_atom Olga Telezhnaya
2018-07-09 8:12 ` [PATCH 2/4] ref-filter: add empty values to technical fields Olga Telezhnaya
2018-07-09 22:39 ` Junio C Hamano
2018-07-10 7:51 ` Оля Тележная
2018-07-09 8:12 ` [PATCH 4/4] ref-filter: use oid_object_info() to get object Olga Telezhnaya
2018-07-09 8:12 ` [PATCH 3/4] ref-filter: merge get_obj and get_object Olga Telezhnaya
2018-07-10 9:19 ` SZEDER Gábor
2018-07-10 9:23 ` Johannes Schindelin
2018-07-10 10:29 ` SZEDER Gábor [this message]
2018-07-10 10:41 ` Оля Тележная
2018-07-13 12:43 ` [PATCH v2 1/4] ref-filter: add info_source to valid_atom Olga Telezhnaya
2018-07-13 12:43 ` [PATCH v2 2/4] ref-filter: fill empty fields with empty values Olga Telezhnaya
2018-07-13 12:43 ` [PATCH v2 3/4] ref-filter: merge get_obj and get_object Olga Telezhnaya
2018-07-13 12:43 ` [PATCH v2 4/4] ref-filter: use oid_object_info() to get object Olga Telezhnaya
2018-07-16 20:53 ` Junio C Hamano
2018-07-17 7:44 ` Оля Тележная
2018-07-17 22:17 ` Junio C Hamano
2018-07-17 8:22 ` [PATCH v3 1/5] ref-filter: add info_source to valid_atom Olga Telezhnaya
2018-07-17 8:22 ` [PATCH v3 4/5] ref-filter: merge get_obj and get_object Olga Telezhnaya
2018-07-17 8:22 ` [PATCH v3 2/5] ref-filter: fill empty fields with empty values Olga Telezhnaya
2018-07-17 8:22 ` [PATCH v3 5/5] ref-filter: use oid_object_info() to get object Olga Telezhnaya
2018-07-17 8:22 ` [PATCH v3 3/5] ref-filter: initialize eaten variable Olga Telezhnaya
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180710102937.12499-1-szeder.dev@gmail.com \
--to=szeder.dev@gmail.com \
--cc=Johannes.Schindelin@gmx.de \
--cc=git@vger.kernel.org \
--cc=olyatelezhnaya@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).