From: David Laight <David.Laight@ACULAB.COM>
To: 'Joe Perches' <joe@perches.com>,
Andrii Nakryiko <andrii.nakryiko@gmail.com>,
"xiakaixu1987@gmail.com" <xiakaixu1987@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>, Martin Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
Andrii Nakryiko <andrii@kernel.org>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>,
Kaixu Xia <kaixuxia@tencent.com>
Subject: RE: [PATCH] libbpf: Remove unnecessary conversion to bool
Date: Sat, 7 Nov 2020 10:46:14 +0000 [thread overview]
Message-ID: <72757066568b4b64b89572e04d783137@AcuMS.aculab.com> (raw)
In-Reply-To: <d1cefb17a0a915fdabe7a80d14895ff3d85970c1.camel@perches.com>
From: Joe Perches
> Sent: 06 November 2020 21:50
>
> On Fri, 2020-11-06 at 13:32 -0800, Andrii Nakryiko wrote:
> > On Thu, Nov 5, 2020 at 11:12 PM <xiakaixu1987@gmail.com> wrote:
> > > Fix following warning from coccinelle:
> > > ./tools/lib/bpf/libbpf.c:1478:43-48: WARNING: conversion to bool not needed here
> []
> > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> []
> > > @@ -1475,7 +1475,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val,
> > > ext->name, value);
> > > return -EINVAL;
> > > }
> > > - *(bool *)ext_val = value == 'y' ? true : false;
> > > + *(bool *)ext_val = value == 'y';
> >
> > I actually did this intentionally. x = y == z; pattern looked too
> > obscure to my taste, tbh.
>
> It's certainly a question of taste and obviously there is nothing
> wrong with yours.
>
> Maybe adding parentheses makes the below look less obscure to you?
>
> x = (y == z);
That just leads to people thinking conditionals need to be in parentheses
and then getting the priorities for ?: all wrong as in:
x = a + (b == c) ? d : e;
It would (probably) be better to make 'ext_val' be a union type
(probably a 'pointer to a union' rather than a union of pointers)
so that all the casts go away.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-11-07 10:46 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-06 7:12 [PATCH] libbpf: Remove unnecessary conversion to bool xiakaixu1987
2020-11-06 21:32 ` Andrii Nakryiko
2020-11-06 21:50 ` Joe Perches
2020-11-06 22:19 ` Andrii Nakryiko
2020-11-07 10:46 ` David Laight [this message]
2021-02-20 9:10 Jiapeng Chong
2021-02-23 1:49 ` Andrii Nakryiko
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
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=72757066568b4b64b89572e04d783137@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=andrii.nakryiko@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=joe@perches.com \
--cc=kafai@fb.com \
--cc=kaixuxia@tencent.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=songliubraving@fb.com \
--cc=xiakaixu1987@gmail.com \
--cc=yhs@fb.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.
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 NNTP newsgroup(s).