linux-kernel - RE: function prototype element ordering

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Message-ID: <6a85bbbf952949118cc5f93b57d48265@AcuMS.aculab.com>
Date:   Sat, 25 Sep 2021 19:40:41 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Linus Torvalds' <torvalds@...ux-foundation.org>,
        Alexey Dobriyan <adobriyan@...il.com>
CC:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Joe Perches <joe@...ches.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        "apw@...onical.com" <apw@...onical.com>,
        Christoph Lameter <cl@...ux.com>,
        Daniel Micay <danielmicay@...il.com>,
        Dennis Zhou <dennis@...nel.org>,
        "dwaipayanray1@...il.com" <dwaipayanray1@...il.com>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Linux-MM <linux-mm@...ck.org>,
        Lukas Bulwahn <lukas.bulwahn@...il.com>,
        "mm-commits@...r.kernel.org" <mm-commits@...r.kernel.org>,
        Nathan Chancellor <nathan@...nel.org>,
        "Nick Desaulniers" <ndesaulniers@...gle.com>,
        Miguel Ojeda <ojeda@...nel.org>,
        "Pekka Enberg" <penberg@...nel.org>,
        David Rientjes <rientjes@...gle.com>,
        Tejun Heo <tj@...nel.org>, Vlastimil Babka <vbabka@...e.cz>,
        "open list:DOCUMENTATION" <linux-doc@...r.kernel.org>
Subject: RE: function prototype element ordering

From: Linus Torvalds
> Sent: 22 September 2021 22:16
...
> We don't put function return types on their own lines either, even if
> some other projects have that rule (just to get function names at the
> beginning of lines or some other odd reason).

If the function name starts at the beginning of a line it is
much easier to grep for the definition.
Trying to find function definitions in the Linux kernel tree
is a PITA - unless they are exported when 'EXPORT.*(function_name)'
will tend to work.

Trying to compile:
static int x(int y) __attribute__((section("x"))) { return y;}
with gcc generates "error: attributes are not allowed on a function-definition".

Putting the attribute anywhere before the function name works fine.
gcc probably accepts:
__inline static __inline int __inline x(void) {return 0;} 

So any of those locations is plausible.
But after the arguments isn't allowed.
So an (extern) function declaration probably should not put them
there - if only for consistency.

I think I'd go for 'first' - optionally on their own line.

	David

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