Date: Wed, 06 Jun 2018 09:57:01 -0400 From: Ravi Pokala <rpokala@freebsd.org> To: Benjamin Kaduk <bjkfbsd@gmail.com> Cc: Mateusz Guzik <mjg@freebsd.org>, src-committers <src-committers@freebsd.org>, <svn-src-all@freebsd.org>, <svn-src-head@freebsd.org> Subject: Re: svn commit: r334702 - head/sys/sys Message-ID: <41069956-C0D7-43C6-93D7-A843D991E47B@panasas.com> In-Reply-To: <CAJ5_RoALt_%2BASNN5E2wBch-CEn0sesJO=1Z2aJsz1EwsesdFiQ@mail.gmail.com> References: <201806060508.w56586c9053686@repo.freebsd.org> <6E6E92B2-7536-4281-8EAF-72823E84902E@panasas.com> <CAJ5_RoALt_%2BASNN5E2wBch-CEn0sesJO=1Z2aJsz1EwsesdFiQ@mail.gmail.com>
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-----Original Message-----
From: <owner-src-committers@freebsd.org> on behalf of Benjamin Kaduk <bjkfbsd@gmail.com>
Date: 2018-06-06, Wednesday at 07:40
To: Ravi Pokala <rpokala@freebsd.org>
Cc: Mateusz Guzik <mjg@freebsd.org>, src-committers <src-committers@freebsd.org>, <svn-src-all@freebsd.org>, <svn-src-head@freebsd.org>
Subject: Re: svn commit: r334702 - head/sys/sys
> On Wed, Jun 6, 2018 at 6:35 AM, Ravi Pokala <rpokala@freebsd.org> wrote:
>>
>> Hi Mateusz,
>>
>> -----Original Message-----
>> From: <owner-src-committers@freebsd.org> on behalf of Mateusz Guzik <mjg@FreeBSD.org>
>> Date: 2018-06-06, Wednesday at 01:08
>> To: <src-committers@freebsd.org>, <svn-src-all@freebsd.org>, <svn-src-head@freebsd.org>
>> Subject: svn commit: r334702 - head/sys/sys
>>
>>> ...
>>> #ifdef _KERNEL
>>> #define malloc(size, type, flags) ({ \
>>
>> Now that I'm taking another look at this, I'm confused as to why the entire macro expansion is inside parentheses? (The braces make sense, since this is a block with local variables which need to be contained.)
>
> This is a gcc (and clang) extension to allow the macro body to be a code block -- standard C gets unhappy with just the curly braces. https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html is a maybe-relevant page that google found me.
"Neat." Thanks Ben.
-Ravi
> -Ben
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