X-Recipient: archive-cygwin AT delorie DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 74DD43858419
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1636029636;
	bh=Xr1O8DUsv7hPLNEVtg4nOXJs5EpVQZ8H9AB8pJosWuI=;
	h=Date:To:Subject:References:In-Reply-To:List-Id:List-Unsubscribe:
	 List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:
	 From;
	b=uZIZ48FmllXb9/tQAsfwLTLnw0jTcYWah9VCoTKg4546z+C/GG64QkqnGOB66scix
	 nfz/0QQKilZryouD5SOhSz5HBW+xKXAfM8oNHDlZH0L7wHT2sypKUyd/9kH66OB15U
	 AbbiabiI4AlLt7+aeyJTKlHEDD6xJaWLX7VbbZvg=
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 743903857C6C
Date: Thu, 4 Nov 2021 13:40:01 +0100
To: cygwin AT cygwin DOT com
Subject: Re: C standard library: standard headers may reserve non-standard
 identifiers which don't begin with an underscore
Message-ID: <YYPUoagJv/Vfcflr@calimero.vinschen.de>
Mail-Followup-To: cygwin AT cygwin DOT com
References: <CAL9Mx1t0nFY37paR+CiQP8-vCRYN=UMaHeaXNeX=XdAmqEv6TA AT mail DOT gmail DOT com>
MIME-Version: 1.0
Content-Disposition: inline
In-Reply-To: <CAL9Mx1t0nFY37paR+CiQP8-vCRYN=UMaHeaXNeX=XdAmqEv6TA@mail.gmail.com>
X-Provags-ID: V03:K1:SMwvWtv9tHgcld+hVDRt4THOMAnFkUbhuQ4fiHx0a380EH3eg2n
 ucW4q3YgpVjpWaCKMPIJV7LxVM0KeTScAQjVSZSsWVArtY6hL6DoF7fN7oF5lUrAT+xKsqp
 98NG8dT3uGSIn65j0Ol492YKAtYUVjFQRXik9Vu7a2hDLf1i1n8BYJKBt5gK5I5QbsWNL7K
 ngMpxuBicXo+bjWfr3EHw==
X-UI-Out-Filterresults: notjunk:1;V03:K0:yIzbQylpHGU=:r5CErWVeSfHJUqVIFuoS61
 8jhDPAdBHkP+e1Uz8rc61BHvBduMbmdnDWxlbvjoYO0VDMVZlekHA2o7y97slbALosqREAn7I
 bTY/sGrvlD1+/dU/X2lYKtxmmjyY4dS40UKrmH1LvznjYYDeF2fwEkiRUG0ELw/STx1XZODtJ
 pV4orAM11FBwzVyFU/5Whbi8AmzuWLySf5kB/96qb0EymAJgIXwlMTQZ88PKglwPv1EUaLNfT
 uMEUB0Ok13kipgKDfvv6RVu1rIt1YiiQi2RCUG1jXqOvYZEnk0KH72Ne4piktn+EJr3c7Cn49
 Gp1TKjuCX5gm6ECHT6z2J5zfTsRUoAPTMAFBFOf6jwcXCLNyLQm8gmerprA/kpW6FA5tvbZGA
 iEZaCo/VnJ7ppvBkD9WMHZiEpk8dgEcjVSoOjUtQMDYNmrtQgpUGN699977AAOMiw3X9QgapW
 nph8uJErTyod2Dchf07ZBRTuFHe0C+eqqKse8o1bQL0V1Vwve5Ms/L9WnXZfWobuN8CRQokrl
 dhky2glyXI8jniQK6qfcOYai0zCAPIghGl98NZOgv2u2o9yWxRGDbXCHZAZGUqfdZSjga+kdA
 oymyCM47FXLwIua+5eCtFYBPTrlO652uZVnZihoQjagKKI2ij1Wi99A3O823fku7oNRoqUalX
 nUOGVhvxad6m9qD9N0Mm71DNPi2w8/rMmAY0Pl309K8+45NDammGtdP5Pv2aE4BVFb8zUv7J7
 spoXGu6+bUkimSp3
X-Spam-Status: No, score=-99.3 required=5.0 tests=BAYES_00,
 GOOD_FROM_CORINNA_CYGWIN, JMQ_SPF_NEUTRAL, KAM_DMARC_NONE, KAM_DMARC_STATUS,
 RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NEUTRAL,
 TXREP autolearn=ham autolearn_force=no version=3.4.4
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on
 server2.sourceware.org
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From: Corinna Vinschen via Cygwin <cygwin AT cygwin DOT com>
Reply-To: cygwin AT cygwin DOT com
Cc: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com
Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com>

On Nov  4 00:23, Pavel M via Cygwin wrote:
> Observation: C standard library: standard headers may reserve non-standard
> identifiers which don't begin with an underscore.
> 
> Invocations:
> $ echo -e "#include <limits.h>\n#define NL_NMAX" | gcc -xc - -std=c11
> -pedantic -Wall -Wextra -E > /dev/null
> <stdin>:2: warning: "NL_NMAX" redefined
> In file included from /usr/lib/gcc/x86_64-pc-cygwin/11/include/limits.h:203,
>                  from
> /usr/lib/gcc/x86_64-pc-cygwin/11/include/syslimits.h:7,
>                  from /usr/lib/gcc/x86_64-pc-cygwin/11/include/limits.h:34,
>                  from <stdin>:1:
> /usr/include/limits.h:507: note: this is the location of the previous
> definition
>   507 | #define NL_NMAX                              INT_MAX
> 
> $ echo -e "#include <limits.h>\n#define PAGESIZE" | gcc -xc - -std=c11
> -pedantic -Wall -Wextra -E > /dev/null
> <stdin>:2: warning: "PAGESIZE" redefined
> In file included from /usr/lib/gcc/x86_64-pc-cygwin/11/include/limits.h:203,
>                  from
> /usr/lib/gcc/x86_64-pc-cygwin/11/include/syslimits.h:7,
>                  from /usr/lib/gcc/x86_64-pc-cygwin/11/include/limits.h:34,
>                  from <stdin>:1:
> /usr/include/limits.h:220: note: this is the location of the previous
> definition
>   220 | #define PAGESIZE __PAGESIZE
> 
> # and so on...

That's ok for limits.h, see
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html

Some of the values also use feature test macros.


Corinna

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple