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Groups > comp.lang.c > #142623
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Question about #error |
| Date | 2019-03-30 15:19 -0700 |
| Organization | None to speak of |
| Message-ID | <lnd0m89f96.fsf@kst-u.example.com> (permalink) |
| References | (1 earlier) <9183709e-58d4-47b5-9e2b-781600729a55@googlegroups.com> <lno95uadtm.fsf@kst-u.example.com> <167a6806-9b54-4b29-bd00-188e286d3c05@googlegroups.com> <554d9166-d9ca-4109-b40e-a79b6f14ac41@googlegroups.com> <41ad852c-4691-43dc-ae82-616efd8b1d83@googlegroups.com> |
Thiago Adams <thiago.adams@gmail.com> writes:
> On Friday, March 29, 2019 at 12:05:53 PM UTC-3, James Kuyper wrote:
> ...
>> #if expressions are evaluated during translation phase 4. Per the rules
>> currently in effect, sizeof(int) gets converted into 0(0) before
>> evaluation (6.10.1p4), resulting in a syntax error.
>
>
> Does anyone uses or find uses of identifiers not defined in
> #if expressions?
>
> Like
> #if IDENTIFIER
>
> and IDENTIFIER was never #defined.
> The normal usage is
> #if defined(X) or
> #if X
> where X is defined as 1 or 0
>
>
> I did a search in windows include directory for #if identifier
> and I didn't find any usage where identifier was not defined.
>
> I think this behavior could be deprecated and generate warning
> or error.
The meaning of
#if UNDEFINED_IDENTIFIER
is currently well defined. Treating it as a fatal error could easily
break existing code. (A Windows include directory is not likely to be a
representative sample.)
What would be the advantage of deprecating it?
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Will write code for food.
void Void(void) { Void(); } /* The recursive call of the void */
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Question about #error gazelle@shell.xmission.com (Kenny McCormack) - 2019-03-27 16:06 +0000
Re: Question about #error Chad <cdalten@gmail.com> - 2019-03-27 10:21 -0700
Re: Question about #error scott@slp53.sl.home (Scott Lurndal) - 2019-03-27 17:35 +0000
Re: Question about #error nobody@example.org (Scott) - 2019-03-28 04:33 +0000
Re: Question about #error Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-04-07 00:15 -0700
Re: Question about #error gazelle@shell.xmission.com (Kenny McCormack) - 2019-04-07 10:22 +0000
Re: Question about #error nobody@example.org (Scott) - 2019-04-07 17:10 +0000
Re: Question about #error Bart <bc@freeuk.com> - 2019-03-27 17:52 +0000
Re: Question about #error luser droog <luser.droog@gmail.com> - 2019-03-27 12:36 -0700
Re: Question about #error luser droog <luser.droog@gmail.com> - 2019-03-27 12:47 -0700
Re: Question about #error John Bode <jfbode1029@gmail.com> - 2019-03-27 14:28 -0700
Re: Question about #error David Brown <david.brown@hesbynett.no> - 2019-03-27 22:38 +0100
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-03-28 13:59 -0700
Re: Question about #error Keith Thompson <kst-u@mib.org> - 2019-03-28 14:28 -0700
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-03-29 07:09 -0700
Re: Question about #error James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-03-29 08:05 -0700
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-03-29 12:08 -0700
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-03-29 12:15 -0700
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-03-29 12:53 -0700
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-03-30 14:40 -0700
Re: Question about #error Keith Thompson <kst-u@mib.org> - 2019-03-30 15:19 -0700
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-03-30 16:17 -0700
Re: Question about #error scott@slp53.sl.home (Scott Lurndal) - 2019-03-31 19:12 +0000
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-04-01 04:32 -0700
Re: Question about #error David Brown <david.brown@hesbynett.no> - 2019-03-31 20:17 +0200
Re: Question about #error Richard Damon <Richard@Damon-Family.org> - 2019-03-31 15:09 -0400
Re: Question about #error David Brown <david.brown@hesbynett.no> - 2019-03-31 21:46 +0200
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-04-01 04:36 -0700
Re: Question about #error James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-04-02 17:47 -0700
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-04-03 05:31 -0700
Re: Question about #error James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-04-03 06:46 -0700
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-04-03 07:44 -0700
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-04-03 09:46 -0700
Re: Question about #error scott@slp53.sl.home (Scott Lurndal) - 2019-03-28 21:29 +0000
Re: Question about #error Thiago Adams <thiago.adams@gmail.com> - 2019-03-29 07:32 -0700
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