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Groups > comp.lang.c > #108239
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: How to fix warning: [-Wdate-time] |
| Date | 2017-04-17 12:02 -0700 |
| Organization | None to speak of |
| Message-ID | <lnmvbesvqv.fsf@kst-u.example.com> (permalink) |
| References | (3 earlier) <8e289215-369a-43c5-aa46-9428ad81a224@googlegroups.com> <lnpogdtjmy.fsf@kst-u.example.com> <195fbe3a-b69c-45e4-ac6e-a45a1913a834@googlegroups.com> <od2p00$v2c$1@dont-email.me> <36a7bba0-fa4d-59e4-16f8-1dcebce0cd84@verizon.net> |
"James R. Kuyper" <jameskuyper@verizon.net> writes:
[...]
>> On 4/16/2017 2:44 PM, supercat@casperkitty.com wrote:
[...]
>>> Further, in the event that a project happens to be built in multiple steps
>>> that occur days apart, I don't think the Standard specifies which moment in
>>> the build process should be identified by __DATE__ and __TIME__.
>
> The standard specifies that __DATE__ describes "The date of translation
> of the preprocessing translation unit:" "The" is singular: only one
> such data can apply in a given preprocessing translation unit. It's
> entirely consistent with that wording for __DATE__ and __TIME__ to have
> different values in different translation units translated at different
> times, but it would be a very odd compiler that takes several days to
> complete translation of a single preprocessing translation unit. Note,
> in particular, that preprocessing translation units cease to exist by
> the end of translation phase 4; linkage doesn't occur until translation
> phase 8. Therefore, you can't justify waiting for the program to be
> linked together before determining the appropriate value of __DATE__ or
> __TIME__.
[...]
It wouldn't have to take several days for the problem to occur.
If translation phase 4 starts at 2017-04-17 23:59:59.99 and completes 20
milliseconds later at 2017-04-18 00:00:00.01, then the start and end
times would be on two different days. If __DATE__ and __TIME__ are
evaluated separately, you could end up with __DATE__ = "Apr 17 2017" and
__TIME__ = "00:00:00", implying a time 24 hours before the actual
translation time.
The use of the phrases "*The* date" and "*The* time" suggest, though
perhaps not strongly enough, that both __DATE__ and __TIME__ should
correspond to a single moment in time for each translation of each
translation unit. (A compiler might perform different phases at
different times, but only phase 4 is relevant here.)
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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How to fix warning: [-Wdate-time] MehdiAmini <atorrses@gmail.com> - 2017-04-13 14:44 +0430
Re: How to fix warning: [-Wdate-time] Barry Schwarz <schwarzb@dqel.com> - 2017-04-13 05:28 -0700
Re: How to fix warning: [-Wdate-time] MehdiAmini <atorrses@gmail.com> - 2017-04-14 12:55 +0430
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-14 08:50 -0700
Re: How to fix warning: [-Wdate-time] Ken Brody <kenbrody@spamcop.net> - 2017-04-14 13:42 -0400
Re: How to fix warning: [-Wdate-time] James Kuyper <jameskuyper@verizon.net> - 2017-04-14 14:26 -0400
Re: How to fix warning: [-Wdate-time] David Brown <david.brown@hesbynett.no> - 2017-04-17 16:26 +0200
Re: How to fix warning: [-Wdate-time] "James R. Kuyper" <jameskuyper@verizon.net> - 2017-04-17 10:52 -0400
Re: How to fix warning: [-Wdate-time] David Brown <david.brown@hesbynett.no> - 2017-04-17 20:00 +0200
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-17 08:08 -0700
Re: How to fix warning: [-Wdate-time] David Brown <david.brown@hesbynett.no> - 2017-04-17 20:04 +0200
Re: How to fix warning: [-Wdate-time] Mehdi Amini <atorrses@gmail.com> - 2017-04-15 07:50 +0430
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-15 15:05 -0700
Re: How to fix warning: [-Wdate-time] Ken Brody <kenbrody@spamcop.net> - 2017-04-17 11:42 -0400
Re: How to fix warning: [-Wdate-time] supercat@casperkitty.com - 2017-04-17 08:55 -0700
Re: How to fix warning: [-Wdate-time] "James R. Kuyper" <jameskuyper@verizon.net> - 2017-04-17 11:57 -0400
Re: How to fix warning: [-Wdate-time] gazelle@shell.xmission.com (Kenny McCormack) - 2017-04-13 13:09 +0000
Re: How to fix warning: [-Wdate-time] jadill33@gmail.com - 2017-04-13 06:27 -0700
Re: How to fix warning: [-Wdate-time] supercat@casperkitty.com - 2017-04-15 08:56 -0700
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-15 15:01 -0700
Re: How to fix warning: [-Wdate-time] supercat@casperkitty.com - 2017-04-16 11:44 -0700
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-16 13:45 -0700
Re: How to fix warning: [-Wdate-time] Ken Brody <kenbrody@spamcop.net> - 2017-04-17 12:14 -0400
Re: How to fix warning: [-Wdate-time] Ken Brody <kenbrody@spamcop.net> - 2017-04-17 12:06 -0400
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-17 09:25 -0700
Re: How to fix warning: [-Wdate-time] "James R. Kuyper" <jameskuyper@verizon.net> - 2017-04-17 12:45 -0400
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-17 12:02 -0700
Re: How to fix warning: [-Wdate-time] "James R. Kuyper" <jameskuyper@verizon.net> - 2017-04-17 15:23 -0400
Re: How to fix warning: [-Wdate-time] Lowell Gilbert <lgusenet@be-well.ilk.org> - 2017-04-18 13:27 -0400
Re: How to fix warning: [-Wdate-time] Ken Brody <kenbrody@spamcop.net> - 2017-04-18 14:23 -0400
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-18 12:10 -0700
Re: How to fix warning: [-Wdate-time] raltbos@xs4all.nl (Richard Bos) - 2017-04-22 21:20 +0000
Re: How to fix warning: [-Wdate-time] James Kuyper <jameskuyper@verizon.net> - 2017-04-22 22:45 -0400
Re: How to fix warning: [-Wdate-time] Tim Rentsch <txr@alumni.caltech.edu> - 2017-04-17 11:30 -0700
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-17 12:30 -0700
Re: How to fix warning: [-Wdate-time] raltbos@xs4all.nl (Richard Bos) - 2017-04-22 21:24 +0000
Re: How to fix warning: [-Wdate-time] Tim Rentsch <txr@alumni.caltech.edu> - 2017-04-27 13:33 -0700
Re: How to fix warning: [-Wdate-time] Tim Rentsch <txr@alumni.caltech.edu> - 2017-04-27 13:26 -0700
Re: How to fix warning: [-Wdate-time] gordonb.5zr1e@burditt.org (Gordon Burditt) - 2017-04-14 13:35 -0500
Re: How to fix warning: [-Wdate-time] supercat@casperkitty.com - 2017-04-14 12:17 -0700
Re: How to fix warning: [-Wdate-time] gordonb.k4gmo@burditt.org (Gordon Burditt) - 2017-04-16 00:04 -0500
Re: How to fix warning: [-Wdate-time] Noob <root@127.0.0.1> - 2017-04-16 11:04 +0200
Re: How to fix warning: [-Wdate-time] supercat@casperkitty.com - 2017-04-16 11:52 -0700
Re: How to fix warning: [-Wdate-time] raltbos@xs4all.nl (Richard Bos) - 2017-04-22 21:28 +0000
Re: How to fix warning: [-Wdate-time] Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2017-04-18 21:34 -0600
Re: How to fix warning: [-Wdate-time] Keith Thompson <kst-u@mib.org> - 2017-04-17 08:09 -0700
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