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Groups > comp.lang.c > #108232
| From | David Brown <david.brown@hesbynett.no> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: How to fix warning: [-Wdate-time] |
| Date | 2017-04-17 20:04 +0200 |
| Organization | A noiseless patient Spider |
| Message-ID | <od2vtv$o57$1@dont-email.me> (permalink) |
| References | (3 earlier) <ln4lxrugws.fsf@kst-u.example.com> <ocr1he$744$2@dont-email.me> <ocr42a$i2o$1@dont-email.me> <od2j51$b8r$1@dont-email.me> <ln4lxnt6la.fsf@kst-u.example.com> |
On 17/04/17 17:08, Keith Thompson wrote: > David Brown <david.brown@hesbynett.no> writes: >> On 14/04/17 20:26, James Kuyper wrote: >>> On 04/14/2017 01:42 PM, Ken Brody wrote: >>>> On 4/14/2017 11:50 AM, Keith Thompson wrote: >>> ... >>>>> Why can't you just invoke the compiler without the "-Wdate-time" option, >>>>> or with "-Wno-date-time"? >>>> >>>> Sometimes you only want to disable a warning for a particular piece of code. >>>> Why force an entire project to be compiled with "-Wno-date-time" for one >>>> macro? >>> >>> Because the entire project is one for which the motivations for that >>> warning don't apply? It is really a rather obscure issue to be warning >>> about. >>> >> >> IMHO, it is a very good thing to be warning about. If your program >> contains the macros __DATA__ or __TIME__, then your builds are not >> reproducible. I cannot think of any other way to make a build >> non-deterministic, at least on compilers I have used. >> >> That means that as long as you avoid these macros, you can use the >> generated binary file as a way to check that you have exactly the same >> build as on a previous occasion. If you are working on software where >> you need to check or qualify your builds in a particular manner, this is >> essential. >> >> So my thoughts about how to "fix" this warning is simply to avoid using >> __DATE__ or __TIME__. > > Sure, the -Wdate-date option is useful if you need reproducible builds. > But if you're using __DATE__ and __TIME__, then you apparently *don't* > need reproducible builds. Yes - or you are using the macros without considering the repercussions for reproducible builds. Whatever the OP was thinking originally, I hope that by now he knows the pros and cons of using the macros, and can make an informed decision. > > The OP, Mehdi Amini, seems to want to use both -Wdate-time and > __DATE__/__TIME__, and is looking for (and has found) a way to turn off > the effect of -Wdate-time for just one source file. That seems frankly > silly. It might be reasonable to have __DATE__ and __TIME__ as part of code that is conditionally compiled in debug or development builds, and disabled at a later date. In such circumstances, you may then want to allow the macros in a piece of code that you know will be disabled before "real" builds. > > I can imagine using -Wdate-time by default and comparing object files, > and then making an exception for the one source file that uses __DATE__ > and __TIME__, but the Mehdi's only stated rationale for using > -Wdate-time is that "IMHO this warning exists for a reason". > Presumably he now understands this reason, and can decide what he wants to do about it.
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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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