Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Table of "safe" methods to suppress "unused parameter" warnings? |
| Date | 2014-04-18 08:58 -0700 |
| Organization | None to speak of |
| Message-ID | <lnbnvy6347.fsf@nuthaus.mib.org> (permalink) |
| References | <lgv0nu$8g1$1@dont-email.me> <kfnmwg8ilj0.fsf@x-alumni2.alumni.caltech.edu> <lhbjd8$gi1$1@dont-email.me> <kfnvbu6buv8.fsf@x-alumni2.alumni.caltech.edu> |
Tim Rentsch <txr@alumni.caltech.edu> writes:
> David Brown <david.brown@hesbynett.no> writes:
[...]
>>> mathog <dmathog@gmail.com> writes:
>>>
>>>> Sometimes the same parameter list must be passed to a lot of
>>>> different functions, and some of those will not use all of the
>>>> parameters, resulting in some compilers emitting "unused
>>>> parameter" warnings. Here are all of the methods I have found
>>>> so far for suppressing these [snipping the first kind; the
>>>> second kind] of UNUSED's is more general and it is applied
>>>> within the function like:
>>>>
>>>> int function (x){
>>>> UNUSED(x);
>>>>
>>>> #define UNUSED(x) ((void)x)
>>>> #define UNUSED(x) x=x
>>>> #define UNUSED(x) ( *(volatile typeof(x) *)&(x) = (x); )
>>>> #define UNUSED(x) if(x);
>>>>
>>>> Unfortunately the members of the second set tend to convert the
>>>> "unused parameter" message into some variant of a "this line
>>>> does nothing" message on other compilers. For instance, that is
>>>> what the "x=x" form, which works with gcc does when clang sees
>>>> it. [snip]
[...]
>> I have yet to see any reason to why anyone would need something
>> other than "(void) x;" as a way to say "do nothing with x".
>> [snip]
>
> Then apparently you haven't been paying attention, since one was
> given in the first message of the thread, and quoted both in my
> reply and your response to it (and shown again above).
We have an assertion that compilers "tend to" warn about several
forms of the UNUSED() macro.
Is there a concrete example of a compiler that complains about
((void)x)?
--
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"
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Table of "safe" methods to suppress "unused parameter" warnings? mathog <dmathog@gmail.com> - 2014-03-26 09:54 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Barry Schwarz <schwarzb@dqel.com> - 2014-03-26 10:55 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Keith Thompson <kst-u@mib.org> - 2014-03-26 11:13 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Javier Lopez <j.lopezg@aol.com> - 2014-03-26 19:45 +0100
Re: Table of "safe" methods to suppress "unused parameter" warnings? Kaz Kylheku <kaz@kylheku.com> - 2014-03-26 19:55 +0000
Re: Table of "safe" methods to suppress "unused parameter" warnings? mathog <dmathog@gmail.com> - 2014-03-26 17:01 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Javier Lopez <j.lopezg@aol.com> - 2014-03-27 01:46 +0100
Re: Table of "safe" methods to suppress "unused parameter" warnings? Thomas Jahns <jahns@idontlikespam.dkrz.de> - 2014-03-27 09:34 +0100
Re: Table of "safe" methods to suppress "unused parameter" warnings? gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-27 10:52 +0000
Re: Table of "safe" methods to suppress "unused parameter" warnings? David Brown <david.brown@hesbynett.no> - 2014-03-27 13:10 +0100
Re: Table of "safe" methods to suppress "unused parameter" warnings? Ian Collins <ian-news@hotmail.com> - 2014-03-27 21:50 +1300
Re: Table of "safe" methods to suppress "unused parameter" warnings? Tim Rentsch <txr@alumni.caltech.edu> - 2014-03-29 17:32 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Ian Collins <ian-news@hotmail.com> - 2014-03-31 09:31 +1300
Re: Table of "safe" methods to suppress "unused parameter" warnings? David Brown <david.brown@hesbynett.no> - 2014-03-31 11:31 +0200
Re: Table of "safe" methods to suppress "unused parameter" warnings? Alain Ketterlin <alain@dpt-info.u-strasbg.fr> - 2014-03-31 12:04 +0200
Re: Table of "safe" methods to suppress "unused parameter" warnings? David Brown <david.brown@hesbynett.no> - 2014-03-31 13:55 +0200
Re: Table of "safe" methods to suppress "unused parameter" warnings? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2014-04-01 02:04 +0300
Re: Table of "safe" methods to suppress "unused parameter" warnings? Kaz Kylheku <kaz@kylheku.com> - 2014-03-31 23:37 +0000
Re: Table of "safe" methods to suppress "unused parameter" warnings? David Brown <david.brown@hesbynett.no> - 2014-04-01 10:16 +0200
Re: Table of "safe" methods to suppress "unused parameter" warnings? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2014-05-22 13:10 +0300
Re: Table of "safe" methods to suppress "unused parameter" warnings? Kaz Kylheku <kaz@kylheku.com> - 2014-05-22 12:05 +0000
Re: Table of "safe" methods to suppress "unused parameter" warnings? David Brown <david.brown@hesbynett.no> - 2014-04-01 09:59 +0200
Re: Table of "safe" methods to suppress "unused parameter" warnings? Ian Collins <ian-news@hotmail.com> - 2014-03-31 23:17 +1300
Re: Table of "safe" methods to suppress "unused parameter" warnings? David Brown <david.brown@hesbynett.no> - 2014-03-31 14:05 +0200
Re: Table of "safe" methods to suppress "unused parameter" warnings? Kaz Kylheku <kaz@kylheku.com> - 2014-03-31 15:24 +0000
Re: Table of "safe" methods to suppress "unused parameter" warnings? Tim Rentsch <txr@alumni.caltech.edu> - 2014-04-15 04:26 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Öö Tiib <ootiib@hot.ee> - 2014-04-23 07:31 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Keith Thompson <kst-u@mib.org> - 2014-04-23 08:45 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Tim Rentsch <txr@alumni.caltech.edu> - 2014-03-29 17:21 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? David Brown <david.brown@hesbynett.no> - 2014-03-31 13:26 +0200
Re: Table of "safe" methods to suppress "unused parameter" warnings? James Kuyper <jameskuyper@verizon.net> - 2014-03-31 07:37 -0400
Re: Table of "safe" methods to suppress "unused parameter" warnings? David Brown <david.brown@hesbynett.no> - 2014-03-31 14:12 +0200
Re: Table of "safe" methods to suppress "unused parameter" warnings? Tim Rentsch <txr@alumni.caltech.edu> - 2014-04-18 07:00 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? gazelle@shell.xmission.com (Kenny McCormack) - 2014-04-18 15:02 +0000
Re: Table of "safe" methods to suppress "unused parameter" warnings? Keith Thompson <kst-u@mib.org> - 2014-04-18 08:58 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Tim Rentsch <txr@alumni.caltech.edu> - 2014-04-27 08:11 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? gazelle@shell.xmission.com (Kenny McCormack) - 2014-04-27 15:26 +0000
Re: Table of "safe" methods to suppress "unused parameter" warnings? Tim Rentsch <txr@alumni.caltech.edu> - 2014-06-10 08:30 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2014-06-11 00:57 +0300
Re: Table of "safe" methods to suppress "unused parameter" warnings? Ike Naar <ike@iceland.freeshell.org> - 2014-06-10 22:12 +0000
Re: Table of "safe" methods to suppress "unused parameter" warnings? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2014-06-11 20:25 +0300
Re: Table of "safe" methods to suppress "unused parameter" warnings? Martin Shobe <martin.shobe@yahoo.com> - 2014-06-10 18:59 -0500
Re: Table of "safe" methods to suppress "unused parameter" warnings? Tim Rentsch <txr@alumni.caltech.edu> - 2014-06-11 21:22 -0700
Re: Table of "safe" methods to suppress "unused parameter" warnings? Kaz Kylheku <kaz@kylheku.com> - 2014-04-28 01:40 +0000
Re: Table of "safe" methods to suppress "unused parameter" warnings? David Brown <david.brown@hesbynett.no> - 2014-04-19 17:52 +0200
Re: Table of "safe" methods to suppress "unused parameter" warnings? Siri Crews <chine.bleu@yahoo.com> - 2014-06-11 02:04 -0700
csiph-web