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Groups > comp.lang.c > #43433

Re: Table of "safe" methods to suppress "unused parameter" warnings?

From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: Table of "safe" methods to suppress "unused parameter" warnings?
Date 2014-04-23 08:45 -0700
Organization None to speak of
Message-ID <ln61m0vylr.fsf@nuthaus.mib.org> (permalink)
References (1 earlier) <bpi725FabtcU4@mid.individual.net> <kfnioqwil03.fsf@x-alumni2.alumni.caltech.edu> <bprd8bFfrepU2@mid.individual.net> <kfn8ur6deb1.fsf@x-alumni2.alumni.caltech.edu> <35dd313f-175a-4f7e-bc66-6b0813306a0d@googlegroups.com>

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Öö Tiib <ootiib@hot.ee> writes:
[...]
> I have seen similar situation without preprocessor slicing:
>
>      int
>      do_something( int x, int y ){
>          // y is reserved for postponed feature; must be 0 now
>          unused(y);
>          assert(y == 0); 
>
>          // further code does not use y
>          // ...
>          return  something;
>      }
>
> When 'NDEBUG' is defined then there may be warning without
> that 'unused'.

There is "preprocessor slicing" here; it's just hidden by the
definition of the assert() macro.  Since y is used in an assert(),
it's not really unused.

You could write this as:

    #ifdef NDEBUG
    unused(y);
    #endif
    assert(y == 0);

-- 
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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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

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