Re: C++ forcing unnecessary changes to C?

From	jacobnavia <jacob@jacob.remcomp.fr>
Newsgroups	comp.lang.c
Subject	Re: C++ forcing unnecessary changes to C?
Date	2016-11-26 20:44 +0100
Organization	A noiseless patient Spider
Message-ID	<o1cok6$vde$1@dont-email.me> (permalink)
References	(5 earlier) <o115k5$84f$1@dont-email.me> <ef0g3cpbude8eivf8ve31aeqdgecemjs61@4ax.com> <ln7f7rb8vr.fsf@kst-u.example.com> <o1ai07$cd4$1@dont-email.me> <c002bed3-4c6e-4085-b5c0-bade2b8ea155@googlegroups.com>

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Le 26/11/2016 à 19:44, supercat@casperkitty.com a écrit :
> There are a number of situations where a single function pointer is
> used to perform some operations that would return something useful, and
> others that wouldn't (perhaps selected with a "mode" parameter); some
> callers will use the return value and some won't.  Failing to specify a
> return value that nothing will care about shouldn't be a defect--a bigger
> defect would be caring about a return value when a function has nothing
> meaningful to return.

That is precisely the mistake. By allowing noise to enter the system, it 
builds a dangerous opportunity for bugs. Now, let's see in detail.

A function is proposed, that should return a valid value "sometimes", 
when the result value is used, I suppose.

So, we have a situation when according to computations local to that 
function, noise or a meaningful value can come out of that function.

When a change needs to be done to some software, a new call to that 
function could be needed. Or that function could be used in a slightly 
different context because of a larger software reorganization.

Is it right to write functions that can return noise sometimes?

If we slightly redesign the function, so that always a valid value is 
returned, the default being EXIT_SUCCESS or zero, we eliminate some noise.

In a debugging situation, a random value is difficult to differentiate 
from actual data. Why has this variable 1285623 as value? Where it was 
computed?

And you start a dead end since that value is just NOISE. Can be 
anything, that value is not a value in fact.

It can be the value of the last operation done with register eax in 
intel/amd machines. Or whatever, something even meaningful in the 
context of the crash, for instance.

To build solid software means avoiding things like this. The language 
can encourage those practices by defining that a non void function must 
always and in all paths of execution return an assigned return value and 
not noise.

Thread

C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 20:34 +0800
  Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-18 05:09 -0800
    Re: C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 21:42 +0800
      Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-18 11:14 -0800
    Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-18 11:10 -0800
      Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-19 15:26 +0100
        Re: C++ forcing unnecessary changes to C? "James R. Kuyper" <jameskuyper@verizon.net> - 2016-11-19 10:09 -0500
          Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-20 13:47 +0100
      Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-21 03:25 -0800
        Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-21 14:15 +0100
          Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-21 05:39 -0800
  Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 14:26 +0100
    Re: C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 21:41 +0800
      Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 15:20 +0100
        Re: conduct in comp.lang.c "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 22:23 +0800
  Re: C++ forcing unnecessary changes to C? Philipp Klaus Krause <pkk@spth.de> - 2016-11-18 15:16 +0100
    Re: C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 22:20 +0800
      Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-18 11:18 -0800
    Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-18 07:15 -0800
      Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 16:55 +0100
        Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-18 08:31 -0800
          Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 17:38 +0100
  Re: C++ forcing unnecessary changes to C? John Bode <jfbode1029@gmail.com> - 2016-11-18 07:09 -0800
    Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-18 07:22 -0800
      Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-18 07:31 -0800
        Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 17:04 +0100
  Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-18 16:37 +0100
    Re: C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 23:53 +0800
    Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-18 08:00 -0800
      Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 17:34 +0100
      Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-18 09:32 -0800
    Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 17:09 +0100
      Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-18 18:02 +0100
        Re: C++ forcing unnecessary changes to C? Robert Wessel <robertwessel2@yahoo.com> - 2016-11-21 03:26 -0600
          Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-22 11:11 +0100
            Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-22 08:55 -0800
            Re: C++ forcing unnecessary changes to C? Robert Wessel <robertwessel2@yahoo.com> - 2016-11-25 03:25 -0600
              Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-25 10:00 -0800
              Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-25 12:30 -0800
                Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-26 00:38 +0100
                Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-26 10:44 -0800
                Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-26 20:44 +0100
                Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-26 12:38 -0800
                Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-26 21:00 +0100
  Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-18 11:04 -0800
    Re: [OT] discipline and obedience "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-19 22:53 +0800
    Re: C & C++ Committee "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-19 22:55 +0800
      Re: C & C++ Committee jameskuyper@verizon.net - 2016-11-19 08:02 -0800
        Re: C & C++ Committee "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-20 00:09 +0800
          Re: C & C++ Committee jameskuyper@verizon.net - 2016-11-19 08:35 -0800
            Re: C & C++ Committee fir <profesor.fir@gmail.com> - 2016-11-19 08:51 -0800
              Re: Do you write C programs? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-20 01:00 +0800
            Re: C & C++ Committee "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-20 00:59 +0800
  Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-22 11:14 +0100
    Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-22 12:05 +0100
      Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-22 14:51 +0100
        Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-22 15:50 +0100
          Re: C++ forcing unnecessary changes to C? BartC <bc@freeuk.com> - 2016-11-22 15:01 +0000
            Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-22 08:58 -0800
              Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-22 18:08 +0100
              Re: C++ forcing unnecessary changes to C? BartC <bc@freeuk.com> - 2016-11-22 18:14 +0000
                Re: C++ forcing unnecessary changes to C? Ian Collins <ian-news@hotmail.com> - 2016-11-23 08:33 +1300
                Re: C++ forcing unnecessary changes to C? BartC <bc@freeuk.com> - 2016-11-22 19:42 +0000
                Re: C++ forcing unnecessary changes to C? Ian Collins <ian-news@hotmail.com> - 2016-11-23 08:51 +1300
                Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-22 12:13 -0800
                Re: C++ forcing unnecessary changes to C? BartC <bc@freeuk.com> - 2016-11-22 21:35 +0000
                Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-23 00:47 +0100
                Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-22 12:09 -0800
                Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-23 00:40 +0100
                Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-26 01:27 +0100
                Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-26 01:48 +0100
              Re: C++ forcing unnecessary changes to C? Nathan Wagner <nw@hydaspes.if.org> - 2016-11-24 18:09 +0000

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