Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #18737

Re: Regression testing for pointers

Path csiph.com!usenet.pasdenom.info!news.albasani.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail
From Ian Collins <ian-news@hotmail.com>
Newsgroups comp.lang.c
Subject Re: Regression testing for pointers
Date Wed, 14 Mar 2012 13:12:28 +1300
Lines 50
Message-ID <9sa63cF8igU3@mid.individual.net> (permalink)
References <jje4jg$l8k$1@speranza.aioe.org>
Mime-Version 1.0
Content-Type text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding 7bit
X-Trace individual.net ThxMgVwtXqQHW96ZcnimTQwwsTRYmPYHLwmlyNLc7/SEsvhaeE
Cancel-Lock sha1:KqJz3Q9NXyT7ZSb9rRp80pHuWt4=
User-Agent Mozilla/5.0 (X11; SunOS i86pc; rv:7.0.1) Gecko/20111228 Thunderbird/7.0.1
In-Reply-To <jje4jg$l8k$1@speranza.aioe.org>
Xref csiph.com comp.lang.c:18737

Show key headers only | View raw

On 03/10/12 12:43 PM, Don Y wrote:
> Hi,
>
> There's rarely a problem generating regression tests for
> functions/procedures that use concrete *values*:
>
> sqrt.test
>
> 3 -->  1.732
> 4 -->  2
> 5 -->  2.236
>
> (apologies if I have misremembered any of these values  :>  )
>
> And, it is easy to erect the necessary scaffolding for those
> sorts of tests without introducing any noticeable uncertainty
> in the veracity of the results obtained.
>
> But, I can't see a way to handle this sort of testing on
> functions that manipulate *pointers* to objects -- without
> adding a fair bit of code to the scaffolding that, itself,
> represents a testing issue!  (i.e., does the scaffolding
> have any bugs that result in false positives or negatives??)
>
> In particular, I am trying to develop a test suite for my
> dynamic memory management functions (e.g., malloc and free
> types of routines).
>
> I.e., I can't come up with "constant" results against
> which to compare test-time results.  Sticking with the
> traditional malloc/free for example (my routines are
> more heavily parameterized), I can create a malloc.test
> that pushes size_t's to malloc.  But, aside from verifying
> the result is not NULL (or, *is* NULL, in some cases!),
> there's nothing I can do to check that the result is
> actually correct!
>
> [Recall, the location and size of the free store might change
> from environment to environment; alignment constraints might
> vary, etc.]

With the hindsight gained from a few days of posts, one simple and 
obvious solution is to consider your allocator as a normal function that 
returns predetermined values.  Not pointers to usable memory, just values.

You can then writes your tests to test for your expected values.  Just 
don't try and dereference the values!

-- 
Ian Collins

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-09 16:43 -0700
  Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-10 12:56 +1300
    Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-09 19:40 -0700
      Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-10 17:53 +1300
        Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-10 18:12 +1300
        Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-10 02:05 -0700
          Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-10 23:17 +1300
            Re: Regression testing for pointers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-03-10 12:00 +0000
              Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-11 11:00 +1300
                Re: Regression testing for pointers Ike Naar <ike@iceland.freeshell.org> - 2012-03-10 22:23 +0000
                Re: Regression testing for pointers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-03-10 22:40 +0000
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-11 12:12 +1300
                Re: Regression testing for pointers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-03-11 00:42 +0000
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-11 14:26 +1300
                Re: Regression testing for pointers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-03-11 03:09 +0000
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-11 18:16 +1300
            Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-10 12:01 -0700
              Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-11 10:35 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-12 09:19 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-13 07:23 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-12 16:23 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-13 17:25 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-13 00:19 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-13 20:34 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-13 01:00 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-13 21:22 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-13 10:19 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-14 07:25 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-14 02:00 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-14 22:18 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-14 11:32 -0700
                Re: Regression testing for pointers nick_keighley_nospam@hotmail.com - 2012-03-15 05:58 -0700
                Re: Regression testing for pointers nick_keighley_nospam@hotmail.com - 2012-03-15 05:55 -0700
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-15 11:32 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-16 18:14 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-20 01:43 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-20 21:59 +1300
                Re: Regression testing for pointers nick_keighley_nospam@hotmail.com - 2012-03-16 03:05 -0700
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-20 02:33 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-24 11:49 +1300
          Re: Regression testing for pointers nick_keighley_nospam@hotmail.com - 2012-03-11 05:01 -0700
            Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-11 09:44 -0700
              Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-12 09:56 +1300
    Re: Regression testing for pointers nick_keighley_nospam@hotmail.com - 2012-03-10 02:28 -0800
      Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-10 11:09 -0700
      Re: Regression testing for pointers Kaz Kylheku <kaz@kylheku.com> - 2012-03-10 18:29 +0000
        Re: Regression testing for pointers nick_keighley_nospam@hotmail.com - 2012-03-11 05:22 -0700
          Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-11 09:50 -0700
            Re: Regression testing for pointers "io_x" <a@b.c.invalid> - 2012-03-13 13:09 +0100
  Re: Regression testing for pointers Kaz Kylheku <kaz@kylheku.com> - 2012-03-10 03:14 +0000
    Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-10 12:42 -0700
  Re: Regression testing for pointers Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-03-10 08:42 +0000
    Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-10 02:19 -0700
      Re: Regression testing for pointers "BartC" <bc@freeuk.com> - 2012-03-10 15:54 +0000
        Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-10 11:49 -0700
          Re: Regression testing for pointers nick_keighley_nospam@hotmail.com - 2012-03-11 06:09 -0700
            Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-11 12:33 -0700
              Re: Regression testing for pointers nick_keighley_nospam@hotmail.com - 2012-03-12 03:29 -0700
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-12 10:01 -0700
                Re: Regression testing for pointers "BartC" <bc@freeuk.com> - 2012-03-13 18:56 +0000
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-13 16:31 -0700
      Re: Regression testing for pointers Jorgen Grahn <grahn+nntp@snipabacken.se> - 2012-03-12 00:30 +0000
        Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-12 16:41 -0700
      Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-12 13:39 +1300
        Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-12 09:36 -0700
          Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-13 07:25 +1300
            Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-12 16:28 -0700
              Re: Regression testing for pointers Kaz Kylheku <kaz@kylheku.com> - 2012-03-13 04:20 +0000
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-13 17:34 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-13 00:29 -0700
              Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-13 17:31 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-13 01:05 -0700
                Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-13 21:30 +1300
                Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-13 10:43 -0700
  Re: Regression testing for pointers Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-03-10 15:41 -0800
    Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-11 11:23 -0700
      Re: Regression testing for pointers Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-03-13 13:43 -0700
        Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-14 01:45 -0700
          Re: Regression testing for pointers Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-03-14 15:15 -0700
            Re: Regression testing for pointers Kaz Kylheku <kaz@kylheku.com> - 2012-03-14 22:57 +0000
              Re: Regression testing for pointers Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-03-15 13:10 -0700
                Re: Regression testing for pointers jgk@panix.com (Joe keane) - 2012-03-16 22:20 +0000
                Re: Regression testing for pointers "io_x" <a@b.c.invalid> - 2012-03-18 07:15 +0100
            Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-14 23:13 -0700
  Re: Regression testing for pointers gordonb.b29ri@burditt.org (Gordon Burditt) - 2012-03-12 19:37 -0500
    Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-12 19:23 -0700
  Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-14 13:12 +1300
    Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-14 01:54 -0700
      Re: Regression testing for pointers Ian Collins <ian-news@hotmail.com> - 2012-03-14 22:05 +1300
        Re: Regression testing for pointers Don Y <this@isnotme.com> - 2012-03-14 11:54 -0700

csiph-web