Re: Regression testing for pointers

From	nick_keighley_nospam@hotmail.com
Newsgroups	comp.lang.c
Subject	Re: Regression testing for pointers
Date	2012-03-12 03:29 -0700
Organization	http://groups.google.com
Message-ID	<32020623.2580.1331548160697.JavaMail.geo-discussion-forums@vbgu10> (permalink)
References	(2 earlier) <jjf6ap$ot3$1@speranza.aioe.org> <jjftfp$ksf$1@dont-email.me> <jjg7o0$hh7$1@speranza.aioe.org> <19145559.3836.1331471399326.JavaMail.geo-discussion-forums@vbas10> <jjium2$4lp$1@speranza.aioe.org>

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On Sunday, March 11, 2012 7:33:27 PM UTC, Don Y wrote:
> On 3/11/2012 6:09 AM, nick_keighley_nospam@hotmail.com wrote:


> [...] Yet that seems to be the most common approach to testing
> nowadays (how many folks have formal specifications, test suites,
> validation procedures, etc.).

there's a system test spec and we have to comply to an international standard. This is verified by an external 3rd party.

> You have to consciously *attack*/challenge a piece of code to
> identify deficiencies.  Where are the boundary conditions?
> What did the developer *not* expect?  etc.
> 
> I tend to be pretty good at coming up with "unexpected"
> operating conditions.  When the developer invariably
> *whines* saying "but you're not supposed to *do* that!"
> I grin and reply, "Then don't LET me!"

I worked in a syetem test department for a while. I collected a list of best excuses "that hardly ever happens", "the customer would never do that" and my all time favourite "but the code says that's what happens!"

<snip>

> >>> Functions such as allocators are very difficult to test. And it 
> >>> might be difficult to just think up suitable tests, without 
> >>> feedback from actual trials.
> >>
> >> How could a "trial" possibly give me more information than I
> >> have available when examining the source?
> >
> > because the real world is a constant surprise
> 
> Engineering is the art of anticipating those surprises!
> In the "ethereal" world of software, this is considerably easier
> than in the physical world  ("What happens if a guy whacks it
> with a 20lb sledge hammer?")

yes but most engineers don't have to cope with millions of potentially interacting parts.

> >> If I know my art,
> >> then I should be able to anticipate damn near every possible
> >> case that the code will encounter -- moreso than an application
> >> is likely to stumble upon in the course of pursuing *its* goal.
> >
> > "should" being the operative word!
> 
> Of course!  That's what makes me good at what I do!  :>

<snip>

> > This is one of the reasons the formal methods approach has been sluggish.
> > In theory you prove a program is correct without ever executing it. But
> > people rarely do this on any large scale.
> 
> Actually, this is common on very large scale projects (which,
> otherwise, would never be able to run a single invocation to
> completion, otherwise).

? why not? Because they don't terminate?

I was talking about actual proofs of correctness. VDM, Z, Sparc. Are these widely used?

> Where it *doesn't* happen is smaller projects, "lone wolf"
> developers, "immature" organizations, etc.  "Pay me now or
> pay me later" is a great mantra when it comes to software
> quality and testing, in general.
> 
> > The writers of the Space Shuttle software might have achieved [] what
> > you're trying to do. At enourmous cost.
> 
> There are many industries where formal testing and validation
> are the norm and "required" practices.

yes. I know. The Space Shuttle software was a step above this. CMM level 5 and all that.

Formal testing is not the same as formal methods

>  Surprisingly, the
> cost for this isn't as great as one would think.  Once a
> module has been validated, that cost is behind you -- any
> future use of the module comes with an *assurance* of proper
> operation (within the constraints of the contract/spec).
> 
> In these environments, you really benefit from code AND
> design reuse.
> 
> OTOH, if you are developing "ad hoc" and testing is left
> to the whims of the developer, chances are you can't
> afford a proper validation environment and you'll just keep
> paying for it in OTHER ways (bugs, feature creep, training,
> etc.) without ever being able to wrap your hands around the
> entire problem.
> 
> [Do you get the impression that I am a big advocate of
> formalized methods?  :> ]

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

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