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| From | jacobnavia <jacob@jacob.remcomp.fr> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Mars lander crash |
| Date | 2016-12-09 17:35 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <o2emds$5ek$1@dont-email.me> (permalink) |
| References | <o2e7s1$ea6$1@dont-email.me> <o2e8sg$hp7$1@dont-email.me> <o2ecu8$v73$1@dont-email.me> <o2eel2$614$1@dont-email.me> <o2eg20$b90$1@dont-email.me> |
Le 09/12/2016 à 15:46, David Brown a écrit :
> In the tests without overflow checking, you have code like this:
>
> if (a) {
> x = y + z;
> }
>
> This gives you two paths to check, one of which involves a calculation.
>
> If you add overflow checking, you have this:
>
> if (a) {
> x = y + z;
> if (overflow) {
> doSomethingAboutTheOverflow();
> }
> }
>
> For every calculation with overflow checking, you have added another
> code path to check. If you have not gone down that path, your tests
> don't have full coverage of the code you have written.
>
> If the action on overflows is all the same - jump to safe mode, deploy
> parachutes and airbags, panic, prey, say your last farewells - then it
> is possible that the testing is feasible if you have some way to
> artificially inject overflows in code that you know cannot possible
> /have/ overflows. But if the action on overflows is a recovery, or an
> exception-type mechanism, then you have hugely multiplied up the number
> of possible code paths in each function. Your cyclomatic complexity
> goes through the roof, and instead of /adding/ an hour to your test, you
> are multiplying it by 2 to the power of the number of calculations in a
> function.
>
Sure, the length of the test has gone up.
SO WHAT?
Compared to the serious consequences of an overflow, making the tests
run for more time doesn't seem (for me) a bad idea.
You seem to imply that because testing for overflow and overflow
handling is difficult, it shouldn't be done.
You are not alone with that idea. At ESA apparently they also had this
very bright idea
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Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-09 13:26 +0100
Re: Mars lander crash Richard Heathfield <rjh@cpax.org.uk> - 2016-12-09 12:44 +0000
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 14:53 +0100
Re: Mars lander crash already5chosen@yahoo.com - 2016-12-09 05:58 -0800
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 15:11 +0100
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-09 16:56 +0100
Re: Mars lander crash supercat@casperkitty.com - 2016-12-09 08:51 -0800
Re: Mars lander crash already5chosen@yahoo.com - 2016-12-11 02:23 -0800
Re: Mars lander crash Gareth Owen <gwowen@gmail.com> - 2016-12-11 10:57 +0000
Re: Mars lander crash "James R. Kuyper" <jameskuyper@verizon.net> - 2016-12-11 12:34 -0500
Re: Mars lander crash Robert Wessel <robertwessel2@yahoo.com> - 2016-12-11 23:33 -0600
Re: Mars lander crash Richard Heathfield <rjh@cpax.org.uk> - 2016-12-09 14:22 +0000
Re: Mars lander crash asetofsymbols@gmail.com - 2016-12-09 06:30 -0800
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 15:48 +0100
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 15:46 +0100
Re: Mars lander crash Richard Heathfield <rjh@cpax.org.uk> - 2016-12-09 14:55 +0000
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 16:08 +0100
Re: Mars lander crash Richard Heathfield <rjh@cpax.org.uk> - 2016-12-09 15:52 +0000
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-09 17:35 +0100
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 18:35 +0100
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-09 19:10 +0100
Re: Mars lander crash "James R. Kuyper" <jameskuyper@verizon.net> - 2016-12-09 19:18 -0500
Re: Mars lander crash Keith Thompson <kst-u@mib.org> - 2016-12-09 16:49 -0800
Re: Mars lander crash "J. Clarke" <j.clarke.873638@gmail.com> - 2016-12-20 20:03 -0500
Re: Mars lander crash <william@wilbur.25thandClement.com> - 2016-12-09 22:04 -0800
Re: Mars lander crash supercat@casperkitty.com - 2016-12-10 10:59 -0800
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-11 13:22 +0100
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-11 14:18 +0100
Re: Mars lander crash already5chosen@yahoo.com - 2016-12-11 06:03 -0800
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-11 15:08 +0100
Re: Mars lander crash already5chosen@yahoo.com - 2016-12-11 06:20 -0800
Re: Mars lander crash luser droog <luser.droog@gmail.com> - 2016-12-11 07:08 -0800
Re: Mars lander crash Keith Thompson <kst-u@mib.org> - 2016-12-11 11:56 -0800
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-11 21:05 +0100
Re: Mars lander crash jameskuyper@verizon.net - 2016-12-11 12:57 -0800
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Re: Mars lander crash supercat@casperkitty.com - 2016-12-11 09:23 -0800
Re: Mars lander crash Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-11 14:01 +0000
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-11 15:11 +0100
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-11 18:57 +0100
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-11 19:23 +0100
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-11 19:55 +0100
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-11 20:52 +0100
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-11 23:37 +0100
Re: Mars lander crash supercat@casperkitty.com - 2016-12-11 16:10 -0800
Re: Mars lander crash BartC <bc@freeuk.com> - 2016-12-12 01:13 +0000
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-12 09:53 +0100
Re: Mars lander crash supercat@casperkitty.com - 2016-12-12 08:30 -0800
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-12 09:25 +0100
Re: Mars lander crash supercat@casperkitty.com - 2016-12-11 10:36 -0800
Re: Mars lander crash Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-11 18:46 +0000
Re: Mars lander crash supercat@casperkitty.com - 2016-12-11 09:12 -0800
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-11 18:53 +0100
Re: Mars lander crash Keith Thompson <kst-u@mib.org> - 2016-12-11 12:09 -0800
Re: Mars lander crash Jean-Marc Bourguet <jm@bourguet.org> - 2016-12-11 21:30 +0100
Re: Mars lander crash Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-11 15:50 -0500
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-11 23:02 +0100
Re: Mars lander crash Keith Thompson <kst-u@mib.org> - 2016-12-11 18:29 -0800
Re: Mars lander crash Keith Thompson <kst-u@mib.org> - 2016-12-11 12:03 -0800
Re: Mars lander crash Keith Thompson <kst-u@mib.org> - 2016-12-11 11:55 -0800
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-11 23:42 +0100
Re: Mars lander crash Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-11 14:53 -0800
Re: Mars lander crash Ian Collins <ian-news@hotmail.com> - 2016-12-12 17:09 +1300
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-12 10:00 +0100
Re: Mars lander crash Ian Collins <ian-news@hotmail.com> - 2016-12-12 22:20 +1300
Re: Mars lander crash Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-12 01:28 -0800
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Re: Mars lander crash Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-12 02:43 -0800
Re: Mars lander crash Ian Collins <ian-news@hotmail.com> - 2016-12-13 08:20 +1300
Re: Mars lander crash Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-12 12:57 -0800
Re: Mars lander crash Ian Collins <ian-news@hotmail.com> - 2016-12-13 14:14 +1300
Re: Mars lander crash Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-13 01:19 -0800
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Re: Mars lander crash Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-13 05:16 -0800
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Re: Mars lander crash supercat@casperkitty.com - 2016-12-13 11:45 -0800
Re: Mars lander crash Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-13 23:10 +0000
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-14 10:18 +0100
Re: Mars lander crash Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-14 12:37 +0000
Re: Mars lander crash Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-14 21:31 -0800
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-15 13:26 +0100
Re: Mars lander crash Ian Collins <ian-news@hotmail.com> - 2016-12-12 22:40 +1300
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-12 13:22 +0100
Re: Mars lander crash supercat@casperkitty.com - 2016-12-12 08:35 -0800
Re: Mars lander crash supercat@casperkitty.com - 2016-12-09 08:43 -0800
Re: Mars lander crash Jerry Stuckle <jstucklex@attglobal.net> - 2016-12-09 09:47 -0500
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 16:11 +0100
Re: Mars lander crash Jerry Stuckle <jstucklex@attglobal.net> - 2016-12-09 10:49 -0500
Re: Mars lander crash already5chosen@yahoo.com - 2016-12-09 05:53 -0800
Re: Mars lander crash asetofsymbols@gmail.com - 2016-12-09 06:04 -0800
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 15:09 +0100
Re: Mars lander crash Jerry Stuckle <jstucklex@attglobal.net> - 2016-12-09 10:06 -0500
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 16:32 +0100
Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-09 17:30 +0100
Re: Mars lander crash BartC <bc@freeuk.com> - 2016-12-09 16:42 +0000
Re: Mars lander crash Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-09 11:43 -0500
Re: Mars lander crash Keith Thompson <kst-u@mib.org> - 2016-12-09 08:59 -0800
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Re: Mars lander crash Noob <root@127.0.0.1> - 2016-12-09 16:07 +0100
Re: Mars lander crash David Brown <david.brown@hesbynett.no> - 2016-12-09 16:03 +0100
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Re: Mars lander crash jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-09 21:56 +0100
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Re: Mars lander crash Jerry Stuckle <jstucklex@attglobal.net> - 2016-12-09 22:46 -0500
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