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Re: C Code "sanity checking" tools

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On 08/ 9/11 02:35 AM, Ben Bacarisse wrote:
> Ian Collins<ian-news@hotmail.com>  writes:
>
>> On 08/ 8/11 11:00 PM, Martin Crouch wrote:
>
>>> If I write some code like this:
>>>
>>> #include<stdio.h>
>>> int main(void)
>>> {
>>>     char mystring[5];
>>>
>>>     printf("String:%s\n",mystring);
>>>
>>>     return 0;
>>> }
>>>
>>> It compiles okay (no warnings),  but when runs it has undefined results
>>> because I've not put anything into mystring before attempting to print
>>> it, so it gets whatever garbage is left in memory.
>>>
>>> Are there any "pre-compiler" code analysis tools out there that would
>>> pick up this sort of problem?  The platform is sparc Solaris 10.
>>
>> Unit tests (written first).
>
> I don't think unit tests should be the first line of defence here.  It's
> too common to find a forgiving environment where, say, an uninitialised
> string happens to be a null string, or where a buffer overrun is silent.

My point was if the code was written to pass a test, the bug probably 
wouldn't have been introduced in the first place.

As the answers here show, this kind of problem is a difficult one for 
compilers and lint to pick up.  None that I know will spot this.

-- 
Ian Collins

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Thread

C Code "sanity checking" tools Martin Crouch <spamspamspam@spaml.com> - 2011-08-08 12:00 +0100
  Re: C Code "sanity checking" tools Richard Kettlewell <rjk@greenend.org.uk> - 2011-08-08 12:09 +0100
    Re: C Code "sanity checking" tools Fritz Wuehler <fritz@spamexpire-201108.rodent.frell.theremailer.net> - 2011-08-09 08:50 +0200
      Re: C Code "sanity checking" tools Måns Rullgård <mans@mansr.com> - 2011-08-09 10:55 +0100
        Re: C Code "sanity checking" tools Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-09 14:15 +0100
        Re: C Code "sanity checking" tools Nomen Nescio <nobody@dizum.com> - 2011-08-10 01:58 +0200
        Re: C Code "sanity checking" tools Nomen Nescio <nobody@dizum.com> - 2011-08-10 12:29 +0200
      Re: C Code "sanity checking" tools Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-09 14:17 +0100
        Re: C Code "sanity checking" tools Keith Thompson <kst-u@mib.org> - 2011-08-09 09:17 -0700
          Re: C Code "sanity checking" tools Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-09 17:36 +0100
            Re: C Code "sanity checking" tools Keith Thompson <kst-u@mib.org> - 2011-08-09 12:19 -0700
              Re: C Code "sanity checking" tools Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-09 20:36 +0100
                Re: C Code "sanity checking" tools Michael Press <rubrum@pacbell.net> - 2011-08-09 19:24 -0700
                Re: C Code "sanity checking" tools Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-10 10:27 +0100
                Re: C Code "sanity checking" tools Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-10 14:01 +0100
                Re: C Code "sanity checking" tools "io_x" <a@b.c.invalid> - 2011-08-13 09:42 +0200
                Re: C Code "sanity checking" tools Keith Thompson <kst-u@mib.org> - 2011-08-13 16:04 -0700
                Re: C Code "sanity checking" tools Rainer Weikusat <rweikusat@mssgmbh.com> - 2011-08-14 19:46 +0100
  Re: C Code "sanity checking" tools Ian Collins <ian-news@hotmail.com> - 2011-08-08 23:12 +1200
    Re: C Code "sanity checking" tools Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-08 15:35 +0100
      Re: C Code "sanity checking" tools Martin Crouch <spamspamspam@spaml.com> - 2011-08-08 16:05 +0100
        Re: C Code "sanity checking" tools Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-08 22:57 +0100
          Re: C Code "sanity checking" tools Måns Rullgård <mans@mansr.com> - 2011-08-08 23:32 +0100
      Re: C Code "sanity checking" tools Ian Collins <ian-news@hotmail.com> - 2011-08-09 08:03 +1200
        Re: C Code "sanity checking" tools Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-08 22:51 +0100
          Re: C Code "sanity checking" tools Ian Collins <ian-news@hotmail.com> - 2011-08-09 10:01 +1200
    Re: C Code "sanity checking" tools jt@toerring.de (Jens Thoms Toerring) - 2011-08-08 22:06 +0000
      Re: C Code "sanity checking" tools Ian Collins <ian-news@hotmail.com> - 2011-08-09 10:18 +1200
        Re: C Code "sanity checking" tools jt@toerring.de (Jens Thoms Toerring) - 2011-08-08 23:25 +0000
  Re: C Code "sanity checking" tools Nobody <nobody@nowhere.com> - 2011-08-08 14:01 +0100
    Re: C Code "sanity checking" tools Måns Rullgård <mans@mansr.com> - 2011-08-08 14:47 +0100
      Re: C Code "sanity checking" tools Martin Crouch <spamspamspam@spaml.com> - 2011-08-08 16:08 +0100
        Re: C Code "sanity checking" tools Marc <marc.glisse@gmail.com> - 2011-08-08 15:39 +0000
      Re: C Code "sanity checking" tools William Ahern <william@wilbur.25thandClement.com> - 2011-08-08 10:20 -0700
      Re: C Code "sanity checking" tools Nobody <nobody@nowhere.com> - 2011-08-09 00:59 +0100
  Re: C Code "sanity checking" tools mathog <dmathog@gmail.com> - 2011-08-08 08:48 -0700

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