Re: is there anything unstandard in the c part here

From	"J. J. Farrell" <jjf@bcs.org.uk>
Newsgroups	comp.lang.c
Subject	Re: is there anything unstandard in the c part here
Date	2011-08-14 04:00 +0100
Organization	A noiseless patient Spider
Message-ID	<j27doe$rgi$1@dont-email.me> (permalink)
References	(4 earlier) <87y5zce4mc.fsf@gmail.com> <TaGdnRol5PU-saXTnZ2dnUVZ_oydnZ2d@bestweb.net> <f18bc647-5cef-46b7-84d1-aa42d207d57a@y24g2000yqb.googlegroups.com> <j1tti6$692$1@dont-email.me> <87k4ahbx5h.fsf@gmail.com>

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Gareth Owen wrote:
> James Kuyper <jameskuyper@verizon.net> writes:
> 
>> Being more direct won't help. He's been repeatedly asked to provide an
>> example, and so far the only bug he's presented would have remained a
>> bug, and remained hidden, even after the cast was "corrected", so it was
>> clearly not the cast which was hiding the bug.
> 
> Stop being a dick, James. The bug becomes a compile time error.
> 
> float * foo;
> // elision
> foo = (float*) malloc(256*sizeof(float));
> 
> becomes
> 
> double * foo;
> foo = (float*) malloc(256*sizeof(float));
> 
> Compile time error. Do you really think someone would fix that compile
> time error by changing *JUST THE CAST*? 

Err ... yes, certainly. I've seen exactly that done, many times, by many 
people.

> foo = (float*)  malloc(256*sizeof(float));
> foo = (double*) malloc(256*sizeof(float));
> 
> "Ohh, the bug is still there."  Yes it is, because you've sent a moron
> to fix it, who doesn't look at the context of the code, and who thinks
> type safety is just fixing casts and hoping for the best.

And because you had a moron write it in a way which wasn't safe in the 
first place, which caused the requirement for it to be "fixed" at all, 
and which included an unhelpful cast which distracted from the unsafe 
code which was the real problem.

> Do you really believe that's how to use the idiom for defensive
> programming?  Nice strawman. The point is, the cast is working as a
> static assertion, flagging the assumption made within size calculation.

If you can be certain that everyone who will ever work on this code in 
the future has been trained to know that an incompatible type warning is 
of course really an indication that the size of the allocation is wrong, 
then yes, it works in that way.

But why make and rely on that remarkable assumption when you can just 
write the allocation in a way which avoids it ever being wrong and ever 
needing to be changed if the type changes?

> The fix is not to change the assertion until you've changed the
> calculation.
> 
> double * foo;
> // elision
> foo = malloc(256*sizeof(float));
> 
> Nasal demons.

The fix is never to write allocations in such a silly way.

Thread

is there anything unstandard in the c part here Uno <Uno@example.invalid> - 2011-07-25 17:45 -0600
  Re: is there anything unstandard in the c part here John Gordon <gordon@panix.com> - 2011-07-25 23:53 +0000
    Re: is there anything unstandard in the c part here gwowen <gwowen@gmail.com> - 2011-07-26 01:50 -0700
      Re: is there anything unstandard in the c part here tom st denis <tom@iahu.ca> - 2011-07-26 06:17 -0700
        Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-07-26 11:08 -0400
          Re: is there anything unstandard in the c part here tom st denis <tom@iahu.ca> - 2011-07-26 10:51 -0700
            Re: is there anything unstandard in the c part here Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-07-27 00:08 -0700
              Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-07-27 13:41 -0400
                Re: is there anything unstandard in the c part here Angel <angel+news@spamcop.net> - 2011-07-28 10:58 +0000
                Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-28 13:58 +0100
            Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-07-27 13:24 -0400
              Re: is there anything unstandard in the c part here Angel <angel+news@spamcop.net> - 2011-07-28 11:07 +0000
                Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-07-28 13:02 -0400
                Re: is there anything unstandard in the c part here Roberto Waltman <usenet@rwaltman.com> - 2011-07-28 17:16 -0400
      Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-26 09:39 -0400
        Re: is there anything unstandard in the c part here Gareth Owen <gwowen@gmail.com> - 2011-07-27 07:24 +0100
          Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-27 07:11 -0400
          Re: is there anything unstandard in the c part here Noob <root@127.0.0.1> - 2011-07-27 15:20 +0200
          Re: is there anything unstandard in the c part here John Gordon <gordon@panix.com> - 2011-07-27 14:25 +0000
            Re: is there anything unstandard in the c part here Keith Thompson <kst-u@mib.org> - 2011-07-27 08:10 -0700
              Re: is there anything unstandard in the c part here John Gordon <gordon@panix.com> - 2011-07-27 17:42 +0000
                Re: is there anything unstandard in the c part here Keith Thompson <kst-u@mib.org> - 2011-07-27 12:02 -0700
                Re: is there anything unstandard in the c part here Tim Rentsch <txr@alumni.caltech.edu> - 2011-07-28 16:04 -0700
                Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-27 22:35 -0400
          Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-07-27 13:34 -0400
            Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-28 02:13 +0100
              Re: is there anything unstandard in the c part here Ike Naar <ike@sverige.freeshell.org> - 2011-07-28 07:33 +0000
                Re: is there anything unstandard in the c part here Willem <willem@toad.stack.nl> - 2011-07-28 07:58 +0000
                Re: is there anything unstandard in the c part here pete <pfiland@mindspring.com> - 2011-07-28 04:25 -0400
                Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-28 12:26 +0100
            Re: is there anything unstandard in the c part here gwowen <gwowen@gmail.com> - 2011-07-28 04:24 -0700
              Re: is there anything unstandard in the c part here Angel <angel+news@spamcop.net> - 2011-07-28 11:36 +0000
                Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-28 15:11 +0100
                Re: is there anything unstandard in the c part here Angel <angel+news@spamcop.net> - 2011-07-28 14:50 +0000
                Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-28 17:28 +0100
                Re: is there anything unstandard in the c part here Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-07-28 10:38 -0600
                Re: is there anything unstandard in the c part here Michael Press <rubrum@pacbell.net> - 2011-08-02 17:20 -0700
                Re: is there anything unstandard in the c part here Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-08-02 23:26 -0600
                Re: is there anything unstandard in the c part here Michael Press <rubrum@pacbell.net> - 2011-08-03 16:09 -0700
                Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-07-28 13:22 -0400
                Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-28 22:22 -0400
                Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-29 04:17 +0100
                Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-28 23:40 -0400
                Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-29 13:52 +0100
                Re: is there anything unstandard in the c part here Gareth Owen <gwowen@gmail.com> - 2011-07-31 09:19 +0100
                Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-31 09:49 -0400
                Re: is there anything unstandard in the c part here Gareth Owen <gwowen@gmail.com> - 2011-08-02 06:56 +0100
                Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-08-02 06:53 -0400
              Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-28 07:36 -0400
              Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-07-28 13:16 -0400
      Re: is there anything unstandard in the c part here John Gordon <gordon@panix.com> - 2011-07-26 14:58 +0000
        Re: is there anything unstandard in the c part here Paul N <gw7rib@aol.com> - 2011-07-26 14:56 -0700
          Re: is there anything unstandard in the c part here Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-07-27 00:13 -0700
          Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-27 07:28 -0400
            Re: is there anything unstandard in the c part here Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-07-27 04:44 -0700
            Re: is there anything unstandard in the c part here Keith Thompson <kst-u@mib.org> - 2011-07-27 08:24 -0700
              Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-27 22:41 -0400
                Re: is there anything unstandard in the c part here Tim Rentsch <txr@alumni.caltech.edu> - 2011-07-28 16:19 -0700
              Re: is there anything unstandard in the c part here Tim Rentsch <txr@alumni.caltech.edu> - 2011-07-28 16:06 -0700
              Re: is there anything unstandard in the c part here Uno <Uno@example.invalid> - 2011-07-30 01:54 -0600
      Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-07-26 11:01 -0400
        Re: is there anything unstandard in the c part here Chad <cdalten@gmail.com> - 2011-07-26 09:49 -0700
          Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-07-26 13:18 -0400
          Re: is there anything unstandard in the c part here John Gordon <gordon@panix.com> - 2011-07-26 17:44 +0000
          Re: is there anything unstandard in the c part here Angel <angel+news@spamcop.net> - 2011-07-26 17:45 +0000
          Re: is there anything unstandard in the c part here Seebs <usenet-nospam@seebs.net> - 2011-07-26 18:42 +0000
            Re: is there anything unstandard in the c part here Bill Waddington <william.waddington@beezmo.com> - 2011-07-26 11:55 -0700
              Re: is there anything unstandard in the c part here lawrence.jones@siemens.com - 2011-07-26 18:11 -0400
                Re: is there anything unstandard in the c part here Uno <Uno@example.invalid> - 2011-07-27 20:58 -0600
            Re: is there anything unstandard in the c part here arnuld <sunrise@invalid.address> - 2011-08-02 05:24 +0000
              Re: is there anything unstandard in the c part here Ian Collins <ian-news@hotmail.com> - 2011-08-02 18:10 +1200
              Re: is there anything unstandard in the c part here Keith Thompson <kst-u@mib.org> - 2011-08-02 00:03 -0700
              Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-08-02 06:59 -0400
              Re: is there anything unstandard in the c part here Seebs <usenet-nospam@seebs.net> - 2011-08-02 16:06 +0000
      Re: is there anything unstandard in the c part here Seebs <usenet-nospam@seebs.net> - 2011-07-26 18:42 +0000
      Re: is there anything unstandard in the c part here Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-07-27 00:06 -0700
        Re: is there anything unstandard in the c part here Gareth Owen <gwowen@gmail.com> - 2011-08-02 06:58 +0100
          Re: is there anything unstandard in the c part here Keith Thompson <kst-u@mib.org> - 2011-08-02 00:01 -0700
            Re: is there anything unstandard in the c part here Gareth Owen <gwowen@gmail.com> - 2011-08-05 06:22 +0100
              Re: is there anything unstandard in the c part here Keith Thompson <kst-u@mib.org> - 2011-08-04 23:54 -0700
              Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-08-05 07:37 -0400
                Re: is there anything unstandard in the c part here Gareth Owen <gwowen@gmail.com> - 2011-08-13 08:05 +0100
                Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-08-13 08:26 -0400
                Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-13 14:09 +0100
          Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-08-02 12:58 -0400
            Re: is there anything unstandard in the c part here Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-08-10 01:31 -0700
              Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-08-10 08:28 -0400
                Re: is there anything unstandard in the c part here Gareth Owen <gwowen@gmail.com> - 2011-08-13 08:14 +0100
                Re: is there anything unstandard in the c part here "io_x" <a@b.c.invalid> - 2011-08-13 10:08 +0200
                Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-08-13 08:35 -0400
                Re: is there anything unstandard in the c part here "J. J. Farrell" <jjf@bcs.org.uk> - 2011-08-14 04:00 +0100
                Re: is there anything unstandard in the c part here Kenneth Brody <kenbrody@spamcop.net> - 2011-08-15 14:43 -0400
          Re: is there anything unstandard in the c part here Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-08-10 01:34 -0700
            Re: is there anything unstandard in the c part here Gareth Owen <gwowen@gmail.com> - 2011-08-13 08:16 +0100
  Re: is there anything unstandard in the c part here Barry Schwarz <schwarzb@dqel.com> - 2011-07-25 17:52 -0700
    Re: is there anything unstandard in the c part here "J. J. Farrell" <jjf@bcs.org.uk> - 2011-07-26 02:10 +0100
    Re: is there anything unstandard in the c part here Seebs <usenet-nospam@seebs.net> - 2011-07-26 06:17 +0000
      Re: is there anything unstandard in the c part here Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-07-26 00:03 -0700
        Re: is there anything unstandard in the c part here "Kleuskes & Moos" <kleuske@xs4all.nl> - 2011-07-26 00:08 -0700
        Re: is there anything unstandard in the c part here Ian Collins <ian-news@hotmail.com> - 2011-07-26 19:43 +1200
        Re: is there anything unstandard in the c part here Seebs <usenet-nospam@seebs.net> - 2011-07-26 07:56 +0000
          Re: is there anything unstandard in the c part here Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-07-26 04:50 -0700
            Re: is there anything unstandard in the c part here Angel <angel+news@spamcop.net> - 2011-07-26 12:03 +0000
            Re: is there anything unstandard in the c part here Seebs <usenet-nospam@seebs.net> - 2011-07-26 18:42 +0000
            Re: is there anything unstandard in the c part here Nobody <nobody@nowhere.com> - 2011-07-27 19:10 +0100
        Re: is there anything unstandard in the c part here Angel <angel+news@spamcop.net> - 2011-07-26 11:53 +0000
  Re: is there anything unstandard in the c part here Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-07-26 00:07 -0700
    Re: is there anything unstandard in the c part here James Kuyper <jameskuyper@verizon.net> - 2011-07-26 06:29 -0400
      Re: is there anything unstandard in the c part here Uno <Uno@example.invalid> - 2011-07-27 21:32 -0600
        Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-28 12:19 +0100
          Re: is there anything unstandard in the c part here pete <pfiland@mindspring.com> - 2011-07-28 20:25 -0400
            Re: is there anything unstandard in the c part here Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-07-28 18:38 -0600
              Re: is there anything unstandard in the c part here pete <pfiland@mindspring.com> - 2011-07-28 21:05 -0400
          Re: is there anything unstandard in the c part here "Morris Keesan" <mkeesan@post.harvard.edu> - 2011-07-29 14:16 -0400
            Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-29 20:27 +0100
            Re: is there anything unstandard in the c part here Uno <Uno@example.invalid> - 2011-07-30 01:10 -0600
          Re: is there anything unstandard in the c part here Uno <Uno@example.invalid> - 2011-07-30 00:56 -0600
            Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-07-30 12:23 +0100
              Re: is there anything unstandard in the c part here Uno <Uno@example.invalid> - 2011-08-01 00:01 -0600
                Re: is there anything unstandard in the c part here Ike Naar <ike@sverige.freeshell.org> - 2011-08-01 07:50 +0000
                Re: is there anything unstandard in the c part here Uno <Uno@example.invalid> - 2011-08-01 07:43 -0600
                Re: is there anything unstandard in the c part here Ike Naar <ike@sdf.lonestar.org> - 2011-08-01 15:20 +0000
                Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-01 14:27 +0100
                Re: is there anything unstandard in the c part here Uno <Uno@example.invalid> - 2011-08-01 08:02 -0600
                Re: is there anything unstandard in the c part here Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-08-01 15:42 +0100

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