Re: I am learning C: a little problem with a simple source code

From	Markus Wichmann <nullplan@gmx.net>
Newsgroups	comp.lang.c
Subject	Re: I am learning C: a little problem with a simple source code
Date	2012-01-28 14:11 +0100
Organization	1&1 Internet AG
Message-ID	<dp8dv8-dj5.ln1@voyager.wichi.de.vu> (permalink)
References	<jfrt8u$1ru$1@reader1.panix.com> <c8bebc7ce903ec5c189bb144c96eea2e@msgid.frell.theremailer.net>

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On 27.01.2012 20:28, Fritz Wuehler wrote:
>> Tim Rentsch wrote:
>>> Second, mandating ever more cases of required diagnostics only
>>> increases the incentive for an implementation to have its default mode
>>> be a non-conforming one.
> 
> Oh I don't think they need any more incentive than they already have. gcc is
> a prime example of non-conformance for non-conformance's sake. 
> 
> Joe wrote:
>>
>> But it's just enforcing the rules that apply to every other function.
>>
>> hdr1.h:
>> 	int f(int *x, float y);
>>
>> hdr2.h:
>> 	int f(long *x, double y);
>>
>> We know that is going to cause trouble, why not warn about it?
> 
> C is a shitty unsafe language designed to be easy to implement. It's been
> applied so inappropriately for so long, no amount of "standardizing" is ever
> going to fix that.

Care to elaborate? What do you mean by unsafe and inappropriate?

> Given the miserable state of the "art" (gcc) it seems
> ill advised to add more bloat and complexity to what is already a house of
> cards on the verge of "The Big One". Better to keep static analysis tools
> like various version of lint, splint etc. up to date with (optional?)
> regression test-like suites of checks for known, bad code.

Well, you could also try to do formal verification, but that takes much
work.

> Typical Linux
> apps already compile with hundreds or thousands of warnings and everybody
> already ignores them.

Well, the thing is, a warning means "you wrote valid C code, but you
used a construction that does something you probably don't want".
However, sometimes I actually know what I'm doing and I refuse to change
my code for the sake of removing a warning if it destroys clarity.

> Very few people are inclined to write correct, safe
> code and of those people only a small percentage of them use C. There are
> better things to spend your time on than improving C compiler diagnostics.

Well, there's the hen-and-egg problem: Actually, nearly every program
contains C code, be it in form of the compiler or the interpreter of
something not C. The only exceptions I know of are freepascal, which is
written in Pascal, and g++, which is written in C++. And even those use
the libc, which is written in C.

> External tools are a better value and probably offer a better platform to do
> those checks from than inside a burning house like gcc. I realize there are
> plenty of C compilers around but unfortunately gcc is the most popular and
> so are forks of it.
> 

Well, you can make your checks part of the compiler or leave the stuff
standalone, I don't see much difference there. Just that it might be
easier to check an AST instead of a raw .c file and you might just take
advantage of the fact that gcc has to build it!

Ciao,
Markus

Thread

I am learning C: a little problem with a simple source code zemir <zemir_fp@libero.it> - 2011-11-01 08:27 -0700
  Re: I am learning C: a little problem with a simple source code Mark Bluemel <mark_bluemel@pobox.com> - 2011-11-01 15:49 +0000
  Re: I am learning C: a little problem with a simple source code nroberts <roberts.noah@gmail.com> - 2011-11-01 08:52 -0700
  Re: I am learning C: a little problem with a simple source code jt@toerring.de (Jens Thoms Toerring) - 2011-11-01 16:22 +0000
  Re: I am learning C: a little problem with a simple source code Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-01 09:31 -0700
    Re: I am learning C: a little problem with a simple source code Ike Naar <ike@sverige.freeshell.org> - 2011-11-01 16:57 +0000
      Re: I am learning C: a little problem with a simple source code zemir <zemir_fp@libero.it> - 2011-11-01 11:51 -0700
        Re: I am learning C: a little problem with a simple source code James Kuyper <jameskuyper@verizon.net> - 2011-11-01 15:04 -0400
          Re: I am learning C: a little problem with a simple source code Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-01 20:21 +0000
            Re: I am learning C: a little problem with a simple source code jacob navia <jacob@spamsink.net> - 2011-11-01 21:41 +0100
        Re: I am learning C: a little problem with a simple source code Ian Collins <ian-news@hotmail.com> - 2011-11-02 08:06 +1300
          Re: I am learning C: a little problem with a simple source code zemir <zemir_fp@libero.it> - 2011-11-01 13:17 -0700
            Re: I am learning C: a little problem with a simple source code James Kuyper <jameskuyper@verizon.net> - 2011-11-01 16:24 -0400
              Re: I am learning C: a little problem with a simple source code zemir <zemir_fp@libero.it> - 2011-11-01 13:27 -0700
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2011-11-01 20:24 -0700
                Re: I am learning C: a little problem with a simple source code gazelle@shell.xmission.com (Kenny McCormack) - 2011-11-02 10:24 +0000
                Re: I am learning C: a little problem with a simple source code "BartC" <bc@freeuk.com> - 2011-11-02 11:04 +0000
                Re: I am learning C: a little problem with a simple source code James Kuyper <jameskuyper@verizon.net> - 2011-11-02 07:41 -0400
                Re: I am learning C: a little problem with a simple source code Seebs <usenet-nospam@seebs.net> - 2011-11-02 18:00 +0000
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2011-11-02 14:06 -0700
                Re: I am learning C: a little problem with a simple source code John Bode <jfbode1029@gmail.com> - 2011-11-03 15:05 -0700
                Re: I am learning C: a little problem with a simple source code Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 22:55 -0800
                Re: I am learning C: a little problem with a simple source code jgk@panix.com (Joe keane) - 2012-01-26 15:59 +0000
                Re: I am learning C: a little problem with a simple source code Fritz Wuehler <fritz@spamexpire-201201.rodent.frell.theremailer.net> - 2012-01-27 20:28 +0100
                Re: I am learning C: a little problem with a simple source code Markus Wichmann <nullplan@gmx.net> - 2012-01-28 14:11 +0100
                Re: I am learning C: a little problem with a simple source code Shao Miller <sha0.miller@gmail.com> - 2012-01-29 09:34 -0500
                Re: I am learning C: a little problem with a simple source code Markus Wichmann <nullplan@gmx.net> - 2012-01-30 13:38 +0100
                Re: I am learning C: a little problem with a simple source code Shao Miller <sha0.miller@gmail.com> - 2012-01-30 12:10 -0500
                Re: I am learning C: a little problem with a simple source code Zoltan Kocsi <zoltan@bendor.com.au> - 2012-01-29 08:55 +1100
                Re: I am learning C: a little problem with a simple source code Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-31 21:48 -0800
                Re: I am learning C: a little problem with a simple source code Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-31 21:46 -0800
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2012-01-31 22:30 -0800
                Re: I am learning C: a little problem with a simple source code Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-08 10:11 -0800
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2012-03-08 13:51 -0800
                Re: I am learning C: a little problem with a simple source code Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-09 12:51 -0800
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2012-03-09 13:36 -0800
                Re: I am learning C: a little problem with a simple source code jacob navia <jacob@spamsink.net> - 2012-03-09 23:50 +0100
                Re: I am learning C: a little problem with a simple source code Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-09 15:01 -0800
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2012-03-09 16:21 -0800
                Re: I am learning C: a little problem with a simple source code gazelle@shell.xmission.com (Kenny McCormack) - 2012-03-10 00:57 +0000
                Re: I am learning C: a little problem with a simple source code jacob navia <jacob@spamsink.net> - 2012-03-10 13:37 +0100
                Re: I am learning C: a little problem with a simple source code gazelle@shell.xmission.com (Kenny McCormack) - 2012-03-10 13:58 +0000
                Re: I am learning C: a little problem with a simple source code Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-10 12:24 -0800
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2012-03-10 14:16 -0800
                Re: I am learning C: a little problem with a simple source code Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-11 12:50 -0700
                Re: I am learning C: a little problem with a simple source code Philip Lantz <prl@canterey.us> - 2012-03-11 00:57 -0800
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2012-03-11 03:20 -0700
                Re: I am learning C: a little problem with a simple source code Philip Lantz <prl@canterey.us> - 2012-03-12 02:10 -0700
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2012-03-12 10:49 -0700
                Re: I am learning C: a little problem with a simple source code Philip Lantz <prl@canterey.us> - 2012-03-14 01:16 -0700
                Re: I am learning C: a little problem with a simple source code Robert Miles <milesrf@Usenet-News.net> - 2012-04-15 06:53 -0500
                Re: I am learning C: a little problem with a simple source code Nomen Nescio <nobody@dizum.com> - 2012-04-15 19:45 +0200
                Re: I am learning C: a little problem with a simple source code Philip Lantz <prl@canterey.us> - 2012-04-15 15:06 -0700
                Re: I am learning C: a little problem with a simple source code 88888 Dihedral <dihedral88888@googlemail.com> - 2012-04-16 10:56 -0700
                Re: I am learning C: a little problem with a simple source code Ian Collins <ian-news@hotmail.com> - 2011-11-03 10:19 +1300
                Re: I am learning C: a little problem with a simple source code Seebs <usenet-nospam@seebs.net> - 2011-11-02 21:10 +0000
                Re: I am learning C: a little problem with a simple source code Kaz Kylheku <kaz@kylheku.com> - 2011-11-03 05:13 +0000
              Re: I am learning C: a little problem with a simple source code zemir <zemir_fp@libero.it> - 2011-11-01 13:29 -0700
            Re: I am learning C: a little problem with a simple source code Seebs <usenet-nospam@seebs.net> - 2011-11-01 21:44 +0000
              Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-03 06:33 -0700
                Re: I am learning C: a little problem with a simple source code Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-03 07:05 -0700
                Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-03 15:32 -0700
                Re: I am learning C: a little problem with a simple source code Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-04 01:44 -0700
                Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-04 07:30 -0700
                Re: I am learning C: a little problem with a simple source code John Gordon <gordon@panix.com> - 2011-11-04 16:03 +0000
                Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-04 09:20 -0700
                Re: I am learning C: a little problem with a simple source code John Gordon <gordon@panix.com> - 2011-11-04 16:45 +0000
                Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-04 11:59 -0700
                Re: I am learning C: a little problem with a simple source code John Gordon <gordon@panix.com> - 2011-11-04 19:32 +0000
                Re: I am learning C: a little problem with a simple source code Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-05 04:07 -0700
                Re: I am learning C: a little problem with a simple source code John Gordon <gordon@panix.com> - 2011-11-04 16:54 +0000
                Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-04 11:58 -0700
                Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-04 18:25 +0100
                Re: I am learning C: a little problem with a simple source code gordonb.e1fpi@burditt.org (Gordon Burditt) - 2011-11-04 13:50 -0500
                Re: I am learning C: a little problem with a simple source code Pasquale Frega <zemir_fp@libero.it> - 2011-11-04 11:57 -0700
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2011-11-04 14:44 -0700
                Re: I am learning C: a little problem with a simple source code "osmium" <r124c4u102@comcast.net> - 2011-11-04 14:03 -0500
                Re: I am learning C: a little problem with a simple source code Kaz Kylheku <kaz@kylheku.com> - 2011-11-04 21:37 +0000
                Re: I am learning C: a little problem with a simple source code Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-06 12:20 +0200
                Re: I am learning C: a little problem with a simple source code Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-04 08:32 -0700
                Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-04 09:04 -0700
                Re: I am learning C: a little problem with a simple source code Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-04 10:28 -0700
                Re: I am learning C: a little problem with a simple source code Seebs <usenet-nospam@seebs.net> - 2011-11-03 18:35 +0000
                Re: I am learning C: a little problem with a simple source code Pasquale Frega <zemir_fp@libero.it> - 2011-11-03 14:50 -0700
                Re: I am learning C: a little problem with a simple source code Keith Thompson <kst-u@mib.org> - 2011-11-03 15:59 -0700
                Re: I am learning C: a little problem with a simple source code Pasquale Frega <zemir_fp@libero.it> - 2011-11-04 12:00 -0700
                Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-04 20:58 +0100
                Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-04 21:13 +0100
                Re: I am learning C: a little problem with a simple source code Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-04 01:56 -0700
                Re: I am learning C: a little problem with a simple source code Pasquale Frega <zemir_fp@libero.it> - 2011-11-04 12:12 -0700
                Re: I am learning C: a little problem with a simple source code Ian Collins <ian-news@hotmail.com> - 2011-11-05 10:09 +1300
                Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-03 15:32 -0700
                Re: I am learning C: a little problem with a simple source code Seebs <usenet-nospam@seebs.net> - 2011-11-03 22:53 +0000
                Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-03 17:57 -0700
                Re: I am learning C: a little problem with a simple source code Robert Wessel <robertwessel2@yahoo.com> - 2011-11-03 21:35 -0500
                Re: I am learning C: a little problem with a simple source code Seebs <usenet-nospam@seebs.net> - 2011-11-04 03:31 +0000
                Re: I am learning C: a little problem with a simple source code Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-04 02:25 -0700
                Re: I am learning C: a little problem with a simple source code Kulin Remailer <remailer@reece.net.au> - 2011-11-03 22:47 +0000
                Re: I am learning C: a little problem with a simple source code Bill Reid <hormelfree@gmail.com> - 2011-11-03 16:14 -0700
                Re: I am learning C: a little problem with a simple source code Robert Wessel <robertwessel2@yahoo.com> - 2011-11-03 21:55 -0500
                Re: I am learning C: a little problem with a simple source code Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-11-04 08:10 -0700
                Re: I am learning C: a little problem with a simple source code ImpalerCore <jadill33@gmail.com> - 2011-11-04 14:21 -0700
                Re: I am learning C: a little problem with a simple source code Robert Wessel <robertwessel2@yahoo.com> - 2011-11-04 16:31 -0500
                Re: I am learning C: a little problem with a simple source code Ian Collins <ian-news@hotmail.com> - 2011-11-05 10:41 +1300
                Re: I am learning C: a little problem with a simple source code Seebs <usenet-nospam@seebs.net> - 2011-11-04 21:38 +0000
                Re: I am learning C: a little problem with a simple source code Robert Wessel <robertwessel2@yahoo.com> - 2011-11-04 22:18 -0500
                Re: I am learning C: a little problem with a simple source code Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-05 11:11 -0400
                Re: I am learning C: a little problem with a simple source code Lew Pitcher <lpitcher@teksavvy.com> - 2011-11-05 11:13 -0400
                Re: I am learning C: a little problem with a simple source code Robert Wessel <robertwessel2@yahoo.com> - 2011-11-05 23:35 -0500
                Re: I am learning C: a little problem with a simple source code Seebs <usenet-nospam@seebs.net> - 2011-11-06 07:40 +0000
                Re: I am learning C: a little problem with a simple source code James Kuyper <jameskuyper@verizon.net> - 2011-11-04 18:15 -0400
                Re: I am learning C: a little problem with a simple source code ImpalerCore <jadill33@gmail.com> - 2011-11-04 20:00 -0700
                Re: I am learning C: a little problem with a simple source code James Kuyper <jameskuyper@verizon.net> - 2011-11-04 23:19 -0400
                Re: I am learning C: a little problem with a simple source code ImpalerCore <jadill33@gmail.com> - 2011-11-04 20:33 -0700
                Re: I am learning C: a little problem with a simple source code Kaz Kylheku <kaz@kylheku.com> - 2011-11-05 03:52 +0000
                Re: I am learning C: a little problem with a simple source code Ian Collins <ian-news@hotmail.com> - 2011-11-05 17:01 +1300
                Re: I am learning C: a little problem with a simple source code ImpalerCore <jadill33@gmail.com> - 2011-11-04 21:48 -0700
          Re: I am learning C: a little problem with a simple source code zemir <zemir_fp@libero.it> - 2011-11-01 13:19 -0700
            Re: I am learning C: a little problem with a simple source code Ian Collins <ian-news@hotmail.com> - 2011-11-02 09:26 +1300
          Re: I am learning C: a little problem with a simple source code zemir <zemir_fp@libero.it> - 2011-11-01 13:23 -0700
            Re: I am learning C: a little problem with a simple source code Ian Collins <ian-news@hotmail.com> - 2011-11-02 09:27 +1300
              Re: I am learning C: a little problem with a simple source code zemir <zemir_fp@libero.it> - 2011-11-01 13:31 -0700
        Re: I am learning C: a little problem with a simple source code jt@toerring.de (Jens Thoms Toerring) - 2011-11-01 22:48 +0000
          Re: I am learning C: a little problem with a simple source code Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 23:09 -0800
        Re: I am learning C: a little problem with a simple source code gordonb.prbii@burditt.org (Gordon Burditt) - 2011-11-01 21:24 -0500
        Re: I am learning C: a little problem with a simple source code Dann Corbit <dcorbit@connx.com> - 2011-11-02 21:03 -0700
          Re: I am learning C: a little problem with a simple source code Ike Naar <ike@sverige.freeshell.org> - 2011-11-03 06:39 +0000
          Re: I am learning C: a little problem with a simple source code Barry Schwarz <schwarzb@dqel.com> - 2011-11-03 18:33 -0700
            Re: I am learning C: a little problem with a simple source code Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-04 03:03 -0700
              Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-04 11:40 +0100
              Re: I am learning C: a little problem with a simple source code Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-11-04 11:36 +0000
                Re: I am learning C: a little problem with a simple source code Kaz Kylheku <kaz@kylheku.com> - 2011-11-04 15:58 +0000
          Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-04 07:24 +0100
            Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-04 10:28 +0100
              Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-04 16:02 +0100
                Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-04 16:20 +0100
                Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-04 16:39 +0100
            Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-06 18:07 +0100
              Re: I am learning C: a little problem with a simple source code Barry Schwarz <schwarzb@dqel.com> - 2011-11-06 09:59 -0800
                Re: I am learning C: a little problem with a simple source code "io_x" <a@b.c.invalid> - 2011-11-06 19:23 +0100
                Re: I am learning C: a little problem with a simple source code James Kuyper <jameskuyper@verizon.net> - 2011-11-06 15:23 -0500
      Re: I am learning C: a little problem with a simple source code zemir <zemir_fp@libero.it> - 2011-11-01 11:52 -0700
        Re: I am learning C: a little problem with a simple source code "BartC" <bc@freeuk.com> - 2011-11-01 23:02 +0000
  Re: I am learning C: a little problem with a simple source code Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-02 03:53 -0700
    Re: I am learning C: a little problem with a simple source code James Kuyper <jameskuyper@verizon.net> - 2011-11-02 08:03 -0400
      Re: I am learning C: a little problem with a simple source code Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-02 06:11 -0700

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