Re: Is 'extern' necessary?

From	BartC <bc@freeuk.com>
Newsgroups	comp.lang.c
Subject	Re: Is 'extern' necessary?
Date	2017-02-14 01:02 +0000
Organization	A noiseless patient Spider
Message-ID	<o7tkra$4al$1@dont-email.me> (permalink)
References	(3 earlier) <kfn37fi2q58.fsf@x-alumni2.alumni.caltech.edu> <o7sd8q$enk$1@dont-email.me> <ln7f4ut1va.fsf@kst-u.example.com> <o7t0ns$pnt$1@dont-email.me> <o7tfl8$lta$1@dont-email.me>

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On 13/02/2017 23:33, David Brown wrote:
> On 13/02/17 20:19, BartC wrote:

>> It's a mystery why gcc-related headers seem to be so full of junk
>> compared with those of other compilers.
>
> Basically, what you are saying is "I don't understand this.  Therefore
> it must be junk".  I don't know whether you are too lazy to look it up,

Why would I want to look it up? Look at the lccwin or MSDN versions 
below; /that's/ how you want these things expressed. Short and sweet. (I 
don't want to think about what your own headers look like if you think 
this is reasonable.)

> or scared that you won't understand what you read, or merely worried
> that if you actually learn what this means then you will lose some
> opportunities to moan about gcc.
>
> First, you have to realise that this is a library, it is not part of
> gcc.  It is written in a way that will work with many compilers (hence
> some macros are used),

I tried that header with 4 other compilers (compiling hello world with 
the include search path set to the one used by this gcc), and they all 
failed.

  but that it should be as optimal as possible
> across a wide range of gcc versions (and compiler flags) since it is
> most commonly used with gcc.  It also aims to give as good static error
> checking as possible.
> This it uses "__restrict__", which will work like "restrict" on C99 for
> more efficient code generation - but will also work on gcc with other
> choices of standards and in C++.  It has the "format" attribute, to give
> error checking - gcc can warn you if your printf format does not match
> with the actual parameters (for a fixed format string).

lccwin also does that checking; /its/ vsnprintf looks like this:

   int vsnprintf(char *,size_t,const char *,va_list);

(How on earth does it manage that?)

You seem to constantly think that things that are bigger and more 
complicated are always better and always justified.

>>
>> This is what that function declares:
>>
>>  extern vsnprintf(char*, size_t, char*, va_list);
>>
>> I think, beyond being in text format, they've given up on making this
>> stuff human-readable. Or tidy and compact.
>
> Yes, but the version from the library you gave does more.  It is also
> more informative (the parameters have names),

This is the same function in the MSDN docs, and the params have names:

int vsnprintf(
    char *buffer,
    size_t count,
    const char *format,
    va_list argptr
);

 >and it is correct (it has a return type).

Yes, the int. Maybe I was using 'implicit' int, or maybe I missed a 
3-letter return type lurking somewhere in the /middle/ of all that 
line-noise.

If implementers don't want this to be readable, then why bother having 
it as source code? That must be reprocessed over and over again. There 
must be more efficient ways of doing it, and AFAIK C doesn't stop an 
implementation from having standard headers inside the compiler already 
built-in.

-- 
bartc

Thread

Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-10 17:16 +0000
  Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-10 09:33 -0800
    Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-10 18:41 +0000
      Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-10 12:09 -0800
        Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-10 20:29 +0000
          Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-10 13:26 -0800
            Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-10 22:56 +0000
              Re: Is 'extern' necessary? jameskuyper@verizon.net - 2017-02-10 20:19 -0800
                Re: Is 'extern' necessary? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-02-11 09:53 -0500
              Re: Is 'extern' necessary? Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-13 05:19 -0800
      Re: Is 'extern' necessary? jameskuyper@verizon.net - 2017-02-10 12:09 -0800
        Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-10 20:50 +0000
          Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-10 13:09 -0800
          Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-10 13:33 -0800
          Re: Is 'extern' necessary? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-10 23:23 +0000
            Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-10 23:35 +0000
              Re: Is 'extern' necessary? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-11 00:34 +0000
            Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-13 12:41 +0100
              Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-13 13:14 +0000
                Re: Is 'extern' necessary? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-13 14:05 +0000
                Re: Is 'extern' necessary? jameskuyper@verizon.net - 2017-02-13 07:49 -0800
          Re: Is 'extern' necessary? jameskuyper@verizon.net - 2017-02-10 19:33 -0800
            Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-11 09:41 -0800
              Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-11 10:19 -0800
                Re: Is 'extern' necessary? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-02-11 13:39 -0500
                Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-12 10:10 -0800
      Re: Is 'extern' necessary? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-02-10 14:59 -0800
      Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-13 12:33 +0100
  Re: Is 'extern' necessary? Siri Cruise <chine.bleu@yahoo.com> - 2017-02-10 09:35 -0800
    Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-10 12:12 -0800
  Re: Is 'extern' necessary? jameskuyper@verizon.net - 2017-02-10 10:38 -0800
  Re: Is 'extern' necessary? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-10 21:10 +0000
    Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-10 13:25 -0800
  Re: Is 'extern' necessary? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-02-10 14:53 -0800
    Re: Is 'extern' necessary? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-02-10 15:06 -0800
    Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-10 23:24 +0000
      Re: Is 'extern' necessary? Ian Collins <ian-news@hotmail.com> - 2017-02-11 12:34 +1300
        Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-13 13:14 +0100
          Re: Is 'extern' necessary? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-02-13 13:44 +0100
            Re: Is 'extern' necessary? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-13 14:13 +0000
            Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-13 15:16 +0100
              Re: Is 'extern' necessary? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-02-13 17:24 +0100
                Re: Is 'extern' necessary? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-02-13 14:24 -0500
                Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-13 23:29 +0100
            Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-13 11:06 -0800
            Re: Is 'extern' necessary? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-02-13 11:15 -0800
          Re: Is 'extern' necessary? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-02-13 11:48 -0500
            Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-13 09:03 -0800
            Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-13 23:37 +0100
      Re: Is 'extern' necessary? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-02-10 15:40 -0800
      Re: Is 'extern' necessary? Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-13 05:09 -0800
        Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-13 13:46 +0000
          Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-13 09:52 -0800
            Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-13 19:19 +0000
              Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-13 11:34 -0800
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-13 20:13 +0000
              Re: Is 'extern' necessary? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2017-02-13 13:11 -0800
              Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-14 00:33 +0100
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-14 01:02 +0000
                Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-14 09:28 +0100
                Re: Is 'extern' necessary? Robert Wessel <robertwessel2@yahoo.com> - 2017-02-14 03:31 -0600
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-14 11:42 +0000
                Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-14 13:29 +0100
                Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-14 05:16 -0800
                Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-14 14:51 +0100
                Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-14 07:24 -0800
                Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-14 21:35 +0100
                Re: Is 'extern' necessary? James Kuyper <jameskuyper@verizon.net> - 2017-02-14 15:53 -0500
                Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-15 09:31 +0100
                Re: Is 'extern' necessary? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-02-15 11:36 -0500
                Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-15 09:12 -0800
                Re: Is 'extern' necessary? "James R. Kuyper" <jameskuyper@verizon.net> - 2017-02-15 12:58 -0500
                Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-15 10:01 -0800
                Re: Is 'extern' necessary? jameskuyper@verizon.net - 2017-02-15 10:55 -0800
                Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-15 11:42 -0800
                Re: Is 'extern' necessary? jameskuyper@verizon.net - 2017-02-15 12:28 -0800
                Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-15 13:58 -0800
                Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-14 08:54 -0800
                Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-14 08:51 -0800
                Re: Is 'extern' necessary? Richard Heathfield <rjh@cpax.org.uk> - 2017-02-14 17:32 +0000
                Re: Is 'extern' necessary? Gareth Owen <gwowen@gmail.com> - 2017-02-14 17:45 +0000
                Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-14 21:38 +0100
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-14 23:26 +0000
                Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-14 16:33 -0800
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-15 00:47 +0000
                Re: Is 'extern' necessary? Jean-Marc Bourguet <jm@bourguet.org> - 2017-02-14 18:17 +0100
                Re: Is 'extern' necessary? Keith Thompson <kst-u@mib.org> - 2017-02-14 09:47 -0800
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-14 18:36 +0000
                Re: Is 'extern' necessary? jameskuyper@verizon.net - 2017-02-14 11:20 -0800
                Re: Is 'extern' necessary? supercat@casperkitty.com - 2017-02-14 11:42 -0800
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-14 20:22 +0000
                Re: Is 'extern' necessary? Robert Wessel <robertwessel2@yahoo.com> - 2017-02-14 17:58 -0600
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-15 01:29 +0000
                Re: Is 'extern' necessary? Robert Wessel <robertwessel2@yahoo.com> - 2017-02-16 05:02 -0600
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-16 11:38 +0000
                Re: Is 'extern' necessary? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-16 14:37 +0000
                Re: Is 'extern' necessary? BartC <bc@freeuk.com> - 2017-02-16 15:43 +0000
                Re: Is 'extern' necessary? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-16 16:08 +0000
                Re: Is 'extern' necessary? GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-02-16 18:42 +0100
                Re: Is 'extern' necessary? David Brown <david.brown@hesbynett.no> - 2017-02-15 09:47 +0100
                Re: Is 'extern' necessary? Robert Wessel <robertwessel2@yahoo.com> - 2017-02-16 05:05 -0600
          Re: Is 'extern' necessary? Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-15 16:53 -0800
    Re: Is 'extern' necessary? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-10 23:55 +0000
  Re: Is 'extern' necessary? Les Cargill <lcargill99@comcast.com> - 2017-02-10 19:24 -0600
  Re: Is 'extern' necessary? void <nathan.gothier@gmail.com> - 2017-02-11 03:17 -0800

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