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Groups > comp.lang.c > #94034

Re: To include or not to include

From Reinhardt Behm <rbehm@hushmail.com>
Newsgroups comp.lang.c
Subject Re: To include or not to include
Date 2016-09-26 00:21 +0800
Organization A noiseless patient Spider
Message-ID <ns8thv$jj3$3@dont-email.me> (permalink)
References (8 earlier) <ns8akc$o3j$1@dont-email.me> <ns8i3i$fks$1@dont-email.me> <ns8m5r$sqi$1@dont-email.me> <ns8qnt$c3b$1@dont-email.me> <1b7fa0kltw.fsf@pfeifferfamily.net>

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AT Monday 26 September 2016 00:04, Joe Pfeiffer wrote:

> Reinhardt Behm <rbehm@hushmail.com> writes:
> 
>> AT Sunday 25 September 2016 22:15, BartC wrote:
>>
>>> On 25/09/2016 14:06, James Harris wrote:
>>>> On 25/09/2016 11:58, BartC wrote:
>>> 
>>>>> It's not just about me. It's illogical and confusing. If I write this
>>>>> in Nasm:
>>>>>
>>>>>       extern bart
>>>>> bart:
>>>>>
>>>>> it says symbol 'bart' is redefined.
>>>>>
>>>>> I thought C was supposed to be higher level than such languages?
>>>>
>>>> Some of C's rules are for compatibility.
>>>>
>>>> Besides, are you interpreting the extern keyword incorrectly. It does
>>>> not mean what it does in Nasm. IIRC it does not mean "external to this
>>>> translation unit".
>>>>
>>>> Wouldn't it be more accurate to say that it means "external to a
>>>> function"?
>>> 
>>> Yes, I remember now that this came up before; extern means external to a
>>> function (and a new entry for my list of quirks!).
>>> 
>>> In which case it's surprising you don't see it more often, in front of
>>> function declarations definitions for example. The answer is that most
>>> such 'extern' names are obviously external-to-functions by context (ie.
>>> placement).
>>> 
>>> So it seems superfluous. Unless, for some bizarre reason, you want to
>>> actually declare a file-scope name inside a function.
>>> 
>>> And it doesn't really explain however why 'extern' needs to be used for
>>> names of file-scope objects and functions that are shared between
>>> modules.
>>
>> The interpretation "extern to a function" does not make sense. A static
>> declaration in file scope is also "extern to a function" but not known
>> outside the compilation unit.
> 
> It may not make sense, but here's what the standard says (6.9, point 4):
>     As discussed in 5.1.1.1, the unit of program text after
>     preprocessing is a translation unit, which consists of a sequence of
>     external declarations. These are described as "external" because
>     they appear outside any function (and hence have file scope).

It may be the word (not even that it's "external" against "extern") but this 
has not much to do with what has been discussed her.

-- 
Reinhardt

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Thread

To include or not to include James Harris <james.harris.1@gmail.com> - 2016-09-23 10:45 +0100
  Re: To include or not to include David Brown <david.brown@hesbynett.no> - 2016-09-23 12:43 +0200
    Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-23 12:17 +0100
      Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-23 13:32 +0100
        Re: To include or not to include David Brown <david.brown@hesbynett.no> - 2016-09-23 14:57 +0200
        Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-24 20:34 +0100
          Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-24 23:55 +0100
            Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-25 01:43 +0100
              Re: To include or not to include Ian Collins <ian-news@hotmail.com> - 2016-09-25 14:38 +1300
              Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-25 11:42 +0100
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-25 11:58 +0100
                Re: To include or not to include James Harris <james.harris.1@gmail.com> - 2016-09-25 14:06 +0100
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-25 15:15 +0100
                Re: To include or not to include Reinhardt Behm <rbehm@hushmail.com> - 2016-09-25 23:33 +0800
                Re: To include or not to include Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-09-25 10:04 -0600
                Re: To include or not to include Reinhardt Behm <rbehm@hushmail.com> - 2016-09-26 00:21 +0800
                Re: To include or not to include "James R. Kuyper" <jameskuyper@verizon.net> - 2016-09-25 13:17 -0400
                Re: To include or not to include James Harris <james.harris.1@gmail.com> - 2016-09-26 00:18 +0100
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-26 17:55 +0100
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-26 20:07 +0100
                Re: To include or not to include supercat@casperkitty.com - 2016-09-26 12:13 -0700
                Re: To include or not to include James Harris <james.harris.1@gmail.com> - 2016-09-27 01:25 +0100
                Re: To include or not to include supercat@casperkitty.com - 2016-09-26 18:05 -0700
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-27 14:27 +0100
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-27 14:49 +0100
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-27 15:15 +0100
                Re: To include or not to include Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-09-27 07:42 -0700
                Re: To include or not to include Keith Thompson <kst-u@mib.org> - 2016-09-27 09:30 -0700
                Re: To include or not to include Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-09-27 10:06 -0700
                Re: To include or not to include supercat@casperkitty.com - 2016-09-27 08:12 -0700
                Re: To include or not to include Tim Rentsch <txr@alumni.caltech.edu> - 2016-09-28 10:46 -0700
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-27 17:55 +0100
                Re: To include or not to include supercat@casperkitty.com - 2016-09-27 10:19 -0700
                Re: To include or not to include Keith Thompson <kst-u@mib.org> - 2016-09-27 11:42 -0700
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-27 19:57 +0100
                Re: To include or not to include Keith Thompson <kst-u@mib.org> - 2016-09-27 12:38 -0700
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-27 21:00 +0100
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-28 01:50 +0100
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-28 10:55 +0100
                Re: To include or not to include Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-09-27 13:33 -0700
                Re: To include or not to include Ike Naar <ike@iceland.freeshell.org> - 2016-09-28 19:13 +0000
                Re: To include or not to include supercat@casperkitty.com - 2016-09-27 12:38 -0700
                Re: To include or not to include James Harris <james.harris.1@gmail.com> - 2016-09-27 20:57 +0100
                Re: To include or not to include supercat@casperkitty.com - 2016-09-27 07:25 -0700
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-28 00:28 +0100
                Re: To include or not to include supercat@casperkitty.com - 2016-09-30 07:53 -0700
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-30 16:06 +0100
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-27 13:53 +0100
                Re: To include or not to include James Harris <james.harris.1@gmail.com> - 2016-09-30 19:46 +0100
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-30 20:27 +0100
                Re: To include or not to include Reinhardt Behm <rbehm@hushmail.com> - 2016-09-25 23:27 +0800
                Re: To include or not to include Jerry Stuckle <jstucklex@attglobal.net> - 2016-09-25 11:38 -0400
                Re: To include or not to include Reinhardt Behm <rbehm@hushmail.com> - 2016-09-25 23:40 +0800
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-25 15:06 +0100
                Re: To include or not to include Jerry Stuckle <jstucklex@attglobal.net> - 2016-09-25 11:49 -0400
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-25 18:05 +0100
                Re: To include or not to include Jerry Stuckle <jstucklex@attglobal.net> - 2016-09-25 16:42 -0400
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-25 21:53 +0100
                Re: To include or not to include Jerry Stuckle <jstucklex@attglobal.net> - 2016-09-25 17:57 -0400
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-25 21:20 +0100
                Re: To include or not to include BartC <bc@freeuk.com> - 2016-09-25 21:49 +0100
                Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-26 00:40 +0100
      Re: To include or not to include David Brown <david.brown@hesbynett.no> - 2016-09-23 14:56 +0200
  Re: To include or not to include Richard Heathfield <rjh@cpax.org.uk> - 2016-09-23 13:31 +0100
    Re: To include or not to include James Harris <james.harris.1@gmail.com> - 2016-09-23 13:52 +0100
      Re: To include or not to include Richard Heathfield <rjh@cpax.org.uk> - 2016-09-23 14:35 +0100
    Re: To include or not to include Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-09-23 18:55 +0100
      Re: To include or not to include Richard Heathfield <rjh@cpax.org.uk> - 2016-09-23 20:33 +0100
  Re: To include or not to include Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-09-23 08:22 -0600
  Re: To include or not to include Richard Damon <Richard@Damon-Family.org> - 2016-09-23 11:37 -0400

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