Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.c > #100449

Re: Octal

From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: Octal
Date 2016-12-28 10:04 -0800
Organization None to speak of
Message-ID <lnshp83p7f.fsf@kst-u.example.com> (permalink)
References (11 earlier) <ln37h87udw.fsf@kst-u.example.com> <o3v2hu$qq5$1@dont-email.me> <lntw9o6cr1.fsf@kst-u.example.com> <o407g6$dgp$1@dont-email.me> <a1f82620-a8cb-472f-b9e1-3b480f084587@googlegroups.com>

Show all headers | View raw


supercat@casperkitty.com writes:
> On Wednesday, December 28, 2016 at 5:27:34 AM UTC-6, Bart wrote:
>> This is contrary to my understanding of how the preprocessor works, 
>> which is that the output is considered to be text-based, not 
>> token-based, and the next compilation phase will see the character 
>> sequence "127.0.0.1" and re-tokenise it whichever way it wants.
>
> Prior to the C Standard, some compilers had a preprocessor stage which ran
> through all the source files and combined them into a preprocessor-output
> text file, which was then fed to subsequent compilation stages, while others
> would have the preprocessor generate data in an internal-use format (either
> in memory or disk) which retained the results of scanning certain parts.
>
> For example, given something like:
>
>     #define plusplus() ++
>     int main(void)
>     {
>       int i=0,=0;
>       return i+plus()j;
>     }
>
> some compilers which ran the preprocessor as a separate stage may have
> converted the return statement into "return i+++j;" which would in turn
> be parsed as "return i++ +j;", but others may have converted the first
> + to a token before expanding the macro "plus()", and thus interpreting
> the statement as "return i+ ++j;".

And the standard made the behavior consistent.

When I fix your typo, changing plus() to plusplus(), the output of
"gcc -E" includes

      return i+ ++j;

The preprocessor inserts a space so that the "+" and "++" will be parsed
as distinct tokens.

I believe the description of the preprocessing phases is specifically
designed to permit a conforming compiler to use text as the output of
the preprocessor.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread


Thread

Octal BartC <bc@freeuk.com> - 2016-12-27 14:08 +0000
  Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 06:19 -0800
    Re: Octal BartC <bc@freeuk.com> - 2016-12-27 14:58 +0000
      Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 07:07 -0800
        Re: Octal BartC <bc@freeuk.com> - 2016-12-27 15:22 +0000
          Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 07:37 -0800
            Re: Octal BartC <bc@freeuk.com> - 2016-12-27 16:24 +0000
              Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 08:30 -0800
              Re: Octal supercat@casperkitty.com - 2016-12-27 09:10 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 09:35 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 10:47 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 12:03 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 12:27 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 12:44 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 13:37 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 16:38 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 17:53 -0800
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-27 20:26 -0600
                Re: Octal supercat@casperkitty.com - 2016-12-27 18:48 -0800
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-27 22:20 -0600
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 18:41 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-27 19:19 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-29 14:52 +1300
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 18:41 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:54 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-27 17:44 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 12:17 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-27 22:39 +0000
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-28 11:49 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-27 23:09 +0000
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-28 12:32 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 00:51 +0000
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-28 14:00 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 01:13 +0000
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-27 20:04 -0600
                Re: Octal supercat@casperkitty.com - 2016-12-27 18:45 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-29 13:35 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-29 14:49 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-29 15:33 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-30 12:35 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-13 15:19 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-13 15:32 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-14 12:35 +1300
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-13 15:51 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-13 18:25 -0800
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-01-14 06:21 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-14 14:00 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 23:08 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 23:02 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-13 18:52 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 23:46 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-16 01:46 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-31 08:33 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 17:19 -0800
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 09:39 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 11:02 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 12:13 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 11:41 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 09:31 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 17:39 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 22:05 +0100
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 12:01 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 20:05 +0000
                Re: Octal asetofsymbols@gmail.com - 2016-12-28 11:20 -0800
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 12:01 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 12:30 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 13:51 +0100
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 16:26 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-28 08:40 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 09:41 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 18:04 +0000
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 19:36 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 19:42 +0000
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-29 00:34 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-28 11:04 -0800
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 12:09 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 16:46 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 00:56 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 17:52 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 11:27 +0000
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 12:09 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-28 08:17 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 17:02 +0000
                Re: Octal Ike Naar <ike@iceland.freeshell.org> - 2016-12-28 17:25 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 17:45 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 10:21 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-28 09:27 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 10:23 -0800
                Re: Octal supercat@casperkitty.com - 2016-12-28 11:18 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 10:19 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 15:54 +0000
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-29 12:57 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 10:01 +1300
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 10:44 +0100
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-29 17:32 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 17:03 +0000
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-29 16:26 -0600
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 11:31 +1300
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-29 16:58 -0600
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 11:59 +1300
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 09:00 +1300
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 10:21 +0100
                Re: Octal asetofsymbols@gmail.com - 2016-12-30 01:29 -0800
                Re: Octal asetofsymbols@gmail.com - 2016-12-30 01:29 -0800
                Re: Octal asetofsymbols@gmail.com - 2016-12-30 01:36 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 11:52 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 17:10 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-29 05:52 -0800
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-28 19:51 -0600
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 21:09 +0000
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 10:15 +1300
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-29 13:53 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 12:07 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 13:04 +0000
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-30 05:31 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 15:00 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 15:55 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2017-01-01 16:00 +0100
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 08:33 +1300
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 09:02 +1300
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 09:38 +1300
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-01-01 13:59 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-01 14:24 -0800
                Re: Octal supercat@casperkitty.com - 2017-01-01 15:51 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 13:09 +1300
                Re: Octal supercat@casperkitty.com - 2017-01-01 16:50 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 14:24 +1300
                Re: Octal David Brown <david.brown@hesbynett.no> - 2017-01-02 01:53 +0100
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2017-01-02 14:15 +1300
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-02 02:28 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 06:24 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 17:53 +0000
                Re: Octal luser droog <luser.droog@gmail.com> - 2016-12-30 10:01 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 09:57 +1300
                Re: Octal supercat@casperkitty.com - 2016-12-30 13:50 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 11:09 +1300
                Re: Octal supercat@casperkitty.com - 2016-12-30 14:46 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 12:28 +1300
                Re: Octal supercat@casperkitty.com - 2016-12-30 16:01 -0800
                Re: Octal Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-30 14:48 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 22:51 +0000
                Re: Octal supercat@casperkitty.com - 2016-12-30 15:20 -0800
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-31 12:34 +1300
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 23:40 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 22:12 +0000
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 21:38 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 12:04 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-29 13:42 +0100
                Re: Octal Ian Collins <ian-news@hotmail.com> - 2016-12-30 08:59 +1300
                Re: Octal supercat@casperkitty.com - 2016-12-29 12:23 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-30 10:56 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 22:09 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-29 12:27 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 21:18 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 20:46 +0000
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 20:55 +0000
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-28 14:54 -0600
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 15:44 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 19:39 +0000
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-28 15:04 -0600
                Re: Octal raltbos@xs4all.nl (Richard Bos) - 2016-12-28 19:52 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-29 09:36 -0800
                Re: Octal BartC <bc@freeuk.com> - 2016-12-29 18:02 +0000
                Re: Octal BartC <bc@freeuk.com> - 2016-12-30 16:17 +0000
                Re: Octal David Brown <david.brown@hesbynett.no> - 2017-01-01 16:09 +0100
                Re: Octal BartC <bc@freeuk.com> - 2016-12-28 20:02 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 12:32 -0800
                Re: Octal Richard Heathfield <rjh@cpax.org.uk> - 2016-12-29 13:45 +0000
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 17:16 +0000
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 10:04 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-02 02:26 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-02 12:35 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-12 23:22 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2017-01-13 10:04 -0800
                Re: Octal Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-14 00:45 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 09:59 -0800
                Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 09:45 -0800
        Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-27 17:14 +0100
          Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-27 08:23 -0800
            Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 10:37 +0100
              Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-28 03:07 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 12:25 +0100
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 11:58 +0000
                Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-28 04:35 -0800
                Re: Octal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-28 17:31 +0000
                Re: Octal "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-28 09:38 -0800
                Re: Octal Robert Wessel <robertwessel2@yahoo.com> - 2016-12-28 15:12 -0600
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 12:01 -0800
              Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 09:20 -0800
                Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-28 13:39 -0800
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-29 12:29 +0100
                Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 22:20 +0100
      Re: Octal Noob <root@127.0.0.1> - 2016-12-28 13:02 +0100
        Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-28 13:30 +0100
        Re: Octal BartC <bc@freeuk.com> - 2016-12-28 13:25 +0000
  Re: Octal Manfred <noname@invalid.add> - 2016-12-27 15:19 +0100
    Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 08:37 -0800
      Re: Octal Manfred <noname@invalid.add> - 2016-12-27 18:43 +0100
        Re: Octal Keith Thompson <kst-u@mib.org> - 2016-12-27 12:07 -0800
    Re: Octal Manfred <noname@invalid.add> - 2016-12-27 18:21 +0100
  Re: Octal David Brown <david.brown@hesbynett.no> - 2016-12-27 15:28 +0100
  Re: Octal BGB <cr88192@hotmail.com> - 2016-12-27 11:42 -0600

csiph-web