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Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle...

From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle...
Date 2015-06-09 08:55 -0700
Organization None to speak of
Message-ID <87a8w8ri4z.fsf@kst-u.example.com> (permalink)
References (6 earlier) <5922caf7-6301-40f8-8f28-64c1346774e2@googlegroups.com> <87mw0aqce9.fsf@kst-u.example.com> <ml4vul$gmm$1@speranza.aioe.org> <87egllrhoy.fsf@kst-u.example.com> <56301485-e5e9-45c7-8357-9a9b21327747@googlegroups.com>

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David Kleinecke <dkleinecke@gmail.com> writes:
> On Monday, June 8, 2015 at 2:52:55 PM UTC-7, Keith Thompson wrote:
[...]
>> 7.1.2p5 says:
>> 
>>     Any definition of an object-like macro described in this clause
>>     shall expand to code that is fully protected by parentheses
>>     where necessary, so that it groups in an arbitrary expression
>>     as if it were a single identifier.
>> 
>> This cannot apply to a macro that expands to a typedef name.
>> 
>> 7.1.4p1 gives explicit permission to define functions as macros.  No
>> such permission is given for type names.
>> 
>> In general, I'd like to say that implementations aren't permitted to
>> define identifiers in ways not explicitly permitted by the standard,
>> but I'm not sure I can justify it rigorously.
>
> The preprocessor should not be aware of niceties like functions. It
> should preprocess any code or chaos according to its rules. But, of
> course, how  do I know I can say "should"?

The preprocessor isn't aware of functions.  Did you think I was implying
that it is?

For example, an implementation of <math.h> may include a macro
definition like:
    #define sqrt(x) __builtin_sqrt(x)
This causes the token sequence
    sqrt ( x )
to be replaced by the token sequence
    __builtin_sqrt ( x )

The preprocessor's behavior does not depend on the fact that sqrt and
__builtin_sqrt are function names.

> I think the preprocessor should operate on its own rules without
> reference to the program structure. That is my opinion.

It does.

> I don't think the standard (any standard) is clear on this point.

I believe it's quite clear.  What do you think is unclear?

-- 
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"

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Thread

Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... G G <gdotone@gmail.com> - 2015-05-07 17:12 -0700
  Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-05-07 18:18 -0700
    Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... G G <gdotone@gmail.com> - 2015-05-07 20:16 -0700
      Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... mark.bluemel@gmail.com - 2015-05-08 01:09 -0700
      Re: Could you please discuss whether casting a size_t variable to   unsigned int variable is the correct way to handle... Tim Prince <tprince@computer.org> - 2015-05-08 09:16 -0400
      Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-05-08 08:03 -0700
        Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-05-08 10:30 -0700
          Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... jadill33@gmail.com - 2015-05-08 11:12 -0700
          Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-05-08 11:22 -0700
            Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-08 18:42 +0000
          Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Bartc <bc@freeuk.com> - 2015-05-08 19:25 +0100
            Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Stephen Sprunk <stephen@sprunk.org> - 2015-05-08 15:12 -0500
              Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Bartc <bc@freeuk.com> - 2015-05-08 22:38 +0100
                Re: Could you please discuss whether casting a size_t variable to   unsigned int variable is the correct way to handle... Ian Collins <ian-news@hotmail.com> - 2015-05-09 11:01 +1200
        Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-10 09:19 -0700
          Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-05-10 11:26 -0700
            Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-11 21:31 -0700
              Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-12 05:50 +0000
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-05-12 10:05 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-12 11:10 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-05-12 12:59 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-22 08:11 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-05-22 11:20 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-24 07:59 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-05-24 13:44 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-12 11:09 -0700
              Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-05-12 11:02 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-22 08:01 -0700
            Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Waldek Hebisch <hebisch@antispam.uni.wroc.pl> - 2015-06-08 01:06 +0000
              Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-06-07 19:12 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... James Kuyper <jameskuyper@verizon.net> - 2015-06-08 11:28 -0400
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Waldek Hebisch <hebisch@antispam.uni.wroc.pl> - 2015-06-09 12:23 +0000
            Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... David Kleinecke <dkleinecke@gmail.com> - 2015-06-08 10:56 -0700
              Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-06-08 11:32 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Bartc <bc@freeuk.com> - 2015-06-08 19:40 +0100
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Richard Heathfield <rjh@cpax.org.uk> - 2015-06-08 20:03 +0100
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-06-08 13:43 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-06-08 21:03 +0000
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-06-08 14:52 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... David Kleinecke <dkleinecke@gmail.com> - 2015-06-09 08:30 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-09 16:48 +0100
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-06-09 08:55 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... David Kleinecke <dkleinecke@gmail.com> - 2015-06-10 10:09 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-06-10 11:05 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... David Kleinecke <dkleinecke@gmail.com> - 2015-06-11 11:04 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-06-11 11:31 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-06-11 13:49 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... David Kleinecke <dkleinecke@gmail.com> - 2015-06-12 09:00 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-11 07:25 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... David Kleinecke <dkleinecke@gmail.com> - 2015-07-11 10:04 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... James Kuyper <jameskuyper@verizon.net> - 2015-07-11 13:39 -0400
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-11 13:44 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Keith Thompson <kst-u@mib.org> - 2015-07-11 16:15 -0700
                Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... David Kleinecke <dkleinecke@gmail.com> - 2015-06-09 08:31 -0700
  Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-05-07 20:34 -0700
    Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... Richard Heathfield <rjh@cpax.org.uk> - 2015-05-08 09:48 +0100
  Re: Could you please discuss whether casting a size_t variable to unsigned int variable is the correct way to handle... glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-08 05:12 +0000

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