Re: What constitutes "standard" C?

From	James Kuyper <jameskuyper@verizon.net>
Newsgroups	comp.lang.c
Subject	Re: What constitutes "standard" C?
Date	2015-04-05 17:56 -0400
Organization	A noiseless patient Spider
Message-ID	<mfsb07$aqd$1@dont-email.me> (permalink)
References	(9 earlier) <kfniodk7qyb.fsf@x-alumni2.alumni.caltech.edu> <87a8ynyab1.fsf@kst-u.example.com> <mfq28k$lej$1@speranza.aioe.org> <mfrs5n$j9v$1@dont-email.me> <mfs53a$eov$1@speranza.aioe.org>

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On 04/05/2015 04:14 PM, glen herrmannsfeldt wrote:
> James Kuyper <jameskuyper@verizon.net> wrote:
> 
> (snip, someone wrote)
>>>>    The implementation shall not successfully translate a
>>>>    preprocessing translation unit containing a #error preprocessing
>>>>    directive unless it is part of a group skipped by conditional
>>>>    inclusion.
>  
> (then I wrote)
>>> OK, but what is it required not to do when it does not successfully
>>> translate?  Does that mean that it is required not to generate an
>>> object file (assuming that is the normal result)?
>  
>> 5.1.1.2 describes "Translation phases". Translation phase 8 is where the
>> separate translation units that make up a program get linked together
>> with the C standard library to produce the "program image". Since
>> translation is not complete until linkage is achieved, translation can
>> be called "unsuccessful" even if translation phase 8 is the only one
>> that failed. However, since 4.8p4 describes something that can be
>> detected during translation phase 4, I'd consider failing only in phase
>> 8 to be a matter of bad design.
> 
> OK, but that is a quality of implementation question. 
> 
> I thought here we were discussing what it required of an implementation.

I mentioned what is required: failure to complete translation, with the
phase during which failure occurs unspecified.

That I choose to discuss an additional closely-related topic is no
legitimate grounds for complaint.

> To get more specific, consider a unix-like system where the linker 
> generates an output file, but doesn't give it the executable attribute.
> 
> According to unix, then, it has not been successful, and unix won't
> execute the file.
> 
> But I can then chmod +x the file, and run it anyway!

I certainly think it would be more appropriate to halt translation at
the earliest possible time, during translation phase 4, and taking the
approach you describe is pretty ridiculous, but I can find no other
fault with that approach.

> It might even do what I wanted it to do, even if it has a #error in it.

That, of course, depends entirely upon what you want it to do.

> Should an implementation try harder to stop me?

I don't see any reason why. It's a tool meant to help you achieve your
goals, not a prison designed to prevent you from straying.
-- 
James Kuyper

Thread

What constitutes "standard" C? Chad <cdalten@gmail.com> - 2015-03-06 23:41 -0800
  Re: What constitutes "standard" C? Morris Dovey <mrdovey@iedu.com> - 2015-03-07 02:57 -0600
  Re: What constitutes "standard" C? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-07 02:51 -0800
    Re: What constitutes "standard" C? Richard Heathfield <rjh@cpax.org.uk> - 2015-03-07 11:25 +0000
      Re: What constitutes "standard" C? Richard Heathfield <rjh@cpax.org.uk> - 2015-03-07 18:34 +0000
      Re: What constitutes "standard" C? James Kuyper <jameskuyper@verizon.net> - 2015-03-09 11:21 -0400
        Re: What constitutes "standard" C? Richard Heathfield <rjh@cpax.org.uk> - 2015-03-09 16:08 +0000
    Re: What constitutes "standard" C? "Bill Cunningham" <nospam@nspam.invalid> - 2015-03-07 15:07 -0500
  Re: What constitutes "standard" C? Richard Heathfield <rjh@cpax.org.uk> - 2015-03-07 11:21 +0000
    Re: What constitutes "standard" C? James Kuyper <jameskuyper@verizon.net> - 2015-03-07 11:24 -0500
      Re: What constitutes "standard" C? Richard Heathfield <rjh@cpax.org.uk> - 2015-03-07 17:09 +0000
        Re: What constitutes "standard" C? James Kuyper <jameskuyper@verizon.net> - 2015-03-07 12:47 -0500
          Re: What constitutes "standard" C? Richard Damon <Richard@Damon-Family.org> - 2015-03-07 17:47 -0500
            Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-03-07 15:43 -0800
              Re: What constitutes "standard" C? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-03-08 01:03 +0000
              Re: What constitutes "standard" C? Richard Damon <Richard@Damon-Family.org> - 2015-03-07 21:02 -0500
                Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-03-07 18:51 -0800
                Re: What constitutes "standard" C? Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-24 16:02 -0700
                Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-03-25 08:52 -0700
                Re: What constitutes "standard" C? Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-25 15:55 -0700
                Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-03-25 16:33 -0700
                Re: What constitutes "standard" C? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-03-27 20:14 +0000
                Re: What constitutes "standard" C? fir <profesor.fir@gmail.com> - 2015-03-27 17:19 -0700
                Re: What constitutes "standard" C? Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-27 17:30 -0700
                Re: What constitutes "standard" C? Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-28 14:27 -0700
                Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-03-28 20:43 -0700
                Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-04-04 12:15 -0700
                Re: What constitutes "standard" C? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-04-05 01:13 +0000
                Re: What constitutes "standard" C? James Kuyper <jameskuyper@verizon.net> - 2015-04-05 13:43 -0400
                Re: What constitutes "standard" C? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-04-05 20:14 +0000
                Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-04-05 13:28 -0700
                Re: What constitutes "standard" C? James Kuyper <jameskuyper@verizon.net> - 2015-04-05 17:56 -0400
  Re: What constitutes "standard" C? Lőrinczy Zsigmond <nospam@for.me> - 2015-03-07 14:03 +0100
    Re: What constitutes "standard" C? Richard Heathfield <rjh@cpax.org.uk> - 2015-03-07 13:30 +0000
      Re: What constitutes "standard" C? Bartc <bc@freeuk.com> - 2015-03-07 14:42 +0000
        Re: What constitutes "standard" C? fir <profesor.fir@gmail.com> - 2015-03-07 08:33 -0800
        Re: What constitutes "standard" C? "Bill Cunningham" <nospam@nspam.invalid> - 2015-03-07 18:53 -0500
      Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-03-07 16:42 -0800
    Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-03-07 15:49 -0800
  Re: What constitutes "standard" C? fir <profesor.fir@gmail.com> - 2015-03-07 05:13 -0800
  Re: What constitutes "standard" C? Kaz Kylheku <kaz@kylheku.com> - 2015-03-07 15:35 +0000
    Re: What constitutes "standard" C? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-03-07 10:49 -0500
      Re: What constitutes "standard" C? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-03-07 10:52 -0500
  Re: What constitutes "standard" C? James Kuyper <jameskuyper@verizon.net> - 2015-03-07 11:21 -0500
    Re: What constitutes "standard" C? Keith Thompson <kst-u@mib.org> - 2015-03-07 17:10 -0800
      Re: What constitutes "standard" C? James Kuyper <jameskuyper@verizon.net> - 2015-03-09 11:32 -0400

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