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Re: ridiculous warning or not?

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Keith Thompson <kst-u@mib.org> writes:

> Tim Rentsch <txr@alumni.caltech.edu> writes:
>> Keith Thompson <kst-u@mib.org> writes:
> [...snip-a-lot...]
>>> So this:
>>>
>>>     char f[];
>>>
>>> is treated as:
>>>
>>>     char f[] = 0;
>>
>> No, it would be  'char f[] = {0};'  as the implementation is
>> obliged to do by 6.7.9p16 -- implementations are obliged to
>> follow "shall" directives.
>
> Implementations are obliged to follow *all* normative requirements
> in the standard.  6.9.2p2 requires an implicit "initializer equal
> to 0".  I wouldn't say that `{0}` is "equal to 0".
>
>[...snip-some-more...]
>
>>> Apparently we have to interpret the "initializer equal to 0" to mean
>>> `{ 0 }` rather than `0` in this case.  And we're supposed to infer
>>> from that that `f` has exactly one element; apparently `{ 0 }` is
>>> "equal to 0" but `{ 0, 0 }` isn't.
>>
>> { 0, 0 } is two initializers, not one.
>
> { 0, 0 } is one initializer, which contains two more initializers.
> [...snip elaboration...]

My comments were kind of half frivolous, because I find
it hard to believe someone would take this question so
seriously, when it seems perfectly obvious what is
intended.  I do think my comments have some degree of
merit (and yours also), but not sufficient to overcome
the level of silliness present (for which I am more
to blame than you).

Therefore, rather than continuing on the particular
points above, I would like to quote from Defect Report #11
(slightly reformatted):

    Question 3  Initialization of tentative definitions
    --------------------------------------------------- 
    If the file scope declaration

        int i[10];

    appears in a translation unit, subclause 6.7.2 suggests
    that it is implicitly initialized as if

        int i[10] = 0;

    appears at the end of the translation unit.  However, this
    initializer is invalid, since subclause 6.5.7 prescribes
    that the initializer for any object of array type must be
    brace-enclosed.  We believe that the intention of subclause
    6.7.2 is that this declaration has an implicit initializer
    of

        int i[10] = {0};

    Is this true?

    Response
    --------
    Subclause 6.7.2 External object definitions contains the
    following excerpt:

        If a translation unit contains one or more tentative
        definitions for an identifier, and the translation unit
        contains no external definition for that identifier,
        then the behavior is exactly as if the translation unit
        contains a file scope declaration of that identifier,
        with the composite type as of the end of the
        translation unit, with an initializer equal to 0.

    This statement describes an effect and not a literal token
    sequence.  Therefore, this example does not contain an
    error.

Please note the first sentence in the last paragraph.

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Thread

ridiculous warning or not? kerravon <kerravon@w3.to> - 2012-08-20 02:41 -0700
  Re: ridiculous warning or not? Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-08-20 07:55 -0400
  Re: ridiculous warning or not? army1987 <army1987@ask-for-it.invalid> - 2012-08-20 19:11 +0000
  Re: ridiculous warning or not? Kenneth Brody <kenbrody@spamcop.net> - 2012-08-20 16:09 -0400
    Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 07:29 -0700
  Re: ridiculous warning or not? Andrew Cooper <amc96@cam.ac.uk> - 2012-08-21 00:36 +0100
  Re: ridiculous warning or not? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-08-21 01:41 +0100
    Re: ridiculous warning or not? Keith Thompson <kst-u@mib.org> - 2012-08-20 18:59 -0700
      Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 08:03 -0700
        Re: ridiculous warning or not? Keith Thompson <kst-u@mib.org> - 2012-09-07 14:37 -0700
          Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 19:17 -0700
            Re: ridiculous warning or not? Keith Thompson <kst-u@mib.org> - 2012-09-07 19:56 -0700
              Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-08 06:30 -0700
    Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 07:57 -0700
      Re: ridiculous warning or not? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-09-08 00:25 +0100
        Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 18:58 -0700
          Re: ridiculous warning or not? Keith Thompson <kst-u@mib.org> - 2012-09-07 19:26 -0700
            Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-08 06:26 -0700
              Re: ridiculous warning or not? Keith Thompson <kst-u@mib.org> - 2012-09-08 11:33 -0700
                Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-17 14:39 -0800
                Re: ridiculous warning or not? Keith Thompson <kst-u@mib.org> - 2012-12-17 15:56 -0800
                Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-20 10:31 -0800
                Re: ridiculous warning or not? Keith Thompson <kst-u@mib.org> - 2012-12-20 16:57 -0800
                Re: ridiculous warning or not? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-12-21 03:11 +0000
                Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-21 09:06 -0800
          Re: ridiculous warning or not? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-09-08 03:42 +0100
            Re: ridiculous warning or not? Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-08 06:01 -0700
              Re: ridiculous warning or not? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-09-08 14:45 +0100
                Re: ridiculous warning or not? Keith Thompson <kst-u@mib.org> - 2012-09-08 11:28 -0700
                Re: ridiculous warning or not? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-09-08 22:53 +0100
  Re: ridiculous warning or not? kerravon <kerravon@w3.to> - 2012-08-21 03:25 -0700
    Re: ridiculous warning or not? 88888 Dihedral <dihedral88888@googlemail.com> - 2012-08-21 11:20 -0700
      Re: ridiculous warning or not? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-08-21 21:07 +0100
        Re: ridiculous warning or not? 88888 Dihedral <dihedral88888@googlemail.com> - 2012-08-21 14:39 -0700
          Re: ridiculous warning or not? Ike Naar <ike@iceland.freeshell.org> - 2012-08-21 22:09 +0000
            Re: ridiculous warning or not? 88888 Dihedral <dihedral88888@googlemail.com> - 2012-08-21 15:13 -0700
              Re: ridiculous warning or not? Fred K <fred.l.kleinschmidt@gmail.com> - 2012-08-22 07:17 -0700

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