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Groups > comp.lang.c > #152056
| From | Keith Thompson <Keith.S.Thompson+u@gmail.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: longer 'char literals' meaning in c |
| Date | 2020-05-05 13:41 -0700 |
| Organization | None to speak of |
| Message-ID | <87h7wu15dv.fsf@nosuchdomain.example.com> (permalink) |
| References | (8 earlier) <4lKqG.254784$mk2.321@fx21.am4> <87lfmc4dwh.fsf@nosuchdomain.example.com> <r8qd3b$hmi$1@z-news.wcss.wroc.pl> <r8qntq$p8s$1@dont-email.me> <r8s6lq$k31$1@z-news.wcss.wroc.pl> |
antispam@math.uni.wroc.pl writes:
[...]
> Then why 4.5 says: "minimum implementation limit". If not for
> other limits it could refer to "minimum translation limit" or
> simply point to 5.2.4.1. I agree that consequences do not look
> nice, but wording strongly suggest that 5.2.4.2 was intended
> to apply. And clearly "minimum implementation limit" applies
> regardless if offending code otherwise affects observable behaviour
> or not. Now, how 5.2.4.2 could apply? Clearly
> "minimum implementation limit" is _not_ intended to affect
> runtime behaviour (actual limits do this). Natural
> troublespot are numeric literals, trying to use large
> literals could exceed compiler limit.
Large numeric literals are handled in a well defined way.
Each constant shall have a type and the value of a constant shall be
in the range of representable values for its type.
A integer or floating constant that's outside the range of any supported
type is a constraint violation.
> In particluar,
> it seems that compiler is allowed to reject at compile
> time literals which otherwise would represent legal
> runtime values.
I don't believe that's correct, but I'm not entirely sure what you
mean. Can you provide an example (even a hypothetical one)?
> I admit that that this looks undesirable,
> but ATM compiler which implements INT_MAX as expression
> and is unable to handle it as literal value looks for
> me as poor quality but legal implementation.
INT_MAX must be a constant expression of type int. N1570 5.2.4.2.1p1:
The values given below shall be replaced by constant expressions
suitable for use in #if preprocessing directives. Moreover,
except for CHAR_BIT and MB_LEN_MAX, the following shall be
replaced by expressions that have the same type as would an
expression that is an object of the corresponding type converted
according to the integer promotions.
[...]
> 4.3 says "...correct in all other aspects, ...". So this means
> that merely containing unspecified behavior is not valid reason
> to reject program. But this does not imply that choice of implementation
> defined value have to be done in way that makes program "correct in
> all other aspects". For example if implementation defined value
> is used in arithmetic, then implementation is _not_ forced to
> find values that avoid undefined behaviour (or other trouble).
> And for me 4.5 and 4.6 together mean that it is responsiblity
> of program (programmer) to avoid exceeding implementation limits.
> In other word when for given program implementation defined rule
> leads to behaviur that exceed capability of given implementation
> then implementation is still conforming: it does not reject
> program due to "unspecified behavior", but because it can
> not handle it... Of course, this leads to question if
> implementation limit is reasonable. Clearly saying "this
> implementation is unable to handle unspecified behavior"
> is a cheat. But saying "this implementation can not fit
> 5 chars into space of 4 chars" is pretty reasonable limit.
Given that character constants are of type int, I'm not at all
convinced by an argument that the implementation can say that
some character constants have values that are outside the range of
type int.
An implementation certainly *can* map a constant like 'ABCDE'
to a value within the range of type int. The question is whether it's
allowed to choose not to.
--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips Healthcare
void Void(void) { Void(); } /* The recursive call of the void */
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longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 04:43 -0700
Re: longer 'char literals' meaning in c Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 13:55 +0200
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 05:17 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 05:22 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 05:24 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 05:29 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 06:16 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 05:44 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 14:00 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 06:13 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 14:41 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 07:18 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 07:31 -0700
Re: longer 'char literals' meaning in c Spiros Bousbouras <spibou@gmail.com> - 2020-04-30 15:49 +0000
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 09:12 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 15:49 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 08:31 -0700
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-30 14:00 -0700
Re: longer 'char literals' meaning in c Spiros Bousbouras <spibou@gmail.com> - 2020-04-30 21:16 +0000
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-30 15:22 -0700
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-04-30 18:36 -0400
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 22:25 +0100
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-30 15:30 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-05-01 00:01 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 16:15 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 16:29 -0700
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-30 17:15 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-05-01 01:47 +0100
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-04-30 18:38 -0700
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-30 18:55 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-05-01 11:35 +0100
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-01 05:47 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-05-01 06:15 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-05-01 15:53 +0100
Re: longer 'char literals' meaning in c Richard Damon <Richard@Damon-Family.org> - 2020-05-01 12:38 -0400
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-01 09:57 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-05-01 20:50 +0100
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-01 13:11 -0700
Re: longer 'char literals' meaning in c jameskuyper@stellarscience.com - 2020-05-01 12:05 -0700
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-01 19:08 -0400
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-01 09:51 -0700
Re: longer 'char literals' meaning in c David Brown <david.brown@hesbynett.no> - 2020-05-02 15:22 +0200
Re: longer 'char literals' meaning in c Richard Damon <Richard@Damon-Family.org> - 2020-05-02 12:13 -0400
Re: longer 'char literals' meaning in c Les Cargill <lcargill99@comcast.com> - 2020-05-04 00:17 -0500
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-04 10:51 -0400
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-04 10:23 -0400
Re: longer 'char literals' meaning in c David Brown <david.brown@hesbynett.no> - 2020-05-04 16:48 +0200
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-04 12:39 -0400
Re: longer 'char literals' meaning in c David Brown <david.brown@hesbynett.no> - 2020-05-04 19:37 +0200
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-04 15:03 -0400
Re: longer 'char literals' meaning in c David Brown <david.brown@hesbynett.no> - 2020-05-05 08:33 +0200
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-05 09:47 -0400
Re: longer 'char literals' meaning in c David Brown <david.brown@hesbynett.no> - 2020-05-05 16:22 +0200
Re: longer 'char literals' meaning in c Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-05-04 10:27 -0700
Re: longer 'char literals' meaning in c antispam@math.uni.wroc.pl - 2020-05-05 00:47 +0000
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-04 20:08 -0700
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-04 23:52 -0400
Re: longer 'char literals' meaning in c antispam@math.uni.wroc.pl - 2020-05-05 17:10 +0000
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-05 13:41 -0700
Re: longer 'char literals' meaning in c antispam@math.uni.wroc.pl - 2020-05-05 22:29 +0000
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-05 16:18 -0700
Re: longer 'char literals' meaning in c antispam@math.uni.wroc.pl - 2020-05-06 02:33 +0000
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-05 20:06 -0700
Re: longer 'char literals' meaning in c antispam@math.uni.wroc.pl - 2020-05-06 18:57 +0000
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-06 13:37 -0700
Re: longer 'char literals' meaning in c Spiros Bousbouras <spibou@gmail.com> - 2020-05-07 13:48 +0000
Re: longer 'char literals' meaning in c Spiros Bousbouras <spibou@gmail.com> - 2020-05-07 13:58 +0000
Re: longer 'char literals' meaning in c Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-05-24 17:36 -0700
Re: longer 'char literals' meaning in c Spiros Bousbouras <spibou@gmail.com> - 2020-05-25 00:56 +0000
Re: longer 'char literals' meaning in c Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-05-29 22:53 -0700
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-07 18:01 -0700
Re: longer 'char literals' meaning in c Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-05-30 10:53 -0700
Re: longer 'char literals' meaning in c Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-05-30 15:11 -0700
Re: longer 'char literals' meaning in c Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-05-24 18:19 -0700
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-24 20:06 -0700
Re: longer 'char literals' meaning in c Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-05-26 07:02 -0700
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-05 20:18 -0400
Re: longer 'char literals' meaning in c antispam@math.uni.wroc.pl - 2020-05-06 20:01 +0000
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-05-06 18:20 -0400
Re: longer 'char literals' meaning in c Siri Cruise <chine.bleu@yahoo.com> - 2020-04-30 20:13 -0700
Re: longer 'char literals' meaning in c Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 16:58 +0200
Re: longer 'char literals' meaning in c Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 16:59 +0200
Re: longer 'char literals' meaning in c Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 17:14 +0200
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 08:33 -0700
Re: longer 'char literals' meaning in c Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 18:15 +0200
Re: longer 'char literals' meaning in c James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-04-30 08:33 -0700
Re: longer 'char literals' meaning in c David Brown <david.brown@hesbynett.no> - 2020-04-30 17:49 +0200
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 17:23 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 09:38 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 17:56 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 10:04 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 18:28 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 10:39 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 19:16 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 11:24 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 19:58 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 12:08 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 20:16 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 12:29 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 12:10 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 11:17 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 10:31 -0700
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 19:20 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 11:28 -0700
Re: longer 'char literals' meaning in c Richard Damon <Richard@Damon-Family.org> - 2020-04-30 13:48 -0400
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 09:01 -0700
Re: longer 'char literals' meaning in c Vir Campestris <vir.campestris@invalid.invalid> - 2020-04-30 21:32 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 13:43 -0700
Re: longer 'char literals' meaning in c Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-04-30 16:54 -0400
Re: longer 'char literals' meaning in c Vir Campestris <vir.campestris@invalid.invalid> - 2020-05-03 21:23 +0100
Re: longer 'char literals' meaning in c Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-05-03 16:48 -0400
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 11:38 -0700
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 11:57 -0700
Re: longer 'char literals' meaning in c Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 21:01 +0200
Re: longer 'char literals' meaning in c Bart <bc@freeuk.com> - 2020-04-30 20:07 +0100
Re: longer 'char literals' meaning in c fir <profesor.fir@gmail.com> - 2020-04-30 12:41 -0700
Re: longer 'char literals' meaning in c Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-05-04 10:30 -0700
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