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Groups > comp.lang.c > #382350
| From | Keith Thompson <Keith.S.Thompson+u@gmail.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Is C ready to become a safer language? |
| Date | 2024-02-11 13:47 -0800 |
| Organization | None to speak of |
| Message-ID | <87o7cmad27.fsf@nosuchdomain.example.com> (permalink) |
| References | (1 earlier) <uq2vjp$21qev$1@dont-email.me> <86eddl5bag.fsf@linuxsc.com> <uq8lus$3dceu$1@dont-email.me> <8734tzdepl.fsf@nosuchdomain.example.com> <uqb5bq$136n4$1@dont-email.me> |
Thiago Adams <thiago.adams@gmail.com> writes:
> Em 2/10/2024 9:31 PM, Keith Thompson escreveu:
>> bart <bc@freeuk.com> writes:
>>> On 10/02/2024 01:59, Tim Rentsch wrote:
>>>> bart <bc@freeuk.com> writes:
>>>> [...]
>>>>
>>>>> This is something which has long been of fascination to me: how
>>>>> exactly do you get a C compiler to actually fail a program with a
>>>>> hard error when there is obviously something wrong, while not also
>>>>> failing on completely harmless matters.
>> The only thing that *requires* a compiler to reject a translation
>> unit
>> is the #error directive. For any violation of a syntax rule or
>> constraint, the standard only requires a *diagnostic message*, which can
>> be a non-fatal warning.
>
> I haven't checked the standard but
>
> #if 1/0
> #endif
>
>
> <source>:4:6: error: division by zero in preprocessor expression
> 4 | #if 1/0
> | ~^~
>
>
> stops compilation.
Then I suggest you check the standard. It's perfectly valid for an
implementation to choose to stop compilation if it encounters 1/0 in a
preprocessor expression, but it's not required. "The resulting tokens
compose the controlling constant expression which is evaluated according
to the rules of 6.6." 6.6, Constraints: "Each constant expression shall
evaluate to a constant that is in the range of representable values for
its type." So that's simply a constraint violation, requiring a
diagnostic but not requiring the translation unit to be rejected.
> With constexpr in C23 I guess division by 0 will stop code generation
> as well.
No, it merely requires a constant expression.
constexpr int n = 1/0;
is a constraint violation, requiring a diagnostic but not requiring
rejection.
--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Medtronic
void Void(void) { Void(); } /* The recursive call of the void */
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Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-08 01:01 -0300
Re: Is C ready to become a safer language? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-02-08 04:40 +0000
Re: Is C ready to become a safer language? Kaz Kylheku <433-929-6894@kylheku.com> - 2024-02-08 05:00 +0000
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-08 09:20 -0300
Re: Is C ready to become a safer language? bart <bc@freeuk.com> - 2024-02-08 17:02 +0000
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-08 14:17 -0300
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-08 14:19 -0300
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-08 09:57 -0800
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-08 09:45 -0800
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-08 14:56 -0300
Re: Is C ready to become a safer language? Kaz Kylheku <433-929-6894@kylheku.com> - 2024-02-08 04:58 +0000
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-07 21:33 -0800
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-07 20:59 -0800
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-08 09:17 +0100
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-08 09:48 -0300
Re: Is C ready to become a safer language? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-02-08 14:42 +0000
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-08 16:25 +0100
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-08 13:15 -0300
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-08 21:42 +0100
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-08 08:04 -0800
Re: Is C ready to become a safer language? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-02-08 16:14 +0000
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-08 08:32 -0800
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-09 08:19 +0100
Re: Is C ready to become a safer language? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-02-09 07:46 +0000
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-09 09:33 +0100
Re: Is C ready to become a safer language? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-02-09 10:03 +0000
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-09 11:17 +0100
Re: Is C ready to become a safer language? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-02-09 10:24 +0000
Re: Is C ready to become a safer language? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-02-09 11:24 +0000
Re: Is C ready to become a safer language? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-02-09 13:28 +0000
Re: Is C ready to become a safer language? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-02-09 14:04 +0000
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-09 15:03 +0100
ustent on that. Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-02-09 16:01 +0000
Re: ustent on that. David Brown <david.brown@hesbynett.no> - 2024-02-09 18:00 +0100
Re: ustent on that. Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-02-10 01:20 +0000
Re: Is C ready to become a safer language? bart <bc@freeuk.com> - 2024-02-09 12:45 +0000
Re: Is C ready to become a safer language? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2024-02-09 13:01 +0000
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-09 15:08 +0100
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-09 08:48 -0800
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-09 08:14 +0100
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-09 08:28 -0800
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-09 20:15 +0100
Re: Is C ready to become a safer language? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-02-10 02:28 -0800
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-10 16:15 -0800
Re: Is C ready to become a safer language? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-02-10 23:22 -0800
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-11 00:12 -0800
Re: Is C ready to become a safer language? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-02-11 23:48 -0800
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-18 15:28 -0800
Re: Is C ready to become a safer language? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-23 10:35 -0700
Re: Is C ready to become a safer language? Richard Kettlewell <invalid@invalid.invalid> - 2024-02-08 15:37 +0000
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-08 13:25 -0300
Re: Is C ready to become a safer language? bart <bc@freeuk.com> - 2024-02-08 16:30 +0000
Re: Is C ready to become a safer language? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-02-09 17:59 -0800
Re: Is C ready to become a safer language? bart <bc@freeuk.com> - 2024-02-10 20:22 +0000
Re: Is C ready to become a safer language? Richard Harnden <richard.nospam@gmail.invalid> - 2024-02-10 21:30 +0000
Re: Is C ready to become a safer language? Kaz Kylheku <433-929-6894@kylheku.com> - 2024-02-10 21:49 +0000
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-10 20:44 -0300
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-11 13:06 +0100
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-11 15:43 -0300
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-11 13:33 -0800
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-12 11:32 +0100
Re: Is C ready to become a safer language? bart <bc@freeuk.com> - 2024-02-11 00:02 +0000
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-10 17:39 -0800
Re: Is C ready to become a safer language? Kaz Kylheku <433-929-6894@kylheku.com> - 2024-02-11 02:46 +0000
Re: Is C ready to become a safer language? bart <bc@freeuk.com> - 2024-02-11 12:24 +0000
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-11 15:06 +0100
Re: Is C ready to become a safer language? Kaz Kylheku <433-929-6894@kylheku.com> - 2024-02-11 18:32 +0000
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-11 13:15 +0100
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-10 16:31 -0800
Re: Is C ready to become a safer language? Thiago Adams <thiago.adams@gmail.com> - 2024-02-11 15:57 -0300
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-11 13:47 -0800
Re: Is C ready to become a safer language? vallor <vallor@cultnix.org> - 2024-02-11 00:40 +0000
Re: Is C ready to become a safer language? bart <bc@freeuk.com> - 2024-02-11 01:06 +0000
Re: Is C ready to become a safer language? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-02-10 17:51 -0800
Re: Is C ready to become a safer language? David Brown <david.brown@hesbynett.no> - 2024-02-11 13:27 +0100
Re: Is C ready to become a safer language? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-02-10 19:54 -0800
Re: Is C ready to become a safer language? vallor <vallor@cultnix.org> - 2024-02-13 06:22 +0000
Re: Is C ready to become a safer language? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-02-11 11:01 +0000
Re: Is C ready to become a safer language? Richard Harnden <richard.nospam@gmail.invalid> - 2024-02-11 11:31 +0000
Re: Is C ready to become a safer language? bart <bc@freeuk.com> - 2024-02-11 12:38 +0000
Re: Is C ready to become a safer language? Richard Harnden <richard.nospam@gmail.invalid> - 2024-02-11 13:23 +0000
Re: Is C ready to become a safer language? bart <bc@freeuk.com> - 2024-02-11 14:17 +0000
Re: Is C ready to become a safer language? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-02-10 22:21 -0800
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