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Groups > comp.lang.c > #382263
| From | Tim Rentsch <tr.17687@z991.linuxsc.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Is C ready to become a safer language? |
| Date | 2024-02-10 02:28 -0800 |
| Organization | A noiseless patient Spider |
| Message-ID | <865xyw62av.fsf@linuxsc.com> (permalink) |
| References | <uq1jnk$1qebo$2@dont-email.me> <87jznfh7p6.fsf@nosuchdomain.example.com> |
Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:
> Thiago Adams <thiago.adams@gmail.com> writes:
>
>> Let's say C compilers can detect all sorts of bugs at compile time.
>>
>> How would C compilers report that? As an error or a warning?
>>
>> Let's use this sample:
>>
>> int main() {
>> int a = 1;
>> a = a / 0;
>> }
>>
>> GCC says:
>>
>> warning: division by zero is undefined [-Wdivision-by-zero]
>> 5 | a = a / 0;
>> | ^ ~
>>
>> In case GCC or any other compiler reports this as an error, then C
>> programmers would likely complain. Am I right?
>
> Someone will always complain, but a conforming compiler can report this
> as a fatal error.
>
> Division by zero has undefine behavior. Under the standard's definition
> of undefined behavior, it says:
>
> NOTE
>
> Possible undefined behavior ranges from ignoring the situation
> completely with unpredictable results, to behaving during
> translation or program execution in a documented manner
> characteristic of the environment (with or without the issuance
> of a diagnostic message), to terminating a translation or
> execution (with the issuance of a diagnostic message).
>
> Though it's not quite that simple. Rejecting the program if the
> compiler can't prove that the division will be executed would IMHO
> be non-conforming. Code that's never executed has no behavior, so
> it doesn't have undefined behavior.
An implementation can refuse to translate the program, but not
because undefined behavior occurs. The undefined behavior here
happens only when the program is executed, but just compiling the
program doesn't do that. No execution, no undefined behavior.
Still the program may be rejected, because it is not strictly
conforming (by virtue of having output depend on the undefined
behavior if the program is ever run).
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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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