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Re: Can extern "C" functions throw exceptions

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Ian Collins <ian-news@hotmail.com> writes:

> On 15/12/2021 16:06, james...@alumni.caltech.edu wrote:
>
>> On Tuesday, December 14, 2021 at 6:21:38 PM UTC-5, Tim Rentsch wrote:
>>
>>> "james...@alumni.caltech.edu" <james...@alumni.caltech.edu> writes:
>>
>> ...
>>
>>>> The language linkage of a function's type is indeed part of
>>>> that type.  The language linkage of a function's name is not.
>>>> The standard's description of language linkage in 9.11p1 starts
>>>> with the sentence "All function types, function names with
>>>> external linkage, and variable names with external linkage have
>>>> a language linkage.", clearly making the point that the
>>>> language linkage of a function's type is a distinct thing from
>>>> the language linkage of a function's name.  The standard could
>>>> have inextricably linked them together - but it does not.  In
>>>> fact, 9.11p5 includes an example demonstrating how they can be
>>>> separated:
>>>>
>>>> extern "C" typedef void FUNC();
>>>> FUNC f2; // the name f2 has C ++ language linkage and the
>>>> // function?s type has C language linkage
>>>>
>>>> [...]
>>>
>>> Thank you for this citation.  It doesn't answer all my questions
>>> but it certainly does provide an illuminating example.
>>
>> If you can figure out words to express your remaining questions,
>> I'd be curious to find out what they are.
>>   >> It appears, however, that in practice there is no difference
>>
>>> between a type with a C language linkage and a C++ language
>>> linkage.  Apparently most compilers ignore the distinction
>>> because following the rules would break too much code.  Here
>>> is a link to stackoverflow with more information:
>>>
>>> https://stackoverflow.com/questions/26647259/
>>> is-extern-c-a-part-of-the-type-of-a-function
>>
>> The standard is quite clear:  "Two function types with different
>> language linkages are distinct types even if they are otherwise
>> identical."  (9.11p1).  I'm annoyed, but unfortunately not
>> surprised, to find that this has been ignored.  I've never had
>> any need to write code where that issue would matter, which is
>> why I've never noticed.
>
> I have only used one compiler, Sun CC, that bothered to enforce
> the rule.  At the time, the main problem this caused me was it
> prevented static member functions being passed to pthread_create,
> I had to use extern "C" qualified friend function on Solaris.

Did you try a pattern like this:

    extern "C" typedef void Whatsit( double * );

    class Foo {
      public:
        static Whatsit fred;
    };

    void
    Foo::fred( double *things ){
        for(  int i = 0;  i < 10;  i++  )  things[i] += i;
    }

This code is accepted by g++ back to -std=c++98.  Of course,
since we know the gnu tools are compromised that doesn't tell us
very much...

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Can extern "C" functions throw exceptions Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-11 12:35 +0200
  Re: Can extern "C" functions throw exceptions Bo Persson <bo@bo-persson.se> - 2021-09-11 13:49 +0200
    Re: Can extern "C" functions throw exceptions "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-09-11 13:57 +0200
    Re: Can extern "C" functions throw exceptions Paavo Helde <myfirstname@osa.pri.ee> - 2021-09-11 15:19 +0300
    Re: Can extern "C" functions throw exceptions Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-11 15:32 +0200
    Re: Can extern "C" functions throw exceptions HorseyWorsey@the_stables.com - 2021-09-11 15:54 +0000
  Re: Can extern "C" functions throw exceptions "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-09-11 13:55 +0200
    Re: Can extern "C" functions throw exceptions Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-11 15:34 +0200
      Re: Can extern "C" functions throw exceptions Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-11 15:58 +0200
      Re: Can extern "C" functions throw exceptions "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-09-11 17:00 +0200
        Re: Can extern "C" functions throw exceptions "daniel...@gmail.com" <danielaparker@gmail.com> - 2021-10-06 13:36 -0700
          Re: Can extern "C" functions throw exceptions Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-06 20:42 +0000
            Re: Can extern "C" functions throw exceptions Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-06 16:12 -0700
              Re: Can extern "C" functions throw exceptions Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-06 23:22 +0000
                Re: Can extern "C" functions throw exceptions Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-06 17:03 -0700
    Re: Can extern "C" functions throw exceptions HorseyWorsey@the_stables.com - 2021-09-11 15:56 +0000
    Re: Can extern "C" functions throw exceptions David Brown <david.brown@hesbynett.no> - 2021-09-11 20:10 +0200
      Re: Can extern "C" functions throw exceptions Juha Nieminen <nospam@thanks.invalid> - 2021-09-12 09:20 +0000
        Re: Can extern "C" functions throw exceptions Paavo Helde <myfirstname@osa.pri.ee> - 2021-09-12 12:34 +0300
        Re: Can extern "C" functions throw exceptions David Brown <david.brown@hesbynett.no> - 2021-09-12 12:24 +0200
          Re: Can extern "C" functions throw exceptions Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-12 12:29 +0200
        Re: Can extern "C" functions throw exceptions Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2021-09-12 14:44 +0100
          Re: Can extern "C" functions throw exceptions James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-12 23:13 -0400
            Re: Can extern "C" functions throw exceptions David Brown <david.brown@hesbynett.no> - 2021-09-13 09:30 +0200
            Re: Can extern "C" functions throw exceptions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-06 13:12 -0700
              Re: Can extern "C" functions throw exceptions "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-10-07 07:09 -0700
                Re: Can extern "C" functions throw exceptions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-14 15:21 -0800
                Re: Can extern "C" functions throw exceptions Richard Damon <Richard@Damon-Family.org> - 2021-12-14 21:17 -0500
                Re: Can extern "C" functions throw exceptions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-16 04:21 -0800
                Re: Can extern "C" functions throw exceptions "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-12-14 19:06 -0800
                Re: Can extern "C" functions throw exceptions Ian Collins <ian-news@hotmail.com> - 2021-12-16 13:14 +1300
                Re: Can extern "C" functions throw exceptions "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-12-15 18:05 -0800
                Re: Can extern "C" functions throw exceptions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-16 04:37 -0800
                Re: Can extern "C" functions throw exceptions Ian Collins <ian-news@hotmail.com> - 2021-12-17 09:39 +1300
                Re: Can extern "C" functions throw exceptions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-16 19:24 -0800
                Re: Can extern "C" functions throw exceptions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-16 04:29 -0800
          Re: Can extern "C" functions throw exceptions Juha Nieminen <nospam@thanks.invalid> - 2021-09-13 05:34 +0000
            Re: Can extern "C" functions throw exceptions Paavo Helde <myfirstname@osa.pri.ee> - 2021-09-13 09:55 +0300
  Re: Can extern "C" functions throw exceptions Paavo Helde <myfirstname@osa.pri.ee> - 2021-09-11 15:12 +0300
  Re: Can extern "C" functions throw exceptions red floyd <no.spam.here@its.invalid> - 2021-09-13 13:21 -0700

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