Re: "Richard Stallman Announces C Reference"

From	Lynn McGuire <lynnmcguire5@gmail.com>
Newsgroups	comp.lang.c++
Subject	Re: "Richard Stallman Announces C Reference"
Date	2022-09-16 16:55 -0500
Organization	A noiseless patient Spider
Message-ID	<tg2rca$3un6v$1@dont-email.me> (permalink)
References	(11 earlier) <tfr0f0$2ppo$1@nyheter.lysator.liu.se> <tfrv41$2rkif$1@dont-email.me> <tfsae7$iac$1@nyheter.lysator.liu.se> <tfsmhf$2vqod$1@dont-email.me> <tg2lik$29qi$1@nyheter.lysator.liu.se>

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On 9/16/2022 3:16 PM, Andreas Kempe wrote:
> Den 2022-09-14 skrev David Brown <david.brown@hesbynett.no>:
>> On 14/09/2022 12:29, Andreas Kempe wrote:
>>> Den 2022-09-14 skrev David Brown <david.brown@hesbynett.no>:
>>>> On 14/09/2022 00:33, Andreas Kempe wrote:
>>>>> Den 2022-09-13 skrev Muttley@dastardlyhq.com <Muttley@dastardlyhq.com>:
>>>>>> On Mon, 12 Sep 2022 20:32:21 +0200
>>>>>> Bo Persson <bo@bo-persson.se> wrote:
>>>>>>> On 2022-09-12 at 17:58, Muttley@dastardlyhq.com wrote:
>>>>>>>>> my_class f(x);
>>>>>>>>
>>>>>>>> And if that instance has virtual functions where will the VFT go and what
>>>>>>>> allocates it? Ditto any non primitive types which may cause an implcit
>>>>>>> cascade
>>>>>>>> of allocations.
>>>>>>>
>>>>>>> Just don't see how we know that int y = f(x); doesn't call other
>>>>>>> functions that allocate structs on the heap? Structs that contain
>>>>>>
>>>>>> It may well do, but you can at least look at them to see how and kernel authors
>>>>>> are extremely careful about how they allocate dynamic memory. Meanwhile
>>>>>> who knows if std::string s = "hello" will allocate on the heap or if it'll
>>>>>> use its small reerved amount of stack.
>>>>>>
>>>>>>
>>>>>
>>>>> In my view, this is not a language problem as much as a standard
>>>>> library implementation problem. As have been brought up earlier, you
>>>>> don't use the normal user space libc in the kernel for C code, but
>>>>> have parts of the standard library implemented in a way to make it fit
>>>>> the kernel.
>>>>>
>>>>> To seriously bring C++ into the kernel world, one would have to do the
>>>>> same. That is, pick functions from the standard library that make
>>>>> sense in the kernel and implement them to work there. One such thing
>>>>> could of course be an std::string without hidden heap allocations.
>>>>>
>>>>> I, and doubtlessly many others, have long toyed with the idea that
>>>>> kernel programming, Linux or *BSD is what I'm familiar with, could be
>>>>> made simpler with a language that supports object oriented programming
>>>>> instead of using C structs with function pointers. The possibility of
>>>>> doing RAII would also be nice. Whether that language should be C++ is
>>>>> another question and I don't have a good answer.
>>>>
>>>> When working on an OS kernel, there are lots of things in the C standard
>>>> library that you avoid, and there is no difference in regard to C++.  It
>>>> has a lot in common with embedded development, and that is often done in
>>>> C++.  With the software I write, on microcontrollers, I am quite happy
>>>> to use C++, but I am careful about the features I use.  Exceptions are
>>>> disabled, virtual inheritance is out (virtual functions are used with
>>>> caution), and there is rarely a good enough reason for anything
>>>> involving dynamic memory in my code.
>>>>
>>>
>>> What size are we talking about? In a professional setting, I've only
>>> worked with embedded systems large enough to run Linux.
>>
>> Smaller than that - usually a /lot/ smaller.  I tend to think of
>> "embedded Linux systems" as primarily /Linux/ systems, rather than
>> primarily /embedded/ systems.  Some people prefer "resource constrained
>> embedded systems" as an alternative name.
>>
>> Basically, I am considering systems where you have a single statically
>> linked program.  (You might have sometimes have an extra boot program,
>> or updater, or test program - but the normal mode of operation is one
>> program.)
>>
> 
> I guess the term embedded is a bit diluted these days with how
> powerful SoCs have become.
> 
> Working on projects for very small processors, I've only used C or
> assembly and my main experience is using PICs. I have toyed with the
> idea of using C++, but there isn't really any free C++ compilers PICs
> as far as I've found.
> 
> Thank you for an informative reply!
> 
>> [...]

What is a PIC ?

Lynn

Thread

"Richard Stallman Announces C Reference" Lynn McGuire <lynnmcguire5@gmail.com> - 2022-09-09 12:49 -0500
  Re: "Richard Stallman Announces C Reference" scott@slp53.sl.home (Scott Lurndal) - 2022-09-09 19:03 +0000
  Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-10 18:16 +0200
    Re: "Richard Stallman Announces C Reference" scott@slp53.sl.home (Scott Lurndal) - 2022-09-10 17:04 +0000
      Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-11 08:29 +0000
      Re: "Richard Stallman Announces C Reference" Manfred <noname@add.invalid> - 2022-09-24 16:24 +0200
        C++ is for real, C is just a toy (Was: "Richard Stallman Announces C Reference") gazelle@shell.xmission.com (Kenny McCormack) - 2022-09-24 15:54 +0000
          Re: C++ is for real, C is just a toy (Was: "Richard Stallman Announces C Reference") Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-24 18:07 +0200
    Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-11 08:29 +0000
      Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-11 11:16 +0200
        Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-11 09:44 +0000
          Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-11 13:42 +0200
            Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-11 15:44 +0000
              Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-11 17:55 +0200
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-11 16:17 +0000
                Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-11 18:22 +0200
                Re: "Richard Stallman Announces C Reference" "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-09-11 12:41 -0700
                Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-12 06:10 +0200
                Re: "Richard Stallman Announces C Reference" "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-09-12 00:27 -0700
              Re: "Richard Stallman Announces C Reference" Bo Persson <bo@bo-persson.se> - 2022-09-12 09:18 +0200
                Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-12 09:42 +0200
                Re: "Richard Stallman Announces C Reference" Bo Persson <bo@bo-persson.se> - 2022-09-12 12:05 +0200
                Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-12 12:12 +0200
                Re: "Richard Stallman Announces C Reference" Manfred <noname@add.invalid> - 2022-09-24 16:31 +0200
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-12 15:58 +0000
                Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-12 18:48 +0200
                Re: "Richard Stallman Announces C Reference" Bo Persson <bo@bo-persson.se> - 2022-09-12 20:32 +0200
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-13 13:27 +0000
                Re: "Richard Stallman Announces C Reference" Andreas Kempe <kempe@lysator.liu.se> - 2022-09-13 22:33 +0000
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-14 06:04 +0000
                Re: "Richard Stallman Announces C Reference" Andreas Kempe <kempe@lysator.liu.se> - 2022-09-14 10:38 +0000
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-14 12:21 +0000
                Re: "Richard Stallman Announces C Reference" Michael S <already5chosen@yahoo.com> - 2022-09-15 12:15 -0700
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-16 06:02 +0000
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-16 10:37 +0000
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-16 11:05 +0000
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-16 13:18 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-16 16:00 +0200
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-16 15:16 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-18 12:13 +0200
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-19 05:45 +0000
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-19 08:33 +0000
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-19 10:41 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-19 13:48 +0200
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-19 15:22 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-16 13:10 +0200
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-19 05:51 +0000
                Re: "Richard Stallman Announces C Reference" Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-09-19 12:27 -0700
                Re: "Richard Stallman Announces C Reference" "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-09-16 11:19 -0700
                Re: "Richard Stallman Announces C Reference" Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-09-16 06:56 -0700
                Re: "Richard Stallman Announces C Reference" scott@slp53.sl.home (Scott Lurndal) - 2022-09-16 14:29 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-16 17:04 +0200
                Re: "Richard Stallman Announces C Reference" Michael S <already5chosen@yahoo.com> - 2022-09-16 08:24 -0700
                Re: "Richard Stallman Announces C Reference" Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-09-16 09:00 -0700
                Re: "Richard Stallman Announces C Reference" Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2022-09-15 00:54 +0100
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-15 05:31 +0000
                Re: "Richard Stallman Announces C Reference" Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2022-09-15 10:19 +0100
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-22 12:41 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-14 09:16 +0200
                Re: "Richard Stallman Announces C Reference" Andreas Kempe <kempe@lysator.liu.se> - 2022-09-14 10:29 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-14 15:55 +0200
                Re: "Richard Stallman Announces C Reference" Andreas Kempe <kempe@lysator.liu.se> - 2022-09-16 20:16 +0000
                Re: "Richard Stallman Announces C Reference" Lynn McGuire <lynnmcguire5@gmail.com> - 2022-09-16 16:55 -0500
                Re: "Richard Stallman Announces C Reference" scott@slp53.sl.home (Scott Lurndal) - 2022-09-16 22:21 +0000
                Re: "Richard Stallman Announces C Reference" Andreas Kempe <kempe@lysator.liu.se> - 2022-09-17 14:52 +0000
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-19 06:06 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-18 12:34 +0200
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-18 12:22 +0200
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-19 06:11 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-19 10:14 +0200
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-14 12:12 +0000
                Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-14 15:58 +0200
              Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-13 06:47 +0000
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-13 13:29 +0000
                Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-14 05:56 +0000
                Re: "Richard Stallman Announces C Reference" Muttley@dastardlyhq.com - 2022-09-14 09:37 +0000
          boost::intrusive. Was: "Richard Stallman Announces C Reference" Michael S <already5chosen@yahoo.com> - 2022-09-11 09:51 -0700
            Re: boost::intrusive. Was: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-11 18:55 +0200
        Re: "Richard Stallman Announces C Reference" scott@slp53.sl.home (Scott Lurndal) - 2022-09-11 16:26 +0000
          Re: "Richard Stallman Announces C Reference" Bonita Montero <Bonita.Montero@gmail.com> - 2022-09-11 18:35 +0200
        Re: "Richard Stallman Announces C Reference" Opus <ifonly@youknew.org> - 2022-09-12 19:22 +0200
          Re: "Richard Stallman Announces C Reference" legalize+jeeves@mail.xmission.com (Richard) - 2022-09-22 19:24 +0000
  Re: "Richard Stallman Announces C Reference" Michael S <already5chosen@yahoo.com> - 2022-09-10 12:56 -0700
    Re: "Richard Stallman Announces C Reference" Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-09-10 15:53 -0700
    Re: "Richard Stallman Announces C Reference" "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-09-11 07:07 +0200
      Re: "Richard Stallman Announces C Reference" Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-09-11 16:17 -0700
    Re: "Richard Stallman Announces C Reference" David Brown <david.brown@hesbynett.no> - 2022-09-11 13:50 +0200
      Re: "Richard Stallman Announces C Reference" Michael S <already5chosen@yahoo.com> - 2022-09-11 05:53 -0700
    Re: "Richard Stallman Announces C Reference" Juha Nieminen <nospam@thanks.invalid> - 2022-09-12 05:47 +0000
  Re: "Richard Stallman Announces C Reference" Manu Raju <MR@invalid.invalid> - 2022-09-11 00:01 +0100
    Re: "Richard Stallman Announces C Reference" Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-09-10 16:26 -0700
  Re: "Richard Stallman Announces C Reference" legalize+jeeves@mail.xmission.com (Richard) - 2022-09-22 19:21 +0000

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