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Groups > comp.lang.c > #155130

Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!!

From Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups comp.lang.c
Subject Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!!
Date 2020-09-18 17:34 -0700
Organization None to speak of
Message-ID <87mu1md2p1.fsf@nosuchdomain.example.com> (permalink)
References (3 earlier) <e4020711-d809-468e-b680-4148ca9bce20o@googlegroups.com> <878sd8m0ew.fsf@bsb.me.uk> <7d838b58-49a1-43ca-a579-a54ff0d7f0e7o@googlegroups.com> <rk3dpq$85a$1@dont-email.me> <IUb9H.2474172$imF1.1348796@fx15.am4>

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Bart <bc@freeuk.com> writes:
[snip]
> Plus the fact that a VLA is the simplest example of what is really a
> variable /type/ specifier:
>
>   void fn(int m,n) {
>       typedef int (*T)[m][n];
>       ....
>       T A;
>       ++m; --n;
>       {T B; ...}
> Does changing m and n here change the value sizeof returns from the
> array parts of A?

No, the size is determined when the declaration is reached (and
most likely stored in some anonymous objects).  Please don't invent
problems that don't exist.

[...]

> The compiler doesn't know (usually) how much stack is left. Detecting
> one 1MB VLA is one thing, how about 100 10KB VLAs in an arbitrary
> pattern of recursive functions?
>
> It's a feature out of place in a language like C.

The depth of recursion can also be unpredictable at compile time,
and can lead to stack overflow.  VLAs aren't *that* much different.

Let's say you want to allocate an array of N objects, where N is at
most 1000.  If you don't want use malloc() for some reason, a VLA
lets you define an array that is no more than 1000 elements long, and
takes up only as much storage as you need.  A common alternative in
the absence of VLAs is to define an array of exactly 1000 elements
and use only the first N of them.  In that particular use case,
VLAs save memory and make stack overflows less likely.

Of course other uses of VLAs can increase the risk of stack overflow.
If you don't want to accept that risk, you can use them with care,
or avoid them altogether, or adopt a coding standard that forbids
their use.

-- 
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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Microsoft Will now support C11 and C17 standard!!!!!!!!!! Real Troll <real.troll@trolls.com> - 2020-09-16 04:55 -1000
  Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Jens Stuckelberger <Jens_Stuckelberger@nowhere.net> - 2020-09-16 15:23 +0000
  Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-16 17:49 +0200
    Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-16 12:53 -0700
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! scott@slp53.sl.home (Scott Lurndal) - 2020-09-16 19:58 +0000
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! doctor@doctor.nl2k.ab.ca (The Doctor) - 2020-09-16 22:31 +0000
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-16 21:10 -0700
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-17 12:28 +0200
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-17 17:00 -0700
    Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Anton Shepelev <anton.txt@gmail.com> - 2020-09-17 02:13 +0300
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-17 07:44 +0200
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Manfred <noname@add.invalid> - 2020-09-18 22:08 +0200
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-19 06:54 +0200
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! gazelle@shell.xmission.com (Kenny McCormack) - 2020-09-17 11:05 +0000
    Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Andrey Tarasevich <andreytarasevich@hotmail.com> - 2020-09-20 00:41 -0700
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-20 11:03 +0200
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Manfred <noname@add.invalid> - 2020-09-20 15:51 +0200
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-09-20 07:41 -0700
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! scott@slp53.sl.home (Scott Lurndal) - 2020-09-20 14:41 +0000
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! scott@slp53.sl.home (Scott Lurndal) - 2020-09-20 14:39 +0000
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-20 16:55 +0200
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! David Brown <david.brown@hesbynett.no> - 2020-09-20 17:10 +0200
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-20 18:14 +0200
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! already5chosen@yahoo.com - 2020-09-20 10:44 -0700
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! David Brown <david.brown@hesbynett.no> - 2020-09-20 21:14 +0200
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! already5chosen@yahoo.com - 2020-09-20 15:40 -0700
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! David Brown <david.brown@hesbynett.no> - 2020-09-21 08:34 +0200
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-20 12:55 -0500
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! David Brown <david.brown@hesbynett.no> - 2020-09-20 21:16 +0200
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-20 20:40 +0100
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-20 19:39 -0500
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! David Brown <david.brown@hesbynett.no> - 2020-09-21 09:20 +0200
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-21 11:25 +0100
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! David Brown <david.brown@hesbynett.no> - 2020-09-21 14:27 +0200
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-21 22:24 -0700
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-22 08:49 +0200
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Manfred <noname@add.invalid> - 2020-09-21 15:09 +0200
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Manfred <noname@add.invalid> - 2020-09-21 15:26 +0200
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-21 11:40 +0100
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! David Brown <david.brown@hesbynett.no> - 2020-09-21 14:48 +0200
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-09-21 06:03 -0700
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-21 16:44 +0100
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-21 12:06 -0500
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-21 20:03 +0100
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-21 18:33 -0500
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-21 11:09 -0500
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-09-20 16:13 +0000
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-09-20 09:53 -0700
  Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-16 12:51 -0700
    Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-16 21:00 +0100
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Thiago Adams <thiago.adams@gmail.com> - 2020-09-17 05:28 -0700
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-17 17:03 -0700
  Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Leo <usenet@gkbrk.com> - 2020-09-17 16:45 +0300
    Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-17 16:59 +0200
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! gazelle@shell.xmission.com (Kenny McCormack) - 2020-09-17 19:36 +0000
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-17 17:08 -0700
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-18 06:11 +0200
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-17 22:38 -0700
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! gazelle@shell.xmission.com (Kenny McCormack) - 2020-09-18 10:12 +0000
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-18 12:26 +0200
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-18 19:18 -0700
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-18 19:19 -0700
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-19 04:21 +0200
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-09-18 19:28 -0700
    Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-17 16:53 +0100
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! already5chosen@yahoo.com - 2020-09-17 16:28 -0700
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-18 00:46 +0100
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! already5chosen@yahoo.com - 2020-09-18 07:31 -0700
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-18 17:53 -0500
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-19 01:02 +0100
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-09-18 17:34 -0700
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-18 20:57 -0500
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-09-18 23:43 -0700
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-19 11:01 +0100
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-19 13:33 -0500
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-11-29 00:23 -0800
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-09-18 20:53 -0400
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-18 21:38 -0500
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-09-18 22:50 -0400
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-09-18 20:09 -0700
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! BGB <cr88192@gmail.com> - 2020-09-18 23:52 -0500
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-09-18 23:42 -0700
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bonita Montero <Bonita.Montero@gmail.com> - 2020-09-19 06:43 +0200
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Manfred <noname@add.invalid> - 2020-09-18 20:32 +0200
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-18 20:06 +0100
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Manfred <noname@add.invalid> - 2020-09-18 22:04 +0200
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-18 21:05 +0100
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-18 23:05 +0100
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-18 23:14 +0100
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-09-18 14:09 -0700
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-18 22:33 +0100
      Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-09-18 23:20 -0700
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-09-18 23:44 -0700
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-09-18 23:59 -0700
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-09-19 11:32 +0000
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-09-19 07:37 -0700
        Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-19 12:43 +0100
          Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-19 13:52 +0100
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-19 13:58 +0100
            Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-19 19:18 +0100
              Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Bart <bc@freeuk.com> - 2020-09-19 23:03 +0100
                Re: Microsoft Will now support C11 and C17 standard!!!!!!!!!! Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-09-19 23:54 +0100

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