Re: Does ANSI C allow free() to always be empty?

From	Keith Thompson <kst-u@mib.org>
Newsgroups	comp.lang.c
Subject	Re: Does ANSI C allow free() to always be empty?
Date	2014-03-10 08:52 -0700
Organization	None to speak of
Message-ID	<lnsiqqt5ja.fsf@nuthaus.mib.org> (permalink)
References	<401aa474-05e6-4cf4-a3c2-5e2c2343157e@googlegroups.com> <20140308224204.214@kylheku.com> <lfiui1$p8q$1@dont-email.me> <ef422329-dc31-4670-ac9b-a486542dd6fa@googlegroups.com> <lfk055$noo$1@dont-email.me>

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David Brown <david.brown@hesbynett.no> writes:
> On 10/03/14 06:37, partremmaps@gmail.com wrote:
[...]
>> And indeed, if I understand correctly, in a freestanding environment,
>> it appears that the standard allows library facilities to be
>> implementation defined - which would allow for free() to be empty.
>
> Yes.  I think there are some restrictions about what the library
> facilities should do, even in a freestanding environment - but you don't
> need to implement everything.  In particular, a freestanding
> implementation does not have to include <stdlib.h>.
[...]

N1570 5.1.2.1:

    Any library facilities available to a freestanding program, other
    than the minimal set required by clause 4, are implementation-defined.

A freestanding implementation needn't provide malloc() and free() at
all.  It can provide functions with those names that compute square
roots (though that would be perverse).  The headers that are required
for freestanding implementations are the ones that don't declare any
functions.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Thread

Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-08 22:08 -0800
  Re: Does ANSI C allow free() to always be empty? Kaz Kylheku <kaz@kylheku.com> - 2014-03-09 06:55 +0000
    Re: Does ANSI C allow free() to always be empty? David Brown <david.brown@hesbynett.no> - 2014-03-10 00:47 +0100
      Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-09 22:37 -0700
        Re: Does ANSI C allow free() to always be empty? David Brown <david.brown@hesbynett.no> - 2014-03-10 10:20 +0100
          Re: Does ANSI C allow free() to always be empty? Keith Thompson <kst-u@mib.org> - 2014-03-10 08:52 -0700
          Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-10 20:51 -0700
            Re: Does ANSI C allow free() to always be empty? Robert Wessel <robertwessel2@yahoo.com> - 2014-03-11 01:08 -0500
            Re: Does ANSI C allow free() to always be empty? David Brown <david.brown@hesbynett.no> - 2014-03-11 12:52 +0100
              Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-12 00:09 -0700
                Re: Does ANSI C allow free() to always be empty? David Brown <david.brown@hesbynett.no> - 2014-03-12 12:59 +0100
      Re: Does ANSI C allow free() to always be empty? Kaz Kylheku <kaz@kylheku.com> - 2014-03-10 09:01 +0000
    Re: Does ANSI C allow free() to always be empty? Nick Bowler <nbowler@draconx.ca> - 2014-03-10 15:56 +0000
  Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-09 01:11 -0800
    Re: Does ANSI C allow free() to always be empty? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-03-09 12:39 +0000
      Re: Does ANSI C allow free() to always be empty? gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-09 13:05 +0000
      Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-09 22:28 -0700
        Re: Does ANSI C allow free() to always be empty? Martin Shobe <martin.shobe@yahoo.com> - 2014-03-10 07:27 -0500
          Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-10 20:55 -0700
            Re: Does ANSI C allow free() to always be empty? Martin Shobe <martin.shobe@yahoo.com> - 2014-03-11 08:19 -0500
              Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-11 23:22 -0700
                Re: Does ANSI C allow free() to always be empty? Martin Shobe <martin.shobe@yahoo.com> - 2014-03-12 08:09 -0500
                Re: Does ANSI C allow free() to always be empty? James Kuyper <jameskuyper@verizon.net> - 2014-03-12 11:29 -0400
      Re: Does ANSI C allow free() to always be empty? Martin Shobe <martin.shobe@yahoo.com> - 2014-03-10 07:29 -0500
  Re: Does ANSI C allow free() to always be empty? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-09 09:14 +0000
    Re: Does ANSI C allow free() to always be empty? Robert Wessel <robertwessel2@yahoo.com> - 2014-03-10 15:33 -0500
  Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-09 23:05 -0700
    Re: Does ANSI C allow free() to always be empty? Martin Shobe <martin.shobe@yahoo.com> - 2014-03-10 07:43 -0500
      Re: Does ANSI C allow free() to always be empty? gordonb.3qcze@burditt.org (Gordon Burditt) - 2014-03-10 12:05 -0500
        Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-10 20:16 -0700
        Re: Does ANSI C allow free() to always be empty? Tim Rentsch <txr@alumni.caltech.edu> - 2014-03-29 16:27 -0700
      Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-10 21:48 -0700
        Re: Does ANSI C allow free() to always be empty? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-11 05:52 +0000
  Re: Does ANSI C allow free() to always be empty? partremmaps@gmail.com - 2014-03-20 19:14 -0700
    Re: Does ANSI C allow free() to always be empty? Kaz Kylheku <kaz@kylheku.com> - 2014-03-21 03:25 +0000
      Re: Does ANSI C allow free() to always be empty? Richard Damon <Richard@Damon-Family.org> - 2014-03-21 20:58 -0400
        Re: Does ANSI C allow free() to always be empty? Tim Rentsch <txr@alumni.caltech.edu> - 2014-03-29 16:11 -0700
          Re: Does ANSI C allow free() to always be empty? Richard Damon <Richard@Damon-Family.org> - 2014-03-29 22:27 -0400
            Re: Does ANSI C allow free() to always be empty? Tim Rentsch <txr@alumni.caltech.edu> - 2014-03-30 13:18 -0700
              Re: Does ANSI C allow free() to always be empty? Richard Damon <Richard@Damon-Family.org> - 2014-03-30 20:49 -0400
                Re: Does ANSI C allow free() to always be empty? Tim Rentsch <txr@alumni.caltech.edu> - 2014-04-17 10:52 -0700
            Re: Does ANSI C allow free() to always be empty? James Kuyper <jameskuyper@verizon.net> - 2014-03-31 11:18 -0400
    Re: Does ANSI C allow free() to always be empty? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-21 03:31 +0000
    Re: Does ANSI C allow free() to always be empty? Tim Rentsch <txr@alumni.caltech.edu> - 2014-03-29 15:39 -0700
      Re: Does ANSI C allow free() to always be empty? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-30 04:22 +0000

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