Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.std.c > #1433

Re: Initial draft proposal: "Safe arrays and pointers for C"

From Hans-Bernhard Bröker <HBBroeker@t-online.de>
Newsgroups comp.std.c
Subject Re: Initial draft proposal: "Safe arrays and pointers for C"
Date 2012-08-14 21:09 +0200
Message-ID <a8vm2oFd68U1@mid.dfncis.de> (permalink)
References <502949DA.9000604@animats.com> <50297066.1010202@loria.fr> <k0cfg2$7a5$1@dont-email.me> <lnr4rarqqz.fsf@nuthaus.mib.org> <k0e4tl$892$1@dont-email.me>

Show all headers | View raw


On 14.08.2012 20:20, John Nagle wrote:
> On 8/13/2012 10:23 PM, Keith Thompson wrote:

>> C does not have parameters of array type.  "a" is not an array, it's a
>> pointer.

> compatible types." This would seem to imply that implementations
> should (or at least could) check VLA size match at function calls.

No, they shouldn't, because, as Keith just told you above, there is no 
such thing as "a VLA ... at function calls".  No other non-VL array, 
either, for that matter.  A function argument simply is _never_ an array.

>   sizeof(a) is the size of a pointer, here 4.  That's questionable.

No, it's not.  That's what C has been doing since the dawn of time. 
sizeof(a) yields the size of a pointer for the least questionable reason 
there could be: because 'a' _is_ a pointer.

>     It's questionable because sizeof results for a local VLA are
> different.

No it's not, because that 'a' is not a VLA at all, so the argument 
doesn't apply to it.

>     Is this intentional, a GCC bug, or an ambiguity in the standard?

The former.

> It's certainly desirable to be able to obtain the size of an array
> when the language knows it.

But in the case at hand the language _doesn't_ know it.

Back to comp.std.c | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-13 11:39 -0700
  Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-13 23:23 +0200
    Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-13 17:04 -0700
    Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-13 20:08 -0700
      Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-13 22:23 -0700
        Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-14 11:20 -0700
          Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 14:54 -0400
            Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-14 21:09 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 16:00 -0400
            Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 18:08 -0400
              Re: Initial draft proposal: "Safe arrays and pointers for C" Philip Lantz <prl@canterey.us> - 2012-08-14 23:05 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 06:48 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 11:22 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 15:13 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 13:00 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-15 22:52 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 17:18 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-16 19:20 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-16 13:40 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-16 11:04 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-16 14:35 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-16 11:47 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-16 14:52 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 14:41 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" "Derek M. Jones" <derek@_NOSPAM_knosof.co.uk> - 2012-08-16 12:39 +0100
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-16 09:57 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-16 13:28 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" "Derek M. Jones" <derek@_NOSPAM_knosof.co.uk> - 2012-08-16 23:52 +0100
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-15 18:56 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 19:23 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Philip Lantz <prl@canterey.us> - 2012-08-15 21:47 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-16 19:14 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-16 20:28 +0200
          Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 15:05 -0400
          Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-14 21:09 +0200
            Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-14 13:24 -0700
              Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 16:39 -0400
              Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 15:23 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Philip Lantz <prl@canterey.us> - 2012-08-14 22:58 -0700
              Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-15 00:37 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 16:42 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-15 22:57 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 17:02 -0700
          Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 14:59 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-14 15:35 -0700
              Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 00:51 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 06:43 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 08:31 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 09:14 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 18:58 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 06:45 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Philip Lantz <prl@canterey.us> - 2012-08-14 22:51 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 07:18 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 14:15 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 14:28 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 14:36 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 14:54 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 15:08 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 12:50 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 23:22 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 14:38 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-16 00:51 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 16:32 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-16 09:05 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 17:22 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-15 20:29 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-15 12:36 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-15 16:09 -0400
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 08:47 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 16:33 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 16:38 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 06:46 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-14 22:28 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-15 08:34 +0200
                Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-15 09:12 +0200
          Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-16 13:09 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" Wojtek Lerch <wojtek_l@yahoo.ca> - 2012-08-16 16:21 -0400
              Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-16 14:22 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-16 15:28 -0700
                Re: Initial draft proposal: "Safe arrays and pointers for C" Wojtek Lerch <wojtek_l@yahoo.ca> - 2012-08-16 19:49 -0400
      Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-14 08:56 +0200
      Re: Initial draft proposal: "Safe arrays and pointers for C" James Kuyper <jameskuyper@verizon.net> - 2012-08-14 06:18 -0400
        Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-14 12:42 +0200
          Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-14 09:43 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-14 19:52 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-14 21:03 +0200
            Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-14 21:39 +0200
      Re: Initial draft proposal: "Safe arrays and pointers for C" Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-08-14 08:26 -0400
  Re: Initial draft proposal: "Safe arrays and pointers for C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-08-13 22:44 +0100
    Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-13 18:05 -0700
  Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-14 21:00 +0200
    Re: Initial draft proposal: "Safe arrays and pointers for C" Marc <marc.glisse@gmail.com> - 2012-08-14 21:18 +0000
      Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-14 23:51 +0200
  Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-17 09:40 -0700
    Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-17 21:00 +0200
      Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-17 13:30 -0700
        Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-17 23:14 +0200
        Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-18 01:07 +0200
          Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-19 23:14 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" Ike Naar <ike@sverige.freeshell.org> - 2012-08-20 07:16 +0000
              Re: Initial draft proposal: "Safe arrays and pointers for C" John Nagle <nagle@animats.com> - 2012-08-20 00:25 -0700
            Re: Initial draft proposal: "Safe arrays and pointers for C" Jens Gustedt <jens.gustedt@loria.fr> - 2012-08-20 11:49 +0200
            Re: Initial draft proposal: "Safe arrays and pointers for C" Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2012-08-20 22:40 +0200
              Re: Initial draft proposal: "Safe arrays and pointers for C" jacob navia <jacob@spamsink.net> - 2012-08-20 23:08 +0200
    Re: Initial draft proposal: "Safe arrays and pointers for C" Keith Thompson <kst-u@mib.org> - 2012-08-17 15:33 -0700

csiph-web