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Groups > comp.lang.c > #10412 > unrolled thread
| Started by | jacob navia <jacob@spamsink.net> |
|---|---|
| First post | 2011-09-18 00:29 +0200 |
| Last post | 2011-09-20 00:22 -0700 |
| Articles | 20 on this page of 284 — 42 participants |
Back to article view | Back to comp.lang.c
Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-18 00:29 +0200
Re: Testing if a pointer is valid Harald van Dijk <truedfx@gmail.com> - 2011-09-17 15:38 -0700
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-18 00:57 +0200
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-18 16:30 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-18 19:25 +0200
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-19 07:53 +1200
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-18 20:00 +0000
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-19 08:23 +1200
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-18 20:32 +0000
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-18 23:28 +0000
Re: Testing if a pointer is valid blp@cs.stanford.edu (Ben Pfaff) - 2011-09-18 16:38 -0700
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-19 04:27 +0000
Re: Testing if a pointer is valid blp@cs.stanford.edu (Ben Pfaff) - 2011-09-18 21:48 -0700
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-19 05:38 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-19 09:14 +0200
Re: Testing if a pointer is valid "BartC" <bc@freeuk.com> - 2011-09-19 10:10 +0100
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-19 05:07 -0700
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-19 14:24 +0100
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-19 16:10 +0200
Re: Testing if a pointer is valid "BartC" <bc@freeuk.com> - 2011-09-19 16:50 +0100
Re: Testing if a pointer is valid Ben Pfaff <blp@cs.stanford.edu> - 2011-09-19 08:11 -0700
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-19 17:21 +0200
Re: Testing if a pointer is valid "BartC" <bc@freeuk.com> - 2011-09-19 16:27 +0100
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-19 10:14 -0700
Re: Testing if a pointer is valid "BartC" <bc@freeuk.com> - 2011-09-19 19:56 +0100
Re: Testing if a pointer is valid blp@cs.stanford.edu (Ben Pfaff) - 2011-09-19 13:20 -0700
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-20 18:31 +0300
Re: Testing if a pointer is valid "BartC" <bc@freeuk.com> - 2011-09-20 17:44 +0100
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-20 17:06 -0700
Re: Testing if a pointer is valid "BartC" <bc@freeuk.com> - 2011-09-21 01:37 +0100
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-22 22:03 +0300
Re: Testing if a pointer is valid Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-28 02:33 -0700
Re: Testing if a pointer is valid ImpalerCore <jadill33@gmail.com> - 2011-09-19 13:01 -0700
Re: Testing if a pointer is valid ImpalerCore <jadill33@gmail.com> - 2011-09-19 14:42 -0700
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-20 10:08 +1200
Re: Testing if a pointer is valid ImpalerCore <jadill33@gmail.com> - 2011-09-20 07:55 -0700
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-19 16:39 +0000
Re: Testing if a pointer is valid blp@cs.stanford.edu (Ben Pfaff) - 2011-09-19 09:48 -0700
Re: Testing if a pointer is valid ImpalerCore <jadill33@gmail.com> - 2011-09-19 12:49 -0700
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-19 22:45 +0200
Re: Testing if a pointer is valid ImpalerCore <jadill33@gmail.com> - 2011-09-19 14:02 -0700
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-19 07:14 +0000
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-19 16:13 +0000
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-19 17:36 +0000
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-19 20:09 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-19 20:36 +0200
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-20 08:05 +1200
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-19 20:18 +0000
Re: Testing if a pointer is valid Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-09-19 23:37 +0000
Re: Testing if a pointer is valid Kenneth Brody <kenbrody@spamcop.net> - 2011-09-21 12:23 -0400
Re: Testing if a pointer is valid Kenneth Brody <kenbrody@spamcop.net> - 2011-09-21 12:09 -0400
Re: Testing if a pointer is valid websnarf <websnarf@gmail.com> - 2011-09-26 22:01 -0700
Re: Testing if a pointer is valid Kenneth Brody <kenbrody@spamcop.net> - 2011-09-19 13:51 -0400
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-19 20:11 +0000
Re: Testing if a pointer is valid Nobody <nobody@nowhere.com> - 2011-09-19 22:21 +0100
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-20 00:05 +0000
Re: Testing if a pointer is valid Nobody <nobody@nowhere.com> - 2011-09-18 23:34 +0100
Re: Testing if a pointer is valid pacman@kosh.dhis.org (Alan Curry) - 2011-09-18 22:47 +0000
Re: Testing if a pointer is valid tom st denis <tom@iahu.ca> - 2011-09-19 04:50 -0700
Re: Testing if a pointer is valid Kenneth Brody <kenbrody@spamcop.net> - 2011-09-19 13:42 -0400
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-19 20:30 +0200
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-20 08:09 +1200
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-19 22:38 +0200
Re: Testing if a pointer is valid Ike Naar <ike@iceland.freeshell.org> - 2011-09-19 20:50 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-19 22:53 +0200
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-19 22:30 +0100
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-20 00:05 +0200
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-20 00:31 +0100
Re: Testing if a pointer is valid Ike Naar <ike@iceland.freeshell.org> - 2011-09-19 22:43 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-20 00:59 +0200
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-20 11:50 +1200
Re: Testing if a pointer is valid blp@cs.stanford.edu (Ben Pfaff) - 2011-09-19 19:03 -0700
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-20 14:11 +1200
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-19 21:49 -0700
Re: Testing if a pointer is valid Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-28 06:17 -0700
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-28 07:02 -0700
Re: Testing if a pointer is valid Ike Naar <ike@sverige.freeshell.org> - 2011-09-20 07:26 +0000
Re: Testing if a pointer is valid Kenneth Brody <kenbrody@spamcop.net> - 2011-09-21 12:31 -0400
Re: Testing if a pointer is valid Kenneth Brody <kenbrody@spamcop.net> - 2011-09-21 12:26 -0400
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-21 21:20 +0200
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-21 19:40 +0000
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-22 07:46 +1200
Re: Testing if a pointer is valid "Rosario Pulvirenti" <NoInUseno1Spam@non.usare.invalid> - 2011-09-22 07:38 +0200
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-20 09:05 +1200
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-20 07:16 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-20 09:50 +0200
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-20 10:38 +0000
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-20 04:29 -0700
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-20 12:04 +0000
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-20 05:25 -0700
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-20 16:49 +0000
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-22 22:35 +0300
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-23 07:59 +0000
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-23 12:33 +0300
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-23 12:23 +0000
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-23 17:34 +0300
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-23 17:08 +0000
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-23 06:49 -0400
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-23 12:20 +0000
Re: Testing if a pointer is valid Seebs <usenet-nospam@seebs.net> - 2011-09-26 22:59 +0000
Re: Testing if a pointer is valid Michael Press <rubrum@pacbell.net> - 2011-09-30 01:27 -0700
Re: Testing if a pointer is valid Willem <willem@toad.stack.nl> - 2011-09-30 08:38 +0000
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-10-04 12:40 +0000
Re: Testing if a pointer is valid Kenneth Brody <kenbrody@spamcop.net> - 2011-09-21 12:00 -0400
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-21 21:17 +0200
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-18 23:21 +0000
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-18 17:32 -0700
Re: Testing if a pointer is valid Joe Wright <joewwright@comcast.net> - 2011-09-18 23:10 -0400
Re: Testing if a pointer is valid gazelle@shell.xmission.com (Kenny McCormack) - 2011-09-19 03:34 +0000
Re: Testing if a pointer is valid Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-09-18 22:32 -0600
Re: Testing if a pointer is valid gazelle@shell.xmission.com (Kenny McCormack) - 2011-09-20 14:18 +0000
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-20 18:15 +0200
Re: Testing if a pointer is valid "BartC" <bc@freeuk.com> - 2011-09-20 17:49 +0100
Re: Testing if a pointer is valid Willem <willem@toad.stack.nl> - 2011-09-20 17:02 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-20 20:35 +0200
Re: Testing if a pointer is valid Ike Naar <ike@iceland.freeshell.org> - 2011-09-20 20:30 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-20 22:35 +0200
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-22 22:07 +0300
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-22 16:11 -0400
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-23 12:28 +0300
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-23 06:44 -0400
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-23 17:33 +0300
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-23 11:31 -0400
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-23 20:09 +0200
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-23 20:02 +0200
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-23 13:49 -0700
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-24 09:01 +1200
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-23 23:08 +0200
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-24 09:43 +1200
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-23 22:13 +0100
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-23 23:45 +0200
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-24 00:01 +0100
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-24 09:47 +1200
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-23 17:22 -0400
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-23 23:47 +0200
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-24 09:50 +1200
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-23 18:06 -0400
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-24 10:25 +1200
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-24 08:02 -0400
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-24 14:13 +0200
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-24 14:07 +0100
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-24 13:15 +0000
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-24 15:20 +0100
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-24 11:28 -0400
Re: Testing if a pointer is valid Willem <willem@toad.stack.nl> - 2011-09-24 15:45 +0000
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-24 20:07 +0300
Re: Testing if a pointer is valid Richard Damon <news.x.richarddamon@xoxy.net> - 2011-09-24 14:31 -0400
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-24 21:49 +0100
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-24 14:40 -0700
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-25 01:14 +0100
Re: Testing if a pointer is valid Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 13:44 -0800
Re: Testing if a pointer is valid Richard Damon <news.x.richarddamon@xoxy.net> - 2011-09-24 20:23 -0400
Re: Testing if a pointer is valid Willem <willem@toad.stack.nl> - 2011-09-24 18:44 +0000
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-25 07:04 -0400
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-24 17:30 +0000
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-24 12:34 -0700
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-25 01:00 -0700
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-25 21:30 +1300
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-25 05:08 -0700
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-26 08:39 +1300
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-24 20:04 +0300
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-23 17:09 -0400
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-23 23:43 +0200
Re: Testing if a pointer is valid Michael Press <rubrum@pacbell.net> - 2011-09-27 20:48 -0700
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-10-03 19:59 +0300
Re: Testing if a pointer is valid Michael Press <rubrum@pacbell.net> - 2011-10-03 17:32 -0700
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-24 13:53 +0100
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-20 21:18 +0100
Re: Testing if a pointer is valid Willem <willem@toad.stack.nl> - 2011-09-20 20:35 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-20 22:45 +0200
Re: Testing if a pointer is valid Willem <willem@toad.stack.nl> - 2011-09-21 08:09 +0000
Re: Testing if a pointer is valid Noob <root@127.0.0.1> - 2011-09-22 13:04 +0200
Re: Testing if a pointer is valid Robert Wessel <robertwessel2@yahoo.com> - 2011-09-22 11:38 -0500
Re: Testing if a pointer is valid Noob <root@127.0.0.1> - 2011-09-23 10:41 +0200
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-22 22:20 +0300
Re: Testing if a pointer is valid Willem <willem@toad.stack.nl> - 2011-09-22 22:15 +0000
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-23 12:30 +0300
Re: Testing if a pointer is valid Seebs <usenet-nospam@seebs.net> - 2011-09-26 22:59 +0000
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-27 02:06 +0100
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-27 03:39 +0000
Re: Testing if a pointer is valid "Rosario Pulvirenti" <NoInUseno1Spam@non.usare.invalid> - 2011-10-03 19:51 +0200
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-03 19:11 +0100
Re: Testing if a pointer is valid "Rosario Pulvirenti" <NoInUseno1Spam@non.usare.invalid> - 2011-10-04 16:20 +0200
Re: Testing if a pointer is valid China Blue Corn Chips <chine.bleu@yahoo.com> - 2011-10-04 08:11 -0700
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-10-04 12:19 -0400
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-27 13:56 +0300
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-27 13:13 +0100
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-27 12:08 +0300
Re: Testing if a pointer is valid Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-29 01:00 -0700
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-20 21:59 +0100
Re: Testing if a pointer is valid Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-22 22:08 +0300
Re: Testing if a pointer is valid Willem <willem@toad.stack.nl> - 2011-09-20 17:00 +0000
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-20 20:32 +0200
Re: Testing if a pointer is valid gazelle@shell.xmission.com (Kenny McCormack) - 2011-09-20 18:53 +0000
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-20 22:55 +0200
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-20 21:50 +0100
Re: Testing if a pointer is valid gazelle@shell.xmission.com (Kenny McCormack) - 2011-09-21 15:48 +0000
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-21 16:12 +0000
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-21 09:42 -0700
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-21 18:01 +0000
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-21 21:00 +0100
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-21 21:32 +0200
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-22 12:40 +0100
Re: Testing if a pointer is valid gazelle@shell.xmission.com (Kenny McCormack) - 2011-09-22 13:00 +0000
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-22 14:54 +0100
Re: Testing if a pointer is valid gazelle@shell.xmission.com (Kenny McCormack) - 2011-09-22 14:03 +0000
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-22 11:39 -0700
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-24 13:44 +0100
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-24 12:23 -0700
Re: Testing if a pointer is valid Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-29 04:52 -0700
Re: Testing if a pointer is valid Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-29 04:51 -0700
Re: Testing if a pointer is valid Willem <willem@toad.stack.nl> - 2011-09-20 19:32 +0000
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-20 22:48 +0200
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-20 17:29 -0400
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-20 23:45 +0200
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-21 10:35 -0400
Re: Testing if a pointer is valid Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-29 05:04 -0700
Re: Testing if a pointer is valid Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-29 04:54 -0700
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-20 17:19 -0700
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-21 23:26 +0200
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-21 14:35 -0700
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-22 00:09 +0200
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-21 19:08 -0400
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-21 05:25 +0000
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-20 21:11 +0100
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-20 23:01 +0200
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-21 03:11 -0700
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-21 12:16 +0200
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-21 03:23 -0700
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-21 20:44 +0100
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-21 22:53 +0200
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-21 23:08 -0400
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-21 21:14 -0700
Re: Testing if a pointer is valid James Kuyper <jameskuyper@verizon.net> - 2011-09-22 07:17 -0400
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-22 16:37 +0100
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-22 16:25 +0100
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-22 11:36 -0700
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-24 13:37 +0100
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-24 13:50 +0000
Re: Testing if a pointer is valid gazelle@shell.xmission.com (Kenny McCormack) - 2011-09-24 14:47 +0000
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-24 20:43 +0100
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-24 20:26 +0100
Re: Testing if a pointer is valid Richard Damon <news.x.richarddamon@xoxy.net> - 2011-09-24 20:53 -0400
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-25 02:30 +0100
Re: Testing if a pointer is valid Richard Damon <news.x.richarddamon@xoxy.net> - 2011-09-24 22:24 -0400
Re: Testing if a pointer is valid Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-09-25 12:36 +0100
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-21 13:56 -0700
Re: Testing if a pointer is valid "Rosario Pulvirenti" <NoInUseno1Spam@non.usare.invalid> - 2011-09-22 07:38 +0200
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-22 02:06 -0700
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-22 15:24 +0100
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-22 11:35 -0700
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-24 13:25 +0100
Re: Testing if a pointer is valid Seebs <usenet-nospam@seebs.net> - 2011-09-26 22:59 +0000
Re: Testing if a pointer is valid Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 13:30 -0800
Re: Testing if a pointer is valid Nobody <nobody@nowhere.com> - 2011-09-22 18:23 +0100
Re: Testing if a pointer is valid gazelle@shell.xmission.com (Kenny McCormack) - 2011-09-21 15:40 +0000
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-21 20:20 +0100
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-19 06:39 +0000
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-19 10:06 -0700
Re: Testing if a pointer is valid Kleuskes & Moos <kleuske@somewhere.else.net> - 2011-09-20 07:03 +0000
Re: Testing if a pointer is valid pete <pfiland@mindspring.com> - 2011-09-19 19:17 -0400
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-20 20:57 +0100
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-19 05:14 +0000
Re: Testing if a pointer is valid Ian Collins <ian-news@hotmail.com> - 2011-09-19 18:02 +1200
Re: Testing if a pointer is valid cri@tiac.net (Richard Harter) - 2011-09-19 06:18 +0000
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-19 17:50 +0200
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-19 20:45 +0200
Re: Testing if a pointer is valid Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-09-28 08:05 -0700
Re: Testing if a pointer is valid Keith Thompson <kst-u@mib.org> - 2011-09-28 09:14 -0700
Re: Testing if a pointer is valid Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-18 23:52 -0700
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-20 20:45 +0100
Re: Testing if a pointer is valid August Karlstrom <fusionfile@gmail.com> - 2011-09-20 23:35 +0200
Re: Testing if a pointer is valid Rui Maciel <rui.maciel@gmail.com> - 2011-09-21 19:53 +0100
Re: Testing if a pointer is valid "BartC" <bc@freeuk.com> - 2011-09-17 23:54 +0100
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-18 00:59 +0200
Re: Testing if a pointer is valid Heikki Kallasjoki <fis+usenet@zem.fi> - 2011-09-17 23:35 +0000
Re: Testing if a pointer is valid jacob navia <jacob@spamsink.net> - 2011-09-18 01:47 +0200
Re: Testing if a pointer is valid Geoff <geoff@invalid.invalid> - 2011-09-17 17:15 -0700
Re: Testing if a pointer is valid Максим Фомин <maxim@maxim-fomin.ru> - 2011-09-18 00:43 -0700
Re: Testing if a pointer is valid "Rosario Pulvirenti" <NoInUseno1Spam@non.usare.invalid> - 2011-09-18 10:34 +0200
Re: Testing if a pointer is valid "Rosario Pulvirenti" <NoInUseno1Spam@non.usare.invalid> - 2011-09-20 09:28 +0200
Re: Testing if a pointer is valid Ike Naar <ike@iceland.freeshell.org> - 2011-09-18 12:55 +0000
Re: Testing if a pointer is valid "Joel C. Salomon" <joelcsalomon@gmail.com> - 2011-09-19 10:29 -0400
Re: Testing if a pointer is valid China Blue Corn Chips <chine.bleu@yahoo.com> - 2011-09-20 00:22 -0700
Page 6 of 15 — ← Prev page 1 … 4 5 [6] 7 8 … 15 Next page →
| From | Michael Press <rubrum@pacbell.net> |
|---|---|
| Date | 2011-09-30 01:27 -0700 |
| Message-ID | <rubrum-819774.01270930092011@news.albasani.net> |
| In reply to | #10566 |
In article <e88e6942-14d8-491d-b072-353e31ec7d4a@z7g2000vbp.googlegroups.com>, Malcolm McLean <malcolm.mclean5@btinternet.com> wrote: > On Sep 20, 3:04 pm, Kleuskes & Moos <kleu...@somewhere.else.net> > wrote: > > On Tue, 20 Sep 2011 04:29:28 -0700, Malcolm McLean wrote: > > > > > The hard problem is whether or not to allow an emergency save. If you > > > don't allow it, the user will lose all the work he did before the last > > > save. If you do allow it, you might save corrupted data which could > > > cause far more serious problems further down the line. > > > > The latter is sufficient reason _not_ to allow that, unless you can guarantee > > the data to be saved isn't corrupted. The proper way to do things _like_ that > > is to generate a dump _in_a_separate_file_, which might later be used to > > restore at least some of the previous state. > > > > But things like that only come into play if your app isn't really critical to > > anyone and you have a damned good reason for doing so. > > > Often you don't know how the app will be used. For instance a > spreadsheet might be used for an undergraduate research project, or it > might hold details of cancer patients in a drugs trial. The > requirements are the same. > Now lets say the program detects an invalid pointer. If it crashes > out, it destroys maybe six hours work by the undergraduate. That's a > major irritation. He won't use that package again and you've lost a > customer. If he has not saved his work in six hours, he learned a valuable lesson. -- Michael Press
[toc] | [prev] | [next] | [standalone]
| From | Willem <willem@toad.stack.nl> |
|---|---|
| Date | 2011-09-30 08:38 +0000 |
| Message-ID | <slrnj8b00c.fhf.willem@toad.stack.nl> |
| In reply to | #11097 |
Michael Press wrote:
) If he has not saved his work in six hours,
) he learned a valuable lesson.
Indeed. He learned that he shouldn't buy software from your company.
SaSW, Willem
--
Disclaimer: I am in no way responsible for any of the statements
made in the above text. For all I know I might be
drugged or something..
No I'm not paranoid. You all think I'm paranoid, don't you !
#EOT
[toc] | [prev] | [next] | [standalone]
| From | Kleuskes & Moos <kleuske@somewhere.else.net> |
|---|---|
| Date | 2011-10-04 12:40 +0000 |
| Message-ID | <j6eus4$889$1@dont-email.me> |
| In reply to | #11098 |
On Fri, 30 Sep 2011 08:38:36 +0000, Willem wrote:
> Michael Press wrote:
> ) If he has not saved his work in six hours, ) he learned a valuable
> lesson.
>
> Indeed. He learned that he shouldn't buy software from your company.
>
>
> SaSW, Willem
If those are your standards, you'll have trouble finding suppliers for most
desktop software. The level of testing and debugging you need in order to
provide that kind of stability just isn't economically viable for humdrum
applications. That's why testing is usually crowd-sourced by releasing
'beta-versions'. The problem with testing is that it can only show the
presence of bugs, not their absence, according to the Proverbs of Dijkstra.
Unless, of course you know of some way to get it right first time, every
time, which has eluded us mere mortals so far.
-------------------------------------------------------------------------------
_______________________________________
< We just joined the civil hair patrol! >
---------------------------------------
\
\
___
{~._.~}
( Y )
()~*~()
(_)-(_)
-------------------------------------------------------------------------------
[toc] | [prev] | [next] | [standalone]
| From | Kenneth Brody <kenbrody@spamcop.net> |
|---|---|
| Date | 2011-09-21 12:00 -0400 |
| Message-ID | <7uOdnTMNjcSil-fTnZ2dnUVZ_jydnZ2d@bestweb.net> |
| In reply to | #10513 |
On 9/19/2011 2:30 PM, jacob navia wrote: > Le 19/09/11 19:42, Kenneth Brody a écrit : >> >> Personally, I prefer debugging a program that crashes at the actual >> point of failure. >> > > Well, it depends where the point of failure is. True. Sometimes the "point of failure" is long after the bug caused something "bad" to happen. > Suppose your library is expecting a pointer to "a" and is passed a pointer > to "b", a similar syructure but with slightly different layout. And I assume you are using the "magic number" entry of structs to verify this? BTW, how did you get this past the compiler? > 1) The program crashes deep inside the library when processing the pointer > data. You have a stack trace that tells you: > > 0x488776AAD() > 0x446655FF4() > MyFunction() myfunction.c 476 > main() main.c 876 > > Now what? I use the debugger to see what line of code crashed. At that point, I would see that an "bad" pointer was passed, and I backtrack the stack to see why. > 2) When you pass a bad pointer the library opens a dialog box: > "Invalid argument to function Library_input(), argument two" > > You see? > > A crash isn't always a good thing. Well, what do you do in (2) after displaying the dialog? Abort? Return an error? Something else? And, how does (2) help you determine the caller, and track down why it was called with a bad argument? -- Kenneth Brody
[toc] | [prev] | [next] | [standalone]
| From | jacob navia <jacob@spamsink.net> |
|---|---|
| Date | 2011-09-21 21:17 +0200 |
| Message-ID | <j5dd7l$2mf$1@speranza.aioe.org> |
| In reply to | #10646 |
Le 21/09/11 18:00, Kenneth Brody a écrit : > > Well, what do you do in (2) after displaying the dialog? Abort? Return > an error? Something else? > Abort, Retry, Ignore? Then the user chooses what to do. In non interactive programs you log that into the log file and depending onthe recovery strategy either you abort, you jump to a restart point, or you return from the function. > And, how does (2) help you determine the caller, and track down why it > was called with a bad argument? > Because of the informative eror message of course, that tells you what library function received the bad argument, the program counter, etc.
[toc] | [prev] | [next] | [standalone]
| From | cri@tiac.net (Richard Harter) |
|---|---|
| Date | 2011-09-18 23:21 +0000 |
| Message-ID | <4e767c92.282513661@text.giganews.com> |
| In reply to | #10440 |
On Sun, 18 Sep 2011 16:30:05 +0000 (UTC), Kleuskes & Moos <kleuske@somewhere.else.net> wrote: >On Sun, 18 Sep 2011 00:57:32 +0200, jacob navia wrote: > >> Le 18/09/11 00:38, Harald van Dijk a écrit : >>> On Sep 18, 12:29 am, jacob navia<ja...@spamsink.net> wrote: >>>> In a recent discussion about preconditions, I argued that testing ALL >>>> preconditions would be unpractical. As an example of a precondition >>>> impossible to test I presented the problem to know if a pointer points >>>> to a really readable place in memory. >>>> >>>> The windows API provides the function bool IsBadReadPtr(const void >>>> *lp, size_t ucb); >>>> >>>> This takes a pointer and a size and returns true if it is OK, zero if >>>> it fails. >>>> >>>> Problem is, that is only present under windows. >>> >>> That is not its biggest problem. Even on Windows, don't use it. Please >>> read >>> <http://blogs.msdn.com/b/oldnewthing/archive/2006/09/27/773741.aspx> >>> for reasons why the concept of IsBadReadPtr (and IsBadWritePtr even >>> more so) is fundamentally flawed. >> >> They aren't "flawed". > >If you need code to check whether or not a pointer is valid, _your code_ >is fundamentally flawed. Any language in which it is possible for a pointer to be invalid but which provides no way to test for validity is fundamentally flawed.
[toc] | [prev] | [next] | [standalone]
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Date | 2011-09-18 17:32 -0700 |
| Message-ID | <lnzki15q2w.fsf@nuthaus.mib.org> |
| In reply to | #10454 |
cri@tiac.net (Richard Harter) writes:
[...]
> Any language in which it is possible for a pointer to be invalid but
> which provides no way to test for validity is fundamentally flawed.
What existing language has pointers and is not "fundamentally flawed"?
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
[toc] | [prev] | [next] | [standalone]
| From | Joe Wright <joewwright@comcast.net> |
|---|---|
| Date | 2011-09-18 23:10 -0400 |
| Message-ID | <H7idnUSmaqgcL-vTnZ2dnUVZ_oGdnZ2d@giganews.com> |
| In reply to | #10459 |
On 9/18/2011 20:32, Keith Thompson wrote: > cri@tiac.net (Richard Harter) writes: > [...] >> Any language in which it is possible for a pointer to be invalid but >> which provides no way to test for validity is fundamentally flawed. > > What existing language has pointers and is not "fundamentally flawed"? > Indeed. Testing a pointer by simple inspection can tell you whether it is null or not. If it is null it is not valid. If not you simply can't tell. -- Joe Wright "If you rob Peter to pay Paul you can depend on the support of Paul."
[toc] | [prev] | [next] | [standalone]
| From | gazelle@shell.xmission.com (Kenny McCormack) |
|---|---|
| Date | 2011-09-19 03:34 +0000 |
| Message-ID | <j56d81$28s$1@news.xmission.com> |
| In reply to | #10468 |
In article <H7idnUSmaqgcL-vTnZ2dnUVZ_oGdnZ2d@giganews.com>,
Joe Wright <joewwright@comcast.net> wrote:
>On 9/18/2011 20:32, Keith Thompson wrote:
>> cri@tiac.net (Richard Harter) writes:
>> [...]
>>> Any language in which it is possible for a pointer to be invalid but
>>> which provides no way to test for validity is fundamentally flawed.
>>
>> What existing language has pointers and is not "fundamentally flawed"?
>>
>Indeed. Testing a pointer by simple inspection can tell you whether it is
>null or not. If it is null it is not valid. If not you simply can't tell.
We just keep going around and around on this.
It is perfectly obvious that it is possible to design and implement a
language in which pointers (or something resembling what we call pointers in
C) are safe. But that language won't be C.
--
Faced with the choice between changing one's mind and proving that there is
no need to do so, almost everyone gets busy on the proof.
- John Kenneth Galbraith -
[toc] | [prev] | [next] | [standalone]
| From | Joe Pfeiffer <pfeiffer@cs.nmsu.edu> |
|---|---|
| Date | 2011-09-18 22:32 -0600 |
| Message-ID | <1bipop9mo6.fsf@pfeifferfamily.net> |
| In reply to | #10469 |
gazelle@shell.xmission.com (Kenny McCormack) writes: > In article <H7idnUSmaqgcL-vTnZ2dnUVZ_oGdnZ2d@giganews.com>, > Joe Wright <joewwright@comcast.net> wrote: >>On 9/18/2011 20:32, Keith Thompson wrote: >>> cri@tiac.net (Richard Harter) writes: >>> [...] >>>> Any language in which it is possible for a pointer to be invalid but >>>> which provides no way to test for validity is fundamentally flawed. >>> >>> What existing language has pointers and is not "fundamentally flawed"? >>> >>Indeed. Testing a pointer by simple inspection can tell you whether it is >>null or not. If it is null it is not valid. If not you simply can't tell. > > We just keep going around and around on this. > > It is perfectly obvious that it is possible to design and implement a > language in which pointers (or something resembling what we call pointers in > C) are safe. But that language won't be C. And in which those "pointers" have semantics somewhat different from what C calls pointers. And, I expect, semantics somewhat different from what most readers of this newsgroup infer from the word pointers.
[toc] | [prev] | [next] | [standalone]
| From | gazelle@shell.xmission.com (Kenny McCormack) |
|---|---|
| Date | 2011-09-20 14:18 +0000 |
| Message-ID | <j5a7cj$itt$1@news.xmission.com> |
| In reply to | #10471 |
In article <1bipop9mo6.fsf@pfeifferfamily.net>, Joe Pfeiffer <pfeiffer@cs.nmsu.edu> wrote: ... >And in which those "pointers" have semantics somewhat different from >what C calls pointers. And, I expect, semantics somewhat different from >what most readers of this newsgroup infer from the word pointers. Quite so. I know of a language that has "pointers" - they call them pointers and use the same "*" and "&" syntax that C uses - but these pointers are entirely safe to use. -- Is God willing to prevent evil, but not able? Then he is not omnipotent. Is he able, but not willing? Then he is malevolent. Is he both able and willing? Then whence cometh evil? Is he neither able nor willing? Then why call him God? ~ Epicurus
[toc] | [prev] | [next] | [standalone]
| From | August Karlstrom <fusionfile@gmail.com> |
|---|---|
| Date | 2011-09-20 18:15 +0200 |
| Message-ID | <j5ae7l$u2u$1@dont-email.me> |
| In reply to | #10572 |
On 2011-09-20 16:18, Kenny McCormack wrote:
> I know of a language that has "pointers" - they call them pointers and use
> the same "*" and "&" syntax that C uses - but these pointers are entirely safe
> to use.
A language with an "address of" operator cannot be safe as is
illustrated by the following example:
T *x;
void f(void)
{
T y;
x = &y;
}
After calling f, x is invalid.
/August
--
The competent programmer is fully aware of the limited size of his own
skull. He therefore approaches his task with full humility, and avoids
clever tricks like the plague. --Edsger Dijkstra
[toc] | [prev] | [next] | [standalone]
| From | "BartC" <bc@freeuk.com> |
|---|---|
| Date | 2011-09-20 17:49 +0100 |
| Message-ID | <j5ag8o$ci4$1@dont-email.me> |
| In reply to | #10579 |
"August Karlstrom" <fusionfile@gmail.com> wrote in message
news:j5ae7l$u2u$1@dont-email.me...
> On 2011-09-20 16:18, Kenny McCormack wrote:
>> I know of a language that has "pointers" - they call them pointers and
>> use
>> the same "*" and "&" syntax that C uses - but these pointers are entirely
>> safe
>> to use.
>
> A language with an "address of" operator cannot be safe as is illustrated
> by the following example:
>
> T *x;
>
> void f(void)
> {
> T y;
>
> x = &y;
> }
>
> After calling f, x is invalid.
It's possible to insist that only static objects (including functions) can
have & applied.
Where & is applied to a dynamic or transient object, then that can also be
protected, depending on how much the language is worried about invalid
pointers. C doesn't worry too much about it, and puts a lot of trust in the
programmer.
(And there are other ways of generating pointers than just using &.)
--
Bartc
[toc] | [prev] | [next] | [standalone]
| From | Willem <willem@toad.stack.nl> |
|---|---|
| Date | 2011-09-20 17:02 +0000 |
| Message-ID | <slrnj7hhor.2b40.willem@toad.stack.nl> |
| In reply to | #10582 |
BartC wrote:
) It's possible to insist that only static objects (including functions) can
) have & applied.
)
) Where & is applied to a dynamic or transient object, then that can also be
) protected, depending on how much the language is worried about invalid
) pointers. C doesn't worry too much about it, and puts a lot of trust in the
) programmer.
Or the language can simply make sure that the pointed-to object keeps
existing untill all pointers to it are gone. Which a lot of languages
do, actually.
SaSW, Willem
--
Disclaimer: I am in no way responsible for any of the statements
made in the above text. For all I know I might be
drugged or something..
No I'm not paranoid. You all think I'm paranoid, don't you !
#EOT
[toc] | [prev] | [next] | [standalone]
| From | jacob navia <jacob@spamsink.net> |
|---|---|
| Date | 2011-09-20 20:35 +0200 |
| Message-ID | <j5amdc$906$1@speranza.aioe.org> |
| In reply to | #10584 |
Le 20/09/11 19:02, Willem a écrit : > BartC wrote: > ) It's possible to insist that only static objects (including functions) can > ) have& applied. > ) > ) Where& is applied to a dynamic or transient object, then that can also be > ) protected, depending on how much the language is worried about invalid > ) pointers. C doesn't worry too much about it, and puts a lot of trust in the > ) programmer. > > Or the language can simply make sure that the pointed-to object keeps > existing untill all pointers to it are gone. Which a lot of languages > do, actually. > > > SaSW, Willem Well, C too does that. Just download lcc-win and see. It has a built-in garbage collector. :-)
[toc] | [prev] | [next] | [standalone]
| From | Ike Naar <ike@iceland.freeshell.org> |
|---|---|
| Date | 2011-09-20 20:30 +0000 |
| Message-ID | <slrn3vfsj7htua.v3.ike@iceland.freeshell.org> |
| In reply to | #10588 |
On 2011-09-20, jacob navia <jacob@spamsink.net> wrote: > Le 20/09/11 19:02, Willem a ?crit : >> BartC wrote: >> ) It's possible to insist that only static objects (including functions) can >> ) have& applied. >> ) >> ) Where& is applied to a dynamic or transient object, then that can also be >> ) protected, depending on how much the language is worried about invalid >> ) pointers. C doesn't worry too much about it, and puts a lot of trust in the >> ) programmer. >> >> Or the language can simply make sure that the pointed-to object keeps >> existing untill all pointers to it are gone. Which a lot of languages >> do, actually. >> >> >> SaSW, Willem > > Well, C too does that. > > Just download lcc-win and see. It has a built-in > garbage collector. We're talking about a pointer to an automatic variable. Does the lcc-win garbage collector handle those? Or does it only handle pointers to allocated memory?
[toc] | [prev] | [next] | [standalone]
| From | jacob navia <jacob@spamsink.net> |
|---|---|
| Date | 2011-09-20 22:35 +0200 |
| Message-ID | <j5ater$rcl$1@speranza.aioe.org> |
| In reply to | #10597 |
Le 20/09/11 22:30, Ike Naar a écrit : > On 2011-09-20, jacob navia<jacob@spamsink.net> wrote: >> Le 20/09/11 19:02, Willem a ?crit : >>> BartC wrote: >>> ) It's possible to insist that only static objects (including functions) can >>> ) have& applied. >>> ) >>> ) Where& is applied to a dynamic or transient object, then that can also be >>> ) protected, depending on how much the language is worried about invalid >>> ) pointers. C doesn't worry too much about it, and puts a lot of trust in the >>> ) programmer. >>> >>> Or the language can simply make sure that the pointed-to object keeps >>> existing untill all pointers to it are gone. Which a lot of languages >>> do, actually. >>> >>> >>> SaSW, Willem >> >> Well, C too does that. >> >> Just download lcc-win and see. It has a built-in >> garbage collector. > > We're talking about a pointer to an automatic variable. > Does the lcc-win garbage collector handle those? Of course not, the code as shown will provoke a warning. But an object will be kept until there are no pointers to it. > Or does it only handle pointers to allocated memory? Yes, only gc malloced memory
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| From | Phil Carmody <thefatphil_demunged@yahoo.co.uk> |
|---|---|
| Date | 2011-09-22 22:07 +0300 |
| Message-ID | <87r5382y6v.fsf@bazspaz.fatphil.org> |
| In reply to | #10597 |
Ike Naar <ike@iceland.freeshell.org> writes: > On 2011-09-20, jacob navia <jacob@spamsink.net> wrote: > > Le 20/09/11 19:02, Willem a ?crit : > >> BartC wrote: > >> ) It's possible to insist that only static objects (including functions) can > >> ) have& applied. > >> ) > >> ) Where& is applied to a dynamic or transient object, then that can also be > >> ) protected, depending on how much the language is worried about invalid > >> ) pointers. C doesn't worry too much about it, and puts a lot of trust in the > >> ) programmer. > >> > >> Or the language can simply make sure that the pointed-to object keeps > >> existing untill all pointers to it are gone. Which a lot of languages > >> do, actually. > >> > >> > >> SaSW, Willem > > > > Well, C too does that. > > > > Just download lcc-win and see. It has a built-in > > garbage collector. > > We're talking about a pointer to an automatic variable. > Does the lcc-win garbage collector handle those? > Or does it only handle pointers to allocated memory? And are such pointers "valid" anyway? If the local variable's out of scope, I would assert that a pointer to it was no longer valid. Dereferencability has never been a sufficient condition for being valid, IMHO. Phil -- "Religion is what keeps the poor from murdering the rich." -- Napoleon
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| From | James Kuyper <jameskuyper@verizon.net> |
|---|---|
| Date | 2011-09-22 16:11 -0400 |
| Message-ID | <j5g4sl$s6p$1@dont-email.me> |
| In reply to | #10720 |
On 09/22/2011 03:07 PM, Phil Carmody wrote: > Ike Naar <ike@iceland.freeshell.org> writes: >> On 2011-09-20, jacob navia <jacob@spamsink.net> wrote: >>> Le 20/09/11 19:02, Willem a ?crit : ... >>>> Or the language can simply make sure that the pointed-to object keeps >>>> existing untill all pointers to it are gone. Which a lot of languages >>>> do, actually. >>>> >>>> >>>> SaSW, Willem >>> >>> Well, C too does that. >>> >>> Just download lcc-win and see. It has a built-in >>> garbage collector. >> >> We're talking about a pointer to an automatic variable. >> Does the lcc-win garbage collector handle those? >> Or does it only handle pointers to allocated memory? > > And are such pointers "valid" anyway? In C, certainly not. I've no idea whether they're valid in lcc. However, this branch of this discussion has been about languages with pointers in general, rather than C or lcc in particular. There's no inherent reason why a language has to specify that a pointer to an object whose name is out of scope is invalid; judging from some of the counter examples that have been provided in this thread, there are some existing languages, including perl, where such pointers remain perfectly dereferenceable. If you have a reason why they shouldn't be valid, it would be helpful to state that reason. With three decades of programming experience, most of it in C, I find the concept of such pointers disconcerting - but I don't see any reason why they shouldn't be allowed. > If the local variable's out of scope, I would assert that > a pointer to it was no longer valid. Dereferencability has > never been a sufficient condition for being valid, IMHO. As assertion is not as good as an argument. Do you have one?
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| From | Phil Carmody <thefatphil_demunged@yahoo.co.uk> |
|---|---|
| Date | 2011-09-23 12:28 +0300 |
| Message-ID | <87obyb1uat.fsf@bazspaz.fatphil.org> |
| In reply to | #10725 |
James Kuyper <jameskuyper@verizon.net> writes: > On 09/22/2011 03:07 PM, Phil Carmody wrote: > > Ike Naar <ike@iceland.freeshell.org> writes: > >> We're talking about a pointer to an automatic variable. > >> Does the lcc-win garbage collector handle those? > >> Or does it only handle pointers to allocated memory? > > If the local variable's out of scope, I would assert that > > a pointer to it was no longer valid. Dereferencability has > > never been a sufficient condition for being valid, IMHO. > > As assertion is not as good as an argument. Do you have one? Stop trying to be clever; do you not think I chose that word for a reason? However, I should be flattered that you interpreted what I wrote as it was intended, which is so rare nowadays, even if you didn't work out my motivation for such wording. However, one cannot have an argument *without* some assertions. Call them axioms, call them postlates, call them whatever, but they are not argued, they are asserted. Phil -- "Religion is what keeps the poor from murdering the rich." -- Napoleon
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