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Groups > comp.lang.forth > #45846
| From | Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: OT: One of Anton's papers makes Hacker News |
| Date | 2016-03-04 21:01 -0500 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <20160304210145.16c87863@_> (permalink) |
| References | <87bn6vytsf.fsf@nightsong.com> |
On Thu, 03 Mar 2016 16:24:16 -0800 Paul Rubin <no.email@nospam.invalid> wrote: > Under the title "what every compiler writer should know about > programmers". The paper criticizes various compiler responses to the > presence of undefined behaviour in C programs, a topic that has come > up here in CLF several times. > > Paper: > [link] I don't have time to read all of your paper, but clearly you still fail to understand the basics of C. You should really, really have a C expert review this stuff first before publishing it ... I got to this part, which I felt I needed to comment on as yet another example of why you still don't understand C: "However, this implementation is C*, but not ``C'', because p<q is not defined in ``C'' if p and q point to different objects." That is a completely wrong conclusion. Look at how memmove() is declared: void *memmove(void *dest, const void *src, size_t n) Here, p represents dest, and q represents src. So, p<q represents dest<src. What objects do dest or src point to? The answer to that question is: none. They point to no objects. So, what objects are you referring to? ... Neither dest nor src point to any data object in C. There is *NO* data type associated with dest or src. That's what "void" means. These are raw pointers to memory without any C object associated with them. The place where memmove is called may have declared data types passed, but nothing is associated with dest and src once they've been through parameter type conversion to be passed into memmove(). If there is no type associated with dest or src, then there can be no object associated with dest or src. Therefore, the fact that p<q is not defined for different objects is irrelevant here since there are no objects involved. p and q, representing, dest and src, work on raw memory which is objectless. And, you continue with the same erroneous understanding: "However, a ``C'' compiler might assume that src and dest point to the same object, ..." It, the C compiler, can do no such thing. dest and src **DO NOT** point to _any_ valid C object. That is what "void" means in C. The compiler cannot assume anything about any object from dest or src. There is no associated data type once in memmove(). dest and src are pointers to "nothing" (i.e., raw addresses for memory) due to the parameter type conversion. char a[10]; memmove(a[2],a[5],5); a[2] and a[5] "reduce" to pointers to char. These pointers to char are converted to pointers to void to be passed into memmove(). All type information is lost at that point. It does not propagate as you've indicated in your article. In memmove(), there is no type association, no object association, etc for dest and src. HTH, Rod Pemberton
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OT: One of Anton's papers makes Hacker News Paul Rubin <no.email@nospam.invalid> - 2016-03-03 16:24 -0800
Re: OT: One of Anton's papers makes Hacker News Julian Fondren <julian.fondren@gmail.com> - 2016-03-03 21:06 -0800
Re: OT: One of Anton's papers makes Hacker News Ron Aaron <rambamist@gmail.com> - 2016-03-04 07:18 +0200
Re: OT: One of Anton's papers makes Hacker News Paul Rubin <no.email@nospam.invalid> - 2016-03-03 21:33 -0800
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-04 17:52 +0000
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-04 12:32 +0000
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-04 18:20 +0000
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-05 02:23 +0000
Re: OT: One of Anton's papers makes Hacker News hughaguilar96@gmail.com - 2016-03-04 19:06 -0800
Re: OT: One of Anton's papers makes Hacker News Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-03-05 20:32 -0500
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-06 11:28 +0000
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-06 18:02 +0000
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-06 23:55 +0000
Re: OT: One of Anton's papers makes Hacker News hughaguilar96@gmail.com - 2016-03-06 14:48 -0800
Re: OT: One of Anton's papers makes Hacker News Julian Fondren <julian.fondren@gmail.com> - 2016-03-07 03:36 -0800
Re: OT: One of Anton's papers makes Hacker News Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-03-07 19:19 -0500
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-12 17:40 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-05 03:35 -0600
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-05 13:37 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-05 15:42 -0600
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-06 00:50 +0000
Re: OT: One of Anton's papers makes Hacker News Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-03-05 20:33 -0500
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-06 02:01 +0000
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-06 11:57 +0000
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-07 07:35 +0000
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-07 12:40 +0000
Re: OT: One of Anton's papers makes Hacker News Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-03-07 19:20 -0500
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-08 00:49 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-06 02:20 -0600
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-07 00:35 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-07 02:53 -0600
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-07 16:07 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-08 05:17 -0600
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-08 22:01 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-09 03:14 -0600
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-09 11:17 +0000
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-09 23:58 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-10 04:45 -0600
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-10 11:39 +0000
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-10 13:29 +0000
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-12 16:02 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-10 08:22 -0600
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-12 15:49 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-12 13:35 -0600
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-10 21:58 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-11 06:11 -0600
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-12 00:05 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-12 04:23 -0600
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-12 12:05 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-12 08:36 -0600
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-12 16:57 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-12 13:44 -0600
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-12 14:29 +0000
Re: OT: One of Anton's papers makes Hacker News "Elizabeth D. Rather" <erather@forth.com> - 2016-03-11 15:02 -1000
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-12 16:20 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-12 13:53 -0600
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-06 13:02 +0000
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-06 11:52 +0000
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-06 12:42 -0600
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-06 13:12 -0600
Re: OT: One of Anton's papers makes Hacker News Ron Aaron <rambamist@gmail.com> - 2016-03-04 07:20 +0200
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-04 17:37 +0000
Re: OT: One of Anton's papers makes Hacker News Julian Fondren <julian.fondren@gmail.com> - 2016-03-04 11:23 -0800
Re: OT: One of Anton's papers makes Hacker News Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-03-09 03:24 -0600
Re: OT: One of Anton's papers makes Hacker News Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-03-04 21:01 -0500
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-05 13:51 +0000
Re: OT: One of Anton's papers makes Hacker News Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-03-05 19:43 -0500
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-06 01:45 +0000
Re: OT: One of Anton's papers makes Hacker News Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-03-07 19:19 -0500
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-12 17:24 +0000
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-13 12:27 +0000
Re: OT: One of Anton's papers makes Hacker News raltbos@xs4all.nl (Richard Bos) - 2016-03-13 13:50 +0000
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-13 19:52 +0000
Re: OT: One of Anton's papers makes Hacker News Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-03-13 16:08 -0400
Re: OT: One of Anton's papers makes Hacker News Keith Thompson <kst-u@mib.org> - 2016-03-13 13:40 -0700
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-14 00:41 +0000
Re: OT: One of Anton's papers makes Hacker News Keith Thompson <kst-u@mib.org> - 2016-03-13 18:23 -0700
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-14 02:59 +0000
Re: OT: One of Anton's papers makes Hacker News Keith Thompson <kst-u@mib.org> - 2016-03-13 20:29 -0700
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-14 22:44 +0000
Re: OT: One of Anton's papers makes Hacker News Keith Thompson <kst-u@mib.org> - 2016-03-14 16:23 -0700
Re: OT: One of Anton's papers makes Hacker News Jan Coombs <jenfhaomndgfwutc@murmic.plus.com> - 2016-03-14 23:55 +0000
Re: OT: One of Anton's papers makes Hacker News Keith Thompson <kst-u@mib.org> - 2016-03-14 17:19 -0700
Re: OT: One of Anton's papers makes Hacker News Robert Wessel <robertwessel2@yahoo.com> - 2016-03-14 19:26 -0500
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-15 00:48 +0000
Re: OT: One of Anton's papers makes Hacker News Keith Thompson <kst-u@mib.org> - 2016-03-14 22:30 -0700
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-15 07:23 +0000
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-15 10:09 +0000
Re: OT: One of Anton's papers makes Hacker News Keith Thompson <kst-u@mib.org> - 2016-03-15 08:56 -0700
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-15 19:33 +0000
Re: OT: One of Anton's papers makes Hacker News Rosario19 <Ros@invalid.invalid> - 2016-03-17 09:46 +0100
Re: OT: One of Anton's papers makes Hacker News Jerry Stuckle <jstucklex@attglobal.net> - 2016-03-17 09:37 -0400
Re: OT: One of Anton's papers makes Hacker News Rosario19 <Ros@invalid.invalid> - 2016-03-17 18:40 +0100
Re: OT: One of Anton's papers makes Hacker News Jerry Stuckle <jstucklex@attglobal.net> - 2016-03-17 13:53 -0400
Re: OT: One of Anton's papers makes Hacker News invalid <address@is.invalid> - 2016-03-17 18:00 +0000
Re: OT: One of Anton's papers makes Hacker News Rosario19 <Ros@invalid.invalid> - 2016-03-17 18:37 +0100
Re: OT: One of Anton's papers makes Hacker News Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-03-18 14:36 +0000
Re: OT: One of Anton's papers makes Hacker News David Brown <david.brown@hesbynett.no> - 2016-03-14 09:17 +0100
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-14 22:56 +0000
Re: OT: One of Anton's papers makes Hacker News Robert Wessel <robertwessel2@yahoo.com> - 2016-03-14 20:00 -0500
Re: OT: One of Anton's papers makes Hacker News David Brown <david.brown@hesbynett.no> - 2016-03-15 11:22 +0100
Re: OT: One of Anton's papers makes Hacker News raltbos@xs4all.nl (Richard Bos) - 2016-03-14 22:38 +0000
Re: OT: One of Anton's papers makes Hacker News Randy Howard <rhoward.mx@EverybodyUsesIt.com> - 2016-03-14 01:40 -0500
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-06 11:00 +0000
Re: OT: One of Anton's papers makes Hacker News Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-03-07 19:19 -0500
Re: OT: One of Anton's papers makes Hacker News Bernd Paysan <bernd.paysan@gmx.de> - 2016-03-08 01:02 +0000
Re: OT: One of Anton's papers makes Hacker News Julian Fondren <ayrnieu@gmail.com> - 2016-03-14 07:29 -0700
Re: OT: One of Anton's papers makes Hacker News anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-03-18 17:45 +0000
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