From: henry@utzoo.UUCP (Henry Spencer)
Subject: Re: "C" vrs ADA
Date: Sat, 29-Aug-87 02:25:25 EDT [thread overview]
Date: Sat Aug 29 02:25:25 1987
Message-ID: <8513@utzoo.UUCP> (raw)
In-Reply-To: 36@sarin.UUCP
> Um... How do these [safe] C environments detect subscript range errors
> in a piece of code like:
>
> strcpy(s,t)
> char *s, *t;
> { while (*s++ = *t++); return s;}
Easy, a pointer becomes a non-trivial data structure that carries bounds
with it; those bounds are checked when it is used. Remember that pointer
arithmetic is technically legal only within a single array. Getting the
little details right must be a bit tricky in spots, but it does work.
> Although an unhandled exception in C "typically" produces a dump,
> it does not "always" produce a dump. Also, the dump may occur long
> after the invalid code was executed, making it more difficult to figure
> out what went wrong.
This property is shared by *all* programming languages that can generate
run-time exceptions; usually the actual exception shows up at some remove
from the bug that actually caused it. Unless Ada is much more radical
than I remember (it's been a long time since I read the definition),
it is just as subject to this problem as C.
--
"There's a lot more to do in space | Henry Spencer @ U of Toronto Zoology
than sending people to Mars." --Bova | {allegra,ihnp4,decvax,utai}!utzoo!henry
next prev parent reply other threads:[~1987-08-29 6:25 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
1987-08-17 21:36 "C" vrs ADA Glen Harman
1987-08-18 14:49 ` spf
1987-08-19 17:03 ` "C" AND Ada Eugene Miya N.
1987-08-20 1:52 ` Richard Harter
1987-08-20 17:29 ` "C" AND Ada (epigram) David Palmer
1987-08-21 9:09 ` "C" AND Ada Kent Paul Dolan
1987-08-19 20:45 ` "C" vrs ADA ark
1987-08-20 20:10 ` Stephen 2. Williams
1987-08-21 0:19 ` Jef Poskanzer
1987-08-21 9:15 ` Webber
1987-08-21 1:04 ` R.A. Agnew
1987-08-21 15:27 ` spf
1987-08-23 0:35 ` Henry Spencer
1987-08-23 18:07 ` wyatt
1987-08-25 17:55 ` John Unekis
1987-08-25 18:57 ` David C. Albrecht
1987-08-27 16:32 ` Henry Spencer
1987-08-28 16:31 ` Renu Raman, Sun Microsystems
1987-08-28 15:51 ` Peter da Silva
1987-08-30 1:05 ` Rahul Dhesi
1987-08-31 13:55 ` sns
1987-09-04 16:51 ` VAX/VMS C Jim Sullivan
1987-08-18 15:17 ` "C" vrs ADA G.Gleason
1987-08-18 18:09 ` John Unekis
1987-08-21 12:07 ` Mr. Patrick J. Kelly Jr. GS-13
1987-08-21 13:00 ` steve
1987-08-21 14:04 ` Stefan M. Vorkoetter
1987-08-22 23:31 ` COBOL vs "C" vs ADA neubauer
1987-08-24 23:11 ` Dave Levenson
1987-08-25 19:18 ` FORTRAN vs COBOL vs Pascal vs C " Stephen the Greatest
1987-08-23 13:13 ` COBOL vrs Ada (was: Re: "C" vrs ADA) Kent Paul Dolan
1987-08-21 14:17 ` "C" vrs ADA M.P.Lindner
1987-08-21 15:10 ` Dave Haynie
1987-08-21 16:07 ` crowl
1987-08-22 2:44 ` hitchens
1987-08-27 18:53 ` jym
1987-08-22 14:31 ` Roy Smith
1987-08-26 16:17 ` Kurt Hoyt
1987-08-23 0:33 ` Henry Spencer
1987-08-18 18:43 ` Dave Haynie
1987-08-22 21:09 ` Eric Beser sys admin
1987-08-25 16:35 ` David Palmer
1987-08-26 14:21 ` spf
1987-08-28 0:49 ` peter
1987-09-03 20:03 ` R.A. Agnew
1987-08-26 3:38 ` Doug Gwyn
1987-08-26 19:32 ` Charles Simmons
1987-08-26 9:25 ` Randell Jesup
1987-08-26 15:40 ` M.P.Lindner
1987-08-27 17:44 ` Jeff Bartlett
1987-08-31 17:53 ` mpl
1987-09-01 22:03 ` Barry Margolin
1987-09-02 0:32 ` eric
1987-08-26 18:30 ` Dave Haynie
1987-08-29 6:25 ` Henry Spencer [this message]
1987-09-01 19:02 ` Jacob Gore
1987-09-02 14:09 ` stt
-- strict thread matches above, loose matches on Subject: below --
1987-08-25 20:44 blackje%sungod.tcpip
[not found] <822@s.cc.purdue.edu>
1987-08-28 12:33 ` kelly
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox