Article View: comp.sys.mac
Article #20429LSC Bug (honest!!)
From: Alen Shapiro
Date: Fri, 16 Oct 1987 22:06
Date: Fri, 16 Oct 1987 22:06
39 lines
1693 bytes
1693 bytes
Can any of you guys out there in THINKland tell me why this program
terminates and do I get a free upgrade to 3.0 (symbolic debugger
and all) for finding a bug (grovel grovel)?
Seems that when I add zero to a register pointer it wants to add 8.
This is an isolation of a problem in a large suite of programs I am
writing. The #define of EXTRA to zero is a place keeper for future
improvements where extra space will be (but is not currently) needed.
Nevertheless I'm sure the compiler should not generate code that
adds a different definition of zero ((-: you know, the one more closely
related to 42 - the definition of zero that we have not yet come
across :-)).
--alen the Lisa slayer (it's a long story)
...!seismo!esosun!cogen!alen
-----cut here----
#include <stdio.h>
/* on */
#define BUG /* adding 0 to a register pointer adds 8 is this an
* overenthusiastic allignment preservation effect?
*/
#define EXTRA 0
main() {
#ifdef BUG
register char *c;
#else BUG
char *c;
#endif BUG
for(c=(char *)0 ; c < (char *)100 ; c += EXTRA)
fprintf(stderr, "c = 0x%lx\n", c);
}
Technical Details
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!mnetor!uunet!seismo!esosun!cogen!alen From: alen@cogen.UUCP (Alen Shapiro) Newsgroups: comp.sys.mac Subject: LSC Bug (honest!!) Message-ID: <372@cogen.UUCP> Date: Fri, 16-Oct-87 18:06:00 EDT Article-I.D.: cogen.372 Posted: Fri Oct 16 18:06:00 1987 Date-Received: Sun, 18-Oct-87 02:37:36 EDT References: <1018@oakhill.UUCP> Reply-To: alen@cogen.UUCP (Alen Shapiro) Organization: Cogensys, LaJolla, Calf. Lines: 39 Keywords: LSC register inc by zero Summary: OK you asked for it