Path: utzoo!utgpu!water!watmath!orchid!tdwest
From: tdwest@orchid.waterloo.edu (Terry D. West)
Newsgroups: comp.sys.amiga
Subject: BIG BUG in Manx3.6a (+L only)
Keywords: OOP ACK (pointer comparisons)
Message-ID: <12325@orchid.waterloo.edu>
Date: 28 Feb 88 22:12:43 GMT
Distribution: comp
Organization: U of Waterloo, Ontario
Lines: 56

Well, I guess I have the dubious honour of reporting the first
major bug in 3.6a 12-18-87 Manx C :-(

Jim, are you listening? Good.

Beware of pointer comparisons and assignments under the +L option.
It seems that the _indirect_ pointer comparison result assigned
_indirectly_ really breaks the compiler.  It gurus during compilation
due to an odd address reference on a move.w instruction.

Here's a short file which bares all:

--------- cut here, compile, and guru during compilation -----------

/* bomber.c
 *
 * This program gurus the MANX 3.6 compiler 
 * when the +L option is used.
 *
 * Copyright 1988 Terry D. West & Jeff A. Voskamp :-)
 * Who'd reserve rights to this?
 *
 */

struct STYPE{ 	
	struct STYPE *next;
	long i;
} *s1,*s2;

main()
{
	long ll;
	struct STYPE *sp1,*sp2;

	/* This one gurus */

	s1->i = (s1->next != s2->next); 

	/* but none of these do! */

	s1->i = ( (long) (s1->next) != (long) (s2->next));

	ll = (s1->next != s2->next); 

	sp1 = s1->next;
	sp2 = s2->next;

	s1->i = (sp1 != sp2);
	s1->i = (sp1 != s2->next); 
	s1->i = (s1->next != sp2);
}

--
Terry D. West
watmath!orchid!tdwest
tdwest@orchid.waterloo.edu