Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!think!ames!amdahl!oliveb!sun!betelgeuse!jamesa
From: jamesa%betelgeuse@Sun.COM (James D. Allen)
Newsgroups: comp.lang.c
Subject: Broken compilers (Was Portability of passing/operating on structures)
Message-ID: <73946@sun.uucp>
Date: 21 Oct 88 04:13:48 GMT
References: <8810111934.AA21941@ucbarpa.Berkeley.EDU> <8308@alice.UUCP> <35317@XAIT.Xerox.COM>
Sender: news@sun.uucp
Lines: 48

In article <35317@XAIT.Xerox.COM>, g-rh@XAIT.Xerox.COM (Richard Harter) writes:
> >As for my opinion:  If your compiler's broken, take it up with your vendor.
>
> ...The things that make programs non
> portable are almost always frills and slop.  Things like passing structures
> are frills.

Among the compiler bugs I have contended with are:

1)
	struct {
		whatever;
	} st;
	. . .
	/* the next will be treated as though it were "foo(&st);"  */
		foo(st);

(To print
	"warning: compiler writer too lazy to implement structure arguments"
 seems far more reasonable than to silently substitute a totally different
 construct just because it *might* have been the programmer's intent.)

2)
	main() {
		short s = -3;
		foo(s);
	}

	foo(s) short s; {
		short *sp = &s;
	/* The next will print -1 rather than -3. */
		printf("%d", *sp);
	}

(I think this arose because a little-Endian compiler was ported to a
 big-Endian machine without ample thought and/or testing.)


These were (supposedly) important commercial compilers, not "toys."
By coincidence they were from the same large vendor.  I won't mention
names but the software house is operated by a magazine columnist
who frequently points out the "design errors" Dennis Ritchie made when
he invented C.  :-}

Moral: Test your compiler.  If it works assume you can use most reasonable
constructs.  If not, warn your fellow netlanders and throw the compiler away.

James D. Allen	-- Still dreaming on my way to H***.