Path: utzoo!attcan!uunet!lll-winken!ubvax!weitek!dms!albaugh
From: albaugh@dms.UUCP (Mike Albaugh)
Newsgroups: comp.lang.misc
Subject: error handling (was Re: Algol-style semicolons)
Message-ID: <584@dms.UUCP>
Date: 16 Dec 88 18:09:26 GMT
References: <8008@aw.sei.cmu.edu>
Organization: Atari Games Inc., Milpitas, CA
Lines: 30

From article <8008@aw.sei.cmu.edu>, by firth@sei.cmu.edu (Robert Firth):
> 
[... many comments about compilers muffing single token corrections ]
> which is a single-token correction.  The real booby price, though, goes
> to the C compiler where omitting a semicolon before a right brace:
> 
> 	if (...) { s1; s2 }
> 
> causes an indefinite number of bogus consequential errors, until either
> the compiler gives up "too many errors - goodbye" or your program text
> ends.  Since the repair here is perhaps the simplest possible, this
> compiler feature represents incompetence of a rare order.
	Actually my nominee is the VAX-11C (vms) compiler which "corrects"

	if ((( ... expression )) { ....
to
	if ((( ... expression ))) ...

	That is, rather than inserting the required paren to balance the
expression, it _replaces_ the '{' with a ')'. Needless to say, the
corresponding brace imbalance leads to a torrent of further errors.
I'm not a compiler writer (But I've played one on occasion :-)), but
I thought that insertion was typically tried before substitution in
this sort of case. Can any of you compiler gurus explain why this
particular choice was made. Oh, yeah, we reported it but no reply and
it's still there 3 versions later...

| Mike Albaugh (albaugh@dms.UUCP || {...decwrl!turtlevax!}weitek!dms!albaugh)
| Atari Games Corp (Arcade Games, no relation to the makers of the ST)
| 675 Sycamore Dr. Milpitas, CA 95035		voice: (408)434-1709
| The opinions expressed are my own (Boy, are they ever)