Path: utzoo!mnetor!uunet!husc6!mit-eddie!uw-beaver!cornell!rochester!ritcv!cci632!ccicpg!nick
From: nick@ccicpg.UUCP (Nick Crossley)
Newsgroups: comp.lang.c
Subject: Re: = vs ==, and do 10 i = 1.3
Message-ID: <8971@ccicpg.UUCP>
Date: 11 Jan 88 23:28:26 GMT
References: <4668@pyr.gatech.EDU> <495@xyzzy.UUCP> <9930@mimsy.UUCP> <609@PT.CS.CMU.EDU> <10109@mimsy.UUCP>
Reply-To: @ccicpg.UUCP (Nick Crossley)
Organization: CCI CPG, Irvine CA
Lines: 39
Keywords: C, lint, checking
Summary: program for checking = in C

I too have often made the error of writing if (a = b) rather than if (a == b),
and was in the position of having to check a lot of my own code and that of
several co-workers on a large project.  So I wrote a program 'check' which
checked the things lint did not, based on the errors I saw in our code.
'check' will produce a warning for :-
	= in any conditional context
	potentially ambiguous else
	if with neither then nor else

The first checks for = not only in if, but while, for, &&, ||, etc.

The second warns about :-
	if	(a)
		if	(b)
			stat1;
		else	stat2;
but not about :-
	if	(a)
	{
		if	(b)
			stat1;
		else	stat2;
	}
which I believe to be better (and since I wrote the program, I made it think
as I do :-))

The third warns about :-
	if	(a);
		stat1;
which is legal, but dubious, and which one of my co-workers wrote, and which
took me a good day of debugging to notice the extra semicolon!!

'check' is by no means complete; there are many additional features I will
get round to adding one day, including software metrics.  However, it works
fine as it stands, so if anyone is interested I can post it.

Nick Crossley
...!uunet!ccicpg!nick
CCI, 9801 Muirlands, Irvine 92718