Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!yale!Horne-Scott
From: Horne-Scott@cs.yale.edu (Scott Horne)
Newsgroups: comp.lang.c
Subject: Re: lint won't verify printf formatting against variable types??
Keywords: lint, cc
Message-ID: <65088@yale-celray.yale.UUCP>
Date: 29 Jun 89 17:44:54 GMT
References: <328@tree.UUCP> <417@siswat.UUCP> <441a30e5.8f55@fiero.engin.umich.edu> <27729@lll-winken.LLNL.GOV>
Sender: root@yale.UUCP
Reply-To: Horne-Scott@cs.yale.edu (Scott Horne)
Organization: Yale University Computer Science Dept, New Haven, CT   06520-2158
Lines: 34
In-reply-to: berry@lll-crg.llnl.gov (Berry Kercheval)

In article <27729@lll-winken.LLNL.GOV>, berry@lll-crg (Berry Kercheval) writes:
> In article <441a30e5.8f55@fiero.engin.umich.edu>, ejd@caen (Edward J Driscoll) writes:
> >It [[ if(x==5); ]]is legal, but I would hope for a warning from such an 
> > obvious semantic error.  
> 
> Goodness, save me from useless warnings for perfectly good C
> constructs.  This is NOT an "obvious" semantic error.  Have you never
> done something like this?
> 
> 	/* skip to end of word */
> 	while(!isspace(*cp++));

You're missing the point.  `if(x == 5);' is not necessarily a semantic error,
but it probably is.

`while' constructs with null bodies are useful, but `if' constructs like the
one above are not.  Consider what `if(x == 5);' does:  *nothing*!  If x == 5,
the program continues; if x != 5, the program continues the same way.  There
aren't even any side effects; but even if there were, they would be obtained
just the same with out the `if'.  I'm sure you'll have a hard time thinking
of an occasion in which a reasonable programmer would write `if(x == 5);'
intentionally.

However, I would of course *allow* such constructs, and I think that the
compiler should give at most a warning.  Such things are best left to
programs like `lint'.

					--Scott

Scott Horne                              Hacker-in-Chief, Yale CS Dept Facility
horne@cs.Yale.edu                         ...!{harvard,cmcl2,decvax}!yale!horne
Home: 203 789-0877     SnailMail:  Box 7196 Yale Station, New Haven, CT   06520
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Dare I speak for the amorphous gallimaufry of intellectual thought called Yale?