Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!uunet!mcvax!ukc!acorn!moncam!paul
From: paul@moncam.co.uk (Paul Hudson)
Newsgroups: comp.lang.c
Subject: Re: lint won't verify printf formatting against variable types??
Message-ID: <PAUL.89Jun30102046@marvin.moncam.co.uk>
Date: 30 Jun 89 09:20:46 GMT
References: <328@tree.UUCP> <417@siswat.UUCP>
	<441a30e5.8f55@fiero.engin.umich.edu> <27729@lll-winken.LLNL.GOV>
Sender: paul@moncam.co.uk
Organization: Monotype ADG, Cambridge, UK.
Lines: 30
In-reply-to: berry@lll-crg.llnl.gov's message of 29 Jun 89 02:27:43 GMT

To: 
In article <27729@lll-winken.LLNL.GOV> berry@lll-crg.llnl.gov (Berry Kercheval) 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++));

   Admittedly, I usually code it as:

	   while(!isspace(*cp++))
		   /* null */ ;

But the first *is* a semantic error - x== 5 has no side-effects
(assuming x isn't volatile). A compiler can check for this before
warning about the null statement.

And in this particular case "if (expre);" is always equivalent to
"expr;" - and is IMHO likely to be a programmer error, so it should be
warned about.
--
Paul Hudson	 MAIL: Monotype ADG, Science Park, Cambridge, CB4 4FQ, UK.
		PHONE: +44 (223) 420018	  EMAIL: paul@moncam.co.uk,
	;"	  FAX: +44 (223) 420911		 ...!ukc!acorn!moncam!paul
 `"";";"        "/dev/null full: please empty the bit bucket"