lclint-interest message 153

From matteo@eolo.usr.dsi.unimi.it Thu Sep 18 13:08:14 1997
From: Matteo Vaccari 
Subject: mixing signed & unsigned arithmetic
To: lclint-interest@larch.lcs.mit.edu
Date: Thu, 18 Sep 1997 11:31:44 +0200 (MET DST)
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Hi all,

I wonder why lclint says the following program contains no errors:

----------------
#include 

int main() {
  unsigned u = 2;
  int i = -2;

  printf("i/u == %d, u/i == %d\n", i/u, u/i);
  return 0;
}
----------------

The results of executing the above are not what I would expect.  
Yes, _now_ I know that I shouldn't mix unsigned and signed
arithmetics, but I think a warning from lclint would be useful.

(The above concern comes from an ad from Gimpel Software,
www.gimpel.com.  They sell a lint program.  See their web pages for
their "bug of the month" series.)

Dave, thanks for being back on Lclint!

	Matteo