This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: Extra warning

From: Neil Booth <neil at daikokuya dot co dot uk>
To: Jeremy Sanders <jss at ast dot cam dot ac dot uk>
Cc: gcc at gcc dot gnu dot org
Date: Wed, 7 Aug 2002 19:19:22 +0100
Subject: Re: Extra warning
References: <Pine.LNX.4.44.0208071908390.6395-100000@xpc1.ast.cam.ac.uk>

Jeremy Sanders wrote:-

> Hi,
> 
> gcc-3.1 doesn't seem to warn for the following code (even with
> -Wconversion -W -Wall).
> 
>   unsigned a;
>   double c;
>   a = 10;
>   c = -10 - a;
> 
> Which makes c 4294967276.00 rather than -20. It also doesn't warn for:
> 
>   unsigned a;
>   int b;
>   double c;
>   a = 10;
>   b = -10;
>   c = b - a;
> 
> (which of course would be harder to warn for).

If you'd really like this addressed at some time in the future,
please file a PR (gcc.gnu.org/bugs.html).  Otherwise it will be
forgotten.

Neil.

References:
- Extra warning
  - From: Jeremy Sanders

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]