Re: [Qemu-devel] Re: [4363] MusicPal: fix gcc4 build (Jan Kiszka).

["Daniel P. Berrange" <berrange@redhat.com>]

On Wed, May 07, 2008 at 12:53:42PM +0100, Paul Brook wrote:
> > I'm not sure what's wrong with void * arithmetics though. They are
> > specified (somewhere) to work as if the type was a char *, and the
> > only annoyance is that you have to remember that.
> 
> It doesn't work in C++ for a start.
> I thought it was a GCC extension, though I could be wrong about that.

IIRC, arithmetic on void * is said to be undefined by the standard - GCC 
treats them the same as char * as a 'convenience' for people...

`-Wpointer-arith'
     Warn about anything that depends on the "size of" a function type
     or of `void'.  GNU C assigns these types a size of 1, for
     convenience in calculations with `void *' pointers and pointers to
     functions.

So I'd say better off just using char * so the behaviour is guarenteed
to be defined & consistent across compilers.

Dan.
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