Re: [Qemu-devel] [PATCH, RFC] More than 2G of memory on 64-bit hosts

[Thiemo Seufer]

Julian Seward wrote:
> 
> > > Unfortunately C99 relaxed this requirement, and allowed abominations like
> > > the win64 ABI.
> > >
> > > This means you have a choice: Write standard conforming code (long) that
> > > works on all known systems except win64, or use features that do't exist
> > > on many systems. IIRC C99 types like intptr_t are not supported on
> > > several fairly common unix systems.
> >
> > In that case I'll vote for unsigned long. I'd pass the issue to those
> > doing a win64 port, if ever that happens.
> 
> In Valgrind-world we use an alternative approach, which is to typedef
> a set of new integral types and use those exclusively, and not use the
> native 'int', 'long' etc.  The new types have a single fixed meaning
> regardless of the host or guest and it is up to the configure script
> to set up suitable typedefs.  At startup Valgrind checks the size and
> signedness of these types is as expected, so any configuration errors
> are caught.  This has proved very helpful in porting to a number of 
> platforms.

FWIW, I agree with that.


Thiemo