[Qemu-devel] Re: [PATCH] Make strtosz() return int64_t instead of ssize_t

[Anthony Liguori]

On 01/05/2011 08:40 AM, Jes Sorensen wrote:
> On 01/05/11 14:46, Anthony Liguori wrote:
>    
> > On 01/05/2011 04:41 AM, address@hidden wrote:
> >      
> > > From: Jes Sorensen<address@hidden>
> > >
> > > strtosz() needs to return a 64 bit type even on 32 bit
> > > architectures. Otherwise qemu-img will fail to create disk
> > > images>= 2GB
> > >
> > > Signed-off-by: Jes Sorensen<address@hidden>
> > >
> > >        
> > off_t would be the proper type to use.
> >      
> I discussed this with Markus, and we both agree that it isn't.
>
> Two reasons, off_t is for filesystem offsets, not random sizes. Second,
> off_t doesn't have an unsigned type or a max to compare against.
>    

That's because the size of off_t depends on whether it's a 32 or 64-bit 
platform and what FILESIZEBITS is defined to be.

Basically, if you're looking for the type to represent offsets in a 
file, it's off_t.  That's why it exists.

That said, using this to represent memory too, I can buy that as a 
justification to use int64_t.

> Using int64_t is cleaner and safer.
>    

I wouldn't make such bold claims but I'll concede that one is not 
significantly better than the other and won't object to int64_t if you 
feel strongly.

Regards,

Anthony Liguori

> Cheers,
> Jes
>