(int)(void*)(int) 64 vs 32

[Neels Hofmeyr]

On Wed, Feb 24, 2016 at 11:38:36PM +0100, Harald Welte wrote:
> On Wed, Feb 24, 2016 at 08:07:21PM +0100, Neels Hofmeyr wrote:
> > On my 64bit system, I get warnings about casting int to pointer of
> > different size and vice versa. However, below patch only shifts the
> > warnings to 32bit systems, right?
>·
> I don't think so.  'long' typically corresponds to the pointer size, at
> least based on my experience.  Of course the C standard doesn't give you
> any guarantees and just states that it should be at least the size of a
> signed 32bit integer.
>·
> according to page 6 of
> http://www.agner.org/optimize/calling_conventions.pdf the only practical
> exception seems to be windows, where on 64bit even a 'long' is only
> 32bit ;)

can't do that then, can we ;)


On Thu, Feb 25, 2016 at 10:03:21AM +0100, Jacob wrote:
> What about using uintptr_t from stdint.h ?

    stdint.h:typedef unsigned long int  uintptr_t;

So that would work indeed. I'd have interpreted the name to mean
  unsigned int*
but it seems to be made for this specific case.

But I agree that the case per se is still odd:


On Wed, Feb 24, 2016 at 11:38:36PM +0100, Harald Welte wrote:
> The more interesting question is probably why is vty->index not pointing
> to 'struct osmo_msc_data' in the first place?  That's what we typically
> use, rather than storing integers in the pointer and then perfomring
> lookups on that.  Holger?

/me escalating to hfreyther

~Neels


-- 
- Neels Hofmeyr <nhofmeyr at sysmocom.de>          http://www.sysmocom.de/
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