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Re: RFC: Cygwin 64 bit?
2012/1/19 Corinna Vinschen:
> [This time with Kai CCed, sorry about that]
>
> On Jan 19 14:48, Kai Tietz wrote:
>> 2012/1/19 Kai Tietz:
>> > 2012/1/19 Corinna Vinschen:
>> >> Did you see http://cygwin.com/ml/cygwin-developers/2012-01/msg00023.html?
>> >> The extra header file is one possible approach I can think of.
>> >>
>> >> Another way to do it would be to drop all `long' and `int' types in
>> >> favor of fixed-size types from stdint.h, int32_t and uint32_t.
>> >
>> > The stdint.h approach I would prefer here, as it is the most portable
>> > way IMHO. ?Using defines can lead easily to issues, especially in
>> > user-land.
>>
>> Well, we might still need an extra-header for this, which defines
>> types for 'long32_t'. ?As we need for LLP64 still the type 'long'. ?We
>
> Oh, ok. ?I guess we should underscore this type so that we don't have
> collisions, something like _ms_long_t, _ms_ulong_t. ?The ms should make
> clear that we refer to the definition of long in the MS sense.
>
> There's also the chicken-egg problem since we just don't *have* any
> stdint.h file for 64 bit Cygwin yet. ?Fixable, but still...
Hmm, isn't gcc providing one by default?
The new header we need can be added to platform-headers and do their
by some magic if-guards the proper type-defines.
>> need to abstract here also constant-numbers using L-postfix. ?But this
>
> Oh, right. ?I didn't think about that.
>
>> issue we know already by Wine-folk. ?So it is doable and would even
>> help to be more in synch to Wine-venture.
>>
>> Another subject about cygwin going 64-bit. ?What ABI you actual want
>> to use by default? ?The sysv-ABI, or the ms-ABI? ?As if you want to
>> use sysv-ABI, ?we need additionally to mark any prototype in
>> platform-headers by attribute to use the ms-ABI.
>
> I read about the ABIs for a while and I guess we should stick to the ms
> ABI for simplicity. ?The sysv ABI can store a few more args in registers,
> but the added complexity is kind of disheartening. ?I wonder if that
> also would break RtlUnwind, for instance.
Agreed. The way via the ms-ABI is for sure the easier road.
>
> Corinna
Kai