_argptr woes

[Sean Kelly]

Frits van Bommel wrote:
> kris wrote:
>> The D spec says:
>>
>> "The implementiations of these variadic functions have a special local 
>> variable declared for them, _argptr, which is a void* pointer to the 
>> first of the variadic arguments. To access the arguments, _argptr must 
>> be cast to a pointer to the expected argument type"
>>
>>
>> To me, this means that a D compiler must implement _argptr in these 
>> terms. Is that indeed the case, Walter? Or is my interpretation 
>> incorrect?
> 
> That would seem to be what it means.
> That would also seem to be a pretty big portability bug in the spec. On 
> amd64 definitely !is(va_list == void*) :P. (at least for current GDC, 
> GCC and any other compiler following 
> http://www.x86-64.org/documentation/abi.pdf)

Perhaps I'm being thick, but why in the world would a CPU spec need to 
contain parameter passing rules?  Or even stack frame information?  I 
can see an OS caring about stack frame, but parameter passing seems like 
it should be language-dependent.


Sean