For the lulz: ddmd vs libdparse lexer timings

[Iain Buclaw via Digitalmars-d]

On 5 January 2015 at 09:23, Daniel Murphy via Digitalmars-d
<digitalmars-d at puremagic.com> wrote:
> "Iain Buclaw via Digitalmars-d"  wrote in message
> news:mailman.4141.1420448690.9932.digitalmars-d at puremagic.com...
>
>> void foo(int bar, ...)
>> {
>>   va_list* va = void;
>>   va_list[1] __va_argsave;
>>   va = &__va_argsave;
>>
>>   ...
>> }
>>
>> The above being compiler generated by DMD.
>
>
> Should that be va = &__va_argsave[0] ?

Yes.  More or less, both should do the same. :-)

>  So what _should_ DMD be generating?

That depends on how we agree to go forward with this.  From memory, we
each do / did things differently.

I have no doubt that the way I've done it is a kludge at best, but
I'll explain it anyway.

GDC *always* uses the real va_list type, our type-strict backend
demands at least that from us.  So when it comes down to the problem
of passing around va_list when it's a static array (extern C expects a
ref), I rely on people using core.vararg/gcc.builtins to get the
proper __builtin_va_list before importing modules such as
core.stdc.stdio (printf and friends) - as these declarations are then
rewritten by the compiler from:

int vprintf(__builtin_va_list[1] va, in char* fmt, ...)

to:

int vprintf(ref __builtin_va_list[1] va, in char* fmt, ...)


This is an *esper* workaround, and ideally, I shouldn't be doing this...