On 08/29/2013 09:28 PM, Benjamin Thaut wrote:
Well no its not that simple. You can't just alias it. You still have to
create a import table. That would mean ALL data accesses to data symbols
would have another level of indirection. Always. The _imp_ symbols don't
refer to the data directly, they refer to the location the data is
stored at. As explained in the article I linked
(http://blog.omega-prime.co.uk/?p=115) this requires different assembly
to be generated. To make this work we would always have to generate
assembly with one level of indirection added for every data symbol
access, because we can not know if the symbol might be imported from a
DLL or not. As D tries to achive near C++ performance I would arther
want to avoid that.
So the alias trick would only work for functions.
For data the _imp_* symbol would need to be a pointer to the data?
How about LTO, when statically linking it should be possible to optimize
away the indirection. Also are there special relocations?
module libA;
export int var;
int* _imp_var = &var; // created by compiler
module foo;
import libA;
void bar()
{
auto val = var; // creates val = *_imp_var;
}
