John Reimer wrote:
Hello Walter,
So are you saying that XPCOM will work on Linux with D if only the
extern(Windows) was actually extern(C++) ?
Yes, I think so. But I should probably test the theory with dmd 2.0
first just to make sure. This is just about over my head since I'm not
too familiar with C++ internals. In terms of XPCOM, I believe that when
an interface is assigned an implementation pointer and the interface
method is called, the most important detail is that the /parameter/
signature at a specific vtable index match that of the implementation's
at the same index: that is, the method names are not important except
as an alias for client to use; it is assumed that the interface methods
will match the calling convention and argument types of the
implementation which was assigned to it).
So my question would be, in terms /calling conventions/ in an
/interface/ (not a class), does extern(System) differ in any way from
extern(C++). Does a "this" pointer get prepended to the argument list
of a C++ method call? I apologize if this is an ignorant question. I'm
almost clueless here. I'm assuming that the only difference in the
extern(C++) is that it:
(1) changes the interface to have a "normal" vtable (as XPCOM needs) and
(2) allows for a system calling convention (method name not being
important other than that the parameters of interface and implementation
match).
The system linkage was devised to match the Microsoft "syscall"
convention. It really has no meaning on linux, so we can make it
whatever it needs to be.
The C++ convention is designed to match whatever C++ does on the target
platform. Since Linux doesn't have any Windows or System calling
convention, it would seem that C++ is the one.
