Re: gcj to assist in porting java applet to activex control?

[Jeff Sturm <jsturm at one-point dot com>]

On 23 Oct 2001, Adam Megacz wrote:
> > Assuming GCC supports COM, which I heard it does, though I've never
> > used it.
> 
> Do you have any linkage for this, or a direction for me to look in?

The Mingw project has some runtime support for COM.  Unfortunately details
are a bit sketchy:

http://www.mingw.org/mingwfaq.shtml#faq-comsupport

Pre-3.0 it was necessary to compile with -fvtable-thunks to make the
object layout binary compatible with COM.  With 3.0 this should be
automatic, and the old flag is no longer supported.

The good news is that gcj creates the same vtable layout as the c++
frontend, so gcj-compiled objects can probably be directly invoked as COM
objects if you have the runtime glue.  I certainly haven't tried it, and
I've had limited success with gcj on Mingw.

> Also, do you know where I can find info on exactly what the
> relationship between ActiveX and COM is, and what makes an ordinary
> DLL magically become a "COM" DLL? Microsoft's website is immensely
> unhelpful...

No idea about ActiveX.  For the low-level details of what makes a DLL into
an in-process COM component, I liked the book "Inside Distributed COM"
from Microsoft Press.

Jeff