On Sat, 17 Jan 2009 06:30:35 +0300, Jordan Miner
<[email protected]> wrote:
Hello,
I recently wrote a binding to Ruby’s extension API , and today finished
writing a simple extension using it. But I ran into something strange.
(I also had a problem compiling the DLL since I use Tango, but searching
the newsgroup yielded the solution.)
Ruby’s API has rb_cObject, rb_cString, etc. as global variables that it
sets to the Object class, String class etc. In ruby.h, they are defined
as
extern unsigned long rb_cObject;
so in my binding I have
extern uint rb_cObject;
But when I try to use rb_cObject from my extension, it is not the right
value... I think rb_cObject should equal rb_eval_string("Object"), but
it does not. (Using the wrong value causes an access violation.)
I produced an OMF import library for Ruby’s runtime DLL by using
coff2omf on the COFF import library that ships with it. I'm linking my
extension with this import library.
If I remove the extern from my binding, I get a multiple definition
error, so I must be linking with the variable in the DLL? But it seems
the value is wrong. I’ve worked around this by calling
rb_eval_string("Object") instead, but I’m really curious what could be
happening here. Using rb_cObject is the usual way of referring to the
Object class in C extensions, and I want to make sure my binding is
correct. Could it be because the DLL was compiled with Visual Studio and
my extension is in D?
Any ideas?
Try the following:
extern(C) extern uint rb_cObject;
