First, it has nothing to do with the number of files that you link
together. It just happened in my previous case that several of the
extra objects that I was linking in were causing the problem (sorry).
It turns out that my problem is with certain C++ operators and
objects, particularly (but I doubt limited to) 'new' and 'cerr'. The
dynamic loader does not seem to be able to resolve these names.
I create my module with the following:
g++ -c testmodule.C -o testmodule.o
ld -o testmodule.so testmodule.0 -lg++
Whenever I try to load the object in Python I get the error:
ld.so: Undefined symbol: ___builtin_new
For example, the following simple module dynamically creates an
integer and passes its value back to python.
----------C++----------
#include "allobjects.h"
object* test_demoTest(object* self, object* args) {
char* myString;
int* myInt;
if(!getargs(args, "s", &myString)) {
return NULL;
}
myInt = new int;
*myInt = 42;
return mkvalue("(si)", myString,*myInt);
}
static struct methodlist testMethods[] = {
{"demoTest", test_demoTest},
{NULL, NULL} // Sentinel
};
extern "C"
void
inittest() {
(void) initmodule("test", testMethods);
}
----------Python----------
import test
print test.demoTest('Hello world.')
--------------------
and the output should be:
('Hello world.', 42)
Sure, for this case I could just use malloc (yuck) insead of new, but
I will still have the same problem when I want dynamic creation of
classes. I also get an undefined symbol error if I use 'cerr' or
'cout', etc., which leads me to believe that something that is
supposed to get linked in, isn't, although I would have thought that
these C++ constructs would have been covered by the inclusion of
'-lg++' in the making of the .so file.
Anyway, I'll keep hacking on this one and let ya'll know if I figure
anything out. This has got to be possible, right?
-Simeon-
--+---------------------------------------------------------------------+ | Simeon H. Fitch Department of Computer Science | | fitch@Virginia.EDU University of Virginia | +---------------------------------------------------------------------+
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