[Python-Dev] Linux Python linking with G++?

[David Abrahams]

Jeff Epler <jepler at unpythonic.net> writes:

> If we change the linker back to gcc, not g++, will it work if extension
> module 1 gets linked with libstdc++ A and ABI Q, and extension module 2
> gets linked with libstdc++ B and ABI Z?

Yes, unless they are using sys.setdlopenflags to force symbols to be
shared across these extension modules.  That's a very intentional act
and should (obviously?) only be undertaken when the extension modules
share an ABI.

> What if a built-in module is written in C++, as it might be for some
> people embedding C++? 

"Embedding" usually refers to embedding a _Python_ interpreter in a
program written in some language other than Python.  But I think
that's what you meant (just correct me if I'm wrong).

> (this will force use of g++ as the linker, right?)

Yes.

> Don't these cases matter too?  

Yes.  But the 2nd case is not one in which the Python executable is
being built.  The person building a program that embeds Python can
control how (s)he does linking.

> Assuming they can fail now, how will changing the use of CXX as the
> linker fix them?

I don't understand the question.

> Jeff
> PS The Python 2.3 and Python 2.4 binaries installed on my Fedora Core
> machine don't list libstdc++ in `rpm -q --requires python' or `ldd
> /usr/bin/python'.  I don't see a patch that would change Python's
> behavior in the SRPM, though.  I wonder what the difference is between
> my FC2 and the other systems...

I don't know; the ones we happen to be testing are Debian ("sarge," I
think).

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com