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

["Martin v. Löwis"]

David Abrahams wrote:
>>>I don't see how that works.  Somehow we need to decide whether to put
>>>main in ccpython.o in the first place, don't we?
>>
>>Yes, that is done through --with-cxx (alone). However, the decision
>>to use CXX for linking is independent on whether --with-cxx was
>>given.
> 
> 
> Is the above a description of existing behavior or a behavior you're
> proposing?

This is the current behaviour. See the code to see for yourself.

>>Somebody reported that the test works better for g++ if the
>>function is marked extern "C". 
> 
> 
> Which function?

foo().

> What does "works better" mean?

It correctly detects that linking with g++ is necessary on the
specific system in question (see bug report #1205568)

>>Ok, it's still different. I see three cases now:
>>1. --without-cxx or --with-cxx=no specified. configure does not look
>>   for a C++ compiler, and does not check whether linking needs
>>   to be done with a C++ compiler, and decides to use Modules/python.c.
>>2. --with-cxx not given. configure does look for a C++ compiler,
>>   and does check whether linking with the C++ compiler is necessary,
>>   and still uses Modules/python.c
>>3. --with-cxx is given. configure requires it to point to a C++
>>   compiler, performs the linking check, and uses Modules/ccpython.cc.
> 
> 
> Is the above a description of existing behavior or is it a behavior
> you're proposing?

This is existing behaviour (or what I believe existing behaviour to
be).

> I don't know what you mean by "use the actual code."  Do you mean,
> refer to the actual code in the discussion, or do you mean actually
> building and running Python --without-cxx myself?  If the latter, I
> don't see a reason to repeat what people I trust have already done.

You wouldn't have to ask these questions if you had investigated the
answers yourself.

Regards,
Martin