Python calling D

[Russel Winder]

On Tue, 2014-02-04 at 07:13 +0000, Artem Tarasov wrote:
> On Sunday, 2 February 2014 at 15:31:30 UTC, Russel Winder wrote:
> > result is:
> >
> >         |> LD_LIBRARY_PATH=. python execute.py
> >         Segmentation fault
> 
> You should call Runtime.initialize() prior to calling any other D 
> functions.

Hummm… obvious once pointed out :-) Thanks for doing exactly that.

The question is how to get this run. I tried a module initializer:

        static this() {
          Runtime.initialize();
        }

but this module never actually gets loaded per se, so that is never
going to work. So this means calling a C linkage function to do the
initialization in every entry point:

        import core.runtime: Runtime;
        import std.stdio: writeln;
        
        auto initialized = false;
        
        extern (C) void initializeIfNotAlreadyDone() {
          if (!initialized) {
            Runtime.initialize();
            initialized = true;
          }
        }
        
        extern(C) {
          void sayHello() {
            initializeIfNotAlreadyDone();
            writeln("Hello World.");
          }
        }

works a treat:

        scons: Building targets ...
        dmd -I. -fPIC -c -fPIC -ofhelloWorld.o helloWorld.d
        dmd -shared -defaultlib=libphobos2.so -oflib_helloWorld.so helloWorld.o -fPIC -L-L.
        LD_LIBRARY_PATH=. python execute.py
        Hello World.
        scons: done building targets.

So D extensions to CPython are possible without PyD!

Now to continue with PyD anyway so as to compare and contrast.

-- 
Russel.
=============================================================================
Dr Russel Winder      t: +44 20 7585 2200   voip: sip:russel.winder at ekiga.net
41 Buckmaster Road    m: +44 7770 465 077   xmpp: russel at winder.org.uk
London SW11 1EN, UK   w: www.russel.org.uk  skype: russel_winder