Implement proper void pointer (void*) support

This change introduces a new type into the shiboken2 module which is
imported by calling "import PySide2.support.VoidPtr".

The type takes care of conversions from / to void* values in function
signatures.

Creating an instance can be done by passing either a shiboken wrapped
object, or an integer representing an address, or a python object that
implements the buffer interface.

For example, this is useful for passing numpy arrays to C OpenGL
functions that take void* parameters. First you convert the array into
a bytestring (using numpy.array.tobytes(), then you instantiate a
VoidPtr from that bytestring, and finally you pass it along to a GL
function.

One corner case that is currently not supported is void** parameters.

Change-Id: I01e291d6856cb6bd8b5175adc3ead6b728036535
Reviewed-by: Christian Tismer <tismer@stackless.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/sources/shiboken2/libshiboken/basewrapper.cpp b/sources/shiboken2/libshiboken/basewrapper.cpp
index ff9158d66..270a5df94 100644
--- a/sources/shiboken2/libshiboken/basewrapper.cpp
+++ b/sources/shiboken2/libshiboken/basewrapper.cpp
@@ -54,6 +54,7 @@
 #include "threadstatesaver.h"
 #include "signature.h"
 #include "qapp_macro.h"
+#include "voidptr.h"
 
 namespace {
     void _destroyParentInfo(SbkObject* obj, bool keepReference);
@@ -567,6 +568,8 @@ void init()
     if (PyType_Ready(reinterpret_cast<PyTypeObject *>(&SbkObject_Type)) < 0)
         Py_FatalError("[libshiboken] Failed to initialise Shiboken.BaseWrapper type.");
 
+    VoidPtr::init();
+
     shibokenAlreadInitialised = true;
 }