[PyQt] sipConvertToInstance failing after sipCanConvertToInstance succeeds.

[Diez B. Roggisch]

Phil Thompson schrieb:
> On Tue, 21 Jul 2009 11:07:19 +0200, "Diez B. Roggisch" <deets at web.de>
> wrote:
>> On Tuesday 21 July 2009 10:43:14 Phil Thompson wrote:
>>> On Tue, 21 Jul 2009 09:26:39 +0200, "Diez B. Roggisch" <deets at web.de>
>>>
>>> wrote:
>>>> Hi,
>>>>
>>>> well, the subject pretty much says it. The below code exectutes fine
> in
>>>> the debugger until it reaches the line
>>>>
>>>> 	  irr::video::S3DVertex *vertex = (irr::video::S3DVertex
>>>> *)sipConvertToInstance(py_vertex, S3DVertexType, NULL, SIP_NOT_NONE,
>>>> NULL, &err);
>>>>
>>>>
>>>> where "err" then gets some seemingly random value & the program
>>>> terminates. The if-statement below the line doesn't work and was a
>>>> feeble attempt at error-handling - a subject that is given not much
>>>> more
>>>> information in the whole
>>>>
>>>> http://www.riverbankcomputing.com/static/Docs/sip4/c_api.html
>>>>
>>>> page.
>>>>
>>>> Any suggestions? Ah, python is 2.6 on osx, SIP is 4.7.9.
>>>>
>>>>
>>>> Diez
>>>>
>>>>
>>>> void append(SIP_PYLIST, SIP_PYLIST);
>>>> %MethodCode
>>>>        PyObject *py_vertices = a0;
>>>>        PyObject *py_indices = a1;
>>>>        irr::u32 numVertices = PyList_Size(py_vertices);
>>>>        irr::video::S3DVertex *vertices = (irr::video::S3DVertex
>>>> *)sipMalloc(sizeof(irr::video::S3DVertex) * numVertices);
>>>>        irr::u32 numIndices = PyList_Size(py_indices);
>>>>        irr::u16 *indices = (irr::u16*)sipMalloc(sizeof(irr::u16) *
>>>> numIndices);
>>>>
>>>>        sipWrapperType *S3DVertexType =
>>>> sipFindClass("irr::video::S3DVertex");
>>>>
>>>>        int err;
>>>>
>>>>        for(irr::u32 i=0; i < numVertices; i++) {
>>>> 	PyObject *py_vertex = PyList_GetItem(py_vertices, i);
>>>> 	if(sipCanConvertToInstance(py_vertex, S3DVertexType, SIP_NOT_NONE)) {
>>>> 	  irr::video::S3DVertex *vertex = (irr::video::S3DVertex
>>>> *)sipConvertToInstance(py_vertex, S3DVertexType, NULL, SIP_NOT_NONE,
>>>> NULL, &err);
>>>> 	  if(err) {
>>>> 	    return -1;
>>>> 	  }
>>>> 	  vertices[i] = *vertex;
>>>> 	} // TODO: raise an exception here!
>>>>        }
>>>>
>>>>        for(irr::u32 i=0; i < numIndices; i++) {
>>>> 	PyObject *py_index = PySequence_GetItem(py_indices, i);
>>>> 	irr::u16 indices[3];
>>>> 	for(int j=0; j < 3; j++) {
>>>> 	  PyObject *item = PySequence_GetItem(py_index, j);
>>>> 	  if(PyLong_Check(item)) {
>>>> 	    indices[j] = (irr::u16)PyLong_AsLong(item);
>>>> 	  } else {
>>>> 	    // TODO: raise an exception here!
>>>> 	  }
>>>> 	}
>>>>        }
>>>>        sipCpp->append((void*)vertices, numVertices, indices,
>>>>        numIndices);
>>>>        sipFree(indices);
>>>>        sipFree(vertices);
>>>> %End
>>> What is S3DVertexType? I would expect it to start with 'sipClass_'.
>> It's a wrapped structure, with the original name "irr::video::S3DVertex".
> 
>> After reading the aforementioned docs, I was under the impression that I
>> need 
>> to get a sipTypeDef to check & convert. At least pointers of that kind
> are 
>> taken from sipConvertToInstance and sipCanConvertToInstance.
> 
> It needs to be what the documentation calls a "generated type object" which
> all begin with "sipClass_" - probably sipClass_irr_video_S3DVertex in this
> case.

I did that, without any success - the behavior is the same. I get err 
set to the value "458520", and the program dies with an bus-error/segfault.

Diez