Updates for Python 3 Support

The following changes have been made to support Python 3:

- in sip-tqt.h, remove the cast in the "sipConvertFromSliceObject"
  macro in versions 3.2+ as the API changed causing a compile error;
- in voidptr.h, alter the precompile conditions to remove the
  PyCObject API cals for version 3.2+ (causes runtime symbol
  resolution error) and amend the flags for "asstring";
- alter module import process in siplib.c to avoid re-loading an
  already loaded module.

Signed-off-by: aneejit1 <aneejit1@gmail.com>
Signed-off-by: Slávek Banko <slavek.banko@axis.cz>

siplib/sip-tqt.h

@@ -208,10 +208,14 @@ extern "C" {
 #define SIPBytes_AS_STRING  PyBytes_AS_STRING
 #define SIPBytes_GET_SIZE   PyBytes_GET_SIZE
 
-#if PY_MINOR_VERSION >= 1
+#if (PY_MAJOR_VERSION > 3) || ((PY_MAJOR_VERSION == 3) && (PY_MINOR_VERSION >= 1))
 #define SIP_USE_PYCAPSULE
 #endif
 
+#if (PY_MAJOR_VERSION == 3) && (PY_MINOR_VERSION < 2)
+#define SIP_SUPPORT_PYCOBJECT
+#endif
+
 #else
 
 #define SIPLong_FromLong    PyInt_FromLong
@@ -227,6 +231,8 @@ extern "C" {
 #define SIP_USE_PYCAPSULE
 #endif
 
+#define SIP_SUPPORT_PYCOBJECT
+
 #endif
 
 #if !defined(Py_REFCNT)
@@ -1465,9 +1471,15 @@ typedef struct _sipTQtAPI {
 
 #define sipIsExactWrappedType(wt)   (sipTypeAsPyTypeObject((wt)->type) == (PyTypeObject *)(wt))
 
+#if PY_VERSION_HEX >= 0x03020000
+#define sipConvertFromSliceObject(o,len,start,stop,step,slen) \
+        PySlice_GetIndicesEx((o), (len), (start), (stop), \
+                (step), (slen))
+#else
 #define sipConvertFromSliceObject(o,len,start,stop,step,slen) \
         PySlice_GetIndicesEx((PySliceObject *)(o), (len), (start), (stop), \
                 (step), (slen))
+#endif
 
 
 /*

siplib/siplib.c

@@ -648,6 +648,8 @@ static int add_all_lazy_attrs(sipTypeDef *td);
 static int objectify(const char *s, PyObject **objp);
 static void add_failure(PyObject **parseErrp, sipParseFailure *failure);
 static PyObject *bad_type_str(int arg_nr, PyObject *arg);
+static sipExportedModuleDef *isModuleLoaded(sipExportedModuleDef *table,
+        char *name);
 
 
 /*
@@ -1200,12 +1202,14 @@ static int sip_api_export_module(sipExportedModuleDef *client,
         {
             PyObject *mod;
 
-            if ((mod = PyImport_ImportModule(im->im_name)) == NULL)
+            em = isModuleLoaded(moduleList, im->im_name);
-                return -1;
 
-            for (em = moduleList; em != NULL; em = em->em_next)
+            if (em == NULL)
-                if (strcmp(sipNameOfModule(em), im->im_name) == 0)
+            {
-                    break;
+                if ((mod = PyImport_ImportModule(im->im_name)) == NULL)
+                    return -1;
+                em = isModuleLoaded(moduleList, im->im_name);
+            }
 
             if (em == NULL)
             {
@@ -1276,6 +1280,22 @@ static int sip_api_export_module(sipExportedModuleDef *client,
 }
 
 
+/*
+ * Find out if a client module has been loaded already.
+ */
+static sipExportedModuleDef *isModuleLoaded(sipExportedModuleDef *table,
+        char *name)
+{
+    sipExportedModuleDef *em = table;
+
+    for (em = moduleList; em != NULL; em = em->em_next)
+        if (strcmp(sipNameOfModule(em), name) == 0)
+            return em;
+
+    return NULL;
+}
+
+
 /*
  * Initialise the contents of a client module.  By this time anything that
  * this depends on should have been initialised.  A negative value is returned

siplib/voidptr.c

@@ -195,6 +195,7 @@ static PyObject *sipVoidPtr_ascapsule(sipVoidPtrObject *v, PyObject *arg)
 #endif
 
 
+#if defined(SIP_SUPPORT_PYCOBJECT)
 /*
  * Implement ascobject() for the type.
  */
@@ -202,6 +203,7 @@ static PyObject *sipVoidPtr_ascobject(sipVoidPtrObject *v, PyObject *arg)
 {
     return PyCObject_FromVoidPtr(v->voidptr, NULL);
 }
+#endif
 
 
 /*
@@ -311,8 +313,10 @@ static PyMethodDef sipVoidPtr_Methods[] = {
 #if defined(SIP_USE_PYCAPSULE)
     {"ascapsule", (PyCFunction)sipVoidPtr_ascapsule, METH_NOARGS, NULL},
 #endif
+#if defined(SIP_SUPPORT_PYCOBJECT)
     {"ascobject", (PyCFunction)sipVoidPtr_ascobject, METH_NOARGS, NULL},
-    {"asstring", (PyCFunction)sipVoidPtr_asstring, METH_KEYWORDS, NULL},
+#endif
+    {"asstring", (PyCFunction)sipVoidPtr_asstring, METH_VARARGS|METH_KEYWORDS, NULL},
     {"getsize", (PyCFunction)sipVoidPtr_getsize, METH_NOARGS, NULL},
     {"setsize", (PyCFunction)sipVoidPtr_setsize, METH_O, NULL},
     {"getwriteable", (PyCFunction)sipVoidPtr_getwriteable, METH_NOARGS, NULL},
@@ -456,9 +460,11 @@ void *sip_api_convert_to_void_ptr(PyObject *obj)
     if (PyCapsule_CheckExact(obj))
         return PyCapsule_GetPointer(obj, NULL);
 #endif
-
+#if defined(SIP_SUPPORT_PYCOBJECT)
     if (PyCObject_Check(obj))
         return PyCObject_AsVoidPtr(obj);
+#endif
+
 
 #if PY_MAJOR_VERSION >= 3
     return PyLong_AsVoidPtr(obj);
@@ -544,8 +550,10 @@ static int vp_convertor(PyObject *arg, struct vp_values *vp)
     else if (PyCapsule_CheckExact(arg))
         ptr = PyCapsule_GetPointer(arg, NULL);
 #endif
+#if defined(SIP_SUPPORT_PYCOBJECT)
     else if (PyCObject_Check(arg))
         ptr = PyCObject_AsVoidPtr(arg);
+#endif
     else if (PyObject_TypeCheck(arg, &sipVoidPtr_Type))
     {
         ptr = ((sipVoidPtrObject *)arg)->voidptr;