C/Python API: Add PyC_RunString_AsIntPtr

Utility to get an int or pointer from a Python expression.

source/blender/python/generic/py_capi_utils.c

@@ -784,7 +784,7 @@ bool PyC_IsInterpreterActive(void)
 }
 
 /* Would be nice if python had this built in
- * See: http://wiki.blender.org/index.php/Dev:Doc/Tools/Debugging/PyFromC
+ * See: https://wiki.blender.org/wiki/Tools/Debugging/PyFromC
  */
 void PyC_RunQuicky(const char *filepath, int n, ...)
 {
@@ -1140,6 +1140,40 @@ bool PyC_RunString_AsNumber(const char *expr, const char *filename, double *r_va
 	return ok;
 }
 
+bool PyC_RunString_AsIntPtr(const char *expr, const char *filename, intptr_t *r_value)
+{
+	PyObject *py_dict, *retval;
+	bool ok = true;
+	PyObject *main_mod = NULL;
+
+	PyC_MainModule_Backup(&main_mod);
+
+	py_dict = PyC_DefaultNameSpace(filename);
+
+	retval = PyRun_String(expr, Py_eval_input, py_dict, py_dict);
+
+	if (retval == NULL) {
+		ok = false;
+	}
+	else {
+		intptr_t val;
+
+		val = (intptr_t)PyLong_AsVoidPtr(retval);
+		if (val == 0 && PyErr_Occurred()) {
+			ok = false;
+		}
+		else {
+			*r_value = val;
+		}
+
+		Py_DECREF(retval);
+	}
+
+	PyC_MainModule_Restore(main_mod);
+
+	return ok;
+}
+
 bool PyC_RunString_AsString(const char *expr, const char *filename, char **r_value)
 {
 	PyObject *py_dict, *retval;

source/blender/python/generic/py_capi_utils.h

@@ -102,6 +102,7 @@ int       PyC_FlagSet_ToBitfield(PyC_FlagSet *items, PyObject *value, int *r_val
 PyObject *PyC_FlagSet_FromBitfield(PyC_FlagSet *items, int flag);
 
 bool PyC_RunString_AsNumber(const char *expr, const char *filename, double *r_value);
+bool PyC_RunString_AsIntPtr(const char *expr, const char *filename, intptr_t *r_value);
 bool PyC_RunString_AsString(const char *expr, const char *filename, char **r_value);
 
 int PyC_ParseBool(PyObject *o, void *p);