attempt to get a full traceback when numpy fails to import

PDAL · Oct 2, 2012 · 095d180 · 095d180
1 parent 8c15723
commit 095d180
Showing 1 changed file with 66 additions and 4 deletions.
diff --git a/src/plang/Invocation.cpp b/src/plang/Invocation.cpp
@@ -61,11 +61,73 @@ void Invocation::numpy_init()
     // this macro is defined be NumPy and must be included
     if (_import_array() < 0)
     {
-        PyObject *ptype, *pvalue, *ptraceback;
-        PyErr_Fetch(&ptype, &pvalue, &ptraceback);
-        char *message = PyString_AsString(pvalue);
+        PyObject* tracebackModule;
+        PyObject* tracebackDictionary;
+        PyObject* tracebackFunction;
+        tracebackModule = PyImport_ImportModule("traceback");
+        if (!tracebackModule)
+        {
+            throw python_error("unable to load traceback module while importing numpy inside PDAL");
+        }
+
+        tracebackDictionary = PyModule_GetDict(tracebackModule);
+
+        tracebackFunction = PyDict_GetItemString(tracebackDictionary, "format_exception");
+        if (!tracebackFunction)
+        {
+            throw python_error("unable to find traceback function while importing numpy inside PDAL");
+        }
+
+        if (!PyCallable_Check(tracebackFunction))
+        {
+            throw python_error("invalid traceback function while importing numpy inside PDAL");
+        }
+
+
+        // get exception info
+        PyObject *type, *value, *traceback;
+        PyErr_Fetch(&type, &value, &traceback);
+        PyErr_NormalizeException(&type, &value, &traceback);
+
+        std::string mssg = "";
+        if (traceback)
+        {
+            // create an argument for "format exception"
+            PyObject* args = PyTuple_New(3);
+            PyTuple_SetItem(args, 0, type);
+            PyTuple_SetItem(args, 1, value);
+            PyTuple_SetItem(args, 2, traceback);
+
+            // get a list of string describing what went wrong
+            PyObject* output = PyObject_CallObject(tracebackFunction, args);
+
+            // print error message
+            int i, n = PyList_Size(output);
+            for (i=0; i<n; i++) mssg += PyString_AsString(PyList_GetItem(output, i));
+
+            // clean up
+            Py_XDECREF(args);
+            Py_XDECREF(output);
+        }
+        else if (value != NULL)
+        {
+            PyObject *s = PyObject_Str(value);
+            const char* text = PyString_AS_STRING(s);
+            Py_DECREF(s);
+            mssg += text;
+        }
+        else
+        {
+            mssg = "unknown error";
+        }
+
+        Py_XDECREF(value);
+        Py_XDECREF(type);
+        Py_XDECREF(traceback);
+
+
         std::ostringstream oss;
-        oss << "unable to initialize NumPy with error '" << std::string(message) << "'";
+        oss << "unable to initialize NumPy with error '" << std::string(mssg) << "'";
         throw python_error(oss.str());
     }
 }