/**
* Convert a python error state to a C++ exception
* @param withTrace If true then a traceback will be included in the exception
* message
* @throws std::runtime_error
*/
void throwRuntimeError(const bool withTrace) {
GlobalInterpreterLock gil;
if (!PyErr_Occurred()) {
throw std::runtime_error(
"ErrorHandling::throwRuntimeError - No Python error state set!");
}
PyObject *exception(nullptr), *value(nullptr), *traceback(nullptr);
PyErr_Fetch(&exception, &value, &traceback);
PyErr_NormalizeException(&exception, &value, &traceback);
PyErr_Clear();
PyObject *str_repr = PyObject_Str(value);
std::stringstream msg;
if (value && str_repr) {
msg << PyString_AsString(str_repr);
} else {
msg << "Unknown exception has occurred.";
}
if (withTrace) {
tracebackToMsg(msg, reinterpret_cast<PyTracebackObject *>(traceback));
}
// Ensure we decrement the reference count on the traceback and exception
// objects as they hold references to local the stack variables that were
// present when the exception was raised. This could include child algorithms
// with workspaces stored that would not otherwise be cleaned up until the
// program exited.
Py_XDECREF(traceback);
Py_XDECREF(exception);
Py_XDECREF(value);
// Raise this error as a C++ error
throw std::runtime_error(msg.str());
}
/**
* Form a traceback
* @param msg The reference to the textstream to accumulate the message
* @param traceback A traceback object
* @param root If true then this is the root of the traceback
*/
void PythonScript::tracebackToMsg(QTextStream &msgStream,
PyTracebackObject *traceback, bool root) {
if (traceback == nullptr)
return;
msgStream << "\n ";
if (root)
msgStream << "at";
else
msgStream << "caused by";
int lineno = traceback->tb_lineno;
QString filename =
QString::fromAscii(TO_CSTRING(traceback->tb_frame->f_code->co_filename));
if (filename == identifier().c_str()) {
lineno = getRealLineNo(lineno);
sendLineChangeSignal(lineno, true);
}
msgStream << " line " << lineno << " in \'" << filename << "\'";
tracebackToMsg(msgStream, traceback->tb_next, false);
}
/**
* This emits the error signal and resets the error state
* of the python interpreter.
*/
void PythonScript::emit_error() {
// gil is necessary so other things don't continue
ScopedPythonGIL lock;
// return early if nothing happened
if (!PyErr_Occurred()) {
emit finished(MSG_FINISHED);
return;
}
// get the error information out
PyObject *exception(nullptr), *value(nullptr), *traceback(nullptr);
PyErr_Fetch(&exception, &value, &traceback);
// special check for system exceptions
if (bool(exception) &&
PyErr_GivenExceptionMatches(exception, PyExc_SystemExit) &&
PyObject_HasAttrString(exception, "code")) {
// value is the return code handed to sys.exit
long code = 0;
if (bool(value) && INT_CHECK(value)) {
code = TO_LONG(value);
}
// if we are returning 0 then cleanup and return
if (code == 0) {
// maybe shouldn't clear the error, but for now this
// is the agreed upon behavior
PyErr_Clear();
Py_XDECREF(traceback);
Py_XDECREF(exception);
Py_XDECREF(value);
emit finished(MSG_FINISHED);
return;
}
}
// prework on the exception handling
PyErr_NormalizeException(&exception, &value, &traceback);
PyErr_Clear();
// convert the traceback into something useful
int lineNumber = 0;
QString filename;
if (traceback) {
PyTracebackObject *tb = (PyTracebackObject *)traceback;
lineNumber = tb->tb_lineno;
filename = TO_CSTRING(tb->tb_frame->f_code->co_filename);
}
// the error message is the full (formated) traceback
PyObject *str_repr = PyObject_Str(value);
QString message;
QTextStream msgStream(&message);
if (value && str_repr) {
if (exception == PyExc_SyntaxError) {
msgStream << constructSyntaxErrorStr(value);
} else {
QString excTypeName(
value->ob_type
->tp_name); // This is fully qualified with the module name
excTypeName = excTypeName.section(".", -1);
msgStream << excTypeName << ": " << TO_CSTRING(str_repr);
}
} else {
msgStream << "Unknown exception has occurred.";
}
tracebackToMsg(msgStream, (PyTracebackObject *)(traceback));
msgStream << "\n";
Py_XDECREF(traceback);
Py_XDECREF(exception);
Py_XDECREF(value);
emit error(msgStream.readAll(), filename, lineNumber);
}
