Helper functions for non-optional integers should fail if the value is None (awslabs#642)

Co-authored-by: Bret Ambrose <bambrose@amazon.com>

Author: bretambrose

source/module.c

@@ -119,57 +119,83 @@ PyObject *PyUnicode_FromAwsString(const struct aws_string *aws_str) {
 uint32_t PyObject_GetAttrAsUint32(PyObject *o, const char *class_name, const char *attr_name) {
  uint32_t result = UINT32_MAX;
 
- PyObject *attr = PyObject_GetAttrString(o, attr_name);
+ PyObject *attr = PyObject_GetAttrString(o, attr_name); /* new reference */
  if (!attr) {
  PyErr_Format(PyExc_AttributeError, "'%s.%s' attribute not found", class_name, attr_name);
  return result;
  }
 
+ if (attr == Py_None) {
+ PyErr_Format(PyExc_AttributeError, "'%s.%s' required integral attribute is None", class_name, attr_name);
+ goto done;
+ }
+
  PyObject_GetAsOptionalUint32(attr, class_name, attr_name, &result);
 
+done:
+
  Py_DECREF(attr);
  return result;
 }
 
 uint16_t PyObject_GetAttrAsUint16(PyObject *o, const char *class_name, const char *attr_name) {
  uint16_t result = UINT16_MAX;
 
- PyObject *attr = PyObject_GetAttrString(o, attr_name);
+ PyObject *attr = PyObject_GetAttrString(o, attr_name); /* new reference */
  if (!attr) {
  PyErr_Format(PyExc_AttributeError, "'%s.%s' attribute not found", class_name, attr_name);
  return result;
  }
 
+ if (attr == Py_None) {
+ PyErr_Format(PyExc_AttributeError, "'%s.%s' required integral attribute is None", class_name, attr_name);
+ goto done;
+ }
+
  PyObject_GetAsOptionalUint16(attr, class_name, attr_name, &result);
 
+done:
+
  Py_DECREF(attr);
  return result;
 }
 
 uint8_t PyObject_GetAttrAsUint8(PyObject *o, const char *class_name, const char *attr_name) {
  uint8_t result = UINT8_MAX;
 
- PyObject *attr = PyObject_GetAttrString(o, attr_name);
+ PyObject *attr = PyObject_GetAttrString(o, attr_name); /* new reference */
  if (!attr) {
  PyErr_Format(PyExc_AttributeError, "'%s.%s' attribute not found", class_name, attr_name);
  return result;
  }
 
+ if (attr == Py_None) {
+ PyErr_Format(PyExc_AttributeError, "'%s.%s' required integral attribute is None", class_name, attr_name);
+ goto done;
+ }
+
  PyObject_GetAsOptionalUint8(attr, class_name, attr_name, &result);
 
+done:
+
  Py_DECREF(attr);
  return result;
 }
 
 bool PyObject_GetAttrAsBool(PyObject *o, const char *class_name, const char *attr_name) {
  bool result = false;
 
- PyObject *attr = PyObject_GetAttrString(o, attr_name);
+ PyObject *attr = PyObject_GetAttrString(o, attr_name); /* new reference */
  if (!attr) {
  PyErr_Format(PyExc_AttributeError, "'%s.%s' attribute not found", class_name, attr_name);
  return result;
  }
 
+ if (attr == Py_None) {
+ PyErr_Format(PyExc_AttributeError, "'%s.%s' required boolean attribute is None", class_name, attr_name);
+ goto done;
+ }
+
  int val = PyObject_IsTrue(attr);
  if (val == -1) {
  PyErr_Format(PyExc_TypeError, "Cannot convert %s.%s to bool", class_name, attr_name);
@@ -185,14 +211,22 @@ bool PyObject_GetAttrAsBool(PyObject *o, const char *class_name, const char *att
 int PyObject_GetAttrAsIntEnum(PyObject *o, const char *class_name, const char *attr_name) {
  int result = -1;
 
- PyObject *attr = PyObject_GetAttrString(o, attr_name);
+ PyObject *attr = PyObject_GetAttrString(o, attr_name); /* new reference */
  if (!attr) {
  PyErr_Format(PyExc_AttributeError, "'%s.%s' attribute not found", class_name, attr_name);
  return result;
  }
 
+ if (attr == Py_None) {
+ PyErr_Format(
+ PyExc_AttributeError, "'%s.%s' required integral enumeration attribute is None", class_name, attr_name);
+ goto done;
+ }
+
  PyObject_GetAsOptionalIntEnum(attr, class_name, attr_name, &result);
 
+done:
+
  Py_DECREF(attr);
  return result;
 }