Backport of r51379 from trunk:
Add asserts to check for 'impossible' NULL values, with comments.
In one place where I'm not 1000% sure about the non-NULL, raise
a RuntimeError for safety.
This should fix the klocwork issues that Neal sent me. If so,
it should be applied to the release25-maint branch also.
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index ab83f8c..5204a7f 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -672,6 +672,7 @@
return PyInt_FromLong(0); /* NULL pointer */
typedict = PyType_stgdict(type);
+ assert(typedict); /* Cannot be NULL for pointer types */
/* If we expect POINTER(<type>), but receive a <type> instance, accept
it by calling byref(<type>).
@@ -3129,6 +3130,13 @@
}
ob = PyTuple_GET_ITEM(argtypes, i);
dict = PyType_stgdict(ob);
+ if (dict == NULL) {
+ /* Cannot happen: _validate_paramflags()
+ would not accept such an object */
+ PyErr_Format(PyExc_RuntimeError,
+ "NULL stgdict unexpected");
+ goto error;
+ }
if (PyString_Check(dict->proto)) {
PyErr_Format(
PyExc_TypeError,
@@ -3726,6 +3734,8 @@
assert(stgdict); /* Cannot be NULL for array object instances */
proto = stgdict->proto;
itemdict = PyType_stgdict(proto);
+ assert(itemdict); /* proto is the item type of the array, a ctypes
+ type, so this cannot be NULL */
if (itemdict->getfunc == getentry("c")->getfunc) {
char *ptr = (char *)self->b_ptr;
return PyString_FromStringAndSize(ptr + ilow, len);
@@ -4159,6 +4169,9 @@
proto = stgdict->proto;
assert(proto);
itemdict = PyType_stgdict(proto);
+ assert(itemdict); /* proto is the item type of the pointer, a ctypes
+ type, so this cannot be NULL */
+
size = itemdict->size;
offset = index * itemdict->size;
@@ -4194,6 +4207,9 @@
assert(proto);
itemdict = PyType_stgdict(proto);
+ assert(itemdict); /* Cannot be NULL because the itemtype of a pointer
+ is always a ctypes type */
+
size = itemdict->size;
offset = index * itemdict->size;