Temporarily instates `TypeTrackingNode` as an alias of `LocalSourceNode`
as having it as a separate class lead to performance regressions.
In the hopes that this will be resolved in the near future, I have left
the current `TypeTrackingNode` implementation in situ, but hidden inside
a `FutureWork` private module.
I realized that if you ever wanted to the way taint-steps works again,
you would have to go to all the 117 places it has been implemented, and
change EVERY ONE OF THEM :( so trying to solve that problem here.
Not super happy with the name, but that was just the best I could come up with :D
Such that it should be next to the other class-related predicates (such
as `instance()`), the class is called `AdditionalTaintStep`, and it
marked private.
I also moved any modeling of attributes as well, while I was at it.
InstanceSourceApiNode is a really good idea, but it just happened too
soon. I can't do what I need if I have to supply an API-node. So to
avoid confusion between deprecating to/from InstanceSource in those
classes, I opted to do some major reorganizing as well 👍
Due to aliasing restrictions, I had to use a little trick with the
`WerkzeugOld` module.
since UploadedFile is the abstract base class, all real usage would be
of one of the subclasses, so removing this to not provide a false hope
that it actually works.
I don't think investing the time into making this work would give any
value, so that's why I didn't do it ;)
Before, results from `dca` would look something like
## + py/meta/alerts/remote-flow-sources-reach
- django/django@c2250cf_cb8f: tests/messages_tests/urls.py:38:16:38:48
reachable with taint-tracking from RemoteFlowSource
- django/django@c2250cf_cb8f: tests/messages_tests/urls.py:38:9:38:12
reachable with taint-tracking from RemoteFlowSource
now it should make it easier to spot _what_ it is that actually changed,
since we pretty-print the node.
This is only a temporary fix, as indicated by the TODO comment.
The real underlying issue is the fact that `isUnused` is defined in
terms of the underlying SSA variables (as these are only created
for variables that are actually used), and the fact that annotated
assignments are always considered to redefine their targets, which may
not actually be the case.
Thus, the correct fix would be to change the extractor to _disregard_
mere type annotations for the purposes of figuring out whether an
SSA variable should be created or not.
However, in the short term the present fix is likely sufficient.
