Summary:
Pulse has an extra invalidation mechanism (introduced in D18726203) to prevent something invalid (e.g. `null`) to be passed by reference to an initialisation function. Therefore, it havocs formals passed by reference to skipped functions. However, I don't think this makes sense in Java. So, let's turn it off.
A nice consequence of this is that in impurity analysis, we do not consider functions that call skipped library calls with object arguments as writing to their formals.
Reviewed By: skcho
Differential Revision: D19697110
fbshipit-source-id: 6e3a71f2a
Summary:
Currently, impurity analysis is oblivious to skipped functions which might e.g. return a non-deterministic value, write to memory or have some other side-effect. This diff fixes that by relying on Pulse's skipped functions to determine impurity. Any unknown function which is not modeled to be pure is assumed to be impure.
This is a heuristic. We could have assumed them to be pure by default as well.
Reviewed By: jvillard
Differential Revision: D19428514
fbshipit-source-id: 82efe04f9
Summary:
Model array length in Java as returning an unknown interval [0, +inf] for now.
Ideally, we can deal with the size in a more precise manner in the future like in InferBo.
Reviewed By: skcho
Differential Revision: D19312123
fbshipit-source-id: 8c51059a4
Summary:
This gets rid of false positives when something invalid (eg null) is
passed by reference to an initialisation function. Havoc'ing what the
contents of the pointer to results in being optimistic about said
contents in the future.
Also surprisingly gets rid of some FNs (which means it can also
introduce FPs) in the `std::atomic` tests because a path condition
becomes feasible with havoc'ing.
There's a slight refinement possible where we don't havoc pointers to
const but that's more involved and left as future work.
Reviewed By: skcho
Differential Revision: D18726203
fbshipit-source-id: 264b5daeb
Summary:
Let's add basic Java support to impurity checker. Since impurity checker relies on pulse, we need to add Java with Pulse callback as well. Pulse doesn't officially support Java yet, but we can enable it for impurity checker for now.
Many Java primitives/operations are not yet modeled (such as creation of new objects, support for collections etc.). Still, it is good to run impurity checker on the existing tests of the purity checker. Also, it is nice to see that we can identify most of the impure functions correctly in the purity dir. There are a lot of FNs though.
Reviewed By: skcho
Differential Revision: D17906237
fbshipit-source-id: 15308d285
Ezgi Çiçek
Jules Villard