Summary:
The boolean lock domain is simple and surprisingly effective.
But it's starting to cause false positives in the case where locks are nested.
Releasing the inner lock also releases the outer lock.
This diff introduces a new locks domain: a map of locks (access paths) to a bounded count representing an underapproximation of the number of times the lock has been acquired.
For now, we just use a single dummy access path to represent all locks (and thus a count actually would have been sufficiently expressive; we don't need the map yet).
But I'm planning to remove this limitation in a follow-up by refactoring the lock models to give us an access path.
Knowing the names of locks could be useful for error messages and suggesting fixes.
Reviewed By: jberdine
Differential Revision: D6182006
fbshipit-source-id: 6624971
Summary:
Previously, we could understand than an access was safe either because it was possibly owned or protected by a thread/lock, but not both. If an access was both protected by a lock and rooted in a paramer (i.e., possibly owned), we would forget the ownership part of the precondition and remember only the lock bit. This leads to false positives in cases where an access protected by a lock is owned, but another unowned access to the same memory is not protected by a lock (see the new `unownedLockedWriteOk` E2E test for an example).
This diff makes access safety conditions disjunctive so we can simultaneously track whether an access is owned and whether an access is protected by a thread/lock. This will fix false positives like the one explained in T24015160.
Reviewed By: jberdine
Differential Revision: D6671489
fbshipit-source-id: d17715f
Summary:
Found the dead code with the script in the next commit, iteratively until no
warnings remained.
Methodology:
1. I kept pretty-printers for values, which can be useful to use from infer's REPL (or
when printf-debugging infer in general)
2. I kept functions that formed some consistent API (but not often, so YMMV), for instance if it looked like `Set.S`, or if it provides utility functions for stuff in development (mostly the procname dispatcher functions)
3. I tried not to lose comments associated with values no longer exported: if the value is commented in the .mli and not the .ml, I moved the comment
4. Some comments needed updating (not claiming I caught all of those)
5. Sometimes I rewrote the comments a bit when I noticed mis-attached comments
Reviewed By: mbouaziz
Differential Revision: D6723482
fbshipit-source-id: eabaafd
Summary:
Due to limitations in our Buck integration, the thread-safety analysis cannot create a trace that bottoms out in a Buck target that is not a direct dependency of the current target.
These truncated traces are confusing and tough to act on.
Until we can address these limitations, let's avoid reporting on truncated traces.
Reviewed By: jeremydubreil
Differential Revision: D5969840
fbshipit-source-id: 877b9de
Sam Blackshear
Jules Villard