Summary:
Litho uses an idiom as follows. `Component.Builder` has an abstract method `T getThis()` which is supposed to be implemented as `{return this;}`.
I believe the reason it's there is to have covariant return types in subclasses, though this doesn't really matter.
We don't do dynamic dispatch, so instead of summarising `getThis` as having a return ownership of `OwnedIf({ 0 })` we just return `Unowned`.
This is generating many false positives, which are really hard to debug.
Here I'm special-casing any abstract method whose return type is equal to that of it's only argument, to return conditional ownership.
Reviewed By: da319
Differential Revision: D8947992
fbshipit-source-id: 33c7e952d
Summary:
Currently, some blocking calls are turning up too many false positives. Adjust severities by fix rate/preexisting numbers.
Also, restrict some calls to exact class, as opposed to superclasses.
Reviewed By: mbouaziz
Differential Revision: D8850599
fbshipit-source-id: 47543d04a
Summary:
- Do not add actuals of a call as unstable.
- Replace access trie with simple set of paths, which is easier to debug/argue correct.
- Fix bug where a prefix path was searched, as opposed to a *proper* prefix.
- Restrict interface to the minimum so that alternative implementations are easier.
Reviewed By: ilyasergey
Differential Revision: D8573792
fbshipit-source-id: 4c4e174
Summary: C/C++ code can, in some cases, generate a large number of temporary (Sil) variables. Since we are already not reporting races on these, not recording them gives some perf back.
Reviewed By: mbouaziz, jvillard
Differential Revision: D8566999
fbshipit-source-id: 148ac46
Summary: Trying to convert a large int literal to an OCaml int raises an exception. The use case here actually needed a float anyway, so add an API for that.
Reviewed By: jeremydubreil
Differential Revision: D8550410
fbshipit-source-id: 382495b
Summary:
I realized that control variable analysis was broken when we had multiple back-edges for the same loop. This is often the case when we have a switch statement combined with continue in a loop (see `test_switch` in `switch_continue.c`) or when we have disjunctive guards in do-while loops.
This diff fixes that by
- defining a loop by its loophead (the target of its backedges) rather than its back-edges. Then it converts back-edge list to a map from loop_head to sources of the loop's back-edges.
- collecting multiple guard nodes that come from potentially multiple exit nodes per loop head
In addition, it also removes the wrong assumption that an exit node belongs to a single loop head.
Reviewed By: mbouaziz
Differential Revision: D8398061
fbshipit-source-id: abaf288
Summary:
We need to report on non-private methods (the opposite even leads to FPs sometimes on deadlocks). To do this, the domain needs to change so that the interpretation of an order pair `a,b` is no longer "lock `a` is taken in the *current method* and held until lock `b` is taken". Instead the meaning is now "lock `a` is taken in some method *of the same class with the current method* and is held until `b` is taken".
These changes are quite drastic because the previous implementation optimised extensively around the previous use case.
Reviewed By: mbouaziz
Differential Revision: D8395351
fbshipit-source-id: a2bd22b
Summary:
The deadlock reports (the actual string) were too low level, in order to avoid bug hash clashes. Now that we deduplicate this is less of an issue, so it's an opportunity to improve readability.
```
Potential deadlock.
Trace 1 (starts at `void Interproc.interproc1Bad(InterprocA)`) first locks `this` in class `Interproc*` (line 9 in `void Interproc.interproc1Bad(InterprocA)`) and then locks `b` in class `InterprocA*` (line 14 in `void Interproc.interproc2Bad(InterprocA)`).
Trace 2 (starts at `void InterprocA.interproc1Bad(Interproc)`), first locks `this` in class `InterprocA*` (line 37 in `void InterprocA.interproc1Bad(Interproc)`) and then locks `d` in class `Interproc*` (line 42 in `void InterprocA.interproc2Bad(Interproc)`).
```
Reviewed By: mbouaziz
Differential Revision: D8394978
fbshipit-source-id: 671ccb0
Summary:
The deadlock reports (the actual string) were too low level, in order to avoid bug hash clashes. Now that we deduplicate this is less of an issue, so it's an opportunity to improve readability.
```
Potential deadlock.
Trace 1 (starts at `void Interproc.interproc1Bad(InterprocA)`) first locks `this` in class `Interproc*` (line 9 in `void Interproc.interproc1Bad(InterprocA)`) and then locks `b` in class `InterprocA*` (line 14 in `void Interproc.interproc2Bad(InterprocA)`).
Trace 2 (starts at `void InterprocA.interproc1Bad(Interproc)`), first locks `this` in class `InterprocA*` (line 37 in `void InterprocA.interproc1Bad(Interproc)`) and then locks `d` in class `Interproc*` (line 42 in `void InterprocA.interproc2Bad(Interproc)`).
```
Reviewed By: mbouaziz
Differential Revision: D8379328
fbshipit-source-id: bc33983
Summary: Deadlocks can be very noisy, so dedup reports on same line by showing only the one with the shortest trace and a count of the suppressed ones.
Reviewed By: mbouaziz
Differential Revision: D8351148
fbshipit-source-id: 8913db2
Summary: Introduce an annotation that forces the summary of a method to be free of blocking events, without suppressing other reports.
Reviewed By: jeremydubreil
Differential Revision: D8276787
fbshipit-source-id: be9eed8
Summary: Create mechanism for suppressing starvation reports. To do that, refactor and expose a Checkers function.
Reviewed By: mbouaziz
Differential Revision: D8259583
fbshipit-source-id: f5b5a63
Summary:
Use the component of the abstract state `events` to report. This set contains reachability facts about blocking calls and lock acquisitions.
The other component, `order`, contained pairs of a reachable event `e'` from an event option with the semantics that if the option is `None` then we have an element that now goes into `events`, and if the option is `Some e` then the element represents a lock acquired and a trace *from* `e` to `e'`
Now, `order` can be simplified to proper pairs of events, without the option.
Reviewed By: jvillard
Differential Revision: D8227665
fbshipit-source-id: e6f4dac
Summary:
It's useful to test that the bucket a given error is classified as doesn't
change over time without notice.
This records the bucket for *all* the tests, even though some never produce a
bucket. This is to be on the safe size instead of risking to forget adding the
bucket information when the test changes, or when copy/pasting from a test that
doesn't have buckets to one that does.
The implementation is pretty crude: it greps the beginning of the qualifier
string for a `[bucket]`.
Reviewed By: mbouaziz
Differential Revision: D8236393
fbshipit-source-id: b3b1eb9
Summary:
Change the license of the source code from BSD + PATENTS to MIT.
Change `checkCopyright` to reflect the new license and learn some new file
types.
Generated with:
```
git grep BSD | xargs -n 1 ./scripts/checkCopyright -i
```
Reviewed By: jeremydubreil, mbouaziz, jberdine
Differential Revision: D8071249
fbshipit-source-id: 97ca23a
Summary:
There can be multiple reports per line, especially when calling in a method which has itself multiple reports.
When reporting at the callsite, report only the issue with the highest severity (picked manually per type of event).
Deadlocks are not de-duplicated, as they are relatively rare and the info in mupltiple reports may be important.
Reviewed By: mbouaziz
Differential Revision: D8160940
fbshipit-source-id: ea6a5c0
Summary: Track and surface the reasons why a method is assessed to run on the UI thread.
Reviewed By: mbouaziz
Differential Revision: D8096099
fbshipit-source-id: 2403c6c
Summary:
The reported location was always the start of the enclosing procedure, which is wrong in many ways.
A nice side-effect is that some code can then be eliminated and Ondemand.analyze used, avoiding getting the procdescs in the process.
Reviewed By: jeremydubreil
Differential Revision: D8056306
fbshipit-source-id: 67c2c8d
Summary:
Before we were computing the size of an abstract state (`range`) using the `NonNegativeBound` domain but it wasn't able to express product of symbolic values.
This diff introduces a domain for that.
The range of an interval is still computed in `NonNegativeBound` but then the product is done in `TopLiftedPolynomial` so all costs end up being of that type.
The //symbols// of a polynomial are `NonNegativeBound` (so the polynomial only represent non-negative values, perfect for a cost), which handles substitution correctly, i.e. it gives zero instead of negative values.
Reviewed By: ddino
Differential Revision: D7397229
fbshipit-source-id: 6868bb7
Summary:
The annotation UiThread can, and is, used on classes as opposed to just methods, so extend the modelling to account for this.
Also, consider the annotation hereditary.
Reviewed By: jeremydubreil
Differential Revision: D7910762
fbshipit-source-id: 0df2c81
Summary: Without the class name, it is not always clear from the error message where the method expecing non-null parameters defined.
Reviewed By: mbouaziz
Differential Revision: D7919492
fbshipit-source-id: 044fb83
Summary:
Make the starvation checker enabled by default.
Add a deadlock issue type, distinct to starvation, which will be kept for UI thread starvation.
Add checks so that checker will do nothing on non-Java code.
Reviewed By: mbouaziz, ddino
Differential Revision: D7908381
fbshipit-source-id: 889f373
Summary: Calling Future.get from UI thread, or under a lock the UI thread may try to take has been associated with ANRs.
Reviewed By: ddino
Differential Revision: D7859296
fbshipit-source-id: b87bd94
Summary:
This simplifies the frontends and backends in most cases. Before this diff,
returning `void` could be modelled either with a `None` return, or a dummy
return variable with type `Tvoid`. Now it's always the latter.
Reviewed By: sblackshear, dulmarod
Differential Revision: D7832938
fbshipit-source-id: 0a403d1
Summary:
The abstract interpreter tried to handle exceptional control-flow by propagating the *pre* of a block that threw an exception rather than the *post*.
This was a half-measure that isn't correct when an exception-throwing instruction isn't in the middle of a block.
The handling of exceptions wasn't actually used anywhere and was leading to further hacks in `ProcCfg`, so let's get rid of it.
Reviewed By: mbouaziz, jvillard
Differential Revision: D7843872
fbshipit-source-id: 2a4a815
Summary: We already suppress race reports if the field is marked in this way; makes sense to do the same thing for these reports.
Reviewed By: ngorogiannis
Differential Revision: D7589275
fbshipit-source-id: 8f0aeab
Summary:
Report nullable inconsistencies by relying on the bytecode, and not on the presence of analysis summary on disk.
This use the `--external-java-packages` to avoid reporting inconsistencies outside of the codebase.
Reviewed By: sblackshear
Differential Revision: D7481101
fbshipit-source-id: 281135d
Summary: This was causing false positives when returning the constant integer 0.
Reviewed By: sblackshear
Differential Revision: D7330143
fbshipit-source-id: 45d19dd
Summary:
At the moment, Java and Clang sources/sinks live in the same inferconfig entry.
If we try to parse a Java procedure that happens to be an invalid Clang qualified name (e.g., `MyClass.<init>`),
parsing will crash.
As a temporary fix, throw an exception and catch it instead.
In the future, we can avoid this by requiring that JSON source/sink specifications to indicate the language.
Reviewed By: mbouaziz
Differential Revision: D7291880
fbshipit-source-id: f8f4502
Summary: Add a new command-line option `--external-java-packages` which allows the user to specify a list of Java package prefixes for external packages. Then the analysis will not report non-actionable warnings on those packages (e.g., inconsistent `Nullable` annotations in external packages).
Reviewed By: jeremydubreil
Differential Revision: D7126960
fbshipit-source-id: c4f3c7c
Summary:
See comment--`Prop(resType = blah) myProp` will generate `.myProp`, `.myPropRes`, and `.myPropAttr`, and any of them can be used to set the prop.
Because our annotation parameter parsing is a bit primitive, handle this by simply checking the `Res` and `Attr` suffixes for every `Prop`.
This shouldn't lead to false negatives because these methods will only exist if the `resType` annotation is specified anyway.
Reviewed By: jeremydubreil
Differential Revision: D6955362
fbshipit-source-id: ec59b21
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
Martino Luca
Nikos Gorogiannis
Ezgi Çiçek
Mehdi Bouaziz
Jeremy Dubreil
Jules Villard
Dino Distefano
Sam Blackshear
Tony Hu