Summary: When we see a call to schedule some work on an executor and we don't have evidence that it is on some specific thread (UI/BG), instead of dropping the work, assign it `UnknownThread` and treat it as running on the background by default.
Reviewed By: jvillard
Differential Revision: D18615649
fbshipit-source-id: e8bad64b6
Summary: Following D18351867, this diff adds more size alias: when initial array size is one.
Reviewed By: ezgicicek
Differential Revision: D18530598
fbshipit-source-id: 26d57fe30
Summary:
- more flexible API
- less error-prone thanks to named parameters
- also takes care of adjusting predecessors of the previous successors!
This fixes some (probably harmless) bugs in the frontends.
Reviewed By: dulmarod
Differential Revision: D18573923
fbshipit-source-id: ad97b3607
Summary: The transition HOLDS-NEXT WITH-TRANSITION Parameters was only implemented for ObjC methods, now it also works on function calls.
Reviewed By: jvillard
Differential Revision: D18572760
fbshipit-source-id: 06e615cbe
Summary:
Now we point to the root cause of the problem, and also provide
actionable way to solve the issue
Reviewed By: artempyanykh
Differential Revision: D18575650
fbshipit-source-id: ba4884fe1
Summary:
Two goals:
1. Be less assertive when speaking about third party code (it might be
written with different conventions).
2. Point to third party signatures folder so the users know how to
proceed
Reviewed By: artempyanykh
Differential Revision: D18571514
fbshipit-source-id: 854d6e746
Summary:
1/ We now support messaging for third-party: show file name and line
number
2/ We did not show information about internal models in case of param
calls
3/ Small change: we don't specify "modelTables.ml" anymore: no need to
expose implementation details
Reviewed By: artempyanykh
Differential Revision: D18569790
fbshipit-source-id: 28586c8ff
Summary:
Whole bunch of changes aimed to make error messages more clear and
concise.
1/ Wording and language is unified. We make errors sound more like a
type system violations, rather than linter reccomendations.
Particularly, we refrain from saying things like "may be null" - this is
a linter-style statement that may provoke discussions (what if the
developer knows it can not be null in this particular case).
Instead, we refer to declared nullability and nullability of actual values. This way, it is more clear that this is not a heuristic, this is how rules of a type-system work.
2/ Additionally, we drop things like field class in places when the
context should be clear by who looks at the error. We expect the user
sees the code and the error caption. So e.g. we don't repeat the word "field"
twice.
3/ In cases when we are able to retrieve formal param name, we include it for
usability.
4/ For Field not initialized error, we refer to Initializer methods:
this is a non-obvious but important nullsafe feature.
Reviewed By: artempyanykh
Differential Revision: D18569762
fbshipit-source-id: 9221d7102
Summary:
It make the message bit less heavy, and also it is kind of obvious that
it is origin.
In follow up diffs we will change the text so it is hopefully even more
obvious.
Reviewed By: artempyanykh
Differential Revision: D18527695
fbshipit-source-id: a305d547b
Summary:
1. We don't want to teach the users to ignore noise origin because
sometimes we are going to render something useful for them.
2. It just looks not cool.
Reviewed By: artempyanykh
Differential Revision: D18527694
fbshipit-source-id: 0ea248122
Summary: Android may spontaneously call these methods on the UI thread, so recognize the fact.
Reviewed By: ezgicicek
Differential Revision: D18530477
fbshipit-source-id: a8a798779
Summary:
First step towards a global analysis. A new command line flag activates the step in `Driver`.
The whole-program analysis is a simple, quadratic (inefficient-as-yet), iteration over all domain elements. However, it is restricted to those elements that are explicitly scheduled to run.
Reviewed By: skcho
Differential Revision: D17787441
fbshipit-source-id: 9fecd766c
Summary:
Note: Disabled by default.
Having some support for values, we can report when a null or constant
value is being dereferenced. The particularity here is that we don't
report when 0 is a possible value for the address, or even if we know
that the value of the address can only be 0 in that branch! Instead, we
allow ourselves to report only when we the address has been *set* to
NULL (or any constant).
This is in line with how pulse deals with other issues: only report when
1. we see an address become invalid, and
2. we see the same address be used later on
Reviewed By: skcho
Differential Revision: D17665468
fbshipit-source-id: f1ccf94cf
Summary:
This diff avoids unqualified variables by `ItvUpdatedBy` are qualified later. For example,
```
z = x & y;
z = z + 1;
```
While `z` should not be selected as a control variable, it wasn't, because it was qualified by the addition. This pattern introduces FPs in many cases.
Reviewed By: ngorogiannis
Differential Revision: D18505894
fbshipit-source-id: 13aec3008
Summary:
This diff excludes integer variables from control variables when their values are calculated by
binary operators.
Reviewed By: ezgicicek
Differential Revision: D18505826
fbshipit-source-id: 710533d4c
Summary: Adding a trace that includes when strongSelf was assigned to, and when it's used without a check.
Reviewed By: skcho
Differential Revision: D18506113
fbshipit-source-id: 778c4b086
Summary:
The variable strongSelf, because it is equal to a weak captured pointer, needs to be checked for null before being used, otherwise it could be null by the time the block is executed.
Added this check to the SelfInBlock checker, and removed it from biabduction.
We want to migrate all the objc checks from biabduction, so it will be easier to change and faster and more reliable. Moreover, this check is more general, it will flag any use of unchecked strongSelf, not just a dereference.
Reviewed By: skcho
Differential Revision: D18403849
fbshipit-source-id: a9cf5d80b
Summary:
There was a precision loss during the substitution of array block. For example:
Callee's abstract memory includes an array block as follows, where `a` is a parameter.
```
a.elements -> { a.elements[*] with a.elements.size }
```
Callers' abstract memory includes a pointer that may point to multiple array blocks.
```
c -> { x, y }
x.elements -> { x.elements[*] with x.elements.size }
y.elements -> { y.elements[*] with y.elements.size }
```
When the callee is called with the parameter `c`, the callees memory is substituted to:
```
x.elements -> { x.elements[*] with top , y.elements[*] with top }
y.elements -> { x.elements[*] with top , y.elements[*] with top }
```
because `a.elements[*]` was substituted to `{ x.elements[*] , y.elements[*] }`
and `a.elements.size` was substituted to `top ( = x.elements.size join y.elements.size )`.
This diff tries to keep the precision in the specific case, not to join the sizes of array blocks.
So now the same callee's abstract memory is substituted to:
```
x.elements -> { x.elements[*] with x.elements.size }
y.elements -> { y.elements[*] with y.elements.size }
```
Reviewed By: ngorogiannis
Differential Revision: D18480585
fbshipit-source-id: b70e63c22
Summary: Due to the weakness of the analysis which can't detect side-effecting prop setting (e.g. as in `builder.prop1(..)`), we currently have many broken chains that do do have any `create` method in their prefixes. Let's not report on these broken chains.
Reviewed By: skcho
Differential Revision: D18503523
fbshipit-source-id: 7506e34b7
Summary:
In some apps executors are obtained by calling standard framework methods (and not by using DI with annotations).
To treat this style, we need to
- Detect calls that return such executors (`do_executor_effect`) and tag the return result with an `Attribute` indicating that it is now an executor, plus what thread it uses.
- Use that information when calling `execute`, to resolve the executor, if any, and its thread (in `do_work_scheduling` via `AttributeDomain.get_executor_constraint`).
- All this requires a new domain component, mapping variables to attributes. This extends the component previously used for remembering whether a variable is the result of a check on whether we run on the UI thread.
At the same time, I un-nested some functions from the transfer function for readability.
Reviewed By: skcho
Differential Revision: D18476122
fbshipit-source-id: bc39b5c2f
Summary:
We consider Java collections to be like c++ std::vectors and add models for
- `Collections.get(..)`
- `__cast`
Reviewed By: skcho
Differential Revision: D18449607
fbshipit-source-id: 448206c84
Summary: `equals1` and `equals2` in `SafeInvertedMap.join` are references that indicate whether given parameters and the result is physically equal or not. This diff fixes a missing update of them.
Reviewed By: ezgicicek
Differential Revision: D18450680
fbshipit-source-id: bae19cbe9
Summary:
It returns non-top value when one of the parameters of band is positive, i.e., `x & 255` returns
`[0, 255]` instead of top.
Reviewed By: ezgicicek
Differential Revision: D18448614
fbshipit-source-id: aaa298a66
Summary:
Let's introduce a set of new cost analysis issue types that are raised when the function is statically determined to run on the UI thread. For this, we rely on the existing `runs_on_ui_thread` check that is developed for RacerD. We also update the cost summary and `jsonbug.cost_item` to include whether a method is on the ui thread so that we don't repeatedly compute this at diff time for complexity increase issues.
Note that `*_UI_THREAD` cost issues are assumed to be more strict than `*_COLD_START` reports at the moment. Next, we can also consider adding a new issue type that combines both such as `*_UI_THREAD_AND_COLD_START` (i.e. for methods that are both on cold start and run on ui thread).
Reviewed By: ngorogiannis
Differential Revision: D18428408
fbshipit-source-id: f18805716
Summary:
This diff tries more narrowing during analysis in order to get preciser results on nested loops.
In the widening phase, it does narrowing a loop right after its widening, for each loops. In general, this may make the widening phase non-terminating because it keeps the abstract state from monotonely increasing to the fixed point in a finite number of iterations. To avoid that situation, this diff applies the narrowing only when the first visit of the loop in the widening phase.
Reviewed By: ngorogiannis
Differential Revision: D18400631
fbshipit-source-id: cc76f7e85
Summary: Sometimes there is a code like `for(int i = 1; i < x; i++){ l.add(); }`, where the first element in a list is addressed specifically. This case was not analyzed precisely, because the alias value is added only when `i` is initialized by 0 by heuristic. This diff extends the heuristic, so it adds a size alias between `i` and `l.size()` when `i` is initialized by 0 or 1.
Reviewed By: ezgicicek
Differential Revision: D18351867
fbshipit-source-id: e7d19a4ec
Summary:
This diff adds semantics of Java function calls of enum `values` inside class initializers.
* Java class initializer function initializes a specific field `$VALUES`, which points to the list
of enum values.
* The `values` function of enum class returns the value of `$VALUES`.
The problem is when the `values` function is called inside the class initializer, for example:
```
enum Color {
RED,
GREEN,
BLUE;
static {
for (Color c : Color.values()) {}
}
}
```
This introduces a recursive dependency: the class initializer calls `Color.values` and the function
returns `Color.$VALUES` the value of which should be initialized in the class initializer.
To address the problem, this diff finds the value of `$VALUES` in its abstract memory when
`values` is called inside the class initializer.
Reviewed By: ezgicicek
Differential Revision: D18349281
fbshipit-source-id: 21766c20f
Summary:
This diff extends bound domain to express Min/Max of another bounds, so it can keep some more
precision in `Math.min/max`.
limitation: `MinMaxB`, the constructor of the bound, can contain only linear expressions or
previous min/max expressions.
Reviewed By: ezgicicek
Differential Revision: D18395365
fbshipit-source-id: fc90d27fd
Summary: Capture locations where work is scheduled to run in parallel (here, just Executors). Also add a test file with cases the upcoming whole-program analysis for starvation should catch.
Reviewed By: dulmarod
Differential Revision: D18346880
fbshipit-source-id: 57411b052
Summary: Follow ups will include error messaging that makes the choice clear
Reviewed By: artempyanykh
Differential Revision: D18347664
fbshipit-source-id: b6f005726
Summary:
In this diff, we just load the info from the storage. Next diff will be
actually using this information to infer nullability.
`ThirdPartyAnnotationGlobalRepo.get_repo` will be used in the next diff,
hence #skipdeadcode
Reviewed By: artempyanykh
Differential Revision: D18347647
fbshipit-source-id: 82a9223c6
Summary:
This diff extends the alias domain, so each variable can have multiple aliases.
It changed `KeyLhs` can be mapped to multiple alias targets in the `AliasMap` domain:
```
before : KeyLhs.t -> KeyRhs.t * AliasTarget.t
after : KeyLhs.t -> KeyRhs.t -> AliasTarget.t
```
Reviewed By: ezgicicek
Differential Revision: D18062178
fbshipit-source-id: b325a6055
Summary:
This diff tries to make less imprecise division by constants results.
For example, the results of the division `[l, u] / c`, where `c` is a positive constant, are:
1. If `l/c` or `u/c` is representable in the bound domain, it uses the precise bounds, i.e., `[l/c, u/c]`.
2. If it is not representable, it tries to make conservative results:
if `0<=l<=u`, it returns `[0, u]` because `0 <= [l/c, u/c] <= u`
if `l<=u<=0`, it returns `[l, 0]` because `l <= [l/c, u/c] <= 0`
if `l<=0<=u`, it returns `[l, u]` because `l <= [l/c, u/c] <= u`
3. otherwise, it returns top, `[-oo, +oo]`
Reviewed By: ezgicicek
Differential Revision: D18270380
fbshipit-source-id: 8fb14c0e4
Summary:
Add precision to analysis by elaborating the thread-status domain. This is done by having unknown (bottom), UI, BG or Any (both/top) elements in the lattice. This way, when we branch on thread-identity (if I am on UI thread do this, otherwise do that), we know that in one branch we are on UI thread and on the other we are *not* on the UI thread (BG thread), where previously the other branch would just go to top.
With this knowledge we can throw away pairs that come from callees which run on a thread that is impossible, given the current caller thread identity. This can happen when annotations are used incorrectly, and since this is the purview of annot-reachability, we just drop those pairs entirely.
Reviewed By: skcho
Differential Revision: D18202175
fbshipit-source-id: be604054e
Summary:
Steal a page from RacerD (and improve interface of) on using certain calls to assert
execution on a particular thread. Reduces FPs and FNs too.
Reviewed By: dulmarod
Differential Revision: D18199843
fbshipit-source-id: 5bdff0dfe
Summary:
The zero cost of node does not make sense especially when the abstract memory is non-bottom. This
resulted in unreasonable zero cost results sometimes, e.g. when the checker could not find
appropriate control varaibles having interval values of iteration. This diff fixes this, so sets
the minimum basic cost as 1, if the abstract memory at the node is non-bottom.
Reviewed By: ezgicicek
Differential Revision: D18199291
fbshipit-source-id: b215d10e5
Summary:
This adds a more interesting value domain to pulse: concrete intervals.
There are still two main limitations:
1. arithmetic operations are all over-approximated: any assignment involving arithmetic operations is replaced by non-determinism
2. abstract values that are discovered to be equal are not merged into one
Reviewed By: skcho
Differential Revision: D18058972
fbshipit-source-id: 0492a590f
Summary:
This does several things because it was hard to split it more:
1. Split most of the arithmetic reasoning to PulseArithmetic.ml. This
doesn't need to be reviewed thoroughly because an upcoming diff
changes the domain from just `EqualTo of Const.t` to an interval domain!
2. When going through a prune node intra-procedurally, abduce arithmetic
facts to the pre (instead of just propagating them). This is the "assume
as assert" trick used by biabduction 1.0 too and allows to propagate
arithmetic constraints to callers.
3. Use 2 when applying summaries by pruning specs whose preconditions
have un-satisfiable arithmetic constraints.
This changes one of the tests! Pulse now does a bit more work to find
the false positive, as can be seen in the longer trace.
Reviewed By: skcho
Differential Revision: D18117160
fbshipit-source-id: af3b2c8c0
Nikos Gorogiannis
Sungkeun Cho
Jules Villard
Dulma Churchill
Mitya Lyubarskiy
Ezgi Çiçek