Summary:
First step in having a value domain: record concrete values. We record
them as equalities to abstract values using a new attribute `Constant`.
In a way, attributes are already our "pure" part in the "formulas" that
are pulse abstract domains, so this is reminiscent of existing
separation logic implementations. Trying to add values directly in the
"heap" part proved very cumbersome whereas this approach is very simple,
allowing us to ignore values most of the time except when we actually
care.
Reviewed By: skcho
Differential Revision: D17665473
fbshipit-source-id: b8033ad9c
Summary:
It's annoying to see `sexp_list` everywhere instead of `list`, eg in
merlin.
See also D17907938.
Reviewed By: ngorogiannis
Differential Revision: D17927994
fbshipit-source-id: 84599e8bc
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
Summary:
By some unfortunate logic, OCaml often decides to use
`sexp_list`/`sexp_option` instead of just `list`/`option`. Sometimes
these get copy/pasted in interface files.
It would be good to tell OCaml not to do that in the first place but in
the meantime: this diff.
Reviewed By: ngorogiannis
Differential Revision: D17907938
fbshipit-source-id: 7546834a2
Summary:
This diff introduces inequality for the iterator alias target, as we
did for the size target before.
Reviewed By: ezgicicek
Differential Revision: D17879208
fbshipit-source-id: cc2f6a723
Summary: If we have no pulse summary (most likely caused by pulse finding a legit issue with the code), let's consider the function as impure.
Reviewed By: jvillard
Differential Revision: D17906016
fbshipit-source-id: 671d3e0ba
Summary:
Describe what the --report-*-* options actually do instead of their
outdated documentation from the time where this was
`--checkers-blacklist-regex`, `--infer-blacklist-regex` and the like.
Reviewed By: dulmarod, mityal
Differential Revision: D17906015
fbshipit-source-id: 204349e9e
Summary:
This diff revises the semantics of hasNext model to add the lengths of
arrays, rather than join them to top.
Reviewed By: ezgicicek
Differential Revision: D17882388
fbshipit-source-id: f5edaedb3
Summary: Not used feature and with no obvious roadmap anymore.
Reviewed By: jberdine, jvillard
Differential Revision: D17855860
fbshipit-source-id: fd75b9d62
Summary: This makes more explicit what we are talking about here. Also, in extending test determinator to clang, the name is incorrect, but the set is generic procnames which is fine to use for clang, just the name is wrong.
Reviewed By: ngorogiannis
Differential Revision: D17855338
fbshipit-source-id: e93bae083
Summary: This diff models the cost of `ImmutableSet.chooseTableSize(setSize)` as `O(log setSize)` and `construct(n, ...)` as `O(n)`.
Reviewed By: ezgicicek
Differential Revision: D17829850
fbshipit-source-id: 0ee318cc3
Summary:
This diff fixes a data race in ProcessPool: out channel flush was
outside of the critical section.
Reviewed By: ezgicicek
Differential Revision: D17853991
fbshipit-source-id: ac0fd2a69
Summary:
[androidx.collection.SimpleArrayMap](https://developer.android.com/reference/androidx/collection/SimpleArrayMap.html) also has `keySet` and `entrySet` methods which make them eligible for inefficient keyset checker. Let's add it.
Title
Reviewed By: skcho
Differential Revision: D17831594
fbshipit-source-id: 32e831e18
Summary:
Starvation analysis keeps a trace documenting why a method is seen as on the UI thread (many reasons possible, often confusing). This was a call-stack plus string, for keeping the explanation of why the last callee is on the UI thread. This is bad, because it takes too much memory/storage (each string is custom-made to the classes/method involved), and is effectively untyped.
Switch to a proper type for explaining this, so the cost is just a few pointers plus shared procnames/types, and then convert to string only when reporting. This will also allow to push the UI trace inside each element of the starvation domain, so as to allow path sensitivity etc, without blowing up summary size.
Reviewed By: ezgicicek, artempyanykh
Differential Revision: D17810007
fbshipit-source-id: cdd743975
Summary:
This diff proceeds work for consolidating nullsafe logic and making it
type-agnostic
Reviewed By: artempyanykh
Differential Revision: D17808485
fbshipit-source-id: 85356c625
Summary:
The current usage has several issues reducing code maintainability and
readability:
1. Null_field_access was misleading: it was used for checking accesing
to arrays as well!
2. But actually, when checking access to array via `length`, we sometimes
pretended it is a field access (hence very tricky code in rendering the
error).
3. "Call receiver consistency" is unclear name, was not obvious that it is all about
calling a method in an object.
Let's also consolidate code.
Reviewed By: artempyanykh
Differential Revision: D17789618
fbshipit-source-id: 9b0f58c9c
Summary:
This proceeds work on abstracting out operations requiring raw
nullability operations from infer core code. This will simplify coming
introducing of intermediate nullability levels
Reviewed By: artempyanykh
Differential Revision: D17789612
fbshipit-source-id: 9a2bea2ed
Summary:
In previous refactoring stages, we operated on AnnotatedNullability
(nullability of a field or method signature together with its origin),
and InferredNullability (nullability of a value in typestate together
with its origin).
Now it is time to extract common Nullability as a type system concept,
together with `<:` and `join` functionality. This was sketched in
`NullsafeRules`, so this diff consolidates this as well.
In follow up diffs, we will reduce/get rid of direct usages of things like
`InferredNullability.is_nullable`. This will simplify introducing
intermediate Nullability types.
Reviewed By: artempyanykh
Differential Revision: D17789599
fbshipit-source-id: f1b9d2dd0
Summary: StarvationModels depended on StarvationDomain which is the wrong way around, and forbids using *Models from *Domain.
Reviewed By: mityal
Differential Revision: D17809431
fbshipit-source-id: 5aa369e7c
Summary: The type hierarchy was traversed multiple times when searching for annotations: once for methods/overrides annotated and once for superclasses. This can be done in one pass.
Reviewed By: dulmarod
Differential Revision: D17787172
fbshipit-source-id: 248dd4c27
Summary: Before, we didn't track litho framework callees on client code which was wrong. Now, we replace this with the following: If the callee is `build()` itself or doesn't contain a `build()` in its summary, then we want to track it in the domain. The former makes sense since we always want to track `build()` methods. The latter also makes sense since such a method could be a setter for a prop (as in the case of `prop1` in `buildPropLithoOK` which we were missing before due to the imprecise heuristic that prevented picking up callees in litho).
Reviewed By: ngorogiannis
Differential Revision: D17810704
fbshipit-source-id: 87d88e921
Summary: As a heuristic, litho library calls on non-litho callers are not tracked. This is very imprecise and results in FPs and FNs as exemplified by newly added tests. Instead, we should check to see if the summary contains a `build()` method as will be done in the next diff. This diff adds these tests and refactors the test code.
Reviewed By: skcho
Differential Revision: D17809536
fbshipit-source-id: 6dff1868c
Summary:
Improve the trace by incorporating the callees and their locations in the call chain (i.e. chain of methods starting from `build()` call)
- extend the domain to contain the callee location
- replace the test results with the new traces
This makes our job much easier to debug FPs in a big codebase.
Reviewed By: skcho
Differential Revision: D17788996
fbshipit-source-id: 31938b5fe
Summary: `litho` checker contained two checkers: required-props and graphQL field accesses. Although they use the same domain, their reporting conditions and analysis details are different. However, they were bundled into the same analysis by adding disjunctions to `exec_instr` to handle both cases. Let's separate them into two different checkers, keeping a modular transfer function and analyzer that is reused by these two checkers.
Reviewed By: skcho
Differential Revision: D17788834
fbshipit-source-id: 47d77063b
Summary: The regexp would match `ge` and is also unnecessary and was compiled on every call. Save some cpu cycles while fixing it.
Reviewed By: jvillard
Differential Revision: D17789586
fbshipit-source-id: a3f6612c6
Summary:
At some point it was thought that we can assume that any annotation starting with "On" means the method is on the UI thread.
That's too imprecise and has led to false positives and negatives. Restrict to a well-known safe set.
Reviewed By: ezgicicek
Differential Revision: D17769376
fbshipit-source-id: 0f8fee059
Summary:
Currently, lock state is a map from locks to stacks of lock acquisitions.
Since we now have the separate acquisitions component, we no longer need to
remember the stack of acquisitions for a lock. Instead we only need a lock count,
thus reducing the memory footprint.
At the same time, change acquire and release so that they make one tree operation per
component (map/acquisition) as opposed to two (search/update) operations.
Reviewed By: ezgicicek
Differential Revision: D17736727
fbshipit-source-id: 7579eb61e
Summary:
If we acquire n nested locks we end up with n critical pairs, and for each pair the held-locks component goes up linearly, thus total space/time is O(n^2).
If the sets of held-locks are constructed with maximal sharing (intuitively, if they derive from the same set by additions) then the total space/time is O(n logn).
To do this, we must avoid constructing a new set every time we ask what the currently held locks are. Here we maintain (care is needed in the presence of recursive locks) that set across lock acquisitons and removals.
Reviewed By: skcho
Differential Revision: D17736252
fbshipit-source-id: 0f9b292c4
Summary:
This diff tries to narrowing the fixpoint of outermost loops, so that over-approximated widened values do not flow to the following code.
Problem: There are two phases for finding a fixpoint, widening and narrowing. First, it finds a fixpoint with widening, in function level. After that, it finds a fixpoint with narrowing. A problem is that sometimes an overly-approximated, imprecise, values by widening are flowed to the following loops. They are hard to narrow in the narrowing phase because there is a cycle preventing it.
To mitigate the problem, it tries to do narrowing, in loop level, right after it found a fixpoint of a loop. Thus, it narrows before the widened values are flowed to the following loops. In order to guarantee the termination of the analysis, this eager narrowing is applied only to the outermost loops.
Reviewed By: ezgicicek
Differential Revision: D17740265
fbshipit-source-id: e2d454036
Summary:
This diff extends the alias domain to analyze loop with list comprehensions form in Java precisely.
```
list2 = new List();
for (Element e : list1) {
list2.add(e);
}
```
1. `IteratorOffset` is a relation between a iterator offset and a length of another array. For example, in the above example, after n-times of iterations, the offset of the iterator (if it exists) and the length of `list2` are the same as `n`.
2. `IteratorHasNext` is a relation between iterator and its `hasNext` result.
3. At the conditional nodes, it prunes the alias list length of `list2` by that of `list1`.
* if `hasNext(list1's iterator)` is true, `list2`'s length is pruned by `< list1's length`
* if `hasNext(list1's iterator)` is false, `list2`'s length is pruned by `= list1's length`
Reviewed By: ezgicicek
Differential Revision: D17667128
fbshipit-source-id: 41fb23a45
Summary: This diff fixes a potential race in writing to pipe channel.
Reviewed By: ngorogiannis
Differential Revision: D17710123
fbshipit-source-id: 477492750
Summary:
The old domain keeps two sets:
- `events` are things (including lock acquisitions) which eventually happen during the execution of a procedure.
- `order` are pairs of `(lock, event)` such that there is a trace through the procedure which at some point acquires `lock` and before releasing it performs `event`.
A deadlock would be reported if for two procedures, `(lock1,lock2)` is in `order` of procedure 1 and `(lock2,lock1)` is in `order` of procedure 2. This condition/domain allowed for the false positive fixed in the tests, as well as was unwieldy, because it required translating between the two sets.
The new domain has only one set of "critical pairs" `(locks, event)` such that there is a trace where `event` occurs, and *right before it occurs* the locks held are exactly `locks` (no over/under approximation). This allows keeping all information in one set, simplifies the procedure call handling and eliminates the known false positive.
Reviewed By: mityal
Differential Revision: D17686944
fbshipit-source-id: 3c68bb957
Summary: Holding a master lock and then acquiring two other locks inside can generate a false positive as shown.
Reviewed By: mityal
Differential Revision: D17710076
fbshipit-source-id: 5bc910ba2
Summary:
Previously deduplication was always on which is not great for testing.
Also split tests so that we can still test deduplication separately.
Reviewed By: mityal
Differential Revision: D17686877
fbshipit-source-id: 280d91473
Summary:
The documentation and uses of filtering disagree. One typical usage is deduplication.
Split that where obvious, add comments where not obvious, and leave alone when obviously unrelated to deduplication.
Reviewed By: mityal
Differential Revision: D17715329
fbshipit-source-id: ec757927b
Summary:
Ideally the analyser should equate locks `this.x.f` and `a.x.f` in different methods if they can alias.
The heuristic removed here was rarely used and is in the way of a re-write of the analysis.
It was also badly implemented, as this should ideally be the comparison relation of `Lock`.
Reviewed By: mityal
Differential Revision: D17602827
fbshipit-source-id: 4f4576c1a
Summary:
This diff generates a symbolic value when a function returns only
exceptions. Previously, the exception expression is evaluated to top,
thus it was propagated to other functions, which made those costs as
top. For preventing that situation, this diff changed:
* exception expressions are evaluated to bottom, and
* if callee's return value is bottom, it generates a symbolic value
for it.
Reviewed By: ezgicicek
Differential Revision: D17500386
fbshipit-source-id: 0fdcc710d
Summary: This diff introduces an inequality for the size alias targets, in order to get preciser array lengths after loops. The alias domain in inferbo was able to express strict equality between alias source and its targets, e.g. x=size(array). Now, for the size alias target, it can express less than or equal relations, e.g. x>=size(array).
Reviewed By: ezgicicek
Differential Revision: D17606222
fbshipit-source-id: 2557d3bd0
Jules Villard
Ezgi Çiçek
Sungkeun Cho
Nikos Gorogiannis
Dulma Churchill
Mitya Lyubarskiy