Summary:
The "access path" memory model (equal access paths iff equal object addresses) is suited to when aliasing occurs only at the roots (i.e. variables). When there is intentional aliasing in the middle of an access path, this model will miss the aliasing. For instance if `[x.f] == [y.g]`, then also `[x.f.h] == [y.g.h]`, but the latter access paths are unequal.
In Java, non-static inner classes consistently alias `this.this$0` inside an inner class, which points to the "parent" outer-class object. So if two inner-class objects (belonging to different inner classes) access `this(type:InnerClassA).this$0.f` and `this(type:InnerClassB).this$0.f` the equality will be missed (many other combinations exist). This isn't strictly due to the memory model -- any alias analysis would have to do some class invariant inference to detect this.
For this purpose `AccessPath.inner_class_normalize` exists (it replaces `this.this$0` with `this` of the appropriate type), but this breaks the invariant that we know which formal parameter is at the root (there may not even exist a `this` parameter if the method is static). So this was buggy.
Here we simply recursively remove the synthetic field prefix of the accesses list, while computing forwards the object type. This is only applied when we check aliasing across threads. This will also allow actuals/parameters substitutions (stacked diff) which normalisation was breaking.
Reviewed By: jberdine
Differential Revision: D19601455
fbshipit-source-id: 7e42667b6
Summary:
Rename DeclaredNonnull -> UncheckedNonnull, Nonnull -> StrictNonnull.
This is a preparatory step to introduce one more nullability option,
specifically CheckedNonnull to support local nullsafe mode.
Reviewed By: ngorogiannis, mityal
Differential Revision: D19619289
fbshipit-source-id: 12a3ff814
Summary:
This will help adoption of non-transitive strictification modes.
The main use-case we are aiming with this function is:
- During strictification, a method is made nullable, but it is not feasible to fix all
callers straight away. Suppressing nullsafe with an appropriate task or
comment will make it easier to unblock the strictification and move
forward.
Reviewed By: artempyanykh
Differential Revision: D19599098
fbshipit-source-id: 3769bbd3d
Summary:
1. I can not imagine a useful usecase for strict node, lets not
complicate the code.
2. Add docs.
Reviewed By: artempyanykh
Differential Revision: D19599091
fbshipit-source-id: 1d37a717f
Summary:
Reorder assertNotNull and assumeNotNull:
1. More useful methods go first.
2. More useful methods explicitly recommended over less useful.
Reviewed By: artempyanykh
Differential Revision: D19599084
fbshipit-source-id: 1b9ad9ef6
Summary: The translation of closures includes a load instruction for the captured variable, then we add that corresponding id to the closure. This doesn't correspond to an actual "use" of the captured variable in the source program though, and causes false positives. Here we remove the ids from the domain when that id is being added to a closure.
Reviewed By: ngorogiannis
Differential Revision: D19557352
fbshipit-source-id: 52b426011
Summary:
- Add `Nullsafe` annotation as a general mechanism to specify
type-checking behaviour for nullsafe.
- Document annotation params and provide usage examples with
explanations.
- Add tests to demonstrate the behaviour with different type-checking
modes.
No implementation is added. This diff serves as an RFC to hash out the
details before I dive into code.
Reviewed By: ngorogiannis
Differential Revision: D19578329
fbshipit-source-id: b1a9f6162
Summary: Keep the type name of the class as the key in the map constructed from class names to their methods in a file. This will be used later, and also why string?
Reviewed By: dulmarod
Differential Revision: D19557707
fbshipit-source-id: aa8569581
Summary: D19496263 had refactored cost to its own subdirectory. In this process, it introduced a perf degradation by bundling of collection and computation of constraints which relies on imperative union find. This diff fixes that by separating them.
Reviewed By: ngorogiannis
Differential Revision: D19598610
fbshipit-source-id: 0e466522d
Summary: Add the interface that will be used to lock Procedures.
Reviewed By: ngorogiannis
Differential Revision: D19580578
fbshipit-source-id: b5e334b18
Summary:
In an equation such as `x = ⟨n,a⟩`, `x` is implicitly an aggregate of
size `n` (or else the equation is ill-typed). Make this explicit by
normalizing such equations to e.g. `⟨|⟨n,a⟩|,x⟩ = ⟨n,a⟩`.
Reviewed By: ngorogiannis
Differential Revision: D19358546
fbshipit-source-id: 77f67a0da
Summary:
Strengthen Equality.solve_for_vars so that it will solve cases such as
```
∃ a. ⟨n,a⟩ = ⟨m,b⟩^⟨o,c⟩
```
Reviewed By: ngorogiannis
Differential Revision: D19356324
fbshipit-source-id: a57625ba6
Summary:
Due to paying closer attention to which terms are already normalized
by the accumulated solution substitution.
Reviewed By: ngorogiannis
Differential Revision: D19356323
fbshipit-source-id: e162414a0
Summary:
The function transforming terms passed to Sh.map might produce trivial
constraints, filter them out.
Reviewed By: ngorogiannis
Differential Revision: D19286628
fbshipit-source-id: e3d9926ce
Summary:
In order for Equality.solve to generate fresh variables, it needs to
be passed the universal context with respect to which variables must
be chosen fresh.
Reviewed By: ngorogiannis
Differential Revision: D19286630
fbshipit-source-id: ebbedd954
Summary:
Aggregate args of Extract and Concat must be aggregate terms, in
particular, not variables. This maintains the property that the size
of any aggregate can be computed.
Reviewed By: ngorogiannis
Differential Revision: D19286625
fbshipit-source-id: 1af1e4183
Summary:
The byte-array theory used for the contents of memory is strong
enough to express all the constraints arising during symbolic
execution without the ability to extract a slice out of a byte-array.
However, without Extract, it is not possible to solve some equations
for some variables, for example solving ⟨n,α⟩^⟨m,β⟩ = ⟨l,γ⟩ for α.
Solving such equations is needed for quantifier elimination and to
formulate the byte-array theory as a Shostak theory.
Reviewed By: ngorogiannis
Differential Revision: D19286632
fbshipit-source-id: 07dc112d0
Summary:
Revise the ad hoc treatment to drop tautologous constraints such as
∃x,y. x = y to only apply when x and y do not appear elsewhere.
Reviewed By: ngorogiannis
Differential Revision: D19282633
fbshipit-source-id: 7fb9951ec
Summary:
Equality.solve_for_var_contexts can produce solution substitutions
that witness existentials in more cases than the
single-existential-occurrence heuristic, and is more conservative in
cases where the latter is incomplete.
Reviewed By: ngorogiannis
Differential Revision: D19282634
fbshipit-source-id: f86f0a9cb
Summary:
```
val trim : bound:Var.Set.t -> Var.Set.t -> t -> t
(** [trim bound kills subst] is [subst] without mappings that mention
[kills] or [bound ∩ fv x] for removed entries [x ↦ u] *)
```
To be used for existential witnessing and quantifier elimination.
Reviewed By: ngorogiannis
Differential Revision: D19282644
fbshipit-source-id: d981a1cb4
Summary:
```
val solve_for_vars : Var.Set.t list -> t -> Subst.t
(** [solve_for_vars \[v₁;…\] r] is a solution substitution that is
entailed by [r] and consists of oriented equalities [x ↦ u] such that
[fv x ⊈ vᵢ ⊇ fv u] where [i] is minimal such that [vᵢ]
distinguishes [fv x] and [fv u], if one exists. *)
```
To be used for existential witnessing and quantifier elimination.
Reviewed By: ngorogiannis
Differential Revision: D19282636
fbshipit-source-id: c5b006cea
Summary: `String.split(regexp)` returns an array that is split by the given regexp. If the regexp doesn't match, the original string is returned. Hence, the resulting array's length must be in `[1, max(1, n_u -1)]` where`n_u` is the upper bound of the string's length.
Reviewed By: dulmarod
Differential Revision: D19578318
fbshipit-source-id: 675af7376
Summary:
Adding a new check as part of the SelfInBlock checker, for cases when a strong pointer to self, that is not self, is captured in the block.
This will cover the following wrong scenarios:
1. strongSelf is a local variable in a block as it should be, and then it's used in a sub-block, in which case it's a captured variable.
2. weakSelf is defined without the weak attribute by mistake.
Reviewed By: ngorogiannis
Differential Revision: D19538036
fbshipit-source-id: 151871745
Summary:
In practice, condition redundant is extremely noisy and low-signal
warning (hence it is turned off by default).
This diff does minor tweaks, without the intention to change anything
substantially:
1/ Change severity to advice
2/ Change "is" to "might be"
3/ Describe the reason in case the origin comes from a method.
The short term motivation is to use 3/ for specific use-case: running nullsafe on codebase and
identify most suspicious functions (that are not annotated by often
compared with null).
Reviewed By: artempyanykh
Differential Revision: D19553571
fbshipit-source-id: 2b43ea0af
Summary:
This is/can be useful for future changes that make the reporting more
precise based on the exact origin.
See the follow up diff as an example.
Reviewed By: artempyanykh
Differential Revision: D19553567
fbshipit-source-id: c2b2c28a1
Summary: Currently, empty summaries are passed to the cluster callbacks. This is pointless and could potentially lead to recomputing already analysed summaries. This change passes only procnames to the callback, and `Ondemand` is used to load the summary or analyse as needed.
Reviewed By: jvillard
Differential Revision: D19544043
fbshipit-source-id: 28ab642c3
Summary: There is no need to provide type environments to cluster analysers, since the execution environment can be used to retrieve those on demand.
Reviewed By: jvillard
Differential Revision: D19543561
fbshipit-source-id: f9b064011
Summary: We were reporting strongSelf Not Checked when the variable was checked in a conditional, this diff fixes that.
Reviewed By: jvillard
Differential Revision: D19535943
fbshipit-source-id: f8e64e1b7
Summary:
This fixes the segmentation fault in docker master build. See
https://github.com/facebook/infer/issues/1194.
Reviewed By: jvillard
Differential Revision: D19449711
fbshipit-source-id: 0e281df5b
Summary: I noticed when looking into a false positive of strongSelf Not Checked, that there were some inconsistencies in the translation of if statements with an and, with an extra redundant join only if using a method in the condition that returned an object. So I could repro the problem and investigate and found the place of the inconsistency in the translation. This diff fixes it without changing things too much.
Reviewed By: jvillard
Differential Revision: D19518368
fbshipit-source-id: 47a6a778c
Summary:
The order by which the scheduler visits odd and even methods here
will determine if there is any report at all. This is a bad test
so remove.
Reviewed By: fgasperij
Differential Revision: D19535537
fbshipit-source-id: 6b64b0de9
Summary: Adding reporting to strongSelf Not Checked when strongSelf is passed to a method in a not explicitly nullable position.
Reviewed By: ezgicicek
Differential Revision: D19330872
fbshipit-source-id: 95871a70a
Summary: After receiving feedback about this, I'm changing the reporting of strongSelf Not Checked to only in cases where it can cause a crash. Here I'm adding reporting for field access, and removing general reporting. In a next diff, I'll also add reporting for passing strongSelf to methods in not explicitly nullable positions.
Reviewed By: skcho
Differential Revision: D19329842
fbshipit-source-id: 35beb2aa3
Summary:
The RestartScheduler needs to know if the worker finished it's task
because:
1. there was no more work to do or
2. found that a needed Procname was already taken (this part is not yet implemented)
This need was addressed by (i) making the functions that the workers execute
return a value of task_result.t intead of unit and (ii) adding a
constructor to the worker_message.t (FinishedTask).
Reviewed By: ngorogiannis
Differential Revision: D19467783
fbshipit-source-id: a76b02b6c
Summary:
1. One should use either a writer or a stream to send a response, but not both.
2. A response should be forwarded only if it was commited.
Both properties are extracted from API comments on classes in the servlet API.
Reviewed By: jvillard
Differential Revision: D19514568
fbshipit-source-id: 79f0257ed
Summary:
If data comes from an outer OutputStream, then this outer OutputStream
needs to be flushed before getting the byte array.
Reviewed By: jvillard
Differential Revision: D19514569
fbshipit-source-id: e3e025394
Nikos Gorogiannis
Artem Pianykh
Fernando Gasperi Jabalera
Mitya Lyubarskiy
Dulma Churchill
Ezgi Çiçek
Jules Villard
Josh Berdine
Sungkeun Cho
Radu Grigore