Summary:
At the end of analysing a procedure we call `simplify
~keep:vars_live_in_pre_post`. Any variable not in
`vars_live_in_pre_post` is not mentioned anywhere else in the state and
therefore is not going to contribute constraints in callers of the
procedure (in other words: they're dead). We want to also forget
arithmetic facts about these variables as this is a good opportunity to
make the path condition smaller, sometimes by a lot!
The main issue is that dead variables may be useful intermediate terms
in the formula, eg trying to keep only facts about `x` in `y = x + 1 &&
y = 0` is going to lose a lot of precision. But, if a variable not in
`keep` is only mentioned in a simple atom `z = 42` atom, for example,
it's safe to forget about it, eg it's safe to remember only `x=0` in
`x=0 && z=42` (if only `x` is live).
In other words, we can get rid of all atoms containing variables not
transitively involved in other atoms that eventually involve live
variables. A graph problem! This is guaranteed not to forget anything
important and can still trim a lot of atoms in certain situations.
Reviewed By: skcho
Differential Revision: D22921313
fbshipit-source-id: 6d5db7cbe
Summary:
Perhaps a bit overkill to introduce all this extra complexity but it
makes the unit tests much more readable. In fact, this uncovered a bug
in the dead variable elimination!
Reviewed By: dulmarod
Differential Revision: D22925548
fbshipit-source-id: d1f411683
Summary:
Do not always add parens around sub-terms, and add more parens around
terms in atoms and normal forms when they can be confused with the atom
or normal form structure.
Reviewed By: skcho
Differential Revision: D22925549
fbshipit-source-id: 8646e96a5
Summary: These will change to more interesting outputs in the next diff.
Reviewed By: dulmarod
Differential Revision: D22921349
fbshipit-source-id: c58c6240a
Summary:
Add unit tests to pulse in order to write tests for the arithmetic
solver, because it is a pain to write programs to do that end to end.
Reviewed By: ezgicicek
Differential Revision: D22864607
fbshipit-source-id: 0a20a3593
Summary:
This is needed to make dune auto-updating of unit tests introduced in
the next diff cohabit peacefully with our tests to make sure code stays
correctly formatted wrt ocamlformat.
Also, more auto-formatting = better.
Reviewed By: da319
Differential Revision: D22865004
fbshipit-source-id: 91c47ab08
Summary:
Normalization is potentially expensive and its result should be
remembered if the formula keeps being used. In the future we might use
this to make normalization more incremental.
Also rename PathCondition.satisfiable -> is_unsat to match
PulseFormula.is_unsat.
Reviewed By: skcho
Differential Revision: D22728264
fbshipit-source-id: 7759b33ac
Summary:
Now that this is a cheap operation, use it whenever we are checking the
satisfiability of the path condition.
Reviewed By: skcho
Differential Revision: D22724373
fbshipit-source-id: df31c6010
Summary:
Pausing the experiment in favour of new PulseFormula. Can be resurrected
later.
Reviewed By: skcho
Differential Revision: D22576274
fbshipit-source-id: 76529d767
Summary:
This time it's personal.
Roll out pulse's own arithmetic domain to be fast and be able to add
precision as needed. Formulas are precise representations of the path
condition to allow for good inter-procedural precision. Reasoning on
these is somewhat ad-hoc (except for equalities, but even these aren't
quite properly saturated in general), so expect lots of holes.
Skipping dead code in the interest of readability as this (at least
temporarily) doesn't use pudge anymore. This may make a come-back as
pudge has/will have better precision: the proposed implementation of
`PulseFormula` is very cheap so can be used any time we could want to
prune paths (see following commits), but this comes at the price of some
precision. Calling into pudge at reporting time still sounds like a good
idea to reduce false positives due to infeasible paths.
#skipdeadcode
Reviewed By: skcho
Differential Revision: D22576004
fbshipit-source-id: c91793256
Summary:
Current handling of lambdas is quite rudimentary. Looking at test
results we can see that errors are all over the place: False Positives,
False Negatives and just plain wrong results.
These tests can be grouped in 2 sets:
1. Basic support which implies:
- understanding method signatures,
- providing comprehensible error messages.
2. Extended support with implies:
- understanding scoping of values captures in lambdas (needs proper aliasing analysis).
- understanding parametric nullability in generics (needs "some"
support for Generics in our Java frontend).
With follow-up patches I'll attempt to implement "Basic" support for
Lambdas. "Extended" support will be out of scope unless there's
significant demand.
Reviewed By: mityal
Differential Revision: D23058673
fbshipit-source-id: 621551cca
Summary:
Absence of kotlin-annotations led to warnings messages during tests compilation:
```
$ make
warning: unknown enum constant MigrationStatus.STRICT
reason: class file for kotlin.annotations.jvm.MigrationStatus not found
```
This doesn't affect test results but is annoying, hence the fix.
Reviewed By: mityal
Differential Revision: D23051769
fbshipit-source-id: e45fbe7be
Summary:
This is part of work aimed to reduce usage of language-agnostics modules
in Java-specific parts of nullsafe.
As usual, in this diff we don't convert everything and take some
shorthands.
Reviewed By: ngorogiannis
Differential Revision: D23054169
fbshipit-source-id: 70913ddfd
Summary:
Note that the current implementation lists classes and methods (not
<class:method> pairs.
This is bit clowny, but works for now (given the list of classes is small).
So I'll leave it out of the scope of this diff.
Reviewed By: ngorogiannis
Differential Revision: D23076671
fbshipit-source-id: 71c94ebd9
Summary: This diff separates purity analysis and its reporting, since sometimes we want to use the purity analysis results in other checkers, but don't want to report purity issues.
Reviewed By: ezgicicek, jvillard
Differential Revision: D23054913
fbshipit-source-id: 12cc1fc42
Summary: Since there is no discernible downside in using the write daemon unless in single-thread mode or in buck, make it only depend on these circumstances, not a command line flag.
Reviewed By: skcho
Differential Revision: D23004451
fbshipit-source-id: 5c1d06ed1
Summary:
This is part of work aimed to reduce usage of language-agnostics modules
in Java-specific parts of nullsafe.
Reviewed By: artempyanykh
Differential Revision: D23052773
fbshipit-source-id: aacd07f27
Summary:
This is part of work aimed to reduce usage of language-agnostics modules
in Java-specific parts of nullsafe.
Reviewed By: artempyanykh
Differential Revision: D23052339
fbshipit-source-id: 665126957
Summary:
This is part of work aimed to reduce usage of language-agnostics modules
in Java-specific parts of nullsafe.
This diff:
1/ migrates AssignmentRule
2/ passes Procname.Java.t around from the start of analysis.
For now we have places where we have both procname and java procname.
This is fine as we can get rid of it in follow up diffs.
Reviewed By: artempyanykh
Differential Revision: D23052226
fbshipit-source-id: 0125de297
Summary:
This is part of work aimed to reduce number of language-agnostic methods
used in Nullsafe codebase.
Reviewed By: artempyanykh
Differential Revision: D23052328
fbshipit-source-id: 2b69f5f7a
Summary:
This diff adds a false positive test that is introduced imprecise loop
invariant detection.
In the example, `i` and a temp variable `$irvar = get_size(arr)` are
all included in the control variables, so the complexity becomes
quadratic. The problem is that `$irvar` is not addressed as a loop
invariant:
* `is.read` is analyzed as modifying a global
* all return variables, including `$irvar`, of unmodeled functions are invalidated
Reviewed By: ezgicicek
Differential Revision: D23051414
fbshipit-source-id: 011fd086b
Summary: To avoid dead store false positives we skip initialization of a variable that has an `unused` attribute. However, this causes uninitialized value false positives when the variable is later used in macros. To fix this, instead of skipping initialization we record the information about `unused` attribute in local variable data that we can later use for filtering out dead store issues.
Reviewed By: jvillard
Differential Revision: D22868050
fbshipit-source-id: 4a2d0e680
Summary:
In the current implementation, we record 3 states: modelled internally,
modelled intenally, not modelled.
The follow up diffs will need to distinct first- and third- party, given
annotated signature. This diff makes it possible.
Reviewed By: artempyanykh
Differential Revision: D22977962
fbshipit-source-id: b8f3616b5
Summary:
We get duplicated variable declaration instruction for primitive type variable initialized using list initializer, e.g.
```
int* p{nullptr};
```
This happens because we add variable declaration instruction when we translate both `DeclStmt` and `InitListExpr`. To fix this, we do not add the duplicated variable declaration when we translate `InitListExpr`.
Reviewed By: jvillard
Differential Revision: D22844726
fbshipit-source-id: 422806924
Summary:
Synthetic/autogenerated methods/fields usually contain `$` in their names.
Reporting nullability violations on such code doesn't make much sense
since the violations are not actionable for users and likely need to be
resolved on another level.
This diff contributes:
1. Several test cases that involve synthetic code of different
complexity.
2. Code that handles some particular types of errors (but not all!).
Reviewed By: mityal
Differential Revision: D22984578
fbshipit-source-id: d25806209
Summary:
Use `Typ.t` for parameter types in procnames, instead of `JavaSplitName.t`. This allows more precise and usable types stored in procnames, as well as not using the string-based representation of `JavaSplitName` which meant parsing strings whenever one needed a `Typ.t`.
This also makes `JavaSplitName` dead code, so it is removed.
Reviewed By: skcho
Differential Revision: D20500423
fbshipit-source-id: a72728e3f
Summary: Since types from the java frontend are a subtype of `Typ.t` provide the means to check and enforce that for return types in procnames.
Reviewed By: ezgicicek
Differential Revision: D20495527
fbshipit-source-id: b99c784af
Summary:
`java_type` aka `JavaSplitName.t` is a pair of strings. It's used in a procname to store the return type. Replace that with `Typ.t`.
This is step one of deleting `JavaSplitName`. Step two will be to replace parameters with `Typ.t`.
Reviewed By: skcho
Differential Revision: D20323748
fbshipit-source-id: f0029c3ca
Summary:
This diff adds an option `max-jobs` that restrict the number of jobs
running simultaneously.
Reviewed By: ngorogiannis
Differential Revision: D22978328
fbshipit-source-id: 544153c1c
Summary:
Currently, the notion of a third party method signature (corresponding to
a single record in a .sig file) is scattered between unique_repr and
nullability.
Logically, ThirdPartyMethod.t should not "know" about unique_repr
because this is a detail needed only for searching for a method
definition in `.sig` storage.
This diff:
1. Introduces ThirdPartyMethod.t which exposes exactly information
stored in .sig file. We are going to use this abstraction more in follow
up diffs.
2. Moves functionality operating with `unique_repr` to the module
responsible for searching in the repository.
3. Deletes `ThirdPartyMethod.nullability` abstraction - we don't need it as we can just store ThirdPartyMethod.t where was previously `nullability` stored.
4. Introduces `to_canonical_string` method that prints back third party
method in a format needed for `.sig` file, and a test ensuring that
parsing works back and forth consistently. We are going to use this
method in follow up diffs as well.
Reviewed By: artempyanykh
Differential Revision: D22950706
fbshipit-source-id: a0e72ccdb
Summary: As per title. Eases next diffs by making Summary the only source of truth for how spec files are accessed/stored.
Reviewed By: ezgicicek
Differential Revision: D22794742
fbshipit-source-id: 0ee20ec1c
Summary: New, experimental for now, integration with buck on Java using the `#infer-java-capture` flavor.
Reviewed By: artempyanykh
Differential Revision: D22187748
fbshipit-source-id: 62cdafe6b
Summary:
This diff removes a dead field `Struct.subs`, which was used in
heuristics finding methods from sub-classes.
Reviewed By: ezgicicek
Differential Revision: D22945346
fbshipit-source-id: 4b3bf0093
Summary: This diff is on par with this change, with the same motivation
Reviewed By: artempyanykh
Differential Revision: D22924891
fbshipit-source-id: 578ca5869
Summary:
This change will simplify the further refactoring I am doing in follow
up diffs.
Logically, AssignmentRule is about passing actual value to the declared
one, and the proper abstactions for this is exactly AnnotatedNullability
and InferredNullability.
This will also make the client less error prone (no way to call if you
don't have a declaration and actual value to compare).
In the next diff, we will do the same in DereferenceRule.
Reviewed By: artempyanykh
Differential Revision: D22923779
fbshipit-source-id: 5f8f0931c
Summary: Before, `NSCollection` are modelled like array, but this will have issue when we want to say add object to array. This diff changes `NSCollection`'s model to use Java's Collection model.
Reviewed By: ezgicicek
Differential Revision: D22840079
fbshipit-source-id: b944b743b
Summary:
In Cost/Inferbo checkers, it tried to find a subclass with heuristics when a method of interface or
abstract class is called. While it makes preciser analysis results in general, sometimes introduced
tricky FPs since the behavior of the heuristics depends on targets. This diff revert the heuristics
to suppress the FPs.
Reviewed By: ngorogiannis
Differential Revision: D22924485
fbshipit-source-id: 9f151231f
Summary: Implement `alloc` and implement initialisation method that uses the return value of `alloc`, i.e. `NSString.init`.
Reviewed By: ezgicicek
Differential Revision: D22840080
fbshipit-source-id: 47a7523e3
Summary:
This diff translates for-in block in objc as a simple for-loop. For example,
`for (item_type item in items) { body }` is translated to
```
NSEnumerator *enumerator = [items objectEnumerator];
item_type item;
while (item = [enumerator nextObject]) { body }
```
Reviewed By: ezgicicek
Differential Revision: D22841524
fbshipit-source-id: 296ee84df
Summary:
Capture of certain Kotlin files fails at the javalib level (probably,
some unanticipated bytecode pattern). We however can't just completely
skip Kotlin class-files during capture as those have NotNull/Nullable
annotations on methods/params that are important for Java <- Kotlin
interop (using Kt classes from Java).
Instead we can skip translation of concrete methods from Kotlin classes
while retaining method signatures with annots in the TEnv.
Reviewed By: ngorogiannis
Differential Revision: D22897638
fbshipit-source-id: 67909aa43
Jules Villard
Artem Pianykh
Mitya Lyubarskiy
Sungkeun Cho
Ezgi Çiçek
Nikos Gorogiannis
Daiva Naudziuniene
Qianyi Shu