Summary:
The unary forms are primitive in ICS, and in uncoming changes which
involve considering the product of a term and an equality relation, it
is more efficient to have unary constructors since the product is then
linear instead of quadratic in the size of the equality relation.
Reviewed By: jvillard
Differential Revision: D22571138
fbshipit-source-id: e0b745cc8
Summary:
Add a Predsym module for uninterpreted (unary) predicate symbols, and
positive and negative literals applying them to a term. As with
uninterpreted functions, tuple terms are used to represent predicates
of other arities.
Using this support, change the Ord and Uno formulas to uninterpreted
literals.
Reviewed By: jvillard
Differential Revision: D22571140
fbshipit-source-id: 5022a91e2
Summary:
`Context.difference` is now just a convenience function that does not
need to be defined internally.
Reviewed By: jvillard
Differential Revision: D22571141
fbshipit-source-id: 58aea9488
Summary: Also, when printing in raw mode, do not print the context.
Reviewed By: jvillard
Differential Revision: D22571145
fbshipit-source-id: b3596d9cc
Summary:
Make the relationship between Sh.is_empty and Sh.pure_approx stronger
and more precise. In particular:
> If [is_empty q], then [pure_approx q] is equivalent to
> [pure (pure_approx q)].
This enables replacing Solver.excise_pure with a simpler pure_entails
function. In particular, the heavy reliance on normalization of pure
formulas to true or false literals is eliminated, and only pure
entailment is needed.
Reviewed By: jvillard
Differential Revision: D22571146
fbshipit-source-id: 2fca64a61
Summary:
Generalize Fol interface to allow checking if a context implies any
formula, rather than restricting to only equalities.
Reviewed By: jvillard
Differential Revision: D22571144
fbshipit-source-id: 726bd87fd
Summary:
There is nothing specific to the Ses representation in the
implementation, and no uses within Ses.
Reviewed By: jvillard
Differential Revision: D22571150
fbshipit-source-id: 8952f0301
Summary:
In Ses, the constant term of a polynomial is represented as a
redundant multiplication by 1. Fix Fol.of_ses to recognize and
normalize this.
Reviewed By: jvillard
Differential Revision: D22571131
fbshipit-source-id: 3e1a12e5f
Summary:
The Ses constructors might simplify terms when called from
Fol.to_ses. Fix Fol.ses_map to account for this.
Reviewed By: jvillard
Differential Revision: D22571151
fbshipit-source-id: 1d573ac5f
Summary:
This is part of work aimed to reduce usage of language-agnostics modules
in Java-specific parts of nullsafe.
Reviewed By: ngorogiannis
Differential Revision: D23075333
fbshipit-source-id: 4029732b4
Summary:
This is one of two files in nullsafe that remains interface-less.
Let's fix it!
Reviewed By: jvillard
Differential Revision: D23056324
fbshipit-source-id: a6592f7ae
Summary: Before we were modelling `vector.end()` as returning a fresh pointer every time is was called. It is common to check if an iterator is not the `end()` iterator and proceed to dereference the iterator in that case. In such code pattern `vector.end()` is called twice and returns different fresh values which causes false positives. To fix this, we add a special internal field `__infer_model_backing_array_pointer_to_last_element` to a vector to denote its end. Now, every time we call `vector.end()` we return the value of this field. We introduce a new attribute `EndOfCollection` to mark `end` iterator as the existing `EndIterator` invalidation is not suitable when we need to read the same value multiple times.
Reviewed By: jvillard
Differential Revision: D23101185
fbshipit-source-id: fa8a33b58
Summary:
Constructing the report is done by reading all the summaries, and using certain parts thereof. However, the payloads, which typically account for the greatest size, are not used (with the exception of costs).
This diff splits the storage of summaries into analysis and report summaries, and only reads and deserialises the latter for the report phase. This makes a big difference for runs with a large number of procedures.
Reviewed By: jvillard
Differential Revision: D23105072
fbshipit-source-id: 359067a0f
Summary:
As preparation for splitting summaries into some of their components, and then iterating over only those when reporting (thus gaining performance) we need procnames in the table.
Also, this fixes the now-broken use case of `infer report` with spec files, by using `--procedures-filter` to restrict printing of summaries accordingly.
Reviewed By: skcho
Differential Revision: D23101853
fbshipit-source-id: 1ae878d8e
Summary: Implement specs storage in DB, apart from biabduction models which are still left in specs files.
Reviewed By: skcho
Differential Revision: D22795638
fbshipit-source-id: 140801d3f
Summary: Extra info helps in debugging frontend issues and such.
Reviewed By: ngorogiannis
Differential Revision: D23101854
fbshipit-source-id: 27024675d
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
Josh Berdine
Mitya Lyubarskiy
Daiva Naudziuniene
Nikos Gorogiannis
Artem Pianykh
Jules Villard
Sungkeun Cho
Ezgi Çiçek