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:
In next diffs, we will:
1/ teach nullsafe to read nullability information from the 3rd party
annotation folder
2/ use this storage in addition to our hard-coded
models to respect nullability during type-checking
Reviewed By: artempyanykh
Differential Revision: D18247538
fbshipit-source-id: ee45bc80e
Summary:
More rigid format for 3rd party annotation repo
To simplify external processing by tools, lets not accept any divergence from a
format, which is:
<fully qualified class name>#<method_name>(<params>)[ Nullable]
<params> = <list of param separated by ", ">
<param> = [Nullable ]<fully qualified type>
Particularly:
- Dont accept spaces in arbitrary places
- Require a single space after each comma separating params
- Require a single space between closing parethesis and nullable
annotation, if present
- Require at least one '.' in a class name (to prevent errors when
somebody did not specify a package).
This diff also makes error messaging more user-friendly, because now it
is easy to do a minor mistake like forget a space after comma.
Reviewed By: asm89
Differential Revision: D18297382
fbshipit-source-id: 91aab6823
Summary:
This is a helper module for reading info from a 3rd party nullability repository.
Next diffs are going to use it for reading nullability repository from
disk.
Reviewed By: artempyanykh
Differential Revision: D18225473
fbshipit-source-id: 06a2dc97e
Summary: The way `<=` is used in `AbstractDomain` prevents infix use and forces bracketing it everywhere. Replace with simple `leq`.
Reviewed By: jvillard
Differential Revision: D18201854
fbshipit-source-id: 8175224e4
Summary:
Primitive types are not annotated. Because of that, we used to implicitly derive
`DeclaredNonnull` type for them. This worked fine, but this leads to errors in Strict mode, which does
not believe DeclaredNonnull type.
Now lets offifically teach nullsafe that primitive types are
non-nullable.
Reviewed By: jvillard
Differential Revision: D18114623
fbshipit-source-id: 227217931
Summary:
The wrong function was used when we tried to see if the class is
annotated with NullsafeStrict. This made it work only for non-static
methods.
Now we use the proper way.
Reviewed By: ngorogiannis
Differential Revision: D18113848
fbshipit-source-id: 02b7555be
Summary: As suggested by artempyanykh, this will make it bit more clear
Reviewed By: artempyanykh
Differential Revision: D18037204
fbshipit-source-id: 65cb96815
Summary:
This is the first take on strict mode semantics.
The main invariant of strict mode is the following:
If the function passes `NullsafeStrict` check and its return value is
NOT annotated as Nullable, then the function does not indeed return
nulls, subject to unsoundness issues (which should either be fixed, or
should rarely happen in practice).
This invariant helps the caller in two ways:
1. Dangerous usages of non strict functions are visible, so the caller is enforced to check them (via assertions or conditions), or strictify them.
2. When the function is strict, the caller does not need to worry about
being defensive.
Biggest known issues so far:
1. Condition redundant and over-annotated warnings don't fully
respect strict mode, and this leads to stupid false positives. (There is
so much more stupid false positives in condition redundant anyway, so
not particularly a big deal for now).
2. Error reporting is not specific to mode. (E.g. we don't distinct real nullables and non-trusted non-nulls, which can be misleading). To be
improved as a follow up.
Reviewed By: artempyanykh
Differential Revision: D17978166
fbshipit-source-id: d6146ad71
Summary:
This is an intermediate nullability type powering future Strict mode.
See the next diff.
Reviewed By: artempyanykh
Differential Revision: D17977909
fbshipit-source-id: 2d5ab66d4
Summary:
Currently, we have NullsafeRules.ml responsible for detecting the
violation fact. All other logic: what should be the error type,
severity, and error message, is in TypeErr.ml.
In this diff, we move logic from NullsafeRules.ml and TypeErr.ml to
dedicated modules like AssignmentRule.ml etc.
Each such module is responsible for:
- detecting the violation fact (this is moved from NullsafeRules.ml)
- rendering the violation error (this is moved from TypeErr.ml).
This approach makes sense for two reasons:
1. The violation fact and the way we show error are logically related to
each other.
2. In future diffs, we will support more features guiding rule behavior,
such as a) decision whether to hide or show the error depending on type
information and mode; b) the way we render error depending on type
information and role.
Having dedicated modules incapsulating knowledge about rules is a natural way to support 2.
Reviewed By: artempyanykh
Differential Revision: D17977891
fbshipit-source-id: a53d916d3
Summary:
1. For each Nullsafe Rule, lets have a dedicated IssueType.
2. Split error reporting to three subfunctions: description, field type,
and infer issue.
This allows to introduce additional capabilities in a consolidated
manner. Example of such capabilities is should we hide or show an error,
what should be error severity depending on strictness mode, and how
exactly the error should be reported depending on how exactly
nullability is violated.
Reviewed By: artempyanykh
Differential Revision: D17977887
fbshipit-source-id: 860d67d2f
Summary:
This function can return `None` if the result is equal to the first
argument of join (why first?). It is unclear if it was an optimization
attempt of over-complicated logic.
Reviewed By: artempyanykh
Differential Revision: D17876561
fbshipit-source-id: 9628fb86e
Summary:
The goal of this logic is unclear:
1/ See the comments
2/ I can not see the scenario where classes and proper types can be
joined in a legit Java program
3/ Even it if was the case, I don't see how this heuristic is justified.
So I assume it is not.
Reviewed By: artempyanykh
Differential Revision: D17876568
fbshipit-source-id: c9c6cd604
Summary:
It is unclear what is the purpose of doing so, and it adds complexity to
codebase.
1/ The semantics of this is not clear, it more or less corresponds to
"where are all original locations that contributed to the type
calculation", but many branches in CFG have nothing to do with
nullability; also it was used not always consistently.
2/ The only place where this was used is logs, so this is no-ops. It is
unclear how seeing all locations can help debugging, given 3/ - see
below
3/ We have the right place to store such informatin, namely TypeOrigin,
where we store locations associated with types where we merge them in
CFG. Currently, we store only "winner" - the most relevant locations
that contributed to nullability in the most informative way. We show
this to the user when we report an error.
4/ If we want to support more things (e.g. show something more to the user), TypeOrigin
seems to be the right place. Or, alternatively, we might still merge
locations in `range`, but this will be better to organize in a tree form
instead of flat list that is not really informative and helpful. It is
all speculative though since need to support things like that seems
unclear.
Reviewed By: artempyanykh
Differential Revision: D17857198
fbshipit-source-id: 6cf6e48a2
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 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:
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:
This is a preparation for coming introducing of Unknown nullability.
When this happens, a value will be able to be neither nullable, nor
non-nullable.
This will break many checks that implicitly assume "not nullable means non-null".
In this diff, we review all such checks and change them accordingly.
Reviewed By: artempyanykh
Differential Revision: D17600177
fbshipit-source-id: c38d87175
Summary:
It took a while for me to figure out what does this method do; the
reasons were:
1. a lot of names were cryptic and/or misleading
2. because everything is inline one needs to read everything to figure
out what is going on here.
So this diff changes the names a bit and moves some of methods outside.
This is still far not perfect, but I believe it is better than was
before.
Reviewed By: artempyanykh
Differential Revision: D17600175
fbshipit-source-id: ca7175b2e
Summary:
Eradicate.ml is way too big to reason about.
This diff is shallow, it does only the following:
1. Moves the module
2. Adds documentation in the header.
3. Exports two public methods as is
4. Adds corresponding params to all methods for values that were
captured in the module-as-closure before
Reviewed By: artempyanykh
Differential Revision: D17600173
fbshipit-source-id: ba7981228
Summary:
Now, that we consistently use `AnnotatedType`, `AnnotatedNullability`,
and `AnnotatedSignature`, `AnnotatedField` is a natural name for this
datatype.
Together `AnnotatedSignature` and `AnnotatedField` represent two entry
points for fetching information about Java type from the codebase.
Reviewed By: artempyanykh
Differential Revision: D17570534
fbshipit-source-id: 31ef52033
Summary:
1. This diff finishes the work of getting rid of using `Annot.Item.t`
for making judgements about nullability. Instead, `AnnotatedNullability`
is now used consistently in the codebase. Corresponding TODO items are
deleted.
2. This diff proceeds consolidating checks to `NullsafeRules` (which
will simplify introducing non-binary nullability in follow up diffs).
3. Code is simplified: we get rid of `fold2/ignore` + inlined
calculation of the param position in favor of
more straightward `zip` + `iteri` combo.
Reviewed By: artempyanykh
Differential Revision: D17570439
fbshipit-source-id: 52acf2c66
Summary:
This continues work of getting rid of using low-level Annot.Item.t in
favor of a new, more specific and flexible data structure.
Migrating this code further to NullsafeRules is bit tricky right now, so
let's defer it.
Reviewed By: ngorogiannis
Differential Revision: D17549479
fbshipit-source-id: 418b4b394
Summary:
This diff also introduces "subtyping function" into NullsafeRule, which
will be the core check for other rules we will introduce in follow up
diffs
Reviewed By: ngorogiannis
Differential Revision: D17500466
fbshipit-source-id: 5821caa6e
Summary:
As suggested by artempyanykh:
1. Since we recently introduced InferredNullability, AnnotatedNullability deserves its own class which now plays nicely with its counterpart.
2. AnnotatedType is more specific then NullsafeType
Reviewed By: artempyanykh
Differential Revision: D17547988
fbshipit-source-id: 785def23a
Summary:
This proceed the work of getting rid of Annot.Item.t.
This diff:
- Moves "check assignment rule" to recently supported NullsafeRules
- Implements their own "check overannotated" (defers consolidating this
check into NullsafeRule for the future diffs).
Note that we don't need PropagatesNullable logic anymore because it is
already ported to NullsafeType (return value will be marked as Nullable
in NullsafeType)!
implicit_nullable (a.k.a. Void types) will require a follow up diff to
model.
Reviewed By: artempyanykh
Differential Revision: D17499246
fbshipit-source-id: 14b473f29
Summary:
In nutshell, Nullsafe is driven by relatively simple set of rules.
It is currently not well reflected in code: we are duplicating the same logic in different places, which is:
- error prone (we need to adjust ensure all places are addressed if a new feature is introduced)
- complicates understanding of nullsafe
Consolidating checks will simplify introducing Unknown Nullability and
strict/partial check modes.
## this diff
This diff does it for one particular check.
See follow up diffs re that proceed consolidation.
## future diffs
Future diffs will:
- consolidate other checks that use 'assignment rule'
- introduce other rules, most notably 'dereference rule' and
'inheritance rule'
Reviewed By: artempyanykh
Differential Revision: D17498630
fbshipit-source-id: 079d36518
Summary:
Now, after series of modifications with TypeAnnotation, we are ready to
rename it to reflect what it means in the code.
See the documentation in the class for details.
Also:
- renamed methods for clarity
- added some documentation
- renamed local variables around the usages
Reviewed By: jvillard
Differential Revision: D17480799
fbshipit-source-id: d4408887a
Summary:
This continues work for eliminating Annot.Item.t from Nullsafe low-level
code.
The introduced function `from_nullsafe_type` is called when we infer
initial type of the equation based on the function or field formal signature.
Before that, we did it via reading the annotation directly, which
complicates the logic and making introducing Unknown nullability tricky.
## Clarifying the semantics of PropagatesNullable
This diff also clarifies (and changes) the behavior of PropagatesNullable params.
Previously, if the return value of a function that has PropagatesNullable params was
annotated as Nullable, nullsafe was effectively ignoring PropagatesNullable effect.
This is especially bad because one can add Nullable annotation based on the logic "if the function can return `null`, it should be annotated with Nullable`.
In the new design, there is no possibility for such a misuse: the code that
applies the rule "any param is PropagatesNullable hence the return
value is nullable even if not explicitly annotated" lives in NullsafeType.ml, so
this will be automatically taken into account.
Meaning that now we implicitly deduce Nullable annotation for the return value, and providing it explicitly as an alternative that does not change the effect.
In the future, we might consider annotating the return value with `Nullable` explicit.
Reviewed By: jvillard
Differential Revision: D17479157
fbshipit-source-id: 66c2c8777
Summary:
As per previous diff, attempt to allocate fewer strings. This doesn't
seem to affect perf although allocating less might reduce memory
pressure.
Reviewed By: mityal
Differential Revision: D17423973
fbshipit-source-id: e2e37b071
Summary:
1/ Nikos Gorogiannis pointed out that
- for highly reused public types, records (especially when >= 3 params) are generally more readable than tuples.
- Records simplify code modifications, especially adding new fields. And we are going to add some, namely param flags, in the future.
2/ Let's make the fact that annotated signature is deprecated more
visible; it will also simplify searching for usages when we will be
getting rid of them.
Reviewed By: ngorogiannis
Differential Revision: D17475033
fbshipit-source-id: 7740c979b
Summary:
`get_field_annotation` is (together with
`get_modelled_annotated_signature`) an entry point when Nullsafe fetches
annotation information.
In follow up diffs we are going to utilize added information; see also
TODO in the code
Reviewed By: ngorogiannis
Differential Revision: D17475034
fbshipit-source-id: dab77bc7b
Summary:
"Unannotated" is misleading and ambiguous concept, it can have different
meanings depending on agreements.
The current logic treats them as Nonnull, which is exactly what we want
to preserve.
(If we need to partially model some functions where we don't have
opinion on some of types in the signature, we can explicitly model
unknown nullability later on).
Note that I am not aiming for substantial refactoring of
modelsTables.ml; the scope of this diff is merely to clarify things.
Reviewed By: ngorogiannis
Differential Revision: D17449347
fbshipit-source-id: 43c798ce7
Summary:
This function is the main entry point for getting annotated signature
for nullsafe.
We will modify it and its callees in follow up diffs to migrate other
features of Annot.items to specialized types.
Reviewed By: ngorogiannis
Differential Revision: D17448082
fbshipit-source-id: be00b4737
Summary:
This is a central abstraction for coming future unknown nullability support.
# Context
Annot.ml is a low-level module:
- it contains lists of raw (string) annotations
- no algebraic datatypes for annotations
- it mixes annotations that Nullsafe should be aware of with all sorts of other annotations
- some annotations make sense for return values, some make sense for params, and some make sense for methods.
But, most importantly, it does not contain information about source of an annotation, making it hard to distinct things like "Nonnull as default" vs "Nonnull as explicitly annotated" vs "Nonnull as modelled". Ditto for nullable.
Because of this, it is tricky to introduce unknown nullability in an elegant way.
Let's get rid of using Annot.Item.t in nullsafe code in the following way:
- Move nullability information associated with the Java type to a dedicated algebraic DT.
- Split other annotations that are important for nullsafe into param flags, ret value flags, and method flags, and introduce corresponding datatypes.
# This diff
This diff introduces NullsafeType and adds this to AnnotatedSignature.
It is not used yet, hence the diff is a no-op.
In future diffs, we are going to (see also TODOs in the code):
- actually use this information instead of accessing Annot.item
- add more information to AnnotatedSignature
- remove Annot.item from AnnnotatedSignature
- when this is done, introduce notion of unknown nullability.
Reviewed By: ngorogiannis
Differential Revision: D17420595
fbshipit-source-id: b30706d9b
Summary:
We historically had Model.Inference, which was an attempt to enhance
models with additional abilities to get the annotation.
This feature got removed in D9805110, including removing of the key
condition Models.Inference.field_is_marked.
This code also is not executed: `Config.eradicate` condition
was an old artefact of migrating Eradicate to callback infrastructure:
D1508451. We run eradicate only as a callback as of now, so this flag is
always true.
In follow up diffs we refactor AnnotationSignature module, and this
cleanup simplifies the refactoring.
Reviewed By: ngorogiannis
Differential Revision: D17419173
fbshipit-source-id: 1b30555de
Summary:
CONDITION_REDUNDANT_NONNULL was an attempt to reduce number of false
positives for condition redundant. (It is the most popular check as of
now).
The root case for most of false positives is that a lot of code is
simply not annotated (but should have been), so blaming developers for defense programming is
not actionable.
In attempt to solve the problem, a special issue type (for case when the
code is explicitly annotated with Nonnull) was introduced.
In follow up diffs we are going to introduce a generic way of doing the
same, not limited to this particular check only.
Namely, we will introduce notion of unknown nullability, so it will be
possible to distinguish not annotated yet (hence no warnings) and already
annotated (hence warnings) parts of code.
This piece of logic is incompatible with the aforementioned work, hence
we need to remove it.
Reviewed By: jvillard
Differential Revision: D17398768
fbshipit-source-id: 8bddf10e5
Summary:
At some point, there was a custom equality function that deliberately ignored some fields in err_instance. It was deleted in D4232422, so having a custom hash function does not serve any purpose anymore.
Since 2016 there was no known problems with the change in D4232422.
If we decide that we need similar behavior that was before D4232422, it will be easier to reimplement the functionality again.
Reviewed By: jberdine
Differential Revision: D17313660
fbshipit-source-id: 5c6c29a0b
Summary:
This check was an incomplete attempt to make nullsafe check nutritious
annotations for fields that get modified.
This was never fully productionized, and this check is turned off by
default.
In near future, we don't anticipate supporting this feature, so let's
remove it to simplify the code.
Reviewed By: artempyanykh
Differential Revision: D17282015
fbshipit-source-id: d63a2f1f7
Summary:
There are currently plenty of ways to suppress the warning, including Inject, Initializer, and SuppressFieldNotInitialized annotations.
This one (annotating field with Nonnull) is counter-intuitive and does not align with gradual nullsafe
semantics we are working on.
Reviewed By: artempyanykh
Differential Revision: D17281702
fbshipit-source-id: 132e1b687
Summary:
This diff makes the checkers, except biabduction, to use `typ` instead
of `root_typ` of `Load`/`Store` statemetns.
Reviewed By: dulmarod
Differential Revision: D17203105
fbshipit-source-id: 8be9b5158
Summary:
It uses inline record for Sil.Load and Sil.Store for preparing the
following extention.
Reviewed By: dulmarod
Differential Revision: D17161288
fbshipit-source-id: 637ea7bfa
Summary:
This abstraction was not always used consistently.
Its usage made more sense when it supported both present annotations and
optional annotation (which got removed in previous diff).
The rought semantic of that was "what is the inferred type for such and
such value (variable or expression) in typestate". So it is not really
_annotation_ in first place, it is more like "what we inferred about
nullability given annotations, known special cases, and current sybmolic
execition state".
Let's explicitly rename `map` to `is_nullable`. If/when we need to
enhance this further (and we likely will), we will do it accordingly.
Reviewed By: jvillard
Differential Revision: D17153434
fbshipit-source-id: 3c85b56df
Summary:
`Present` annotation was an experiment made many years ago that never
got into real usage. The idea was to annotate Optional<> types with
Present, which means that it is safe to call get().
We don't plan to support `Present` annotation for optional types in the
near future.
Support of `Present` annotation requires extra levels of abstraction
that make the changing the behavior and introducing new features harder.
A lot of checks for nullability are written in generic way so they also
check for presense.
Getting rid of that will allow us to simplify our
work for introducing new semantics for nullsafe.
Reviewed By: ngorogiannis
Differential Revision: D17153432
fbshipit-source-id: c5ea9bdf1
Summary:
`nullsafe` currently allows the following:
```
public void Nonnull Object willBeOK() { return null; }
```
But disallows the following:
```
public void Object willBeAnIssue() { return null; }
```
This was a deliberate choice made back in 2014.
The motivation was to provide a way to tell the checker "I know it can not be null, trust me".
A huge problem with that approach is that it is extremely non-intuitive and surprising, and contradicts with pretty much everything when Nonnull or similar annotations are used in external world.
This is not the way how checkers should be supressed.
We do provide 2 options to express this intention, namely `assertNotNull` and `assumeNotNull` would do the thing.
This is a much better approach for additional reason: assertNotNull is
granular and applies only to the exact expression that is under
question. In contrast, suppressing the check on the whole function level
make any modifications of a function dangerous.
Reviewed By: artempyanykh
Differential Revision: D16984213
fbshipit-source-id: 0ba0f623b
Summary:
Summary.ml defines both a bunch of types and how to use them and a
mechanism to save and store summaries on disk while maintaining a
complex in-memory cache of what's on disk. Make the distinction clear.
Reviewed By: ngorogiannis
Differential Revision: D16358869
fbshipit-source-id: 9d4c6cb77
Mitya Lyubarskiy
Nikos Gorogiannis
Jules Villard
Sungkeun Cho