Summary:
By and large issues of a given type (eg NULL_DEREFERENCE) are always
reported with the same severity (eg ERROR), but that severity is hard to
tease out from the code. This makes it more explicit by favouring the
default in `IssueType.t` in many cases without changing infer's
behaviour. The checkers typically use `Reporting.log_{error,warning}`;
these are taken care of in the next diff.
Reviewed By: skcho
Differential Revision: D21904590
fbshipit-source-id: 47c76cd4c
Summary:
- "visibility" (whether an issue to report is something to show the user
or something that is only used for debugging or for detecting other
issues) is an intrinsic property of an issue type and thus belongs in
`IssueType.t`.
- "severity" (warning/error/...) is something that each issue should
have a default for ("a memory leak is by default an ERROR", a
"condition always true is by default a warning"), but can also be
overriden at run-time. Right now only nullsafe uses that capability:
when in "strict mode", some warnings become errors. We can imagine
extending this to other issue types, or even providing config flags to
turn warnings into errors, like compilers often have.
To guess the default severity (since it's dynamic it can be hard to know
for sure!), I tried to find places where it was reported as the source
of truth, but also later diffs test these defaults against our tests (by
removing most of the dynamic changes in severity).
With this diff there are 3 places where severity is set:
1. The default severity in IssueType.t: this is unused for now.
2. The severity from `Exceptions.recognize_exception`: this is
semi-statically determined and, if set, takes precedence over number 3 (which looks wrong to me!)
3. The severity passed to `Errlog.log_issue` when we actually add an
issue to the error log: this is used only when (2) is unset.
The next diffs will make 1 the default, delete 2, and make 3 optional
but override 1 when passed.
Reviewed By: skcho
Differential Revision: D21904538
fbshipit-source-id: a674b42d8
Summary:
The Java frontend translates java field accesses on an object reference as field (`.`) followed by dereference (`*`) exactly like the arrow operator in C. However, when the field is static, it generates just a field access `.`. This is a bug.
This diff mitigates its effects for printing locks in starvation.
Reviewed By: skcho
Differential Revision: D21882875
fbshipit-source-id: 79846d826
Summary: Add models for `View` methods that schedule on the UI thread.
Reviewed By: skcho
Differential Revision: D21767954
fbshipit-source-id: 015441ea7
Summary:
Add an extra argument everywhere we report about the identity of the
checker doing the reporting. This isn't type safe in any way, i.e. a
checker can masquerade as another. But, hopefully it's enough to ensure
checker writers (and diff reviewers) have a chance to reflect on what
issue type they are reporting.
Reviewed By: ngorogiannis
Differential Revision: D21638823
fbshipit-source-id: b4a4b0c0a
Summary:
The global analysis is doing funky stuff directly with `Summary.OnDisk`.
In order to make starvation/ its own dune library this part needs to
either use ondemand or moved elsewhere. Let's do the latter for now to
avoid changing the behaviour in the middle of the refactoring.
Reviewed By: ngorogiannis
Differential Revision: D21425699
fbshipit-source-id: ab9e2f429
Summary:
Needed to move a bunch of files around to make this happen. Notably,
moving "preanal.ml" outside of checkers/ into backend/ since it needs to
modify the proc desc in the summary. Also hoisting goes to cost/.
Reviewed By: skcho
Differential Revision: D21407069
fbshipit-source-id: ebb9b78ec
Summary: The contract for reporting races in C++ is to flag races between writes under lock with reads without a lock. This diff restores that contract which had been violated by recent changes.
Reviewed By: jberdine
Differential Revision: D21383876
fbshipit-source-id: 6a84e1506
Summary: As per title. Also, hide most deduplication functionality inside a module.
Reviewed By: skcho
Differential Revision: D21382377
fbshipit-source-id: d979f5b54
Summary:
Looks like this one was already causing circular dependency issues!
Saves threading the callback through *many* functions.
Reviewed By: ngorogiannis
Differential Revision: D21261636
fbshipit-source-id: 2b23aa07d
Summary:
`ProcData.t` contains a `Summary.t`. Eventually we want to fix this too
so that checkers don't depend on backend/, i.e. on all the other
checkers via Summary.ml. But in order to migrate progressively we can
first migrate absint/ and one step on the way is for it to not know what
kind of analysis data it is passing around.
This extra flexibility only costs us passing an extra `Procdesc.t` in a
couple more functions so it's actually not a bad change in itself.
Reviewed By: ngorogiannis
Differential Revision: D21257466
fbshipit-source-id: a91f7b191
Summary: The transition function was using a complicated-looking and possibly-inefficient pattern of options for everything, when simple pattern matching with guards is sufficient.
Reviewed By: skcho
Differential Revision: D21179606
fbshipit-source-id: a37f97594
Summary: Specialise the above option to `true` and remove resulting dead code.
Reviewed By: dulmarod
Differential Revision: D21177041
fbshipit-source-id: 4a1c65850
Summary: Java has this pattern of wrapping non-thread-safe containers in factory methods producing identically-typed results, but wrapped in a synchronised shell. This diff teaches RacerD about some common factory methods and uses the attribute domain to track the dynamic type of their results.
Reviewed By: ezgicicek
Differential Revision: D21155538
fbshipit-source-id: 42ebe6251
Summary: Complete the set of models for java containers that Infer should not report thread safety violations.
Reviewed By: ezgicicek
Differential Revision: D21138280
fbshipit-source-id: 01e1944b6
Summary: Models were partial and/or simply missing (`Map` writes!). Now the modelled containers use inheritance for conciseness (`List` reads are only those not caught by the `Collection` matcher, etc). Also, add URLs to documentation sources.
Reviewed By: ezgicicek
Differential Revision: D21132069
fbshipit-source-id: fefb360f0
Summary:
One source of false positives on container races is when the container member field is initialised to a concurrent version in a constructor, but the static type of the field doesn't reflect the thread safety of it.
This solution
- tracks flows from constructors of safe data structures to abstract addresses;
- initialises the initial attribute state when analysing a non-constructor method to that achieved by all constructors/class-initializers.
- checks for that attribute when recording container accesses.
Reviewed By: jvillard
Differential Revision: D21089428
fbshipit-source-id: 02a88f6e8
Summary:
Now that only races rooted at formals or globals are reported, there is no point using the ownership domain to exclude accesses to locals, so remove the code that initialises the ownership of those.
Also, remove an accidentally quadratic use of `Map.bindings |> List.find` in `FormalMap` and simplify the analysis driver.
Reviewed By: skcho
Differential Revision: D21066855
fbshipit-source-id: 126080778
Summary: Move state to summary conversion into the domain file, move a model matcher into the models file and simplify.
Reviewed By: skcho
Differential Revision: D21064351
fbshipit-source-id: bb5b07b6b
Summary:
The full inventory of everything in infer-out/. The main change is
around "issues directories": instead of registering them dynamically
they are now all declared statically (well, they kind of were already in
Config.ml).
Reviewed By: ngorogiannis
Differential Revision: D20894305
fbshipit-source-id: 1a06ec09d
Summary:
Fix all the docstrings that `odoc` or `ocamlformat` is not happy about.
Delete all `[@@ocamlformat "parse-docstring = false"]` pragmas as a
result.
Reviewed By: jberdine, ngorogiannis
Differential Revision: D20798913
fbshipit-source-id: 728d9e45c
Summary:
`IssueLog` is used by the file-level analysis callbacks to store reports outside error logs so as to avoid racing on spec files. Each file should generate a single issue log which is then written to an appropriate file. The starvation checker was breaking that contract because it ostensibly needs to write out multiple issue files when analysing a single source file.
This is unnecessary, because the existing mechanisms for deduplication ensure only one issue file needs to be written out.
The whole-program mode still needs that capability, but this is implemented outside the file-analysis callback.
Reviewed By: mityal
Differential Revision: D20736135
fbshipit-source-id: 620e5484d
Summary:
The text is ambiguous because it sounds as if it recommends annotating the current class as `ThreadSafe`, not the interface invoked.
Also, remove the not useful part "or using an interface known to be thread-safe" because developers don't know in general what interfaces Infer thinks are thread-safe.
Reviewed By: skcho
Differential Revision: D20675729
fbshipit-source-id: 9da438621
Summary:
Morally, INTERFACE_NOT_THREAD_SAFE is issued when an interface method is invoked from `ThreadSafe`-annotated code on an interface that is not known to be thread-safe or annotated so.
However, the ultimate purpose is to prevent races. Thus it should never be issued on an owned object or on objects we would not report races on for any reason (local variables, non-source variables, etc).
This diff equips interface call records with the abstract address they are invoked on, and uses the same rules for maintaining those records or not.
Reviewed By: skcho
Differential Revision: D20669259
fbshipit-source-id: 6c7841e6a
Summary:
For historical reasons, the record of an access is a three-level record:
1. `AccessSnapshot`, a record with info such as ownership and lock status, including
2. `TraceElem`, a record with a trace and an element which is
3. Access, the abstract addressed accessed and the type of access.
This stack flips the order to 2, 1, 3, leading up to the possibility of merging 1 and 3.
This diff improves the domain interface and consolidates all the various validity invariant checking for accesses inside their constructors.
Reviewed By: skcho
Differential Revision: D20668611
fbshipit-source-id: 45806d40d
Summary:
For historical reasons, the record of an access is a three-level record:
1. `AccessSnapshot`, a record with info such as ownership and lock status, including
2. `TraceElem`, a record with a trace and an element which is
3. Access, the abstract addressed accessed and the type of access.
This stack flips the order to 2, 1, 3, leading up to the possibility of merging 1 and 3.
This diff inverts 2 and 1.
Reviewed By: skcho
Differential Revision: D20644100
fbshipit-source-id: 89d810b68
Summary:
For historical reasons, the record of an access is a three-level record:
1. `AccessSnapshot`, a record with info such as ownership and lock status, including
2. `TraceElem`, a record with a trace and an element which is
3. `Access`, the abstract addressed accessed and the type of access.
This stack flips the order to 2, 1, 3, leading up to the possibility of merging 1 and 3.
This diff introduces functions in (1) that mask calls to (2), making the flip easier.
Reviewed By: skcho
Differential Revision: D20619614
fbshipit-source-id: 19fda0916
Summary: There are no plans currently to track which lock protects each access, so reduce to the functional equivalent of having a singleton lock domain.
Reviewed By: skcho
Differential Revision: D20595013
fbshipit-source-id: d5100ac49
Summary:
This function is used to adapt the callee summary at a call site. It did two things for every domain element in the callee summary:
- A linear search through the list of actuals.
- For each such actual, it would (repeatedly) compute its ownership (!).
For large summaries this can be substantial. The right way is to precompute the ownership for all actuals once and then simply retrieve it (via an array).
Reviewed By: jberdine
Differential Revision: D20564447
fbshipit-source-id: 1ca3121c2
Summary: The attribute types present are exclusive, so sets are not needed for the attribute map domain. This changes `Attribute` to a flat domain and removes the set on top of that.
Reviewed By: jberdine
Differential Revision: D20560240
fbshipit-source-id: 83e59d73e
Summary:
Both modules define properties the analysis maps to addresses, there is no reason to have two modules for this.
Also remove an instance of `Caml.Not_found` usage.
Reviewed By: jberdine
Differential Revision: D20558683
fbshipit-source-id: eacafd780
Summary: There has never been a sufficient formal basis for soundness nor completeness of reports on locals. This diff changes the domain to effectively concern only expressions rooted at formals or globals.
Reviewed By: ezgicicek
Differential Revision: D19769201
fbshipit-source-id: 36ae04d8c
Summary:
# Current design
Infer analysis is currently two staged:
1) proc-level callbacks calculate summary, including writing down the
issues if applicable.
2) file-level callbacks (formerly cluster callbacks, see the prev diff) are executed next; they are supposed to emit
additional issues that are impossible to emit based on mere
proc-context.
Currently RacerD and Starvation use file-level callback; in near future
we plan to onboard Nullsafe checker as well.
# Problem
Contract of callback (1) is clear: given a proc and existing
summary, the checker updates it and returns a modified summary. This
summary later on gets serialized (in-memory + external) and can be consumed by
other chechers. Issues written in summary will get reported when
analysis is over.
In constrast, contract of (2) is wild west: the function returns unit.
In practice, what the checkers do is create IssueLog and serialize it to
checker-specific directory.
Then another part of program (InferPrint.ml) knows about this side
effect, reads the error log for checkers and ultimately get it reported
together with errors written at stage (1).
This is problematic because it is hard to reason about the system and it
makes onboarding new checkers to (2) error-prone.
# This diff
This diff brings (2) on par with (1): now file-level callback has a
clear contract: it should be side effect free, and the only
responsibility is to fill out and return IssueLog.
Additionally, we make the notion of "checker-specific issue directory"
an official thing, so the checker only needs to specify the name,
everything else will be made automatically by orchestation layer,
including cleanup.
# Starvation
Implementing the new contract is starvation is possible and desirable, but involved: see comment
in the code, so we leave it up to the future work to fix that.
Reviewed By: ngorogiannis
Differential Revision: D20115024
fbshipit-source-id: fb2f9b7e6
Summary:
1. Some invariants are tricky enough to be documented. This is especially
important for cases related with error reporting. Lets document it.
2. Cluster callback -> File callback rename.
Reviewed By: ngorogiannis
Differential Revision: D20093932
fbshipit-source-id: e716f1f5b
Summary:
Previous implementation supported only stringy params (strings and
stringified bools). Current one exposes a proper variant `Annot.t`,
with support for all possible param values in Java except
numbers (more on that below).
This change is required for implementing `Nullsafe(LOCAL)` as the
annotation used to specify nullsafe behaviour has a more complex
structure than what we've dealt with before.
**Why support for number values was not added**: supporting numbers
requires using `int64`. Unfortunately, adding another variant `Vnum
int64` to `Annot.t` causes a runtime failure on assert in
`MaximumSharing.ml:133`. It seems that it might be enough to flip
`fail_on_nonstring` from `true` to `false`, but since this would
require additional testing and is not required for my case, I'll leave
checking this to whoever needs to use numeric annot params in future.
Reviewed By: ezgicicek
Differential Revision: D19855923
fbshipit-source-id: 878e33856
Summary:
The big one:
- stop using polymorphic `<>`, `<`, `>`, ..
- add `<>` to `PolyVariantEqual` escape hatch now that `<>` is as taboo as `=`
- Interestingly, there were a lot of uses of `Z.(x < y)`, which although
they seem to use `Z.lt` actually used polymorphic comparison. The actual
comparison infix operators of `Z` are cleverly hidden in `Z.Compare`
instead, which makes them impractical to use...
Reviewed By: jberdine
Differential Revision: D19861584
fbshipit-source-id: 5dce08ad9
Summary:
The domain has a notion of lock state (taken/not taken) and any access occurring will remember the current lock state.
Methods in Java can be `synchronized` meaning the lock is taken automatically at method start and release on return.
Currently, instead of starting analysis of a `synchronized` method with an initial lock state of "lock taken", the summary would be computed as if there is no lock, and then a caller would peek at whether the callee is `synchronized` and change the callee summary accordingly before taking it into account. Also, when an access happens (not a call) the analysis always consults the pdesc of the current method to check whether the method is `synchronized`.
Do things the right way: if method is `synchronized`, start with the lock taken. When the method exits, the lock-state postcondition is computed by releasing once the lock.
This is a behaviour-preserving change.
Reviewed By: mityal
Differential Revision: D19742559
fbshipit-source-id: 1d0fce3f6
Summary:
The goals are:
- Increase precision in C-languages by ditching access paths.
- Help with eventually sharing the abstract address module with RacerD.
- Reports are now language-mode specific (eg `->` in clang vs `.` in Java).
It's not exactly access expressions used here. Instead the pattern `(base, access list)` is used where `access` is `HilExp.Access.t`. This is done to ease the way `deriving` is used for creating two comparison functions, one that cares about the root variable and one that doesn't; and also because the main function that recurses over accesses (`normalise_access_list`) visits the accesses from innermost to outermost.
Also, kill some dead code.
Reviewed By: skcho
Differential Revision: D19741545
fbshipit-source-id: 013bf1a89
Summary:
The problem with is_override that it can be misleading: it does not
check that that class of the first method is a subtype of the second; in
fact it totally ignores the classes.
This method is publicly exposed so lets just call what it does.
Reviewed By: jvillard
Differential Revision: D19724295
fbshipit-source-id: dc0919193
Summary:
To emulate the `ThreadSafe` contract in C++/ObjC, reporting was gated behind a check that ensured a C++/ObjC class has a `std::mutex` member (plus other filters). This is reasonable, but it has some drawbacks
- other locks may be used, and therefore must be added to the member check;
- locking mechanisms that use the object itself as a monitor cannot be modelled (`synchronized` in ObjC)
RacerD already has `ThreadsDomain` which models our guess on whether a method is expected to run in a concurrent context, and which in C++/ObjC boils down to whether the method non-transitively acquires a lock. This should be a good enough indicator that the class should be checked regardless of whether the locks are member fields. This diff gates the C++/ObjC check on that abstract property.
Reviewed By: dulmarod
Differential Revision: D19558355
fbshipit-source-id: 229d7ff82
Jules Villard
Nikos Gorogiannis
Josh Berdine
Ezgi Çiçek
Mitya Lyubarskiy
Artem Pianykh