Summary: StarvationModels depended on StarvationDomain which is the wrong way around, and forbids using *Models from *Domain.
Reviewed By: mityal
Differential Revision: D17809431
fbshipit-source-id: 5aa369e7c
Summary: The type hierarchy was traversed multiple times when searching for annotations: once for methods/overrides annotated and once for superclasses. This can be done in one pass.
Reviewed By: dulmarod
Differential Revision: D17787172
fbshipit-source-id: 248dd4c27
Summary:
At some point it was thought that we can assume that any annotation starting with "On" means the method is on the UI thread.
That's too imprecise and has led to false positives and negatives. Restrict to a well-known safe set.
Reviewed By: ezgicicek
Differential Revision: D17769376
fbshipit-source-id: 0f8fee059
Summary:
Currently, lock state is a map from locks to stacks of lock acquisitions.
Since we now have the separate acquisitions component, we no longer need to
remember the stack of acquisitions for a lock. Instead we only need a lock count,
thus reducing the memory footprint.
At the same time, change acquire and release so that they make one tree operation per
component (map/acquisition) as opposed to two (search/update) operations.
Reviewed By: ezgicicek
Differential Revision: D17736727
fbshipit-source-id: 7579eb61e
Summary:
If we acquire n nested locks we end up with n critical pairs, and for each pair the held-locks component goes up linearly, thus total space/time is O(n^2).
If the sets of held-locks are constructed with maximal sharing (intuitively, if they derive from the same set by additions) then the total space/time is O(n logn).
To do this, we must avoid constructing a new set every time we ask what the currently held locks are. Here we maintain (care is needed in the presence of recursive locks) that set across lock acquisitons and removals.
Reviewed By: skcho
Differential Revision: D17736252
fbshipit-source-id: 0f9b292c4
Summary:
The old domain keeps two sets:
- `events` are things (including lock acquisitions) which eventually happen during the execution of a procedure.
- `order` are pairs of `(lock, event)` such that there is a trace through the procedure which at some point acquires `lock` and before releasing it performs `event`.
A deadlock would be reported if for two procedures, `(lock1,lock2)` is in `order` of procedure 1 and `(lock2,lock1)` is in `order` of procedure 2. This condition/domain allowed for the false positive fixed in the tests, as well as was unwieldy, because it required translating between the two sets.
The new domain has only one set of "critical pairs" `(locks, event)` such that there is a trace where `event` occurs, and *right before it occurs* the locks held are exactly `locks` (no over/under approximation). This allows keeping all information in one set, simplifies the procedure call handling and eliminates the known false positive.
Reviewed By: mityal
Differential Revision: D17686944
fbshipit-source-id: 3c68bb957
Summary:
Previously deduplication was always on which is not great for testing.
Also split tests so that we can still test deduplication separately.
Reviewed By: mityal
Differential Revision: D17686877
fbshipit-source-id: 280d91473
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:
Ideally the analyser should equate locks `this.x.f` and `a.x.f` in different methods if they can alias.
The heuristic removed here was rarely used and is in the way of a re-write of the analysis.
It was also badly implemented, as this should ideally be the comparison relation of `Lock`.
Reviewed By: mityal
Differential Revision: D17602827
fbshipit-source-id: 4f4576c1a
Summary: When we have an annotation like `Prop(varArg = X)` or ` ThreadSafe(enableChecks = true)`, we were not able to pick up the names of the parameters like `varArg` or `enableChecks`. This diff fixes that.
Reviewed By: skcho, ngorogiannis
Differential Revision: D17571377
fbshipit-source-id: 5293b5810
Summary:
Events can be many things, including lock acquisitions. Lock state keeps a set of events, all of which must be lock acquisitions.
Enforce this via the type checker by specialising the types so that lock state satisfies this by construction.
Reviewed By: ezgicicek
Differential Revision: D17571428
fbshipit-source-id: 2f5a33b98
Summary:
Instead of polluting the signature of trace endpoints, have
the call printer be a module argument to the functors
producing trace elements.
Reviewed By: skcho
Differential Revision: D17550111
fbshipit-source-id: ab5af94c6
Summary:
The access path format forced some weird patterns on this code, simplify
using the access expression structure.
Reviewed By: ezgicicek
Differential Revision: D16960660
fbshipit-source-id: e8faf619e
Summary:
Use whatever information we can to decide whether to use C or Java
syntax when outputting an access expression, now that we store them as
such.
Also, make cluster callbacks explicitly set the language, as this was not done before and led to some confusion (Clang being set when analysing a Java file).
Reviewed By: skcho
Differential Revision: D16884160
fbshipit-source-id: 40adf9f35
Summary:
Access paths are too coarse to properly address C/C++ instructions, and lead to false positives and negatives. Begin the process of porting the underlying domains to access expressions, in a results-preserving way. This roughly consists in:
- Adding missing functions in `AccessExpression` to mirror those in `AccessPath`.
- Replacing `AccessExpression` for `AccessPath` and removing conversions from the former to the latter except in:
- Printing functions, to ensure formatting issues won't change tests/CI.
- Reporting/deduplication still happens through access path conversion, as we need an analogue of `ModuloThis` for `AccessExpression`.
- In selected places, ignore any access type not present in `AccessPath` (ie. dereference/take address of).
Reviewed By: jberdine
Differential Revision: D16856721
fbshipit-source-id: 5e3a88b75
Summary: The pattern "check if an access has already been reported, otherwise see if it is a violation, report it, then add it to the set of reported accesses" is too much copy pasta. Push that into the reporting functions.
Reviewed By: ezgicicek
Differential Revision: D16859208
fbshipit-source-id: 5370efd41
Summary: I'm not entirely sure why this function was written in such a horrendous way :)
Reviewed By: skcho
Differential Revision: D16858396
fbshipit-source-id: d998e17f3
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
Summary:
The fields `tenv` and `integer_type_widths` can be obtained from the `exe_env` field of `proc_callback_args`
This commit removes the redundant fields
Reviewed By: ngorogiannis
Differential Revision: D16149520
fbshipit-source-id: d37526fd4
Summary:
Cluster checkers call `SummaryPayload.read` but set the `caller_summary` to correspond to the same summary as gives the `callee_pname`
This change introduces a new method `read_toplevel_procedure` that does not require a `caller_summary`, to be used by the cluster checkers
Reviewed By: ngorogiannis
Differential Revision: D16131660
fbshipit-source-id: 12caa1000
Summary:
Change the datatype `ProcData` to include a field of type `Summary.t` instead of a field of type `Procdesc.t`
This will enable a later commit to supply a summary to `Ondemand.analyze_proc_desc` and `Ondemand.analyze_proc_name`
Reviewed By: ngorogiannis
Differential Revision: D16121405
fbshipit-source-id: 342374121
Summary:
The record `proc_callback_args` (defined in `callbacks.ml`) contains the fields `proc_desc` and `summary`.
The field `proc_desc` is redundant because it can be obtained from `summary`.
This diff removes `proc_desc` and uses the summary to obtain it where needed.
Reviewed By: ngorogiannis
Differential Revision: D16090783
fbshipit-source-id: 5632d1f4a
Summary:
Bundle all non-semantic-bearing instructions into a `Metadata _`
instruction in SIL.
- On a documentation level this makes clearer the distinction between
instructions that encode the semantics of the program and those that are
just hints for the various backend analysis.
- This makes it easier to add more of these auxiliary instructions in
the future. For example, the next diff introduces a new `Skip` auxiliary
instruction to replace the hacky `ExitScope([], Location.dummy)`.
- It also makes it easier to surface all current and future such
auxiliary instructions to HIL as the datatype for these syntactic hints
can be shared between SIL and HIL. This diff brings `Nullify` and
`Abstract` to HIL for free.
Reviewed By: ngorogiannis
Differential Revision: D14827674
fbshipit-source-id: f68fe2110
Summary:
Add support for GuardedBy: we deviate from the spec as follows:
- No warnings issued for any access within a private method, unless that method is called from a public method and the lock isn't held when the access occurs.
- Warnings are suppressed with the general RacerD mechanism, ie `ThreadSafe(enableChecks=false)`
- GuardedBy warnings override thread-safety violation warnings on the same access, because GuardedBy has a clearer and simpler contract.
Also, some simplifications, cleanups and perf improvements (eg avoid unreportable procs at the top level as opposed to on each of their accesses).
Reviewed By: jeremydubreil
Differential Revision: D14506161
fbshipit-source-id: b7d794051
Summary:
Context: "quandary" traces optimise for space by only storing a call site (plus analysis element) in a summary, as opposed to a list of call sites plus the element (i.e., a trace). When forming a report, the trace is expanded to a full one by reading the summary of the called function, and then matching up the current element with one from the summary, iterating until the trace cannot be expanded any more. In the best case, this can give a quadratic saving, as a real trace gets longer the higher one goes in the call stack, and therefore the total cost of saving that trace in each summary is quadratic in the length of the trace. Quandary traces give a linear cost.
HOWEVER, these have been a source of many subtle bugs.
1. The trace expansion strategy is very arbitrary and cannot distinguish between expanded traces that are invalid (i.e., end with a call and not an originating point, such as a field access in RacerD). Plus the strategy does not explore all expansions, just the left-most one, meaning the left most may be invalid in the above sense, but another (not left-most) isn't even though it's not discovered by the expansion. This is fixable with major surgery.
2. All real traces that lead to the same endpoint are conflated -- this is to save space because there may be exponentially many such traces. That's OK, but these traces may have different locking contexts -- one may take the lock along the way, and another may not. The expansion cannot make sure that if we are reporting a trace we have recorded as taking the lock, will actually do so. This has resulted in very confusing race reports that are superficially false positives (even though they point to the existence of a real race).
3. Expansion completely breaks down in the java/buck integration when the trace goes through f -> g -> h and f,g,h are all in distinct buck targets F,G,H and F does not depend directly on H. In that case, the summary of h is simply not available when reporting/expanding in f, so the expanded trace comes out as truncated and invalid. These are filtered out, but the filtering is buggy and kills real races too.
This diff completely replaces quandary traces in RacerD with plain explicit traces.
- This will incur the quadratic space/time cost previously saved. See test plan: there is indeed a 30% increase in summary size, but there is no slowdown. In fact, on openssl there is a 10-20% perf increase.
- For each endpoint, up to a single trace is used, as before, so no exponential explosion. However, because there is no such thing as expansion, we cannot get it wrong and change the locking context of a trace.
- This diff is emulating the previous reporting format as much as possible to allow good signal from the CI. Further diffs up this stack will remove quandary-trace specific things, and simplify further the code.
- 2 is not fully addressed -- it will require pushing the `AccessSnapshot` structure inside `TraceElem`. Further diffs.
Reviewed By: jberdine
Differential Revision: D14405600
fbshipit-source-id: d239117aa
Summary:
In ObjC there are no access modifiers. The strongest alternative is to put methods in the implementation but omit them from the interface declaration.
Put exported ObjC methods in their own field in the class structure and use that in RacerD to decide whether to report on the method.
Reviewed By: mbouaziz
Differential Revision: D13597504
fbshipit-source-id: c4a3d2705
Summary:
A lot of functors that take a `Make{SIL,HIL}` can take a `{SIL,HIL}`
directly instead. This makes my head hurt a bit less.
Reviewed By: mbouaziz
Differential Revision: D13416967
fbshipit-source-id: eb0b33bc4
Summary:
`AccessExpression.t` and `HilExp.t` are about to become mutually
recursive, this will help distinguish the actual changes from the moving
of code around.
This deletes the file left around in the previous commit to preserve
callers of `AccessExpression`.
Reviewed By: mbouaziz
Differential Revision: D13377645
fbshipit-source-id: 71338d1f3
Summary:
It's useful for checkers to know when variables go out of scope to
perform garbage collection in their domains, especially for complex
domains with non-trivial joins. This makes the analyses more precise at
little cost.
This could have been added as a custom function call to a builtin, but I
decided against it because this instruction doesn't have the semantics
of any function call. It's better for each checker to explicitly not
deal with the custom instruction instead.
Reviewed By: jberdine
Differential Revision: D13102951
fbshipit-source-id: 33be22fab
Summary:
Currently, if there are several reports on the same line, the most important one is reported together with a message containing how many reports were suppressed.
This is sometimes causing the bug hash we use believe that a report is introduced (eg if the number of suppressed reports changes).
Reviewed By: mbouaziz
Differential Revision: D13067306
fbshipit-source-id: 1cc0c6d3a
Summary:
The upcoming ocamlformat has the ability to parse and format
docstrings. This requires that the docstrings conform to the ocamldoc
spec a bit more strongly. If a docstring does not parse, it is left
alone, but if it is morally ill-formed but parses by chance, it can be
reformatted incorrectly. This patch fixes the existing instances of
this problem.
Reviewed By: mbouaziz
Differential Revision: D12911937
fbshipit-source-id: 1c2eb590b
Summary:
There were several lists constructed unnecessarily -- replaced them with find_maps
and hopefully simplified the logic.
Reviewed By: mbouaziz, jvillard
Differential Revision: D12823559
fbshipit-source-id: 1f06b20f3
Summary: To avoid reporting on private methods, ignore those starting with underscore. Other cleanups.
Reviewed By: jvillard
Differential Revision: D10558970
fbshipit-source-id: 0572f1e70
Summary: Reports will now be issued for the class loads of the methods specified by the option `--class-loads-roots`.
Reviewed By: jvillard
Differential Revision: D10466492
fbshipit-source-id: 91456d723
Summary: Since we only care about reachability, drop the interpreter and just fold over all instructions in the procdesc.
Reviewed By: mbouaziz
Differential Revision: D10461783
fbshipit-source-id: 3e0b42a48
Summary: We don't need the machinery of HIL, or its complexity for this analysis.
Reviewed By: ddino
Differential Revision: D10461641
fbshipit-source-id: 2e7d3ab8e
Summary: First version of an analyzer collecting classes transitively touched.
Reviewed By: mbouaziz
Differential Revision: D10448025
fbshipit-source-id: 0ddfefd46
Summary: Even though we recognize the lock/unlock methods of various classes in C++, to report we insist that the class must have a `mutex` member. Equalize the two sets of types recognized.
Reviewed By: da319
Differential Revision: D10446527
fbshipit-source-id: f42ae1a35
Summary:
Use same code for deciding whether two accesses conflict across java/clang, by adapting that of the clang version.
Eliminate/simplify some code.
Reviewed By: mbouaziz, jberdine
Differential Revision: D10217383
fbshipit-source-id: dc0986d05
Summary:
An order constraint (A,B) means we take lock A and before releasing it we perform B (whatever that is).
Previously if a method call crossed class boundaries, we removed the callee's order constraints before integrating the callee's summary to that of the caller. The reasoning was that this may lead to reports blaming a caller for something they are very far from, plus a proliferation of reports with the same bad endpoint.
The first reason still applies, but this is a general problem. It may be better to report and let developers deal with it.
The second reason is moot, since in differential mode most of these reports are hidden.
Reviewed By: jberdine
Differential Revision: D10173200
fbshipit-source-id: 9afbf292c
Summary:
Make distinct reports on strict mode violations.
For now, restrict to direct violations (UI threads calls transitively a violating method).
Will assess impact and enable indirect reports later (via locks).
Reviewed By: mbouaziz
Differential Revision: D10126780
fbshipit-source-id: 9c75930bc
Summary: Option is not needed, just set `default` record to agree with function default arguments.
Reviewed By: da319
Differential Revision: D10050463
fbshipit-source-id: e7d13bbd5
Summary:
The 2nd iteration of analysis of the Android core implementation did not yield actionable models, so delete those.
Turn on strict-mode reporting by default, when doing starvation analysis (which is disabled by default).
Reviewed By: jvillard
Differential Revision: D9991448
fbshipit-source-id: 67504591d
Summary: We may want to use these traces more generally, so put them into their own module.
Reviewed By: mbouaziz
Differential Revision: D10084404
fbshipit-source-id: 8f87c17f4
Summary:
The method matcher is now used sufficiently it warrants refactoring out into its own module.
Also, kill dev-android-strict-mode and leave starvation-strict-mode as the stronger option.
Reviewed By: jeremydubreil
Differential Revision: D9990753
fbshipit-source-id: 626a70a19
Summary: There may be several reasons why we think a method is on the UI thread. Choose to keep the shortest via join.
Reviewed By: jeremydubreil
Differential Revision: D9806944
fbshipit-source-id: 89d27456d
Summary: Sometimes it's very confusing to see why infer believes a method is running on the UI thread. Make a trace out of all the relevant info.
Reviewed By: mbouaziz
Differential Revision: D9781212
fbshipit-source-id: 6d018e400
Summary:
Turn off by default until mature enough.
Also rename the dev-strict-mode test dir to highlight the dev part.
Reviewed By: mbouaziz
Differential Revision: D9775571
fbshipit-source-id: c3a41bbdf
Summary:
First step in writing an analyzer that is meant to run only on Android core library implementation.
This will, when finished, compute the library entrypoints that may lead to a strict mode violation.
The normal analyzer will use those to statically flag strict mode violations in app code.
Strict Mode is an Android debug mode, where doing certain things (like disk read/write or network activity) on the UI thread will raise an exception. We want to statically catch these, as well as indirect versions (the UI thread takes a lock and another thread holding that lock calls a method that would be a strict mode violation).
Reviewed By: mbouaziz
Differential Revision: D9634407
fbshipit-source-id: c30bcedb3
Summary:
- changes the `Ondemand` callbacks to take the execution environment instead of a `get_proc_desc` function.
- removes all the cases passing `get_proc_desc` as parameter to use `Ondemand.get_proc_desc` instead.
Reviewed By: jvillard
Differential Revision: D9200583
fbshipit-source-id: d16c218b5
Summary: Treat calls to Thread.sleep as blocking, even when the timeouts are less than the ANR limit.
Reviewed By: da319
Differential Revision: D9027950
fbshipit-source-id: 001409896
Summary:
The current message is confusing when the current class is marked UIThread.
See picture attached to task.
Reviewed By: jeremydubreil
Differential Revision: D8996593
fbshipit-source-id: cf52ee5d6
Summary:
Guava subclasses Future in ways that make .get() calls safe from the UI thread.
Treat such methods as skip.
Reviewed By: jeremydubreil
Differential Revision: D9013475
fbshipit-source-id: 38373aa5f
Summary:
Litho uses an idiom as follows. `Component.Builder` has an abstract method `T getThis()` which is supposed to be implemented as `{return this;}`.
I believe the reason it's there is to have covariant return types in subclasses, though this doesn't really matter.
We don't do dynamic dispatch, so instead of summarising `getThis` as having a return ownership of `OwnedIf({ 0 })` we just return `Unowned`.
This is generating many false positives, which are really hard to debug.
Here I'm special-casing any abstract method whose return type is equal to that of it's only argument, to return conditional ownership.
Reviewed By: da319
Differential Revision: D8947992
fbshipit-source-id: 33c7e952d
Summary: `ownership_of_expr` is already doing some of the work in `propagate_return`. Also, split and move into abstract domain, where it belongs.
Reviewed By: jeremydubreil
Differential Revision: D8855257
fbshipit-source-id: 7756552d8
Summary:
Currently, some blocking calls are turning up too many false positives. Adjust severities by fix rate/preexisting numbers.
Also, restrict some calls to exact class, as opposed to superclasses.
Reviewed By: mbouaziz
Differential Revision: D8850599
fbshipit-source-id: 47543d04a
Summary:
Do no computation of stability abstract state if not explicitly requested via the command line flag.
Also, simplify the reporting.
Reviewed By: jeremydubreil
Differential Revision: D8614885
fbshipit-source-id: 25dd9de
Summary:
- Do not add actuals of a call as unstable.
- Replace access trie with simple set of paths, which is easier to debug/argue correct.
- Fix bug where a prefix path was searched, as opposed to a *proper* prefix.
- Restrict interface to the minimum so that alternative implementations are easier.
Reviewed By: ilyasergey
Differential Revision: D8573792
fbshipit-source-id: 4c4e174
Summary: C/C++ code can, in some cases, generate a large number of temporary (Sil) variables. Since we are already not reporting races on these, not recording them gives some perf back.
Reviewed By: mbouaziz, jvillard
Differential Revision: D8566999
fbshipit-source-id: 148ac46
Summary: Trying to convert a large int literal to an OCaml int raises an exception. The use case here actually needed a float anyway, so add an API for that.
Reviewed By: jeremydubreil
Differential Revision: D8550410
fbshipit-source-id: 382495b
Summary:
The execution environment is really just a cache. It happens to point to a
particular source file which is where the analysis was started from, but that
is not relevant, and in fact is confusing because it suggests that it is
somewhat tied to that file. In reality, exe_env caches information about any
procedure and source file encountered by the analysis.
This will make it easier to make further changes but I think it also brings a
bit more clarity to the code.
Reviewed By: jeremydubreil
Differential Revision: D8513735
fbshipit-source-id: f4b38ce
Summary: Code auto generated by annotation processors or by the compiler is creating non-actionable reports, so skip it for now.
Reviewed By: jeremydubreil
Differential Revision: D8395781
fbshipit-source-id: 9832814
Nikos Gorogiannis
Ezgi Çiçek
Jules Villard
Phoebe Nichols
Artem Pianykh
Josh Berdine
Mehdi Bouaziz
Jeremy Dubreil
Calascibetta Romain
Nikos Gorogiannis