Summary:
This diff revises memory model of enumerator in ObjC to enable passing it as a parameter.
The cost checker was not able to analyze a function precisely when it gets an enumerator as a
parameter because the offset of an enumerator was available only when the analyzer knew the correct
relation between the enumerator and an array.
This diff simplifies the enumerator to have a similar value with `array->elements`, so its offset can
be taken without the relation between enumerator and array to get them.
Reviewed By: ezgicicek
Differential Revision: D24446574
fbshipit-source-id: 27cdc051e
Summary:
This diff adds an option hiding function pointers in costs to users: `cost-suppress-func-ptr` is
true by default.
Reviewed By: ezgicicek
Differential Revision: D24448212
fbshipit-source-id: 88f6b5ea1
Summary:
This diff adds a model for NSFileManager.contentsOfDirectoryAtURL as returning a constant-length
collection.
The analyzer cannot know files in a directory. We have some options to handle such unknown data.
1. Use `Unknown` value, ie `top`
2. Use a symbolic value
3. Use a constant value
We had been used the first option. An upside of this is that the analyzer can remain as sound.
However, a downside of this is the top value can be propagated to other procedures, making their
costs top, thus we may miss some cost changes of them.
The second option is to introduce a symbolic value, ie. that for the number of files. A problem is
that the symbolic value will never be concretized. As a result, the symbol can be propagated to
other procedures, increasing the coefficient of the complexity or making top costs. Note that handling multiple
symbols is somewhat limited in Inferbo's interval domain.
The last option is to introduce a constant value. I think this is the best approach we can take among above.
Even though we may have FNs when there are a lot of files in a directory, we cannot reason or expect about
that at the analysis time anyway.
Reviewed By: ezgicicek
Differential Revision: D24418099
fbshipit-source-id: bf8cf3538
Summary: This diff adds closure symbols to operation/allocation costs, when function pointer is called.
Reviewed By: ezgicicek
Differential Revision: D24308550
fbshipit-source-id: 6c5889d41
Summary:
This diff extended the polynomial domain to include symbols for closure calls.
When the closure symbol is added to the polynomial? Unknown closure is called inside a function
like,
```
foo() {
self->closure_field();
}
```
Thus, the cost of `foo` becomes `|self->flosure_field|`, rather than unknown. (Note that this
semantics is added only for autoreleasepool size at the moment.)
When the symbol is instantiated? `foo` is called with correct closure contexts.
```
goo() {
self->closure_field = ^(){ ... };
foo();
}
```
The summary of `goo` will have instantiated summary of the closure.
Reviewed By: ezgicicek
Differential Revision: D23992590
fbshipit-source-id: d1d228403
Summary:
In ObjC, `NSObject.copy` returns the object returned by `copyWithZone:` on the given class. This method must be implemented if the class complies with `NSCopying` protocol. Since we don't have access to `NSObject`'s code, to follow calls into `copyWithZone:`, we replace such `copy` calls with calls to `copyWithZone:` when a) such a method exists in the class and b) the class conforms to `NSCopying` protocol.
This is done in the preanalysis because
- we need to know if there is a `copyWithZone:` method in the class.
- so that other analyses also benefit (as opposed to doing this in cost and inferbo models).
Note that `NSObject` doesn't itself conform to `NSCopying` but all its subclasses must confrom to the protocol and support the same behavior as above.
https://developer.apple.com/documentation/objectivec/nsobject/1418807-copy
Similarly for `mutableCopy` -> `mutableCopyWithZone:` for classes implementing `NSMutableCopying` protocol.
Reviewed By: skcho
Differential Revision: D24218102
fbshipit-source-id: 42900760e
Summary: Model it similar to `NSArray.initWithArray` as copying from the given dictionary elements. Removes a FP as expected.
Reviewed By: ngorogiannis
Differential Revision: D24136868
fbshipit-source-id: ed31c3c8f
Summary:
This diff extends inferbo's domain to include closure values. The goal of this extension is to
follow missing semantics where closures are handled as values, for example, a closure is assigned to
an object field, then it is got later to call.
Due to the bottom-up nature of the analyzer, sometimes we don't know which values are written in a
field, which is the same for the other non-closure values.
Reviewed By: ezgicicek
Differential Revision: D23932186
fbshipit-source-id: 4a575d0de
Summary: Dispatch & function call mechanism was so jumbled up together. Let's refactor it to be cleaner.
Reviewed By: skcho
Differential Revision: D24049889
fbshipit-source-id: 42a218016
Summary:
Take another page from the Incorrectness Logic book and refrain from reporting issues on paths unless we know for sure that this path will be taken.
Previously, we would report on paths that are merely *not impossible*. This goes very far in the other direction, so it's possible we'll want to go back to some sort of middle ground. Or maybe not. See the changes in the tests to get a sense of what we're missing.
Reviewed By: ezgicicek
Differential Revision: D24014719
fbshipit-source-id: d451faf02
Summary: We add a naive model for `forEach` idiom for Java's Iterable and Maps. The model is naive because it doesn't take the cost of the lambda into account. This will be fixed later.
Reviewed By: da319
Differential Revision: D23868203
fbshipit-source-id: 37d169c6f
Summary:
The problem: current enumerator semantics does not work on symbolic enumerator that is given as a
parameter.
Reviewed By: ezgicicek
Differential Revision: D24017059
fbshipit-source-id: 378e75bb0
Summary:
This can be used by additional tooling for further analysis (e.g.
codemods, autofixes, etc).
Reviewed By: ngorogiannis
Differential Revision: D23987694
fbshipit-source-id: b9fa343ac
Summary:
This diff keeps closure parameters in closure-specializated procedures.
What the closure-specialization is doing is a propagation of concrete closures. For example, it
translates:
```
foo(block b) {
b();
}
goo() {
foo(^{...});
}
```
to
```
foo_new() {
(^{...})();
}
goo() {
foo_new();
}
```
However, if `foo` addresses `b` as a normal value like
```
foo(block b) {
block c = b;
}
```
this is translated to
```
foo_new() {
block c = b;
}
```
Note that the closure parameter of `foo` is removed, thus `b` becomes a free variable. Not good.
To avoid the situation, this diff keeps the closure parameters intact.
Reviewed By: da319
Differential Revision: D23905580
fbshipit-source-id: 014989fbf
Summary: Subtle false positives and negatives in Hil make Sil preferable. This diff gets rid of the CFG-emulation of Hil, while still using Hil expressions.
Reviewed By: da319
Differential Revision: D23815026
fbshipit-source-id: 731a6d299
Summary: Without curly braces, it is declaration of globals, not fields.
Reviewed By: ezgicicek
Differential Revision: D23866604
fbshipit-source-id: dd685c8d6
Summary:
The previous diffs recorded it for the case when the unvetted value is
dereferenced or otherwise used wrongly. This case finishes the work,
recording the needed signature for the remaining case (when the
offending third party has a non-nullable param with nullable passed
inside)
Reviewed By: ngorogiannis
Differential Revision: D23706679
fbshipit-source-id: e6f641223
Summary: This diff adds a test, in which autoreleasing lambda is written in an object field, then called later. The test is not analyzed precisely because it cannot follow that a lambda value is written to a field of an object as of now.
Reviewed By: ezgicicek
Differential Revision: D23843089
fbshipit-source-id: 62ba153aa
Summary:
This diff substitutes closure parameter when it is given via variable. For example,
```
x = ^{ ... }
foo(x)
```
this diff substitutes the closure variable `x`,
```
x = ^{ ... }
foo(^{ ... })
```
so that the specialization of `foo` can be done by `CCallSpecializaedWithClosures.process`.
Reviewed By: jvillard
Differential Revision: D23814595
fbshipit-source-id: a89f1530f
Summary:
Upgrade to latest clang release, needed for xcode12.
clang-8/9 won't be able to read the Xcode 12 SDK since there's annotations that will fail compilation.
Also removing unused (and hard to compile) binary `ast_exporter_bin` from facebook-clang-plugins/libtooling.
Reviewed By: ngorogiannis
Differential Revision: D23780089
fbshipit-source-id: 2314125a9
Summary:
This diff add a model of `NSArray.index_of_object_passing_test` in
autoreleasepool size model.
Worst case autorelease cost is "array size x cost of given test function (lambda)".
Reviewed By: ezgicicek
Differential Revision: D23785165
fbshipit-source-id: 95ec9700a
Summary:
Nullifying these leads to observable side-effects, like in the added
test.
Reviewed By: da319
Differential Revision: D23759756
fbshipit-source-id: 559a6486b
Summary: ObjC objects can be added to autorelease pool by `CFAutorelease`.
Reviewed By: ezgicicek
Differential Revision: D23625632
fbshipit-source-id: 694e5bffb
Summary:
This diff regards some methods of NSKeyedUnarchiver as autorelease, because they may call
autorelease.
Reviewed By: ezgicicek
Differential Revision: D23600232
fbshipit-source-id: a9fc1cc56
Summary:
This diff increases autoreleasepool size when
* caller is non-ARC-compiled
* callee is ARC-compiled
* return type is a pointer to objc object
To distinguish non-ARC-/ARC-compiled:
* extended `translation_unit_decl_info` to have a boolean field `is_objc_arc_on`
* then copied it to `ProcAttributes.t` for each procedures.
Reviewed By: ezgicicek
Differential Revision: D23565003
fbshipit-source-id: dee22ea82
Summary: Structs captured both by reference or by value should have reference in their type. Struct captured by value should first call copy constructor. In this diff we fix the type of the captured variable to include reference. Copy constructor injection is left for the future.
Reviewed By: jvillard
Differential Revision: D23688713
fbshipit-source-id: d13748b5d
Summary: Variables captured without initialization do not have correct type inside lambda's body. This diff sets the correct type of captured reference variables inside procdesc and makes sure the translation of captured variables is correct. The translation of lambda's body will then take into account the type of captured var from procdesc.
Reviewed By: jvillard
Differential Revision: D23678371
fbshipit-source-id: ed16dc978
Summary: Add missing reference to the type of variable captured by reference without initialization.
Reviewed By: jvillard
Differential Revision: D23567685
fbshipit-source-id: b4e2ac0b6
Summary:
We were missing assignment to captured variables with initializers.
Consider the following example:
```
S* update_inside_lambda_capture_and_init(S* s) {
S* object = nullptr;
auto f = [& o = object](S* s) { o = s; };
f(s);
return object;
}
```
which was translated to
```
VARIABLE_DECLARED(o:S*&);
*&o:S*&=&object
*&f =(_fun...lambda..._operator(),([by ref]&o &o:S*&))
```
However, we want to capture `o` (which is an address of `object`), rather `&o` in closure.
After the diff
```
VARIABLE_DECLARED(o:S*&);
*&o:S*&=&object
n$7=*&o:S*&
*&f =(_fun...lambda..._operator(),([by ref]n$7 &o:S*&))
```
Reviewed By: jvillard
Differential Revision: D23567346
fbshipit-source-id: 20f77acc2
Summary:
If the issue is related to the use of an unvetted third party method
that can not be trusted, we record this fact.
Reviewed By: ngorogiannis
Differential Revision: D23705626
fbshipit-source-id: 851328fe5
Summary:
It was inconsistent before (we recorded it only for meta issues).
Now we always record it, which will simplify further diffs.
In the next diffs, we are going to add more fields inside `nullsafe_extra`.
Reviewed By: ngorogiannis
Differential Revision: D23705592
fbshipit-source-id: 8bbb0e7c8
Summary:
This can be useful to make pulse forget about tricky parts of the code.
Treat "skipped" procedures as unknown so heuristics for mutating the
return value and parameters passed by reference are applied.
Reviewed By: ezgicicek
Differential Revision: D23729410
fbshipit-source-id: d7a4924a8
Summary: This diff selects an autorelease trace that has a bigger polynomial.
Reviewed By: ezgicicek
Differential Revision: D23731155
fbshipit-source-id: 243591583
Summary:
This diff reports paths under the xcode isysroot as relative in tests.
This was a problem when another machine that has a different isysroot
directory is running the test.
Reviewed By: ezgicicek
Differential Revision: D23729222
fbshipit-source-id: 4e9681f65
Summary:
Handle the case of
- computing the range of `[lb, ub]` where `lb` contains length path and `ub` is constant. E.g. `[a.length, 2]` would give `3` range
- simplifying `c1 +/- min(c2, a.length)` to `c1 +/- min(c2, 0)`
since the length of a collection/array is always nonnegative.
This also removes some existing FPs in tests results.
Facebook
Context: we stumbled upon this issue in ObjC results TV109717121 which is corresponding to the added test case.
Reviewed By: skcho
Differential Revision: D23648807
fbshipit-source-id: 1e89ea246
Summary: This diff adds trace field for autoreleasepool size. Unlike to the other checkers, eg inferbo and operation cost, the autoreleasepool size checker should have traces for constants.
Reviewed By: ezgicicek
Differential Revision: D23678084
fbshipit-source-id: 35e6cf5f5
Summary:
The `attr_kind` column has now exactly two possible values: defined and undefined (since D22187238 (61ae2d1e1b)). This is also what should be stored in the field `is_defined` in the procedure attributes. Finally, the cfg can be `NULL` or not. This diff makes all three of these agree, in order to allow for the removal of the `attr_kind` column up the stack, since it will be equivalent to `cfg is NOT NULL`.
The changes in the tests indicate improved correctness: previously, specialising a modelled callee would result in a dummy entry in the procedures table, because all clang procedures were given a procdesc, so the specialisation would specialise the empty procdesc. Now, the model is not shadowed by the specialised dummy procdesc, and is specialised itself (and that's why it also ends up in the capture DB, which is slightly counter-intuitive).
Reviewed By: jvillard
Differential Revision: D23536931
fbshipit-source-id: 983216cb6
Summary:
We defined cost's plus as "zero+unreachable = unreachable" for the operation cost. The meaning of
the zero cost is that no statment is analyzed yet, and the unreachable(bottom) cost means a program
point is analyzed as unreachable. We thought "zero+unreachable" happens in very specific cases we
need to check, or due to an analyzer bug. For debugging purpose, we defined it to return more
specific unreachable cost.
However, in allocation/autoreleasepool costs, the zero cost is not very special value. If there is
no alloc/autorelease calls, they can have the zero cost. "zero+unreachable = unreachable" doesn't
make sense there.
This diff changes the plus as "zero+unreachable = zero" for the non-operation costs.
Reviewed By: ezgicicek
Differential Revision: D23578869
fbshipit-source-id: 5392eca1c
Summary: This diff adds some tests run with ARC/non-ARC compiled objective-c sources.
Reviewed By: ezgicicek
Differential Revision: D23542135
fbshipit-source-id: 8e089666b
Summary:
This diff adds a new experimental checker for detecting size of objects in autorelease pool in ObjC. The basic mechanism is almost the same with the previous cost calculation:
* Autorelease pool size is increased at explicit `autorelease` call
* Autorelease pool size is set as zero by the `autoreleasepool` block.
While it only supports the explicit calls as of now, we will extend the checker to handle more cases in the following diffs.
Reviewed By: ezgicicek
Differential Revision: D23473145
fbshipit-source-id: 416488176
Summary:
As title.
Facebook
Found this case by examining db.
>
D23394545
Time complexity of `_registerTabPreloadables` has **decreased** from `Top` to `O(1)`. Please make sure this is an expected change. You can inspect the trace to understand the complexity increase:
Reviewed By: ezgicicek
Differential Revision: D23448099
fbshipit-source-id: 108fd1ef2
Summary:
This diff adds translation of `dictionaryWithObjects:forKeys:count:`. In the previous implementation it was
translated as if it was `dictionaryWtihObjectsAndKeys:`, but their function parameters are different.
In this diff, it translates an array literal `NSDictionary* a = @ [ @"firstName": @"Foo", @"lastName":@"Bar" ];` to
```
n$1=NSString.stringWithUTF8:(@"firstName")
n$2=NSNumber.stringWithUTF8:(@"Foo")
n$3=NSNumber.stringWithUTF8:(@"lastName")
n$4=NSNumber.stringWithUTF8:(@"Bar")
temp1[0]:objc_object*=n$1
temp1[1]:objc_object*=n$3
temp2[0]:objc_object*=n$2
temp2[1]:objc_object*=n$4
n$3=NSDictionary.dictionaryWithObjects:forKeys:count:(temp2:objc_object* const [2*8], temp1:objc_object*const [2*8], 2:int)
```
where `temp` is an additional local variable declared as array.
See,
https://developer.apple.com/documentation/foundation/nsdictionary/1574184-dictionarywithobjects?language=objchttps://developer.apple.com/documentation/foundation/nsdictionary/1574181-dictionarywithobjectsandkeys
{F316854542}
Reviewed By: skcho
Differential Revision: D23447042
fbshipit-source-id: 14b7c3f2b
Summary: Added a model for copy constructor for `std::function`. In most cases, the SIL instruction `std::function::function(&dest, &src)` gives us pointers to `dest` and `src`, hence, we model the copy constructor as a shallow copy. However, in some cases, e.g. `std::function f = lambda_literal`, SIL instruction contains the closure itself `std::function::function(&dest, (operator(), captured_vars)`, hence, we need to make sure we copy the right value.
Reviewed By: ezgicicek
Differential Revision: D23396568
fbshipit-source-id: 0acb8f6bc
Summary: We only added suffix-stripped prefixes of props but this causes FPS if a component declares props that actually contain suffixes since we strip them when we are adding builder calls. The fix is to add both normal and stripped versions.
Reviewed By: skcho, Katalune
Differential Revision: D23375405
fbshipit-source-id: e99cb4dd8
Summary:
This diff finishes the migration from the specialization of methods that take blocks as arguments. Here we delete all the old code and change the way we model dispatch functions so that the tests pass.
- Remove the code for specializing the methods in biabduction.
- Remove the call flags `cf_with_block_parameters` that was only used in this algorithm.
- Removes models for dispatch functions.
- Adds models for dispatch functions as program transformation only in biabduction. To be added in other checkers in the future.
Reviewed By: ngorogiannis
Differential Revision: D23345342
fbshipit-source-id: b5e8542ce
Summary:
This preanalysis in general aims to create specialized clones of methods that have blocks as arguments and that are called with concrete closures, and then call these clone methods instead of the original ones.
One complication is what happens with the captured variables in the closure. What we do is we add them to the formals of the cloned method and passed them through to the concrete blocks.
We do this transformation in two steps:
1. Go through all the callers of methods with blocks as parameters, and create the clone methods. In this preanalysis we only create the attributes for the new method, not the code. We also update the call instructions in the callers to represent a call to the cloned method with updated arguments: we don't need to pass closures arguments anymore, we instead pass the captured variables as new arguments.
2. We add the corresponding code to the newly created clones: this means swapping the call to the block variable with a call to the corresponding block. Moreover, we add some of the new formals (that correspond to the captured variables) to the arguments of the call.
This diff implements step 1 of the analysis. The next diff D23216021 implements step 2.
Reviewed By: ngorogiannis
Differential Revision: D23109204
fbshipit-source-id: 91a5eb16b
Summary: There was a mismatch between formals and actuals in `std::function::operator()` because we were not passing the first argument corresponding to the closure.
Reviewed By: ezgicicek
Differential Revision: D23372104
fbshipit-source-id: d0f9b27d6
Summary: When we evaluate lambdas in pulse, we create a closure object with `fake` fields to store captured variables. However, during the function call we were not linking the captured values from the closure object. We address this missing part here.
Reviewed By: jvillard
Differential Revision: D23316750
fbshipit-source-id: 14751aa58
Summary:
Report errors found by running Topl on top of Pulse, when using
--topl-pulse. Topl tests now run on top of Pulse.
Reviewed By: jvillard
Differential Revision: D23030771
fbshipit-source-id: 8770c2902
Summary:
Two issues are fixed
1. For this diff, when the condition `curr_langauge_is Java` is removed in some part of the analysis, some c bufferoverrun tests are broken. This is fixed in this diff by inspecting if we are dealing with a `Size` alias referring to an `objc_internal_collection_array`.
2. Previously, when we are modifying mutable array in a loop, e.g. adding element to the array or removing element from the array, we are unable to give an estimable size of the array after exiting the loop. This is now fixed, and the corresponding FPs are resolved.
Reviewed By: skcho
Differential Revision: D23342350
fbshipit-source-id: 200f5261c
Summary:
The generated code used to contain Prune statements that had boolean
connectives in their conditions. After this commit, all conditions
should have no boolean connective (LNot, LOr, LAnd) at top-level; that
is, prune conditions should be atomic.
The main motivation behind this change is that (a) frontends follow this
convention, and (b) Pulse assumes this convention.
Reviewed By: jvillard
Differential Revision: D23022273
fbshipit-source-id: 1313328e4
Summary:
In the previous diffs, we implement enumerator in order to estimate the cost of for-each loop in ObjC, but when we have FP case when enumerator is used not in for-each loop. For example, the following code has top cost before the fix.
```
void nsarray_enumerator_linear_FP(NSArray* array) {
id obj;
NSInteger sum = 0;
NSEnumerator* enumerator = [array objectEnumerator];
while (obj = [enumerator nextObject]) {
sum += (NSInteger)obj;
}
}
```
Reviewed By: skcho
Differential Revision: D23294895
fbshipit-source-id: 50c7b359f
Summary:
`delete` works exactly like `free` so merge both models together. Also
move the `free(0)` test to nullptr.cpp as it seems more appropriate.
Reviewed By: da319
Differential Revision: D23241297
fbshipit-source-id: 20a32ac54
Summary:
Fix the FP when iterating through constant collection.
facebook
This fix is a hack for now.
Reviewed By: ezgicicek, skcho
Differential Revision: D23241338
fbshipit-source-id: e2e0c05f8
Summary:
As title.
This diff is co-authored by SungKeun Cho and me.
facebook
This diff is co-authored by skcho and me.
Original comments from skcho
"For the record:
1. Rory and I tried to write models for ObjC iterator.
2. We could not use Java's iterator semantics: In Java's, `hasNext` returns the size of collection, rather than a boolean, and which is used as a control variable. On the other hand, in ObjC, it calls only `nextObject`, not calling `hasNext`, and the return value of which is being checked as `null`.
3. We added an artificial field `objc_iterator_offset` to keep the index of the iterator, and the models added in this diff are handling that integer value.
A problem is that `array.objc_iterator_offset` is not included in the control variables, since the condition of the loop is `nextObject() != null` that does not include the iterator offset. We need to make `array.objc_iterator_offset` as a control variable, by changing the part collecting control variables.
"
Reviewed By: ezgicicek, skcho
Differential Revision: D22944278
fbshipit-source-id: 7e71b79c1
Summary: In the frontend captured variables for blocks are added as formal parameters in procdesc at the beginning.
Reviewed By: dulmarod
Differential Revision: D23163619
fbshipit-source-id: 2bcbe9b9c
Summary:
When implementing iterator, we find out that because some semantics of inferbo is Java-specific, we cannot simply use Java's `Collection` model for `NSCollection`.
So this diff writing `NSCollection` model separately.
This diff also extracts the common parts of `NSCollection` and `Collection` into `AbstractCollection` to combine the duplicate the parts.
Reviewed By: ezgicicek
Differential Revision: D22975159
fbshipit-source-id: daed3f99f
Summary:
We already take into account inheritance if the method inherits a known
modelled initializer method (e.g. Activity.onCreate()).
But if the method is explicitly marked as Initializer, we require its
overrides to be also marked.
This diffs fixes the behavior and makes it consistent, now this is
enough to annotate only parent class.
Reviewed By: jvillard
Differential Revision: D23135177
fbshipit-source-id: a21ff4a0e
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:
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:
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:
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:
`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 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: 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:
There are two ways to suppress it.
1. Field level suppression annotation (was already tested). This will
apply to all constructors.
2. Constructor level annotation (this is what this test does). Sometimes
there are "fake" constructors that are not intended to be called in
prod, they might leave some fields not initialized.
Note that there are two ways to add a suppression; one has a known
problem that is documented here.
Reviewed By: artempyanykh
Differential Revision: D22864869
fbshipit-source-id: f95aaa26a
Summary:
When expressions use generics or typecasts, CFG contains intermediate `_fun_cast` nodes which break some nullsafe heuristics and lead to false positives.
This affects different types of checks (null-check on assignment expressions, `map.containsKey` checks in assignment expressions, regular typecasts, etc.
See added tests for examples.
Reviewed By: mityal
Differential Revision: D22815631
fbshipit-source-id: 80d444b1c
Summary:
We check for supertypes in Java. Why not ObjC?
Would be good to get dulmarod's input here.
Reviewed By: roro47
Differential Revision: D22817126
fbshipit-source-id: 52c1c3f3c
Summary:
The old --topl-only is now --topl-biabd-only, and there's also
--topl-pulse-only. This is WIP: the latter runs pulse, but it doesn't yet
extract Topl errors from pulse summaries. (The citv part of pulse path
conditions appears to have the necessary information.)
Reviewed By: jvillard
Differential Revision: D22815250
fbshipit-source-id: a01792945
Summary:
This diff:
1. Adds general capability to model any field as nullable /
non-nullable.
2. Uses it for Boolean.TRUE and Boolean.FALSE
Reviewed By: artempyanykh
Differential Revision: D22794226
fbshipit-source-id: 95f586592
Summary: D17500386 had added the ability to give symbolic values on functions returning exceptions. However, this might cause FPs or cryptic complexity reports (especially with subclass heuristics). This diff aims to revert it back.
Reviewed By: skcho
Differential Revision: D22764266
fbshipit-source-id: 1615544d8
Summary: We model internal builtin `__new` function to return a non-null value. This fixes nullptr_dereference false positives where we explicitly check the result of a function call for nullptr when the function returns a newly created object.
Reviewed By: jvillard
Differential Revision: D22772217
fbshipit-source-id: 37d209697
Summary:
The java frontend used an unsound flow insensitive class analysis to devirtualize
some virtual calls. We remove it and let the recent devirtualizer preanalysis do the job.
This unsoudness in the Java frontend may have been here for a long time. Removing it may
modify several analysis results (specially Nullsafe) where virtual calls may look different
now.
Reviewed By: jvillard
Differential Revision: D22662739
fbshipit-source-id: c45296dce
Summary:
This diff adds translation of `arrayWithObjects:count:`. In the previous implementation it was
translated as if it was `arrayWithObjects:`, but their function parameters are different.
In this diff, it translates an array literal `NSArray* a = @ [ 2, 3 ];` to
```
n$1=NSNumber.numberWithInt:(2:int)
n$2=NSNumber.numberWithInt:(3:int)
temp[0]:objc_object*=n$1
temp[1]:objc_object*=n$2
n$3=NSArray.arrayWithObjects:count:(temp:objc_object* const [2*8],2:int)
a:NSArray*=n$3
```
where `temp` is an additional local variable declared as array.
See,
https://developer.apple.com/documentation/foundation/nsarray/1460145-arraywithobjectshttps://developer.apple.com/documentation/foundation/nsarray/1460096-arraywithobjects?language=objc
Reviewed By: jvillard
Differential Revision: D22631305
fbshipit-source-id: 5be0a55d4
Summary:
Add a test to the repo to try and detect perf regressions in pulse.
Currently analyzed in ~0.1s. With `--pudge`, takes ~10s.
Sledge does eager normalization and canonicalization when incorporating new facts into formula contexts and the algorithm is polynomial in the number of equalities. This example generates one equality per location in the array => boom. This bypasses the recency model of arrays because the formula needs to be constructed before it can be simplified to get rid of dead variables.
The new arithmetic is not as complete as sledge's algorithm but linear in time. We could use it to simplify the formula *before* passing it to sledge. In fact, that was the original motivation.
Reviewed By: skcho
Differential Revision: D22574366
fbshipit-source-id: e9044ae09
Summary:
When applying function summaries, we are careful not to violate the
summary's assumptions about non-aliasing. For example, the summary we
generate for `foo(x,y) { *x = *y; }` will have `x` and `y` be allocated
to two different `AbstractValue.t` in the heap, representing
disjointness.
However, the current logic is too coarse and also rejects passing the
same pure value to functions that made no assumption about them being
equal or different, eg `goo(int x,int y) { int z = x + y; }`. This is
because the corresponding `AbstractValue.t` are different in the
callee's summary, but are represented by only one same value in callers
such as `goo(i,i)`.
This diff restricts the "don't violate aliasing" condition to only
consider heap-allocated values. This is consistent with separation logic
by the way: we use the implication `x|->- * y|->- |- x≠y`, which is
valid only when both `x` and `y` are both allocated in the heap as in
the left-hand-side of `|-`.
Reviewed By: skcho
Differential Revision: D22574297
fbshipit-source-id: 206a18499
Summary:
This will allow all the analyses to be able to call closures without any special treatment: we transform the call to variables that point to closures into normal function calls. We treat only ObjC blocks at the moment, with C++ lambdas to be done as a next step.
We aimed to achieve certain results in Pulse (see tests: avoid memory leaks and NPEs FPs) while also keeping the biabduction analysis working as before.
We also checked that for the examples analyzed Pulse behaves like the correct semantics of ObjC programs with blocks.
Reviewed By: jvillard
Differential Revision: D22547333
fbshipit-source-id: efe56ed51
Summary: Lambda is called using `operator()`. We need to know the information of captured variables when `operator()` procedure is being analysed. This diff records lambda captured variables in `operator()` procdesc. The complication arises from the fact that procdesc for `operator()` is created before translating lambda expression or during the translation of lambda expression where captured variables are translated. To solve this issue, we update existing `operator()` procdesc attributes with captured variable information when we translate lambda expression.
Reviewed By: jvillard
Differential Revision: D22374495
fbshipit-source-id: 44909adea
Summary: Add cost model for most common `NSString` functions in cost analysis
Reviewed By: skcho
Differential Revision: D22433005
fbshipit-source-id: 2f57bbda9
Summary: If a node is unreachable and the cost of the node is Top, we were giving Top cost :( Let's fix it.
Reviewed By: skcho
Differential Revision: D22548269
fbshipit-source-id: d79743669
Summary:
We update the type of captured variables to include information about capture mode (`ByReference` or `ByValue`) both for procdesc attributes and the closure expression.
For lambda: closure expression now contains correct capture mode for capture variables. Procdesc still does not contain information about captured variables which we will address in the next diff.
For objc blocks: at the moment all captured variables have mode `ByReference`. Added TODOs to fix this.
Reviewed By: jvillard
Differential Revision: D22572054
fbshipit-source-id: 4c88678ee
Summary:
As title
Model `NSString` as `JavaString`.
Since `NSArray` does not contain information about its type of element, we do not use associate string with collection as in Java and C++. In Java, String model is implemented using java collection, and for C++, string model is implemented using vector.
So instead, we use existing `JavaString` model.
Reviewed By: skcho
Differential Revision: D22431949
fbshipit-source-id: 7cdde1ad7
Summary: To avoid NULLPTR_DEREFERENCE false positives we want to model some functions as returning non-null. A new flag --pulse-model-return-nonnull allows us to provide a list of such functions.
Reviewed By: ezgicicek
Differential Revision: D22431564
fbshipit-source-id: 9944c7382
Summary: `addAll` adds elements one by one and hence takes linear time. We didn't have a model for this and considered it O(1).
Reviewed By: skcho
Differential Revision: D22375157
fbshipit-source-id: 65b82bfae
Summary: This diff prevents printing line numbers of loop in the trace description, which helps to keep the same descriptions even when the line number of a function is changed in tests.
Reviewed By: ezgicicek
Differential Revision: D22375584
fbshipit-source-id: 676d1a7cc
Summary:
Keyword `thread_local` in cpp allows us to create a variable with thread storage duration, meaning that the object's lifetime begins when the thread begins and ends when the thread ends.
We get `NULLPTR_DEREFERENCE` false positive for `thread_local` variable since we reallocate it in the `VariableLifetimeBegins` metadata instruction and we do not see further updates to the variable. To solve the issue we special case `VariableLifetimeBegins` instruction for global variables.
Reviewed By: jvillard
Differential Revision: D22284135
fbshipit-source-id: 13c14ef90
Summary: Create test for the most common unmodeled function in inferbo that acts as control variable.
Reviewed By: skcho
Differential Revision: D22331168
fbshipit-source-id: 1913682db
Summary: Add objc test for customized class and blocks. Mostly sanity test.
Reviewed By: ezgicicek
Differential Revision: D22043918
fbshipit-source-id: 917deeea7
Summary:
This diff adds a model of `File.listFiles` as returning an array with
a symbolic length.
Reviewed By: ezgicicek
Differential Revision: D22332258
fbshipit-source-id: 6ca593b8b
Summary: This diff adds support for `com.facebook.litho.sections.Section` which mimics the behavior for `com.facebook.litho.Component`.
Reviewed By: skcho
Differential Revision: D22309039
fbshipit-source-id: 3510441a8
Summary:
We already had a heuristic to deal with assignment expressions, but it
relied on the very previous CFG node to have a non-empty list of instrs.
In some cases, however, this previous node is a Join_node with no instrs,
so we need to take one more step back to find what we're looking for.
I've also added a bit more logging around this functionality, so it's
easier to debug/tune in future.
Reviewed By: ngorogiannis
Differential Revision: D22282930
fbshipit-source-id: 024eec145
Summary:
This model is very important in the analysis of ObjC classes because the pattern
```
- (instancetype)init {
if (self = [super init]) {
...
}
return self;
}
```
is very common, so we need to know that if the super class is `NSObject`, the implementation of `init` is returning `self`, otherwise it's a skip function and we don't get the correct spec for the function. We fix some memory leak FP with this model, see test.
Reviewed By: ezgicicek
Differential Revision: D22259281
fbshipit-source-id: 3ee48c827
Summary:
We need to check if `folly::Optional` is not `folly::none` if we want to retrieve the value, otherwise a runtime exception is thrown:
```
folly::Optional<int> foo{folly::none};
return foo.value(); // bad
```
```
folly::Optional<int> foo{folly::none};
if (foo) {
return foo.value(); // ok
}
```
This diff adds a new issue type that reports if we try to access `folly::Optional` value when it is known to be `folly::none`.
Reviewed By: ezgicicek
Differential Revision: D22053352
fbshipit-source-id: 32cb00a99
Summary: This linters were not used much anymore, so we can delete them.
Reviewed By: ngorogiannis
Differential Revision: D22233895
fbshipit-source-id: f31180a05
Summary: There is now a compilation check for UNAVAILABLE_API_IN_SUPPORTED_IOS_SDK so this check is less useful. Also the check REGISTERED_OBSERVER_BEING_DEALLOCATED is useful only in an old version of iOS.
Reviewed By: ngorogiannis
Differential Revision: D22231851
fbshipit-source-id: 72151fef5
Summary:
This diff tries to support a specific form of linked list iteration in Java.
```
while (p != null) {
p = p.getNext();
}
```
This example was a constant cost before because the cost checker could not detect that it is an iteration on a linked list.
The heuristic this diff implemented is:
(1) `p = p.getNext()`: It tries to find this specific form of assignment. Then, it increments `p.linked_list_index` by 1. Note that `linked_list_index` is a virtual field for keeping an index in the linked list. Its initial value is always 0.
(2) At `p != null`, it tries to prune the value of `p.linked_list_index`: the upper-bound of `p.linked_list_index` is pruned by `<= p.linked_list_length`. Here again, `p.linked_list_length` is also a virtual field to denote the length of the linked list.
Reviewed By: ezgicicek
Differential Revision: D22234892
fbshipit-source-id: 2fee176bb
Summary: These models for Memory Leaks have been ported to Pulse, so we can remove the models in biabduction and corresponding tests.
Reviewed By: skcho
Differential Revision: D22206287
fbshipit-source-id: e17499ad3
Summary:
Move the implementation of implicit getters and setters from the biabduction to the clang frontend so these methods are accessible to all the checkers.
*Background*: In Objective-C when properties are created in the interface of a class, the compiler creates automatically the instance variable for it and also the getter and setter in the implementation of the class. In the frontend we collect the information about which method is the implicit getter and setter of which instance variable (we get the method declaration but not the implementation), and here we add the implicit implementation.
Reviewed By: skcho
Differential Revision: D22187238
fbshipit-source-id: 76e0508ed
Summary: Let's make package name match the directory name to follow Java's file lookup conventions
Reviewed By: skcho
Differential Revision: D22183964
fbshipit-source-id: b9958b975
Summary:
Document FP due to imprecision in tracking outer lock release. In a nested `synchronized` block the outer release is not registered by the abstract domain. The reason is that HIL is not resolving what `$bcvarX` is pointing to (in this case to `lockE`).
Reported by Andreea Costea.
Reviewed By: ezgicicek
Differential Revision: D22186240
fbshipit-source-id: 84e5e72b1
Summary:
Nullability of the assignment result is not refined in code snippets
like:
```
while ((a = foo.getA()) != null) {
nonNullableVal = a;
}
```
Let's add a test for this.
Reviewed By: jvillard
Differential Revision: D22136218
fbshipit-source-id: 206c368d6
Summary:
Add objc test for ```NSArray``` and ```NSMutableArray```.
```NSMutableArray``` is a subclass of ```NSArray```.
For documentation of ```NSArray```, https://developer.apple.com/documentation/foundation/nsarray?language=objc
For documentation of ```NSMutableArray```, https://developer.apple.com/documentation/foundation/nsmutablearray?language=objc
The underlying mechanism for ```NSMutableArray``` is quite complicated. It changes the underlying data structure during runtime, so it is possible to have say O(log n) complexity for accessing element in array. (See here https://opensource.apple.com/source/CF/CF-855.11/CFArray.h) However, this is unlikely to happen if the engineer does not abuse the usage of the class ```NSMutableArray``` according to at least two ios engineers. So here the complexity is set to match the normal expectation of the complexity.
Reviewed By: ezgicicek
Differential Revision: D22041277
fbshipit-source-id: c27f43167
Summary:
This diff adds a prototype of a new checker that collects config checkings between markers.
Basically, what the checker is doing is a taint analysis.
* Taint source: function calls of "marker start"
* Taint sink: function calls of config checking
* Taint remove: function calls of "marker end"
By the taint analysis, the analysis results will say that which taints can reach to the sink. In other words, which marker ID that has been started can reach to the config checks, before marker's ending.
I am separating the diff into three steps:
(1/3) Add basic abstract semantics
(2/3) Add trace information
(3/3) Add reporting with test examples
Reviewed By: jvillard
Differential Revision: D21998170
fbshipit-source-id: e7759f62f
Summary: Pulse has now a better version of this check, so let's delete it.
Reviewed By: ngorogiannis
Differential Revision: D22019247
fbshipit-source-id: 344678225
Summary:
This issue type was not giving good results and can be replaced by
Pulse's version.
Reviewed By: ngorogiannis
Differential Revision: D22019551
fbshipit-source-id: 5cf3db46d
Summary:
Add objc test case for ```NSInteger``` and ```NSString```.
The test cases are adapted from java test case: ```IntTest.java```, ```StringBuilder.java```, and ```StringTest.java```.
Inspection of the record will be done later.
Reviewed By: ezgicicek
Differential Revision: D21994620
fbshipit-source-id: 0c1d7b34e
Summary: To avoid NULLPTR_DEREFERENCE false positives we want to treat some functions as `abort`. A new flag `--pulse-model-abort` allows us to provide a list of such functions.
Reviewed By: ezgicicek
Differential Revision: D21962555
fbshipit-source-id: d46b93c99
Summary: The new memory leaks analysis is now ready to be enabled by default and turned on in production. This also replaces the biabduction one which is now disabled.
Reviewed By: jvillard
Differential Revision: D21998666
fbshipit-source-id: 9cd95e894
Summary:
This models ARC implementation of dealloc, see https://clang.llvm.org/docs/AutomaticReferenceCounting.html#dealloc. Dealloc methods can be added to ObjC classes to free C memory for example, but the deallocation of the ObjC instance variables of the object is done automatically. So here we add this explicitly to Infer:
1. First, we add an empty dealloc method when it is not written explicitly.
2. For each dealloc method (including the implicitly added ones) we add calls to dealloc of the ObjC instance variables.
Reviewed By: jvillard
Differential Revision: D21883546
fbshipit-source-id: f5d4930f2
Summary: We don't rely on `external-java-packages` in the inferconfig anymore. Let's remove it altogether.
Reviewed By: jvillard
Differential Revision: D21997962
fbshipit-source-id: 7a2e13cfe
Summary:
Similarly as for issue types, we want to generate the website
documentation from infer itself so we can easily cross-reference
checkers and the issue types they report.
This imports the website documentation written for some (very few) of
the checkers. I wrote some cursory one-liners for the rest.
Reviewed By: dulmarod
Differential Revision: D21934375
fbshipit-source-id: 8c9dc2b08
Summary:
See previous diff: issues are always reported with the same severity so
recognise that and just use their default severity in "modern" checkers.
Reviewed By: ngorogiannis
Differential Revision: D21904591
fbshipit-source-id: fb5387e35
Summary:
This diff implements part of the memory management for Objective-C classes in ARC, namely that `dealloc` is called when the objects become unreachable. In reality the semantics of ARC says that this happens when their reference count becomes 0, but we are not modelling this yet in Pulse. However, we could in the future.
This fixes false positives memory leaks when the memory is freed in dealloc.
`dealloc` is often implicit in Objective-C, it also calls the dealloc of instance variables and superclass. None of this is implemented yet, and will be done in a future diff. This will be added in the frontend probably, similarly to how it's done for C++ destructors.
This is an important part of modelling Objective-C semantics in Infer, I looked at whether this should be a preanalysis to be used by all analyses but this needs Pulse. So the idea is that any analysis that needs to understand Objective-C memory model well, should have Pulse as a preanalysis.
Reviewed By: jvillard
Differential Revision: D21762292
fbshipit-source-id: ced014324
Summary:
Since Java8, interfaces mays contain implementations
(default methods). We modify the resolve algorith in the Java frontend
to take care of that.
Reviewed By: jvillard
Differential Revision: D21785182
fbshipit-source-id: ffab8124c
Summary: We do not use an arbitrary threshold to test cost results anymore but instead rely on `cost-issues` which do not have any trace attached. This diff adds traces to `costs-report.json` so that we can test cost issues with traces.
Reviewed By: skcho
Differential Revision: D21858846
fbshipit-source-id: e73321a92
Summary:
Now that we have a way to write cost issues, let's not rely on some arbitrary threshold (and also get rid of `EXPENSIVE_EXECUTION_TIME` issues in tests).
One consequence of this is that we will loose the cost traces in tests since `costs-report.json` doesn't have any traces. Next diff fixes that.
Reviewed By: skcho
Differential Revision: D21837574
fbshipit-source-id: 86b4d028d
Summary:
The model returns an array the length of which is the same to that of enum entries.
It takes the length of enum entries from the summary of `Enum.values` because it is not written in `tenv`. In order to do that, the model semantics should be able to request the summary of the function with `get_summary`, so I extended `model_env` to include the functionality.
Reviewed By: ezgicicek
Differential Revision: D21843319
fbshipit-source-id: d6f10eb91
Summary:
The model returns an array the length of which is the number of known
fields in `tenv`.
Reviewed By: ezgicicek
Differential Revision: D21840375
fbshipit-source-id: 891517c6e
Summary: D21816312 forgot to add the new cost testing mechanism to `fb-performance` and `performance-exlusive` directories. This diff fixes that.
Reviewed By: skcho
Differential Revision: D21837912
fbshipit-source-id: 407dafcd3
Summary: The models were too naive before since they invalidated the underlying array completely (copying C++'s push_back model), causing spurious vector invalidation issues in Java. This diff adds more reasonable models.
Reviewed By: skcho
Differential Revision: D21787543
fbshipit-source-id: a5a59ff69
Summary:
In order to test cost analysis results, currently we rely on having an arbitrary cost threshold (200) and report issues that exceed this cost. For instance, a cost of 201 is considered expensive and reported as `EXPENSIVE_EXECUTION_TIME` issue in cost tests.
This means, if we change the cost analysis in a slight way that results in some constant cost increase under 200, we wouldn't able to detect it. I find this unsatisfactory and somewhat hacky.
This diff adds the ability to write the result of `costs-report.json` into a separate `cost-issues.exp` and then compare the actual costs (not only than relying on this arbitrary threshold reporting mechanism).
Reviewed By: skcho
Differential Revision: D21816312
fbshipit-source-id: 93b531928
Summary: Add models for `View` methods that schedule on the UI thread.
Reviewed By: skcho
Differential Revision: D21767954
fbshipit-source-id: 015441ea7
Summary:
Android OS calls certain overridden class methods always on the UI thread. The function changed here attempted to build a list of all these methods, one by one. It's much more complete to simply consider a method as callable on the UI thread if it's an override of an Android library method, and it starts with "on". Only a single instance is known not to obey this pattern, so it's easier to blacklist than to whitelist.
Also clarify the name to `is_android_lifecycle_method`.
Reviewed By: ezgicicek
Differential Revision: D21703365
fbshipit-source-id: 41ca3e998
Summary:
I think `Analysis_stops` ought to achieve roughly the same thing (except
that weird filtering logic which I removed).
Reviewed By: dulmarod
Differential Revision: D21686562
fbshipit-source-id: 53d40729f
Summary: Assigning `nullptr` to `std::function` was causing `NULLPTR_DEREFERENCE` as our model was expecting to get an object in the right hand side of the assignment (`std::function::operator=`) and was dereferencing that object. Assigning `nullptr` to `std::function` removes callable object from it. We model this special case by creating a fresh value.
Reviewed By: skcho
Differential Revision: D21685318
fbshipit-source-id: 2d4af1933
Summary:
Introduce BIABD_ prefixes for a few issue types that were duplicated
between analyses, and also prefix the lab exercise issue type to avoid
sharing with biabduction.
Reviewed By: ngorogiannis
Differential Revision: D21660226
fbshipit-source-id: 3435916e6
Summary:
This seems to make sense as it's a separate analysis (that depends on
biabduction). This introduces unpleasant `|| is_checker_enabled TOPL`
whenever we try to figure out if biabduction will run. I think this is a
more general problem that deserves a more general solution to express
the fact that checkers can depend on others, so that, eg,
`is_checker_enabled Purity` is true when we pass `--loop-hoisting`. Will
address in another diff.
Reviewed By: ngorogiannis
Differential Revision: D21618460
fbshipit-source-id: 8b0c9a015
Summary: Later on, this can be changed again or made customizable.
Reviewed By: artempyanykh
Differential Revision: D21618730
fbshipit-source-id: fe517c766
Summary:
Start with tests about dynamic dispatch to test the upcoming
pre-analysis.
Reviewed By: ezgicicek
Differential Revision: D21594496
fbshipit-source-id: 1771ea968
Summary:
This function had been computing the name for ObjC methods wrong, with only the class name. This was causing wrong error messages in Pulse.
The main issue was that `Procname.to_simplified_string` was writing `Classname::methodname` for ObjC methods, which is not the convention. This confused the `hashable_name` funtion. So changing the method name to `Classname.methodname` which is more standard, and this also fixes `hashable_name`.
Reviewed By: ngorogiannis, jvillard
Differential Revision: D21570880
fbshipit-source-id: 13ed62cf8
Summary: In an intra-procedural analysis, we assume that parameters passed by reference to a function will be initialized inside that function. To do that we use the type information of a formal parameter to initialize the fields of the struct. This was causing false positives if the formal parameter in function signature had type `void*`. To solve this, we used type information from local variables instead. However, we also get false positives for any kind of pointer if we use cast. We fix this by using type information of local variables as in `void*` case.
Reviewed By: jvillard
Differential Revision: D21522979
fbshipit-source-id: 4222ff134
Summary:
Previous translation of enum constants were wrong since they assumed that the enum constant didn't include any global variable (hence they just looked up the enum exp from the map, forgetting to tie the respective instructions into the cfg).
```
const int gvar = 0;
enum {
evar = gvar,
};
int dangling() {
return evar;
}
```
as a result, the CFG was missing the instruction for the load of the `gvar`.
{F237004587}
This diff fixes this issue by hooking up the instructions that load the enum constant in to the CFG. Note that in this example, it is only a load instruction but there could be more instructions (e.g. if we had `gvar > 1`, we would have prune +join).
{F237004493}
Reviewed By: ezgicicek
Differential Revision: D21549781
fbshipit-source-id: 525534fb2
Summary:
Just like `CFBridgingRelease` we want to be able to model functions that are specific to a given codebase that make a transfer of memory ownership so that developers don't need to worry about releasing that memory anymore, and hence, we don't want to report leaks on that memory.
Things get a little more complicated, because some of the functions we want to model are in a specific namespace, so with this flag we take both cases into account, when we are dealing with namespaces or not.
Reviewed By: jvillard
Differential Revision: D21404409
fbshipit-source-id: c36bd7afc
Summary: Currently we get false positive if we apply `operator--` to the `end()` iterator. To solve this, we model iterator `operator--` not to raise an error for the `EndIterator` invalidation, but to create a fresh element in the underlying array.
Reviewed By: ezgicicek
Differential Revision: D21476353
fbshipit-source-id: 5c722372e
Summary:
It is undefined behavior to dereference end iterator.
To catch end iterator dereferencing issues we change iterator model: instead of having `internal pointer` storing the current index, we model it as a pointer to a current index. This allows us to model `end()` iterator as having an invalid pointer and there is no need to create an invalidated element in the vector itself.
Reviewed By: ezgicicek
Differential Revision: D21178441
fbshipit-source-id: fd6a94b0b
Summary: We mistakenly invalidated the set element which causes spurious vector invalidation errors. Instead, we should modify it without any invalidation.
Reviewed By: jvillard
Differential Revision: D21521943
fbshipit-source-id: 67963967e
Summary:
This diff adds semantics of assume null, heuristics. When `assume(x == null)`, it removes the
methods called on the builder `*x` from the abstract state.
```
x -> {p}
p -> {method1 called}
assume(x == null)
x -> {p}
```
This heuristics is unsound: Even though `x` (a pointer to builder object) points-to an builder
object, which cannot imply that the object `p` does not exist in the concrete semantics. The
unsoundness may appear when there is an alias (see the FP test added).
Reviewed By: ezgicicek
Differential Revision: D21502923
fbshipit-source-id: 2e392bd89
Summary: Java's iterator models were wrong. This causes `VECTOR_INVALIDATION` errors in fbandroid projects. This diff aims to fix it by modeling Java iterators with a current pointer and an underlying collection array.
Reviewed By: skcho
Differential Revision: D21448322
fbshipit-source-id: 7d44354b5
Summary:
These 2 methods are automatically supplied for all enums, with
predefined behavior and nullability: https://www.geeksforgeeks.org/enum-in-java/
(Note that they are not part of java.lang.Enum class).
This will allow using them in unvetted third part and under strict mode.
Reviewed By: artempyanykh
Differential Revision: D21501716
fbshipit-source-id: 104082d15
Summary:
Because in the real semantics CFRelease can be used more than once, and also the variables can be used after CFRelease in general, modelling this as `free` causes many `USE_AFTER_FREE` errors. Now we change the model to not add the `Invalid CFree` attribute, but to just remove the `Allocated` attribute. So we can model memory leaks in the simple case of `Create` and not `CFRelease` before going out of scope, but we avoid the `USE_AFTER_FREE`.
Since the model for CFRelease now diverges from free, changed the command line option for modelling to `pulse-model-release-pattern`.
Reviewed By: jvillard
Differential Revision: D21324895
fbshipit-source-id: ab323d981
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:
This diff changes way we treat classes w.r.t. to Nullsafe modes when
issuing meta-issues.
Previously, we considered nested class independently of the outer one.
This was leading to a tricky case: when the class is clean but nested
class needs fixing, meta-info told that class can be Nullsafe.
This is counter-intutive and lead to problems when users tried to follow
wrong nullsafe suggestions for this case.
After this diff we:
1. Start calculating meta-issues only on the outermost level. This will simplify
reasoning about nullsafe stats.
2. Aggregate all nested issues counters to corresponding outer-level class.
Among others, CLASS_CAN_BE_NULLSAFE Advice will finally become
actionable in all known cases.
Reviewed By: artempyanykh
Differential Revision: D21353607
fbshipit-source-id: a17c6958a
Summary:
List of things happening in this unreviewable diff:
- moved PulsePathCondition to PulseSledge
- renamed --pulse-path-conditions to --pudge
- PulsePathCondition now contains all the arithmetic of pulse
(inferbo+concrete intervals+pudge). In particular, moved arithmetic
attributes into PulsePathCondition.t. PulsePathCondition plays the
role of PulseArithmetic (combining all domains).
- added tests for a false positive involving free()
- PulseArithmetic is now just a thin wrapper around PulsePathCondition
to operate on states directly (instead of on path conditions).
- The rest is mostly moving code into PulsePathCondition (eg, from
PulseInterproc) and adjusting it.
Reviewed By: jberdine
Differential Revision: D21332073
fbshipit-source-id: 184c8e0a9
Summary:
We have a common entry point where we skip analysis in nullsafe.
This logic is copied from `Reporting.log_issue_from_summary`.
I believe this should not exist in Reporting: it is not the right place
to decide whether to suppress issues: we should not try to report it in
first place.
Because of that we falsely report "needs improvement" meta-issue while
we don't issue any (they were suppressed but participated in needs
improvement count calculations).
Now this change will make meta-issue to be synced with what the user
actually sees.
Down the line we should have a more reliable fix for that.
So far I reviewed suppressing code and looks like we should not suppress
anything else (unless explicitly SuppressLint-ed, which is fine).
Reviewed By: artempyanykh
Differential Revision: D21328634
fbshipit-source-id: 120ce06d1
Summary:
Add a new data structure and use it for the map of memory accesses to
limit the number of destinations reachable from a given address. This
avoids remembering details of each index in large arrays, or even each
field in large structs.
Reviewed By: skcho
Differential Revision: D18246091
fbshipit-source-id: 5d3974d9c
Summary:
The C++ tests were a bit of a mess. This diff tries to enforce the following principles:
- mark every function with `_ok` or `_bad` so that when a function appears in `issues.exp` it's easy to figure out the intention;
- mark every false negative and positive with `FP_` and `FN_` to document expectations;
- make every function access one field and participate in at most one issue report so that it's easier to assess changes.
Reviewed By: jvillard
Differential Revision: D21278627
fbshipit-source-id: 9698f716f
Summary:
We were invalidating "*(vec.__infer_backing_array)" instead of the
address of the field itself.
Reviewed By: ezgicicek
Differential Revision: D21280357
fbshipit-source-id: 48b984800
Summary:
The directory was created to have several sets of nullsafe tests but
there is only one in the end. Remove the redundant "-default".
Reviewed By: mityal
Differential Revision: D21300205
fbshipit-source-id: 46ed8b032
Summary:
The directory names had some interesting variety due to historical
reasons.
- {c,cpp,objc,objcpp}/errors/ date from the time when infer was only
biabduction
- java/infer/ dates from the time when we had an "--analyzer" option and
"infer" was one of them (sic), and eg another was "eradicate".
- c/biabduction/ dates from the time when the biabduction analysis was
being migrated to the "checkers" (AI) framework. For some reasons the
tests there are not a subset of c/infer/ but seem to be entirely new
tests.
The convention now dictates that we should name all of these
*/biabduction/. This diff moves the existing tests from c/biabduction/
into c/biabduction/misc/.
Reviewed By: mityal
Differential Revision: D21300147
fbshipit-source-id: 516d1cb15
Summary: We currently don't support abducing the spec that we need to delete an attribute, that makes the model for `CFBridgingRelease` work les well when it is, for instance, wrapped in a method. We show examples of how this doesn't work at the moment.
Reviewed By: jvillard
Differential Revision: D21176108
fbshipit-source-id: 79aed7a5d
Summary:
We model `malloc` in Objective-C as `malloc_not_fail` I think because the null case is not normally handled in iOS apps because the OS will just killed the app after giving some memory warnings.
So adding `malloc_not_fail` model to Pulse.
Reviewed By: jvillard
Differential Revision: D21278527
fbshipit-source-id: 17a5008fe
Summary:
This translates the construct `ObjCBridgedCastExpr` when the cast_kind is `OBC_BridgeTransfer`, or in syntax, the cast (`__bridge_transfer`).
This cast means that the object is passed from manual memory management to ARC, so one doesn't need to call `release` manually. It is important to model this to avoid false positives.
It translates it as a builtin that we then model in Pulse, the same way we modelled `CFBridgingRelease` which does the same thing.
The name of the builtin is `__free_cf` which is not ideal but I left it like that for compatibility with biabduction. We can change it once we remove this check from biabduction.
update-submodule: facebook-clang-plugins
Reviewed By: jvillard
Differential Revision: D21176337
fbshipit-source-id: 736ceeb9b
Summary:
In the previous diffs, nullsafe behavior was changed to the following:
nested class mode is inherited from the outer class mode.
Though it is possible to e.g. make nested class Nullsafe and outer not,
or make nested class STRICT and outer just LOCAL, this is an edge case
and we don't want to recommend annotating nested classes by default. The
right way is to make outer class Nullsafe instead.
In this decision, we take into account user experience and codebase
readability.
Reviewed By: ngorogiannis
Differential Revision: D21255806
fbshipit-source-id: 0200cb555
Summary:
With this change, set of possibilities will be more actionable. Most
importantly, this will also educate users and make them realize how
Nullsafe trust works.
NOTE: yes, parenthesis are bit clumsy, but it was the easiest way to
make this change and let the phrase remain grammatically correct.
Reviewed By: artempyanykh
Differential Revision: D21231468
fbshipit-source-id: 4b5349fb5
Summary:
In the previous diff we changed the semantics of nested classes w.r.t.
to Nullsafe.
Let's make it clear if users will attempt to misuse it.
Reviewed By: artempyanykh
Differential Revision: D21230717
fbshipit-source-id: 0ecc0dd06
Summary: Similarly to Enum.name, we model Class.getCanonicalName as returning an arbitrary non-empty string.
Reviewed By: ngorogiannis
Differential Revision: D21207120
fbshipit-source-id: 1e2dbd1fd
Summary:
From the user perspective, the current behavior is confusing.
The users intutitively expect the inner class to inherit Nullsafe mode
from the outer one.
Having a class that is Nullsafe but the inner is not is hence dangerous
and misleading.
For the sake of completeness and to support gradual strictification, we
allow the nested class to improse additional strictness. Particularly,
the inner class can be Nullsafe but the outer can be not.
A follow up to this diff will include warnings telling about redundant and wrong usages of nested annotations.
Reviewed By: artempyanykh
Differential Revision: D21228055
fbshipit-source-id: 75755ad1d
Summary: Iterator invalidation traces were based on vector rather than iterator itself.
Reviewed By: ezgicicek
Differential Revision: D21202047
fbshipit-source-id: 62ce8a488
Summary:
We model Enum.name as returing a constant name, rather than getting real field names. We did this
because we couldn't think of any big gains, in terms of analysis precision/performance, from getting
the real names.
Reviewed By: ezgicicek
Differential Revision: D21201730
fbshipit-source-id: a2dc01a44
Summary: This diff revises the models of Collection.set and get to handle its elements.
Reviewed By: ezgicicek
Differential Revision: D21201242
fbshipit-source-id: 9c248453d
Summary:
We ignored allocator models for vectors, and were not able to initialize vectors properly. This diff fixes this issue.
It also adds a test which was a FN before.
Reviewed By: skcho, jvillard
Differential Revision: D21089492
fbshipit-source-id: 6906cd1d1
Summary: D21155014 replaced `skip` call with a Load but this was not right. Instead, let's add a new builtin function (rather than skip) so that other analyses can freely model it as they want.
Reviewed By: jvillard
Differential Revision: D21178286
fbshipit-source-id: c214ccfb0
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: `CFBridgingRelease` and `__bridge_transfer` which I'll model later, transfer the memory model from manual memory ref count to ARC (automatic ref count), so to avoid false positives this needs to be modelled. We can simply remove the Allocated attribute from the state, which means we won't try to track that memory anymore.
Reviewed By: skcho
Differential Revision: D21088218
fbshipit-source-id: 3520a0d59
Summary: This diff suppresses cost issues on lambda and auto-generated procedures, since they were too noisy.
Reviewed By: ezgicicek
Differential Revision: D21153619
fbshipit-source-id: 65ad6dcc3
Summary:
Replace horrible hack with ok hack.
The main difficulty in implementing the disjunctive domain is to avoid
the quadratic time complexity of executing the same disjuncts over and
over again when going around loops:
First time around a loop, assuming for example a single disjunct `d`:
```
[d]
loop body
[d1' \/ d2']
```
Second time around the same loop: the new pre will be the join of the
posts of predecessor nodes, so `old_pre \/ post(loop,old_pre)`, i.e.
`d \/ d1' \/ d2'`. Now we need to execute `loop body` again
*without running the symbolic execution of `d` again* (and the time after
that we'll want to not execute `d`, `d1'`, or `d2'`).
Horrible hack (before): Disjuncts have a boolean "visited" attached
that does its best to keep track of whether a given disjunct is old or
new. When executing a single *instruction* look at the flag and skip the
state if it's old. Of course we have no way to know for sure so it turns
out it was often wrongly re-executing old disjuncts. This was also
producing the wrong results over even simple loops: only the last
iteration would make it outside the loop for some reason. Overall, the
semantics were pretty untractable and shady at best.
New hack (this diff): only run instructions of a given *node* on
disjuncts that are not physically equal to the "pre" ones already in the
invariant map for the current node.
This gives the correct result over simple loops and a nice performance
improvement in general (probably the old heuristic was hitting the
quadratic bad case more often).
Reviewed By: skcho
Differential Revision: D21154063
fbshipit-source-id: 5ee38c68c
Summary:
We translated the expression `CXXStdInitializerListExpr` naively in D3058895 as a call to
a skip function, with the hope that it would be translated better in the future. However, the naive means that we lose access to the initialized list/array because we are simply skipping it. So, even if we want to model the initializer properly, we have to deal with the skip specially.
This diff tries to solve this problem by removing the skip call whenever
possible. Instead, we translate the underlying array/list as a Load, so
that when it is passed to the constructor, we can pick it up.
For the following initialization:
``` std::vector<int*> vec = {nullptr};
```
Before, we translated it as
```
*&0$?%__sil_tmpSIL_materialize_temp__n$7[0]:int* const =null
n$8=_fun___infer_skip_function(&0$?%__sil_tmpSIL_materialize_temp__n$7:int* const [1*8] const )
n$9=_fun_std::vector<int*,std::allocator<int*>>::vector(&vec:std::vector<int*,std::allocator<int*>>*,n$8:std::initializer_list<int*>)
```
However, this means, `n$8` would be result of something skipped which we can't reason about. Instead, we just pass the underlying initialized array now, so we get the following translation:
```
*&0$?%__sil_tmpSIL_materialize_temp__n$7[0]:int* const =null
n$8=*&0$?%__sil_tmpSIL_materialize_temp__n$7:int* const [1*8] const
n$9=_fun_std::vector<int*,std::allocator<int*>>::vector(&vec:std::vector<int*,std::allocator<int*>>*,n$8:std::initializer_list<int*>)
```
Reviewed By: jvillard
Differential Revision: D21155014
fbshipit-source-id: 75850b1e6
Summary:
When encountering a constant, pulse creates an abstract value (a
variable) to represent it, and remembers that it's equal to it. The
problem is that pulse doesn't yet know how to deal with the fact that
some variables are going to be equal to each other.
This hacks around this issue in the case of constants, within the same
procedure, by remembering which constants have been assigned to which
place-holder variables, and serving those variables again when the same
constant is translated again.
Limitation: this doesn't work across procedure calls as the "constant
maps" are not saved in summaries.
Something to look out for: we don't want to make `if (p == NULL)` create
a path where `p` is invalid (we only make null invalid when we see an
assignment from 0, i.e. `p = NULL;`).
Reviewed By: ezgicicek
Differential Revision: D21089961
fbshipit-source-id: 5ebb85d0a
Summary:
1. Package will make the error too verbose.
2. We don't even need to say it is "class" because we say it in the error
description ("Class has 0 issues and can be marked Nullsafe").
Reviewed By: artempyanykh
Differential Revision: D21131998
fbshipit-source-id: 6ccca7615
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: Modeling vector iterator with two internal fields: an internal array and an internal pointer. The internal array field points to the internal array field of a vector; the internal pointer field represents the current element of the array. For now `operator++` creates a fresh element inside the array.
Reviewed By: ezgicicek
Differential Revision: D21043304
fbshipit-source-id: db3be49ce
Summary:
Add a path condition to each symbolic state, represented in sledge's arithmetic domain. This gives a precise account of arithmetic constraints. In particular, it is relation and thus is more robust in the face of inter-procedural analysis.
This is gated behind a flag for now as there are performance issues with the new arithmetic.
Reviewed By: jberdine
Differential Revision: D20393947
fbshipit-source-id: b780de22a
Summary:
There are two types of anonymous classes (not user defined classes):
- classic anonymous classes (defined as $<int> suffixes)
- lambda classes (corresponding to lambda expressions). Experimentally,
they all have form `$Lambda$_<int>_<int>`, but the code just uses
`$Lambda$` as a heuristic so it is potentially more robust.
# Problem this diff solves
When generate meta-issues for nullsafe, we are interested only in
user-defined classes, so we merge all nested anonymous stuff to
corresponding user-defined classes and hence aggregate the issues.
Without this diff, for each lambda in the code, we would report this as
a separate meta-issue, which would both screw up stats and be confusing
for the user (when we start reporting mode promo suggestions!).
Reviewed By: artempyanykh
Differential Revision: D21042928
fbshipit-source-id: a7be266af
Summary:
This diff revises how to handle the unknown location in inferbo in two ways:
* stop appending field to the `Unknown` location, e.g. `Unknown.x.a` is evaluated to `Unknown`
* redesign the abstract of multiple locations, like `Bottom` < `Unknown` < `Known` locations
I am doing them in one diff since applying only one of them showed bad results.
Background: `Unknown` was adopted for abstracting all unknown concrete locations, so we could avoid missing semantics of assignments to unknown locations. We tried to keep soundness. However, it brought some other problems related to precision and performance.
1. Sometimes especially when Inferbo failed to reason precise pointer values, `Unknown` may point to many other abstract locations.
2. At that time, value assignments to `*Unknown` makes the situation worse: many abstract locations are updated with imprecise values.
This problem harmed not only its precision, but also its performance since it introduced more location entries in the abstract memory.
Reviewed By: jvillard
Differential Revision: D21017789
fbshipit-source-id: 0bb6bd8b5
Summary: The flags `--biabduction-fallback-model-alloc-pattern` and `--biabduction-fallback-model-free-pattern` were unused because we removed the models from .inferconfig a while ago because of too many false positives. We are implementing a better memory leak check based on Pulse, and are adding the similar flags `--pulse-model-alloc-pattern` and `--pulse-model-free-pattern`.
Reviewed By: jvillard
Differential Revision: D21061511
fbshipit-source-id: 1b3476c22
Summary:
See the code comment re: why don't we also recommend "strict" at this
stage. We can always change it later when we think users are happy with
strict.
Reviewed By: artempyanykh
Differential Revision: D21039553
fbshipit-source-id: 758ccf32c
Sungkeun Cho
Ezgi Çiçek
Jules Villard
Mitya Lyubarskiy
Daiva Naudziuniene
Martin Trojer
Nikos Gorogiannis
Qianyi Shu
Dulma Churchill
Radu Grigore
Artem Pianykh
David Pichardie