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
Sungkeun Cho
Ezgi Çiçek
Jules Villard
Mitya Lyubarskiy
Daiva Naudziuniene
Martin Trojer
Nikos Gorogiannis
Qianyi Shu
Dulma Churchill
Radu Grigore
Artem Pianykh
David Pichardie