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:
Extend BasicCost to BasicCostWithReason which contains a record of the form
```{cost: BasicCost.t; proc_name_list: Procname.t list}```
This is done so that we can keep track of top cost function.
So the idea is that 80% of functions with Top cost are caused by calling top-costed callees, i.e. callee's Top cost is simply propagated to its transitive callers, so the aim is to investigate such root callees along with the number of their transitive callers.
Therefore, we create an extension that match `cost` to the root cause function.
This diff only handles the extension. Details about how we update the root cause function is in the next diff.
Reviewed By: skcho
Differential Revision: D22158717
fbshipit-source-id: 6498d904f
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: Log unmodeled function in cost analysis and send result to scuba.
Reviewed By: ezgicicek
Differential Revision: D22158510
fbshipit-source-id: c6eade67e
Summary: This continues on the previous diff by removing the model for `__bridge_transfer` in biabduction. This also had the name __free_cf which we kept for compatibility with biabduction until now but that we can now change.
Reviewed By: ezgicicek
Differential Revision: D22207396
fbshipit-source-id: 7a175eca6
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:
There is a lot of subtlety in our parsing of buck targets on the command line, that is then just thrown away. Push this one level up, getting rid of the special case where in Clang mode if we only have "normal" targets we don't resolve them.
Also introduce a proper variant for buck target types.
Reviewed By: skcho
Differential Revision: D22160490
fbshipit-source-id: 500c1b12c
Summary:
This diff revises assignment semantics, so it can store/load from the
heap location.
Reviewed By: ezgicicek
Differential Revision: D22042823
fbshipit-source-id: 20d91bfc5
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:
Better API for creating issue types:
- distinguish hidden/normal/dynamic issue types
- normal issue types should always be documented
- add "TODO" to missing documentation
- dynamic issue types are the only ones that can be created outside of
IssueType.ml
I had to document the new CCBM and the resource leak lab exercise to
keep Help.ml happy, did `make doc-publish`.
Reviewed By: ngorogiannis
Differential Revision: D22118766
fbshipit-source-id: 3d0194518
Summary:
A bug in docusaurus makes relative URLs fail depending on how the page
was accessed, because the URL of a page in docs/ will end in / if
accessed directly or via hyperlink, but that / will be omitted when
clicking on the sidebar. The final / makes all the difference when
interpreting relative URLs so relative URLs are essentially broken.
See https://github.com/facebook/docusaurus/issues/2832 for more details.
This changes URL generation to generate URLs /docs/next/..., and
manually substitute relative URLs that had been written by hand.
Also fix a few other things about outdated links/comments.
Finally, `make doc-publish`.
Reviewed By: dulmarod
Differential Revision: D22117187
fbshipit-source-id: 32e2ba7e1
Summary: Buck uses its own estimate for how many workers to spawn, there is no need to pass our own estimate for capture.
Reviewed By: ezgicicek
Differential Revision: D22065565
fbshipit-source-id: 4c062a9aa
Summary:
Needed to remove user_documentation for the new
CONFIG_CHECK_BETWEEN_MARKERS issue type otherwise it violated the
invariant that the corresponding checker should be documented too but
its development has just started.
Reviewed By: skcho
Differential Revision: D22065820
fbshipit-source-id: 4b3a58850
Summary:
alicelieutier graciously contributed this React component to savagely
include the HTML from the man pages into docusaurus. Now they render
like the rest of the documentation!
Reviewed By: cristianoc
Differential Revision: D22050580
fbshipit-source-id: e8e314109
Summary:
A space in user's path will lead to a make failure on line 899 of
Makefile. Let's espace the path to avoid that.
Reviewed By: jvillard
Differential Revision: D22044934
fbshipit-source-id: 5a949be1d
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:
Refactor `Equality.ppx_classes_diff` into `diff_classes` to construct
the difference between classes maps explicitly, and change
`ppx_classes` to accept such a difference instead of computing it
internally.
This more flexibly composable interface allows elimination of extra
calls to `Equality.entails` to check if the difference is empty.
Reviewed By: jvillard
Differential Revision: D22038488
fbshipit-source-id: c19c18fc8
Summary:
The list interpreted as a conjunction of individual terms in `Sh.pure`
is now redundant with `Term.And`. This patch removes the redundant
list.
Reviewed By: jvillard
Differential Revision: D22035852
fbshipit-source-id: 49c01a078
Summary:
With the current handling of fresh variable generation during symbolic
execution, it is now possible to delay generating fresh variables in
individual small axioms until the precondition is known. In
particular, the existential variables of the precondition formula can
be bound, and then the small axiom can be generated with variables
fresh with respect to them. Previously, the small axioms were
generated with fresh variables that could later clash with the
precondition's existentials, necessitating renaming. This
double-freshening is now eliminated.
Reviewed By: jvillard
Differential Revision: D21974022
fbshipit-source-id: f217bfb9f
Summary:
When fresh variables are generated to name the overwritten value in an
assignment, they should be included in the ghost variables of the
resulting small axiom. This change should have been included in the
elimination of SSA.
Also strengthen assertion checking of small specs during symbolic
execution.
Reviewed By: jvillard
Differential Revision: D21974019
fbshipit-source-id: a66d8dac6
Summary:
Currently the symbolic execution code in `Exec` manually threads
universal and existential variable contexts through virtually every
function. It is easy to mistakenly pass on a context that is not the
latest-extended one, or to forget to add generated variables to the
contexts.
This patch adds a state monad, `Fresh`, to manage the generation of
fresh variables in `Exec`. This is a standard state monad where the
state is two sets of variables: those to which fresh variables must be
chosen fresh, and those which have been generated. This yields an
abstraction where an `'a Fresh.t` value represents a value of type
`'a` which may contain as-yet-unnamed variables, and `Fresh.gen ~wrt
a` generates names that are fresh with respect to `wrt` for all
unnamed variables in `a`, and yields the set of generated variables
together with `a` expressed in terms of those variables.
Reviewed By: jvillard
Differential Revision: D21974018
fbshipit-source-id: 1917e82c0
Summary: Minor code simplification and optimization of `extend_us` in no-op case.
Reviewed By: jvillard
Differential Revision: D21974021
fbshipit-source-id: a8b12b564
Summary:
Change the `Var.Subst` `freshen` and `restrict` constructors to return
the domain and range of the substitution explicitly. Clients generally
need to compute them immediately, and they are at least partially
constructed during the initial substitution construction anyhow. This
may be an incidental minor optimization.
This allows removing the `apply_set` operation, as it's use can be
handled directly from the domain and range sets.
This also allows `Sh.rename` to be split into a function that assumes
that the substitution is restricted to the vocabulary of the formula,
and a wrapper that does this restriction and calls through. This
allows `Sh.freshen_xs` to be simplified slightly, and avoids some
redundant restriction, domain, and range computations.
Reviewed By: jvillard
Differential Revision: D21974017
fbshipit-source-id: aa8b3db24
Artem Pianykh
Dulma Churchill
Daiva Naudziuniene
Qianyi Shu
Sungkeun Cho
Nikos Gorogiannis
Ezgi Çiçek
Jules Villard
Andrew V. Jones
Josh Berdine