Summary:
This was left as a TODO before: where to place calls to destructors for
C++ temporaries that are only conditionally creating when evaluating an
expression. This can happen inside the branches of a conditional
operation `b?e:f` or in potentially-short-circuited conditions on the
righ-hand side of `&&` and `||` operators.
Following the compilation scheme of clang (observed by looking at the
generated LLVM bitcode), we instrument the program with "marker"
variables, so that for instance `X x = true?X():y;` becomes (following
the execution on the true branch):
```
marker1 = 0; // initialize all markers to 0
PRUNE(true) // entering true branch
X::X(&temporary); // create temporary...
marker1 = 1; // ...triggers setting its marker to 1
X::X(&x, &temporary); // finish expression
if (marker1) {
X::~X(&temporary); // conditionally destroy the temporary
}
```
In this diff, you'll find code for:
- associating markers to temporaries that need them
- code to initialize markers to 0 before full-expressions
- code to conditionally destroy temporaries based on the values of the
markers once the full-expression has finished evaluating
Reviewed By: da319
Differential Revision: D24954070
fbshipit-source-id: cf15df7f7
Summary:
The translation of `switch` cases needs to insert nodes around the
translation of each `case` sub-statement, so we need to force node
creation in these sub-statements so the nodes around it can be connected
to the translation of the sub-statements.
Also added more logging I found useful when debugging that.
Reviewed By: da319
Differential Revision: D24991455
fbshipit-source-id: d3a622142
Summary:
The current source parser is based on ocamllex only.
In order to track field declaration locations, we propose a
new parser using ocamllex/menhir. This is a more ambitious
project that closely follows the official Java syntax.
Reviewed By: jvillard
Differential Revision: D24858280
fbshipit-source-id: 22d6766e5
Summary:
In all other places, we index params from 0, but accidentally recorded
the wrong number in json. It was because of the confusion between index
and user-visible param position that we show for the user message.
This diff fixes it: now we use 0-based indices internally (but of course still
report 1-based ones in the error message).
Reviewed By: artempyanykh
Differential Revision: D24916878
fbshipit-source-id: 45532c5ff
Summary:
Split the translation of return more aggressively between:
1. the instruction that has to happen before the translation of the sub-expr
2. the sub-expr
3. the instruction that has to happen after the sub-expr
This is needed for the next diff which creates potentially large CFGs in
(2).
Reviewed By: da319
Differential Revision: D24954071
fbshipit-source-id: a7e7e2527
Summary: Model `folly::Optional::get_pointer` which returns an address to a value if exists or `nullptr` if empty.
Reviewed By: jvillard
Differential Revision: D24935677
fbshipit-source-id: 9d990fe07
Summary:
We deliberately stopped as soon as an error was detected when applying a
function call. This is not good as other pre/posts of the function may
apply cleanly, which would allow us to cover more behaviours of the
code.
Went on a bit of a refactoring tangeant while fixing this, to clarify
the `Ok None`/`Ok Some _`/`Error _` datatype returned by PulseInterproc.
Now we report errors as soon as we find them during function calls but
continue accumulating specs afterwards.
Reviewed By: da319
Differential Revision: D24888768
fbshipit-source-id: d5f2c29d7
Summary:
Communicate new facts from the arithmetic domain to the memory domain to
detect contradictions between the two.
Reviewed By: jberdine
Differential Revision: D24832079
fbshipit-source-id: 2caf8e9af
Summary:
This is several inter-connected changes together to keep the tests
happy.
The ConditionalOperator `b?t:e` is translated by first creating a
placeholder variable to temporarily store the result of the evaluation
in each branch, then the real thing we want to assign to reads that
variable. But, there are situations where that changes the semantics of
the expression, namely when the value created is a struct on the stack
(eg, a C++ temporary). This is because in SIL we cannot assign the
*address* of a program variable, only its contents, so by the time we're
out of the conditional operator we cannot set the struct value
correctly anymore: we can only set its content, which we did, but that
results in a "shifted" struct value that is one dereference away from
where it should be.
So a batch of changes concern `conditionalOperator_trans`:
- instead of systematically creating a temporary for the conditional,
use the `trans_state.var_exp_typ` provided from above if available
when translating `ConditionalOperator`
- don't even set anything if that variable was already initialized by
merely translating the branch expression, eg when it's a constructor
- fix long-standing TODO to propagate these initialization facts
accurately for ConditionalOperator (used by `init_expr_trans` to also
figure out if it should insert a store to the variable being
initialised or not)
The rest of the changes adapt some relevant other constructs to deal
with conditionalOperator properly now that it can set the current
variable itself, instead of storing stuff inside a temp variable. This
change was a problem because some constructs, eg a variable declaration,
will insert nodes that set up the variable before calling its
initialization, and now the initialization happens *before* that setup,
in the translation of the inner conditional operator, which naturally
creates nodes above the current one.
- add a generic helper to force a sequential order between two
translation results, forcing node creation if necessary
- use that in `init_expr_trans` and `cxxNewExpr_trans`
- adjust many places where `var_exp_typ` was incorrectly not reset when translating sub-expressions
The sequentiality business creates more nodes when used, and the
conditionalOperator business uses fewer temporary variables, so the
frontend results change quite a bit.
Note that biabduction tests were invaluable in debugging this. There
could be other constructs to adjust similarly to cxxNewExpr that were
not covered by the tests though.
Added tests in pulse that exercises the previous bug.
Reviewed By: da319
Differential Revision: D24796282
fbshipit-source-id: 0790c8d17
Summary:
The starvation domain keeps a domain element per distinct pair of lock object and source location. This was used to counteract the imprecision of implicit Quandary-style traces. Starvation has used explicit traces for a long time now, so keeping all these elements is expensive (in fact, in some cases exponential) and of no value. Now, lock object identity is the only distinguishing feature of a domain element.
Also, fix some pretty printing for debugging purposes.
Reviewed By: jvillard
Differential Revision: D24829306
fbshipit-source-id: 22e12f9c1
Summary: We recently introduced a more precise model for constructing an optional from a value by making a shallow copy. However, this introduced Use After Delete false positives. For now, we go back to a less precise model by creating a fresh value. A proper model would be to either make a deep copy or call the copy constructor for a value. We will address this in the following diff.
Reviewed By: jvillard
Differential Revision: D24826749
fbshipit-source-id: 3e5e4edeb
Summary: Refactor `folly::Optional` models to make them easier to reuse for `std::optional`
Reviewed By: jvillard
Differential Revision: D24760053
fbshipit-source-id: f665e84c8
Summary:
If the issue one of:
- Field Not Nullable
- Field Not Initialized
- Field Overannotated,
we record field_name to .json result.
NoTE: Design choice for representation. For Field Not Initialized and Field Overannotated
this is always internal (relative to the class) field, but for Field Not
Nullable it can be either internal or external. We could have a
structured output, or always output full name. I preferred to output
short name for convenience of the main usacase I am anticipating.
NOTE: not to be confused with the case where the field is nullable but
we e.g. try to dereference it. This is indirectly related to the issue
(can be several such fields for starters) and if we one day output it,
it will be provided in a separate way (similarly to how we output
nullable_methods).
Reviewed By: artempyanykh
Differential Revision: D24730320
fbshipit-source-id: c995ec221
Summary:
We never tested params dependent on things (tested only things dependend
on params).
Reviewed By: artempyanykh
Differential Revision: D24726858
fbshipit-source-id: a0861cfc3
Summary:
Since we report issues types without a prefix (e.g. ERADICATE_) and
with spaces we should also allow for prefix-less issue types in
SuppressLint, so both should work
- SuppressLint("eradicate-field-not-initialized")
- SuppressLint("Field Not Initialized")
Reviewed By: jvillard
Differential Revision: D24760341
fbshipit-source-id: 1590cf6d0
Summary:
There is a feature in Nullsafe that is interfering with "annotation
graph" feature. Because of this we would not detect provisional
violations for misuses of params of equals() (They will be recorded
as user facing rather than provisional issues).
This diff turns this feature off for annotation graph mode.
Reviewed By: artempyanykh
Differential Revision: D24726655
fbshipit-source-id: 4b7577667
Summary:
Virtual "this" invisible param exists in the annotated signature, but
does not exist in some other places, which causes a lot of annoyance in
different places.
This diff does not intend to solve all this, but makes one step forward.
1/ AnnotatedNullability now explicitly distincts normal params and
VirtualThis.
2/ AnnotatedSignature accounts for this via: a) not having redundant
fake annotation points b) having corrent param indices (those were off
by 1 in non-virtul methods).
Reviewed By: artempyanykh
Differential Revision: D24726480
fbshipit-source-id: fdb8bb0fb
Summary: This is a complex enough feature so iterating on it in a safe manner will be useful.
Reviewed By: artempyanykh
Differential Revision: D24725406
fbshipit-source-id: 81b247143
Summary: `folly::Optional::value()` returns a reference, hence an error was shown when the actual value was being accessed. Since `value()` throws an exception in case of `folly::none`, we want to show the error message at the call site of `value()`. We do this by dereferencing the result of `value()` in the model.
Reviewed By: jvillard
Differential Revision: D24702875
fbshipit-source-id: ca9f30349
Summary:
The problem in Reporting.ml:log_issue_from_summary is that it merely
checks the presence of `SuppressLint` annotation on method's body to
decide whether to log or not the issue. This means that regardless of
issue types specified in `SuppressLint`, all issues on such method will
get blocked.
Here we fix that.
Reviewed By: ngorogiannis, mityal
Differential Revision: D24726604
fbshipit-source-id: c9cae3833
Summary:
Before we were creating a fresh internal value when we were constructing `folly::Optional`. This diff models `folly::Optional` constructor more precisely by copying the given value.
There was also a missing dereference in the model of `value_or`
Reviewed By: jvillard
Differential Revision: D24621016
fbshipit-source-id: c86d3c157
Summary:
Namely `enumerateObjectsUsingBlock` which takes a collection and a block as an arg and the iterates over the collection and applies the block to each element of the collection.
This is a common way to iterate over Objc collections, so let's add a model for it.
Reviewed By: skcho
Differential Revision: D24604590
fbshipit-source-id: 1ceeb4b40
Summary:
This diff revises the translation of message expression's arguments in ObjC frontend. In the
frontend, it massages the arguments when calling a static method, so the class or object value is
not given to the static method as the first parameter.
The problem is that it used a raise-exception-and-catch way to detect where we remove the first
parameter. This way of using an exception is not only hard to understand, but also incorrectly
removed the first parameter, with breaking abstract semantics sometimes. (See the added test.) This diff
avoids using the exception.
Reviewed By: jvillard
Differential Revision: D24565513
fbshipit-source-id: 0a84ca394
Summary:
The `make clean` did not remove objects and dot files, so
```
infer/tests/codetoanalyze/objc/frontend$ make test
infer/tests/codetoanalyze/objc/frontend$ make clean
infer/tests/codetoanalyze/objc/frontend$ make test
```
the second `make test` did nothing. This diff adds additional regular
expressions to clean all objects and dot files generated.
Reviewed By: ngorogiannis
Differential Revision: D24566169
fbshipit-source-id: b8c50c922
Summary: This diff fixes on-demand symbolic value generation of a class that inherits NSEnumerator.
Reviewed By: ngorogiannis
Differential Revision: D24504955
fbshipit-source-id: bcb20e8aa
Summary:
This diff replaces overridden method calls in ObjC when possible, ie the first parameter of the
method has a sub-class type of the method's class. For example,
when `MyEnumerator` is a sub-class of `NSEnumerator` and there is overridden `nextObject`,
```
[my_enumerator nextObject]
```
in Sil, it was translated to like
```
NSEnumerator.nextObject(my_enumerator : MyEnumerator*)
```
and the analyzer missed the overridden method. This diff replaces the function call to
```
MyEnumerator.nextObject(my_enumerator : MyEnumerator*)
```
Reviewed By: ezgicicek
Differential Revision: D24477290
fbshipit-source-id: 6842a76f8
Summary: Model `folly::Optional::value_or(default)` to return value if not-empty and `default` if empty.
Reviewed By: jvillard
Differential Revision: D24539456
fbshipit-source-id: cc9e176cc
Summary:
This diff revises `nextObject` model to handle multiple symbolic enumerators. Instead joining the
symbolic offsets of them, which sometimes introduces top, it sums the offsets. This is a sound &
conservative semantics since they are all non-negative integers.
Reviewed By: ezgicicek
Differential Revision: D24474513
fbshipit-source-id: 6707aa907
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
Jules Villard
David Pichardie
Mitya Lyubarskiy
Daiva Naudziuniene
Sungkeun Cho
Nikos Gorogiannis
Artem Pianykh
Ezgi Çiçek
Josh Berdine