Summary:
Array types where the length is not statically known were represented
using fresh variables. This diff:
- Makes array type length optional, reducing the amount of work needed
for renaming, substitution, and normalization.
- Revises uses of array length so that the length component of a
Tarray type represents only the statically determined constant
length of an array type, and the length component of a Sizeof
expression represents the dynamically determined length of an array
value.
- Restricts the type of static lengths from a general expression
(Sil.exp) to an integer (Sil.Int.t), enforcing that static types are
constant. This in particular ensures that types contain no
variables, and so are invariant under operations such as renaming
and substitution.
- Removes the type substitution and renaming functions typ_sub,
typ_normalize, and typ_captured_ren. Now that array type lengths
are constant integers, all of these functions are the identity.
Reviewed By: cristianoc
Differential Revision: D3387343
fbshipit-source-id: b5db768
Summary:
The extra dereference in stmtexpr was wrong. When a dereference is needed, we have a cast.
This was causing one dereference too many, and creating wrong results.
Reviewed By: akotulski
Differential Revision: D3393294
fbshipit-source-id: 7a1ec8e
Summary:
Pass object by reference every time struct object is passed by value
in C++. Do it only for C++/objC++ where we have guarantee that the
object which is passed will be temporary one (created by copy constructor).
Reviewed By: jberdine
Differential Revision: D3346271
fbshipit-source-id: d3e5daa
Summary:
Make analyzer find out when null dereference comes from std::vector method.
If it does, it means that it's really empty vector access (due to the
way infer models std::vector)
Reviewed By: sblackshear
Differential Revision: D3327933
fbshipit-source-id: b9e11d6
Summary:
Turns out, analyzer was getting confused with complicated
model and it was reporting empty access in places it
shouldn't. Fixing backend is not trivial (tracing mode is the answer),
but the model can be simplified.
It introduces the problem that get() method doesn't return fresh value
every time, but we should be able to change backend later to deal with it.
Reviewed By: sblackshear
Differential Revision: D3328228
fbshipit-source-id: dddbaf8
Summary:
Create model of C++ std::vector to find occurrences when vector which might be empty is accessed. Do it by triggering null dereference every time empty vector access is performed.
Note: model will be used only when c++11 (or c++14) are used.
Reviewed By: sblackshear
Differential Revision: D3276203
fbshipit-source-id: 420a95a
Summary:
The philosophy of the tracing mode reporting is to not report the errors in a method if reaching this error does depend on information that can be false at call site. Typically with:
void foo(Object obj, int x) {
if (x == 3) {
obj.toString();
}
}
it may be that we always call `foo` with a non-null parameter or `x != 3`.
Thechnically, the reporting code matches the pairs of the form (precondition, error) and filtering out the cases where the precondtions was not imposing constraints on the calling context, and report the other cases. So the NPE could be reported in the following case:
void bar() {
foo(null, 3);
}
However, we were missing the case where there was anyway no way to call a method in a safe way, i.e. all the preconditions were of the form: (precondition, error), for example:
void baz(boolean b) {
if (b) {
foo(null, 3);
} else {
foo(null, 3);
}
}
In that case, the summary is of the form
PRE (1): b = false
POST: NullPointerException
PRE (2): b = true
POST: NullPointerException
In which case it is legit to report `NullPointerException` in `baz`.
Reviewed By: sblackshear, jberdine
Differential Revision: D3220501
fb-gh-sync-id: 7fb7d70
fbshipit-source-id: 7fb7d70
Summary: Example of dynamic dispatch with interfaces were already working. Adding some tests now so that we don't break this.
Reviewed By: sblackshear
Differential Revision: D3220360
fb-gh-sync-id: 11395dd
fbshipit-source-id: 11395dd
Summary: For performance critical sections of the code, this checker detects memory allocations or calls to methods annotated as expensive. However, such cases of memory allocations or expensive calls are acceptable is occuring in rare cases. This diff adds supports for the "unlikely" branch prediction method and does not track expensive calls in unlikely branches.
Reviewed By: sblackshear
Differential Revision: D3193473
fb-gh-sync-id: ea87e49
fbshipit-source-id: ea87e49
Summary:BinaryConditionalOperator should evaluate condition expression once, but we used to evaluate it twice.
Fix translation to account for it.
Reviewed By: dulmarod
Differential Revision: D3179803
fb-gh-sync-id: a801a7e
fbshipit-source-id: a801a7e
Summary:This diff translate cpp lambdas. For the moment it does not take care of
captured variables. Captured variables will come in the next diff.
Reviewed By: dulmarod
Differential Revision: D3114790
fb-gh-sync-id: bf36450
fbshipit-source-id: bf36450
Summary:public
When a conditional is the last instruction, there will be a join node leading directly to the exit node.
Some instructions, such as nullification of dead variables, and abstraction, are added to the control flow graph automatically. But, join nodes cannot contain instructions. So when a procedure ends with a conditional, there might be no place to store these instructions.
This diff adds one extra node between the join and the exit node in that situation.
Reviewed By: jvillard
Differential Revision: D3179056
fb-gh-sync-id: 2b9cd7e
fbshipit-source-id: 2b9cd7e
Summary:public
Add modeling of methods that can raise exceptions when parameters are
nil, and that return nil when passed nil.
Reviewed By: dulmarod
Differential Revision: D3101739
fb-gh-sync-id: 76af5a2
fbshipit-source-id: 76af5a2
Peter O'Hearn
Josh Berdine
Dulma Churchill
Jeremy Dubreil
Sam Blackshear
Dino Distefano
Andrzej Kotulski
Cristiano Calcagno