Summary:
The captured variables of a closure are tuples (id, var, typ) with the implicit assumption
that &var -> id holds in the heap. This is true when the closure is created, but is not enforce otherwise.
This becomes a problem when the closure is stored in the heap, goes passed a bi-abduction, and then it's executed
(see new test). This was failing before this diff and now succeeds.
We add the verification of this constraint to the normalization of sigma.
At the moment I expect Precondition_not_met to be removed, but also later, we will be able to compute retain cycles
over the closures, as the correct captured variable info is kept through the execution.
Reviewed By: jvillard
Differential Revision: D6796525
fbshipit-source-id: a8a7655
Summary:
The diff is very big but it's mostly removing code. It was inspired by the fact that we were getting Dead Store FPs because we were modeling some functions from CoreFoundation and CoreGraphics directly as alloc in the frontend, which caused the parameters of the function to be seen as dead. See the new test.
To deal with this, if we are going to skip the function, we model it as malloc instead. Given how many models we had for those "model as malloc" functions, I removed them to rely solely on the new mechanism.
The modeling of malloc and release was still based on the old retain count implementation, even though all we do here is a malloc/free kind of analysis. I also changed
that to be actually malloc/free which removed many Assert false in the tests. CFRelease is not exactly free though, and it's possible to use the variable afterwards. So used a custom free builtin that only cares about removing the Memory attribute and focuses on minimizing Memory Leaks FPs.
Otherwise we were translating CFBridgingRelease as a special cast, and this wasn't working. To simplify this as well, I removed all the code for the special cast, and just modeled CFBridgingRelease and CFAutorelease also as free_cf, to avoid Memory Leak false positives. I also treated the cast __bridge_transfer as a free_cf model. This means we stopped trying to report Memory Leaks on those objects.
The modeling of CoreGraph release functions was done in the frontend, but seemed simpler to also simplify that code and model all the relevant functions.
Reviewed By: sblackshear
Differential Revision: D6397150
fbshipit-source-id: b1dc636
Summary: This check is deprecated and will be replaced by a dedicated checker to detect unitialized values.
Reviewed By: mbouaziz
Differential Revision: D6133108
fbshipit-source-id: 1c0e9ac
Summary: Atoms of the form `identifier = footprint var` naturally occurs with the angelic analysis mode. So it is not clear to me why we should drop those.
Reviewed By: sblackshear
Differential Revision: D5654754
fbshipit-source-id: 9dd2eb5
Summary: Those are not particularly relevant for the biabduction analysis. It would be easy to have a dedicated checker for this if we happen to need one day.
Reviewed By: sblackshear
Differential Revision: D5530834
fbshipit-source-id: 316e60f
Summary: Using a dedicated abstract domain, like Quandary does, is more suitable for taint analysis.
Reviewed By: sblackshear
Differential Revision: D5473794
fbshipit-source-id: c917417
Summary:
Both `stringWithUTF8String` and `stringWithString` implements copy semantics that copies the content of their parameter into a newly allocated buffer. We modeled this as pointer assignment in the past, which means that once we write
```
NSString* foo() {
char buf[...];
...
return [NSString stringWithUTF8String:buf];
}
```
We are going to get a spurious stack variable address escape report because local pointer `buf` is assigned to the newly created string and the string gets returned.
This diff tries to address the issue by heap-allocating a buffer and `memcpy` the contents in `stringWithUTF8String` and `stringWithString`. But this change will create another problem: the allocated buffer will be reported as leaked by the backend, while in reality those buffers won't actually be leaked as they are allocated in a region that will be periodically autoreleased. To suppress spurious memory leak FPs, I added another attribute `Awont_leak` that will suppress the leakage report on any expressions that get tagged with it.
Reviewed By: jeremydubreil
Differential Revision: D5403084
fbshipit-source-id: df6de7f
Summary:
This diff tries to achieve the followings: if we have the following C++ codes:
```
bool foo(int x, int y) {
return &x == &y;
}
```
We want the C++ frontend to emit Sil as if the input is written as
```
bool foo(int x, int y) {
if (&x == &y) return 1; else return 0;
}
```
This matches the behavior of our Java frontend.
The reason why we prefer an explicit branch is that it will force the backend to eagerly produce two different specs for `foo`. Without the explicit branch, for the above example the backend would produce one spec with `return = (&x == &y)` as the post condition, which is not ideal because (1) we don't want local variables to escape to the function summary, and (2) with the knowledge that no two local variables may alias each other, the backend could actually determines that `&x == &y` is always false, emitting a more precise postcondition `return = 0`. This is not possible if we do not eagerly resolve the comparison expression.
Reviewed By: akotulski
Differential Revision: D5260745
fbshipit-source-id: 6bbbf99
Summary:
Adds a new type and branching for a missing path of execution.
closes#575
Reviewed By: jvillard
Differential Revision: D4738681
fbshipit-source-id: f72344c
Summary:
In particular, the method for retrieving an element from the array, this should never be nil. Also added a model for count
similar to the one for NSString length.
Reviewed By: ddino
Differential Revision: D4306655
fbshipit-source-id: 0ecb25a
Summary:
Dealing with symbolic links in project root is tricky. To avoid it, always normalize all paths to sources with `realpath`.
Changes to tests are expected - infer started to resolve symbolic links which screws up with our testing mechanism.
Reviewed By: jberdine
Differential Revision: D4237587
fbshipit-source-id: fe1cb01
Summary:
Run all clang tests with project-root at `infer/tests`. I need it because we'll start resolving symbolic links
soon and some tests would lead outside of project root which means we'd start seeing absolute paths in recorded tests.
Diff that does same thing for java tests: D4233236
Reviewed By: jberdine
Differential Revision: D4233194
fbshipit-source-id: c261a2b
Summary:
Record an abstraction of the bug traces in the tests. The abstraction of a
trace is the sequence of descriptions. In practice, descriptions are either
empty, or of the form "start/end/return from/call to procedure X". They seem
pretty stable.
Motivation: there is nothing testing the traces reported by Infer right now,
even though they are surfaced to developers. For instance, Quandary uses
--issues-txt instead of --issues-tests to make sure the traces do not regress.
This change would make this approach more widespread.
Reviewed By: sblackshear
Differential Revision: D4159597
fbshipit-source-id: 9c83952
Dulma Churchill
Jeremy Dubreil
Mehdi Bouaziz
Daiva Naudziuniene
Jia Chen
Paco Estevez Garcia
Andrzej Kotulski
Josh Berdine
Cristiano Calcagno
Jules Villard