Summary:
With current model, there are issues with cxx range loop. It looks like
it comes from std::vector::size model.
example of such FP:
```
int t = vec.size();
for(auto& elem : vec) {
auto x = elem
}
```
Reviewed By: jvillard
Differential Revision: D5545914
fbshipit-source-id: fbe55b3
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:
Bumps facebook-clang-plugins to a version that outputs sizeof() info in bytes and not bits.
update-submodule: facebook-clang-plugins
Reviewed By: akotulski
Differential Revision: D5526747
fbshipit-source-id: 6019542
Summary: The `--failures-allowed` was doing for the Clang frontend what `--keep-doing` was doing for the backend. This revision merges the two options to simplify the Infer CLI and our tests.
Reviewed By: jvillard
Differential Revision: D5474347
fbshipit-source-id: 09bcea4
Summary:
update-submodule: facebook-clang-plugins
Moving to a newer version of clang, see ffb5dd0114
Reviewed By: jvillard
Differential Revision: D5452529
fbshipit-source-id: 28bc215
Summary:
Pretty basic: warn when we see an assignment instruction `x = ...` and `x` is not live in the post of the instruction.
Only enabled for Clang at the moment because linters already warn on this for Java. But we can enable it later if we want to (should be fully generic).
Reviewed By: jeremydubreil
Differential Revision: D5450439
fbshipit-source-id: 693514c
Summary:
This commit avoids precision loss on pruning.
// x -> [s$1, s$2]
if(x) { ... }
// x -> ?
before: x -> [min(0, s$1), max(0, s$2)]
because two x values, [0, 0] (true case) and [s$1, s$2] (false case), were joined after the if branch.
after: x -> [s$1, s$2]
Reviewed By: mbouaziz
Differential Revision: D5431009
fbshipit-source-id: 14a9efe
Summary:
Problem: The analyzer did not know that the value of `v.size()` is an alias of `v.infer_size`, so `v.infer_size` is not pruned by the if condition. As a result it raises a false alarm.
void safe_access(std::vector<int> v) {
if (v.size() >= 10) {
v[9] = 1; // error: BUFFER_OVERRUN Offset: [9, 9] Size: [5, 5]
}
}
void call_safe_access_Good() {
std::vector<int> v(5, 0);
safe_access(v);
}
Solution: Adding alias for return value to the abstract domain.
Now Inferbo can prune `v.infer_size` because it knows that the value of `v.size()` is an alias of `v.infer_size`. There is already an alias domain in Inferbo, so we added a specific room for the retrun value.
Reviewed By: jvillard, mbouaziz
Differential Revision: D5396988
fbshipit-source-id: 4a4702c
Summary:
:
because otherwise people would believe they can use the internal representation of these std lib but it fails for our models.
Reviewed By: jvillard
Differential Revision: D5368671
fbshipit-source-id: 4e53d5a
Summary:
:
Get rid of model location in reports.
The goal is to avoid changing `issues.exp` whenever a model is updated.
Reviewed By: jvillard
Differential Revision: D5356608
fbshipit-source-id: 88ecaba
Summary:
Indexing into a string literal expression would generate a fresh
variable on every application of a transformer. This violated
finiteness of the domain, and caused divergence.
Reviewed By: da319
Differential Revision: D5342951
fbshipit-source-id: e95e84e
Summary:
It instantiates fields of structures when a pointer to which is given
as a function parameter, e.g., `foo(&s);`.
Reviewed By: mbouaziz, jvillard
Differential Revision: D5337645
fbshipit-source-id: c06da29
Summary:
We keep track of both `beginPtr` and `endPtr` but the modelling was mostly
about `beginPtr` as some sort of approximation I guess. This shouldn't change
much but will be useful later when doing more iterator stuff.
Reviewed By: mbouaziz
Differential Revision: D5255772
fbshipit-source-id: 0f6e3e8
Summary: This seems to move in the right direction. Also, `const operator[]` did not do an `access_at`, which I fixed.
Reviewed By: mbouaziz
Differential Revision: D5320427
fbshipit-source-id: c31c5ea
Summary: Unknown library returns the unknown pointer as well as the top interval.
Reviewed By: mbouaziz, jvillard
Differential Revision: D5282669
fbshipit-source-id: 34c7e18
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:
:
There are throw wrapper functions like `std::__throw_bad_alloc()` defined in both libstdc++ (https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-v3/include/bits/functexcept.h) and libc++ (e.g. 907c1196a7/include/new (L145)). Folly actually exports some of them as well (diffusion/FBS/browse/master/fbcode/folly/portability/BitsFunctexcept.h). The function body of those wrappers merely throws the corresponding exception. My understanding is that the primary purpose of the wrappers is to throw the exception if everything goes well and to fall back to something reasonable when exception is disabled (e.g. when `-fno-exceptions` is passed to the compiler).
The problem is that infer doesn't really understand what those functions do, and I've seen some false positives get reported as a result of it. So to remove those FPs we need to either model them or handle them specially. Modeling those wrappers by either whitelisting them or overriding the include files turns out to be difficult, as those wrappers are only declared but not defined in the STL headers. Their implementations are not available to Infer so whitelisting them does nothing, and if I provide custom implementations in the headers then normal compilation process will be disrupted because the linker would complain about duplicated implementation.
What I did here is to replace functions whose name matches one of the throw wrapper's name with a `BuiltinDecls.exit`. I have to admit that this is a bit hacky: initially I was trying to do something more general: replacing functions with `noreturn` attribute with `BuitinDecls.exit`. That did not work because, CMIIW, the current frontend only exports function attributes for functions with actual bodies, not declaration-only functions. I'd love to be informed if there are better ways to handle those wrappers.
Reviewed By: jeremydubreil
Differential Revision: D5266030
fbshipit-source-id: 4580227
Summary:
Read/write race errors should always show one trace for a read and one trace for a write.
We forget to pass the conflicting writes to the reporting function in one case, which prevented us from showing a well-formed trace.
Fixed it by making the `conflicts` parameter non-optional
Reviewed By: jberdine
Differential Revision: D5209332
fbshipit-source-id: 05da01a
Summary:
For now, we just support clearing the taint on a return value.
Ideally, we would associate a kind with the sanitizer and only clear taint that matches that kind.
However, it's fairly complicated to make that work properly with footprint sources.
I have some ideas about how to do it with passthroughs instead, but let's just do the simple thing for now.
Reviewed By: jeremydubreil
Differential Revision: D5141906
fbshipit-source-id: a5b8b5e
Summary:
This is a minimal change to (poorly) recognize and model std::mutex
lock and unlock methods, and to surface all thread safety issues for
C++ based on the computed summaries with no filtering.
This ignores much of the Java analysis, including everything about the
Threads domain. The S/N is comically low at this point.
Reviewed By: sblackshear
Differential Revision: D5120485
fbshipit-source-id: 0f08caa
Summary: Gflags is a popular library used to create command line arguments. Flags shouldn't flow directly to `exec` etc.
Reviewed By: jvillard, mbouaziz
Differential Revision: D5058393
fbshipit-source-id: ab062f8
Summary: String are very important for taint analysis, have to make sure that we have the right models/the right behaviors for unknown code.
Reviewed By: jvillard
Differential Revision: D5054832
fbshipit-source-id: 7e7ee07
Summary:
This commit fixes a problem that the buffer overrun checker incorrectly
stops when a global variable (bottom) is involved in control flow.
In the new version, abstract memories return Top for unanalyzed abstract
variables.
Reviewed By: mbouaziz
Differential Revision: D5016447
fbshipit-source-id: 5132448
Summary:
The code was pretty fragile, it's less fragile now. We should probably just
delete that and start outputting proper class/package info directly in the
report.json instead of reverse-engineering them.
Fixes#640
Reviewed By: jeremydubreil
Differential Revision: D4905973
fbshipit-source-id: 1590067
Summary:
An array has a static or dynamic length (number of elements), but it also has a
stride, determined by the type of the element: `sizeof(element_type)`. We don't
have a good `sizeof()` function available on SIL types, so record that stride
in the array type.
update-submodule: facebook-clang-plugins
Reviewed By: mbouaziz
Differential Revision: D4969697
fbshipit-source-id: 98e0670
Summary: In particular, the heuristics for propagating taint via unknown code needs to be aware of the frontend's trick of introducing dummy return variables.
Reviewed By: mbouaziz
Differential Revision: D5046345
fbshipit-source-id: da87665
Summary:
HIL had only been tested in Java, and it made some assumptions about what array expressions look like (the LHS is always resolvable to an access path) and assignments (the LHS is always an access path) that aren't true in C.
Fixed the code so we won't crash in this case.
Thanks to jeremydubreil for catching this.
Reviewed By: jeremydubreil
Differential Revision: D5047649
fbshipit-source-id: e8484f4
Summary:
There are two pointer-related operations you can do in C++ but not Java that we need to support in taint analysis:
(1) `*formal_ptr = ...` when `formal_ptr` is a formal that's a pointer type. Java doesn't have raw pointers, so we didn't need to handle this case.
(2) Passing by reference, which Java also doesn't have (everything is pass-by-value).
Reviewed By: mbouaziz
Differential Revision: D5041246
fbshipit-source-id: 4e8f962
Summary: Same as D5026082, but allowing specification in JSON rather than harcoded in Infer.
Reviewed By: jeremydubreil
Differential Revision: D5030042
fbshipit-source-id: 8a6cfee
Summary: A lot of C++ library functions look like this, so it's important to have.
Reviewed By: mbouaziz
Differential Revision: D5026082
fbshipit-source-id: 6f421b6
Summary: Making sure simple passthroughs like the identity function work in C++.
Reviewed By: mbouaziz
Differential Revision: D5024031
fbshipit-source-id: ce48ead
Summary:
Needed because this is how the Clang frontend translates returns of non-POD, non pointer values (I think)?
Will handle the more general case of pass by reference soon.
Reviewed By: jvillard
Differential Revision: D5017653
fbshipit-source-id: 1fbcea5
Summary:
`[a, b] < [a, _]` and `[_, a] < [b, a]` are most probably false (it comes from size < size)
Mark definitely unsatisfied conditions as B1, others as B2+
Reviewed By: KihongHeo, jvillard
Differential Revision: D4962107
fbshipit-source-id: ba8f469
Summary:
The bufferoverrun checkers can now be run with:
infer -a checkers --bufferoverrun -- ...
Reviewed By: jeremydubreil
Differential Revision: D5010689
fbshipit-source-id: 2eaa396
Summary:
The Siof checkers can now be run with:
infer -a checkers --siof -- ...
and also runs by default using:
infer -a checkers -- ...
Reviewed By: jberdine
Differential Revision: D5009731
fbshipit-source-id: e0e2168
Summary:
Don't store redundant information in C++ template Type.Name.t.
New signature:
```
| CppClass (qual_name, template_args)
```
For example, for `std::shared_ptr<int>`, will look like this:
```
| CppClass (["std", "shared_ptr"], Template [int])
```
While it used to be:
```
| CppClass (["std", "shared_ptr<int>"], Template (["std", "shared_ptr"], [int]))
```
Reviewed By: jberdine, mbouaziz
Differential Revision: D4834512
fbshipit-source-id: cb1c570
Summary:
Title.
The way types are printed is completely valid, but little weird for some C++ programmers:
`int const` - same as `const int`
`int * const` - pointer is `const`, value under it is not
`int const *` - pointer is not `const`, but the value is
`int const * const` - both pointer and value are const
Reviewed By: jberdine
Differential Revision: D4962180
fbshipit-source-id: dcb02e3
Summary:
- Use Logging for logging
- Add a few extra debug (not ON by default)
- No space before colon
Depends on D4961957
Reviewed By: KihongHeo
Differential Revision: D4961989
fbshipit-source-id: 7c8697d
Summary:
As an interprocedural checker, SIOF should not run unless explicitly required.
Make it a new type of analyzer like other similar checkers.
Reviewed By: mbouaziz
Differential Revision: D4937820
fbshipit-source-id: a9e2d38
Summary: `bufferoverrun` is not part of `checkers` yet so bufferoverrun tests require their own Makefile
Reviewed By: jvillard
Differential Revision: D4937558
fbshipit-source-id: 20380f1
Summary: The flakiness is exercised by upgrading the OCaml compiler to 4.04.0.
Reviewed By: jberdine
Differential Revision: D4859904
fbshipit-source-id: 0dd7ff6
Summary:
Make it possible to write one model which will be used by all template instantiations.
There is one big missing piece: infer never tries to do template instantiation by itself. With current code, it's possible to use generic models
as long as header contains `__infer_generic_model` annotation (see the test as an example).
This is not viable to modify all headers with this annotation hence infer will try to do template instantiation for generic models in later diffs.
Reviewed By: jberdine
Differential Revision: D4826365
fbshipit-source-id: 2233e42
Summary: `__attribute__((annotate("")))` is better way of passing information to the frontend
Reviewed By: jberdine
Differential Revision: D4818805
fbshipit-source-id: 6e8add2
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