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:
We would previously skip any function that had one of these.
A no-op translation is sufficient to fix this issue (see new E2E test).
Reviewed By: mbouaziz
Differential Revision: D6317323
fbshipit-source-id: 0855bd8
Summary:
Change ocamlformat installation procedure to use opam instead of
pinning.
Reformat all code with v0.2, which has a few improvements.
Reviewed By: jvillard
Differential Revision: D6292057
fbshipit-source-id: 759967f
Summary:
This confuses the SIOF checker and causes false positives. This dummy deref is
generated for constructors of classes that are modeled as being pointer types
instead of the actual class in infer, typically for smart pointers. I do not
understand how this works.
The biabduction also analyses this code, so might now get confused itself.
Reviewed By: jberdine
Differential Revision: D6221817
fbshipit-source-id: 050c5a9
Summary:
Install ocamlformat from github as part of `make devsetup`, and use it
for formatting OCaml (and jbuild) code.
Reviewed By: jvillard
Differential Revision: D6092464
fbshipit-source-id: 4ba0845
Summary:
We need to make sure that destructors of virtual base classes are called only once. Similarly to what clang does, we have two destructors for a class: a destructor wrapper and an inner destructor.
Destructor wrapper is called from outside, i.e., when variables go out of scope or when destructors of fields are being called.
Destructor wrappers have calls to inner destructors of all virtual base classes in the inheritance as their bodies.
Inner destructors have destructor bodies and calls to destructor wrappers of fields and inner destructors of non-virtual base classes.
Reviewed By: dulmarod
Differential Revision: D5834555
fbshipit-source-id: 51db238
Summary:
The "placement new" operator `new (e) T` constructs a `T` in the pre-allocated memory address `e`.
We weren't translating the `e` part, which was leading to false positives in the dead store analysis.
Reviewed By: dulmarod
Differential Revision: D5814191
fbshipit-source-id: 05c6fa9
Summary:
Simple instance of the problem: analyzing the following program times out.
```
#include <tuple>
void foo() {
std::tuple<std::tuple<int>> x;
}
```
Replacing `std::tuple<std::tuple<int>>` by `std::tuple<int>` makes the analysis
terminate.
In the AST, both tuple<tuple<int>> and tuple<int> have the same template
specialization type: "Pack" (which means we're supposed to go look into the
arguments of the template to get their values). This is not information enough
and that's the plugin fault.
On the backend side, this means that two types have the same Typ.Name.t, namely
"std::tuple<_>", so they collide in the tenv. The definition of
tuple<tuple<int>> is the one making it into the tenv. One of the fields of the
corresponding CxxRecord is of type "tuple<int>", which we see as the same
"tuple<_>", which causes the loop.
update-submodule: facebook-clang-plugins
Reviewed By: mbouaziz
Differential Revision: D5775840
fbshipit-source-id: 0528604
Summary:
The clang frontend uses `assert false` for unimplemented features that should
abort method translations, as well as for genuine internal errors.
Distinguishing between the two, we can fail hard on the latter and not the
former.
1. This introduces a new exception `Unimplemented` that is used instead of `assert false` where appropriate.
2. Changed some other cases into `die ...` (when there's an error message to display)
3. Wherever a path in the code that we assumed to be unreachable was observed reachable, we now raise `IncorrectAssumption`. These should be fixed, but the fixes are not obvious.
Reviewed By: sblackshear
Differential Revision: D5784384
fbshipit-source-id: 61b55af
Summary:
In the most recent version of clang plugin, lambda captures were moved from `LambdaExpr` to `CXXRecordDecl`. Updating infer to reflect this change.
update-submodule: facebook-clang-plugins
Reviewed By: jvillard
Differential Revision: D5823034
fbshipit-source-id: dd5fc45
Summary: Destroying local variables that are out of scope after `continue`.
Reviewed By: jberdine
Differential Revision: D5804120
fbshipit-source-id: 638cff5
Summary: Destroying local variables that are out of scope after `break`.
Reviewed By: jberdine
Differential Revision: D5764647
fbshipit-source-id: a7e06ae
Summary: The successor node of `continue` was not correct inside the `do while`.
Reviewed By: sblackshear
Differential Revision: D5769578
fbshipit-source-id: d7b0843
Summary:
The behaviour of infer was observed to be different in 4.04.2 vs (4.05.0 or
4.04.2+flambda). Investigating further, the behaviour is also different in byte
vs native versions of infer under 4.04.2. Looking at the Changelog of 4.05.0
(thanks mbouaziz), there are fixes for inconsistent behaviours between byte
and native relative to evaluation order.
Lots of debugging later, this 1 line patch is born. Also use `List.concat_map`
instead of re-implementing it.
Reviewed By: jberdine
Differential Revision: D5793809
fbshipit-source-id: 374fb4c
Summary:
Not translating these properly was causing false positives for the dead store analysis in cases like
```
int i = 0;
return [j = i]() { return j; }();
```
Reviewed By: da319
Differential Revision: D5731562
fbshipit-source-id: ae79ac8
Summary: We inject destructor calls of base classes inside destructor bodies after the destructor calls of fields.
Reviewed By: dulmarod
Differential Revision: D5745499
fbshipit-source-id: 90745ec
Summary: Refactoring destructor translation to take type pointer instead of qual type as a parameter, as we only have type pointers for base classes.
Reviewed By: dulmarod
Differential Revision: D5745490
fbshipit-source-id: 121f492
Summary: We used to crash whenever we hit these. The simple translation implemented here is not particularly inspiring, but it is better than crashing.
Reviewed By: jvillard
Differential Revision: D5702095
fbshipit-source-id: 3795d43
Summary:
Previous version was hard to understand because it was doing many things within same code. New version has different code for Arrays, Structs and others.
There is some copy-paste, but it's easier to follow code (open to suggestions though)
Reviewed By: dulmarod
Differential Revision: D5547999
fbshipit-source-id: 77ecb24
Summary: Working on making CFG immutable by killing refs to functions that mutate them. This is an easy one because it doesn't do anything :).
Reviewed By: jeremydubreil, mbouaziz
Differential Revision: D5551521
fbshipit-source-id: bec76a9
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: CFG nodes were not connected and some instructions ended up in wrong place. Fix those issues
Reviewed By: dulmarod
Differential Revision: D5406720
fbshipit-source-id: 2a70e1a
Summary:
Conversion and reformat of infer source using ocamlformat
auto-formatting tool.
Current status:
- Because Reason does not handle docstrings, the output of the
conversion is not 'Warning 50'-clean, meaning that there are
docstrings with ambiguous placement. I'll need to manually fix
them just before landing.
Reviewed By: jvillard
Differential Revision: D5225546
fbshipit-source-id: 3bd2786
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:
Change the API of `Logging` wrt to writing to files and to the console (see
changes in logging.mli).
Write only to one log file: infer-out/log. Prefix each line with the kind of
warning and the PID of the process emitting it. Writing with `O_APPEND` is
atomic so the file should not get garbled by concurrent writes. To get the
output of a single process, find out which one interests you by looking at
infer-out/log, then `grep ^[<PID>] infer-out/log`.
Introduce 3 log levels for debug output and command-line options to set them
for various categories individually.
Change tons of `"\n"` to `"@\n"` so the `Format` module is aware of newlines
without us having to look through every character of every logged string for
`\n` characters.
Reviewed By: mbouaziz
Differential Revision: D5165317
fbshipit-source-id: 93c922f
Summary:
Spacetime profiling showed that this was allocating a lot more than it needs
to. Switching to a `Hashtbl` makes the memory overhead go away, and halves the
memory consumption of the whole frontend on some pathological files.
This also brings the file "clang_ast_main.ml" into the infer repo, renamed to
"ClangPointers.ml" (and given an mli). It's useful to have something like
"clang_ast_main.ml" checked into the facebook-clang-plugins repo to illustrate
how to use the OCaml AST visitor generated by atdgen, but it can be simplified
to be more pedagogical instead of being the visitor used in infer.
Reviewed By: jberdine
Differential Revision: D4884383
fbshipit-source-id: 88f324a
Summary:
A recent diff tried to replace `L.out "error message"; assert false` with
`failwith "error message"` but infer relies on the type of raised exceptions to
sometimes keep going. A more careful change will be needed but in the meantime
restore the old behaviour.
Reviewed By: jberdine
Differential Revision: D5112969
fbshipit-source-id: 713fe20
Dulma Churchill
Sam Blackshear
Josh Berdine
Jules Villard
Mehdi Bouaziz
Daiva Naudziuniene
Andrzej Kotulski
Martino Luca
Jia Chen