Summary: Errors that include temporary variables are difficult to understand. Do not report stack variable address escape on temporary variables.
Reviewed By: jvillard
Differential Revision: D9117517
fbshipit-source-id: 9ebd75ecc
Summary: Exceptional successors were not meant to be created for return nodes, but they were created if try block had a single return statement.
Reviewed By: jvillard
Differential Revision: D8913371
fbshipit-source-id: 6ac85b21d
Summary:
Do no computation of stability abstract state if not explicitly requested via the command line flag.
Also, simplify the reporting.
Reviewed By: jeremydubreil
Differential Revision: D8614885
fbshipit-source-id: 25dd9de
Summary:
The addresses of global variables do not need initialisation to exist and be valid as they are part of the code or data segment of the program. This means that taking the address of a global is not in itself a danger for SIOF. However, dereferencing such an address would be. In order to avoid false positives but avoid being too unsound, only ignore them when the address is taken only to set another global. The general case would require a more complicated abstract domain.
Fixes#866
Reviewed By: ngorogiannis
Differential Revision: D8055627
fbshipit-source-id: 92307b2
Summary:
These just point to expressions that we know how to translate.
Fixes#950
Reviewed By: mbouaziz
Differential Revision: D8713784
fbshipit-source-id: 9eafa39
Summary:
- Do not add actuals of a call as unstable.
- Replace access trie with simple set of paths, which is easier to debug/argue correct.
- Fix bug where a prefix path was searched, as opposed to a *proper* prefix.
- Restrict interface to the minimum so that alternative implementations are easier.
Reviewed By: ilyasergey
Differential Revision: D8573792
fbshipit-source-id: 4c4e174
Summary: C/C++ code can, in some cases, generate a large number of temporary (Sil) variables. Since we are already not reporting races on these, not recording them gives some perf back.
Reviewed By: mbouaziz, jvillard
Differential Revision: D8566999
fbshipit-source-id: 148ac46
Summary: We were missing reads of `a` if it was used in void cast, i.e. `(void) a;` This caused dead store false positives: we were not using `exp` that was the result of translating `a`. This diff creates a call to built-in skip function with `exp` as its argument, which causes the analyses to see reads of `exp`.
Reviewed By: mbouaziz
Differential Revision: D8332092
fbshipit-source-id: f3b0e10
Summary: There is a number of dangling pointer dereference false positives coming from our treatment of union in c/cpp. For now, do not treat union fields as uninitialised.
Reviewed By: mbouaziz
Differential Revision: D8279802
fbshipit-source-id: a339b0e
Summary: We get a lot of false positives for union types as union fields are treated as separate memory locations at the moment. For now we do not treat union fields as uninitialised.
Reviewed By: mbouaziz
Differential Revision: D8277363
fbshipit-source-id: efe5b4a
Summary:
It's useful to test that the bucket a given error is classified as doesn't
change over time without notice.
This records the bucket for *all* the tests, even though some never produce a
bucket. This is to be on the safe size instead of risking to forget adding the
bucket information when the test changes, or when copy/pasting from a test that
doesn't have buckets to one that does.
The implementation is pretty crude: it greps the beginning of the qualifier
string for a `[bucket]`.
Reviewed By: mbouaziz
Differential Revision: D8236393
fbshipit-source-id: b3b1eb9
Summary:
Change the license of the source code from BSD + PATENTS to MIT.
Change `checkCopyright` to reflect the new license and learn some new file
types.
Generated with:
```
git grep BSD | xargs -n 1 ./scripts/checkCopyright -i
```
Reviewed By: jeremydubreil, mbouaziz, jberdine
Differential Revision: D8071249
fbshipit-source-id: 97ca23a
Summary:
Moving away from C++ include-based models means that we cannot reliably detect
anymore whether a file includes <iostream> or not. In order not to be too
spammy, let's always assume standard streams are initialized for now when the
include models are off.
Recent versions of libstdc++ make these models redundant so there is hope that in a
bright future the analysis of std streams initialisation will work correctly without infer
having to have its own models anyway.
Reviewed By: mbouaziz
Differential Revision: D8043467
fbshipit-source-id: d118043
Summary: Treat array accesses as initialised if they are passed by reference.
Reviewed By: jvillard
Differential Revision: D8071247
fbshipit-source-id: 5480e90
Summary: Use AccessExpressions instead of AccessPath in uninit analysis. This will allow us to distinguish between pointers and their dereferences.
Reviewed By: jvillard
Differential Revision: D8042359
fbshipit-source-id: 604bcbc
Summary:
Labels inside switch statements were causing havoc (see test), and the translation of switch statements in general could be improved to handle more cases.
It turns out that `case` (and `default`) statements are more or less fancy labels into the code. In other words, if you erase all the `case XXX:` and `default:` strings in the `switch` statement you get the real structure of the program, and `switch` just jumps straight to the first `case` directives (and to the second if the first one is not satisfied, etc. until all `case`/`default` have been considered).
This suggests an alternative implementation: translate the body of the `switch` and simply record the list of switch cases inside that body, along with where they point to. Then post-process this list to construct the control flow of the `switch`, which points into the control-flow of the `body`. In order not to modify every function in `CTrans` to propagate the current list of cases, I created an ugly `ref` inside `SwitchCase` instead (but it cannot be directly accessed and it's guaranteed to be well-parenthesised wrt nested switches by the `SwitchCase` API so it's not too bad).
[unrelated] Also make translation failures output more information about what exactly in the source code is causing the crash, and the ancestors in the AST that lead to the crash site.
Reviewed By: martinoluca
Differential Revision: D8011046
fbshipit-source-id: 8455090
Summary:
This diff:
- translates C++ `catch` blocks
- adds an exceptional control-flow edge from the end of a `try` block to the beginning of a `catch` block
This obviously doesn't reflect the way exceptions actually work, but I think it is better than what we have now. For one thing, we'll see/translate code inside `catch` blocks, which were opaque before. If Clang analyses don't want this behavior, they can simply use `ProcCfg.Normal` (which, up until this diff, behaved identically to `ProcCfg.Exceptional`.
In the future, we can extend `trans_state` to track blocks that might throw an exception, and have each of these blocks transition to `catch` instead.
Reviewed By: jvillard
Differential Revision: D7814521
fbshipit-source-id: 67b86a6
Summary:
Previously, the type of `trans_result` contained a list of SIL expressions.
However, most of the time we expect to get exactly one, and getting a different
number is a soft(!) error, usually returning `-1`.
This splits `trans_result` into `control`, which contains the information
needed for temporary computation (hence when we don't necessarily know the
return value yet), and a new version of `trans_result` that includes `control`,
the previous `exps` list but replaced by a single `return` expression instead,
and a couple other values that made sense to move out of `control`. This allows
some flexibility in the frontend compared to enforcing exactly one return
expression always: if they are not known yet we stick to `control` instead (see
eg `compute_controls_to_parent`).
This creates more garbage temporary identifiers, however they do not show up in
the final cfg. Instead, we see that temporary IDs are now often not
consecutive...
The most painful complication is in the treatment of `DeclRefExpr`, which was
actually returning *two* expressions: the method name and the `this` object.
Now the method name is a separate (optional) field in `trans_result`.
Reviewed By: mbouaziz
Differential Revision: D7881088
fbshipit-source-id: 41ad3b5
Summary:
This is an attempt to make things more consistent, and maybe save some work
from the `Format` module in case flambda doesn't have our backs.
Reviewed By: jberdine
Differential Revision: D7775496
fbshipit-source-id: 59a6314
Summary: std::lock allows for locking multiple lockable objects, while avoiding deadlock. This will fix some FPs in C++.
Reviewed By: da319
Differential Revision: D7844198
fbshipit-source-id: 2b7140a
Summary:
This simplifies the frontends and backends in most cases. Before this diff,
returning `void` could be modelled either with a `None` return, or a dummy
return variable with type `Tvoid`. Now it's always the latter.
Reviewed By: sblackshear, dulmarod
Differential Revision: D7832938
fbshipit-source-id: 0a403d1
Summary: Returning the list of sub-expressions is not right and can cause assertion failures elsewhere in the frontend.
Reviewed By: dulmarod
Differential Revision: D7813493
fbshipit-source-id: 33ac9c1
Summary:
When looking at large CFGs, at least in `xdot`, it's often difficult to find
the procedure you're looking for. Sorting the proc names puts them in
alphabetical order, which makes searching one procedure easier.
Reviewed By: mbouaziz
Differential Revision: D7758521
fbshipit-source-id: 8e9997f
Summary: Currently when we look for already abduced expression and find an assertion [exp|->strexp:typexp], we use typexp rather than strexp.
Reviewed By: sblackshear
Differential Revision: D7617193
fbshipit-source-id: c089720
Summary:
This information is already available in the trace, and can contain absolute
paths to system includes (or infer's own clang runtime), which confuses the
diff analysis.
Reviewed By: mbouaziz
Differential Revision: D7534609
fbshipit-source-id: 5bd8f8b
Summary:
If an aggregate `a` has a field `f` whose type has a constructor (e.g., `std::string`), we translate creating a local aggregate `A { "hi" }` as `string(&(a.f), "hi")`.
This diff makes sure that we recognize this as initializing `a`.
Reviewed By: jeremydubreil
Differential Revision: D7404624
fbshipit-source-id: 0ba90a7
Summary:
Show where the invalidation occurred in the trace.
Should make things easier to understand.
Reviewed By: jeremydubreil
Differential Revision: D7312182
fbshipit-source-id: 44ba9cc
Summary: It adds an issue type, `BUFFER_OVERRUN_U5`, for alarms involving unknown values, i.e., when the trace set includes an unknown function call.
Reviewed By: mbouaziz
Differential Revision: D7178841
fbshipit-source-id: bfe857b
Summary:
Aggregate initialization (e.g., `S s{1, 2}`) doesn't invoke a contructor.
Our frontend translates aggregation initialization as assigning to each field in the struct.
To avoid the appearance of the struct being uninitialized, count any assignment to a field of an aggregate struct as initializing the struct.
Reviewed By: jeremydubreil
Differential Revision: D7189671
fbshipit-source-id: ace02fc
Summary:
Show some `SymAssign`s (corresponding to parameters) in the trace.
Depends on D7194448
Reviewed By: skcho
Differential Revision: D7194479
fbshipit-source-id: 0deff6c
Summary: It simply resizes the target structure instead of allocating new heap memories and copying values.
Reviewed By: mbouaziz
Differential Revision: D7179353
fbshipit-source-id: 9c20f64
Summary: If a `Closure` expression `e` captures variable `x`, consider `e` as borrowing from `x`. When the closure is invoked via `operator()`, check that the borrow is still valid.
Reviewed By: jeremydubreil
Differential Revision: D7071839
fbshipit-source-id: d923a6a
Summary: It collects array accesses from all sub expressions in commands.
Reviewed By: mbouaziz
Differential Revision: D7165098
fbshipit-source-id: 584dc80
Summary: It does not only malloc a new heap memory, but also copy its contents.
Reviewed By: mbouaziz
Differential Revision: D7152194
fbshipit-source-id: 58cba5e
Summary: This is to make sure than the analysis produces the same results independently from the order in which the members of a call cycle are analyzed.
Reviewed By: sblackshear, mbouaziz
Differential Revision: D6881971
fbshipit-source-id: 23872e1
Summary:
Fairly simple approach here:
- If the RHS of an assignment is a frontend-generated temporary variable, assume it transfers ownership to the LHS variable
- If the RHS of an assignment is a program variable, assume that the LHS variable is borrowing from it.
- If we try to access a variable that has borrowed from a variable that is now invalid, complain.
Reviewed By: jeremydubreil
Differential Revision: D7069947
fbshipit-source-id: 99b8ee2
Summary:
At function calls, it copies a subset of heap memory that is newly
allocated by callees and is reachable from the return value.
Reviewed By: mbouaziz
Differential Revision: D7081425
fbshipit-source-id: 1ce777a
Summary:
Before D7100561, the frontend translated capture-by-ref and capture-by-value in the same way.
Now we can tell the difference and report bugs in the capture-by-value case.
Reviewed By: jeremydubreil
Differential Revision: D7102214
fbshipit-source-id: e9d3ac7
Summary:
The `may_last_field` boolean value in the `decl_sym_val` function presents that the location *may* (not *must*) be a flexible array member.
By the modular analysis nature, it is impossible to determine whether a given argument is a flexible array member or not---because of lack of calling context. For example, there are two function calls of `foo` below: (2) passes a flexible array member as an argument and (1) passes a non-flexible array, however it is hard to notice when analyzing the `foo` function.
```
struct T {
int c[1];
};
struct S {
struct T a;
struct T b;
};
void foo(struct T x) { ... }
void goo () {
struct S* x = (struct S*)malloc(sizeof(struct S) + 10 * sizeof(int));
foo(&(x->a)); // (1)
foo(&(x->b)); // (2)
}
```
We assume that any given arguments may stem from the last field of struct, i.e., flexible array member. (This is why `decl_sym_val` is called with `may_last_field:true` at the first time.) With some tests, we noticed that the assumption does not harm the analysis precision, because whether regarding a parameter as a flexible array member or not is about using a symbolic array size instead of a constant array size written in the type during the analysis of callee. Therefore still it can raise correct alarms if the actual parameter is given in its caller.
Reviewed By: mbouaziz
Differential Revision: D7081295
fbshipit-source-id: a4d57a0
Summary:
Switch to the current stable branch for clang.
update-submodule: facebook-clang-plugins
Reviewed By: mbouaziz
Differential Revision: D7067890
fbshipit-source-id: aedff90
Summary:
You can capture a variable by reference in a lambda, assign to it, and then invoke the lambda.
This looks like a dead store from the perspective of the current analysis.
This diff mitigates the problem by computing an additional analysis that tracks variables captured by ref at each program point.
It refuses to report a dead store on a variable that has already been captured by reference.
Later, we might want to incorporate the results of this analysis directly into the liveness analysis instead of just using it to gate reporting.
Reviewed By: jeremydubreil
Differential Revision: D7090291
fbshipit-source-id: 25eeffa
Summary:
It supports flexible array member using the following heuristic:
- a memory for a class is allocated by `malloc(sizeof(C) + n * sizeof(T))` format
- the last field of the class is an array
- the static size of the last field is one, i.e., `T field_name[1]`
When allocating and initializing members of classes, it sets the size of flexible array to `n+1` if the above conditions are met.
Reviewed By: mbouaziz
Differential Revision: D7056291
fbshipit-source-id: 31c5868
Summary:
The semantics of "placement new" is defined simply as an assignment.
For example, `C* x = new (y) C();` is analyzed as if `C* x = y;`.
Reviewed By: mbouaziz
Differential Revision: D7054007
fbshipit-source-id: 1c6754f
Summary:
The struct fields in Cil have been sorted for long time, however the
checkers do not seem to depend on the sortedness.
Reviewed By: sblackshear
Differential Revision: D7027858
fbshipit-source-id: 9e7ab96
Summary:
This commit improves precision of symbol instantiations.
When a return value of a callee is `[s1 + s2, _]` and if we want to
instantiate `s1` to `c3 + max(c4, s5)`, the lower bound was
substituted to `-oo` because our domain cannot express `c3 + max(c4,
s5) + s2`.
However, we can have instantiations that are preciser than `-oo`:
(1) `c3 + c4 + s2`
(2) or `c3 + s5 + s2`
because they are smaller than the ideal instantiation, `c3 + max(c4,
s5) + s2` and it is on the lower bound position.
For now, the implementation instantiates to (1) between the two ones,
because constant values introduced by `assert` or `assume`(`if`)
command are often used as safety conditions, e.g., `assert(index >=
0);` can place before array accesses. (We can change the stratege
later if we find that it doesn't work on some other cases.)
Reviewed By: mbouaziz
Differential Revision: D7020063
fbshipit-source-id: 62fb390
Summary:
A simple intraprocedural analysis that tracks when a storage location is read or deleted.
For now, this works only with local variable storage locations; field and array accesses are ignored.
In order to test this, I added a new "use-after-lifetime" warning. It complains when a variable is read or deleted after it has already been deleted.
Reviewed By: jeremydubreil
Differential Revision: D6961314
fbshipit-source-id: 75e95a2
Summary: We do not inject a destructor call if the destructor declaration does not contain a body in AST. We miss all the cases where the destructor is declared in `.h` file and defined in `.cpp` file as other files include `.h` file and do not contain the body of the destructor when destructor calls are being injected based on AST information. After this diff we inject destructor calls even if we do not have body for the destructor in AST.
Reviewed By: sblackshear
Differential Revision: D6796567
fbshipit-source-id: 1c187ec
Summary:
It prunes abstract memories on `assert` commands.
Problem: Since the assert command is sometimes translated to two
sequential `if` statments, it was not able to prune the memory
precisely at `assert` commands in Inferbo---the pruned memory at the
first branch was joined before the second branch.
Solution: To avoid losing the pruning information at the first branch,
now, it records which locations are pruned at the first branch and
applies the same pruning at the next branch if they have
semantically the same condition.
Reviewed By: mbouaziz
Differential Revision: D6895919
fbshipit-source-id: 15ac1cb
Summary: In Obj-C blocks, we explicitly insert reads of the captured vars. This does the same thing for C++. For example, `foo() { int x = 1; [x]() { return x; } }` would previously not contain a read of `x` in `foo`. Now, we'll create a temporary that reads from `x` and pass it to the closure value.
Reviewed By: dulmarod
Differential Revision: D6939997
fbshipit-source-id: f218afc
Summary:
Added a check for recursive calls not to add abduced reference parameters constraints. Abduced reference parameters constraints were causing assertion failure when renaming variables in specs, in particular, when transforming variables into callee variables.
A similar check is already in place for abduced retvals constraints.
Reviewed By: jeremydubreil
Differential Revision: D6856919
fbshipit-source-id: acfe840
Summary:
The boolean lock domain is simple and surprisingly effective.
But it's starting to cause false positives in the case where locks are nested.
Releasing the inner lock also releases the outer lock.
This diff introduces a new locks domain: a map of locks (access paths) to a bounded count representing an underapproximation of the number of times the lock has been acquired.
For now, we just use a single dummy access path to represent all locks (and thus a count actually would have been sufficiently expressive; we don't need the map yet).
But I'm planning to remove this limitation in a follow-up by refactoring the lock models to give us an access path.
Knowing the names of locks could be useful for error messages and suggesting fixes.
Reviewed By: jberdine
Differential Revision: D6182006
fbshipit-source-id: 6624971
Summary:
This diff fixes the translation of `new` and `placement new` with one argument. If `placement new` has more than one argument it means that it is user-defined (this will be addressed in another diff).
update-submodule: facebook-clang-plugins
Reviewed By: sblackshear, mbouaziz
Differential Revision: D6807751
fbshipit-source-id: 7cf0290
Summary: This should allow to report several occurences of the an issue appearing several times within the same method.
Reviewed By: jvillard
Differential Revision: D6783298
fbshipit-source-id: 5555906
Summary:
Not sure what an "iCFG" is but the dotty is only about CFGs anyway.
Diff obtained by mass-`sed`.
Reviewed By: sblackshear
Differential Revision: D6324280
fbshipit-source-id: b7603bb
Summary:
In Java, static variables are distinguished by package/class:
the file where they are defined doesn't matter.
Fixes#831.
Closes https://github.com/facebook/infer/pull/833
Reviewed By: jeremydubreil
Differential Revision: D6661240
Pulled By: sblackshear
fbshipit-source-id: beeb2f9
Summary: Previously we had a single sanitizer kind for escaping, but this isn't quite right. A function that escapes a URL doesn't necessarily make a string safe to execute in SQL, for example.
Reviewed By: the-st0rm
Differential Revision: D6656376
fbshipit-source-id: 572944e
Summary:
Model for `folly::split` that handles the representation in the cpp model.
Depends on D6544992
Reviewed By: jvillard
Differential Revision: D6545006
fbshipit-source-id: 2b7a139
Summary: This is to allow the bi-abduction analysis and the nullable checker for Clang languages to run together without stepping on each other toes.
Reviewed By: sblackshear
Differential Revision: D6567934
fbshipit-source-id: a318c33
Summary: As Dulma pointed out, adding or removing paramters in a method in Objective C is changing the name of the method. Such changes should not make pre-exisiting issues reported as introduced. This diff is to prevent this by only keeping in the bug hash the part of the name that is before the first colon.
Reviewed By: dulmarod
Differential Revision: D6491215
fbshipit-source-id: 3c00fae
Summary:
Our model of unique_ptr and shared_ptr relied on the fact that we could C-style cast a pointer to the internal pointer type used in the smart pointer.
This is wrong when the smart pointer is used with a custom deleter that declares its own pointer type whose is not constructible from just a single pointer.
Reviewed By: dulmarod
Differential Revision: D6496203
fbshipit-source-id: 1305137
Summary: This will avoid collisions when the inner classes are implementing the same methods. For example, the previous version of the bug hash could conflate the issues when several annonymous inner classes are implementing the same method, e.g. a annonymous subclass of `Runnable` implementing `run()`.
Reviewed By: sblackshear
Differential Revision: D6461594
fbshipit-source-id: 2bb8545
Summary:
Simpler bug hash that is more independent of the underlying analysis. This now computes the hash based on:
- the bug type.
- the base filename: i.e for my/source/File.java, just keep File.java. So the hash will not change when moving files around.
- the simple method name: i.e. without package information and list of parameters. So changing the list of parameters will not affect the bug hash.
- the error message were the line numbers have been removed. So moving code or reformatting will not affect the hash.
Reviewed By: jberdine
Differential Revision: D6445639
fbshipit-source-id: 82e3cbe
Summary: To avoid false positives, we treat `operator[]` in cpp as container read. Moreover, if a container `c` is owned, we make all accesses `c[i]` to be also owned.
Reviewed By: sblackshear
Differential Revision: D6396574
fbshipit-source-id: 94aabff
Summary:
It seems that the abstraction instructions were not previously added the the CFG.
This is a functional changes to make sure that the abstraction state is always added. We can simplify the code later and just run this step before storing the CFG instead of after loading them.
Reviewed By: sblackshear, jvillard
Differential Revision: D6383672
fbshipit-source-id: cedcb8a
Summary:
As da319 points out, we did not handle this case correctly before. There were a few reasons why:
(1) An assignment like `struct S s = mk_s()` gets translated as `tmp = mk_s(); S(&s, tmp)`, so we didn't see the write to `s`.
(2) We counted uses of variables in destructors and dummy `_ = *s` assignments as reads, which meant that any struct values were considered as live.
This diff fixes these limitations so we can report on dead stores of struct values.
Reviewed By: da319
Differential Revision: D6327564
fbshipit-source-id: 2ead4be
Summary:
This resolves#796 . Effectively it adds file specific suffix to name of all global initializers (so initializersof two global variable of the same name will have unique Typ.Procname). which is the same rule as currently used by constructing Procname for the static functions. However this change applies to initializers of all global variables and not just static (arguably it's a right thing. since GCC used to allow multiple global variables with the same name).
Consequences of this change that it becomes impossible to know name of generated initialization function of global ('extern') variables. However get_initializer_pname function is only referenced by the frontend (when creating initializer for the defined global variables) and by the SIOF checker.
Closes https://github.com/facebook/infer/pull/801
Reviewed By: jvillard
Differential Revision: D6335034
Pulled By: dulmarod
fbshipit-source-id: 1a92c08
Summary: The clang compiler introduces a materialized temporary expression which should be treated similarly to the Infer internal temporary variables.
Reviewed By: sblackshear
Differential Revision: D6331237
fbshipit-source-id: 81d8196
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: Just changing ClangTrace to actually look at the different sanitizer kinds.
Reviewed By: jeremydubreil
Differential Revision: D6325086
fbshipit-source-id: 5da236d
Summary: In a thread safety report we used the access path from the final sink. This diffs change the report to include the expanded access path from the initial sink.
Reviewed By: sblackshear
Differential Revision: D6297848
fbshipit-source-id: 2386063
Summary: The checker should not report unitinialzed values on the throw branch.
Reviewed By: ddino
Differential Revision: D6267019
fbshipit-source-id: 05768f1
Summary: We were conflating reads/writes with container reads/writes that created false positives.
Reviewed By: sblackshear
Differential Revision: D6232768
fbshipit-source-id: 39159cb
Summary: This is a hack to removes most of the false positives of this checker in Objective C.
Reviewed By: sblackshear
Differential Revision: D6239914
fbshipit-source-id: 1cf05de
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:
The issue is with classes defining static data members:
```
$ cat foo.h
struct A {
static int foo;
};
$ cat foo.cpp
#include "foo.h"
int A::foo = 12;
int f() { return A::foo; // should see A::foo as defined in this translation unit
$ cat bar.cpp
#include "foo.h"
void g() { return A::foo; // should see A::foo defined externally
```
Previously, both foo.cpp and bar.cpp would see `A::foo` as defined within their
translation unit, because it comes from the header. This is wrong, and static
data members should be treated as extern unless they're defined in the same
file.
This doesn't change much except for frontend tests. SIOF FP fix in the next diff.
update-submodule: facebook-clang-plugins
Reviewed By: da319
Differential Revision: D6221744
fbshipit-source-id: bef88fd
Summary: The checker should not report nullable violations on repeated calls
Reviewed By: sblackshear
Differential Revision: D6195471
fbshipit-source-id: 16ff76d
Summary: Functions that do not belong to a class or a struct are translated to c-style functions even in the context of cpp. We need to add ownership to locals for c-style functions too.
Reviewed By: sblackshear
Differential Revision: D6196882
fbshipit-source-id: 715f129
Summary:
vector::data returns a pointer to the first value of the vector.
- The size of the (array) pointer should be the same with the vector.
- The pointer should point to the same abstract value with the vector.
Reviewed By: mbouaziz
Differential Revision: D6196592
fbshipit-source-id: cc17096
Summary: `std::unique_lock` constructor allows to create a unique lock without locking the mutex. `std::unique_lock::try_lock` returns true if mutex has been acquired successfully, and false otherwise. It could be that an exception is being thrown while trying to acquire mutex, which is not modeled.
Reviewed By: jberdine
Differential Revision: D6185568
fbshipit-source-id: 192bf10
Summary:
Code often uses std::unique_lock::owns_lock to test if a deferred lock
using the 2-arg std::unique_lock constructor actually acquired the
lock.
Reviewed By: sblackshear
Differential Revision: D6181631
fbshipit-source-id: 11e9df2
Summary:
Use a distinct issue type for the Java and C++ concurrency analyses,
as the properties they are checking are significantly different.
Reviewed By: sblackshear
Differential Revision: D6151682
fbshipit-source-id: 00e00eb
Summary:
In a summary, you never want to see a trace where non-footprint sources flow to a sink.
Such a trace is useless because nothing the caller does can make more data flow into that sink.
Reviewed By: jeremydubreil
Differential Revision: D5779983
fbshipit-source-id: d06778a
Summary: In HIL, allow deref'ing a magic address like `0xdeadbeef` for debugging purposes. Previously, we would crash on code like this.
Reviewed By: mbouaziz
Differential Revision: D6143802
fbshipit-source-id: 4151924
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: Previously, this would incorrectly classify types like `map<std::string, int>` as a buffer
Reviewed By: mbouaziz
Differential Revision: D6125530
fbshipit-source-id: c8564de
Summary:
Refactor `RegisterCheckers` to give a record type to checkers instead of a tuple type.
Print active checkers with their per-language information.
Improve the manual entries slightly.
Reviewed By: sblackshear
Differential Revision: D6051167
fbshipit-source-id: 90bcb61
Summary: This commit adds unsigned symbol for preciser analysis results with less number of uses of min/max operators.
Reviewed By: mbouaziz
Differential Revision: D6040437
fbshipit-source-id: 999ca4c
Summary:
1. Mark some Makefile targets as depending on `MAKEFILE_LIST` so they get rebuilt on Makefile changes
2. Do not show boolean options with no documentation in the man pages (like we do for other option types).
3. Default to Lazy dynamic dispatch for the checkers.
4. In the tests, use `--<checker>-only` instead of relying on `--no-default-checkers`
5. `--no-filtering` is redundant if `--debug-exceptions` is passed
Reviewed By: jeremydubreil
Differential Revision: D6030578
fbshipit-source-id: 3320f0a
Summary: Stack-allocated variables cannot be raced on in cpp as every thread has its own stack. At the beginning of the analysis we add ownership to the local variables.
Reviewed By: jberdine
Differential Revision: D6020506
fbshipit-source-id: 0a90a97
Summary: Now that we report write-write races involving more than one write, we need to improve the traces accordingly.
Reviewed By: jberdine
Differential Revision: D6026845
fbshipit-source-id: b1366dd
Summary:
Next step to issue deduplication: do not keep safety conditions that are subsumed by others.
Only do it if they do not have infinite bound: replacing `0 < size` by `1 < size` is ok, but replacing it by `+oo < size` is not because it looks much more like a lack of precision.
Reviewed By: skcho
Differential Revision: D5978455
fbshipit-source-id: acc2384
Summary:
A specific type of alias is added for the vector::empty() result and it is used at pruning.
Now, there are two types of aliases:
- "simple" alias: x=y
- "empty" alias: x=v.empty() and y=v.size
So, if x!=0, y is pruned by (y=0). Otherwise, i.e., x==0, y is pruned by (y>=1).
Reviewed By: mbouaziz
Differential Revision: D6004968
fbshipit-source-id: bb8d50d
Summary:
Attempting to translate these will not go well as the declaration still depends
on some template arguments. Added a test that was previously crashing the
frontend.
Also extend the catching of "Unimplemented" and other errors to `translate_one_decl` as it was useful to debug this issue. In particular, reraise all exceptions and log some additional context when doing so.
update-submodule: facebook-clang-plugins
Reviewed By: mbouaziz
Differential Revision: D5976357
fbshipit-source-id: fca8e38
Summary:
Indicate if read or write is protected, and do not print only the
field but also the object involved in the race.
Reviewed By: sblackshear
Differential Revision: D5974250
fbshipit-source-id: 351a576
Summary:
Inject a marker using a global variable in <iostream>, and whitelist it so that
the frontend translates it.
Use the marker in the SIOF checker to tell whether a file includes <iostream>.
If so, start the analysis of its methods assuming that the standard streams are
initialised.
Reviewed By: sblackshear
Differential Revision: D5941343
fbshipit-source-id: 3388d55
Summary:
The previous domain for SIOF was duplicating some work with the generic Trace
domain, and basically was a bit confused and confusing. A sink was a set of
global accesses, and a state contains a set of sinks. Then the checker has to
needlessly jump through hoops to normalize this set of sets of accesses into a
set of accesses.
The new domain has one sink = one access, as suggested by sblackshear. This simplifies
a few things, and makes the dedup logic much easier: just grab the first report
of the list of reports for a function.
We only report on the fake procedures generated to initialise a global, and the
filtering means that we keep only one report per global.
Reviewed By: sblackshear
Differential Revision: D5932138
fbshipit-source-id: acb7285
Summary: The tests are slower when running in debug mode, and it creates a lot of html outputs
Reviewed By: sblackshear
Differential Revision: D5916511
fbshipit-source-id: 07c90b7
Summary:
This diff does two things:
# Infer no longer add the contrains that the return value of a skip function is never null. This was leading to false negatives and is not necessary as those return value are treated angelically
# Infer now support `Nonnull` on the return value of skip functions.
Reviewed By: jberdine, sblackshear
Differential Revision: D5840324
fbshipit-source-id: bbd8d82
Summary: Example of combination between annotating fields with nullable and the biabduction analysis in Objective C
Reviewed By: dulmarod
Differential Revision: D5906016
fbshipit-source-id: b95c6e0
Summary:
The interval bound of the abstract domain is extended.
`[min|max](int, symbol)` => `int [+|-] [min|max](int, symbol)`
As a result, `vector::empty` can be modelled to return a more precise value: `1 - min(1, size)`.
Reviewed By: mbouaziz
Differential Revision: D5899404
fbshipit-source-id: c8c3f49
Summary:
With this change and the previous facebook-clang-plugins change, infer no
longer exhausts the biniou buffer when reading the serialized C++ AST.
update-submodule: facebook-clang-plugins
Reviewed By: mbouaziz
Differential Revision: D5891081
fbshipit-source-id: cf48eac
Summary:
Since D5381239, infer is careful not to delete directories that do not "look
like" results directories on startup, in case the user passed, eg, `-o /`.
In our repo, lots of results dir are created by build/test of infer, and when
the version of infer changes and the expected contents of results directories
change then it might start refusing to delete the results directories created
with another version of infer.
Add an option to force infer to delete the results directory no matter how
dodgy it looks, and use it in our repo by adding the option in every
.inferconfig.
Reviewed By: mbouaziz
Differential Revision: D5870984
fbshipit-source-id: 09412de
Summary: Will then be easier to understand if some changes in the test results is legit or not.
Reviewed By: sblackshear
Differential Revision: D5863961
fbshipit-source-id: 7eb3f33
Summary:
Suggesting to add `_Nullable` on the fields checked for, or assigned to, `nullptr` will allow the biabduction analysis to report null dereferences that are related to the lifetime of objects.
Depends on D5832147
Reviewed By: sblackshear
Differential Revision: D5836538
fbshipit-source-id: c1b8e48
Summary: The prune nodes where translated as `prune (expr = false)` and `prune ( expr != false)`. This case is a bit tricky to deconstruct in HIL. This diff translates the prune instructions as just `prune !expr` for the true branch and `prune expr` for the false branch.
Reviewed By: dulmarod
Differential Revision: D5832147
fbshipit-source-id: 2c3502d
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: 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:
We supported globals as sources before, but we did so by allowing ClangTrace etc. to match against any access path in the footprint of the trace.
This is very powerful/flexible, but it's ultimately not a good idea because it leads to traces that are hard to read.
This is because a footprint source doesn't have any information about its provenance: we might know that the value came from a global, but we don't know where the read occurred.
The mechanism for handling procedure calls as sources already knows how to solve this problem.
This diff implements globals as sources as a special case of procedure call sources instead.
This will give us much nicer traces with full provenance of the read from the global.
Reviewed By: mbouaziz
Differential Revision: D5772299
fbshipit-source-id: 491ae81
Summary:
When a lambda has an `auto` parameter, the inferred type of the parameter because part of the name.
Our heuristic for identifying lambda was checking if the lambda's name was exactly `operator()`, which won't catch this case.
Reviewed By: jvillard
Differential Revision: D5753323
fbshipit-source-id: 85ff75a
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: 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: This makes the traces more readable when involving skipped functions.
Reviewed By: sblackshear
Differential Revision: D5731683
fbshipit-source-id: 49d363b
Summary:
In looking at summaries that Quandary took a long time to compute, one thing I notice frequently is redundancy in the footprint sources (e.g., I might see `Footprint(x), Footprint(x.f), Footprint(x*)`).
`sudo perf top` indicates that joining big sets of sources is a major performance bottleneck, and a large number of footprint sources is surely a big part of this (since we expect the number of non-footprint sources to be small).
This diff addresses the redundancy issue by using a more complex representation for a set of sources. The "known" sources are still in a set, but the footprint sources are now represented as a set of access paths (via an access trie).
The access path trie is a minimal representation of a set of access paths, so it would represent the example above as a simple `x*`.
This should make join/widen/<= faster and improve performance
Reviewed By: jberdine
Differential Revision: D5663980
fbshipit-source-id: 9fb66f8
Summary:
The previous widening operator added stars to the *end* of paths that existed in `next` but not `prev`. This is not enough to ensure termination in the case where the trie is growing both deeper and wider at the same time.
The newly added test demonstrates this issue. In the code, there's an ever-growing path of the form `tmp.prev.next.prev.next...` that wasn't summarized by the previous widening operator. The new widening is much more aggressive: it replaces *any* node present in `next` but not `prev` with a `*` (rather than trying to tack a star onto the end). This fixes the issue.
This issue was causing divergence on tricky doubly-linked list code in prod.
Reviewed By: jeremydubreil
Differential Revision: D5665719
fbshipit-source-id: 1310a92
Summary:
This makes it easier to test a single checker.
Also refactor the code to make it harder to mess up the list of default/all checkers.
Reviewed By: sblackshear
Differential Revision: D5583209
fbshipit-source-id: 7c919b2
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: It wasn't using code from `std::vector::empty` which recently was improved. Instead of inlining `std::vector::empty`, call it to know whether vector is empty or not.
Reviewed By: jvillard
Differential Revision: D5573379
fbshipit-source-id: e024a42
Summary: Useful for identifying user-controlled array accesses that could lead to buffer overflows
Reviewed By: mbouaziz
Differential Revision: D5520985
fbshipit-source-id: 92984f6
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
Summary:
This issue was spotted in the wild. There may be more of those, unfortunately it's hard to predict
More general problem is that types in infer frontend diverge from clang's types for DerivedToBase cast.
Then, infer uses types from clang anyway and that confuses backend. Getting it always right is very hard
Reviewed By: jvillard
Differential Revision: D4754081
fbshipit-source-id: 5fb7069
Summary:
All tests were redirecting `stderr` into duplicates.txt which made it much harder to see other error messages in stderr (such as uncaught exceptions).
To mitigate it, write duplicates to separate file and don't redirect `stderr` to another file.
Reviewed By: jvillard
Differential Revision: D4728938
fbshipit-source-id: 8ad2fc8
Summary:
We were including hex of empty string if mangled name was not empty (so for all C++ functions).
Instead, include hex of a source file only if it's not empty
Reviewed By: mbouaziz
Differential Revision: D4705388
fbshipit-source-id: 55b6587
Summary:
Procnames files are now reversed qualifier lists with `#` as separator (instead of `::` which needs to be escaped in bash).
Because of the mechanism that is used to obtain qualifiers, it also affects naming for ObjC classes.
Examples:
```
std::unique_ptr<int>::get -> get#unique_ptr<int>#std#__MANGLED,...__ // C++ method
folly::split -> split#folly#__MANGLED,..._ // function within namespace
NSNumber numberWithBool: -> numberWithBool:#NSNumber#class // ObjC method
```
Reviewed By: jvillard
Differential Revision: D4689701
fbshipit-source-id: c3acfc6
Summary:
Updated version of the plugin exports some missing `VarDecls`. To make sure it doesn't break again,
add a test that didn't work before.
Reviewed By: dulmarod
Differential Revision: D4674123
fbshipit-source-id: 0c1677a
Summary:
Enrich the domain of SIOF to contain, as well as the globals needed by a
procedure, the globals that the procedure initializes. Also add the possibility
to model some procedures as initializing some variables. Use that mechanism to
teach the checker about `std::ios_base::Init`.
Reviewed By: mbouaziz
Differential Revision: D4588284
fbshipit-source-id: d72fc87
Summary:
This gives a way for users to flag safe methods regarding SIOF, for instance if
the problematic paths in the method cannot happen before `main()` has started.
Reviewed By: akotulski
Differential Revision: D4578700
fbshipit-source-id: 6542dcf
Summary:
Infer used to report null dereference when field was accessed later:
```
vector<int> v;
int& a = v[0]; // should be EMPTY_VECTOR_ACCESS here, but it wasn't reported
int b = a; // was NULL_DEREFERENCE here
```
To avoid this problem, model all accesses to vector as dereference of its internal `beginPtr` field.
Reviewed By: jberdine
Differential Revision: D4481942
fbshipit-source-id: 2142894
Summary:
This modifies `CTrans_utils.dereference_value_from_result` function. Reasons:
1. Type in Sil.Load tuple is supposed to be the type of Ident.t field (result), not Exp.t (source)
2. Inside `dereference_value_from_result` we used wrong type when `~strip_pointer:true` - it used original type instead of the resulting one
3. Fixing (2), uncovered similar issue in `CTrans_utils.cast_operation` - it should have used resulting type, not original one
Changed tests are expected:
1. `deprecated_hack.cpp` test was how I discovered this issue (it was very wrong)
2. the other test also had issues, now it's correct
Sadly, there was no logic I followed when writing this change - I stuffed changes in a way that fits, but it may be breaking something somewhere else.
Reviewed By: jberdine
Differential Revision: D4481895
fbshipit-source-id: b139c59
Summary: Access to std::vector shouldn't be treated as SKIP. Implementation is simple enough to use one from std:: headers
Reviewed By: jvillard
Differential Revision: D4339577
fbshipit-source-id: d1fbbee
Summary:
Change the domain of SIOF to be based on sets of pvar * location instead of
single pvars. This allows us to group several accesses together. However, we
still get different trace elems for different instructions in a proc. We do two
things to get around this limitation and get a trace where all accesses within
the same proc are grouped together, instead of one trace for each access:
1. A post-processing phase at the end of the analysis of one proc collects all
the globals directly accessed in the proc into a single trace elem.
2. When creating the error trace, unpack this set into several trace elements
to see each access (at its correct location) separately in the trace.
This is a bit hacky and another way would be to extend the API of traces to
handle in-procedure accesses natively instead of shoe-horning them. However
since SIOF is the only one to use this, it introduces less boilerplate to do it
that way for now.
Also, a few .mlis for good measure.
Reviewed By: sblackshear
Differential Revision: D4299070
fbshipit-source-id: 3bbb5c2
Summary: These direct tests were still mostly relying on PHONY targets.
Reviewed By: jberdine
Differential Revision: D4326469
fbshipit-source-id: 37b2d0a
Summary: Our C++ model magic didn't work when instantiating smart pointers with volatile types. Fix it
Reviewed By: jvillard
Differential Revision: D4313271
fbshipit-source-id: 55ffb98
Summary: Globals that are constexpr-initializable do not participate in SIOF.
Reviewed By: sblackshear
Differential Revision: D4277216
fbshipit-source-id: fd601c8
Summary:
Remember which globals are static locals.
It's useful to distinguish those from global variables in objc and in the SIOF
checker. Previously in ObjC we would accomplish that by looking at the name of
the variable, but that wouldn't work reliably in C++. Keep the old method around for
now as the way we deal with static locals in ObjC needs some fixing.
Reviewed By: akotulski
Differential Revision: D4198993
fbshipit-source-id: 357dd11
Summary:
Currently cfg nodes are written into dot files in whatever order they
appear in a hash table. This seems unnecessarily sensitive, so this
diff sorts the nodes.
Reviewed By: dulmarod
Differential Revision: D4232377
fbshipit-source-id: a907cc6
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: These are dangerous if you are trying to compare a type to a string, and they're also unsightly.
Reviewed By: jvillard
Differential Revision: D4189956
fbshipit-source-id: 14ce127
Summary:
SIOF is only for interactions between objects of non-POD types. Previously the
checker was also reporting for POD types.
Reviewed By: akotulski
Differential Revision: D4197620
fbshipit-source-id: 7c56571
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
Summary:
`make` doesn't delay variable evaluation in targets' dependencies, so
`$(OBJECTS)` was always empty. Including clang.make after having defined
`OBJECTS` fixes it.
Reviewed By: jberdine
Differential Revision: D4159522
fbshipit-source-id: 6925f8a
Summary:
When loading results from a json file, sort them. This prints results in some
sane order for both --issues-test and --issues-txt, removing the need for
post-processing of the result.
Reviewed By: cristianoc
Differential Revision: D4167029
fbshipit-source-id: 37e9f1c
Summary:
This adds generic support for reporting error traces as usual infer issues
traces (instead of putting them in the textual description of the error) to
Trace.ml and SinkTrace.ml.
The siof checker is made to use these new traces, and gets an improved error
message mentioning the name of the problematic global as well, which requires a
slight API change in Pvar.re.
The support in Trace.ml is incomplete: passthroughs are ignored. This missing
feature will be needed by Quandary to migrate its error messages.
Reviewed By: sblackshear
Differential Revision: D4159542
fbshipit-source-id: 8c1101d
Summary:
- set SHELL to bash explicitly in Makefiles (Debian uses dash)
- avoid using system headers when using our own clang's headers in tests
- do not rely on the name of the object file to write the frontend debugging scripts. It turns out that `-o` is *not* always present in the arguments of `-cc1` functions so the `Option.get` could crash. Since we don't actually need to get the object file name, just a nice enough name, don't try to be smarter at guessing what object will be created and pick a different name built from the source name instead.
Reviewed By: akotulski
Differential Revision: D4159516
fbshipit-source-id: c7bc2b9
Summary:
Instead of the custom filtering done by `InferPrint --issues-tests`, use the
filtering done by `infer` and run without filtering for our e2e tests. We still
test the filtering for our build systems integration tests, and this diff
restores that behaviour for the ant test (hence the bugs removed from
ant/issues.exp).
Also add internal exceptions to most tests to get more signal out of them (eg,
knowing when we add assertion failures and the like).
Retire the old `--issues-tests` to limit the number of ways we do filtering.
Reviewed By: jeremydubreil
Differential Revision: D4131308
fbshipit-source-id: 35805cc
Summary:
This makes the tests depend on much fewer phony targets, thus reducing the need
to rerun the tests when nothing has changed.
Reviewed By: jberdine
Differential Revision: D4118457
fbshipit-source-id: 664b6e3
Summary: A must-have for reporting taint errors and any other interprocedural error where the trace is sufficiently complex.
Reviewed By: jvillard
Differential Revision: D4124072
fbshipit-source-id: 26b3b2b
Summary:
New version of clang plugin exports `-x` arg information as a part of
TranslationUnitDecl. Get it from there instead of reading it from
clang argv
Reviewed By: jvillard
Differential Revision: D4112652
fbshipit-source-id: 5c3af1f
Summary:
Previously, we recorded direct sinks as sinks and transitive sinks as passthroughs. This makes it difficult to create an expanded interprocedural trace when recording an error because we can't distinguish between sinks (which we want to expand) and passthroughs (which we don't). This diff changes recording of sinks so that a sink is now the *last* function in a trace to call a sink. To find out what the original sink was, the summary for the transitive sink in the trace will now need to be (recursively) expanded until we bottom out in the original sink.
Will do the same for sources in a follow-up diff.
Reviewed By: cristianoc
Differential Revision: D4103759
fbshipit-source-id: 6f435f5
Summary:
Needed to support upcoming diff(s) that change the nature of sources/sinks in a trace. Today they are the *original* source/sink, but in the future they will be the *transitive* source/sink (last procedure to return a source/call a sink).
This new convention will make the `returnAllSources`/`callAllSinks` form of these tests not so useful, since `returnAllSources`/`callAllSinks` will now show up as a single source/sink in the trace (at least without expanding the trace). By making these tests intraprocedural, we can make sure that we're still testing everything that we want to.
Reviewed By: cristianoc
Differential Revision: D4103754
fbshipit-source-id: 1733ecf
Summary:
This diff revises the makefiles for java tests so that they are based on
the files actually produced and depended on, instead of the existing
imperative style. This is, I think, clearer and easier to modify, and
enables a little more parallelism.
Reviewed By: jvillard
Differential Revision: D4072560
fbshipit-source-id: c16d4bd
Summary:
- do a semantic analysis of each variable initializer to figure out if they need initialization
- add a flag to globals that is true when they are `constexpr`. In that case, no analysis is needed as the user + compile guarantee that it is a compile-time constant.
Reviewed By: sblackshear
Differential Revision: D4081273
fbshipit-source-id: 44dbe29
Summary:
In several places the tests were using whatever 'infer' executable was
found in PATH, instead of the one build from the source to be tested.
Reviewed By: jeremydubreil
Differential Revision: D4065019
fbshipit-source-id: 9b65099
Summary:
Checker for the Static Initialization Order Fiasco pattern:
https://isocpp.org/wiki/faq/ctors#static-init-order
1. Collect all globals (transitively) accessed in any given procedure.
2. Once the interprocedural analysis has finished, look at globals accessed in
initializers that do not belong to the current translation unit.
Reviewed By: sblackshear
Differential Revision: D3780266
fbshipit-source-id: 1d07161
Summary:
Create dummy functions representing the initializers of global variables. This
is so we can implement checks in the backend that can look at the initializer
expressions of global variables. We try not to create these dummy functions
when the initializer is not present, although for some reason we sometimes end
up with empty initializers.
Also add source file info to global variables in the backend (Pvar.re).
Reviewed By: sblackshear
Differential Revision: D3780238
fbshipit-source-id: 2dca87e
Summary:
It's not necessary if compiling tests in infer environemnt. It may be required if compiling some C++ tests
without infer. `infer/tests/codetoanalyze/cpp/shared/attributes/depracated_hack.cpp` is one of them
Reviewed By: cristianoc
Differential Revision: D4008850
fbshipit-source-id: 5d94bdf
Summary:
This changes executions of the former InferClang into a function call. In
particular, it can be called several times per execution.
The new InferClang must be called as if it was clang, and knows how to run
clang with our plugin to get the AST of the source file.
Reviewed By: akotulski
Differential Revision: D3981017
fbshipit-source-id: 7af6490
Summary:
1. models no longer need access to private fields (shared_ptr needed that)
2. create macro for __attribute__((deprecated("__infer_replace_with_deref_first_arg"))) and use it in models
Reviewed By: jberdine
Differential Revision: D3791113
fbshipit-source-id: 532dd33
Summary:
Follow strategy that was done to `std::shared_ptr` model and translate
`std::unique_ptr<T>` as raw pointer `T*`.
As a bonus, model `operator[]` of array overload as dereference
Reviewed By: jvillard
Differential Revision: D3785031
fbshipit-source-id: 2c5b0a4
Summary:
1. Add capability to clang frontend to replace some function calls with another SIL code based on `__deprecated__` attribute.
2. Given this capability, use those attributes for shared_ptr getters to generate `Sil.Load` instruction instead of method call
3. Add test that mimics shared_ptr model, but it doesn't have that much scary C++ templated code
Reviewed By: jvillard, jberdine
Differential Revision: D3729176
fbshipit-source-id: 2a330d5
Summary:
Make std::shared_ptr<T> translated as T* inside infer. This will make reporting better
since smart pointers are really pointers not structs - this form is much easier for the analyzer to understand.
This requires changes to the model of shared_ptr as well.
Reviewed By: jvillard
Differential Revision: D3587255
fbshipit-source-id: b86fb36
Summary:
This helps avoid some unintended reports where the actual is known to point to
a specific object before a call to a skipped function. This requires a change
in the plugin to export more info about const types.
Reviewed By: dulmarod
Differential Revision: D3711901
fbshipit-source-id: f5c903e
Summary: With this approach, all the global consts will be inlined in the places where they are used.
Reviewed By: dulmarod
Differential Revision: D3703133
fbshipit-source-id: 3c19479
Summary: Follow up D3579581. We forget about memory acquired in resources with assumption that developers use raii and free memory in destructors.
Reviewed By: jvillard
Differential Revision: D3614056
fbshipit-source-id: 08fa112
Summary:
Previously, we would translate `throw` with `return`. However, `throw` in
ObjC/C++ is often used to mean "abort". We now translate `throw` the same as
`exit` to prune these paths.
Reviewed By: akotulski
Differential Revision: D3594156
fbshipit-source-id: 81083bb
Summary:
No longer allow pointer types to be passed inside var_exp_typ. We used to accept both forms,
but it won't be possible any longer once shared_ptr becomes pointer type.
Reviewed By: dulmarod
Differential Revision: D3593003
fbshipit-source-id: a830914
Summary:
When analyzing C model in C++, we were seeing some SKIP function triggered by generated constructors/operators= for C structs.
In C they weren't present, but in C++ compiler generates them for us. To avoid this (and future) problems
with models, translate all functions that are needed when computing the model
Reviewed By: dulmarod
Differential Revision: D3561873
fbshipit-source-id: f8ad2a0
Summary:
This call was producing confusing false positives when deleted object was possible to be null.
Changing frontend to add that check is not trivial so I turned it off for now (we don't handle
destructors in other cases anyway)
Reviewed By: dulmarod
Differential Revision: D3509354
fbshipit-source-id: c23dc81
Summary:
When clang instantiates template function with argument pack, it will
give the same name to all parameters coming from the pack. To avoid
name collisions, always add index of argument's position to mangled part
of the variable.
Seemingly unrelated changes are to make existing tests pass (don't use
simple variable name where it matters)
Reviewed By: dulmarod
Differential Revision: D3503608
fbshipit-source-id: 794093a
Summary: Those functions have simple enough implementations for infer to understand them
Reviewed By: jvillard
Differential Revision: D3463084
fbshipit-source-id: f84160f
Summary:
Assume that std::vector::resize will always create nonempty vector. While this is clearly
wrong for resize(0), it removes many FPs for `resize(n)` calls, where value of `n` is unknown.
Without it, infer was thinking that `n` could be 0 and reported empty vector access.
Reviewed By: jvillard
Differential Revision: D3424355
fbshipit-source-id: cb476de
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:
Now all code in tests is reachable by the analyzer which increases
test quality.
Reviewed By: dulmarod
Differential Revision: D3358591
fbshipit-source-id: d54877e
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:Local variable created by conditional operator translation is now declared in scope of whole
procedure. Semantically there is no difference, hopefuly backend will not complain about this
change. Also, nullifying that variable is deferred to preanalysis instead of calling it manually
Reviewed By: jvillard
Differential Revision: D3155733
fb-gh-sync-id: 6cec8fc
fbshipit-source-id: 6cec8fc
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
Daiva Naudziuniene
Dino Distefano
Martino Luca
Kai Yang
Nikos Gorogiannis
Jules Villard
Mehdi Bouaziz
Dulma Churchill
Sam Blackshear
Oliver Castillo
Ezgi Çiçek
Sungkeun Cho
Jeremy Dubreil
Radu Grigore
Josh Berdine
Jia Chen
Andrzej Kotulski
Kihong Heo
Paco Estevez Garcia
Cristiano Calcagno