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 should fix the issue with broken invariants when the method specialization on pointer ends up doing a substitution on non pointer types
Reviewed By: sblackshear
Differential Revision: D4487232
fbshipit-source-id: f3fce84
Summary: The method `junit.framework.TestCase.setUp()` is always run before the other methods by the JUnit testing framework. So the method act as a class initializer.
Reviewed By: sblackshear
Differential Revision: D4487371
fbshipit-source-id: 1998801
Summary: Just adding some more test cases on how Infer handles dynamic dispatch.
Reviewed By: jberdine
Differential Revision: D4486529
fbshipit-source-id: d90ef42
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:
This diff adds a set of access paths holding a value returned from a method annotated with Functional to the domain.
If a "functional" value is written to a field, we won't count that right as an unprotected access.
The idea is to be able to use the Functional annotation to get rid of benign race false positive, such as:
```
Functional T iAlwaysReturnTheSameThing();
T mCache;
T memoizedGetter() {
if (mCache == null) {
mCache = iAlwaysReturnTheSameThing();
}
return mCache;
}
```
Although there is a write-write race on `mCache`, we don't care because it will be assigned to the same value regardless of which writer wins.
Reviewed By: peterogithub
Differential Revision: D4476492
fbshipit-source-id: cfa5dfc
Summary:
We warn on unsafe accesses to fields that occur in a public method (or are reachable from a public method).
We ought not to consider VisibleForTesting methods as public, since they are only public for testing purposes.
Reviewed By: peterogithub
Differential Revision: D4477648
fbshipit-source-id: 5f58914
Summary: Simple model for List methods that write to the collection.
Reviewed By: peterogithub
Differential Revision: D4453381
fbshipit-source-id: 19edc51
Summary:
Sometimes some instructions were never part of any CFG node and were not written to CFG at all. Add a mechanism that will create node and add them to CFG when they reach compoundStmt translation.
This is step forward to make `*x;` instruction actualy dereference x (it works in C already in C++ AST looks different though)
Reviewed By: dulmarod
Differential Revision: D4469139
fbshipit-source-id: b03b11c
Summary:
Previously, we would correctly be silent on code like `x = new T(); x.f = ...`, but would wrongly warn on code like `x = makeT(); x.f = ...`.
The reason is that we only allowed ownership through direct allocation.
This diff adds a boolean that specifies whether the return value is owned as part of the summary.
This allows us to correctly handle many common cases of (transitively) returning a freshly allocated object, but still won't work for understanding that ownership is maintained in examples like
`x = new T(); y = id(x); y.f = ...`.
Reviewed By: jvillard
Differential Revision: D4456864
fbshipit-source-id: b5eec02
Summary:
Eradicate currently considers a field initialized if it's simply accessed (not written to),
or initialized with another initialized field.
This fixes the issue.
Reviewed By: jvillard
Differential Revision: D4449541
fbshipit-source-id: 06265a8
Summary:
If we have code like
```
o.setF(source())
sink(o)
```
and `setF` is an unknown method, we probably want to report.
Reviewed By: jeremydubreil, mburman
Differential Revision: D4438896
fbshipit-source-id: 5edd204
Summary:
In code like
```
foo(o) {
iWriteToF(o)
}
```
, the condtional write to `f` in `iWriteToF` should become a conditional write for `foo`.
Reviewed By: peterogithub
Differential Revision: D4429160
fbshipit-source-id: f111ac4
Summary:
In code like
```
foo() {
Object local = new Object();
iWriteToAField(local);
}
```
, we don't want to warn because the object pointed to by `local` is owned by the caller, then ownership is transferred to the callee.
This diff supports this by introducing a notion of "conditional" and "unconditional" writes.
Conditional writes are writes that are rooted in a formal of the current procedure, and they are safe only if the actual bound to that formal is owned at the call site (as in the `foo` example above).
Unconditional writes are rooted in a local, and they are only safe if a lock is held in the caller.
Reviewed By: peterogithub
Differential Revision: D4429131
fbshipit-source-id: 2c6112b
Summary:
Races on volatile fields are less concerning than races on non-volatile fields because at least the read/write won't result in garbage.
For now, let's de-prioritize these writes by ignoring them.
Reviewed By: peterogithub
Differential Revision: D4434023
fbshipit-source-id: 05043ba
Summary:
This replaces the previous integration written in Python, which consisted in 1)
run the mvn command and parse its output to locate "directories containing
source files", 2) run on files named "*.java" in these directories. This meant
we had to run javac twice on each source file, and more importantly this
mechanism of finding source files was very fragile. In fact, I could not make
it work on several mvn projects I tried.
The new integration is based on parsing "pom.xml" to add an "infer-capture"
profile which instructs mvn to run `/path/to/infer` instead of `javac`. We also
add this profile to each maven submodule.
Users can specify an "infer-capture" profile themselves if the default one
doesn't work; in that case we don't inject our own "infer-capture" profile.
Reviewed By: jeremydubreil
Differential Revision: D4409613
fbshipit-source-id: d664274
Summary:
Also make sure we don't introduce deprecated options in our repo, eg when
calling infer from infer.
Reviewed By: jeremydubreil
Differential Revision: D4430379
fbshipit-source-id: 77ea7fd
Summary: Just cleanup; gives us slightly less test code to maintain.
Reviewed By: jeremydubreil
Differential Revision: D4429265
fbshipit-source-id: d43c308
Summary: This allows to modify the structure of the buck project under test with less risk of breaking the tests
Reviewed By: sblackshear
Differential Revision: D4411721
fbshipit-source-id: 6ee2cc5
Summary:
This makes it more obvious why infer would force a path to be absolute since we
base that decision on the resolved path. For instance:
```
$ mkdir foo
$ cd foo
$ ln -s ../examples goo
$ infer -- clang -c goo/hello.c
[...]
/home/jul/infer/examples/hello.c:14: error: NULL_DEREFERENCE
```
We see that the path is outside of the current directory clearly, whereas
before infer would report on "goo/hello.c".
Reviewed By: akotulski
Differential Revision: D4409579
fbshipit-source-id: 7172005
Summary:
Similar to marking classes ThreadConfined, we want to support marking fields as well.
The intended semantics are: don't warn on writes to the marked field outside of syncrhonization, but continue to warn on accesses to subfields.
Reviewed By: peterogithub
Differential Revision: D4406890
fbshipit-source-id: af8a114
Summary:
- Only generate one extra genrule for running infer. Remove all other java library rules currently being generated
- Generate infer genrule only if the `java_library` has `srcs`, otherwise there is nothing to analyze
- Use `SRCDIR` to avoid making a copy of the target sources as buck will just symlink them instead
- Added support for `android_library` rules as well
- Added support to generate both `infer` and `eradicate` genrules
Closes https://github.com/facebook/infer/pull/558
Reviewed By: sblackshear
Differential Revision: D4400365
Pulled By: jeremydubreil
fbshipit-source-id: 24750e2
Summary: Generalized the CppTrace into a Clang trace because we don't currently have separate checkers for Obj-C and Cpp. Happy to separate them later if there is a good reason
Reviewed By: akotulski
Differential Revision: D4394952
fbshipit-source-id: e288761
Summary:
Adding models that allow us to warn on unguarded accesses to subclasses of `Map`, but not on accesses of threadsafe containers like `ConcurrentMap`.
Lots more containers to model later, but stopping at `Map`s for now to make sure the approach looks ok.
Reviewed By: jvillard
Differential Revision: D4385306
fbshipit-source-id: d791eee
Summary:
If we don't delete infer-out then it gets polluted with files from previous
versions of infer resulting in segfaults during `make test`.
Reviewed By: cristianoc
Differential Revision: D4397723
fbshipit-source-id: 1211d40
Summary:
The cmake test removes the _build dirs, and the utf8_in_pwd test
rsyncs them.
Reviewed By: akotulski
Differential Revision: D4375554
fbshipit-source-id: 3fa088c
Summary: Need to upgrade in order to specify some taint properties on a more recent `WebView` API.
Reviewed By: cristianoc
Differential Revision: D4382590
fbshipit-source-id: 0925742
Summary: These methods should only be called from other methods that also run on the UI thread, and they should not be starting new threads.
Reviewed By: peterogithub
Differential Revision: D4383133
fbshipit-source-id: 6cb2e40
Summary: Use the lazy dynamic dispatch by default in prod for the Java analysis
Reviewed By: sblackshear
Differential Revision: D4356872
fbshipit-source-id: 491e92e
Summary:
Without this it's not always obvious which test fails. It also makes it easier
to mass-patch test failures from the CI jobs to replace expected outputs with
actual outputs (eg, when debugging osx frontend tests from linux).
Reviewed By: jberdine
Differential Revision: D4352205
fbshipit-source-id: 8887d7b
Summary:
We currently can only model the return values of functions as sources.
In order to model inputs of endpoints as sources, we need the capability to treat the formals of certain functions as sources too.
This diff adds that capability by adding a function for getting the tainted sources to the source module, then using that info in the analysis.
Reviewed By: jeremydubreil
Differential Revision: D4314738
fbshipit-source-id: dd7d423
Summary:
Seems like we cannot run 2 instances of Buck in parallel even when one uses
buck-out/ and the other buck-out/foo/.
Reviewed By: sblackshear
Differential Revision: D4347090
fbshipit-source-id: 7e65d2f
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:
Previously, summaries worked by flattening the access tree representing the post of the procedure into (in essence) a list of functions from caller input traces to callee output traces.
This is inefficient in many ways, and is also much more complex than just using the original access tree as the summary.
One big inefficiency of the old way is this: calling `Trace.append` is slow, and we want to do it as few times as possible.
Under the old summary system, we would do it at most once for each "function" in the summary list.
Now, we'll do it at most once for each node in the access tree summary.
This will be a smaller number of calls, since each node can summarize many input/output relationships.
Reviewed By: jeremydubreil
Differential Revision: D4271579
fbshipit-source-id: 34e407a
Summary: Don't warn on NotThreadSafe class, particularly when super is ThreadSafe
Reviewed By: sblackshear
Differential Revision: D4334417
fbshipit-source-id: 0df3b9d
Summary:
This will simplify the InferPrint logic of checking what should/should-not be reported.
I will remove the issue names in Localise in a next diff.
Reviewed By: ddino
Differential Revision: D4334327
fbshipit-source-id: ebcfd6c
Summary:
SuppressWarnings annotations are hardly used and add considerable
complexity due to requiring recompilation with an annotation processor.
Reviewed By: jvillard
Differential Revision: D4312193
fbshipit-source-id: c4fc07e
Summary:
Most of the diff adds a way to run an existing test with different infer
options.
Also, do not run the Python script when capturing "analyze".
fixes https://github.com/facebook/infer/issues/518
Reviewed By: jberdine
Differential Revision: D4333762
fbshipit-source-id: 642acff
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:
We don't need to have separate `--` integration for compilation database. Instead use:
infer --compilation-db-files db.json <other_infer_options> // no -- anywhere!
Reviewed By: jberdine
Differential Revision: D4327570
fbshipit-source-id: caf0dc9
Summary:
If these collections don't encapsulate their state properly, there are bigger problems than thread safety issues :).
Plus, these warnings are less-than-actionable for non-Guava maintainers.
Reviewed By: peterogithub
Differential Revision: D4324277
fbshipit-source-id: cacfbf0
Summary:
Maintain an "ownership" set of access paths that hold locally allocated memory that has not escaped.
This memory is owned by the current procedure, so modifying it outside of synchronization is safe.
If an owned access path does escape to another procedure, we remove it from the ownership set.
Reviewed By: peterogithub
Differential Revision: D4320034
fbshipit-source-id: 64f9169
Summary: Allow backend to trigger compilation of extra files when it needs them. This will allow infer to capture less files initally and possibly speed up compilation
Reviewed By: cristianoc, jberdine
Differential Revision: D4231581
fbshipit-source-id: 181abea
Summary:
In particular, the method for retrieving an element from the array, this should never be nil. Also added a model for count
similar to the one for NSString length.
Reviewed By: ddino
Differential Revision: D4306655
fbshipit-source-id: 0ecb25a
Summary: 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: Rename the intermediate .exp.test files to .exp.test.noreplace so that they don't match the regexp used by `make test-replace`. Otherwise they can accidentally become .exp files that will show up in `git status`.
Reviewed By: cristianoc
Differential Revision: D4319436
fbshipit-source-id: df2ef21
Summary:
Before the diff, the code was considering as Nullable any annotation ending with `...Nullable`, including `SuppressParameterNotNullable`.
Closes#533
Reviewed By: jberdine
Differential Revision: D4317356
fbshipit-source-id: 6091c0f
Summary: Adding Buck `DEFS` macros for generating Infer genrules. The generated genrules can be used to run the analysis on any existing `java_library` targets.
Reviewed By: sblackshear
Differential Revision: D4291234
fbshipit-source-id: 6430e2e
Summary:
The Java frontend translates exceptions by assigning them to the return value.
This leads to weird behavior when the return type of the function is void.
Already handled one case of this in Quandary (ignoring assignments of exceptions to return value), but was missing the case where null is assigned to the return value.
The frontend does this to "clear" the value of previously assigned exceptions.
Reviewed By: jeremydubreil
Differential Revision: D4294060
fbshipit-source-id: 6bef5ef
Summary: Globals that are constexpr-initializable do not participate in SIOF.
Reviewed By: sblackshear
Differential Revision: D4277216
fbshipit-source-id: fd601c8
Summary:
Although the Builder pattern is not actually thread-safe, Builder's are not expected to be shared between threads.
Handle this by ignoring all unprotected accesses in classes the end with "Builder".
We might be able to soften this heuristic in the future by ensuring rather than assuming that Builder are not shared between methods (or, ideally, between threads).
Reviewed By: peterogithub
Differential Revision: D4280761
fbshipit-source-id: a4e6738
Summary:
When calling function g_realloc(gpointer mem,gsize n_bytes) one of the spec considers the case
whereby n_bytes is zero. In that case g_realloc would return null.
If we call with sizeof(int), infer would compare sizeof(int) with zero. But the prover would fail to
understand that sizeof(int) != 0.
This diff fix this. We try to convert expression to constant when they can be converted (eg in case of sizeof).
The method currently make a partial set of conversion. This could be extended.
Reviewed By: jberdine
Differential Revision: D4166944
fbshipit-source-id: 3ec4fd7
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:
Whenever header file is in changed-files-index, it should be captured and analyzed on demand.
It was already being captured, but ondemand analysis wasn't triggered for code in header file. This diff does it.
Use hacky header->source mapping to go from header to source (cluster) and then analyze everything in that cluster (inlucing code coming from header)
Reviewed By: jberdine
Differential Revision: D4265495
fbshipit-source-id: 61606f4
Summary: When infer runs on preprocessed source, original files may not be around anymore. Don't crash infer when that happens.
Reviewed By: jvillard, jberdine
Differential Revision: D4258285
fbshipit-source-id: a19569c
Summary: This should no work even when Infer is not setup in the PATH
Reviewed By: jvillard
Differential Revision: D4262356
fbshipit-source-id: e3fa779
Summary: `ReentrantReadWriteLock.ReadLock` and `ReentrantReadWriteLock.WriteLock` are commonly used lock types that were not previously modeled.
Reviewed By: peterogithub
Differential Revision: D4262032
fbshipit-source-id: 4ff81a7
Summary:
`o.<init>` cannot be called in parallel with other methods of `o` from outside, so it's less likely to have thread safety violations in `o.<init>`.
This diff suppresses reporting of thread safety violations for fields touched (transitively) by a constructor.
We can do better than this in the future (t14842325).
Reviewed By: peterogithub
Differential Revision: D4259719
fbshipit-source-id: 20db71f
Summary: Originially, there was a missing package declaration meaning that the generated class was ending in a different place. I also added a test for equality of Integer to complement the test of no equality, which could be always true.
Reviewed By: sblackshear
Differential Revision: D4263676
fbshipit-source-id: 86ab0d3
Summary:
We only ought to report a source-sink flow at the call site where the sink is introduced.
Otherwise, we will report silly false positives.
Reviewed By: jeremydubreil
Differential Revision: D4234766
fbshipit-source-id: 118051f
Summary: This should make it easier to understand complex error reports.
Reviewed By: peterogithub
Differential Revision: D4254341
fbshipit-source-id: fb32d73
Summary: We'll eventually want fancy interprocedural traces. This diff adds the required boilerplate for this and adds the line number of each access to the error message. Real traces will come in a follow-up
Reviewed By: peterogithub
Differential Revision: D4251985
fbshipit-source-id: c9d9823
Summary: Adding this so we can test interprocedural trace-based reporting in a subsequent diff.
Reviewed By: peterogithub
Differential Revision: D4243046
fbshipit-source-id: 7d07f20
Summary: We're at risk for some silly false positives without these models.
Reviewed By: peterogithub
Differential Revision: D4244795
fbshipit-source-id: b0367e6
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: Add some basic command line API to run Infer using Buck genrules. Remains to fix issues with absolute vs relative paths and to see how to create these genrules on the fly for a given java or android library.
Reviewed By: sblackshear
Differential Revision: D4245622
fbshipit-source-id: 1cda4ee
Summary:
Implement heuristic to capture more of the user code:
In C++ there is a lot of interesting code in header files. On the other hand,
that code gets included in multiple places and we don't want to capture it by default (for performance reasons).
Right now we capture everything from source file + all symbols from headers that source file needs.
New heuristic will extend "capturing everything" to matching header files (ie. capture everything in X.h if source file is X.cpp)
Reviewed By: jberdine
Differential Revision: D4238008
fbshipit-source-id: 0528250
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:
Before, we were using a set domain of strings to model a boolean domain.
An explicit boolean domain makes it a bit clear what's going on.
There are two things to note here:
(1) This actually changed the semantics from the old set domain. The set domain wouldn't warn if the lock is held on only one side of a branch, which isn't what we want.
(2) We can't actually test this because the modeling for `Lock.lock()` etc doesn't work :(.
The reason is that the models (which do things like adding attributes for `Lock.lock`) are analyzed for Infer, but not for the checkers.
We'll have to add separate models for thread safety.
Reviewed By: peterogithub
Differential Revision: D4242487
fbshipit-source-id: 9fc599d
Summary: Add new integration test for compilation databse integration. Because new test needs another flags in infer invocation, I created one directory per test.
Reviewed By: jberdine
Differential Revision: D4231659
fbshipit-source-id: 81bb355
Summary:
In Java, we handle unknown code by propagating behavior from the parameters of the unknown function call to the return value (or constructed object, in the case of a constructor). But we do this in a somewhat silly way--generating a new summary with these semantics at each unknown call site. Instead, this diff introduces these two options as predefined behaviors and adds specialized code for them.
As a side effect of this approach, unknown functions are no longer counted as passthroughs. This is ok; the original behavior was less of a reasoned decision and more of an unintended consequence of the way we decided to handle unknown code.
This new approach ought to be more efficient than the old one, and as a virtuous side effect it will be easier to specify how to handle unknown code in other languages like C++.
Reviewed By: jeremydubreil
Differential Revision: D4205624
fbshipit-source-id: bf97445
Summary: Run all java tests with project-root at `infer/tests`. Do it to keep things consistent between clang and java tests
Reviewed By: sblackshear
Differential Revision: D4233236
fbshipit-source-id: c3f24fd
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:
Let's introduce some concepts. A "known unknown" function is one for which no Java code exists (e.g., `native`, `abstract`, and `interface methods`). An "unknown unknown" function is one for which Java code may or may not exist, but we don't have the code or we choose not to analyze it (e.g., non-modeled methods from the core Java or Android libraries).
Previously, Quandary handled both known unknowns and unknown unknowns by propagating taint from the parameters of the unknown function to its return value. It turns out that it is really expensive to do this for known unknown functions. D4142697 was the diff that starting handling known unknown functions in this way, and bisecting shows that it was the start of the recent performance problems for Quandary.
This diff essentially reverts D4142697 by handling known unknowns as skips instead. Pragmatically, doing the propagation trick for Java/Android library functions (e.g., `String` functions!) matters much more, so i'm not too worried about the missed behaviors from this. Ideally, we will go back to the old handling once performance has improved (have lots of ideas there). But I need this to unblock me in the meantime.
Reviewed By: jeremydubreil
Differential Revision: D4205507
fbshipit-source-id: 79cb9c8
Summary:
Add test for compilation database and --changed-files-index option
Fix one bug that the test uncovered
Reviewed By: dulmarod
Differential Revision: D4198502
fbshipit-source-id: 9039c65
Summary:
Developers will sometimes write GuardedBy("T.f") with the intended semantics: "guarded by the field f of the object with type T in the current state".
We want to support this to avoid false positives.
Reviewed By: peterogithub
Differential Revision: D4197476
fbshipit-source-id: acd00d9
Summary:
The way interfaces are dealt with led to a false positive,
where tryLock() works OK for a Lock but not for a ReentrantLock.
The solution is just to provide the model.
While I am at it I am adding some more standard tests for Lock and ReentrantLock, which were not present.
Reviewed By: sblackshear
Differential Revision: D4204551
fbshipit-source-id: 9b6de28
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
Andrzej Kotulski
Jeremy Dubreil
Sam Blackshear
Kihong Heo
Dulma Churchill
Jules Villard
Cristiano Calcagno
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