Summary:
Previously, we would first compute which build command is at hand, based on the
first argument after "infer --", then do everything depending on that piece of
information. However, the build command alone is not enough to know in which
"build mode" we are operating. For instance, there are several build modes
corresponding to "buck" build commands.
This led to duplication of the logic (to retrieve which build mode we are in in
the various phases of an infer run), and some invariants that had to be
re-asserted at various points in the code, eg that the arguments are not empty.
This diff adds a `build_mode` type (renaming the previous `build_mode` to
`build_system`) that identifies the various integrations we support. We compute
the build mode at the start of infer, then pass the build mode around.
Also, move `run_javac` to a new `integration/Javac.ml` file given that it's a
bit large.
Reviewed By: jberdine
Differential Revision: D4415074
fbshipit-source-id: db854a0
Summary:
If an access path rooted in some parameter `p` is accessed outside of synchronizaton, but `p` is owned by the caller, then we should not warn.
We will implement this by separating writes into "conditional" (safe if a certain parameter is owned by the caller" and "unconditional" (safe only if the caller synchronizes appropriately).
This diff just introduces the map type for conditional writes and changes the transfer functions accordingly.
We'll actually use the map in a follow-up.
Reviewed By: peterogithub
Differential Revision: D4400987
fbshipit-source-id: d2b8af8
Summary: `Toplevel` name is confusing - in ocaml world it means interactive ocaml shell (we call that "interactive"). In infer it meant "Toplevel infer binary". We already call it "driver" to avoid confusion, let's rename the code as well.
Reviewed By: jvillard
Differential Revision: D4415111
fbshipit-source-id: 1002f27
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 fixes compilation database integration with buck. Some directories from command don't exist (specifically ones that should hold `dep.tmp`). To workaround this problem, create those directories when invoking clang command
Reviewed By: jvillard, martinoluca
Differential Revision: D4403580
fbshipit-source-id: 57bcfc7
Summary:
Fixes issue with template argument deduction with enable_shared_from_this as argument
```
#include<memory>
template<class T>
void makeWeak(const std::shared_ptr<T>& x) {}
struct X : public std::enable_shared_from_this<X>{
};
void test() {
X x
makeWeak(x.shared_from_this()); // compilation failed here - it was unable to deduce template parameter of makeWeak
}
```
Reviewed By: jvillard
Differential Revision: D4414788
fbshipit-source-id: 4d19c53
Summary:
1. One call to `Core.Std.String.slice` was wrong and caused the program to crash, and
2. The crash was silently ignored because the error code of uncaught OCaml
exceptions was the same as `CheckCopyright.copyright_malformed_exit_code` (=2)
Address both issues. Also build CheckCopyright with debug options.
Reviewed By: jberdine
Differential Revision: D4410306
fbshipit-source-id: d73b086
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:
`make byte` will populate infer/bin/ with bytecode version of each executable,
plus infer/bin/infer.byte (used to remember which of the native or byte
executables have been built most recently). `make infer` now also creates
infer/bin/infer.native, so that we're sure to replace the executables with
native/byte versions as appropriate.
This is to make debugging a tad easier:
make byte
ledit ocamldebug $(which infer) <infer args>
Whereas previously one had to:
make -C infer/src byte
ledit ocamldebug infer/_build/infer/backend/infer.byte <infer args>
Reviewed By: jberdine
Differential Revision: D4409476
fbshipit-source-id: ab5f57d
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:
Currently, if we don't find `-d` or `-classes_out` on the command line then we
tell javac to redirect the compiled classes in some other directory, by default
the initial working directory. But we don't detect when these arguments are
hidden inside files (`foo` arguments on the javac command line) so the
heuristic was incomplete. Look inside these files to better tell whether we need
to make up an output directory or not.
Reviewed By: jeremydubreil
Differential Revision: D4397716
fbshipit-source-id: 30c5e4f
Summary: Deleting a couple of unused classes/Makefile cruft that was left around.
Reviewed By: jeremydubreil
Differential Revision: D4406007
fbshipit-source-id: 4b78494
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: This will be useful in upcoming changes to the thread-safety analysis as well.
Reviewed By: dkgi
Differential Revision: D4402146
fbshipit-source-id: c750127
Summary:
Sometimes we don't want to analyze but a message gets printed that there was
nothing to analyze and we exit with error, which is confusing.
Reviewed By: jberdine
Differential Revision: D4398120
fbshipit-source-id: 43ce3ab
Summary:
Add more debug output to be able to trace the calls to javac more easily
when --stats or --debug is passed to infer.
Reviewed By: sblackshear
Differential Revision: D4398100
fbshipit-source-id: 3012900
Summary:
This would fail before and works as expected now:
```
$ infer -- clang -c hello.c
$ cd infer-out/ && ln -s ../foo && cd ..
$ infer -- clang -c hello.c # crashes because it fails to delete infer-out/foo
```
Reviewed By: jberdine
Differential Revision: D4398763
fbshipit-source-id: 38465f8
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:
One of the tests was failing without `make clean` because infer-out didn't get
deleted when rerunning the clang db test. This was because infer thinks it's in
`Analyze` mode when capturing clang db files.
Reviewed By: akotulski
Differential Revision: D4397731
fbshipit-source-id: 26f423a
Summary:
This error message is confusing when the user is not actually running
InferPrint, eg `infer foo`: `Load Error: file foo: arguments must be .specs
files`.
With this diff, we don't get any error for `infer foo`, which is not great
either and will need to be addressed (do we support all the python arguments in
OCaml now too and are able to turn on argument parsing errors in OCaml land?).
Reviewed By: jberdine
Differential Revision: D4397765
fbshipit-source-id: e7ca48f
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:
Module CFrontend_utils is a container for two modules: Ast_utils and General_utils.
Instead of opening CFrontend_utils in several places, it is now split into two separate modules CAst_utils and CGeneral_utils, which are now accessed directly.
Reviewed By: jberdine
Differential Revision: D4392710
fbshipit-source-id: ea756a2
Summary:
Change Utils.filename_to_relative to return None in case the filename
is not under root, rather than returning the filename unchanged.
Reviewed By: akotulski
Differential Revision: D4391075
fbshipit-source-id: bf753af
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:
This diff allows to use the linters written in DSL to check for bugs.
Now new checkers can be written directly in the DSL.
The diff also remove some weirdness and simplify the CTL semantics.
For example no need to unwrap a node when evaluating the IN operator.
Also no need to distinguish anymore between stmt and decl in the
semantics of EX and EF.
Moreover, the diff de-couple hard-coded checkers (eg checks on component kit)
from those checkers parsed in the .al files.
Reviewed By: martinoluca
Differential Revision: D4375207
fbshipit-source-id: 9ac2d47
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: The logic for filtering reports based on their buckets lives in InferPrint, so this code isn't doing anything.
Reviewed By: jvillard
Differential Revision: D4379966
fbshipit-source-id: 5a69304
Summary:
A domain should not definite its initial state, since distinct users of the domain may want to choose different initial values.
For example, one user might want to bind all of the formals to some special values, and one user might want the initial domain to be an empty map
This diff makes this distinction clear in the types by (a) requiring the initial state to be passed to the abstract interpreter and (b) lifting the requirement that abstract domains define `initial`.
Reviewed By: jberdine
Differential Revision: D4359629
fbshipit-source-id: cbcee28
Summary:
Force clients to specify the path relative to which relative paths
should be made absolute.
Reviewed By: akotulski
Differential Revision: D4370262
fbshipit-source-id: 36a2807
Summary:
Now that the toplevel driver's cwd is passed through realpath, the
dance to preserve symlinks is redundant.
Reviewed By: jeremydubreil
Differential Revision: D4371055
fbshipit-source-id: c8aebaf
Summary:
For example: `infer --print-logs --stats -- clang -c hello.c`.
The option is not on by default.
This forwards all the output to log files to stdout or stderr as appropriate.
The multiplexing is very crude and can be improved later if needed if
stdout/err is too garbled by concurrent partial writes.
Reviewed By: jberdine
Differential Revision: D4365996
fbshipit-source-id: 7f2ab98
Summary:
Remove the need for a dummy initialization of log files.
The fact that we were not setting log files in some cases doesn't seem to be
relevant so I killed it. I observed no difference in output on simple clang and
javac examples. It will be easy to restore a better version of it in the next
diff if needed.
Also fix an fd leak: when opening new log files, previous ones were not being
flushed and closed (except at exit).
Reviewed By: jberdine
Differential Revision: D4365992
fbshipit-source-id: 940bc16
Summary:
There is not much to redirect except for an uninformative line before proper
logging files are set up. This is from before the current logging system, which
has builtin support for logging into custom files.
Reviewed By: jberdine
Differential Revision: D4365988
fbshipit-source-id: 044290a
Summary:
Instead of opening new log files each time with non-deterministic names, keep
appending to the same log files. This only removes the randomized part of the
names in the files. In particular, it keeps the name prefixes for, eg, clang
source files.
Also changed most "<executable>/<executable>-out.log" to simply "<executable>/out.log".
Reviewed By: jberdine
Differential Revision: D4365983
fbshipit-source-id: 46792dc
Summary: This more easily allow to switch between the different modes for handeling dynamic dispatch
Reviewed By: sblackshear
Differential Revision: D4367556
fbshipit-source-id: 795d2c4
Summary: 957b243 removed the last use of `Exe_env.get_tenv ~create:true`
Reviewed By: jeremydubreil
Differential Revision: D4364521
fbshipit-source-id: 819efee
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: Adding the information that a procedure has been modelled as part of the attributes, during the translation, instead of getting this information from where is the summary loaded from. This is more consistent with the use of the attributes in other parts of the analysis, but is also useful in the context of the lazy dynamic dispatch algorithm where the procedures, including the models, are cloned and reanalyzed with more specialized parameters. The information about whether a procedure is a model must persist when cloning the procedures.
Reviewed By: sblackshear
Differential Revision: D4356892
fbshipit-source-id: 40ff5ca
Summary:
When you try to log an error on a procedure P and a summary for P doesn't exist, the error gets quietly dropped on the floor.
But we should fail loudly instead, because this should only happen in the case of a user error.
Got burned by this today; I was trying to log an error on the *caller* of `Integer.parseInt`, but was accidentally logging it to `Integer.parseInt` itself instead.
Since no summary for that method exists, my error wasn't appearing.
Reviewed By: jvillard, jeremydubreil
Differential Revision: D4355546
fbshipit-source-id: db2a0e6
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:
The two concepts are not negation of each other. The type environment created by the different frontends is not guaranteed to contain a full view of the type hierarchy. In this case, there can be holes preventing Infer to prove that `t <: t'` if the type definition between `t` and `t'` is missing. There are now two functions:
# `is_known_subtype` when the subtyping relation can be proven
# `is_known_not_subtype` when it can be proven that there is no subtyping relation between two types
This diff is intended to make no functional changes but to add functionality to detect cast error angelically, i.e. assuming that the program is probably fine where there is not enough information to prove the cast error.
Reviewed By: jberdine
Differential Revision: D4345803
fbshipit-source-id: 39b79bc
Summary:
There's a lot of boilerplate work to be done when adding a new kind of source.
This diff tries to reduce the boilerplate by making a functor do all the work.
The functor:
(1) adds a notion of "footprint kind" to the source
(2) packages the source with a call site
Reviewed By: jvillard
Differential Revision: D4349224
fbshipit-source-id: 5e1701a
Summary:
The specialization of the methods based on the type of the arguments should only be performed when the type is an object type. This should in theory be always the case according to the Java semantics but the previous version of the code was relying on Infer to be correct all the way down the the method call:
Before this diff, the analysis on examples like this:
String foo(Object object) {
object.toString();
}
String bar() {
int[] array = {1, 2, 3};
foo(array);
}
This is a legit code that Infer is getting wrong because Java objects are translated as C objects instead of objects containing a C-style object. There may be other issues like this so it is safer to filter out the types when performing the substitution.
Reviewed By: jberdine
Differential Revision: D4345760
fbshipit-source-id: 1c74593
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: Different analyses need different preanalyses to run. It doesn't make sense for all of the pre-analyses to be bundled together into one package.
Reviewed By: jvillard
Differential Revision: D4348243
fbshipit-source-id: 46a8ebd
Summary:
Adding #infer-capture-all et al. by hand is annoying and I always forget to do
it. Let infer figure that out.
Reviewed By: dulmarod
Differential Revision: D4339799
fbshipit-source-id: 55e52dc
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: reactive capture spawns clang from within analysis. Time it takes to compile source code shouldn't be counted towards timout
Reviewed By: jvillard, cristianoc
Differential Revision: D4334037
fbshipit-source-id: 64f417d
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: pattern matching we had before allowed many unintended functions to pass (such as `max_element`). Make matching much more strict
Reviewed By: jvillard
Differential Revision: D4313428
fbshipit-source-id: 189c522
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:
This commit avoids using the join operator for the widening
of the Map functor in ```abstractDomain.ml```
and ensures termination when ```ValueDomain``` is infinite
by using ```ValueDomain.widen```.
Closes https://github.com/facebook/infer/pull/535
Differential Revision: D4319797
Pulled By: sblackshear
fbshipit-source-id: 16f15e4
Summary: Don't warn on NotThreadSafe class, particularly when super is ThreadSafe
Reviewed By: sblackshear
Differential Revision: D4334417
fbshipit-source-id: 0df3b9d
Summary:
Most of the time code outside of project root is not interesting to the user - it's either system library or infer C++ model. Skip all of them.
Previous logic was doing something similar, but in more selective way.
I also need this change for D4313428
Reviewed By: jvillard
Differential Revision: D4339298
fbshipit-source-id: c7b5544
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:
This diff parses the build command args to directly handle the -version
option passed to java and javac, to make the integration with buck more
robust by ensuring that the version and no additional debug logging is
generated for `infer --debug -- javac -version`.
Reviewed By: jeremydubreil
Differential Revision: D4158011
fbshipit-source-id: e7d6b4d
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:
This option is only useful if you want to treat casts angelically, but nothing else.
Since angelic is on by default and this option is off by default, it's basically useless.
Reviewed By: jeremydubreil
Differential Revision: D4334030
fbshipit-source-id: 3c0b0ed
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:
Turns out that swapping stdout and stderr using a temporary fd 3 was screwing
up with make's jobserver, who also uses fd 3!
Also, infer is partly to blame as it also calls `make`. Unsetting `MAKEFLAGS`
in infer tells `make` that the way infer calls `make` is independent from
parent `make` invocations.
Also, simplify the rules for direct tests and build system tests.
Reviewed By: jberdine
Differential Revision: D4328979
fbshipit-source-id: 96818e8
Summary:
The list of argument specs is a global ref inside `CommandLineOptions`, which
need to be reset to the empty list every time `parse` is called. Otherwise, we
get duplicated sections:
```
$ infer --help
Infer version v0.9.4-84d61cb
Copyright 2009 - present Facebook. All Rights Reserved.
Toplevel options
--inferconfig-home <dir> Path to the .inferconfig file
--project-root | -pr <dir> Specify the root directory of the project (default: /home/jul/infer)
Analysis (backend) options
Clang frontend options
Java frontend options
Toplevel options
[... the rest of the options -- without --inferconfig-home or --project-root,
with all the section headers again ...]
```
Reviewed By: jberdine
Differential Revision: D4333448
fbshipit-source-id: f91ea66
Summary:
The javac -classes_out option is used to set the results directory for
the buck build system integration.
Reviewed By: jeremydubreil
Differential Revision: D4162907
fbshipit-source-id: 75d0a6d
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:
This change is to support the development of CTL's DSL, where issues can be specified directly from the language, in the form of strings.
Severity is specified locally to the place where the check is defined
Reviewed By: ddino
Differential Revision: D4326594
fbshipit-source-id: 7b146ac
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: Turns out I forgot to close the fd returned by dup(2) so we were leaking a lot.
Reviewed By: jeremydubreil
Differential Revision: D4327389
fbshipit-source-id: 74574ac
Summary: This is required to maintain a set of owned access paths in a subsequent diff.
Reviewed By: jberdine
Differential Revision: D4318859
fbshipit-source-id: bd1a9fa
Summary:
This diff introduces place-holders strings in error messages and evaluates them
when an error needs to be reported.
Place-holders strings are of the form %name_of_helper_function%. They will be evaluated
using and helper function that gives a value.
For example if we need to display the name of a variable in the error message we will have:
".... %var_name%...."
then %var_name% will be evaluated in the ast node calling the appropriate
helper function and the results will replace %var_name% in the message.
Reviewed By: dulmarod
Differential Revision: D4313133
fbshipit-source-id: bf521ca
Summary:
We've had some issues with names like `arr$` appearing in error reports.
Any identifier name that contains $ cannot have come from source code because it is not a legal Java identifier.
This change should stop these reports because Errdesc.ml refuses to use temporary var names in error reports.
Reviewed By: jeremydubreil
Differential Revision: D4322305
fbshipit-source-id: 16237fe
Summary:
These checks were useful when developing Quandary, but do not fire anymore.
`AccessPath.raw_equal` is implicated as one of the top time-consuming functions in Quandary, so gating the assertion that calls it needlessly might save us some time.
Also minor cleanup: made the error messages a bit clearer and added an mli.
Reviewed By: jeremydubreil
Differential Revision: D4323653
fbshipit-source-id: 2a723b5
Summary:
The debug script wants to run InferClang on the file at hand, but that often
involves running a -cc1 command with InferClang, which is no longer supported.
This removes this functionality. The debug script now only dumps the AST to
biniou and its text representation.
Reviewed By: dulmarod
Differential Revision: D4319431
fbshipit-source-id: ef64912
Summary:
C stubs were causing issues with building:
- need OCaml stubs of the C stubs for byte compilation!
- brittle (to remain polite) support in ocamlbuild
Ctypes is awesome, use it instead.
Slight wrinkle on the previous statement:
- ioctl(2) is variable arguments, which is not officially supported by Ctypes but should work in our use-case
- I'm hardcoding the value of a C macro found in system headers
Reviewed By: jberdine
Differential Revision: D4319507
fbshipit-source-id: 352804a
Summary:
<ugly shameful hack>
Temporarily redirect stderr to /dev/null before calling `Javalib.get_class` so
as to avoid getting spammed with "Warning: unexpected attribute: Code" messages
when parsing Java files.
</ugly shameful hack>
I suspect that now that Javalib handles Java 8 this issue is more prevalent. An
issue/PR should be sent to Javalib too so that it's fixed upstream and we can
eventually remove the hack (t15039096).
Reviewed By: jberdine
Differential Revision: D4319466
fbshipit-source-id: af855ba
Summary:
This removes support for developing infer using Eclipse. If you use Eclipse,
consider using Atom/Emacs/vim instead, which have good OCaml/Reason support.
This allows us to get rid of a couple quirks:
- do not generated ocaml annots (this is very slow)
- move OCaml _build directory to infer/src/ where it makes more sense
Reviewed By: jberdine
Differential Revision: D4319480
fbshipit-source-id: 6f063fc
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:
Before, the Interprocedural functor was a bit inflexible. You couldn't do custom postprocessing like normalizing the post state or coverting the post from an astate type to a summary type.
Now, you can do whatever you want by passing a custom `~compute_post` function.
Since `AbstractInterpreter.compute_post` can be used by clients who don't care to do anything custom, this doesn't create too much boilerplate.
Reviewed By: jvillard
Differential Revision: D4309877
fbshipit-source-id: 8d1d85d
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:
This is to prevent clang from changing AST to make it more performant and less readable.
Reported in https://github.com/facebook/infer/issues/522
+ unrelated `refmt` fix
Reviewed By: jvillard
Differential Revision: D4319731
fbshipit-source-id: 176dfcf
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: lines end in '\n' so the last item in `lines.split('\n')` is always empty.
Reviewed By: jeremydubreil
Differential Revision: D4299036
fbshipit-source-id: b3cacbf
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: We're about to add another element to the abstract domain, and a 4-tuple is a bit too cumbersome to work with.
Reviewed By: jberdine
Differential Revision: D4315292
fbshipit-source-id: d04699f
Summary:
Substituting modules into Core.Std breaks the linking behavior of
module aliases, and so does including the module type of Core.Std in a
signature. So, for now, this diff exposes the broken functions in
Core's Gc, Signal, and Sys modules.
Reviewed By: cristianoc
Differential Revision: D4313140
fbshipit-source-id: d8fea00
Summary:
In checkers we use "let" clause to define formulas abbreviation.
This diff expands the use of such formula id when used.
This allows to evaluate the formula.
For example.
let f = f_def
let g = g_def
let h = f or g
will expand the use of f and g with their definition.
Reviewed By: martinoluca
Differential Revision: D4299542
fbshipit-source-id: 9d37dd0
Summary:
This diff adds basic support for parsing the arguments passed to the
build command directly from Config.
Reviewed By: dulmarod
Differential Revision: D4201480
fbshipit-source-id: bba6056
Summary:
Several Core functions silently wrap argument functions with catch-all
exception handlers that exit. This diff protects against these from
ever being used by deprecating them, which causes compilation failure if
they are used.
Reviewed By: jvillard
Differential Revision: D4271781
fbshipit-source-id: a096171
Summary:
Use In_channel and Out_channel operations instead of those in Pervasives. Don't
use physical equality on values that aren't heap-allocated since it doesn't help
the compiler generate faster code and the semantics is unspecified. Also use
phys_equal for physical equality.
Reviewed By: sblackshear
Differential Revision: D4232459
fbshipit-source-id: 36fcfa8
Summary:
Utils contains definitions intended to be in the global namespace for
all of the infer code-base, as well as pretty-printing functions, and
assorted utility functions mostly for dealing with files and processes.
This diff changes the module opened into the global namespace to
IStd (Std conflict with extlib), and moves the pretty-printing
definitions from Utils to Pp.
Reviewed By: jvillard
Differential Revision: D4232457
fbshipit-source-id: 1e070e0
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: Using multicore introduces some flakiness when building the models. This leads to summries for the models that are not always the same after rebuidling from scratch.
Reviewed By: jberdine
Differential Revision: D4306468
fbshipit-source-id: 96933d6
Summary:
Make sl_file field strongly typed in the AST - store SourceFile.t instead of string. This will make it harder
to access raw string which shouldn't really be accessed before going through `SourceFile` module
Reviewed By: jvillard
Differential Revision: D4299468
fbshipit-source-id: e8ff87e
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:
We previously used `Procname.java_get_parameters` to compute the indices of parameters to taint, but this doesn't always work.
`java_get_parameters` omits the `this` param, which we may sometimes want to taint.
Use the actuals (already passed to `Sink.get`) instead
Reviewed By: jvillard
Differential Revision: D4285164
fbshipit-source-id: d462a0b
Summary: Globals that are constexpr-initializable do not participate in SIOF.
Reviewed By: sblackshear
Differential Revision: D4277216
fbshipit-source-id: fd601c8
Summary:
Functions related to source files were already namespaced by `source_file_` prefix. Make separate module for them.
In high level it replaces all `source_file_` with `SourceFile.` and then fixes all remaining compilation errors
Reviewed By: jvillard
Differential Revision: D4299053
fbshipit-source-id: 20b1d39
Summary: This is very useful to debug issues that have to do with types, for example the cast errors
Reviewed By: sblackshear
Differential Revision: D4289790
fbshipit-source-id: ef5a8bf
Summary: Enabling `--cxx` flag makes C++ analysis much better. It's time to turn it on by default
Reviewed By: dulmarod, jvillard
Differential Revision: D4285327
fbshipit-source-id: 261359a
Summary:
This is legacy code that dates back from when we needed the fields in the models to match exactly the fields in the classes being modeled. We no longer need to this. Besides, it seems that this `android.jar` stopped being part of the release for a while. So this change will not affect the results in prod
I check in details the difference on the code of Guava and it seems to remove (weird) false positives only.
Reviewed By: sblackshear
Differential Revision: D4242444
fbshipit-source-id: 84dd782
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:
Now that the terminal output is truncated to max 10 issues, it's useful to have
some place where all bugs with source excerpts can be found. Since bugs.txt is
already unstructured (to the extend that it's just text), hopefully no one was
relying on it having a particular format so it's safe to change it to add
source excerpts.
Anyone wanting the old behaviour should consider parsing report.json instead,
which is intended to be more stable.
Closes https://github.com/facebook/infer/issues/520
Reviewed By: akotulski
Differential Revision: D4284175
fbshipit-source-id: 764f291
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:
Trying to stop other users of the trace domain from making the mistake that Quandary made before D4234766.
This should also improve the performance of Quandary, since the filtering of FP's is now done before building up the full interprocedural trace (which requires disk reads).
Reviewed By: jeremydubreil
Differential Revision: D4234770
fbshipit-source-id: e7e9291
Summary:
source_file_[to|from]_string were dangerous. While removing source_file_to_string is hard/impossible, source file should never be created from string.
Also include many random changes related to `source_file`:
- improve comments in DB.mli
- define behavior of changed-files-index and improve its description
- move some of the "dangerous" code inline to discourage its reuse
This mostly concludes cleanup of DB.source_file, the last bit is to unify filtering by filename (we have duplicated logic in `InferConfig`, `CLocation` and `JMain`)
Reviewed By: jvillard
Differential Revision: D4258795
fbshipit-source-id: 36735a8
Summary:
`DB.source_file_to_string` is very easy to misuse and it shouldn't even exist.
In preparation for that day, replace most of `source_file_to_string` with `source_file_pp`
Reviewed By: jvillard
Differential Revision: D4258390
fbshipit-source-id: 447cf5a
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: we no longer use buck for tests and the script has no reason to exist
Reviewed By: dulmarod
Differential Revision: D4212713
fbshipit-source-id: 7bd1cca
Summary: Noticed this when I was writing the documentation for the abstract interpretation framework and was curious about why `Ondemand.analyze_proc` needs the type environment. It turns out that the type environment is only used to transform/normalize Infer bi-abduction specs before storing them to disk, but this can be done elsewhere. Doing this normalization elsewhere simplifies the on-demand API, which is a win for all of its clients.
Reviewed By: cristianoc
Differential Revision: D4241279
fbshipit-source-id: 957b243
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:
Clean up code related to --changed-files-index option:
1. Store DB.SourceFileSet.t in DB.changed_source_files_set
2. Refactor rest of the code to use it
3. Bunch of minor changes to make code more consise
Reviewed By: jberdine
Differential Revision: D4238736
fbshipit-source-id: 51e5684
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:
Useful for refactoring purposes, to provide a list of modules in
dependency order.
Reviewed By: jeremydubreil
Differential Revision: D4232363
fbshipit-source-id: 2adaaf5
Summary:
Implement heuristics to get from corresponding source files for header files.
We already had initial implementation for CaptureCompilationDatabase - moved it and extended it
to handle C/C++/objC/objC++
Reviewed By: jberdine
Differential Revision: D4231864
fbshipit-source-id: 4516287
Summary:
introduce `AttributesTable.load_defined_attributes` which will return proc attributes only if the procedure is defined. In order to not mess up
with existing caching, create another hashmap to store those procdescs.
We need to do that because with reactive capture we no longer can assume that all proc attributes are final before analysis starts
Reviewed By: jberdine
Differential Revision: D4231575
fbshipit-source-id: e795bcb
Summary: The default `android.jar` used to compile Android code is just a list of empty method stubs that is used for the type checking. In order to improve the type information, we used to redirect the bootclasspath to another `android.jar` that was containing the method bodies and all the fields including the private ones. Since we no longer need the types in the models and the types in the libraries to match, this is now dead code.
Reviewed By: jberdine
Differential Revision: D4230510
fbshipit-source-id: 93417f3
Summary:
This will help during the creation of new checkers, and will prevent errors like misspelling of AST node names.
It will also make it possible to fail immediately during the parsing of CTL inputs.
Reviewed By: ddino
Differential Revision: D4205434
fbshipit-source-id: ed8631a
Summary: Make backend know filenames of compilation database. It will allow it to compile extra files when needed
Reviewed By: cristianoc
Differential Revision: D4231521
fbshipit-source-id: c462448
Summary: Pure refactoring simplifying the code doing the case analysis for execturing the cast instruction.
Reviewed By: dulmarod
Differential Revision: D4215238
fbshipit-source-id: 9f0f163
Summary: Currently the thread safety checker neglects to analyze and files methods we don't want to report on. Like constructors and private methods, and classes where no superclass is marked ThreadSafe. For interprocedural analysis we want to analyze all these to get summaries, even if we don't report on them.
Reviewed By: jberdine
Differential Revision: D4226515
fbshipit-source-id: 7571573
Summary:
`abs_source_file_from_path` is dangerous because
1. It's not trying to make path relative to `project_root` - you can't compare two files created with two different methods
2. It's making relative paths relative to `getcwd` instead of `project_root` which is different from `from_string` function.
Also remove unused `DB.inode_equal`
Reviewed By: cristianoc
Differential Revision: D4204891
fbshipit-source-id: c4c2f99
Summary:
1. Always store cpp model source_file with relative path. This will make them cache friendly independent of infer location
2. Distinguish between "relative to project root" and "relative to infer models src"
3. Unify `source_file_from_path` used by java and C frontends into one function. There are no improvements to that logic yet
4. Move `is_cpp_model_file` to use `source_file` instead of `filename`
Reviewed By: jberdine
Differential Revision: D4204548
fbshipit-source-id: 6e21771
Summary:
This will help during the creation of new checkers, and will prevent errors like misspelling of operators' kinds.
It will also make it possible to fail immediately during the parsing of CTL inputs.
Reviewed By: ddino
Differential Revision: D4212956
fbshipit-source-id: c3c7fe7
Summary: This option is unused and it's making DB.source_file_* API harder to simplify
Reviewed By: cristianoc
Differential Revision: D4219803
fbshipit-source-id: 23ce697
Summary:
Sometimes, we'll need to have extra information in compilation database.
To keep the code simple just keep information about all files and filter
data when scheduling jobs. Perf shouldn't be much worse since we only start one
process for infer invocation.
Reviewed By: jvillard
Differential Revision: D4130884
fbshipit-source-id: 9920c11
Summary:
Using DB.source_file_to_string may return relative path which may or may not be relative to current location.
I went through all calls to `DB.source_file_to_string` and fixed ones that used that output to open files
Reviewed By: jeremydubreil
Differential Revision: D4205407
fbshipit-source-id: b285b7e
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:
This diff adds a dependency on ctypes.foreign and uses the example
binding of fts to implement remove_directory_tree.
Reviewed By: yunxing
Differential Revision: D4115569
fbshipit-source-id: 3509955
Summary: D4189956 killed the phantom space printed after types, but the Context leak message was relying on it :).
Reviewed By: jeremydubreil
Differential Revision: D4208591
fbshipit-source-id: 9f0d709
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:
- fix python calling function with wrong number of arguments (sic)
- print legend of analysis output, this was lost in translation ('F', '.', ...)
- add "Capturing in <mode> mode..." message before capture
- remove version from "Analyzing..." message (users don't even paste the full output, so this is not as useful as initially hoped)
Reviewed By: akotulski
Differential Revision: D4205072
fbshipit-source-id: 2b6505c
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
Summary:
This diff implements enough of the functionality in the python code in
the OCaml toplevel driver that executing `infer -- analyze` is done
with direct procedure calls instead of forking the python interpreter.
Except for some reporting code that remains in report.py.
Reviewed By: jvillard
Differential Revision: D4074718
fbshipit-source-id: 56a794d
Summary: Using address equality check to short-circuit comparison of equal lists faster + kill use of `next`.
Reviewed By: jeremydubreil
Differential Revision: D4189581
fbshipit-source-id: bdf5d1e