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: The frontend replaces global variables that are constant with their values as a quick hack to improve the precision of the analysis. This should apply to `constexpr` too.
Reviewed By: dulmarod
Differential Revision: D4058097
fbshipit-source-id: be4fea6
Summary:
Also be more careful when escaping arguments and create a module for shared
functionality between the clang frontend and the buck compilation database.
Reviewed By: jberdine
Differential Revision: D4036627
fbshipit-source-id: c981184
Summary:
Fix an issue where, when `-reactive` mode is used, files captured in the first second are not considered modified, and are not analyzed. This happens because file timestamps are used, and the resolution is one second.
Change the front-ends to change the timestamp of the directory where artifacts are created, so that the timestamps are 1 second in the future.
Small reactive commands such as the following now analyze correctly:
rm -rf infer-out && infer --reactive -- clang -c test.c
Reviewed By: jberdine
Differential Revision: D4050689
fbshipit-source-id: 6271860
Summary:
Move compilation database into separate module which loads said database from json file.
It will allow to load database from json file without calling buck.
Reviewed By: dulmarod
Differential Revision: D4049255
fbshipit-source-id: b2fa29f
Summary: This avoids issues where the command-line may get too large.
Reviewed By: jberdine
Differential Revision: D4008328
fbshipit-source-id: c1558b9
Summary:
This also adds `-a compile` support to `InferClang`. This is needed for the
`xcodebuild` integration, which is hard to fold into the same binary as the
rest.
Reviewed By: jberdine
Differential Revision: D4008262
fbshipit-source-id: 0bbd53f
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:
During the development/debugging of AST checks, it will be possible to emit dotty graphs with a representation of the evaluation of formulas.
The formulas, expressed using the notation of CTL (https://en.wikipedia.org/wiki/Computation_tree_logic) are represented in a graph alongside the current ast-node and their final evaluation result (green for true, red for false)
To get the dotty graph, run infer with the `--debug` flag
Reviewed By: ddino
Differential Revision: D3937787
fbshipit-source-id: 163e17d
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: it seems to have no effect on analysis. As such it should be ok to add cg nodes for builtin model calls
Reviewed By: jberdine
Differential Revision: D3967399
fbshipit-source-id: 06c32e5
Summary:
This is needed for later: InferClang will no longer be started once for each
source file to be analysed. Instead, it will be called to analyse several files
at once, and will analyse them one by one. Thus, `clang_lang` and `source_file`
are moved to `cFrontend_config` as references.
The biggest change this entailed was the new logging infrastructure, which was
depending on `Config.source_file`. This diff moves the logic entirely to
`Logging`, and changes the API so that executables wishing to log into files
have to set it up using `Logging.set_log_file_identifier`. This can be called
several times during the execution, allowing to dynamically change the log file
(eg, when analysing several source files one by one!).
Reviewed By: jberdine
Differential Revision: D3944148
fbshipit-source-id: 6129090
Summary: That data was never used and removing it can simplify frontends quite a bit.
Reviewed By: jberdine
Differential Revision: D3967389
fbshipit-source-id: d65c3da
Summary:
- Use the module types in cModule_types.ml instead of redefining them.
- A few occurrences of \n in formatted output replaced by @\n to let the
formatter know of line breaks (by no means complete, these were just a few I
came across while doing something else)
Reviewed By: jberdine
Differential Revision: D3944081
fbshipit-source-id: 4460427
Summary:
This diff introduces a first version of a front-end checkers specification
language. The language is based on the CTL temporal logic that is interpreted
on trees. In this case the model for a formula is the AST of the program produced
by clang.
This diff introduce the language and translate most of the existing checks on
this new language. In other diff I will translate all the other checks.
Then I will generalize the framework to allow the developer to specify only
the CTL formula.
Reviewed By: martinoluca
Differential Revision: D3819211
fbshipit-source-id: f8e01eb
Summary:
Change Sil.Call instruction to have only a single optional return
identifier, insted of a list. Essentially none of the code handled
multiple return identifiers. Also, add the type of the return
identitifier to Call instructions.
Reviewed By: sblackshear
Differential Revision: D3919358
fbshipit-source-id: d2d4f72
Summary:
Refactor Sil.struct_typ and associated operations into a separate
StructTyp module. This is possible now that Typ.Tstruct only carries a
type name instead of the definition directly, and is helpful to simplify
module dependencies.
Reviewed By: cristianoc
Differential Revision: D3919357
fbshipit-source-id: a37a656
Summary:
It is no longer necessary to keep the name of a struct within the
struct, as the name will just have been used to look it up.
Reviewed By: cristianoc
Differential Revision: D3919355
fbshipit-source-id: ab65168
Summary:
The global reference `DB.current_source` is used internally in the module DB, by all the front-ends, and directly and indirectly by the back-end, including saving and restoring the state in case of on-demand procedure calls. In particular, it is heavily used in printing functions.
This diff cleans up the flow of information about what the current file is, making it explicit, and removes the reference.
Reviewed By: jberdine
Differential Revision: D3901247
fbshipit-source-id: ef596bd
Summary:
This diff removes the redundancy in the representation of types where
struct types could be represented either directly using Tstruct or
indirectly using Tvar to refer to the type environment. A consequence
is that it is much harder to construct large type values.
Reviewed By: sblackshear, cristianoc
Differential Revision: D3839753
fbshipit-source-id: cf04ea5
Summary:
Rename Typ.mk_struct to internal_mk_struct, and add Tenv.mk_struct that
ensures types are added to the environment under the right name.
Reviewed By: cristianoc
Differential Revision: D3791865
fbshipit-source-id: fd4b667
Summary:
The Typ.struct_typ.csu field is now redundant with the Csu.t in the
name: Typename.t field.
Reviewed By: cristianoc
Differential Revision: D3791861
fbshipit-source-id: 5370885
Summary: Replace the struct_name: Mangled.t option field of Typ.struct_typ with name: Typename.t
Reviewed By: sblackshear
Differential Revision: D3791860
fbshipit-source-id: 3ee1d00
Summary:
Given that mangling now respects `extern "C" {}` declarations, pnames of C function will have no mangling and we don't need to discard mangled part from procname.
Move `malloc` detection to `get_builtin_pname_opt` function (together with all others)
Reviewed By: dulmarod
Differential Revision: D3804402
fbshipit-source-id: 9ae9991
Summary:
There were overly complex and different ways of identifying C++/objC languages. Simplify and unify them.
How I came up with naming - there are two languages C and C++. You can apply "Objective-" extention to both of them.
We usually need to differentiate C and C++ (different AST) and whether it's extended (checks specific to ObjC)
Reviewed By: dulmarod
Differential Revision: D3804457
fbshipit-source-id: 685e40a
Summary:
ti_raw field tends to grow exponensially for template instantiations.
ASTexporter no longer gives this bit of information and infer needs to stop using it.
Reviewed By: jvillard
Differential Revision: D3798192
fbshipit-source-id: ba7cbb9
Summary:
We already have logic that deals with adding custom procnames in `function_deref_trans`. This diff simplifies `callExpr_trans` and removes
complex logic responsible for finding type of function.
There is no functional change intended (it will come in future diffs)
Reviewed By: dulmarod
Differential Revision: D3797839
fbshipit-source-id: 21fc13f
Summary:
Translate code coming from std::headers only when it's reachable from user code during translation.
This way, we reduce number of functions analyzer sees and decreases size of cfg/number of .attr files
Reviewed By: jvillard
Differential Revision: D3797550
fbshipit-source-id: 2a9eb4c
Summary: This breaks a dependency to allow cFrontend_utils.ml to call into cLocation.ml.
Reviewed By: sblackshear
Differential Revision: D3779514
fbshipit-source-id: 6ca83d6
Summary: Fix pattern matching of the `parameters` field of `DeprecatedAttr`
Reviewed By: akotulski
Differential Revision: D3782788
fbshipit-source-id: df8dd40
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:
Adding a new mode linters. Now if the analyzer is linters, we do the linters and don't translate,
then, if the analyzer is Infer, we do the translation and the backend and not the linters checks, and the
default is that we do capture, backend and lint checks.
Made the tests separated, which saves time and also shows that the linters mode works.
Reviewed By: jvillard
Differential Revision: D3723472
fbshipit-source-id: 9d828d8
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:
Make necessary changes so that the clang frontend compiles with the
corresponding changes to the facebook clang plugins. Does not actually use the
extra qualifier information yet.
depends on D3684150
Reviewed By: akotulski
Differential Revision: D3684173
fbshipit-source-id: f715f75
Summary:
Enable warning 23 (Useless record with clause), make fatal, and fix the
existing instance.
Reviewed By: sblackshear
Differential Revision: D3685950
fbshipit-source-id: 8ee415d
Summary:
Move the Sil.attribute type and associated types and operations to a new
PredSymb module.
Reviewed By: cristianoc
Differential Revision: D3683834
fbshipit-source-id: d3606a8
Summary:
Cosmetic changes to comments to improve the results of the Reason
comment attachment logic.
These were found using `git grep -nH -e 'in[ ]*(\*'` although the
attachment logic seems ok if the associated `let` is on the same line.
Some others were found with `git grep -nH -e ')[ ]*(\*'` although the
attachment logic seems ok if the associated `(` is on the same line.
Reviewed By: jvillard
Differential Revision: D3654027
fbshipit-source-id: 122aa3b
Summary:
Make checks context-aware, to increase flexibility.
As an example application of this change, whenever an atomic property is accessed from within a synchronized block, skip reporting a `DIRECT_ATOMIC_PROPERTY_ACCESS` warning.
Reviewed By: jvillard
Differential Revision: D3648831
fbshipit-source-id: c033f45
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:
Minor stuff:
- GCCAst -> GCCAsm
- separate constants and mutable global state in cFrontend_config
- alphabetical ordering in cFrontend_config
Reviewed By: akotulski
Differential Revision: D3593858
fbshipit-source-id: 6f4d9c3
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:
1. Attempt to simplify callExpr_trans by merging multiple if-else branches into one in `CTrans_utils.builtin_trans`. Not every special case works that way, so some of them are still there.
2. On top of that, make type of parameters in `CTrans_models` functions `Procname.t` instead `Procname.t option`. This triggered some more changes to `callExpr_trans`.
3. Semi-randomly reorder instructions in `callExpr_trans`
This is mainly an attempt to clean up the code so any suggestions how to make it better are welcome.
Reviewed By: jvillard
Differential Revision: D3586419
fbshipit-source-id: aef8580
Summary:
Store more information inside Procname.objc_cpp type: replace mangling info
with "kind" info, which also contains mangling info when appropriate.
Reviewed By: akotulski
Differential Revision: D3580283
fbshipit-source-id: b1197ed
Summary: ClassTemplateSpecializationDecl now contains structures information about the specialization
Reviewed By: jvillard
Differential Revision: D3586446
fbshipit-source-id: d567a0b
Summary:
Use Itanium mangling for C++ functions/methods instead of raw type name. This is a step towards removing expensive `ti_raw` field from `type_info`.
For virtual methods, use mangled name of the method from base class in order for dynamic dispatch to work.
Reviewed By: dulmarod
Differential Revision: D3556118
fbshipit-source-id: e45edb5
Summary:
Class names fragile, easy to break and they introduce another level of indirection.
Since C++ translation doesn't need names, pass decl pointers everywhere.
Doing otherwise will most likely result in assert false.
Handling of class names in objc translation is more involving and it's left
for now. Later, objc can use same mechanism as C++.
Reviewed By: dulmarod
Differential Revision: D3570176
fbshipit-source-id: b957aba
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:
Move Sil.call_flags type and operations into separate CallFlags
module.
Reviewed By: dulmarod
Differential Revision: D3548086
fbshipit-source-id: 6d264e9
Summary: Move Sil.binop type and operations into separate Binop module.
Reviewed By: dulmarod
Differential Revision: D3548082
fbshipit-source-id: 356bee3
Summary: Move Sil.unop type and operations into separate Unop module.
Reviewed By: dulmarod
Differential Revision: D3548077
fbshipit-source-id: 49d3d83
Summary: Move Sil.const type and operations into separate Const module.
Reviewed By: dulmarod
Differential Revision: D3548073
fbshipit-source-id: 388d03e
Summary:
Move closure values from const to exp. They are not constants, and
this reduces interdependence between Sil types.
Reviewed By: sblackshear
Differential Revision: D3541364
fbshipit-source-id: 1a2f998
Summary:
Backend has the same treatment for all Typ.Int types and so UnaryOperator
should be translated the same for all of them
Reviewed By: jvillard
Differential Revision: D3534277
fbshipit-source-id: 8569b65
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: lambdaExpr now has more information, make infer compile with that new version
Reviewed By: dulmarod
Differential Revision: D3515291
fbshipit-source-id: d239bd3
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:
1. Fetch newest changes to ast exporter. Now we'll hash template instantiations inside declaration names if their string representation is too long (ie. 40 characters)
2. Increase biniou buffer to allow for long type names - they happen when dumping type raw name with long template instantiation (it's not hashed there yet, but infer doesn't use `ti_raw` field much
Reviewed By: dulmarod
Differential Revision: D3462743
fbshipit-source-id: 9152ae5
Summary: They were reusing same type and it lead to wrong type in cache for one of them
Reviewed By: jvillard
Differential Revision: D3462759
fbshipit-source-id: 8e10678
Summary:
Now that array types record only static - and therefore constant -
lengths, Sil typ and exp no longer need to be mutually recursive.
This diff:
- splits the recursion in the type definitions of typ and exp,
- splits the recursion in the comparison and pretty-printing
functions,
- and then refactors typ into a separate module.
Reviewed By: cristianoc
Differential Revision: D3423575
fbshipit-source-id: 6130630
Summary:
This diff refactors Sil.Int, which represents integer literals, into a
separate module IntLit. There are no dependencies forcing Sil.Int to
be a submodule of Sil, and it is also no simpler as a submodule.
Reviewed By: cristianoc
Differential Revision: D3422910
fbshipit-source-id: 63013f2
Summary:
Array types where the length is not statically known were represented
using fresh variables. This diff:
- Makes array type length optional, reducing the amount of work needed
for renaming, substitution, and normalization.
- Revises uses of array length so that the length component of a
Tarray type represents only the statically determined constant
length of an array type, and the length component of a Sizeof
expression represents the dynamically determined length of an array
value.
- Restricts the type of static lengths from a general expression
(Sil.exp) to an integer (Sil.Int.t), enforcing that static types are
constant. This in particular ensures that types contain no
variables, and so are invariant under operations such as renaming
and substitution.
- Removes the type substitution and renaming functions typ_sub,
typ_normalize, and typ_captured_ren. Now that array type lengths
are constant integers, all of these functions are the identity.
Reviewed By: cristianoc
Differential Revision: D3387343
fbshipit-source-id: b5db768
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:
This diff extends Sizeof expressions with an optional expression for the
length of the final extensible array, if any. For example, sizeof a
simple array `sizeof(t[n])` is represented by (modulo subtyping info)
`Sizeof t (Some n)`, and sizeof a struct whose final member is an array
`sizeof(struct s {... t[n] f})` is represented by `Sizeof (struct s
{... t[n] f}) (Some n)`.
This is an intermediate step toward eliminating expressions from types,
the redundancy between the length in the types and in the sizeof
expressions will be eliminated later.
Reviewed By: cristianoc
Differential Revision: D3358763
fbshipit-source-id: 2239bca
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:
Part of the migration of .inferconfig-specific options into options accepted
both by .inferconfig and the CLI.
Reviewed By: jberdine
Differential Revision: D3322508
fbshipit-source-id: 1820a9d
Summary:
Part of the migration of .inferconfig-specific options into options accepted
both by .inferconfig and the CLI.
Reviewed By: jberdine
Differential Revision: D3304784
fbshipit-source-id: 0c39b39
Summary:
Now we can add to inferconfig an option
skip-translation-file to skip completely the translation
and analysis of some file.
Reviewed By: jberdine
Differential Revision: D3311129
fbshipit-source-id: 58fd179
Summary:
Non-fatal warnings are only checked by `make -C infer/src test_build`,
which should be part of `make test`
Reviewed By: sblackshear
Differential Revision: D3301913
fbshipit-source-id: 8196e03
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:
Reimplement command line options in preparation for uniformly passing
options from the top-level infer driver that invokes a build command
through the build system to the descendant infer processes.
All command line options of all executables are collected into Config,
and declared using a new CommandLineOption module that supports
maintining backward compatibility with the current command line
interface. Very few values representing command line options are
mutable now, as they are set once during parsing but are constant
thereafter. All ordering dependencies are contained within the
implementation of Config, and the implementation of Config is careful to
avoid unintended interactions and ordering dependencies between options.
Reviewed By: jvillard
Differential Revision: D3273345
fbshipit-source-id: 8e8c6fa
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:Make node ids be `private int` to make sure we don't mix them with random
integers from other sources.
Reviewed By: sblackshear, cristianoc
Differential Revision: D3179670
fb-gh-sync-id: 4bcf4f0
fbshipit-source-id: 4bcf4f0
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
Summary:public
Report statistics on consumed time and memory in results_dir/perf_stats.json.
Reviewed By: martinoluca
Differential Revision: D3162381
fb-gh-sync-id: e802faa
fbshipit-source-id: e802faa
Summary:public
Instead of translating code from headers blindly, translate only gets transitively referenced from source code.
It won't translate functions from system headers, but in the future we could do that as well
since most of them aren't used and it shouldn't add much overhead.
For now this functionality is hidden behind --cxx-experimental flag
Reviewed By: dulmarod
Differential Revision: D3163519
fb-gh-sync-id: 0c53b10
fbshipit-source-id: 0c53b10
Summary:public
Eliminate the use of the -open Utils command line option passed to the compiler in favor of `open! Utils` in each source file. While slightly convenient, this option causes more headaches than it is worth with other tools e.g. merlin.
Reviewed By: jvillard
Differential Revision: D3168193
fb-gh-sync-id: 4285ef6
fbshipit-source-id: 4285ef6
Summary:public
This will allow us to run translation of more than one function at the same time.
Reviewed By: dulmarod
Differential Revision: D3167965
fb-gh-sync-id: 41e9935
fbshipit-source-id: 41e9935
Summary:public
This information is no longer needed - ASTExporter always exports pointer to parent for C++/objC methods.
This code is from time it was not true.
Reviewed By: jvillard
Differential Revision: D3162455
fb-gh-sync-id: 35570da
fbshipit-source-id: 35570da
Summary:public
Instead of using location of init_stmt, use location of variable when translating initialization.
Most of the time it change anything with some exceptions:
// example1 - C/C++/objC
int x = // now: assignment happens in this line
3; // past: assignment happens in this line
// example2: valid in C++11 only
struct X {
int x = 0; // now: one assignment here
int y = 2; // now: one assigmnent here
X() = default; // before: 2 assignments in this line
};
Reviewed By: dulmarod
Differential Revision: D3155870
fb-gh-sync-id: f38c78c
fbshipit-source-id: f38c78c
Jules Villard
Dulma Churchill
Cristiano Calcagno
Sam Blackshear
Ryan Rhee
Dino Distefano
Andrzej Kotulski
Josh Berdine
Martino Luca