Summary:
Range lists are contained in a separate object file section called .debug_ranges. A range list is
indicated by a DW_AT_ranges attribute whose value is represented as an offset from the
beginning of the .debug_ranges section to the beginning of the range list.

Each entry in a range list is either:
- a range list entry,
- a base address selection entry, or
- an end of list entry.

Reviewed By: luciang

Differential Revision: D19438098

fbshipit-source-id: 12f1d5c60067b0674c44f35ef2731781eb93f1d5

Summary:
Here is an example for class inline member function declared and defined in the same file:

```
Definition:
0x00004c0a:           DW_TAG_subprogram [55] *
                        DW_AT_linkage_name [DW_FORM_strp] ( .debug_str[0x00177124] = "_ZNK5folly10symbolizer4test24ClassWithInlineFunctions9inlineBarERNS0_10FrameArrayILm100EEE")
                        DW_AT_name [DW_FORM_strp] ( .debug_str[0x00089a73] = "inlineBar")
                        DW_AT_decl_file [DW_FORM_data1] (0x1a)
                        DW_AT_decl_line [DW_FORM_data1] (0xa5)
                        DW_AT_declaration [DW_FORM_flag_present]  (true)
                        DW_AT_external [DW_FORM_flag_present] (true)
                        DW_AT_accessibility [DW_FORM_data1] (0x01)
…

Declaration:   -- no DW_AT_decl_file
0x000164c1:   DW_TAG_subprogram [228] *
                DW_AT_specification [DW_FORM_ref4]  (cu + 0x48ea => {0x00004c0a})
                DW_AT_inline [DW_FORM_data1]  (0x01)
                DW_AT_object_pointer [DW_FORM_ref4] (cu + 0x161ac => {0x000164cc})

…

Inline function call
0x0001657b:     DW_TAG_inlined_subroutine [140] *
                  DW_AT_abstract_origin [DW_FORM_ref4]  (cu + 0x161a1 => {0x000164c1})
                  DW_AT_low_pc [DW_FORM_addr] (0x000000000040fa6e)
                  DW_AT_high_pc [DW_FORM_data4] (0x00000055)
                  DW_AT_call_file [DW_FORM_data1] (0x1a)
                  DW_AT_call_line [DW_FORM_data1] (0xe2)
```

Here is an example for class inline member function declared and defined in different files:

```
Definition:  DW_AT_decl_file: 0x01  --> SymbolizerTestUtils.h
0x00004c3d:           DW_TAG_subprogram [55] *
                        DW_AT_linkage_name [DW_FORM_strp] ( .debug_str[0x0017717f] = "_ZNK5folly10symbolizer4test22InlineFunctionsWrapper9inlineBarERNS0_10FrameArrayILm100EEE")
                        DW_AT_name [DW_FORM_strp] ( .debug_str[0x00089a73] = "inlineBar")
                        DW_AT_decl_file [DW_FORM_data1] (0x01)
                        DW_AT_decl_line [DW_FORM_data1] (0x30)
                        DW_AT_declaration [DW_FORM_flag_present]  (true)
                        DW_AT_external [DW_FORM_flag_present] (true)
                        DW_AT_accessibility [DW_FORM_data1] (0x01)

…

Declaration:   DW_AT_decl_file: 0xbf  --> SymbolizerTestUtils-inl.h
0x00017ee8:   DW_TAG_subprogram [231] *
                DW_AT_decl_file [DW_FORM_data1] (0xbf)
                DW_AT_decl_line [DW_FORM_data1] (0x21)
                DW_AT_specification [DW_FORM_ref4]  (cu + 0x491d => {0x00004c3d})
                DW_AT_inline [DW_FORM_data1]  (0x01)
                DW_AT_object_pointer [DW_FORM_ref4] (cu + 0x17bd5 => {0x00017ef5})

…

Inline function call
0x00017fa5:     DW_TAG_inlined_subroutine [158] *
                  DW_AT_abstract_origin [DW_FORM_ref4]  (cu + 0x17bc8 => {0x00017ee8})
                  DW_AT_low_pc [DW_FORM_addr] (0x00000000004104ee)
                  DW_AT_high_pc [DW_FORM_data4] (0x00000055)
                  DW_AT_call_file [DW_FORM_data1] (0x1a)
                  DW_AT_call_line [DW_FORM_data2] (0x0101)
```

Reviewed By: luciang

Differential Revision: D19444082

fbshipit-source-id: 5a552404609073af04b0cc0b86b5e19d5149a1e1

Summary: Linkage name (DW_AT_linkage_name) contains more information than the identifier name (DW_AT_name).

Reviewed By: luciang

Differential Revision: D19437477

fbshipit-source-id: 1755a71678cbe9e90ba7bc085e4c46b7784c273e

Summary:
Actually class inline functions exist in both .debug_info and .debug_types sections. In this diff, only the information in .debug_info is used.

Step 1. Find the DW_TAG_inlined_subroutine debug info entry (DIE) based on the given address.
Step 2. Find the DW_TAG_subprogram DIE based on the DW_AT_abstract_origin attr in inlined_subroutine, but this DIE is just a declaration.
Step 3. Find the actual definition DW_TAG_subprogram DIE based on the DW_AT_specification attr.

```
.debug_info

0x00003657:           DW_TAG_subprogram [56] *   ---- step 3
                        DW_AT_linkage_name [DW_FORM_strp] ( .debug_str[0x0002932d] = "_ZN5folly10symbolizer4test24ClassWithInlineFunctions9inlineBarERNS0_10FrameArrayILm100EEE")
                        DW_AT_name [DW_FORM_strp] ( .debug_str[0x00014064] = "inlineBar")
                        DW_AT_decl_file [DW_FORM_data1] (0x18)
                        DW_AT_decl_line [DW_FORM_data1] (0xa1)
                        DW_AT_declaration [DW_FORM_flag_present]  (true)
                        DW_AT_external [DW_FORM_flag_present] (true)
                        DW_AT_accessibility [DW_FORM_data1] (0x01)

…

0x0000cd74:   DW_TAG_subprogram [203] * .   ---- step 2
                DW_AT_specification [DW_FORM_ref4]  (cu + 0x358f => {0x00003657})
                DW_AT_inline [DW_FORM_data1]  (0x01)
                DW_AT_object_pointer [DW_FORM_ref4] (cu + 0xccb7 => {0x0000cd7f})

…
0x0000cda0:   DW_TAG_subprogram [181] *
                DW_AT_low_pc [DW_FORM_addr] (0x00000000002a4980)
                DW_AT_high_pc [DW_FORM_data4] (0x00001e22)
                DW_AT_frame_base [DW_FORM_exprloc]  (<0x1> 56 )
                DW_AT_object_pointer [DW_FORM_ref4] (cu + 0xccf0 => {0x0000cdb8})
                DW_AT_specification [DW_FORM_ref4]  (cu + 0x312f => {0x000031f7})

…

0x0000ce02:     DW_TAG_inlined_subroutine [157] *               ---- step 1
                  DW_AT_abstract_origin [DW_FORM_ref4]  (cu + 0xccac => {0x0000cd74})
                  DW_AT_low_pc [DW_FORM_addr] (0x00000000002a4f66)
                  DW_AT_high_pc [DW_FORM_data4] (0x000000c0)
                  DW_AT_call_file [DW_FORM_data1] (0x18)
                  DW_AT_call_line [DW_FORM_data1] (0xe6)

.debug_types

0x00020fdf:         DW_TAG_class_type [33] *
                      DW_AT_calling_convention [DW_FORM_data1]  (0x05)
                      DW_AT_name [DW_FORM_strp] ( .debug_str[0x00067094] = "ClassWithInlineFunctions")
                      DW_AT_byte_size [DW_FORM_data1] (0x08)
                      DW_AT_decl_file [DW_FORM_data1] (0x18)
                      DW_AT_decl_line [DW_FORM_data1] (0x9f)

…

0x00020ff5:           DW_TAG_subprogram [56] *
                        DW_AT_linkage_name [DW_FORM_strp] ( .debug_str[0x0002932d] = "_ZN5folly10symbolizer4test24ClassWithInlineFunctions9inlineBarERNS0_10FrameArrayILm100EEE")
                        DW_AT_name [DW_FORM_strp] ( .debug_str[0x00014064] = "inlineBar")
                        DW_AT_decl_file [DW_FORM_data1] (0x18)
                        DW_AT_decl_line [DW_FORM_data1] (0xa1)
                        DW_AT_declaration [DW_FORM_flag_present]  (true)
                        DW_AT_external [DW_FORM_flag_present] (true)
                        DW_AT_accessibility [DW_FORM_data1] (0x01)

```

Reviewed By: luciang

Differential Revision: D19384064

fbshipit-source-id: a2a6397b94aab9de58d013cf4ad19e658e180d31

Summary: In cases where `addBenchmark` is called directly the name often resides in `std::string` which requires calling `c_str()`. Make it possible to pass `std::string` by making the function take `StringPiece` instead of `const char*`.

Reviewed By: rhodo

Differential Revision: D19507553

fbshipit-source-id: 49dd2bb77daefffeda3fc2153215de77b530f214

Summary: When building folly with clang, backtrace was marked as not found. This diff uses `find_package(Backtrace)` instead which allowed us to use the symbolizer libs.

Reviewed By: simpkins

Differential Revision: D19497120

fbshipit-source-id: a8f8b4ffe9a2d53a53b6c7be32ac2a832a840877

Summary: Use functional style cast on literal value instead of static_cast

Reviewed By: yfeldblum, jdonald

Differential Revision: D19459138

fbshipit-source-id: 103f644322394779fc5cd8512d7a5244d2231091

Summary:
Pull Request resolved: https://github.com/facebook/folly/pull/1306

The current documentation for Folly::synchronize_rcu and Folly::rcu_barrier is lacking, this commit adds comment headers.

Reviewed By: magedm

Differential Revision: D18618910

fbshipit-source-id: 39e18d52b2380234ec6f33a1ec220acc97abdd50

Summary:
With this change the getdeps' CargoBuilder will support depencies between cargo builds.

The way how it works is documented in the code and required few assumptions about how a cargo project has to be defined in order to support this.

This change also adds the "mononoke" manifest and few Cargo.toml files to the mononoke project to prove that this new feature works.

Reviewed By: farnz

Differential Revision: D19468912

fbshipit-source-id: f299733cbbc2ec7bca399c898ec8d710334d0fa9

Reviewed By: yfeldblum

Differential Revision: D19391772

fbshipit-source-id: 4dffdd2d4c42591c9a8b4841fcb63d2284649350

Summary:
FBOSS needs to use header files from more directories in OpenNSA,
so make those available in include directory.

Differential Revision: D19461874

fbshipit-source-id: 1fe3fbbc39477baecf9cd4f7c7a964be40cbbb12

Summary:
Fix linter issue

(Note: this ignores all push blocking failures!)

Reviewed By: danobi

Differential Revision: D19435633

fbshipit-source-id: 858755eda1873b20cd7dae6e24b39ce21d15608a

Summary: Corrects incorrect logging function being called.

Reviewed By: lewissbaker

Differential Revision: D19453995

fbshipit-source-id: 5268a8ed5ef8379da84e83ec05db9e88317f3b9a

Summary: Workaround for warning caused by clang pretending to be cl

Differential Revision: D19426072

fbshipit-source-id: ba59913fe9b6c27f32db06f341429952fc4312b5

Summary:
This is an interim solution that unblocks failing FBOSS OSS builds.

Broadcom's OpenNSA is available on github and contains large precompiled
libraries. For large files (> 100Mb), github uses git-lfs.

git clones to OpenNSA started failing yesterday with:

Error downloading object: lib/x86-64/libopennsa.a (7f21d94): Smudge error:
Error downloading lib/x86-64/libopennsa.a
(7f21d941ac32ccae38adb05b3386be739bdccd502a878364d386e7a5cb172f35): batch
response: This repository is over its data quota. Account responsible for LFS
bandwidth should purchase more data packs to restore access.

Github documents (refer:
https://help.github.com/en/github/managing-large-files/about-storage-and-bandwidth-usage)
“When you download a file tracked with Git LFS, the total file size is counted
against the repository owner’s bandwidth limit”. It appears we are hitting that
limit.

Thus, github is not a good choice here. Even if we create a 'github release
tarball', the tarball continues to carry lfs files and thus downloading those
counts towards the quota (which is limited).

Broadcom paid some amount to bump up the quota, but it is matter of time before
we hit it esp given that these builds run on-diff.

A better solution is to download a tarball (that contains real files, not lfs),
and then allow Facebook lfs to cache it.

While github does not support that, it seems bitbucket does.

Thus, we forked OpenNSA from github into a bitbucket repo and this patch
modifies the manifest to download a tarball from bitbucket that will be cached.

Broadcom is working on a cleaner solution but this will keep our FBOSS OSS build
clean in the interim.

Reviewed By: wez

Differential Revision: D19437386

fbshipit-source-id: b1213a186a0af57b9fd71b30e8899e80affd4cc0

Summary: Add a call in folly init to folly::start_hazptr_thread_pool_executor() to make the default hazptr domain use a CPUThreadPoolExecutor by default.

Reviewed By: davidtgoldblatt

Differential Revision: D19107125

fbshipit-source-id: 1cebe0864de14b54349f723061c4c2b5905b105b

Summary:
This allows the caller to, for example, pass their own ManualExecutor or EventBase
and have the task scheduled onto that executor and have the current thread drive
that executor until it completes.

Reviewed By: yfeldblum

Differential Revision: D19205803

fbshipit-source-id: 6042f68decf8d7d9bb1d37977e5804b0504daa41

Summary: add the socket to the callback parameter

Reviewed By: yangchi

Differential Revision: D19192549

fbshipit-source-id: 068bdb560273ab3203a1b7eaefa5b01c4e4e9968

Summary: Add support for registered fds

Reviewed By: kevin-vigor

Differential Revision: D19313387

fbshipit-source-id: 19527958b3986992cdafbad2c4c4902c887a9e9f

Summary:
Broadcom has formally replaced OpenNSL with newer OpenNSA:
https://github.com/Broadcom-Network-Switching-Software/OpenNSA/blob/master/README.md

With D16401189, FBOSS no longer depends on OpenNSL, but uses the new OpenNSA
instead. Remove this manifest.

Reviewed By: wez

Differential Revision: D19413708

fbshipit-source-id: f3662f1101d59a5e0e59cb7238797d652564ff90

Summary:
[Folly] Use `getrandom` instead of `/dev/urandom` when available.

The C library function `getrandom` is available on linux >= 3.17 and glibc >= 2.25.

Reviewed By: ot, simpkins, luciang

Differential Revision: D19211519

fbshipit-source-id: 07e7e856fc81d1f04efca4a6cfa0b76ada08f443

Summary:
When reading a `std::exception_ptr` out of a moved-from `folly::exception_wrapper`, we end up reading a `std::exception_ptr` field of a deleted `ExceptionPtr` object. This was causing MSAN much consternation.

The fix is to test for emptiness in `to_exception_ptr` and return a default-constructed `std::exception_ptr`.

This commit also adds extra test cases, since `to_exception_ptr` does something slightly different depending on whether the `exception_wrapper` object is `const` or not.

Reviewed By: yfeldblum

Differential Revision: D19403528

fbshipit-source-id: fde74a5c4b2ddb2025703432c1ac5a19d26b9426

Summary:
I have been encountering

```
AddressSanitizer:DEADLYSIGNAL
=================================================================
==937752==ERROR: AddressSanitizer: SEGV on unknown address 0x24a12000e4f18 (pc 0x7f3902a6e696 bp 0x7f37bc5e4380 sp 0x7f37bc5e42a0 T107)
==937752==The signal is caused by a READ memory access.
SCARINESS: 20 (wild-addr-read)

    #0 0x7f3902a6e695 in folly::ThreadLocalPtr<folly::SingletonThreadLocal<folly::hazptr_tc<std::atomic>, void, folly::detail::DefaultMake<folly::hazptr_tc<std::atomic> >, void>::Wrapper, void, void>::get() const folly/ThreadLocal.h:160
    #1 0x7f3902a6d600 in get folly/ThreadLocal.h:69
    #2 0x7f3902a6d600 in folly::ThreadLocal<folly::SingletonThreadLocal<folly::hazptr_tc<std::atomic>, void, folly::detail::DefaultMake<folly::hazptr_tc<std::atomic> >, void>::Wrapper, void, void>::operator*() const folly/ThreadLocal.h:78
    #3 0x7f3902a6ca1b in folly::SingletonThreadLocal<folly::hazptr_tc<std::atomic>, void, folly::detail::DefaultMake<folly::hazptr_tc<std::atomic> >, void>::getWrapper() folly/SingletonThreadLocal.h:149
    #4 0x7f3902a6cbe5 in folly::SingletonThreadLocal<folly::hazptr_tc<std::atomic>, void, folly::detail::DefaultMake<folly::hazptr_tc<std::atomic> >, void>::LocalLifetime::~LocalLifetime() folly/SingletonThreadLocal.h:121
    #5 0x7f38f04d9fd5 in (anonymous namespace)::run(void*) /data/users/kirkshoop/gcc/trunk/libstdc++-v3/libsupc++/atexit_thread.cc:75:16
    #6 0x7f38ef9ee551 in __nptl_deallocate_tsd.part.8 /home/engshare/third-party2/glibc/2.26/src/glibc-2.26/nptl/pthread_create.c:301:8
    #7 0x7f38ef9ef7c8 in __nptl_deallocate_tsd /home/engshare/third-party2/glibc/2.26/src/glibc-2.26/sysdeps/nptl/futex-internal.h:200:3
    #8 0x7f38ef9ef7c8 in start_thread /home/engshare/third-party2/glibc/2.26/src/glibc-2.26/nptl/pthread_create.c:475:3
```

I tried using a unique Tag for the SingletonThreadLocal for debugging purposes and this seemed to fix the issue.

Reviewed By: magedm

Differential Revision: D19356179

fbshipit-source-id: a18c6b02f0a40e0509753075614eeff71d859bf7

Summary:
With the release of OpenNSA (https://github.com/Broadcom-Network-Switching-Software/OpenNSA), we can stop using opennsal altogether!

This diff was created using following steps:

cd fboss/agent
find . ! -path "*\/oss*" -type f \( ! -iname "*TARGETS*" \) -exec sed -i -e 's/opennsl_spl_//g' {} \;
find . ! -path "*\/oss*" -type f \( ! -iname "*TARGETS*" \) -exec sed -i -e 's/opennsl/bcm/g' {} \;
find . ! -path "*\/oss*" -type f \( ! -iname "*TARGETS*" \) -exec sed -i -e 's/OPENNSL/BCM/g' {} \;
find . ! -path "*\/oss*" -type f \( ! -iname "*TARGETS*" \) -exec sed -i -e 's/OpenNSL/Bcm/g' {} \; # for symbols like snmpBcmTransmittedPkts2048to4095Octets

Furthermore:

- In all TARGETS under fboss/agent replace wrapped_opennsl_symbols with wrapped_bcm_symbols.
- hg mv agent/facebook/test/OpenNSLInterface.h agent/facebook/test/BcmInterface.h
- BcmEgress.cpp remove operator== overload for opennsl API altogether, and remove operator== BCM API version from inside unnamed namespace, and put it in fboss namespace.
- BcmCinter.h and BcmCinter.cpp now have some duplicate definitions as opennsl_ got renamed to bcm_. Delete one of the definitions "as appropriate".
- Similarly, remove duplicate definitions in FakeSdk.h and FakeSdk.cpp
- Similarly, remove duplicate definitions in SdkTracer.cpp (remove definitions calling CALL_WRAPPERS_RV_NO_CINTER). And lastly, remove CALL_WRAPPERS_RV_NO_CINTER itself.
- arc lint
- Remove OpennslCompatTests.cpp
- Fix ./agent/hw/bcm/tests/facebook/BcmEgressTest.cpp to have #include
  "fboss/agent/facebook/test/MockOpenNSL.h" instead of MockBcm.h

TODO:
- This patch retains the directory structure (facebook/ subdirectory), which will be fixed in subsequent patches.
- Remove opennsl references from TARGETS file, additional cleanup etc.
- Remove all oss directories...

Differential Revision: D16401189

fbshipit-source-id: 607b6c0f97ffcacf3707f6b7a4c9454cc0b24476

Summary:
Broadcom provides this library and they decided to rename it from OpenBCM to
OpenNSA. Thus, rename corresponding fbcode_builder code.

Reviewed By: wez

Differential Revision: D19396687

fbshipit-source-id: 8233dbf4de9342b5a0e54ae275d6c73d43abe6d0

Summary: [Folly] Cut unused `AsyncSocketException::SASL_HANDSHAKE_TIMEOUT`.

Reviewed By: vitaut

Differential Revision: D19343864

fbshipit-source-id: ed4374bc2b376ff71e592323ed8c37290700e870

Summary: Add recvmmsg

Differential Revision: D18927890

fbshipit-source-id: de500dd1c266f21fbfc39c2972df787da50c7a80

Summary:
UndefinedBehaviorSanitizer: implicit-integer-truncation buck-out/dev/gen/folly/synchronization/atomic_util#header-mode-symlink-tree-with-header-map,headers/folly/synchronization/AtomicUtil-inl.h:115:28
```

Here both `mask` and the first argument in `std::atomic<..>::fetch_and` have type  `unsigned char`. Before bitwise not operation `mask` variable undergoes [integral promotion](https://en.cppreference.com/w/cpp/language/implicit_conversion#Integral_promotion) resulting in truncation error.

Since here this is intentional add a `static_cast` to be explicit about it.

Reviewed By: yfeldblum

Differential Revision: D19320340

fbshipit-source-id: 41c987c19b77fa21ee9aa83cf06dfc7cddba91c8

Summary:
Found with readability-simplify-boolean-expr
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Pull Request resolved: https://github.com/facebook/folly/pull/1301

Reviewed By: yfeldblum

Differential Revision: D19302630

Pulled By: Orvid

fbshipit-source-id: 9833e4ab3fe93592fa8f868f6ed2d56a263949fe

Summary: Enable `INSTALL_PYTHON_LIB=ON` for internal builds of Eden on Windows.

Reviewed By: pkaush

Differential Revision: D19060630

fbshipit-source-id: 40d4f8784958fbeaad4f0d332c55fa0cb810cb5e

Summary:
Add `FOLLY_NO_UNIQUE_ADDRESS ` to expose C++20's `[[no_unique_address]]` where available.

(Note: this ignores all push blocking failures!)

Reviewed By: pixelb

Differential Revision: D19375089

fbshipit-source-id: 9a83ae791002e02df5b93b61f20209e5f467a959

Reviewed By: yfeldblum

Differential Revision: D19359860

fbshipit-source-id: b084d8cd603238e76d61de1eed3f233cf5b7fb27

Reviewed By: yfeldblum

Differential Revision: D19359673

fbshipit-source-id: 610ae77e205038267e0e331a04486eef0329c165

Summary:
For long-lived IOBufs, it can be useful to know whether their memory footprint
can be usefully shrunk. This diff exposes a method that lets users see the
smallest capacity an IOBuf could have while wrapping a particularly sized
object.

Without this, they have to do hacky math.

Reviewed By: yfeldblum

Differential Revision: D18440359

fbshipit-source-id: 1324700b58f0b2762cb3347b907ca5e04ebecb99

Summary: This constructor would never be called since the class is abstract (the method `add` from `Executor` is not implemented). This causes a warning which fails builds because of `-Werror`.

Reviewed By: yfeldblum

Differential Revision: D19345492

fbshipit-source-id: 20f185e0903a03acbde2e55e5a575e20deb5ad2a

Summary: This variable shadows the field `options_`, so rename it to get rid of the warning `constructor parameter 'options_' shadows the field 'options_' of 'FiberManager'` (which is turned into an error because of `-Werror`). This happens on clang 8.

Reviewed By: yfeldblum

Differential Revision: D19331755

fbshipit-source-id: 3615cf9b6c7516775f1dc198a08bc784a52c0fb4

Summary: Add non persistent events overflow tests

Reviewed By: danobi, kevin-vigor

Differential Revision: D19349804

fbshipit-source-id: 360d1f41d074b3d1af5f163213dadfc35f28c353

Reviewed By: yfeldblum

Differential Revision: D19357723

fbshipit-source-id: d099419271f74b013a276079723250ce842e2b24

Summary: [Folly] Fix evaluation-order assumption in futures varidic collect - argument evaluation order is unspecified so it must not be relied on when side-effects must occur in a specific order.

Reviewed By: lewissbaker

Differential Revision: D19347873

fbshipit-source-id: db4326d995a241619f96ff2bacdf5a5fa2332091

Summary:
There have been weird edge cases we haven't tracked down yet that saw python segfaulting at shutdown, caused by drive() run from the destructor of AsyncioExecutor after Python had run Py_Finalize shutting down the runtime.

This fix uses new checks from Python >=3.7 to check if Python is finalizing

Reviewed By: yfeldblum, nanshu

Differential Revision: D19321677

fbshipit-source-id: 79a6f95df383a86d80e064eb55a8a81e29d50ace