Summary:
If FOLLY_SETTING_DEFINE(...) is put into .cpp file right now you will get linker error about undefined references.

According to http://en.cppreference.com/w/cpp/language/inline
  2) The definition of an inline function or variable (since C++17) must be present in the translation unit where it is accessed (not necessarily before the point of access).

Hence the linker error. This diff fixes that.

Reviewed By: alikhtarov, mnv104

Differential Revision: D7567469

fbshipit-source-id: 02049e4881e50c414aeb506745e02eed1256daad

Summary:
Update `cmake_configure()`, `cmake_install()`, and `fb_github_cmake_install()`
to support specifying the directory where CMakeLists.txt is found, relative to
the directory where the build is being performed.  Previously these functions
where hardcoded to assume that CMakeLists.txt was always found at '..'

Reviewed By: snarkmaster

Differential Revision: D7540689

fbshipit-source-id: efd3d044345fadc0346e436c01d0a247e1b6fd70

Summary:
Add a macro to help users define the `getBaseLoggingConfig()` function.

While I would prefer to avoid macros if possible, this seems worthwhile.  This
saves 4 or 5 lines of boilerplate code in each program that sets a custom base
logger setting.  It also reduces the likelihood of a developer accidentally
having a typo in the function name, which would still build successfully but
not have the desired results.

Reviewed By: chadaustin

Differential Revision: D7457652

fbshipit-source-id: 1c316c7ea6949c16bd7b61c0440cc1ee69ecb83e

Summary:
Add folly::initLoggingOrDie(), which behaves like `initLogging()` but handles
errors by printing a message to stderr and then calling `exit(1)`.

Most programs are expected to initialize logging early on during program
start-up, and will likely use a command line argument or other configuration
value as the logging settings.  If an error occurs they usually want to print
the message to stderr and exit unsuccesfully. `initLoggingOrDie()` makes it
easy to perform these steps without requiring programs to write their own
exception handlers to handle errors from `initLogging()`.

Reviewed By: chadaustin

Differential Revision: D7164830

fbshipit-source-id: d688046f1b6240c948e4aaabfc9fb24ba3d9ff89

Summary:
- Let's enforce a single definition. Also makes the implementation much simpler.
- Collect all static info about a setting in a Metadata struct

Differential Revision: D7544210

fbshipit-source-id: d3f2ef617bd817d355a37e11fa9425b6a4259384

Summary:
Currently, the memory used by a map instance is available only via computeStats(),
which is quite expensive. A lightweight method is needed for getting the map memory
footprint on a hot code path.

Reviewed By: nbronson

Differential Revision: D7544180

fbshipit-source-id: 3cbc98bb9f1c5e7f75fd9eb7f89016580fbb6523

Summary: Which only supports C++11 style constepxr.

Reviewed By: simpkins

Differential Revision: D7546457

fbshipit-source-id: 52db98379096dd3b25f656e7e62238ce10537bf7

Summary:
According to http://en.cppreference.com/w/cpp/language/operators
  The overload of operator -> must either return a raw pointer or return an object (by reference or by value), for which operator -> is in turn overloaded.

Hence this change.

Reviewed By: mnv104

Differential Revision: D7548832

fbshipit-source-id: d98ff1f96bc00dc6e2e5cb084b96091a61421627

Summary:
Tudor who wrote this left the company... so RB.. you are the reviewers :)

1. make default commands as constants
2. remove fake message about ",h"
3. align quota usage from mix to '
4. add support for version command
5. add function to identify built-in command (is needed for an external application to make a decision if something is mandatory or not)

Reviewed By: marcinpe

Differential Revision: D7048169

fbshipit-source-id: b48cf7df28cfa387e028a1cc869332407314c906

Summary: Adds a few more OpenSSL compatibility functions for working with X509_STORE and its objects.

Reviewed By: knekritz

Differential Revision: D7540930

fbshipit-source-id: 0275a200d673386988bc25140b1d827859b04364

Summary: hazptr_obj is copyable and moveable, but doing so would cause a bug, because the next ptr would point to the object that was copied/moved from, which can oftentimes be garbage or another object that has not yet retired. This diff changes the copy/move constructors and assignment operators to simply check that the rhs has not been retired.

Reviewed By: magedm

Differential Revision: D7539444

fbshipit-source-id: f9325c7b886fcf4b553344ee37f2355ca41268b6

Summary:
Install the CMake package configuration file under lib/cmake/folly rather than
share/folly.  CMake will automatically search both of these locations, but
lib/cmake/folly appears to be a more commonly-used location across other open
source projects.

Reviewed By: Orvid

Differential Revision: D7479056

fbshipit-source-id: becd3d4c05e774d2aede20f6a7a50f57d6c05875

Summary:
- Use CMakePackageConfigHelpers to help generate the file
- Print a message about where folly was found if not using QUIET
- Make the include, lib, and cmake installation directories configurable

Reviewed By: wez

Differential Revision: D7479058

fbshipit-source-id: 2548acc9d6de90d11da02ac576a58ce5ca939766

Summary: Include the new `UTF8String.h` header where needed.

Reviewed By: Orvid

Differential Revision: D7473655

fbshipit-source-id: 9d1b820123a786d8eb3d6405a4ff35331de41694

Summary: Neither Folly nor Thrift actually version anymore and haven't in multiple years, so just remove the code to do this.

Reviewed By: yfeldblum

Differential Revision: D7512580

fbshipit-source-id: 89c61cf4ef3d78ea7c09ba6855e0717cfbe022d6

Summary: Fix compile error: error: variable 'b' set but not used [-Werror=unused-but-set-variable]

Reviewed By: yfeldblum

Differential Revision: D7471259

fbshipit-source-id: 784e874200bb44ec9bddf4a3c12f7a90be12d17b

Summary:
Added missing installation of UTF8String.h
Closes https://github.com/facebook/folly/pull/813

Reviewed By: yfeldblum

Differential Revision: D7506038

Pulled By: Orvid

fbshipit-source-id: 9821a0040c44715cfd68852743b64a32df0dcf57

Summary: MSVC 2015 Update 3 can't parse these with curly-brace init'd, so swap the assignment. The result is the exact same.

Reviewed By: simpkins

Differential Revision: D7508756

fbshipit-source-id: 5e60607f978a87ae8bfed22086d1dccef15759ac

Summary:
Optimized builds of //folly/experimental/coro test Coro.Sleep
would almost always fail because the compiler would generate
code that would only sleep for 0.98 seconds. Perform some
simple rounding in order to ignore slight optimizations like
these.

Reviewed By: wqfish

Differential Revision: D7496416

fbshipit-source-id: f81ff30922fbf3e5d2086fde50f4a469bdf72e51

Summary:
F14HashToken encapsulates the work of hash_function(), which
is the same across F14 containers that have the same key_type and equal
hash_function() (same type and operator==).  This diff adds documentation
that callers may rely on this fact, which means they can use this feature
to reduce work if a single key is access in multiple maps/sets.

(Note: this ignores all push blocking failures!)

Reviewed By: shixiao

Differential Revision: D7506737

fbshipit-source-id: 321032d619434501b1e0544962e54732bfc4c970

Summary:
Allow the user to give their own pair implementation. This allows
using a packed pair.

Reviewed By: yfeldblum

Differential Revision: D7504521

fbshipit-source-id: 11888594b8b3ef3f530ebd95b8006ef6f5afbc65

Summary: Terabytes aren't Web Scale.

Reviewed By: ot, philippv, luciang

Differential Revision: D7479752

fbshipit-source-id: fd353933e642b1ee024c28107c8fcb6a55fe755e

Summary: Until I do a PR on `double_conversion`, we need to work around this by catching the trailing 'e' case.

Reviewed By: luciang

Differential Revision: D7481130

fbshipit-source-id: 2734dbe834e6cd69c6dfe41d6b4e9a7a548a7da8

Summary:
When `startFail()` is called, it sets the state to StateEnum::ERROR.
There is a chance that immediate read callback is scheduled to run in
next event loop. The callback calls handleRead() then triggers
`assert(state_ == StateEnum::ESTABLISHED)` in `AsyncSokcet::handleRead`.

Cancel any immediate read callback when startFail is called.

Reviewed By: yfeldblum

Differential Revision: D7051956

fbshipit-source-id: 0d6693d851b272355a4f36ab8d001969fa47750e

Summary:
At `-O0` each coroutine call results in a heap allocation. This
combined with the increased memory pressure when using ASAN
results in an invalid memory access beyond the maximum address.
Avoid the problem by limiting the recursion to 5,000 frames deep,
instead of 10,000. This still fulfills the intent of the test,
but without pushing the limits of ASAN.

Reviewed By: wqfish

Differential Revision: D7503976

fbshipit-source-id: 7850a9d9db23328d42c25b74a1290caa7773e6a7

Summary: sendRequestSync should only be implemented by channels, which own threads looping EventBases.

Reviewed By: phoad

Differential Revision: D7464392

fbshipit-source-id: bde6edc85438bb406592291330869972f88c787a

Summary:
Using an array of prehash tokens is quite inconvenient without
the ability to default construct them.

Reviewed By: shixiao

Differential Revision: D7490113

fbshipit-source-id: f802a7dc6dc2c603c4682e5f384d9f135220cd54

Summary:
Apple Clang 9 (clang-900.0.39.2) on macOS 10.13.3, when configured with
`FOLLY_USE_LIBCPP`, fails to build `SynchronizedTest.cpp` with the following
error:

    In file included from /Users/awang/code/folly/folly/test/SynchronizedTest.cpp:20:
    /Users/awang/code/folly/folly/Synchronized.h:511:9: error: no matching constructor for
          initialization of 'folly::Synchronized<int, NonDefaultConstructibleMutex>'
          : Synchronized{std::piecewise_construct,
            ^           ~~~~~~~~~~~~~~~~~~~~~~~~~~
    /Users/awang/code/folly/folly/test/SynchronizedTest.cpp:539:25: note: in instantiation
          of function template specialization 'folly::Synchronized<int,
          NonDefaultConstructibleMutex>::Synchronized<int &&, int &&>' requested here
      auto&& synchronized = folly::Synchronized<int, NonDefaultConstructibleMutex>{
                            ^
    /Users/awang/code/folly/folly/Synchronized.h:499:12: note: candidate constructor not
          viable: no known conversion from 'const std::__1::piecewise_construct_t' to
          'in_place_t' (aka 'folly::in_place_tag (&)(folly::in_place_tag)') for 1st argument
      explicit Synchronized(in_place_t, Args&&... args)
               ^
    /Users/awang/code/folly/folly/Synchronized.h:764:3: note: candidate template ignored:
          could not match 'std::__1::integer_sequence' against 'folly::integer_sequence'
      Synchronized(
      ^
    <other constructors not viable due to number-of-parameter mismatches>

The proximate cause of the error is that `make_index_sequence` is
generating a `folly::index_sequence`, but the delegatee constructor only
accepts `std::index_sequence`.

Changing the delegatee constructor to take an unqualified `index_sequence`
solves the problem, since the return type for an unqualified
`make_index_sequence` should be the same as the unqualified
`index_sequence`.

This appears to have been introduced in
8581e9e0.

Clang ends up using the Folly implementation of
`make_integer_sequence` because `__cpp_lib_integer_sequence` is
still not defined, even though `integer_sequence` support was added
to libc++ way back in mid-2013, in revision 185343. There is a bug open
 on the LLVM bug tracker (#18584 [1]) to add the
`__cpp_lib_integer_sequence` and other feature test macros,
but the last activity on it was in late 2014. This results in
the compiler successfully finding the definition for `std::index_sequence`
(unlike what would happen with C++11 compilers), but using the folly
implementation for `make_index_sequence`.

Qualified `std::index_sequence` is used in a few other places, but `std::`
was not removed from those usages because they reside in functions that
have C++14 features that would prevent a C++11 compiler from compiling
them at all, let alone with a `std::` v.s. `folly::`
mismatch:

    - folly/test/FormatBenchmark.cpp
        - decltype(auto) is used for format20Numbers()
    - folly/container/Foreach-inl.h
        - decltype(auto) and generic lambdas are used in a few of the
          for_each_range_impl() overloads
        - decltype(auto) is used in some of the impl() overloads
        - decltype(auto) is used as the return type for fetch()
    - folly/container/Iterator.h
        - decltype(auto) is used as the get_emplace_arg() and unwrap_emplace_arg() return type

A different way of solving the problem would be to add a special case
for Clang to the `integer_sequence` check, similar to what is done for
MSVC, but that seemed like partially papering over the problem. The best
solution would be to get those feature macros into libc++, but that
wouldn't help for already-released versions of LLVM.

    [0]: https://blogs.msdn.microsoft.com/vcblog/2014/06/06/c14-stl-features-fixes-and-breaking-changes-in-visual-studio-14-ctp1/
    [1]: https://bugs.llvm.org/show_bug.cgi?id=18584
Closes https://github.com/facebook/folly/pull/810

Reviewed By: aary

Differential Revision: D7482813

Pulled By: yfeldblum

fbshipit-source-id: 36310acbc227bfe646d6fad877a406b8d57407e5

Summary:
Continuing from D7482813, ensure everywhere in folly is using the folly versions of integer and index sequences.
Also implement index_sequence_for and use it.

Reviewed By: aary

Differential Revision: D7490483

fbshipit-source-id: 082209dd6c6ca11f67b38dbe4529d46e9dce57ce

Summary:
This has functionality not overlapping with `FBString` or `folly::fbstring` or `folly::StringPiece`; and a pretty expensive dependency on `boost/regex`.

Much of the thrift-gen `_types.h` code comes from this inclusion chain:

* `_types.h` uses strings (for `str` fields in thrift structs); these are represented by `folly::fbstring`, from...
* `folly/String.h` includes `FBString.h` and other things to support string-related stuff; simple enough.  But it has a class `UTF8StringPiece`, which uses an iterator, from Boost called `boost::u8_to_u32_iterator<char const *>`.  So then we have...
* `boost/regex/pending/unicode_iterator.hpp` includes tons of things in the usual boost header avalanche: iterator facades, lots of `mpl` code.

Reviewed By: meyering

Differential Revision: D7373577

fbshipit-source-id: efdb920b6fe8c7b7c57d3becf2bf0710975fcf73

Summary:
Upon `erase`, F14 vector containers destroys the value and erases the item
(i.e., index into the `values_` vector) from the underlying hashtable. However,
the item still needs to be hashable when erasing from the hashtable, so we have
to destroy the value _afterwards_.

This diff fixes the bug.

There are a couple of reasons that this was previous undetected / did not cause
a problem:
  * for POD types, `allocator_traits::destroy` is a no-op.
  * this code path is only hit if the chunk of the destroyed item has hosted
    overflowed items
  * the use was immediately after free
  * our test coverage did not have vector policy + non-SSO string keys

Reviewed By: nbronson

Differential Revision: D7488050

fbshipit-source-id: ea29e875a0c7a39b8deed40a15777a6983438836

Summary:
A library that provides gflags-like functionality, with the addition of:
- Threadsafe read/writes for all flags
- Arbitrary C++ types
- No declare/define split, all setting definitions are declaration and are safe to place in headers
- Runtime introspection of all flags
- Compile time and runtime collision checks
- Namespaces per project

Down the road:
- Overlay support (change a set of settings based on some context)
- Construct arbitrary user types from string
- Support multiple library instances with distinct settings in a single process
- Callbacks on setting updates

Reviewed By: aary, mnv104

Differential Revision: D6217956

fbshipit-source-id: 7c03d79c7601ce7b266df78e62b7193712d8331e

Summary: This diff change the `FOLLY_USE_SYMBOLIZER` gates to check for a value of `1`.

Reviewed By: yfeldblum

Differential Revision: D7471272

fbshipit-source-id: 74dbb4d56e1adc56ec75af5b4950ca2c027851cc

Summary:
We used `link_whole` to make sure the `setStackTraceGetter` constructor is
always linked when using Singleton's to setup symbolizer for stack traces.
However, using `link_whole` means we always link in the singleton library, even
if it's never used.

This diff merges `SingletonStackTrace.cpp` into `Singleton.cpp` to avoid the
need for `link_whole` and to link the former if and only if we use the latter.

Reviewed By: pixelb

Differential Revision: D7230733

fbshipit-source-id: de9be51a4eefee201563523d25800ab19ea777e3

Summary: These were being mangled as C++ functions rather than C functions.

Reviewed By: yfeldblum

Differential Revision: D7462668

fbshipit-source-id: e4e83e16aafad3d888599dd78bdbb4ac2711ad7f

Summary: It's unused, remove it.

Reviewed By: yfeldblum

Differential Revision: D7462683

fbshipit-source-id: 604c5691d69f2576c83c25350d29515efbc77a7b

Summary: `timespec` is defined in `sys/time.h`, so don't rely on `<chrono>` including it.

Reviewed By: yfeldblum

Differential Revision: D7462731

fbshipit-source-id: 590954e2230a0da322e2f5eb966bb49b18aa56f7

Summary:
Add API to AsyncUdpSocket to support three options on the socket.

- SO_RCVBUF and SO_SNDBUG options are responsible for the size of the queues that contain received and sent messages, respectively.
- SO_BUSY_POLL sets the approximate time in microseconds to busy poll on a blocking receive when there is no data

Details in socket man: http://man7.org/linux/man-pages/man7/socket.7.html

Reviewed By: yfeldblum

Differential Revision: D7372123

fbshipit-source-id: 5fd92489cbe86879d63df208c3821febdadb0020

Summary: MSVC calls this out explicitly as a non-standard cast and errors.

Reviewed By: yfeldblum

Differential Revision: D7451404

fbshipit-source-id: 9261b15fdc47b6ffbc1b53e83cbfbe9f9af894a9

Reviewed By: ouj

Differential Revision: D7424982

fbshipit-source-id: 3190564d3e79d10d7d64c1822a53e058a201f87d