Summary:
This makes a large number of implicit truncations and sign conversions into explicit casts, in preparation for eventually enabling `-Wconversion` on Folly.
This set of changes should have zero semantic change.

This focuses on the core of Folly and leaves the tests alone for the most part. A future diff will cleanup the warnings in the tests as well.

Reviewed By: yfeldblum

Differential Revision: D4454096

fbshipit-source-id: af1e1831675a804ec5679266c30c1fae62e8c35c

Summary:
HHVM uses this heavily in it's ARM JIT, so provide an implementation. With GCC & Clang this function is a no-op on x86_64 where the requirement doesn't exist, so do the same in the portability header.
This doesn't include the Windows portability header on x64 specifically because it is a very heavy header and this is currently very lightweight.

Reviewed By: yfeldblum

Differential Revision: D4451032

fbshipit-source-id: 0af57448577635f9cd690ea9b09ce46a244191e1

Summary:
This is needed if you want to test other scenarios where the
server has other OpenSSL settings.

Differential Revision: D4463587

fbshipit-source-id: ffd4019e921649dee703363b2ff028b4d8063210

Summary: `setenv`/`unsetenv` is not always declared the same way on all of the places folly is compiled.

Reviewed By: matbd

Differential Revision: D4462056

fbshipit-source-id: 6dd68f6fc5a6a435f145cbaa43bee02b5fa7170c

Summary:
The TestSSLServer is useful to have on its own for reuse. This
diff separates it out to make reuse possible.

Reviewed By: yfeldblum

Differential Revision: D4457976

fbshipit-source-id: 1fe6b71e930859ef04487e29047dcf603a79834b

Summary: HHVM compiles without `folly-config.h`, so this was preventing us from updating to the newest version of Folly.

Reviewed By: yfeldblum

Differential Revision: D4456890

fbshipit-source-id: ed118ff0cf7f254a5f99be68f171d1b34ebf5c5c

Summary: Similar to AsyncSocket, allow setting reserved sockopt after bind(). This will be recognized by intercepted accept4() call and forked sockets will properly have the TLS flag disabled.

Reviewed By: djwatson

Differential Revision: D4458831

fbshipit-source-id: fa753b9d849bd661563364d36229113f7abb0ee0

Summary:
It wasn't actually SFINAE the way it was setup previously, which meant it was just a hard error under MSVC.
Whoops.

Reviewed By: yfeldblum

Differential Revision: D4453702

fbshipit-source-id: 5be600fb5ecdc8255795fefbd37c1fe26e7266dd

Summary:
Found with our include analysis tool.

I had to tweak `portability/Environment.h` to avoid a false positive breaking win32.

Reviewed By: yfeldblum, Orvid

Differential Revision: D4452463

fbshipit-source-id: e2e862e204892037ddde8815218e4deab1bfbb06

Summary:
This patch adds a function to AsyncSSLSocket, so the user can check if the peer cert
should be verified. This allows the user to implement custom logic for peer cert validation.

Reviewed By: Orvid

Differential Revision: D4456402

fbshipit-source-id: 2f8a5c932d0341d6c9290bcb52264dd4fa174263

Summary: Because OpenSSL is evil to Windows, and you have to forcefully include winsock2 before winsock.

Reviewed By: yfeldblum

Differential Revision: D4453742

fbshipit-source-id: 3b1b5b1f999722559693164148245f52b1e94104

Summary: see title

Reviewed By: meyering

Differential Revision: D4441266

fbshipit-source-id: 4a8f589e2995a463e54b3979035a623824acf39e

Summary:
As suggested by the C++ committee in November 2016, made atomics generic to allow other atomic types (e.g.,  folly::DeterministicAtomic<T*>),

Also removed obsolete comments.

Reviewed By: davidtgoldblatt

Differential Revision: D4443355

fbshipit-source-id: d9e21a959f2c7e3dd07c0ed4808236da80ef6dcd

Summary: It's the exact same as `PF_LOCAL`, and is used interchangibly.

Reviewed By: yfeldblum

Differential Revision: D4439558

fbshipit-source-id: fd1ff813db5349369fc77888dfd854fc36a2a3be

Summary: SSL_CTX_load_verify_locations interally end up using X509_load_cert_crt_file, which has an unchecked call to X509_STORE_add_cert. This can fail and add an error to the error stack without causing SSL_CTX_load_verify_locations to return an error.

Reviewed By: siyengar

Differential Revision: D4442017

fbshipit-source-id: a4cf7f5ee2c18d90d5d61baf3acb99ffca6b8af0

Summary: This reverts commit 12da254d6b281c2b9d522ba19999b2489c0083a2

Differential Revision: D4389970

fbshipit-source-id: 7651425adcf3b86c066d657308af1a0aa6bce5dd

Summary: EOR flag was hardcoded to "false" in folly::AsyncSocket. This diff enables changing EOR flag using AsyncSocket::setEorTracking() method.

Reviewed By: yfeldblum

Differential Revision: D4421966

fbshipit-source-id: 2e1b9b19ced6555845396ec33bfd3d5feb710640

Summary: Changes nothing fundamental, just makes it easier to work on in the future.

Reviewed By: yfeldblum

Differential Revision: D4435805

fbshipit-source-id: 725944a12922abde137bb7e21726c97beb558b5f

Summary: Limits number of fibers printed for each FiberManager.

Reviewed By: yfeldblum

Differential Revision: D4432488

fbshipit-source-id: 1791c2bfe6d5b0c2f54142dc068b473fd72f5d5d

Summary: There is "operator|()" defined for folly::WriteFlags enum class, but no "operator=|()". Because of that adding a new flag to an existing set of flags looks awkward. Adding the missing operator.

Reviewed By: yfeldblum

Differential Revision: D4421892

fbshipit-source-id: a053a8cc5b1d07579c233d19029a9801b8188413

Summary:
'Nuf said.

Depends on D4413112

Reviewed By: yfeldblum, spacedentist

Differential Revision: D4425605

fbshipit-source-id: a7c98867cfa5c859a1b4d2eb78724710c4f1115f

Summary: It was killed in an earlier diff.

Reviewed By: yfeldblum

Differential Revision: D4418832

fbshipit-source-id: c9a5134fa100b24a3394607dea20e6e8a8d341e1

Summary:
Pthread is currently a dependency of Folly that is not really necessary on Windows, or even with standard C++ for the most part, so start work on killing it in Folly.
This switches EventBase to using `std::thread::id`'s instead, which also means we aren't reliant on the implementation detail that thread id 0 is invalid. Well, we are, but it's now the standard library's fault not ours.

Reviewed By: yfeldblum

Differential Revision: D4418128

fbshipit-source-id: a9c95ac6c7305c960156a4ad684b6db89b5856d9

Summary: It's possible via some hackery, so wrap it up nicely into the API.

Reviewed By: yfeldblum

Differential Revision: D4418728

fbshipit-source-id: f00aed95cdbdc3cc83a0ab96565117cd01141c2e

Summary:
Our internal version of boost contains a patch that reverts the following commit to boost filesystem module:
https://github.com/boostorg/program_options/commit/88dea3c6fdea8c9ea894911897b1770599c383e4

It was done due to a breaking change that disallows the use of "--key value" for implicit options, allowing only "--key=value" style syntax. Since there are too many tests to fix, and it's probably going to be reverted in the upstream as well (see below), removing the `override` keyword here to fix folly build.

https://github.com/boostorg/program_options/issues/25

Reviewed By: meyering

Differential Revision: D4415347

fbshipit-source-id: c215331338b3aa218d26890a83aa0b363514fe79

Summary:
While running a UBSan enabled binary, I got:

  folly/io/IOBuf.cpp:671:15: runtime error: null pointer passed as argument 2, which is declared to never be null

This change protects all calls to memcpy from passing `nullptr`.

Reviewed By: pixelb

Differential Revision: D4415355

fbshipit-source-id: a27ba74244abcca8cd4e106967222890a67f5b6d

Summary:
This started when many fbvector-related tests began failing with reports of
ASAN-detected heap abuse (usually invalid free of an address 16 bytes
into an already-freed buffer).

It was very specific, though. The bug struck only when:
  - gcc-5-based platform
  - compiling with clang (~3.8) and GCC5's libstdc++, not gcc
  - strings were short enough to reside within an in-situ std::string

Why? because FBVector.h:1588's conditional:

  if (folly::IsRelocatable<T>::value && usingStdAllocator::value) {

was true for clang (erroneously), but false for gcc. The difference
was in `IsRelocatable<std::string>::value`.  However, manual tests showed that
each component from the definition of `IsRelocatable` were the same for both
gcc and clang. Then Jay Feldblum realized that we'd probably specialized
that trait for `std::string`, and sure enough, I found the culprit:

```
FOLLY_ASSUME_FBVECTOR_COMPATIBLE_3(std::basic_string)
```

Reviewed By: pixelb

Differential Revision: D4414159

fbshipit-source-id: 60e3fb4b096ec77cbd2b48c561e5c6ec8f128fff

Summary:
prefer creating an exception_wrapper with a reference to the active exception

Depends on D4410421

Reviewed By: spacedentist

Differential Revision: D4410455

fbshipit-source-id: d6b6aeb5fa72782e31d754a0b853514af5fdb8cd

Summary: Folly parts of D4383906.

Reviewed By: plapukhov

Differential Revision: D4387254

fbshipit-source-id: 3c039720c88c91b7292d60a85272dd1978510296

Summary: [Folly] Slight simplification of `exception_wrapper` constructor.

Reviewed By: ericniebler

Differential Revision: D4391899

fbshipit-source-id: ddb066723bcd10abb0dbbaeab12b1e9be4f39acc

Summary:
Normally clearing out the error before calling into an openssl method
is a bad idea. However there might be other code outside AsyncSSLSocket
calling into openssl in the same thread that doesn't use openssl
correctly. This allows users of AsyncSSLSocket to safeguard themselves
from such code.

Reviewed By: anirudhvr

Differential Revision: D4389970

fbshipit-source-id: 12da254d6b281c2b9d522ba19999b2489c0083a2

Summary:
[Folly] Fix an inefficiency in json-serializing a `dynamic` with sorted keys.

The inefficiency is that, at each level of the `dynamic` which is map-typed, we effectively make a full copy of the `dynamic` object. This can be expensive.

Reviewed By: Gownta

Differential Revision: D4389671

fbshipit-source-id: 223739397f913d3e65a421a9a4dcb089ec757ec6

Summary:
`unitialized` seems to be typo.
Closes https://github.com/facebook/folly/pull/538

Reviewed By: igorsugak

Differential Revision: D4397318

Pulled By: yfeldblum

fbshipit-source-id: a2e6c665b4dfe95d769430405886b0725423aac2

Summary:
[Folly] Rename `exception_wrapper::getExceptionPtr` to `to_exception_ptr`.

Make it clear that this will sometimes be an expensive operation. Using the word `to` evokes the possibility of an expensive conversion, while using the word `get` implies cheap access.

Reviewed By: djwatson

Differential Revision: D4391621

fbshipit-source-id: 33ca051d9be5a6050ba9f30b20faee35b7e58afb

Fix dynamic MPMCQueue tryObtainPromisedPushTicket() to prevent tryWriteUntil() and writeIfNotFull() from blocking indefinitely for a matching read.

Summary:
The bug was reported by Alexander Pronchenkov in https://fb.facebook.com/groups/560979627394613/permalink/837052843120622/

Under certain conditions a `tryWriteUntil()`--and also `writeIfNotFull()`--operation may block indefinitely awaiting a matching read. This could happen because in each dynamic MPMCQueue expansion, typically one or two tickets are associated with the closed array not the new one. In the incorrect code, a `tryWriteUntil()` operation that induced expansion but gets a ticket associated with the closed array, incorrectly assumes that because the expansion succeeded then there is space for it. However because the ticket is associated with the closed array, the operation needs to wait (possibly indefinitely) for space to open in the closed array.

The fix: Changed the code in tryObtainPromisedPushTicket() such that the operation tries to acquire a ticket only if there is promised space in the array associated with that ticket. If there is no space, an expansion is attempted if the ticket is not associated with a closed array. If not or if expansion fails because of reaching maximum capacity or for being out-of-memory, then the operation returns false without attempting to acquire the ticket.

Other changes:
- Added a note about this difference in semantic between the dynamic and non-dynamic version to the main comment about the dynamic version.
- Changed `oldCap` to `curCap` because the value is actually current not old.
- Added two tests for checking that tryWriteUntil() never blocks indefinitely for both dynamic and non-dynamic versions.
- Removed all the `never_fail` tests for the dynamic version, because such operations may fails as described above.
- Added `asm_volatile_pause` when spinning on the seqlock.

Reviewed By: djwatson

Differential Revision: D4389347

fbshipit-source-id: c46dbefc9fe08e146250d2ad8ba68b0887f97436

Summary: This was accidentally changed in D4375539.

Reviewed By: philippv

Differential Revision: D4393574

fbshipit-source-id: 0420223575bad0c6b0e89f8cf5ed138e063462b9

Summary: This allows something else (ie fizz) to read data from a socket, and then later decide to to accept an SSL connection with OpenSSL by inserting the data it read in front of future reads on the socket.

Reviewed By: anirudhvr

Differential Revision: D4325634

fbshipit-source-id: 05076d2d911fda681b9c4e5d9d3375559293ea35

Summary: Similar to the bio write method. This should be essentially a no-op, bioRead has the same functionality as the openssl version. This is needed in the next diff.

Reviewed By: siyengar

Differential Revision: D4325622

fbshipit-source-id: a90b9ec06bee920a1a73551a3ea4c77e1ee0ab08

Summary: Closes https://github.com/facebook/folly/pull/537

Reviewed By: yfeldblum

Differential Revision: D4391871

Pulled By: Orvid

fbshipit-source-id: 80401dd65ae376f9ebbb0b079577d0a1fd15475b

Summary:
This constructor is unsafe. The check it uses before doing the comparison isn't a safe enough check to see if the cast is valid. For example, this is broken in the presence of multiple inheritance because it doesn't adjust the pointer offset to the correct vtable.

e.g.
  struct A {
    virtual ~A() {};
    virtual void doSomething() = 0;
  };
  struct B {
    virtual ~B() {}
    virtual void doSomethingElse() = 0;
  };
  struct C : public B, public A {
    virtual ~C() {}
    void doSomething() override {
      std::cout << "Something!" << std::endl;
    }
    void doSomethingElse() override {
      std::cout << "Something Else!" << std::endl;
    }
  };
  int main (int argc, char **argv) {
    auto c = folly::makeFuture<std::shared_ptr<C>>(std::make_shared<C>());
    folly::Future<std::shared_ptr<A>> a = std::move(c);
    a.get()->doSomething();
    return 0;
  }
This code will print "Something else!" when run.

Reviewed By: siyengar

Differential Revision: D3679673

fbshipit-source-id: dcbf40ca82d458f17ee11191591f8b8daf58c919