Summary:
On Windows the build artifacts cannot be easily run directly from the build
output directory without installing them.  The `$PATH` environment variable
needs to be set correctly so that the runtime library dependencies can be
found.

This updates the builder code to emit a `run.ps1` wrapper script in the build
output directory that sets `$PATH` to support running build artifacts directly
from the build directory.

Additionally, this updates the CMake-specific builder to set properly when
running the tests with `ctest`.

Reviewed By: wez

Differential Revision: D20688290

fbshipit-source-id: 5d0f4d685692bca7e37370bd88309cf7634d87f0

Summary:
This still requires support from EdenFS in order to do much
of use, but it takes us a step closer:

* Pull in cpptoml when building with Eden support
* On Windows, when we locate the `.eden` directory, load and parse
  the config file in order to determine the socket path
* If the EdenView constructor throws, treat it as a terminal error
  so that we don't fallback to the regular filesystem watcher.
  This is important because current EdenFS builds don't implement
  the journal thrift API endpoint yet.

Reviewed By: pkaush

Differential Revision: D20504752

fbshipit-source-id: 48bbad49f1641698aa7d7b85674e3ddf4d4e617d

Summary:
We have a global `--install-prefix` argument that can be used to set
the prefix for all projects, but that is only suitable if you are running with
sufficient privileges to install each of the deps to that location during the
build.  Cmake dependency resolution won't work from the build directory in that
situation; it can only see the final installed location and it will error out
if those files are not present, or link against the currently installed version
instead of the version we just built; not great!

This commit adds a project specific `--project-install-prefix` that can be used
on just the leaf project in a set of deps.  That sidesteps the dependency
concern because only the last stage is built in that mode.  This option
can technically be applied to an arbitrary set of projects, but in light
of the above, in practice it only makes sense to use it for the final
cmake project.  Only the CMakeBuilder respects this option.

In the watchman repo, this commit adjusts the autogen.sh script to allow
specifying the installation prefix; it defaults to `/usr/local` as you
might expect.

refs: https://github.com/facebook/watchman/issues/760

Reviewed By: yfeldblum

Differential Revision: D20674439

fbshipit-source-id: 52799dbd47f3c295e2d6469ee2b74cedeaa20138

Summary:
The math that figures out the biggest possible formatted
number, for a stack buffer size, computed 65 bytes for "binary" format:

```
    // #b: 0b prefix + 64 bytes = 65 bytes
```

But with that 2-byte "0b" prefix this of course sums to 66 bytes.

This turns out to be harmless, rather than causing a buffer overrun,
because the buffer size additionally reserves two more bytes for
"prefix shenanigans", which are redundant with the two prefix bytes
explicitly reserved for "0b" (but in this case were covering up the
off-by-one error).

I cleaned up a few things while I was there:

- I fixed the size computation for binary buffers, including
  making it use kMaxBinaryLength, which is based on `sizeof(uintmax_t)`,
  rather than hardcoding `64`.
- I removed the redundant prefix shenanigans reservation.
- I fixed the places that were reserving two bytes for a prefix
  (like "0x") right after asserting that no prefix is allowed,
  e.g. for chars and decimal numbers.
- I stopped reserving a byte for NUL, because these days this code
  uses folly::StringPiece and never NUL-terminates.

Reviewed By: yfeldblum

Differential Revision: D20694395

fbshipit-source-id: 6658675d9993d2fe223675db55c8040ddee143a8

Summary:
Not sure if this is a transient issue, but the URL we've been using to obtain boost has started to return 403 errors.
Switch to a sourceforge download link instead.

Refs: https://github.com/facebook/watchman/pull/797

Reviewed By: chadaustin

Differential Revision: D20739351

fbshipit-source-id: 47483c675d59201a410c9d2a8f6db0f63ea5da69

Summary:
My recent change to ensure that we were using python3 to launch everything failed on windows: the GH actions environment has `python.exe` in the path and it is python version 3.  There is no such thing as `python3` in that environment, although there is a `python2`.

Refs: https://github.com/facebook/watchman/pull/797

Reviewed By: chadaustin

Differential Revision: D20740411

fbshipit-source-id: 0e40590ccedc18e327ebb84901e2509588fdd0ff

Summary:
This diff is a more complete fix for the problem addressed
by D19561643, in which private inheritance caused an incorrect
inaccessibility error for a type that was derived via an alternate
construction from a template param.

Reviewed By: lnicco

Differential Revision: D20718329

fbshipit-source-id: 778d246d07030f6abb9e08e127a98d48c736a7d7

Summary: Upstream range-v3 has changed in accordance with C++20's standard ranges such that view types now need to explicitly opt-in to the `view` concept. This diff adds the hook needed so that the latest version of the range library will recognize `folly::Range` as a view.

Reviewed By: yfeldblum

Differential Revision: D20569727

fbshipit-source-id: 2f8bca017b2f8036b02568997a0b7c76d9c41646

Summary: Fix broken oss build

Reviewed By: simpkins

Differential Revision: D20689035

fbshipit-source-id: 1d287f59fb35cf88482a471dfdf63e89d579e6fc

Summary:
Avoid a forward declaration mismatch between `libiberty.h` and
`libgen.h` that dirs in modular builds (likely related to T35368090).
This defines `HAVE_DECL_BASENAME`, which is normally defined
in the `config.h` generated during the binutils build, to prevent this
conflicting declaration.

Reviewed By: igorsugak

Differential Revision: D20600924

fbshipit-source-id: 0fb6287719abb3cf52d7eda457efbe567985d1d4

Summary: SemiFuture::delayed should pass the SemiFuture all the way through.

Reviewed By: yfeldblum

Differential Revision: D20684503

fbshipit-source-id: e7d1299a177d347cb5b92e9e700c607fc9f7c4c3

Summary: This diff makes it possible to relay on the thrift structures from configerator in OSS.

Reviewed By: ahornby

Differential Revision: D20279457

fbshipit-source-id: 39df1c7a6f78b10a0a5bdeeebe476249ab674cc8

Reviewed By: vitaut

Differential Revision: D20650610

fbshipit-source-id: add9ff42c7c35696767c0c4d004235885fcd1565

Summary:
We are using Folly inside RocksDB, and we noticed a build failure due to cache line sizing on s390x. I fixed it in our copy of Folly, and am sending you the changes upstream.

CC pdillinger
Pull Request resolved: https://github.com/facebook/folly/pull/1340

Reviewed By: WillerZ

Differential Revision: D20628323

Pulled By: Orvid

fbshipit-source-id: 03ea68b023fa1fdf7fae2e283687530ab5b6ead3

Summary: Add signal handling support for the PollIoBackend derived backends

Reviewed By: kevin-vigor

Differential Revision: D20612200

fbshipit-source-id: 5a92e2b46a9fa102bfc02958058679bac6c22269

Summary:
This takes some pressure off both cpu and memory
on a laptop.

Reviewed By: pkaush

Differential Revision: D20562474

fbshipit-source-id: a058c71c47f25c3a2b3c1e34a0d0caf83e642021

Summary:
On linux we didn't account for the `--final-install-prefix` argument
which meant that the binaries would always be rewritten to be relative to
the destdir.

This commit fixes that.

Refs: https://github.com/facebook/watchman/issues/760

(this doesn't deal with the compiled in statedir being in the scratch path though)

Reviewed By: simpkins

Differential Revision: D20659749

fbshipit-source-id: 1e8e198a58361882249c33a67f54a7d97b849257

Summary:
The GH actions defaults for git prevent it from being able
to checkout the fbthrift repo due the length of the java related
files in the fbthrift repo.

This commit tells git to use long filenames and allows the checkout
to succeed.

Reviewed By: fanzeyi

Differential Revision: D20659750

fbshipit-source-id: 060b36d312d52a0769cf2f2dd9af60f7446f94a8

Summary:
Ensure that we are referencing python3 in the paths
that we generate for the github actions workflows, and remove
some shebangs that influence how our internal linters process
the python code.

Reviewed By: fanzeyi

Differential Revision: D20659747

fbshipit-source-id: 6f300f8e91edf7701bb27babc7b1418958cf0a10

Summary: Remove unused files

Reviewed By: yfeldblum

Differential Revision: D20658959

fbshipit-source-id: b387aa4a58ee6a610d71567f5dcd6932e49f7411

Summary: The `|` operation causes the  `int to uint8` conversion warning that be treated as an error on some targets and prevent them use F14Map.

Reviewed By: yfeldblum

Differential Revision: D20654932

fbshipit-source-id: 6c909b7b58f4be263b0e30b1aa3acd82b5b9479d

Summary: We will `std::terminate` if a destructor throws, so it would be better to complain about throwing destructors in the first place.

Reviewed By: nbronson

Differential Revision: D20604722

fbshipit-source-id: d36c771f36d0d0a26f356720698606de628ca747

Summary:
The current implementation of `std::is_nothrow_move_constructible` in libstdc++ implies `std::is_nothrow_destructible`. However, this doesn't seem to be required by the standard, see the notes section of https://en.cppreference.com/w/cpp/types/is_constructible.

Since we know that all Vector and Value sets/maps already satisfy this requirement, let's codify it explicitly.

Reviewed By: nbronson

Differential Revision: D20604544

fbshipit-source-id: bae1e8442585cedb062308b6332bd018cccca2f4

Summary:
F14Node{Map,Set} doesn't require `is_nothrow_destructible<value_type>`.  `clear()` and the destructor are both marked `noexcept`, so they will both terminate if the destructor throws. But `erase()` is not marked `noexcept`, so when the destructor throws during `erase()` the value is left in the map. This could be problematic if the value is half destroyed, or if `eraseInto()` is used.

This diff fixes the problem by marking `destroyItem()` as `noexcept`, so `std::terminate` is called whenever the value destructor throws.

Reviewed By: nbronson

Differential Revision: D20604276

fbshipit-source-id: c52c932d78d6ed61368985a749adf77c27a5a0de

Summary: Add support for non libevent based backends in the AsyncSignalHandler

Reviewed By: kevin-vigor

Differential Revision: D20524116

fbshipit-source-id: fdd49cf75bd51599055239270dd704c496d567e3

Summary:
Compiling with gcc 10.0.1 and -std=gnu++2a, we have the following errors:
```
folly/FBString.h:1013:33: error: no type named 'reference' in 'class std::allocator<char>'
 1013 |   typedef typename A::reference reference;
      |                                 ^~~~~~~~~
folly/FBString.h:1014:39: error: no type named 'const_reference' in 'class std::allocator<char>'
 1014 |   typedef typename A::const_reference const_reference;
```
This is due to the fact many members in `std::allocator` have been remove in C++20: https://en.cppreference.com/w/cpp/memory/allocator

We also have this one due to the new way C++ resolves the comparison operators:
```
folly/dynamic-inl.h:854:20: error: ambiguous overload for 'operator!=' (operand types are 'folly::dynamic::const_item_iterator' and 'folly::dynamic::const_item_iterator')
  854 |   return find(key) != items().end() ? 1u : 0u;
      |          ~~~~~~~~~ ^~ ~~~~~~~~~~~~~
      |              |                   |
      |              |                   folly::dynamic::const_item_iterator
      |              folly::dynamic::const_item_iterator
In file included from folly/dynamic-inl.h:25,
                 from folly/dynamic.h:796,
                 from folly/dynamic.cpp:17:
folly/detail/Iterators.h:80:8: note: candidate: 'bool folly::detail::IteratorFacade<D, V, Tag>::operator==(const D&) const [with D = folly::dynamic::const_item_iterator; V = const std::pair<const folly::dynamic, folly::dynamic>; Tag = std::f
orward_iterator_tag]' (reversed)
   80 |   bool operator==(D const& rhs) const {
      |        ^~~~~~~~
folly/detail/Iterators.h:98:3: note: candidate: 'typename std::enable_if<std::is_convertible<D, D2>::value, bool>::type folly::detail::IteratorFacade<D, V, Tag>::operator==(const D2&) const [with D2 = folly::dynamic::const_item_iterator; D =
 folly::dynamic::const_item_iterator; V = const std::pair<const folly::dynamic, folly::dynamic>; Tag = std::forward_iterator_tag; typename std::enable_if<std::is_convertible<D, D2>::value, bool>::type = bool]' (reversed)
   98 |   operator==(D2 const& rhs) const {
      |   ^~~~~~~~
folly/detail/Iterators.h:84:8: note: candidate: 'bool folly::detail::IteratorFacade<D, V, Tag>::operator!=(const D&) const [with D = folly::dynamic::const_item_iterator; V = const std::pair<const folly::dynamic, folly::dynamic>; Tag = std::f
orward_iterator_tag]'
   84 |   bool operator!=(D const& rhs) const {
      |        ^~~~~~~~
folly/detail/Iterators.h:103:8: note: candidate: 'bool folly::detail::IteratorFacade<D, V, Tag>::operator!=(const D2&) const [with D2 = folly::dynamic::const_item_iterator; D = folly::dynamic::const_item_iterator; V = const std::pair<const f
olly::dynamic, folly::dynamic>; Tag = std::forward_iterator_tag]'
  103 |   bool operator!=(D2 const& rhs) const {
      |        ^~~~~~~~
```
Pull Request resolved: https://github.com/facebook/folly/pull/1329

Reviewed By: markisaa

Differential Revision: D20458078

Pulled By: yfeldblum

fbshipit-source-id: 15a6a4cfa0f71d45046ee2a13914672b3746b9eb

Summary:
LoopController::runLoop is responsible for managing Executor/EventBase keep-alive handle.
This diff introduces a similar level of indirection (LoopController::addTaskEager) to solve the same problem for eager variants of addTask*.

Reviewed By: yfeldblum

Differential Revision: D20613287

fbshipit-source-id: 22388ca3b31664c5fedfd509f2d9bab3d86aab47

Summary:
Modify the TrySemiAwaitable adapter so that it customises the co_withCancellation() customisation-point and passes through the CancellationToken to the underlying awaitable (eg. a Task).

This fixes code that tries to do the following so that the cancellation token propagates to a Task adapted with co_awaitTry().
```
co_await co_withCancellation(cancelToken, co_awaitTry(co_foo()));
```

Reviewed By: andriigrynenko

Differential Revision: D20443798

fbshipit-source-id: 945e0f98abad4cdef0be29365642006c5687ad5f

Summary: Actually use vendored Rust crates when building with CMake. The `--offline` option make sure cargo do not go to the Internet for missing crates.

Reviewed By: simpkins

Differential Revision: D20542672

fbshipit-source-id: ab4af40150c6af8b531a75f503a4fa848b3914da

Summary:
This allows to avoid unnecessary copy of `shared_ptr`.

(Note: this ignores all push blocking failures!)

Reviewed By: andriigrynenko

Differential Revision: D20596972

fbshipit-source-id: 6411ee2f735c1db1984bcd83ceddf80e4ec6f22b

Summary:
Add sampled logging of blocking operations made on folly::Baton from within an executor task.

Relies on thread_local state recording whether we are in a context where blocking is disallowed, which means within a task running on an executor with support for the functionality. Functionality is currently limited to certain executors, and to blocking operations on Baton, but this covers common user-facing APIs like Future.

Reviewed By: andriigrynenko

Differential Revision: D20010963

fbshipit-source-id: c0598e1a3a9c4e3641581e561b678a2b241998ff

Summary:
If you have built the `eden/scm` subdirectory with `make local` in your
repository it will have left a bunch of build output artifacts in the source
tree.  Update the getdeps shipit path map for eden to explicitly exclude many
of these build artifacts.

In particular:
- Exclude `eden/scm/build/` since this directory can contains a lot of files.
- Exclude all `*.pyc` files since there may be a reasonable number of these.
- Exclude several Cargo-related files since these will cause problems when
  trying to build Rust code.

Reviewed By: chadaustin

Differential Revision: D20570720

fbshipit-source-id: a60dec4854ae470fdb58e9651fd8a3b910c76004

Summary:
The default warning settings for the MSVC compiler result in an
extremely noisy build output, to the point where it can take minutes of reading
through pages of output to locate the actual error when debugging a build
problem.  The majority of these warnings are the result of implicit integer
narrowing that is silently permitted in our posix builds.

Rather than blanket suppress these conversion warnings and mask potential bugs,
this commit makes a pass over the code and adds `folly::to_narrow` to a number
of call sites to make it explicit that a narrowing operation is taking place
and that it is (probably!) intentional.   We make a lot of assumptions
throughout our various projects that we won't allow data larger than 2GB
through eg: thrift and as a result, a lot of wire/serialization related code
uses `uint32_t` for sizes instead of `size_t`.

Reviewed By: yfeldblum

Differential Revision: D20562029

fbshipit-source-id: 706ba9cf330d40a2b3f911e5e9a8b9de325ebc80

Summary:
`setCallback()` functions just store the argument as a `Function`, so we don't need to specialize the templates all the way down, we can pass directly a `Function`.

This reduces code size, and should not have runtime impact: either the move is elided in both cases, or if not there's no particular reason why a `Function` move should be more expensive than an arbitrary functor's (could even be faster).

Reviewed By: yfeldblum, luciang

Differential Revision: D20561695

fbshipit-source-id: 1973c47a5410a43eb44beea36cb1105663094eb3

Summary:
OpenNSA has prebuilt SDK but kernel modules have to be built from sources. Add
a utility script to build and extend packaging script.

In future, we can consider folding this build into fbcode_builder itself.

Differential Revision: D20549883

fbshipit-source-id: f9475b7e0223e9f357117d7d7d27df8904fa1d73

Summary: Correct typo

Reviewed By: lewissbaker

Differential Revision: D20544820

fbshipit-source-id: f9edffd0a44448fd558b3e659585044f9be81035

Summary: Updated fmt version to be on par with buck build. It was causing inconsistencies.

Reviewed By: vitaut

Differential Revision: D20528011

fbshipit-source-id: d9e04ed2c28b839eaeff24120162c4db4732fa55

Summary: [Folly] Cut unused `#include`s in `folly/experimental/symbolizer/ElfCache.h`.

Reviewed By: Orvid

Differential Revision: D20482493

fbshipit-source-id: 426ebe0aa55e116e3f3c8095b0c9d0f1babdb354

Summary:
This enables fetching blobs from the LFS server. For now, this is limited to
fetching them, but the protocol specify ways to also upload. That second part
will matter for commit cloud and when pushing code to the server.

One caveat to this code is that the LFS server is not mocked in tests, and thus
requests are done directly to the server. I chose very small blobs to limit the
disruption to the server, by setting a test specific user-agent, we should be
able to monitor traffic due to tests and potentially rate limit it.

Reviewed By: DurhamG

Differential Revision: D20445628

fbshipit-source-id: beb3acb3f69dd27b54f8df7ccb95b04192deca30

Summary: Helper observer which only triggers updates when the value changes.

Reviewed By: bithree

Differential Revision: D20521319

fbshipit-source-id: 77e45d92f710b1701552cf29445f44aa9d9487f4