This change introduces a new compilation target platform to the Swift compiler - visionOS.
- Changes to the compiler build infrastrucuture to support building compiler-adjacent artifacts and test suites for the new target.
- Addition of the new platform kind definition.
- Support for the new platform in language constructs such as compile-time availability annotations or runtime OS version queries.
- Utilities to read out Darwin platform SDK info containing platform mapping data.
- Utilities to support re-mapping availability annotations from iOS to visionOS (e.g. 'updateIntroducedPlatformForFallback', 'updateDeprecatedPlatformForFallback', 'updateObsoletedPlatformForFallback').
- Additional tests exercising platform-specific availability handling and availability re-mapping fallback code-path.
- Changes to existing test suite to accomodate the new platform.
This is set to hidden in `stdlib/CMakeLists.txt`, but in some Apple
internal configurations we build the compatibility archives by directly
importing `stdlib/toolchain`, thus skipping these directives and
causing some symbols to become unexpected visible.
Addresses rdar://73709695
Apparently `-fvisibility=hidden` is not sufficient to hide some of the
symbols in this library. I've explicitly marked the symbols that were
flagged as being incorrectly exported as "hidden" so hopefully no one
drags them out again.
This is a statically linked library, so the symbols shouldn't need to be
exported for this work work. To ensure that this is the case and that
we're still hitting the overridden API with all of the hidden symbols, I
added a debug log line to the fixed `AsyncTask::waitFuture`
implementation and have verified that we see the compat56 log message
emitted from executables that need the compat56 library.
If we include this file, it generates inline assembly, which would be fine
except that when apps are being built with bitcode, that isn't allowed.
rdar://103274667
Upstream build system zippering support.
Setting the `SWIFT_ENABLE_MACCATALYST` flag will build the compatibility
libraries with zippering enabled.
Note that AppleClang and LLVM Clang use different flags to write
zippered files. The Swift stdlib build doesn't know what clang we're
using, so we can't ask it for the compiler ID to determine which whether
we're using AppleClang or LLVM clang, hence the nasty `execute_process`
trick to figure out whether the compiler that's actually compiling the
stdlib knows about the flag or not.
* Backdeploy swift_task_future_wait
This patch adds the implementation for `swift_task_future_wait`
entrypoint to the backdeploy library.
This involves pulling in `AsyncTask::waitFuture`, which relies on a fair
bit.
Please note, this pulls in the `StaticMutex` implementation from Swift
5.6. There are some challenges here. The concurrency version of the
`StaticMutex` involves a fairly nasty set of ODR violations in the
normal setup. See `public/Concurrency/Mutex.cpp`, which includes the
Mutex implementations cpp files directly, while defining a single macro
to replace the implementation of swift::fatalError with
swift_concurrency_fatalError. We only need the concurrency mutex (at
least for now), so I have hard-coded the `swift_concurrency_fatalError`
version into this library. If we should need the other implementation,
we are forced to include ODR-related undefined behavior.
We need symbols from C++, so I've added an implicit linker flag whenever
the static library is used, namely, it passes `-lc++` to the linker.
Since we only backdeploy on Apple platforms, this should be fine.
Some of the platform runtimes we need to backdeploy to have the
enter/exitThreadLocalContext functions defined, while others don't. We
define our own backdeploy56 shim function that dlsym's the function
pointer for these symbols if we have exclusivity checking available.
Otherwise, it doesn't do anything. If concurrency exclusivity checking
is available, we'll use it, otherwise we wont'.
The same dlsym check is done for `swift_task_escalate`. Not all
platforms we need to backdeploy to have a concurrency runtime. The
symbols that do need to use pieces of the concurrency runtime should not
be getting hit when deploying to systems that don't have concurrency. In
the event that you've gotten around the language blocking you from
calling these symbols and you've managed to call concurrency pieces
without using concurrency, we'll abort because something is seriously
wrong.
* Backdeploy swift_task_future_wait_throwing
Drop the remaining pieces in for adding
`swift_task_future_wait_throwing`.
* Apply task_wait_future fix
Actually apply the fix from ef80a315f8.
This deviates slightly from the original patch.
AsyncTask::PrivateStorage::_Status() does not exist in the Swift 5.6
library. Instead I am using `AsyncTask::PrivateStorage::Status`.
* Workaround missing compiler-rt linking
Working around the missing link against compiler-rt in these test.
They are a bit brittle as if anything in them uses compiler-rt, they
will start failing. The backdeploy 5.6 library uses some symbols from
compiler-rt, thus causes them to fail to link.
Disabling the runtime compatibility version checking to avoid these
symbols. This should be fine for the MicroStdlib test, but we should fix
'%target-ld' to handle this better in the future.
rdar://100868842
This patch gets everything to the point of building the library, but it
doesn't run yet since I have missing symbols.
Unlike previous compatibility libraries and the concurrency
compatibility library, I'm organizing the headers a bit more. This is
because we're merging the two libraries into one. They share some common
header names, and while I could rename them for namespacing purposes,
it's easier to just use a directory structure for this.
The `include/Runtime` and corresponding `Runtime/` directories are for
backdeployed changes to the stdlib itself.
The `include/Concurrency` and corresponding `Concurrency/` directories
are for backdeployed changes to the concurrency runtimes.
