A previous commit [1] identified and fixed a benign race on
`_swiftEmptyArrayStorage`. Unfortunately, we have some code duplication
and the fix was not applied to all the necessary places. Essentially,
we need to ensure that the "empty array storage" object that backs many
"array like types" is never written to.
I tried to improve the test to capture this, however, it is very
finicky. Currently, it does not go red on my system even when I remove
the check to avoid the benign race in Release mode.
Relevant classes: Array, ArraySlice, ContiguousArray, ArrayBuffer,
ContiguousArrayBuffer, SliceBuffer.
[1] b9b4c789f3
rdar://55161564
Add `--enable-experimental-differentiable-programming` build-script flag.
The build-script flag enables/disables standard library additions
related to differentiable programming. This will allow official Swift
releases to disable these additions.
The build-script flag is on by default to ensure testing of
differentiable programming standard library additions. An additional
driver flag must be enabled to use differentiable programming features:
https://github.com/apple/swift/pull/27446
The introduction of += and -= default implementations on
AdditiveArithmetic introduces an ambiguity with the += and -=
implementations on SIMD (where Scalar: FloatingPoint). Break the
ambiguity by adding another set of definitions of += and -= on
AdditiveArithmetic & SIMD where Self.Scalar: FloatingPoint.
Fixes rdar://problem/55278156.
Returns `true` if `T.Type` is known to refer to a concrete type. The
implementation allows for the optimizer to specialize this at -O and
eliminate conditional code.
Includes `Swift._isConcrete<T>(T.Type) -> Bool` wrapper function.
It is causing bots to fail.
* Revert "The __has_include(<os/system_version.h>) branch here wasn't quite right, we'll just use the dlsym one for now"
This reverts commit f824922456.
* Revert "Remove stdlib and runtime dependencies on Foundation and CF"
This reverts commit 3fe46e3f16.
rdar://54709269
These were previously removed in SE-0246, so they weren't modified when Float80 was removed elsewhere on Android. Reverting SE-0246 on master triggers an Android break.
* Revert "Add availability information to the new Math function protocols (#24187)"
This reverts commit d2f695935f.
* Revert "SE-0246: Protocols and static functions (#23824)"
This reverts commit 57a4553832.
* Expected abi changes.
This improves code generation in -Onone mode. (UnsafeRawPointer.load/.storeBytes isn’t @_transparent and it doesn’t get specialized in unoptimized builds.)
AutoreleasingUnsafeMutablePointer is pointing to a +0 reference, but in its pointee property’s getter/setter implementations, it is loading the pointer into regular Unsafe[Mutable]Pointers. Those are assuming that the addressed memory contain a +1 reference, which can mislead the compiler into doing optimizations that aren’t valid.
Change the getter/setter implementations so that they use UnsafeRawPointer and load/store Unmanaged values instead. As long as Unmanaged.passUnretained(_:) and Unmanaged.takeUnretainedValue() do the right thing, then AutoreleasingUnsafeMutablePointer won’t have issues, either. (This boils down to ensuring that loading a strong reference out of an unmanaged(unsafe) value works correctly.)
