- Use _HashTable to unify low-level hashing operations across Set and Dictionary.
- Store the capacity directly inside the storage header. This allows the maximum load factor to be controlled by non-inlinable code.
- Introduce a dedicated class for the empty singleton.
- Add _BridgingHashBuffer, a standalone flat hash buffer for use in deferred bridging. Use it to eliminate the need to support non-hashable storage/wrapper variants and to improve memory use in cases where Key or Value are verbatim bridged.
- Eliminate the “TypedNative*Storage” class and _NativeSet/_NativeDictionary’s support for non-hashable keys.
- Rename storage classes as follows:
_RawNativeSetStorage ⟹ _RawSetStorage
_RawNativeDictionaryStorage ⟹ _RawDictionaryStorage
_TypedNativeSetStorage ⟹ (removed)
_TypedNativeDictionaryStorage ⟹ (removed)
_HashableTypedNativeSetStorage ⟹ _SetStorage
_HashableTypedNativeDictionaryStorage ⟹ _DictionaryStorage
The new names make it obvious which ivar layout is in use.
This allows us to move the empty NSSet/NSDictionary overrides out of the root storage class; they don’t really belong there. More importantly, it makes empty sets/dictionaries super obvious to lldb and other runtime tools.
Having a single initializer function lets us not set a randomized seed in deterministic mode, slightly simplifying the stdlib.
Set related stdlib properties to be always inlined.
- Hash seed randomization can now be disabled by defining the SWIFT_DETERMINISTIC_HASHING environment value with a value of "1".
- The random hash seed is now generated using arc4random, where available. On platforms where it isn't, don't construct std::random_device twice.
- _Hasher._secretKey is renamed _Hashing._seed, with no setter.
- _Hasher._isDeterministic is a new property exposing whether we're running with non-random hashes. (Set/Dictionary will need this information to decide if they're allowed to use per-instance seeding.)
- `_swiftEmpty{Array,Dictionary,Set}Storage` should be marked with `SWIFT_RUNTIME_STDLIB_INTERFACE` so that they can be linked from the standard library implementation.
- Runtime export symbols ought to have protected visibility.
Changes:
* Terminate all namespaces with the correct closing comment.
* Make sure argument names in comments match the corresponding parameter name.
* Remove redundant get() calls on smart pointers.
* Prefer using "override" or "final" instead of "virtual". Remove "virtual" where appropriate.
Provides a new fallback for Process arguments for those instances where we do
not own main (e.g. Frameworks, Objective-C owns main.m or main.c, etc.). This
includes a number of platform-specific specializations of argument grabbing
logic and a new thread-safe interface to Process.unsafeArgv.
main() | _NSGetArgc/_NSGetArgv | /proc/self/cmdline | __argc/__argv
--------|--------------------------|------------------------|---------------
Scripts | OS X, iOS, tvOS, watchOS | Linux, FreeBSD, Cygwin | Windows
For interpreted Swift where we must filter out the arguments we now do so by
loading the standard library and calling into new SPI to override the arguments
that would have been grabbed by the runtime. This implementation completely
subsumes the use of the entry point '_stdlib_didEnterMain' and it will be
removed in a future commit.
...and explicitly mark symbols we export, either for use by executables or for runtime-stdlib interaction. Until the stdlib supports resilience we have to allow programs to link to these SPI symbols.
