These objects can escape into ObjC without their class being realized first, which can cause a crash if the unrealized class gets passed into the ObjC runtime.
rdar://problem/59295395
Old Swift and new Swift runtimes and overlays need to coexist in the same process. This means there must not be any classes which have the same ObjC runtime name in old and new, because the ObjC runtime doesn't like name collisions.
When possible without breaking source compatibility, classes were renamed in Swift, which results in a different ObjC name.
Public classes were renamed only on the ObjC side using the @_objcRuntimeName attribute.
This is similar to the work done in pull request #19295. That only renamed @objc classes. This renames all of the others, since even pure Swift classes still get an ObjC name.
rdar://problem/46646438
- Remove __SwiftNativeNSEnumerator from the ABI. (It’s only used in internal classes and in the Objective-C runtime.)
- Remove inlinability of init() and deinit for all the __SwiftNativeNSFoo superclasses except Array’s and Data’s.
Like before, allow the use of Cocoa indices to access native sets/dictionaries, but approximate the same mutation count-based check as we do for native indices.
- Ensure that native collections that were converted from Cocoa have an age generated from the address of the original Cocoa object.
- To get the age of a Cocoa index, regenerate one from the object embedded in it.
- Compare self.age to index.age and trap if it doesn’t match.
# Conflicts:
# stdlib/public/core/HashTable.swift
The mutation count will allow us to recognize and trap on invalid indices more reliably. (However, it won’t be foolproof — some invalid indices may pass through the checks.)
- Change _scale to Int8 to make space for an extra Int32 without enlarging the storage header.
- Add an _age field inside the new gap.
- Initialize the age to a scrambled version of the storage address.
- Generate a new counter for every newly allocated storage instance, except for identical copy-on-write copies.
- Increment the mutation counter after every removal.
- Don’t expose the raw execution seed to _rawHashValue.
- Change the type of _rawHashValue’s seed from (UInt64,UInt64) to a single Int. Working with a pair of UInt64s is unwieldy, and overkill in practice. Int as a seed also integrates nicely with Int as a hash value.
- Remove _HasherCore._generateSeed(). Instead, simply call finalize() on a copy of the hasher to get a seed suitable for _rawHashValue.
- Update Set and Dictionary to store a single Int as the seed value.
Note that this doesn’t affect the core hasher, which still mixes in the actual 128-bit execution seed during its initialization. To reduce the potential of confusion, use the name “rawSeed” to refer to an actual 128-bit seed value.
