[Stdlib][Overlays] Rename various classes to avoid conflicting ObjC names.

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 swiftlang#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

Author: mikeash

stdlib/public/Darwin/AppKit/NSGraphics.swift

@@ -181,7 +181,10 @@ extension NSWindow.Depth {
 }
 
 extension NSAnimationEffect {
-  private class _CompletionHandlerDelegate : NSObject {
+  // NOTE: older overlays called this class _CompletionHandlerDelegate.
+  // The two must coexist without a conflicting ObjC class name, so it
+  // was renamed. The old name must not be used in the new runtime.
+  private class __CompletionHandlerDelegate : NSObject {
     var completionHandler: () -> Void = { }
     @objc func animationEffectDidEnd(_ contextInfo: UnsafeMutableRawPointer?) {
       completionHandler()
@@ -190,7 +193,7 @@ extension NSAnimationEffect {
   @available(swift 4)
   public func show(centeredAt centerLocation: NSPoint, size: NSSize,
                    completionHandler: @escaping () -> Void = { }) {
-    let delegate = _CompletionHandlerDelegate()
+    let delegate = __CompletionHandlerDelegate()
     delegate.completionHandler = completionHandler
     // Note that the delegate of `__NSShowAnimationEffect` is retained for the
     // duration of the animation.
@@ -199,7 +202,7 @@ extension NSAnimationEffect {
         centerLocation,
         size,
         delegate,
-        #selector(_CompletionHandlerDelegate.animationEffectDidEnd(_:)),
+        #selector(__CompletionHandlerDelegate.animationEffectDidEnd(_:)),
         nil)
   }
 }

stdlib/public/Darwin/Dispatch/Block.swift

@@ -34,7 +34,12 @@ public struct DispatchWorkItemFlags : OptionSet, RawRepresentable {
 	public static let enforceQoS = DispatchWorkItemFlags(rawValue: 0x20)
 }
 
+// NOTE: older overlays had Dispatch.DispatchWorkItem as the ObjC name.
+// The two must coexist, so it was renamed. The old name must not be
+// used in the new runtime. _TtC8Dispatch17_DispatchWorkItem is the
+// mangled name for Dispatch._DispatchWorkItem.
 @available(macOS 10.10, iOS 8.0, *)
+@_objcRuntimeName(_TtC8Dispatch17_DispatchWorkItem)
 public class DispatchWorkItem {
 	internal var _block: _DispatchBlock
 

stdlib/public/Darwin/Foundation/CharacterSet.swift

@@ -29,7 +29,10 @@ private func _utfRangeToCFRange(_ inRange : ClosedRange<Unicode.Scalar>) -> CFRa
 
 // MARK: -
 
-fileprivate final class _CharacterSetStorage : Hashable {
+// NOTE: older overlays called this class _CharacterSetStorage.
+// The two must coexist without a conflicting ObjC class name, so it
+// was renamed. The old name must not be used in the new runtime.
+fileprivate final class __CharacterSetStorage : Hashable {
     fileprivate enum Backing {
         case immutable(CFCharacterSet)
         case mutable(CFMutableCharacterSet)
@@ -58,7 +61,7 @@ fileprivate final class _CharacterSetStorage : Hashable {
         }
     }
 
-    fileprivate static func ==(lhs : _CharacterSetStorage, rhs : _CharacterSetStorage) -> Bool {
+    fileprivate static func ==(lhs : __CharacterSetStorage, rhs : __CharacterSetStorage) -> Bool {
         switch (lhs._backing, rhs._backing) {
         case (.immutable(let cs1), .immutable(let cs2)):
             return CFEqual(cs1, cs2)
@@ -73,12 +76,12 @@ fileprivate final class _CharacterSetStorage : Hashable {
 
     // MARK: -
 
-    fileprivate func mutableCopy() -> _CharacterSetStorage {
+    fileprivate func mutableCopy() -> __CharacterSetStorage {
         switch _backing {
         case .immutable(let cs):
-            return _CharacterSetStorage(mutableReference: CFCharacterSetCreateMutableCopy(nil, cs))
+            return __CharacterSetStorage(mutableReference: CFCharacterSetCreateMutableCopy(nil, cs))
         case .mutable(let cs):
-            return _CharacterSetStorage(mutableReference: CFCharacterSetCreateMutableCopy(nil, cs))
+            return __CharacterSetStorage(mutableReference: CFCharacterSetCreateMutableCopy(nil, cs))
         }
     }
 
@@ -223,7 +226,7 @@ fileprivate final class _CharacterSetStorage : Hashable {
 
 
     // When the underlying collection does not have a method to return new CharacterSets with changes applied, so we will copy and apply here
-    private static func _apply(_ lhs : _CharacterSetStorage, _ rhs : _CharacterSetStorage, _ f : (CFMutableCharacterSet, CFCharacterSet) -> ()) -> CharacterSet {
+    private static func _apply(_ lhs : __CharacterSetStorage, _ rhs : __CharacterSetStorage, _ f : (CFMutableCharacterSet, CFCharacterSet) -> ()) -> CharacterSet {
         let copyOfMe : CFMutableCharacterSet
         switch lhs._backing {
         case .immutable(let cs):
@@ -239,10 +242,10 @@ fileprivate final class _CharacterSetStorage : Hashable {
             f(copyOfMe, cs)
         }
 
-        return CharacterSet(_uncopiedStorage: _CharacterSetStorage(mutableReference: copyOfMe))
+        return CharacterSet(_uncopiedStorage: __CharacterSetStorage(mutableReference: copyOfMe))
     }
 
-    private func _applyMutation(_ other : _CharacterSetStorage, _ f : (CFMutableCharacterSet, CFCharacterSet) -> ()) {
+    private func _applyMutation(_ other : __CharacterSetStorage, _ f : (CFMutableCharacterSet, CFCharacterSet) -> ()) {
         switch _backing {
         case .immutable(let cs):
             let r = CFCharacterSetCreateMutableCopy(nil, cs)!
@@ -267,47 +270,47 @@ fileprivate final class _CharacterSetStorage : Hashable {
     fileprivate var inverted : CharacterSet {
         switch _backing {
         case .immutable(let cs):
-            return CharacterSet(_uncopiedStorage: _CharacterSetStorage(immutableReference: CFCharacterSetCreateInvertedSet(nil, cs)))
+            return CharacterSet(_uncopiedStorage: __CharacterSetStorage(immutableReference: CFCharacterSetCreateInvertedSet(nil, cs)))
         case .mutable(let cs):
             // Even if input is mutable, the result is immutable
-            return CharacterSet(_uncopiedStorage: _CharacterSetStorage(immutableReference: CFCharacterSetCreateInvertedSet(nil, cs)))
+            return CharacterSet(_uncopiedStorage: __CharacterSetStorage(immutableReference: CFCharacterSetCreateInvertedSet(nil, cs)))
         }
     }
 
-    fileprivate func union(_ other: _CharacterSetStorage) -> CharacterSet {
-        return _CharacterSetStorage._apply(self, other, CFCharacterSetUnion)
+    fileprivate func union(_ other: __CharacterSetStorage) -> CharacterSet {
+        return __CharacterSetStorage._apply(self, other, CFCharacterSetUnion)
     }
 
-    fileprivate func formUnion(_ other: _CharacterSetStorage) {
+    fileprivate func formUnion(_ other: __CharacterSetStorage) {
         _applyMutation(other, CFCharacterSetUnion)
     }
 
-    fileprivate func intersection(_ other: _CharacterSetStorage) -> CharacterSet {
-        return _CharacterSetStorage._apply(self, other, CFCharacterSetIntersect)
+    fileprivate func intersection(_ other: __CharacterSetStorage) -> CharacterSet {
+        return __CharacterSetStorage._apply(self, other, CFCharacterSetIntersect)
     }
 
-    fileprivate func formIntersection(_ other: _CharacterSetStorage) {
+    fileprivate func formIntersection(_ other: __CharacterSetStorage) {
         _applyMutation(other, CFCharacterSetIntersect)
     }
 
-    fileprivate func subtracting(_ other: _CharacterSetStorage) -> CharacterSet {
+    fileprivate func subtracting(_ other: __CharacterSetStorage) -> CharacterSet {
         return intersection(other.inverted._storage)
     }
 
-    fileprivate func subtract(_ other: _CharacterSetStorage) {
+    fileprivate func subtract(_ other: __CharacterSetStorage) {
         _applyMutation(other.inverted._storage, CFCharacterSetIntersect)
     }
 
-    fileprivate func symmetricDifference(_ other: _CharacterSetStorage) -> CharacterSet {
+    fileprivate func symmetricDifference(_ other: __CharacterSetStorage) -> CharacterSet {
         return union(other).subtracting(intersection(other))
     }
 
-    fileprivate func formSymmetricDifference(_ other: _CharacterSetStorage) {
+    fileprivate func formSymmetricDifference(_ other: __CharacterSetStorage) {
         // This feels like cheating
         _backing = symmetricDifference(other)._storage._backing
     }
 
-    fileprivate func isSuperset(of other: _CharacterSetStorage) -> Bool {
+    fileprivate func isSuperset(of other: __CharacterSetStorage) -> Bool {
         switch _backing {
         case .immutable(let cs):
             switch other._backing {
@@ -363,43 +366,43 @@ fileprivate final class _CharacterSetStorage : Hashable {
 public struct CharacterSet : ReferenceConvertible, Equatable, Hashable, SetAlgebra {
     public typealias ReferenceType = NSCharacterSet
 
-    fileprivate var _storage : _CharacterSetStorage
+    fileprivate var _storage : __CharacterSetStorage
 
     // MARK: Init methods
 
     /// Initialize an empty instance.
     public init() {
         // It's unlikely that we are creating an empty character set with no intention to mutate it
-        _storage = _CharacterSetStorage(mutableReference: CFCharacterSetCreateMutable(nil))
+        _storage = __CharacterSetStorage(mutableReference: CFCharacterSetCreateMutable(nil))
     }
 
     /// Initialize with a range of integers.
     ///
     /// It is the caller's responsibility to ensure that the values represent valid `Unicode.Scalar` values, if that is what is desired.
     public init(charactersIn range: Range<Unicode.Scalar>) {
-        _storage = _CharacterSetStorage(immutableReference: CFCharacterSetCreateWithCharactersInRange(nil, _utfRangeToCFRange(range)))
+        _storage = __CharacterSetStorage(immutableReference: CFCharacterSetCreateWithCharactersInRange(nil, _utfRangeToCFRange(range)))
     }
 
     /// Initialize with a closed range of integers.
     ///
     /// It is the caller's responsibility to ensure that the values represent valid `Unicode.Scalar` values, if that is what is desired.
     public init(charactersIn range: ClosedRange<Unicode.Scalar>) {
-        _storage = _CharacterSetStorage(immutableReference: CFCharacterSetCreateWithCharactersInRange(nil, _utfRangeToCFRange(range)))
+        _storage = __CharacterSetStorage(immutableReference: CFCharacterSetCreateWithCharactersInRange(nil, _utfRangeToCFRange(range)))
     }
 
     /// Initialize with the characters in the given string.
     ///
     /// - parameter string: The string content to inspect for characters.
     public init(charactersIn string: __shared String) {
-        _storage = _CharacterSetStorage(immutableReference: CFCharacterSetCreateWithCharactersInString(nil, string as CFString))
+        _storage = __CharacterSetStorage(immutableReference: CFCharacterSetCreateWithCharactersInString(nil, string as CFString))
     }
 
     /// Initialize with a bitmap representation.
     ///
     /// This method is useful for creating a character set object with data from a file or other external data source.
     /// - parameter data: The bitmap representation.
     public init(bitmapRepresentation data: __shared Data) {
-        _storage = _CharacterSetStorage(immutableReference: CFCharacterSetCreateWithBitmapRepresentation(nil, data as CFData))
+        _storage = __CharacterSetStorage(immutableReference: CFCharacterSetCreateWithBitmapRepresentation(nil, data as CFData))
     }
 
     /// Initialize with the contents of a file.
@@ -409,26 +412,26 @@ public struct CharacterSet : ReferenceConvertible, Equatable, Hashable, SetAlgeb
     public init?(contentsOfFile file: __shared String) {
         do {
             let data = try Data(contentsOf: URL(fileURLWithPath: file), options: .mappedIfSafe)
-            _storage = _CharacterSetStorage(immutableReference: CFCharacterSetCreateWithBitmapRepresentation(nil, data as CFData))
+            _storage = __CharacterSetStorage(immutableReference: CFCharacterSetCreateWithBitmapRepresentation(nil, data as CFData))
         } catch {
             return nil
         }
     }
 
     fileprivate init(_bridged characterSet: __shared NSCharacterSet) {
-        _storage = _CharacterSetStorage(immutableReference: characterSet.copy() as! CFCharacterSet)
+        _storage = __CharacterSetStorage(immutableReference: characterSet.copy() as! CFCharacterSet)
     }
 
     fileprivate init(_uncopiedImmutableReference characterSet: CFCharacterSet) {
-        _storage = _CharacterSetStorage(immutableReference: characterSet)
+        _storage = __CharacterSetStorage(immutableReference: characterSet)
     }
 
-    fileprivate init(_uncopiedStorage : _CharacterSetStorage) {
+    fileprivate init(_uncopiedStorage : __CharacterSetStorage) {
         _storage = _uncopiedStorage
     }
 
     fileprivate init(_builtIn: __shared CFCharacterSetPredefinedSet) {
-        _storage = _CharacterSetStorage(immutableReference: CFCharacterSetGetPredefined(_builtIn))
+        _storage = __CharacterSetStorage(immutableReference: CFCharacterSetGetPredefined(_builtIn))
     }
 
     // MARK: Static functions