Remove all uses of CF from the framework's interface outside of Linux or Darwin

Author: millenomi

Sources/Foundation/Port.swift

@@ -659,7 +659,7 @@ open class SocketPort : Port {
     }
 
     open override func schedule(in runLoop: RunLoop, forMode mode: RunLoop.Mode) {
-        let loop = runLoop.getCFRunLoop()
+        let loop = runLoop.currentCFRunLoop
         let loopKey = ObjectIdentifier(loop)
 
         core.lock.synchronized {
@@ -685,7 +685,7 @@ open class SocketPort : Port {
     }
 
     open override func remove(from runLoop: RunLoop, forMode mode: RunLoop.Mode) {
-        let loop = runLoop.getCFRunLoop()
+        let loop = runLoop.currentCFRunLoop
         let loopKey = ObjectIdentifier(loop)
 
         core.lock.synchronized {

Sources/Foundation/RunLoop.swift

@@ -7,7 +7,11 @@
 // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 //
 
+#if os(Linux) || os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
 import CoreFoundation
+#else
+@_implementationOnly import CoreFoundation
+#endif
 
 internal let kCFRunLoopEntry = CFRunLoopActivity.entry.rawValue
 internal let kCFRunLoopBeforeTimers = CFRunLoopActivity.beforeTimers.rawValue
@@ -83,10 +87,24 @@ open class RunLoop: NSObject {
         }
     }
 
+    // On platforms where it's available, getCFRunLoop() can be overridden and we use it below.
+    // Make sure we honor the override -- var currentCFRunLoop will do so on platforms where overrides are available.
+
+    #if os(Linux) || os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
+    internal var currentCFRunLoop: CFRunLoop { getCFRunLoop() }
+
     @available(*, deprecated, message: "Directly accessing the run loop may cause your code to not become portable in the future.")
     open func getCFRunLoop() -> CFRunLoop {
         return _cfRunLoop
     }
+    #else
+    internal var currentCFRunLoop: CFRunLoop { _cfRunLoop }
+
+    @available(*, unavailable, message: "Core Foundation is not available on your platform.")
+    open func getCFRunLoop() -> Never {
+        fatalError()
+    }
+    #endif
 
     open func add(_ timer: Timer, forMode mode: RunLoop.Mode) {
         CFRunLoopAddTimer(_cfRunLoop, timer._cfObject, mode._cfStringUniquingKnown)
@@ -206,7 +224,7 @@ extension RunLoop {
     }
 
     public func perform(inModes modes: [RunLoop.Mode], block: @escaping () -> Void) {
-        CFRunLoopPerformBlock(getCFRunLoop(), (modes.map { $0._cfStringUniquingKnown })._cfObject, block)
+        CFRunLoopPerformBlock(currentCFRunLoop, (modes.map { $0._cfStringUniquingKnown })._cfObject, block)
     }
 
     public func perform(_ block: @escaping () -> Void) {
@@ -219,13 +237,13 @@ extension RunLoop {
 extension RunLoop {
     @available(*, deprecated, message: "For XCTest use only.")
     public func _stop() {
-        CFRunLoopStop(getCFRunLoop())
+        CFRunLoopStop(currentCFRunLoop)
     }
 
     @available(*, deprecated, message: "For XCTest use only.")
     public func _observe(_ activities: _Activities, in mode: RunLoop.Mode = .default, repeats: Bool = true, order: Int = 0, handler: @escaping (_Activity) -> Void) -> _Observer {
         let observer = _Observer(activities: activities, repeats: repeats, order: order, handler: handler)
-        CFRunLoopAddObserver(self.getCFRunLoop(), observer.cfObserver, mode._cfStringUniquingKnown)
+        CFRunLoopAddObserver(self.currentCFRunLoop, observer.cfObserver, mode._cfStringUniquingKnown)
         return observer
     }
 

Sources/Foundation/Stream.swift

@@ -172,11 +172,11 @@ open class InputStream: Stream {
     }
 
     open override func schedule(in aRunLoop: RunLoop, forMode mode: RunLoop.Mode) {
-        CFReadStreamScheduleWithRunLoop(_stream, aRunLoop.getCFRunLoop(), mode.rawValue._cfObject)
+        CFReadStreamScheduleWithRunLoop(_stream, aRunLoop.currentCFRunLoop, mode.rawValue._cfObject)
     }
 
     open override func remove(from aRunLoop: RunLoop, forMode mode: RunLoop.Mode) {
-        CFReadStreamUnscheduleFromRunLoop(_stream, aRunLoop.getCFRunLoop(), mode.rawValue._cfObject)
+        CFReadStreamUnscheduleFromRunLoop(_stream, aRunLoop.currentCFRunLoop, mode.rawValue._cfObject)
     }
 }
 
@@ -251,11 +251,11 @@ open class OutputStream : Stream {
     }
 
     open override func schedule(in aRunLoop: RunLoop, forMode mode: RunLoop.Mode) {
-        CFWriteStreamScheduleWithRunLoop(_stream, aRunLoop.getCFRunLoop(), mode.rawValue._cfObject)
+        CFWriteStreamScheduleWithRunLoop(_stream, aRunLoop.currentCFRunLoop, mode.rawValue._cfObject)
     }
 
     open override func remove(from aRunLoop: RunLoop, forMode mode: RunLoop.Mode) {
-        CFWriteStreamUnscheduleFromRunLoop(_stream, aRunLoop.getCFRunLoop(), mode.rawValue._cfObject)
+        CFWriteStreamUnscheduleFromRunLoop(_stream, aRunLoop.currentCFRunLoop, mode.rawValue._cfObject)
     }
 }