[SR-2416] allow non-NSObject types to be archived

This patch fixes a number of issues that were preventing non-NSObject types
from being archived, even though the new method signatures imply that they can
be (by taking Any).

* fix regression introduced aa504dc where non-hashable objects could not be
  encoded
* fix bug where non-NSObjects would be replaced with nil, causing a crash
* remove explicit check that the encoded object is a NSObject
* possibly should be a separate patch: transparently bridge value types to the
  corresponding reference type before encoding
* tests for all over the above

Author: lhoward

Foundation/NSKeyedArchiver.swift

@@ -271,15 +271,17 @@ open class NSKeyedArchiver : NSCoder {
             return NSKeyedArchiveNullObjectReference
         }
 
-        uid = self._objRefMap[objv as! AnyHashable]
+        let value = _SwiftValue.store(objv)!
+        
+        uid = self._objRefMap[value]
         if uid == nil {
             if conditional {
                 return nil // object has not been unconditionally encoded
             }
 
             uid = UInt32(self._objects.count)
 
-            self._objRefMap[objv as! AnyHashable] = uid
+            self._objRefMap[value] = uid
             self._objects.insert(NSKeyedArchiveNullObjectReferenceName, at: Int(uid!))
         }
 
@@ -293,7 +295,7 @@ open class NSKeyedArchiver : NSCoder {
         if objv == nil {
             return true // always have a null reference
         } else {
-            return self._objRefMap[objv as! AnyHashable] != nil
+            return self._objRefMap[_SwiftValue.store(objv)] != nil
         }
     }
 
@@ -362,10 +364,10 @@ open class NSKeyedArchiver : NSCoder {
      */
     private func replaceObject(_ object: Any, withObject replacement: Any?) {
         if let unwrappedDelegate = self.delegate {
-            unwrappedDelegate.archiver(self, willReplace: object as! AnyHashable, with: replacement)
+            unwrappedDelegate.archiver(self, willReplace: object, with: replacement)
         }
 
-        self._replacementMap[object as! AnyHashable] = replacement
+        self._replacementMap[_SwiftValue.store(object)] = replacement
     }
 
     /**
@@ -477,9 +479,8 @@ open class NSKeyedArchiver : NSCoder {
 
         // object replaced by NSObject.replacementObjectForKeyedArchiver
         // if it is replaced with nil, it cannot be further replaced
-        if objectToEncode == nil {
-            let ns = object as? NSObject
-            objectToEncode = ns?.replacementObjectForKeyedArchiver(self)
+        if let ns = objectToEncode as? NSObject {
+            objectToEncode = ns.replacementObjectForKeyedArchiver(self)
             if objectToEncode == nil {
                 replaceObject(object!, withObject: nil)
                 return nil
@@ -511,7 +512,12 @@ open class NSKeyedArchiver : NSCoder {
 
         haveVisited = _haveVisited(objv)
         object = _replacementObject(objv)
-
+        
+        // bridge value types
+        if let bridgedObject = object as? _ObjectBridgeable {
+            object = bridgedObject._bridgeToAnyObject()
+        }
+        
         objectRef = _referenceObject(object, conditional: conditional)
         guard let unwrappedObjectRef = objectRef else {
             // we can return nil if the object is being conditionally encoded
@@ -532,12 +538,9 @@ open class NSKeyedArchiver : NSCoder {
                 _pushEncodingContext(innerEncodingContext)
                 codable.encode(with: self)
 
-                guard let ns = object as? NSObject else {
-                    fatalError("Attempt to encode non-NSObject");
-                }
-
-                let cls : AnyClass = ns.classForKeyedArchiver ?? type(of: object) as! AnyClass
-
+                let ns = object as? NSObject
+                let cls : AnyClass = ns?.classForKeyedArchiver ?? type(of: object!) as! AnyClass
+                
                 _setObjectInCurrentEncodingContext(_classReference(cls), forKey: "$class", escape: false)
                 _popEncodingContext()
                 encodedObject = innerEncodingContext.dict

Foundation/NSKeyedUnarchiver.swift

@@ -375,7 +375,7 @@ open class NSKeyedUnarchiver : NSCoder {
             unwrappedDelegate.unarchiver(self, willReplace: object, with: replacement)
         }
 
-        self._replacementMap[object as! AnyHashable] = replacement
+        self._replacementMap[_SwiftValue.store(object)] = replacement
     }
 
     private func _decodingError(_ code: CocoaError.Code, withDescription description: String) -> NSError {
@@ -392,7 +392,7 @@ open class NSKeyedUnarchiver : NSCoder {
         }
 
         // check replacement cache
-        object = self._replacementMap[decodedObject as! AnyHashable]
+        object = self._replacementMap[_SwiftValue.store(decodedObject)]
         if object != nil {
             return object
         }
@@ -489,9 +489,8 @@ open class NSKeyedUnarchiver : NSCoder {
             }
         } else {
             // reference to a non-container object
-            // FIXME remove these special cases
-            if let str = dereferencedObject as? String {
-                object = str._bridgeToObjectiveC()
+            if let bridgedObject = dereferencedObject as? _ObjectBridgeable {
+                object = bridgedObject._bridgeToAnyObject()
             } else {
                 object = dereferencedObject
             }

TestFoundation/TestNSKeyedArchiver.swift

@@ -16,7 +16,7 @@
     import SwiftXCTest
 #endif
 
-public class UserClass : NSObject, NSSecureCoding {
+public class NSUserClass : NSObject, NSSecureCoding {
     var ivar : Int
 
     public class var supportsSecureCoding: Bool {
@@ -37,19 +37,53 @@ public class UserClass : NSObject, NSSecureCoding {
 
     public override var description: String {
         get {
-            return "UserClass \(ivar)"
+            return "NSUserClass \(ivar)"
         }
     }
 
     public override func isEqual(_ object: Any?) -> Bool {
-        if let custom = object as? UserClass {
+        if let custom = object as? NSUserClass {
             return self.ivar == custom.ivar
         } else {
             return false
         }
     }
 }
 
+public class UserClass : CustomStringConvertible, Equatable, Hashable, NSSecureCoding {
+    var ivar : Int
+    
+    public class var supportsSecureCoding: Bool {
+        return true
+    }
+    
+    public func encode(with aCoder : NSCoder) {
+        aCoder.encode(ivar, forKey:"$ivar") // also test escaping
+    }
+    
+    init(_ value: Int) {
+        self.ivar = value
+    }
+    
+    public required init?(coder aDecoder: NSCoder) {
+        self.ivar = aDecoder.decodeInteger(forKey: "$ivar")
+    }
+    
+    public var description: String {
+        get {
+            return "UserClass \(ivar)"
+        }
+    }
+    
+    public static func ==(lhs: UserClass, rhs: UserClass) -> Bool {
+        return lhs.ivar == rhs.ivar
+    }
+    
+    public var hashValue: Int {
+        return ivar
+    }
+}
+
 class TestNSKeyedArchiver : XCTestCase {
     static var allTests: [(String, (TestNSKeyedArchiver) -> () throws -> Void)] {
         return [
@@ -62,14 +96,16 @@ class TestNSKeyedArchiver : XCTestCase {
             ("test_archive_string", test_archive_string),
             ("test_archive_mutable_array", test_archive_mutable_array),
             ("test_archive_mutable_dictionary", test_archive_mutable_dictionary),
+            ("test_archive_ns_user_class", test_archive_ns_user_class),
             ("test_archive_nspoint", test_archive_nspoint),
             ("test_archive_nsrange", test_archive_nsrange),
             ("test_archive_nsrect", test_archive_nsrect),
             ("test_archive_null", test_archive_null),
             ("test_archive_set", test_archive_set),
             ("test_archive_url", test_archive_url),
             ("test_archive_user_class", test_archive_user_class),
-            ("test_archive_uuid", test_archive_uuid),
+            ("test_archive_uuid_bvref", test_archive_uuid_byref),
+            ("test_archive_uuid_byvalue", test_archive_uuid_byvalue),
         ]
     }
 
@@ -85,7 +121,7 @@ class TestNSKeyedArchiver : XCTestCase {
         XCTAssertTrue(decode(unarchiver))
     }
 
-    private func test_archive(_ object: NSObject, classes: [AnyClass], allowsSecureCoding: Bool = true, outputFormat: PropertyListSerialization.PropertyListFormat) {
+    private func test_archive(_ object: Any, classes: [AnyClass], allowsSecureCoding: Bool = true, outputFormat: PropertyListSerialization.PropertyListFormat) {
         test_archive({ archiver -> Bool in
                 archiver.requiresSecureCoding = allowsSecureCoding
                 archiver.outputFormat = outputFormat
@@ -97,26 +133,26 @@ class TestNSKeyedArchiver : XCTestCase {
                 unarchiver.requiresSecureCoding = allowsSecureCoding
 
                 do {
-                    let rootObj = try unarchiver.decodeTopLevelObject(of: classes, forKey: NSKeyedArchiveRootObjectKey)
-                    guard let root = rootObj as? NSObject else {
+                    guard let rootObj = try unarchiver.decodeTopLevelObject(of: classes, forKey: NSKeyedArchiveRootObjectKey) else {
                         XCTFail("Unable to decode data")
                         return false
                     }
-                    XCTAssertEqual(object, root, "unarchived object \(root) does not match \(object)")
+                
+                    XCTAssertEqual(object as? AnyHashable, rootObj as? AnyHashable, "unarchived object \(rootObj) does not match \(object)")
                 } catch {
                     XCTFail("Error thrown: \(error)")
                 }
                 return true
         })
     }
 
-    private func test_archive(_ object: NSObject, classes: [AnyClass], allowsSecureCoding: Bool = true) {
+    private func test_archive(_ object: Any, classes: [AnyClass], allowsSecureCoding: Bool = true) {
         // test both XML and binary encodings
         test_archive(object, classes: classes, allowsSecureCoding: allowsSecureCoding, outputFormat: PropertyListSerialization.PropertyListFormat.xml)
         test_archive(object, classes: classes, allowsSecureCoding: allowsSecureCoding, outputFormat: PropertyListSerialization.PropertyListFormat.binary)
     }
 
-    private func test_archive(_ object: NSObject, allowsSecureCoding: Bool = true) {
+    private func test_archive(_ object: AnyObject, allowsSecureCoding: Bool = true) {
         return test_archive(object, classes: [type(of: object)], allowsSecureCoding: allowsSecureCoding)
     }
 
@@ -252,8 +288,18 @@ class TestNSKeyedArchiver : XCTestCase {
         test_archive(userClass)
     }
 
-    func test_archive_uuid() {
+    func test_archive_ns_user_class() {
+        let nsUserClass = NSUserClass(5678)
+        test_archive(nsUserClass)
+    }
+    
+    func test_archive_uuid_byref() {
         let uuid = NSUUID()
         test_archive(uuid)
     }
+    
+    func test_archive_uuid_byvalue() {
+        let uuid = UUID()
+        return test_archive(uuid, classes: [NSUUID.self])
+    }
 }