Merge pull request swiftlang#11315 from itaiferber/fix-sr-5206-hack

Remove previous hack for SR-5206

Author: itaiferber

stdlib/public/SDK/Foundation/Data.swift

@@ -1926,27 +1926,11 @@ extension NSData : _HasCustomAnyHashableRepresentation {
 
 extension Data : Codable {
     public init(from decoder: Decoder) throws {
-        // FIXME: This is a hook for bypassing a conditional conformance implementation to apply a strategy (see SR-5206). Remove this once conditional conformance is available.
-        do {
-            let singleValueContainer = try decoder.singleValueContainer()
-            if let decoder = singleValueContainer as? _JSONDecoder {
-                switch decoder.options.dataDecodingStrategy {
-                case .deferredToData:
-                    break /* fall back to default implementation below; this would recurse */
-
-                default:
-                    // _JSONDecoder has a hook for Datas; this won't recurse since we're not going to defer back to Data in _JSONDecoder.
-                    self = try singleValueContainer.decode(Data.self)
-                    return
-                }
-            }
-        } catch { /* fall back to default implementation below */ }
-
         var container = try decoder.unkeyedContainer()
 
         // It's more efficient to pre-allocate the buffer if we can.
         if let count = container.count {
-            self = Data(count: count)
+            self.init(count: count)
 
             // Loop only until count, not while !container.isAtEnd, in case count is underestimated (this is misbehavior) and we haven't allocated enough space.
             // We don't want to write past the end of what we allocated.
@@ -1955,7 +1939,7 @@ extension Data : Codable {
                 self[i] = byte
             }
         } else {
-            self = Data()
+            self.init()
         }
 
         while !container.isAtEnd {
@@ -1965,21 +1949,6 @@ extension Data : Codable {
     }
 
     public func encode(to encoder: Encoder) throws {
-        // FIXME: This is a hook for bypassing a conditional conformance implementation to apply a strategy (see SR-5206). Remove this once conditional conformance is available.
-        // We are allowed to request this container as long as we don't encode anything through it when we need the unkeyed container below.
-        var singleValueContainer = encoder.singleValueContainer()
-        if let encoder = singleValueContainer as? _JSONEncoder {
-            switch encoder.options.dataEncodingStrategy {
-            case .deferredToData:
-                break /* fall back to default implementation below; this would recurse */
-
-            default:
-                // _JSONEncoder has a hook for Datas; this won't recurse since we're not going to defer back to Data in _JSONEncoder.
-                try singleValueContainer.encode(self)
-                return
-            }
-        }
-
         var container = encoder.unkeyedContainer()
 
         // Since enumerateBytes does not rethrow, we need to catch the error, stow it away, and rethrow if we stopped.

stdlib/public/SDK/Foundation/Date.swift

@@ -287,40 +287,13 @@ extension Date : CustomPlaygroundQuickLookable {
 
 extension Date : Codable {
     public init(from decoder: Decoder) throws {
-        // FIXME: This is a hook for bypassing a conditional conformance implementation to apply a strategy (see SR-5206). Remove this once conditional conformance is available.
         let container = try decoder.singleValueContainer()
-        if let decoder = container as? _JSONDecoder {
-            switch decoder.options.dateDecodingStrategy {
-            case .deferredToDate:
-                break /* fall back to default implementation below; this would recurse */
-
-            default:
-                // _JSONDecoder has a hook for Dates; this won't recurse since we're not going to defer back to Date in _JSONDecoder.
-                self = try container.decode(Date.self)
-                return
-            }
-        }
-
         let timestamp = try container.decode(Double.self)
-        self = Date(timeIntervalSinceReferenceDate: timestamp)
+        self.init(timeIntervalSinceReferenceDate: timestamp)
     }
 
     public func encode(to encoder: Encoder) throws {
-        // FIXME: This is a hook for bypassing a conditional conformance implementation to apply a strategy (see SR-5206). Remove this once conditional conformance is available.
-        // We are allowed to request this container as long as we don't encode anything through it when we need the keyed container below.
         var container = encoder.singleValueContainer()
-        if let encoder = container as? _JSONEncoder {
-            switch encoder.options.dateEncodingStrategy {
-            case .deferredToDate:
-                break /* fall back to default implementation below; this would recurse */
-
-            default:
-                // _JSONEncoder has a hook for Dates; this won't recurse since we're not going to defer back to Date in _JSONEncoder.
-                try container.encode(self)
-                return
-            }
-        }
-
         try container.encode(self.timeIntervalSinceReferenceDate)
     }
 }

stdlib/public/SDK/Foundation/Decimal.swift

@@ -471,17 +471,6 @@ extension Decimal : Codable {
     }
 
     public init(from decoder: Decoder) throws {
-        // FIXME: This is a hook for bypassing a conditional conformance implementation to apply a strategy (see SR-5206). Remove this once conditional conformance is available.
-        do {
-            // We are allowed to request this container as long as we don't decode anything through it when we need the keyed container below.
-            let singleValueContainer = try decoder.singleValueContainer()
-            if singleValueContainer is _JSONDecoder {
-                // _JSONDecoder has a hook for Decimals; this won't recurse since we're not going to defer to Decimal in _JSONDecoder.
-                self  = try singleValueContainer.decode(Decimal.self)
-                return
-            }
-        } catch { /* Fall back to default implementation below. */ }
-
         let container = try decoder.container(keyedBy: CodingKeys.self)
         let exponent = try container.decode(CInt.self, forKey: .exponent)
         let length = try container.decode(CUnsignedInt.self, forKey: .length)
@@ -509,15 +498,6 @@ extension Decimal : Codable {
     }
 
     public func encode(to encoder: Encoder) throws {
-        // FIXME: This is a hook for bypassing a conditional conformance implementation to apply a strategy (see SR-5206). Remove this once conditional conformance is available.
-        // We are allowed to request this container as long as we don't encode anything through it when we need the keyed container below.
-        var singleValueContainer = encoder.singleValueContainer()
-        if singleValueContainer is _JSONEncoder {
-            // _JSONEncoder has a hook for Decimals; this won't recurse since we're not going to defer to Decimal in _JSONEncoder.
-            try singleValueContainer.encode(self)
-            return
-        }
-
         var container = encoder.container(keyedBy: CodingKeys.self)
         try container.encode(_exponent, forKey: .exponent)
         try container.encode(_length, forKey: .length)

stdlib/public/SDK/Foundation/JSONEncoder.swift

@@ -99,7 +99,7 @@ open class JSONEncoder {
     open var userInfo: [CodingUserInfoKey : Any] = [:]
 
     /// Options set on the top-level encoder to pass down the encoding hierarchy.
-    internal struct _Options {
+    fileprivate struct _Options {
         let dateEncodingStrategy: DateEncodingStrategy
         let dataEncodingStrategy: DataEncodingStrategy
         let nonConformingFloatEncodingStrategy: NonConformingFloatEncodingStrategy
@@ -155,14 +155,14 @@ open class JSONEncoder {
 
 // MARK: - _JSONEncoder
 
-internal class _JSONEncoder : Encoder {
+fileprivate class _JSONEncoder : Encoder {
     // MARK: Properties
 
     /// The encoder's storage.
     fileprivate var storage: _JSONEncodingStorage
 
     /// Options set on the top-level encoder.
-    internal let options: JSONEncoder._Options
+    fileprivate let options: JSONEncoder._Options
 
     /// The path to the current point in encoding.
     public var codingPath: [CodingKey]
@@ -827,7 +827,7 @@ open class JSONDecoder {
     open var userInfo: [CodingUserInfoKey : Any] = [:]
 
     /// Options set on the top-level encoder to pass down the decoding hierarchy.
-    internal struct _Options {
+    fileprivate struct _Options {
         let dateDecodingStrategy: DateDecodingStrategy
         let dataDecodingStrategy: DataDecodingStrategy
         let nonConformingFloatDecodingStrategy: NonConformingFloatDecodingStrategy
@@ -871,14 +871,14 @@ open class JSONDecoder {
 
 // MARK: - _JSONDecoder
 
-internal class _JSONDecoder : Decoder {
+fileprivate class _JSONDecoder : Decoder {
     // MARK: Properties
 
     /// The decoder's storage.
     fileprivate var storage: _JSONDecodingStorage
 
     /// Options set on the top-level decoder.
-    internal let options: JSONDecoder._Options
+    fileprivate let options: JSONDecoder._Options
 
     /// The path to the current point in encoding.
     fileprivate(set) public var codingPath: [CodingKey]

stdlib/public/SDK/Foundation/URL.swift

@@ -1214,17 +1214,6 @@ extension URL : Codable {
     }
 
     public init(from decoder: Decoder) throws {
-        // FIXME: This is a hook for bypassing a conditional conformance implementation to apply a strategy (see SR-5206). Remove this once conditional conformance is available.
-        do {
-            // We are allowed to request this container as long as we don't decode anything through it when we need the keyed container below.
-            let singleValueContainer = try decoder.singleValueContainer()
-            if singleValueContainer is _JSONDecoder {
-                // _JSONDecoder has a hook for URLs; this won't recurse since we're not going to defer back to URL in _JSONDecoder.
-                self = try singleValueContainer.decode(URL.self)
-                return
-            }
-        } catch { /* Fall back to default implementation below. */ }
-
         let container = try decoder.container(keyedBy: CodingKeys.self)
         let relative = try container.decode(String.self, forKey: .relative)
         let base = try container.decodeIfPresent(URL.self, forKey: .base)
@@ -1238,15 +1227,6 @@ extension URL : Codable {
     }
 
     public func encode(to encoder: Encoder) throws {
-        // FIXME: This is a hook for bypassing a conditional conformance implementation to apply a strategy (see SR-5206). Remove this once conditional conformance is available.
-        // We are allowed to request this container as long as we don't encode anything through it when we need the keyed container below.
-        var singleValueContainer = encoder.singleValueContainer()
-        if singleValueContainer is _JSONEncoder {
-            // _JSONEncoder has a hook for URLs; this won't recurse since we're not going to defer back to URL in _JSONEncoder.
-            try singleValueContainer.encode(self)
-            return
-        }
-
         var container = encoder.container(keyedBy: CodingKeys.self)
         try container.encode(self.relativeString, forKey: .relative)
         if let base = self.baseURL {